Medical Microbiology Research Papers - Academia.edu (original) (raw)

HCV is a leading cause of hepatocellular carcinoma and cirrhosis all over the world. Claudins belong to family of tight junction's proteins that are responsible for establishing barriers for controlling the flow of molecules around cells.... more

HCV is a leading cause of hepatocellular carcinoma and cirrhosis all over the world. Claudins belong to family of tight junction's proteins that are responsible for establishing barriers for controlling the flow of molecules around cells. For therapeutic strategies, regulation of viral entry into the host cells holds a lot of promise. During HCV infection claudin-1 is highly expressed in liver and believed to be associated with HCV virus entry after HCV binding with or without co-receptor CD81. The claudin-1 assembly with tight junctions is regulated by post translational modifications. During claudins assembly and disassembly with tight junctions, phosphorylation is required at C-terminal tail. In cellular proteins, interplay between phosphorylation and O-b-GlcNAc modification is believed to be functional switch, but it is very difficult to monitor these functional and vibrant changes in vivo. Netphos 2.0 and Disphos 1.3 programs were used for potential phosphorylation; NetPhosK 1.0 and KinasePhos for kinase prediction; and YinOYang 1.2 and OGPET to predict possible O-glycosylation sites. We also identified Yin Yang sites that may have potential for O-b-GlcNAc and phosphorylation interplay at same Ser/Thr residues. We for the first time proposed that alternate phosphorylation and O-b-GlcNAc modification on Ser 192, Ser 205, Ser 206; and Thr 191 may provide an on/off switch to regulate assembly of claudin-1 at tight junctions. In addition these phosphorylation sites may be targeted by novel chemotherapeutic agents to prevent phosphorylation lead by HCV viral entry complex.

Persons at high risk for human immunodeficiency virus (HIV) infection are also likely to be at risk for other infectious pathogens, including hepatitis B virus (HBV) or hepatitis C virus (HCV). These are bloodborne pathogens transmitted... more

Persons at high risk for human immunodeficiency virus (HIV) infection are also likely to be at risk for other infectious pathogens, including hepatitis B virus (HBV) or hepatitis C virus (HCV). These are bloodborne pathogens transmitted through similar routes; for example, via injection drug use (IDU), sexual contact, or from mother to child during pregnancy or birth. In some settings, the prevalence of coinfection with HBV and/or HCV is high. In the context of effective antiretroviral therapy (ART), liver disease has emerged as a major cause of morbidity and mortality in HIV-infected persons. Further, coinfection with viral hepatitis may complicate the delivery of ART by increasing the risk of drug-related hepatoxicity and impacting the selection of specific agents (e.g., those dually active against HIV and HBV). Expert guidelines developed in the United States and Europe recommend screening of all HIV-infected persons for infection with HCV and HBV and appropriate management of those found to be chronically infected. Treatment strategies for HBV infection include the use of nucleos(t)ide analogues with or without anti-HIV activity and/or peginterferon alfa (PegIFN) whereas HCV treatment is limited to the combination of PegIFN and ribavirin (RBV). Current approaches to management of HIVinfected persons coinfected with HBV or HCV are discussed in this review.

P16 INK4a is a cyclin-dependent kinase inhibitor that regulates the transition from the G1 to S phase and negatively influences cell proliferation in conjunction with other tumour suppressor proteins, such as the retinoblastoma gene (pRb)... more

P16 INK4a is a cyclin-dependent kinase inhibitor that regulates the transition from the G1 to S phase and negatively influences cell proliferation in conjunction with other tumour suppressor proteins, such as the retinoblastoma gene (pRb) ). As pRb is functionally inactivated by the high-risk human papillo-human papilloma virus (HPV) oncoprotein E7, there is a concomitant overexpression of p16 INK4a . New data suggest that p16 overexpression in E7-expressing cells does not appear to result from pRB degradation, but from the induction of histone demethylases by HPV E7 . Although p16 INK4a immunostaining has been correlated with the severity of cytological and histological abnormalities in cervical lesions, variations in interpretation and a lack of standardised methodologies has resulted in uncertainty regarding the most appropriate cut-offs for the analysis of P16 INK4a levels ). This dilemma is underscored by the fact that P16 INK4a expression can be upregulated in non-dysplastic cervical lesions, including common squamous metaplasia. Moreover, published studies for the diagnostic performance of P16 INK4a in human immunodeficiency virus (HIV)infected patients remain limited ). In the present study, we assessed the expression of p16 INK4a in normal and abnormal cervical epithelium in HIV-positive and negative women and determined the diagnostic performance [receiving operating characteristics curve (ROC), sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV)] of P16 INK4a for detecting cervical intraepithelial neoplasia (CIN) and invasive cervical cancer in tissue microarray (TMA) samples in each group.

Detection of the Mycobacterium tuberculosis cell wall antigen lipoarabinomannan (LAM) in urine permits diagnoses of tuberculosis (TB) to be made in HIV-infected patients with advanced immunodeficiency. This can be achieved at the... more

Detection of the Mycobacterium tuberculosis cell wall antigen lipoarabinomannan (LAM) in urine permits diagnoses of tuberculosis (TB) to be made in HIV-infected patients with advanced immunodeficiency. This can be achieved at the point-of-care within just 30 minutes using the Determine TB-LAM, which is a commercially available, lateral-flow urine 'strip test' assay. The assay has been shown to have useful diagnostic accuracy in patients enrolling in antiretroviral treatment services or in HIV-infected patients requiring admission to hospital medical wards in sub-Saharan Africa. Such patients have high mortality risk and have most to gain from rapid diagnosis of TB and immediate initiation of treatment. However, few studies using this assay have yet been reported and many questions remain concerning the correct use of the assay, interpretation of results, the role of the assay as an add-on test within existing diagnostic algorithms and the types of further studies needed. In this paper we address a series of questions with the aim of informing the design, conduct and interpretation of future studies. Specifically, we clarify which clinical populations are most likely to derive benefit from use of this assay and how patients enrolled in such studies might best be characterised. We describe the importance of employing a rigorous microbiological diagnostic reference standard in studies of diagnostic accuracy and discuss issues surrounding the specificity of the assay in different geographical areas and potential cross-reactivity with non-tuberculous mycobacteria and other organisms. We highlight the importance of careful procedures for urine collection and storage and the critical issue of how to read and interpret the test strips. Finally, we consider how the assay could be used in combination with other assays and outline the types of studies that are required to build the evidence base concerning its use.

This study compared growth, nodulation, nitrogen fixation, and nodular enzyme activities in response to salinity in some common bean-rhizobia symbiotic combinations. Seeds of Paulista and Efequince, two varieties of the common bean... more

This study compared growth, nodulation, nitrogen fixation, and nodular enzyme activities in response to salinity in some common bean-rhizobia symbiotic combinations. Seeds of Paulista and Efequince, two varieties of the common bean (Phaseolus vulgaris) were germinated and seedlings were transferred to pots containing vermiculite inoculated with the reference Rhizobium strain CIAT899 or with RhM11 or RhM14, two local strains. Plants were grown in a temperature-controlled glasshouse at 28°C and irrigated with a nutrient solution without NaCl (control) or supplemented with 25 mM NaCl (stressed). Plants were harvested at the flowering stage. The results showed that in controls, inoculation with RhM11 improved plant and nodule growth compared with those inoculated with RhM14 and CIAT 899. NaCl treatment generally had a negative affect on plant and nodule growth. Under the saline treatment, symbiotic nitrogen fixation was not significantly affected in the CIAT899-Paulista, CIAT899-Efequince and RhM11-Paulista combinations. Plant mineral nutrition was negatively affected under salt treatment for all of the tested symbiotic combinations. Inoculation with CIAT899 and RhM11 conferred more plant tolerance to salinity than inoculation with RhM14. The nodular phosphoenolpyruvate carboxylase (PEPC) and malate dehydrogenase (MDH) exhibited higher activities and were less affected by salinity in plants inoculated with the reference strain CIAT899 than those inoculated with local strains. We conclude that plants inoculated with CIAT899 and RhM11 showed more salinity stress tolerance than those inoculated with RhM14.

Background: As efforts to contain artemisinin resistance and eliminate Plasmodium falciparum intensify, the accurate diagnosis and prompt effective treatment of malaria are increasingly needed in Myanmar and the Greater Mekong Sub-region... more

Background: As efforts to contain artemisinin resistance and eliminate Plasmodium falciparum intensify, the accurate diagnosis and prompt effective treatment of malaria are increasingly needed in Myanmar and the Greater Mekong Sub-region (GMS). Rapid diagnostic tests (RDTs) have been shown to be safe, feasible, and effective at promoting appropriate treatment for suspected malaria, which are of particular importance to drug resistance containment. The informal private sector is often the first point of care for fever cases in malaria endemic areas across Myanmar and the GMS, but there is little published information about informal private provider practices, quality of service provision, or potential to contribute to malaria control and elimination efforts. This study tested different incentives to increase RDT use and improve the quality of care among informal private healthcare providers in Myanmar.

Inoculation of maize silage with Lactobacillus buchneri (5 x 10(5) c.f.u. g(-1) of maize silage) prior to ensiling results in the formation of aerobically stable silage. After 9 months, lactic acid bacterium counts are approximately... more

Inoculation of maize silage with Lactobacillus buchneri (5 x 10(5) c.f.u. g(-1) of maize silage) prior to ensiling results in the formation of aerobically stable silage. After 9 months, lactic acid bacterium counts are approximately 10(10) c.f.u. g(-1) in these treated silages. An important subpopulation (5.9 x 10(7) c.f.u. g(-1)) is able to degrade 1,2-propanediol, a fermentation product of L. buchneri, under anoxic conditions to 1-propanol and propionic acid. From this group of 1,2-propanediol-fermenting, facultatively anaerobic, heterofermentative lactobacilli, two rod-shaped isolates were purified and characterized. Comparative 16S rDNA sequence analysis revealed that the newly isolated bacteria have identical 16S rDNA sequences and belong phylogenetically to the L. buchneri group. DNA-DNA hybridizations, whole-cell protein fingerprinting and examination of phenotypic properties indicated that these two isolates represent a novel species, for which the name Lactobacillus diolivo...

In 1989, a new type of antibody was identified, first in the sera of dromedaries and later also in all other species of the Camelidae family. These antibodies do not contain a light chain and also lack the first constant heavy domain.... more

In 1989, a new type of antibody was identified, first in the sera of dromedaries and later also in all other species of the Camelidae family. These antibodies do not contain a light chain and also lack the first constant heavy domain. Today it is still unclear what the evolutionary advantage of such heavy chain-only antibodies could be. In sharp contrast, the broad applicability of the isolated variable antigen-binding domains (VHH) was rapidly recognized, especially for the development of therapeutic proteins, called Nanobodies Ò . Here we summarize first some of the unique characteristics and features of VHHs. These will next be described in the context of different experimental therapeutic applications of Nanobodies against different viruses: HIV, Hepatitis B virus, influenza virus, Respiratory Syncytial virus, Rabies virus, FMDV, Poliovirus, Rotavirus, and PERVs. Next, the diagnostic application of VHHs (Vaccinia virus, Marburg virus and plant Tulip virus X), as well as an industrial application (lytic lactococcal 936 phage) will be described. In addition, the described data show that monovalent Nanobodies can possess unique characteristics not observed with conventional antibodies. The straightforward formatting into bivalent, multivalent, and/or multispecific Nanobodies allowed tailoring molecules for potency and cross-reactivity against viral targets with high sequence diversity.

Whole-genome nucleotide sequencing has revolutionized the genetic, biochemical and molecular biology research on bacteria and indeed, many higher organisms. The genome sequences of the strains of two subspecies of Lactococcus lactis, L.... more

Whole-genome nucleotide sequencing has revolutionized the genetic, biochemical and molecular biology research on bacteria and indeed, many higher organisms. The genome sequences of the strains of two subspecies of Lactococcus lactis, L. lactis subsp. lactis and L. lactis subsp. cremoris, have been determined. These genomic sequences have permitted two important new approaches to be applied in the research of L. lactis. The analysis of the regulation of expression of all genes under specific circumstances at a given point in time is now possible by DNA microarray technology. The elucidation of the full protein complement of the organism as a function of intrinsic or external factors has been made possible by high-throughput protein identification and analysis techniques combined with the gene-derived know-how of the total protein encoding capacity of the genome. These techniques from the genomics arena, transcriptomics and proteomics, have been recently implemented in the study of various aspects of growth and functioning of L. lactis. In this paper we discuss a number of similarities and differences between the two lactococcal genome sequences and review the current status of genomics research in L. lactis. We also propose future directions with respect to both answering fundamental questions more quickly and more completely, as well as opening new avenues for biotechnological applications.

The gastrointestinal tract is a complex ecosystem that associates a resident microbiota and cells of various phenotypes lining the epithelial wall expressing complex metabolic activities. The resident microbiota in the digestive tract is... more

The gastrointestinal tract is a complex ecosystem that associates a resident microbiota and cells of various phenotypes lining the epithelial wall expressing complex metabolic activities. The resident microbiota in the digestive tract is a heterogeneous microbial ecosystem containing up to 1 Â 10 14 colony-forming units (CFUs) of bacteria. The intestinal microbiota plays an important role in normal gut function and maintaining host health. The host is protected from attack by potentially harmful microbial microorganisms by the physical and chemical barriers created by the gastrointestinal epithelium. The cells lining the gastrointestinal epithelium and the resident microbiota are two partners that properly and/or synergistically function to promote an efficient host system of defence. The gastrointestinal cells that make up the epithelium, provide a physical barrier that protects the host against the unwanted intrusion of microorganisms into the gastrointestinal microbiota, and against the penetration of harmful microorganisms which usurp the cellular molecules and signalling pathways of the host to become pathogenic. One of the basic physiological functions of the resident microbiota is that it functions as a microbial barrier against microbial pathogens. The mechanisms by which the species of the microbiota exert this barrier effect remain largely to be determined. There is increasing evidence that lactobacilli and bifidobacteria, which inhabit the gastrointestinal microbiota, develop antimicrobial activities that participate in the host's gastrointestinal system of defence. The objective of this review is to analyze the in vitro and in vivo experimental and clinical studies in which the antimicrobial activities of selected lactobacilli and bifidobacteria strains have been documented.

Background: Computational models play an increasingly important role in the assessment and control of public health crises, as demonstrated during the 2009 H1N1 influenza pandemic. Much research has been done in recent years in the... more

Background: Computational models play an increasingly important role in the assessment and control of public health crises, as demonstrated during the 2009 H1N1 influenza pandemic. Much research has been done in recent years in the development of sophisticated data-driven models for realistic computer-based simulations of infectious disease spreading. However, only a few computational tools are presently available for assessing scenarios, predicting epidemic evolutions, and managing health emergencies that can benefit a broad audience of users including policy makers and health institutions. Results: We present "GLEaMviz", a publicly available software system that simulates the spread of emerging human-to-human infectious diseases across the world. The GLEaMviz tool comprises three components: the client application, the proxy middleware, and the simulation engine. The latter two components constitute the GLEaMviz server. The simulation engine leverages on the Global Epidemic and Mobility (GLEaM) framework, a stochastic computational scheme that integrates worldwide high-resolution demographic and mobility data to simulate disease spread on the global scale. The GLEaMviz design aims at maximizing flexibility in defining the disease compartmental model and configuring the simulation scenario; it allows the user to set a variety of parameters including: compartment-specific features, transition values, and environmental effects. The output is a dynamic map and a corresponding set of charts that quantitatively describe the geo-temporal evolution of the disease. The software is designed as a client-server system. The multi-platform client, which can be installed on the user's local machine, is used to set up simulations that will be executed on the server, thus avoiding specific requirements for large computational capabilities on the user side. Conclusions: The user-friendly graphical interface of the GLEaMviz tool, along with its high level of detail and the realism of its embedded modeling approach, opens up the platform to simulate realistic epidemic scenarios. These features make the GLEaMviz computational tool a convenient teaching/training tool as well as a first step toward the development of a computational tool aimed at facilitating the use and exploitation of computational models for the policy making and scenario analysis of infectious disease outbreaks.

The central dogma of molecular biology defines the major route for the transfer of genetic information from genomic DNA to messenger RNA to three-dimensional proteins that affect structure and function. Like alternative splicing, the... more

The central dogma of molecular biology defines the major route for the transfer of genetic information from genomic DNA to messenger RNA to three-dimensional proteins that affect structure and function. Like alternative splicing, the post-transcriptional conversion of adenosine to inosine (A-to-I) by RNA editing can dramatically expand the diversity of the transcriptome to generate multiple, functionally distinct protein isoforms from a single genomic locus. While RNA editing has been identified in virtually all tissues, such post-transcriptional modifications have been best characterized in RNAs encoding both ligand-and voltage-gated ion channels and neurotransmitter receptors. These RNA processing events have been shown to play an important role in the function of the encoded protein products and, in several cases, have been shown to be critical for the normal development and function of the nervous system.

Herbaspirillum seropedicae is an endophytic diazotrophic bacterium that associates with economically important crops. NifA protein, the transcriptional activator of nif genes in H. seropedicae, binds to nif promoters and, together with... more

Herbaspirillum seropedicae is an endophytic diazotrophic bacterium that associates with economically important crops. NifA protein, the transcriptional activator of nif genes in H. seropedicae, binds to nif promoters and, together with RNA polymerase-s 54 holoenzyme, catalyzes the formation of open complexes to allow transcription initiation. The activity of H. seropedicae NifA is controlled by ammonium and oxygen levels, but the mechanisms of such control are unknown. Oxygen sensitivity is attributed to a conserved motif of cysteine residues in NifA that spans the central AAAþ domain and the interdomain linker that connects the AAAþ domain to the C-terminal DNA binding domain. Here we mutagenized this conserved motif of cysteines and assayed the activity of mutant proteins in vivo. We also purified the mutant variants of NifA and tested their capacity to bind to the nifB promoter region. Chimeric proteins between H. seropedicae NifA, an oxygen-sensitive protein, and Azotobacter vinelandii NifA, an oxygen-tolerant protein, were constructed and showed that the oxygen response is conferred by the central AAAþ and C-terminal DNA binding domains of H. seropedicae NifA. We conclude that the conserved cysteine motif is essential for NifA activity, although single cysteine-to-serine mutants are still competent at binding DNA.

Changes in reimbursement policies have focused attention on the use of indwelling catheters in the critical care unit as well as their role in hospital-acquired urinary tract infections. Implementation of an evidence-based prevention... more

Changes in reimbursement policies have focused attention on the use of indwelling catheters in the critical care unit as well as their role in hospital-acquired urinary tract infections. Implementation of an evidence-based prevention program can significantly reduce both the prevalence of indwelling catheterization and the incidence of hospitalacquired catheter-associated urinary tract infection. This article describes the epidemiology and pathophysiology of catheter-associated urinary tract infection, and outlines essential elements of an evidence-based prevention program for the critical care unit. Changes in the US Centers for Medicare & Medicaid Services (CMS) inpatient prospective payment system continue to impact care delivery in the critical care unit. The Medicare Severity Diagnosis Related Group (MS-DRG) was launched in 2007, and the revised payment system was implemented in October 2008. One component of this program that has particularly impacted care delivery in the critical care unit is the identification of a number of high-cost, high-volume conditions that can be reasonably prevented via application of evidence-based interventions. 1 If the conditions are hospital acquired, the CMS will no longer reimburse the costs associated with them. Back to Top | Article Outline Catheter-Associated Urinary Tract Infection Not surprisingly, catheter-associated urinary tract infection (CAUTI) was identified as one of the original 8 potentially preventable conditions. Urinary tract infections (UTIs) account for approximately 40% of all hospital-acquired infections in the United States 2 ; more than 80% are associated with an indwelling catheter. 3 The prevalence of CAUTI in

An extremely halophilic archaeon was isolated from a sample of the brine-sediment interface of the Shaban Deep in the northern Red Sea. Phylogenetic analysis of the 16S rRNA gene sequence revealed a close proximity to Halorhabdus... more

An extremely halophilic archaeon was isolated from a sample of the brine-sediment interface of the Shaban Deep in the northern Red Sea. Phylogenetic analysis of the 16S rRNA gene sequence revealed a close proximity to Halorhabdus utahensis (99.3 %), the sole species of the genus Halorhabdus. Strain SARL4B T formed non-pigmented colonies and showed optimum growth at 45 6C, in 27 % (w/v) NaCl and at pH 6.5-7.0. This organism utilized a few complex substrates, such as yeast extract and starch, for growth. Strain SARL4B T grew under anaerobic and microaerophilic conditions but grew extremely poorly under aerobic conditions. The ether lipids were diphytanyl derivatives. The DNA G+C content of the type strain was 61.7 mol%. On the basis of the phylogenetic data and physiological and biochemical characteristics, strain SARL4B T represents a novel species of the genus Halorhabdus, for which the name Halorhabdus tiamatea is proposed. The type strain is SARL4B T (5DSM 18392 T 5JCM 14471 T). An emended description of the genus Halorhabdus is also proposed.

We present a case of disseminated Chromobacterium violaceum sepsis with multiple liver and splenic abscesses presenting with skin lesions and cardiogenic shock, and later diagnosed to have chronic granulomatous disease. The patient was... more

We present a case of disseminated Chromobacterium violaceum sepsis with multiple liver and splenic abscesses presenting with skin lesions and cardiogenic shock, and later diagnosed to have chronic granulomatous disease. The patient was treated with prolonged antimicrobial therapy, after which she recovered and remained asymptomatic on follow-up.

Effective sub-gingival debridement is crucial to prevent serious systemic infections in hospitalized patients. Lack of compliance and the impracticality of repeated treatment in a short span of time are identified barriers to the... more

Effective sub-gingival debridement is crucial to prevent serious systemic infections in hospitalized patients. Lack of compliance and the impracticality of repeated treatment in a short span of time are identified barriers to the performance of full mouth scaling and root planing (SRP). The aim of this randomized study was to evaluate the clinical and microbiological effects of the adjunctive administration of a locally delivered desiccant liquid with molecular hygroscopic properties (HYBENX® Oral Tissue Decontaminant™; HBX) in association with sub-gingival ultrasonic debridement (UD) in a hospital setting. Sixteen patients presenting moderate to severe chronic periodontitis were followed in a randomized 3 month, split mouth, single-blind, prospective study. At baseline (T1) control and test sides were treated with supra and subgingival UD with or without the association of a locally delivered desiccant liquid (HBX). Treatment was repeated after 6 weeks (T2). Clinical and microbiolo...

The Mosquito A Human History of Our Deadliest Predator

Background: The scale-up of malaria interventions in sub-Saharan Africa has been accompanied by a dramatic increase in insecticide resistance in Anopheles spp. In Zimbabwe resistance to pyrethroid insecticides was reported in Gokwe... more

Background: The scale-up of malaria interventions in sub-Saharan Africa has been accompanied by a dramatic increase in insecticide resistance in Anopheles spp. In Zimbabwe resistance to pyrethroid insecticides was reported in Gokwe District in 2008. This study reports results of the first nationwide assessment of insecticide susceptibility in wild populations of Anopheles gambiae sensu lato (s.l.) in Zimbabwe, and provides a comprehensive review of the insecticide resistance status of An. gambiae s.l. in southern African countries. Methods: World Health Organization (WHO) insecticide susceptibility tests were performed on 2,568 field collected mosquitoes originating from 13 sentinel sites covering all endemic regions in Zimbabwe in 2011-2012. At each site, 24-hour mortality and knock-down values for 50% and 90% of exposed mosquitoes (KD 50 and KD 90 , respectively) were calculated for pools of 20-84 (mean, 54) mosquitoes exposed to 4% DDT, 0.1% bendiocarb, 0.05% λcyhalothrin or 5% malathion. Susceptibility results from Zimbabwe were compiled with results published during 2002-2012 for all southern African countries to investigate the resistance status of An. gambiae s.l. in the region. Results: Using WHO criteria, insecticide resistance was not detected at any site sampled and for any of the insecticide formulations tested during the malaria transmission season in 2012. Knock-down within 1 hr post-insecticide exposure ranged from 95% to 100%; mortality 24 hours post-insecticide exposure ranged from 98% to 100%. Despite the lack of insecticide resistance, high variability was found across sites in KD 50 and KD 90 values. A total of 24 out of 64 (37.5%) sites in southern Africa with reported data had evidence of phenotypic insecticide resistance in An. gambiae s.l. to at least one insecticide. Conclusion: Despite a long history of indoor residual spraying of households with insecticide, up to 2012 there was no evidence of phenotypic resistance to any of the four insecticide classes in An. gambiae s.l. collected across different eco-epidemiological areas in Zimbabwe. Results reinforce the need for careful monitoring over time in sentinel sites in order to detect the potential emergence and propagation of insecticide resistance as insecticidal vector control interventions in Zimbabwe continue to be implemented.

Guidelines were obtained from France, Germany, Italy, Netherlands, Poland, Portugal, Sweden and the UK. Most guidelines recommend neuraminidase inhibitors over M2 inhibitors, but three countries were unclear or suggested M2 inhibitor use... more

Guidelines were obtained from France, Germany, Italy, Netherlands, Poland, Portugal, Sweden and the UK. Most guidelines recommend neuraminidase inhibitors over M2 inhibitors, but three countries were unclear or suggested M2 inhibitor use in some circumstances. Clinical ...

This study aimed at detecting and quantifying biogenic amines (cadaverine, spermidine, histamine, putrescine and tyramine) in four different types of cheese using high-performance liquid chromatography (HPLC). For this study, ten samples... more

This study aimed at detecting and quantifying biogenic amines (cadaverine, spermidine, histamine, putrescine and tyramine) in four different types of cheese using high-performance liquid chromatography (HPLC). For this study, ten samples of gouda, minas, mozzarella and prato, four types of cheese, were purchased in retail markets of Rio de Janeiro. Biogenic amines were previously extracted and derivatizated; then, these amines were detected and quantified by HPLC-UV. For assessing differences among the analyzed cheeses, data were submitted to Anova and Tukey’s test. Minas cheese showed the lowest amount of amine (24.26 mg.kg-1), and the highest contents (489.15 mg.kg-1) were found in gouda. As for the investigated biogenic amines, tyramine showed the highest concentrations (623.60 mg.kg-1), and spermidine was found at the lowest concentration (0.80 mg.kg-1) in all four types of cheese. This study indicates that gouda seems to demand a much more careful monitoring of biogenic amines ...

Background: India has a large and evolving HIV epidemic. Little is known about cancer risk in Indian persons with HIV/AIDS (PHA) but risk is thought to be low. Methods: To describe the state of knowledge about cancer patterns in Indian... more

Background: India has a large and evolving HIV epidemic. Little is known about cancer risk in Indian persons with HIV/AIDS (PHA) but risk is thought to be low. Methods: To describe the state of knowledge about cancer patterns in Indian PHA, we reviewed reports from the international and Indian literature. Results: As elsewhere, non-Hodgkin lymphomas dominate the profile of recognized cancers, with immunoblastic/large cell diffuse lymphoma being the most common type. Hodgkin lymphoma is proportionally increased, perhaps because survival with AIDS is truncated by fatal infections. In contrast, Kaposi sarcoma is rare, in association with an apparently low prevalence of Kaposi sarcoma-associated herpesvirus. If confirmed, the reasons for the low prevalence need to be understood. Cervical, anal, vulva/vaginal and penile cancers all appear to be increased in PHA, based on limited data. The association may be confounded by sexual behaviors that transmit both HIV and human papillomavirus. Head and neck tumor incidence may also be increased, an important concern since these tumors are among the most common in India. Based on limited evidence, the increase is at buccal/palatal sites, which are associated with tobacco and betel nut chewing rather than human papillomavirus. Conclusion: With improving care of HIV and better management of infections, especially tuberculosis, the longer survival of PHA in India will likely increase the importance of cancer as a clinical problem in India. With the population's geographic and social diversity, India presents unique research opportunities that can be embedded in programs targeting HIV/AIDS and other public health priorities.

The insertion and the permanence of central venous catheters (CVC) represent potential sources of infection contracted in hospital. The evaluation of the risk of CVC-associated infections was evaluated in a retrospective study during the... more

The insertion and the permanence of central venous catheters (CVC) represent potential sources of infection contracted in hospital. The evaluation of the risk of CVC-associated infections was evaluated in a retrospective study during the period 2007-2010 in a Hospital of Central Italy. A total of 514 CVC were collected and examined by microbiological techniques and, among the examined patients, 450 CVC blood cultures were collected. Cultures were performed collecting a portion of 5-6 cm of intravenous catheters in liquid medium and spread on selective media for Gram-positive and Gram-negative bacteria and yeasts; blood specimens were obtained through peripheral venous punctures and analyzed by a commercial automated system. 308/514 (59.90%) samples were positive to the microbiological culture. Staphylococcus aureus, S. epidermidis and other coagulase negative Staphylococci (CNS) were the prevalent Gram-positive bacteria. Among Gram-negative bacteria, Enterobacteriaceae and Pseudomon...

Infection of red blood cells (RBC) subjects the malaria parasite to oxidative stress. Therefore, efficient antioxidant and redox systems are required to prevent damage by reactive oxygen species. Plasmodium spp. have thioredoxin and... more

Infection of red blood cells (RBC) subjects the malaria parasite to oxidative stress. Therefore, efficient antioxidant and redox systems are required to prevent damage by reactive oxygen species. Plasmodium spp. have thioredoxin and glutathione (GSH) systems that are thought to play a major role as antioxidants during blood stage infection. In this report, we analyzed a critical component of the GSH biosynthesis pathway using reverse genetics. Plasmodium berghei parasites lacking expression of gamma-glutamylcysteine synthetase (c-GCS), the rate limiting enzyme in de novo synthesis of GSH, were generated through targeted gene disruption thus demonstrating, quite unexpectedly, that c-GCS is not essential for blood stage development. Despite a significant reduction in GSH levels, blood stage forms of pbggcs 2 parasites showed only a defect in growth as compared to wild type. In contrast, a dramatic effect on development of the parasites in the mosquito was observed. Infection of mosquitoes with pbggcs 2 parasites resulted in reduced numbers of stunted oocysts that did not produce sporozoites. These results have important implications for the design of drugs aiming at interfering with the GSH redox-system in blood stages and demonstrate that de novo synthesis of GSH is pivotal for development of Plasmodium in the mosquito.

While conceptual principles governing plant immunity are becoming clear, its systems-level organization and the evolutionary dynamic of the hostpathogen interface are still obscure. We generated a systematic protein-protein interaction... more

While conceptual principles governing plant immunity are becoming clear, its systems-level organization and the evolutionary dynamic of the hostpathogen interface are still obscure. We generated a systematic protein-protein interaction network of virulence effectors from the ascomycete pathogen Golovinomyces orontii and Arabidopsis thaliana host proteins. We combined this data set with corresponding data for the eubacterial pathogen Pseudomonas syringae and the oomycete pathogen Hyaloperonospora arabidopsidis. The resulting network identifies host proteins onto which intraspecies and interspecies pathogen effectors converge. Phenotyping of 124 Arabidopsis effector-interactor mutants revealed a correlation between intraspecies and interspecies convergence and several altered immune response phenotypes. Several effectors and the most heavily targeted host protein colocalized in subnuclear foci. Products of adaptively selected Arabidopsis genes are enriched for interactions with effector targets. Our data suggest the existence of a molecular host-pathogen interface that is conserved across Arabidopsis accessions, while evolutionary adaptation occurs in the immediate network neighborhood of effector targets.

Identification of Candida cultured from various clinical specimens to the species level is increasingly necessary for clinical laboratories. Although sn PCR identifies the species within hours but its cost-effectiveness is to be... more

Identification of Candida cultured from various clinical specimens to the species level is increasingly necessary for clinical laboratories. Although sn PCR identifies the species within hours but its cost-effectiveness is to be considered. So there is always a need for media which help in the isolation and identification at the species level. The study aimed to evaluate the performance of different chromogenic media and to compare the effectiveness of the traditional phenotypic methods vs. seminested polymerase chain reaction (sn PCR) for identification of Candida species. One hundred and twenty seven Candida strains isolated from various clinical specimens were identified by conventional methods, four different chromogenic media and sn PCR. HiCrome Candida Differential and CHROMagar Candida media showed comparably high sensitivities and specificities in the identification of C. albicans, C. tropicalis, C. glabrata and C. krusei. CHROMagar Candida had an extra advantage of identify...

Glossina species epidemiological studies were conducted in "fly-belt" endemic zone of southwest Nigeria. Two major study areas were identified and four Nzi traps were set in each site for tsetse collection. This study was conducted to... more

Glossina species epidemiological studies were conducted in "fly-belt" endemic zone of southwest Nigeria. Two major study areas were identified and four Nzi traps were set in each site for tsetse collection. This study was conducted to determine the prevalence of endosymbionts (Wigglesworthia glossinidia, Sodalis glossinidius and Wolbachia) in natural field-trapped populations of G. p. palpalis and G. tachinoides and investigate the corresponding interactions with African trypanosomes. A total of 64 tsetse flies were collected, these included G. p. palpalis (n = 28) and G. tachinoides (n = 36). Trypanosome infection and endosymbionts of these flies were determined using polymerase chain reaction (PCR) amplification. The infection rates of W. glossinidia was 100.0% in both species, no flies were positive for Wolbachia. Sodalis glossinidius prevalence was similar between the two-tsetse species, with G. p. palpalis and G. tachinoides showing prevalence of 35.7% (95%CI: 20.7-54.2) and 27.8% (95%CI: 15.9-44.0) respectively. No relationship was found between the endosymbionts and trypanosomes in trapped tsetse flies. More studies are needed to enhance the potential control interventions mediated by endosymbionts to reduce parasitic infections.

17th ECCMID / 25th ICC, Oral presentations zAG, and all BALF samples negative for zAg were also negative for zygomycete DNA by PCR. Conclusion: zAg and zygomycete DNA are present in BALF of patients with IZ, and might be a useful tool for... more

17th ECCMID / 25th ICC, Oral presentations zAG, and all BALF samples negative for zAg were also negative for zygomycete DNA by PCR. Conclusion: zAg and zygomycete DNA are present in BALF of patients with IZ, and might be a useful tool for early diagnosis. The presence of both markers in BALF samples from high-risk patients without a clinically manifest disease might indicate the presence of colonisation or subclinical infection.

Among about 50 Paragonimus species, Paragonimus proliferus is a rare species characterized by extremely large metacercariae, most of which are present excysted in the crab hosts. Recently, this species was discovered by us in northern... more

Among about 50 Paragonimus species, Paragonimus proliferus is a rare species characterized by extremely large metacercariae, most of which are present excysted in the crab hosts. Recently, this species was discovered by us in northern Vietnam as the first record outside of China. DNA sequences of both second internal transcribed spacer region (ITS2) and cytochrome oxidase subunit 1 gene (CO1) genes of the metacercariae and adult worms of P. proliferus of the Vietnamese isolates were identical with those of Paragonimus hokuoensis in the DNA database of the GenBank. To confirm those observations and to clarify the molecular phylogenetic status of P. proliferus, we determined the ITS2 and CO1 sequences of the metacercariae of P. proliferus obtained in Yunnan province, China where the original specimen was discovered. The results show that both ITS2 and CO1 sequences of P. proliferus of the Chinese isolates are identical with those of P. proliferus of the Vietnamese isolates and are also identical with those of P. hokuoensis that appeared in the DNA database (obtained in Yunnan province), suggesting the synonymy of P. hokuoensis with P. proliferus. By phylogenetic tree analyses, all samples of P. proliferus from China and Vietnam together with P. hokuoensis constructed a distinct group within, or very close to, Paragonimus skrjabini complex in both trees.

Mycoplasma genitalium has been proposed as a suitable model for an in-depth understanding of the biology of a free-living organism. This paper reports that the expression of the aminoglycoside resistance gene aac(69)-aph(20), the only... more

Mycoplasma genitalium has been proposed as a suitable model for an in-depth understanding of the biology of a free-living organism. This paper reports that the expression of the aminoglycoside resistance gene aac(69)-aph(20), the only selectable marker hitherto available for M. genitalium genetic studies, correlates with a growth impairment of the resistant strains. In light of this finding, a tetM438 construction based on the tetracycline resistance gene tetM was developed; it can be used efficiently in M. genitalium and confers multiple advantages when compared to aac(69)-aph(20). The use of tetM438 significantly improves transformation efficiency and generates visible colonies faster. Finally, the improvements in the pMTnTetM438 construction made it possible to obtain insertions in genes which have not been previously considered to be dispensable under laboratory growth conditions.

N-acetyl-β-D-hexosaminidase was purified from wheat bran and characterized. The purified enzyme showed two protein bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with molecular mass of 75 and 78 kDa. The... more

N-acetyl-β-D-hexosaminidase was purified from wheat bran and characterized. The purified enzyme showed two protein bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with molecular mass of 75 and 78 kDa. The enzyme exhibited optimum pH and temperature at 5.0 and 50 o C, respectively. The enzyme was active on the substrates of p-nitrophenyl-Nacetyl-β-D-glucosaminide (pNP-GlcNAc) and p-nitrophenyl-Nacetyl-β-D-galactosaminide (pNP-GalNAc), whereas inactive on pNP-β-D-glucopyranoside, pNP-β-D-galactopyranoside, swollen chitin, and colloidal chitin, suggesting high substrate specificity. The enzyme activity for pNP-GlcNAc was stable at pH 3-6 and under 50 o C. The K m , V max and K cat for pNP-GlcNAc were 0.014 mM, 0.05 µmol/min, and 3.01×10 6 min −1 , respectively. The enzyme could be completely inhibited at 1-10 mM HgCl 2 and AgNO 3, suggesting that the intact thiol group is essential for activity. β-N-Acetylhexosaminidase from wheat bran could inhibit the conidial germination and digest the hyphae of Fusarium solani.

Fructose 2,6-bisphosphate is present at high concentrations in many established lines of transformed cells. It plays a key role in the maintenance of a high glycolytic rate by coupling hormonal and growth factor signals with metabolic... more

Fructose 2,6-bisphosphate is present at high concentrations in many established lines of transformed cells. It plays a key role in the maintenance of a high glycolytic rate by coupling hormonal and growth factor signals with metabolic demand. The concentration of fructose 2,6-bisphosphate is controlled by the activity of the homodimeric bifunctional enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFK-2). We report here the PFKFB-3 gene expression control by insulin in the human colon adenocarcinoma HT29 cell line. The incubation of these cells with 1 WM insulin resulted in an increase in the PFK-2 mRNA level after 6 h of treatment, this effect being blocked by actinomycin D. Furthermore, insulin induced ubiquitous PFK-2 protein levels, that were evident after a lag of 3 h and could be inhibited by incubation with cycloheximide. ß

This report describes the generation of novel encapsidated RNA particles and their evaluation as in-tube internal controls in diagnostic real-time reverse-transcription PCR (rRT-PCR) assays for the detection of RNA viruses. A cassette... more

This report describes the generation of novel encapsidated RNA particles and their evaluation as in-tube internal controls in diagnostic real-time reverse-transcription PCR (rRT-PCR) assays for the detection of RNA viruses. A cassette containing sequences of 2 diagnostic primer sets for foot-and-mouth disease virus (FMDV) and a set for swine vesicular disease virus (SVDV) was engineered into a full-length cDNA clone containing the RNA-2 segment of Cowpea Mosaic Virus (CPMV). After co-inoculation with a plasmid that expressed CPMV RNA-1, recombinant virus particles were rescued from cowpea plants (Vigna unguiculata). RNA contained in these particles was amplified in diagnostic rRT-PCR assays used for detection of FMDV and SVDV. Amplification of these internal controls was used to confirm that rRT-PCR inhibitors were absent from clinical samples, thereby verifying negative assay results. The recombinant CPMVs did not reduce the analytical sensitivity of the rRT-PCRs when amplification of the insert was performed in the same tube as the diagnostic target. This system provides an attractive solution to the production of internal controls for rRT-PCR assays since CPMV grows to high yields in plants, the particles are thermostable, RNase resistant and simple purification of RNA-2 containing capsids yields a preparation which is non-infectious.

A retrospective epidemiological analysis was performed of Mycobacterium tuberculosis infections in the Al Ain Medical District, Al Ain, United Arab Emirates (U.A.E.) during the period 1995-2000. The mean incidence for the study period was... more

A retrospective epidemiological analysis was performed of Mycobacterium tuberculosis infections in the Al Ain Medical District, Al Ain, United Arab Emirates (U.A.E.) during the period 1995-2000. The mean incidence for the study period was 7.1%, more than 3 times that reported for the period 1983-1992 (2.1%). For the years 1997 through 2000, the highest incidences (-5-7% of tested) were from health care facilities that cater exclusively for citizens and long-term residents of the U.A.E. Corresponding rates for the immigrant visa applicants (non-citizens) were lower and showed a dramatic decrease from -18% in 1995 to -2% in 2000. Most importantly, the number of multidrug-resistant cases showed an increase from 1.4% during the period August 1997-December 1998 to 8.5% during the period January 1999-July 2000. Analysis of 7 different isolates by restriction fragment length polymorphism (RFLP) showed RFLP patterns that did not match >4000 individual patterns from 32 countries, suggesting the possible presence of M. tuberculosis strains unique to the U.A.E. Our data demonstrate local transmission of M. tuberculosis in the Al Ain Medical Region of the U.A.E.

Infection by human hepatitis C virus (HCV) is the principal cause of post-transfusion hepatitis and chronic liver diseases worldwide. A reliable in vitro culture system for the isolation and analysis of this virus is not currently... more

Infection by human hepatitis C virus (HCV) is the principal cause of post-transfusion hepatitis and chronic liver diseases worldwide. A reliable in vitro culture system for the isolation and analysis of this virus is not currently available, and, as a consequence, HCV pathogenesis is poorly understood. We report here the first robust in vitro system for the isolation and propagation of HCV from infected donor blood. This system involves infecting freshly prepared macrophages with HCV and then transmission of macrophage-adapted virus into freshly immortalized B-cells from human fetal cord blood. Using this system, newly isolated HCV have been replicated in vitro in continuous cultures for over 130 weeks. These isolates were also transmitted by cell-free methods into different cell types, including B-cells, T-cells and neuronal precursor cells. These secondarily infected cells also produced in vitro transmissible infectious virus. Replication of HCV-RNA was validated by RT-PCR analysis and by in situ hybridization. Although nucleic acid sequencing of the HCV isolate reported here indicates that the isolate is probably of type 1a, other HCV types have also been isolated using this system. Western blot analysis shows the synthesis of major HCV structural proteins. We present here, for the first time, a method for productively growing HCV in vitro for prolonged periods of time. This method allows studies related to understanding the replication process, viral pathogenesis, and the development of anti-HCV drugs and vaccines.

code VAL-0008 versie 5.0 pagina 1 / 16 verantw GD revisie 9-3-2012 De inhoud van dit afgedrukte document is enkel geldig indien het overeenstemt met de meest recente elektronische versie © nadruk verboden I) Scope Implementatie van een... more

code VAL-0008 versie 5.0 pagina 1 / 16 verantw GD revisie 9-3-2012 De inhoud van dit afgedrukte document is enkel geldig indien het overeenstemt met de meest recente elektronische versie © nadruk verboden I) Scope Implementatie van een moleculaire test: Parameter: Neisseria gonorrhoeae kwalitatief Matrix: Urine (M) en genitale wissers (V) in eSwab transportmedium Toestel: Rotorgene 6000 (Qiagen) Techniek: Real-time PCR Kit: Diagenode Neisseria gonorrhoeae real-time PCR kit + Qiagen Quantifast Probe PCR Master Mix Een nieuwe moleculaire test is nodig ter vervanging van de vroegere in-house NG NASBA assay, die specificiteitsproblemen vertoonde (commensale Neisseria species werden opgepikt). De kit van Diagenode is CE-IVD approved en is gevalideerd in combinatie met de Nuclisens EasyMAG en de Rotorgene 6000. De Master Mix wordt apart aangekocht bij Qiagen (Quantifast Probe PCR Master Mix). Onze start-en elutievolumes zijn verschillend met wat in de bijsluiter wordt aangeraden, dus zullen we de LOD opnieuw moeten bepalen. De kit is gebaseerd op het artikel "A duplex Neisseria gonorrhoeae real-time polymerase chain reaction assay targeting the gonococcal porA pseudogene and multicopy opa genes. Namray Goire, Michael D. Nissen, Genevera M. LeCornec, Theo P.Sloots, David M. Whiley. Diagnostic Microbiology and infectious disease 61 (2008) 6-12" en gebruikt dezelfde primers en probes voor de detectie van Neisseria gonorrhoeae. Hierdoor kunnen we de data uit dit artikel en gerelateerde artikels gebruiken in het validatiedossier.

Despite ongoing preventive chemotherapy campaigns, intestinal schistosomiasis is hyper-endemic in shoreline communities living along Lake Albert, Uganda. To provide a deeper insight into the local epidemiology of Schistosoma mansoni, a... more

Despite ongoing preventive chemotherapy campaigns, intestinal schistosomiasis is hyper-endemic in shoreline communities living along Lake Albert, Uganda. To provide a deeper insight into the local epidemiology of Schistosoma mansoni, a variety of field-based studies were undertaken focusing upon schistosome-snail interactions and confirmation of transmission foci. Cercarial shedding patterns of fieldcaught Biomphalaria spp., as identified by morphology, were hourly observed over a ten day period and showed that Biomphalaria stanleyi produced significantly more cercariae than Biomphalaria sudanica. Peak production times in both species were between 12.00 and 14.00 h indicating greatest infection risk from lake water exposure is during the early afternoon. Laboratory-bred snails were exposed to locally hatched miracidia and susceptibility of Biomphalaria spp. was confirmed experimentally. Biomphalaria stanleyi was a more permissive host. After ascertaining appropriate conditions for infection of laboratory mice, 28 groups of between 5 and 6 naïve mice were placed in floatation cages at four suspected shoreline transmission sites for a 30 minute period of exposure. Eight weeks later, mice (n = 142) were culled and S. mansoni adult worms were retrieved from 10 animals. Taken as a whole, these observations highlight the local importance of B. stanleyi in transmission of intestinal schistosomiasis and clearly demonstrate the risk of infection on the Lake Albert shoreline. To mitigate this risk local environmental modification(s), i.e. improvement in sanitation and hygiene and control of snail populations, is needed to bolster the impact of chemotherapybased interventions.

A new extracellular charged polysaccharide composed mainly by galactose, with lower amounts of mannose, glucose and rhamnose, was produced by the cultivation of Pseudomonas oleovorans NRRL B-14682 using glycerol as the sole carbon source.... more

A new extracellular charged polysaccharide composed mainly by galactose, with lower amounts of mannose, glucose and rhamnose, was produced by the cultivation of Pseudomonas oleovorans NRRL B-14682 using glycerol as the sole carbon source. Thermal and solid-state NMR analysis showed that this polymer is essentially amorphous, with a glass transition temperature of 155.7°C. The exopolysaccharide aqueous solutions have viscoelastic properties similar to that of Guar gum, but with affinity to salts as a result of its polyelectrolyte character. In addition, the exopolysaccharide has demonstrated good flocculating and emulsifying properties and film-forming capacity. These properties make this polymer a good alternative to more expensive natural polysaccharides, such as Guar gum, in several applications in the food, pharmaceutical, cosmetic, textile, paper and petroleum industries.

A novel real-time quantitative PCR (QPCR) assay is described for monitoring CMV DNA load in clinical specimens using the LightCycler™. The assay is rapid ( B 40 min), easy to carry out, robust, reliable and is capable of detecting from 10... more

A novel real-time quantitative PCR (QPCR) assay is described for monitoring CMV DNA load in clinical specimens using the LightCycler™. The assay is rapid ( B 40 min), easy to carry out, robust, reliable and is capable of detecting from 10 to over 2 ×10 5 CMV DNA copies with a wide linear range. Amplification and detection occur simultaneously, avoiding the need for post-PCR analysis and thereby minimising the risk of carryover contamination. The assay proved to be accurate, specific and reproducible when evaluated in three different laboratories. In addition, LightCycler™ results were comparable with those of TaqMan™, an independent real-time QPCR assay.