Klebsiella pneumoniae Research Papers - Academia.edu (original) (raw)

Powdered grape seeds and bagasse were extracted with petroleum ether to remove fatty material and then re-extracted with different solvent mixtures to determine their total phenolics and antibacterial activities. In the grape seeds extracts the content of total phenolic compounds was found to be 627.98 mg gallic acid equivalent (GAE)/g with acetone:water:acetic acid (90:9.5:0.5) and 667.87 mg GAE/g with ethyl acetate:methanol:water (60:30:10). The bagasse extracts contained 45.44 mg GAE/g and 29.55 mg GAE/g with ethyl acetate:methanol:water (60:30:10) and ethanol:water (95:5), respectively. These extracts at 1%, 2%, 4% and 20% concentrations were tested for their antibacterial effects by using the paper disc diffusion method against some food spoilage and pathogenic bacteria including Aeromonas hydrophila ATCC 7965, Bacillus amyloliquefaciens ATCC 3842, Bacillus brevis FMC 3,

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- Escherichia coli, Listeria monocytogenes, Staphylococcus aureus, Pseudomonas aeruginosa

Neonatal sepsis is one of the most prevalent infections today, claiming the lives of almost one million newborns in developing countries. Our objective is to determine the bacteria that cause sepsis in newborns in Egyptian hospitals, as well as to discover their resistance profiles, allowing for the selection of appropriate drug combinations against multidrug resistant (MDR) bacteria. Nine hundred and eighty-nine blood samples were collected from neonates in Al Demerdash and Ain Shams University Specialized Hospital from March 2019 to March 20121 according to the standard protocols. Bacterial identification and antimicrobial susceptibility test AST were performed using VITEK® 2 system. The results revealed that 51.4 % of patients had positive blood cultures, with 60.3 % females and 39.7 %. Males. Sepsis with late onset was detected in 95% of positive cases, while sepsis with early onset was observed in only 5% of the total positive cases. According to the Original Research Article

- by Dr. Farouk Hassan
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- Antibiotic Resistance, Real-time RT-PCR, Multidrug Resistance, Neonates

Tigecycline resistance has been attributed to ramA overexpression and subsequent acrA upregulation. The ramA locus, originally identified in Klebsiella pneumoniae, has homologues in Enterobacter and Salmonella spp. In this study, we identify in silico that the ramR binding site is also present in Citrobacter spp. and that Enterobacter, Citrobacter and Klebsiella spp. share key regulatory elements in the control of the romA-ramA locus. RACE (rapid amplification of cDNA ends) mapping indicated that there are two promoters from which romA-ramA expression can be regulated in K. pneumoniae. Correspondingly, electrophoretic binding studies clearly showed that purified RamA and RamR proteins bind to both of these promoters. Hence, there appear to be two RamR binding sites within the Klebsiella romA-ramA locus. Like MarA, RamA binds the promoter region, implying that it might be subject to autoregulation. We have identified changes within ramR in geographically distinct clinical isolates of K. pneumoniae. Intriguingly, levels of romA and ramA expression were not uniformly affected by changes within the ramR gene, thereby supporting the dual promoter finding. Furthermore, a subset of strains sustained no changes within the ramR gene but which still overexpressed the romA-ramA genes, strongly suggesting that a secondary regulator may control ramA expression.

- by Thamarai Schneiders
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- Genetics, Medical Microbiology, Antimicrobial agents, In Silico

Extended-spectrum β-lactamases (ESBLs), e.g., ESBLs of the TEM or SHV type, compromise the efficacies of expanded-spectrum cephalosporins. An SHV non-ESBL that hydrolyzes only narrow-spectrum cephalosporins can be converted into an SHV ESBL through substitutions at three amino acid positions, 179, 238, or 238–240. In order to improve detection of SHV ESBLs, a novel method, based on real-time PCR monitored with fluorescently labeled hybridization probes and followed by melting curve analysis, was developed. It is able to (i) detect bla SHV genes with high degrees of sensitivity and specificity, (ii) discriminate between bla SHV non-ESBL and bla SHV ESBL , and (iii) categorize the SHV ESBL producers into three phenotypically relevant subgroups. This method, termed the SHV melting curve mutation detection method, represents a powerful tool for epidemiological studies with SHV ESBLs. It even has the potential to be used in the diagnostic microbiology laboratory, because up to 32 clinica...

- by Herbert Hächler
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- Genetics, Microbiology, Medical Microbiology, real time PCR

Background Suppression of immune system in treated cancer patients may lead to secondary infections that obviate the need of antibiotics. In the present study, an attempt was made to understand the occurrence of secondary infections in immuno-suppressed patients along with herbal control of these infections with the following objectives to: (a) isolate the microbial species from the treated oral cancer patients along with the estimation of absolute neutrophile counts of patients (b) assess the in vitro antimicrobial activity medicinal plants against the above clinical isolates. Methods Blood and oral swab cultures were taken from 40 oral cancer patients undergoing treatment in the radiotherapy unit of Regional Cancer Institute, Pt. B.D.S. Health University, Rohtak, Haryana. Clinical isolates were identified by following general microbiological, staining and biochemical methods. The absolute neutrophile counts were done by following the standard methods. The medicinal plants selected...

- by Vivek Kaushal
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- Biology, Fungi, Medicine, Escherichia coli

The widespread use of ␤-lactam antimicrobial agents as first-line therapy for the treatment of serious infections has led to the development of various resistances that have compromised the use of some agents. In certain countries, the lack of local or national surveillance programs limits the ability to detect these resistant strains and prevent their dissemination. A 10 medical center study in India was initiated to benchmark prevailing resistance rates for a range of bacterial pathogens to ␤-lactams, and it found high rates of ␤-lactamase-mediated resistance in Escherichia coli and Klebsiella spp. These rates included: cephalosporins (55.6-61.3% resistance), with extended-spectrum ␤-lactamase (ESBL) phenotypes noted in over 60% of E. coli isolates and in Salmonella spp. (3.2-8.1%). Imipenem, a carbapenem, was the only antimicrobial agent tested with 100% activity against Enterobacteriaceae. Cefpirome was the most active of the tested cephalosporins, and all were fully active against methicillin-susceptible staphylococci with the exception of ceftazidime. Molecular and susceptibility characterization of 52 selected ESBL-producing strains showed a high level of co-resistance with aminoglycosides and fluoroquinolones, and clonal dissemination of resistant strains within medical centers. Collaborative studies, such as those presented here, can accurately detect changes in resistance patterns, and their continued use may help limit the further development and spread of bacterial resistances in India.

- by Dilip Mathai
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- Microbiology, Medical Microbiology, Biology, Japan

Bacterial, viral and protozoal infections may cause severe reproductive losses. The present paper reviews the risk factors, clinical signs and preventive measures for the most important venereal or potential sexually transmitted diseases in horses. The stallion and use of semen for artificial insemination represent major risk factors for the transmission of bacterial contaminants of the penis, including Streptococcus equi subspecies zooepidemicus, Pseudomonas aeruginosa and Klebsiella pneumoniae, known to cause endometritis and infertility in the mare. The role of the stallion in disease transmission is also due to the non-clinical manifestation of diseases such as contagious equine metritis and equine viral arteritis. Dourine has been eradicated from many countries, but continues to be a problem in other areas of the globe. Strategies for the prevention of introduction and transmission of diseases in breeding operation are discussed.

- by Ahmed Tibary
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- Epidemiology, Prevention, Biological Sciences, Horses

The antibacterial activity of essential oils and their derivatives has been recognized for a long time. In the present study, the chemical composition and the antibacterial properties of the essential oils obtained from the aerial parts of the four Lamiaceae species, wild oregano (Origanum minutiflorum) (endemic in Turkey), oregano (Origanum onites), black thyme (Thymbra spicata) and wild savory (Satureja cuneifolia), with commercial importance in Turkey, were evaluated. The major constituent of the oils determined by GC was cavracrol (86.9% in O. onites, 84.6% in O. minutiflorum, 75.5% in T. spicata and 53.3% in S. cuneifolia). Four essential oils were investigated for activity against Aeromonas hydrophila, Bacillus amyloliquefaciens, B. brevis, B. cereus, B. subtilis, Corynebacterium xerosis, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, Micrococcus luteus, Mycobacterium smegmatis, Proteus vulgaris, Staphylococcus aureus and Yersinia enterocolitica, using a paper disc diffusion method. All essential oils inhibited all bacteria at concentrations of <1/100 (v/v). The essential oil of T. spicata was the most active. B. amyloliquefaciens was the most sensitive. The results of this study confirmed the possibility of using these four essential oils in food systems to prevent the growth of foodborne bacteria and extend the shelf life of processed foods.

- by Mohammad Jalali
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- Essential Oil, SHELF LIFE, Escherichia coli, Listeria monocytogenes
- by Bilge Sener
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- Multidisciplinary, Escherichia coli, Natural Product, Antibacterial activity
- by Seema Kumari
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- Medical Microbiology, Bacteriophages, Treatment Outcome, Antibiotic Resistance

Klebsiella pneumoniae, an important opportunistic pathogen, exists as a biofilm in persistent infections and in-dwelling medical devices. With the objective of identifying natural compounds inhibiting biofilm formation in K. pneumoniae, 35clinical isolates were screened,out of which 7 strong biofilm producers were identified. Six natural compounds were tested for their inhibitory effects on bacterial growth and biofilm formation by determining the minimum inhibitory concentration and minimum concentration for biofilm inhibition (MBIC) for each compound. The results show that reserpine followed by linoleic acid, were the most potent biofilm inhibitors. Reserpine, an efflux pump inhibitor was effective at biofilm inhibition at a concentration of 0.0156 mg/mL, 64-fold lower concentration than its MIC. Linoleic acid, an essential fatty acid was effective as a biofilm inhibitor at 0.0312 mg/mL, which is 32-fold lower than its MIC. Berberine, another plant derived antimicrobial, chitosan and eugenol had an MBIC value of 0.0635 mg/mL. Curcumin, a natural phenolic compound was effective at biofilm inhibition at a concentration of 0.25 mg/mL, which is 50 fold less than its MIC. Notably, the MIC and MBIC data on these 6 natural compounds was reproducible in all seven high biofilm forming isolates of K. pneumoniae. The present report is a comprehensive comparative analysis of the dose dependent inhibition of various natural compounds on biofilm formation in K. pneumoniae.

The aim of this study was to investigate the presence and prevalence of bla TEM , bla SHV , and bla CTX-M and bla GESlike genes, responsible for extended spectrum beta-lactamases (ESBLs) production in clinical isolates of Klebsiella pneumoniae collected from a Brazilian tertiary care hospital. Sixty-five ESBL producing K. pneumoniae isolates, collected between 2005 and 2007, were screened by polymerase chain reaction (PCR). Identification of bla genes was achieved by sequencing. Genotyping of ESBL producing K. pneumoniae was performed by the enterobacterial repetitive intergenic consensus-PCR with cluster analysis by the Dice coefficient. The presence of genes encoding ESBLs was confirmed in 59/65 (90.8%) isolates, comprising 20 bla CTX-M-2 , 14 bla CTX-M-59 , 12 bla CTX-M-15 , 9 bla SHV-12 , 1 bla SHV-2 , 1 bla SHV-2a , 1 bla SHV-5 , and 1 bla SHV-31 genes. The ESBL genes bla SHV-12 , bla SHV-31 , and bla CTX-M-15 , and the chromosome-encoded SHV-type beta-lactamase capable of hydrolyzing imipenem were detected in Brazil for the first time. The analysis of the enterobacterial repetitive intergenic consensus-PCR band patterns revealed a high rate of multiclonal bla CTX-M carrying K. pneumoniae isolates (70.8%), suggesting that dissemination of encoding plasmids is likely to be the major cause of the high prevalence of these genes among the K. pneumoniae isolates considered in this study.

- by Maurício Nogueira
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- Brazil, Biological Sciences, Polymerase Chain Reaction, Prevalence

Patogeensed gramnegatiivsed pulkbakterid on kogu maailmas olulised hospitaalinfektsioonide tekitajad (1), mille levik intensiivravi osakondades ja antibiootikumiresistentsus (2, 3) põhjustab ravi ebaõnnestumist, suurt suremust ja ravikulude kasvu (4). Olulisemad multiresistentsed patogeenid on Acinetobacter baumannii, Pseudomonas aeruginosa ja Klebsiella pneumoniae, millest kaks esimest on mittefermentatiivsed keskkonnast pärinevad bakterid, viimane aga ka tervete inimeste seedekulglas esinev enterobakter (5-7). Eesti haiglate IR-osakondades levinud A. baumannii, P. aeruginosa ja K. pneumoniae tüvede osakaal teiste patogeenide seas ning antibiootikumitundlikkus ei ole teada. Samas on lokaalne mikroobide liigiline jaotus ja antibiootikumitundlikkus abiks empiirilise ravi valikul. Eesti mikrobioloogialaborites on kasutusel peamiselt patogeenide kvalitatiivne (tundlik/mõõ

Olson, P., Hedhammar, J~., Faris, A., m, T., 1985. Enterotoxigenic Escherichia coli (ETEC) and Klebsiella pneurnoniae isolated from dogs with diarrhoea. Vet. Microbiol., 10: 577--589.

- by Ahmed Faris
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- Microbiology, Veterinary Microbiology, Veterinary, Diarrhea

Empirical antimicrobial therapy is usually started in febrile neutropenic patients without having culture results. The aim of this study was to help determine the policies of empirical antibiotic usage in febrile neutropenic children by detecting the antimicrobial susceptibility profile in this group of patients. In this study 811 blood cultures taken from neutropenic children hospitalized at the Department of Oncology of Gaziantep Children Hospital November 2007 and February 2010 were retrospectively evaluated. Blood cultures were routinely collected in aerobic and anaerobic media and incubated using the BACTEC system. Identification and antimicrobial susceptibility testing of the isolates to antimicrobial agents was performed using the Vitek2 Ò system according to the recommendations of the Clinical and Laboratory Standards Institute. Of 811 isolates analyzed, 128 (56.4%) were gram positive cocci, 43 (18.9%) were gram negative bacilli and fungi accounted for 56 (24.7%). The main isolated Gram-positive bacteria from blood were coagulase-negative staphylococcus (56.7%), followed by methicillin-resistant Staphylococcus aureus (14.1%). S. aureus and Streptococcus spp. were all susceptible to linezolid, vancomycin and teicoplanin. S aureus was still susceptible to few other antimicrobial agents such as tetracycline (82.4%), chloramphenicol (55.6%). Seven E. faecium, 7 E. fecalis and 1 E. hirae was isolated from blood cultures. Vancomycin resistance was detected in 6 out of 15 (40%) Enterococcus spp. isolates. Among gram-negative bacteria E. coli (30.2%) was followed by Klebsiella pneumoniae (20.9%) and Proteus spp. (18.6%). Imipenem (89.2%), meropenem (86.6%), chloramphenicol (88.9%), amicasin (82.4%) and fosfomycin (81.3%) showed highest susceptibility in vitro activity against all Gram-negative isolates. To know the antimicrobial susceptibility profile of the pathogens frequently isolated from febrile neutropenic children and to consider this profile before starting an empirical antibiotic therapy would help the clinics which have any role in the treatment of these patients to determine the empirical antibiotic usage policies.

- by Elvan Citak and +1
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- Microbiology, System Identification, Medical Microbiology, Antimicrobial susceptibility

Introduction Nosocomial infections are induced in hospitalized patients. These patients do not have these infections at the time of reference, but are infected at the time of hospitalization (1). Nosocomial infections are caused two days after hospitalization or discharge from the hospital (2). Despite the efforts and measures to control nosocomial infections, economic costs and mortality, are high (3). Nosocomial infections are the sixth cause of death in the United States with 9900 fatalities per annum approximately (4). Klebsiella pneumoniae is the most important cause of nosocomial infections among gram-negative bacteria (5). K. pneumoniae is an opportunistic pathogen in hospitals, which causes the most common nosocomial infections, such as urinary tract, pneumonia, septicemia, wound, and bloodstream (5). K. pneumoniae is gram-negative, rod-shaped, aerobic and facultative anaerobic, nonmotile, nitrate positive, with mucoid colonies, and large polysaccharide capsule (6). Four spe...

- by Dr. Samah DJEDDI
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- Organic Chemistry, Plant Biology, Algeria, Natural Product

Ten new azo Schiff bases 5a-h and 7a-b were prepared in excellent yields via the condensation of different aromatic amines and a new azoaldehyde, 2-hydroxy-3methoxy-5-(4-methoxyphenylazo)benzaldehyde (4) by two different methods. All new compounds were tested against five microorganisms: Staphylococcus aureus (Gram positive and methicillin resistant), Bacillus subtilis (Gram positive), Kelebsiella pneumonia, Pseudomonas aeruginosa and Escherichia coli (all Gram negative). Compounds 4, 5a, 5c, 5d and 5g were moderately active against Staphylococcus aureus and Bacillus subtilis. Compound 7b was highly active against Bacillus subtilis and moderately active against Staphylococcus aureus. Other compounds were inactive against these strains of bacteria. The antifungal activities of these compounds were also tested against eight different fungal species. None of them were active against the fungi species tested.

We have previously described an inhibition enzyme-linked immunosorbent assay method for the O typing of O1 lipopolysaccharide from Klebsiella pneumoniae which overcomes the technical problems and limitations of the classical O-typing method. In this study, we have extended the method to all of the currently recognized O types. The method was validated by studying the prototype strains that have defined the O groups by the classical tube agglutinatination O-typing method. Based on these results, we confirmed the O types of 60 of 64 typeable strains, and we propose a revised O-antigenic scheme, with minor but necessary changes, consisting of serogroups or serotypes O1, O2, O2ac, O3, O4, O5, O7, O8, and O12. Application of this typing method to 638 K. pneumoniae clinical isolates from Denmark, Spain, and the United States from different sources (blood, urine, and others) showed that up to 80% of these isolates belong to serotypes or serogroups O1, O2, O3, and O5, independently of the source of isolation, and that a major group of nontypeable isolates, representing about 17% of the total, consists of half O ؉ and half O ؊ strains. Differences were observed, however, in the prevalence of the lipopolysaccharide O types or groups, depending on the country and isolation source.

- by Juan Tomas
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- Quality Control, Spain, Clinical Microbiology, Biological Sciences

In June 2010, a bla KPC -negative, ertapenem-resistant ST-258 Klebsiella pneumoniae strain was isolated from a patient in the Laniado Medical Center (LMC). Our aims were (i) to describe its molecular characteristics and resistance mechanisms and (ii) to assess whether the bla KPC -negative ST-258 K. pneumoniae clone spreads as efficiently as its KPC-producing isogenic strain. In a prospective study, surveillance of all ertapenem-resistant, carbapenemase-negative K. pneumoniae (ERCNKP) isolates was conducted from June 2010 to May 2011 at LMC (314 beds) and from July 2008 to December 2010 at the Tel Aviv Sourasky Medical Center (TASMC) (1,200 beds). Molecular typing was done by arbitrarily primed PCR, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). A total of 8 of 42 (19%) ERCNKP isolates in LMC and 1 of 32 (3.1%) in TASMC belonged to the ST-258 clone. These strains carried the bla CTX-M-2 or the bla CTX-M-25 extended-spectrum ␤-lactamase (ESBL) gene. Sequencing of the ompK genes showed a frameshift mutation in the ompK35 gene. The fate of the bla KPC -carrying plasmid, pK-pQIL, was determined by S1 analysis and by PCR of the Tn4401 transposon, repA, and the truncated bla OXA-9 . Plasmid analysis of the ERCNKP ST-258 isolates showed variability in plasmid composition and absence of the Tn4401 transposon and the pK-pQIL plasmid. In addition, the ST-258 clone was identified in 35/35 (100%) of KPC-producing K. pneumoniae isolates but in none of 62 ertapenem-susceptible K. pneumoniae isolates collected in the two centers. Our results suggest that ERCNKP ST-258 evolved by loss of the bla KPC -carrying plasmid pKpQIL. ERCNKP ST-258 appears to have low epidemic potential.

- by Yelena Sterlin
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- Israel, Molecular Epidemiology, Clinical Microbiology, Biological Sciences

b u r n s 3 6 ( 2 0 1 0 ) 1 1 7 2 -1 1 8 4 a b s t r a c t Background: Topical antimicrobials are employed for prophylaxis and treatment of burn wound infections despite no established susceptibility breakpoints, which are becoming vital in an era of multidrug-resistant (MDR) bacteria. We compared two methods of determining topical antimicrobial susceptibilities.

The goal of the North American Urinary Tract Infection Collaborative Alliance (NAUTICA) study was to determine antibiotic susceptibility to commonly used agents for urinary tract infections against outpatient urinary isolates obtained in various geographic regions in the USA and Canada. Forty-one medical centres (30 from the USA and 11 from Canada) participated, with each centre submitting up to 50 consecutive outpatient midstream urine isolates. Isolates were identified to species level by the standard protocol of each laboratory. Susceptibility testing was determined using the National Committee for Clinical Laboratory Standards (NCCLS) microdilution method. Resistance breakpoints used were those published by the NCCLS, including: ampicillin (resistant ≥32 μg/mL), sulphamethoxazole/trimethoprim (SMX/TMP) (resistant ≥4 μg/mL), nitrofurantoin (resistant ≥128 μg/mL), ciprofloxacin (resistant ≥4 μg/mL) and levofloxacin (resistant ≥8 μg/mL). Of the 1990 isolates collected, 75.1% (1494) were collected from the USA and 24.9% (496) were collected from Canada. The mean age of the patients was 48.3 years (range 1 month to 99 years), and 79.5% and 20.5% of isolates were obtained from women and men, respectively. The most common organisms were Escherichia coli (57.5%), Klebsiella pneumoniae (12.4%), Enterococcus spp. (6.6%), Proteus mirabilis (5.4%), Pseudomonas aeruginosa (2.9%), Citrobacter spp. (2.7%), Staphylococcus aureus (2.2%), Enterobacter cloacae (1.9%), coagulase-negative staphylococci (1.3%), Staphylococcus saprophyticus (1.2%), Klebsiella spp. (1.2%), Enterobacter aerogenes (1.1%) and Streptococcus agalactiae (1.0%). Among all 1990 isolates, 45.9% were resistant to ampicillin, 20.4% to SMX/TMP, 14.3% to nitrofurantoin, 9.7% to ciprofloxacin and 8.1% to levofloxacin. Fluoroquinolone resistance was highest in patients ≥65 years of age. For the 1142 E. coli isolates, resistance rates were: ampicillin 37.7%, SMX/TMP 21.3%, ciprofloxacin 5.5%, levofloxacin 5.1% and nitrofurantoin 1.1%. For all 1990 isolates and for the 1142 E. coli only, resistance rates were significantly higher in US compared with Canadian medical centres. This study reports higher rates of antibiotic resistance in US versus Canadian outpatient urinary isolates and demonstrates the continuing evolution of resistance to antimicrobial agents.

- by Jack Johnson
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- Medical Microbiology, Adolescent, Antibiotic Resistance, Child

"Adequate supply of potable table water is a basic necessity for all mankind. Unfortunately,this basic necessity of man has been grossly deprived especially in the developing countries. Water meant for consumption must be potable: free from contamination by microorganisms and possess stable physicochemical parameters. And this is the essence of this research study. In this study, physico-chemical parameters such as colour, pH, odour, temperature and microbial indices: Escherichia coli, Klebsiella pneumonia, Salmonella typhmurium and Streptococcus aureus were investigated in potable packaged water sold in Nnamdi Azikiwe University, Nnewi Campus, Anambra State,Nigeria. Six different bottled and sachet water samples obtained from different manufacturers labeled B1,B2,B3,B4,B5,B6 and S1,S2,S3,S4,S5,S6, respectively were examined physically, chemically and microbiologically. Physical examination of the samples showed that they were colourless and odourless. Chemical examination of the samples showed they were within the WHO standards for temperature and pH except for water samples S1, B4 and B5 whose pH (8.6; 6.2 & 6.0) deviated from the standard . Water samples S4, B3, B4 and B5 indicated presence of E. coli where as S6 indicated presence of Klebsiella pneumoiae. Streptococcus aureus was present in B3. From our study, its suggestive that the packaged water analyzed were not chemically and microbiological fit for consumption though this need to be further investigated. P.N. Ogueche | P.A. Ejiribe | R.U. Udeh | C.O. Obiezue | A.G. Obalim | N.C. Nwankwo | J.O. Uzoigwe | I.C. Maduka""Physio-Chemical and Microbial Screening of Selected Potable Water Sold in the Nnamdi Azikiwe University, Nnewi Campus"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-5 , August 2017, URL: http://www.ijtsrd.com/papers/ijtsrd2228.pdf
Article URL: http://www.ijtsrd.com/biological-science/biological-system/2228/physio-chemical-and-microbial-screening-of-selected-potable-water-sold-in-the-nnamdi-azikiwe-university-nnewi-campus/pn-ogueche"

- by siddharth garaniya
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- Pharmacology, Microbiology, Pharmacy, Escherichia coli

Increasing global antibiotic resistance has resulted in more use of antibiotic combinations. There is a lack of a gold standard for in vitro testing of these combinations for synergy or antagonism. Time-kill assay (TKA) may be used but is labor intensive and not practical for clinical use. Etest® synergy methods are more rapid and easier to perform, but there is no agreement regarding which method is best. We tested 31 clinical genetically unique Klebsiella pneumoniae carbapenemase-producing Klebsiella isolates with the combination of meropenem and polymyxin B by TKA and 3 Etest methods, each in triplicate: Method 1, MIC:MIC; Method 2, direct overlay; and Method 3, cross. Overall, testing with Etest synergy methods showed the following agreement with TKA: Method 1: 25/31 (80.6%), Method 2: 7/31 (22.6%), and Method 3: 8/31 (25.8%). The MIC:MIC method had the highest agreement (80.6%, κ = 0.59, P b 0.001) and should be evaluated more extensively.

- by George Pankey
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- Microbiology, Medical Microbiology, Clinical Sciences, Anti-Bacterial Agents

In the crude ethanol extracts obtained from the rhizome and roots of Rheum palmatum L., Rheum undulatum L. and Rheum rhaponticum L. growing in Poland concentration of polyphenols ranged from 46.11 to 76.45 mg/g. Concentration of tannins ranged from 7.07% to 8.67%, while anthracene derivatives and anthraquinones varied by species -R. palmatum measured 36.3 and 34 mg/g, while R. undulatum or R. rhaponticum did not exceed 20.4 and 18.1 or 19.8 mg/g and 16.6 mg/g, respectively. Using a broth microdilution method it was found that all of the Rheum spp. extracts were more active against reference strains of Gram-positive bacteria (Staphylococcus spp.) than against those of Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis). The strongest inhibitory effect against Staphylococcus spp. was exerted by R. undulatum extract with MIC = 125-250 μg/mL. The moderate in vitro antibacterial activity of R. undulatum suggests that this plant, often used in the European cuisine to improve flavour, may be also important and useful as an alternative or auxiliary medicine remedy in the treatment of uncomplicated superficial infections caused especially by clinically important staphylococci, potentially pathogenic S. aureus or opportunistic S. epidermidis.

- by Christian Perronne
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- Energy Economics, Mitral Valve Repair, Aged, Anti-Bacterial Agents
- by Alberto Farese
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- Environmental Science, Nursing, Moral Philosophy, Medicine

A fraction obtained from the culture fluids ofPycnoporus sanguineus fungus was shown to contain a compound with biological activity against strains of Escherichia coil, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Staphylococcus aureus and members of the genus Streptococcus. The fraction was clearly more active on Gram-positive cocci than on Gram-negative bacilli.

The volatile constituents of the sterile stems of Equisetum arvense L. (Equisetaceae) were investigated for the first time using GC, GC/MS and 13 C-NMR. Twenty-five compounds were identified. Hexahydrofarnesyl acetone (18.34%), cis-geranyl acetone (13.74%), thymol (12.09%) and trans-phytol (10.06%) were the major constituents. A disk diffusion method was used for the evaluation of the antimicrobial activity of this oil against a panel of microorganisms (bacteria: Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella enteritidis; fungi: Aspergillus niger and Candida albicans). The 1:10 dilution of the essential oil of Equisetum arvense L. was shown to possess a broad spectrum of a very strong antimicrobial activity against all tested strains.

- by Gordana Stojanović
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- Biological Sciences, Essential Oil, Phytotherapy, GC-MS

The antioxidant and antimicrobial activities of various solvent extracts from Mirabilis jalapa tubers (MJT) were investigated using various in vitro assays. The total phenolic and flavonoid contents varied from 21.45 to 364.6 mg gallic acid equivalent (GAE)/g dried extract and 5.2 to 71.6 mg quercetin/g dried extract, respectively. Water extract of MJT was the most potent antioxidant in all assays used, followed by methanol extract. The five solvent extracts were screened for antibacterial and antifungal activities. Water extract was the most effective with minimum inhibitory concentration <200 g/ml against Staphylococcus aureus, Micrococcus luteus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Bacillus cereus and Enterococcus faecalis. Only water extract showed antifungal activity against Aspergillus niger, Fusarium solani, Fusarium oxysporium and Fusarium granularium. GC/MS analysis of MJT dichloromethane and methanol extracts showed that oleic acid and ␤-sitosterol were, respectively, the major compounds. LC/MS analysis of the aqueous extract showed a high content of flavanol and flavonol compounds. Phenolic acids such as ferulic and caffeic acid were also detected.

- by Raoudha Jarraya
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- Process, Solvent Extraction, Antimicrobial activity, Staphylococcus aureus

The metallo beta-lactamase (MBL) mediated resistance patterns remain unknown in most countries. We aimed to investigate the existence and antimicrobial resistance of MBL-producing strains among carbapenemresistant Gram-negative bacteria that were isolated from nosocomial infections in patients in an university hospital in Turkey. Fifteen of 52 Pseudomonas aeruginosa strains (29%), 5 of 24 Acinetobacter baumanii strains (21%), and 2 of 2 Klebsiella pneumoniae strains (100%) were found to be metallo enzyme producers, with the Etest MBL technique. The in vitro antibiotic susceptibility of the MBL-positive organisms was investigated by the Etest method. Of the ten drugs tested, isepamicin was the most active agent against the MBL-producing strains. Overall, the rank order of activity of the ten antibiotics, in terms of the percentages of susceptible strains, was: isepamicin, 73%; ciprofloxacin, 64%; amikacin, 59%; aztreonam, 18%; tobramycin, 18%; meropenem, 14%; cefoperazone-sulbactam, 5%; piperacillin-tazobactam, 0%; ticarcillin-clavulanate, 0%; and cefepim, 0%. The meropenem minimum inhibitory concentrations (MICs) of the metallo enzyme-producing and nonproducing carbapenem-resistant strains were compared, and the MBL-producers were found to have higher meropenem MICs than the nonMBL-producing carbapenem-resistant strains. Early preventive measures should be taken against MBL-producing nosocomial pathogens that are associated with wide spread and high antimicrobial resistance.

- by zulal ascı toraman
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- Biology, Medicine, Antibiotic Resistance, Child

Five hundred fecal samples from 462 patients (68.4% ambulatory) (February-April, 2007) from Madrid (Spain) were screened for extended-spectrum β-lactamase (ESBL) producers using ceftazidime and cefotaxime (1 mg/L) MacConkey (MAC) agar plates and a chromogenic media (chromID ESBL; bioMérieux, Marcy-l'Etoile, France). bla ESBL , qnr, aac(6′)Ib-cr, and 16S rRNA methylase genes were assessed. A prevalence of 8.2% of ESBL fecal carriers was observed (8.9% hospitalized, 7.9% nonhospitalized patients), higher than that previously observed (1991, 0.6%; 2003, 7.0%). Sensitivity, specificity, and positive and negative predicted values were 100%, 94.8%, 63%, and 100% for chromID ESBL and 87.8%, 89.8%, 43.4%, and 98.9% for MAC, respectively. ESBL distribution was as follows: CTX-M-9group, 40% (mainly CTX-M-14); CTX-M-1-group, 26.6% (mainly CTX-M-15); SHV-type, 29% (mainly SHV-12); and TEM-type, 4.4%. These enzymes were found in pulsed-field gel electrophoresis nonclonally related Escherichia coli and Klebsiella pneumoniae isolates. Transferable quinolone resistance was confirmed in CTX-M-9 (qnrS1), CTX-M-15 [aac(6′)Ib-cr, qnrS1], and SHV-12 (qnrB7, qnrS1) producers but not 16S rRNA methylase genes. The chromID ESBL medium was reliable to screen ESBL fecal carriers with a general decrease in the laboratory workload. Time-to-time monitoring of ESBL fecal carriers is useful to ascertain current trend of ESBL epidemiology.

- by Teresa Coque
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- Microbiology, Epidemiology, Medical Microbiology, Community

The effect of temperature on a population of Klebsiella pneumoniae was examined together with the imposition of mild starvation conditions at temperatures of 35 ~ 41 o, 49 ~ 55 ~ and 60 ~ Results for changes in biomass, protein and metabolic activity are presented in terms of gross population changes and show that these parameters decline with increasing temperature. Increases in the amount of dissolved organic carbon, together with a decrease in the number of cells present with increasing temperature, suggest that death and ly~is processes are occurring. Regrowth in the bioreactor occurred after returning the temperature to 35 ~ and starting a flow of carbon and other nutrients. This was probably due to reinoculation from head space wall growth drainage rather than reversion of heat-stressed microbes. The consequences of this for thermophilic sludge treatment processes are discussed. The concept of endogenous metabolism is questioned with respect to it being a realistic description of the survival process.

We have investigated bottom-up chemical synthesis of quaternary ammonium (QA) groups exhibiting antibacterial properties on stainless steel (SS) and filter paper surfaces via nonequilibrium, low-pressure plasma-enhanced functionalization. Ethylenediamine (ED) plasma under suitable conditions generated films rich in secondary and tertiary amines. These functional structures were covalently attached to the SS surface by treating SS with O 2 and hexamethyldisiloxane plasma prior to ED plasma treatment. QA structures were formed by reaction of the plasmadeposited amines with hexyl bromide and subsequently with methyl iodide. Structural compositions were examined by electron spectroscopy for chemical analysis and Fourier transform infrared spectroscopy, and surface topography was investigated with atomic force microscopy and water contact angle measurements. Modified SS surfaces exhibited greater than a 99.9% decrease in Staphylococcus aureus counts and 98% in the case of Klebsiella pneumoniae. The porous filter paper surfaces with immobilized QA groups inactivated 98.7% and 96.8% of S. aureus and K. pneumoniae, respectively. This technique will open up a novel way for the synthesis of stable and very efficient bactericidal surfaces with potential applications in development of advanced medical devices and implants with antimicrobial surfaces.

- by Majid Sarmadi
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- Water, Filtration, Atomic Force Microscopy, Multidisciplinary
- by Tatiana Salerno and +2
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- Bovine Mastitis, Veterinary Sciences, Klebsiella pneumoniae
- by Peter Coombes
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- Water, Water quality, Multidisciplinary, Water Cycle

This study aims to check the antibacterial activity of various branded soaps against bacteria that are normally present in the environment. The proposed study includes selection of most common bacterial strains from the environment.... more

- by Shahida Hasnain
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- African, Pseudomonas aeruginosa, Antibacterial activity, Pseudomonas Aeruginosa

Okpiye is a food condiment prepared by the fermentation of Prosopis africana seeds. The traditional process for the production and microbiological characteristics of the condiment were investigated. During laboratory fermentation that lasted 96 h, the mesquite seeds underwent a natural fermentation that was characterised by the growth of microorganisms to 106.108 cfu/g. Several species of bacteria especially B. subtilis, B. licheniformis, B. megaterium, Staphylococcus epidermidis and Micrococcus spp were found to be the most actively involved organisms. However, significant contributions to the microbial ecology were made by Enterobacter cloacae and Klebsiella pneumoniae. Lactobacillus spp were present in low numbers towards the end of the fermentation. The presence of Proteus and Pseudomonas spp in traditional fermented samples demonstrate the variability which may exist in the microflora of individual fermented samples. Variations in the important microbial groups show that Bacillus spp were the most prevalent species and occurred until the end of fermentation. Temperature, pH and titratable acidity varied with time and were influenced by the metabolic activities of the microorganisms.

- by Ome Achi
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- Microbial Ecology, Medicinal Plants, Food Microbiology, Lactobacillus

Antimicrobial fabrics are increasingly important in a great variety of applications and thus several standard methods to evaluate their efficiency have been developed. However, there is no consensus on the most adequate method to be used. Therefore, aim of this work was to compare the practical applicability of the best known standards: AATCC 147, ISO 20645:2004, AATCC:100 and JIS L 1902. Four samples, with different amounts of antimicrobial agents, were used. It was tested 3 qualitative methods (AATCC 147, ISO 20645 and JIS L 1902-Halo method) and 2 quantitative (AATCC 100 and JIS L 1902-Absorption method). For each method, both Gram-positive (Staphylococcus aureus) and Gram-negative (Klebsiella pneumoniae) bacteria were used. Textiles samples assayed did not present diffusible activity, thus only the qualitative results from the AATCC 147 and the Halo method could be analyzed and no differences were observed between them. Therefore, the AATCC 147 or the JIS L 1902-Halo method can be used for a simple and expedite screening of a large amount of samples with or without diffusible antimicrobial activity. In contrast, the ISO 20645 can only be used when diffusible antimicrobial agents are present. Concerning the two quantitative methods, the results showed that the JIS L 1902 method is more sensitive to the amount of antimicrobial agent than the AATCC 100 test. An additional assay also showed that the JIS L 1902 is sensitive enough to distinguish serial dilutions of the antimicrobial agent.

- by Eva Pinho
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- Microbiology, Medical Microbiology, Gram Positive, Antimicrobial activity

Bacterial count in prepared food or water is a key factor in assessing the quality and safety of food. It also reveals the level of hygiene adopted by food handlers in the course of preparation of such foods. This comparative study evaluated the bacteriological quality of food and water consumed in Nsukka, Enugu state, Nigeria, using three bacteria enumeration methods. Data obtained are assumed to reflect the level of personal and environmental hygiene in the study population. Ten types of foods-beans, yam, abacha, okpa, moimoi, pear, cassava foofoo, rice, agidi, and garri-and 10 water samples were evaluated for bacteriological quality, precisely determining the level of coliform contamination, using the most probable number (MPN), lactose fermentation count (LFC), and Escherichia coli count (ECC) methods. Bacterial counts differed significantly (p<0.05) among the various food samples. However, this did not differ significantly in the three methods used for the enumeration of coliforms, suggesting that any of the three methods could be validly used for such studies with confidence. Escherichia coli and Klebsiella pneumoniae were the two major coliforms identified among 98 coliform isolates obtained from the various food samples, of which 78 (79.6%) were assumed to be of human origin on account of their ability to grow at 44 o C. The level of coliform contamination in the food samples from vendors and restaurants (geometric mean count 7.64-9.21; MPN ≥50) were above the accepted 10 4 colony-forming unit/g or MPN ≤10 limits. The results of the study, therefore, call for stringent supervision and implementation of food-safety practices and regular education on food and personal hygiene among food vendors.

- by Chukwuemeka Nkere
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- Demography, Chemistry, Nutrition and Dietetics, Food

Background: Contaminated surfaces can act as a reservoir for pathogenic microorganisms and potentially exacerbate the risk of infection. Surface disinfection and decontamination provide temporary amelioration against bacterial colonization. Disinfected surfaces eventually become contaminated, thus, mitigating the benefit of the initial disinfection. It is hypothesized that to improve on the current state of the art, a disinfectant should not only immediately disinfect a surface but also provide persistent antimicrobial action after the product has been applied. We describe here a silver-based disinfectant technology designed to provide long-lasting sanitization and disinfection to treated surfaces as evaluated on hard surfaces after repeated environmental insults.

- by Adebayo Olugbenga
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- Nursing, Environmental microbiology, Health Care, Control

Extracts obtained from 10 trees used in South African traditional medicine were screened for antibacterial, anti-inflammatory (COX-1 and COX-2) and anti-cholinesterase activities and investigated for potential mutagenic effects using the Ames test. Antibacterial activity was detected using the disc-diffusion and micro-dilution assays. The extracts were tested against Gram-positive bacteria: Bacillus subtilis, Staphylococcus aureus, Micrococcus luteus and Gram-negative bacteria: Escherichia coli and Klebsiella pneumoniae. Of the 78 different plant extracts investigated, 80% showed activity against both Gram-positive and Gram-negative bacteria in the disc-diffusion assay. In the micro-dilution assay, 60% of the plant extracts showed minimum inhibitory concentration (MIC) values ≤1.56 mg ml−1. The lowest MIC value (0.092 mg ml−1) was recorded for an ethyl acetate root extract of Acacia sieberiana against Staphylococcus aureus and Escherichia coli. In the anti-inflammatory assay, 70% of the investigated plant extracts (0.25 mg ml−1) inhibited both COX-1 and COX-2 activity (>50% and 70% for water and organic solvent extracts, respectively). An ethyl acetate leaf extract of Trichilia dregeana showed selective inhibition of COX-2 (81%). In the acetylcholinesterase inhibitory test, 21% of the plant extracts were active at a concentration ≤1 mg ml−1 using the micro-dilution assay. The lowest IC50 value was 0.04 mg ml−1 obtained with an ethanol bark extract of Combretum kraussii. None of the investigated plants showed any potential mutagenic effects.

- by Damak Mohamed and +1
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- Process, Solvent Extraction, Antimicrobial activity, Staphylococcus aureus

Fruit juices are becoming an important part of the modern diet in many communities. Data regarding the microbiological quality of foods, particularly fruit juices, sold in Libya and the neighboring North African countries are few if not lacking. Using standard microbiological procedures, 146 fruit juice samples sold in Tripoli were examined. Total bacterial counts (TBC) of samples examined ranged between <1 and 3 · 10 5 CFU/ml (mean = 5 · 10 4 ). Almond juice showed the highest TBC ranging between 1.8 · 10 3 and 3 · 10 5 (mean = 1.7 · 10 5 ). Staphylococcus aureus was detected in 8 (5.5%) samples, Streptococcus spp. in 4 (2.7%), coliforms in 33 (22.6%), Escherichia coli (none were of serogroup O157) in 3 (2.1%), Klebsiella pneumonia in 17 (11.6%), Aeromonas spp. in 3 (2.1%), Pseudomonas aeruginosa in 6 (4.1%), Candida albicans in 18 (12.3%), Candida spp. in 109 (74.7%) and other yeasts in 85 (58.2%). Many of these organisms can cause disease in humans, which indicates that a large number of juices tested did not fulfill the Libyan guidelines for the microbiological quality of juices. Application of the HACCP system should be introduced into the food industry sector to improve the quality of fruit juices and other foods manufactured in Libya.

- by Khalifa Sifaw Ghenghesh
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- Escherichia coli, Staphylococcus aureus, Candida albicans, Food Industry
- by Abdolhossein Rustaiyan
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- Organic Chemistry, Natural Products Chemistry, Plant Biology, Venezuela
- by Teena Chopra
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- Drug Resistance, Gram Positive Bacteria, Clinical Sciences, Spectrum

The complete amino acid sequence of 3T3-L1

- by Fay Zhang
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- Carbon Dioxide, Multidisciplinary, DNA, Adipose tissue

The present study was taken up as an exploratory study to test if some natural dyes have inherent antimicrobial activity with a view to develop protective clothing from these. Four natural dyes Acacia catechu, Kerria lacca, Quercus infectoria, Rubia cordifolia and Rumex maritimus were tested against common pathogens Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae, Proteus vulgaris and Pseudomonas aeruginosa. Quercus infectoria dye was most effective and showed maximum zone of inhibition thereby indicating best antimicrobial activity against all the microbes tested. Minimum inhibitory concentration was found to be varying from 5 to 40 mg. The textile material impregnated with these natural dyes, however, showed less antimicrobial activity, as uptake of these dyes in textile material is below MIC.