Narges Darabi - Academia.edu (original) (raw)

Papers by Narges Darabi

2-Aminothiazole has great biological and medicinal interest. Some of the marketed drugs also poss... more 2-Aminothiazole has great biological and medicinal interest. Some of the marketed drugs also possessed this heterocyclic moiety. This manuscript reports the synthesis of a series of 2-Aminothiazole derivatives. The reaction between secondary amines, benzoyl isothiocyanate, and dialkyl acetylene dicarboxylates(=dialkyl but-2-ynedioates) in the presence of silica gel (SiO2), led to alkyl 2-(dialkylamino)-4-phenylthiazole-5-carboxylates (6a-6l) in fairly high yields. All title compounds were characterized by IR, NMR and Mass spectroscopy. The antimicrobial activity of the compounds were evaluated against the following microorganisms: Staphylococcus epidermidis ATCC.14990, Bacillus subtilis ATCC.12711, Pseudomonas aeruginosa ATCC 27853Staphylococcus aureus ATCC 25923, Acinetobacter calcoaceticus ATCC 23055, and Escherichia coli ATCC 25922. The broth macrodilution method was used for determination of the minimum inhibitory concentration (MIC) during preliminary evaluation of antibacteria...

Journal of Cellular Physiology, 2018

Mammalian intestine contains a large diversity of commensal microbiota, which is far more than th... more Mammalian intestine contains a large diversity of commensal microbiota, which is far more than the number of host cells. Probiotics play an insecure and protective role against the colonization of intestinal pathogenic microbes and increase mucosal integrity by stimulating epithelial cells. Probiotics have innate capabilities in many ways, including receptor antagonism, receptor expression, binding and expression of adapter proteins, expression of negative regulatory signal molecules, induction of microRNAs, endotoxin tolerance, and ultimately secretion of immunomodulatory proteins, lipids, and metabolites to modulate the immune system. Probiotic bacteria

Journal of Cellular Physiology, 2019

Recent studies demonstrated that a combination of the gut microbiome has the vital effect on the ... more Recent studies demonstrated that a combination of the gut microbiome has the vital effect on the efficacy of anticancer immune therapies. Regulatory effects of microbiota have been shown in different types of cancer therapies such as chemotherapy and immunotherapy. Immune-checkpoint-blocked therapies are the recent efficient cancer immunotherapy strategies. The target of immunecheckpoint blocking is cytotoxic T lymphocyte protein-4 (CTLA-4) or blockade of programmed death-1 (PD-1) protein and its ligand programmed death ligand 1 (PD-L1) that they have been considered as cancer immunotherapy in recent years. In the latest studies, it have been demonstrated that several gut bacteria such as Akkermansia muciniphila, Bifidobacterium spp., Faecalibacterium spp., and Bacteroides fragilis have the regulatory effects on PD-1, PD-L1, and CTLA-4 blocked anticancer therapy outcome.

The reaction between secondary amines, benzoyl isothiocyanate, and dialkyl acetylene dicarboxylat... more The reaction between secondary amines, benzoyl isothiocyanate, and dialkyl acetylene dicarboxylates (dialkyl but- 2-ynedioates) in the presence of silica gel (SiO2) led to alkyl 2-(dialkylamino)-4-phenylthiazole-5-carboxylates in fairly high yields. The structures of these products were confirmed by their IR, 1H and13CNMR, and mass spectra determination. All compounds have been screened for antimicrobial activity against Mycobacterium smegmatis by broth dilution and agar well diffusion methods. All the synthesized derivatives exhibited remarkable activity against this bacterium.

Multiple drug resistance among Klebsiella pneumoniae isolates is one of the most important challe... more Multiple drug resistance among Klebsiella pneumoniae isolates is one of the most important challenges for treating of such infections. Fosfomycin is a broad-spectrum peptidoglycan biosynthesis inhibitor. The purpose of this study was to evaluate the effect of fosfomycin on imipenem resistant clinical isolates of Klebsiella pneumoniae. Materials & Methods: This study included 43 isolates of imipenem resistant Klebsiella pneumoniae were collected from educational hospitals of Urmia and were identified by using the standard methods. Susceptibility of isolates to various antibiotics was determined by disk diffusion method. The minimum inhibitory and minimum bactericidal concentrations of fosfomycin were determined in the range of 8- 1024 mg/mL. Results: All tested isolates were resistant to fosfomycin. The minimum inhibitory and bactericidal concentrations for investigated isolates were determined in the range of 512-1024 mg/mL. According to EUCAST criteria if the minimum inhibitory con...

In recent years, the emergence of multi drug resistant Klebsiella pneumonia is responsible for ma... more In recent years, the emergence of multi drug resistant Klebsiella pneumonia is responsible for many therapeutic problems all over the world. Nowadays carbapenems are often considered as the final options for antibiotic treatment of infections caused by most Gram-negative bacilli. The aim of this study was to determine antibiotic resistance pattern (with focus on carbapenems) of K. pneumoniaeisolates from clinical specimens of in-patients and out-patients admitted to Urmia University of Medical Sciences teaching hospitals. Materials & Methods: In this descriptive-analytical study, 182 isolates of K. pneumonia were investigated. All bacterial isolates were identified as K. pneumoniae by using standard microbiological tests. Antimicrobial susceptibility testing of confirmed isolates was carried out by disk diffusion method proposed by (Kirby-Bauer) against 12 different antibiotics. The minimum inhibitory concentration (MIC) of imipenem for each isolate was determined using E-test metho...

mSphere

Escherichia coli sequence type 131 (ST131) is a globally dominant multidrug-resistant clone that ... more Escherichia coli sequence type 131 (ST131) is a globally dominant multidrug-resistant clone that is commonly associated with extraintestinal infections. Specific sublineages have been shown to have emerged and spread within ST131, highlighting the complex nature of ST131 epidemiology.

Annals of Clinical Microbiology and Antimicrobials

Background Klebsiella pneumoniae is a public health concern because of its ability to develop mul... more Background Klebsiella pneumoniae is a public health concern because of its ability to develop multidrug resistance and hypervirulent genotypes, of those capsular types K1 and K2 cause community and nosocomial life-threatening infections. This study aimed to determine the antibiotic susceptibility patterns and genotypic traits of a collection of Klebsiella spp. isolates. Furthermore, the clonal relatedness of blaNDM producing strains was investigated. Methods During a 19-months surveillance study, 122 Klebsiella spp. isolates were cultured from extraintestinal specimens of patients admitted to the tertiary referral hospital in Semnan, Iran. Isolates were identified using biochemical tests and subjected to determination of phylogroups, capsular types and virulence/resistance genes content. Hypervirulent K. pneumoniae (hvKp) strains were detected genotypically, and Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR fingerprinting was used to determine the clonality of blaNDM p...

BMC Microbiology

Background: The Escherichia coli sequence type 131 (ST131) is a well established clone causing si... more Background: The Escherichia coli sequence type 131 (ST131) is a well established clone causing significant extraintestinal infections worldwide. However, no studies have been reported the phenotypic and molecular traits of ST131 isolates in comparison to other clones of E. coli from Iran. So, we determined the differences between 69 ST131 strains collected during a one year surveillance study and 84 non-ST131 isolates, including 56 clinical fluoroquinolone resistant and 28 broiler colibacillosis isolates in terms of clonality and genetic background. Results: ST131 isolates were associated with phylogroup B2 (68 out of 69 isolates, 98.4%), while clinical non-ST131 and fluoroquinolone resistant broiler isolates mainly belonged to phylogroup A. The highest virulence score was observed in ST131 clone, while they showed less diversity in virulence profiles than other clinical isolates. Almost all of the ST131 isolates (95.6%) were ExPEC and had the highest virulence scores, but their resistance scores were less than clinical non-ST131 isolates. Broiler isolates showed higher prevalence of ExPEC-associated virulence genes and CTX-M-G1/G9 resistance determinants as compared to clinical non-ST131 isolates. While bla OXA-48/NDM carbapenemases were mostly found in ST131 clone, resistance rate against ertapenem was higher among clinical non-ST131 strains. According to ERIC-based fingerprinting, the ST131 strains were more genetically similar, followed by non-ST131 and broiler isolates. Conclusions: ST131 isolates possess the ability to make a balance between clonality and extent of resistance/virulence genes content, so this phenomenon gives a fitness advantage over other E. coli clones. The broilers E. coli population poses a potential zoonotic risk which could be transmitted to the community through the food chain. A number of factors are involved in the dissemination of and infections due to ST131 clone.

The most important lineage of Escherichia coli, named sequence type 131 (ST131) is a pandemic clo... more The most important lineage of Escherichia coli, named sequence type 131 (ST131) is a pandemic clone which drives the increasing rates of antibiotic resistance. While the pervasiveness of ST131 clade C, especially subclades C2 and C1-M27 has been demonstrated in numerous global surveys, no report about the ST131 clades and its virotypes has been published from Iran, so far. So, in this study we investigated and compared the virotypes, antibiotic susceptibility patterns, resistance/virulence determinants and clonality of ST131 clades collected during one-year surveillance study.Most of isolates belonged to clade C2 (34/76 [44.7%]), with the highest virulence factor (VF) scores and resistance rates. The distinctive profiles of clade C2 virulence genes were revealed by “principle coordinates analysis” (PcoA) test. The distribution of hlyA/cnf1virulence genes among clade C2 was not uniform, so that positive strains showed significantly higher rates of resistance markers (blaCTX-M-15, bla...

The Journal of Infection in Developing Countries

Introduction: Klebsiella pneumoniae is an opportunistic pathogen accounting for 5-7% of hospital ... more Introduction: Klebsiella pneumoniae is an opportunistic pathogen accounting for 5-7% of hospital acquired infections. The emergence of carbapenem-resistant Klebsiella pneumoniae has been increasing rapidly over recent years causing many therapeutic problems worldwide. This study aimed to research the antimicrobial resistance profile, detect β-lactamase genes among clinical isolates of K. pneumoniae, and determine their clonal relatedness. Methodology: All Klebsiella pneumoniae isolates were obtained from teaching hospitals in Urmia, Iran. Antimicrobial susceptibility testing was done by the disk diffusion method. Furthermore, minimum inhibitory concentrations of imipenem were determined by applying Etest strips. Screening of β-lactamase-producing isolates was performed by the combined disk method and modified Hodge test. The detection of β-lactamase genes was conducted by polymerase chain reaction (PCR), and isolates’ clonal relatedness was evaluated by random amplified polymorphic ...

Infection and Drug Resistance

Objectives: Escherichia coli sequence types (STs) 69, 73, 95, 127, and 131 are major STs frequent... more Objectives: Escherichia coli sequence types (STs) 69, 73, 95, 127, and 131 are major STs frequently causing extraintestinal infections. The prevalence of specific clones and their virulence and resistance profiles has not been described from Iran. The aim of this study was to characterize antimicrobial-susceptibility profiles and virulence traits of five major clones of E. coli recovered from human extraintestinal infections in Semnan, Iran. We compared these traits between major ST clones and also between O25b and O16 subgroups of the ST131 clone. Methods: We characterized the five major ST clones among 335 collected E. coli isolates obtained from extraintestinal infections, and phylogenetic groups, antimicrobial susceptibility, and virulence/resistance-gene profiles of these major STs were studied. Results: The highest rates of the multidrug-resistance phenotype were detected among ST131 (85.7%) and ST69 (41.7%), and trimethoprim/sulfamethoxazole resistance was detected significantly among the latter clone. Of the 151 isolates belonging to major ST clones, bla OXA-48 was detected among all except the ST127 clone, while bla NDM genes were harbored by 14 (9.2%) isolates, which all belonged to the ST131 clone. Aggregate virulence scores (median) of ST131 isolates (11) were slightly higher than ST69 (8.50) strains, but were lower than ST73 (16), ST95 (16), and ST127 (12.50) isolates. Principal-coordinate analysis revealed distinct virulence profiles with the ST131 clone. ST73, ST95 and ST131 were enriched with "urovirulence" traits, including phylogroup B2 and group B2-associated accessory traits (chuA, iutA, yfcV, papGII, usp, kpsMTII and malX) and the derived variables extraintestinal pathogenic E. coli and uropathogenic E. coli. In contrast, ST69 was depleted of these traits, but enriched with phylogroups D and E. Conclusion: Our data emphasize that isolates of the ST131 clone have the ability to make a balance between resistance and virulence traits to establish a wider clone in extraintestinal pathogenic E. coli.

International Microbiology

Open Forum Infectious Diseases

Background Sequence type 131 (ST131) of Escherichia coli is a pandemic clone that drives the incr... more Background Sequence type 131 (ST131) of Escherichia coli is a pandemic clone that drives the increasing rates of antibiotic resistance. While the pervasiveness of ST131 clade C, especially subclades C2 and C1-M27, has been demonstrated in numerous global surveys, no report about the ST131 clades and their virotypes has been published from Iran so far. Methods A collection of 73 consecutive ST131 isolates from extraintestinal specimens was investigated for determination of virotypes, antibiotic susceptibility patterns, resistance/virulence determinants, and clade subsets. Results Most of the isolates belonged to subclade C2 (33/73; 45.2%), which had the highest virulence factor (VF) scores and resistance rates, followed by C1-M27 (18; 24.6%), C1-non-M27 (14; 19.1%), and A (8; 10.9%). The distinctive profiles of subclade C2 virulence genes were revealed by principle coordinates analysis testing. The distribution of the hlyA virulence gene among subclade C2 was not uniform, so that pos...