Expansion of a Subset Within the C2 Subclade of Sequence Type 131 (ST131) Is Driving the Increasing Rates of Aminoglycoside Resistance.

Background: Sequence type 131 (ST131) of 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.

The emergence of the hypervirulent Klebsiella pneumoniae (hvKp) strains among circulating clonal complex 147 (CC147) harbouring bla carbapenemases in a tertiary care center of Iran.

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.

Clonal diversity, virulence genes content and subclone status of Escherichia coli sequence type 131: comparative analysis of E. coli ST131 and non-ST131 isolates from Iran.

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.

Characterization of antibiotic-susceptibility patterns and virulence genes of five major sequence types of isolates cultured from extraintestinal specimens: a 1-year surveillance study from Iran.

Objectives: 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 recovered from human extraintestinal infections in Semnan, Iran.

Evaluation of the commercial combined disk test and minimum inhibitory concentration (MIC) determination for detection of carbapenemase producers among Gram-negative bacilli isolated in a region with high prevalence of bla and bla.

Carbapenem-resistant Gram-negative bacilli (GNB) are a concern in the Middle East and worldwide. Simple screening methods have been sought to detect carbapenemase producers to determine appropriate therapeutic measures and implement infection control interventions. In this study, we evaluated the efficiency of agar disc diffusion, commercial combined disc test (Rosco), and carbapenem MIC determination in comparison to molecular detection of carbapenemase genes among 82 carbapenem non-susceptible Enterobacteriaceae (CNSE) and 37 Acinetobacter/Pseudomonas isolates.

Comparative Evaluation of RUT, PCR and ELISA Tests for Detection of Infection with Cytotoxigenic H. pylori.

Purpose: Helicobacter pylori is one of the most prevalent infectious agents in the world which causes a variety of gastrointestinal diseases including gastritis, peptic ulcer and gastric carcinoma. The objective of this study was to comparatively evaluate invasive (rapid urease test and polymerase chain reaction) and non-invasive (enzyme-linked immunosorbent assay) tests in diagnosis of infection with cytotoxigenic H. pylori.

Molecular and Phenotypic Characterization of Multidrug-Resistant Clones of Staphylococcus epidermidis in Iranian Hospitals: Clonal Relatedness to Healthcare-Associated Methicillin-Resistant Isolates in Northern Europe.

The aim of the study was to investigate the molecular epidemiology of Staphylococcus epidermidis in Iranian hospitals and to compare the genotypes with a previously characterized collection of >1,300 S. epidermidis isolates of nosocomial and community origin from Northern Europe, Australia, and USA. In total, 82 clinical S.

Efficient Inactivation of Multi-Antibiotics Resistant Nosocomial Enterococci by Purified Hiracin Bacteriocin.

Purpose: Because of the emergence of multi-antibiotic resistant bacteria, a number of infectious diseases have become a major concern to treat in health care services worldwide. This situation is worsened by the fact that very limited progress has been made in developing new and potent antibiotics in recent years. In this context antimicrobial peptides (AMPs) represent new potential therapeutic compounds with bactericidal or bacteriostatic activity against closely related bacterial strains.

Determination of antimicrobial resistance profile and inducible clindamycin resistance of coagulase negative staphylococci in pediatric patients: the first report from Iran.

Background: Currently, coagulase negative staphylococci (CoNS) have got much attention as a serious health problem especially in neonates and children. High incidence of antibiotic resistance, in particular methicillin resistance, has complicated the treatment of these organisms. The aim of this study is to determine the susceptibility to different antimicrobial agents and the prevalence of macrolideslincosamides-streptogramins B (MLSB) resistance in CoNS isolates obtained from pediatric patients.

The prevalence of aminoglycoside-modifying enzymes among coagulase negative staphylococci in Iranian pediatric patients.

In spite of widespread emergence of aminoglycoside resistance, these drugs are still used in the treatment of staphylococcal infections. This study aimed to investigate the distribution of aminoglycoside resistance and genes encoding aminoglycoside - modifying enzymes (AMEs) as well as Staphylococcal Cassette Chromosome mec (SCCmec) type in coagulase negative staphylococci (CoNS) in pediatric patients. Totally, 93 CoNS isolates were examined for susceptibility to aminoglycosides using disk diffusion and/or E-test methods.

Role of efflux pumps: MexAB-OprM and MexXY(-OprA), AmpC cephalosporinase and OprD porin in non-metallo-β-lactamase producing Pseudomonas aeruginosa isolated from cystic fibrosis and burn patients.

Purpose Of The Research: In order to gain a better understanding of the role of several mechanisms in antibiotic resistance in Pseudomonas aeruginosa clinical isolates obtained from CF and burn patients, we evaluated gene expression of efflux pumps MexAB-OprM and MexXY(-OprA), the natural β-lactamase AmpC and outer membrane porin protein OprD. Also, the presence of genes encoding Ambler classes A, B β-lactamases and aminoglycoside modifying enzymes (AMEs) was examined.

Principal Results: Piperacillin-tazobactam and amikacin retained the highest in vitro activities among 21 CF and 27 burn P.

Molecular epidemiology of Acinetobacter baumannii in Iran: endemic and epidemic spread of multiresistant isolates.

Objectives: We examined the molecular epidemiology of Acinetobacter baumannii clinical isolates from two cities (Tehran and Tabriz) of Iran.

Methods: DiversiLab repetitive extragenic palindromic PCR (rep-PCR), multilocus sequence typing and sequence group multiplex PCR were performed. The presence of resistance mechanisms including metallo-β-lactamases, extended-spectrum β-lactamases, OXA carbapenemases, aminoglycoside-modifying enzymes and RNA methylases was also investigated.

Comparison of in Vitro Activity of Doripenem versus Old Carbapenems against Pseudomonas Aeruginosa Clinical Isolates from both CF and Burn Patients.

Purpose: The antimicrobial activity of doripenem in comparison of imipenem, meropenem and ertapenem among Pseudomonas aeruginosa isolated from burn and Cystic Fibrosis (CF) patients were determined.

Methods: Metallo-β-lactamase (MBL) genes in imipenem non susceptible P. aeruginosa isolates were detected using PCR method.

Study of the carbapenem resistance mechanisms in clinical isolates of Acinetobacter baumannii: comparison of burn and non-burn strains.

We examined the prevalence of various carbapenem resistance mechanisms in clinical isolates of Acinetobacter baumannii collected from hospitalized burn and non-burn patients. Antimicrobial susceptibility testing was performed for 43 burn and 32 non-burn isolates. Carbapenem resistance genes were identified and repetitive extragenic palindromic PCR (REP-PCR) was used to define clonal relatedness.

Prevalence of Ambler class A β-lactamases and ampC expression in cephalosporin-resistant isolates of Acinetobacter baumannii.

We examined the prevalence of various cephalosporins' resistance mechanisms in Acinetobacter baumannii clinical isolates. Phenotypic and molecular detection of Ambler classes A, B and D β-lactamases was performed on 75 isolates. Clonal relatedness was defined using Repetitive Extragenic Palindromic PCR.

Dissemination of aminoglycoside-modifying enzymes and 16S rRNA methylases among acinetobacter baumannii and Pseudomonas aeruginosa isolates.

Aims: The purpose of the present study was to investigate the diversity of the genes encoding aminoglycoside-modifying enzymes (AMEs) and their associations with resistance phenotypes and clonality in Acinetobacter baumannii and Pseudomonas aeruginosa isolates.

Methods: Seventy six P. aeruginosa and 75 A.