The emergence of bla_OXA-48 and bla_NDM among ESBL-producing Klebsiella pneumoniae in clinical isolates of a tertiary hospital in Iran

The aim of this study was to investigate the prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKP) and the most common types of carbapenemases, metallo-beta-lactamases (MBLs), and extended-spectrum beta-lactamases (ESBLs) among CRKP isolates in a tertiary hospital in Isfahan, Iran. Eighty non-repetitive clinical isolates of K. pneumoniae were obtained from different clinical specimens. Antibiotic resistance pattern of isolates was determined by disk diffusion method and production of carbapenemases and MBLs was confirmed using modified Hodge test and E-test, respectively. Molecular detection of the antibiotic resistance genes was performed using PCR. Fifty-one (63.8%) isolates have decreased susceptibility to carbapenems, of which 46 (90.2%) isolates were as carbapenemase producer and four (7.8%) isolates were positive for MBLs, phenotypically. The results of PCR showed that the prevalence of blaOXA-48, blaNDM, blaSHV, blaCTX-M, and blaTEM genes among CRKP isolates were 90.2%, 15.7%, 98%, 96.1%, and 90.2%, respectively. No isolates carrying the blaKPC, blaGES, blaIMI, blaVIM, and blaIMP genes were detected. This study showed that the production of OXA-48 is one of the main mechanisms of resistance to carbapenems in CRKP isolates in Isfahan. In addition, the dissemination of NDM-producing CRKP isolates is a potential risk for the health care system of this area in the near future

Prevalence of blaCTX-M Gene among Extended-Spectrum β-Lactamases Producing Klebsiellapneumoniae Clinical Isolates in Iran: A Meta-Analysis

Background: CTX-M-type extended-spectrum β-lactamases (ESBLs) are the most prevalent ESBLs in bacterial members of Enterobacteriaceaefamily including Klebsiella pneumoniae. The global spread of CTX-M-producing K. pneumoniae is a major concern in most countries including Iran. The aim of this meta-analysis was to determine the relative frequency (RF) of blaCTX-M gene among ESBLs-producing K. pneumoniae clinical isolates in Iran and to report an overall prevalence. Methods: A comprehensive literature search of studies published up to July 2016 was carried out. The keywords “Enterobacteriaceae”, “Klebsiella pneumoniae”, “ESBLs”, “CTX-M” and “Iran” were searched in PubMed, Scopus, EBSCO, Google Scholar, Scirus, SID and IranMedex in both English and Persian. Selected articles were published between July 2010 and July 2016 and all of them were in English. STATA SE version 11.0 was used for statistical analysis. Results: Twenty-four articles/abstracts were included in this analysis. Selected studies were performed in Ahvaz, Arak, Ilam, Kashan, Kerman, Mashhad, Shiraz, Tabriz, Tehran, Zabol, and Zahedan. Our pooled evidence showed that the RF of blaCTX-M gene among ESBLs-producing K. pneumoniae clinical isolates varied from 7.7% in Tabriz to 100% in Mashhad, Tehran, and Zahedan, with an overall RF of 56.7%. Conclusion: Our meta-analysis revealed that the RF of CTX-M-type ESBLs-producing K. pneumoniae is diverse in different regions of Iran, and the central and eastern regions had higher prevalence rates compared to western regions

High rate of carbapenem-resistant Klebsiella pneumoniae detected from hospital equipments in Iran

The objective of this study was to assess the prevalence, antibiogram, and related genes of carbapenem-resistant Klebsiella pneumoniae (CRKP) among hospital environment samples. A total of 250 samples were taken from different surfaces and medical devices of three hospitals in Isfahan, Iran. All samples were cultured and K. pneumoniae strains were identified by conventional microbiological methods and polymerase chain reaction (PCR). Antibiogram of isolates was performed by disk diffusion method and production of carbapenemases and metallo-β-lactamases (MBLs) was confirmed using modified Hodge test and E-test, respectively. Molecular detection of the related genes was carried out by PCR. Overall, 37 (14.8%) K. pneumoniae strains were isolated, of which 34 (91.9%) strains were resistant to carbapenems. Twenty-eight (82.4%) isolates were positive for carbapenemases and seven (20.6%) isolates were phenotypically MBL producers. The results of PCR showed that the prevalence of blaOXA-48, blaNDM, blaIMP, blaSHV, blaCTX-M, blaTEM, and class 1 integron among CRKP isolates was 70.6%, 52.9%, 2.9%, 100%, 82.4%, 55.9%, and 76.5%, respectively. However, blaKPC, blaGES, blaIMI, blaVIM, and class 2 integron were not detected in any of the isolates. This study showed that the environment of our hospitals is contaminated with CRKP and it emphasizes the importance of using standard methods for infection control

High Prevalence of Multiple Drug Resistance among ESBLs-Producing Klebsiella pneumoniae Isolated from Hospitalized Patients in Isfahan, Iran

Background:   This study was to evaluate the prevalence of CTX-Mand TEM type ESBLs-producing K. pneumoniae and determination of MDR, XDR, and PDR phenotypes of these isolates as well as find out the genetic relationship and molecular typing of these isolates using phenotypic and genotypic methods. Methods:   Non-repetitive 96 K. pneumonia isolates were isolated from hospitalized patients in Al-Zahra hospital of Isfahan, Iran. The antibiotic susceptibility test was assessed for 20 antibiotics using Kirby-Bauer disk diffusion method. The frequency of ESBL-producing isolates was determined by phenotypic confirmatory test. All ESBLs-producing isolates were assessed for blaTEM and blaCTX-M genes using PCR method. Molecular typing was performed by enterobacterial repetitive intergenic consensus sequence-based PCR (ERIC-PCR). Results:  Among 96 isolates, 58 isolates (60.4%) were ESBL-producers. In this study, 85.7% and 30.3% of ESBL-producing isolates showed MDR and XDR phenotypes, respectively. No PDR isolate was found. PCR amplification on ESBL-producing isolates showed that 47 (81%) isolates were carried blaTEM gene, while blaCTX-M was detected in all isolates (100%). ERIC-PCR typing was characterized the high genetic similarity among ESBL-producing K. pneumonia isolates and revealed 32 band pattern for the isolates.   Conclusion:  This study showed high prevalence of important ESBL genes (blaCTX-M and blaTEM genes) among the K. pneumoniae isolated from in-patients. Constant following of ESBLs, also identification of their types, in bacteria isolated from hospitalized patients has an important clinical impact. It can provide valuable information for the choice of appropriate antibacterial therapy and decrease of antibiotic resistance

Study of MazEF, sam, and phd-doc putative toxin–antitoxin systems in Staphylococcus epidermidis

Today, to replace the antibacterial targets to overcome antibiotic resistance, toxin–antitoxin (TA) system is noticeable, where the unstable antitoxin neutralizes the stable toxin and protects the bacteria against the toxic effects. The presence and expression of TA genes in clinical and non-clinical strains of Staphylococcus epidermidis were investigated in this study. After identification of three TA pairs (mazEF, sam, and phd-doc) via existing databases (earlier, there has been no information in the case of S. epidermidis isolates), the presence and expression of these pairs were investigated by PCR and q-PCR, respectively. We detected three TA modules in all antibiotic sensitive and resistant isolates. In addition, q-PCR analysis revealed that the transcripts were produced from the three TA modules. This study showed the significant prevalence of these systems in pathogenic bacteria and they were equally found in both oxacillin-resistant and oxacillin-susceptible bacteria. The high prevalence of three systems can make them suitable as potential targets for antibiotic therapy

First report of TEM-104-, SHV-99-, SHV-108-, and SHV-110-producing Klebsiella pneumoniae from Iran

Abstract: INTRODUCTION: Extended-spectrum beta-lactamases (ESBLs) are bacterial enzymes capable of hydrolyzing beta-lactams. The aim of this study was to describe the prevalence of TEM- and SHV-type ESBL-producing Klebsiella pneumoniae strains in Zahedan, Southeast Iran. METHODS: A total of 170 non-repetitive K. pneumoniae strains were collected from patients referred to three teaching hospitals of Zahedan. Antibiotic susceptibility testing was determined for 17 antibiotics using the Kirby-Bauer disc diffusion method. The frequency of ESBL-producing strains was calculated, and minimum inhibitory concentrations of ESBL-producing strains were determined for cefotaxime, ceftazidime, ceftriaxone, and cefpodoxime. The presence of bla TEM and bla SHV genes was tested in all ESBL-producing strains using polymerase chain reaction and DNA sequencing. RESULTS: Among the 170 K. pneumoniae clinical isolates, 55 (32.4%) were ESBL producers; 92.7% (n=51) and 72.7% (n=40) of the isolates carried the bla SHV and bla TEM genes, respectively, and 67.3% (n=37) carried both genes. The sequencing results showed that all bla TEM types were bla TEM-1, except for two isolates that were bla TEM-104. The bla SHV types were bla SHV-1, bla SHV-11, bla SHV-12, bla SHV-99, bla SHV-108, and bla SHV-110. CONCLUSIONS: The percentage of bla TEM and bla SHV among ESBL-producing K. pneumoniae isolates from Zahedan is relatively high, indicating the need for further surveillance and consideration in antibiotic use. To the best of our knowledge, this is the first report of TEM-104-, SHV-99-, SHV-108-, and SHV-110-type ESBLs among clinical isolates of K. pneumoniae from Iran, and TEM-1, SHV-1, SHV-11, and SHV-12 appear to be the dominant ESBLs in this region