<p>The first report of emerging mobilized colistin-resistance (<em>mcr</em>) genes and ERIC-PCR typing in <em>Escherichia coli</em> and <em>Klebsiella pneumoniae</em> clinical isolates in southwest Iran</p>

Abstract

Background: The emergence of the plasmid-mediated mcr colistin-resistance gene in bacteria poses a potential threat for treatment of patients, especially when hospitalized. The aims of this study were to search for the presence of mcr-1 and mcr-2 genes among colistin-resistant Escherichia coli ( E. coli ) and Klebsiella pneumoniae ( K. pneumoniae ) isolates from clinical specimens and to determine the fingerprint of strains by enterobacterial repetitive intergenic consensus sequences PCR (ERIC-PCR) method. Methods: In this study, 712 nonduplicate Enterobacteriaceae isolates from clinical specimens were examined. All of the isolates were subcultured on suitable media, and the isolated colonies were identified by standard biochemical tests. Antimicrobial susceptibility test on 7 antibiotics was performed by disk diffusion method, and minimal inhibitory concentration (MIC) of isolates to colistin was determined by the E-test method. These isolates were typed by ERIC-PCR method, and the presence of mcr-1 and mcr-2 genes was investigated by PCR method. Results: Out of 712 nonduplicate Enterobacteriaceae, 470 isolates, including 351 (74.7%) E. coli and 119 (25.3%) K. pneumoniae, were detected. The results of antibiogram tests showed that most of the isolates (81.3%) were resistant to ceftazidime; however, the most susceptibility among of E. coli and K. pneumoniae isolates was observed (81.5%) to colistin. The typing results by ERIC-PCR method showed 36 and 23 fingerprint patterns for colistin-resistant E. coli and K. pneumoniae strains, respectively. Among 64 (13.6%) colistin-phenotypically-resistant Enterobacteriaceae, 8 isolates (1.7%) had mcr-1 gene. These 8 isolates were attributed to E. coli and K. pneumoniae with 6 and 2 isolates, respectively. Whereas no isolates carrying the mcr-2 gene was found. These colistin-resistant isolates displayed colistin MIC values >2 μg/ml in the antibiotic concentration by E-test method. Conclusion: Spreading of Enterobacteriaceae strains harboring plasmid-mediated mcr could fail the colistin-included therapy regimen as the last line of treatment against multidrug-resistant bacterial infections.

<p>Fecal Carriage and Molecular Epidemiology of Carbapenem-Resistant <em>Enterobacteriaceae</em> from Inpatient Children in a Pediatric Hospital of Shanghai</p>

“…The ERIC-PCR was applied using the ERIC-F (5ʹ-ATGTAAGCTCCTGGGGATTCAC-3ʹ) and ERIC-R (5ʹ-AAGTAAGTGACTGGGGTGAGCG-3ʹ) primers for E. aerogenes, K. pneumoniae and E. coli isolates, and the amplification conditions were adjusted according to the reports published previously. 22,23 The gel electrophoresis image was analyzed by BioNumerics7.6 version software (Applied Maths; NV Keistraat, Sint-Martens-Latem, Belgium). Dice coefficients were used to calculate the similarity of ERIC-PCR patterns, of which optimization set at 1% and tolerance at 1%.…”

Emergence of plasmid-mediated mcr genes from Gram-negative bacteria at the human-animal interface

“…To date, more than 40 countries have reported mcr variants (mcr-1 to mcr-9) from five different continents across the globe, indicating the epidemicity of the mcr gene [6]. The mcr genes have been reported in seven Asian and nine European countries, and they were recently identified in Pakistan, Iran, Italy, Finland, America, South Africa, and some other territories [7][8][9][10]. The plasmid-borne mcr gene has been found in several enterobacteria, including Escherichia coli, Salmonella, Aeromonas, Enterobacter cloacae, Klebsiella pneumoniae, Escherichia fergusonii, Kluyvera ascorbata, Citrobacter braakii, Cronobacter sakazakii, Klebsiella aerogenes, and, most recently, Raoultella ornithinolytica [6].…”

Molecular Typing of Klebsiella pneumoniae Clinical Isolates by Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction

“…Nosocomial infections are developed after hospital admission besides the main health problem and are known as a global health issue. Multidrug-resistant pathogens usually are involved in such infections, and K. pneumoniae is one of the main culprits associated with pneumonia, urinary tract infection, wound infection, bacteremia, and septicemia [2][3][4].…”