NDM-1 Metallo-β-Lactamase and ArmA 16S rRNA methylase producing Providencia rettgeri clinical isolates in Nepal

Tatsuya Tada,Rajan K Dahal,Bharat M Pokhrel,Hiroshi Ohara,Kayo Shimada,Manoj K Sah,Tohru Miyoshi-Akiyama,Teruo Kirikae

doi:10.1186/1471-2334-14-56

Abstract

BackgroundDrug-resistant Providencia rettgeri producing metallo-β-lactamase and 16S rRNA methylase has been reported in several countries. We analyzed P. rettgeri clinical isolates with resistance to carbapenems and aminoglycosides in a hospital in Nepal.MethodsFive clinical isolates of multidrug-resistant P. rettgeri were obtained in a hospital in Nepal. Antimicrobial susceptibilities were determined using the microdilution method and entire genomes were sequenced to determine drug-resistant genes. Epidemiological analysis was performed by pulsed-field gel electrophoresis.ResultsFour of the 5 isolates were resistant to carbapenems (imipenem and meropenem), with MICs ≥16 mg/L, with the remaining isolate showing intermediate resistance to imipenem, with an MIC of 2 mg/L and susceptibility to meropenem with an MIC ≤1 mg/L. All 5 isolates had blaVEB-1. Of the 4 carbapenem-resistant strains, 3 had blaNDM-1 and 1 had blaOXA-72. All isolates were highly resistant to aminoglycosides (MICs ≥1,024 mg/L) and harbored armA. As the result of pulsed-field gel electrophoresis pattern analysis in the 5 P. rettgeri isolates, 4 had identical PFGE patterns and the fifth showed 95.7% similarity.ConclusionsThis is the first report describing multidrug-resistant P. rettgeri strains harboring blaNDM-1 or blaOXA-72 and armA isolated from patients in Nepal.

Highlights

Drug-resistant Providencia rettgeri producing metallo-β-lactamase and 16S rRNA methylase has been reported in several countries
NDM-type MBL was initially identified in Klebsiella pneumoniae and Escherichia coli in 2009 in Sweden [8]
Acquired 16S rRNA methylase genes responsible for very high levels of resistance to various aminoglycosides are widely distributed among Enterobacteriaceae and glucose-nonfermentative microbes [11]

Summary

Introduction

Drug-resistant Providencia rettgeri producing metallo-β-lactamase and 16S rRNA methylase has been reported in several countries. Providencia rettgeri has been associated with hospital acquired infections, including catheter-related urinary tract infections, bacteremia, skin infections, diarrhea, and gastroenteritis [1,2]. There have been 5 reports of P. rettgeri isolates harboring metallo-β-lactamase (MBL) encoding genes, including IMP-type MBL producers in Japan [3,4]; VIM-type MBL, PER-1 extended-spectrum βlactamase (ESBL) and 16S rRNA methylase ArmA in Korea [5]; and NDM-type MBL in Israel [6] and Brazil [7]. Acquired 16S rRNA methylase genes responsible for very high levels of resistance to various aminoglycosides are widely distributed among Enterobacteriaceae and glucose-nonfermentative microbes [11]. Gram-negative pathogens producing 16S rRNA methylase ArmA have been isolated in various countries [11]

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