A Novel 6'-N-Aminoglycoside Acetyltransferase, AAC(6')-Ial, from a Clinical Isolate of Serratia marcescens.

Serratia marcescens IOMTU115 has a novel 6'-N-aminoglycoside acetyltransferase-encoding gene, aac(6')-Ial. The encoded protein AAC(6')-Ial has 146 amino acids, with 91.8% identity to the amino acid sequence of AAC(6')-Ic in S. marcescens SM16 and 97.3% identity to the amino acid sequence of AAC(6')-Iap in S. marcescens WW4. The minimum inhibitory concentrations of aminoglycosides for Escherichia coli expressing AAC(6')-Ial were similar to those for E. coli expressing AAC(6')-Ic or AAC(6')-Iap. Thin-layer chromatography showed that AAC(6')-Ial, AAC(6')-Ic, or AAC(6')-Iap acetylated all the aminoglycosides tested, except for apramycin, gentamicin, and lividomycin. Kinetics assays revealed that AAC(6')-Ial is a functional acetyltransferase against aminoglycosides. The aac(6')-Ial gene was located on chromosomal DNA.

Identification of a novel 6'-N-aminoglycoside acetyltransferase, AAC(6')-Iak, from a multidrug-resistant clinical isolate of Stenotrophomonas maltophilia.

Stenotrophomonas maltophilia IOMTU250 has a novel 6'-N-aminoglycoside acetyltransferase-encoding gene, aac(6')-Iak. The encoded protein, AAC(6')-Iak, consists of 153 amino acids and has 86.3% identity to AAC(6')-Iz. Escherichia coli transformed with a plasmid containing aac(6')-Iak exhibited decreased susceptibility to arbekacin, dibekacin, neomycin, netilmicin, sisomicin, and tobramycin. Thin-layer chromatography showed that AAC(6')-Iak acetylated amikacin, arbekacin, dibekacin, isepamicin, kanamycin, neomycin, netilmicin, sisomicin, and tobramycin but not apramycin, gentamicin, or lividomycin.

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

BACKGROUND: Drug-resistant Providencia rettgeri producing metallo-ß-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. METHODS: Five 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. RESULTS: Four 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. CONCLUSIONS: This is the first report describing multidrug-resistant P. rettgeri strains harboring blaNDM-1 or blaOXA-72 and armA isolated from patients in Nepal.

Fact-finding Survey of Nosocomial Infection Control in Hospitals in Kathmandu, Nepal-A Basis for Improvement.

The purpose of this study was to investigate the actual conditions of nosocomial infection control in Kathmandu City, Nepal as a basis for the possible contribution to its improvement. The survey was conducted at 17 hospitals and the methods included a questionnaire, site visits and interviews. Nine hospitals had manuals on nosocomial infection control, and seven had an infection control committee (ICC). The number of hospitals that met the required amount of personal protective equipment preparation was as follows: gowns (13), gloves (13), surgical masks (12). Six hospitals had carried out in-service training over the past one year, but seven hospitals responded that no staff had been trained. Eight hospitals were conducting surveillance based on the results of bacteriological testing. The major problems included inadequate management of ICC, insufficient training opportunities for hospital staff, and lack of essential equipment. Moreover, increasing bacterial resistance to antibiotics was recognized as a growing issue. In comparison with the results conducted in 2003 targeting five governmental hospitals, a steady improvement was observed, but further improvements are needed in terms of the provision of high quality medical care. Particularly, dissemination of appropriate manuals, enhancement of basic techniques, and strengthening of the infection control system should be given priority.

NDM-8 metallo-ß-lactamase in a multidrug-resistant Escherichia coli strain isolated in Nepal.

A novel metallo-ß-lactamase, NDM-8, was identified in a multidrug-resistant Escherichia coli isolate, IOMTU11 (NCGM37), obtained from the respiratory tract of a patient in Nepal. The amino acid sequence of NDM-8 has substitutions at positions 130 (Asp to Gly) and 154 (Met to Leu) compared with NDM-1. NDM-8 showed enzymatic activities against ß-lactams similar to those of NDM-1.

Multidrug-resistant and extended-spectrum beta-lactamase (ESBL)-producing Salmonella enterica (serotypes Typhi and Paratyphi A) from blood isolates in Nepal: surveillance of resistance and a search for newer alternatives.

OBJECTIVES: We evaluated the prevalence of multidrug resistance (MDR) and production of extended spectrum beta-lactamase (ESBL) by Salmonella enterica (serotypes Typhi and Paratyphi A) in a teaching hospital in Nepal. The MDR strains of S. enterica were also tested for susceptibility to newer antibiotics. METHODS: Blood cultures were obtained from 4105 patients with febrile illnesses. Isolates of S. enterica were serotyped and antibiotic susceptibility testing was carried out using disk diffusion (Kirby-Bauer) and E-tests. ESBL screening and phenotype confirmation were done following National Committee for Clinical Laboratory Standards (NCCLS) recommendations for Escherichia coli. RESULTS: A total of 541 isolates of S. enterica serotypes Typhi (47%) and Paratyphi A (53%) were grown. Twenty-eight isolates (5%) of S. enterica were resistant to two or more antibiotics (MDR isolates), with a greater prevalence among serotype Paratyphi A (7%). All ESBL producers (three isolates) were serotype Paratyphi A. Most of the MDR S. enterica showed reduced susceptibility to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, ofloxacin, and ciprofloxacin, and had good susceptibility to extended-spectrum cephalosporins and carbapenems. Among the fluoroquinolones, gatifloxacin demonstrated better in vitro activity compared to levofloxacin, ciprofloxacin, and ofloxacin. CONCLUSIONS: A greater prevalence of S. enterica serotype Paratyphi A with higher rates of multidrug resistance and ESBL production is concerning for natives as well as travelers in Nepal since the current typhoid vaccines do not provide protection against this serotype.