Distribution of adeG, adeB, adeE, adeY, abeM, and adeJ Efflux Pump Genes in Clinical Isolates of Acinetobacter Species from Korea

BACKGROUND: The aim of the present study was to determine the frequency of six efflux pump genes in Acinetobacter clinical isolates collected from South Korean hospitals. METHODS: In this study, we used a total of 339 Acinetobacter strains, comprising 279 Acinetobacter calcoaceticus–Acinetobacter baumannii (ACB) complex and 60 non-ACB complex strains. We performed specific PCR assays to detect adeG, adeB, adeE, adeY, abeM, and adeJ, transporter genes of the multidrug efflux pumps AdeFGH, AdeABC, AdeDE, AdeXYZ, AbeM, and AdeIJK, respectively. RESULTS: Frequencies of six efflux pump genes varied according to the species of Acinetobacter. Frequencies of adeE, abeM, and adeJ between A. baumannii group and A. nosocomialis group were found to be significantly different. Significant differences were found in the frequencies of adeB, adeE, adeY, and adeJ among the susceptible A. baumannii (SAB), multidrug-resistant A. baumannii (MDRAB), and extensively drug-resistant A. baumannii (XDRAB) groups within the 154 strains of A. baumannii. The frequencies of efflux pump genes in imipenem-susceptible and imipenem-nonsusceptible groups were significantly different for adeB, adeY, and adeJ. The frequencies of efflux pump genes in ciprofloxacin-susceptible and ciprofloxacin-nonsusceptible groups were significantly different for adeB and adeY. No significant difference was found in the frequency of efflux pump genes among groups sampled from different regions of Korea, across 86 strains of A. baumannii collected in 2012. CONCLUSIONS: The frequencies of six efflux pump genes obtained in this study demonstrate the fundamental epidemiological feature of efflux pump genes in Korean Acinetobacter clinical isolates.

A Study of Efflux Pump Genes in Mycobacterium tuberculosis Clinical Isolates / 대한임상미생물학회지

The efflux pump system has been suggested as an important mechanism in the drug resistance of Mycobacterium tuberculosis (MTB). In this study, molecular analysis of five genes in the efflux pump system of MTB isolates from Korean patients was performed in order to identify appropriate molecular targets. In this study, 35 culture-positive specimens were included. PCR was performed for five efflux genes, mmpL7, efpA, mmr, p55 and tap-like gene. In the 35 clinical isolates, molecular analysis of five kinds of efflux pump genes was performed. Only one clinical isolate showed negative PCR results for all five efflux pump genes. All the rest 34 isolates presented concurrent positive results for the five efflux pump genes. In the near future, gene expression study with quantitative PCR should be performed using these genes.