사람과 해양환경으로부터 분리된 Staphylococci의 Tetracycline 내성 유전자 특성

Abstract

Aims of this study was to do comparison of the characterization between tetracycline resistant Staphylococci isolated from environmental water and human. For this, we used 35 Staphylococcus spp. and 9 S. aureus isolates obtained from environmental water in Busan, Korea, and 50 S. aureus fro patients in hospital of Busan. With antibiotic susceptibility to Tetracycline (Tc), Ampicillin (Am), Erythromycin (Em), PCR assays were also performed to analyse tetracycline resistance genes, and macrolide resistance genes with specific primers. Out of 14 tetracycline-resistant Staphylococcus spp. from environmental water, 6 Staphylococcus spp. isolates were appeared to be positive for tet(M) by PCR, and 1 out of those 6 Tc-resistant Staphylococcus spp. was classified as S. aureus. Interestingly, erm(B) that has been known to be related to tet(M) in many gram positive bacteria was only detected in Tc- and Em-resistant isolates from aquatic environment. It was different from S. aureus isolates from human carrying erm(A) or erm(C) independent from Tc resistance. As sources of tet(M), Tc-resistant Staphylococci isolates and S. aureus from human were utilizing tet(M) on Tn916/1545-like transposons and Tn5801, respectively. It confirmed by PCR with integrase (int)-specific primers on each different transposon. Additionally, in structural genomic alignment, tet(M)s in environmental isolates were similar with each other but different from those in human isolates. In conjugal transfer analysis, Staphylococci isolates both from environmental water and human were able to transfer their tet(M) to fish pathogenic Lactococcus garvieae, and allowed us to speculate risks of communication of the resistant genes between resistant microorganism in aquatic environment. In conclusion, we confirmed the different characteristics of antibiotics resistance depend upon source of Staphylococci, from environmental water and human. Certainly, environmental water still may be an ecosystem for exchange of antibiotic resistance genes, like tet(M), among Staphylococci and related genera, and correspondence with aquatic environment, human is important because of affect to aquaculture industry which performed in aquatic environment.