Occurrence of tetracycline resistance genes tet(M) and tet(S) in bacteria from marine aquaculture sites.
Occurrence of tetracycline resistance genes encoding ribosomal protection proteins was examined in 151 tetracycline-resistant bacterial isolates from fish and seawater at coastal aquaculture sites in Japan and Korea. The tet(M) gene was detected in 34 Japanese and Korean isolates, which included Vibrio sp., Lactococcus garvieae, Photobacterium damsela subsp. piscicida, and unidentified Gram-positive bacteria. The majority of these bacterial isolates displayed high-level resistance with a minimum inhibitory concentrations (MICs) equal to or greater than 250 microg/ml of oxytetracycline and only four isolates had MICs less than 31.3 microg/ml. 16S rDNA RFLP typing of tet(M)-positive Vibrio isolates suggests that these are clonal populations of the same phylotype specific to a particular location. One Vibrio clone (phylotype III), however, is widely disseminated, being detected during different sampling years, at different locations, and in different fish species in both Japan and Korea. The tet(S) gene was detected in L. garvieae from yellowtail in Japan and in Vibrio sp. from seawater in Korea. This is the first report of tet(S) occurrence in Gram-negative facultative anaerobes. These results suggest that tet(M) and tet(S) genes are present in fish intestinal and seawater bacteria at aquaculture sites and could be an important reservoir of tetracycline resistance genes in the marine environment.
Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama 790-8577, Japan.
Seok-Ryel
SR
Kim
Lisa
L
Nonaka
Satoru
S
Suzuki
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D017756:Aquaculture; D001419:Bacteria / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000032:analysis / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000032:analysis / Q000302:isolation & purification; D005399:Fishes / Q000382:microbiology; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D007564:Japan; D007723:Korea; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D010118:Oxytetracycline / Q000494:pharmacology; D010776:Photobacterium / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology; D013753:Tetracycline Resistance / Q000235:genetics*; D014733:Vibrio / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D014871:Water Microbiology
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D010118:Oxytetracycline