Drug resistance and random amplified polymorphic DNA analysis of Photobacterium damselae ssp. piscicida isolates from cultured Seriola (yellowtail, amberjack and kingfish) in Japan.
OBJECTIVE
To investigate the antimicrobial susceptibility and genetic characteristics of Photobacterium damselae ssp. piscicida isolates obtained from cultured Seriola in Japan.


RESULTS
Minimal inhibitory concentrations of 14 antimicrobials for 74 isolates from Seriola in Japan in 2002 were determined. Isolates showed high frequencies of resistance to sulfamonomethoxine (SMMX) (97.3%), oxytetracycline (OTC) (77.0%), flumequine (FMQ) (77.0%), chloramphenicol (CP) (75.7%), kanamycin (KM) (63.5%) and oxolinic acid (OA) (62.0%), but low to ampicillin (ABPC) (2.8%). All isolates were susceptible to bicozamycin (BCM), fosfomycin (FOM) and florfenicol (FF). Of these isolates, 45 (60.8%) showed same resistance pattern (SMMX-OTC-FMQ-OA-CP-KM). In random amplified polymorphic DNA (RAPD) analysis, no difference was observed among our 74 field isolates and ATCC51736 isolated from Seriola in 1974 in Japan, but different from ATCC 17911 isolated from white perch in USA.


CONCLUSIONS
FF, BCM, FOM and ABPC were useful antimicrobials for treating pseudotuberculosis. However, the frequency of multidrug resistance was high. RAPD analysis showed homogeneity of isolates from Seriola in Japan.


CONCLUSIONS
This study demonstrates that some antimicrobials were still useful for treating pseudotuberculosis and that P. damselae ssp. piscicida strains of same origin might have spread among Seriola in Japan since 1974.
Kawanishi
M
M
National Veterinary Assay Laboratory, Ministry of Agriculture, Forestry and Fisheries, Kokubunji, Tokyo, Japan. michiko_kawanishi@nm.maff.go.jp
Kijima
M
M
Kojima
A
A
Ishihara
K
K
Esaki
H
H
Yagyu
K
K
Takahashi
T
T
Suzuki
S
S
Tamura
Y
Y
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D017756:Aquaculture; D024881:Drug Resistance, Bacterial; D005393:Fish Diseases / Q000382:microbiology; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology / Q000662:veterinary*; D007564:Japan; D008826:Microbial Sensitivity Tests; D010473:Perciformes / Q000254:growth & development / Q000382:microbiology*; D010776:Photobacterium / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D019105:Random Amplified Polymorphic DNA Technique
D000900:Anti-Bacterial Agents