GENETIC DI VERSITY OF A MPI CILLIN-RE SI STANT Vibri o ISOLATED FROM VAR IOUS STA GES OF TIGER SHRIMP LARVA E DEVELOPMENT

This research was carri ed out to st udy genetic di versity of ampici llin-resi sta nt Vi brio from variou s stages o f t iger shrimp larvae (Penaeus Monodon) de velopment from,Ta mbak Inti Raky at hatchery, near Labuan, West Jav a, Indonesia. A total of 25 am picillin- resistant Vi brio is ol at es were isolated using thiosul pha te citrat e bi le -sal t sucr os e agar ( TCBS -Aga r) a nd s eawa ter complet e agar (SWC-Agar). Physiological and bioc he mical cha racteri zation showed that the i solates could be grouped into only two species, i.e. V. har veyi from the egg s tage; and V. metschnikovii from larvae and post-larval stage (i.e nauplius, zoe a, mysis, PLi, P L5, PL,0, and P L,5). Thes e is olates were also present i n t heir r espective rearing wate r of each s tage and som e natural feed. Schi zoty ping analysis e mployin g rest riction endonuclease Noll (5 '-GC4GGCCGC) indicate d that the is ol at es could be grouped i nto at l east 13 differ en t ge no ty pe s. Therefore, schizoty ping was more di sc ri mi native than phy siologica l charac te riz ati on . This stud y showed that particu lar grou ps of Vi brio colonize d all s tages of shrimp la rvae and de monstrated cl os ed ph yl og en et ic r elationsh ip. These gro ups of Vi brio mi gh t be the do mi na nt microbiota whic h could suppress the de velopment of othe r Vi brio in cl ud ing th e pathogen ic Vi brio.