Genetic heterogeneity of non-O1 and non-O139 Vibrio cholerae isolates from shrimp aquaculture system: a comparison of RS-, REP- and ERIC-PCR fingerprinting approaches.
OBJECTIVE
The genetic diversity of Vibrio cholerae isolated from black tiger shrimp (Penaeus monodon) aquaculture farms was determined using three PCR typing methods based on enterobacterial repetitive intergenic consensus (ERIC) sequences, ribosomal gene spacer (RS) sequence and repetitive extragenic palindromic (REP) sequences.


RESULTS
Non-O1 and non-O139 V. cholerae isolates were obtained from shrimp pond water, pond sediment, shrimp head and shrimp muscle. RS-PCR yielded fewer bands than REP-PCR and ERIC-PCR. Higher similarity was observed in RS-PCR (75-100%) than in REP-PCR (60-95%) and ERIC-PCR (40-95%).


CONCLUSIONS
A 100% similarity between V. cholerae isolates was only noticed in RS-PCR. The choleratoxigenic V. cholerae (non-O1 and non-O139) showed greater genetic similarity with ctx-negative V. cholerae than among ctx-positive V. cholerae.


CONCLUSIONS
The greater similarity of ctx-positive V. cholerae with ctx-negative V. cholerae isolates indicates that the ctx-positive strains (non-O1 and non-O139) might have originated from autochthonous V. cholerae in the aquatic niche.
Rao
B Madhusudana
BM
Microbiology, Fermentation & Biotechnology Division, Central Institute of Fisheries Technology, Cochin, India.
Surendran
P K
PK
D000818:Animals; D017756:Aquaculture; D015373:Bacterial Typing Techniques / Q000379:methods*; D016000:Cluster Analysis; D016172:DNA Fingerprinting / Q000379:methods*; D004269:DNA, Bacterial / Q000235:genetics; D020459:Genes, rRNA; D014644:Genetic Variation; D005838:Genotype; D033561:Penaeidae / Q000382:microbiology*; D012091:Repetitive Sequences, Nucleic Acid; D014734:Vibrio cholerae / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D014871:Water Microbiology
D004269:DNA, Bacterial