Isolation, detection of virulence genes, antibiotic resistance genes, plasmid profile, and molecular typing among isolated in Malaysian seawater from recreational beaches and fish.

BACKGROUND AND AIM

Despite the importance of the global emergence of infections worldwide, there has been scanty information on its occurrence in Malaysian seawaters and fish. This study aimed to determine the occurrence of isolates using polymerase chain reaction targeted at toxin operon gene, thermostable direct hemolysin (), and -related hemolysin genes and to determine antibiotic resistance pattern, genes, and plasmid profile of from Malaysian seawaters and fish.

MATERIALS AND METHODS

Samples were collected from four recreational beaches in Malaysia (Port Klang; Bachok; Port Dickson; and Mersing). Thiosulfate-citrate-bile salts-sucrose (TCBS) agar and chromogenic agar were used for isolation and identification. Colonies with yellow color on TCBS and green color on chromogenic vibrio (CV) agar were considered to be and they were subjected to biochemical tests. All isolates were further subjected to identification using seven specific gene markers.

RESULTS

Seventy-three isolates were recovered. Only one gene thermostable direct hemolysin () from seawater isolates of has high virulence gene percentage (95.23%). Two genes alkaline serine protease () and () had high percentage of virulence (83.87% and 80.64%, respectively) from fish. Comparatively, fish isolates have a higher virulence percentage compared to seawater isolates. Only gene streptomycin resistance B () from seawater had 100% of the resistance genes. All isolates were multi-antibiotic resistant. Seventeen antibiotic resistance patterns were observed. The isolates had plasmids of varying sizes ranging from 2.7 kb to 42.4 kb. Dendrogram based on antibiotic resistance patterns of isolates discriminated the isolates into three clusters.

CONCLUSION

This study demonstrated the occurrence of pathogenic, multi-antibiotic-resistant strains in Malaysian coastal waters and fish, and this could constitute potential public health risks.