Investigating the Antibacterial Activity of Bacteria Isolated From Fish Epidermal Mucus

Abstract

Aquaculture has become one of the most viable industries. Antibiotics have been used to minimize the occurrence of infection, thus enabling the industry to meet the rising demand of fish production. The introduction of this compound, however, has created a rising trend in antibiotic resistance genes. In regards to this, natural substances such as, fish epidermal mucus have been acknowledged for its ability to combat pathogens-causing infection. Here, the antibacterial activity of bacteria isolated from fish epidermal mucus was investigated. The isolated bacteria from two different fish species were initially purified and antibiotic resistance test against tetracycline was conducted. The non-resistant bacteria were tested for its antibacterial activity against pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Aeromonas hydrophila, and Edwardsiella) by means of cross- streak method. The bacteria showing inhibitory activity were selected for further analysis using PCR and agarose gel electrophoresis. It was found that four isolates from species A exhibited inhibitory or antibacterial activity against S. aureus and two isolates from species B were active against Edwardsiella. The present findings revealed potential alternatives to minimize the occurrence of pathogen infection by co-cultivation of fish epidermal mucus bacteria.