Microbiological Assessment of Three Common Species of Bycatch from Visakhapatnam Fishing Harbour

The present study was carried out for microbiological analysis of three bycatch species in the fishing harbour of Visakhapatnam, east cost of India. The study was performed during the period of Aug 2014 to Jul 2016. The samples were inoculated and counted using standard plate count method and enumeration of total coliforms and fecal coliforms by most probable number method. The microbial count was done by TOTAL BACTERIAL COUNT (TBC) and TOTAL COLIFORM COUNT (TCC) in the fishes of Trichiurus lepturus, Upeneus vittatus and Leiognathus equulus. The presence of specific fish pathogens Salmonella sp. , Staphylococcus sp. , Pseudomonas sp. and Vibrio sp. were investigated. Bacterial infested fish have no or low market value resulting in loss to fishery industry. Hence it is relevant to identify such infectious agents and suggest measures for prevention and elimination of such infections. T.Sasikala, C.Manjulatha*, DVSN Raju Department of Zoology, Andhra University, Visakhapatnam. Submission: 25 May 2019 Accepted: 30 May 2019 Published: 30 June 2019 www.ijsrm. humanjournals.com Citation: C.Manjulatha et al. Ijsrm.Human, 2019; Vol. 12 (4): 31-39. 32 INTRODUCTION Fish is an important dietary component of man. It is important the fish that are consumed should be healthy and free of infection ensuring food safety. An infection, which is caused by viruses, bacteria and parasites among the fishes in natural and man-made culture systems are harmful for fish health and growth and sometimes are very fatal, causing high mortalities. The present study was carried out for microbiological analysis to assess the quality of raw fish sold in the fishing harbour of Visakhapatnam, east coast of India. The study was performed during Aug 2014 to Jul 2016. The aim of the study is to identify the microbial flora and pathogenic bacteria present in the selected bycatch species were Trichiurus lepturus, Upeneus vittatus and Leiognathus equulus. The Visakhapatnam fishing harbour has special yard with modern facilities like ice manufacturing plants, display trays, trained personnel, electric balances and attractive packing system available in harbour for selling and transportation of fish in different areas [1]. Improper hygienic conditions and disposal of waste material favors the adaptability of microbial population to alter. Microbial contamination of the environment may be transferred to the food products directly through surface content by personal, pests, air movements and cleaning regimes [2]. There can be a wide range of microbiota on the skin and gills, and in the intestine, which depends greatly on the microbiological quality of the environment. This can be influenced by the production system, temperature, proximity to settlements and agricultural areas, and fish feeding and harvesting [3 & 4]. While vertical transmission through the egg may be the most common mode of transmission for viruses [5], horizontal transmission from other infected fish, including bycatch is likely [6 & 7]. The direct infection of cultured fish through the consumption of bycatch containing high bacterial loads, particularly of the streptococcal types, is also well-documented [8]. The present authors also reported on diversity of bycatch, organic and inorganic components of bycatch collected from Visakhapatnam fishing harbour [9,10&11]. The quality of fish is based on the physical, chemical and microbiological forms of deterioration are implicated [12]. www.ijsrm. humanjournals.com Citation: C.Manjulatha et al. Ijsrm.Human, 2019; Vol. 12 (4): 31-39. 33 MATERIALS AND METHODS In Visakhapatnam fishing harbour, fin fish species of T. lepturus, U.vittatus and L.equulus are fished throughout the year and used of consumption as fresh forms. These fishes are characterized as short lived, fast growing fishes with relatively high rates of natural mortality. Collection of fish samples In the present study, fresh fish samples were collected from the fishing harbour during the early hours of the day between 7:00 and 8:00 AM and transferred to lab processed within 1 hour. The fish sample is collected from the fish hold into a sterile aseptic container together with ice. For analysis of microbial populations, above 3 species of commonly edible fish were selected. T. lepturus, U. vittatus and L. equulus are the fishes that were selected for the present study. Identification of fish was done according to Food and Agriculture Organization (F.A.O) manuals. In the present study, four microbial parameters for examination of sample fishes were considered which includes TOTAL PLATE COUNT (TPC), TOTAL COLIFORM COUNT (TCC) and qualitative analysis of Staphylococcus sp. , Pseudomonas sp. , Salmonella sp. and Vibrio sp. Preparation of samples The sample was using the method described by Obi and Krakoviaka. Care was taken to avoid any damage to the specimens. Alimentary canal was cut to avoid damage to parasites. About 10 grams of muscle with skin is swabbed from the dorsal region with a sterile knife. The sample was crushed in a sterile mortar with 10 ml sterile water. From the crushed sample, 1ml of aliquot volume was measured and homogenized in a clean and dry sterile beaker containing 9 ml of distilled water giving a 1:10 dilution. This method is followed for all the 3 fish samples. Each sample was serially diluted and aliquots of each diluted sample were placed on marine agar and incubated at 37c for 24 hours.