Isolation, Characterization, and Identification of Gut Bacteria from Piscine Ectoparasite, Argulus Bengalensis (Ramakrishna 1951) and their Relationship with Haematophagy

Abstract

Gut microbiome plays a pivotal role in health and nutrition of most organisms. Argulus bengalensis is a haematophagus ectoparasite of fresh water carp and its infection causes extensive damage to fish farms. The present study aims at isolation, characterization and identification of the gut bacteria from Argulus bengalensis and to decipher its potential contribution in haematophagy of the parasite. The gut bacteria were isolated, cultured and identified based on analysis of its morphological, physiological and biochemical features as well as 16s rDNA analyses against the NCBI genetic database. Antibiotic sensitivity was tested. Haemolytic activity and ability of the isolates to produce anticoagulant substance were also tested to justify the hypothesis. Two isolates were identified to be similar type strains of Acenatobacter baumanii and Aeromonas hydrophila respectively which have accession number MW811800 and MW806655 respectively. Both bacteria were found sensitive to most antibiotics. Both Acenatobacter baumanii and Aeromonas hydrophila showed their haemolytic activities and able to secrete anticoagulant substances establishing their mutualistic association which increase the fitness of the parasitic host facilitating haematophagy. The outcome of the study thus may provide a scientific direction to develop novel methods to control of Argulosis.