Title: Identification and pathogenicity study of emerging fish pathogens <i>Acinetobacter junii</i> and <i>Acinetobacter pittii</i> recovered from a disease outbreak <i>in Labeo catla</i> (Hamilton, 1822) and <i>Hypophthalmichthys molitrix</i> (Valenciennes, 1844) of freshwater wetland in West Bengal, India
Abstract: Aquaculture ResearchVolume 51, Issue 6 p. 2410-2420 ORIGINAL ARTICLE Identification and pathogenicity study of emerging fish pathogens Acinetobacter junii and Acinetobacter pittii recovered from a disease outbreak in Labeo catla (Hamilton, 1822) and Hypophthalmichthys molitrix (Valenciennes, 1844) of freshwater wetland in West Bengal, India Ramesh Chandra Malick, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorAsit Kumar Bera, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorHemanta Chowdhury, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorManojit Bhattacharya, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorTanuja Abdulla, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorHimanshu Sekhar Swain, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorRaju Baitha, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorVikas Kumar, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorBasanta Kumar Das, Corresponding Author [email protected] orcid.org/0000-0002-6629-8992 ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, India Correspondence Basanta Kumar Das, ICAR - Central Inland Fisheries Research Institute, Monirampore, Barrackpore, Kolkata 700 120, West Bengal, India. Email: [email protected] for more papers by this author Ramesh Chandra Malick, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorAsit Kumar Bera, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorHemanta Chowdhury, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorManojit Bhattacharya, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorTanuja Abdulla, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorHimanshu Sekhar Swain, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorRaju Baitha, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorVikas Kumar, ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, IndiaSearch for more papers by this authorBasanta Kumar Das, Corresponding Author [email protected] orcid.org/0000-0002-6629-8992 ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal, India Correspondence Basanta Kumar Das, ICAR - Central Inland Fisheries Research Institute, Monirampore, Barrackpore, Kolkata 700 120, West Bengal, India. Email: [email protected] for more papers by this author First published: 09 March 2020 https://doi.org/10.1111/are.14584Citations: 7Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Abstract The disease outbreaks in aquaculture system of wetlands are the major cause of fish mortality. Among various bacterial septicaemic diseases, fish mortality caused by Acinetobacter spp. is recently reported in different fish species. Fish disease outbreak was investigated in a wetland of West Bengal, India to identify the aetiological factors involved. The moribund fish were examined and subjected to bacterial isolation. Two bacterial causative agents were identified as Acinetobacter junii and Acinetobacter pittii by biochemical characterization and 16S rRNA gene amplification. Both the isolates were oxidase-negative, nitrate-negative, catalase-positive and indole-negative. The molecular identification using 16S rRNA gene sequencing and phylogenetic tree analysis further confirmed the two Acinetobacter spp. with 97%–99% similarity. The antibiotic resistance patterns of these two bacteria revealed that both of them were resistant to β-lactam, cefalexin, cephalothin, amoxyclav, cefuroxime, cefadroxil, clindamycin, vancomycin and penicillin. In addition, A. pittii was also resistant to other antibiotics of cephams group such as ceftazidime and cefotaxime. In the challenge experiment, both A. junii and A. pittii were found to be pathogenic with LD50 of 1.24 × 105 and 1.88 × 107 cfu/fish respectively. Histopathological examination of gill, liver and kidney revealed prominent changes supporting bacterial septicaemia. The investigation reports for the first time on concurrent infection by A. junii and multidrug-resistant (MDR)-A. pittii as emerging fish pathogens to cause severe mortality in Labeo catla and Hypophthalmichthys molitrix in a freshwater wetland. Open Research DATA AVAILABILITY STATEMENT The data that support the findings of this study are available on request from the corresponding author. Citing Literature Volume51, Issue6June 2020Pages 2410-2420 RelatedInformation