Vet World Vol.10 July-2017 Article-4
Research Article
Veterinary World, 10(7): 738-742
https://doi.org/10.14202/vetworld.2017.738-742
Detection and characterization of pathogenic Pseudomonas aeruginosa from bovine subclinical mastitis in West Bengal, India
2. Avian Influenza Laboratory, Institute of Animal Health & Veterinary Biologicals (R&T), Government of West Bengal, Kolkata, West Bengal, India.
3. Department of Veterinary Public Health, Faculty of Veterinary and Animal Sciences, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal.
Background and Aim: Subclinical mastitis in bovines is mainly responsible for the huge economic loss of the dairy farmers, of which Pseudomonas aeruginosa is one of the causative agents. The study was aimed at a screening of suspected milk samples from different cattle farms of West Bengal for detection and confirmation of P. aeruginosa strains followed by their characterization.
Materials and Methods: Around 422 milk samples were screened from different dairy farms primarily by on-spot bromothymol blue (BTB) test and then in the lab by somatic cell counts (SCC) to finally consider 352 samples for detection of P. aeruginosa. Selective isolation and confirmation of the isolates were done using selective media, viz., cetrimide and Pseudomonas agar followed by confirmation by fluorescent technique. Molecular characterization of the strains was done by polymerase chain reaction for the presence of toxA (enterotoxin A, 352 bp) and exoS (exoenzyme S, 504 bp) genes.
Results: Approximately, 371 (87.9%) samples were positive in on-spot BTB test among which 352 (94.8%) samples revealed high SCC values (more than 3 lakh cells/ml) showing infection when screened. Among these, 23 (6.5%) samples yielded typical Pseudomonas sp. isolates out of which only 19 (5.4%) isolates were confirmed to be P. aeruginosa which showed characteristic blue-green fluorescence due to the presence of pigment pyoverdin under ultraviolet light. Out of these 19 isolates, 11 isolates were positive for toxA, 6 isolates for exoS, and 2 for both these pathogenic genes.
Conclusion: Approximately, 5.4% cases of bovine subclinical mastitis infections in South Bengal were associated with P. aeruginosa which possess pathogenic genes such as toxA (63.2%) and exoS (36.8%). Keywords: bovines, characterization, exoS, Pseudomonas aeruginosa, subclinical mastitis, toxA.
Keywords: bovines, characterization, exoS, Pseudomonas aeruginosa, subclinical mastitis, toxA.
How to cite this article: Banerjee S, Batabyal K, Joardar SN, Isore DP, Dey S, Samanta I, Samanta TK, Murmu S (2017) Detection and characterization of pathogenic Pseudomonas aeruginosa from bovine subclinical mastitis in West Bengal, India, Veterinary World, 10(7): 738-742.
Received: 25-01-2017 Accepted: 13-05-2017 Published online: 04-07-2017
Corresponding author: K. Batabyal E-mail: drkb.micro@gmail.com
DOI: 10.14202/vetworld.2017.738-742
Copyright: Banerjee, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.