Study on bacterial pathogens through multiplex polymerase chain reaction system and their antimicrobial resistance...

Goat is one of the major livestock species, plays an important role in the economy of Bangladesh. However, the outbreak of different infectious diseases in goats causes high mortality and economic losses due to lack of proper diagnosis and treatment. Conventional culture-based methods for detecting specific pathogens as confirmatory diagnosis are laborious as well as time-consuming in comparison to multiplex polymerase chain reaction (mPCR), by which multiple pathogens can be detected at a time. The present study was aimed to perform faster molecular identification of bacterial pathogens from goats presumed with fever and/or diarrhea and their antimicrobial resistance (AMR) pattern.

A total of 200 blood samples were collected from goats at S. A. Quaderi Teaching Veterinary Hospital (SAQTVH) in Chattogram Veterinary and Animal Sciences University for the period of July 2017-April 2018. DNA was extracted and subsequently, mPCR assay was performed for the screening of several bacterial pathogens (Salmonella spp., Listeria monocytogenes, Bacillus cereus, Yersinia enterocolitica, Campylobacter jejuni, Campylobacter coli, Clostridium perfringens, Vibrio cholerae, and Staphylococcus aureus). An antimicrobial susceptibility test against ten antimicrobials for positive samples of each organism was conducted using the Kirby-Bauer Disk-Diffusion Method on selective media.

S. aureus, C. perfringens, L. monocytogenes, and Salmonella spp. were detected from collected samples and their overall prevalence was 11.5%, 3.5%, 1%, and 20.5%, respectively. The most common clinical signs were mild fever, nasal discharge, dyspnea, and coughing (39.1%) for S. aureus, diarrhea, convulsion, abdominal pain, and incoordination (57.1%) for C. perfringens, fever, protrusion of tongue, and incoordination (100%) for L. monocytogenes, and fever, anorexia, dehydration with mucous feces (36.6%) for Salmonella spp. infection in goats. AntimGentamicinicrobial diagram of S. aureus showed resistance against Cefotaxime (74%), Cefixime (65%), and Tetracycline (65%); highly sensitive against Amoxicillin (48%), Ciprofloxacin (44%), and Gentamicin (44%). On the other hand, C. perfringens showed highly resistant against Ampicillin (71%), Gentamicin (71%), sensitive against Penicillin (57%), and Cefotaxime (57%). L. monocytogenes were found to be sensitive to Penicillin (100%) and Cefixime (100%) and Salmonella spp. showed resistance to Ampicillin (78%) and Amoxicillin (59%) but sensitive to Ciprofloxacin (54%).

This study identified pathogens with their specific clinical signs in goats presumed fever and/or diarrhea through mPCR with their AMR pattern in SAQTVH, Chattogram. Potential risk factors, measuring the strength of association of disease caused by these particular pathogens, were also determined. mPCR may use as an effective tool for rapid detection of pathogens in animal.