Genetic diversity of different avian strains of Pasteurella multocida recovered during four outbreaks in India

Ramalingam Mahaprabhu,Kumaragurubaran Karthik,Ramasamy Bharathi,Vishwanathan Dillibabu,Kaliyaperumal Manimaran,Kulasekaran Shoba

doi:10.3906/vet-1710-29

Abstract

Pasteurella multocida causes fowl cholera in avian species and type A is predominantly reported from outbreaks of fowl cholera. Biochemical, serological, and molecular methods are employed for its diagnosis and typing. Utilizing rapid molecular tools like repetitive extragenic palindromic (REP) PCR and enterobacterial repetitive intergenic consensus (ERIC) PCR, P. multocida isolates from four outbreaks (three from Chennai and one from Ahmadabad, India) were characterized and typed to determine their relationships. A total of 36 isolates were recovered from the outbreaks, including one isolate from a parakeet, which was also subjected to characterization by conventional and molecular analysis. All of the isolates were found to be capsular type A based on PCR assay capsular typing. ERIC- and REP-PCR showed differences in the banding patterns among different outbreak isolates, and also among the geographical regions. Differences were also noticed among different host species, as the banding pattern in the ERIC- and REP-PCR differed; the analysis of results also revealed the same. All of the isolates were found to be sensitive to enrofloxacin and cefotaxime among the antibiotics used in the study. It was found that different strains might have been involved in the different outbreaks reported in the study. The results show that molecular typing methods like ERIC- and REP-PCR are useful epidemiological tools for classifying the strains.

Highlights

Fowl cholera (FC) is an acute septicemic deadly disease of various poultry species caused by Pasteurella multocida, a gram-negative, nonmotile, nonspore-forming, aerobic, rod-shaped bacterium [1]
Recent advances in diagnosis have aided in molecular characterization of the isolates using techniques like enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction (PCR), restriction endonuclease analysis (REA), random amplified polymorphic DNA (RAPD), multilocus sequencing typing (MLST), and repetitive extragenic palindromic (REP) PCR [4,11,12]
All of the DNA was later subjected to a multiplex PCR assay using five primer sets as per the method described by Townsend et al [17], so as to type isolates based on their capsules

Summary

Introduction

Fowl cholera (FC) is an acute septicemic deadly disease of various poultry species caused by Pasteurella multocida, a gram-negative, nonmotile, nonspore-forming, aerobic, rod-shaped bacterium [1]. Recent advances in diagnosis have aided in molecular characterization of the isolates using techniques like enterobacterial repetitive intergenic consensus (ERIC) PCR, restriction endonuclease analysis (REA), random amplified polymorphic DNA (RAPD), multilocus sequencing typing (MLST), and repetitive extragenic palindromic (REP) PCR [4,11,12]. These methods have higher reproducibility and better discriminatory power; these methods can be employed for epidemiological studies of the isolates [12]. The present study was undertaken to characterize the P. multocida isolates using molecular tools to determine their diversity in different avian species among the same and different outbreaks

Materials and methods

Results

Discussion