Variability in in vitro biofilm production and antimicrobial sensitivity pattern among Pasteurella multocida strains

Abstract

Biofilm production, hitherto an uncharacterized feature among circulating Pasteurella multocida strains, was studied along with the antibiotic susceptibility pattern. On the basis of biofilm formation ability, all the strains were categorized into four groups under six different culture conditions: strong biofilm-forming (22%), moderate (19%), weak (51%), and non-adherent (7%). Strains from serogroups A and B formed significant biofilms in at least one culture condition whereas strains from serogroup D were unable to form biofilms. All strains were found to be susceptible to tetracycline. In addition, the correlation between diverse factors (host, capsule type, clinical condition and the tadD gene) as well as antimicrobial susceptibility in biofilm production were analyzed by Joint distribution models, and showed that enrofloxacin and azithromycin resistant strains were positively correlated with strong biofilm production.

Keywords:

• Antimicrobial resistance
• biofilm
• strain diversity
• Model based analysis
• Pasteurella multocida

Acknowledgements

The authors are grateful to the Indian Council of Agricultural Research (ICAR), New Delhi, and ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Benglauru, Karnataka, India, for providing the necessary facilities and financial assistance to carry out the research on Pasteurella multocida. The authors also thank Dr S S Shivakumara for critical editing of the manuscript. This study was a part of doctoral research carried out by AP under the institute project (Code: IXX12176) entitled ‘Epidemiology of Haemorrhagic septicaemia (HS) in India’ granted to SBS.

Disclosure statement

No potential conflict of interest was reported by the author(s).