Antibiotic susceptibility of Pasteurella multocida strains, genetic background of antimicrobial resistance Literature review

Pasteurella multocida, a member of the Pasteurellaceae family, is a widespread Gram-negative veterinary pathogen with the potential to cause zoonotic infection in humans. Primarily, it is involved in the etiology of fowl cholera in birds, hemorrhagic septicemia in ungulates, and atrophic rhinitis in swine. As an opportunistic pathogen it is associated with respiratory diseases in various host species. The spread of antibiotic resistance is one of the most outstanding challenges of our time. This article attempts to summarize the phenotypic and genotypic methods available for testing the antibiotic sensitivity of bacterial strains, their advantages and disadvantages. It covers how resistance can develop against different families of antibiotics. Based on literature data, we summarize the changes in the antibiotic sensitivity patterns of P. multocida strains by time, considering the different host species and the geographical location. The presented literature shows that the determination of minimum inhibitory concentration (MIC) is increasingly replacing the disk diffusion test over time. Furthermore, more and more studies are reporting on the investigation of resistance genes. Analysing the available data, they showed differences in the antibiotic sensitivity profiles between the different parts of the world and between the host species. Moreover, these profiles may change from year to year depending on the spread of resistance, so tracking them is very useful for identifying trends. In general, ceftiofur, florfenicol, and enrofloxacin continue to be effective against P. multocida. On the other hand, the proportion of strains resistant to sulfamethoxazoletrimethoprim, gentamicin, erythromycin, amoxicillin and various tetracyclines is increasing. Particularly outstanding resistance can be found in the case of some sulphonamides and clindamycin.