Virulence attributes and antimicrobial profile of Pasteurella multocida isolated from pneumonic goats in Northern Tanzania

Pneumonic pasteurellosis caused by Pasteurella multocida can significantly impact animal health and productivity, leading to substantial economic losses for producers. This study aimed to understand the prevalence of antimicrobial resistance and virulence genes in P. multocida isolated from goats with pneumonic pasteurellosis in northern Tanzania, where the disease poses a significant economic burden for small-scale farmers. A total of 200 nasal swabs were collected from goats exhibiting clinical signs of pneumonic condition, and P. multocida and its virulence attributes were identified through conventional and molecular diagnostic methods. These isolates were subsequently tested for their susceptibility to various antimicrobials. P. multocida was isolated in 2.5 % (5, n = 200) of the collected samples. Capsular serogrouping identified 20 % (1, n = 5) of the isolates as belonging to serogroup A, reported circulating in goats in Tanzania for the first time, while 80 % were classified as untypable. All isolates possessed the iron acquisition gene exbD, while the adhesin gene ptfA was present in 60 %. This study revealed high resistance against a wide range of antimicrobials, including cefotaxime, sulfamethoxazole/trimethoprim, amoxicillin, erythromycin, ampicillin, chloramphenicol, tetracycline, and pefloxacin. However, they remained 100 % susceptible to gentamicin and ciprofloxacin. Of all the isolates, 100 % ( n = 5) exhibited multidrug resistance phenotypically. Further analysis revealed that 40 % of the isolates harboured at least one antimicrobial resistance gene, with ermX , blaTEM and sul1 being the most prevalent. These findings highlight the growing threat of antimicrobial resistance in P. multocida in northern Tanzania, emphasising the need for novel strategies to manage pneumonic pasteurellosis. The presence of untypable strains necessitates further research to understand their significance and develop alternative typing methods for effective control.