Phenotype and serotype of Pasteurella multocida isolates from diseases of dogs and cats in Zimbabwe.

A variety of disease manifestations, comprising skin bite wounds, pyothorax, respiratory and genitourinary tract infections, in 202 dogs and cats presented to the University Clinic, were investigated for the presence of Pasteurella multocida. Of these, 25-42% of various cases (69) were found to be infected with P. multocida. P. multocida-associated respiratory tract infections were more common than bite wounds or genitourinary tract infections. The regimen of treatment consisted of those antibiotics, sensitivity to which had been confirmed in vitro. Following detailed characterization of the isolates of P. multocida, in order to assign them to the reclassified taxa of Pasteurella, a preponderance of P. multocida subspecies multocida and septica were recorded. There did not appear to be a correlation between the reclassified taxa and their serotypes. Certain strains of different species or subspecies belonged to a common serotype and vice versa. However, the strains which were serotyped belonged to capsular type A, except for a solitary isolate from a cat which was capsular type D. Type D is known to cause atrophic rhinitis and does not appear to have been isolated either from a dog or a cat. Two strains, one from a dog and another from a cat, were identified as group EF-4 bacteria. This group of organisms has been incriminated in human wounds resulting from dog/cat bites, and has so far not been reported in Africa. Three different species, P. stomatis, P. dagmatis and P. multocida subspecies multocida were simultaneously isolated from a case of chronic bronchitis in a dog. There was no evidence of any relationship between disease manifestation in a host and the isolation of a particular taxon of Pasteurella, except that P. canis and Pasteurella taxon 16 were only isolated from dogs.