Veterinary session

The oral microbiome of pet and assistance dogs is diverse, yet relatively understudied. Through dog bite the human body can be exposed to a range of pathogenic bacteria, with the potential for subsequent wound infections and in immuncompromised individuals the onset of systemic disease.

The aim of the present study was to investigate the prevalence of Pasteurella species in the oral mucosa of pet dogs from different age groups, breeds and health statuses as well as in bite wounds caused by dogs. Based on the relevant literature and the antibiotics used in veterinary medicine, antibiograms of the isolates were assessed.

Swab samples from the oral cavity or bite wound were streaked on sheep blood agar and Pasteurella-selective agar, following incubation, colonies were selected based on their morphology and biochemical properties. Pure cultures of these colonies were identified through species-specific PCR or 16S rRNA sequencing and MALDI biotyping. The susceptibility of the strains to 12 antibiotics was determined using the Kirby-Bauer disc diffusion method.

A total of 75 Pasteurella strains were isolated from the 55 oral swab samples. Of these, 42 strains were identified as Frederiksenia canicola, 12 as Pasteurella canis, 7 as Pasteurella dagmatis, 6 as Pasteurella stomatis and 1 as Pasteurella pneumotropica. From the bite wound samples a P. canis and a F. canicola strain were identified.

All the strains were resistant to linkomycin and decreased susceptibility to clindamycin, erytromycin and amoxicillin-clavulanic acid was observed. 15 strains were identified as MDR (multi-drug resistant), most of them resistant to three classes of antibiotics. Our measurements indicate that tetracycline, ampicillin, sulphamethoxazole-trimetoprim (SXT), penicillin G, cefalexin, cefovecin and enrofloxacin could be effective treatments.

Development of resistance to antibiotics commonly used for dental procedures and for the treatment of respiratory diseases is a significant concern. Therefore, use of AMEG (Antimicrobial Advice Ad Hoc Expert Group) „Category D” antibiotics (tetracycline, ampicillin, SXT or penicillin G) is recommended as first-line treatment of bite wounds.