[Sharing bacterial microbiota between owners and their pets (dogs, cats)]

The microbiological aspect of a relationship between pets (dogs/cats) and their owners is mainly concerned with the incidence of shared bacterial species, in particular potential pathogens. Given the great popularity of sharing homes with pets (dogs/cats) in the Czech Republic, there is an increased possibility of communication between microbiota of the two macroorganisms (pet and owner). The aim of the study was to determine the biodiversity of shared bacteria and possibility of exchange of genes of resistance to antimicrobial agents between potential pathogens based on the close relationship between pets and humans.

A total of 103 samples were collected from 20 pairs (20 owners, 16 dogs and 4 cats). All owners completed a questionnaire with their pets' veterinarians. In owners, swabs were collected from the nasal mucosa, armpit and interdigital spaces of the foot. In pets, swabs were obtained from the external auditory meatus and nasal mucosa. In individuals with skin lesions, samples were also collected from the affected areas. Bacterial species were identified by culture and matrix-assisted laser desorption/ionization - time of flight (MALDI-TOF) mass spectrometry. In shared species, susceptibility to antibiotics was tested by the disk diffusion method. Statistical methods were used to correlate the closeness of relationship with the number of shared bacterial species and to correlate previous antimicrobial therapy with shared resistance of the common bacteria.

Analysis of the questionnaires showed that 65 % of owners who participated in the study kept more pets at home than only the tested one. In the previous year, 5 % of pets and 5 % of owners received antimicrobial therapy. As many as 45 % of dogs or cats slept in their owners' beds and 80 % rested on a sofa together with their owners. Also, 45 % owners had their faces licked by pets. Eighty percent of pets were fed with several types of food (dry food and cooked food). Further, 70 % of pets lived permanently with their owners in the same household. A total of 76 bacterial species of 33 genera were identified. The most frequently isolated species (29 samples) was S. intermedius. Seventeen bacterial species occurring in both humans and animals were found and identified. At least one bacterial species was shared by 11 pairs and two shared species were found in two pairs. The shared species were S. intermedius, E. coli, E. faecalis, A. lwoffii, P. putida and S. aureus. Antimicrobial susceptibility was tested in the shared species. Common antimicrobial resistance was found in four pairs. In one pair, shared E. faecalis showed identical resistance to co-trimoxazole; in another pair, S. intermedius was resistant to gentamycin, erythromycin, clindamycin and co-trimoxazole. The third resistant bacterial species was E. coli; in one pair, it showed borderline resistance to colistin; in the second case, it was fully resistant to this antimicrobial agent. The other pairs with shared bacteria did not show any common resistance.

The study results showed that there was an association between closeness of the human-pet relationship and the prevalence of shared bacterial species. Pairs with a close relationship were 37.5 % more likely to share bacteria than pairs with a less close relationship. The study suggests that antimicrobial therapy in at least one pair member may increase the risk of shared bacterial resistance.