Epidemiology of bacteria and viruses in the respiratory tract of humans and domestic pigs.

Bunke, Jennifer; Receveur, Kerstin; Christin Oeser, Ann; Gutsmann, Imke; Schubert, Sabine; Podschun, Rainer; Zell, Roland; Fickenscher, Helmut; Krumbholz, Andi

Bacteria and viruses were analysed in the upper respiratory tract of symptomatic pig-farmers and their domestic pigs. 86 human nasal and 495 (50 pools) porcine snout swabs were collected in Schleswig-Holstein, Germany. Staphylococcus (S.) aureus (62.8%, 54/86), human rhino- and coronaviruses (HRV, 29.1%, 25/86; HCoV, 16.3%, 14/86) were frequently detected in humans while Haemophilus parasuis (90.0%, 45/50), Mycoplasma hyorhinis (78.6%, 11/14), Enterovirus G (EV-G, 56.0%, 28/50), and S. aureus (36.0%, 18/50), respectively, were highly prevalent in pigs. The detection of S. aureus in human follow-up samples indicates a carrier status. The methicillin-resistant phenotype (MRSA) was identified in 33.3% (18/54) of nasal swabs and in one of 18 (5.6%) of pooled snout swabs tested positive for S. aureus. Strains were indicative of the livestock-associated clonal complex CC398, with t011 being the most common staphylococcal protein a type. Enterobacterales and non-fermenters were frequently isolated from swabs. Their detection in follow-up samples suggests a carrier status. All were classified as being non-multiresistant. There was no example for cross-species transmission of viruses. In contrast, transmission of S. aureus through occupational contact to pigs seems possible. The study contributes to the "One Health" approach.