Formation and transmission of Staphylococcus aureus (including MRSA) aerosols carrying antibiotic-resistant genes in a poultry farming environment

There is a rather limited understanding concerning the antibiotic-resistance of the airborne S. aureus and the transmission of the antibiotic-resistant genes it carries Therefore, we isolated 149 S. aureus strains from the samples collected from the feces, the indoor air and the outdoor air of 6 chicken farms, and performed the research on them with 15 types of antibiotics and the REP-PCR trace identification. The 100% homologous strains were selected to conduct the research on the carrying and transmission status of the antibiotic-resistant genes. The results revealed that 5.37% strains (8/149) were resistant to methicillins (MRSA), and 94% strains (140/149) were resistant to compound sulfamethoxazole, etc. In addition, these strains displayed a resistance to multiple antibiotics (4, 5 or 6 types) and there were also 3 strains resistant to 9 antibiotics. It should be noted that the antibiotic-resistance of some strains isolated from the feces, the indoor and outdoor air was basically the same, and the strains with the same REP-PCR trace identification result carried the same type of antibiotic-resistant genes. The results showed that airborne transmission not only causes the spread of epidemic diseases but also exerts threats to the public health of a community.

► The study revealed that 5.37% S. aureus strains (8/149) were resistant to methicillins.
► 94% of the strains (140/149) were resistant to compound sulfamethoxazole.
► Most of the strains (63.8%, 95/149) displayed a resistance to 4–6 antibiotics, and 3 resistant to 9 antibiotics.
► The S. aureus carrying antibiotic-resistant genes could form aerosols and spread to surrounding environment of the farm.