Staphylococcus aureus CC398 and pig-specific fecal Bacteroidales qPCR concentrations decline with increasing time away from work among industrial hog operation workers
Methods: 22 IHO workers collected 316 nasal swabs before and after an IHO work shift over 7 d and again 14 d after enrollment and recorded time since last IHO shift. Swabs were cultured for S. aureus presence and assessed for multidrug-resistance (MDR = resistant >2 antimicrobial drug classes), tetracycline-resistance, clonal complex (CC), and absence of the scn gene (marker of livestock association). femA, mecA, S. aureus CC398, and pig-specific fecal Bacteroidales (Pig-2-Bac) DNA per nasal swab were estimated by qPCR.
Results: femA and mecA qPCR estimates remained stable in nose swabs with increasing time since last IHO work shift, whereas S. aureus CC398 and Pig-2-Bac qPCR estimates declined significantly. Declines of S. aureus CC398 and Pig-2-Bac qPCR estimates were strongest among persistent carriers of S. aureus as well as during periods of tetracycline-resistant, MDR, CC398, and scn-negative S. aureus nasal carriage.
Conclusion: S. aureus CC398 and Pig-2-Bac qPCR declined with increasing time since last IHO shift, particularly among persistent S. aureus nasal carriers and during periods of drug-resistant, livestock-associated S. aureus nasal carriage. qPCR estimates of S. aureus CC398 and Pig-2-Bac appear to improve knowledge of IHO work as a source of drug-resistant, livestock-associated S. aureus exposure among IHO workers and warrant further consideration in studies of S. aureus transmission dynamics between IHO workers and household and community contacts.
M. Nadimpalli, None
J. Rinsky, None
D. Love, None
K. Nachman, None
T. M. Perl, None
S. Wing, None
J. Stewart, None