Inactivation of carbapenemase-producing Enterobacterales during anaerobic co-digestion of food waste and pig manure

Abstract

Animal manures and food wastes are significant reservoirs of antimicrobial resistant bacteria, among which carbapenemase-producing Enterobacterales (CPE) are resistant to almost all antibiotics and have been detected in these wastes. This study investigated the inactivation of three different CPE strains (KPC-3, OXA-48 and NDM-1 carbapenemase-producing Klebsiella pneumoniae) during anaerobic co-digestion of food waste and pig manure at various total solids (TS) contents. The results showed that the elimination of CPE strains was more efficient at higher TS contents. While increasing the TS contents from 5% to 20%, the survival time of CPE decreased from 9 days to 2 days. Statistical analysis revealed significant negative correlations between total volatile fatty acids (VFAs) and the survival time of two CPE strains (KPC-3 and OXA-48 producing Klebsiella pneumoniae) (P < 0.05), indicating the possible elimination effects of VFAs on antibiotic resistant bacteria.