Efficient reduction of antibiotic residues and associated resistance genes in tylosin antibiotic fermentation waste using hyperthermophilic composting

TY - JOUR

T1 - Efficient reduction of antibiotic residues and associated resistance genes in tylosin antibiotic fermentation waste using hyperthermophilic composting

AU - Liao, Hanpeng

AU - Zhao, Qian

AU - Cui, Peng

AU - Chen, Zhi

AU - Yu, Zhen

AU - Geisen, Stefan

AU - Friman, Ville-Petri

AU - Zhou, Shungui

N1 - 6900, TE; Data Archiving: no data data in China

PY - 2019

Y1 - 2019

N2 - Insufficient removal of antibiotics and antibiotic resistance genes (ARGs) from waste products can increase the risk of selection for antibiotic resistance in non-clinical environments. While composting is an efficient way to reduce ARGs, most conventional methods are ineffective at processing highly contaminated antibiotic fermentation waste. Here we explored the efficacy and underlying mechanisms of hyperthermophilic composting at removing tylosin antibiotic fermentation residues (TFR) and associated ARGs and mobile genetic elements (MGEs; plasmids, integrons and transposon). Hyperthermophilic composting removed 95.0% of TFR, 75.8% of ARGs and 98.5% of MGEs and this reduction mainly occurred after extended exposure to temperatures above 60 °C for at least 6 days. Based on sequencing and culture-dependent experiments, reduction in ARGs and MGEs was strongly associated with a decrease in the number of bacterial taxa that were initially associated with ARGs and MGEs. Moreover, we found 94.1% reduction in plasmid genes abundances (ISCR1 and IncQ-oriV) that significantly correlated with reduced ARGs during the composting, which suggests that plasmids were the main carriers for ARGs. We verified this using direct culturing to show that ARGs were more often found in plasmids during the early phase of composting. Together these results suggest that hyperthermophilic composting is efficient at removing ARGs and associated resistance genes from antibiotic fermentation waste by decreasing the abundance of antibiotic resistance plasmids and associated host bacteria.

AB - Insufficient removal of antibiotics and antibiotic resistance genes (ARGs) from waste products can increase the risk of selection for antibiotic resistance in non-clinical environments. While composting is an efficient way to reduce ARGs, most conventional methods are ineffective at processing highly contaminated antibiotic fermentation waste. Here we explored the efficacy and underlying mechanisms of hyperthermophilic composting at removing tylosin antibiotic fermentation residues (TFR) and associated ARGs and mobile genetic elements (MGEs; plasmids, integrons and transposon). Hyperthermophilic composting removed 95.0% of TFR, 75.8% of ARGs and 98.5% of MGEs and this reduction mainly occurred after extended exposure to temperatures above 60 °C for at least 6 days. Based on sequencing and culture-dependent experiments, reduction in ARGs and MGEs was strongly associated with a decrease in the number of bacterial taxa that were initially associated with ARGs and MGEs. Moreover, we found 94.1% reduction in plasmid genes abundances (ISCR1 and IncQ-oriV) that significantly correlated with reduced ARGs during the composting, which suggests that plasmids were the main carriers for ARGs. We verified this using direct culturing to show that ARGs were more often found in plasmids during the early phase of composting. Together these results suggest that hyperthermophilic composting is efficient at removing ARGs and associated resistance genes from antibiotic fermentation waste by decreasing the abundance of antibiotic resistance plasmids and associated host bacteria.

KW - international

KW - Antibiotic residue

KW - Hyperthermophilic composting

KW - Horizontal gene transfer

KW - Plasmids

KW - Antibiotic resistance genes

U2 - 10.1016/j.envint.2019.105203

DO - 10.1016/j.envint.2019.105203

M3 - Article

SN - 0160-4120

VL - 133

JO - Environment International

JF - Environment International

M1 - 105203

ER -