Fate of antibiotic resistance genes in abandoned swine feedlots in China: seasonal variation

Abstract

Background Environmental hygiene concerns are needed to be settled before the reuse of abandoned swine feedlot sites. However, few researchers have focused on the fate of antibiotic resistance genes (ARGs) in soil microbiota around abandoned swine feedlots. In this study, we examined the seasonal alterations of ARGs and bacterial community composition in soil using quantitative PCR and high-throughput sequencing of 16S rRNA gene. Results The seasonal variation patterns were different for different ARG subtypes and soil sampling sites. The bacterial community composition at the genus level generally showed no significant alteration from winter to summer. Moreover, the co-occurrence network suggested that the bacterial genera host range of ARGs was broader in the summer than in the winter. Conclusion This study offers further data on ARG transfer risk in soil, emphasizing the necessity of continuous concern before land-reuse of abandoned feedlots.

Distribution analysis of tetracycline resistance genes in Escherichia coli isolated from floor surface and effluent of pig slaughterhouses in Banten Province, Indonesia

“…The tetA , tetM , tetO , and tetX genes were amplified with the procedure proposed by Li et al . [ 22 ] using a two-step qPCR program with the following protocol: 3 min of initial heating at 95°C followed by 40 cycles of denaturation for 10 s at 95°C, 60 s of annealing at the TM adjusted for the primers listed in Table-1 , and extension at 72°C for 1 min. The tetB , tetC , and tetE genes were amplified by referring to the procedure of Jia et al .…”

“…In the qPCR SYBR Green method, melting was performed using Q-Rex software (Qiagen). The tetA, tetM, tetO, and tetX genes were amplified with the procedure proposed by Li et al [22] using a two-step qPCR program with the following protocol: 3 min of initial heating at 95°C followed by 40 cycles of denaturation for 10 s at 95°C, 60 s of annealing at the TM adjusted for the primers listed in Table-1, and extension at 72°C for 1 min. The tetB, tetC, and tetE genes were amplified by referring to the procedure of Jia et al [23] as follows: Initial heating at 94°C for 5 min, followed by 40 cycles of denaturation for 60 s at 94°C, 30 s of annealing at the TM adjusted for the primers listed in Table-1 [19][20][21], and extension at 72°C for 90 s. The specificity of the amplified product was analyzed using the melting curve (95°C for 10 s, 65°C-95°C with 0.5°C increment every 0.05 s).…”

Detection of tetracycline resistance genes and their diversity in Escherichia coli isolated from pig farm waste in Banten province, Indonesia

“…The results were considered positive when the cycle threshold (CT) value was <40 with an amplification curve [ 27 , 35 ] and a single melt peak was formed with a melting temperature range smaller than 2°C. However, the results were considered negative/undetectable when the CT value exceeded 40 and no amplification curve was detected.…”

“…Subsequently, qPCR and melting were performed using Q-Rex software (Qiagen). The amplification process for tetA, tetM, tetO, and tetX followed the procedure proposed by Li et al [35] using a two-step qPCR program. This involved initial heating at 95°C for 3 min, followed by 40 cycles of denaturation at 10 s 95°C, annealing for 60 s at a temperature adjusted for the primers of the target genes (as specified in Table-1), and extension for 1 min at 72°C.…”