Combination of antibiotics suppressed the increase of a part of ARGs in fecal microorganism of weaned pigs.
The presence of antibiotic resistance genes (ARGs) is one of the most important public health concerns. Six tetracycline resistance genes (TRGs-tetA, tetC, tetL, tetO, tetW, and tetX) were quantified using real-time quantitative polymerase chain reaction (qPCR) in the fecal microorganisms of weaned pigs. Two hundred 35-day-old weaned pigs were fed different dietary antibiotics for 28 days: (1) no antibiotic as the control treatment (CT); (2) chlortetracycline, bacitracin zinc and colistin sulfate (CBC); (3) bacitracin zinc and colistin sulfate (BC); and (4) chlortetracycline (CTC). The detection frequencies (DFs) of tetC, tetL, and tetW were 100 %; and the DFs of tetA, tetD, tetM, tetO, and tetX were 65 %. The relative abundances (tet/16S rRNA gene copy numbers) of six tet genes (tetA, tetC, tetL, tetO, tetW and tetX) were between 1.5 × 10(-4) and 2.0 × 10(-1). In the group CTC, the relative abundances of tetC (P < 0.01), tetL (P < 0.01), tetO (P < 0.05), tetW (P < 0.01), and tetX (P < 0.01) were greater than those of the group CT. Compared with the group CTC, the relative abundances of tetC (P < 0.01), tetL (P < 0.01), and tetW (P < 0.01) were decreased in the CBC and BC groups. These results indicate that a combination of different antibiotics suppressed the abundance increase of a part of tet genes, which suggests that a combination of antibiotics produces multiple selection pressures on fecal microorganism of pigs.
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
Huizhi
H
Li
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
Qingpo
Q
Chu
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
Feilong
F
Xu
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
Lingling
L
Fu
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
Tingting
T
Liang
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
Yuan
Y
Li
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China. zhoubo@njau.edu.cn.
Bo
B
Zhou
D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D005243:Feces / Q000382:microbiology*; D005798:Genes, Bacterial; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013552:Swine; D013752:Tetracycline / Q000494:pharmacology; D013753:Tetracycline Resistance
D000900:Anti-Bacterial Agents; D012336:RNA, Ribosomal, 16S; D013752:Tetracycline
Chlortetracycline; Fecal microorganism; Pigs; Tetracycline resistance; qPCR; tet genes