Detection of Tn7-Like Transposons and Antibiotic Resistance in Enterobacterales From Animals Used for Food Production With Identification of Three Novel Transposons Tn6813, Tn6814, and Tn6765

Abstract

Enterobacterales are widely distributed in the gastro-intestinal system of animals and may cause opportunistic infections. Worse still, multidrug-resistant Enterobacterales also poses a serious threat to public health. Tn7-like transposons have been found in several species of the Enterobacterales order and play an important role in dissemination of antibiotic resistance. This study aimed to investigate the distribution and genetic characterization of Tn7-like transposons in Enterobacterales isolates from food animals and their association with antibiotic resistance. Enterobacterales isolated from the samples were identified and classified according to the 16S rDNA sequence. Tn7-like transposons and associated integrons were detected by polymerase chain reaction (PCR) and sequencing. The antibiotic resistance of each Tn7-like transposon positive isolate was detected according to the Kirby-Bauer disk diffusion method. Then, six representative strains were selected to study the genetic environment by whole-genome sequencing (WGS). In total, we isolated 377 Tn7-like transposons positive strains of Enterobacterales. Class 2 integrons were detected in 99.5% of the isolates, and there were high frequency mutation sites especially in base 535, a stop mutation. Many isolates (54.9%) were multidrug-resistant and observed high resistance rates to trimethoprim/sulfamethoxazole and streptomycin. Among these strains, we found three new types of Tn7-like transposons, named Tn6813, Tn6814, and Tn6765. This is the first comprehensive survey that shows Tn7-like transposons in Enterobacterales from animals used for food production in different regions of China. This study also provides an insight into the horizontal transfer of resistance genes associated with Tn7-like transposons.

Effects of therapeutic levels of dietary antibiotics on the cecal microbiome composition of broiler chickens

“…(2011) , dietary supplementation with SA resulted in enrichment of family Enterobacteriaceae, which includes many potentially pathogenic bacteria, such as Escherichia coli, Shigella, Salmonella , and Klebsiella, in the cecal microbiome on d 35. The family Enterobacteriaceae constitutes less than 1% of healthy intestinal microbiome ( He et al., 2020 ). Although their presence is important for maintaining immunological balance in the intestine ( Scarpa et al., 2011 ), the increased abundance of members of this family may result in economically significant enteric diseases including mucosal ulceration ( He et al., 2020 ).…”

“…The family Enterobacteriaceae constitutes less than 1% of healthy intestinal microbiome ( He et al., 2020 ). Although their presence is important for maintaining immunological balance in the intestine ( Scarpa et al., 2011 ), the increased abundance of members of this family may result in economically significant enteric diseases including mucosal ulceration ( He et al., 2020 ).…”

“…Furthermore, supplementation with salinomycin has been shown to increase the abundance of pathogenic bacteria, including order Gastranaerophilales ( Li et al., 2020 ), class Gammaproteobacteria ( Gorecki et al., 2019 ; Abaidullah et al., 2019 ) and family Enterobacteriaceae ( He et al., 2020 ) that have been previously shown to be associated with metabolic disorders and gastrointestinal diseases.…”

Emergence and genomic characterization of Proteus mirabilis harboring blaNDM-1 in Korean companion dogs

“…Tn 7 -like transposons contribute to the horizontal transfer of AMR genes among bacterial species via transposases [ 47 ]. However, the role of Tn 7 -like transposons in MDR isolates in our society remains largely unexplored.…”

Antimicrobial Peptides: From Design to Clinical Application

“…The bacterial Tn family belongs to DNA Tns, which can transfer between plasmids or between DNA chromosome and plasmid [44]. For example, Tn7-like transposons such as Tn6813, Tn6814, and Tn6765 were found in Enterobacterales isolated from food animals, which were associated with resistance to sulfamethoxazole and streptomycin [45]. The presence of class 1 integrons in commensal E. coli strains is associated with tetracycline-resistant genes tet(A) and tet(B) [46].…”