A Novel Structure Harboring blaCTX-M-27 on IncF Plasmids in Escherichia coli Isolated from Swine in China

Abstract

The aim of this study was to elucidate the prevalence of blaCTX-M-27-producing Escherichia coli and transmission mechanisms of blaCTX-M-27 from swine farms in China. A total of 333 E. coli isolates were collected from two farms from 2013 to 2016. Thirty-two CTX-M-27-positive E. coli were obtained, and all were multidrug-resistant. Pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) profiles indicated a wide range of strain types that carried blaCTX-M-27, and the sequence type ST10 predominated. Conjugation, replicon typing, S1-PFGE and hybridization experiments confirmed that 28 out of 32 CTX-M-27 positive isolates carried blaCTX-M-27 genes on plasmids F18:A-:B10 (16) and F24:A-:B1 (12).The blaCTX-M-27 genes for 24 isolates were transmitted by plasmids with sizes ranging from 40 to 155 kb. A comparative analysis with blaCTX-M-27-plasmids indicated that the tra-trb region of F24:A-:B1 plasmids was destroyed by insertion of a complex region (eight isolates) and a novel structure containing blaCTX-M-27 in the F18:A-:B10 plasmids (12 isolates). The novel structure increased the stability of the blaCTX-M-27 gene in E. coli. This study indicated that the predominant vehicle for blaCTX-M-27 transmission has diversified over time and that control strategies to limit blaCTX-M-27 transmission in farm animals are necessary.

Genotypic Diversity and Antimicrobial Resistance of Escherichia Coli Isolated From Pigs in Hubei, China

“…It reveals that there is diversity in ST types in Hubei province. In some other surveys, ST101 (7/53, 13.21%) [22] and ST101 (3/32, 9.4%) [14] were common STs, these are similar to our result ST101 (3/29, 10.3%). In Yang′s study, the common ST was ST10 (22/171, 12.9%), followed by ST744 (8/171, 4.7%), ST101 (7/171, 4.1%), ST165 (5/171, 2.9%) [17] .…”

“…Recently, E. coli ST10 has not only been presented by animals in China but also raised the ST10 from human infections in China [23] . Zhang et al showed that the most prevalent ST was ST10 (16/32, 50%) [14] . However, ST10 (2/29, 6.9 %) of the result in this study seem to con ict with those from most previous studies.…”

“…From 2003 to 2009, the prevalence of E. coli isolates from pig farms was 77.78% in China [21] . From 2013 to 2016, the positive rates of E. coli between farm 1 and farm 2 were 40.25% and 59.75% in Guangdong province [14] . Between 2016 and 2017, a survey indicated that the separation rate of E. coli isolated from pig fecal swabs reached 88% in northeastern China, including Heilongjiang, Jilin and Liaoning [8] .…”

“…From 2011 to 2012, a survey of drug resistance in pigs demonstrated that the great majority of swine-origin E. coli isolates resistance to tetracycline (79.57%), trimethoprim-sulfamethoxazole (73.12%) and kanamycin (55.91%) [13] . A survey in Guangdong Province showed that a total of 333 E. coli isolates were acquired from pig farms from 2013 to 2016, which were all multidrug-resistant strains [14] . Multidrug-resistance Gram-negative bacterial clinical isolates are responsible for high rates globally [15] and comprise a challenge for animal treatment.…”

Evaluation of canine raw food products for the presence of extended-spectrum beta-lactamase- and carbapenemase-producing bacteria of the order Enterobacterales

“…47 Studies investigating the role of certain veterinary drugs in the emergence of particular ESBL enzymes are lacking. Ceftazidime use is prohibited in food production animals, 48 but the gene encoding CTX-M-27 has been reported in E. coli isolated from swine, 49,50 beef cattle, 50 and poultry. 51 In this study, food containing all of these major proteins also had E. coli with a bla CTX-M-27 gene present.…”