F33: A-: B-, IncHI2/ST3, and IncI1/ST71 plasmids drive the dissemination of fosA3 and blaCTX−M−55/−14/−65 in Escherichia coli from chickens in China

Abstract

The purpose of this study was to examine the occurrence of fosfomycin-resistant Escherichia coli from chickens and to characterize the plasmids carrying fosA3. A total of 661 E. coli isolates of chicken origin collected from 2009 to 2011 were screened for plasmid-mediated fosfomycin resistance determinants by PCR. Plasmids were characterized using PCR-based replicon typing, plasmid multilocus sequence typing, and restriction fragment length polymorphisms. Associated addiction systems and resistance genes were identified by PCR. PCR-mapping was used for analysis of the genetic context of fosA3. Fosfomycin resistance was detected in 58 isolates that also carried the fosA3 gene. Fifty-seven, 17, and 52 FosA3-producers also harbored blaCTX−M, rmtB, and floR genes, respectively. Most of the 58 fosA3-carrying isolates were clonally unrelated, and all fosA3 genes were located on plasmids belonged to F33:A-:B- (n = 18), IncN-F33:A-:B- (n = 7), IncHI2/ST3 (n = 10), IncI1/ST71 (n = 3), IncI1/ST108 (n = 3), and others. The genetic structures, IS26-ISEcp1-blaCTX−M−55-orf477-blaTEM-1-IS26-fosA3-1758bp-IS26 and ISEcp1-blaCTX−M−65-IS903-iroN-IS26-fosA3-536bp-IS26 were located on highly similar F33:A-:B- plasmids. In addition, blaCTX−M−14-fosA3-IS26 was frequently present on similar IncHI2/ST3 plasmids. IncFII plasmids had a significantly higher frequency of addiction systems (mean 3.5) than other plasmids. Our results showed a surprisingly high prevalence of fosA3 gene in E. coli isolates recovered from chicken in China. The spread of fosA3 can be attributed to horizontal dissemination of several epidemic plasmids, especially F33:A-:B- plasmids. Since coselection by other antimicrobials is the major driving force for the diffusion of the fosA3 gene, a strict antibiotic use policy is urgently needed in China.

Complete Sequence of a Novel IncR-F33:A–:B– Plasmid, pKP1034, Harboring fosA3 , bla KPC-2 , bla CTX-M-65 , bla SHV-12 , and rmtB from an Epidemic Klebsiella pneumoniae Sequence Type 11 Strain in China

“…It was originally isolated from a dog in Guangzhou, China. Recently, pHN7A8-like plasmids have disseminated widely in food-producing animals and pets in China, playing an important role in the spread of resistance genes bla CTX-M-65 , rmtB, and fosA3 (9,17,22,23). To date, pHN7A8-and pHN7A8-like plasmids have not been detected in human strains yet.…”

Characterization of a Novel IncHI2 Plasmid Carrying Tandem Copies of bla CTX-M-2 in a fosA6 -Harboring Escherichia coli Sequence Type 410 Strain

“…S1). ST3-IncHI2 plasmids are reportedly widely disseminated in Chinese poultry and livestock farms, and they carry fosA3, bla CTX-M-9 -group genes (bla CTX-M-14/65/27 ), and/or oqxAB (17,19). In previous studies, ST1-IncHI2 plasmids were associated with bla CTX-M-9 in Europe, while ST2-or APEC-O1-R-type IncHI2 plasmids linked to bla CTX-M-2 were found in Salmonella spp.…”

“…KT347600.1) (15), bla VIM (accession no. LN555650.1) (16), bla IMP , armA, qnrA, oqxAB, fosA3, and mcr-1 (12,(17)(18)(19)(20)(21). So far, no IncHI2 plasmid carrying bla CTX-M-2 has been characterized fully.…”

Plasmids of Diverse Inc Groups Disseminate the Fosfomycin Resistance Gene fosA3 among Escherichia coli Isolates from Pigs, Chickens, and Dairy Cows in Northeast China

“…While resistance to fosfomycin is mainly due to chromosomal mutations (4), two plasmid-borne fosfomycin resistance genes, fosA3 and fosC2, were first identified in human Escherichia coli in Japan in 2010 (5). Thereafter, a relatively high prevalence of fosfomycin-resistant E. coli isolates carrying fosA3 was found in food animals, pets, and wild rodents in China, although fosfomycin has not been approved for veterinary use in China (6)(7)(8).…”