Detection of clinically important β-lactamases in commensal Escherichia coli of human and swine origin in western China

Abstract

Data correlating b-lactamases found in commensal Escherichia coli of human and animal origin are limited. In this study, 447 commensal E. coli isolates from the faeces of humans and swine (280 human isolates from four hospitals and 167 swine isolates from seven farms) were collected between September 2006 and January 2009 in western China. For extended-spectrum b-lactamase (ESBL)-producing and other cephalosporin-resistant isolates, the relevant b-lactamase genes (bla TEM , bla SHV , bla CTX-M-1/2/9 group, bla CMY-2 and bla KPC ) were detected by PCR analysis. Of the 447 isolates tested, 120 (26.8 %) were confirmed as producing ESBL. Among these, 70 and 40 human isolates carried a member of the bla CTX-M-1 group (13 bla CTX-M-3 , 21 bla CTX-M-15 , four bla CTX-M-22 , eight bla CTX-M-28 , four bla CTX-M-36 , 15 bla CTX-M-55 and five bla CTX-M-69 ) or bla SHV (14 bla SHV-2 , seven bla SHV-5 , ten bla SHV-12 , five bla SHV-57 and four bla SHV-97 ), respectively, whilst six and four swine isolates carried a member of the bla CTX-M-1 group (one bla CTX-M-15 and five bla CTX-M-22 ) or bla SHV (three bla SHV-2 and one bla SHV-12 ), respectively. Furthermore, 59 human and swine isolates and seven human isolates carried bla CMY-2 and bla KPC , respectively. These findings indicate that the bla CTX-M-1 group, including the novel variant bla CTX-M-69 , and bla SHV are the predominant ESBL genes in both humans and swine in western China, and bla CMY-2 is also common in both groups. The carriage rates of broad-spectrum b-lactamases among commensal E. coli was much lower in swine than in humans, suggesting that b-lactamase genes have not established themselves in animal ecosystems in western China.

Prevalence and Molecular Characterization of Extended-Spectrum-β-Lactamase-Producing Enterobacteriaceae in a Pediatric Patient Population

“…In the present study, CTX-M-15, CTX-M-14, and CTX-M-27 enzymes were identified, further highlighting the diversity of the CTX-M groups in pediatric populations. CTX-M-27 enzymes have been reported from farm animals in Asia but are rarely observed in human beings (4,35,36,38). While a diverse mix of CTX-M enzymes was detected in our study, the majority of isolates produced CTX-M-15; thus, the globally prevalent CTX-M-15 enzyme may represent an increasing threat to pediatric populations in the United States as well.…”

High Diversity of CTX-M Extended-Spectrum β-Lactamases in Municipal Wastewater and Urban Wetlands

“…1 and Supplementary Table S2. Most reports of these alleles have come from Asia, 24,52,58,65,66 with a few isolated accounts from Africa, 23 Europe, 8,34 Australia, 67 South America, 17 Russia, 45 and Canada. 1 Thus, it would appear that this study represents the first report of many CTX-M group 1 alleles in the United States.…”

A Review of SHV Extended-Spectrum β-Lactamases: Neglected Yet Ubiquitous

“…A few variants seem to be geographically constrained: (i) bla SHV-106 , only described in Portuguese isolates of K. pneumoniae together with bla TEM-1 , and/or bla CTX- M -32 (Mendonça et al, 2009); (ii) bla SHV-55 , in Portugal (Mendonça et al, 2006; Machado et al, 2007) and recently in Brazil (Dropa et al, 2015); and (iii) bla SHV-57 , in E. coli isolates from Taiwan and China (Ma et al, 2005; Tian et al, 2012). A variant worth to mention is bla SHV-27 (Corkill et al, 2001), that has been detected on different plasmids in E. coli, K. pneumoniae and Enterobacter cloacae , associated with a vast array of antibiotic resistance genes ( bla DHA−1 , bla TEM-1 , bla TEM−1b , bla CMY-2 , bla IMP , bla CTX- M -14 , bla CTX- M -15 , bla SHV-12 , bla SHV-45 , bla OXA-1 , dfrA5, ereA2 ; Muratani et al, 2006; Abbassi et al, 2008; Kiratisin et al, 2008; Duval et al, 2009; Hammami et al, 2011).…”