Predominance of pHK01-like incompatibility group FII plasmids encoding CTX-M-14 among extended-spectrum beta-lactamase–producing Escherichia coli in Hong Kong, 1996–2008

doi:10.1016/j.diagmicrobio.2012.03.009

Diagnostic Microbiology and Infectious Disease

Volume 73, Issue 2, June 2012, Pages 182-186

https://doi.org/10.1016/j.diagmicrobio.2012.03.009 Get rights and content

Abstract

This study assessed the temporal changes in the molecular epidemiology of bacteremic Escherichia coli isolates producing CTX-M-14 in Hong Kong. Blood isolates from 1996 to 1998 (period 1, n = 50) and 2007 to 2008 (period 2, n = 117) were investigated by molecular methods. CTX-M–type ESBL was carried by 98.2% (164/167) of the isolates. In both periods, the CTX-M-9 group and CTX-M-14 allele were the predominant ESBL type. The major clones were found to change from ST68 and ST405 in period 1 to ST131, ST69, and ST12 in period 2. Among 65 CTX-M-14–producing plasmids investigated further, 54 had the FII replicon. Replicon sequence typing and plasmid polymerase chain reaction–restriction fragment length polymorphism showed that 79.6% (43/54) of the FII plasmid subset was similar to the completely sequenced plasmid, pHK01 (human urine, Hong Kong, 2004). These pHK01-like plasmids were found to have spread to the major clones (ST68, ST405, and ST131) and multiple singleton isolates of all 4 phylogenetic groups.

Introduction

In Asia, the burdens of cefotaximase (CTX-M)-producing Enterobacteriaceae have increased dramatically in the last decade (Hawkey, 2008, Ho et al., 2005, Ho et al., 2007). Studies from Hong Kong, mainland China, South Korea, and Thailand have consistently showed that CTX-M-14 is the most prevalent enzyme (Ho et al., 2007, Lo et al., 2010, Nguyen et al., 2010, Yi et al., 2010). This CTX-M allele was first described in 2001 among Escherichia coli, Klebsiella pneumoniae, and Shigella isolates collected from different parts of South Korea in 1995 (Pai et al., 2001). While clonal spread has been reported in Japan and Canada (Pitout et al., 2005, Suzuki et al., 2009), the spread of CTX-M-14 has been found to be mainly caused by conjugative plasmids (Cottell et al., 2011, Ho et al., 2011c, Valverde et al., 2009). In Spain, the spread of CTX-M-14 from 2000 to 2005 was largely due to pRYC105-like plasmids of the IncK incompatibility group disseminated among diverse E. coli lineages (Valverde et al., 2009). Recently, it has been shown that pRYC105 is similar to the pCT plasmid that has been found in bacteria from the United Kingdom, mainland China, and Australia (Cottell et al., 2011). Recently, we sequenced the IncFII epidemic plasmid, pHK01, and showed that it has disseminated widely among E. coli isolates collected from patients with community-acquired urinary tract infections in 2004 (Ho et al., 2007, Ho et al., 2011c).Variants closely related to pHK01 have been identified among Enterobacteriaceae isolates from mainland China and Vietnam (Ho et al., 2011c, Nguyen et al., 2010, Yi et al., 2010).

In this study, we investigated the clonal structure and relatedness of plasmids encoding CTX-M-14 for a collection of blood culture E. coli isolates from patients treated in a healthcare region from 1996 to 2008.

Section snippets

Bacterial strains and susceptibility testing

The E. coli isolates were recovered from blood cultures of patients who were treated in a healthcare region in Hong Kong (Ho et al., 2002, Ho et al., 2005). The healthcare region (QMH) includes a network of 5 public hospitals, including 1 acute care university teaching hospital with 1500 beds and all the clinical disciplines including renal, liver, and bone marrow transplantation service, and 4 convalescence care hospitals with 110 to 524 beds. (Ho et al., 2005). This study included isolates

Antimicrobial susceptibilities and ESBL types

The isolates often exhibit co-resistance to the non–β-lactam antibiotics. The overall resistance rates for isolates from period 1 (n = 50) and period 2 (n = 117) were as follows: cotrimoxazole, 84% and 54.7%; ciprofloxacin, 78% and 59.8%; and gentamicin, 78% and 48.7%. Most isolates were susceptible to amikacin (98% and 97.4%) and piperacillin–tazobactam (84% and 97.4%). All isolates were susceptible to imipenem at the traditional breakpoint (inhibition zone diameter ≥16 mm, equivalent to MIC

Discussion

This study demonstrated the dissemination of pHK01-like plasmids encoding CTX-M-14 among hospital E. coli isolates of diverse genetic lineages and their persistence in our locality from more than a decade ago. These pHK01-like plasmids were widespread among the collection of community CTX-M-14–producing E. coli strains reported by us earlier (Ho et al., 2007, Ho et al., 2011c).The finding confirms the suspicion that the same epidemic plasmid was involved in the dissemination of CTX-M-14 among

References (33)

A. Carattoli et al.
Identification of plasmids by PCR-based replicon typing
J Microbiol Methods
(2005)
O. Clermont et al.
Determination of Escherichia coli O types by allele-specific polymerase chain reaction: application to the O types involved in human septicemia
Diagn Microbiol Infect Dis
(2007)
P.M. Hawkey
Prevalence and clonality of extended-spectrum beta-lactamases in Asia
Clin Microbiol Infect
(2008)
P.L. Ho et al.
Effect of applying the new Clinical and Laboratory Standards Institute ceftazidime and ceftriaxone susceptibility breakpoints for Escherichia coli in Hong Kong
Int J Antimicrob Agents
(2011)
W.U. Lo et al.
Fecal carriage of CTXM type extended-spectrum beta-lactamase-producing organisms by children and their household contacts
J Infect
(2010)
M. Saladin et al.
Diversity of CTX-M beta-lactamases and their promoter regions from Enterobacteriaceae isolated in three Parisian hospitals
FEMS Microbiol Lett
(2002)
J. Shin et al.
Comparison of CTX-M-14- and CTX-M-15-producing Escherichia coli and Klebsiella pneumoniae isolates from patients with bacteremia
J Infect
(2011)
J. Blanco et al.
National survey of Escherichia coli causing extraintestinal infections reveals the spread of drug-resistant clonal groups O25b:H4-B2-ST131, O15:H1-D-ST393 and CGA-D-ST69 with high virulence gene content in Spain
J Antimicrob Chemother
(2011)
O. Clermont et al.
Rapid detection of the O25b-ST131 clone of Escherichia coli encompassing the CTX-M-15-producing strains
J Antimicrob Chemother
(2009)
Clinical and Laboratory Standard Institute
Performance standards for antimicrobial susceptibility testing: twentieth informational supplement M100-S21. 1-1-2011
(2011)

J.L. Cottell et al.

Complete sequence and molecular epidemiology of IncK epidemic plasmid encoding blaCTX-M-14

Emerg Infect Dis

(2011)

C. Deschamps et al.

Multiple acquisitions of CTX-M plasmids in the rare D2 genotype of Escherichia coli provide evidence for convergent evolution

Microbiology

(2009)

S. Ferjani et al.

Virulence determinants, phylogenetic groups and fluoroquinolone resistance in Escherichia coli isolated from cystitis and pyelonephritis

Pathol Biol (Paris)

(2011)

P.L. Ho et al.

Bacteremia caused by Escherichia coli producing extended-spectrum beta-lactamase: a case-control study of risk factors and outcomes

Scand J Infect Dis

(2002)

P.L. Ho et al.

Extended-spectrum-beta-lactamase-positive Escherichia coli mainly adds to, rather than replaces, extended-spectrum-beta-lactamase-negative E. coli in causing bacteraemia in Hong Kong, 2000-10

J Antimicrob Chemother

(2011)

P.L. Ho et al.

Complete sequencing of the FII plasmid pHK01, encoding CTX-M-14, and molecular analysis of its variants among Escherichia coli from Hong Kong

J Antimicrob Chemother

(2011)

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The increasing incidence of nosocomial infections with extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli represents a significant threat to public health, given the limited treatment options available for such infections. The rapid ESBL spread is suggested to be driven by localization of the resistance genes on conjugative plasmids.
The prevalence of extended-spectrum beta-lactamases (ESBLs) among clinical isolates of Escherichia coli has been increasing, with this spread driven by ESBL-encoding plasmids. However, the epidemiology of ESBL-disseminating plasmids remains understudied, obscuring the roles of individual plasmid lineages in ESBL spread. To address this, we performed an in-depth genomic investigation of 149 clinical ESBL-like E. coli isolates from a tertiary care hospital. We obtained high-quality assemblies for 446 plasmids, revealing an extensive map of plasmid sharing that crosses time, space, and bacterial sequence type boundaries. Through a sequence-based network, we identified specific plasmid lineages that are responsible for the dissemination of major ESBLs. Notably, we demonstrate that IncF plasmids separate into 2 distinct lineages that are enriched for different ESBLs and occupy distinct host ranges. Our work provides a detailed picture of plasmid-mediated spread of ESBLs, demonstrating the extensive sequence diversity within identified lineages, while highlighting the genetic elements that underlie the persistence of these plasmids within the clinical E. coli population.
IMPORTANCE The increasing incidence of nosocomial infections with extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli represents a significant threat to public health, given the limited treatment options available for such infections. The rapid ESBL spread is suggested to be driven by localization of the resistance genes on conjugative plasmids. Here, we identify the contributions of different plasmid lineages in the nosocomial spread of ESBLs. We provide further support for plasmid-mediated spread of ESBLs but demonstrate that some ESBL genes rely on dissemination through plasmids more than the others. We identify key plasmid lineages that are enriched in major ESBL genes and highlight the encoded genetic elements that facilitate the transmission and stable maintenance of these plasmid groups within the clinical E. coli population. Overall, our work provides valuable insight into the dissemination of ESBLs through plasmids, furthering our understating of factors underlying the increased prevalence of these genes in nosocomial settings.
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In addition, the IncHI2 plasmid with blaCTX-M-14 was very stable in the dominant E. coli ST6802 in the effluent samples. The conjugative frequencies of blaCTX-M-14-positive plasmids vary among studies (10−1–10−6) (Ho et al., 2012a; Ho et al., 2012b; Hounmanou et al., 2021), which may be associated with different experimental conditions rather than plasmid transfer potential. Moreover, the proliferation of E. coli ST6802 also benefited blaCTX-M-14.
Livestock waste is a known reservoir of Escherichia coli (E. coli) carrying clinically important CTX-M-type extended-spectrum β-lactamase genes (bla_CTX-M), however, the occurrence and transfer characteristics of bla_CTX-M genes during anaerobic digestion (AD) remain unclear. Herein, four full-scale and two parallel lab-scale AD systems treating swine waste under ambient and mesophilic conditions were investigated by both molecular- and culture-based methods to reveal the occurrence and transfer behaviors of bla_CTX-M genes during AD. Real-time TaqMan polymerase chain reaction revealed 1.3 × 10⁴–6.8 × 10⁵ and 3.0 × 10⁴–7.0 × 10⁵ copies/mL of bla_CTX-M groups 1 and 9 in all feeding substrates. While AD reduced the absolute abundance of groups 1 and 9 by 0.63–2.24 and 0.08–1.30 log (P < 0.05), 5.0 × 10²–4.1 × 10³ and 1.1 × 10⁴–3.5 × 10⁴ copies/mL of groups 1 and 9 remained in the anaerobic effluent, respectively. In total, 141 bla_CTX-M-carrying E. coli isolates resistant to cefotaxime were obtained from the AD reactors. Whole-genome sequencing showed that bla_CTX-M-65 mainly carried by E. coli ST155 was the most frequently detected group 9 subtype in the feeding substrate; whereas bla_CTX-M-14 associated with the dominant clones E. coli ST6802 and ST155 became the major subtype in AD effluent. Furthermore, bla_CTX-M-14 was flanked by ΔIS26 upstream and ΔIS903B downstream. The ΔIS26-bla_CTX-M-14-ΔIS903B element was mainly located on the IncHI2 plasmid in E. coli ST48 and ST6802 and also the IncFIB plasmid in ST155 in anaerobic effluent. Conjugation assays showed that the plasmids harboring bla_CTX-M-14 could be successfully transferred at a frequency of 10⁻³–10⁻² cells per recipient cell. This study revealed that bla_CTX-M genes remained in both the full-scale and lab-scale AD effluents of swine waste. Thus, additional efforts should be implemented to block the discharge and spread of antibiotic resistance genes to the environment.
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These plasmid matches come from different E. coli STs, indicating plasmid movement between strains. For example, pERB4a2 was isolated from an E. coli ST2732 strain, whereas the BLASTn match pHK01 has been found in many different STs [12]. Similarly, pERB12a3 (from an ST43 strain) matches to pEK204 (ST131 strain) [14].
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Thirty-five percent of CTX-M-EC isolates tested transferred the bla_CTX-M plasmid by conjugation. Travel-acquired CTX-M-EC carried bla_CTX-M on a plasmid in 62% of isolates, whereas 38% of isolates had bla_CTX-M on the chromosome. CTX-M-EC plasmids acquired after travel to South Asia had close homology to previously described epidemic plasmids which are widely disseminated in humans, animals and the natural environment.
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Although there are increasing reports of blaCTX-M-14 linked with ISCR1 elements (Bae et al., 2007), downstream association with ISEcp1 remains blaCTX-M-14’s prevailing genetic context. Additionally, blaCTX-M-14 is found upon a diverse range of conjugative plasmid types, including IncA/C, IncHI2, IncI, but favouring IncF and IncK in Asian and Iberian regions, respectively (Wang et al., 2012; Ho et al., 2012; Valverde et al., 2009). CTX-M-positive infections are striking in their high rates of community incidence when compared to that of nosocomial settings (Pitout et al., 2005a,b).
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Two primer pairs were designed for the detection of hybrid blaCTX-M by monoplex PCR assays: CTXM-1F and CTXM9-506B for blaCTX-M-64/123/132–like hybrid genes and CTXM9-F and CTXM1-600B for blaCTX-M-137–like hybrid genes (Supplementary file, Table S1). The CTX-M allele was determined by sequencing the full length of the blaCTX-M gene using different combination of primers (Ho et al., 2012a, 2012b). Previously described primers were used to investigate for the presence of the plasmid-mediated fosfomycin resistance genes (fosA, fosA3, fosA4, and fosC2) (Ho et al., 2013a).
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^☆: Funding: This work was supported by grants from the Research Fund for the Control of Infectious Diseases (RFCID) of the Health, Welfare and Food Bureau of the Government of the HKSAR and from the Consultancy Service for Enhancing Laboratory Surveillance of Emerging Infectious Disease for the HKSAR Department of Health.

^☆☆: Conflict of interest: None for all authors.

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Antimicrobial SurveillancePredominance of pHK01-like incompatibility group FII plasmids encoding CTX-M-14 among extended-spectrum beta-lactamase–producing Escherichia coli in Hong Kong, 1996–2008☆,☆☆

Abstract

Introduction

Section snippets

Bacterial strains and susceptibility testing

Antimicrobial susceptibilities and ESBL types

Discussion

J Microbiol Methods

Diagn Microbiol Infect Dis

Clin Microbiol Infect

Int J Antimicrob Agents

J Infect

FEMS Microbiol Lett

J Infect

National survey of Escherichia coli causing extraintestinal infections reveals the spread of drug-resistant clonal groups O25b:H4-B2-ST131, O15:H1-D-ST393 and CGA-D-ST69 with high virulence gene content in Spain

J Antimicrob Chemother

Rapid detection of the O25b-ST131 clone of Escherichia coli encompassing the CTX-M-15-producing strains

J Antimicrob Chemother

Performance standards for antimicrobial susceptibility testing: twentieth informational supplement M100-S21. 1-1-2011

Complete sequence and molecular epidemiology of IncK epidemic plasmid encoding blaCTX-M-14

Emerg Infect Dis

Multiple acquisitions of CTX-M plasmids in the rare D2 genotype of Escherichia coli provide evidence for convergent evolution

Microbiology

Virulence determinants, phylogenetic groups and fluoroquinolone resistance in Escherichia coli isolated from cystitis and pyelonephritis

Pathol Biol (Paris)

Bacteremia caused by Escherichia coli producing extended-spectrum beta-lactamase: a case-control study of risk factors and outcomes

Scand J Infect Dis

Extended-spectrum-beta-lactamase-positive Escherichia coli mainly adds to, rather than replaces, extended-spectrum-beta-lactamase-negative E. coli in causing bacteraemia in Hong Kong, 2000-10

J Antimicrob Chemother

Complete sequencing of the FII plasmid pHK01, encoding CTX-M-14, and molecular analysis of its variants among Escherichia coli from Hong Kong

J Antimicrob Chemother

Antimicrobial Surveillance
Predominance of pHK01-like incompatibility group FII plasmids encoding CTX-M-14 among extended-spectrum beta-lactamase–producing Escherichia coli in Hong Kong, 1996–2008☆,☆☆