scholarly journals Molecular Epidemiological Analysis of Escherichia coli Sequence Type ST131 (O25:H4) andblaCTX-M-15among Extended-Spectrum-β-Lactamase-Producing E. coli from the United States, 2000 to 2009

2012 ◽  
Vol 56 (5) ◽  
pp. 2364-2370 ◽  
Author(s):  
James R. Johnson ◽  
Carl Urban ◽  
Scott J. Weissman ◽  
James H. Jorgensen ◽  
James S. Lewis ◽  
...  

ABSTRACTEscherichia colisequence type ST131 (from phylogenetic group B2), often carrying the extended-spectrum-β-lactamase (ESBL) geneblaCTX-M-15, is an emerging globally disseminated pathogen that has received comparatively little attention in the United States. Accordingly, a convenience sample of 351 ESBL-producingE. coliisolates from 15 U.S. centers (collected in 2000 to 2009) underwent PCR-based phylotyping and detection of ST131 andblaCTX-M-15. A total of 200 isolates, comprising 4 groups of 50 isolates each that were (i)blaCTX-M-15negative non-ST131, (ii)blaCTX-M-15positive non-ST131, (iii)blaCTX-M-15negative ST131, or (iv)blaCTX-M-15positive ST131, also underwent virulence genotyping, antimicrobial susceptibility testing, and pulsed-field gel electrophoresis (PFGE). Overall, 201 (57%) isolates exhibitedblaCTX-M-15, whereas 165 (47%) were ST131. ST131 accounted for 56% ofblaCTX-M-15-positive- versus 35% ofblaCTX-M-15-negative isolates (P< 0.001). Whereas ST131 accounted for 94% of the 175 total group B2 isolates, non-ST131 isolates were phylogenetically distributed byblaCTX-M-15status, with groups A (blaCTX-M-15-positive isolates) and D (blaCTX-M-15-negative isolates) predominating. BothblaCTX-M-15and ST131 occurred at all participating centers, were recovered from children and adults, increased significantly in prevalence post-2003, and were associated with molecularly inferred virulence. Compared with non-ST131 isolates, ST131 isolates had higher virulence scores, distinctive virulence profiles, and more-homogeneous PFGE profiles.blaCTX-M-15was associated with extensive antimicrobial resistance and ST131 with fluoroquinolone resistance. Thus,E. coliST131 andblaCTX-M-15are emergent, widely distributed, and predominant among ESBL-positiveE. colistrains in the United States, among children and adults alike. Enhanced virulence and antimicrobial resistance have likely promoted the epidemiological success of these emerging public health threats.

2017 ◽  
Vol 83 (6) ◽  
Author(s):  
James R. Johnson ◽  
Stephen B. Porter ◽  
Brian Johnston ◽  
Paul Thuras ◽  
Sarah Clock ◽  
...  

ABSTRACT Chicken meat products are hypothesized to be vehicles for transmitting antimicrobial-resistant and extraintestinal pathogenic Escherichia coli (ExPEC) to consumers. To reassess this hypothesis in the current era of heightened concerns about antimicrobial use in food animals, we analyzed 175 chicken-source E. coli isolates from a 2013 Consumer Reports national survey. Isolates were screened by PCR for ExPEC-defining virulence genes. The 25 ExPEC isolates (12% of 175) and a 2:1 randomly selected set of 50 non-ExPEC isolates were assessed for their phylogenetic/clonal backgrounds and virulence genotypes for comparison with their resistance profiles and the claims on the retail packaging label (“organic,” “no antibiotics,” and “natural”). Compared with the findings for non-ExPEC isolates, the group of ExPEC isolates had a higher prevalence of phylogroup B2 isolates (44% versus 4%; P < 0.001) and a lower prevalence of phylogroup A isolates (4% versus 30%; P = 0.001), a higher prevalence of multiple individual virulence genes, higher virulence scores (median, 11 [range, 4 to 16] versus 8 [range, 1 to 14]; P = 0.001), and higher resistance scores (median, 4 [range, 0 to 8] versus 3 [range, 0 to 10]; P < 0.001). All five isolates of sequence type 131 (ST131) were ExPEC (P = 0.003), were as extensively resistant as the other isolates tested, and had higher virulence scores than the other isolates tested (median, 12 [range, 11 to 13] versus 8 [range, 1 to 16]; P = 0.005). Organic labeling predicted lower resistance scores (median, 2 [range, 0 to 3] versus 4 [range, 0 to 10]; P = 0.008) but no difference in ExPEC status or virulence scores. These findings document a persisting reservoir of extensively antimicrobial-resistant ExPEC isolates, including isolates from ST131, in retail chicken products in the United States, suggesting a potential public health threat. IMPORTANCE We found that among Escherichia coli isolates from retail chicken meat products purchased across the United States in 2013 (many of these isolates being extensively antibiotic resistant), a minority had genetic profiles suggesting an ability to cause extraintestinal infections in humans, such as urinary tract infection, implying a risk of foodborne disease. Although isolates from products labeled “organic” were less extensively antibiotic resistant than other isolates, they did not appear to be less virulent. These findings suggest that retail chicken products in the United States, even if they are labeled “organic,” pose a potential health threat to consumers because they are contaminated with extensively antibiotic-resistant and, presumably, virulent E. coli isolates.


mSphere ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Shivdeep Singh Hayer ◽  
Seunghyun Lim ◽  
Samuel Hong ◽  
Ehud Elnekave ◽  
Timothy Johnson ◽  
...  

ABSTRACT Fluoroquinolones and cephalosporins are critically important antimicrobial classes for both human and veterinary medicine. We previously found a drastic increase in enrofloxacin resistance in clinical Escherichia coli isolates collected from diseased pigs from the United States over 10 years (2006 to 2016). However, the genetic determinants responsible for this increase have yet to be determined. The aim of the present study was to identify and characterize the genetic basis of resistance against fluoroquinolones (enrofloxacin) and extended-spectrum cephalosporins (ceftiofur) in swine E. coli isolates using whole-genome sequencing (WGS). blaCMY-2 (carried by IncA/C2, IncI1, and IncI2 plasmids), blaCTX-M (carried by IncF, IncHI2, and IncN plasmids), and blaSHV-12 (carried by IncHI2 plasmids) genes were present in 87 (82.1%), 19 (17.9%), and 3 (2.83%) of the 106 ceftiofur-resistant isolates, respectively. Of the 110 enrofloxacin-resistant isolates, 90 (81.8%) had chromosomal mutations in gyrA, gyrB, parA, and parC genes. Plasmid-mediated quinolone resistance genes [qnrB77, qnrB2, qnrS1, qnrS2, and aac-(6)-lb′-cr] borne on ColE, IncQ2, IncN, IncF, and IncHI2 plasmids were present in 24 (21.8%) of the enrofloxacin-resistant isolates. Virulent IncF plasmids present in swine E. coli isolates were highly similar to epidemic plasmids identified globally. High-risk E. coli clones, such as ST744, ST457, ST131, ST69, ST10, ST73, ST410, ST12, ST127, ST167, ST58, ST88, ST617, ST23, etc., were also found in the U.S. swine population. Additionally, the colistin resistance gene (mcr-9) was present in several isolates. This study adds valuable information regarding resistance to critical antimicrobials with implications for both animal and human health. IMPORTANCE Understanding the genetic mechanisms conferring resistance is critical to design informed control and preventive measures, particularly when involving critically important antimicrobial classes such as extended-spectrum cephalosporins and fluoroquinolones. The genetic determinants of extended-spectrum cephalosporin and fluoroquinolone resistance were highly diverse, with multiple plasmids, insertion sequences, and genes playing key roles in mediating resistance in swine Escherichia coli. Plasmids assembled in this study are known to be disseminated globally in both human and animal populations and environmental samples, and E. coli in pigs might be part of a global reservoir of key antimicrobial resistance (AMR) elements. Virulent plasmids found in this study have been shown to confer fitness advantages to pathogenic E. coli strains. The presence of international, high-risk zoonotic clones provides worrisome evidence that resistance in swine isolates may have indirect public health implications, and the swine population as a reservoir for these high-risk clones should be continuously monitored.


mBio ◽  
2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Nicole Stoesser ◽  
Anna E. Sheppard ◽  
Louise Pankhurst ◽  
Nicola De Maio ◽  
Catrin E. Moore ◽  
...  

ABSTRACT Escherichia coli sequence type 131 (ST131) has emerged globally as the most predominant extraintestinal pathogenic lineage within this clinically important species, and its association with fluoroquinolone and extended-spectrum cephalosporin resistance impacts significantly on treatment. The evolutionary histories of this lineage, and of important antimicrobial resistance elements within it, remain unclearly defined. This study of the largest worldwide collection ( n = 215) of sequenced ST131 E. coli isolates to date demonstrates that the clonal expansion of two previously recognized antimicrobial-resistant clades, C1/ H 30R and C2/ H 30Rx, started around 25 years ago, consistent with the widespread introduction of fluoroquinolones and extended-spectrum cephalosporins in clinical medicine. These two clades appear to have emerged in the United States, with the expansion of the C2/ H 30Rx clade driven by the acquisition of a bla CTX-M-15 -containing IncFII-like plasmid that has subsequently undergone extensive rearrangement. Several other evolutionary processes influencing the trajectory of this drug-resistant lineage are described, including sporadic acquisitions of CTX-M resistance plasmids and chromosomal integration of bla CTX-M within subclusters followed by vertical evolution. These processes are also occurring for another family of CTX-M gene variants more recently observed among ST131, the bla CTX-M-14/14-like group. The complexity of the evolutionary history of ST131 has important implications for antimicrobial resistance surveillance, epidemiological analysis, and control of emerging clinical lineages of E. coli . These data also highlight the global imperative to reduce specific antibiotic selection pressures and demonstrate the important and varied roles played by plasmids and other mobile genetic elements in the perpetuation of antimicrobial resistance within lineages. IMPORTANCE Escherichia coli , perennially a major bacterial pathogen, is becoming increasingly difficult to manage due to emerging resistance to all preferred antimicrobials. Resistance is concentrated within specific E. coli lineages, such as sequence type 131 (ST131). Clarification of the genetic basis for clonally associated resistance is key to devising intervention strategies. We used high-resolution genomic analysis of a large global collection of ST131 isolates to define the evolutionary history of extended-spectrum beta-lactamase production in ST131. We documented diverse contributory genetic processes, including stable chromosomal integrations of resistance genes, persistence and evolution of mobile resistance elements within sublineages, and sporadic acquisition of different resistance elements. Both global distribution and regional segregation were evident. The diversity of resistance element acquisition and propagation within ST131 indicates a need for control and surveillance strategies that target both bacterial strains and mobile genetic elements.


2011 ◽  
Vol 55 (12) ◽  
pp. 5666-5675 ◽  
Author(s):  
Bashar W. Shaheen ◽  
Rajesh Nayak ◽  
Steven L. Foley ◽  
Ohgew Kweon ◽  
Joanna Deck ◽  
...  

ABSTRACTResistance to extended-spectrum cephalosporins (ESC) among members of the familyEnterobacteriaceaeoccurs worldwide; however, little is known about ESC resistance inEscherichia colistrains from companion animals. Clinical isolates ofE. coliwere collected from veterinary diagnostic laboratories throughout the United States from 2008 to 2009.E. coliisolates (n= 54) with reduced susceptibility to ceftazidime or cefotaxime (MIC ≥ 16 μg/ml) and extended-spectrum-β-lactamase (ESBL) phenotypes were analyzed. PCR and sequencing were used to detect mutations in ESBL-encoding genes and the regulatory region of the chromosomal geneampC. Conjugation experiments and plasmid identification were conducted to examine the transferability of resistance to ESCs. All isolates carried theblaCTX-M-1-group β-lactamase genes in addition to one or more of the following β-lactamase genes:blaTEM,blaSHV-3,blaCMY-2,blaCTX-M-14-like, andblaOXA-1.DifferentblaTEMsequence variants were detected in some isolates (n= 40). Three isolates harbored ablaTEM-181gene with a novel mutation resulting in an Ala184Val substitution. Approximately 78% of the isolates had mutations in promoter/attenuator regions of the chromosomal geneampC, one of which was a novel insertion of adenine between bases −28 and −29. Plasmids ranging in size from 11 to 233 kbp were detected in the isolates, with a common plasmid size of 93 kbp identified in 60% of isolates. Plasmid-mediated transfer of β-lactamase genes increased the MICs (≥16-fold) of ESCs for transconjugants. Replicon typing among isolates revealed the predominance of IncI and IncFIA plasmids, followed by IncFIB plasmids. This study shows the emergence of conjugative plasmid-borne ESBLs amongE. colistrains from companion animals in the United States, which may compromise the effective therapeutic use of ESCs in veterinary medicine.


2015 ◽  
Vol 59 (6) ◽  
pp. 3606-3610 ◽  
Author(s):  
Sibylle H. Lob ◽  
Krystyna M. Kazmierczak ◽  
Robert E. Badal ◽  
Meredith A. Hackel ◽  
Samuel K. Bouchillon ◽  
...  

ABSTRACTAntimicrobial resistance inEnterobacteriaceae, including resistance to carbapenems, is increasing worldwide. However, using U.S. Study for Monitoring Antimicrobial Resistance Trends (SMART) data for 2009 to 2013, no statistically significant decreasing susceptibility trends were found overall forEscherichia coliisolates from patients with intra-abdominal infections. In the subset of isolates from community-associated infections, susceptibility to levofloxacin decreased significantly and the increasing rate of multidrug-resistantE. coliapproached statistical significance. In 2013, ertapenem, imipenem, and amikacin showed the highest susceptibility rates (≥99%) and fluoroquinolones the lowest (<70%). The 10 non-ertapenem-susceptible isolates (0.3% of allE. coliisolates) encoded one or more carbapenemases, extended-spectrum β-lactamases (ESBLs), AmpC β-lactamases, or non-ESBL β-lactamases.


2017 ◽  
Vol 61 (8) ◽  
Author(s):  
James R. Johnson ◽  
Stephen Porter ◽  
Paul Thuras ◽  
Mariana Castanheira

ABSTRACT The H30 subclone of Escherichia coli sequence type 131 (ST131-H30) has become the leading antimicrobial resistance E. coli lineage in the United States and often exhibits resistance to one or both of the two key antimicrobial classes for treating Gram-negative infections, extended-spectrum cephalosporins (ESCs) and fluoroquinolones (FQs). However, the timing of and reasons for its recent emergence are inadequately defined. Accordingly, from E. coli clinical isolates collected systematically across the United States by the SENTRY Antimicrobial Surveillance Program in 2000, 2003, 2006, and 2009, 234 isolates were selected randomly, stratified by year, within three resistance categories: (i) ESC-reduced susceptibility, regardless of FQ phenotype (ESC-RS); (ii) FQ resistance, ESC susceptible (FQ-R); and (iii) FQ susceptible, ESC susceptible (FQ-S). Susceptibility profiles, phylogroup, ST, ST131 subclone, and virulence genotypes were determined, and temporal trends and between-variable associations were assessed statistically. From 2000 to 2006, concurrently with the emergence of ESC-RS and FQ-R strains, the prevalence of (virulence-associated) phylogroup B2 among such strains also rose dramatically, due entirely to rapid emergence of ST131, especially H30. By 2009, H30 was the dominant E. coli lineage overall (22%), accounting for a median of 43% of all single-agent and multidrug resistance (68% for ciprofloxacin). H30's emergence increased the net virulence gene content of resistant (especially FQ-R) isolates, giving stable overall virulence gene scores despite an approximately 4-fold expansion of the historically less virulent resistant population. These findings define more precisely the timing and tempo of H30's emergence in the United States, identify possible reasons for it, and suggest potential consequences, including more frequent and/or aggressive antimicrobial-resistant infections.


2017 ◽  
Vol 4 (2) ◽  
Author(s):  
James R. Johnson ◽  
Stephen Porter ◽  
Paul Thuras ◽  
Mariana Castanheira

Abstract Background Extraintestinal Escherichia coli infections are increasingly challenging due to emerging antimicrobial resistance, including resistance to extended-spectrum beta-lactams and fluoroquinolones. Sequence type 131 (ST131) is a leading contributor. Methods Three hundred sixty E. coli clinical isolates from across the United States (2011–2012), selected randomly from the SENTRY collection within 3 resistance categories (extended-spectrum cephalosporin [ECS]–reduced susceptibility [RS]; fluoroquinolone-resistant, ESC-susceptible; and fluoroquinolone-susceptible, ESC-susceptible) were typed for phylogroup, sequence type complex (STc), subsets thereof, virulence genotype, O type, and beta-lactamase genes. Molecular results were compared with susceptibility profile, specimen type, age, and sex. Results Phylogroup B2 accounted for most isolates, especially fluoroquinolone-resistant isolates (83%). Group B2–derived ST131 and its H30 subclone (divided between H30Rx and H30R1) predominated, especially among ESC-RS and fluoroquinolone-resistant isolates. In contrast, among fluoroquinolone-susceptible isolates, group B2–derived STc73 and STc95 predominated. Within each resistance category, ST131 isolates exhibited more extensive resistance and/or virulence profiles than non-ST131 isolates. ST131-H30 was distributed broadly by geographical region, age, and specimen type and exhibited distinctive beta-lactamase genes. Back-calculations indicated that within the source population ST131 accounted for 26.4% of isolates overall (vs 17% in 2007), including 19.8% ST131-H30, 13.2% ST131-H30R1, and 6.6% each ST131-H30Rx and non-H30 ST131. Conclusions ST131-H30, with its ESC resistance-associated H30Rx subset, caused most antimicrobial-resistant E. coli infections across the United States in 2011–2012 and, since 2007, increased in relative prevalence by &gt;50%. Focused attention to this strain could help combat the current E. coli resistance epidemic.


2011 ◽  
Vol 55 (6) ◽  
pp. 2986-2988 ◽  
Author(s):  
Gisele Peirano ◽  
Paul C. Schreckenberger ◽  
Johann D. D. Pitout

ABSTRACTAn NDM-1 carbapenemase-producingEscherichia coliisolate of sequence type 131 (ST131) that belonged to phylogenetic group B2 was obtained from a patient with a urinary tract infection who returned to the United States after a recent hospitalization while visiting India. NDM-1-producingE. coliST131 had significantly more virulence factors than NDM-1-producingE. coliST101, previously isolated from a patient in Canada. The presence of NDM β-lactamases in a very successful and virulentE. colisequence type is of concern.


2014 ◽  
Vol 58 (11) ◽  
pp. 6953-6957 ◽  
Author(s):  
Fupin Hu ◽  
Jessica A. O'Hara ◽  
Jesabel I. Rivera ◽  
Yohei Doi

ABSTRACTWe characterized 30 community-associated extended-spectrum-β-lactamase-producingEscherichia coliisolates collected from five hospitals in the United States. Nineteen sequence types were identified. All sequence type 131 (ST131) isolates had thefimH30 allele. IncFII-FIA-FIB was the most common replicon type among theblaCTX-M-carrying plasmids, followed by IncFII-FIA and IncA/C. Restriction analysis of the IncFII-FIA-FIB and IncFII-FIA plasmids yielded related profiles for plasmids originating from different hospitals. The plasmids containingblaCTX-MorblaSHVwere stably maintained after serial passages.


2013 ◽  
Vol 57 (12) ◽  
pp. 6385-6388 ◽  
Author(s):  
Ritu Banerjee ◽  
Ari Robicsek ◽  
Michael A. Kuskowski ◽  
Stephen Porter ◽  
Brian D. Johnston ◽  
...  

ABSTRACTWe assessedEscherichia coliST131 and its H30 and H30-Rx subclones for virulence genes, antimicrobial resistance, and extended-spectrum beta-lactamase (ESBL) type. Although both subclones were associated with ESBL production, H30-Rx isolates had higher resistance scores and were associated specifically with CTX-M-15. Three virulence genes (iha,sat, andiutA) were more prevalent among H30 than non-H30 ST131 isolates. Thus, the H30 and H30-Rx subclones are more antimicrobial resistant and have virulence profiles that are distinct from those of non-H30 ST131 isolates.


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