scholarly journals Susceptibility to Alternative Oral Antimicrobial Agents in Relation to Sequence Type ST131 Status and Coresistance Phenotype among Recent Escherichia coli Isolates from U.S. Veterans

2013 ◽  
Vol 57 (10) ◽  
pp. 4856-4860 ◽  
Author(s):  
James R. Johnson ◽  
Sarah M. Drawz ◽  
Stephen Porter ◽  
Michael A. Kuskowski

ABSTRACTThe rising prevalence of resistance to first-line antimicrobial agents inEscherichia coli, which has paralleled the emergence ofE. colisequence type ST131, has created a need for alternative oral options for use in treating outpatients with infections such as cystitis and chronic prostatitis. Accordingly, we determined susceptibility to six alternative oral agents (azithromycin, chloramphenicol, doxycycline, fosfomycin, minocycline, and rifampin) by Etest or disk diffusion for 120 recently obtainedE. coliclinical isolates from Veterans Affairs Medical Centers across the United States. Isolates were randomly selected in three subgroups of 40 isolates each based on coresistance to fluoroquinolones with and without extended-spectrum cephalosporins (ESCs). Results were stratified according to trimethoprim-sulfamethoxazole (TMP-SMZ) phenotype. Overall, the prevalence of susceptible (or susceptible plus intermediate) isolates varied by agent, with rifampin being lowest (0%), fosfomycin highest (98 to 99%), and others in the mid-range (37 to 88%). Substantial proportions of isolates (15 to 27%) yielded intermediate results for azithromycin, chloramphenicol, doxycycline, and minocycline. Among isolates resistant (versus susceptible) to fluoroquinolones with or without ESCs, susceptibility to the above four agents declined significantly among non-ST131 isolates but not ST131 isolates. In contrast, in the presence of resistance to TMP-SMZ, susceptibility to azithromycin, doxycycline, and minocycline was significantly reduced among both ST131 and non-ST131 isolates. These findings identify potential alternative oral agents for use withE. coliisolates resistant to fluoroquinolones, ESCs, and/or TMP-SMZ and suggest that determination of ST131 status could help guide initial antimicrobial selection, pending susceptibility results.

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.


2015 ◽  
Vol 60 (3) ◽  
pp. 1888-1891 ◽  
Author(s):  
James R. Johnson ◽  
Stephen B. Porter ◽  
Brian D. Johnston ◽  
Paul Thuras

Eravacycline is a novel broad-spectrum fluorocycline with potent Gram-negative activity, including for multidrug-resistant strains. Among 472Escherichia coliclinical isolates from 24 Veterans Affairs medical centers (in 2011), divided equally as susceptible versus resistant to fluoroquinolones, broth microdilution eravacycline MICs were distributed unimodally, ranging from 0.03 to 1.0 μg/ml (MIC50of 0.125 μg/ml, MIC90of 0.25 μg/ml). Eravacycline MICs were ∼2-fold higher among fluoroquinolone-resistant, gentamicin-resistant, multidrug-resistant, and sequence type 131 (ST131) isolates (P< 0.01 for each comparison).


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.


2019 ◽  
Vol 57 (5) ◽  
Author(s):  
James R. Johnson ◽  
Brian D. Johnston ◽  
Stephen B. Porter ◽  
Connie Clabots ◽  
Tricia L. Bender ◽  
...  

ABSTRACT Escherichia coli sequence type 1193 (ST1193) is an emerging multidrug-resistant pathogen. We performed longitudinal and cross-sectional surveillance for ST1193 among clinical and fecal E. coli isolates from Minneapolis Veterans Affairs Medical Center (VAMC) patients and their household members, other Minnesota centers, and national VAMCs and compared these ST1193 isolates with archival human and canine ST1193 isolates from Australia (2008). We also developed and extensively validated a novel multiplex PCR assay for ST1193 and its characteristic fimH64 (type 1 fimbrial adhesin) allele. We found that ST1193-H64 (where “H64” refers to a phylogenetic subdivision within ST1193 that is characterized by the fimH64 allele), which was uniformly fluoroquinolone resistant, appeared to emerge in the United States in a geographically staggered fashion beginning around 2011. Its prevalence among clinical and fecal E. coli isolates at the Minneapolis VAMC rose rapidly beginning in 2013, peaked in early 2017, and then plateaued or declined. In comparison with other ST14 complex (STc14) isolates, ST1193-H64 isolates were more extensively multidrug resistant, whereas their virulence genotypes were less extensive but included (uniquely) K1 capsule and fimH64. Pulsed-field gel electrophoresis separated ST1193-H64 isolates from other STc14 isolates and showed genetic commonality between archival Australian versus recent U.S. isolates, fecal versus clinical isolates, and human versus canine isolates. Three main ST1193 pulsotypes differed significantly in resistance profiles and capsular types; emergent pulsotype 2123 was associated with trimethoprim-sulfamethoxazole resistance and K1 (versus K5) capsule. These findings clarify ST1193-H64’s temporal prevalence trends as a fluoroquinolone-resistant pathogen and commensal; document clonal subsets with distinctive geographic, temporal, resistance, and virulence gene associations; and establish a new laboratory tool for rapid and simple detection of ST1193-H64.


2019 ◽  
Vol 58 (1) ◽  
Author(s):  
Noble Selasi Gati ◽  
Barbara Middendorf-Bauchart ◽  
Stefan Bletz ◽  
Ulrich Dobrindt ◽  
Alexander Mellmann

ABSTRACT Hybrid Shiga toxin-producing Escherichia coli (STEC) and uropathogenic E. coli (UPEC) strains of multilocus sequence type 141 (ST141) cause both urinary tract infections and diarrhea in humans and are phylogenetically positioned between STEC and UPEC strains. We used comparative genomic analysis of 85 temporally and spatially diverse ST141 E. coli strains, including 14 STEC/UPEC hybrids, collected in Germany (n = 13) and the United States (n = 1) to reconstruct their molecular evolution. Whole-genome sequencing data showed that 89% of the ST141 E. coli strains either were STEC/UPEC hybrids or contained a mixture of virulence genes from other pathotypes. Core genome analysis and ancestral reconstruction revealed that the ST141 E. coli strains clustered into two lineages that evolved from a common ancestor in the mid-19th century. The STEC/UPEC hybrid emerged ∼100 years ago by acquiring an stx prophage, which integrated into previously unknown insertion site between rcsB and rcsD, followed by the insertion of a pathogenicity island (PAI) similar to PAI II of UPEC strain 536 (PAI II536-like). The two variants of PAI II536-like were associated with tRNA genes leuX and pheU, respectively. Finally, microevolution within PAI II536-like and acquisition of the enterohemorrhagic E. coli plasmid were observed. Our data suggest that intestinal pathogenic E. coli (IPEC)/extraintestinal pathogenic E. coli (ExPEC) hybrids are widespread and that selection pressure within the ST141 E. coli population led to the emergence of the STEC/UPEC hybrid as a clinically important subgroup. We hypothesize that ST141 E. coli strains serve as a melting pot for pathogroup conversion between IPEC and ExPEC, contrasting the classical theory of pathogen emergence from nonpathogens and corroborating our recent phenomenon of heteropathogenicity among pathogenic E. coli strains.


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.


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.


2014 ◽  
Vol 58 (9) ◽  
pp. 4997-5004 ◽  
Author(s):  
Ritu Banerjee ◽  
James R. Johnson

ABSTRACTEscherichia colisequence type 131 (ST131) is an extensively antimicrobial-resistantE. coliclonal group that has spread explosively throughout the world. Recent molecular epidemiologic and whole-genome phylogenetic studies have elucidated the fine clonal structure of ST131, which comprises multiple ST131 subclones with distinctive resistance profiles, including the (nested) H30, H30-R, and H30-Rx subclones. The most prevalent ST131 subclone, H30, arose from a single common fluoroquinolone (FQ)-susceptible ancestor containing allele 30 offimH(type 1 fimbrial adhesin gene). An early H30 subclone member acquired FQ resistance and launched the rapid expansion of the resulting FQ-resistant subclone, H30-R. Subsequently, a member of H30-R acquired the CTX-M-15 extended-spectrum beta-lactamase and launched the rapid expansion of the CTX-M-15-containing subclone within H30-R, H30-Rx. Clonal expansion clearly is now the dominant mechanism for the rising prevalence of both FQ resistance and CTX-M-15 production in ST131 and inE. coligenerally. Reasons for the successful dissemination and expansion of the key ST131 subclones remain undefined but may include increased transmissibility, greater ability to colonize and/or persist in the intestine or urinary tract, enhanced virulence, and more-extensive antimicrobial resistance compared to otherE. coli. Here we discuss the epidemiology and molecular phylogeny of ST131 and its key subclones, possible mechanisms for their ecological success, implications of their widespread dissemination, and future research needs.


2014 ◽  
Vol 58 (12) ◽  
pp. 7240-7249 ◽  
Author(s):  
Arif Hussain ◽  
Amit Ranjan ◽  
Nishant Nandanwar ◽  
Anshu Babbar ◽  
Savita Jadhav ◽  
...  

ABSTRACTIn view of the epidemiological success of CTX-M-15-producing lineages ofEscherichia coliand particularly of sequence type 131 (ST131), it is of significant interest to explore its prevalence in countries such as India and to determine if antibiotic resistance, virulence, metabolic potential, and/or the genetic architecture of the ST131 isolates differ from those of non-ST131 isolates. A collection of 126E. coliisolates comprising 43 ST131E. coli, 40 non-ST131E. coli, and 43 fecalE. coliisolates collected from a tertiary care hospital in India was analyzed. These isolates were subjected to enterobacterial repetitive intergenic consensus (ERIC)-based fingerprinting, O typing, phylogenetic grouping, antibiotic sensitivity testing, and virulence and antimicrobial resistance gene (VAG) detection. Representative isolates from this collection were also analyzed by multilocus sequence typing (MLST), conjugation, metabolic profiling, biofilm production assay, and zebra fish lethality assay. All of the 43 ST131E. coliisolates were exclusively associated with phylogenetic group B2 (100%), while most of the clinical non-ST131 and stool non-ST131E. coliisolates were affiliated with the B2 (38%) and A (58%) phylogenetic groups, respectively. Significantly greater proportions of ST131 isolates (58%) than non-ST131 isolates (clinical and stoolE. coliisolates, 5% each) were technically identified to be extraintestinal pathogenicE. coli(ExPEC). The clinical ST131, clinical non-ST131, and stool non-ST131E. coliisolates exhibited high rates of multidrug resistance (95%, 91%, and 91%, respectively), extended-spectrum-β-lactamase (ESBL) production (86%, 83%, and 91%, respectively), and metallo-β-lactamase (MBL) production (28%, 33%, and 0%, respectively). CTX-M-15 was strongly linked with ESBL production in ST131 isolates (93%), whereas CTX-M-15 plus TEM were present in clinical and stool non-ST131E. coliisolates. Using MLST, we confirmed the presence of two NDM-1-positive ST131E. coliisolates. The aggregate bioscores (metabolite utilization) for ST131, clinical non-ST131, and stool non-ST131E. coliisolates were 53%, 52%, and 49%, respectively. The ST131 isolates were moderate biofilm producers and were more highly virulent in zebra fish than non-ST131 isolates. According to ERIC-based fingerprinting, the ST131 strains were more genetically similar, and this was subsequently followed by the genetic similarity of clinical non-ST131 and stool non-ST131E. colistrains. In conclusion, our data provide novel insights into aspects of the fitness advantage ofE. colilineage ST131 and suggest that a number of factors are likely involved in the worldwide dissemination of and infections due to ST131E. coliisolates.


2019 ◽  
Vol 63 (11) ◽  
Author(s):  
Oumar Ouchar Mahamat ◽  
Manon Lounnas ◽  
Mallorie Hide ◽  
Abelsalam Tidjani ◽  
Julio Benavides ◽  
...  

ABSTRACT We detected for the first time blaNDM-5 and blaOXA-181 in Escherichia coli isolates from hospitalized patients and healthy volunteers in Chad. These resistance genes were located on IncX3 and IncF plasmids. Despite the large diversity of E. coli clones, the identified resistant intestinal isolates belonged mainly to the same sequence type.


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