scholarly journals Recent Emergence of Escherichia coli with Cephalosporin Resistance Conferred byblaCTX-Mon Washington State Dairy Farms

2015 ◽  
Vol 81 (13) ◽  
pp. 4403-4410 ◽  
Author(s):  
Margaret A. Davis ◽  
William M. Sischo ◽  
Lisa P. Jones ◽  
Dale A. Moore ◽  
Sara Ahmed ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dairy Farms ◽  
Washington State ◽  
Human Populations ◽  
Human Pathogens ◽  
Content Type ◽  
E Coli ◽  
The Past ◽  
Recent Emergence ◽  
Cephalosporin Resistance

ABSTRACTEnterobacteriaceae-associatedblaCTX-Mgenes have become globally widespread within the past 30 years. Among isolates from Washington State cattle,Escherichia colistrains carryingblaCTX-M(CTX-ME. colistrains) were absent from a set of 2008 isolates but present in a set of isolates from 2011. On 30 Washington State dairy farms sampled in 2012, CTX-ME. coliprevalence was significantly higher on eastern than on northwestern Washington farms, on farms with more than 3,000 adult cows, and on farms that recently received new animals. The addition of fresh bedding to calf hutches at least weekly and use of residual fly sprays were associated with lower prevalence of CTX-ME. coli. In Washington State, the occurrence of human pathogens carryingblaCTX-Mgenes preceded the emergence ofblaCTX-M-associatedE. coliin cattle, indicating that these resistance determinants and/or their bacterial hosts may have emerged in human populations prior to their dissemination to cattle populations.

scholarly journals Potentially Human-Pathogenic Escherichia coli O26 in Norwegian Sheep Flocks

2011 ◽  
Vol 77 (14) ◽  
pp. 4949-4958 ◽  
Author(s):  
C. Sekse ◽  
M. Sunde ◽  
B.-A. Lindstedt ◽  
P. Hopp ◽  
T. Bruheim ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Variable Number Tandem Repeat ◽  
Variable Number ◽  
Human Pathogens ◽  
Content Type ◽  
Representative Sampling ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Close Relationship ◽  
Large Survey

ABSTRACTA national survey ofEscherichia coliO26 in Norwegian sheep flocks was conducted, using fecal samples to determine the prevalence. In total, 491 flocks were tested, andE. coliO26 was detected in 17.9% of the flocks. One hundred forty-twoE. coliO26 isolates were examined for flagellar antigens (H typing) and four virulence genes, includingstxandeae, to identify possible Shiga toxin-producingE. coli(STEC) and enteropathogenicE. coli(EPEC). Most isolates (129 out of 142) were identified asE. coliO26:H11. They possessedeaeand may have potential as human pathogens, although only a small fraction were identified as STEC O26:H11, giving a prevalence in sheep flocks of only 0.8%. Correspondingly, the sheep flock prevalence of atypical EPEC (aEPEC) O26:H11 was surprisingly high (15.9%). The genetic relationship between theE. coliO26:H11 isolates was investigated by pulsed-field gel electrophoresis (PFGE) and multilocus variable number tandem repeat analysis (MLVA), identifying 63 distinct PFGE profiles and 22 MLVA profiles. Although the MLVA protocol was less discriminatory than PFGE and a few cases of disagreement were observed, comparison by partition mapping showed an overall good accordance between the two methods. A close relationship between a few isolates of aEPEC O26:H11 and STEC O26:H11 was identified, but all theE. coliO26:H11 isolates should be considered potentially pathogenic to humans. The present study consisted of a representative sampling of sheep flocks from all parts of Norway. This is the first large survey of sheep flocks focusing onE. coliO26 in general, including results of STEC, aEPEC, and nonpathogenic isolates.

scholarly journals Evaluation of Aerated Steam Treatment of Alfalfa and Mung Bean Seeds To Eliminate High Levels of Escherichia coli O157:H7 and O178:H12, Salmonella enterica, and Listeria monocytogenes

2013 ◽  
Vol 79 (15) ◽  
pp. 4613-4619 ◽  
Author(s):  
Patrick Studer ◽  
Werner E. Heller ◽  
Jörg Hummerjohann ◽  
David Drissner
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Salmonella Enterica ◽  
Mung Bean ◽  
Germination Rate ◽  
Steam Treatment ◽  
Heat Sensitivity ◽  
Human Pathogens ◽  
Content Type ◽  
E Coli

ABSTRACTSprouts contaminated with human pathogens are able to cause food-borne diseases due to the favorable growth conditions for bacteria during germination and because of minimal processing steps prior to consumption. We have investigated the potential of hot humid air, i.e., aerated steam, to treat alfalfa and mung bean seeds which have been artificially contaminated withEscherichia coliO157:H7,Salmonella entericasubsp.entericaserovar Weltevreden, andListeria monocytogenesScott A. In addition, a recently collectedE. coliO178:H12 isolate, characterized by a reduced heat sensitivity, was exposed to the treatment described. Populations ofE. coliO157:H7 andS. entericaon alfalfa and mung bean seeds could be completely eliminated by a 300-s treatment with steam at 70 ± 1°C as revealed by enrichment studies.L. monocytogenesandE. coliO178:H12 could not be completely eliminated from artificially inoculated seeds. However, bacterial populations were reduced by more than 5 log CFU/g on alfalfa and by more than 4 log CFU/g on mung bean seeds. The germination rate of mung beans was not affected by the 300-s treatment compared to the germination rate of untreated seeds whereas that of alfalfa seeds was significantly lower by 11.9%. This chemical-free method is an effective alternative to the 20,000-ppm hypochlorite treatment presently recommended by the U.S. Food and Drug Administration (FDA).

scholarly journals Occurrence of Potentially Human-Pathogenic Escherichia coli O103 in Norwegian Sheep

2013 ◽  
Vol 79 (23) ◽  
pp. 7502-7509 ◽  
Author(s):  
Camilla Sekse ◽  
Marianne Sunde ◽  
Petter Hopp ◽  
Torkjel Bruheim ◽  
Kofitsyo Sewornu Cudjoe ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Human Pathogens ◽  
Outbreak Strain ◽  
Banding Patterns ◽  
Sheep Population ◽  
Content Type ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Uremic Syndrome ◽  
Low Prevalence

ABSTRACTThe investigation of an outbreak of hemorrhagic-uremic syndrome in Norway in 2006 indicated that the outbreak strainEscherichia coliO103:H25 could originate from sheep. A national survey of the Norwegian sheep population was performed, with the aim of identifying and describing a possible reservoir of potentially human-pathogenicE. coliO103, in particular of the H types 2 and 25. The investigation of fecal samples from 585 sheep flocks resulted in 1,222E. coliO103 isolates that were analyzed for the presence ofeaeandstxgenes, while a subset of 369 isolates was further examined for flagellar antigens (H typing),stxsubtypes,bfpA,astA, and molecular typing by pulsed-field gel electrophoresis (PFGE). The total ovineE. coliO103 serogroup was genetically diverse by numbers of H types, virulotypes, and PFGE banding patterns identified, although a tendency of clustering toward serotypes was seen. The flocks positive for potentially human-pathogenicE. coliO103 were geographically widely distributed, and no association could be found with county or geographical region. The survey showed thateae-negative,stx-negativeE. coliO103, probably nonpathogenic to humans, is very common in sheep, with 27.5% of flocks positive. Moreover, the study documented a low prevalence (0.7%) of potentially human-pathogenic Shiga toxin-producingE. coliO103:H2, while STEC O103:H25 was not detected. However, 3.1% and 5.8% of the flocks were positive for enteropathogenicE. coliO103 belonging to H types 2 and 25, respectively. These isolates are of concern as potential human pathogens by themselves but more importantly as possible precursors for human-pathogenic STEC.

scholarly journals Escherichia coliSequence Type 410 Is Causing New International High-Risk Clones

mSphere ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. e00337-18 ◽  
Author(s):  
Louise Roer ◽  
Søren Overballe-Petersen ◽  
Frank Hansen ◽  
Kristian Schønning ◽  
Mikala Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Risk ◽  
Antimicrobial Resistance ◽  
Sequence Type ◽  
Recurrent Infections ◽  
Content Type ◽  
E Coli ◽  
The Past ◽  
Carbapenemase Gene ◽  
Globally Distributed

ABSTRACTEscherichia colisequence type 410 (ST410) has been reported worldwide as an extraintestinal pathogen associated with resistance to fluoroquinolones, third-generation cephalosporins, and carbapenems. In the present study, we investigated national epidemiology of ST410E. coliisolates from Danish patients. Furthermore,E. coliST410 was investigated in a global context to provide further insight into the acquisition of the carbapenemase genesblaOXA-181andblaNDM-5of this successful lineage. From 127 whole-genome-sequenced isolates, we reconstructed an evolutionary framework ofE. coliST410 which portrays the antimicrobial-resistant clades B2/H24R, B3/H24Rx, and B4/H24RxC. The B2/H24R and B3/H24Rx clades emerged around 1987, concurrently with the C1/H30R and C2/H30Rx clades inE. coliST131. B3/H24Rx appears to have evolved by the acquisition of the extended-spectrum β-lactamase (ESBL)-encoding geneblaCTX-M-15and an IncFII plasmid, encoding IncFIA and IncFIB. Around 2003, the carbapenem-resistant clade B4/H24RxC emerged when ST410 acquired an IncX3 plasmid carrying ablaOXA-181carbapenemase gene. Around 2014, the clade B4/H24RxC acquired a second carbapenemase gene,blaNDM-5, on a conserved IncFII plasmid. From an epidemiological investigation of 49E. coliST410 isolates from Danish patients, we identified five possible regional outbreaks, of which one outbreak involved nine patients withblaOXA-181- andblaNDM-5-carrying B4/H24RxC isolates. The accumulated multidrug resistance inE. coliST410 over the past two decades, together with its proven potential of transmission between patients, poses a high risk in clinical settings, and thus,E. coliST410 should be considered a lineage with emerging “high-risk” clones, which should be monitored closely in the future.IMPORTANCEExtraintestinal pathogenicEscherichia coli(ExPEC) is the main cause of urinary tract infections and septicemia. Significant attention has been given to the ExPEC sequence type ST131, which has been categorized as a “high-risk” clone. High-risk clones are globally distributed clones associated with various antimicrobial resistance determinants, ease of transmission, persistence in hosts, and effective transmission between hosts. The high-risk clones have enhanced pathogenicity and cause severe and/or recurrent infections. We show that clones of theE. coliST410 lineage persist and/or cause recurrent infections in humans, including bloodstream infections. We found evidence of ST410 being a highly resistant globally distributed lineage, capable of patient-to-patient transmission causing hospital outbreaks. Our analysis suggests that the ST410 lineage should be classified with the potential to cause new high-risk clones. Thus, with the clonal expansion over the past decades and increased antimicrobial resistance to last-resort treatment options, ST410 needs to be monitored prospectively.

scholarly journals Influence of Antibiotic Selection on Genetic Composition of Escherichia coli Populations from Conventional and Organic Dairy Farms

2007 ◽  
Vol 73 (19) ◽  
pp. 5982-5989 ◽  
Author(s):  
Seth T. Walk ◽  
Janice M. Mladonicky ◽  
Jaclyn A. Middleton ◽  
Anthony J. Heidt ◽  
Julie R. Cunningham ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Organic Farming ◽  
Dairy Farms ◽  
Farm Animals ◽  
Human Pathogens ◽  
Genetic Composition ◽  
Bacterial Strains ◽  
E Coli ◽  
Farm Type ◽  
Resistant Strains

ABSTRACT The widespread agricultural use of antimicrobials has long been considered a crucial influence on the prevalence of resistant genes and bacterial strains. It has been suggested that antibiotic applications in agricultural settings are a driving force for the development of antimicrobial resistance, and epidemiologic evidence supports the view that there is a direct link between resistant human pathogens, retail produce, farm animals, and farm environments. Despite such concerns, little is understood about the population processes underlying the emergence and spread of antibiotic resistance and the reversibility of resistance when antibiotic selective pressure is removed. In this study, hierarchical log-linear modeling was used to assess the association between farm type (conventional versus organic), age of cattle (calf versus cow), bacterial phenotype (resistant versus susceptible), and the genetic composition of Escherichia coli populations (E. coli Reference Collection [ECOR] phylogroup A, B1, B2, or D) among 678 susceptible and resistant strains from a previously published study of 60 matched dairy farms (30 conventional and 30 organic) in Wisconsin. The analysis provides evidence for clonal resistance (ampicillin resistance) and genetic hitchhiking (tetracycline resistance [Tetr]), estimated the rate of compositional change from conventional farming to organic farming (mean, 8 years; range, 3 to 15 years), and discovered a significant association between low multidrug resistance, organic farms, and strains of the numerically dominant phylogroup B1. These data suggest that organic farming practices not only change the frequency of resistant strains but also impact the overall population genetic composition of the resident E. coli flora. In addition, the results support the hypothesis that the current prevalence of Tetr loci on dairy farms has little to do with the use of this antibiotic.

scholarly journals Epidemic Emergence in the United States of Escherichia coli Sequence Type 131-H30 (ST131-H30), 2000 to 2009

2017 ◽  
Vol 61 (8) ◽  
Author(s):  
James R. Johnson ◽  
Stephen Porter ◽  
Paul Thuras ◽  
Mariana Castanheira
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
Single Agent ◽  
Temporal Trends ◽  
Virulence Gene ◽  
The United States ◽  
Sequence Type ◽  
Content Type ◽  
E Coli ◽  
Recent Emergence

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.

scholarly journals Shielding Effect of Escherichia coli O-Antigen Polysaccharide on J5-Induced Cross-Reactive Antibodies

mSphere ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Pascal Rainard ◽  
Maryline Repérant-Ferter ◽  
Christophe Gitton ◽  
Pierre Germon
Keyword(s):  
Escherichia Coli ◽  
Vaccine Development ◽  
Dairy Farms ◽  
Shielding Effect ◽  
Coliform Bacteria ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cell Mediated Immunity ◽  
Content Type ◽  
E Coli ◽  
O Antigen

ABSTRACT Escherichia coli is the leading cause of severe mastitis in dairy farms. As E. coli mastitis is refractory to the hygienic control measures adapted to contagious mastitis, efficient vaccines are in demand. Existing mastitis vaccines, based on the use of killed rough E. coli J5 as the antigen, aim at inducing phagocytosis by neutrophils. We assessed the binding of J5-induced antibodies to isogenic rough and smooth strains along with a panel of mastitis-associated E. coli. Analysis by enzyme-linked immunosorbent assay revealed that antibodies to OmpA or killed J5 bind readily to rough E. coli but poorly to smooth strains. Flow cytometry analysis indicated that immunization with J5 induced antibodies that cross-reacted with rough E. coli strains but with only a small subpopulation of smooth strains. We identified type 1 fimbriae as the target of most antibodies cross-reacting with the smooth strains. These results suggest that the O-polysaccharide of lipopolysaccharide shields the outer membrane antigens and that only fiber antigens protruding at the bacterial surface can elicit antibodies reacting with mastitis-associated E. coli. We evaluated J5-induced antibodies in an opsonophagocytic killing assay with bovine neutrophils. J5 immune serum was not more efficient than preimmune serum, showing that immunization did not improve on the already high efficiency of naturally acquired antibodies to E. coli. In conclusion, it is unlikely that the efficiency of J5 vaccines is related to the induction of opsonic antibodies. Consequently, other research directions, such as cell-mediated immunity, should be explored to improve E. coli mastitis vaccines. IMPORTANCE Despite intensive research, mastitis remains an important disease in dairy cattle with a significant impact on animal welfare, use of antibiotics, and, in the end, the economy of dairy farms. Although vaccines available so far have shown limited efficacy against coliform mastitis, vaccination is considered one of the measures that could limit the consequences of mastitis. One reason for the lack of efficiency of current vaccines likely stems from the current evaluation of vaccines that relies mostly on measuring antibody production against vaccine antigens. This report clearly shows that vaccine-induced antibodies fail to bind to most mastitis-associated E. coli strains because of the presence of an O-antigen and, thus, do not allow for improved phagocytosis of pathogens. As a consequence, this report calls for revised criteria for the evaluation of vaccines and suggests that cell-mediated immunity should be targeted by new vaccinal strategies. More generally, these results could be extended to other vaccine development strategies targeting coliform bacteria.

Characterization of extended-spectrum and CMY-2 ß-lactamases, and associated virulence genes in Escherichia coli from food of animal origin in México

2018 ◽  
Vol 120 (7) ◽  
pp. 1457-1473 ◽  
Author(s):  
Edwin Barrios-Villa ◽  
Gerardo Cortés-Cortés ◽  
Patricia Lozano Zarain ◽  
Sergio Romero-Romero ◽  
Norarizbeth Lara Flores ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Food Samples ◽  
Animal Origin ◽  
Content Type ◽  
E Coli ◽  
Extended Spectrum ◽  
Food Of Animal Origin ◽  
Cephalosporin Resistance

Purpose Broad-spectrum cephalosporin resistance is rapidly increasing in Escherichia coli, representing a food safety problem. The purpose of this paper is to characterize eight extended-spectrum-ß-lactamase (ESBL) and acquired AmpC ß-lactamase-producing E. coli isolates and virotypes associated, obtained from chicken and pork food samples in Puebla, Mexico. Design/methodology/approach Samples (36 from chicken and 10 from pork) were cultured on Levine agar plates supplemented with cefotaxime (2 mg/L) for isolation of cefotaxime-resistant (CTXR) E. coli. CTXR-E. coli isolates were detected in 33 of 46 samples (72 percent), and one isolate/sample was characterized (28 from chicken and 5 from pork), for ESBL production, phylogenetic group, sequence typing, resistance and virulence genes by PCR and sequencing. Findings Results showed 16 ESBL-E. coli (35 percent) (12/16 belonging to phylogroup B1) and 8 CMY-2-E. coli (17 percent). ESBL detected were as follows (number of isolates): CTX-M-2 (8); CTX-M-1 (2); CTX-M-15 (1); SHV-2a (4) and TEM-52c (1). In total, 20 different sequence types (STs) were identified among the ESBL- or CMY-2-producing E. coli strains, which included four new ones. The CTX-M-15 β-lactamase was detected in one E. coli ST617-ST10 Cplx-B1 strain that also carried ibeA gene. One CMY-2-positive strain of lineage ST224-B2 was detected and it carried the qnrA1 gene. Originality/value In this study, a ST131-based virotyping scheme for strains from food of animal origin was established since this kind of strains constitutes an important vehicle of virulent ESBL- and CMY-2-producing E. coli isolates, which could be transmitted to humans by direct contact or through the food chain.

scholarly journals Multifactorial Effects of Ambient Temperature, Precipitation, Farm Management, and Environmental Factors Determine the Level of Generic Escherichia coli Contamination on Preharvested Spinach

2015 ◽  
Vol 81 (7) ◽  
pp. 2635-2650 ◽  
Author(s):  
Sangshin Park ◽  
Sarah Navratil ◽  
Ashley Gregory ◽  
Arin Bauer ◽  
Indumathi Srinath ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Negative Binomial ◽  
Precipitation Amount ◽  
Farm Management ◽  
Content Type ◽  
E Coli ◽  
The Past ◽  
Average Maximum ◽  
Average Precipitation ◽  
Contamination Event

ABSTRACTA repeated cross-sectional study was conducted to identify farm management, environment, weather, and landscape factors that predict the count of genericEscherichia colion spinach at the preharvest level.E. coliwas enumerated for 955 spinach samples collected on 12 farms in Texas and Colorado between 2010 and 2012. Farm management and environmental characteristics were surveyed using a questionnaire. Weather and landscape data were obtained from National Resources Information databases. A two-part mixed-effect negative binomial hurdle model, consisting of a logistic and zero-truncated negative binomial part with farm and date as random effects, was used to identify factors affectingE. colicounts on spinach. Results indicated that the odds of a contamination event (non-zero versus zero counts) vary by state (odds ratio [OR] = 108.1). Odds of contamination decreased with implementation of hygiene practices (OR = 0.06) and increased with an increasing average precipitation amount (mm) in the past 29 days (OR = 3.5) and the application of manure (OR = 52.2). On contaminated spinach,E. colicounts increased with the average precipitation amount over the past 29 days. The relationship betweenE. colicount and the average maximum daily temperature over the 9 days prior to sampling followed a quadratic function with the highest bacterial count at around 24°C. These findings indicate that the odds of a contamination event in spinach are determined by farm management, environment, and weather factors. However, once the contamination event has occurred, the count ofE. colion spinach is determined by weather only.

scholarly journals Molecular Epidemiology of Escherichia coli Producing CTX-M and pAmpC β-Lactamases from Dairy Farms Identifies a Dominant Plasmid Encoding CTX-M-32 but No Evidence for Transmission to Humans in the Same Geographical Region

2020 ◽  
Vol 87 (1) ◽  
Author(s):  
Jacqueline Findlay ◽  
Oliver Mounsey ◽  
Winnie W. Y. Lee ◽  
Nerissa Newbold ◽  
Katy Morley ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Geographical Location ◽  
Dairy Farms ◽  
Generation Cephalosporin ◽  
Sequencing Analysis ◽  
Third Generation ◽  
Content Type ◽  
E Coli ◽  
Animal Populations ◽  
Close Relatives

ABSTRACT Third-generation cephalosporin resistance (3GC-R) in Escherichia coli is a rising problem in human and farmed-animal populations. We conducted whole-genome sequencing analysis of 138 representative 3GC-R isolates previously collected from dairy farms in southwest England and confirmed by PCR to carry acquired 3GC-R genes. This analysis identified blaCTX-M (131 isolates encoding CTX-M-1, -14, -15, -and 32 and the novel variant CTX-M-214), blaCMY-2 (6 isolates), and blaDHA-1 (1 isolate). A highly conserved plasmid was identified in 73 isolates, representing 27 E. coli sequence types. This novel ∼220-kb IncHI2 plasmid carrying blaCTX-M-32 was sequenced to closure and designated pMOO-32. It was found experimentally to be stable in cattle and human transconjugant E. coli even in the absence of selective pressure and was found by multiplex PCR to be present on 26 study farms representing a remarkable range of transmission over 1,500 square kilometers. However, the plasmid was not found among human urinary E. coli isolates we recently characterized from people living in the same geographical location, collected in parallel with farm sampling. There were close relatives of two blaCTX-M plasmids circulating among eight human and two cattle isolates, and a closely related blaCMY-2 plasmid was found in one cattle and one human isolate. However, phylogenetic evidence of recent sharing of 3GC-R strains between farms and humans in the same region was not found. IMPORTANCE Third-generation cephalosporins (3GCs) are critically important antibacterials, and 3GC resistance (3GC-R) threatens human health, particularly in the context of opportunistic pathogens such as Escherichia coli. There is some evidence for zoonotic transmission of 3GC-R E. coli through food, but little work has been done examining possible transmission via interaction of people with the local near-farm environment. We characterized acquired 3GC-R E. coli found on dairy farms in a geographically restricted region of the United Kingdom and compared these with E. coli from people living in the same region, collected in parallel. While there is strong evidence for recent farm-to-farm transmission of 3GC-R strains and plasmids—including one epidemic plasmid that has a remarkable capacity to be transmitted—there was no evidence that 3GC-R E. coli found on study farms had a significant impact on circulating 3GC-R E. coli strains or plasmids in the local human population.

Sign in / Sign up

Export Citation Format

Share Document