Escherichia coli Producing Extended-Spectrum β-lactamases (ESBL) from Domestic Camels in the Canary Islands: A One Health Approach

Objective: This work aimed to determine the carriage rate of ESBL-producing Escherichia coli as well as their genetic characteristics in camels from the Canary Islands, Spain. Methods: Fecal samples were recovered from 58 healthy camels from Gran Canaria (n = 32) and Fuerteventura Islands (n = 26) during July 2019. They were seeded on MacConkey (MC) agar no supplemented and supplemented (MC + CTX) with cefotaxime (2 µg/mL). Antimicrobial susceptibility was determined by disk diffusion test (CLSI, 2018). The presence of blaCTX-M, blaSHV, blaTEM,blaCMY-2 and blaOXA-1/48 genes was tested by PCR/sequencing. Furthermore, the mcr-1 (colistin resistance), tetA/tetB (tetracycline resistance), int1 (integrase of class 1 integrons) and stx1,2 genes were analyzed. Phylogenetic groups and sequence types were determined by specific-PCR/sequencing for selected isolates. Results: E. coli was obtained from all the 58 camels in MC media (100%) and in five of them in MC + CTX media (8.6%). Furthermore, 63.8% of E. coli isolates recovered from MC agar were susceptible to all the antibiotics tested. The five E. coli isolates recovered from MC + CTX media were characterized and two of them were ESBL-producers (3.4%). Both ESBL-producer isolates carried the blaCTX-M-15 gene and belonged to the lineages ST3018 (phylogroup A) and ST69 (phylogroup B1). The 3 ESBL-negative isolates recovered from MC-CTX plates were ascribed to phylogroup-B1. Conclusions: Camels can be a source of ESBL-producer bacteria, containing the widespread blaCTX-M-15 gene associated with the lineages ST3018 and ST69.

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Antimicrobial Resistance Genes and Diversity of Clones among ESBL- and Acquired AmpC-Producing Escherichia coli Isolated from Fecal Samples of Healthy and Sick Cats in Portugal

Antibiotics ◽

10.3390/antibiotics10030262 ◽

2021 ◽

Vol 10 (3) ◽

pp. 262

Author(s):

Isabel Carvalho ◽

Nadia Safia Chenouf ◽

Rita Cunha ◽

Carla Martins ◽

Paulo Pimenta ◽

...

Keyword(s):

Escherichia Coli ◽

Public Health Problem ◽

Phylogenetic Groups ◽

Disk Diffusion Test ◽

Extended Spectrum Beta Lactamase ◽

E Coli ◽

Specific Pcr ◽

Flight Mass Spectrometry ◽

Antimicrobial Resistance Genes ◽

Esbl Producers

The aim of the study was to analyze the mechanisms of resistance in extended-spectrum beta-lactamase (ESBL)- and acquired AmpC (qAmpC)-producing Escherichia coli isolates from healthy and sick cats in Portugal. A total of 141 rectal swabs recovered from 98 sick and 43 healthy cats were processed for cefotaxime-resistant (CTXR) E. coli recovery (in MacConkey agar supplemented with 2 µg/mL cefotaxime). The matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) method was used for E. coli identification and antimicrobial susceptibility was performed by a disk diffusion test. The presence of resistance/virulence genes was tested by PCR sequencing. The phylogenetic typing and multilocus sequence typing (MLST) were determined by specific PCR sequencing. CTXRE. coli isolates were detected in seven sick and six healthy cats (7.1% and 13.9%, respectively). Based on the synergy tests, 11 of 13 CTXRE. coli isolates (one/sample) were ESBL-producers (ESBL total rate: 7.8%) carrying the following ESBL genes: blaCTX-M-1 (n = 3), blaCTX-M-15 (n = 3), blaCTX-M-55 (n = 2), blaCTX-M-27 (n = 2) and blaCTX-M-9 (n = 1). Six different sequence types were identified among ESBL-producers (sequence type/associated ESBLs): ST847/CTX-M-9, CTX-M-27, CTX-M-1; ST10/CTX-M-15, CTX-M-27; ST6448/CTX-M-15, CTX-M-55; ST429/CTX-M-15; ST101/CTX-M-1 and ST40/CTX-M-1. Three of the CTXR isolates were CMY-2-producers (qAmpC rate: 2.1%); two of them were ESBL-positive and one ESBL-negative. These isolates were typed as ST429 and ST6448 and were obtained in healthy or sick cats. The phylogenetic groups A/B1/D/clade 1 were detected among ESBL- and qAmpC-producing isolates. Cats are carriers of qAmpC (CMY-2)- and ESBL-producing E. coli isolates (mostly of variants of CTX-M group 1) of diverse clonal lineages, which might represent a public health problem due to the proximity of cats with humans regarding a One Health perspective.

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Comparative analysis of genetic characterization of β-lactam-resistant Escherichia coli from bulk tank milk in Korea

Irish Veterinary Journal ◽

10.1186/s13620-021-00203-4 ◽

2021 ◽

Vol 74 (1) ◽

Author(s):

Hye-Ri Jung ◽

Koeun Kim ◽

Young Ju Lee

Keyword(s):

Escherichia Coli ◽

Clinical Mastitis ◽

Phylogenetic Groups ◽

Bulk Tank Milk ◽

Genetic Characteristics ◽

E Coli ◽

Intestinal Infections ◽

Antimicrobial Resistance Genes ◽

Bulk Tank ◽

Genotypic Characteristics

Abstract Background This study was conducted to analyze the genetic characteristics of 41 β-lactam-resistant Escherichia coli isolates, which are one of the common causes of environmental mastitis, isolated from the bulk tank milk of 290 dairy farms in five factories operated by three dairy companies in Korea. Results Analysis of the phenotypic and genotypic characteristics of β-lactam-resistant E. coli isolates revealed differences between factories even within the same company. Isolates from factory A1 and C1 showed high resistance to cephalothin (76.9 and 100%, respectively), which is a first-generation cephalosporins, whereas resistance to tetracycline was showed by only the isolates from factories B1 (60.0%), C2 (66.7%), and C3 (100%). Although all the 41 β-lactam-resistant E. coli isolates were positive for blaOXA-1, blaTEM-1 was highly prevalent in isolates from factories C2 (100%) and C3 (100%). Among 17 isolates resistant to both β-lactams and aminoglycosides, the most common multilocus sequence type was ST399 (13isolates, 76.5%). Furthermore, 2 (11.8%) and 12 (70.6%) isolates belonged to the phylogenetic groups B2 and D, respectively, which are invasive strains that cause intestinal infections, respectively. The predominant serogroup was O15 (70.6%), which is a globally distributed extraintestinal pathogen. Interestingly, one isolate from factory A1 belonged to O157 and carried six virulence genes, simultaneously. Conclusions Although E. coli isolates were isolated from bulk tank milk, and not the clinical mastitis samples, the presence of the phylogenetic groups B2 and D, and the serogroups O15 and O157, which harbor antimicrobial resistance genes and virulence factors, can pose a threat to public health.

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Phylogenetic Groups and Antimicrobial Resistance Genes in Escherichia coli from Different Meat Species

Antibiotics ◽

10.3390/antibiotics10121543 ◽

2021 ◽

Vol 10 (12) ◽

pp. 1543

Author(s):

Angelika Sacher-Pirkelbauer ◽

Daniela Klein-Jöbstl ◽

Dmitrij Sofka ◽

Anne-Béatrice Blanc-Potard ◽

Friederike Hilbert

Keyword(s):

Escherichia Coli ◽

Antimicrobial Resistance ◽

Resistance Genes ◽

Tetracycline Resistance ◽

Kanamycin Resistance ◽

Phylogenetic Group ◽

Phylogenetic Groups ◽

E Coli ◽

Antimicrobial Resistance Genes ◽

Meat Species

Escherichia coli isolated from meat of different animal species may harbour antimicrobial resistance genes and may thus be a threat to human health. The objectives of this study were to define antimicrobial resistance genes in E. coli isolates from pork, beef, chicken- and turkey meat and analyse whether their resistance genotypes associated with phylogenetic groups or meat species. A total number of 313 E. coli samples were isolated using standard cultural techniques. In 98% of resistant isolates, a dedicated resistance gene could be identified by PCR. Resistance genes detected were tet(A) and tet(B) for tetracycline resistance, strA and aadA1 for streptomycin resistance, sulI and sulII for resistance against sulphonamides, dfr and aphA for kanamycin resistance and blaTEM for ampicillin resistance. One stx1 harbouring E. coli isolated from pork harboured the tet(A) gene and belonged to phylogenetic group B2, whilst another stx1 positive isolate from beef was multi-resistant and tested positive for blaTEM,aphA, strA–B, sulII, and tet(A) and belonged to phylogenetic group A. In conclusion, the distribution of resistance elements was almost identical and statistically indifferent in isolates of different meat species. Phylogenetic groups did not associate with the distribution of resistance genes and a rather low number of diverse resistance genes were detected. Most E. coli populations with different resistance genes against one drug often revealed statistically significant different MIC values.

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Phylogenetic Grouping and Virulence Potential of Extended-Spectrum-β-Lactamase-Producing Escherichia coli Strains in Cattle

Applied and Environmental Microbiology ◽

10.1128/aem.00351-12 ◽

2012 ◽

Vol 78 (13) ◽

pp. 4677-4682 ◽

Cited By ~ 38

Author(s):

Charlotte Valat ◽

Frédéric Auvray ◽

Karine Forest ◽

Véronique Métayer ◽

Emilie Gay ◽

...

Keyword(s):

Escherichia Coli ◽

Virulence Determinants ◽

Phylogenetic Groups ◽

Content Type ◽

E Coli ◽

Extended Spectrum ◽

Specific Distribution ◽

Extended Spectrum Beta Lactamases ◽

Phylogenetic Grouping ◽

Almost All

ABSTRACTIn line with recent reports of extended-spectrum beta-lactamases (ESBLs) inEscherichia coliisolates of highly virulent serotypes, such as O104:H4, we investigated the distribution of phylogroups (A, B1, B2, D) and virulence factor (VF)-encoding genes in 204 ESBL-producingE. coliisolates from diarrheic cattle. ESBL genes, VFs, and phylogroups were identified by PCR and a commercial DNA array (Alere, France). ESBL genes belonged mostly to the CTX-M-1 (65.7%) and CTX-M-9 (27.0%) groups, whereas those of the CTX-M-2 and TEM groups were much less represented (3.9% and 3.4%, respectively). One ESBL isolate wasstx1andeaepositive and belonged to a major enterohemorrhagicE. coli(EHEC) serotype (O111:H8). Two other isolates wereeaepositive butstxnegative; one of these had serotype O26:H11. ESBL isolates belonged mainly to phylogroup A (55.4%) and, to lesser extents, to phylogroups D (25.5%) and B1 (15.6%), whereas B2 strains were quasi-absent (1/204). The number of VFs was significantly higher in phylogroup B1 than in phylogroups A (P= 0.04) and D (P= 0.02). Almost all of the VFs detected were found in CTX-M-1 isolates, whereas only 64.3% and 33.3% of them were found in CTX-M-9 and CTX-M-2 isolates, respectively. These results indicated that the widespread dissemination of theblaCTX-Mgenes within theE. colipopulation from cattle still spared the subpopulation of EHEC/Shiga-toxigenicE. coli(STEC) isolates. In contrast to other reports on non-ESBL-producing isolates from domestic animals, B1 was not the main phylogroup identified. However, B1 was found to be the most virulent phylogroup, suggesting host-specific distribution of virulence determinants among phylogenetic groups.

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Molecular types, virulence profiles and antimicrobial resistance of Escherichia coli causing bovine mastitis

Veterinary Record Open ◽

10.1136/vetreco-2019-000369 ◽

2019 ◽

Vol 6 (1) ◽

pp. e000369 ◽

Cited By ~ 5

Author(s):

Magdalena Nüesch-Inderbinen ◽

Nadine Käppeli ◽

Marina Morach ◽

Corinne Eicher ◽

Sabrina Corti ◽

...

Keyword(s):

Escherichia Coli ◽

Bovine Mastitis ◽

Tetracycline Resistance ◽

Diffusion Method ◽

Sample Population ◽

Disk Diffusion Method ◽

E Coli ◽

Phylogenetic Grouping ◽

Resistance Rates ◽

Susceptibility Profiles

BackgroundEscherichia coli is an important aetiological agent of bovine mastitis worldwide.MethodsIn this study, 82 E. coli from bovine mastitis milk samples from 49 farms were analysed for their genetic diversity using phylogenetic grouping and multilocus sequence typing. The isolates were examined by PCR for a selection of virulence factors (VFs). Antimicrobial susceptibility profiles were assessed using the disk diffusion method.ResultsThe most prevalent phylogroups were group B1 (41.5 per cent of the isolates) and group A (30.5 per cent). A variety of 35 different sequence types (STs) were identified, including ST1125 (11 per cent), ST58 (9.8 per cent), ST10 (8.5 per cent) and ST88 (7.3 per cent). Aggregate VF scores (the number of unique VFs detected for each isolate) ranged from 1 to 3 for 63.4 per cent of the isolates and were at least 4 for 12.2 per cent. For 24.4 per cent of the isolates, the score was 0. The three most frequent VFs were traT, fyuA and iutA. The majority (72 per cent) of the isolates harboured traT. The majority (68.3 per cent) of the isolates were fully susceptible to all antimicrobials tested, with 22 per cent resistant to ampicillin and 14.6 per cent to tetracycline. Resistance rates were low for gentamicin (3.7 per cent), amoxicillin/clavulanic acid (2.4 per cent) and ceftiofur (1.2 per cent), respectively.ConclusionAmong the study’s sample population, E. coli strains were genotypically diverse, even in cows from the same farm, although some STs occurred more frequently than others. Susceptibility to clinically relevant compounds remained high.

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Characterization of Extended-Spectrum β-Lactamase–Producing Escherichia coli Strains Isolated from Retail Foods in Shaanxi Province, China

Journal of Food Protection ◽

10.4315/0362-028x.jfp-14-490 ◽

2015 ◽

Vol 78 (5) ◽

pp. 1018-1023 ◽

Cited By ~ 14

Author(s):

MEILI XI ◽

QIAN WU ◽

XIN WANG ◽

BAOWEI YANG ◽

XIAODONG XIA ◽

...

Keyword(s):

Escherichia Coli ◽

Shaanxi Province ◽

People’S Republic Of China ◽

People's Republic Of China ◽

M Gene ◽

Disk Diffusion Test ◽

Republic Of China ◽

E Coli ◽

Extended Spectrum

Extended-spectrum β-lactamase (ESBL)–producing Escherichia coli strains have been reported worldwide; however, the incidence and characterization of foodborne ESBL-producing E. coli strains have been rarely reported in the People's Republic of China. Among a collection of 659 E. coli isolates recovered from retail foods in Shaanxi Province, People's Republic of China, 223 cefoxitin-resistant and/or cefoperazone-resistant isolates were screened for ESBL production with the double disk diffusion test. The ESBL-producing isolates were characterized for antimicrobial resistance and the presence of blaTEM, blaSHV, and blaCTX-M genes. Isolates with blaCTX-M were further classified by PCR as having blaCTX-M-1, blaCTX-M-2, blaCTX-M-8, blaCTX-M-9, or blaCTX-M-25. One hundred forty-seven isolates were identified as ESBL positive. PCR detection revealed that 146 isolates (99.3%) contained the blaCTX-M gene. Among these isolates, 42 (28.8%) were positive for the enzyme CTX-M-1, 5 (3.4%) for CTX-M-2, and 99 (67.8%) for CTX-M-9. No CTX-M-8 and CTX-M-25 were found in this study. One hundred fifteen isolates (78.2%) were positive for the blaTEM gene, but blaSHV was not detected. Among the 147 ESBL-producing E. coli isolates, 75 (51.0%), 35 (23.8%), and 4 (2.7%) isolates were positive for blaTEM and blaCTX-M-9, blaTEM and blaCTX-M-1, and blaTEM and blaCTX-M-2, respectively. All of the 147 ESBL-producing isolates were resistant to three or more non–β-lactam antibiotics. This study provides evidence that foodborne E. coli can harbor ESBL-encoding genes. Thus, food could be a vehicle for the dissemination of ESBL-producing E. coli strains, a situation that requires surveillance and appropriate management strategies.

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Allelic types of long polar fimbriae in bovine and human Escherichia coli O157 strains

Acta Veterinaria Hungarica ◽

10.1556/avet.2012.001 ◽

2012 ◽

Vol 60 (1) ◽

pp. 1-15 ◽

Cited By ~ 4

Author(s):

Domonkos Sváb ◽

István Tóth

Keyword(s):

Escherichia Coli ◽

Escherichia Coli O157 ◽

Phylogenetic Groups ◽

Genetic Lineages ◽

E Coli ◽

Typing Scheme ◽

Healthy Cattle ◽

Reference Collection ◽

Group D ◽

Atypical Strains

Long polar fimbriae (Lpf) are recently discovered adhesins and increasingly important genetic markers of pathogenicEscherichia colistrains. The presence and genotype diversity of Lpf operons was screened in a collection of 97Escherichia coliO157 strains representing different pathotypes, isolated from healthy cattle (n = 43) and human patients (n = 54) in several countries. Individual structural genes of Lpf were scanned by PCR, and allelic variants were detected with a recently developed typing scheme. Ninety-five strains carried at least one whole Lpf operon (geneslpfABCDand/orlpfABCDE). The 64 enterohaemorrhagic (EHEC) and 24 enteropathogenic (EPEC) strains all carried two Lpf operons, allele 3 oflpfA1and allele 2 oflpfA2, a combination characteristic of the O157:H7/NM serotype. Out of the 9 bovine atypical (AT;stx-, eae-) strains, 7 carried one complete Lpf operon, allele 1 oflpfA2. The atypical strains belonged to main phylogenetic groups A and B1, while the EHEC and EPEC strains were from group D. Lpf variants carried by the 72 strains of theEscherichia coliReference Collection (ECOR) were determined with the same typing scheme. Alleles were detected in 25 strains, of which 6 were found negative for the respective Lpf operons in earlier studies. The marker value of the Lpf allelic combination for the O157:H7/NM serotype was confirmed, and further evidence was given for the presence of at least two different genetic lineages of atypical bovineE. coliO157 strains.

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Antimicrobial Resistance in Campylobacter, Salmonella, and Escherichia coli Isolated from Retail Grain-Fed Veal Meat from Southern Ontario, Canada

Journal of Food Protection ◽

10.4315/0362-028x.jfp-10-483 ◽

2011 ◽

Vol 74 (8) ◽

pp. 1245-1251 ◽

Cited By ~ 11

Author(s):

ANGELA COOK ◽

RICHARD J. REID-SMITH ◽

REBECCA J. IRWIN ◽

SCOTT A. McEWEN ◽

VIRGINIA YOUNG ◽

...

Keyword(s):

Public Health ◽

Escherichia Coli ◽

Antimicrobial Resistance ◽

Antimicrobial Susceptibility ◽

Susceptibility Testing ◽

Tetracycline Resistance ◽

Antimicrobial Susceptibility Testing ◽

E Coli ◽

Testing Resistance ◽

Resistance Patterns

This study estimated the prevalence of Salmonella, Campylobacter, and Escherichia coli isolates in fresh retail grain-fed veal obtained in Ontario, Canada. The prevalence and antimicrobial resistance patterns were examined for points of public health significance. Veal samples (n = 528) were collected from February 2003 through May 2004. Twenty-one Salmonella isolates were recovered from 18 (4%) of 438 samples and underwent antimicrobial susceptibility testing. Resistance to one or more antimicrobials was found in 6 (29%) of 21 Salmonella isolates; 5 (24%) of 21 isolates were resistant to five or more antimicrobials. No resistance to antimicrobials of very high human health importance was observed. Ampicillin-chloramphenicol-streptomycin-sulfamethoxazole-tetracycline resistance was found in 5 (3%) of 21 Salmonella isolates. Campylobacter isolates were recovered from 5 (1%) of 438 samples; 6 isolates underwent antimicrobial susceptibility testing. Resistance to one or more antimicrobials was documented in 3 (50%) of 6 Campylobacter isolates. No Campylobacter isolates were resistant to five or more antimicrobials or category I antimicrobials. E. coli isolates were recovered from 387 (88%) of 438 samples; 1,258 isolates underwent antimicrobial susceptibility testing. Resistance to one or more antimicrobials was found in 678 (54%) of 1,258 E. coli isolates; 128 (10%) of 1,258 were resistant to five or more antimicrobials. Five (0.4%) and 7 (0.6%) of 1,258 E. coli isolates were resistant to ceftiofur and ceftriaxone, respectively, while 34 (3%) of 1,258 were resistant to nalidixic acid. Ciprofloxacin resistance was not detected. There were 101 different resistance patterns observed among E. coli isolates; resistance to tetracycline alone (12.7%, 161 of 1,258) was most frequently observed. This study provides baseline prevalence and antimicrobial resistance data and highlights potential public health concerns.

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Evaluation of ESBL (Extended Spectrum Beta-Lactamase) Producing Escherichia Coli Isolated from Patients with Urinary Tract Infection by Phenotypic and Genotypic Methods

10.21203/rs.3.rs-23726/v1 ◽

2020 ◽

Author(s):

Mohammad Hasan Namaei ◽

Hengameh Hamzei ◽

Marzie Moghanni ◽

Azadeh Ebrahimzadeh

Keyword(s):

Escherichia Coli ◽

Urinary Tract Infection ◽

Urinary Tract ◽

Tract Infection ◽

Antibiotic Use ◽

M Gene ◽

Esbl Producer ◽

Accurate Identification ◽

E Coli ◽

Tract Infections

Abstract Background: Urinary Tract Infection (UTI) is the most common bacterial infection in the world. E. coli is the predominant Pathogen. This study evaluates the prevalence of ESBL in E. colis isolated from patients with urinary tract infections with phenotypic and genotypic methods.Methods: This descriptive-analytical study was done on 155 isolates of E. coli isolated from patients with urinary tract infection who had received the study consent. After accurate identification of E. coli strains. ESBL production for Escherichia coli isolates which are resistant to ceftriaxone or ceftazidime was evaluated by CDT method. TEM, SHV and CTX-M genes were identified by PCR.Results: The results showed that 30 strains from 155 strains of E. coli had ESBL. Strains of ESBL producer were more in males was lower in educated persons. 38.9% of ESBL producer had antibiotic use, 29.9% -producing Escherichia hospitalization and 31.6% uti history. The highest level of drug allergy in the ESBL was related to nitrofurantoin, and the highest resistance was related to cefazolin, co-trimoxazole. The CTX-M and the CTX-M15 gene were found in 92.7% and 57.1% of cases, respectively; also the SHV and TEM genes were not found in any of ESBL-producing Escherichia coli strains. Most therapeutic response in patients was related to cefexime, ciprofloxacin and nitrofurantoin 27.4%, 26% 21.9%, respectively.Conclusion: This study showed that the history of antibiotic use, hospitalization, uti related to increase of ESBL-producing in E. coli isolates., the CTMX-M gene is the most common gene in ESBL-producing E. coli strains.

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Survey and Sequence Characterization of Bovine Mastitis-Associated Escherichia coli in Dairy Herds

Frontiers in Veterinary Science ◽

10.3389/fvets.2020.582297 ◽

2020 ◽

Vol 7 ◽

Author(s):

John I. Alawneh ◽

Ben Vezina ◽

Hena R. Ramay ◽

Hulayyil Al-Harbi ◽

Ameh S. James ◽

...

Keyword(s):

Escherichia Coli ◽

Antibiotic Resistance ◽

Bovine Mastitis ◽

Antibiotic Resistance Genes ◽

Tetracycline Resistance ◽

Sequence Type ◽

Genotypic Differences ◽

Beta Lactam ◽

Sequence Characterization ◽

E Coli

Escherichia coli is frequently associated with mastitis in cattle. “Pathogenic” and “commensal” isolates appear to be genetically similar. With a few exceptions, no notable genotypic differences have been found between commensal and mastitis-associated E. coli. In this study, 24 E. coli strains were isolated from dairy cows with clinical mastitis in three geographic regions of Australia (North Queensland, South Queensland, and Victoria), sequenced, then genomically surveyed. There was no observed relationship between sequence type (ST) and region (p = 0.51). The most common Multi Locus Sequence Type was ST10 (38%), then ST4429 (13%). Pangenomic analysis revealed a soft-core genome of 3,463 genes, including genes associated with antibiotic resistance, chemotaxis, motility, adhesion, biofilm formation, and pili. A total of 36 different plasmids were identified and generally found to have local distributions (p = 0.02). Only 2 plasmids contained antibiotic resistance genes, a p1303_5-like plasmid encoding multidrug-resistance (trimethoprim, quaternary ammonium, beta-lactam, streptomycin, sulfonamide, and kanamycin) from two North Queensland isolates on the same farm, while three Victorian isolates from the same farm contained a pCFSAN004177P_01-like plasmid encoding tetracycline-resistance. This pattern is consistent with a local spread of antibiotic resistance through plasmids of bovine mastitis cases. Notably, co-occurrence of plasmids containing virulence factors/antibiotic resistance with putative mobilization was rare, though the multidrug resistant p1303_5-like plasmid was predicted to be conjugative and is of some concern. This survey has provided greater understanding of antibiotic resistance within E. coli-associated bovine mastitis which will allow greater prediction and improved decision making in disease management.

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