Pathogenic Escherichia coli in Dogs Reveals the Predominance of ST372 and the Human-Associated ST73 Extra-Intestinal Lineages

Comparative genetic and pathogenic approaches of Escherichia coli isolated simultaneously from pyometra and urine of bitches

Escherichia coli (E. coli) are widely related to pyometra and cystitis in dogs, and these infections can occur simultaneously. The goal of this study was to determine genetic and pathogenic insights of 14 E. coli isolated simultaneously from pyometra content and bladder urine of seven bitches. To achieve this, in silico and in vitro comparative analyses were conducted. Whole-genome comparisons demonstrated that E. coli isolated from pyometra and urine of the same animal were predominantly genetic extraintestinal E. coli clones belonging to the same Sequence Type and phylogroup. The E. coli clones identified in this study included ST372, ST457, ST12, ST127, ST646, and ST961. Five isolates (35.7%) belonged to the ST12 complex. Except for two E. coli, all other isolates belonged to the B2 Clermont phylogroup. Interestingly, some genomes of E. coli from urine carried more virulence genes than those E. coli from pyometra. Both pyometra and urine E. coli isolates demonstrated a strong affinity for adhering to HeLa and T24 cells, with a low affinity for invading them. However, certain isolates from urine exhibited a greater tendency to adhere to T24 cells in qualitative and quantitative assays compared to isolates from pyometra. In conclusion, this study revealed the high genomic similarity between pyometra and urine E. coli isolates, as well as the virulent capacity of both to colonize endometrial and urothelial cells. The findings of this study underscore the importance of concurrently managing both infections clinically and could potentially contribute to future resources for the prevention of cystitis and pyometra.

Characterization of ESBL/AmpC-producing extraintestinal Escherichia coli (ExPEC) in dogs treated at a veterinary hospital in Brazil

The clinical aspects and lineages involved in Extraintestinal pathogenic Escherichia coli (ExPEC) infections in dogs remain largely unknown. In this study, we investigated the antimicrobial resistance and molecular structures of ExPECs isolated from infected dogs in Brazil. Samples were obtained from dogs (n = 42) with suspected extraintestinal bacterial infections. Phylogroup B2 was predominant (65.1%). No association was observed between the site of infection, phylogroups, or virulence factors. Almost half of the isolates (44.2%) were MDR, and 20.9% were extended-spectrum β-lactamase (ESBL)-positive. E. coli isolates that were resistant to fluoroquinolones (27.9%) were more likely to be MDR. The CTX-M-15 enzyme was predominant among the ESBL-producing strains, and seven sequence types were identified, including the high-risk clones ST44 and ST131. Single SNPs analysis confirmed the presence of two clonal transmissions. The present study showed a high frequency of ExPECs from phylogroup B2 infecting various sites and a high frequency of ESBL-producing strains that included STs frequently associated with human infection. This study also confirmed the nosocomial transmission of ESBL-producing E. coli, highlighting the need for further studies on the prevention and diagnosis of nosocomial infections in veterinary settings.

Genotypic Characterization of Uropathogenic Escherichia coli from Companion Animals: Predominance of ST372 in Dogs and Human-Related ST73 in Cats

Extraintestinal pathogenic Escherichia coli (ExPEC) account for over 80% and 60% of bacterial urinary tract infections (UTIs) in humans and animals, respectively. As shared uropathogenic E. coli (UPEC) strains have been previously reported among humans and pets, our study aimed to characterize E. coli lineages among UTI isolates from dogs and cats and to assess their overlaps with human UPEC lineages. We analysed 315 non-duplicate E. coli isolates from the UT of dogs (198) and cats (117) collected in central Germany in 2019 and 2020 utilizing whole genome sequencing and in silico methods. Phylogroup B2 (77.8%), dog-associated sequence type (ST) 372 (18.1%), and human-associated ST73 (16.6%), were predominant. Other STs included ST12 (8.6%), ST141 (5.1%), ST127 (4.8%), and ST131 (3.5%). Among these, 58.4% were assigned to the ExPEC group and 51.1% to the UPEC group based on their virulence associated gene (VAG) profile (ExPEC, presence of ≥VAGs: papAH and/or papC, sfa/focG, afaD/draBC, kpsMTII, and iutA; UPEC, additionally cnf1 or hlyD). Extended-spectrum cephalosporin (ESC) resistance mediated by extended-spectrum β-lactamases (ESBL) and AmpC-β-lactamase was identified in 1.9% of the isolates, along with one carbapenemase-producing isolate and one isolate carrying a mcr gene. Low occurrence of ESC-resistant or multidrug-resistant (MDR) isolates (2.9%) in the two most frequently detected STs implies that E. coli isolated from UTIs of companion animals are to a lesser extent associated with resistance, but possess virulence-associated genes enabling efficient UT colonization and carriage. Detection of human-related pandemic lineages suggests interspecies transmission and underscores the importance of monitoring companion animals.

Carbapenem-resistant Escherichia coli in Black-headed gulls, the Danube, and human clinical samples: A One Health comparison of contemporary isolates

OBJECTIVES

Our aim was to characterize and compare contemporary carbapenem-resistant Enterobacterales (CRE) isolates from gulls, the River Danube, and humans in Hungary, Budapest.

METHODS

Multiresistant Enterobacterales were sought for in 227 gull faecal and 24 Danube water samples from 2019 to 2020. Eosin-methylene blue agar containing 2 mg/L cefotaxime and Colilert-test containing 10 mg/L cefotaxime were used for gull and water samples, respectively. Isolates were characterized by polymerase chain reactions (PCRs); acquired carbapenemase producers were further analysed by whole-genome sequencing, together with 21 Hungarian human CR Escherichia coli (CREc) isolates.

RESULTS

Gull and water samples exhibited a CRE prevalence of 7.4% (9/122) and 6.7% (7/105), none and 5/12 water samples yielded CRE from 2019 and 2020, respectively; CRE were found only in samples taken downstream of Budapest. The dominant species was Escherichia coli and the most prevalent carbapenemase was blaNDM-1. High-risk CREc clones were found both in gulls (ST224, ST372, ST744) and the Danube (ST10, ST354, ST410); the closest associations were between ST410 from humans and the Danube, among ST1437 among gulls, and between ST1437 in gulls and the Danube (46, 0, and 22-24 allelic distances, respectively). Direct links between human and gull isolates were not demonstrated.

CONCLUSION

The study demonstrates potential epidemiological links among humans, a river crossing a city, and urbanised birds, suggesting a local transmission network. Water bodies receiving influent wastewater, together with animals using such habitats, may serve as a local reservoir system for CRE, highlighting the importance of One Health in CRE transmission, even in a country with a low CRE prevalence in humans.

Longitudinal examination of urine pH, specific gravity, protein, culture, and antimicrobial resistance profiles in healthy dogs

BACKGROUND

Urine is routinely evaluated in dogs to assess health. Reference ranges for many urine properties are well established, but the scope of variation in these properties over time within healthy dogs is not well characterized.

OBJECTIVES

Longitudinally characterize urine properties in healthy dogs over 3 months.

ANIMALS

Fourteen healthy client-owned dogs.

METHODS

In this prospective study, dogs were evaluated for health; then, mid-stream free-catch urine was collected from each dog at 12 timepoints over 3 months. Urine pH, urine specific gravity (USG), protein, cultures, and antimicrobial resistance profiles were assessed at each timepoint.

RESULTS

Urine pH varied within and between dogs over time (Friedman's test: within P = .03; between P < .005). However, USG, protein, and bacterial diversity of urine were consistent within dogs over time, and only varied between dogs (Kruskal-Wallis: between all P < .005). Antimicrobial resistant isolates were identified in 12 out of 14 dogs with 34 of 48 of the isolates demonstrating resistance to amoxicillin.

CONCLUSIONS AND CLINICAL IMPORTANCE

Urine pH should be assessed at multiple timepoints via pH meter before making clinical decisions. Mid-stream free-catch urine with high concentrations of bacteria (>105  CFU/mL) should not be considered the only indicator of urinary tract infection. Bacterial isolates from dogs in this study had widespread resistance to amoxicillin/oxacillin underscoring the need for antimicrobial stewardship.

Occurrence of Major Human Extraintestinal Pathogenic Escherichia coli Sequence Types Among Diarrheic Pet Animals: A Potential Public Health Threat

Background: Extraintestinal pathogenic Escherichia coli (ExPEC) has become a mounting public health concern. The present study was conducted to address the role of diarrheic pet animals as potential reservoirs for major human ExPEC sequence types (STs). Materials and Methods: Rectal swabs were collected from 145 diarrheic pet animals (75 dogs and 70 cats). Samples were processed for isolation and identification of E. coli by culture methods. Afterward, ExPEC isolates were identified on a molecular basis through detection of ExPEC phylogroups (B2 and D) coupled with carriage of two or more of the virulence genes associated with ExPEC (papAH, papC, sfa/focDE, afa/draBC, iutA, and kpsMT II). ExPEC STs 131, 73, 69, and 95 were identified among ExPEC isolates by quadruplex PCR and tested for their antimicrobial susceptibility. Eventually, two isolates underwent gene sequencing for the phylogenetic analysis. Results: Of 145 pet animals, 16 (11%) E. coli strains were identified as ExPEC, in which 15 (10.3%) isolates belonged to phylogroup B2 and 1 (0.69%) strain belonged to phylogroup D. The major human ExPEC STs were detected in 13 (9%) isolates, whereas the prevalence rates were 5.3% and 12.9% for dogs and cats, respectively. The isolation rates of ExPEC STs were 4.8%, 2.8%, 0.69%, and 0.69% for ST73, ST131, ST95, and ST69, respectively. Regarding the prevalence of virulence genes among ExPEC STs, the most prevalent ones were papC and sfa/focDE (92.3%), followed by papAH (76.9%), iutA (53.8%), afa/draBC (30.8%), and kpsMT II (30.8%). Moreover, 38.5% of the obtained human ExPEC STs were multidrug resistant. The phylogenetic analysis of two ExPEC ST73 gene sequences showed high genetic relatedness to those isolated from humans in different countries. Conclusions: The fecal carriage of major human ExPEC STs among diarrheic dogs and cats poses a potential zoonotic hazard with serious public health implications.

Previous Antibiotic Exposure Reshapes the Population Structure of Infecting Uropathogenic Escherichia coli Strains by Selecting for Antibiotic Resistance over Urovirulence

Antibiotic therapy is the standard of care for urinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC). However, previous antibiotic therapy may impart a selective pressure that influences the population structure and pathogenic potential of infecting UPEC strains. Here, we conducted a 3-year study using whole-genome-sequencing analysis and retrospective medical record review to characterize how antibiotic exposure influenced the phenotypic antibiotic resistance, acquired resistome, virulome, and population structure of 88 UTI-causing E. coli strains from dogs. A majority of UTI-associated E. coli strains were from phylogroup B2 and clustered within sequence type 372. Previous antibiotic exposure was associated with a population shift toward UPEC from phylogroups other than the typical urovirulent phylogroup B2. The specific virulence profiles within the accessory virulome that were associated with antibiotic use were elicited by the effect of antibiotics on UPEC phylogenetic structure. Among phylogroup B2, antibiotic exposure increased the quantity of genes within the resistome and the odds of developing reduced susceptibility to at least one antibiotic. Non-B2 UPEC strains harbored a more diverse and greater resistome that conferred reduced susceptibility to multiple antibiotic classes following antibiotic exposure. Collectively, these data suggest that previous antibiotic exposure establishes an environment that provides a selective edge to non-B2 UPEC strains through their diverse and abundant antibiotic resistance genes, despite their lack of urovirulence genes. Our findings highlight the necessity for judicious use of antibiotics as we uncover another mechanism by which antibiotic exposure and resistance can influence the dynamics of bacterial infectious disease. IMPORTANCE Urinary tract infections (UTIs) are one of the most common infections of dogs and humans. While antibiotic therapy is the standard of care for UTIs and other infections, antibiotic exposure may influence the pathogenic profile of subsequent infections. We used whole-genome sequencing and retrospective medical record review to characterize the effect of systemic antibiotic therapy on the resistance, virulence, and population structure of 88 UTI-causing UPEC strains isolated from dogs. Our results indicate that antibiotic exposure alters the population structure of infecting UPEC strains, providing a selective edge for non-B2 phylogroups that harbor diverse and abundant resistance gene catalogues but fewer urovirulence genes. These findings highlight how antibiotic resistance can influence pathogen infection dynamics and have clinical implications for the judicious use of antibiotics for bacterial infections.

Dogs Can Be Reservoirs of Escherichia coli Strains Causing Urinary Tract Infection in Human Household Contacts

This study aimed to investigate the role played by pets as reservoirs of Escherichia coli strains causing human urinary tract infections (UTIs) in household contacts. Among 119 patients with community-acquired E. coli UTIs, we recruited 19 patients who lived with a dog or a cat. Fecal swabs from the household pet(s) were screened by antimicrobial selective culture to detect E. coli displaying the resistance profile of the human strain causing UTI. Two dogs shed E. coli isolates indistinguishable from the UTI strain by pulsed-field gel electrophoresis. Ten months later, new feces from these dogs and their owners were screened selectively and quantitatively for the presence of the UTI strain, followed by core-genome phylogenetic analysis of all isolates. In one pair, the resistance phenotype of the UTI strain occurred more frequently in human (108 CFU/g) than in canine feces (104 CFU/g), and human fecal isolates were more similar (2-7 SNPs) to the UTI strain than canine isolates (83-86 SNPs). In the other pair, isolates genetically related to the UTI strain (23-40 SNPs) were only detected in canine feces (105 CFU/g). These results show that dogs can be long-term carriers of E. coli strains causing UTIs in human household contacts.

Dominance of Escherichia coli sequence types ST73, ST95, ST127 and ST131 in Australian urine isolates: a genomic analysis of antimicrobial resistance and virulence linked to F plasmids

Extraintestinal pathogenic Escherichia coli (ExPEC) are the most frequent cause of urinary tract infections (UTIs) globally. Most studies of clinical E. coli isolates are selected based on their antimicrobial resistance (AMR) phenotypes; however, this selection bias may not provide an accurate portrayal of which sequence types (STs) cause the most disease. Here, whole genome sequencing (WGS) was performed on 320 E. coli isolates from urine samples sourced from a regional hospital in Australia in 2006. Most isolates (91%) were sourced from patients with UTIs and were not selected based on any AMR phenotypes. No significant differences were observed in AMR and virulence genes profiles across age sex, and uro-clinical syndromes. While 88 STs were identified, ST73, ST95, ST127 and ST131 dominated. F virulence plasmids carrying senB-cjrABC (126/231; 55%) virulence genes were a feature of this collection. These senB-cjrABC+ plasmids were split into two categories: pUTI89-like (F29:A-:B10 and/or >95 % identity to pUTI89) (n=73) and non-pUTI89-like (n=53). Compared to all other plasmid replicons, isolates with pUTI89-like plasmids carried fewer antibiotic resistance genes (ARGs), whilst isolates with senB-cjrABC+/non-pUTI89 plasmids had a significantly higher load of ARGs and class 1 integrons. F plasmids were not detected in 89 genomes, predominantly ST73. Our phylogenomic analyses identified closely related isolates from the same patient associated with different pathologies and evidence of strain-sharing events involving isolates sourced from companion and wild animals.

Characterization of the pathogenicity of extraintestinal pathogenic Escherichia coli isolates from pneumonia-infected lung samples of dogs and cats in South Korea

This study aimed to investigate the pathogenicity of extraintestinal pathogenic Escherichia coli (ExPEC) isolated from dog and cat lung samples in South Korea. A total of 101 E. coli isolates were analyzed for virulence factors, phylogroups, and O-serogroups, and their correlation with bacterial pneumonia-induced mortality was elucidated. P fimbriae structural subunit (papA), hemolysin D (hlyD), and cytotoxic necrotizing factor 1 (cnf1) were highly prevalent in both species, indicating correlation with bacterial pneumonia. Phylogroups B1 and B2 were the most prevalent phylogroups (36.6% and 32.7%, respectively) and associated with high bacterial pneumonia-induced mortality rates. Isolates from both species belonging to phylogroup B2 showed high frequency of papA, hlyD, and cnf1. O-serogrouping revealed 21 and 15 serogroups in dogs and cats, respectively. In dogs, O88 was the most prevalent serogroup (n = 8), and the frequency of virulence factors was high for O4 and O6. In cats, O4 was the most prevalent serogroup (n = 6), and the frequency of virulence factors was high for O4 and O6. O4 and O6 serogroups were mainly grouped under phylogroup B2 and associated with high bacterial pneumonia-induced mortality. This study characterized the pathogenicity of ExPEC and described the probability of ExPEC pneumonia-induced mortality.

Swine Colibacillosis: Global Epidemiologic and Antimicrobial Scenario

Swine pathogenic infection caused by Escherichia coli, known as swine colibacillosis, represents an epidemiological challenge not only for animal husbandry but also for health authorities. To note, virulent E. coli strains might be transmitted, and also cause disease, in humans. In the last decades, diverse successful multidrug-resistant strains have been detected, mainly due to the growing selective pressure of antibiotic use, in which animal practices have played a relevant role. In fact, according to the different features and particular virulence factor combination, there are four different pathotypes of E. coli that can cause illness in swine: enterotoxigenic E. coli (ETEC), Shiga toxin-producing E. coli (STEC) that comprises edema disease E. coli (EDEC) and enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), and extraintestinal pathogenic E. coli (ExPEC). Nevertheless, the most relevant pathotype in a colibacillosis scenario is ETEC, responsible for neonatal and postweaning diarrhea (PWD), in which some ETEC strains present enhanced fitness and pathogenicity. To explore the distribution of pathogenic ETEC in swine farms and their diversity, resistance, and virulence profiles, this review summarizes the most relevant works on these subjects over the past 10 years and discusses the importance of these bacteria as zoonotic agents.

Identification of genes influencing the evolution of Escherichia coli ST372 in dogs and humans

ST372 are widely reported as the major Escherichia coli sequence type in dogs globally. They are also a sporadic cause of extraintestinal infections in humans. Despite this, it is unknown whether ST372 strains from dogs and humans represent shared or distinct populations. Furthermore, little is known about genomic traits that might explain the prominence of ST372 in dogs or presence in humans. To address this, we applied a variety of bioinformatics analyses to a global collection of 407 ST372 E. coli whole-genome sequences to characterize their epidemiological features, population structure and associated accessory genomes. We confirm that dogs are the dominant host of ST372 and that clusters within the population structure exhibit distinctive O:H types. One phylogenetic cluster, 'cluster M', comprised almost half of the sequences and showed the divergence of two human-restricted clades that carried different O:H types to the remainder of the cluster. We also present evidence supporting transmission between dogs and humans within different clusters of the phylogeny, including M. We show that multiple acquisitions of the pdu propanediol utilization operon have occurred in clusters dominated by isolates of canine source, possibly linked to diet, whereas loss of the pdu operon and acquisition of K antigen virulence genes characterize human-restricted lineages.

Genetic Diversity and New Sequence Types of Escherichia coli Coharboring β-Lactamases and PMQR Genes Isolated from Domestic Dogs in Central Panama

Background: β-lactamase-producing Escherichia coli are a widely distributed source of antimicrobial resistance for animals and humans. Little is known about the susceptibility profile and genetic characteristics of E. coli strains isolated from domestic dogs in Latin America. Methods: We report on a cross-sectional study that evaluated E. coli strains isolated from fecal samples of domestic dogs in central Panama. The extended-spectrum β-lactamase (ESBL), AmpC genes, and plasmid-mediated quinolone resistance were investigated. Molecular typing using Pasteur’s multilocus sequence typing (MLST) was conducted. Results: A total of 40 E. coli isolates were obtained, of which 80% (32/40) were resistant to at least one of the antibiotics tested, while 20% (8/40) were sensitive to all antibiotics analyzed in this study (p < 0.001). Forty percent of the strains were resistant to three or more antibiotics. The most common resistance was to tetracycline (45%) and ampicillin (30%) while 2.5% showed an ESBL phenotype. Antibiotic resistance genes were detected for one β-lactamase (blaTEM-1) and two plasmid-mediated quinolone resistance (PMQR) enzymes (qnrS and qnrB). In addition, mutations in the chromosomal AmpC gene were observed at positions −35, −28, −18, −1, and +58. Fourteen different sequence types (STs) were identified; the most frequent were ST399 and ST425 (12% each). ST3 and ST88, which have been previously identified in human clinical isolates, were also evidenced. Three new STs were found for the first time: ST1015, ST1016 (carrier of the blaTEM-1 gene), and ST1017 (carrier of the blaTEM-1, qnrS, and qnrB genes). Conclusions: In the intestinal strains of E. coli isolated from domestic dogs, there was a high frequency of resistance to antibiotics. The presence of genes from plasmids and chromosomal mutations that conferred antibiotic resistance, the identification of isolates previously reported in humans, and the genetic diversity of STs (including three that were newly identified) confirmed the determinants of resistance to antibiotics in the domestic dogs from central Panama.

Transmission of Escherichia coli Causing Pyometra between Two Female Dogs

Despite its clinical relevance, the pathogenesis of canine pyometra remains poorly understood. To date, it is recognized as a non-transmissible infectious disease. In this study, the simultaneous occurrence of pyometra and Escherichia coli in two cohabitant female dogs underwent in-depth investigation due to the hypothesis of transmission between these animals. Two 5-year-old Chow Chow dogs (namely, dogs 23 and 24-D23 and D24) were referred to a veterinary hospital with suspected pyometra. Both animals showed prostration, anorexia, and purulent vulvar discharge over a 1-week period. After ovariohysterectomy, uterine tissue, uterine contents, and rectal swabs were collected for histopathological and microbiological analysis. Uterine histology demonstrated purulent material and multifocal necrosis with endometrial ulceration, and a morphological diagnosis of pyometra was confirmed. Furthermore, E. coli from the same phylogroup (B2) and positive for the same virulence factors with the same antimicrobial susceptibility profile was isolated from the uterine contents of both dogs and the rectum of D23. Conversely, the E. coli strains recovered from D24 differed in phylogroup (one isolate), virulence factors (all three isolates), and antimicrobial susceptibility (all three isolates). Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) suggested that all isolates from the uterine content of both dogs and the rectal swab of D23 were 100% the same, but different from all isolates in the rectal swab of D24. One isolate from the uterine content of each animal as well as rectal swabs were subjected to whole-genome sequencing (WGS). Both whole-genome multilocus sequence typing(wgMLST) and single-nucleotide polymorphism (SNP) analysis supported the hypothesis that the isolates from the uterine content of both animals and the rectal swab of D23 were clonal. Taken together, these clinical features, pathology, microbiology, and molecular findings suggest, to the best of our knowledge, the first transmission of E. coli associated with pyometra between two animals. These results could impact the management of sites where several females cohabit in the same local area such as kennels.

Carbapenem resistance in critically important human pathogens isolated from companion animals: a systematic literature review

This study aimed to describe the presence and geographical distribution of Gram-negativebacteria considered critical on the priority list of antibiotic-resistant pathogens publishedby the World Health Organization, including carbapenem-resistant Enterobacteriaceae,carbapenem-resistant Acinetobacter spp., and carbapenem-resistant Pseudomonas aeruginosa.A systematic review of original studies published in 5 databases between 2010 and 2021 wasconducted, including genotypically confirmed carbapenem-resistant isolates obtained fromcanines, felines, and their settings. Fifty-one articles met the search criteria. Carbapenemresistant isolates were found in domestic canines and felines, pet food, and on veterinarymedical and household surfaces. The review found that the so-called "big five"-that is, the5 major carbapenemases identified worldwide in Enterobacterales (New Delhi metallo-βlactamase, active-on-imipenem, Verona integron-encoded metallo-β-lactamase, Klebsiellapneumoniae carbapenemase, and oxacillin [OXA]-48-like)-and the 3 most importantcarbapenemases from Acinetobacter spp. (OXA-23-like, OXA-40-like, and OXA-58-like) hadbeen detected in 8 species in the Enterobacteriaceae family and 5 species of glucose nonfermenting bacilli on 5 continents. Two publications used molecular analysis to confirmcarbapenem-resistant bacteria transmission between owners and dogs. Isolating criticallyimportant human carbapenem-resistant Gram-negative bacteria from domestic canines andfelines highlights the importance of including these animal species in surveillance programsand antimicrobial resistance containment plans as part of the One Health approach.

Antimicrobial resistance trends among canine Escherichia coli isolated at a New York veterinary diagnostic laboratory between 2007 and 2020

Dogs are a potential source of drug-resistant Escherichia coli, but very few large-scale antimicrobial resistance surveillance studies have been conducted in the canine population. Here, we assess the antimicrobial susceptibility patterns, identify temporal resistance and minimum inhibitory concentration (MIC) trends, and describe associations between resistance phenotypes among canine clinical E. coli isolates in the northeastern United States. Through a retrospective study design, we collected MICs from 7709 E. coli isolates from canine infections at the Cornell University Animal Health Diagnostic Center between 2007 and 2020. The available clinical data were limited to body site. Isolates were classified as resistant or susceptible to six (urinary) and 22 (non-urinary) antimicrobials based on Clinical and Laboratory Standards Institute breakpoints. We used the Mann-Kendall test (MKT) and Sen's slope to identify the presence of a significant trend in the percent of resistant isolates over the study period. Multivariable logistic regression (MLR) models were built with ceftiofur, enrofloxacin, or trimethoprim-sulfamethoxazole resistance as the outcome and either body site and isolation date, or resistance to other antimicrobials as predictors. MIC trends were characterized with survival analysis models, controlling for body site and year of isolation. Overall, 16.4% of isolates were resistant to enrofloxacin, 14.3% to ceftiofur, and 14% to trimethoprim-sulfamethoxazole. The MKT and Sen's slope revealed a significant decreasing temporal trend for gentamicin and trimethoprim-sulfamethoxazole resistance among non-urinary isolates. No significant temporal resistance trends were detected by MKT for other antimicrobials. However, controlling for body-site in MLR models identified a decrease in resistance rates to enrofloxacin and trimethoprim-sulfamethoxazole after 2010. Similarly, survival analysis data confirmed these findings and showed a decrease in MIC values after 2010 for gentamicin and trimethoprim-sulfamethoxazole, but an increase in cephalosporin MICs. MLR showed that non-urinary isolates were significantly more likely than urinary isolates to demonstrate in vitro resistance to ceftiofur, enrofloxacin, and trimethoprim-sulfamethoxazole after controlling for year of isolation. We identified a higher level of ceftiofur resistance among enrofloxacin resistant isolates from urinary and non-urinary origins. Our findings confirmed that dogs are still a non-negligeable reservoir of drug-resistant E. coli in the northeastern United States. The increase in extended-spectrum cephalosporin MIC values in 2018-2020 compared to 2007-2010 constitutes a particularly worrying issue; the relationship between ceftiofur and enrofloxacin resistance suggests that the use of fluoroquinolones could contribute to this trend. Trimethoprim-sulfamethoxazole may be a good first-line choice for empiric treatment of E. coli infections; it is already recommended for canine urinary tract infections.

Identification of faecal Escherichia coli isolates with similar patterns of virulence and antimicrobial resistance genes in dogs and their owners

BACKGROUND

The presence of antimicrobial resistance and virulence genes in Escherichia coli allows them to survive and cause infections. The close contact between humans and pets can reinforce the risk of transmitting resistant and virulent bacteria between them.

OBJECTIVES

This study aims to compare the patterns of the presence of tetracycline and streptomycin resistance genes, as well as important virulence genes in E. coli isolated from faeces of healthy dogs and their owners.

METHODS

Polymerase chain reactions were performed for detection of antimicrobial resistance (tetA, tetB, tetC, tetD, strA and strB) and virulence (fimH, iss, sitA and malX) genes in 144 faecal E. coli isolates from 28 dog-owner pairs and 16 humans who did not keep any pets as controls.

RESULTS

Among the investigated antimicrobial resistance and virulence genes, tetA (52.1%) and fimH (86.8%) genes had the highest prevalence. No statistically significant difference was found between the prevalence of antimicrobial resistance and virulence genes in isolates of dogs and their owners. In total, 46.4% of dog-owner pairs had the same patterns of presence or absence of six antimicrobial resistance genes, 50.0% had the same patterns of presence or absence of four virulence genes and 25.0% had the same patterns of presence or absence of all 10 tested genes.

CONCLUSION

The presence of antimicrobial-resistant virulent E. coli in humans and pets may predispose them to infections that are hard to cure with conventional antibiotics. Notable frequency of dogs' and their owners' E. coli isolates with similar patterns of antimicrobial resistance and virulence genes may indicate the possibility of sharing virulent antimicrobial resistant E. coli between them.

Genomic and Temporal Trends in Canine ExPEC Reflect Those of Human ExPEC

Companion animals and humans are known to share extraintestinal pathogenic Escherichia coli (ExPEC), but the extent of E. coli sequence types (STs) that cause extraintestinal diseases in dogs is not well understood. Here, we generated whole-genome sequences of 377 ExPEC collected by the University of Melbourne Veterinary Hospital from dogs over an 11-year period from 2007 to 2017. Isolates were predominantly from urogenital tract infections (219, 58.1%), but isolates from gastrointestinal specimens (51, 13.5%), general infections (72, 19.1%), and soft tissue infections (34, 9%) were also represented. A diverse collection of 53 STs were identified, with 18 of these including at least five sequences. The five most prevalent STs were ST372 (69, 18.3%), ST73 (31, 8.2%), ST127 (22, 5.8%), ST80 (19, 5.0%), and ST58 (14, 3.7%). Apart from ST372, all of these are prominent human ExPEC STs. Other common ExPEC STs identified included ST12, ST131, ST95, ST141, ST963, ST1193, ST88, and ST38. Virulence gene profiles, antimicrobial resistance carriage, and trends in plasmid carriage for specific STs were generally reflective of those seen in humans. Many of the prominent STs were observed repetitively over an 11-year time span, indicating their persistence in the dogs in the community, which is most likely driven by household sharing of E. coli between humans and their pets. The case of ST372 as a dominant canine lineage observed sporadically in humans is flagged for further investigation. IMPORTANCE Pathogenic E. coli that causes extraintestinal infections (ExPEC) in humans and canines represents a significant burden in hospital and veterinary settings. Despite the obvious interrelationship between dogs and humans favoring both zoonotic and anthropozoonotic infections, whole-genome sequencing projects examining large numbers of canine-origin ExPEC are lacking. In support of anthropozoonosis, we found that most STs from canine infections are dominant human ExPEC STs (e.g., ST73, ST127, ST131) with similar genomic traits, such as plasmid carriage and virulence gene burden. In contrast, we identified ST372 as the dominant canine ST and a sporadic cause of infection in humans, supporting zoonotic transfer. Furthermore, we highlight that, as is the case in humans, STs in canine disease are consistent over time, implicating the gastrointestinal tract as the major community reservoir, which is likely augmented by exposure to human E. coli via shared diet and proximity.

F74 plasmids are major vectors of virulence genes in bovine NTEC2

Necrotoxigenic Escherichia coli 2 (NTEC2) are defined as E. coli producing the toxin known as cytotoxic necrotizing factor 2 (CNF2), a potent toxin primarily found in bovine but also in humans. NTEC2 are mostly associated with bovine, and cnf2 is known to be carried by pVir-like plasmids. In this study, we looked for NTEC2 in a collection of E. coli collected between 2011 and 2018 in French bovine. Thirty-two isolates, collected from both sick (n=19) and healthy (n=13) animals, were identified and characterized using whole-genome sequencing. One F74 plasmid of this bacterial collection was long-read sequenced: its size was 138 121 bp and it carried the cnf2, F17cA-eG, cdtB, iutA, iucC, and ompP virulence factors (VFs), but no resistance gene. A large variety of genetic backgrounds was observed, but all cnf2-carrying plasmids belonged to the IncF family, and most of them (78.1%) were of the F74 group. Similar F74 plasmids were also reported from bovine in the United Kingdom and USA, as identified in the publically available databases. Consequently, these F74 plasmids, which are widely disseminated among E. coli from cattle in the French territory, are vectors of virulence determinants that largely went unnoticed until now.

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): antimicrobial‐resistant Escherichia coli in dogs and cats, horses, swine, poultry, cattle, sheep and goats

Escherichia coli (E. coli) was identified among the most relevant antimicrobial‐resistant (AMR) bacteria in the EU for dogs and cats, horses, swine, poultry, cattle, sheep and goats in previous scientific opinions. Thus, it has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on its eligibility to be listed, Annex IV for its categorisation according to disease prevention and control rules as in Article 9 and Article 8 for listing animal species related to the bacterium. The assessment has been performed following a methodology previously published. The outcome is the median of the probability ranges provided by the experts, which indicates whether each criterion is fulfilled (lower bound ≥ 66%) or not (upper bound ≤ 33%), or whether there is uncertainty about fulfilment. Reasoning points are reported for criteria with uncertain outcome. According to the assessment here performed, it is uncertain whether AMR E. coli can be considered eligible to be listed for Union intervention according to Article 5 of the AHL (33–66% probability). According to the criteria in Annex IV, for the purpose of categorisation related to the level of prevention and control as in Article 9 of the AHL, the AHAW Panel concluded that the bacterium does not meet the criteria in Sections 1, 2, 3 and 4 (Categories A, B, C and D; 0–5%, 5–10%, 10–33% and 10–33% probability of meeting the criteria, respectively) and the AHAW Panel was uncertain whether it meets the criteria in Section 5 (Category E, 33–66% probability of meeting the criteria). The animal species to be listed for AMR E. coli according to Article 8 criteria include mammals, birds, reptiles and fish.

Characterisation of AmpC / ESBL genes in some pathogen gram-negatives isolated from clinical cases of livestock and companion animals

This study was aimed to search and characterize the AmpC and/or ESBL genes of Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa isolated from clinical cases of local livestock and companion animals between 2017 and 2019. A total of eight ceftiofur-resistant E. coli (n= 7) and ceftiofur-resistant K. pneumoniae (n= 1) and seven P. aeruginosa were isolated from different cases in local animals. By combination disc method, six E. coli isolates and one K. pneumoniae isolate were found to be ESBL producers. By combination of the disc method and double disc synergy test, no P. aeruginosa isolates were found as ESBL producers. In the agar disc diffusion test (ADDT) performed with cefoxitin and cefoxitin-boronic, only one E. coli was determined as AmpC producer. In ESBL-producing isolates, only the CTX-M class gene was detected by polymerase chain reaction (PCR) and subsequent sequence analysis revealed CTX-M-3 and CTX-M-15 variants. An AmpC positive E. coli isolate was found to carry plasmidic ampC gene in cmy-2 variant from CIT family. It was observed that P. aeruginosa isolates did not carry the plasmidic ampC gene. After the chromosomal ampC gene of one P. aeruginosa was amplified by PCR and sequenced, R79Q and T105A mutations in the chromosomal ampC gene was revealed. This showed that overproduction of the ampC enzyme is involved in the resistance to β-lactams in P. aeruginosa isolates in the study.

Interplay between Bacterial Clones and Plasmids in the Spread of Antibiotic Resistance Genes in the Gut: Lessons from a Temporal Study in Veal Calves

Intestinal carriage of extended spectrum β-lactamase (ESBL)-producing Escherichia coli is a frequent, increasing, and worrying phenomenon, but little is known about the molecular scenario and the evolutionary forces at play. We screened 45 veal calves, known to have high prevalence of carriage, for ESBL-producing E. coli on 514 rectal swabs (one randomly selected colony per sample) collected over 6 months. We characterized the bacterial clones and plasmids carrying bla_ESBL genes with a combination of genotyping methods, whole genome sequencing, and conjugation assays. One hundred and seventy-three ESBL-producing E. coli isolates [bla_CTX-M-1 (64.7%), bla_CTX-M-14 (33.5%), or bla_CTX-M-15 (1.8%)] were detected, belonging to 32 bacterial clones, mostly of phylogroup A. Calves were colonized successively by different clones with a trend in decreasing carriage. The persistence of a clone in a farm was significantly associated with the number of calves colonized. Despite a high diversity of E. coli clones and bla_CTX-M-carrying plasmids, few bla_CTX-M gene/plasmid/chromosomal background combinations dominated, due to (i) efficient colonization of bacterial clones and/or (ii) successful plasmid spread in various bacterial clones. The scenario "clone versus plasmid spread" depended on the farm. Thus, epistatic interactions between resistance genes, plasmids, and bacterial clones contribute to optimize fitness in specific environments. IMPORTANCE The gut microbiota is the epicenter of the emergence of resistance. Considerable amount of knowledge on the molecular mechanisms of resistance has been accumulated, but the ecological and evolutionary forces at play in nature are less studied. In this context, we performed a field work on temporal intestinal carriage of extended spectrum β-lactamase (ESBL)-producing Escherichia coli in veal farms. Veal calves are animals with one of the highest levels of ESBL producing E. coli fecal carriage, due to early high antibiotic exposure. We were able to show that calves were colonized successively by different ESBL-producing E. coli clones, and that two main scenarios were at play in the spread of bla_CTX-M genes among calves: efficient colonization of several calves by a few bacterial clones and successful plasmid spread in various bacterial clones. Such knowledge should help develop new strategies to fight the emergence of antibiotic-resistance.

Extended-Spectrum-β-Lactamase- and AmpC-Producing Escherichia coli in Domestic Dogs: Spread, Characterisation and Associated Risk Factors

In veterinary medicine, the issue of antimicrobial resistance was mainly addressed in food-producing animals (although companion animals also deserve attention). Indeed, these species may be reservoir of resistant microorganisms, such as extended-spectrum β-lactamase and AmpC (ESBL/AmpC)-producing bacteria. Dogs in particular may transmit them to close-contact humans. Overall 266 faecal samples of healthy dogs were microbiologically and molecularly analyzed to investigate ESBL/AmpC-producing Escherichia coli and the effects of host and environmental factors on their spread. A prevalence of 25.9% of ESBL/AmpC-producing E. coli, supported by bla_CTX-M (79.7%), bla_TEM (47.8%), bla_CMY (13%), and bla_SHV (5.8%) gene detection, emerged. Dogs frequenting extra-urban environments showed significantly higher odds of being positive to ESBL/AmpC E. coli (30.2%) compared to urban dogs (16.7%) identifying the environment as a risk factor. About 88.4% of isolates were resistant to cephalosporins, 8.7% to cephalosporins and carbapenems, and 2.9% to cephalosporins, carbapenems, and penicillins. ESBL/AmpC-producing E. coli expressing bla_CMY were significantly more resistant to cefoxitin, cefotaxime/clavulanic acid and ceftazidime/clavulanic acid, highlighting its negative effects. Our results suggest the role of domestic dogs as a maintenance host of ESBL/AmpC-producing E. coli leading to a constant health monitoring. The recorded resistances to carbapenems implies attention and further investigations.

Surveillance for Antibiotic-Resistant E. coli in the Salish Sea Ecosystem

E. coli was isolated from the Salish Sea (Puget Sound) ecosystem, including samples of marine and fresh water, and wildlife dependent on this environment. E. coli isolates were assessed for phenotypic and genotypic resistance to antibiotics. A total of 305 E. coli isolates was characterized from samples collected from: marine water obtained in four quadrants of the Salish Sea; select locations near beaches; fresh water from streams near marine beaches; and fecal samples from harbor porpoises (Phocoena phocoena), harbor seals (Phoca vitulina), river otters (Lontra canadensis), and English sole (Parophrys vetulus). Isolates were evaluated using antimicrobial susceptibility typing, whole-genome sequencing, fumC, and multilocus sequence typing. Resistance and virulence genes were identified from sequence data. Of the 305 isolates from Salish Sea samples, 20 (6.6%) of the E. coli were intermediate, and 31 (10.2%) were resistant to ≥1 class of antibiotics, with 26.9% of nonsusceptible (resistant and intermediate resistant) E. coli isolates from marine mammals and 70% from river otters. The proportion of nonsusceptible isolates from animals was significantly higher than samples taken from marine water (p < 0.0001). A total of 196 unique STs was identified including 37 extraintestinal pathogenic E. coli (ExPEC)-associated STs [ST10, ST38, ST58, ST69, ST73, ST117, ST131, and ST405]. The study suggests that animals may be potential sentinels for antibiotic-resistant and ExPEC E. coli in the Salish Sea ecosystem.

A Retrospective Study on Bacteriology, Clinicopathologic and Radiographic Features in 28 Cats Diagnosed with Pyothorax

This retrospective study aimed to determine the etiological, clinicopathological, and radiographic features and outcome of feline pyothorax cases. Medical records from twenty-eight cats with pyothorax aged from 4 months to 10 years (median 10 months) diagnosed between 2013 and 2020 were reviewed. Dyspnoea (75.0%), abnormal lung sounds (75.0%) and open-mouth breathing (64.3%) were the predominant respiratory signs. Leucocytosis (61.5%), particularly monocytosis (68.0%), and hyperglobulinaemia (65.4%) were among the most prominent findings in blood analysis. Bilateral pleural effusion was found in 67.9% of the thoracic radiographs. A total of 47.4% of the cytological samples revealed the presence of bacteria, while all had positive bacterial growth. Pasteurella multocida, E. coli, Streptococcus spp., and Staphylococcus spp. were the predominant aerobic bacteria isolated from pleural effusion samples. A chest tube was placed in 64.3% of the cats and 66.7% of cats with chest tubes survived. In total, 46.4% of cats with pyothorax recovered. Amoxicillin-clavulanate was the antimicrobial of choice against aerobic bacteria found in this study and should be given in combination with antimicrobials that cover anaerobic bacteria. Chest tube placement is crucial for treatment success. Cytological results and bacterial culture may not be consistent; thus, bacterial culture should be performed for every case.

Temporal, Spatial, and Genomic Analyses of Enterobacteriaceae Clinical Antimicrobial Resistance in Companion Animals Reveals Phenotypes and Genotypes of One Health Concern

Background

Antimicrobial resistance (AMR) is a globally important one health threat. The impact of resistant infections on companion animals, and the potential public health implications of such infections, has not been widely explored, largely due to an absence of structured population-level data.

Objectives

We aimed to efficiently capture and repurpose antimicrobial susceptibility test (AST) results data from several veterinary diagnostic laboratories (VDLs) across the United Kingdom to facilitate national companion animal clinical AMR surveillance. We also sought to harness and genotypically characterize isolates of potential AMR importance from these laboratories.

Methods

We summarized AST results for 29,330 canine and 8,279 feline Enterobacteriaceae isolates originating from companion animal clinical practice, performed between April 2016 and July 2018 from four VDLs, with submissions from 2,237 United Kingdom veterinary practice sites.

Results

Escherichia coli (E. coli) was the most commonly isolated Enterobacteriaceae in dogs (69.4% of AST results, 95% confidence interval, CI, 68.7-70.0) and cats (90.5%, CI 89.8-91.3). Multi-drug resistance was reported in 14.1% (CI 13.5-14.8) of canine and 12.0% (CI 11.1-12.9) of feline E. coli isolates. Referral practices were associated with increased E. coli 3rd generation ≤ cephalosporin resistance odds (dogs: odds ratio 2.0, CI 1.2-3.4). We selected 95 E. coli isolates for whole genome analyses, of which seven belonged to sequence type 131, also carrying the plasmid-associated extended spectrum β-lactamase gene bla _{CTX-M- 15}. The plasmid-mediated colistin resistance gene mcr-9 was also identified for the first time in companion animals.

Conclusions

Linking clinical AMR data with genotypic characterization represents an efficient means of identifying important resistance trends in companion animals on a national scale.

Antibiotic Resistant and Biofilm-Associated Escherichia coli Isolates from Diarrheic and Healthy Dogs

Bacteria isolated from companion animals are attracting concerns in a view of public health including antimicrobial resistance and biofilm development, both contributing to difficult-to-treat infections. The purpose of this study was to evaluate the minimum inhibitory concentrations (MIC) of 18 antibiotics in Escherichia coli isolated from two groups of dogs (healthy and diarrheic). Isolates were classified into phylogroups, examined for the presence of resistance genes and biofilm-formation capacity. In healthy dogs, phylogenetic analysis showed that 47.37% and 34.22% of E. coli isolates belonged to commensal groups (A; B1) in contrast to diarrheic dogs; 42.2% of isolates were identified as the B2 phylogroup, and these E. coli bacteria formed a stronger biofilm. The results of healthy dogs showed higher MIC levels for tetracycline (32 mg/L), ampicillin (64 mg/L), ciprofloxacin (8 mg/L) and trimethoprim-sulphonamide (8 mg/L) compared to clinical breakpoints. The most detected gene encoding plasmid-mediated resistance to quinolones in the healthy group was qnrB, and in dogs with diarrhea, qnrS. The resistance genes were more frequently detected in healthy dogs. The presence of the integron int1 and the transposon tn3 increases the possibility of transfer of many different cassette-associated antibiotic-resistance genes. These results suggest that dogs could be a potential reservoir of resistance genes.

Multidrug-Resistant Extended-Spectrum β-Lactamase-Producing Escherichia coli Isolated from Vegetable Farm Soil in South Korea

The populations of extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) have increasingly disseminated in humans, animals, and the environment. This study aimed to determine the prevalence, antimicrobial susceptibilities, and molecular characteristics of ESBL-EC isolates obtained from vegetable farm soil. In total, 200 soil samples were collected from vegetable farms in Incheon, South Korea, between 2018 and 2019 and cultured on MacConkey screening plates supplemented with 2 μg/mL cefotaxime. Cefotaxime-resistant ESBL-EC isolates were recovered from 4.0% (8/200) of the soil samples. All eight isolates were nonsusceptible to ampicillin, piperacillin, cefazolin, cefotaxime, and cefepime and harbored bla_CTX-M-type ESBL genes, including bla_CTX-M-15 (50.0%), bla_CTX-M-55 (25.0%), and bla_CTX-M-14 (25.0%). Phylogenetic analysis showed that the B1 lineage was predominant (75.0%), followed by A (12.5%) and B2 (12.5%) lineages. Multilocus sequence typing revealed eight different E. coli sequence types (STs), including ST10, ST73, ST155, ST847, ST2521, ST3285, ST5173, and ST9479. Notably, ST10 and ST73 belong to the global extraintestinal pathogenic E. coli lineages. Our findings demonstrated that the farm soil environment may serve as a reservoir of human-associated multidrug-resistant ESBL-producing pathogens.

Bacterial zoonoses transmitted by household pets and as reservoirs of antimicrobial resistant bacteria

Numerous individuals are committed to growing pet creatures like cats, dogs, and rats etc., pay care for them and as a result of this, there's a boost of their populace in advanced culture. The close interaction between family pets and individuals offers ideal conditions for bacterial transmission. Distinctive sorts of antimicrobial agents are exploited for animal husbandry and studies have revealed that many bacteria have attained confrontation against them viz., Staphylococcus intermedius, Escherichia coli, methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococci and multidrug-resistant Salmonella typhi etc. and a few of these are a prospective for zoonotic transmission. In the current review, the attention has been paid on how household pets, especially dogs disperse the antimicrobial resistance in contrast to that of food animals. A lot of evidences are accessible on food animals and nation-wide scrutiny programmes solely hub on food animals; therefore, for steerage antimicrobial use policy in small animal veterinary exercise as well as for gauging the chance of transmission of antimicrobial resistance to humans' statistics on pet animals are sincerely needed. Transmission of such organisms, especially pathogenic staphylococci, occurs between pets, owners, and veterinary staff, and pets can act as reservoirs of such bacteria; this may additionally have an impact on the use of antimicrobials in human medicine. There is a need to generate statistics concerning each the levels of carriage of such microorganism in pets and the risk factors associated with the switch of the microorganism to human beings who have contact with infected pets, as nicely as to improve hygiene measures in veterinary practice.

Genome evolution and the emergence of pathogenicity in avian Escherichia coli

Chickens are the most common birds on Earth and colibacillosis is among the most common diseases affecting them. This major threat to animal welfare and safe sustainable food production is difficult to combat because the etiological agent, avian pathogenic Escherichia coli (APEC), emerges from ubiquitous commensal gut bacteria, with no single virulence gene present in all disease-causing isolates. Here, we address the underlying evolutionary mechanisms of extraintestinal spread and systemic infection in poultry. Combining population scale comparative genomics and pangenome-wide association studies, we compare E. coli from commensal carriage and systemic infections. We identify phylogroup-specific and species-wide genetic elements that are enriched in APEC, including pathogenicity-associated variation in 143 genes that have diverse functions, including genes involved in metabolism, lipopolysaccharide synthesis, heat shock response, antimicrobial resistance and toxicity. We find that horizontal gene transfer spreads pathogenicity elements, allowing divergent clones to cause infection. Finally, a Random Forest model prediction of disease status (carriage vs. disease) identifies pathogenic strains in the emergent ST-117 poultry-associated lineage with 73% accuracy, demonstrating the potential for early identification of emergent APEC in healthy flocks.

Molecular Characteristics of Extraintestinal Pathogenic E. coli (ExPEC), Uropathogenic E. coli (UPEC), and Multidrug Resistant E. coli Isolated from Healthy Dogs in Spain. Whole Genome Sequencing of Canine ST372 Isolates and Comparison with Human Isolates Causing Extraintestinal Infections

Under a one health perspective and the worldwide antimicrobial resistance concern, we investigated extraintestinal pathogenic Escherichia coli (ExPEC), uropathogenic E. coli (UPEC), and multidrug resistant (MDR) E. coli from 197 isolates recovered from healthy dogs in Spain between 2013 and 2017. A total of 91 (46.2%) isolates were molecularly classified as ExPEC and/or UPEC, including 50 clones, among which (i) four clones were dominant (B2-CH14-180-ST127, B2-CH52-14-ST141, B2-CH103-9-ST372 and F-CH4-58-ST648) and (ii) 15 had been identified among isolates causing extraintestinal infections in Spanish and French humans in 2015 and 2016. A total of 28 (14.2%) isolates were classified as MDR, associated with B1, D, and E phylogroups, and included 24 clones, of which eight had also been identified among the human clinical isolates. We selected 23 ST372 strains, 21 from healthy dogs, and two from human clinical isolates for whole genome sequencing and built an SNP-tree with these 23 genomes and 174 genomes (128 from canine strains and 46 from human strains) obtained from public databases. These 197 genomes were segregated into six clusters. Cluster 1 comprised 74.6% of the strain genomes, mostly composed of canine strain genomes (p < 0.00001). Clusters 4 and 6 also included canine strain genomes, while clusters 2, 3, and 5 were significantly associated with human strain genomes. Finding several common clones and clone-related serotypes in dogs and humans suggests a potentially bidirectional clone transfer that argues for the one health perspective.

Multidrug-Resistant CTX-M and CMY-2 Producing Escherichia coli Isolated from Healthy Household Dogs from the Great Metropolitan Area, Costa Rica

Objective: This study aimed to determine the prevalence of fecal carriage of antibiotic-resistant Escherichia coli of healthy household dogs with an emphasis on extended-spectrum β-lactamases (ESBL), AmpC-type β-lactamases and resistance to quinolones.

Materials and Methods: Rectal swabs were collected from 74 dogs without any clinical evidence of gastrointestinal disease. Samples were cultured on MacConkey agar plates and MacConkey supplemented with 2 μg/mL cefotaxime or 5 μg/mL ciprofloxacin. Isolates were identified with Vitek 2 Compact and susceptibility testing performed by Kirby Bauer disk diffusion method. Minimal inhibitory concentration (MIC) was done on isolates resistant to cefotaxime, ciprofloxacin, and nalidixic acid. PCR amplification was performed to detect CTX-M and CMY-2. Isolates positive for CTX-M and/or CMY-2 were selected for whole-genome sequencing.

Results: Multiresistance was detected in 56% of the isolates. A high percentage of resistance was detected for cefazolin (63%), ampicillin (54%), streptomycin (49%), nalidixic acid (42%) and tetracycline (38%). The MIC₅₀ and MIC₉₀ for isolates resistant to cefotaxime (24%) was determined as 16 and >250 μg/mL, respectively; for ciprofloxacin (18%), 125 and 250 μg/mL, respectively. ESBL (CTX-M type) and AmpC (CMY-2 type) were detected in 6 (7.1%) and 14 (19%) of the isolates, respectively. Whole-genome sequence analysis showed high genetic diversity in most of the isolates and a large variety of resistance mechanisms, including mobile genetic elements.

Conclusion: The frequency of multidrug-resistant E. coli is worrying, mainly because of the presence of many isolates producing ESBL and AmpC β-lactamases. Based on the “One Health” concept, considering the relationships between animals, humans, and the environment, these data support the notion that companion animals are important reservoirs of multidrug-resistant bacteria.

Antibiotic-Resistant Escherichia coli and Sequence Type 131 in Fecal Colonization in Dogs in Taiwan

Background: Most drug-resistant Escherichia coli isolates in dogs come from diseased dogs. Prior to this study, the prevalence and risk factors of fecal carriage drug-resistant E. coli and epidemic clone sequence type (ST) 131 (including subtypes) isolates in dogs were unknown. Methods: Rectal swabs were used for E. coli isolation from 299 non-infectious dogs in a veterinary teaching hospital in Taiwan. Antibiotic resistance and multiplex PCR analyses of E. coli for major STs were performed. Result: There were 43.1% cefazolin-resistant, 22.1% fluoroquinolone-resistant, and 9.4% extended-spectrum beta-lactamase-producing E. coli in our cohort. In the phylogenetic study, B2 was the predominant group (30.1%). The cefazolin-resistant group and ciprofloxacin-resistant group had greater antibiotic exposure in the last 14 days (p < 0.05). The age, sex, and dietary habits of the antibiotic-resistant and -susceptible groups were similar. In the seven isolates of ST131 in fecal colonization, the most predominant subtypes were FimH41 and FimH22. Conclusion: Recent antibiotic exposure was related to the fecal carriage of antibiotic-resistant E. coli isolates. Three major subtypes (FimH41, H22, and H30) of ST131 can thus be found in fecal carriage in dogs in Taiwan.

Companion Animals Are Spillover Hosts of the Multidrug-Resistant Human Extraintestinal Escherichia coli Pandemic Clones ST131 and ST1193

Escherichia coli sequence types 131 (ST131) and 1193 are multidrug-resistant extraintestinal pathogens that have recently spread epidemically among humans and are occasionally isolated from companion animals. This study characterized a nationwide collection of fluoroquinolone-resistant (FQ ^R ) E. coli isolates from extraintestinal infections in Australian cats and dogs. For this, 59 cat and dog FQ ^R clinical E. coli isolates (representing 6.9% of an 855-isolate collection) underwent PCR-based phylotyping and whole-genome sequencing (WGS). Isolates from commensal-associated phylogenetic groups A (14/59, 24%) and B1 (18/59, 31%) were dominant, with ST224 (10/59, 17%), and ST744 (8/59, 14%) predominating. Less prevalent were phylogenetic groups D (12/59, 20%), with ST38 (8/59, 14%) predominating, and virulence-associated phylogenetic group B2 (7/59, 12%), with ST131 predominating (6/7, 86%) and no ST1193 isolates identified. In a WGS-based comparison of 20 cat and dog-source ST131 isolates with 188 reference human and animal ST131 isolates, the cat and dog-source isolates were phylogenetically diverse. Although cat and dog-source ST131 isolates exhibited some minor sub-clustering, most were closely related to human-source ST131 strains. Furthermore, the prevalence of ST131 as a cause of FQ ^R infections in Australian companion animals was relatively constant between this study and the 5-year-earlier study of Platell et al. (2010) (9/125 isolates, 7.2%). Thus, although the high degree of clonal commonality among FQ ^R clinical isolates from humans vs. companion animals suggests the possibility of bi-directional between-species transmission, the much higher reported prevalence of ST131 and ST1193 among FQ ^R clinical isolates from humans as compared to companion animals suggests that companion animals are spillover hosts rather than being a primary reservoir for these lineages.

Characteristics of Extended-Spectrum β-Lactamase-Producing Escherichia coli From Dogs and Cats Admitted to a Veterinary Teaching Hospital in Taipei, Taiwan From 2014 to 2017

Extended-spectrum β-lactamases (ESBLs) are enzymes that mediate resistance to newer β-lactam antibiotics, including extended-spectrum cephalosporins and monobactams. The production of ESBL is primarily plasmid mediated, and such plasmids often comprise the genes that encode resistance to other classes of antimicrobials, such as aminoglycosides and fluoroquinolones. Therefore, ESBL-producing microorganisms leave clinicians with limited therapeutic options in both human and veterinary medicine. Compared with human medicine, information regarding ESBL-producing microorganisms is limited in veterinary medicine. We screened for ESBL-producing Escherichia coli in dogs and cats admitted to National Taiwan University Veterinary Hospital, Taipei, from 2014 to 2017 and further analyzed the genotypes and phylogenetic traits of these ESBL producers. Double disk tests specified by the Clinical and Laboratory Standards Institute were performed on 283 E. coli isolates and revealed a total of 65 E. coli (54 from dogs and 11 from cats) with the ESBL phenotype (22.8%). bla_{CTX−M−1group} and bla_{CTX−M−2group} were the most commonly identified ESBL gene groups. bla_CTX−M−55 was the main ESBL gene within the bla_{CTX−M−1group}, whereas the bla_{CTX−M−2group} contained only bla_{CTX−M−124}. The ESBL-producing E. coli were all resistant to ampicillin. The resistance rate to ceftiofur, doxycycline, enrofloxacin, and ciprofloxacin was 93.8, 73.8, 80, and 78.5%, respectively. Of the antibiotics tested, greater sensitivity to imipenem and gentamicin was noted. Multilocus sequence typing indicated that ST457, ST131, and ST648 were the most common sequence types. Our study identified eight ST131/O25b isolates, which is a global zoonotic clone of public health concern. The major ESBL genes of these clones were bla_{CTX−M−174} and bla_{CTX−M−194}. Because companion animals such as dogs and cats are in close contact with humans, the characterization of ESBL producers originating from them is crucial from the perspective of both public health and veterinary medicine.

Genomic analysis of phylogenetic group B2 extraintestinal pathogenic E. coli causing infections in dogs in Australia

This study investigated the prevalence of extraintestinal pathogenic E. coli (ExPEC)-associated sequence types (STs) from phylogenetic group B2 among 449 fluoroquinolone-susceptible dog clinical isolates from Australia. Isolates underwent PCR-based phylotyping and random amplified polymorphic DNA analysis to determine clonal relatedness. Of the 317 so-identified group B2 isolates, 77 underwent whole genome sequencing (WGS), whereas the remainder underwent PCR-based screening for ST complexes (STc) STc12, STc73, STc372, and ST131. The predominant ST was ST372 according to both WGS (31 % of 77) and ST-specific PCR (22 % of 240), followed by (per WGS) ST73 (17 %), ST12 (7 %), and ST80 (7 %). A WGS-based phylogenetic comparison of ST73 isolates from dogs, cats, and humans showed considerable overall phylogenetic diversity. Although most clusters were species-specific, some contained closely related human and animal (dog > cat) isolates. For dogs in Australia these findings both confirm ST372 as the predominant E. coli clonal lineage causing extraintestinal infections and clarify the importance of human-associated group B2 lineage ST73 as a cause of UTI, with some strains possibly being capable of bi-directional (i.e., dog-human and human-dog) transmission.