ESBL-producing uropathogenic Escherichia coli isolated from dogs and cats in Switzerland

Escherichia coli sequence type 410 with carbapenemases: a paradigm shift within E. coli toward multidrug resistance

Escherichia coli sequence type ST410 is an emerging carbapenemase-producing multidrug-resistant (MDR) high-risk One-Health clone with the potential to significantly increase carbapenem resistance among E. coli. ST410 belongs to two clades (ST410-A and ST410-B) and three subclades (ST410-B1, ST410-B2, and ST410-B3). After a fimH switch between clades ST410-A and ST410-B1, ST410-B2 and ST410-B3 subclades showed a stepwise progression toward developing MDR. (i) ST410-B2 initially acquired fluoroquinolone resistance (via homologous recombination) in the 1980s. (ii) ST410-B2 then obtained CMY-2, CTX-M-15, and OXA-181 genes on different plasmid platforms during the 1990s. (iii) This was followed by the chromosomal integration of blaCMY-2, fstl YRIN insertion, and ompC/ompF mutations during the 2000s to create the ST410-B3 subclade. (iv) An IncF plasmid "replacement" scenario happened when ST410-B2 transformed into ST410-B3: F36:31:A4:B1 plasmids were replaced by F1:A1:B49 plasmids (both containing blaCTX-M-15) followed by blaNDM-5 incorporation during the 2010s. User-friendly cost-effective methods for the rapid identification of ST410 isolates and clades are needed because limited data are available about the frequencies and global distribution of ST410 clades. Basic mechanistic, evolutionary, surveillance, and clinical studies are urgently required to investigate the success of ST410 (including the ability to acquire successive MDR determinants). Such information will aid with management and prevention strategies to curb the spread of carbapenem-resistant E. coli. The medical community can ill afford to ignore the spread of a global E. coli clone with the potential to end the carbapenem era.

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.

Rapid identification of canine uropathogens by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry and the clinical factors that correlated bacterial species and antimicrobial resistance

Using the matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) method for bacterial diagnosis, rapid urine sample preparation can reduce time relapsing of diagnosis and improve discriminatory power in coinfection cases. We aimed to evaluate rapid urine preparation procedures before MALDI-TOF MS application using dog clinical urine samples in comparison with standard microbiological diagnostic methods by agreement analysis. We determined the frequency and distribution of bacteria and bacterial resistance and their correlations to clinical history. Three experimental procedures comprising direct centrifugation, 10% sodium dodecyl sulfate digestion, and ultrasonic preparation were performed for method validation and sensitivity. Sterile urine containing Escherichia coli and/or Staphylococcus aureus were used as simulated samples. By ultrasonic preparation, the microorganisms could be detected 1.46-1.51 × 105 CFU, which was considered the most suitable technique. This preparation was significantly consistent with the routine method based on data from Hospital Information Systems for 50 urine samples from canine cystitis. By standard protocol, Enterobacteriaceae and Staphylococcus pseudintermedius were found in most of the 155 urine samples with cystitis. Extended-spectrum beta-lactamase-producing Enterobacteriaceae was found in 25-30% of the samples. Imipenem resistance was found in 70% of Acinetobacter baumannii cases; almost all were resistant to second-generation fluoroquinolones and tetracyclines. The most efficient antibiotic for treating bacterial urinary tract infection was amoxicillin plus clavulanic acid. A. baumannii and Pseudomonas aeruginosa were susceptible to pradofloxacin. Prolonged urine catheterization was linked to lower urinary tract infections by Enterobacter spp., which also correlated with chronic kidney disease.

Domestic Pets in the United Arab Emirates as Reservoirs for Antibiotic-Resistant Bacteria: A Comprehensive Analysis of Extended-Spectrum Beta-Lactamase Producing Escherichia coli Prevalence and Risk Factors

Extended-spectrum β-lactamases resistant (ESBL-R) Escherichia coli (E. coli) has been reported from healthy and sick pets. However, data from Middle Eastern countries, including the United Arab Emirates (UAE), are minimal. This study provides the first evidence of ESBL-R E. coli carriage among pets in the UAE. A total of 148 rectal swabs were collected from domestic cats (n = 122) and dogs (n = 26) attending five animal clinics in the UAE. Samples were cultured directly onto selective agar, and suspected colonies were confirmed as ESBL-producing using phenotypic and molecular methods. Confirmed isolates were screened for their phenotypic resistance to twelve antimicrobial agents using the Kirby Bauer method. The owners of the pets completed a questionnaire at the time of sampling, and the data were used to identify risk factors. ESBL-R E. coli was detected in rectal swabs of 35 out of 148 animals (23.65%) (95% confidence interval [CI]: 17.06-31.32). Multivariable logistic regression analysis identified cats and dogs with access to water in ditches and puddles as 3.71 (p-value = 0.020) times more likely to be positive to ESBL-R E. coli than those without access to open water sources. Ciprofloxacin resistance was evident in 57.14% (44/77) of the ESBL-R E. coli isolates. The percentage of resistance to azithromycin and cefepime was 12.99% (10/77) and 48.05% (37/77), respectively. The bla_CTX-M gene was detected in 82% of the PCR-screened isolates (n = 50). Multidrug resistance (MDR) phenotypes were evident in 91% (70/77) of the isolates. In conclusion, ESBL-R E. coli was detected at a noticeable rate among healthy pet cats and dogs in the UAE, and the majority are MDR to clinically important antimicrobials such as fluoroquinolones and 3rd and 4th generation cephalosporins. Our results call for strengthening antimicrobial stewardship among companion animal veterinarians in the UAE to reduce the potential transmission of ESBL-R E. coli between pets, humans, and urban environments.

Carriage of Extended Spectrum Beta Lactamase-Producing Escherichia coli: Prevalence and Factors Associated with Fecal Colonization of Dogs from a Pet Clinic in Lower Saxony, Germany

Extended spectrum beta-lactamase (ESBL)-producing Escherichia coli are an emerging problem in veterinary and human medicine. Our study concentrated on the estimation of the prevalence and factors associated with the carriage of ESBL-producing E. coli in dogs who visited a veterinary clinic in northern Germany in 2017. For this reason, 1000 patients (healthy and sick dogs) were tested, resulting in 1000 samples originating from rectal swabs. Additional data were collected using a self-reported questionnaire that was completed by the dog owner. Factors associated with ESBL carriage were considered for further modeling if p < 0.05 using a two-sided Fisher test. Using a backward elimination procedure, the variables for the final multivariable logistic regression model were identified. In total, 8.9% of the dogs tested were positive for carriage of ESBL-producing E. coli. Seven factors were associated with the colonization of dogs with ESBL-E. coli within the multivariable model, namely husbandry system (p = 0.0019, OR = 3.00; 95% CI: 1.50-6.00), contact with puppies (p = 0.0044, OR = 2.43; 95% CI: 1.32-4.46), feeding of raw meat (p = 0.011, OR = 2.28; 95% CI: 1.21-4.31), food residues (p = 0.0151, OR = 2.31; 95% CI: 1.18-4.53) and food supplements (p = 0.0487, OR = 0.426; 95% CI: 0.18-0.96), and antibiotic treatments of dogs (p = 0.0005, OR = 3.030; 95% CI: 1.62-5.68) or owners (p = 0.041, OR = 2.74; 95% CI: 1.04-7.19) prior to the study. These factors refer to the animals themselves as well as to the owners and their habits or medical treatments. Although the causality and direction of transmission from owners to their dogs cannot be proven, the factor of antibiotic treatment of the owner is clearly associated with the dog's status.

Prevalence and Risk Factors Associated with Multidrug Resistance and Extended-Spectrum β-lactamase Producing E. coli Isolated from Healthy and Diseased Cats

Household cats have been identified as potential antimicrobial resistance (AMR) reservoirs, and the extended-spectrum β-lactamases (ESBL) producing E. coli circulating among cats has been more frequently reported globally, but the factors linked to its colonization remain poorly understood. Thus, the objectives of this study were to determine E. coli shedding and the occurrence of multidrug resistant (MDR)- and ESBL-producing E. coli, as well as to determine risk factors associated with colonization of MDR and ESBL-producing E. coli isolated from both healthy and diseased cats in the Eastern Province of Saudi Arabia. In a cross-sectional study, 2000 swabs were collected from five anatomical regions (anus, skin, ear canal, nares, and conjunctival sac) of 209 healthy and 191 diseased cats that were admitted to a veterinary clinic in the Eastern Province of Saudi Arabia. In addition, each cat owner filled out a questionnaire about their cat's demographics, management, health status, and antimicrobial usage. E. coli was detected in 165 (41.3%) of all cats, including 59 (28.2%) healthy and 106 (55.5%) diseased cats. In total, 170 E. coli isolates were found in healthy (35.3%) and diseased (64.7%) cats. Susceptibility testing revealed that 123 (72.4%) of the E. coli isolates were resistant to at least one of the tested antimicrobials. Overall, 17.6% (30/170) of E. coli isolates were MDR, with 10 (5.9%) and 20 (11.8%) isolates found in healthy and diseased cats, respectively. However, only 12 (7.1%) E. coli isolates were resistant to cefotaxime and harbored the bla_CTX-M gene (ESBL-producer), with seven (4.1%) in healthy and five (2.9%) in diseased cats. Risk factor analysis showed that the odds of MDR and ESBL-producing E. coli were (20 and 17) and (six and eight) times higher when the family and cats were previously treated with antimicrobials, respectively. The presence of a child in the cat's family was also linked to an increased risk of MDR E. coli colonization (OR = 3.4). In conclusion, a high frequency of MDR and ESBL-producing E. coli was detected among healthy and diseased cats in Saudi Arabia, raising concerns about transmission to humans and supporting the need of a "One Health" approach to address the potential threats of cats as AMR reservoirs.

Prevalence, incidence and risk factors for acquisition and colonization of extended-spectrum beta-lactamase- and carbapenemase-producing Enterobacteriaceae from dogs attended at a veterinary hospital in Spain

The last 10 years have seen a progressive increase in antibiotic resistance rates in bacteria isolated from companion animals. Exposure of individuals to resistant bacteria from companion animals, such as extended-spectrum beta-lactamase- (ESBL) and carbapenemase- (CPE) producing Enterobacteriaceae, can be propitiated. Few studies evaluate the incidence and risk factors associated with colonization by multidrug-resistant bacteria in dogs. This work aims to estimate the prevalence, incidence and risk factors associated with colonization of ESBL-E and CPE-E in 44 canine patients hospitalized in a veterinary hospital. The antimicrobial susceptibility of Enterobacteriaceae strains was analyzed and the molecular detection of resistant genes was performed. A prevalence of 25.0% and an incidence of ESBL-E of 45.5% were observed in dogs colonized by Enterobacteriaceae at hospital admission and release, respectively. Escherichia coli, Klebsiella pneumoniae, Citrobacter koseri and Morganella morganii were identified as ESBL-producing bacterial species. Resistance genes were detected for ESBL-producing strains. No CPE isolates were obtained on the CPE-selective medium. The administration of corticosteroids prior to hospitalization and the presence of concomitant diseases were associated with colonization by these bacteria in dogs. Considering that one-quarter of the patients evaluated were colonized by ESBL-E, companion animals should be considered as potential transmission vehicles and ESBL-E reservoirs for humans. Special care should be taken in animals attended at veterinary hospitals, as the length of stay in the hospital could increase the risks.

Isolation of Escherichia coli and Klebsiella pneumoniae strains producing extended spectrum β-lactamases from dog urine of the Metropolitan Area of the Aburrá Valley Antioquia-Colombia

Escherichia coli and Klebsiella pneumoniae are the most common pathogens causing urinary tract infections in humans and animals. Close contact between humans and companion animals can facilitate the spread of multidrugresistant pathogens between both species. Objective: To characterize extended-spectrum β-lactamases (ESBL) -producing E. coli and K. pneumoniae isolated from dogs with urinary tract infections in the metropolitan area of Valle del Aburrá (Antioquia, Colombia). Methods: Three-hundred seventy-one urine samples collected from March 2018 to March 2019 in a veterinary clinical laboratory were analyzed. E. coli and K. pneumoniae isolates were detected in chromogenic agar and identified by biochemical tests. Susceptibility testing was performed by disc diffusion and ESBL production was evaluated by the double disk test in all isolates. MIC determination of ESBL-positive isolates were performed on the automated VITEK®2 system. Multiple PCR was used for the detection of CTX-M beta-lactamases (group 1, 2, 9 and 8/25), SHV, TEM and AmpC of plasmid origin in ESBL-positive isolates. Results: In total 22 out 371 isolates were positive for ESBL production by double disc test, 11 E. coli (ESBL-Ec) and 11 K. pneumoniae (ESBL-Kp). The multiple PCR detected CTX-M group 1 in the 22 ESBL-positive isolates. Multi-drug resistance was observed in all ESBL-producing isolates Conclusions:  A high frequency of antibiotic multi-resistance was found in ESBL-Ec and ESBL-Kp. The main ESBL detected was CTX-M group 1, which also prevails in human isolates.

Companion Animals as Potential Reservoirs of Antibiotic Resistant Diarrheagenic Escherichia coli in Shandong, China

Antibiotic resistance genes of Escherichia coli (E. coli) from companion animals were still poorly understood. Here, we investigated the extended-spectrum β-lactamases (ESBLs) resistance genes of E. coli from companion animals in Shandong, China. A total of 79 isolates (80.6%) were recovered from 98 healthy or diarrheal companion animals in 2021, among which ESBLs-producing isolates accounted for 43.0% (34/79), and more than half of ESBL E. coli (ESBL-EC) strains (n = 19) were isolated from healthy companion animals. Diarrheagenic E. coli isolates (45.6%, n = 36) were represented by enterotoxigenic (ETEC) (32.9%), enteropathogenic (EPEC) (10.1%) and enteroinvasive (EIEC) (2.6%), 20 isolates of which were from healthy pets. Among tested antibiotics, resistance to tetracycline (64.6%) was the most commonly observed, followed by doxycycline (59.5%) and ampicillin (53.2%). Notably, all isolates were susceptible to meropenem. The multidrug-resistant (MDR) rate was 49.4%, 20 isolates of which were ESBLs producers; moreover, 23.4%, 16.4% of ESBL-EC strains were resistant to 5 or more, 7 or more antibiotics, respectively. Among the 5 β-lactamase resistance genes, the most frequent gene was bla_CTX-M (60.76%), followed by bla_SHV (40.51%). The plasmid-mediated quinolone resistance (PMQR) gene aac(6')-Ib-cr was detected in 35 isolates. Additionally, ESBL-associated genes (i.e., bla_CTX-M, bla_SHV) were found in 76.5% ESBL-EC strains, with six isolates carrying bla_CTX-M and bla_SHV. The marker gene of high-pathogenicity island gene irp2 (encoding iron capture systems) was the most frequency virulence gene. Our results showed that ESBL-EC were widespread in healthy or diarrhea companion animals, especially healthy pets, which may be a potential reservoir of antibiotic resistance, therefore, enhancing a risk to public and animal health.

ESBL/pAmpC-Producing Escherichia coli Causing Urinary Tract Infections in Non-Related Companion Animals and Humans

Urinary tract infections (UTI) caused by Escherichia coli are frequently diagnosed in humans and companion animals. Extended-spectrum beta-lactamase (ESBL)- and cephalosporinase (pAmpC)-producing Escherichia coli are worldwide-disseminated and frequently multidrug-resistant, hence leading to treatment failure and public health concerns. This study aimed to characterize and compare ESBL/pAmpC-producing E. coli strains causing community-acquired UTI in companion animals and non-related humans. Third-generation cephalosporin (3GC)-resistant E. coli (companion animals n = 35; humans n = 85) isolated from patients with UTI were tested against 14 antimicrobials following CLSI guidelines. PCR-based assays were used to detect the major E. coli phylogenetic groups, pathogenicity associated-islands (PAIs), virulence genes, and ESBLs/pAmpC resistance genes. ESBL/pAmpC-producing E. coli isolates were typed by multi-locus sequence typing (MLST) and PCR. E. coli strains from companion animals and humans shared two MDR high-risk clonal lineages: ST131 and ST648. To the best of our knowledge, this study reports the first description of E. coli ST131 clade C1-M27 and the clonal lineage ST131 clade A in humans with community-acquired UTI in Portugal. Considering that companion animals with UTI are generally treated at home by the owners, measures should be implemented to avoid the spread of multidrug-resistant high-risk clones to humans and their household environment.

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.

Presence of the Extended-Spectrum-β-Lactamase and Plasmid-Mediated AmpC-Encoding Genes in Escherichia coli from Companion Animals-A Study from a University-Based Veterinary Hospital in Taipei, Taiwan

Extended-spectrum-β-lactamase (ESBL) and AmpC β-lactamase are two enzymes commonly found in Enterobacteriaceae that confer resistance to major antibiotics, such as third-generation cephalosporins that are widely prescribed for both human and animals. We screened for Escherichia coli producing ESBL and plasmid-mediated AmpC β-lactamase (pAmpC) from dogs and cats brought to National Taiwan University Veterinary Hospital, Taipei, Taiwan from 29 June 2020, to 31 December 2020. The genotypes and phylogenetic relatedness of these E. coli were also analyzed. Fifty samples of E. coli obtained from 249 bacterial isolates were included in this study. Among them, eight isolates had ESBL, seven had pAmpC, and one had both. Thirty-two percent (16/50) of E. coli isolates were resistant to third-generation cephalosporins. The detected ESBL genes included the bla_CTX-M-1 and bla_CTX-M-9 groups, and the bla_CMY-2 group was the only gene type found in pAmpC. ESBL-producing E. coli belonged to the pathogenic phylogroup B2, and the sequence types (STs) were ST131 and ST1193. Three isolates were determined to be ST131-O25b, a highly virulent epidemic clone. The pAmpC-producing E. coli were distributed in multiple phylogroups, primarily the commensal phylogroup B1. The STs of the pAmpC-producing E. coli included ST155, ST315, ST617, ST457, ST767, ST372, and ST93; all of these have been reported in humans and animals. Imipenem was active against all the ESBL/pAmpC-producing E. coli; however, since in humans it is a last-resort antimicrobial, its use in companion animals should be restricted.

Prevalence of extended-spectrum β-lactamase-producing Escherichia coli in companion dogs in animal clinics, Surabaya, Indonesia

Background and Aim: The practice of keeping animals as pets is becoming increasingly common. The upsurge of extended-spectrum β-lactamase (ESBL)-producing organisms of animal origin is a health threat globally. This study aimed to identify the presence of extended-spectrum β-lactamase-producing Escherichia coli in companion dogs in animal clinics in Surabaya, Indonesia. Materials and Methods: A total of 85 rectal swab samples were collected from companion dogs at five animal clinics in different regions of Surabaya, Indonesia. The presence of E. coli was identified from the samples using standard methods, followed by antibiotic sensitivity testing. The resistant isolates were examined for the presence of ESBL using the double-disk synergy test method. The phenotypically identified ESBL-producing E. coli was further confirmed with an automated system using Vitek-2. Results: The rectal swab samples (n=85) tested were 100% positive for E. coli isolates. Eight (9.41%) out of the 85 E. coli obtained from rectal swabs were extended-spectrum β-lactamase producers. All eight ESBL-producing E. coli were identified by automated Vitek-2 confirmatory tests. Conclusion: This study provides insight into the prevalence of ESBL-producing organisms isolated from companion dogs in Indonesia. This work indicates the need for the general public to be more aware of the role of companion animals in disseminating pathogenic organisms, since they serve as potential reservoirs in the spread of antibiotic resistance affecting human health.

Multiple and High-Risk Clones of Extended-Spectrum Cephalosporin-Resistant and blaNDM-5-Harbouring Uropathogenic Escherichia coli from Cats and Dogs in Thailand

Resistance to extended-spectrum cephalosporins (ESC) and carbapenems in Escherichia coli (E. coli), increasingly identified in small animals, indicates a crisis of an antimicrobial resistance situation in veterinary medicine and public health. This study aimed to characterise the genetic features of ESC-resistant E. coli isolated from cats and dogs with urinary tract infections in Thailand. Of 72 ESC-resistant E. coli isolated from diagnostic samples (2016-2018), blaCTX-M including group 1 (CTX-M-55, -15 and -173) and group 9 (CTX-M-14, -27, -65 and -90) variants were detected in 47 isolates (65.28%) using PCR and DNA sequencing. Additional antimicrobial resistance genes, including plasmid-mediated AmpC (CIT and DHA), blaNDM-5, mcr-3, mph(A) and aac(6')-Ib-cr, were detected in these isolates. Using a broth microdilution assay, all the strains exhibited multidrug-resistant phenotypes. The phylogroups were F (36.11%), A (20.83%), B1 (19.44%), B2 (19.44%) and D (4.17%), with several virulence genes, plasmid replicons and an integrase gene. The DNA fingerprinting using a repetitive extragenic palindromic sequence-PCR presented clonal relationships within phylogroups. Multiple human-associated, high-risk ExPEC clones associated with multidrug resistance, including sequence type (ST) 38, ST131, ST224, ST167, ST354, ST410, ST617 and ST648, were identified, suggesting clonal dissemination. Dogs and cats are a potential reservoir of ESC-resistant E. coli and significant antimicrobial resistance genes.

High prevalence of blaCTX-M and blaSHV among ESBL producing E. coli isolates from beef cattle in China's Sichuan-Chongqing Circle

Enterobacteria that produce extended-spectrum β-lactamase (ESBL) such as Escherichia coli (E. coli) are common in our environment and known to cause serious health implications in humans and animals. β-lactam antibiotics such as penicillins, cephalosporins and monobactams are the most commonly used anti-bacterials in both humans and animals, however, Gram negative bacteria (such as E. coli) that produces extended-spectrum β-lactamases (ESBLs) have the ability to hydrolyze most β-lactams therefore making them resistant to β-lactam antibiotics. Recent extensive researches on the epidemiology and genetic characteristics of extended-spectrum β-lactamase (ESBL)-producing E. coli reported the existence of ESBL-producing E. coli in humans, companion animals and poultry. Therefore, this experiment was performed to investigate the prevalence and genetic characteristics of β-lactamase producing E. coli isolated from beef cattle farms in the Sichuan-Chongqing circle of China. Phenotypic confirmation of ESBL-producing E. coli was performed using the double disk synergy test. Polymerase Chain Reaction (PCR) was used to detect bla_CTX-M, bla_SHV and bla_TEM gene codes, then after, isolates were divided into different phylogenetic groups and multi-locus sequence typing (MLST). The results showed that out of the 222 E. coli strains isolated from the beef cattle, 102 strains showed ESBL phenotypes. The PCR results showed that bla_CTX-M was the predominant ESBL gene identified among the E. coli strains with 21 (9.5%) isolates having this gene, followed by bla_SHV which was found in 18 (8.1%) isolates. The majority of these ESBL positive isolates were assigned to phylogroup A (19.8%) followed by phylogroup B1 (13.5%). In addition, from the MLST results on ESBL positive isolates (n = 30) we identified 19 STs, ST398 (ST398cplx) and ST7130 which were the prevalent population (20%). In conclusion, the high prevalence of CTX-M, and SHV in the study confirmed its association with E. coli infection; therefore, this calls for health concerns on ESBL-producing E. coli. As far as we know, this is the first comprehensive research report relating to ESBL-producing E. coli incidence in Chinese beef cattle.

Global prevalence and molecular characterization of extended-spectrum β-lactamase producing-Escherichia coli in dogs and cats - A scoping review and meta-analysis

Antimicrobial resistance (AMR) represents a major threat to human and animal health. Part of the AMR dimension is the circulation of extended-spectrum β-lactamases producing-Escherichia coli (ESBL-E. coli), which is now commonly reported among companion animals. However, the global perspective of the prevalence and population structure of ESBL-E. coli circulating in dogs and cats has not been estimated limiting our understanding of their role in the dissemination of ESBL-E. coli. The aim of this study was to compare the prevalence of ESBL-E. coli between dogs and cats and across countries through meta-analysis. We also performed a scoping review to summarize the current knowledge on ESBL genes and E. coli clones circulating among companion animals. A total of 128 studies published in PubMed, Web of Science, and Scopus up to April 2020 were selected and contained information on prevalence and/or molecular characterization of ESBL genes and ESBL-E. coli clones. Our review shows an increase in the number of publications between 2000 and 2019, concentrated mainly in Europe. Prevalence varied across continents, ranging from 0.63% (Oceania) to 16.56% (Africa) in dogs and from 0% (Oceania) to 16.82% (Asia) in cats. Although there were twice as many studies reporting prevalence on dogs (n = 61) than on cats (n = 32), and only 9 studies focused exclusively on cats, our meta-analysis showed no difference in the global prevalence of ESBL-E. coli between dogs (6.87% [95% CI: 4.46-10.45%]) and cats (5.04% [95% CI: 2.42-10.22%]). A considerable diversity of ESBL genes (n = 60) and sequence types (ST) (n = 171) were recovered from companion animals. ESBL-E. coli encoded by CTX-M-15 (67.5%, 77/114) and SHV-12 (21.9%, 25/114), along with resistant strains of ST38 (22.7%, 15/66) and ST131 (50%, 33/66) were widespread and detected in all continents. While presence of ESBL-E. coli is widespread, the drivers influencing the observed ESBL-E. coli prevalence and the clinical relevance in veterinary medicine and public health along with economic impact of ESBL-E. coli infections among companion animals need to be further investigated.

Antibiotic-Resistant Enterobacteriaceae in Wastewater of Abattoirs

Antibiotic-resistant Enterobacteriaceae are regularly detected in livestock. As pathogens, they cause difficult-to-treat infections and, as commensals, they may serve as a source of resistance genes for other bacteria. Slaughterhouses produce significant amounts of wastewater containing antimicrobial-resistant bacteria (AMRB), which are released into the environment. We analyzed the wastewater from seven slaughterhouses (pig and poultry) for extended-spectrum β-lactamase (ESBL)-carrying and colistin-resistant Enterobacteriaceae. AMRB were regularly detected in pig and poultry slaughterhouse wastewaters monitored here. All 25 ESBL-producing bacterial strains (19 E. coli and six K. pneumoniae) isolated from poultry slaughterhouses were multidrug-resistant. In pig slaughterhouses 64% (12 of 21 E. coli [57%] and all four detected K. pneumoniae [100%]) were multidrug-resistant. Regarding colistin, resistant Enterobacteriaceae were detected in 54% of poultry and 21% of pig water samples. Carbapenem resistance was not detected. Resistant bacteria were found directly during discharge of wastewaters from abattoirs into water bodies highlighting the role of slaughterhouses for environmental surface water contamination.

Characterization of antimicrobial-resistant Escherichia coli causing urinary tract infections in dogs: Passive surveillance in Saskatchewan, Canada 2014 to 2018

BACKGROUND

Urinary tract infections (UTIs) are common in dogs and can be caused by multidrug-resistant Escherichia coli (E coli).

OBJECTIVE

To describe the frequency and mechanisms of antimicrobial resistance (AMR) among E coli causing UTIs in dogs in Western Canada during a 4-year surveillance period.

ANIMALS

Urine from 516 dogs.

METHODS

From November 2014 to 2018, 516 nonduplicate E coli isolates from the urine of dogs were collected from a diagnostic laboratory. Susceptibility testing was determined for a panel of 14 antimicrobials belonging to 7 drug classes. Resistant isolates were screened for the presence of extended-spectrum beta-lactamases (ESBLs), AmpC β-lactamases, and plasmid-mediated quinolone resistance (PMQR) genes. Epidemiological relationships were assessed by MLST.

RESULTS

80.2% (414/516) of isolates were susceptible to all antimicrobials tested. There was no significant increase in the proportion of isolates resistant to any of the tested antimicrobials during the study period. Resistance to ampicillin was the most common (14.9%, 77/516). Overall, 12 isolates had blaCMY-2 -type AmpC β-lactamases, and 7 produced CTX-M-type ESBLs. A single isolate had the aac(6')-Ib-cr PMQR gene. The qnr and qepA determinants were not detected. A single isolate belonging to the pandemic lineage ST131 was identified.

CONCLUSION

Escherichia coli isolated from the urine of dogs in our region remain susceptible to first-line therapies, though resistance, particularly to the aminopenicillins, warrants monitoring. This is the first description of E coli ST131 from a companion animal in Canada.

Identification and Characterization of Multidrug-Resistant Extended-Spectrum Beta-Lactamase-Producing Bacteria from Healthy and Diseased Dogs and Cats Admitted to a Veterinary Hospital in Brazil

The objective of this study was to identify the main extended-spectrum beta-lactamase (ESBL)-producing bacteria and to detect the frequency of the major genes responsible to trigger this resistance in hospitalized animals. We collected 106 rectal swabs from cats (n = 25) and dogs (n = 81) to detect ESBL-producing isolates. ESBL-positive samples were submitted to the antimicrobial susceptibility test, and polymerase chain reaction was performed to detect TEM, SHV, and CTX-M genes from different groups. We observed that 44.34% of these samples (11 cats and 36 dogs) were positive for ESBL-producing bacteria. Thirteen animals (27.66%-seven cats and six dogs) were hospitalized for elective castration (healthy animals). Only a single animal was positive for ESBL-producing bacteria at hospital admission (the animal also showed an ESBL-positive isolate after leaving the hospital), whereas 11 were positive only at the hospital discharge. Of the 73 ESBL-producing isolates, 13 were isolated from cats (8 sick and 7 healthy) and 60 from dogs (53 sick and 7 healthy). Escherichia coli was the major ESBL-producing bacterium isolated (53.42%), followed by Pseudomonas aeruginosa (15.07%), Salmonella sp., and Proteus mirabilis (5.48% each one). Antimicrobial resistance profile of ESBL-producing isolates showed that 67 isolates (91.78%) were resistant to 3 or more antibiotic classes, while 13 of them (17.81%-2 healthy cats and 11 sick dogs) were resistant to all tested antimicrobial classes. The bla_TEM gene exhibited the highest frequency in ESBL-producing isolates, followed by the bla_CTX-M group 8/25, bla_CTX-M group 1 and bla_CTX-M group 9 genes. These results are useful to assess the predominance of ESBL-producing isolates recovered from dogs and in cats in Brazil. Consequently, we draw attention to these animals, as they can act as reservoirs for these microorganisms, which are the major pathogens of nosocomial infections worldwide.

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.

Genetic diversity, antimicrobial resistance and extended-spectrum β-lactamase type of Escherichia coli isolates from chicken, dog, pig and yak in Gansu and Qinghai Provinces, China

OBJECTIVES

In this study, the genetic diversity, phylogenetic grouping, antimicrobial resistance and extended-spectrum β-lactamase (ESBL) types of Escherichia coli isolates from chickens, dogs, pigs and yaks in six prefectures of Gansu and Qinghai Provinces, China, were investigated.

METHODS

E. coli was isolated from diarrhoeic and healthy faecal samples. Multilocus sequence typing (MLST), phylogenetic grouping, antimicrobial resistance and ESBL profiles were investigated.

RESULTS

A total of 142 MLST sequence types (STs) were identified from 400 E. coli isolates. eBURST clustering analysis resolved the 142 STs into 19 clonal complexes (CCs) and 67 singletons. PCR phylogenetic typing determined the isolation rate of potentially pathogenic B2/D group isolates among all E. coli to be 12.5% from healthy animal samples and 17.5% from diarrhoeic samples. Antimicrobial susceptibility testing revealed 78 antimicrobial resistance patterns. E. coli resistance rates were highest to doxycycline, ampicillin and tetracycline, whereas polymyxin B and meropenem had the lowest resistance rates. All polymyxin B-resistant E. coli isolates were positive for the mcr-1 gene. A total of 62 ESBL-producing isolates were identified. The ESBL prevalence was 55.0% in diarrhoeic samplings and 5.6% in healthy animals. TEM (82.3%) was the predominant ESBL type, followed by CTM (43.5%) and SHV (19.4%).

CONCLUSION

E. coli isolates in the study area have a high diversity of genetic and antimicrobial resistance patterns but a relatively low isolation rate of potentially pathogenic phylogroups. However, the somewhat high isolation rate of multidrug-resistant E. coli, particularly ESBL-producing isolates, requires continual surveillance of E. coli from animals in these areas.

Broad-Spectrum Cephalosporin-Resistant and/or Fluoroquinolone-Resistant Enterobacterales Associated with Canine and Feline Urogenital Infections

The aim of the present study was to characterize Enterobacterales resistant to 3rd and 4th generation cephalosporins, carbapenems and/or fluoroquinolones, isolated from dogs and cats with urogenital infections. In total, 36 strains (Escherichia coli (n = 28), Klebsiella pneumoniae (n = 3), Serratia marcescens, Raoultella ornithinolytica, Proteus mirabilis, Citrobacter portucalensis and Enterobacter cloacae (each n = 1)) were included in the present study, 28 from Austria and 8 from Serbia. Isolates were characterized by a polyphasic approach including susceptibility pheno- and genotyping and microarray-based assays. Escherichia (E.) coli isolates were additionally characterized by two-locus (fumC and fimH) sequence phylotyping and multi-locus sequence typing (MLST) of selected isolates. MLST of carbapenem-resistant Enterobacter cloacae isolates was also performed. Among E. coli, the most dominant phylogenetic group was B1 (27.8%), followed by C, (16.6%), A and Clade II (5.5% each), B2 and F (2.77% each). The most predominant β-lactam resistance genes were blaTEM (70%) and blaCTX-M (38.8%), blaCMY (25%). blaNDM was detected in one carbapenem-resistant Enterobacter cloacae ST114. The most common ST among selected E. coli was 744 (10.7% isolates). The pandemic clones ST131 and ST648 carrying CTX-M-15 were also detected. Remaining STs belonged to 469, 1287, 1463 and 1642. E. coli clonotyping revealed 20 CH types. Based on the presence of certain virulence genes, three isolates were categorized as ExPEC/UPEC. The most prevalent virulence factors were fimH detected in 61%, iucD and iss both in 55%, iroN in 27.8%, papC in 13.8% and sat in 8.3% isolates.

Detection of multidrug resistance and extended-spectrum/plasmid-mediated AmpC beta-lactamase genes in Enterobacteriaceae isolates from diseased cats in Italy

OBJECTIVES

The aim of this study was to determine the antimicrobial susceptibility of Enterobacteriaceae isolated from cats affected by diseases commonly encountered in practice, and to characterise the third-generation cephalosporin (3GC)-resistance molecular mechanisms involved.

METHODS

Clinical samples (n = 100) included 58 rectal swabs from cats with diarrhoea, 31 nasal swabs from cats with clinical signs of upper respiratory tract disease, four ear swabs from cats with otitis, three conjunctival swabs from cats with conjunctivitis, two oral swabs from cats with stomatitis, one swab from a skin abscess and one urine sample from a cat with cystitis. A total of 125 Enterobacteriaceae were isolated from 90 cats. Escherichia coli was the most frequently isolated species (n = 65), followed by Enterobacter species (n = 20), Proteus species (n = 13), Citrobacter species (n = 12) and others (n = 15). Bacterial susceptibility testing was performed with respect to eight antimicrobial classes. Beta (β)-lactamase genes were identified by PCR and nucleotide sequencing.

RESULTS

Overall, the higher frequency of resistance was to amoxicillin-clavulanate (61.3%), trimethoprim/sulfamethoxazole (33.6%) and cefotaxime (32.8%). Thirty-six percent of the isolates (n = 45) were resistant to 3GCs. Of these isolates, 34 were tested by PCR and nucleotide sequencing and 23 were confirmed as encoding β-lactamase genes. Fourteen 3GC-resistant isolates harboured extended-spectrum β-lactamases (ESBLs) belonging to groups CTX-M-1 (n = 12, two of which were CTX-M-79), CTX-M-2 (n = 1) and CTX-M-9 (n = 1), as well as SHV-12 (n = 1) and TEM-92 (n = 1). Nine isolates had CMY-2 plasmid-mediated AmpC β-lactamases (pAmpC). Thirty-one percent (n = 39) of the isolates were multidrug resistant (MDR) and were isolated from 34% (n = 31/90) of the cats.

CONCLUSIONS AND RELEVANCE

A high frequency of MDR and ESBL/pAmpC β-lactamase-producing Enterobacteriaceae were detected among bacteria isolated from a feline population in southern Italy with a variety of common clinical conditions, which poses limitations on therapeutic options for companion animals. We describe the first detection of CTX-M-79 and TEM-92 ESBL genes in isolates from cats.

Antimicrobial prescriptions and adherence to prudent use guidelines for selected canine diseases in Switzerland in 2016

Background

Antimicrobial resistance is an increasing problem in human and veterinary medicine and is closely linked to the use of antimicrobials. The objective of this study was to describe antimicrobial prescriptions for selected canine diseases in Switzerland during 2016.

Methods

Dogs presented to two university hospitals and 14 private practices for acute diarrhoea (AD; n=371), suspected or confirmed urinary tract infections (UTIs; n=245), respiratory tract infections (RTIs; n=274) or wound infections (WIs; n=175) were included. Clinical history, diagnostic work-up and antimicrobial prescription (class, dosage and duration) were retrospectively assessed. A justification score was applied to evaluate appropriateness of antimicrobial therapy based on available national and international consensus guidelines.

Results

Antimicrobials were prescribed in 65 per cent of dogs with AD, 88 per cent with UTI, 62 per cent with RTI and 90 per cent with WI. The most prescribed antimicrobial classes (monotherapy and combination therapy) were potentiated aminopenicillins (59 per cent), nitroimidazoles (22 per cent), non-potentiated aminopenicillins (16 per cent) and fluoroquinolones (13 per cent). Overall, 38 per cent (95 per cent CI 0.35 to 0.41) of the prescriptions were in accordance with consensus guidelines. In dogs with AD, antimicrobial therapy was associated with the presence of haemorrhagic diarrhoea (P<0.05) and complied in 32 per cent with consensus guidelines, which recommend antimicrobial treatment only when sepsis is suspected. A bacterial aetiology was confirmed via culture and/or sediment examination in 36 per cent of dogs with suspected UTI.

Conclusions

Overall, adherence to consensus guidelines was poor both, at university hospitals and private practices. Antimicrobial stewardship measures are therefore needed to improve prudent use.

The Occurrence and Characterization of Extended-Spectrum-Beta-Lactamase-Producing Escherichia coli Isolated from Clinical Diagnostic Specimens of Equine Origin

Escherichia coli isolates were recovered from clinical specimens of equine patients admitted to the Texas A&M Veterinary Medical Teaching Hospital over a five-year period. Ceftiofur resistance was used as a marker for potential extended-spectrum beta-lactamase (ESBL)-activity, and of the 48 ceftiofur-resistant E. coli isolates, 27.08% (n = 13) were phenotypically ESBL-positive. Conventional PCR analysis followed by the _large-scalebla Finder multiplex PCR detected the ESBL genes, CTX-M-1 and SHV, in seven out of the 13 isolates. Moreover, beta-lactamase genes of TEM-1-type, BER-type (AmpC), and OXA-type were also identified. Sequencing of these genes resulted in identification of a novel TEM-1-type gene, called bla_TEM-233, and a study is currently underway to determine if this gene confers the ESBL phenotype. Furthermore, this report is the first to have found E. coli ST1308 in horses. This subtype, which has been reported in other herbivores, harbored the SHV-type ESBL gene. Finally, one out of 13 E. coli isolates was PCR-positive for the carbapenemase gene, bla_IMP-1 despite the lack of phenotypically proven resistance to imipenem. With the identification of novel ESBL gene variant and the demonstrated expansion of E. coli sequence types in equine patients, this study underscores the need for more investigation of equines as reservoirs for ESBL-producing pathogens.

Extended-spectrum β-lactamase-producing Escherichia coli isolated from healthy Thoroughbred racehorses in Japan

Extended-spectrum β-lactamase-producing Escherichia coli (ESBLEC) have become a major health concern in both human and veterinary medicine. These bacteria could become a critical problem in equine medicine due to the limited number of antimicrobial drugs available. However, there are no previous reports of ESBLEC isolated from horses in Japan. The objectives of this study were to investigate the occurrence of ESBLEC isolated from feces in healthy Thoroughbred racehorses in Japan. Feces samples were collected from 147 healthy Thoroughbred racehorses by equine veterinarians at the Japan Racing Association (103 from Miho Training Center and 44 from Ritto Training Center) between March 2017 and April 2018. Samples were screened for ESBLECs using MacConkey agar supplemented with 1 µg/ml cefotaxime. Detection of ESBL genes was performed by PCR and confirmed by DNA sequencing. Horizontal transmission was demonstrated by conjugation assay. In this study, 24 ESBLECs were isolated from twelve horse feces samples (8.2%). All ESBLECs harbored bla_CTX-M-2, and both bla_TEM-1 and bla_CTX-M-2 were detected in nine isolates (37.5%). ESBLECs showed resistance to all β-lactam antibiotics (100%) tested, followed by trimethoprim (66.7%), streptomycin (62.5%), tetracycline (25.0%), and oxytetracycline (25.0%). Horizontal transmission was successfully demonstrated by conjugation assay in eight of 13 isolates, and bla_CTX-M-2 was detected by PCR in all transconjugants. This study showed that racehorses in Japan are potential reservoirs of ESBLECs.

Repeated Isolation of Extended-Spectrum-β-Lactamase-Positive Escherichia coli Sequence Types 648 and 131 from Community Wastewater Indicates that Sewage Systems Are Important Sources of Emerging Clones of Antibiotic-Resistant Bacteria

Antibiotic resistance in bacteria is an emerging problem globally. Resistant bacteria are found in human and animal microbiota, as well as in the environment. Wastewater receives bacteria from all these sources and thus can provide a measurement of abundance and diversity of antibiotic-resistant bacteria circulating in communities. In this study, water samples were collected from a wastewater pump station in a Norwegian suburban community over a period of 15 months. A total of 45 daily samples were cultured and analyzed for the presence of Escherichia coli Eighty E. coli-like colonies were collected from each daily sample and then phenotyped and analyzed for antibiotic resistance using the PhenePlate-AREB system. During the sampling period, two unique E. coli phenotypes with resistance to cefotaxime and cefpodoxime indicating carriage of extended-spectrum β-lactamases (ESBL) were observed repeatedly. Whole-genome sequencing of 15 representative isolates from the two phenotypes identified these as two distinct clones belonging to the two globally spread E. coli multilocus sequence types (STs) ST131 and ST648 and carrying blaCTX-M-15 The number of ESBL-positive E. coli strains in the community wastewater pump station was 314 of 3,123 (10%) analyzed E. coli strains. Of the ESBL-positive isolates, 37% belonged to ST648, and 7% belonged to ST131. Repeated findings of CTX-M-15-positive ST648 and ST131 over time indicate that these STs are resident in the analyzed wastewater systems and/or circulate abundantly in the community.

Occurrence of plasmid-mediated quinolone resistance determinants among Escherichia coli strains isolated from animals in Tunisia: Specific pathovars acquired qnr genes

OBJECTIVES

The aim of this study was to characterise Escherichia coli strains harbouring plasmid-mediated quinolone resistance (PMQR) genes recovered from various samples (n = 116) from healthy and diarrhoeic animals in Tunisia.

METHODS

All nalidixic acid-resistant E. coli isolates were screened for the presence of PMQR genes. Isolates positive for PMQR genes were investigated by PCR for chromosomal mutations in the quinolone resistance-determining regions (QRDRs) of GyrA and ParC, the presence of class 1 and class 2 integrons, genes encoding tetracycline and sulfonamide resistance, genes encoding virulence factors, and phylogenetic group. Genetic relationships was determined by pulsed-field gel electrophoresis (PFGE).

RESULTS

Amongst 51 nalidixic acid-resistant isolates, 9 harboured PMQR genes (5 co-harbouredqnrS1 and qnrB1, 3 harboured qnrS1 and 1 harboured qnrB1). Two types of mutation in the QRDR of GyrA were observed: S83L and D87N (eight isolates) and S83L (one isolate). For the QRDR of ParC, the substitution S80I was observed in four isolates. A class 1 integron was found in six isolates. The tetA or tetB gene was observed in six isolates and both tetA and tetB were co-harboured by two isolates. The sul1, sul2 and sul3 genes were detected in six, four and one isolates, respectively. According to the presence of specific virulence genes, the nine strains were classified as UPEC (5), EAEC (3) and EPEC (1). Three isolates from turkey faeces were clonally related by PFGE.

CONCLUSION

These findings highlight the plausible role of the avian industry as a reservoir of human pathogenic E. coli strains.

High prevalence of CTX-M belonging to ST410 and ST889 among ESBL producing E. coli isolates from waterfowl birds in China's tropical island, Hainan

The epidemiology and genetic characteristics of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) have been widely studied in human and veterinary settings. ESBL-producing E. coli are generally reported in pigs, poultry, and dairy farm animals. Here, we report on the prevalence and genetic characteristics of beta-lactamase producing E. coli isolated from waterfowl birds in Hainan, China. After phenotypic confirmation, genes encoding bla_CTX-M, bla_SHV and bla_TEM were detected by polymerase chain reaction (PCR). The isolates were assigned to different phylogenetic groups, and multi-locus sequence typing (MLST). Taken as a whole, 289 (92.9%) out of 311 E. coli isolates from waterfowl birds were confirmed as ESBL phenotypes by double-disk synergy testing. Subsequent PCR analysis revealed that bla_CTX-M was the predominant ESBL gene identified in 146 (46.9%) isolates, followed by the combination of bla_CTX-M and bla_TEM in 70 (22.5%) isolates. The majority of these positive isolates were assigned to phylogroup B2 (46.2%) followed by phylogroup A (43.6%). In addition, MLST assigned representative ESBL positive isolates (n = 40) to 18 STs, and ST410 (ST23cplx) was the most prevalent population (22.5%). The high prevalence of CTX-M and STs frequently associating with E. coli infections should be of concern as it poses threats to animal and public health. To the best of our knowledge, this is the first comprehensive study to report on the occurrence of ESBL producing E. coli from waterfowl birds in China.

Genetic structure, antimicrobial resistance and frequency of human associated Escherichia coli sequence types among faecal isolates from healthy dogs and cats living in Canberra, Australia

Extraintestinal pathogenic Escherichia coli (ExPEC) cause clinical infections in humans. Understanding the evolution and dissemination of ExPEC strains via potential reservoirs is important due to associated morbidity, health care costs and mortality. To further understanding this survey has examined isolates recovered from the faeces of 221 healthy dogs and 427 healthy cats. The distribution of phylogroups varied with host species, and depended on whether the animal was living in a shelter or a home. The human associated STs 69, 73, 95, 131 and 127 were prevalent, with 30.5% of cat isolates and 10.3% of dog isolates representing these ExPEC sequence types. Resistance to the antibiotics ampicillin and tetracycline was common, but resistance to other antimicrobials was negligible.

The co-transfer of plasmid-borne colistin-resistant genes mcr-1 and mcr-3.5, the carbapenemase gene blaNDM-5 and the 16S methylase gene rmtB from Escherichia coli

We found an unusual Escherichia coli strain with resistance to colistin, carbapenem and amikacin from sewage. We therefore characterized the strain and determined the co-transfer of the resistance determinants. Whole genome sequencing was performed using both Illumina HiSeq X10 and MinION sequencers. Short and long reads were subjected to de novo hybrid assembly. Sequence type, antimicrobial resistance genes and plasmid replicons were identified from the genome sequences. Phylogenetic analysis of all IncHI2 plasmids carrying mcr-1 available in GenBank was performed based on core genes. Conjugation experiments were performed. mcr-3.5 was cloned into E. coli DH5α. The strain belonged to ST410, a type with a global distribution. Two colistin-resistant genes, mcr-1.1 and mcr-3.5, a carbapenemase gene bla_NDM-5, and a 16S methylase gene rmtB were identified on different plasmids of IncHI2(ST3)/IncN, IncP, IncX3 and IncFII, respectively. All of the four plasmids were self-transmissible and mcr-1.1, mcr-3.5, bla_NDM-5 and rmtB were transferred together. mcr-1-carrying IncHI2 plasmids belonged to several sequence types with ST3 and ST4 being predominant. MIC of colistin (4 μg/ml) for DH5α containing mcr-3.5 was identical to that containing the original mcr-3 variant. In conclusion, carbapenem resistance, colistin resistance and high-level aminoglycoside resistance can be transferred together even when their encoding genes are not located on the same plasmid. The co-transfer of multiple clinically-important antimicrobial resistance represents a particular challenge for clinical treatment and infection control in healthcare settings. Isolates with resistance to both carbapenem and colistin are not restricted to a given sequence type but rather are diverse in clonal background, which warrants further surveillance. The amino acid substitutions of MCR-3.5 have not altered its activity against colistin.

Occurrence and Antibiogram of Generic Extended-Spectrum Cephalosporin-Resistant and Extended-Spectrum β-Lactamase-Producing Enterobacteria In Horses

This study was conducted to isolate generic extended-spectrum cephalosporin (ESC)-resistant and extended-spectrum β-lactamase (ESBL)-producing enterobacteria from horses in Nigeria, and to determine the antibacterial resistance profile. Rectal swabs were collected from 155, systematic randomly selected, apparently-healthy horses. Isolation of ESC-resistant enterobacteria was done using Mac Conkey agar with ceftazidime. ESBL production was assessed by combination disc method. Resistance of the isolates was determined using disc diffusion method. Out of 155 samples, 5.2% gave positive growth. From these, 11 ESC-resistant enterobacteria comprising of 36.4% E. coli, 36.4% Salmonella spp. and 27.2% Proteus spp., were obtained. From 11 isolates, 45.5% consisting of all the 4 E. coli and 1 Proteus isolates, were ESBL-producers, these were recovered from 4 (2.6%) out of the 155 horses sampled. Resistance of the E. coli isolates was 25% to aztreonam (AZT), 75% to amoxicillin-clavulanic acid (AMC), gentamicin (GEN), perfloxacin (PEF), and sulphamethoxazoletrimethoprim (SXT-TRI), 50% to ofloxacin (OFL) and 100% to ampicillin (AMP), ceftazidime (CTZ), cefotaxime (CTX), chloramphenicol (CHL), streptomycin (STR), tetracycline (TET), sparfloxacin (SPA), ciprofloxacin (CIP), norfloxacin (NOR) and enrofloxacin (ENR). Resistance of the Salmonella isolates was 50% to PEF and 100% to CTZ, CTX, AMP, AZT, AMC, CHL, GEN, STR, TET, SPA, CIP, OFL, NOR and ENR. Resistance of the Proteus isolates was 25% to AMC, CHL, STR, TET, SPA and NOR, and 100% to CTZ, CTX, AZT and AMP. Resistance of the isolates to more than 3 classes of antibacterial agents tested was 75% for Proteus and 100% for E. coli and Salmonella, respectively. This study showed that horses in Nigeria are potential reservoirs and disseminators of ESC-resistant and ESBL-producing Enterobacteriaceae.

Phenotypic characterization and whole genome analysis of extended-spectrum beta-lactamase-producing bacteria isolated from dogs in Germany

Asymptomatic colonization with extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae has been described for humans, various mammal species, and birds. Here, antimicrobial resistant bacteria were recovered from dog feces originating in Germany, Kosovo, Afghanistan, Croatia, and Ukraine, with a subset of mostly E. coli isolates obtained from a longitudinal collection over twelve months. In vitro antimicrobial resistance testing revealed various patterns of resistance against single or all investigated beta-lactam antibiotics, with none of the 101 isolates resistant against two tested carbapenem antibiotics. Whole genome sequence analysis revealed bacteria species-specific patterns for 23 antimicrobial resistance coding DNA sequences (CDS) that were unapparent from the in vitro analysis alone. Phylogenetic analysis of single nucleotide polymorphisms (SNP) revealed clonal bacterial isolates originating from different dogs, suggesting transmission between dogs in the same community. However, individual resistant E. coli clones were not detected over a period longer than seven days. Multi locus sequence typing (MLST) of 85 E. coli isolates revealed 31 different sequence types (ST) with an accumulation of ST744 (n = 9), ST10 (n = 8), and ST648 (n = 6), although the world-wide hospital-associated CTX-M beta-lactamase producing ST131 was not detected. Neither the antimicrobial resistance CDSs patterns nor the phylogenetic analysis revealed an epidemiological correlation among the longitudinal isolates collected from a period longer than seven days. No genetic linkage could be associated with the geographic origin of isolates. In conclusion, healthy dogs frequently carry ESBL-producing bacteria, independent to prior treatment, which may be transmitted between individual dogs of the same community. Otherwise, these antimicrobial resistant bacteria share few commonalities, making their presence eerily unpredictable.

International high-risk clonal lineages of CTX-M-producing Escherichia coli F-ST648 in free-roaming cats, South America

The dissemination of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli belonging to high-virulent pandemic lineages has become a global problem with serious consequences for public health worldwide. In this regard, E. coli lineages belonging to the sequence type ST648, which are mostly associated with human infections, have begun to be reported in animals. In this study, we report the identification and genomic characterization of international CTX-M-producing E. coli ST648/F lineages in free-roaming cats from an urban slum, in Brazil. Moreover, we have performed a comparative genomic analysis of worldwide reported E. coli ST648 strains, highlighting an epidemiologic linkage between human and companion animals.

Prevalence and molecular features of ESBL/pAmpC-producing Enterobacteriaceae in healthy and diseased companion animals in Brazil

Extended-spectrum beta-lactamase (ESBL)- and plasmid-mediated AmpC (pAmpC)-carrying Enterobacteriaceae have widely disseminated in human, animal and environmental reservoirs. Pets have been recognized as a source of ESBL/pAmpC worldwide, and are possibly also a source of human contamination. The aim of this study was to document to what extent cats and dogs may act as a driving force in the spread of ESBLs and pAmpCs in Brazil. A total of 113 healthy stray cats and dogs and 74 sick pets were sampled, and extended-spectrum cephalosporin-resistant Enterobacteriaceae (ESC-R) were detected in 28/113 (24.8%) and 8/74 (10.8%) tested animals, respectively. Different Enterobacteriaceae isolates (mostly E. coli), a large number of E. coli clones (with ST90, ST457, ST973 and ST2541 being predominant), and several ESBL/pAmpC genes and plasmids were characterized, highlighting the ability of stray and pet cats and dogs to further spread a wide range of ESC-resistance determinants. The ESBL phenotype was due to the bla_CTX-M-2 and bla_CTX-M-8 genes, as found in human epidemiology in Brazil, but bla_CTX-M-9 and bla_CTX-M-15 were also identified. The pAmpC phenotype was systematically due to the presence of the bla_CMY-2 gene, mostly carried by IncI1 ST12 plasmids. Our results showed that pets can be considered a significant reservoir of multidrug-resistant bacteria in Brazil. This is especially true for healthy stray dogs that displayed the highest prevalence (24.8%) of ESBLs/pAmpC resistance determinants, which can then be further spread both to the environment and to other animals or humans by contact.

Occurrence and characterization of extended-spectrum cephalosporin-resistant Enterobacteriaceae in healthy household dogs in Greece

Extended-spectrum cephalosporin- and/or carbapenem-resistant (ESC^R and/or Carb^R) Enterobacteriaceae constitute a public health hazard because of limited treatment options and are endemic among humans in Greece. Recently, ESC^R and Carb^REnterobacteriaceae have been increasingly isolated from companion animals, stressing their potential role as a reservoir for humans. However, the presence of ESC^R bacteria in companion animals within Greek households has not been determined yet. Genes conferring the ESC^R and Carb^R phenotype were detected among canine isolates and their chromosomal or plasmid location was determined. Standard methods were applied for plasmid characterization. The clonal relatedness of the recovered isolates was examined by multilocus sequence typing (MLST). Here, we report the first findings on the presence of ESC^REnterobacteriaceae in healthy Greek dogs. ESC^REscherichia coli isolates were associated with different sequence types (STs), including the human pandemic ST131 clone. The occurrence of human-related ESBL/pAmpC genes, plasmid types and/or strain STS in this animal reservoir suggests possible bilateral transmission.

Molecular characterization of carbapenem-resistant Gram-negative bacilli clinical isolates in Algeria

Objectives

The aims of this study were to investigate the occurrence of carbapenem-resistant Gram-negative bacilli (GNB) isolated from inpatients and outpatients in Algeria between July and September 2015, and to screen their resistance mechanisms and genetic relatedness.

Materials and methods

A total of 68 non-redundant isolates were identified using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) antibiotic susceptibility testing was performed using disk diffusion and Etest methods. Carbapenemase activity was carried out using modified Carba NP test, EDTA assay, and the modified Hodge test. Molecular characterization of carbapenemases and extended-spectrum β-lactamase (ESBL) genes were detected by standard PCR and sequencing. Genotyping of carbapenem-resistant isolates was performed by multilocus sequence typing (MLST) analysis.

Results

Of the 68 GNB isolates, 13 (19%) showed reduced susceptibility to carbapenems, including, four Klebsiella pneumoniae, one Escherichia coli, six Acinetobacter baumannii, and two Pseudomonas aeruginosa. bla_OXA-48 gene was detected in the five Enterobacteriaceae isolates, and bla_OXA-23 was identified in all A. baumannii isolates. OprD mutations were revealed in the two P. aeruginosa isolates. A total of 11 out of the 13 carbapenem-resistant GNB were detected in inpatients, and the two remaining strains were isolated from outpatients. Molecular typing showed the presence of four sequence types (STs) among the OXA-48-producing K. pneumoniae isolates: ST101, ST147, ST163, and ST2017. ST533 was identified for the OXA-48 producing E. coli isolate. All of the A. baumannii and P. aeruginosa were assigned to the international clonal lineages ST2 and ST654, respectively.

Conclusion

This study reports the first detection of the epidemic multidrug-resistant lineage, K. pneumoniae ST147 coproduced bla_OXA-48 and ESBL genes in Algeria and represents the first description of OXA-48-producing E. coli ST533 and K. pneumoniae ST163 and ST2017. In addition, this study describes for the first time the emergence of OXA-48-producing E. coli and K. pneumoniae in the community in Algeria, leading to major problems for managing microbial infections.

High Prevalence of Extended-Spectrum β-Lactamase Producing Enterobacteriaceae Among Clinical Isolates From Cats and Dogs Admitted to a Veterinary Hospital in Switzerland

Objectives

This study aimed to identify and characterize extended-spectrum β-lactamase (ESBL) producing Enterobacteriaceae among clinical samples of companion animals.

Methods

A total of 346 non-duplicate Enterobacteriaceae isolates were collected between 2012 and 2016 from diseased cats (n = 115) and dogs (n = 231). The presence of bla_ESBL, PMQR genes, and the azithromycin resistance gene mph(A) was confirmed by PCR and sequencing of bla genes. Isolates were further characterized by antimicrobial resistance profiling, multilocus sequence typing, phylogenetic grouping, identification of mutations in the QRDR of gyrA and parC, and screening for virulence-associated genes.

Results

Among the 346 isolates, 72 (20.8%) were confirmed ESBL producers [58 Escherichia coli (E. coli), 11 Klebsiella pneumoniae (K. pneumoniae), and 3 Enterobacter cloacae]. The strains were cultured from urine (n = 45), skin and skin wounds (n = 8), abscesses (n = 6), surgical sites (n = 6), bile (n = 4), and other sites (n = 3). ESBL genes included bla_CTX-M-1, ₁₄, ₁₅, ₂₇, ₅₅, and bla_SHV-12, predominantly bla_CTX-M-15 (54.8%, 40/73), and bla_CTX-M-1 (24.7%, 18/73). Further genes included qnrB (4.2%, 3/72), qnrS (9.7%, 7/72), aac(6')-Ib-cr (47.2%, 34/72), and mph(A) (38.9%, 28/72). Seventeen (23.6%) isolates belonged to the major lineages of human pathogenic K. pneumoniae ST11, ST15, and ST147 and E. coli ST131. The most prevalent ST was E. coli ST410 belonging to phylogenetic group C.

Conclusion

The high prevalence of ESBL producing clinical Enterobacteriaceae from cats and dogs in Switzerland and the presence of highly virulent human-related K. pneumoniae and E. coli clones raises concern about transmission prevention as well as infection management and prevention in veterinary medicine.

Antimicrobial resistance, multilocus sequence types and virulence profiles of ESBL producing and non-ESBL producing uropathogenic Escherichia coli isolated from cats and dogs in Switzerland

Among 64 uropathogenic Escherichia coli (UPEC) isolated from 13 cats and 51 dogs, 35 were extended-spectrum beta-lactamase (ESBL) producers, and 29 were non-ESBL producers. Forty-six (71.9%) of the isolates were multidrug resistant (MDR). Among the ESBL producers, bla_CTX-M-15 (n = 17/48.6% of the bla_ESBLs), bla_CTX-M-1 (n = 10/28.6%), bla_CTX-M-55 (n = 4/11.4%), bla_CTX-M-14 (n = 3/8.6%), and bla_CTX-M-27 (n = 1/2.9%) were identified. The plasmid-mediated fluoroquinolone resistance genes aac(6')-Ib-cr, qnrB and the azithromycin resistance gene mph(A) were detected in 17 (26.6% of all isolates), one (1.6%) and in 13 (20.3%) respectively. The most frequent phylogenetic groups were C (n = 19) and B2 (n = 15). Twenty-six different sequence types (STs) were identified, with two being novel. The most frequent STs were ST410 (n = 16/25%), ST131, and ST73 (both n = 5/7.8%), and ST361 (n = 4/6.3%). Ten (15.6%) of the STs have been associated with urinary tract infection (UTI) in humans, suggesting zoonotic potential. Among seven virulence-associated genes, fyuA was the most prevalent. The overall aggregate virulence factor (VF) score was highest for isolates belonging to phylogenetic group B2 (median aggregate VF score 6, mean score 5,5, range 3-7), and lowest for isolates belonging to phylogenetic group C (0/ 0.5/0-3). The most frequent ST in this study, ST410, harboured the lowest number of VF (0/0,3/0-2). VF scores were higher in NDR (4/3.8/3-4) than in MDR (1/1,9/0-7), and higher in non-ESBL producing isolates (3/3/0-7) than in ESBL producers (1/1,7/0-7). Our data advance our knowledge of the phenotypic and genotypic characteristics of UPEC in companion animals and their potential for infection, zoonotic transmission and dissemination of antimicrobial resistance determinants.

Raw pet food as a risk factor for shedding of extended-spectrum beta-lactamase-producing Enterobacteriaceae in household cats

Background

Close contact between pets and owners provides the opportunity for transmission of antimicrobial resistant organisms like extended-spectrum beta-lactamase (ESBL)/AmpC beta-lactamase (AmpC)-producing Enterobacteriaceae, posing a risk to public health.

Objectives

To investigate whether raw feed is a risk factor for household cats to shed ESBL-producing Enterobacteriaceae, a cohort study was designed. Additionally, raw and non-raw commercial pet food products were screened for the presence of ESBL-producing Enterobacteriaceae.

Methods

Weekly fecal samples of 17 cats in the control group and 19 cats in the exposed group were collected for three weeks and analyzed for the presence of ESBL-producing Enterobacteriaceae. Questionnaires were obtained to determine additional risk factors. Fecal samples were cultured on MacConkey agar supplemented with 1 mg/L cefotaxime. PCR and sequence analysis was used for screening for ESBL genes in suspected isolates. Pet food samples were cultured in LB broth supplemented with 1 mg/L cefotaxime and processed as described above.

Results

In the cohort study, ESBL-producing bacteria were isolated from 3 of 51 (5.9%) samples in the control group compared to 37 of 57 (89.5%) samples in the exposed group. A significant association was found between ESBL shedding and feeding raw pet food products (OR = 31.5). No other risk factors were identified in this study. ESBL-producing Enterobacteriaceae were isolated from 14 of 18 (77.8%) raw pet food products and 0 of 35 non-raw pet food products.

Conclusions

This study shows a strong association between shedding of ESBL-producing bacteria in household cats and feeding raw pet food. Raw pet food was often contaminated with ESBL-producing Enterobacteriaceae.

Antimicrobial-resistant Escherichia coli in hospitalised companion animals and their hospital environment

INTRODUCTION

Antimicrobial resistance is a growing concern with implications for animal health. This study investigated the prevalence of antimicrobial resistance among commensal and environmental Escherichia coli isolated from animals sampled in referral hospitals in the UK.

MATERIALS AND METHODS

Resistant Escherichia coli isolated from animal faeces and practice environments were tested for susceptibility to antimicrobial agents. PCR and sequencing techniques were used to identify extended spectrum beta-lactamase and AmpC-producer genotypes.

RESULTS

In total, 333 faecal and 257 environmental samples were collected. Multi-drug resistant Escherichia coli were found in 13·1% of faecal and 8·9% of environmental samples. Extended spectrum beta-lactamase and AmpC genes were identified 14% and 7·7% of faecal samples and 8·6% and 8·6% of environmental samples, respectively. The most common extended spectrum beta-lactamase gene type detected was blaCTX-M -15 , although blaTEM-158 was detected in faecal and environmental samples from one practice.

CLINICAL SIGNIFICANCE

Escherichia coli resistant to key antimicrobials were isolated from hospitalised animals and the practice environment. We identified the emergence of the inhibitor resistant and extended spectrum beta-lactamase blaTEM-158 in companion animals. Further investigation to determine risk factors for colonisation with antimicrobial-resistant bacteria is needed to provide evidence for antimicrobial stewardship and infection control programmes.

Nosocomial Intravascular Catheter Infections with Extended-spectrum Beta-lactamase-producing Escherichia coli in Calves after Strain Introduction from a Commercial Herd

An outbreak of intravascular catheter-related infections by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in calves in an animal teaching hospital is reported. Pulsed-field gel electrophoresis was used for strain typing to determine the origin and dissemination of these strains. All 19 strains harboured the blaCTX-M-14, and six strains also overexpressed their chromosomal AmpC gene. Evidence on the introduction of the strain from a beef herd, experiencing neonatal diarrhoea and increased mortality, to the clinic through admission of diarrhoeic calves was provided. Strains isolated from phlebitis cases from other herds up to 5 months later showed a high similarity with the initial strain, suggesting that the strain had become nosocomial. The catheter infections with ESBL/AmpC-producing E. coli resulted in a prolonged hospitalization, increased anti-microbial use and mortality. This report points towards the potential dangers of the emergence of ESBL/AmpC-producing bacteria in susceptible food animals and warns farmers and veterinarians for the facility by which they are introduced into another environment.

Rapid and Specific Detection of the Escherichia coli Sequence Type 648 Complex within Phylogroup F

The Escherichia coli sequence type 648 complex (STc648) is an emerging lineage within phylogroup F-formerly included within phylogroup D-that is associated with multidrug resistance. Here, we designed and validated a novel multiplex PCR-based assay for STc648 that took advantage of (i) four distinctive single-nucleotide polymorphisms in icd allele 96 and gyrB allele 87, two of the multilocus sequence typing alleles that define ST648; and (ii) the typical absence within STc648 of uidA, an E. coli-specific gene encoding β-glucuronidase. Within a diverse 212-strain validation set that included 109 STs other than STc648, from phylogroups A, B1, B2, C, D, E, and F, the assay exhibited 100% sensitivity (95% confidence interval [CI], 82% to 100%) and specificity (95% CI, 98% to 100%). It functioned similarly well in two distant laboratories that used boiled lysates or DNAzol-purified DNA as the template DNA. Thus, this novel multiplex PCR-based assay should enable any laboratory equipped for diagnostic PCR to rapidly, accurately, and economically screen E. coli isolates for membership in STc648.

The occurrence of ESBL-producing Escherichia coli carrying aminoglycoside resistance genes in urinary tract infections in Saudi Arabia

Background

The infection and prevalence of extended-spectrum β-lactamases (ESBLs) is a worldwide problem, and the presence of ESBLs varies between countries. In this study, we investigated the occurrence of plasmid-mediated ESBL/AmpC/carbapenemase/aminoglycoside resistance gene expression in Escherichia coli using phenotypic and genotypic techniques.

Methods

A total of 58 E. coli isolates were collected from hospitals in the city of Makkah and screened for the production of ESBL/AmpC/carbapenemase/aminoglycoside resistance genes. All samples were subjected to phenotypic and genotypic analyses. The antibiotic susceptibility of the E. coli isolates was determined using the Vitek-2 system and the minimum inhibitory concentration (MIC) assay. Antimicrobial agents tested using the Vitek 2 system and MIC assay included the expanded-spectrum (or third-generation) cephalosporins (e.g., cefoxitin, cefepime, aztreonam, cefotaxime, ceftriaxone, and ceftazidime) and carbapenems (meropenem and imipenem). Reported positive isolates were investigated using genotyping technology (oligonucleotide microarray-based assay and PCR). The genotyping investigation was focused on ESBL variants and the AmpC, carbapenemase and aminoglycoside resistance genes. E. coli was phylogenetically grouped, and the clonality of the isolates was studied using multilocus sequence typing (MLST).

Results

Our E. coli isolates exhibited different levels of resistance to ESBL drugs, including ampicillin (96.61%), cefoxitin (15.25%), ciprofloxacin (79.66%), cefepime (75.58%), aztreonam (89.83%), cefotaxime (76.27%), ceftazidime (81.36%), meropenem (0%) and imipenem (0%). Furthermore, the distribution of ESBL-producing E. coli was consistent with the data obtained using an oligonucleotide microarray-based assay and PCR genotyping against genes associated with β-lactam resistance. ST131 was the dominant sequence type lineage of the isolates and was the most uropathogenic E. coli lineage. The E. coli isolates also carried aminoglycoside resistance genes.

Conclusions

The evolution and prevalence of ESBL-producing E. coli may be rapidly accelerating in Saudi Arabia due to the high visitation seasons (especially to the city of Makkah). The health authority in Saudi Arabia should monitor the level of drug resistance in all general hospitals to reduce the increasing trend of microbial drug resistance and the impact on patient therapy.

High Prevalence of β-lactamase and Plasmid-Mediated Quinolone Resistance Genes in Extended-Spectrum Cephalosporin-Resistant Escherichia coli from Dogs in Shaanxi, China

Objective: The aim of this study was to investigate the occurrence and molecular characterization of extended-spectrum β-lactamases (ESBL), plasmid-mediated AmpC β-lactamase (pAmpC) and carbapenemases as well as plasmid-mediated quinolone-resistant (PMQR) among extended-spectrum cephalosporin-resistant (ESC-R) Escherichia coli from dogs in Shaanxi province in China.

Methods: A total of 40 ESC-R Escherichia coli selected from 165 Extraintestinal pathogenic E. coli (ExPEC) isolated from dogs were screened and characterized for the genes encoding for the ESBLs, pAmpC, carbapenemases and PMQR genes by PCR and sequencing. Phylogenetic groups, virulence gene profiles and multilocus sequence typing (MLST) were used to investigate the genetic background of the ESC-R E. coli isolates.

Results: Among 40 ESC-R E. coli, the predominant β-lactamase gene was bla_CTX−Ms (n = 35), and followed by bla_TEM−1 (n = 31), bla_SHV−12 (n = 14), bla_OXA−48 (n = 8), bla_TEM−30 (n = 4), bla_CMY−2 (n = 3) and bla_DHA−1 (n = 2). The most common specific bla_CTX−M gene subtype was bla_CTX−M−15 (n = 31), and followed by bla_{CTX−M−123} (n = 14), bla_CTX−M−1 (n = 10), bla_CTX−M−14 (n = 10) and bla_CTX−M−9 (n = 7). PMQR genes were detected in 32 (80%) isolates, and the predominant PMQR gene was aac(6′)-Ib-cr (n = 26), followed by qnrS (n = 12), qnrD (n = 9), qnrB (n = 8), qepA (n = 4), and all PMQR genes were detected in co-existence with β-lactamase genes. traT (n = 34) and fimH (n = 32) were the most prevalent virulence genes, and virulence genes fimH, iutA, fyuA, malX, iha, and sat were more prevalent in phylogenetic group B2. The 40 ESC-R isolates analyzed were assigned to 22 sequence types (STs), and the clonal lineages ST131 (n = 10) and ST10 (n = 9) were the predominant STs.

Conclusion: High prevalence of β-lantamases and PMQR genes were detected among ESC-R E. coli from companion animals. This is also the first description of the co-existence of six β-lantamase genes and five PMQR genes in one E. coli isolate. Moreover, 10 ST131 clones harboring CTX-M-15 were detected.