Antibiotic resistance among fecal indicator bacteria from healthy individually owned and kennel dogs

Antimicrobial pressure in healthy breeding dogs vs household animals assessed through the resistance profile of Escherichia coli and coagulase positive Staphylococci

Antimicrobials are sometimes inappropriately administered in dog breeding facilities in an attempt to improve fertility or reduce neonatal losses, but these practices lead to an increased prevalence of resistant bacteria. The aim of this study was to assess antibiotic use intensity in breeding kennels by comparing the resistance profiles of Escherichia coli and coagulase positive Staphylococci isolated from breeding bitches and from household animals. A rectal and a perivulvar swab were collected from 80 healthy bitches, half of which were housed in breeding kennels and the other half in domestic environments. The resistance of Escherichia coli, Staphylococcus pseudintermedius and S.aureus to a range of antimicrobials was evaluated through the Minimum Inhibitory Concentration test. Antibiotic resistance rates, the percentage of Extended Spectrum Beta-Lactamase (ESBL)-producing E.coli strains, the percentage of mecA positive methicillin-resistant Staphylococci and of Multi-Drug Resistant (MDR) isolates were compared between breeding bitches and privately owned ones using Fisher's exact test. The percentage of resistance to the antimicrobials tested was generally higher in dogs from breeding kennels than in owned animals, with statistically significant differences in E.coli for cefazolin (p < 0.0001), third-generation cephalosporins (p = 0.0015), tetracycline (p = 0.0079), kanamycin (p = 0.0291) and trimethoprim-sulfamethoxazole (p = 0.0007). Furthermore, the prevalence of ESBL E.coli was significantly higher in breeding dogs (p = 0.0002). 38.5 % of breeding bitches and 12.5 % of household dogs carried methicillin-resistant mecA positive S.pseudintermedius strains. S.aureus was only isolated from household animals, and one of the three isolates was mecA positive and MDR. Our data indicate a higher exposure of kennel dogs to antimicrobials. The pattern of antibiotic resistance, particularly to aminopenicillins but also to amoxicillin-clavulanic acid, suggests a large use of these agents. The results confirm that healthy dogs can harbour commensal bacteria that have acquired antimicrobial resistances, which may be exchanged between hosts; the potential role of the two dog typologies as reservoirs for resistance genes was demonstrated. The risk of household dogs being exposed to resistant bacteria, probably of human origin, was also observed. Our study reveals a generally high exposure of dogs to antimicrobials and highlights the need to sensitise veterinarians and breeders to better antibiotic stewardship.

Prevalence and Risk Factors of Multidrug-Resistant Enterococcal Infection in Clinical Dogs and Cats - China, 2018-2021

What is already known about this topic?

Enterococcus spp., while naturally occurring as commensal bacteria in the gastrointestinal tract of animals and humans, have emerged as significant opportunistic pathogens in healthcare settings.

What is added by this report?

A comprehensive surveillance study revealed enterococci in 14.39% of clinical samples from dogs and cats across China during 2018-2021. Multidrug-resistant enterococcal infections showed significant correlation with urinary tract catheterization and extended hospitalization periods. Notably, pet-derived Enterococcus faecalis isolates demonstrated high genetic similarity with strains isolated from humans, farm animals, and environmental sources.

What are the implications for public health practice?

These findings underscore the critical need for enhanced surveillance of enterococcal infections and implementation of stringent aseptic protocols in veterinary clinical settings. Particular attention should be directed toward linezolid-resistant Enterococcus faecalis infections due to their demonstrated potential for transmission between pets and humans.

Prevalence and antimicrobial resistance trends among vaginal bacteria isolates from pregnant bitches

Many of the reproductive tract infections in the bitches are caused by bacteria that can normally be present on the vaginal mucosa. These bacteria also might have an important role as the cause responsible for pregnancy loss and fetal deaths. The choice of antibiotic therapy for the pregnant animal is narrow and represents a severe problem in veterinary practice, especially due to increased antimicrobial resistance. Due to incorrect antimicrobials use in breeding kennels, the aim of the present study was to assess the occurrence of the bacterial flora isolated from the pregnant bitches and their antibiotic sensitivity. The study was carried out at the private Veterinary clinic in Novi Sad, Serbia. The vaginal swabs were taken from 60 bitches diagnosed with pregnancy and were sent to be laboratory tested. Based on the results, the most common isolated pathogens were Staphylococcus pseudintermedius (20%) and beta-hemolytic streptococci (18.33%). Furthermore, significant resistance to antibiotics from beta-lactams group was detected. It is of particular importance that antimicrobial treatment be evidence based in order to reduce the overuse of antimicrobials due to increased concern regarding antimicrobial resistance.

In Vitro Microevolution and Co-Selection Assessment of Amoxicillin and Cefotaxime Impact on Escherichia coli Resistance Development

The global spread of antimicrobial resistance has become a prominent issue in both veterinary and public health in the 21st century. The extensive use of amoxicillin, a beta-lactam antibiotic, and consequent resistance development are particularly alarming in food-producing animals, with a focus on the swine and poultry sectors. Another beta-lactam, cefotaxime, is widely utilized in human medicine, where the escalating resistance to third- and fourth-generation cephalosporins is a major concern. The aim of this study was to simulate the development of phenotypic and genotypic resistance to beta-lactam antibiotics, focusing on amoxicillin and cefotaxime. The investigation of the minimal inhibitory concentrations (MIC) of antibiotics was performed at 1×, 10×, 100×, and 1000× concentrations using the modified microbial evolution and growth arena (MEGA-plate) method. Our results indicate that amoxicillin significantly increased the MIC values of several tested antibiotics, except for oxytetracycline and florfenicol. In the case of cefotaxime, this increase was observed in all classes. A total of 44 antimicrobial resistance genes were identified in all samples. Chromosomal point mutations, particularly concerning cefotaxime, revealed numerous complex mutations, deletions, insertions, and single nucleotide polymorphisms (SNPs) that were not experienced in the case of amoxicillin. The findings suggest that, regarding amoxicillin, the point mutation of the acrB gene could explain the observed MIC value increases due to the heightened activity of the acrAB-tolC efflux pump system. However, under the influence of cefotaxime, more intricate processes occurred, including complex amino acid substitutions in the ampC gene promoter region, increased enzyme production induced by amino acid substitutions and SNPs, as well as mutations in the acrR and robA repressor genes that heightened the activity of the acrAB-tolC efflux pump system. These changes may contribute to the significant MIC increases observed for all tested antibiotics. The results underscore the importance of understanding cross-resistance development between individual drugs when choosing clinical alternative drugs. The point mutations in the mdtB and emrR genes may also contribute to the increased activity of the mdtABC-tolC and emrAB-tolC pump systems against all tested antibiotics. The exceptionally high mutation rate induced by cephalosporins justifies further investigations to clarify the exact mechanism behind.

Drug prescription pattern in exotic pet and wildlife animal practice: a retrospective study in a Spanish veterinary teaching hospital from 2018 to 2022

Exotic companion animals have had an important role in our society since ancient times. Preserving animal health is necessary to do a responsible use of veterinary medicines. This study aimed to describe the prescription patterns of drugs in exotic pets and wildlife animals attending the Veterinary Teaching Hospital of the University of León (HVULE). A retrospective study was carried out between 2018 and 2022. Birds were the largest group of exotic animals attending the HVULE. Visits were related to emergency reasons and for musculoskeletal disorders. One-third of the animals were eventually euthanised. Regarding pharmacological treatments, the most frequently active ingredients used were pentobarbital, isoflurane, meloxicam, and within antibiotics, marbofloxacin (category B in the classification of European Medicines Agency).

Antimicrobial Resistance in Escherichia coli Isolated from Healthy Dogs and Cats in South Korea, 2020-2022

The occurrence of antimicrobial-resistant bacteria in companion animals poses public health hazards globally. This study aimed to evaluate the antimicrobial resistance profiles and patterns of commensal E. coli strains obtained from fecal samples of healthy dogs and cats in South Korea between 2020 and 2022. In total, 843 E. coli isolates (dogs, n = 637, and cats, n = 206) were assessed for susceptibility to 20 antimicrobials. The resistance rates of the most tested antimicrobials were significantly higher in dog than in cat isolates. Cefalexin (68.9%) demonstrated the highest resistance rates, followed by ampicillin (38.3%), tetracycline (23.1%), and cefazolin (18.7%). However, no or very low resistance (0-0.6%) to amikacin, imipenem, piperacillin, and colistin was found in both dog and cat isolates. Overall, 42.3% of the isolates exhibited multidrug resistance (MDR). MDR in isolates from dogs (34.9%) was significantly higher than in those from cats (20.9%). The main components of the resistance patterns were cefalexin and ampicillin in both dog and cat isolates. Additionally, MDR patterns in isolates from dogs (29.2%) and cats (16%) were shown to encompass five or more antimicrobials. Multidrug-resistant commensal E. coli could potentially be spread to humans or other animals through clonal or zoonotic transmission. Therefore, the incidence of antimicrobial resistance in companion animals highlights the urgent need to restrict antimicrobial resistance and ensure the prudent use of antimicrobials in Korea.

Antimicrobial Resistance Profiles of Enterococcus faecium and Enterococcus faecalis Isolated from Healthy Dogs and Cats in South Korea

Enterococcus spp. are typically found in the gastrointestinal tracts of humans and animals. However, they have the potential to produce opportunistic infections that can be transmitted to humans or other animals, along with acquired antibiotic resistance. In this study, we aimed to investigate the antimicrobial resistance profiles of Enterococcus faecium and Enterococcus faecalis isolates obtained from companion animal dogs and cats in Korea during 2020-2022. The resistance rates in E. faecalis towards most of the tested antimicrobials were relatively higher than those in E. faecium isolated from dogs and cats. We found relatively higher resistance rates to tetracycline (65.2% vs. 75.2%) and erythromycin (39.5% vs. 49.6%) in E. faecalis isolated from cats compared to those from dogs. However, in E. faecium, the resistance rates towards tetracycline (35.6% vs. 31.5%) and erythromycin (40.3% vs. 35.2%) were comparatively higher for dog isolates than cats. No or very few E. faecium and E. faecalis isolates were found to be resistant to daptomycin, florfenicol, tigecycline, and quinupristin/dalfopristin. Multidrug resistance (MDR) was higher in E. faecalis recovered from cats (44%) and dogs (33.9%) than in E. faecium isolated from cats (24.1%) and dogs (20.5%). Moreover, MDR patterns in E. faecalis isolates from dogs (27.2%) and cats (35.2%) were shown to encompass five or more antimicrobials. However, E. faecium isolates from dogs (at 13.4%) and cats (at 14.8%) were resistant to five or more antimicrobials. Taken together, the prevalence of antimicrobial-resistant enterococci in companion animals presents a potential public health concern.

Detection of Potential Zoonotic Agents Isolated in Italian Shelters and the Assessment of Animal Welfare Correlation with Antimicrobial Resistance in Escherichia coli Strains

Welfare conditions in shelters, where dogs might be housed for a long period of time, may have a possible correlation with the occurrence of bacterial pathogens and their antimicrobial resistance (AMR). In this study, we assessed the occurrence of AMR in 54 strains of Escherichia coli isolated from dogs housed in 15 Italian shelters and we correlated the resistance patterns to animal welfare. We also aimed to evaluate the presence of specific pathogens with zoonotic potential in sheltered dogs. Thus, nasopharyngeal, rectal, and oral swabs were collected from a group of 20 dogs in each shelter and totaled 758 swabs. We identified 9 Staphylococcus pseudointermedius, 1 Pasteurella multocida, 9 Staphylococcus aureus, 12 Campylobacter spp., 54 Escherichia coli, 2 Salmonella enterica, and 246 Capnocytophaga spp. The antimicrobial susceptibility was assessed for the E. coli isolates using a panel of 14 antibiotics. The highest level of relative AMR was recorded for ampicillin and sulfamethoxazole. The association found between AMR and the levels of animal welfare scores in shelters was evident although not statistically significant. These results support the hypothesis that the good management of shelters can increase the level of animal welfare, thus reducing the use of antibiotics and, as a consequence, the AMR occurrence found in dogs that share their domestic environment with humans.

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.

Genomic Characterization of ESBL/AmpC-Producing Escherichia coli in Stray Dogs Sheltered in Yangzhou, China

Purpose

Limited data are available on the prevalence and antimicrobial resistance of extended spectrum β-lactamase- (ESBL) and AmpC β-lactamase-producing Escherichia coli in stray dogs. We aimed to investigate the genomic characteristics of ESBL/AmpC-producing E. coli isolated from stray dogs sheltered in Yangzhou, China.

Methods

We collected 156 samples including 115 fecal swabs, 35 kennel floor swabs, two breeder hand and shoe sole swabs, and four feed samples. The isolates were tested for resistance by antimicrobial susceptibility testing and further analyzed for cefotaxime-resistant E. coli isolates by whole genome sequencing.

Results

We identified 80 cefotaxime-resistant E. coli isolates (51.3%), 59 isolates (73.8%) from feces and 21 (26.2%) from the environment. Whole-genome sequencing analysis showed that bla _CTX-M-15 (n=30) and bla _CTX-M-55 (n=29) were the most prevalent genotypes. Two isolates only carried the AmpC β-lactamase gene bla _CMY-2; one isolate had a combination of AmpC β-lactamase gene bla _DHA-1 and ESBL β-lactamase gene bla _CTX-M-14. Other important resistance genes such as bla _OXA-10, bla _TEM-1B, bla _TEM-135, bla _TEM-106, tet(A), qnrS1, qnrB4, and oqxAB were also detected. The serotype combination was highly abundant, with O10:H25 predominating (n=12). Most cefotaxime-resistant E. coli isolates belonged to phylogroup A (62.5%, n=50), followed by phylogroup B1 (26.3%, n=21). Thirty different sequence types (STs) and 27 distinct plasmid replicons were identified, among which ST2325 (n=12) and IncFII (n=38) was the most frequent ST and plasmid, respectively. ESBL/AmpC-producing isolates were divided into four major clades; clade IV was the primary lineage containing 37 isolates from feces and 13 from the environment. Three high-risk E. coli clone ST23 strains and one ST10 strain belonged to clades III and IV, respectively.

Conclusion

Our study provides a comprehensive overview of resistance profiles and genomic characteristics in ESBL/AmpC-producing E. coli and highlights the possible role of stray dogs as an antibiotic resistance gene reservoir.

Antimicrobial susceptibility and risk factors for resistance among Escherichia coli isolated from canine specimens submitted to a diagnostic laboratory in Indiana, 2010–2019

Escherichia coli (E. coli) is the most common Gram-negative pathogen isolated in human infections. Antimicrobial resistant (AMR) E. coli originating from dogs may directly or indirectly cause disease in humans. The objective of this study was to calculate the proportion of antimicrobial susceptible E. coli isolated from canine specimens submitted to the Indiana Animal Disease Diagnostic Laboratory and to identify temporal patterns of susceptibility among these isolates. Susceptibility data of 2,738 E. coli isolates from dogs from 2010 through 2019 were used in this study. Proportions of isolates susceptible to the various antimicrobials were calculated using SAS statistical software and the Cochran-Armitage trend test was used to investigate the temporal trends in susceptibility. A multivariable binary logistic regression model was built to investigate the association between host factors and AMR. Overall, 553/2,738 (20.2%) of the isolates were susceptible to 17 of the 27 antimicrobials examined. Of the 2,638 isolates examined for amikacin susceptibility, 2,706 (97.5%) were susceptible, 2,657/2,673 (99.4%) isolates were susceptible to imipenem, and 2,099/2,670 (78.6%) were susceptible to marbofloxacin. A significant decreasing trend in susceptibility was observed for amoxicillin-clavulanic acid (P<0.0001), ampicillin (P<0.0001), Cefazolin (P<0.0001), ceftazidime (P = 0.0067), chloramphenicol (P<0.0001), and orbifloxacin (P = 0.008). The overall percentage of AMR isolates (isolates not susceptible to at least one antimicrobial) was 61.7% (1,690/2,738) and 29.3% (801/2,738) of isolates were multidrug resistant. Multivariable regression analyses showed significant associations between AMR and age (P = 0.0091), breed (P = 0.0008), and sample isolation site/source (P<0.0001). The decreasing trend in the proportion of isolates susceptible to several beta-lactam antimicrobials suggests that resistance of Escherichia coli in dogs to these antimicrobials could be increasing in Indiana. The decreasing trend in susceptibility to these drugs could be due to selection pressure from antimicrobial use.

Bacterial Prevalence in Skin, Urine, Diarrheal Stool, and Respiratory Samples from Dogs

The emergence of bacterial infections in companion animals is a growing concern as humans can also be infected through the transmission of pathogenic bacteria. Because there have been few studies conducted on companion animals, the extent and significance of prevalence in veterinary practices remain unknown. This is the first nationwide surveillance report aimed at elucidating the prevalence pattern and associated infections of isolated bacteria from dogs in Korea. Bacterial isolates were collected from seven different laboratories participating in the Korean Veterinary Antimicrobial Resistance Monitoring System from 2018 to 2019. The samples were obtained from the diarrheal stool, skin/ear, urine, and respiratory samples of veterinary hospital-visited dogs. Isolation and identification of bacterial species was carried out using a bacterial culture approach and then confirmed with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF) and polymerase chain reaction (PCR). Out of 3135 isolates in dogs, 1085, 1761, 171, and 118 were extracted from diarrheal stool, skin/ear, urine, and respiratory samples, respectively. The overall prevalence of bacteria was higher among two age groups (1-5 and 6-10 years) with a 66.5 percent prevalence. This study showed that Escherichia coli was the most prevalent species among isolated bacterial species of diarrheal and urine origin, whereas Staphylococcus pseudintermedius was the most prevalent among skin and respiratory sample isolates. The data on the prevalence of bacteria for each dog specimen could provide basic information to estimate the extent of bacterial infection and antimicrobial resistance development and to guide veterinarians in therapeutic decisions in clinical practices throughout Korea.

Trends in antimicrobial resistance among Escherichia coli from defined infections in humans and animals

OBJECTIVES

To characterize and compare resistance trends in clinical Escherichia coli isolates from humans, food-producing animals (poultry, cattle and swine) and pets (dogs and cats).

METHODS

Antibiogram results collected between January 2014 and December 2017 by MedQual [the French surveillance network for antimicrobial resistance (AMR) in bacteria isolated from the community] and RESAPATH (the French surveillance network for AMR in bacteria from diseased animals) were analysed, focusing on resistance to antibiotics of common interest to human and veterinary medicine. Resistance dynamics were investigated using generalized additive models.

RESULTS

In total, 743 637 antibiograms from humans, 48 170 from food-producing animals and 7750 from pets were analysed. For each antibiotic investigated, the resistance proportions of isolates collected from humans were of the same order of magnitude as those from food-producing animals or pets. However, resistance trends in humans differed from those observed in pets and food-producing animals over the period studied. For example, resistance to third-generation cephalosporins and fluoroquinolones was almost always below 10% for both humans and animals. However, in contrast to the notable decreases in resistance observed in both food-producing animals and pets, resistance in humans decreased only slightly.

CONCLUSIONS

Despite several potential biases in the data, the resistance trends remain meaningful. The strength of the parallel is based on similar data collection in humans and animals and on a similar statistical methodology. Resistance dynamics seemed specific to each species, reflecting different antibiotic-use practices. These results advocate applying the efforts already being made to reduce antibiotic use to all sectors and all species, both in human and veterinary medicine.

[Use of antimicrobials in acute canine diarrhea - overview of potential risks, indications and alternatives]

In Germany, antibiotics are frequently used in dogs with gastrointestinal disorders such as acute diarrhea. In line with global efforts to limit antibiotic use, this literature review aims to provide a guideline for the rational and judicious use of antibiotics in acute canine diarrhea. Antibiotics can lead to gastrointestinal side effects and may exert a negative influence on the intestinal microbiota in addition to increasing the occurrence of resistant bacteria. There is also evidence that chronic immunological diseases may be triggered by the administration of antibiotics. Therefore, these should not be administered in uncomplicated acute diarrhea without signs of sepsis or systemic inflammatory reaction. In addition, enteropathogenic bacteria usually do not play a role in the etiology of acute diarrhea. For select clinical entities such as acute hemorrhagic diarrhea syndrome, antibiotic therapy should only be recommended in cases displaying signs of bacterial translocation with subsequent sepsis. In the case of parvovirosis, on the other hand, the administration of antibiotics is unavoidable due to the immunological incompetence of the dog caused by the accompanying severe neutropenia.

High Levels of Antibiotic Resistance in Isolates From Diseased Livestock

Overuse of antimicrobials in livestock health and production beyond therapeutic needs has been highlighted in recent years as one of the major risk factors for the acceleration of antimicrobial resistance (AMR) of bacteria in both humans and animals. While there is an abundance of reports on AMR in clinical isolates from humans, information regarding the patterns of resistance in clinical isolates from animals is scarce. Hence, a situational analysis of AMR based on clinical isolates from a veterinary diagnostic laboratory was performed to examine the extent and patterns of resistance demonstrated by isolates from diseased food animals. Between 2015 and 2017, 241 cases of diseased livestock were received. Clinical specimens from ruminants (cattle, goats and sheep), and non-ruminants (pigs and chicken) were received for culture and sensitivity testing. A total of 701 isolates were recovered from these specimens. From ruminants, Escherichia coli (n = 77, 19.3%) predominated, followed by Staphylococcus aureus (n = 73, 18.3%). Antibiotic sensitivity testing (AST) revealed that E. coli resistance was highest for penicillin, streptomycin, and neomycin (77-93%). In addition, S. aureus was highly resistant to neomycin, followed by streptomycin and ampicillin (68-82%). More than 67% of E. coli isolates were multi-drug resistant (MDR) and only 2.6% were susceptible to all the tested antibiotics. Similarly, 65.6% of S. aureus isolates were MDR and only 5.5% were susceptible to all tested antibiotics. From non-ruminants, a total of 301 isolates were recovered. Escherichia coli (n = 108, 35.9%) and Staphylococcus spp. (n = 27, 9%) were the most frequent isolates obtained. For E. coli, the highest resistance was against amoxicillin, erythromycin, tetracycline, and neomycin (95-100%). Staphylococcus spp. had a high level of resistance to streptomycin, trimethoprim/sulfamethoxazole, tetracycline and gentamicin (80-100%). The MDR levels of E. coli and Staphylococcus spp. isolates from non-ruminants were 72.2 and 74.1%, respectively. Significantly higher resistance level were observed among isolates from non-ruminants compared to ruminants for tetracycline, amoxicillin, enrofloxacin, and trimethoprim/sulfamethoxazole.

Pet and Stray Dogs as Reservoirs of Antimicrobial-Resistant Escherichia coli

The close contact between dogs and humans creates the best bridge for interspecies transmission of antimicrobial-resistant bacteria. The surveillance of its resistance including the detection of extended-spectrum beta-lactamases (ESBLs) in Escherichia coli as indicator bacteria is an important tool to control the use of antimicrobials. The aim of this research was to evaluate the E. coli resistance in strains by phenotypic methods, isolated from pet and stray dogs of La Plata city, Argentina. Faecal samples were collected using rectal swabs from 50 dogs with owners (home dogs = HD) and 50 homeless dogs (stray dogs = SD). They were cultured in 3 MacConkey agar plates, with and without antibiotics (ciprofloxacin and cefotaxime). 197 strains were isolated, of which only 95 strains were biochemically identified as E. coli, 46 strains were from HD, and 49 were from SD. Antimicrobial susceptibility was evaluated by the Kirby-Bauer disk diffusion method. The most prevalent resistance was for tetracycline, streptomycin, and ampicillin. In both groups, the level of resistance to 3rd generation cephalosporins was high, and there were multiresistant strains. There was a higher level of antimicrobial resistance in strains from SD compared to HD. There were 8% of strains suspected of being ESBLs among samples of HD and 36% of SD. One (2%) of the strains isolated from HD and 11 (22%) from SD were phenotypically confirmed as ESBL. Pets and stray dogs are a potential source of E. coli antibiotic resistance in Argentina; therefore, its surveillance must be guaranteed.

Impact of European pet antibiotic use on enterococci and staphylococci antimicrobial resistance and human health

Due to the inappropriate use of antibiotics described in both human and veterinary medicine, there is emerging evidence of antimicrobial-resistant organisms isolated from humans and pets, forming a multifaceted problem. Although the true magnitude of antimicrobial resistance in pets and other animals, as well as humans, are not fully known; pets, in particular dogs and cats, can contribute to the spread of antimicrobial resistance due to close contact with humans and their status as a family member in urban households. This review summarizes and highlights the current data concerning the antibiotic use on pets, and the European distribution of the increasing prevalence of multiresistant bacterial pathogens, such as enterococci and methicillin-resistant staphylococci on pets, as well as its implications for public health.

Implications of antibiotics use during the COVID-19 pandemic: present and future

COVID-19 is caused by the SARS-CoV-2 virus, which has infected more than 4 million people with 278 892 deaths worldwide as of 11 May 2020. This disease, which can manifest as a severe respiratory infection, has been declared as a public health emergency of international concern and is being treated with a variety of antivirals, antibiotics and antifungals. This article highlights the administration of antimicrobials in COVID-19 patients worldwide, during the 2019-20 pandemic. It is imperative to be aware of the unreported amounts of antibiotics that have been administered worldwide in just a few months and a marked increase in antimicrobial resistance should therefore be expected. Due to the lack of data about antimicrobial use during this pandemic, the global impact on the emergence of new antimicrobial resistance is as yet unknown. This issue must be at the forefront of public health policymaking and planning in order that we are prepared for the potentially severe consequences for human and animal health and the environment.

Catching a glimpse of the bacterial gut community of companion animals: a canine and feline perspective

Dogs and cats have gained a special position in human society by becoming our principal companion animals. In this context, efforts to ensure their health and welfare have increased exponentially, with in recent times a growing interest in assessing the impact of the gut microbiota on canine and feline health. Recent technological advances have generated new tools to not only examine the intestinal microbial composition of dogs and cats, but also to scrutinize the genetic repertoire and associated metabolic functions of this microbial community. The application of high-throughput sequencing techniques to canine and feline faecal samples revealed similarities in their bacterial composition, with Fusobacteria, Firmicutes and Bacteroidetes as the most prevalent and abundant phyla, followed by Proteobacteria and Actinobacteria. Although key bacterial members were consistently present in their gut microbiota, the taxonomic composition and the metabolic repertoire of the intestinal microbial population may be influenced by several factors, including diet, age and anthropogenic aspects, as well as intestinal dysbiosis. The current review aims to provide a comprehensive overview of the multitude of factors which play a role in the modulation of the canine and feline gut microbiota and that of their human owners with whom they share the same environment.

Distribution and antimicrobial resistance profiles of bacterial species in stray dogs, hospital-admitted dogs, and veterinary staff in South Korea

Transferring antimicrobial-resistant bacteria from companion animals to human hosts has become increasingly common. Data regarding antimicrobial susceptibility could help veterinarians to select the most appropriate antibiotic treatment. However, standardized and ongoing surveys regarding antimicrobial resistance remain limited. In this study, we investigated the antimicrobial-susceptibility patterns and trends of bacteria isolated from stray dogs, hospital-admitted dogs, and veterinary staff in South Korea from 2018 to 2019. The minimum inhibitory concentrations of different antimicrobials for Staphylococcus spp., Enterobacterales, and Enterococcus spp. were determined to establish representatives of different antibiotic classes relevant for treatment or surveillance. For coagulase-positive and -negative Staphylococci, resistance to gentamicin was <27 %, while that to ampicillin and penicillin was high (33-80 %). The mecA-detection rates among staphylococcal isolates were 28.5 %, 42.6 %, and 32 % from stray dogs, hospital-admitted dogs, and veterinary staffs, respectively. For Enterobacterales, resistance to carbapenems was low (0-6%). A total of 31.2 % and 18.9 % of Enterobacterales isolates from stray dogs and hospital-admitted dogs were confirmed to possess at least one of bla_CTX-M, bla_SHV, or bla_TEM. Additionally, Enterococcus spp. isolates showed no resistance to vancomycin. These results demonstrate that dogs are commonly colonized with antimicrobial-resistant bacteria and highlight the need for further investigation.

Antimicrobial Usage and Resistance in Companion Animals: A Cross-Sectional Study in Three European Countries

Companion animals have been described as potential reservoirs of antimicrobial resistance (AMR), however data remain scarce. Therefore, the objectives were to describe antimicrobial usage (AMU) in dogs and cats in three European countries (Belgium, Italy, and The Netherlands) and to investigate phenotypic AMR. A questionnaire and one fecal sample per animal (n = 303) were collected over one year and AMU was quantified using treatment incidence (TI). Phenotypic resistance profiles of 282 Escherichia coli isolates were determined. Nineteen percent of the animals received at least one antimicrobial treatment six months preceding sampling. On average, cats and dogs were treated with a standard daily dose of antimicrobials for 1.8 and 3.3 days over one year, respectively. The most frequently used antimicrobial was amoxicillin-clavulanate (27%). Broad-spectrum antimicrobials and critically important antimicrobials for human medicine represented 83% and 71% of the total number of treatments, respectively. Resistance of E. coli to at least one antimicrobial agent was found in 27% of the isolates. The most common resistance was to ampicillin (18%). Thirteen percent was identified as multidrug resistant isolates. No association between AMU and AMR was found in the investigated samples. The issue to address, regarding AMU in companion animal, lies within the quality of use, not the quantity. Especially from a One-Health perspective, companion animals might be a source of transmission of resistance genes and/or resistant bacteria to humans.

Co-resistance to Amoxicillin and Tetracycline as an Indicator of Multidrug Resistance in Escherichia coli Isolates From Animals

OBJECTIVES

To examine the relevance of co-resistance to amoxicillin and tetracycline as an indicator of multidrug resistance (MDR) in animal health.

METHODS

Escherichia coli isolates collected between 2012 and 2016 by the French surveillance network for antimicrobial resistance in diseased animals (RESAPATH) were analyzed. The proportions of MDR isolates and the proportions of isolates presenting co-resistance to amoxicillin and tetracycline were calculated for seven animal species (cattle, horse, dog, swine, poultry, duck, and turkey). The degree of agreement between these two proportions was estimated by calculating the kappa value.

RESULTS

In total, 55,904 isolates were analyzed. MDR proportions were variable among animal species, ranging from 21.9% [20.2; 23.7] in horses to 56.0% [55.4; 56.7] in cattle. A similar situation was observed for proportions of isolates with co-resistance to amoxicillin and tetracycline, with the highest value for cattle 65.0% [64.3; 65.6]. This co-resistance was also most often associated with resistance to other antibiotics, regardless of the animal species considered. Comparative analysis showed substantial agreement between MDR and this co-resistance, with a kappa value of 0.75, all animal species considered.

CONCLUSION

Given the widespread use of penicillins and tetracyclines in animal health, co-resistance to amoxicillin and tetracycline could be an efficient indicator of MDR in E. coli isolates. Based on a specific resistance profile and not an arbitrary number of resistances compared with MDR, this potential indicator is also precise, convenient and suitable for routine use.

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.

Comparative epidemiology of E. coli resistance to third-generation cephalosporins in diseased food-producing animals

Categorized by WHO as critically important antibiotics, third-generation cephalosporins (3GCs) are one of the latest therapeutic alternatives to fight severe infectious diseases in humans. Some antibiotics belonging to this class are prescribed to treat food-producing animals in specific pathological contexts. Preserving the effectiveness of 3GCs requires characterization and careful monitoring of 3GCs resistance and the identification and implementation of measures that can limit this antimicrobial resistance (AMR). Here, we characterized the 3GCs resistance in Escherichia coli isolated from diseased animals. Using data collected from broilers, hens, calves, piglets, sows, turkeys and ducks between 2006 and 2016 by the French surveillance network of AMR in pathogenic bacteria of animal origin (called RESAPATH), we investigated the dynamics of resistance to 3GCs. Our non-linear analysis applied to time series showed that the evolution of E. coli resistance to 3GCs is specific to each animal category. From 2006 to 2010, resistance to 3GCs increased for most animal categories. We observed peaks of high-level of resistance for hens (21.5% in 2010) and broilers (26.7% in 2011), whereas trends stayed below 10% for the other animal categories throughout the study period. Resistance later decreased and, since 2014, 3GCs resistance has dropped below 10% for all animal categories. The parallel between trends and measures to limit AMR over the period shed lights on the impact of practices changes, public policies (EcoAntibio Plan) and sector-led initiatives (moratorium in swine sector). Finally, they highlight the usefulness and importance of AMR surveillance networks in animal health, such as RESAPATH.

Effects of oral orbifloxacin on fecal coliforms in healthy cats: a pilot study

The study objective was to determine the effect of oral orbifloxacin (ORB) on antimicrobial susceptibility and composition of fecal coliforms in cats. Nine cats were randomized to two groups administered a daily oral dose of 2.5 and 5.0 mg ORB/kg for 7 days and a control group (three cats per group). Coliforms were isolated from stool samples and were tested for susceptibilities to ORB and 5 other drugs. ORB concentration in feces was measured using high-performance liquid chromatography (HPLC). The coliforms were undetectable after 2 days of ORB administration, and their number increased in most cats after termination of the administration. Furthermore, only isolates of Escherichia coli were detected in all cats before administration, and those of Citrobacter freundii were detected after termination of the administration. E. coli isolates exhibited high ORB susceptibility [Minimum inhibitory concentration (MIC), ≤0.125 µg/ml] or relatively low susceptibility (MIC, 1-2 µg/ml) with a single gyrA mutation. C. freundii isolates largely exhibited intermediate ORB susceptibility (MIC, 4 µg/ml), in addition to resistance to ampicillin and cefazolin, and harbored qnrB, but not a gyrA mutation. HPLC revealed that the peaks of mean concentration were 61.3 and 141.0 µg/g in groups receiving 2.5 and 5.0 mg/kg, respectively. Our findings suggest that oral ORB may alter the total counts and composition of fecal coliform, but is unlikely to yield highly fluoroquinolone-resistant mutants of E. coli and C. freundii in cats, possibly because of the high drug concentration in feces.

Oral tylosin administration is associated with an increase of faecal enterococci and lactic acid bacteria in dogs with tylosin-responsive diarrhoea

The term tylosin-responsive diarrhoea (TRD) is used for canine recurrent diarrhoea cases for which no underlying cause can be found after extensive diagnostic investigations, but which show a response to the antibiotic tylosin in a few days. The objective of this prospective, one-arm longitudinal trial was to assess the effects of oral tylosin administration on the faecal levels of potentially probiotic bacteria, such as Enterococcus spp. and lactic acid bacteria (LAB), in dogs with TRD. This trial included 14 client-owned suspected TRD dogs that were on tylosin treatment and had firm faeces. Treatment was then terminated and dogs were followed up for up to 2 months to determine the recurrence of diarrhoea. Once diarrhoea started, dogs received tylosin (orally, 25 mg/kg, once daily for 7 days). At the end of the treatment period, stools were firm again in 11 dogs (TRD dogs); three dogs continued having diarrhoea and were excluded from the study. Faecal samples were collected at all three time-points for culture of LAB and enterococci. In TRD dogs, the colony counts of Enterococcus spp. (P = 0.003), LAB (P = 0.037), tylosin-resistant Enterococcus spp. (P <0.001) and LAB (P <0.001) were significantly higher when the dogs were on tylosin treatment and had normal faecal consistency compared to when they had diarrhoea following discontinuation of tylosin. In conclusion, cessation of diarrhoea in TRD dogs with tylosin treatment could be mediated by selection of a specific lactic acid population, the Enterococcus spp., due to their potential probiotic properties.

Diversity of Plasmids and Antimicrobial Resistance Genes in Multidrug-Resistant Escherichia coli Isolated from Healthy Companion Animals

The presence and transfer of antimicrobial resistance genes from commensal bacteria in companion animals to more pathogenic bacteria may contribute to dissemination of antimicrobial resistance. The purpose of this study was to determine antimicrobial resistance gene content and the presence of genetic elements in antimicrobial resistant Escherichia coli from healthy companion animals. In our previous study, from May to August, 2007, healthy companion animals (155 dogs and 121 cats) from three veterinary clinics in the Athens, GA, USA area were sampled and multidrug-resistant E. coli (n = 36; MDR, resistance to ≥ 2 antimicrobial classes) were obtained. Of the 25 different plasmid replicon types tested by PCR, at least one plasmid replicon type was detected in 94% (34/36) of the MDR E. coli; four isolates contained as many as five different plasmid replicons. Nine replicon types (FIA, FIB, FII, I2, A/C, U, P, I1 and HI2) were identified with FIB, FII, I2 as the most common pattern. The presence of class I integrons (intI) was detected in 61% (22/36) of the isolates with eight isolates containing aminoglycoside- and/or trimethoprim-resistance genes in the variable cassette region of intI. Microarray analysis of a subset of the MDR E. coli (n = 9) identified the presence of genes conferring resistance to aminoglycosides (aac, aad, aph and strA/B), β-lactams (ampC, cmy, tem and vim), chloramphenicol (cat), sulfonamides (sulI and sulII), tetracycline [tet(A), tet(B), tet(C), tet(D) and regulator, tetR] and trimethoprim (dfrA). Antimicrobial resistance to eight antimicrobials (ampicillin, cefoxitin, ceftiofur, amoxicillin/clavulanic acid, streptomycin, gentamicin, sulfisoxazole and trimethoprim-sulfamethoxazole) and five plasmid replicons (FIA, FIB, FII, I1 and I2) were transferred via conjugation. The presence of antimicrobial resistance genes, intI and transferable plasmid replicons indicate that E. coli from companion animals may play an important role in the dissemination of antimicrobial resistance, particularly to human hosts during contact.

Antimicrobial resistance risk factors and characterisation of faecal E. coli isolated from healthy Labrador retrievers in the United Kingdom

Antimicrobial resistant bacteria are increasingly detected from canine samples but few studies have examined commensal isolates in healthy community dogs. We aimed to characterise faecal Escherichia coli from 73 healthy non-veterinarian-visiting and non-antimicrobial treated Labrador retrievers, recruited from dog shows in the North West United Kingdom between November 2010 and June 2011. Each enrolled dog provided one faecal sample for our study. E. coli were isolated from 72/73 (99%) faecal samples. Disc diffusion susceptibility tests were determined for a range of antimicrobials, including phenotypic extended-spectrum beta-lactamase (ESBL) and AmpC-production. PCR assay detected phylogenetic groups and resistance genes (blaCTX-M, blaSHV, blaTEM, blaOXA, blaCIT, qnr), and conjugation experiments were performed to investigate potential transfer of mobile genetic elements. Multivariable logistic regression examined potential risk factors from owner-questionnaires for the presence of antimicrobial resistant faecal E. coli. Antimicrobial resistant, multi-drug resistant (≥3 antimicrobial classes; MDR) and AmpC-producing E. coli were detected in 63%, 30% and 16% of samples, respectively. ESBL-producing E. coli was detected from only one sample and conjugation experiments found that blaCTX-M and blaCIT were transferred from commensal E. coli to a recipient strain. Most isolates were phylogenetic groups B1 and A. Group B2 isolates were associated with lower prevalence of resistance to at least one antimicrobial (P<0.001) and MDR (P<0.001). Significant at P<0.003, was the consumption of raw meat for clavulanate-amoxicillin (OR: 9.57; 95% CI: 2.0-45.7) and third generation cephalosporin resistance (3GCR) (OR: 10.9; 95% CI: 2.2-54.0). AMR E. coli were surprisingly prevalent in this group of non-antimicrobial treated and non-veterinarian-visiting dogs and consumption of raw meat was a significant risk factor for antimicrobial resistance. These findings are of concern due to the increasing popularity of raw-meat canine diets, and the potential for opportunistic infection, zoonotic transmission and transmission of antimicrobial resistant determinants from commensal isolates to potential pathogenic bacteria.

Carriage of methicillin-resistant staphylococci by healthy companion animals in the US

Antimicrobial-resistant staphylococci have been associated with wounded or ill companion animals, but little is known about the prevalence of resistant staphylococci among healthy animals. In this study, 276 healthy dogs and cats from veterinary clinics were tested for the presence of antimicrobial-resistant Staphylococcus spp. Isolates were tested for antimicrobial susceptibility and the presence of select resistance genes, and typed using Pulsed-Field Gel Electrophoresis (PFGE). Staphylococcus aureus and Staphylococcus pseudintermedius were also characterized using multilocus sequence typing (MLST), spa typing and SCCmec typing. Approximately 5% (14/276) of the animals were positive by enrichment for five species of staphylococci [Staph. aureus (n = 11), Staph. pseudintermedius (n = 4), Staphylococcus sciuri (n = 6), Staphylococcus simulans (n = 1) and Staphylococcus warneri (n = 1)]. Seventy-eight per cent (18/23) of staphylococci were resistant to oxacillin and also multidrug resistant (resistance to ≥ 2 antimicrobials). All Staph. aureus isolates were mecA+ and blaZ+, SCCmec type II, spa type t002, ST5 and clonal using PFGE. Staphylococcus pseudintermedius were SCCmec type IV or V, spa type t06 and ST170; two of the isolates were pvl(+) . These results suggest that healthy companion animals may be a reservoir of multidrug-resistant staphylococci, which may be transferred to owners and others who handle companion animals.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this study, antimicrobial-resistant coagulase-negative and coagulase-positive staphylococci were isolated from various body sites on healthy dogs and cats. Resistance to 14 antimicrobials was observed including resistance to oxacillin; the majority of staphylococci were also multidrug resistant. Results from this study suggest that healthy dogs and cats may act as reservoirs of antimicrobial-resistant bacteria that may be transferred to people by simple interaction with the animals. Such carriage poses an underlying risk of infection, which should be considered during handling of healthy dogs and cats by pet owners and veterinary personnel.

Antimicrobial resistance and characterisation of staphylococci isolated from healthy Labrador retrievers in the United Kingdom

BACKGROUND

Coagulase-positive (CoPS) and coagulase-negative (CoNS) staphylococci are normal commensals of the skin and mucosa, but are also opportunist pathogens. Meticillin-resistant (MR) and multidrug-resistant (MDR) isolates are increasing in human and veterinary healthcare. Healthy humans and other animals harbour a variety of staphylococci, including MR-CoPS and MR-CoNS. The main aims of the study were to characterise the population and antimicrobial resistance profiles of staphylococci from healthy non-vet visiting and non-antimicrobial treated Labrador retrievers in the UK.

RESULTS

Nasal and perineal samples were collected from 73 Labrador retrievers; staphylococci isolated and identified using phenotypic and biochemical methods. They were also confirmed by matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF-MS), PCR of the nuc gene and PCR and sequencing of the tuf gene. Disc diffusion and minimum inhibitory concentration (MIC) susceptibility tests were determined for a range of antimicrobials. In total, 102 CoPS (S. pseudintermedius n = 91, S. aureus n = 11) and 334 CoNS isolates were detected from 99% of dogs in this study. In 52% of dogs CoNS only were detected, with both CoNS and CoPS detected in 43% dogs and CoPS only detected in 4% of dogs. Antimicrobial resistance was not common among CoPS, but at least one MDR-CoNS isolate was detected in 34% of dogs. MR-CoNS were detected from 42% of dogs but no MR-CoPS were isolated. S. epidermidis (52% of dogs) was the most common CoNS found followed by S. warneri (30%) and S. equorum (27%), with another 15 CoNS species isolated from ≤ 15% of dogs. S. pseudintermedius and S. aureus were detected in 44% and 8% of dogs respectively.

CONCLUSIONS

MR- and MDR-CoPS were rare. However a high prevalence of MR- and MDR-CoNS were found in these dogs, even though they had no prior antimicrobial treatment or admission to veterinary premises. These findings are of concern due to the potential for opportunistic infections, zoonotic transmission and transmission of antimicrobial resistant determinants from these bacteria to coagulase positive staphylococci.

A cross-sectional study examining the prevalence and risk factors for anti-microbial-resistant generic Escherichia coli in domestic dogs that frequent dog parks in three cities in south-western Ontario, Canada

Anti-microbial resistance can threaten health by limiting treatment options and increasing the risk of hospitalization and severity of infection. Companion animals can shed anti-microbial-resistant bacteria that may result in the exposure of other dogs and humans to anti-microbial-resistant genes. The prevalence of anti-microbial-resistant generic Escherichia coli in the faeces of dogs that visited dog parks in south-western Ontario was examined and risk factors for shedding anti-microbial-resistant generic E. coli identified. From May to August 2009, canine faecal samples were collected at ten dog parks in three cities in south-western Ontario, Canada. Owners completed a questionnaire related to pet characteristics and management factors including recent treatment with antibiotics. Faecal samples were collected from 251 dogs, and 189 surveys were completed. Generic E. coli was isolated from 237 of the faecal samples, and up to three isolates per sample were tested for anti-microbial susceptibility. Eighty-nine percent of isolates were pan-susceptible; 82.3% of dogs shed isolates that were pan-susceptible. Multiclass resistance was detected in 7.2% of the isolates from 10.1% of the dogs. Based on multilevel multivariable logistic regression, a risk factor for the shedding of generic E. coli resistant to ampicillin was attending dog day care. Risk factors for the shedding of E. coli resistant to at least one anti-microbial included attending dog day care and being a large mixed breed dog, whereas consumption of commercial dry and home cooked diets was protective factor. In a multilevel multivariable model for the shedding of multiclass-resistant E. coli, exposure to compost and being a large mixed breed dog were risk factors, while consumption of a commercial dry diet was a sparing factor. Pet dogs are a potential reservoir of anti-microbial-resistant generic E. coli; some dog characteristics and management factors are associated with the prevalence of anti-microbial-resistant generic E. coli in dogs.

Comparison of antimicrobial resistance patterns of Salmonella spp. and Escherichia coli recovered from pet dogs from volunteer households in Ontario (2005-06)

OBJECTIVES

To compare the antimicrobial resistance (AMR) patterns of Salmonella spp. and Escherichia coli in the faeces of pet dogs from volunteer households in Southwestern Ontario, Canada.

METHODS

From October 2005 to May 2006, 138 dogs from 84 Ontario households were recruited to participate in a cross-sectional study. Five consecutive daily faecal samples were collected from each dog and cultured for Salmonella spp. and E. coli. A panel of 15 antimicrobials from seven antimicrobial classes was used for susceptibility testing.

RESULTS

E. coli and Salmonella spp. were recovered from 96.4% and 23.2% of dogs, respectively. In total, 515 bacterial isolates from 136 dogs from 83 households were sent for antimicrobial susceptibility testing with 80.4% of isolates being pan-susceptible. The most common resistance pattern was to amoxicillin/clavulanic acid, ampicillin, cefoxitin, ceftiofur and ceftriaxone, present in 13.3% of Salmonella isolates and 1.3% of E. coli isolates. Fifty-eight of the isolates were resistant to two or more drug classes, with 70.7% and 29.3% being E. coli and Salmonella, respectively. Based on multilevel logistic regression, the odds of resistance were greater in E. coli than Salmonella [odds ratio = 3.2; 95% confidence interval (CI) = 1.22-8.43]. Agreement in resistance between E. coli and Salmonella isolates from the same dog was low [prevalence-adjusted, bias-adjusted kappa (PABAK) = 0.38; 95% CI = 0.30-0.46].

CONCLUSIONS

Pet dogs are a potential household source of antimicrobial-resistant Salmonella spp. and E. coli. However, extrapolating the epidemiology of antimicrobial resistance in pathogens, like Salmonella, from E. coli should be done with caution.

Prevalence of antimicrobial-resistant Escherichia coli in dogs in a cross-sectional, community-based study

The prevalence of carriage of antimicrobial-resistant (AMR) and extended-spectrum β-lactamase (ESBL)-producing Escherichia coli was determined in 183 healthy dogs from a semi-rural community in Cheshire. Isolates were tested against a panel of antimicrobials and by PCR to detect resistance genes. In the suspected ESBL-producing isolates, the presence of bla(SHV), bla(TEM), bla(CTX-M) and bla(AmpC) genes was determined by PCR and sequencing. A total of 53 (29 per cent, 95 per cent confidence interval [CI] 22.4 to 35.5 per cent) dogs carried at least one AMR E coli isolate. Twenty-four per cent (95 per cent CI 17.9 to 30.2 per cent) of dogs carried isolates resistant to ampicillin, 19.7 per cent (95 per cent CI 13.9 to 25.4 per cent) to tetracycline and 16.9 per cent (95 per cent CI 11.5 to 22.4 per cent) to trimethoprim. A bla(TEM) gene was detected in 39 of 54 ampicillin-resistant isolates, a tet(B) gene in 12 of 45 tetracycline-resistant isolates, and a dfr gene in 22 of 33 trimethoprim-resistant isolates. Multidrug-resistant isolates were demonstrated in 15 per cent (28 of 183; 95 per cent CI 10.1 to 20.5 per cent) of dogs. Nine suspected ESBL-producing E coli were isolated, of which only one was confirmed by double disc diffusion testing. Two of these isolates carried the bla(TEM-1) gene and seven carried the bla(CMY-2) gene.

Clonal spread of antimicrobial-resistant Escherichia coli isolates among pups in two kennels

Although the dog breeding industry is common in many countries, the presence of antimicrobial resistant bacteria among pups in kennels has been infrequently investigated. This study was conducted to better understand the epidemiology of antimicrobial-resistant Escherichia coli isolates from kennel pups not treated with antimicrobials. We investigated susceptibilities to 11 antimicrobials, and prevalence of extended-spectrum β-lactamase (ESBL) in 86 faecal E. coli isolates from 43 pups in two kennels. Genetic relatedness among all isolates was assessed using pulsed-field gel electrophoresis (PFGE). Susceptibility tests revealed that 76% of the isolates were resistant to one or more of tested antimicrobials, with resistance to dihydrostreptomycin most frequently encountered (66.3%) followed by ampicillin (60.5%), trimethoprim-sulfamethoxazole (41.9%), oxytetracycline (26.7%), and chloramphenicol (26.7%). Multidrug resistance, defined as resistance against two or more classes of antimicrobials, was observed in 52 (60.5%) isolates. Three pups in one kennel harboured SHV-12 ESBL-producing isolates. A comparison between the two kennels showed that frequencies of resistance against seven antimicrobials and the variation in resistant phenotypes differed significantly. Analysis by PFGE revealed that clone sharing rates among pups of the same litters were not significantly different in both kennels (64.0% vs. 88.9%), whereas the rates among pups from different litters were significantly different between the two kennels (72.0% vs. 33.3%, P < 0.05). The pups in the two kennels had antimicrobial-resistant E. coli clones, including multidrug-resistant and ESBL-producing clones. It is likely that resistant and susceptible bacteria can clonally spread among the same and/or different litters thus affecting the resistance prevalence.

Canine bacterial urinary tract infections: new developments in old pathogens

Uncomplicated bacterial urinary tract infections (UTIs) occur commonly in dogs. Persistent or recurrent infections are reported less frequently. They typically occur in dogs with an underlying disease and are sometimes asymptomatic, especially in dogs with predisposing chronic disease. Escherichia coli is the organism most frequently cultured in both simple and complicated UTIs. Organisms such as Enterococcus spp. and Pseudomonas spp. are less common in uncomplicated UTI, but become increasingly prominent in dogs with recurrent UTI. The ability of bacteria to acquire resistance to antimicrobials and/or to evade host immune defence mechanisms is vital for persistence in the urinary tract. Antimicrobial therapy limitations and bacterial strains with such abilities require novel control strategies. Sharing of resistant bacteria between humans and dogs has been recently documented and is of particular concern for E. coli O25b:H4-ST131 strains that are both virulent and multi-drug resistant. The epidemiology of complicated UTIs, pathogenic traits of uropathogens and new therapeutic concepts are outlined in this review.

Anatomical distribution and genetic relatedness of antimicrobial-resistant Escherichia coli from healthy companion animals

AIMS

Escherichia coli have been targeted for studying antimicrobial resistance in companion animals because of opportunistic infections and as a surrogate for resistance patterns in zoonotic organisms. The aim of our study is to examine antimicrobial resistance in E. coli isolated from various anatomical sites on healthy dogs and cats and identify genetic relatedness.

METHODS AND RESULTS

From May to August, 2007, healthy companion animals (155 dogs and 121 cats) from three veterinary clinics in the Athens, GA, USA, were sampled. Escherichia coli was isolated from swabs of nasal, oral, rectal, abdomen and hindquarter areas. Antimicrobial susceptibility testing against 16 antimicrobials was performed using broth microdilution with the Sensititre™ system. Clonal types were determined by a standardized pulsed-field gel electrophoresis protocol. Although rectal swabs yielded the most E. coli (165/317; 52%) from dogs and cats, the organism was distributed evenly among the other body sites sampled. Escherichia coli isolates from both dogs and cats exhibited resistance to all antimicrobials tested with the exception of amikacin, cephalothin and kanamycin. Resistance to ampicillin was the most prevalent resistance phenotype detected (dogs, 33/199; 17%; and cats, 27/118; 23%). Among the resistant isolates, 21 resistance patterns were observed, where 18 patterns represented multidrug resistance (MDR; resistance ≥ 2 antimicrobial classes). Also among the resistant isolates, 33 unique clonal types were detected, where each clonal type contained isolates from various sampling sites. Similar resistance phenotypes were exhibited among clonal types, and three clonal types were from both dogs and cats.

CONCLUSIONS

Healthy companion animals can harbour antimicrobial-resistant E. coli on body sites that routinely come in contact with human handlers.

SIGNIFICANCE AND IMPACT OF THE STUDY

  This study is the first report that demonstrates a diverse antimicrobial-resistant E. coli population distributed over various sites of a companion animal's body, thereby suggesting potential transfer of resistant microflora to human hosts during contact.

Isolation of methicillin-resistant Staphylococcus pseudintermedius from breeding dogs

The overuse of antimicrobials can select resistant bacteria strains; staphylococci have the ability to become resistant to all beta-lactam antimicrobials and are a significant concern in human medicine and a growing issue for veterinary medicine. Because antimicrobials are sometimes incorrectly used in breeding kennels, the objective of the work was to assess the occurrence of methicillin-resistant coagulase-positive staphylococci in breeding dogs. The research was carried out in 13 kennels that were allotted to three categories according to the intensity of antimicrobial use. Vaginal and milk swabs were taken from 87 healthy bitches around parturition and also from multiple organs of 27 of their pups that died within the first 2 weeks. Standard bacteriological examinations were carried out and coagulase-positive staphylococci were identified. All the coagulase-positive staphylococci resulted to be Staphylococcus pseudintermedius. Susceptibility to oxacillin and the presence of the mecA gene were tested. Nine out of 89 strains (six isolated from the bitches' milk and three from dead puppies, all belonging to kennels characterized by an excessive use of antimicrobials) were multidrug-resistant, methicillin-resistant and mecA positive. Our results confirm that excessive use of antimicrobials entails the risk of selecting resistant staphylococci strains. Our data also indicate that the bacterial flora of healthy dogs belonging to specific populations may act as a reservoir of resistance genes.

Prevalence of antimicrobial resistance in fecal Escherichia coli isolates from stray pet dogs and hospitalized pet dogs in Korea

A total of 628 Escherichia coli isolates recovered from 877 intestinal samples of stray pet dogs (n = 565) and hospitalized pet dogs (n = 312) in Korea were analyzed for resistance to 15 antimicrobial agents. Most common resistance observed in E. coli isolated from both groups of dogs was to tetracycline (52.4-53.6%), streptomycin (35.8-41.7%), ampicillin (32.9-47.1%), nalidixic acid (21.6-37.4%), and trimethoprim/sulfamethoxazole (19.7-36.4%). Resistance to chloramphenicol, gentamicin, and ciprofloxacin was observed in 19.4% (17.1-24.3%), 18% (16.1-21.8%), and 16.1% (13.5-21.4%) of the isolates, respectively. No E. coli isolated from hospitalized dogs showed resistance to imipenem and cefepime, whereas three (0.7%) isolates from stray dogs were resistant to cefepime. Some of the isolates from both groups showed resistance to cefotaxime (2.4-3.9%) and amikacin (0.5-1.5%). In general, the frequency of resistance tended to be higher in isolates from hospitalized dogs than isolates from stray dogs against most antimicrobials tested. Around 39% (162/422) and 27% (55/206) of E. coli isolates from stray dogs and hospitalized dogs were susceptible to all antimicrobials tested, respectively. Multiresistance (> or = 3 subclasses of antimicrobials) was observed in 32% and 48% of E. coli isolates from stray dogs and hospitalized dogs, respectively. More attention should be paid to the use of antimicrobials and the occurrence of antimicrobial resistance in companion animals.

Antimicrobial resistance and phylogenetic groups in isolates of Escherichia coli from seagulls at the Berlengas nature reserve

Fifty-three faecal samples from yellow-legged gulls (Larus cachinnans) at the Berlengas nature reserve in Portugal were cultured on Levine agar plates not supplemented with antimicrobial agents, and one Escherichia coli colony was isolated and identified from each sample. The percentages of resistant isolates for each of the drugs were ampicillin (43.4 per cent), tetracycline (39.6 per cent), nalidixic acid (34.0 per cent), streptomycin (32.1 per cent), trimethoprim-sulfamethoxazole (SXT) (26.4 per cent), ciprofloxacin (18.9 per cent), chloramphenicol (18.9 per cent), gentamicin (7.5 per cent), tobramycin (7.5 per cent) amikacin (5.7 per cent) and amoxicillin-clavulanic acid (1.9 per cent). All the isolates were susceptible to cefoxitin, ceftazidime, cefotaxime, aztreonam and imipenem. The following resistance genes were detected: bla(TEM) (17 of 23 ampicillin-resistant isolates), tet(A) and/or tet(B) (18 of 21 tetracycline-resistant isolates), aadA (12 of 17 streptomycin-resistant isolates), cmlA (all chloramphenicol-resistant isolates), aac(3)-II with or without aac(3)-IV (all four gentamicin-resistant isolates), and sul1 and/or sul2 and/or sul3 (all 14 SXT-resistant isolates). The intI1 gene was detected in 10 of 14 SXT-resistant isolates, and three of them also contained class 2 integrons; four different gene cassette arrangements were identified among class 1 integrons (aadA, dfrA1+aadA1, dfrA12+orfF+aadA2 and sat+psp+aadA2) and one among the class 2 integrons (dfrA1+sat+aadA1). Ninety per cent of the isolates were included in the A or B1 phylogenetic groups.

Prevalence, species distribution and antimicrobial resistance of enterococci isolated from dogs and cats in the United States

AIMS

The contribution of dogs and cats as reservoirs of antimicrobial resistant enterococci remains largely undefined. This is increasingly important considering the possibility of transfer of bacteria from companion animals to the human host. In this study, dogs and cats from veterinary clinics were screened for the presence of enterococci.

METHODS AND RESULTS

A total of 420 enterococci were isolated from nasal, teeth, rectal, belly and hindquarters sites of 155 dogs and 121 cats from three clinics in Athens, GA. Eighty per cent (124 out of 155) of the dogs and 60% (72 out of 121) of the cats were positive for enterococci. From the total number of dog samples (n = 275), 32% (n = 87) were from hindquarter, 31% (n = 86) were rectal, and 29% (n = 79) were from the belly area. The majority of isolates originated from rectal samples (53 out of 145; 37%) from cats. The predominant species identified was Enterococcus faecalis (105 out of 155; 68%) from dogs and E. hirae (63 out of 121; 52%) from cats. Significantly more E. faecalis were isolated from rectal samples than any other enterococcal species (P < 0.05) for both dogs and cats suggesting site specific colonization of enterococcal species. The highest levels of resistance were to ciprofloxacin in E. faecium (9 out of 10; 90%), chloramphenicol resistance in E. faecalis (17 out of 20; 85%) and gentamicin resistance in E. faecalis (19 out of 24; 79%) from dog samples and nitrofurantoin resistance in E. faecium (15 out of 19; 79%) from cats. Multi-drug resistance (MDR) (resistance > or =2 antimicrobials) was observed to as few as two and as many as eight antimicrobials regardless of class.

CONCLUSION

This study demonstrated that dogs and cats are commonly colonized with antimicrobial resistant enterococci.

SIGNIFICANCE AND IMPACT OF THE STUDY

Dogs and cats may act as reservoirs of antimicrobial resistance genes that can be transferred from pets to people.

Antimicrobial resistance in companion animals

Antimicrobial resistance (AMR) is an emerging problem in companion animals, because of difficult-to-treat infections, possible pressure to use antimicrobials that are important in human medicine, and potential zoonotic transmission. The extent and importance of AMR in companion animals are poorly understood, in part because of limited surveillance; however, it is clear that resistance is problematic in many pathogens and commensals, including staphylococci, enterococci, Escherichia coli and Salmonella.

Retrospective study of bacterial isolates and their antimicrobial susceptibilities in equine uteri during fertility problems

Bacterial pathogens are a potential cause when a mare fails to conceive to a fertile stallion on a well-managed breeding farm on one or more cycles in the same season. Furthermore, emerging bacterial resistance to commonly used (topical) antibiotics has been demonstrated. In this study, a total of 586 uterine swabs from mares with fertility problems were evaluated and the bacterial isolates were identified and measured for resistance to 10 antibiotics most commonly used during bacterial equine infection. Forty-nine percent of the examined mares were positive at bacteriological investigations. Amongst 347 successful isolations, 31.7% were Streptococcus group C and 18.4% Escherichia (E.) coli, both considered frequently associated with fertility problems. Determination of the antibiotic susceptibility pattern of Streptococcus group C (110 organisms) revealed that only the amoxicillin/clavulanic acid was highly active with 82.7% of the isolates being inhibited. For E. coli, a major number of drugs displayed a high potency.

Susceptibility to vancomycin and other antibiotics of 165 Enterococcus strains isolated from dogs in Italy

The prevalence of antibiotic resistance, with special attention to vancomycin, in 165 Enterococcus strains isolated from dogs subjected or not to previous antibiotics treatment(s) was determined. For each strain, the minimum inhibitory concentration (MIC) to 9 antibiotics was assessed. All strains were sensible to vancomycin. High frequencies of resistance to erythromycin, tetracycline, rifampicin, and enrofloxacin were detected. E. faecium strains isolated from dogs subjected to antibiotic treatment were more resistant to tetracycline with respect to control dogs. Although enterococci from dog show a high degree of antibiotic resistance, they are sensitive to vancomycin. Therefore, the risk of transmission of vancomycin-resistant enterococcal strains from dogs to man is close to zero.