Acquisition and persistence of antimicrobial-resistant bacteria isolated from dogs and cats admitted to a veterinary teaching hospital

Active surveillance of antimicrobial resistance in companion animals: A pilot study in a Spanish Veterinary Teaching Hospital

The role of small animal veterinary hospitals in the onset and dissemination of antimicrobial-resistant organisms (AMROs) is still not clear, and the implementation of an internal surveillance systems is a cost-effective tool to better understand their impact. The aim of this study was to describe a pilot program of active surveillance in a Spanish Veterinary Teaching Hospital, developed to estimate the detection frequency of AMROs in the commensal flora of patients and in the environment. Surveillance was focused on Methicillin-resistant Staphylococci (MRS), third generation cephalosporins resistant gram-negative bacteria (3GCR-GNB), and carbapenems-resistant gram-negative bacteria (CR-GNB). Oral and perirectal swabs were collected in the same dogs and cats hospitalized > 48 h, at their admission and before their discharge. Out of 50 patients sampled, 24% (12/50) were carriers at admission of at least one of the three investigated AMROs. Twenty-eight percent of patients (14/50) acquired at least one AMRO during the hospital stay. MRS detection frequency at admission was 12% (6/50), while acquisition was 6% (3/50). 3GCR-GNB detection frequency was 14% at admission (7/50) and acquisition 22% (11/50), while CR-GNB detection frequency was 2% at admission (1/50) and acquisition 2% (1/50). Environmental surveillance (98 samples) showed a total detection frequency of 22.4% for MRS (22/98), 2% for 3GCR-GNB and CR-GNB (2/98). Clinical staff' shoe soles showed high detection frequency for MRS (50%). 3GCR Escherichia coli was the most isolated species in patients (n = 17). The results show how active surveillance can be used as a tool to assess the impact of AMROs in veterinary hospitals to subsequently build up tailored control plans based on specific issues.

Mechanisms of Antibiotic and Biocide Resistance That Contribute to Pseudomonas aeruginosa Persistence in the Hospital Environment

Pseudomonas aeruginosa is an opportunistic bacterial pathogen responsible for multiple hospital- and community-acquired infections, both in human and veterinary medicine. P. aeruginosa persistence in clinical settings is worrisome and is a result of its remarkable flexibility and adaptability. This species exhibits several characteristics that allow it to thrive under different environmental conditions, including the ability to colonize inert materials such as medical equipment and hospital surfaces. P. aeruginosa presents several intrinsic mechanisms of defense that allow it to survive external aggressions, but it is also able to develop strategies and evolve into multiple phenotypes to persevere, which include antimicrobial-tolerant strains, persister cells, and biofilms. Currently, these emergent pathogenic strains are a worldwide problem and a major concern. Biocides are frequently used as a complementary/combination strategy to control the dissemination of P. aeruginosa-resistant strains; however, tolerance to commonly used biocides has also already been reported, representing an impediment to the effective elimination of this important pathogen from clinical settings. This review focuses on the characteristics of P. aeruginosa responsible for its persistence in hospital environments, including those associated with its antibiotic and biocide resistance ability.

Risk Factors, Genetic Diversity, and Antimicrobial Resistance of Staphylococcus spp. Isolates in Dogs Admitted to an Intensive Care Unit of a Veterinary Hospital

Intensive Care Units (ICU) usually provide an excellent environment for the selection of pathogens associated with hospital-acquired infections (HAI), leading to increased mortality and hospitalization costs. Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is a major cause of HAI in dogs worldwide, but the risk factors and dynamics of colonization by MRSP are largely unknown. This study aimed to evaluate the risk factors associated with the acquisition of MRSP in dogs admitted to an ICU, and to report the antimicrobial resistance profiles and genetic relatedness of MRSP isolates. Sterile swabs from the nostril, axilla, and rectum were collected daily during the hospitalization of 54 dogs. Samples were subjected to Mannitol Salt Agar, and colonies were identified by MALDI-ToF, polymerase chain reaction (PCR), and sequencing of the rpoB gene. Antimicrobial susceptibility testing and PCR detection of mecA were performed. Staphylococcus spp. was isolated from 94% of the dogs, and the most frequently isolated species was S. pseudintermedius (88.2%). Carriage of multidrug resistant (MDR) staphylococci was observed in 64.4% of the dogs, and approximately 39% had methicillin-resistant Staphylococcus sp. (MRS), of which 21.6% had MRSP and 1.9% had methicillin-resistant S. aureus (MRSA). The acquisition of MRSP during ICU hospitalization was associated with sex (female), age (>7 years), and dogs that had previously been treated with antimicrobials. Animals colonized by MRSP resistant to ≥9 antimicrobial classes had longer hospital stays than those colonized by other MRS strains. Among the 13 MRSP isolates that were subjected to whole-genome sequencing, ten were classified as ST71. A single nucleotide polymorphism (SNP) analysis revealed three clones, including one that was detected in infected dogs outside the ICU. This study indicates novel risk factors associated with colonization by MRSP. The detection of the same MRSP clone causing HAI outside the ICU reinforces the need for improved infection prevention and control practices at veterinary hospitals in general and at the ICU in particular.

Antibiotic resistant Escherichia coli in wild birds hospitalised in a wildlife rescue centre

The aim of this work was to evaluate the consequence of a hospitalisation period on antimicrobial resistance in Escherichia coli isolated from wild bird species admitted in the wildlife rescue centre of the Department of Veterinary Sciences (Turin University, Italy). Samples were collected from 121 raptors and 51 synanthropic animals, at the time of arrival as well as 5 and 10 days afterwards for a total of 372 faecal samples, and the susceptibility of E. coli strains was tested to a panel of seven antibacterials. Of the total, 109 animals (63.37 %) presented at least one sample positive for E. coli, 36 strains (39.6 %) were multi-drug resistant (MDR) and 12 (13.2 %) were extended spectrum beta-lactamase (ESBL)-producing E. coli. During the first 10 days of hospitalisation E. coli strains increased the number of resistances towards each antimicrobial principle, the number of ESBL E. coli and the therapy with fluoroquinolones developed resistance towards ceftriaxone, marbofloxacin, sulfamethoxazole-trimethoprim and tetracycline. Our results suggest that wild birds act as reservoirs of MDR bacteria, being potential sources for their spreading in the environment and to other species.

Microflora of boxes for holding veterinary patients in clinics

A significant element of the prophylaxis of nosocomial infection in veterinary clinics is monitoring ambient objects, air, equipment, and instruments. In order to determine the role of boxes for keeping ill animals as a source of transmission of pathogens of nosocomial infections in veterinary clinics, we studied the microflora of surfaces of boxes and bioaerosol prior and after sanitation. For this purpose, we collected rinses from the surfaces of plastic and steel boxes, air samples prior to morning sanitation, after cleaning and wiping the surfaces with water and detergents and after disinfection. From the surfaces of the boxes for holding animals, we mostly isolated bacteria of Staphylococcus spp., Streptococcus spp., Micrococcus spp., Corynebacterium spp., Enterococcus spp. and Bacillus spp. Gram-negative species we found were bacteria of Escherichia spp., Acinetobacter spp. and Enterobacter spp. After wet cleaning and disinfection of plastic boxes, we detected species of Staphylococcus spp. and Enterococcus spp. in 5.4% of the samples, Micrococcus spp. in 8.1% and Bacillus spp. in 2.7%. Gram-negative bacteria of Enterobacter spp. were found in 2.7% of the samples. At the same time, the number of microorganisms in samples in which the bacteria were found after disinfection on the surfaces of stainless-steel boxes was 2.0 times lower than in such from the surfaces of plastic boxes. We determined that after wet disinfection of boxes’ surfaces, there occurred decrease in the microbial number in the air, equaling 3.7 times on average, compared with prior to disinfection. The basis of the air microflora after disinfection comprised species of Micrococcus spp., Corynebacterium spp. and Staphylococcus spp., which can be airborne-transmitted. Bacteria that were isolated from the boxes after disinfection (Micrococcus spp., Staphylococcus spp.) formed highly dense biofilms, which probably ensure the survival of the microbial cells, thus making the boxes a probable source of nosocomial infection.

Phenotypic and Molecular Traits of Staphylococcus coagulans Associated with Canine Skin Infections in Portugal

Staphylococcus coagulans is among the three most frequent pathogens of canine pyoderma. Yet, studies on this species are scarce. Twenty-seven S. coagulans and one S. schleiferi, corresponding to all pyoderma-related isolations from these two species at two veterinary laboratories in Lisbon, Portugal, between 1999 and 2018 (Lab 1) or 2018 (Lab 2), were analyzed. Isolates were identified by the analysis of the nuc gene and urease production. Antibiotic susceptibility towards 27 antibiotics was evaluated by disk diffusion. Fourteen antibiotic resistance genes were screened by PCR. Isolates were typed by SmaI-PFGE. Two S. coagulans isolates (2/27, 7.4%) were methicillin-resistant (MRSC, mecA+) and four (4/27, 14.8%) displayed a multidrug-resistant (MDR) phenotype. We observed resistance to penicillin (17/27, 63.0%), fluoroquinolones (11/27, 40.7%), erythromycin and clindamycin (3/27, 11.1%), fusidic acid (3/27, 11.1%) and tetracycline (1/27, 3.7%). The blaZ and erm(B) genes were carried by 16 and 1 isolates resistant to penicillin and erythromycin/clindamycin, respectively. Only three S. coagulans carried plasmids. The single S. schleiferi isolate presented an MDR phenotype. SmaI-PFGE revealed a limited genetic diversity of S. coagulans, with a predominant lineage present from 2001 to 2018. This study describes the first MRSC causing canine infection in Portugal and reveals a high burden of antimicrobial resistance, with the emergence of MDR phenotypes within the main lineages.

Development of a method for creating antibiograms for use in companion animal private practices

OBJECTIVE

To identify a method for developing antibiograms for use in companion animal private practices (PPs).

SAMPLES

Reports (n = 532) of aerobic bacterial culture and antimicrobial susceptibility testing performed between January 1, 2018, and December 31, 2018, at 11 PPs and 1 academic primary care practice (APCP).

PROCEDURES

Data extracted from reports included patient identification number, laboratory accession number, patient signalment, collection method, body site, and results of bacterial culture and antimicrobial susceptibility testing. A custom antibiogram was then constructed with the help of commonly available software by adapting methods used by human hospitals. Susceptibility patterns of bacteria isolated by PPs and the APCP were compared to identify challenges associated with collating data from multiple laboratories.

RESULTS

4 bacterial species (Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, and Staphylococcus pseudintermedius) and 3 bacterial groups (Enterobacteriaceae, Enterococcus spp, and coagulase-positive Staphylococcus spp) met the minimum requirement of ≥ 15 isolates for construction of an antibiogram. For urine samples, 3 bacterial species and 2 bacterial groups met the minimum requirement of ≥ 10 isolates. For samples from skin, 2 bacterial species and 2 bacterial groups met the minimum requirement of ≥ 10 isolates. Patient signalment, sample source, and distribution of bacterial isolates were similar between PP and APCP patients.

CONCLUSIONS AND CLINICAL RELEVANCE

Results demonstrated that it was feasible to adapt existing guidelines for developing antibiograms in human medicine to the veterinary outpatient setting. Use of antibiograms could aid in empirical antimicrobial drug selection in a manner that supports antimicrobial stewardship principles.

Acquisition and carriage of multidrug-resistant organisms in dogs and cats presented to small animal practices and clinics in Switzerland

BACKGROUND

The emergence and spread of multidrug-resistant organisms (MDRO) present a threat to human and animal health.

OBJECTIVES

To assess acquisition, prevalence of and risk factors for MDRO carriage in dogs and cats presented to veterinary clinics or practices in Switzerland.

ANIMALS

Privately owned dogs (n = 183) and cats (n = 88) presented to 4 veterinary hospitals and 1 practice.

METHODS

Prospective, longitudinal, observational study. Oronasal and rectal swabs were collected at presentation and 69% of animals were sampled again at discharge. Methicillin-resistant (MR) staphylococci and macrococci, cephalosporinase-, and carbapenemase-producing (CP) Enterobacterales were isolated. Genetic relatedness of isolates was assessed by repetitive sequence-based polymerase chain reaction and multilocus sequence typing. Risk factors for MDRO acquisition and carriage were analyzed based on questionnaire-derived and hospitalization data.

RESULTS

Admission prevalence of MDRO carriage in pets was 15.5% (95% confidence interval [CI], 11.4-20.4). The discharge prevalence and acquisition rates were 32.1% (95% CI, 25.5-39.3) and 28.3% (95% CI, 22-35.4), respectively. Predominant hospital-acquired isolates were extended spectrum β-lactamase-producing Escherichia coli (ESBL-E coli; 17.3%) and β-lactamase-producing Klebsiella pneumoniae (13.7%). At 1 institution, a cluster of 24 highly genetically related CP (bla_oxa181 and bla_oxa48 ) was identified. Multivariate analysis identified hospitalization at clinic 1 (odds ratio [OR], 5.1; 95% CI, 1.6-16.8) and days of hospitalization (OR 3-5 days, 4.4; 95% CI, 1.8-10.9; OR > 5 days, 6.2; 95% CI, 1.3-28.8) as risk factors for MDRO acquisition in dogs.

CONCLUSIONS

Veterinary hospitals play an important role in the selection and transmission of MDRO among veterinary patients.

Higher Prevalence of Extended-Spectrum Cephalosporin-Resistant Enterobacterales in Dogs Attended for Enteric Viruses in Brazil Before and After Treatment with Cephalosporins

The extensive use of antibiotics is a leading cause for the emergence and spread of antimicrobial resistance (AMR) among dogs. However, the impact of using antibiotics to treat viral infections on AMR remains unknown. In this study, we compared the prevalence of extended-spectrum cephalosporin-resistant Enterobacterales (ESCR-E) between dogs with a suspected infection of canine parvovirus (CPV) and canine distemper (CDV) before and after treatment with third-generation cephalosporins. We found a higher prevalence of ESCR-E faecal carriage in dogs suspected of CPV (37%) and CDV (15%) compared to dogs with noninfectious pathologies (9%) even prior to the start of their treatment. A 7-day course of ceftriaxone or ceftiofur administrated to CPV and CDV-suspected dogs substantially increased their ESCR-E faecal carriage during treatment (85% for CPV and 57% for CDV), and 4 weeks after the treatment ended (89% for CPV and 60% for CDV) when dogs were back in their households. Most of the observed resistance was carried by ESCR-E. coli carrying bla_CTX-M genes. Our results suggest the need to optimize prophylactic antibiotic therapy in dogs treated for a suspected viral infection to prevent ESCR-E emergence and spread in the community.

Antimicrobial agent use in small animals what are the prescribing practices, use of PK-PD principles, and extralabel use in the United States?

In this review, the availability and deficiencies of current antimicrobial agents for companion animals in the United States are described. Although several active agents are FDA-approved for small animals, there are many unmet needs. These needs are greatest for cats, for the treatment of antibiotic drug-resistant infections, and to treat new or emerging pathogens that were not considered on older labels. The older agents approved before 1997 are often outdated, unavailable, or have inaccurate labeling. Subsequently, veterinarians treat dogs and cats with many unapproved antimicrobial agents that are licensed for human use. Although these drugs may be effective, there are also concerns that this use can produce drug-resistant bacteria that may be a public health risk. Although this concern is real, there is also evidence that any antimicrobial use in small animals can produce resistant fecal bacteria and stewardship principles should aim at reducing any unnecessary antibiotic use. This could be accomplished by avoiding some of the older, ineffective, or outdated agents described in this paper. There is a need for incentives to approve new agents that will be more appropriate for treating infections in companion animals without increasing the risk of drug-resistant bacteria that could potentially be transferred to humans and the environment and create a public health risk.

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.

Extended-Spectrum β-Lactamase-Producing Enterobacterales Shedding by Dogs and Cats Hospitalized in an Emergency and Critical Care Department of a Veterinary Teaching Hospital

Extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PE) gut shedding in human medicine is considered as a major reservoir for ESBL-associated infections in high risk patients. In veterinary medicine, data regarding ESBL-PE gut shedding on admission to emergency and critical care department is scarce. We aimed to determine ESBL-PE shedding rates by dogs and cats in this setting and to determine the risk factors for shedding, at two separate periods, three-years apart. Rectal swabs were collected from animals, on admission and 72 h post admission, enriched and plated on Chromagar ESBL plates, followed by bacterial identification. ESBL phenotype was confirmed and antibiotic susceptibility profiles were determined (Vitek 2). Medical records were reviewed for risk factor analysis (SPSS). Overall, 248 animals were sampled, including 108 animals on period I (2015-2016) and 140 animals on period II (2019). In both periods combined, 21.4% of animals shed ESBL-PE on admission, and shedding rates increased significantly during hospitalization (53.7%, p-value < 0.001). The main ESBL-PE species were Escherichia coli and Klebsiella pneumoniae, accounting for more than 85% of the isolates. In a multivariable analysis, previous hospitalization was a risk factor for ESBL-PE gut shedding (p-value = 0.01, Odds ratio = 3.05, 95% Confidence interval 1.28-7.27). Our findings demonstrate significant ESBL-PE gut shedding among small animals in the emergency and critical care department, posing the necessity to design and implement control measures to prevent transmission and optimize antibiotic therapy in this setting.

Epidemiology of the colonization and acquisition of methicillin-resistant staphylococci and vancomycin-resistant enterococci in dogs hospitalized in a clinic veterinary hospital in Spain

Antibiotic resistance is one of the biggest threats to human and animal health. Methicillin-resistant Staphylococcus spp. (MRS) and vancomycin-resistant Enterococcus spp. (VRE) are of increasing importance in hospital and/or nosocomial infections and represent a potential risk of transmission to humans from infected or colonized companion animals. Studies on the risk factors associated with colonization by multiresistant bacteria in animals are scarce. The present study aimed to estimate the prevalence and incidence of MRS and VRE in canine patients hospitalized in a veterinary hospital and to identify the risk factors for its acquisition and persistence. Nasal and perianal swabs were obtained from 72 dogs. Antimicrobial susceptibility assays and molecular detection of mecA and van genes were performed. A prevalence of 13.9% and incidence of 26.5% was observed in dogs colonized by MRS at hospital admission and release, respectively, higher values than those described in most veterinary studies. Thirty-five Staphylococcus isolates had mecA gene and showed higher resistance levels to most of the antimicrobials evaluated. Previous and concomitant use of antibiotics and corticosteroids has been associated with an increase in MRS colonization. The use of antibiotics in other animals living with the canine patients has also been identified as an associated factor, suggesting cross transmission. The presence of van-resistant genes from Enterococcus spp. was not detected. Pets should be considered possible vehicles of transmission and reservoirs for MRS bacteria and veterinary hospitals should be considered high-risk environments for the occurrence and spread of nosocomial infections and resistant bacteria.

Long-lasting nosocomial persistence of chlorhexidine-resistant Serratia marcescens in a veterinary hospital

Healthcare-associated infections (HAIs) are often overlooked in veterinary medicine. Serratia marcescens isolates were recovered over a ten-year period from companion animals in a French veterinary hospital. The pets were sampled either for diagnostic purposes or to monitor colonization. A retrospective study showed that 32 S. marcescens isolates were identified as HAI cases and a further 22 cases were associated with colonization of the surgical site. Two S. marcescens lineages were responsible for two different outbreaks during the study period. Chlorhexidine solution (1%) used to impregnate gauze was found to be the source of the second S. marcescens outbreak and all isolates had high MIC values for chlorhexidine (MIC = 128 mg/L). This study reports, for the first time to our knowledge, the nosocomial spread of chlorhexidine-resistant S. marcescens in a veterinary setting and highlights consequences of the improper use of disinfectants.

Antibiotic Resistance and Virulence Traits in Vancomycin-Resistant Enterococci (VRE) and Extended-Spectrum β-Lactamase/AmpC-producing (ESBL/AmpC) Enterobacteriaceae from Humans and Pets

Background: We investigated the virulence factors, genes, antibiotic resistance patterns, and genotypes (VRE and ESBL/AmpC) production in Enterococci and Enterobacteriaceae strains isolated from fecal samples of humans, dogs, and cats. Methods: A total of 100 fecal samples from 50 humans, 25 dogs, and 25 cats were used in the study. MICs of nine antimicrobials were determined using the broth microdilution method. Polymerase chain reaction was used for the detection of genes responsible for antibiotic resistance (VRE and ESBL/AmpC) and virulence genes both in Enterococcus species, such as cytolysin (cylA, cylB, cylM), aggregation substance (agg), gelatinase (gelE), enterococcal surface protein (esp), cell wall adhesins (efaAfs and efaAfm), and in Enterobacteriaceae, such as cytolysin (hemolysin) and gelatinase production (afa, cdt, cnf1, hlyA, iutA, papC, sfa). Results: Enterococcus faecium was the most prevalent species in humans and cats, whereas Enterococcus faecalis was the species isolated in the remaining samples. A total of 200 Enterobacteriaceae strains were also detected, mainly from humans, and Escherichia coli was the most frequently isolated species in all types of samples. In the Enterococcus spp, the highest percentages of resistance for ampicillin, amoxicillin/clavulanate, erythromycin, tetracycline, ciprofloxacin, teicoplanin, and vancomycin were detected in cat isolates (41.6%, 52.8%, 38.9%, 23.6%, 62.5%, 20.8%, and 23.6% respectively), and in E. coli, a higher rate of resistance to cefotaxime and ceftazidime emerged in cat and dog samples, if compared with humans (75.4% and 66.0%, 80.0% and 71.4%, and 32.0% and 27.2%, respectively). Regarding the total number of enterococci, 5% and 3.4% of the strains were vancomycin and teicoplanin resistant, and the vancomycin resistance (van A) gene has been detected in all samples by PCR amplification. All the Enterobacteriaceae strains were confirmed as ESBL producers by PCR and sequencing, and the most frequent ESBL genes in E. coli strains from humans and pet samples were bla_CTX-M-1 and bla_CTX-M-15. Conclusions: Our results provide evidence that one or more virulence factors were present in both genera, underlining again the ability of pet strains to act as pathogens.

High rates of CTX-M group-1 extended-spectrum β-lactamases producing Escherichia coli from pets and their owners in Faisalabad, Pakistan

PURPOSE

Pet animals have been considered a potential carrier of clinically important multi-drug-resistant Escherichia coli. However, little is known about the role of pets as reservoirs of extended-spectrum β-lactamase (ESBL) producing E. coli in Pakistan. This study was designed to determine the prevalence and genetic relatedness of ESBL-producing multidrug-resistant E. coli in pets, their owners, and veterinary professionals.

METHODS

A total of 105 fecal samples were collected from dogs, cats, their owners, and veterinary professionals from veterinary clinics. Isolates of ESBL-producing E. coli were subjected to antimicrobial susceptibility testing. The presence of bla CTX-M genes and CTX-M groups I and II in multidrug-resistant E. coli was detected using PCR. Clonal diversity was checked using BOX-PCR.

RESULTS

Of the 105 fecal samples screened, 73 (69.5%) were found to contain ESBL-producing E. coli. The percentage of ESBL-producing E. coli isolates in dogs and dog owners was found to be 81.8% (18/22) and 59% (13/22), respectively. In cats, this percentage was 73.9% (17/23) and in cat owners, 56.5% (13/23). Furthermore, 80% (12/15) of E. coli isolates in veterinary professionals were ESBL producers. Of these 73 ESBL-producing E. coli isolates, 23 isolates exhibited a multidrug-resistant phenotype. The most prevalent multidrug-resistant pattern (17.4%) identified was resistant to ampicillin, cefotaxime, ciprofloxacin, and nitrofurantoin. In the multidrug-resistant E. coli, bla CTX-M was identified as the most common ESBL-producing genotype (19/23), with bla CTX-M-1 dominating in all 19 isolates. Furthermore, BOX-PCR analysis exhibited genetically diverse clonal groups among isolates of the CTX-M-1 group.

CONCLUSION

Our results provide important baseline information on the potential burden of multidrug-resistant E. coli among companion animals in Pakistan. Further studies are needed to understand the drivers of antimicrobial resistance at human-animal-environmental intersections.

β-Lactam and Fluoroquinolone-Resistant Enterobacteriaceae Recovered from the Environment of Human and Veterinary Tertiary Care Hospitals

The dissemination of Enterobacteriaceae expressing resistance to clinically important antibiotics such as extended-spectrum cephalosporins (ESC), carbapenems, and fluoroquinolones is of critical concern to both human and veterinary medicine. In healthcare facilities, the movement of patients, personnel, and equipment provides an opportunity for Enterobacteriaceae carrying antibiotic resistance genes to disseminate in the hospital environment where they pose a threat to patients, staff, and hospital visitors. We collected environmental samples using electrostatic cloths to estimate the frequency of resistant Enterobacteriaceae contamination on human and veterinary hospital surfaces. Samples were enriched in nutrient broth modified with antibiotics to provide specific selection pressure to select for bacteria expressing AmpC β-lactamase (bla_CMY), extended-spectrum β-lactamase (ESBL, bla_CTX-M), carbapenemase, quinolone, and fluoroquinolone-resistant phenotypes. A total of 31 contact surfaces were sampled at each of five visits to two human hospitals. In addition, 34 surfaces were sampled at each of three visits to a veterinary hospital serving both farm animal and companion animal patients. Isolates expressing the bla_CMY phenotype were recovered from 0.6%, 100%, and 18.2% of human hospitals, veterinary farm animal, and veterinary companion animal hospital surfaces, respectively. Isolates expressing the bla_CTX-M phenotype were recovered from 0.6%, 55%, and 16.7% of human hospitals, farm animal, and companion animal veterinary hospital surfaces, respectively. Carbapenemase-producing Enterobacteriaceae (CPE) were detected from 1.3% of human hospital surfaces, but none were recovered from the veterinary hospital. Fluoroquinolone resistance was detected in 0.6%, 5.0%, and 37.9% of human hospitals, farm animal, and companion animal veterinary hospital surfaces, respectively. Our results indicate that ESC and fluoroquinolone-resistant Enterobacteriaceae can contaminate surfaces in both human and veterinary medical settings, with higher prevalence observed in veterinary hospitals, although the recovery of CPE from human hospital environments is concerning. Hospital medical trolleys or carts may serve as fomites for the dissemination of clinically relevant resistant bacteria.

Impact of systemic antimicrobial therapy on mucosal staphylococci in a population of dogs in Northwest England

BACKGROUND

Antimicrobial-resistant bacteria are increasingly isolated from veterinary patients.

OBJECTIVES

To determine risk factors for antimicrobial resistance (AMR) among canine mucosal staphylococci following routine antimicrobial treatment with cefalexin (CFX), clavulanate-amoxicillin (AC), cefovecin (CVN), clindamycin (CD) or a fluoroquinolone (FQ).

ANIMALS

Mucosal swab samples (n = 463) were collected from 127 dogs pre-treatment, immediately, and at one- and three-months post-treatment.

METHODS

Staphylococci were identified phenotypically and biochemically as coagulase negative (CoNS) or coagulase positive (CoPS); CoPS were speciated by nuc gene PCR. Antimicrobial susceptibility was determined using disc diffusion and mecA gene carriage by PCR. Multilevel, multivariable models examined associations between risk factors and presence/absence of CoPS, meticillin resistance (MR), multidrug-resistance (MDR) and fluoroquinolone resistance (FQR).

RESULTS

The percentage of samples with CoNS increased and with CoPS (including S. pseudintermedius) decreased immediately post-treatment with CFX, CVN and CD (P ≤ 0.001) and one month post-treatment with CD (P = 0.003). By three months post-treatment, there was no significant difference compared to pre-treatment samples. Immediately post-treatment with FQs there was significantly increased risk of isolating MRS (P = 0.002), MDR (P = 0.002) or FQR (P = 0.013) staphylococci and of MDR following CFX treatment (P = 0.019). The percentage of samples with AMR staphylococci declined from immediately to three months post-treatment and there was no significant difference between resistance prevalence at one or three months post-treatment for most AMR traits and treatment groups. Exceptions include increased MDR following FQ (P = 0.048) or CFX (P = 0.021), at one and three months post-treatment, respectively.

CONCLUSIONS AND CLINICAL IMPORTANCE

Systemic antimicrobials impact on mucosal staphylococci. Immediately after therapy, the mucosa may be a reservoir for AMR staphylococci that are a source of mobile genetic elements carrying AMR genes.

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.

Is the Colonisation of Staphylococcus aureus in Pets Associated with Their Close Contact with Owners?

In human beings and animals, staphylococci constitute part of the normal microbial population. Staphylococcus aureus could be classified as an opportunistic pathogen because the bacteria are noted in clinically healthy individuals, but when the immune system becomes compromised, they can also cause a wide range of infections. The objective of this study was to test the hypothesis that cats who are in close contact with their owners are at the greatest risk of being colonised with S. aureus. Two groups of cats were investigated: single, pet (domestic) cats that do not have outdoor access; and a local population of feral cats living in urban areas. The prevalence of S. aureus in domestic cats was 19.17%, while it's prevalence in the feral cat population was only 8.3%; which was statistically significant. Analysis of antibiotic resistance, at the genotypic as well as phenotypic level, showed that S. aureus isolates from pet cats were more likely to harbour antibiotic resistant determinants. The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in households was 10.21%, while in feral cats it was only 1.4%. In conclusion, this study has revealed a correlation between close contact with humans and a higher risk of the cats being colonised with S. aureus and harbouring the antibiotic resistant determinants.

Prevalence of antimicrobial resistance in faecal enterococci from vet-visiting pets and assessment of risk factors

The objective of this study was to determine the prevalence of antimicrobial resistance (AMR) exhibited by enterococci isolated from faeces of pets and its underlying risk factors. From September 2009 to May 2012, rectal swabs were collected from 74 dogs and 17 cats, selected from the population of animals visiting the Veterinary Hospital of University of Porto, UPVet, through a systematic random procedure. Animal owners answered a questionnaire about the risk factors that could influence the presence of AMR in faecal enterococci. Enterococci isolation, identification and antimicrobial (AM) susceptibility testing were performed. Data analyses of multilevel, univariable and multivariable generalised linear mixed models were conducted. From all enterococci isolated (n=315), 61 per cent were considered multidrug-resistant, whereas only 9.2 per cent were susceptible to all AMs tested. Highest resistance was found to tetracycline (67.0 per cent), rifampicin (60.3 per cent), azithromycin (58.4 per cent), quinupristin/dalfopristin (54.0 per cent) and erythromycin (53.0 per cent). Previous fluoroquinolone treatments and coprophagic habits were the features more consistently associated with the presence of AMR for three (chloramphenicol, ciprofloxacin and azithromycin) and seven (tetracycline, rifampicin, gentamicin, chloramphenicol, ciprofloxacin, erythromycin and azithromycin), respectively, out of nine AMs assessed. Evaluating risk factors that determine the presence of drug-resistant bacteria in pets, a possible source of resistance determinants to human beings, is crucial for the selection of appropriate treatment guidelines by veterinary practitioners.

The distribution of pathogens and their antimicrobial susceptibility patterns among canine surgical wound infections in Sweden in relation to different risk factors

Background

Surgical site infection (SSI) is a common nosocomial infection in dogs and a growing concern in veterinary hospitals as an increase in multidrug-resistant pathogens is reported. Despite the need for rational and prudent antimicrobial use, few peer-reviewed and published veterinary studies have investigated the pathogenic growth including susceptibility patterns of the isolated pathogens in canine SSIs.

The first objective of the present study was to estimate the distribution of bacterial pathogens in dogs with SSI and to investigate whether this was influenced by type of surgical procedure (clean, clean-contaminated, contaminated or dirty), duration of hospitalization, wound classification and depth of the infection, or antimicrobial treatment. The second objective was to assess susceptibility patterns to clinically relevant antimicrobials.

During three years, four animal referral hospitals and three small animal clinics submitted bacterial swabs from canine SSIs for culture and susceptibility, together with a questionnaire completed by the attending clinician.

Results

Approximately two thirds of the in total 194 isolates were staphylococci. Staphylococcus pseudintermedius was the most prevalent finding (46%) followed by beta haemolytic Streptococcus spp. (24%). No associations between distribution of the isolated pathogens and classification of the surgical procedure, duration of hospitalization or depth of the SSI were shown, with the exception of Escherichia coli isolates being significantly more often found in deep wound infections than in superficial skin infections.

Overall the possibilities of finding first generations antimicrobials to treat the SSIs included in the study were favorable, as the isolated pathogens were mostly without acquired antimicrobial resistance and multidrug resistance was uncommon. There were only three cases of methicillin-resistant S. pseudintermedius-infections (one percent of all isolates), one case of extended-spectrum beta-lactamase producing E. coli-infection, and no methicillin-resistant Staphylococcus aureus infections.

Conclusions

None of the investigated factors were shown to influence the distribution of bacterial pathogens. The majority of SSIs were caused by staphylococci, and S. pseudintermedius was the most prevalent pathogen. Based on the study results, use of first-line antimicrobials prior to receiving culture and susceptibility results is a rational empirical antimicrobial therapy for the studied dog population.

Multidrug-resistant pathogens in the food supply

Antimicrobial resistance, including multidrug resistance (MDR), is an increasing problem globally. MDR bacteria are frequently detected in humans and animals from both more- and less-developed countries and pose a serious concern for human health. Infections caused by MDR microbes may increase morbidity and mortality and require use of expensive drugs and prolonged hospitalization. Humans may be exposed to MDR pathogens through exposure to environments at health-care facilities and farms, livestock and companion animals, human food, and exposure to other individuals carrying MDR microbes. The Centers for Disease Control and Prevention classifies drug-resistant foodborne bacteria, including Campylobacter, Salmonella Typhi, nontyphoidal salmonellae, and Shigella, as serious threats. MDR bacteria have been detected in both meat and fresh produce. Salmonellae carrying genes coding for resistance to multiple antibiotics have caused numerous foodborne MDR outbreaks. While there is some level of resistance to antimicrobials in environmental bacteria, the widespread use of antibiotics in medicine and agriculture has driven the selection of a great variety of microbes with resistance to multiple antimicrobials. MDR bacteria on meat may have originated in veterinary health-care settings or on farms where animals are given antibiotics in feed or to treat infections. Fresh produce may be contaminated by irrigation or wash water containing MDR bacteria. Livestock, fruits, and vegetables may also be contaminated by food handlers, farmers, and animal caretakers who carry MDR bacteria. All potential sources of MDR bacteria should be considered and strategies devised to reduce their presence in foods. Surveillance studies have documented increasing trends in MDR in many pathogens, although there are a few reports of the decline of certain multidrug pathogens. Better coordination of surveillance programs and strategies for controlling use of antimicrobials need to be implemented in both human and animal medicine and agriculture and in countries around the world.

An individual-based model of transmission of resistant bacteria in a veterinary teaching hospital

Veterinary nosocomial infections caused by antibiotic resistant bacteria cause increased morbidity, higher cost and length of treatment and increased zoonotic risk because of the difficulty in treating them. In this study, an individual-based model was developed to investigate the effects of movements of canine patients among ten areas (transmission points) within a veterinary teaching hospital, and the effects of these movements on transmission of antibiotic susceptible and resistant pathogens. The model simulates contamination of transmission points, healthcare workers, and patients as well as the effects of decontamination of transmission points, disinfection of healthcare workers, and antibiotic treatments of canine patients. The model was parameterized using data obtained from hospital records, information obtained by interviews with hospital staff, and the published literature. The model suggested that transmission resulting from contact with healthcare workers was common, and that certain transmission points (housing wards, diagnostics room, and the intensive care unit) presented higher risk for transmission than others (lobby and surgery). Sensitivity analyses using a range of parameter values demonstrated that the risk of acquisition of colonization by resistant pathogens decreased with shorter patient hospital stays (P<0.0001), more frequent decontamination of transmission points and disinfection of healthcare workers (P<0.0001) and better compliance of healthcare workers with hygiene practices (P<0.0001). More frequent decontamination of heavily trafficked transmission points was especially effective at reducing transmission of the model pathogen.