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

Pathogenicity potential of enterococci isolated from a Veterinary Biological Isolation and Containment Unit

Introduction

Enterococcus are considered an important genus in terms of Hospital-Acquired Infections (HAIs), which means that their characterization regarding resistance and virulence profiles in the hospital environment is of extreme importance. This article addresses this issue through the characterization of enterococci collected from a Veterinary Biological Isolation and Containment Unit (BICU).

Methods

A total of 73 isolates, collected from different surfaces of a Veterinary BICU, were identified as Enterococcus through PCR at species level, after which 34 isolates were selected as representatives using (GTG)5 fingerprinting. These isolates were further characterized phenotypically in terms of antimicrobial resistance through disk diffusion and of virulence factors' expression.

Results

The majority of the enterococci isolated presented resistance to erythromycin (79.4%), ampicillin (73.5%), amoxicillin-clavulanic acid (70.6%), tetracycline (67.6%), ciprofloxacin (58.8%) and levofloxacin (50.0%), and were able to produce hemolysin (88.2%) and biofilm (82.3%). Furthermore, in terms of pathogenicity, three isolates (8.8%) were classified as high threats and two (5.9%) as moderate threats.

Discussion

The degree of resistance, production of virulence factors and the percentage of isolates classified as moderate or high threat means that a constant vigilance of such strains in veterinary units, but also in clinics and hospitals in general, is an important tool in terms of infection prevention and consequent reduction of HAIs.

Dog Owners’ Attitude toward Veterinary Antibiotic Use and Antibiotic Resistance with a Focus on Canine Diarrhea Management

An ad hoc questionnaire was designed in order to investigate AMR knowledge amongst Italian dog owners, owner expectations concerning pharmacological treatment of canine AD, and client attitudes towards and compliance with alternative strategies to antimicrobial administration. A total of 250 questionnaires were returned. Most of respondents were female, aged 36–70 and workers. More than a half of participants owned one dog with mixed breed, with Labrador retriever, golden retriever, dachshund, and border collie being the most represented breeds. On average, each dog was treated with an oral antibiotic 1.044 times per year. Intestinal diseases were among the main reasons (19%) for antibiotic prescription. Oral antibiotic courses without veterinary consultation (21%) and anticipated termination of the therapy (17.1%) were less common than reported elsewhere. The majority of respondents knew the meaning of AMR with a significant inverse association between the level of education and the tendency to administer antimicrobials without consulting a clinician (p = 0.004). Most of the owners expected a rapid recovery of clinical signs after a first episode of AD and accepted natural dietary supplementation for treating the condition. Ninety-five percent of the respondents believed that public funding should be spent to study AMR. Even though an acceptable degree of AMR awareness emerged, we feel that further efforts should be made to increase public AMR knowledge and to stimulate proactive measures to fight the phenomenon. On the other hand, the development of guidelines for the treatment of uncomplicated canine AD would help clinicians to rationalize antimicrobial use.

An in-house 45-plex array for the detection of antimicrobial resistance genes in Gram-positive bacteria

Identifying antimicrobial resistance (AMR) genes and determining their occurrence in Gram-positive bacteria provide useful data to understand how resistance can be acquired and maintained in these bacteria. We describe an in-house bead array targeting AMR genes of Gram-positive bacteria and allowing their rapid detection all at once at a reduced cost. A total of 41 AMR probes were designed to target genes frequently associated with resistance to tetracycline, macrolides, lincosamides, streptogramins, pleuromutilins, phenicols, glycopeptides, aminoglycosides, diaminopyrimidines, oxazolidinones and particularly shared among Enterococcus and Staphylococcus spp. A collection of 124 enterococci and 62 staphylococci isolated from healthy livestock animals through the official Belgian AMR monitoring (2018-2020) was studied with this array from which a subsample was further investigated by whole-genome sequencing. The array detected AMR genes associated with phenotypic resistance for 93.0% and 89.2% of the individual resistant phenotypes in enterococci and staphylococci, respectively. Although linezolid is not used in veterinary medicine, linezolid-resistant isolates were detected. These were characterized by the presence of optrA and poxtA, providing cross-resistance to other antibiotics. Rarer, vancomycin resistance was conferred by the vanA or by the vanL cluster. Numerous resistance genes circulating among Enterococcus and Staphylococcus spp. were detected by this array allowing rapid screening of a large strain collection at an affordable cost. Our data stress the importance of interpreting AMR with caution and the complementarity of both phenotyping and genotyping methods. This array is now available to assess other One-Health AMR reservoirs.

Mobile Tigecycline Resistance: An Emerging Health Catastrophe Requiring Urgent One Health Global Intervention

Mobile tigecycline resistance (MTR) threatens the clinical efficacy of the salvage antibiotic, tigecycline (TIG) used in treating deadly infections in humans caused by superbugs (multidrug-, extensively drug-, and pandrug-resistant bacteria), including carbapenem- and colistin-resistant bacteria. Currently, non-mobile tet(X) and mobile plasmid-mediated transmissible tet(X) and resistance-nodulation-division (RND) efflux pump tmexCD-toprJ genes, conferring high-level TIG (HLT) resistance have been detected in humans, animals, and environmental ecosystems. Given the increasing rate of development and spread of plasmid-mediated resistance against the two last-resort antibiotics, colistin (COL) and TIG, there is a need to alert the global community on the emergence and spread of plasmid-mediated HLT resistance and the need for nations, especially developing countries, to increase their antimicrobial stewardship. Justifiably, MTR spread projects One Health ramifications and portends a monumental threat to global public and animal health, which could lead to outrageous health and economic impact due to limited options for therapy. To delve more into this very important subject matter, this current work will discuss why MTR is an emerging health catastrophe requiring urgent One Health global intervention, which has been constructed as follows: (a) antimicrobial activity of TIG; (b) mechanism of TIG resistance; (c) distribution, reservoirs, and traits of MTR gene-harboring isolates; (d) causes of MTR development; (e) possible MTR gene transfer mode and One Health implication; and (f) MTR spread and mitigating strategies.

Antimicrobial-Resistant Enterococcus spp. in Wild Avifauna from Central Italy

Bacteria of the genus Enterococcus are opportunistic pathogens, part of the normal intestinal microflora of animals, able to acquire and transfer antimicrobial resistance genes. The aim of this study was to evaluate the possible role of wild avifauna as a source of antimicrobial-resistant enterococci. To assess this purpose, 103 Enterococcus spp. strains were isolated from the feces of wild birds of different species; they were tested for antimicrobial resistance against 21 molecules, vancomycin resistance, and high-level aminoglycosides resistance (HLAR). Furthermore, genes responsible for vancomycin, tetracycline, and HLAR were searched. E. faecium was the most frequently detected species (60.20% of isolates), followed by E. faecalis (34.95% of isolates). Overall, 99.02% of the isolated enterococci were classified as multidrug-resistant, with 19.41% extensively drug-resistant, and 2.91% possible pan drug-resistant strains. Most of the isolates were susceptible to amoxicillin/clavulanic acid (77.67%) and ampicillin (75.73%), with only 5.83% of isolates showing an ampicillin MIC ≥ 64 mg/L. HLAR was detected in 35.92% of isolates, mainly associated with the genes ant(6)-Ia and aac(6′)-Ie-aph(2″)-Ia. Few strains (4.85%) were resistant to vancomycin, and the genes vanA and vanB were not detected. A percentage of 54.37% of isolates showed resistance to tetracycline; tet(M) was the most frequently detected gene in these strains. Wild birds may contribute to the spreading of antimicrobial-resistant enterococci, which can affect other animals and humans. Constant monitoring is essential to face up to the evolving antimicrobial resistance issue, and monitoring programs should include wild avifauna, too.

Evaluation of a Biocide Used in the Biological Isolation and Containment Unit of a Veterinary Teaching Hospital

Hospital-acquired infections (HAIs) are a rising problem worldwide, and the best way of coping with them is through infection tracking and surveillance systems, combined with prevention strategies, namely efficient disinfection protocols, that employ various biocides. However, increasing reports about reductions in biocide susceptibility and the development of cross-resistance to antimicrobials emphasize the need for identifying the factors influencing biocide efficiency. In this study, 29 bacterial isolates (n = 3 E. coli, n = 2 Pseudomonas spp., n = 23 Enterococcus spp., and n = 1 Staphylococcus pseudintermedius), obtained from environmental samples collected from the Biological Isolation and Containment Unit (BICU), of the Veterinary Teaching Hospital of the Faculty of Veterinary Medicine, University of Lisbon, were tested in order to determine their antimicrobial susceptibility to various antibiotics. Thirteen of these isolates were further selected in order to determine their antimicrobial susceptibility to Virkon™ S, with and without the presence of organic matter. Afterward, seven of these isolates were incubated in the presence of sub-lethal concentrations of this formulation and, subsequently, new susceptibility profiles were determined. Fourteen of the 29 isolates (48.3%) were classified as multidrug resistant, all previously identified as enterococci. Concerning Virkon™ S's susceptibility, the Minimal Bactericidal Concentration (MBC) of this biocide regarding all isolates was at least eight times lower than the concentration regularly used, when no organic matter was present. However, when organic matter was added, MBC values rose up to 23 times. After exposure to sub-lethal concentrations of Virkon™ S, four enterococci presented a phenotypical change regarding antimicrobial susceptibility towards gentamicin. Virkon™ S also resulted in higher MBC values, up to 1.5 times, in the presence of low concentrations of organic matter, but no rise in these values was observed in assays without interfering substance. Virkon™ S seemed to be an efficient formulation in eliminating all bacteria isolates isolated from the BICU. However, organic matter could represent a hindrance to this ability, which emphasizes the importance of sanitization before disinfection procedures. The changes seen in antimicrobial susceptibility could be explained by a general stress-induced response promoted by the sub-lethal levels of Virkon™ S. Additionally, when no organic matter was present, a decrease in susceptibility to this biocide seemed to be non-existent.

Wildlife-pet markets in a one-health context

Background and Aim: Wildlife markets are centers of trade involving live animals and their derivatives from wild-caught and captive-bred non-domesticated animals, including for the culinary, fashion, traditional medicine, curio, and pet sectors. These markets occur in Southeast Asia, India, North America, Latin America, Europe, Africa, and elsewhere. This study aims to address a diversity of related issues that have a one-health bearing while focusing on wildlife markets in relation to the pet trade. Across relevant regions and countries, all major animal classes are traded at wildlife-pet markets. Wildlife markets, in general, are considered distinct from so-called "wet markets" at which domesticated animals, fish, and other "seafood" are offered only for consumption. Several aspects of wildlife markets have attracted scientific and popular scrutiny, including animal welfare concerns, species conservation threats, legality, ecological alteration, introduction of invasive alien species, presence of undescribed species, and public and agricultural animal health issues. Materials and Methods: Onsite inspections were conducted for markets in the United States, Spain, Germany, The Netherlands, and the UK, as well as observational research of visual imagery of market conditions, and we compared these conditions with evidence-based standards for animal welfare and public health management. Results: Wildlife markets globally shared common similar structures and practices including the presence of sick, injured, or stressed animals; mixing of animals of uncertain origin and health state; and no specific or any hygiene protocols, with issues of animal welfare, public health and safety, agricultural animal health, and other one-health concerns being inherently involved. Conclusion: We conclude that wildlife markets are incompatible with responsible standards and practices, and we recommend that such events are banned globally to ameliorate inherent major problems.

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.

Antimicrobial resistance profiles and phylogenetic groups of Escherichia coli isolated from healthy Thoroughbred racehorses in Japan

In this study, we investigated the occurrence of antimicrobial resistance in commensal Escherichia coli isolated from healthy Thoroughbred (TB) racehorses in Japan. A total of 212 fecal samples were individually collected from TB racehorses from March 2017 to August 2018 at Japan Racing Association training centers. E. coli was isolated by using selective agar media, deoxycholate-hydrogen sulfide-lactose (DHL) and eosin methylene blue (EMB). A total of 417 E. coli isolates were examined against 10 antimicrobial agents by using the broth microdilution method. The 417 E. coli isolates were phylogenetically grouped using a multiplex polymerase chain reaction. The highest proportion of resistance was observed for streptomycin (30.9%, 129/417) followed by ampicillin (19.4%, 81/417), trimethoprim (15.8%, 66/417), tetracycline (8.4%, 35/417), chloramphenicol (2.6%, 11/417), kanamycin (1.2%, 5/417), nalidixic acid (0.5%, 2/417), cefazolin (0.2%, 1/417), colistin (0.2%, 1/417), and gentamycin (0%). Multidrug-resistant (MDR) E. coli was detected in 7.9% (33/417) of isolates. The proportions of resistance against ampicillin, streptomycin, kanamycin, and chloramphenicol and of multidrug-resistant phenotypes in E. coli belonging to phylogenetic group B2 were significantly higher than those of other groups. This study clarified the distribution of antimicrobial-resistant (AMR) E. coli in Japanese racehorses. A continuous monitoring program for antimicrobial resistance is required to control the spread of AMR bacteria in racehorses.

Effect of amoxicillin-clavulanic acid on clinical scores, intestinal microbiome, and amoxicillin-resistant Escherichia coli in dogs with uncomplicated acute diarrhea

Background

Despite limited evidence of efficacy, antibiotic treatment is still frequently prescribed in dogs with uncomplicated acute diarrhea (AD).

Objective

To assess whether amoxicillin‐clavulanic acid has a clinical benefit, an effect on the fecal microbiome, and the proportion of amoxicillin‐resistant Escherichia coli in dogs with AD.

Animals

Sixteen dogs with AD of <3 days duration.

Methods

Prospective, placebo‐controlled, double‐blinded study. Clinical scores were compared between client‐owned dogs randomly assigned to an antibiotic (AG) or a placebo (PG) group. The intestinal microbiome was analyzed using quantitative PCR assays. Amoxicillin‐resistant fecal E. coli were assessed semiquantitatively with microbiological methods.

Results

There was no difference in clinical recovery between treated dogs or controls (CADS index day 10: AG group median: 2 (range: 1‐3; CI [1.4; 2.6]); PG group median: 1.6 (range: 1‐3; CI [1.1; 2.4]); P > .99). All dogs gained normal clinical scores (CADS index ≤3) after 1 to 6 days (median 2 days) after presentation. There was no significant difference in the fecal dysbiosis index (during treatment: AG mean −2.6 (SD 3.0; CI [−5.1; 0.0]); PG mean −0.8 (SD 4.0; CI [−4.2; 2.5]; P > .99) or its bacterial taxa. The proportion of resistant fecal E. coli increased (to median: 100%; range: 35%‐100%) during treatment with amoxicillin‐clavulanic acid and was still increased (median: 10%; range 2%‐67%) 3 weeks after treatment, both of which were significantly higher proportions than in the placebo group for both time points (during treatment AG median 100% versus PG median 0.2% (P < .001); after treatment AG median 10% versus PG median 0.0% (P = .002)).

Conclusions and Clinical Importance

Our study suggests that treatment with amoxicillin‐clavulanic acid confers no clinical benefit to dogs with AD, but predisposes the development of amoxicillin‐resistant E. coli, which persist for as long as 3 weeks after treatment. These findings support international guideline recommendations that dogs with diarrhea should not be treated with antimicrobials unless there are signs of sepsis.