Prevalence and Patterns of Antimicrobial Resistance among Escherichia coli and Staphylococcus spp. in a Veterinary University Hospital

Antimicrobial resistance, enterotoxin and biofilm production genes in Staphylococcus spp. isolated from facilities and fomites in veterinary hospital in the Caatinga biome

The Caatinga biome occurs only in Brazil and offers epidemiological conditions that should be assessed differently from other regions of Brazil and the world. Thus, the aim of this survey was to identify antimicrobial resistance, enterotoxin and biofilm production genes in Staphylococcus spp. isolated from facilities and fomites in a veterinary hospital in Caatinga biome. Samples were collected from surfaces of small animal clinical care tables (n =8), cages in the dog and cat hospitalisation sector and animals with infectious diseases (n = 21), small animal surgical centre (n =8), sterilisation sector (n =7) and stethoscopes (n = 32) by using sterile swabs. Bacterial isolation and identification, antimicrobial resistance phenotypic test and molecular detection of antimicrobial resistance, biofilm formation and enterotoxin genes were carried out. Ninety-five bacterial isolates were obtained, and 29 (30.5%) were identified as Staphylococcus spp. Overall, 13 isolates (44.8%) of six species of Staphylococcus spp. showed antimicrobial resistance profile, as well as S. haemolyticus expressed phenotypic profile of multidrug resistance. The antimicrobials with the highest resistance rates were penicillin and tetracycline. The most frequent resistance genes were blaZ and tetM, both detected in 10 (76.9%) isolates. The mecA, tetL and tetK genes had frequencies of 38.5% (5/13), 23.1% (3/13) and 15.4% (2/13), respectively. The biofilm production marker, icaD gene, was detected in one S. sciuri strain. SEE gene, which encodes enterotoxins, was detected in 15.4% (2/13) of the strains (S. pseudintermedius and S. intermedius). The occurrence of Staphylococcus spp. carrying resistance genes to diferent classes of antimicrobials, presenting MDR phenotypic pattern and carrying enterotoxins and biofim encoding genes recovered from veterinary hospital facilities and fomites in the Caatinga biome reinforce the need to implement prevention cares in veterinary practices to avoid One Health-concerning conditions.

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

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

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.

In vitro porphyrin-based photodynamic therapy against mono and polyculture of multidrug-resistant bacteria isolated from integumentary infections in animals

Multidrug-resistant (MDR) organisms have been frequently isolated from integumentary lesions of animals, and these lesions are usually infected by more than one pathogen. This study evaluated an in vitro antimicrobial photodynamic therapy (aPDT) using two water-soluble tetra-cationic porphyrins (3-H₂TMeP and 4-H₂TMeP) against mono and polyculture of MDR bacteria isolated from dogs, cats, and horses. Ten isolates of MDR bacteria (two of each species: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, and Staphylococcus pseudointermedius) were used to evaluate aPDT against the monoculture using a non-cytotoxic concentration of 3-H₂TMeP and 4-H₂TMeP porphyrins (40 µM), with 30 min of light irradiation in Gram-positive and 90 min for Gram-negative bacteria. The aPDT using the 4-H₂TMeP porphyrin was also tested against five different polycultures (Coagulase positive Staphylococcus (CPS) and Pseudomonas sp.; E. coli and Proteus sp.; Pseudomonas sp. and Proteus sp.; CPS and E. coli; and CPS and Proteus sp.) for 90 min. The efficacy of both treatments was evaluated by plating the solution exposed to light or kept in the dark and counting the colonies forming units after 24 h of incubation at 37 °C. Atomic force microscope analysis was used to map bacteria morphological changes and extract adhesion force parameters from the bacteria membranes. Only the 4-H₂TMeP porphyrin had antibacterial activity against MDR bacteria in monoculture, especially S. pseudointermedius and P. aeruginosa. In polyculture, the 4-H₂TMeP porphyrin reduced bacterial concentrations (p < 0.05) in the associations of E. coli and S. pseudointermedius, P. aeruginosa and S. pseudointermedius, and P. aeruginosa and P. mirabilis. These results showed that aPDT using 4-H₂TMeP is a good option for future associations of aPDT and other therapies or in vivo research.

Hostage to history - questioning the duration of systemic antimicrobial therapy for the treatment of canine superficial bacterial folliculitis

Current guidelines for the use of systemic antimicrobials for the treatment of superficial bacterial folliculitis in dogs include the recommendation that the disease be treated for a minimum of 3 weeks and for at least 1 week beyond clinical resolution. With increasing antimicrobial resistance being noted for bacteria involved in this condition, as well as the increased use of evidence-based medicine, this dogma needs to be reevaluated.

Massive Spread of OXA-48 Carbapenemase-Producing Enterobacteriaceae in the Environment of a Swiss Companion Animal Clinic

Background: Companion animal clinics contribute to the spread of antimicrobial resistant microorganisms (ARM) and outbreaks with ARM of public health concern have been described. Methods: As part of a project to assess infection prevention and control (IPC) standards in companion animal clinics in Switzerland, a total of 200 swabs from surfaces and 20 hand swabs from employees were collected during four days in a medium-sized clinic and analyzed for extended spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E), carbapenemase-producing Enterobacteriaceae (CPE), vancomycin-resistant enterococci (VRE), and methicillin-resistant staphylococci (MRS). Results: A total of 22 (11.0%) environmental specimen yielded CPE, 14 (7.0%) ESBL-E, and 7 (3.5%) MRS; MR Staphylococcus aureus were isolated from two (10.0%) hand swabs. The CPE isolates comprised Escherichia coli, Klebsiella pneumoniae, Enterobacter hormaechei, Citrobacter braakii, and Serratia marcescens. Whole genome sequencing revealed that all CPE carried closely related bla_OXA-48 plasmids, suggesting a plasmidic spread within the clinic. The clinic exhibited major deficits in surface disinfection, hand hygiene infrastructure, and hand hygiene compliance. CPE were present in various areas, including those without patient contact. The study documented plasmidic dissemination of bla_OXA-48 in a companion animal clinic with low IPC standards. This poses a worrisome threat to public health and highlights the need to foster IPC standards in veterinary clinics to prevent the spread of ARM into the community.