Katariina Thomson

Background: Extended-spectrum β-lactamase producingEnterobacterales(ESBL-E) are important causative agents for infections in humans and animals. At the Equine Veterinary Teaching Hospital of the University of Helsinki, the first infections caused by ESBL-E were observed at the end of 2011 leading to enhanced infection surveillance. Contact patients were screened for ESBL-E by culturing infection sites and rectal screening. This study was focused on describing the epidemiology and microbiological characteristics of ESBL-E from equine patients of the EVTH during 2011–2014, and analysing putative risk factors for being positive for ESBL-E during an outbreak ofKlebsiella pneumoniaeST307.Results: The number of ESBL-E isolations increased through 2012–2013 culminating in an outbreak of multi-drug resistantK. pneumoniaeST307:bla_CTX-M-1:bla_TEM:bla_SHVduring 04–08/2013. During 10/2011–05/2014, altogether 139 ESBL-E isolates were found from 96 horses. Of these, 26 were from infection-site specimens and 113 from rectal-screening swabs. A total of 118 ESBL-E isolates from horses were available for further study, the most numerous beingK. pneumoniae(n = 44),Escherichia coli(n = 31) andEnterobacter cloacae(n = 31). Hospital environmental specimens (N = 47) yielded six isolates of ESBL-E. Two identicalE. cloacaeisolates originating from an operating theatre and a recovery room had identical or highly similar PFGE fingerprint profiles as five horse isolates. In the multivariable analysis, mare–foal pairs (OR 4.71, 95% CI 1.57–14.19, P = 0.006), length of hospitalisation (OR 1.62, 95% CI 1.28–2.06, P < 0.001) and passing of a nasogastric tube (OR 2.86, 95% CI 1.03–7.95, P = 0.044) were associated with being positive for ESBL-E during theK. pneumoniaeoutbreak.Conclusions: The occurrence of an outbreak caused by a pathogenic ESBL-producingK. pneumoniaeST307 strain highlights the importance of epidemiological surveillance of ESBL-E in veterinary hospitals. Limiting the length of hospitalisation for equine patients may reduce the risk of spread of ESBL-E. It is also important to acknowledge the importance of nasogastric tubing as a potential source of acquiring ESBL-E. As ESBL-E were also found in stomach drench pumps used with nasogastric tubes, veterinary practices should pay close attention to appropriate equipment cleaning procedures and disinfection practices.

Background: Surgical site infections (SSI) are associated with increased morbidity and mortality. To lower the incidence of SSI, antimicrobial prophylaxis is given 30–60 min before certain types of surgeries in both human and veterinary patients. However, due to the increasing concern of antimicrobial resistance, the benefit of antimicrobial prophylaxis in clean orthopaedic and neurosurgeries warrants investigation. The aims of this retrospective cross-sectional study were to review the rate of SSI and evaluate the compliance with antimicrobial guidelines in dogs at a veterinary teaching hospital in 2012–2016. In addition, possible risk factors for SSI were assessed.Results: Nearly all dogs (377/406; 92.9%) received antimicrobial prophylaxis. Twenty-nine dogs (7.1%) did not receive any antimicrobials and only four (1.1%) received postoperative antimicrobials. The compliance with in-house and national protocols was excellent regarding the choice of prophylactic antimicrobial (cefazolin), but there was room for improvement in the timing of prophylaxis administration. Follow-up data was available for 89.4% (363/406) of the dogs. Mean follow-up time was 464 days (range: 3–2600 days). The overall SSI rate was 6.3%: in orthopaedic surgeries it was 6.7%, and in neurosurgeries it was 4.2%. The lowest SSI rates (0%) were seen in extracapsular repair of cranial cruciate ligament rupture, ulnar ostectomy, femoral head and neck excision, arthrotomy and coxofemoral luxation repair. The highest SSI rate (25.0%) was seen in arthrodesis. Omission of antimicrobials did not increase the risk for SSI (P = 0.56; OR 1.7; CI_95%0.4–5.0). Several risk factors for SSI were identified, including methicillin-resistantStaphylococcus pseudintermediuscarriage (P = 0.02; OR 9.0; CI_95%1.4–57.9) and higher body temperature (P = 0.03; OR 1.69; CI_95%1.0–2.7; mean difference + 0.4 °C compared to dogs without SSI).Conclusions: Antimicrobial prophylaxis without postoperative antimicrobials is sufficient to maintain the overall rate of SSI at a level similar to published data in canine clean orthopedic and neurosurgeries.

Two surveys were carried out to investigate how antimicrobials are used in cats in Finland. Information was retrieved from 419 prescriptions and 311 questionnaire sheets concerning antimicrobial treatment for feline patients. Infected wounds, skin disorders and urinary tract infections were the most common reasons for antimicrobial treatment in cats. Compliance with prudent use guidelines was good. β-Lactams such as amoxycillin and amoxycillin with clavulanic acid were frequently used. Fluoroquinolones were used judiciously. The median length of treatment was 10 days for most conditions. Diagnosis was mainly based on clinical signs, and bacteriological culture and sensitivity testing was rarely performed. This study provides basic descriptive information on how antimicrobials are used in cats and that could help when revising guidelines for the condition-based use of antimicrobials in animals.

Indication-based data on the use of antimicrobials in animals were collected using a prospective cross-sectional survey, similarly as for surveys carried out in human medicine, but adapting the questionnaire to include veterinary-specific issues. The participating veterinarians were randomly selected from a sample population of practising veterinarians. The sampling was stratified to take into account the proportions of different types of veterinary practice in the country. All patients consulting the veterinary practice during a 1-week period were included in the study and veterinarians returned a completed questionnaire for each patient receiving antimicrobial treatment. As cattle received most of the treatments, results from the survey are given using cattle as an example species.