Outbreaks of methicillin-resistant Staphylococcus aureus among staff and dogs in Swedish small animal hospitals

Transmission chains and molecular characterizations of extended-spectrum β-lactamase producing Enterobacteriaceae at a veterinary hospital in Chengdu, China

The rapid emergence of Extended-spectrum β-lactamase producing Enterobacteriaceae (ESBL-E) is a major global public health concern. Previous studies have identified that intensive medical care of dogs and cats in veterinary hospitals have accelerated the infections and spread of ESBL-E. To investigate the spread of ESBL-E in a veterinary hospital, a total of 202 samples including hospitalized animals, veterinary healthcare workers and environment were collected from a veterinary hospital in Chengdu, China. ESBL-E were identified by antimicrobial susceptibility testing and 16 s rRNA sequencing and were further conducted on ESBL gene detection and multilocus sequence typing (MLST). At last, strains with transmission potential were analyzed by whole genome sequencing (WGS). Our results showed that the overall prevalence of ESBL-positive isolates was 34.7% (70/202), with 55.3% (26/47) in animals, 29.3% (12/41) in healthcare workers and 28.1% (32/114) in environment swabs. Twenty diverse MLST types were detected, with ST744, ST231 as the most prevalent ones. Transmission chains of two ESBL-E.coli (ST744 blaCTX-M-18, blaTEM-1) from cat_21 to cat_14, and two ESBL-Kp (ST231 blaCTX-M-27, blaTEM-1, blaSHV-1) from cat_20 to cat_37 were further confirmed by WGS. Furthermore, interdisciplinary investigation and cooperation of AMR are needed to better limit the transmissions of high-risk strains and to implement effective public health interventions.

Educational intervention to improve infection prevention and control practices in four companion animal clinics in Switzerland

BACKGROUND

Infection prevention and control (IPC) practices vary among companion animal clinics, and outbreaks with carbapenemase-producing Enterobacterales (CPE) have been described.

AIM

To investigate the effect of an IPC intervention (introduction of IPC protocols, IPC lectures, hand hygiene campaign) in four companion animal clinics.

METHODS

IPC practices, environmental and hand contamination with antimicrobial-resistant micro-organisms (ARM) and hand hygiene (HH) were assessed at baseline, and 1 and 5 months after the intervention.

RESULTS

Median IPC scores (% maximum score) improved from 57.8% (range 48.0-59.8%) to 82.9% (range 81.4-86.3%) at 1-month follow-up. Median cleaning frequency assessed by fluorescent tagging increased from 16.7% (range 8.9-18.9%) to 30.6% (range 27.8-52.2%) at 1-month follow-up and 32.8% (range 32.2-33.3%) at 5-month follow-up. ARM contamination was low in three clinics at baseline and undetectable after the intervention. One clinic showed extensive contamination with ARM including CPE before and after the intervention (7.5-16.0% ARM-positive samples and 5.0-11.5% CPE-positive samples). Mean HH compliance improved from 20.9% [95% confidence interval (CI) 19.2-22.8%] to 42.5% (95% CI 40.4-44.7%) at 1-month follow-up and 38.7% (95% CI 35.7-41.7%) at 5-month follow-up. Compliance was lowest in the pre-operative preparation area at baseline (11.8%, 95% CI 9.3-14.8%) and in the intensive care unit after the intervention (28.8%, 95% CI 23.3-35.1%). HH compliance was similar in veterinarians (21.5%, 95% CI 19.0-24.3%) and nurses (20.2%, 95% CI 17.9-22.7%) at baseline, but was higher in veterinarians (46.0%, 95% CI 42.9-49.1%) than nurses (39.0%, 95% CI 36.0-42.1%) at 1-month follow-up.

CONCLUSION

The IPC intervention improved IPC scores, cleaning frequency and HH compliance in all clinics. Adapted approaches may be needed in outbreak situations.

Hand Hygiene Evaluation Using Two Different Evaluation Tools and Hand Contamination of Veterinary Healthcare Workers in a Swiss Companion Animal Clinic

Hand hygiene (HH) is the most important measure to prevent nosocomial infections. HH compliance in companion animal clinics has been reported to be poor. The present study compared an online application with the WHO evaluation form to assess the WHO five moments of HH in a Swiss companion animal clinic. In 202 hand swabs from 87 staff members, total viable count (TVC) before and after patient contact was evaluated and the swabs were tested for selected antimicrobial resistant microorganisms of public health importance. HH compliance (95% confidence interval) was 36.6% (33.8–39.5%) and was similar when assessed with the two evaluation tools. HH differed between hospital areas (p = 0.0035) and HH indications (p < 0.0001). Gloves were worn in 22.0% (18.0–26.6%) of HH observations and were indicated in 37.2% (27.3–48.3%) of these observations. Mean TVC before patient contact was lower (0.52 log CFU/cm²) than after patient contact (1.02 log CFU/cm²) but was similar before patient contact on gloved and ungloved hands. Three hand swabs (1.5% (0.4–4.3%)) were positive for methicillin-resistant Staphylococcus aureus. Gloving should not be regarded as a substitute for HH. Overall, HH in companion animal medicine should urgently be fostered.

Hand hygiene compliance in companion animal clinics and practices in Switzerland: An observational study

Background: Hand hygiene (HH) is one of the most important measures to prevent healthcare‐associated infections. Data on HH compliance in companion animal veterinary institutions in Europe are sparse.

Methods: This observational study assessed HH according to WHO standards in three large and two medium‐sized clinics and two primary care practices in Switzerland. Associations with HH indication, professional group, clinical area and institution were determined using a generalized linear mixed effects model.

Results: Based on 2056 observations, overall HH compliance [95% confidence interval] was 32% [30%‐34%]. HH compliance was highest in the consultation area (41% [38%‐45%]) and after contact to body fluids (45% [40%‐50%]), and lowest in the pre‐OR area (20% [15%‐24%]) and before clean/aseptic procedures (12% [9%‐15%]). Veterinarians showed a higher HH compliance (37% [34%‐40%]) than veterinary nurses (25% [22%‐28%]). HH compliance was lower before clean/aseptic procedures compared to all other indications (all p < 0.015 except ‘before touching a patient’ in medium‐sized clinics/practices, p = 0.095) and higher in the consultation area compared to all other areas in large clinics (all p < 0.04).

Conclusion: Effective HH training should urgently be promoted for all veterinary personnel with special emphasis on the importance of HH before clean/aseptic procedures.

Transmission Chains of Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae at the Companion Animal Veterinary Clinic-Household Interface

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) among animals and humans are a public health threat. This study analyzed the occurrence of ESBL-E in a high-risk environment in a companion animal clinic and two animal patients’ households. In an intensive care unit (ICU), rectal swabs from 74 dogs and cats, 74 hand swabs from staff and 298 swabs from surfaces were analyzed for ESBL-E. Seventeen hospitalized patients (23%) and ten (3%) surfaces in the ICU tested ESBL-E positive. Transmission chains for Klebsiella pneumoniae ST307 bla_CTX-M-15 and Escherichia coli ST38 bla_CTX-M-14, ST88 bla_CTX-M-14 and ST224 bla_CTX-M-1 were observed over extended periods of time (14 to 30 days) with similar strains isolated from patients and the clinical environment. After discharge, two colonized dogs (dogs 7 and 12) and their household contacts were resampled. Dog 7 tested repeatedly positive for 77 days, dog 12 tested negative; six (24%) surfaces in the household of the persistently colonized dog tested ESBL-E positive. The owner of dog 7 and one of the owners of dog 12 were colonized. Based on whole genome sequencing, isolates from the owners, their dogs and other ICU patients belonged to the same clusters, highlighting the public health importance of ESBL-E in companion animal clinics.

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 prescriptions in cats in Switzerland before and after the introduction of an online antimicrobial stewardship tool

BACKGROUND

Antimicrobial stewardship activities are essential to improve prudent antimicrobial use. The aim of the present study was to evaluate changes in antimicrobial prescriptions in cats after the introduction of prudent use guidelines promoted by an online antimicrobial stewardship tool (AntibioticScout.ch) in Switzerland. Data from 792 cats presented to two university hospitals and 14 private practices in 2018 were included and compared to 776 cases from 2016. Cats were diagnosed with acute upper respiratory tract disease (aURTD), feline lower urinary tract disease (FLUTD) and abscesses. Clinical history, diagnostic work-up and antimicrobial prescriptions (class, dosage, duration) were assessed. Type and proportions [95% confidence intervals] of antimicrobial prescriptions were compared between the two evaluation periods and a mixed effects logistic regression model was applied to evaluate compliance with Swiss prudent use guidelines.

RESULTS

From 2016 to 2018, the proportion of antimicrobial prescription in all included cases decreased from 75.0% [71.8-78.0] to 66.7% [63.3-69.9]; this decrease was most pronounced for treatments at university hospitals (67.1% [59.5-74.0] to 49.3% [40.9-57.8]) and for cats with FLUTD (60.1% [54.6-65.4] to 48.8% [43.2-54.4]). Use of 3rd generation cephalosporins in private practices declined from 30.7% [26.5-35.1] to 22.1% [18.4-26.2], while overall use of non-potentiated aminopenicillins increased from 19.6% [16.4-23.0] to 27.8% [24.1-31.9]. In cases where antimicrobial therapy was indicated, compliance with guidelines did not increase (33.3% [26.6-40.6] to 33.5% [27.2-40.2]), neither at universities nor in private practices. On the other hand, antimicrobial treatment was more often withheld in cases with no indication for antimicrobial therapy (35.6% [30.1-41.4] to 54.0% [47.6-60.4]); this was found for private practices (26.7% [20.8-33.4] to 46.0% [38.4-53.7]) and for aURTD cases (35.0% [26.5-44.2] to 55.4% [44.7-65.8]).

CONCLUSIONS

Overall proportions of antimicrobial prescription, unjustified antimicrobial therapy and, in private practices, use of 3rd generation cephalosporins decreased from 2016 to 2018 for the investigated feline diseases. However, overall compliance with Swiss prudent use guidelines was still low, implying that further efforts are required to foster prudent antimicrobial use in cats.

Poor infection prevention and control standards are associated with environmental contamination with carbapenemase-producing Enterobacterales and other multidrug-resistant bacteria in Swiss companion animal clinics

Background

Intensive medical care in companion animal clinics could pose a risk for the selection and dissemination of multidrug-resistant organisms (MDROs). Infection prevention and control (IPC) concepts are key measures to reduce the spread of MDROs, but data on IPC standards in companion animal clinics is sparse. The study assessed IPC standards in seven companion animal clinics and practices in Switzerland by structured IPC audits and combined results with environmental MDRO contamination and MDRO carriage of the personnel.

Methods

IPC audits were held between August 2018 and January 2019. The observations in 34 IPC areas were scored based on predefined criteria (not fulfilled/partially fulfilled/fulfilled = score 0/1/2). Environmental swabs and nasal and stool samples from veterinary personnel were tested for methicillin-resistant (MR) staphylococci and macrococci and for colistin-resistant, extended-spectrum β-lactamase- and carbapenemase-producing (CP) Enterobacterales (CPE). Species was identified by MALDI-TOF MS, antimicrobial resistance determined by microdilution and β-lactam resistance gene detection, and genetic relatedness assessed by REP−/ERIC-PCR and multilocus sequence typing.

Results

Of a maximum total IPC score of 68, the institutions reached a median (range) score of 33 (19–55). MDROs were detected in median (range) 8.2% (0–33.3%) of the sampling sites. Clinics with low IPC standards showed extensive environmental contamination, i.e. of intensive care units, consultation rooms and utensils. CPE were detected in two clinics; one of them showed extensive contamination with CP Klebsiella pneumoniae (ST11, bla_OXA-48) and MR Staphylococcus pseudintermedius (ST551, mecA). Despite low IPC scores, environmental contamination with MDROs was low in primary opinion practices. Three employees were colonized with Escherichia coli ST131 (bla_CTX-M-15, bla_CTX-M-27, bla_CTX-M-14). Two employees carried CP E. coli closely related to environmental (ST410, bla_OXA-181) and patient-derived isolates (ST167, bla_NDM-5). MR Staphylococcus aureus (ST225, mecA) and MR S. pseudintermedius (ST551, mecA) of the same sequence types and with similar resistance profiles were found in employees and the environment in two clinics.

Conclusions

The study indicates that IPC standards in companion animal clinics are variable and that insufficient IPC standards could contribute to the evolution of MDROs which can be transferred between the environment and working personnel. The implementation of IPC concepts in companion animal clinics should urgently be promoted.

Antimicrobial prescriptions and adherence to prudent use guidelines for selected canine diseases in Switzerland in 2016

Background

Antimicrobial resistance is an increasing problem in human and veterinary medicine and is closely linked to the use of antimicrobials. The objective of this study was to describe antimicrobial prescriptions for selected canine diseases in Switzerland during 2016.

Methods

Dogs presented to two university hospitals and 14 private practices for acute diarrhoea (AD; n=371), suspected or confirmed urinary tract infections (UTIs; n=245), respiratory tract infections (RTIs; n=274) or wound infections (WIs; n=175) were included. Clinical history, diagnostic work-up and antimicrobial prescription (class, dosage and duration) were retrospectively assessed. A justification score was applied to evaluate appropriateness of antimicrobial therapy based on available national and international consensus guidelines.

Results

Antimicrobials were prescribed in 65 per cent of dogs with AD, 88 per cent with UTI, 62 per cent with RTI and 90 per cent with WI. The most prescribed antimicrobial classes (monotherapy and combination therapy) were potentiated aminopenicillins (59 per cent), nitroimidazoles (22 per cent), non-potentiated aminopenicillins (16 per cent) and fluoroquinolones (13 per cent). Overall, 38 per cent (95 per cent CI 0.35 to 0.41) of the prescriptions were in accordance with consensus guidelines. In dogs with AD, antimicrobial therapy was associated with the presence of haemorrhagic diarrhoea (P<0.05) and complied in 32 per cent with consensus guidelines, which recommend antimicrobial treatment only when sepsis is suspected. A bacterial aetiology was confirmed via culture and/or sediment examination in 36 per cent of dogs with suspected UTI.

Conclusions

Overall, adherence to consensus guidelines was poor both, at university hospitals and private practices. Antimicrobial stewardship measures are therefore needed to improve prudent use.

Antimicrobial use for selected diseases in cats in Switzerland

Background

Antibiotic use in human and veterinary medicine is considered a main driver of antimicrobial resistance. Although guidelines to promote appropriate use of antimicrobials in veterinary patients have been developed, antibiotic overprescription is assumed to be a common problem. The goal of this study was to investigate antimicrobial use in cats in Switzerland with acute upper respiratory tract disease (aURTD), feline lower urinary tract disease (FLUTD) and abscesses, and to assess compliance of prescription with consensus guidelines. A total of 776 cases (aURTD, n = 227; FLUTD, n = 333; abscesses, n = 216) presented to two university hospitals and 14 private veterinary practices in Switzerland during 2016 were retrospectively evaluated. Clinical history, diagnostic work-up and antimicrobial prescription (class, dosage, duration) were assessed.

Results

A total of 77% (aURTD), 60% (FLUTD) and 96% (abscesses) of the cases received antibiotic therapy; 13–24% received combination or serial therapy. The cats were treated for a median of 7 (abscesses) and 10 days (aURTD, FLUTD). Treatments with potentiated aminopenicillins (40–64%), third generation cephalosporins (25–28%), aminopenicillins (12–24%) and fluoroquinolones (3–13%) were most common. Prescriptions were judged in complete accordance with consensus guidelines in 22% (aURTD), 24% (FLUTD) and 17% (abscesses) of the cases. Antibiotics were prescribed although not indicated in 34% (aURTD), 14% (FLUTD) and 29% (abscesses) of the cases. The presence of lethargy, anorexia or fever in cats with aURTD, and the detection of bacteriuria in cats with FLUTD were significantly associated with antibiotic therapy. Although diagnostic work-up was significantly more common (aURTD: university hospitals, 58%; private practices, 1%; FLUTD: university hospitals, 92%; private practices, 27%) and the use of critically important antibiotics significantly less common at the university hospitals (aURTD, 10%; FLUTD, 14%) compared to private practices (aURTD, 38%; FLUTD, 54%), the frequency of antibiotic treatment was not different between the university hospitals and private practices.

Conclusions

Our results indicate that overprescription of antibiotics in cats in Switzerland is common and accordance with guidelines is poor. The study highlights the need to promote antimicrobial stewardship in small animal medicine.

Public health risk of antimicrobial resistance transfer from companion animals

Antimicrobials are important tools for the therapy of infectious bacterial diseases in companion animals. Loss of efficacy of antimicrobial substances can seriously compromise animal health and welfare. A need for the development of new antimicrobials for the therapy of multiresistant infections, particularly those caused by Gram-negative bacteria, has been acknowledged in human medicine and a future corresponding need in veterinary medicine is expected. A unique aspect related to antimicrobial resistance and risk of resistance transfer in companion animals is their close contact with humans. This creates opportunities for interspecies transmission of resistant bacteria. Yet, the current knowledge of this field is limited and no risk assessment is performed when approving new veterinary antimicrobials. The objective of this review is to summarize the current knowledge on the use and indications for antimicrobials in companion animals, drug-resistant bacteria of concern among companion animals, risk factors for colonization of companion animals with resistant bacteria and transmission of antimicrobial resistance (bacteria and/or resistance determinants) between animals and humans. The major antimicrobial resistance microbiological hazards originating from companion animals that directly or indirectly may cause adverse health effects in humans are MRSA, methicillin-resistant Staphylococcus pseudintermedius, VRE, ESBL- or carbapenemase-producing Enterobacteriaceae and Gram-negative bacteria. In the face of the previously recognized microbiological hazards, a risk assessment tool could be applied in applications for marketing authorization for medicinal products for companion animals. This would allow the approval of new veterinary medicinal antimicrobials for which risk levels are estimated as acceptable for public health.

High Prevalence of Multidrug-Resistant Community-Acquired Methicillin-Resistant Staphylococcus aureus at the Largest Veterinary Teaching Hospital in Costa Rica

Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen associated with severe infections in companion animals present in the community, and it is diagnosed in animals admitted to veterinary hospitals. However, reports that describe the circulation of MRSA in animal populations and veterinary settings in Latin America are scarce. Therefore, the objective of this study was to determine the prevalence and investigate the molecular epidemiology of MRSA in the environment of the largest veterinary teaching hospital in Costa Rica. Preselected contact surfaces were sampled twice within a 6-week period. Antimicrobial resistance, SCCmec type, Panton-Valentine leukocidin screening, USA type, and clonality were assessed in all recovered isolates. Overall, MRSA was isolated from 26.5% (27/102) of the surfaces sampled, with doors, desks, and examination tables most frequently contaminated. Molecular analysis demonstrated a variety of surfaces from different sections of the hospital contaminated by three highly related clones/pulsotypes. All, but one of the isolates were characterized as multidrug-resistant SCCmec type IV-USA700, a strain sporadically described in other countries and often classified as community acquired. The detection and frequency of this unique strain in this veterinary setting suggest Costa Rica has a distinctive MRSA ecology when compared with other countries/regions. The high level of environmental contamination highlights the necessity to establish and enforce standard cleaning and disinfection protocols to minimize further spread of this pathogen and reduce the risk of nosocomial and/or occupational transmission of MRSA.

Amphixenosic Aspects of Staphylococcus aureus Infection in Man and Animals

According to the mode of transmission, Staphylococcus aureus infection between hosts is classified as "direct zoonoses," or infection that is transmitted from an infected vertebrate host to a susceptible host (man) by direct contact, by contact with a fomite or by a mechanical vector. The agent itself undergoes little or no propagative or developmental changes during transmission. According to the reservoir host, staphylococcosis is most precisely defined as "zooanthroponoses" or infections transmitted from man to lower vertebrate animals (e.g., streptococci, diphtheria, Enterobacteriaceae, human tuberculosis in cattle and parrots), but also "anthropozoonoses" or infections transmitted to man from lower vertebrate animals. In particular, actually, the correct definition of S. aureus infections between humans and animals is "amphixenoses" or infections maintained in both man and lower vertebrate animals and transmitted in either direction. S. aureus exhibits tropisms to many distinct animal hosts. While spillover events can occur wherever there is an interface between host species, changes in host tropism only occur with the establishment of sustained transmission in the new host species, leading to clonal expansion. Although the genomic variation underpinning adaptation in S. aureus genotypes infecting bovids and poultry has been well characterized, the frequency of switches from one host to another remains obscure. In this review, we sought to identify the sustained switches in host tropism in the S. aureus population, both anthroponotic and zoonotic, and their distribution over the species phylogeny. S. aureus is an organism with the capacity to switch into and adapt to novel hosts, even after long periods of isolation in a single host species. Based on this evidence, animal-adapted S. aureus lineages exhibiting resistance to antibiotics must be considered a major threat to public health, as they can adapt to the human population.