Nosocomial infections

Microorganism colonization of peripheral venous catheters in a small animal clinical setting

OBJECTIVE

To compare the incidence of microorganism colonization of peripheral venous catheters (PVCs) placed in the Emergency Department (ED) to those placed in a routine preoperative setting. The relationship between catheter tip colonization and patient urgency (as assessed by triage priority) was also evaluated.

DESIGN

Prospective, observational study from January 2021 to October 2021.

SETTING

Emergency room and clinical areas of a large, urban, tertiary referral center.

ANIMALS

Three hundred dogs and 94 cats with a PVC in place for a minimum of 24 hours were enrolled in the study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Two hundred and eighty-eight PVCs were placed in the ED and 106 were placed preoperatively. The overall colonization rate was 10.4% (41/394). Sixteen bacterial and 1 fungal genera were cultured. Eight of these bacterial genera (25/51 [49%] bacterial isolates) were resistant to at least 1 antimicrobial class. Twenty-nine of 288 (10.1%) catheters positive for colonization were placed in the ED, whereas 12 of 106 (11.3%) were placed preoperatively. There was no association between microorganism growth on catheters and clinical area of catheter placement. There was also no association between ED patient urgency and positive catheter tip culture. No significant risk factors were identified predisposing to colonization of PVCs.

CONCLUSIONS

The overall incidence of microorganism colonization of PVCs in this study population was equivalent to, or lower than, previously reported in veterinary literature. There was no statistical difference between the catheters placed in the ED and those placed for routine surgical procedures. Patient urgency did not affect the incidence of positivity of peripheral catheter tip cultures.

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.

Longitudinal environmental Staphylococcus contamination in a new small animal veterinary hospital and utility of cleaning checklists

Staphylococci are inhabitants of skin and mucous membranes with Staphylococcus pseudintermedius (SP) and Staphylococcus aureus (SA) serving as important pathogens for animals and people, respectively. Previous research has identified the environment as potentially important in hospital-associated infections and zoonotic transmission in veterinary settings. The objective of this pilot study was to determine the longitudinal prevalence over repeated samplings of environmental coagulase-positive Staphylococcus (CPS) in a new veterinary hospital and evaluate associations between contamination and environmental and clinical (caseload, cleaning checklists and staff numbers) factors. Cleaning and disinfection compliance, based on staff-completed checklists, were reviewed for the three shifts immediately prior to sampling. We hypothesized that over time, environmental contamination would increase as the clinic developed and caseload increased and compliance to cleaning checklists would decrease with increasing caseload. Over 18 months, 351 environmental samples were collected at five sampling times (sampling occurred before opening the hospital and every 3 to 6 months thereafter). Overall contamination with CPS was 30.8% (108/351), with SA (16.8%) and SP (13.1%) identified from the contaminated surfaces. Overall, methicillin-resistant strains (MRSA and MRSP) were infrequently recovered (combined n = 3; <1%). Point prevalence of CPS contamination was relatively stable over the study period (22.5%-28.4%), with the exception of an increase at the fourth sampling (52.9%). Cleaning compliance varied over the study period (57.9%-100%); the lowest reported cleaning coincided with the highest proportion of CPS contamination. The most commonly contaminated surfaces were chairs (7/15; 46.7%), examination tables (19/47; 40.4%) and computers (12/35; 34.3%); these items were infrequently included on cleaning lists. Surfaces not included in the checklist were 2.3 times more likely to be contaminated by CPS than those that were included (OR: 2.3, CI 95%: 1.02 -5.35, p-value=.04). MRSA and MRSP were rarely isolated from the environment in the newly opened hospital, indicating it may take time for resistant strains to enter the environment and persist on surfaces. This study identified the possible utility of cleaning checklists for directing cleaning practices and reducing the environmental contamination.

Widespread Environmental Presence of Multidrug-Resistant Salmonella in an Equine Veterinary Hospital That Received Local and International Horses

Salmonella enterica is a highly infectious microorganism responsible for many outbreaks reported in equine hospitals. Outbreaks are characterized by high morbidity and mortality rates, nosocomial transmission to other patients, zoonotic transmission to hospital personnel, and even closure of facilities. In this study, 545 samples (environmental and hospitalized patients) were collected monthly during a 1-year period from human and animal contact surfaces in an equine hospital that received local and international horses. A total of 22 Salmonella isolates were obtained from human contact surfaces (e.g., offices and pharmacy) and animal contact surfaces (e.g., stalls, surgery room, and waterers), and one isolate from a horse. Molecular serotyping revealed 18 isolates as Salmonella Typhimurium and three as Salmonella Infantis. Nineteen isolates were resistant to at least one antimicrobial class, and only two isolates were susceptible to all antimicrobials tested. In addition, we identified nine multidrug-resistant (MDR) isolates in S. Typhimurium, which displayed resistance to up to eight antimicrobials (i.e., amoxicillin/clavulanate, ampicillin, ciprofloxacin, chloramphenicol, streptomycin, gentamicin, trimethoprim/sulfamethoxazole, and tetracycline). Pulsed-field gel electrophoresis (PFGE) revealed the presence of three PFGE patterns permanently present in the environment of the hospital during our study. The persistent environmental presence of MDR Salmonella isolates, along with the fact that local and international horses are attended in this hospital, highlights the importance of improving biosecurity programs to prevent disease in horses and the hospital personnel and also for the global dissemination and acquisition of MDR Salmonella.

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.

Are the Hands of Veterinary Staff a Reservoir for Antimicrobial-Resistant Bacteria? A Randomized Study to Evaluate Two Hand Hygiene Rubs in a Veterinary Hospital

Hand hygiene (HH) is the most successful intervention for hospital infection control. HH rubs with residual action are desired. This study aimed to compare the efficacy of alcohol (A-HH) and lactic acid (LA-HH) rubs, with the latter being marketed as having residual activity. We investigated reductions in bacterial colony-forming units (CFUs), prevalence of antimicrobial-resistant (AMR) organisms, and risk factors for increased counts on the hands of veterinary staff. A randomized, crossover study (53 individuals) was performed in a referral veterinary teaching hospital. Hand plates were taken before, immediately after, and 6 hours after HH. A blinded investigator counted CFUs per plate. Methicillin-resistant Staphylococcus aureus/pseudintermedius (MRSA/MRSP), Enterobacteriaceae, and Pseudomonas species (spp.) were characterized. Gender, profession, time point, and HH product were included as variables within multivariable analyses. A significant reduction in bacterial CFU was seen immediately after A-HH rub application (p < 0.001); however, neither product showed any significant residual action. Veterinarians had higher bacterial CFUs than nurses (p = 0.005); contact with patients, rather than the environment, was also associated with higher counts (p < 0.001). MRSA, MRSP, Enterobacteriaceae spp., and Pseudomonas spp. were detected on 7%, 2%, 14%, and 2% of study participant's hands (n = 208 samples), respectively. Frequent HH administration using an A-HH rub was effective at reducing bacterial CFU on hands in vivo in this veterinary hospital setting, but its use needs further encouragement in veterinary staff. The high prevalence of antimicrobial bacteria on hands is of concern; they might act as reservoirs for patients, the environment, and in-contact people.

Comparative clinical effectiveness of preoperative skin antiseptic preparations of chlorhexidine gluconate and povidone iodine for preventing surgical site infections in dogs

Contamination of surgical sites often resulting from inadequate surgical site preparation and poor asepsis is a common cause of surgical site infection (SSI) and postoperative complications. Standard practice ensuring preoperative skin disinfection helps to prevent the incidence of SSI. The choice of antiseptic therefore poses a serious counterbalance for the surgeon. This study was carried out to determine whether skin asepsis immediately prior to surgical site incision will reduce skin microbial burden that may potentiate the incidence of SSI and to compare the clinical effectiveness of chlorhexidine gluconate B.P 0.3%W/V, Cetrimide B.P 3.05 W/V (CG + Cetrimide) against povidone iodine 10% (PI) in pre-surgical skin preparation and asepsis in dogs. A total of 15 dogs were used for the study. Both side of each dog was used for the study, right side for CG + Certrimide and left side for PI; (n = 30). Aseptic agents’ chlorhexidine gluconate 0.3% and Cetrimide 3.0% and povidine iodine 10% were used as pre surgical scrub solutions prior to surgery. Swab samples were evaluated before scrubbing, 0, 30, 60 and 90 min after scrubbing. Percent reductions of bacterial colony forming units were determined for all site scrub techniques. Mixed-design ANOVA results revealed significant difference (P < 0.05) within groups and no significant difference (P > 0.05) in the disinfectant effects between groups treated with CG + Cetrimide and povidone iodine respectively across the various time periods. Changes in the mean bacteria count were observed to be equivalent using CG + Cetrimide and povidone iodine. It was concluded that there was no significant difference between CG + Cetrimide and PI in preoperative surgical skin preparations.

Incidence of and associated factors for bacterial colonization of intravenous catheters removed from dogs in response to clinical complications

BACKGROUND

Infection rate associated with intravenous (IV) catheter placement is emerging as an important issue in small animal veterinary medicine, mostly because of the economic costs associated with these infections. Identification of possible associated factors may provide useful information for the surveillance and prevention of such infections.

OBJECTIVES

To determine the incidence of positive bacterial cultures obtained from IV catheters used in dogs hospitalized for at least 48 hours and removed because of clinical complication. To identify the bacteria involved and factors associated with bacterial colonization.

ANIMALS

One-hundred eighty-two dogs that underwent IV catheterization from January 2015 to July 2015 at the Veterinary Teaching Hospital of Alfonso X el Sabio University of Madrid were enrolled in the study.

RESULTS

The bacterial colonization rate of all IV catheters removed in response to clinical complications was 39.6%, the cumulative proportion of catheters that remained in place at 24, 48, and 72 hours after placement was 89.5, 78, and 59.4%, respectively. Multivariable Cox proportional hazards regression indicated significant associations for staff who performed catheterization (junior, P = .002; student, P = .034) and use of steroidal anti-inflammatory drugs (P = .036). The most frequently isolated bacterium was Acinetobacter spp. (21.7%).

CONCLUSIONS AND CLINICAL IMPORTANCE

The bacterial colonization incidence related to IV catheter placement was slightly higher than the incidence described in other veterinary studies. Associated factors not previously described in veterinary medicine were found. The most frequently isolated organism was Acinetobacter spp., indicating its importance as an emerging pathogen in catheter colonization.

Evaluation of the placement and maintenance of central venous jugular catheters in critically ill dogs and cats

OBJECTIVE

To describe problems noted during central venous jugular catheter (CVJC) placement, conditions associated with unsuccessful catheterization, and CVJC maintenance complications.

DESIGN

Prospective observational study from September 2014 to September 2015.

SETTING

University veterinary teaching hospital.

ANIMALS

Twenty-seven dogs and 20 cats hospitalized in a veterinary ICU. Patients were excluded if previously hospitalized with a CVJC or lacked sufficient data.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Ninety-one percent of indwelling CVJCs were placed successfully (43/47, 95% CI: 80%, 98%). Procedural-related difficulties that resulted in the inability to place a CVJC totaled 18/63 (28.6%, 95% CI: 18%, 41%) and included the inability to puncture the vessel (10), hematoma (6), malposition (1), and dislodgement (1). Procedural complications occurred in 24/47 patients (51%, 95% CI: 36%, 66%) and included cardiac dysrhythmias (13), hematoma (6), CVJC placement failure (4), and malposition (1). Risk factors associated with multiple catheterization attempts included increased age (7.5 years [± 4.2] vs 10.6 years [± 4.1], P = 0.04), smaller size (8.0 kg [0.6-51.9 kg] vs 4.4 kg [2.6-6.8 kg], P < 0.01) and thinner body condition score (median 5/9 [2/9-9/9] vs 4/9 [2/9-7/9], P = 0.04). The risk factor associated with dysrhythmias was smaller patient size (6.8 kg [2.6-51.9 kg] vs 4.8 kg [0.6-29.5 kg], P = 0.04). Eighteen indwelling complications occurred in 14 patients and included mechanical obstruction (7), skin irritation (6), malposition (4), and inflammation (1). Risk factors for indwelling complications included longer dwell time (5 days [2-30] vs 3 days [1-10], P < 0.01) and the administration of an irritant medication (P = 0.02).

CONCLUSIONS

Complications were documented in the placement and maintenance of CVJCs in critically ill patients with a low incidence of life-threatening sequelae. Risk factors associated with both unsuccessful CVJC placement and indwelling CVJC complications were identified.

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.

A prospective observational study of needle-handling practices at a University Veterinary Teaching Hospital

AIM

To determine the period prevalence of needlestick injury (NSI) at the Massey University Veterinary Teaching Hospital (VTH) and to identify handling and disposal practices that may contribute to the risk of NSI.

METHODS

Observations of personnel were conducted in the equine (EVH) and companion animal (CAH) clinics of the VTH during scheduled clinical activities over 9- and 10-day periods, respectively. The number and type of NSI incidents, needle uncapping, capping and disposal events were recorded for veterinarians, nurses and other personnel (visitors and students). The number of needle-related practices, as a proportion of observations, were compared between CAH and EVH, and veterinarians, nurses and others using χ(2) tests.

RESULTS

Needlestick injury was not observed during 190 and 163 needle handling and disposal observations in the CAH and EVH, respectively. Uncapping of needles by mouth was observed and was practised more by veterinarians (15/119; 13%) than nurses (2/42; 5%) and others (6/193; 3%) (p=0.001). Two-handed needle recapping after use was observed 265/354 times, and the one handed scooping technique was rarely observed (8/352). In the case of needle disposal, EVH workers used a container that was not purpose built for disposal more than CAH staff (p=0.02), or placed them in a pocket more frequently (p=0.003). Needle disposal containers were available on adjacent bench tops for 65/190 (34%) CAH observations, but no EVH observations. For 51/163 (31%) EVH observations the needle disposal containers were located on the ground, whereas none were observed there in the CAH. No approved sharps containers were observed in the immediate EVH and CAH work areas for 47/163 (28.8%) and 1/191 (0.5%) needle-handling activities, respectively.

CONCLUSIONS

Unsafe needle-handling practices must be reduced by policies and training programmes to encourage safe needle-related practices, and ensuring that approved sharps containers are available in close proximity to where needles are used.

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.

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.

Case-control risk factor study of methicillin-resistant Staphylococcus pseudintermedius (MRSP) infection in dogs and cats in Germany

Methicillin-resistant Staphylococcus pseudintermedius (MRSP) has emerged as a highly drug-resistant small animal veterinary pathogen. Although often isolated from outpatients in veterinary clinics, there is concern that MRSP follows a veterinary-hospital-associated epidemiology. This study's objective was to identify risk factors for MRSP infections in dogs and cats in Germany. Clinical isolates of MRSP cases (n=150) and methicillin-susceptible S. pseudintermedius (MSSP) controls (n=133) and their corresponding host signalment and medical data covering the six months prior to staphylococcal isolation were analysed by multivariable logistic regression. The identity of all MRSP isolates was confirmed through demonstration of S. intermedius-group specific nuc and mecA. In the final model, cats (compared to dogs, OR 18.5, 95% CI 1.8-188.0, P=0.01), animals that had been hospitalised (OR 104.4, 95% CI 21.3-511.6, P<0.001), or visited veterinary clinics more frequently (>10 visits OR 7.3, 95% CI 1.0-52.6, P=0.049) and those that had received topical ear medication (OR 5.1, 95% CI 1.8-14.9, P=0.003) or glucocorticoids (OR 22.5, 95% CI 7.0-72.6, P<0.001) were at higher risk of MRSP infection, whereas S. pseudintermedius isolates from ears were more likely to belong to the MSSP-group (OR 0.09, 95% CI 0.03-0.34, P<0.001). These results indicate an association of MRSP infection with veterinary clinic/hospital settings and possibly with chronic skin disease. There was an unexpected lack of association between MRSP and antimicrobial therapy; this requires further investigation but may indicate that MRSP is well adapted to canine skin with little need for selective pressure.

Using syndromic surveillance to estimate baseline rates for healthcare-associated infections in critical care units of small animal referral hospitals

BACKGROUND

Expected rates of healthcare-associated infections (HCAI) have not been established in veterinary hospitals. Baseline rates are critically needed as benchmarks for quality animal care.

OBJECTIVE

To estimate the occurrence of events related to HCAI identified using a standardized syndromic surveillance system in small animals in critical care cases at referral hospitals.

ANIMALS

Weaned dogs and cats (n = 1,951) that were hospitalized in the critical care unit of referral teaching hospitals during a 12-week period.

METHODS

Multicenter, prospective longitudinal study. A survey was completed for all enrolled animals to record basic demographics, information about procedures and treatments that animals received, and to document the occurrence of defined nosocomial syndromes. Data were analyzed to identify risk factors associated with the occurrence of these nosocomial syndromes.

RESULTS

Controlling for hospital of admission, 16.3% of dogs (95% confidence intervals [CI], 14.3-18.5) and 12% of cats (95% CI, 9.3-15.5) were reported to have had ≥ 1 nosocomial syndrome occur during hospitalization. Risk factors found to have a positive association with the development of a nosocomial syndrome were longer hospital stays, placement of a urinary catheter, surgical procedures being performed, and the administration of antiulcer medications and antimicrobial drugs excluding those given perioperatively.

CONCLUSIONS AND CLINICAL IMPORTANCE

Syndromic surveillance systems can be successfully standardized for use across multiple hospitals to effectively collect data pertinent to HCAI rates and risk factors for occurrence.

Risk factors for dogs becoming rectal carriers of multidrug-resistant Escherichia coli during hospitalization

This study aimed to identify risk factors for dogs becoming rectal carriers of multidrug-resistant (MDR) Escherichia coli while hospitalized in a veterinary teaching hospital. Exposures to potential risk factors, including treatments, hospitalization, and interventions during a 42-day pre-admission period and hospitalization variables, were assessed for 90 cases and 93 controls in a retrospective, risk-based, case-control study. On multivariable analyses, hospitalization for >6 days [odds ratio (OR) 2·91-8·00], treatment with cephalosporins prior to admission (OR 5·04, 95% CI 1·25-20·27), treatment with cephalosporins for >1 day (OR 5·18, 95% CI 1·86-14·41), and treatment with metronidazole (OR 7·17, 95% CI 1·01-50·79) while hospitalized were associated with increased risk of rectal carriage of MDR E. coli during hospitalization. The majority of rectal isolates obtained during the study period conformed to MDR E. coli clonal groups previously obtained from extraintestinal infections. These results can assist the development of improved infection control guidelines for the management of dogs in veterinary hospitals to prevent the occurrence of nosocomial clinical infections.

Pets and antimicrobial resistance

Antimicrobial resistance is a growing problem and is a significant public health issue. An increasing number of organisms are developing resistance to many of the antimicrobial agents available for treatment of infections in both humans and animals. These resistant organisms often result in greater disease severity, longer hospitalization, and increased care and treatment costs. This article reviews the current situation of antimicrobial resistance in companion small animals and highlights how important it is for veterinarians to recognize the significance of antimicrobial resistance and to commit to the judicious use of antimicrobial agents.

An investigation of the bacterial contamination of small animal breathing systems during routine use

OBJECTIVE

To investigate the need for sterilization of anaesthetic breathing systems to prevent cross-infection between animals due to the re-use of anaesthetic circuit tubing.

STUDY DESIGN

Prospective microbiological study.

METHODS

Bacteriology samples were taken from 37 sterile breathing systems, each used for 1 day, at two sampling sites (one proximal and one distal to the animal). The number of patient connections, cumulative anaesthesia time, culture results, number of colony-forming units and the number of different species were recorded. Secondly, four sterile breathing systems were used for 2 months under routine conditions and sampled every 2 weeks and the same parameters recorded. Finally, the inner surfaces of four sterile breathing systems were inoculated with a known load of canine oropharyngeal bacteria. Bacteriology samples were taken at 1 minute, 1 hour and 1 day post-deposition. The number of colonies identified was compared with the initial load.

RESULTS

Only a very small number of micro-organisms were isolated and these were generally organisms of low pathogenic potential. The proximal site was found to be significantly more colonized than the distal site (p < 0.001). Neither longer daily connection time (p = 0.54), nor a higher number of connections (p = 0.81) increased the incidence of proximal site colonization. Over the 2-month study period, the bacterial population did not increase. There was no correlation between cultures isolated from successive samples taken from the same tubing. There was rapid loss of viability of the micro-organisms deliberately inoculated onto the tubing surface: the number of colonies isolated from the breathing system after 1 minute was significantly lower than in the inoculum (p = 0.042).

CONCLUSIONS AND CLINICAL RELEVANCE

Sterile anaesthesia breathing systems were colonized by environmental micro-organisms of low pathogenicity. Although long-term survival of recognized pathogens in a dry environment is still possible, the use of a bacterial filter or a sterilized breathing system for routine veterinary anaesthesia cannot be supported by current evidence.

Surveillance of infections associated with intravenous catheters in dogs and cats in an intensive care unit

Positive catheter-tip culture rates and risk factors associated with bacterial colonization of intravenous (i.v.) catheters were assessed in dogs and cats. Aerobic and anaerobic bacterial cultures were performed on 151 catheters, and 24.5% were positive. Of the positive cultures, 46.0% grew Enterobacter spp. The type of catheter used, blood sampling through the catheter, the type of i.v. infusate administered, the duration the catheter was in place, the catheter location, complications with the catheter, and the final outcome of the animal were not associated with an increased risk of a positive bacterial culture from the catheter tip.