Screening petting zoo animals for the presence of potentially pathogenic Escherichia coli.

Several outbreaks of Escherichia coli O157 have been reported in petting zoos, resulting in hospitalization of many children. At present, no standard procedure has been adopted to monitor the presence of enterohemorrhagic E. coli (EHEC) or Shiga-toxin-producing E. coli (STEC) in petting zoo animals. Direct detection of these strains from rectal swabs of animals in petting zoos was developed and obviated the need to culture the organisms. DNA extracted from bacteria in the swabs was tested for the presence of wecA gene specific for E. coli by polymerase chain reaction (PCR). The wecA positive samples were further tested for Shiga-toxin genes stxl and stx2, and the intimin eae by multiplex PCR and for the presence of O157 and H7. Swabs (n=104) from 15 animal species in a petting zoo were tested; 7 goats and 3 cows were found to carry STEC. The method is rapid and convenient for monitoring potentially pathogenic E. coli in petting zoo animals.     

Agroenvironmental determinants associated with the presence of antimicrobial-resistant Escherichia coli in beach waters in Quebec, Canada

Exposure to microorganisms resistant to antimicrobials may constitute a health risk to human populations. It is believed that one route of exposure occurs when people engage in recreational activities in water contaminated with these microorganisms. The main objective of this study was to explore population-level and environmental determinants specifically associated with the presence of antimicrobial resistant (AMR) generic Escherichia coli isolated from recreational waters sampled from beaches located in southern Quebec, Canada. Water samples originated from the Quebec provincial beach surveillance program for the summers of 2004 and 2005. This study focused on three classes of determinants, namely: agricultural, population-level and beach characteristics for a total of 19 specific factors. The study was designed as a retrospective observational analysis and factors were assessed using logistic regression methods. From the multivariable analysis, the data suggested that the percentage of land used for spreading liquid manure was a significant factor associated with the presence of AMR E. coli (OR=27.73). Conceptually, broad factors potentially influencing the presence of AMR bacteria in water must be assessed specifically in addition to factors associated with general microbial contamination. Presence of AMR E. coli in recreational waters from beaches in southern Quebec may represent a risk for people engaging in water activities and this study provides preliminary evidence that agricultural practices, specifically spreading liquid manure in agricultural lands nearby beaches, may be linked to the contamination of these waters by AMR E. coli.     

Clonal spread of antimicrobial-resistant Escherichia coli isolates among pups in two kennels

Although the dog breeding industry is common in many countries, the presence of antimicrobial resistant bacteria among pups in kennels has been infrequently investigated. This study was conducted to better understand the epidemiology of antimicrobial-resistant Escherichia coli isolates from kennel pups not treated with antimicrobials. We investigated susceptibilities to 11 antimicrobials, and prevalence of extended-spectrum β-lactamase (ESBL) in 86 faecal E. coli isolates from 43 pups in two kennels. Genetic relatedness among all isolates was assessed using pulsed-field gel electrophoresis (PFGE). Susceptibility tests revealed that 76% of the isolates were resistant to one or more of tested antimicrobials, with resistance to dihydrostreptomycin most frequently encountered (66.3%) followed by ampicillin (60.5%), trimethoprim-sulfamethoxazole (41.9%), oxytetracycline (26.7%), and chloramphenicol (26.7%). Multidrug resistance, defined as resistance against two or more classes of antimicrobials, was observed in 52 (60.5%) isolates. Three pups in one kennel harboured SHV-12 ESBL-producing isolates. A comparison between the two kennels showed that frequencies of resistance against seven antimicrobials and the variation in resistant phenotypes differed significantly. Analysis by PFGE revealed that clone sharing rates among pups of the same litters were not significantly different in both kennels (64.0% vs. 88.9%), whereas the rates among pups from different litters were significantly different between the two kennels (72.0% vs. 33.3%, P < 0.05). The pups in the two kennels had antimicrobial-resistant E. coli clones, including multidrug-resistant and ESBL-producing clones. It is likely that resistant and susceptible bacteria can clonally spread among the same and/or different litters thus affecting the resistance prevalence.     

Prevalence of antimicrobial-resistant Escherichia coli in dogs in a cross-sectional, community-based study

The prevalence of carriage of antimicrobial-resistant (AMR) and extended-spectrum β-lactamase (ESBL)-producing Escherichia coli was determined in 183 healthy dogs from a semi-rural community in Cheshire. Isolates were tested against a panel of antimicrobials and by PCR to detect resistance genes. In the suspected ESBL-producing isolates, the presence of bla(SHV), bla(TEM), bla(CTX-M) and bla(AmpC) genes was determined by PCR and sequencing. A total of 53 (29 per cent, 95 per cent confidence interval [CI] 22.4 to 35.5 per cent) dogs carried at least one AMR E coli isolate. Twenty-four per cent (95 per cent CI 17.9 to 30.2 per cent) of dogs carried isolates resistant to ampicillin, 19.7 per cent (95 per cent CI 13.9 to 25.4 per cent) to tetracycline and 16.9 per cent (95 per cent CI 11.5 to 22.4 per cent) to trimethoprim. A bla(TEM) gene was detected in 39 of 54 ampicillin-resistant isolates, a tet(B) gene in 12 of 45 tetracycline-resistant isolates, and a dfr gene in 22 of 33 trimethoprim-resistant isolates. Multidrug-resistant isolates were demonstrated in 15 per cent (28 of 183; 95 per cent CI 10.1 to 20.5 per cent) of dogs. Nine suspected ESBL-producing E coli were isolated, of which only one was confirmed by double disc diffusion testing. Two of these isolates carried the bla(TEM-1) gene and seven carried the bla(CMY-2) gene.     

Cross-sectional study of antimicrobial-resistant bacteria in horses. Part 1: Prevalence of antimicrobial-resistant Escherichia coli and methicillin-resistant Staphylococcus aureus

Reasons for performing study: The increasing prevalence of antimicrobial‐resistant bacteria such as methicillin‐resistant Staphylococcus aureus (MRSA) and antimicrobial‐resistant Escherichia coli represents a significant problem. However, the carriage of such bacteria by horses in the UK has not been well characterised. Objectives: To estimate the prevalence of nasal carriage of MRSA and faecal carriage of antimicrobial‐resistant E. coli amongst horses in the general equine community of the mainland UK. Methods: A cross‐sectional study of horses recruited by 65 randomly selected equine veterinary practices was conducted, with nasal swabs and faecal samples collected. Faecal samples were cultured for antimicrobial‐resistant E. coli. Nasal swabs were cultured for staphylococcal species; methicillin‐resistant isolates identified as S. aureus were characterised by SCCmec and spa gene typing. Multilevel logistic regression models were used to calculate prevalence estimates with adjustment for clustering at practice and premises levels. Spatial variation in risk of antimicrobial resistance was also examined. Results: In total, 650 faecal samples and 678 nasal swabs were collected from 692 horses located on 525 premises. The prevalence of faecal carriage of E. coli with resistance to any antimicrobial was 69.5% (95% CI 65.9–73.1%) and the prevalence of extended‐spectrum β‐lactamase (ESBL)‐producing E. coli was 6.3% (95% CI 4.1–9.6%). The prevalence of nasal carriage of MRSA was 0.6% (95% CI 0.2–1.5%). Spatial analysis indicated variation across the UK for risk of carriage of resistant and multidrug‐resistant (resistant to more than 3 antimicrobial classes) E. coli. Conclusions and potential relevance: Carriage of MRSA by horses in the community appears rare, but the prevalence of antimicrobial‐resistant E. coli (including ESBL‐producing E. coli) is higher. A high prevalence of antimicrobial‐resistant bacteria could have significant health implications for the horse population of the UK.     

Cross-sectional study of antimicrobial-resistant bacteria in horses. Part 2: Risk factors for faecal carriage of antimicrobial-resistant Escherichia coli in horses

Reasons for performing study: The increasing prevalence of antimicrobial resistant bacteria such as antimicrobial‐resistant and extended spectrum β‐lactamase (ESBL)‐producing Escherichia coli represents a significant problem for human and veterinary medicine. Despite this, the risk factors for faecal carriage of such bacteria by horses in the UK, particularly those in the wider community, have not been well described. Objectives: To characterise the risk factors for faecal carriage of antimicrobial‐resistant E. coli amongst horses in the mainland UK. Methods: A cross‐sectional study of horses recruited by 65 randomly selected equine veterinary practices was conducted, with a faecal sample collected and self‐administered questionnaire completed by the horse owner. Faecal samples were cultured for antimicrobial‐resistant E. coli, with isolates confirmed as E. coli having their antimicrobial resistance profile determined. Multilevel, multivariable logistic regression models were used to investigate risk factors for the carriage of antimicrobial‐resistant E. coli in the sample population. Results: Faecal samples and completed questionnaires were obtained for 627 horses located on 475 premises. Recent hospitalisation, contact with specific types of nonequid animals, the type of premises, the surrounding land use, the reason for veterinary treatment received in the last 6 months and antimicrobial treatment in the previous 10 days were identified as risk factors for many of the antimicrobial‐resistance outcomes considered. Being stabled on the same yard as a recently hospitalised horse was identified as a risk factor for increased risk of carriage of ESBL‐producing E. coli. Conclusions and potential relevance: Increasing antimicrobial resistance may have significant health implications for the horse population of Great Britain. This form of epidemiological investigation highlights potential risk factors that may be controlled to limit the extent of the problem.     

The prevalence of antimicrobial-resistant Escherichia coli in two species of invasive alien mammals in Japan

The prevalence of antimicrobial resistance in 128 Escherichia coli isolates was investigated in two species of invasive alien mammals (IAMs): the small Asian mongoose (SAM) and Japanese weasel (JW). The SAM is found on the main island of Okinawa, Japan, where a large number of livestock is available, and the JW is present on a small island, where is isolated from the main island, and have a small number of livestock. We focused on the two IAMs, inhabiting under the different environments, and compared their prevalence of antimicrobial-resistant E. coli. In the comparison of the frequencies of antimicrobial-resistant E. coli isolates between the SAM and JW, JW showed significantly higher prevalence of resistance against three drugs, ampicillin, chlortetracycline and nalidixic acid, compared with SAM's test results (P<0.05). The bla(TEM) gene and the aph1 gene were detected in 35 subjects (91%) of ampicillin-resistant isolates and 6 subjects (100%) of kanamycin-resistant isolates, respectively. The tet (A) gene was detected in 62 subjects (46%) of CTC-resistant isolates, and the tet (B) gene was detected in 25 subjects (8%) of those in IAM. The present results suggest that some IAMs were the carrier of antimicrobial-resistant bacteria and their genes, and the frequencies of these resistances were different between two IAM species.     

The prevention of distemper in zoo animals

The distemper virus infection of different non-domestic carnivorous zoo animals is known since long. All species involved belonged to the suborder Fissipedia. In 1988 a distemper or morbillivirus-like infection occurred in harbour seals, a member of the suborder pinnipedia. For the prophylaxis of distemper in dogs attenuated live vaccines are commonly used. In zoo animals, however, these vaccines caused distemper several times. In contrast, an inactivated virus vaccine proved both its safety and efficacy in more than hundred zoo animals of various species.     

Medical treatment of dystocia in zoo animals

Kasuistics of Zoo animals with dystocia (Anoa, Giraffe, Snow goat, Scimitar horned Antelope, Bactrian camel, Tiger, Diana monkey) treated with special pharmaceuticals (glukokortikoids, cienbuterol, denaverine, carbetocin) and distance injections by blow darts are introduced. These procedures are described as very effective and save methods of obstetrics especially in Zoo animals.     

Longitudinal study of antimicrobial-resistant commensal Escherichia coli in the faeces of horses in an equine hospital

The increasing prevalence of antimicrobial resistance in bacteria represents a considerable problem for human and veterinary medicine, causing complications in the treatment of infections. Resistance in Escherichia coli from horses has been documented in commensal and pathogenic strains, but little information exists regarding the prevalence of such bacteria in hospitalised horses or associated risk factors. A longitudinal cohort study was conducted of 103 horses admitted to a referral equine hospital for more than 48 h, with faecal samples collected on hospital admission and subsequently every two days until discharge. Horses undergoing radioactive gamma scintigraphic examination, un-weaned foals and mares with un-weaned foals were excluded. Data were collected from enrolled animals, including antimicrobial treatment history and hospitalisation details. Samples were cultured for resistant E. coli; isolates had their antimicrobial resistance profile determined. High sample prevalence for resistant E. coli was identified for all antimicrobials examined except co-amoxiclav. The prevalence of resistance was consistently lower at admission, rising to a peak 4 days post-admission. Risk factors were analysed using multilevel, multivariable modelling, which identified significant clustering of resistance outcomes within horses. For all outcomes except trimethoprim resistance, the day the sample was obtained was significant, with increased risk of resistance for samples taken on day 2 or later. Antimicrobial treatment in the previous seven days and increased total daily dosages of cotrimoxazole prescribed in the hospital in the previous 24-48 h were associated with increased risk. Location within the hospital and admission reason were significant risk factors for some resistance outcomes. High levels of multidrug-resistant E. coli (47.7% of samples) and extended spectrum β-lactamase-producing E. coli (27.3% of samples) were recovered; such bacteria could significantly complicate treatment if they were the cause of infection and may represent a risk to personnel in close contact with hospitalised horses.     

Escherichia coli associated endotoxemia in dogs with parvovirus infection

Escherichia coli bacteremia and endotoxemia were observed in 3 adult mongrel dogs which had been prediagnosed as canine parvoviral disease. The endotoxin level was 46.5 pg/ml in the plasma of clinical cases, while 2.3 pg/ml in healthy controls. The microflora of the feces was confused in the clinical cases. The percentage of E. coli was major in the feces. Serologically similar strains were isolated from the blood. These strains did not produce enterotoxins such as heat-stable enterotoxin (ST) and heat-labile enterotoxin (LT). Histopathologically, the lesions in the small intestine consisted of epithelial degeneration and necrosis. Viral inclusion bodies were frequently observed in the epithelial cells. Disseminated intravascular coagulation was observed in various tissues including the liver and small intestinal submucosa. After experimental infection with CPV, all dogs showed various clinical signs. CPV was positive in the feces. Endotoxin level in the plasma gradually increased and high level continued for long period from 10 to 30 days. Mean maximum level of endotoxin in the experimental dogs was 73.6 pg/ml. These results indicate that intestinal flora plays a important role in the pathogenesis of CPV infection and that endotoxin is one of the factors which predispose to severe disease after the infection.     

Necrotising fasciitis associated with Escherichia coli in a dog

CASE HISTORY: Lameness and limb pain associated with a laceration in the inner thigh of a Border Collie dog progressed over 4 days to extensive necrosis of the full-thickness of skin and subcutaneous (S/C) tissue. A successful outcome was achieved using surgical debridement and intensive supportive care, followed by limited local closure, axial pattern flap development, and free skin grafting.

CLINICAL FINDINGS: Clinical findings included severe pain, depression, pyrexia and hypoalbuminaemia, and full-thickness loss of skin from the caudal thigh to the hock. Histopathologically, debrided tissue showed extensive necrosis of the dermis, adipose and muscle tissues, and the presence of numerous Gram-negative rods. Escherichia coli was cultured from deep tissue samples.

DIAGNOSIS: Necrotising fasciitis (NF) associated with E. coli infection.

CLINICAL RELEVANCE: NF associated with E. coli has not been previously reported in dogs. The importance of early diagnosis and surgical debridement is noted and the relevant medical literature is reviewed.     

Necrotising fasciitis associated with Escherichia coli in a dog

CASE HISTORY: Lameness and limb pain associated with a laceration in the inner thigh of a Border Collie dog progressed over 4 days to extensive necrosis of the full-thickness of skin and subcutaneous (S/C) tissue. A successful outcome was achieved using surgical debridement and intensive supportive care, followed by limited local closure, axial pattern flap development, and free skin grafting. CLINICAL FINDINGS: Clinical findings included severe pain, depression, pyrexia and hypoalbuminaemia, and full-thickness loss of skin from the caudal thigh to the hock. Histopathologically, debrided tissue showed extensive necrosis of the dermis, adipose and muscle tissues, and the presence of numerous Gram-negative rods. Escherichia coli was cultured from deep tissue samples. DIAGNOSIS: Necrotising fasciitis (NF) associated with E. coli infection. CLINICAL RELEVANCE: NF associated with E. coli has not been previously reported in dogs. The importance of early diagnosis and surgical debridement is noted and the relevant medical literature is reviewed.     

Non-typhi Salmonella serovars found in Mexican zoo animals

The aim of the present study was to determine the bacteriological prevalence of subclinical non-typhi Salmonella infections in zoo animals and to determine the most frequently isolated serovars of the bacteria. A total of 267 samples were analyzed, including fecal samples from zoo animals and rodents, insects (Musca domestica and Periplaneta americana) and samples of the zoo animal's food. Salmonella was detected in 11.6% of the samples analyzed. Characterization of the isolates was performed with serotyping and pulsed-field gel electrophoresis. The following serovars were isolated: S. San Diego, S. Oranienburg, S. Weltevreden, S. Braenderup, S. Derby, S. 6,7, H:en x:- and S. 3,10, H:r:-. The isolates showed seven pulsed-field gel electrophoresis patterns with a Jaccard coefficient ?0.75 indicating a possible common origin. The prevalence of asymptomatic infections caused by Salmonella spp. in zoo animals was high. These findings demonstrate the diversity of Salmonella serovars in several captive wild animal species.