PubMed Health⌕ Search

Biomedical subjects

Patrick Boerlin

Publications and source records attributed to Patrick Boerlin.

14 recordsLinked to original sources

Evaluation of catheter-associated urinary tract infections and multi-drug-resistant Escherichia coli isolates from the urine of dogs with indwelling urinary catheters.

OBJECTIVE: To determine the frequency of urinary tract infections (UTIs) in dogs with indwelling urinary catheters in an intensive care unit (ICU) and the frequency of multi-drug-resistant (MDR) Escherichia coli UTIs in those dogs. DESIGN: Prospective study. ANIMALS: All dogs in the ICU with an indwelling urinary catheter from January 2003 through December 2003. PROCEDURES: Urine samples and rectal swab specimens were collected at admission and every 3 days until discharge from the hospital. Escherichia coli isolates from urine samples and rectal swab specimens and those from dogs that were temporally or spatially associated with dogs with MDR E coli UTIs underwent antimicrobial susceptibility testing. Pulsed-field gel electrophoresis was performed on MDR isolates from urine and rectal swab specimens. RESULTS: Urinary catheters were placed in 137 dogs. Twenty-six UTIs were diagnosed, 15 on the day of admission and 11 after 3 or more days of catheterization. Of 12 dogs with E coli UTIs, 6 were infected at admission and 6 acquired the infection in the ICU. Two MDR E coli UTIs were detected, 1 of which was acquired in the ICU. One MDR E coli urinary isolate had an electrophoresis pattern similar to that of rectal isolates from the same dog. Urinary E coli isolates were most frequently resistant to ampicillin and cephalothin. CONCLUSIONS AND CLINICAL RELEVANCE: The ICU-acquired MDR E coli UTI likely originated from the dog's intestinal flora during hospitalization. Dogs that have been referred from a community practice may have MDR E coli UTIs at the time of admission.

Animals↗

paa, originally identified in attaching and effacing Escherichia coli, is also associated with enterotoxigenic E. coli.

Previous studies on virotypes and antimicrobial resistance in a collection of porcine enterotoxigenic Escherichia coli (ETEC) O149 strains from Quebec revealed an increase in the number of multiresistant strains (in particular to tetracycline) and the appearance of new virulence factors with time. Among these factors is paa (for porcine attaching- and effacing-associated), originally identified in a porcine enteropathogenic strain, but also present in enterohemorrhagic E. coli O157:H7. In the present study, the association of paa with other ETEC virulence genes, its conservation and expression were investigated in the O149 ETEC collection. All 37 paa-positive strains possessed estB, elt, astA and faeG, and more than half also carried the estA gene, defining two main virotypes, estA(+) and estA(-). Most strains were tetA- or tetB-positive, or both. paa is carried on high molecular weight plasmids. On tetA plasmids, paa is mostly found with enterotoxin gene estA and autotransporter gene sepA. Paa, a 30 kDa protein, is highly conserved and expressed in these strains. Moreover, paaETEC and porcine EPEC/EHEC contain IS signatures, suggesting that paa could be derived from a common ancestor. All these observations suggest a broader role than previously assessed in virulence for paa.

Amino Acid Sequence↗

Development of antimicrobial drug resistance in rectal Escherichia coli isolates from dogs hospitalized in an intensive care unit.

OBJECTIVE: To determine whether duration of hospitalization in the intensive care unit (ICU) of a veterinary teaching hospital was associated with prevalence of antimicrobial resistance among rectal Escherichia coli isolates from dogs, whether antimicrobial treatment was associated with prevalence of antimicrobial resistance, and whether there were associations among antimicrobial drugs to which isolates were resistant. DESIGN: Prospective observational study. ANIMALS: 116 dogs hospitalized in an ICU for >or= 3 days. PROCEDURES: Rectal swab specimens were obtained every 3 days and submitted for bacterial culture for E coli. Isolates were tested for susceptibility to 12 antimicrobial agents by means of disk diffusion. RESULTS: For each additional day that a dog was hospitalized in the ICU, the odds of being colonized with an E coli isolate resistant to 1 or more of the 12 antimicrobials tested increased by a factor of 1.5, independent of antimicrobial treatment. Dogs that were treated with enrofloxacin were 25.6 times as likely to be colonized by a quinolone-resistant E coli strain as were dogs that did not receive any antimicrobials. Significant correlations were found for resistance to agents in the extended-spectrum cephalosporin group and the quinolone group. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that the proportion of rectal E coli isolates obtained from dogs housed for >or= 3 days in a veterinary teaching hospital ICU that were resistant to antimicrobial agents increased as the duration of hospitalization in the ICU increased. Thus, ICU hospitalization time should be as short as possible to prevent development of antimicrobial resistance among rectal E coli isolates.

Animals↗

Chloramphenicol and kanamycin resistance among porcine Escherichia coli in Ontario.

OBJECTIVES: The purpose of this study was to compare the distribution of chloramphenicol and kanamycin resistance genes across three populations of porcine Escherichia coli. METHODS: PCR was used to assess the distribution of the major chloramphenicol and kanamycin resistance genes catA1, cmlA and floR, and aphA1, aphA2 and aadB in enterotoxigenic E. coli (ETEC), non-ETEC isolates from cases of diarrhoea and commensal E. coli from healthy pigs. Associations between these genes and resistance genes for other antimicrobials or virulence genes were assessed. RESULTS: The chloramphenicol and kanamycin resistance genes were distributed differently among the three E. coli populations. While aphA1, aphA2 and aadB were evenly distributed among resistant ETEC, non-ETEC and commensals, the catA1 gene was significantly more frequent in ETEC than in non-ETEC and commensals. Transformation experiments confirmed statistical associations by demonstrating that elt, estB, astA, aadA and sul1 were located with catA1 on a large ETEC plasmid. Plasmids carrying cmlA also carried sul3 and aadA. Other plasmids carrying floR and aadB also carried tet(A), sul2, strA/strB, bla(CMY-2) and occasionally aac(3)IV. CONCLUSIONS: The clustering of genes observed is a likely cause for chloramphenicol resistance persistence. Similar to tetracycline, chloramphenicol resistance genes are physically linked to virulence genes. This is not the case for kanamycin resistance determinants, which were linked to other resistance genes only.

Animals↗

Antimicrobial resistance and virulence genes of Escherichia coli isolates from swine in Ontario.

A total of 318 Escherichia coli isolates obtained from diarrheic and healthy pigs in Ontario from 2001 to 2003 were examined for their susceptibility to 19 antimicrobial agents. They were tested by PCR for the presence of resistance genes for tetracycline, streptomycin, sulfonamides, and apramycin and of 12 common virulence genes of porcine E. coli. Antimicrobial resistance frequency among E. coli isolates from swine in Ontario was moderate in comparison with other countries and was higher in isolates from pigs with diarrhea than in isolates from healthy finisher pigs. Resistance profiles suggest that cephamycinases may be produced by > or = 8% of enterotoxigenic E. coli (ETEC). Resistance to quinolones was detected only in enterotoxigenic E. coli (< or = 3%). The presence of sul3 was demonstrated for the first time in Canada in porcine E. coli isolates. Associations were observed among tetA, sul1, aadA, and aac(3)IV and among tetB, sul2, and strA/strB, with a strong negative association between tetA and tetB. The paa and sepA genes were detected in 92% of porcine ETEC, and strong statistical associations due to colocation on a large plasmid were observed between tetA, estA, paa, and sepA. Due at least in part to gene linkages, the distribution of resistance genes was very different between ETEC isolates and other porcine E. coli isolates. This demonstrates that antimicrobial resistance epidemiology differs significantly between pathogenic and commensal E. coli isolates. These results may have important implications with regards to the spread and persistence of resistance and virulence genes in bacterial populations and to the prudent use of antimicrobial agents.

Animals↗

Development of two real-time PCR assays for the detection of Mycoplasma hyopneumoniae in clinical samples.

In order to improve the diagnosis of enzootic pneumonia (EP) in pigs two real-time polymerase chain reaction (rtPCR) assays for the detection of Mycoplasma hyopneumoniae in bronchial swabs from lung necropsies were established and validated in parallel. As a gold standard, the current "mosaic diagnosis" was taken, including epidemiological tracing, clinical signs, macro- and histopathological lesions of the lungs and immunofluorescence. One rtPCR is targeting a repeated DNA element of the M. hyopneumoniae genome (REP assay), the other a putative ABC transporter gene (ABC assay). Both assays were shown to be specific for M. hyopneumoniae and did not cross react with other bacteria and mollicutes from pig. With material from pigs of defined EP-negative farms the two assays showed to be 100% specific. When testing lungs from pig farms with EP, the REP assay detected 50% and the ABC assay 90% of the farms as positive. Both tests together detected all positive farms. Within a positive herd the two assays tested similarly with on average over 90% of the lung samples analysed from a single farm showing positive scores. A series of samples with suspicion of EP and samples from pigs with diseases other than respiratory taken from current routine diagnostic was assayed. None of the assays showed false positive results. The sensitivities in this sample group were 50% for the REP and 70% for the ABC assays and for both assays together 85%. The two assays run in parallel are therefore a valuable tool for the improvement of the current diagnosis of EP.

ATP-Binding Cassette Transporters↗

Molecular epidemiology of antimicrobial resistance in veterinary medicine: where do we go?

Molecular epidemiology allows us to trace specific microorganisms and mobile genetic elements and to assess their epidemiological and evolutionary relationships. Examples of molecular epidemiology investigations in veterinary hospitals are discussed. They demonstrate the great similarities with the situation in human medicine and the potential usefulness of molecular epidemiology in our fight against antimicrobial resistance and nosocomial infections in veterinary hospitals. A broad knowledge of the diversity of antimicrobial resistance determinants in some major groups of pathogens and commensals from animals such as Enterobacteriaceae, Pasteurellaceae, enterococci and staphylococci is emerging. However, there are important gaps in this knowledge, which are discussed here. Many more molecular epidemiology studies will be necessary to understand and follow the evolution of the problem in veterinary medicine and agriculture on a global scale. To be able to build useful surveillance programs and reliable epidemiological models, and to identify critical intervention points, we need to improve our understanding of antimicrobial resistance at the animal and farm levels. Studies assessing the dynamics of bacterial populations and of resistance determinants at these levels are desperately needed. Understanding the relationships between antimicrobial resistance, colonization factors, and virulence also represents a major issue for which molecular epidemiology investigations will be needed.

Animals↗

Nicoletella semolina gen. nov., sp. nov., a new member of Pasteurellaceae isolated from horses with airway disease.

Gram-negative, nonmotile bacteria that are catalase, oxidase, and urease positive are regularly isolated from the airways of horses with clinical signs of respiratory disease. On the basis of the findings by a polyphasic approach, we propose that these strains be classified as Nicoletella semolina gen. nov, sp. nov., a new member of the family Pasteurellaceae. N. semolina reduces nitrate to nitrite but is otherwise biochemically inert; this includes the lack of an ability to ferment glucose and other sugars. Growth is fastidious, and the isolates have a distinctive colony morphology, with the colonies being dry and waxy and looking like a semolina particle that can be moved around on an agar plate without losing their shape. DNA-DNA hybridization data and multilocus phylogenetic analysis, including 16S rRNA gene (rDNA), rpoB, and infB sequencing, clearly placed N. semolina as a new genus in the family Pasteurellaceae. In all the phylogenetic trees constructed, N. semolina is on a distinct branch displaying approximately 5% 16S rDNA, approximately 16% rpoB, and approximately 20% infB sequence divergence from its nearest relative within the family Pasteurellaceae. High degrees of conservation of the 16S rDNA (99.8%), rpoB (99.6%), and infB (99.7%) sequences exist within the species, indicating that N. semolina isolates not only are phenotypically homogeneous but also are genetically homogeneous. The type strain of N. semolina is CCUG43639(T) (DSM16380(T)).

Animals↗

Antimicrobial resistance and resistance gene determinants in clinical Escherichia coli from different animal species in Switzerland.

Antimicrobial susceptibility testing was performed on a total of 581 clinical Escherichia coli isolates from diarrhea and edema disease in pigs, from acute mastitis in dairy cattle, from urinary tract infections in dogs and cats, and from septicemia in laying hens collected in Switzerland between 1999 and 2001. Among the 16 antimicrobial agents tested, resistance was most frequent for sulfonamides, tetracycline, and streptomycin. Isolates from swine presented significantly more resistance than those from the other animal species. The distribution of the resistance determinants for sulfonamides, tetracycline, and streptomycin was assessed by hybridization and PCR in resistant isolates. Significant differences in the distribution of resistance determinants for tetracycline (tetA, tetB) and sulfonamides (sulII) were observed between the isolates from swine and those from the other species. Resistance to sulfonamides could not be explained by known resistance mechanisms in more than a quarter of the sulfonamide-resistant and sulfonamide-intermediate isolates from swine, dogs and cats. This finding suggests that one or several new resistance mechanisms for sulfonamides may be widespread among E. coli isolates from these animal species. The integrase gene (intI) from class I integrons was detected in a large proportion of resistant isolates in association with the sulI and aadA genes, thus demonstrating the importance of integrons in the epidemiology of resistance in clinical E. coli isolates from animals.

Animal Diseases↗

A new sulfonamide resistance gene (sul3) in Escherichia coli is widespread in the pig population of Switzerland.

A new gene, sul3, which specifies a 263-amino-acid protein similar to a dihydropteroate synthase encoded by the 54-kb conjugative plasmid pVP440 from Escherichia coli was characterized. Expression of the cloned sul3 gene conferred resistance to sulfamethoxazole on E. coli. Two copies of the insertion element IS15Delta/26 flanked the region containing sul3. The sul3 gene was detected in one-third of the sulfonamide-resistant pathogenic E. coli isolates from pigs in Switzerland.

Amino Acid Sequence↗

Methods for identification of Staphylococcus aureus isolates in cases of bovine mastitis.

A total of 272 staphylococcal isolates from cases of bovine mastitis (159 Staphylococcus aureus) belonging to 12 different species were identified with ID32 STAPH galleries, and 51 of them were confirmed by 16S rRNA gene (rrs) sequencing. The same isolates were examined for their hemolytic activity on sheep blood agar, DNase activity, and coagulase activity and with two rapid identification kits (Slidex Staph Plus kit and RAPIDEC Staph from Bio-Merieux). The results of this study confirm those obtained by other groups with hemolysis, DNase, and coagulase. Only 50% of S. aureus isolates from mastitis cases show coagulase activity after 4 h of incubation, and a 24-h incubation is necessary for the full sensitivity of this test. In contrast to results from other studies with human isolates, the Slidex Staph Plus kit was not sensitive enough for the identification of S. aureus from bovine mastitis samples. The aurease test of the RAPIDEC Staph kit showed 100% sensitivity and 100% specificity. Used in conjunction with hemolysis patterns, the RAPIDEC Staph kit is therefore very well adapted to rapid, efficient, and cost-effective identification of S. aureus in cultures from bovine mastitis samples. Sequencing of rrs genes also proved very efficient in identifying the Staphylococcus species encountered in these samples and confirming phenotypical identification results with unsatisfactory scores. With continuously improving technologies and decreasing costs, genetic identification methods like rrs gene sequencing will soon find a place in routine veterinary diagnostics.

Animals↗

Use of listeriolysin O and internalin A in a seroepidemiological study of listeriosis in Swiss dairy cows.

Recombinant listeriolysin O and internalin A were used as antigens in an enzyme-linked immunosorbent assay (ELISA) for the specific detection of anti-Listeria monocytogenes antibodies in cattle. The results showed sensitivities and specificities of 82 and 92%, respectively, for the listeriolysin O ELISA, and 100 and 90%, respectively, for the internalin A ELISA, respectively. The test may be useful for the confirmation of listeria-related abortions and mastitis but does not seem to be indicated for use in the diagnosis of listeria-related encephalitis in cattle. A representative sample of 1,652 serum samples from the healthy dairy cattle population in Switzerland was tested by both ELISAs. The results showed that 11% of the healthy dairy cows in Switzerland simultaneously presented antibodies toward listeriolysin O and internalin A, and 48% of the farms had one or several animals simultaneously positive by assays with both antigens. Multivariable analysis at the farm level confirmed that feeding of silage represents a significant risk factor for a positive listeria serology. Detailed analysis identified corn silage but not grass silage as the major factor in this association. Cattle breed and hygiene on the farm were also identified as significant factors associated with the serological status of farms. In conclusion, the results of the study show that internalin A is a promising new antigen for use in listeria serology and that specific anti-L. monocytogenes antibodies are found in a significant proportion of healthy dairy cows in Switzerland.

Animals↗

A prospective study of postoperative surgical site infections in dogs and cats.

OBJECTIVE: To assess postoperative surgical site infection (SSI) rate and to identify associated predictive factors. STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs and cats that had surgery (1010 interventions) during 58 weeks from April 1999 to June 2000. METHODS: Data sheets were completed by clinicians. Patients were controlled for clinical evidence of SSI at suture removal. Two definitions of SSI ("infection" and "infection/inflammation") were developed specifically for this study and used for statistical analysis. Logistic regression models were built in order to identify significant predictive factors for SSI. RESULTS: Wounds with "infection/inflammation" occurred in 5.8% and "infected" wounds in 3% of patients. The outcome "infection" was associated with 3 major risk factors (duration of surgery, increasing number of persons in the operating room, dirty surgical site) and 1 protective factor (antimicrobial prophylaxis). The outcome "infection/inflammation" was associated with 6 significant factors (duration of anesthesia, duration of postoperative intensive care unit stay, wound drainage, increasing patient weight, dirty surgical site, and antimicrobial prophylaxis). CONCLUSIONS: SSI frequency in companion animals is comparable with the frequency observed in human surgical patients. Several significant predictive factors for SSI in small animals surgery were identified. CLINICAL RELEVANCE: Baseline information for SSI surveillance in our hospital and for comparison with other studies was defined. The factors identified may help to predict infections in surgical patients and to take adequate preventive measures for patients at risk.

Animals↗