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Background -Meticillin-resistant staphylococci are significant pathogens in veterinary dermatology, yet longitudinal studies of the impact of routine antimicrobial therapy on emergence or resolution of resistance are lacking.Objectives -To determine the prevalence of meticillin-resistant staphylococci on skin and carriage sites in dogs with bacterial pyoderma and evaluate the prevalence of meticillin-resistant Staphylococcus pseudintermedius (MRSP) colonization after successful treatment of pyoderma.Animals -One hundred and seventy-three dogs that presented to a dermatology referral service with pyoderma and 41 healthy control dogs.Methods -Skin, nasal and rectal swabs for bacterial culture were collected at the time of referral and after clinical resolution of the pyoderma. Meticillin resistance was confirmed by demonstration of penicillin binding protein 2a antigen.Results -Initially, skin cultures yielded MRSP in 70 (40.5%) dogs, meticillin-resistant Staphylococcus aureus (MRSA) in three (1.7%) and meticillin-resistant Staphylococcus schleiferi ssp. coagulans (MRSScoag) in five (2.9%). Samples collected from the nose and rectum (carriage sites) yielded MRSP in 59 (34.1%) dogs, MRSA in 11 (6.4%) and MRSScoag in seven (4.0%). One hundred and two dogs were available for follow-up cultures after clinical cure. Of 42 dogs initially diagnosed with MRSP pyoderma, MRSP was isolated at follow-up from skin in 19 (45.2%) and carriage sites in 20 (47.6%). Of 60 dogs that did not have MRSP pyoderma initially, MRSP was isolated post-treatment from the skin in 17 (28.3%), and MRSP from carriage sites increased from 7.8% (initially) to 26.7% (P = 0.0022).Conclusions and clinical importance -Colonization by MRSP often persists after resolution of MRSP pyoderma. Acquisition of MRSP during treatment appears to be common.

There is little information on the genetic basis of resistance to the critically important extended-spectrum cephalosporins (ESCs) in Enterobacteriaceae from dogs in Canada. This study assessed the frequency of ESC resistance in Enterobacteriaceae isolated from dogs in Ontario and the distribution of major ESC resistance genes in these bacteria. A total of 542 Enterobacteriaceae were isolated from 506 clinical samples from two diagnostic laboratories in Ontario. Eighty-eight ESC-resistant Enterobacteriaceae and 217 Escherichia coli were isolated from 234 fecal samples from dogs collected at leash-free dog parks. These fecal isolates were tested for ESC resistance along with the clinical isolates. Isolates with reduced ESC susceptibility were screened for bla, bla, and bla, and all CTX-M-positive isolates underwent whole-genome sequencing. The prevalence of ESC resistance in clinical Enterobacteriaceae was 10.4%. The average frequency of fecal carriage of ESC-resistant Enterobacteriaceae in healthy dogs was 26.5%. The majority of ESC-resistant isolates were E. coli and the other major Enterobacteriaceae carrying ESC resistance genes were Klebsiella pneumoniae and Proteus mirabilis. The results show that the same ESC resistance genes can be found in clinical and fecal Enterobacteriaceae in dogs. The identified E. coli sequence types (including ST131 and ST648) and CTX-M variants (including CTX-M-14, -15, and -27) support the hypothesis of transfer of resistant bacteria between humans and dogs. CTX-M-1 was frequently found in canine fecal Enterobacteriaceae, while it is still rare in human Enterobacteriaceae in Canada, thus suggesting transfer of resistant bacteria to dogs from food animals or other sources.

SK Fung, H Dick, H Devlin, E Tullis. Transmissibility and infection control implications of OBJECTIVE:To describe the microbiology and potential virulence factors of Burkholderia cepacia; to discuss the studies that have investigated its mode of transmission among cystic fibrosis patients; and to identify the major risk factors associated with acquisition of this pathogen inside and outside of the hospital environment. DATA SOURCES: MEDLINE search of the literature published between 1986 and 1997 using the key words/subject words Pseudomonas cepacia, Burkholderia cepacia, cystic fibrosis, infection control and transmissibility, and the bibliography of selected papers. DATA EXTRACTION: Selected studies examining epidemiology, microbiology, virulence factors and mode of transmission of B cepacia in cystic fibrosis. DATA SYNTHESIS AND CONCLUSIONS: B cepacia is a multidrug-resistant Gram-negative bacillus that has recently been recognized as a major respiratory pathogen in patients with cystic fibrosis. Colonization by this organism can lead to rapid pulmonary deterioration and premature death. Recent studies based on genomic subtyping techniques have suggested that it can be transmitted from person to person. Close social contact and hospitalization have been identified as risk factors for cross-infection. With the implementation of strict infection control policies such as segregation according to colonization status, the rate of new colonization has substantially decreased in most cystic fibrosis treatment centres. Key Words: Burkholderia cepacia, Cystic fibrosis, Infection control, Pseudomonas cepacia, Pulmonary infection, TransmissibilityTransmissibilité et implications du contrôle de l'infection à Burkholderia cepacia dans la fibrose kystique OBJECTIF : Décrire la microbiologie et les facteurs potentiels de virulence de Burkholderia cepacia ; examiner les études portant sur son mode de transmission parmi les patients atteints de fibrose kystique ; et identifier les facteurs de risque majeur associés à une contamination par ce pathogène en milieu hospitalier ou extrahospitalier. SOURCES DES DONNÉES : Recherche dans Medline des articles publiés entre 1986 et 1997 en utilisant les mots clés/mots sujets Pseudomonas cepacia, Burkholderia cepacia, fibrose kystique, contrôle de l'infection et transmissibilité, et la bibliographie d'articles choisis. EXTRACTION DES DONNÉES : Études choisies examinant l'épidémiologie, la microbiologie, les facteurs de virulence et le mode de transmission de B cepacia dans la fibrose kystique. SYNTHÈSE DES DONNÉES ET CONCLUSIONS : B cepacia est un bacille Gram négatif résistant à l'action de plusieurs médicaments et que l'on a récemment identifié comme un des plus importants pathogènes respiratoires chez les patients voir page suivante C ystic fibrosis (CF) is the most common lethal genetic disease affecting Caucasians (1). The most frequent mutation that gives rise to this autosomal recessive condition involves the deletion of a phenylalanine residue at position 508 of the gene encodin...

We investigated the utility of PCR to detect Burkholderia cepacia directly in sputum samples at two cystic fibrosis (CF) centers serving children and adults. Following liquefaction of the sputa by using N-acetyl-l-cysteine, DNA was isolated and analyzed by PCRs with three different primer pairs directed toward bacterial rRNA loci. Two primer pairs were putatively specific for B. cepacia. The other pair, which universally amplifies a band from all bacteria, served as a control. Sputum samples were obtained from 219 patients and analyzed independently by culture and by PCR to detect B. cepacia. The analyses were performed blinded with respect to each other. The results of the PCR with sputa demonstrated that the primers directed to the 16S loci demonstrated approximately 95% concordance with culture results and were more specific than those amplifying the 16S to 23S spacer region. In addition, the 16S primer pair putatively identified B. cepacia in seven patients whose sputa were culture negative at this time. Of these culture-negative patients, five had sputum samples that were culture positive for B. cepacia either prior or subsequent to this study. The results of this study indicate the utility of PCR as a diagnostic method for the rapid identification of B. cepacia in sputum samples of CF patients. We anticipate that improvements in our taxonomic understanding may allow the design of more specific primers for detection of each species of the B. cepacia complex in sputum samples.