Showing papers by "Robert Higgins published in 2003"

Identification of Catalase-Negative, Non-Beta-Hemolytic, Gram-Positive Cocci Isolated from Milk Samples

Abstract: This study was undertaken in an effort to improve the identification scheme of catalase-negative, non-beta-hemolytic, gram-positive cocci isolated from milk samples obtained from cows. First, the sensitivity and specificity of the identification procedure currently in use in our laboratory were compared to the results obtained with API 20 STREP strips which were set as the gold standard. Second, a number of other identification tests, which could contribute to increase the sensitivity and specificity of the identification procedure of these microorganisms, were evaluated and selected. The data have shown that there is a necessity to review the identification procedure. Some modifications are suggested to laboratories doing milk sample analyses. A standardized procedure, using the CAMP test, esculin and sodium hippurate hydrolysis, the presence of the enzymes pyrolidonyl arylaminase and leucine aminopeptidase, and acid production from 1% inulin and raffinose broth, would not only improve the results of the identification process of gram-positive cocci isolated from milk samples but also ensure greater uniformity of the epidemiological data.

Allofustis seminis gen. nov., sp. nov., a novel Gram-positive, catalase-negative, rod-shaped bacterium from pig semen

Abstract: An unknown Gram-positive, catalase-negative, facultatively anaerobic, non-spore-forming, rod-shaped bacterium originating from semen of a pig was characterized using phenotypic, molecular chemical and molecular phylogenetic methods Chemical studies revealed the presence of a directly cross-linked cell wall murein based on l-lysine and a DNA G+C content of 39 mol% Comparative 16S rRNA gene sequencing showed that the unidentified rod-shaped organism formed a hitherto unknown subline related, albeit loosely, to Alkalibacterium olivapovliticus, Alloiococcus otitis, Dolosigranulum pigrum and related organisms, in the low-G+C-content Gram-positive bacteria However, sequence divergence values of >11 % from these recognized taxa clearly indicated that the novel bacterium represents a separate genus Based on phenotypic and phylogenetic considerations, it is proposed that the unknown bacterium from pig semen be classified as a new genus and species, Allofustis seminis gen nov, sp nov The type strain is strain 01-570-1T (=CCUG 45438T=CIP 107425T)

Evolution of bacterial resistance to certain antibacterial agents in horses in a veterinary hospital

Abstract: Evolution of bacterial resistance to certain antibacterial agents in horses in a veterinary hospital. A total of 255 antibiograms, conducted according to the Kirby-Bauer method from bacterial isolates collected from horses at the Hopital Veterinaire d'Enseignement at the Universite de Montreal between 1996 and 1998 were compared with the results obtained about 10 years ago with corresponding bacterial species. A significant increase in the percentage of strains resistant to trimethoprim-sulfamethoxazole (TMP-SXT), penicilline, tetracycline, and to gentamicin was observed. The percentages of isolates of Actinobacillus spp. and coagulase-positive staphylococci resistant to TMP-SXT increased from 0% to 17% and from 0% to 33%, respectively, (P < 0.05). The percentage of isolates of Actinobacillus spp resistant to penicilline also increased from 33% to 73% (P < 0.05). Regular monitoring of the evolution of bacterial resistance to antibacterial agents is indispensable in a hospital structure. The adoption of "good antibiotherapy practices" is essential to guarantee a decrease in the risks of selection and dissemination of a resistant bacterial strain.

Évolution de la résistance bactérienne envers certains agents antibactériens chez les chevaux dans un centre hospitalier vétérinaire

Abstract: Un total de 255 antibiogrammes, realises selon la methode Kirby-Bauer a partir d'isolats bacteriens preleves chez des chevaux a l'Hopital Veterinaire d'Enseignement de l'Universite de Montreal entre 1996 et 1998, ont ete compares avec les resultats obtenus il y a une dizaine d'annees avec des especes bacteriennes correspondantes. Une augmentation significative du pourcentage de souches resistantes au trimethoprime-sulfamethoxazole (TMP-SXT), a la penicilline, a la tetracycline et a la gentamicine a ete observee. Les pourcentages des isolats d'Actinobacillus spp. et de staphylocoques coagulase positive, resistants au TMP-SXT, ont augmente de 0 % a 17 % et de 0 % a 33 %, respectivement (P < 0,05). Le pourcentage des isolats d'Actinobacillus spp resistants a la penicilline a, quant a lui, augmente de 33 % a 73 % (P < 0,05). Le suivi regulier de l'evolution de la resistance bacterienne envers les agents antibacteriens est indispensable dans une structure hospitaliere. L'adoption des «bonnes pratiques de l'antibiotherapie» est essentielle pour garantir une diminution des risques de selection et de dissemination d'une souche bacterienne resistante.

Serotypes of Streptococcus agalactiae cultured from dairy milk samples in Québec.

Abstract: Streptococcus agalactiae remains an important pathogen of dairy herds in Quebec, but data about antigenic characteristics of this microorganism are sparse. This study was conducted to determine the variety of S. agalactiae serotypes in dairy herds in Quebec. Two hundred and ninety-five isolates cultured from the milk of individual cows from 7 regions of Quebec were serotyped. Sixty-two percent of the isolates were untypeable. Among the 38% of typeable isolates, serotype III was found most frequently. In conclusion, the heterogeneity found among antigenic determinants of isolates from bovine milk suggests that an immunological method for the detection of S. agalactiae performed directly on bovine milk would not be a practical approach.