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M Jacques

Publications and source records attributed to M Jacques.

At least 91 records · Page 5Linked to original sources
PubMed1991

Evaluation of the An-Ident system and an indole spot test for the rapid differentiation of porcine treponemes.

The An-Ident strip system (Analytab Products Inc., St-Laurent, Quebec, Canada) was evaluated for its ability to differentiate Treponema hyodysenteriae from Treponema innocens. Of the 20 tests included on this strip, 15 yielded identical results for the two species. Among the other five assays, none could be considered as a positive discriminator for the two species. However, when an indole spot test with 1% p-dimethylaminocinnamaldehyde was used in parallel, all reference strains and 97% of the isolates of T. hyodysenteriae were positive, whereas all isolates of T. innocens were negative. Our results indicate that An-Indent is of little value for the differentiation of the two species. Our results also suggest that a rapid and simple differentiation between T. hyodysenteriae and T. innocens can be achieved by using the hemolysis and ring phenomenon tests in conjunction with an indole spot test.

Alkaline Phosphatase↗
PubMed1991

Isolation and characterization of Streptococcus suis capsular types 9-22.

The incidence and biochemical patterns of Streptococcus suis capsular types 9-22 are presented. Of 148 untypeable (with types 1-8 antisera) isolates of S. suis recovered from diseased pigs, 10% were not capsulated. Of the remaining 134 isolates, only 53% belonged to capsular types 9-22; capsular types 22 and 9 were the most prevalent, representing 19% and 13%, respectively. Capsular type 15 (de Moor's group T Streptococcus) is reported here for the first time in North America since it was described in 1963 in Europe. Of 188 untypeable isolates recovered from clinically healthy pigs, 25% were noncapsulated. Of the remaining 141 isolates, 90% belonged to the new capsular types, and 87% were identified as 1 of 4 types: 17, 18, 19, and 21. Capsular types 12 and 20 were not detected among the Canadian isolates. Almost half of strains were arginine dihydrolase-negative, and 45% fermented mannitol, which is seldom a positive test with capsular types 1-8. Although some strains were negative with salicin or trehalose, none were negative for both sugars. Only 54% of isolates tested with 1 rapid multitest system were correctly identified as S. suis. A tentative biochemical profile that might be used with a microplate identification system is also presented. Biochemical identification using the conventional system instead of the rapid multitest system is preferable.

Agglutination Tests↗
PubMed1991

Resistance to antimicrobial agents and prevalence of R plasmids in Pasteurella multocida from swine.

Twenty-nine field isolates of porcine Pasteurella multocida were characterized for their capsular and somatic types and were evaluated for their susceptibility to 10 antimicrobial agents. Plasmid DNA-screening experiments were conducted to determine whether a relationship existed between the presence of plasmids and antibiotic resistance. Field isolates of P multocida were susceptible to most of the antimicrobials tested, but all isolates were resistant to clindamycin. Eleven isolates of serogroup D were resistant to 1 or 2 antimicrobial agents. Resistance to sulfonamides and streptomycin was observed in 7 isolates. These isolates contained R plasmids conferring resistance to streptomycin and sulfonamides. The R plasmids belonged to 2 groups, one of 5.6 kilobase and the other of 5.9 kilobase. Restriction endonuclease mapping and DNA hybridization revealed that these R plasmids were related to RSF1010 from Salmonella panama, which also confers resistance to streptomycin and sulfonamides.

Animals↗
PubMed1991

Adherence of Streptococcus suis capsular type 2 to porcine lung sections.

The present study was undertaken to evaluate the ability of 33 Streptococcus suis capsular type 2 isolates to adhere to frozen sections of porcine lung. Twenty isolates originated from diseased pigs and 13 from the nasal cavities of clinically healthy pigs. All isolates from diseased animals adhered to lung sections; isolates from pneumonia adhered, in general, in greater numbers than isolates from meningitis. Only four isolates from clinically healthy animals showed a weak adherence to lung sections. Hydrophobic surface properties were also evaluated. All isolates tested appeared to possess a hydrophilic cell surface. The thickness of the capsular material correlated well with the degree of adherence. However, when the adherence capacity of a noncapsulated mutant was compared with that of the parent strain, it was found that the mutant strain had at least the same adherence capacity as the capsulated parent strain. The data suggest that S. suis capsular type 2 isolates involved in pathological conditions can adhere to porcine lung tissue. The adherence activity does not seem to involve hydrophobic interactions. The amount of capsular material seems to influence the adherence activity, but is probably not the only mechanism involved.

Animals↗
PubMed1991

Determination of affinity of Pasteurella multocida isolates for porcine respiratory tract mucus, and partial characterization of the receptors.

The ability of 25 Pasteurella multocida isolates to adhere in vitro to porcine respiratory tract mucus was examined. Microplate wells were coated with crude mucus preparation, then bacteria were added. After incubation, unbound bacteria were removed by washing, and the number of mucus-bound bacteria was estimated by quantitation of the adherent colony-forming units and by use of an ELISA. Pasteurella multocida had affinity to respiratory tract mucus, although significant differences were not observed in affinity of capsular type-A and type-D isolates. Preliminary characterization, using ultrafiltration, gel filtration chromatography, electrophoresis, and enzymatic treatments, indicated that the receptors may be a class of protein molecules of low molecular weight (less than 25,000). The origin of these receptors, however, is not known at this time.

Animals↗
PubMed1990

Immunoelectron microscopic demonstration that Renibacterium salmoninarum is encapsulated.

The cell surfaces of four strains of Renibacterium salmoninarum, including the type strain Lea-7-74T, were examined by transmission electron microscopy after immuno-stabilization and staining with ruthenium red. Cells were covered with a layer of capsular material whose thickness varied between 30 to 60 nm. Our results indicate that R. salmoninarum is encapsulated.

Animals↗
PubMed1990

Purification, and biochemical and structural characterization of a fimbrial haemagglutinin of Renibacterium salmoninarum.

Renibacterium salmoninarum was shown to possess peritrichous fimbriae. Electron microscopy of strains FMV 84-01 and ATCC 33209T revealed short, flexible fimbriae less than 2 nm in diameter. These surface appendages were isolated from the bacteria by a procedure involving water extraction and urea solubilization. The fimbrin was purified to homogeneity by Fast Pressure Liquid Chromatography, and shown by SDS-PAGE to be a protein of 57 kDa. Isoelectric focusing under non-denaturing conditions indicated a pI of 4.8. The protein had an amino acid composition rich in glycine, Asx (aspartic acid and asparagine), valine and alanine; methionine was absent. Approximately 33% of the amino acid residues were hydrophobic. Immunoblotting using a polyclonal antiserum raised against whole cells showed that the 57 kDa protein was the immunodominant antigen on the cell surface. Immunogold labelling using polyclonal antibodies raised against the fimbrin revealed an alignment of gold particles along the fimbriae. Purified fimbriae caused agglutination of rabbit erythrocytes and antifimbrial serum inhibited this haemagglutination. Altogether the results indicate that the fimbriae on the surface of R. salmoninarum are responsible for the haemagglutinating activity.

Amino Acids↗
PubMed1990

Adherence of Bordetella bronchiseptica 276 to porcine trachea maintained in organ culture.

Two organ culture models have been adapted for porcine tracheae in order to study colonization by Bordetella bronchiseptica. Rings or segments excised from tracheae of newborn piglets were incubated overnight at 37 degrees C in a nutrient medium under 5% CO2-95% air conditions. Tracheal segments were infected with B bronchiseptica 276, and after different incubation times, bacterial counts were done. B. bronchiseptica adhered well to tracheae maintained in culture, and no statistically significant differences between the two models were observed. Noninfected tracheal mucosae maintained a normal appearance for several days, whereas infected mucosae showed typical damage caused by B. bronchiseptica, namely, loss of ciliary activity and cilia and sloughing of ciliated cells. Our data indicated that porcine tracheal organ culture could be advantageously used to study in vitro colonization by B. bronchiseptica.

Animals↗
PubMed1990

Role of lipopolysaccharides in adherence of Actinobacillus pleuropneumoniae to porcine tracheal rings.

The ability of 17 Actinobacillus pleuropneumoniae isolates, representing serotypes 1, 2, 5, and 7, to adhere to tracheal rings maintained in culture was examined. Porcine tracheal rings were infected, and 8 h after inoculation, adherent bacterial cells were evaluated. A. pleuropneumoniae adhered to tracheal rings, and marked variations were observed between and even within serotypes, suggesting that adherence of this microorganism is not primarily related to the serotype of the isolate. No relationship was found between adherence to porcine tracheal rings and plasmid profiles, virulence in mice, hemagglutination, capsular material thickness, or whole-cell protein profiles. On the other hand, we observed that all isolates of serotypes 1 and 5 had a semirough-type lipopolysaccharide (LPS), whereas isolates of serotypes 2 and 7 had a smooth-type LPS (75%) or a semirough-type LPS (25%). Results showed that 83% of isolates with a smooth-type LPS adhered in large numbers to tracheal rings, whereas 80% of isolates with a semirough-type LPS adhered poorly (P less than 0.007). Our data indicated that the degree of adherence of A. pleuropneumoniae to porcine tracheal rings appeared to be related, at least in part, to LPS profiles. Furthermore, LPS seemed to be the adhesin of A. pleuropneumoniae, since purified LPS blocked adherence of this microorganism to porcine tracheal rings.

Actinobacillus↗
PubMed1990

Ultrastructural study of surface components of Streptococcus suis.

The presence of capsular material on cells of nine reference strains of Streptococcus suis representing serotypes 1 to 8 and 1/2 was determined by transmission electron microscopy after polycationic ferritin labeling, immunostabilization, or fixation with a combination of glutaraldehyde and lysine. All the cells of the reference strains examined were covered with a layer of capsular material whose thickness varied between 20 to 30 nm and 350 to 375 nm when examined by immunostabilization. Capsular material from cells exposed to homologous antiserum was usually thicker than that from polycationic ferritin-labeled cells or cells fixed with glutaraldehyde-lysine. Negative staining revealed detectable surface structures on S. suis strains. All strains carried peritichous, thin, and flexible fimbriae with a diameter of approximately 2 nm and a length of up to 250 nm. This study indicated that morphological differences of surface structure exist among S. suis reference strains.

Ferritins↗
PubMed1990

Hemagglutination properties of Streptococcus suis.

A total of 49 strains (23 reference strains and 26 field isolates) of Streptococcus suis were tested for their ability to agglutinate erythrocytes from different animal species. Ten different hemagglutination patterns were established. Thirty-three strains (67%) did not agglutinate any of the erythrocytes tested; sixteen strains (33%) agglutinated erythrocytes from one or more animal species. Different strains belonging to the same capsular type presented different hemagglutination patterns. No correlation was found between the tissue origin and/or the virulence (evaluated in 4-week-old mice) of different field isolates and their hemagglutination activity. Hydrophobic surface properties were also evaluated. All S. suis strains studied appeared to possess a hydrophilic cell surface. Morphologically similar fimbriae were observed on hemagglutinating as well as on nonhemagglutinating strains of S. suis. This study provides evidence that certain strains of S. suis possess hemagglutinating properties which do not appear to involve hydrophobic interactions. The possible role of fimbriae in hemagglutination remains unclear.

Animals↗
PubMed1990

Restriction endonuclease analysis of porcine Pasteurella multocida isolates from Quebec.

We have used restriction endonuclease analysis (REA) of genomic DNA to classify porcine Pasteurella multocida isolates with similar capsular and somatic serotypes, and to monitor the distribution of isolates from 12 different herds in Quebec. Within herds, P. multocida isolates of similar capsular and somatic serotypes showed similar REA fingerprints. Between herds, some isolates had similar REA fingerprints. However, differences in REA enabled subtyping of many P. multocida isolates with the same antigen types. Our data indicate that REA would enable accurate epidemiological typing of P. multocida in conjunction with classical capsular and somatic typing.

Animals↗
PubMed1989

Clinical and pharmacokinetic evaluation of controlled-release levodopa/carbidopa (CR-4) in parkinsonian patients with severe motor fluctuations: a six month follow-up study.

The results of a six month open-label study comparing the efficacy of controlled-release levodopa-carbidopa (Sinemet CR-4 200 mg/50 mg) with standard levodopa/carbidopa (250 mg/25 mg) in 17 patients with idiopathic Parkinson's disease and severe response fluctuations, are reported. Major clinical benefits included; improvement of disability, reduction of the number of 'off' periods (predominantly end-of-dose hypokinesia) and a slight increase in 'on' time. No improvement was observed in two of our patients. Mean levodopa plasma levels were comparable between the two types of formulations during optimal treatment, however systemic bioavailability was significantly higher with CR-4. Delayed onset of antiparkinsonian effect of CR-4, resulting from an increase of Tmax for levodopa, was one of the major complaints and required additional small amounts of standard levodopa in three patients.

Adult↗
PubMed1989

Description of 14 new capsular types of Streptococcus suis.

Fourteen new capsular types of Streptococcus suis (types 9 to 22) are described. All reference strains are morphologically and biochemically similar to types previously described. Reference strain types 9 to 13, 15, 16, and 22 were isolated from diseased pigs, whereas types 17 to 19 and 21 came from clinically healthy pigs; type 14 was isolated from a human case of meningitis, and type 20 was isolated from a diseased calf. The group T streptococcus of de Moor has been included in the typing system as type 15. Two-way cross-reactions between types 6 and 16 and a one-way cross-reaction between types 2 and 22 have been demonstrated. In addition, several cross-reactions probably not due to capsular material were detected among different types by using the coagglutination test. This test should not be used alone; weak or multiple positive reactions must be confirmed by the capsular reaction test or the capillary precipitation test.

Agglutination Tests↗
PubMed1989

Extensive colonization of the porcine colonic epithelium by a spirochete similar to Treponema innocens.

Specimens of colonic mucosa from two pigs with diarrhea were examined by light and electron microscopy. The epithelial surfaces of both pigs were extensively colonized by large spirochetes morphologically compatible with Treponema hyodysenteriae or Treponema innocens. The microorganisms were intimately attached end-on to the luminal cells. A weakly beta-hemolytic spirochete similar to T. innocens was isolated from the colon of one of the pigs.

Animals↗