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S Messier

Publications and source records attributed to S Messier.

At least 37 records · Page 2Linked to original sources
PubMed1996

Development of an experimental model allowing discrimination between virulent and avirulent isolates of Serpulina (Treponema) hyodysenteriae.

Variation in virulence among different strains of Serpulina hyodysenteriae was studied by oral inoculation of specific pathogen free piglets and CD-1 mice. Piglets infected with serotype 2 reference strain B204 and an untypable field strain LHV-90-9-I had severe diarrhea tainted intermittently with mucus and fresh blood. The piglets inoculated with B169, B8044, B6933, and ACK300-8 reference strains representing serotypes 3, 5, 6, and 7 respectively developed moderate diarrhea. However, reference strains B234 and A-1 of serotypes 1 and 4, respectively, failed to cause any diarrhea. None of the S. hyodysenteriae strains caused diarrhea in mice. The results indicate a great variation in virulence among strains of different serotypes of S. hyodysenteriae. Mice were less susceptible to infection with S. hyodysenteriae.

Animals↗
PubMed1994

A national survey to estimate the prevalence of Salmonella species among Canadian registered commercial turkey flocks.

In 1990-1991, a national survey was conducted to estimate the prevalence of Salmonella species among Canadian commercial turkey flocks. Two hundred and seventy flocks were randomly selected across Canada. The proportion sampled from each province was selected according to each province's share of the national turkey market. Samples, consisting of 12 pooled litter and four pooled dust samples, were used to determine the Salmonella status of the environment of each flock. Additionally, a one kilogram sample of feed was taken from each flock premise. Salmonella was recovered from environmental samples in 234/270 (86.7%) of flocks and from feed samples in 26/266 (9.8%) of flocks. Forty-eight different Salmonella serovars were isolated from flock environmental samples. The most prevalent serovars were S. anatum, S. hadar, S. agona, S. heidelberg and S. saintpaul which were isolated from 53/270 (19.6%), 49/270 (18.1%), 49/270 (18.1%), 42/270 (15.6%) and 34/270 (12.6%) flocks, respectively.

Animals↗
PubMed1993

Exposure for different license categories through a phone survey: validity and feasibility studies.

This paper presents: (i) an operational definition of risk exposure, (ii) a questionnaire developed to measure exposure, (iii) validity studies of estimates of the distance traveled and time spent driving for different permit holder categories, and (iv) a feasibility study for a telephone survey on exposure. Results show that long-distance truck drivers from one company studied estimated accurately their distance driven on the last worked day; Montreal Urban Community Transport Commission bus drivers estimated well their time behind the wheel; while a convenience sample of private car drivers (coworkers and friends) estimated well their previous week distance and time on the road. Phone surveys appear to be an efficient and cost-effective method for risk exposure data collection.

Automobile Driving↗
PubMed1993

Identification and partial characterization of a group of weakly beta-hemolytic intestinal spirochetes of swine distinct from Serpulina innocens isolate B256.

Comparative analyses of a group of 16 weakly beta-hemolytic spirochetes isolated from feces and mucosal scrapings of intestines of swine in the midwestern United States, and eastern Canada revealed the existence of a phenotypically and genotypically related group of 7 isolates. Although isolates in this group differed from all known reference isolates of intestinal spirochetes of swine, partial similarity was detected with S. joneseae isolate 16, a newly identified weakly beta-hemolytic intestinal spirochete of human beings. In addition to producing weak beta-hemolysis on blood agar plates, S. innocens isolates B256 and 4/71, S. joneseae isolate 16, and the 16 field isolates lacked the characteristic ring phenomenon described for Serpulina hyodysenteriae, an enteropathogenic spirochete of swine. All but one of the field isolates of weakly beta-hemolytic intestinal spirochetes gave negative results for indole production. The same isolates yielded variable results for alpha-galactosidase production. By transmission electron microscopic examination of negatively-stained cross-sections of spirochetes, the isolates segregated into groups containing either 4 to 7 or 9 to 16 profiles of axial filaments per cell cross-section. Analyses of genomic DNA of selected isolates using whole-genome cross-hybridization revealed a single genetic type consisting of 7 field isolates of weakly beta-hemolytic intestinal spirochetes. The 7 field isolates were distinct from the reference isolates S. innocens isolates B256 and 4/71, S. hyodysenteriae isolates B78 and B204, and Treponema succinifaciens isolate 6091 based on the number of axial filaments per cell cross-section and lack of cross-hybridization signal. S. joneseae isolate 16, had the same number of axial filaments per cell cross-section and produced a weak hybridization signal with a representative isolate of the 7 weakly beta-hemolytic field isolates from swine. This report suggests the existence of a widely distributed group of closely related weakly beta-hemolytic intestinal spirochetes of swine with genotypic characteristics distinct from S. innocens isolate B256.

Animals↗
PubMed1993

Detection of Actinobacillus pleuropneumoniae in the porcine upper respiratory tract as a complement to serological tests.

Attempts were made to isolate Actinobacillus pleuropneumoniae from the nasal cavities and tonsils of 442 healthy pigs from 15 herds. Samples were streaked onto different media formulations. Serum samples were assayed for antibodies to A. pleuropneumoniae by enzyme-linked immunosorbent assay and complement fixation test. Actinobacillus pleuropneumoniae was isolated from the nasal cavities only in 24 pigs, from tonsils only in 90 pigs, and from both the nasal cavities and the tonsils in 11 pigs. A PPLO medium supplemented with lincomycin, bacitracin and crystal violet allowed recovery of A. pleuropneumoniae from more animals than a tryptic soy agar medium from both sites. Incubation of plates in an enriched CO2 atmosphere did not affect the recovery rate. Actinobacillus pleuropneumoniae belonging to serotypes 1, 2, 3, 5a, 5b, 7, 8, 10 and 12 were isolated, and, in several herds, more than one serotype were recovered. Serotypes of A. pleuropneumoniae were isolated from nine herds which were found seronegative to these. The isolation of A. pleuropneumoniae from the upper respiratory tract can be useful for detection of carrier pigs and complements serological screening.

Actinobacillus Infections↗
PubMed1992

Comparison of six different culture media for isolation of Treponema hyodysenteriae.

Fecal material from pigs experimentally infected with Treponema hyodysenteriae was collected and inoculated on six different selective media to compare their abilities for recovery of T. hyodysenteriae. Additionally, various types of samples were compared to find the most appropriate for submitting material to laboratories. Isolation rates for T. hyodysenteriae were 89.7% on BJ medium, 88.3% on TSA-BJ medium, 76.6% on SVC medium, 76.6% on BA2-BJ medium, 75.2% on BA2-SVC medium, and 52.4% on TSA-S400 medium. BJ medium was the most useful, yielding good growth of T. hyodysenteriae and inhibition of the normal fecal flora. Also, undiluted fecal material kept at refrigeration temperature allowed better recovery of T. hyodysenteriae during storage than swabs.

Animals↗
PubMed1992

Prevalence of Salmonella spp., Campylobacter spp. and Listeria spp. in ring-billed gulls (Larus delawarensis).

Cloacal swabs collected from 264 ring-billed gulls (Larus delawarensis) at four sites near Montréal, Canada were cultured for the presence of Salmonella spp., Campylobacter spp. and Listeria spp. All birds were apparently healthy when captured or killed. Of all birds examined, 8.7%, 15.9% and 9.5%, respectively, were infected with Salmonella spp., Campylobacter spp. and Listeria monocytogenes. Overall, 29.9% of gulls sampled harbored one or more of these bacteria. Gulls probably play only a minor role in the epizootiology of these bacteria.

Animals↗
PubMed1991

A comparative study of the 'FDA' and 'USDA' methods for the detection of Listeria monocytogenes in foods.

Nineteen laboratories across Canada took part in a comparative study of the 'FDA' and 'USDA' methods for the detection of Listeria monocytogenes in foods and environmental samples. The results show that the enrichment period of the FDA method can be shortened from 7 to 2 days without substantially reducing the number of positive samples. With a limited number of samples, the USDA method proved to be slightly more efficient in isolating L. monocytogenes than the FDA method. Fraser broth, in principle, proved to be useful as a screening tool but is not very selective. Oxford agar and lithium chloride-phenylethanol-moxalactam medium were better than modified McBride's agar in isolating this microorganism.

Agriculture↗
PubMed1991

The prevalence of Salmonella enteritidis and other Salmonella sp. among Canadian registered commercial chicken broiler flocks.

A nation-wide survey was conducted to estimate the prevalence of Salmonella enteritidis and other salmonellas among Canadian commercial broiler flocks. Environmental (litter and/or water) samples from 226 of 294 (76.9%) randomly selected flocks were contaminated with salmonellas. Litter samples were more often contaminated with salmonellas than water samples (47.4 v. 12.3%). Fifty different salmonella serovars were isolated. The most prevalent serovars were S. hadar, S. infantis, and S. schwarzengrund; they were isolated from samples of 98/294 (33.3%), 26/294 (8.8%), and 21/294 (7.1%) flocks, respectively. Feed samples of 39/290 (13.4%) flocks were contaminated with salmonellas. Salmonella enteritidis was isolated from the environmental samples of 9/294 (3.1%) flocks. Salmonella enteritidis phage type (PT) 8 was isolated from seven flocks, and PT 13a from two flocks.

Animal Feed↗
PubMed1991

Identification of Treponema hyodysenteriae and Treponema innocens using two four-hour identification systems.

Two 4-hour identification systems, the RapID-ANAII (Innovative Diagnostic Systems) and the ANI card (Vitek Systems), were used to identify isolates of Treponema hyodysenteriae and T. innocens. Twenty-one isolates of T. innocens and 53 isolates of T. hyodysenteriae were tested with both systems. With the ANI system, alpha-galactosidase was the only test that differentiated the two species. With the RapID-ANAII system, alpha-galactosidase and indole tests allowed differentiation of the two species. Treponema hyodysenteriae was alpha-galactosidase negative and indole positive, whereas T. innocens produces the opposite reactions. Three isolates were alpha-galactosidase negative and indole negative. These isolates represent a group intermediate between the two officially described species. The two species of swine Treponema can be identified by commercial identification kits and a third group of isolates intermediate between the two species was identified.

Animals↗
PubMed1991

Interactions of Mycoplasma hyopneumoniae membranes with porcine lymphocytes.

Nonspecific mitogenicity of Mycoplasma hyopneumoniae membranes for blood lymphocytes (BL) and bronchial lymph node lymphocytes (LNL) from swine was investigated. Additionally, the influence of respiratory tract exposure to the same membrane preparation on responsiveness of these cells was evaluated. Membranes utilized in lymphocyte transformation tests and for inoculation of swine were prepared by osmotic lysis of mycoplasma cells. Conventionally reared and cesarean-derived, colostrum-deprived swine were given membranes intratracheally and responses of BL and LNL to membranes were assessed from postinoculation day 0 to 14. Utilizing a stimulation index of 3 as the cutoff, heated (56 C) M hyopneumoniae membranes exerted moderate nonspecific stimulation of BL 11 of 12 times when BL were collected from normal (control or preinoculation) swine. Similarly, LNL from conventionally reared and control groups of swine were stimulated nonspecifically 4 of 6 times by the same membrane preparations. Exposure of the respiratory tract to membranes appeared to have no influence on stimulation responses of BL at postinoculation days 6 or 13, whereas moderate to marked increases in responsiveness of LNL were detected when collected at necropsy on postinoculation days 7 or 14. These findings indicated that compartmentalization of lymphocyte sensitization in the bronchial lymph nodes resulted from respiratory tract exposure to mycoplasmal membranes. Results obtained confirm that M hyopneumoniae has a moderate nonspecific stimulatory effect on porcine lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Minimal inhibitory concentrations of five antimicrobials against Treponema hyodysenteriae and Treponema innocens.

The minimal inhibitory concentrations of carbadox, dimetridazole, lincomycin, ronidazole, and tiamulin against isolates of Treponema hyodysenteriae and Treponema innocens were determined by an agar-dilution method. The results obtained indicated that tiamulin was the most effective antimicrobial in vitro against T. hyodysenteriae, followed by carbadox. Dimetridazole, lincomycin, and ronidazole had poor efficacy in vitro against the T. hyodysenteriae isolates. Isolates of T. innocens were more sensitive to the various antimicrobials. Carbadox and tiamulin were the most effective in vitro, followed by ronidazole, dimetridazole, and lincomycin.

Animals↗
PubMed1990

Humoral and cellular immune responses of pigs inoculated with Mycoplasma hyopneumoniae.

Cellular and humoral immune responses of pigs inoculated with Mycoplasma hyopneumoniae were investigated at postinoculation weeks (PIW) 2, 4, and 6. The response of blood lymphocytes (BL) and bronchial lymph node lymphocytes (LNL) to stimulation by M hyopneumoniae antigens was evaluated by a lymphocyte-stimulation test. Specific antibodies in serum and lung washing samples were assayed by ELISA. Immunoglobulin-positive cells in lungs and bronchial lymph nodes were identified by indirect fluorescent antibody test, using isotype-specific monoclonal antibodies. At PIW 0 to 6, BL from control and M hyopneumoniae-inoculated pigs were stimulated by M hyopneumoniae cells; however, BL from inoculated pigs generally had higher stimulation indices, especially at PIW 6. The response of LNL was influenced by previous exposure to M hyopneumoniae, as indicated by higher stimulation indices (P less than 0.01) of LNL from inoculated pigs killed at PIW 2 and 6. Specific ELISA antibodies to M hyopneumoniae in lung washings from inoculated pigs consisted mainly of IgG and IgA isotypes. Examination of lung sections by indirect immunofluorescence revealed that cells producing IgM and IgA were in controls as well as M hyopneumoniae-inoculated pigs, but IgG-positive cells were only in lungs of inoculated pigs. Resolution of pneumonia appeared to correlate with development of increased sensitization of BL, as well as development of marked increases in immunoglobulins, particularly IgG in lung washings at PIW 6.

Animals↗
PubMed1989

Survival of Salmonella typhimurium and Staphylococcus aureus in Genoa salami of varying salt concentration.

Genoa salami prepared using three different salt concentrations (2.0, 2.75 and 3.3%) were inoculated with 2.0 x 10(3) and 1.1 x 10(3) bacteria/g of Salmonella typhimurium and Staphylococcus aureus respectively. Over a period of 74 days samples were taken and analyzed for water activity and pH, counts of S. aureus and presence of Salmonella. After 11 days of dry-curing Salmonella could no longer be detected by preenrichment followed by selective enrichment procedures. Viable S. aureus were still found after 74 days of dry-curing. The results of this study would suggest that water activity and pH measurements are useful in evaluating the safety of dry-cured products.

Animals↗
PubMed1989

Destruction of Trichinella spiralis spiralis during the preparation of the "dry cured" pork products proscuitto, proscuittini and Genoa salami.

Genoa salami, proscuittini and proscuitto were prepared from pork carcasses that were heavily infected experimentally with Trichinella spiralis spiralis. Genoa salami was prepared with salt concentrations of 2.0%, 2.75% and 3.3%. Proscuitto was prepared by two procedures approved by Agriculture Canada. At various times postpreparation, samples of the various cured products were taken and examined by pepsin digestion and rat bioassay for the presence of viable trichinae. Water activity and pH of the cured meat were also determined. Curing of the various products was shown to destroy the Trichinella larvae. Pepsin digestion revealed that larvae progressively became loosely coiled, uncoiled and more subject to digestion (ghost larvae) during the curing process. Rat bioassay revealed the presence of viable trichinae in the proscuitto prepared using a sodium chloride salt mixture at day 34 but not at day 48 postpreparation. All other bioassays carried out on Genoa salami between 13 and 42 days postpreparation, on proscuittini between days 27 and 69 and on proscuitto between days 34 and 69 were negative for viable trichinae. Under the conditions of this study, preparing Genoa salami with salt concentrations as low as 2% did not appear to affect the destruction of Trichinella larvae.

Animals↗