Biomedical subjects

M R Baccaro

Publications and source records attributed to M R Baccaro.

7 recordsLinked to original sources

PubMed2003

Use of single-enzyme amplified fragment length polymorphism for typing Pasteurella multocida subsp. multocida isolates from pigs.

Single-enzyme amplified fragment length polymorphism (SE-AFLP) analyses were used to differentiate 97 isolates of porcine Pasteurella multocida subsp. multocida. The strains, isolated from animals with pneumonia, rhinitis, and septicemia, were classified as capsular types A, D, and F. SE-AFLP showed a discriminatory index of 0.87 and identified 18 different profiles.

Animals↗

PubMed2001

Virulence properties of Escherichia coli isolated from ostriches with respiratory disease.

Eight Escherichia coli isolates from ostriches with respiratory disease were investigated for the presence of genes encoding the following adhesins: type 1 pili (fim), pili associated with pyelonephritis (pap), S fimbriae (sfa), afimbrial adhesin (afaI), temperature regulated adhesin, curli (crl, csgA) and temperature-sensitive hemagglutinin (tsh). Genes for heat labile (LT) and heat stable (STa and STb) enterotoxins, Shiga toxins (stx1 and stx2), cytotoxic necrotizing factor 1 (cnf), alpha-haemolysin (hly) and aerobactin (aer) production were also investigated. Other characteristics investigated were the presence of hemagglutination activity, growth on an iron-deficient medium, aerobactin production, serum resistance, adherence to chicken tracheal cells, pathogenicity for day-old chicks, and serogroup. Serogrouping showed that four isolates belonged to serogroup O2, two to serogroup O78, one to serogroup O9, and one to serogroup O21. The virulence genes found were: fim in all eight isolates, csgA in seven, aer in six, and pap, crl and tsh in one isolate each. All isolates analyzed were positive for mannose-resistant hemagglutination, adhered in vitro to ciliated tracheal epithelium, grew on iron-deficient medium, and showed serum resistance. Pathogenicity tests on day-old chickens revealed one highly pathogenic isolate, three of low pathogenicity and four isolates with intermediate pathogenicity.

Adhesins, Escherichia coli↗

PubMed1997

Endocardial fibroelastosis in a dog.

Endocardial fibroelastosis is an uncommon congenital heart disease in dogs that may be manifested by signs of left-sided congestive heart failure. A three-month-old, male, Fila Brasileiro dog developed signs of generalised heart failure. Physical examination revealed normal temperature, ascites, and pale and cyanotic mucous membranes. The pup died just after radiography which revealed ascites, hepatomegaly, severe cardiac enlargement and pulmonary oedema. At necropsy, serosanguineous fluid in the thorax and abdomen, pulmonary oedema, right ventricular dilatation, hypertrophy and dilatation of the left ventricle, and mitral valve incompetence were observed. The histopathological examination demonstrated that the thickening of the endocardium of the left atrium and left ventricle was due to the presence of elastic and collagen fibres, although there were no signs of an inflammatory process.

Animals↗

PubMed1995

Studies on feeding of Argas (Persicargas) miniatus larvae (Acari: Argasidae) on naive chicks.

The histology of skin responses to infestation with Argas (Persicargas) miniatus Koch, 1844, larvae was investigated on previously unexposed 1-mo-old chicks. An amorphous, acidophilic substance, referred to as cement, was observed from 24 h after infestation until the ticks had detached. The morphology of the lesions changed gradually during the time of infestation. Initially, dissociation of collagen fibers and a mild infiltration with heterophil and mononuclear cells (12-24 h) was observed. Then, fibroblastic cords, mononuclear cell focuses, erythrocytes, and some heterophils (48-72 h) could be observed. Finally, predominance of fibroblast proliferation was noted.

Animals↗

PubMed1991

[Morphobiology and pathogenicity of Eimeria falciformis var. pragensis Cerna, Seraud, Mehlhorn & Scholtyseck, 1974 in mouse (Mus musculus)].

The life cycle of a species of murine Eimeria, isolated from a commercial source of mice is described using experimental infections. A pure strain was established starting from a single oocyst administered to Eimeria-free Swiss white mice. The prepatent period was 6 1/2 to 7 days, and the patent period lasted 6 to 10 days. Oocysts were subspherical or ovoid, with a smooth double-layered colourless membrane. Micropila was absent. The sporulated oocysts measured 15.7-25.1 x 14.1-22.0 microns (X780 = 21.3 x 16.9 microns). One to 4 polar granules were present. The oocyst residuum was absent. Sporocysts were ellipsoid, measured 11.5 x 6.3 microns (n = 780), with Stieda body and a compact subspherical sporocyst residuum. The sporozoites were elongated, 17.7 x 3.2 microns (n = 100), partially curled around each other. The endogenous stages were found only in the large intestine, with at least 4 generations of schizonts. Mature 1st generation schizonts, first seen 24 hr post-infection (HPI) measured 10.3 x 10.6 microns and had 8 to 25 merozoites 5.0-10.0 x 1.0-3.0 microns. Mature 2nd generation schizonts were first seen 48 HPI, measured 14.4 x 8.1 microns and had 8 to 20 merozoites 11.0-16.0 x 2.0-3.0 microns. Two forms of presumably 3rd generation schizonts appeared between 72 and 96 HPI: one measuring 13.9 x 8.5 microns, containing large merozoites (17.0-19.0 x 2.0-4.0 microns) and the other measuring 7.3 x 10.4 microns, where 6 to 10 merozoites (8.0-13.0 x 1.0-3.0 microns) were found. Fourth generation schizonts measuring 10.4 x 11.9 microns, with 26 a 48 or more merozoites (8.0-13.0 x 2.0-3.0 microns) were first seen at 132 HPI. Mature macro and microgamonts were first observed at 144 HPI. The sporulation of 72.0% of the oocysts in 2.0% (w/v) potassium dichromate at 23-24 degrees C occurred in 9 days. Usually the infected mice showed depression, anorexia, weight loss, diarrhea or dysentery, and dehydration. The clinical picture w as more pronounced at 6 to 10 days post-infection (DPI). Mortality was highest between the 8th and 13th DPI, with a peak at 9 DPI in groups which received 1.1 x 10(4) to 4.4 x 10(4) oocysts. Groups infected with 5.5 x 10(3), 8.8 x 10(4) or 1.76 x 10(5) oocysts showed different results. Epithelial destruction, edema, inflammation, necrotizing enteritis followed by glandular regeneration and realing were observed restricted to the large intestine. The isolated Eimeria was named E. falciformis var. pragensis based on its morphobiological characteristics.

Animals↗

PubMed1990

Chronically inflamed tissue activates plasma mediators of vascular permeability.

1. After inflammation was induced in the foot-pad of rats with nistatin or BCG, injection of "non-activated" homologous plasma at the inflamed site caused a significant increase in the vascular permeability of the lesions (Evans blue test), which was more intense in older lesions, increasing from 7.83 +/- 1.11 to 8.70 +/- 1.18 (nistatin, 4 and 21 days) and 7.30 +/- 0.66 to 7.54 +/- 0.80 (BCG, 4 and 21 days). 2. Steroidal (acetyltriamcinolone, 2 mg/kg) and non-steroidal (indomethacin, 25 mg/kg) [corrected] anti-inflammatory drugs markedly decreased this effect on 14-day old lesions induced by nistatin plus "non-activated" plasma (2.37 +/- 0.10 for acetyltriamcinolone treatment vs 8.15 +/- 1.22 for untreated animals; 3.34 +/- 0.41 for indomethacin treatment vs 8.15 +/- 1.22 for untreated animals) and BCG plus "non-activated" plasma (1.67 +/- 0.11 for acetyltriamcinolone treatment vs 10.27 +/- 0.52 for untreated animals; 5.87 +/- 0.35 for indomethacin treatment vs 9.14 +/- 0.23 for untreated animals). 3. These data suggest that an increase in exudation in chronic lesions might result in "reactivation" of the process as observed clinically, for example, in rheumatoid arthritis in man.

Animals↗

PubMed1989

Do connective tissue components induce plasma activation in vivo?

1. This paper describes the effect of homologous plasma in contact with connective tissue on vascular permeability, edema and cell migration. 2. The contact of "non-activated" plasma with connective tissue structures does not result in generation of mediators responsible for increase in vascular permeability or in edema. 3. "Activated" plasma is able to induce vascular permeability and edema when in contact with connective tissue components. 4. Injection of "non-activated" or "activated" plasma induced a mild inflammatory cell migration.

Animals↗