Nivaldo da Silva

Coagulase gene polymorphism of Staphylococcus aureus isolated from goat mastitis in Brazilian dairy herds.

Aims:  To investigate the coagulase gene polymorphism of Staphylococcus aureus isolated from mastitic goats milk.

Detecção da toxina-1 da síndrome do choque tóxico em amostras de Staphylococcus aureus isoladas de mastite bovina

A total of 127 strains of Staphylococcus aureus were examined for the production of toxic shock syndrome toxin (TSST-1) and staphylococcal enterotoxins (SE) A, B, C and D. The strains were isolated from milk samples from cows with mastitis in dairy herds of Minas Gerais State, Brazil, from 1994 to 1997. The toxins were detected using the optimum-sensitivity plate method. Of 127 isolates, 60 (47%) produced TSST-1 and 54 (43%) produced SE, 38 (30%) produced SED, 24 (19%) SEB, 8 (6%) SEC and 4 (3%) enterotoxin A..

Antibioticoterapia para controle da mastite subclínica de vacas em lactação

The efficiency of antibiotic therapy to control subclinical mastitis in lactating cows was evaluated. Eighty three udder quarters with subclinical mastitis from three dairy herds were treated with 250mg of cephalothin by intramammary doses. Group 1 included 16 cows in lactation, 15 to 100 days in milk and group 2 included 23 cows in lactation, 101 to 200 days in milk. Therapeutic success was controlled with bacteriological examinations, somatic cells counts (SCC), California Mastitis Test (CMT) and milk production on days zero, 14, 25 and 40 after treatment. Fourteen cows with 28 infected udder quarters were maintained as a control. Staphylococcus aureus and coagulase-negative Staphylococci were the most prevalent microorganism among bacterial isolates. Other pathogens as Bacillus spp, Corynebacterium bovis, Streptococcus uberis and Escherichia coli were present. Concerning bacteriological healing the intramammary therapy reached a 61.4% elimination rate of pathogenic bacteria at the 14th day post treatment. SCC and CMT reactions were decreased too. However, 40 days post-treatment the differences were not significant (P> 0.05). No differences among treated groups before and after intramammary treatment (P> 0.05) on milk production were observed. Antibiotic treatment of lactating cows with subclinical mastitis was not efficient for controlling the udder infections.

Mastite por leveduras em bovinos leiteiros do Sul do Estado de Minas Gerais, Brasil

The objective of this study was to report the frequency of intramammary infections by yeasts, in Minas Gerais State, from milk samples (n = 1710) collected in 40 dairy herds. Fifty six yeast strains of the genus Candida and one strain of Trichosporon loubieri were isolated. Candida albicans was the dominant species (28.1% of the strains), followed by Candida parapsilosis (19.3%), Candida catenulata (14.0%), Candida glabrata (14.0%), Candida tropicalis (8.8%). Mixed infections were detected in 29.8% of yeast-positive cows. The yeast infection was more frequent (84%) in cows with subclinical mastitis. The low rate of isolation of yeasts suggests that these microorganisms are not relevant to bovine mastitis in the studied region.

Isolamento e teste de susceptibilidade a antimicrobianos de bactérias em infecçöes uterinas de éguas

This study examined 206 cervical and uterine swabs collected from infected mares from herds in the Minas Gerais State, Brazil, from 1986 to 1996. Amongst 164 successful isolations, 25.7% were identified as Streptococcus equi, subsp. zooepidemicus, and 15.1% as Escherichia coli, both considered the most important isolates. Other bacteria found included Staphylococcus aureus (9.2%), Streptococcus a-hemolytic (9.2%), Pseudomonas aeruginosa (3.9%), coagulase negative Staphylococcus (6.3%), Bacillus spp. (1.9%), Rhodococcus equi (3.4%) and Proteus mirabilis (1.5%). The antibiotic susceptibility tests revealed amikacin and gentamicin (70.2%), ampicillin and chloramphenicol (59.5%) as the most effective in vitro antibiotics against these microorganisms.

Avaliação da qualidade microbiológica do leite UAT integral comercializado em Belo Horizonte

Samples of UHT whole milk from eight different trademarks commercialized in Belo Horizonte, Brazil were examined for microbiological aspects from January to April, 1999. Of 80 milk samples, 33 (41.2%) showed high viable of aerobic mesophilic counts ranging from 1.3´104 to 1.4´105 CFU/ml (4.1 e 5.1 log CFU/ml) and were in disagreement with from Ministry of Agriculture of Brazil Official Microbiological Standards (RTIQ). Of 174 isolated microorganisms, 162 (93.0%) belonged to genus Bacillus, 3 (1.7%) were Micrococcus, 9 (5.2%) were Gram positive pleomorphic rods without spores. The last bacteria were suggestive of Corynebacterium like-organisms, however they were not classified as such. It was concluded that the UHT whole milk commercialized in Belo Horizonte does not fit the microbiological aspects set by RTIQ, when applied to the retail sale. Bacteria from Bacillus genus were the most isolated.

Detection of toxic shock syndrome toxin 1 in Staphylococcus aureus strains isolated from cases of bovine mastitis.

A total of 127 strains of Staphylococcus aureus were examined for the production of toxic shock syndrome toxin (TSST-1) and staphylococcal enterotoxins (SE) A, B, C and D. The strains were isolated from milk samples from cows with mastitis in dairy herds of Minas Gerais State, Brazil, from 1994 to 1997. The toxins were detected using the optimum-sensitivity plate method. Of 127 isolates, 60 (47%) produced TSST-1 and 54 (43%) produced SE, 38 (30%) produced SED, 24 (19%) SEB, 8 (6%) SEC and 4 (3%) enterotoxin A..

Estudo epidemiológico de problemas reprodutivos em rebanhos bovinos na bacia leiteira de Goiânia

An epidemiological study was carried out on 2823 cows from 34 dairy herds from Goiania in the State of Goias-Brazil during 2001 to 2002. The pregnancy rate was 47.8%. In 1473 non-pregnant cows, causes of reproductive failure problems were sought. The most prevalent uterine infection was endometritis (17.0%). Uterine disorders such as partial hypoplasia of the genital system (0.04%), macerate fetus (0.01%), adhesion of ovaries (0.04%), stillbirth (0.04%), retained placenta (0.01%), cervix inflammation (0.6%) and abortion (0.88%) also were found. Uterine swabs were collected aseptically for microbiological culture. Gram positives cocci (41.3%) and Gram negatives rods (52.6%) were found, and Staphylococcus aureus and Escherichia coli were the most prevalent pathogens. Susceptibility patterns of microorganisms suggested the use of chloramphenicol, gentamicin and neomycin for antimicrobial therapy.

Identificação e susceptibilidade a antimicrobianos de Staphylococcus spp. isolados de cães com otite externa crônica

Swab samples obtained from 96 dogs with chronic otitis externa were cultured for the isolation of Staphylococcus species. Of 57 staphylococcal strains, 41 (72%) were coagulase-negative (CNS). The identification of staphylococci strains was made by standard procedures for the routine identification of staphylococci in clinical practice. S. sciuri was the most frequent species isolated (22.8%) from chronic otitis externa in dogs followed by S. intermedius (12.3%), S. auricularis (10.5%) and S. aureus (8.8%). Three (5.2%) CNS strains could not be identified. Bacterial isolates were susceptible to enrofloxacin, gentamicin, cephalothin, chloramphenicol and neomycin. Resistance was most common to penicillin G, oxacillin and ampicillin.

Determinação do perfil protéico da membrana externa da Leptospira interrogans sorovariedade Hardjoprajitno

The protein profile of the outer membrane of Leptospira interrogans serovar Hardjoprajitno was determined by two-dimensional gel electrophoresis. The outer membrane was extracted with Triton x 114 and the proteins were precipitated with acetone. The images were analyzed for the determination of the molecular weight of the detected proteins. Thirty-five spots for the proteins that are predominant in the outer membrane of this Leptospira were observed and five proteins were found in higher quantities: 22.54KDa (LipL22), 30/26KDa (LipL32), 34.41KDa (PME34) (2), 42.75KDa (LipL41), and 58.59KDa (LipL63).