INTRAGASTRIC INFECTION OF CONVENTIONAL AND GERM-FREE MICE WITH GIARDIA-LAMBLIA

The effects of experimental infection with Giardia lamblia were studied in 30-day old conventional and germfree CFW mice (7 animals in each group) of both sexes. Cysts were observed in the feces of both groups 6 to 7 days after intragastric infection of each animal with about 2.5 x 10(5) G. lamblia trophozoites. Fecal cyst level was statistically higher in germfree mice (about 10(5) cysts/g feces) when compared with the conventional group (about 10(4) cysts/g feces). The peak of infection in the conventional group apparently occurred on the 10th day after infection as indicated by an increase of fecal weight and by histopathological examination. Intense infiltration of the lamina propria and high reactional hyperplasia of the lymphoid component were observed in the conventional group. There was no infiltration or hyperplasia in germfree infected mice and fecal weight was relatively constant throughout the experiment. These results suggest that, as is the case for other intestinal pathogenic protozoa, the intestinal microflora is indispensable for the expression of the pathogenicity but not for the multiplication of G. lamblia.

Prevalência de Cryptosporidium sp. em cães de instituições da cidade de São Paulo

Objective Dogs play an important role as infection source of human cryptosporidiosis. The objective of the study was to determine the prevalence of Cryptosporidium sp. in dogs as well as to compare two techniques of fecal analysis.Methods Four-hundred and fifty canine fecal samples from the city of São Paulo were analyzed between 2003 and 2004. Fecal samples were randomly selected from dogs housed in a university veterinary hospital (group 1, n=200) and private kennels (group 2, n=250). The detection of Cryptosporidium was performed using modified Ziehl-Neelsen staining and Polymerase Chain Reaction (PCR) technique. Statistical analysis was performed using the two-tailed test of significance at 5% confidence interval (z critical=+/- 1.645).Results Only Cryptosporidium parvum oocysts were found the prevalences found by light microscopy examination and PCR techniques were 8.8% and 9.5%, respectively. Young animals showed a lower frequency (5.5%) compared to adults (10.1%). There was no statistically significant difference in Cryptosporidium prevalence between males and females.Conclusions the prevalence of C. parvum in the canine population studied was similar to that one found in the literature and affects equally males and females. The use of PCR allowed the detection of more positive cases than light microscopy.

PATHOGENIC OR POTENTIALLY PATHOGENIC BACTERIA AS CONTAMINANTS OF FRESH-WATER FROM DIFFERENT SOURCES IN ARARAQUARA, BRAZIL

The microbiological quality of various fresh waters in the Araraquara region, state of São Paulo, Brazil was investigated. Ninety-nine water samples were taken from rivers, reservoirs, artesian and non-artesian wells, springs and tap waters, and these waters were analysed using: plate counts of heterotrophic microorganisms (per 1 ml); Most Probable Number (MPN) of fecal coliforms and E. coli (per 100 ml); tests for presence of Salmonella, Shigella, Yersinia, the E. coli pathogens of classes EPEC, ETEC and EIEC and Mycobacterium, Shigella, Yersinia and enteroinvasive E. coli (EIEC) were not isolated. The other types of microorganisms were isolated in varying proportions. We conclude that the waters investigated represent a potential microbiological health risk.

Skin hypersensitivity tests in buffaloes parasitized with Toxocara vitulorum.

Skin tests were done using larval extract and excretory-secretory (ES) antigens injected intradermally in the neck area of 30, 11- to 200-day-old buffalo calves and nine 27- to 100-day postparturition buffalo cows, the skin of the buffaloes infected with Toxocara vitulorum, mainly calves, demonstrated a hypersensitive response to antigens, especially to the larval extract antigens. Skin hypersensitivity responses were characterized by the presence of dermal nodules with progressive induration and an increase of up to four times the size of the original area at 30 min (immediate type) and at 72 h (delayed type) after injection, Histological preparations of skin reactions at 72 h showed a typical mononuclear cell infiltration, with eosinophils and perivascular cuffing in most of the animals, Fecal examination of 75 animals showed that 65 (86.7%) buffalo calves (9-115 days old) were parasitized with T. vitulorum. The peak of egg output from these animals occurred when they were approximately 45 days old.

Estimativas do Consumo e da Taxa de Passagem do Capim-Elefante (Pennisetum purpureum Schum.) sob Pastejo de Vacas em Lactação

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Food intake and digestive efficiency in temperate wool and tropic semi-arid hair lambs fed different concentrate: forage ratio diets

This work was conducted to evaluate food intake and digestive efficiency of temperate wool and tropic semi-arid hair lambs, according to different concentrate: forage ratios in diet. Twenty-four lambs, averaging 90 +/- 1.8 days old and a mean body weight of 20 +/- 0.69 kg, 12 of them wool lambs, F, from Ideal x Ile de France crossing, and 12 others pure Santa Ines hair lambs, were distributed into a four replication 3 x 2 factorial arrangement consisting of three diets and two genotypes. Experimental diets consisted of: D1 = 60% concentrate mix (C) and 40% Cynodon sp. cv. Tifton-85 hay (F), D2 = 40% C and 60% F, and D3 = 20% C and 80% F. D1 was formulated for a daily gain of 300g per animal. Increasing forage levels in diets resulted in linear reductions (P < 0.01) in DM, OM, CP, TCH and metabolizable energy (ME) intake, and a linear increase (P < 0.01) in NDF ingestion. Tropic semi-arid hair lambs had higher DM, OM, NDF, CP, and TCH intake than temperate wool lambs. Although there were no genotype effects in OM and GE coefficient of digestibility, hair lambs showed more efficient (P < 0.05) digestibility of DM, CP, NDF and TCH. Increases in forage levels of diets corresponded to a negative linear effect (P < 0.01) in the apparent digestibility of DM, OM, CP, TCH and GE, while apparent digestibility of NDF increased linearly (P < 0.01). Total endogenous nitrogen (fecal plus urinary N) for F(1) Ideal x Ilede France wool and Santa Ines hair lambs were, respectively, 182 and 312 mg/kg(0.75) per day. Thus, Santa Ines tropic semi-arid hair lambs showed to be more responsive than F(1) Ideal x Ile de France temperate wool lambs to low quality fibrous diets. (C) 2004 Elsevier B.V. All rights reserved.

Yeasts and others parameters of pollution of the Ribeirao Claro stream in Rio Claro, São Paulo

The main water source of the Rio Claro municipal district (DAAE) was analysed for determining the level of organic contamination. Temperature, pH, light penetration, conductivity, dissolved oxygen, total dissolved phosphate, ortophosphate, ammonia, heterotrofic bacteria, total coliforms, fecal coliforms, total yeasts and fermentative yeasts were analysed during one year with samples being collected on a monthly basis. Bathing quality of the water from sites 1, 2 and 3 were classified, respectively, as Satisfactory, Very Good and Improper based on fecal coliform counts. Total yeast counts were appropriate as a complement for the appraisal of fresh water contamination by coliform counts. Seventeen yeast species belonging to genera Candida, Cryptococcus, Kloeckera, Pichia and Rhodotorula were found but none of them could be correlated with a level of contamination. Candida famata, C. robusta-like and C. colliculosa were isolated at all of the sites and between the five species found only at the more polluted site, Rhodotorula mucilaginosa was prevalent.

Regulation of contextual conditioning by the median raphe nucleus

The median raphe nucleus (MRN) has been suggested as the origin of a behavioral inhibition system that projects to the septum and hippocampus. Electrical stimulation of this mesencephalic area causes behavioral and autonomic manifestations characteristic of fear such as, freezing, defecation and micturition. In this study we extend these observations by analyzing the behavioral and autonomic responses of rats with lesions in the MRN submitted to a contextual conditioning paradigm. The animals underwent electrolytic or sham lesions of the median raphe nucleus. One day (acute) or 7 days (chronic) later they were tested in an experimental chamber where they received 10 foot-shocks (0.7 mA, 1 s with 20-s interval). The next day, sham and MRN-lesioned animals were tested again either in the same or in a different experimental chamber. During this, the duration of freezing, rearings, bouts of micturition and number of fecal boli were recorded. Sham-operated rats placed in the same chamber showed more freezing than rats exposed to a different context. This freezing behavior was clearly suppressed in rats with acute or chronic lesions in the MRN. MRN lesions also reduced the bouts of micturition and number of fecal boli. These rats showed a reduced number of rearings than sham-lesioned rats. This effect is probably the result of the displacement effect provoked by freezing since no significant differences in the number of rearings could be observed between these animals and the NMR-lesioned rats tested in an open field. This lesion produced higher horizontal locomotor activity in this test than the controls (sham-lesioned rats). These results point to the importance of the median raphe nucleus in the processing of fear conditioning with freezing being the most salient feature of it. Behavioral inhibition is also under control of MRN but its neural substrate seems to be dissociated from that of contextual fear. (C) 1998 Elsevier B.V. B.V.

Investigação de parasitoses e/ou comensais intestinais em manipuladores de alimentos de escolas públicas

The objective of this work was to identify intestinal parasites and/or commensals among food handlers of public schools in the city of Patos of Minas (MG). The fecal samples were analyzed by Lutz's method (1919). The positive results were 21.7% (13 cases) for parasites and/or commensal. The frequence of intestinal parasites and/or commensal of food handlers in the public schools showed low positive, probably as a result of good habits of personal hygiene and prophylactic treatment of parasitic.

Passive Immunity of Progeny from Broiler Breeders Vaccinated with Oil-Emulsion Bacterin Against Salmonella Enteritidis

Young poultry are very susceptible to Salmonella Enteritidis (SE) infections because of the absence of complete intestinal flora colonization and an immature immune system. This study evaluated the role of passive immunity on the resistance of young birds against early infections caused by SE. The progeny of broiler breeders vaccinated with an oil-emulsion bacterin was compared to the progeny of unvaccinated birds. Efficacy was determined by challenging birds at 1 and 14 days of age with SE Nal Spc strain, phage type 4. After challenge at 1 day of age, the progeny of vaccinated birds presented a significantly lower number (log(10)) of SE Nal Spc reisolation (P < 0.05) in liver (2.21), spleen (2.31), and cecal contents (2.85) compared with control groups (2.76, 3.02, and 6.03, respectively). The examination of the internal organs, 3 days after infection, revealed that 28% of the birds (7/25) from vaccinated breeders were positive, whereas 100% (25/25) of the chicks derived from unvaccinated birds were positive. Birds challenged at 14 days of age presented a lower number of positive samples compared with those challenged at 1 day of age, and the progeny of vaccinated birds presented statistically lower numbers (log(10)) of colony-forming units/ml of SE Nal Spc only in the cecal contents compared with nonvaccinated breeder progeny (2.11 vs. 2.94). Age seems to influence the susceptibility of birds to SE infections: in control groups, the number of positive birds at 14 days of age (9/25) was lower when compared with the group infected at 1 day of age (25/25). The number of positive fecal samples of the progeny of vaccinated birds was significantly lower (36) than those of the control group (108) after challenge at 1 day of age. Unchallenged progeny of vaccinated birds presented passive antibodies detectable by enzyme-linked immunosorbent assay (ELISA) up to 21 days of age. on the other hand, antibodies of the control group were detected by ELISA 14 days after challenge. These results show a significant contribution of breeder vaccination by increasing the resistance of the progeny against early SE infections. However, the bacteria were not completely eliminated, suggesting that additional procedures are needed to effectively control SE infections.

Physical, epidemiological, and molecular evaluation of infection by Cryptosporidium galli in Passeriformes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Natural Infection with Cryptosporidium galli in Canaries (Serinus canaria), in a Cockatiel (Nymphicus hollandicus), and in Lesser Seed-Finches (Oryzoborus angolensis) from Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparison of two methods of synchronization of estrus in brown brocket deer (Mazama gouazoubira)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Genetically Diverse Coronaviruses in Captive Bird Populations in a Brazilian Zoological Park

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fatores de riscos associados à ocorrência de helmintos gastrintestinais em cabras leiteiras mantidas em sistema de pastejo

Infection due to the gastrointestinal nematodes can negatively interact with the productive performance of dairy goats, and in some cases can induce mortality in the flocks. The objective was to study the influence of season, parturition order, postpartum, lactation and breed standard on the population of helminths in dairy goats. 31 goats were used, with 15 Saanen and 16 F1 (1/2 Boer + 1/2 Saanen). of these, 13 were from the 1st lactation and 18 from the 2nd or more lactations. The highest fecal egg counts occurred during the summer and spring, with FEC in Saanen higher (p < 0.01) than in F1 animals (1/2 Boer + 1/2 Saanen). The animals with 1st lactation showed higher FEC (p < 0.004) than the animals in 2nd or more lactation. During the peripartum the largest FEC for both breeds standards were in the week of the birth (p < 0.05), followed by post-partum and pre-partum. In peripartum the Saanen goats showed higher FEC (p < 0.02) than the F1 and primiparous (p < 0.008) in relation to pluriparous. F1 animals are resistant to helminthes when compared to Saanen animals, demonstrating that crossing of resistant breeds with high production breeds is a viable alternative to increase productivity without compromising the parasitary stability of the herd. The peripartum period is a risk factor associated to the occurrence of gastrointestinal helminths, especially in Saanen goats from first lactation.