Isolamento de Yersinia pseudotuberculosis de fezes de búfalo (Bubalus bubalis)

Fecal samples from 119 healthy buffaloes, from 5 farms, diluted in 10% brain heart infusion, were maintained for 3 weeks at 4°C and subcultured weekly onto Mac Conckey agar and Yersinia selective agar with antimicrobial supplement. Yersinia pseudotuberculosis serotype Olll was isolated from only one farm, where an outbreak of yersiniosis was occurring. The bacteria was isolated in 21 of the 25 samples from adult, healthy females and in all the 9 samples from healthy calves. It was not isolated in the samples from other farms, 2 especially, where yersiniosis had been diagnosed 1 and 5 years before. Of the 30 isolates, 14 (46.7%) were recovered from both culture media, one (3.3%) only in Mac Conckey and 15 (50%) only in Yersinia selective agar. Of the 15 isolates recovered in Mac Conckey, 12 (80%) were isolated after 1 week of cold enrichment, 3 (20%) after 2 weeks and none after 3 weeks. Of the 29 isolates recovered in selective Yersinia agar, 22 (75.1%) were isolated after 1 week of cold enrichment, 6 (20.7%) after 2 weeks and 1 (3.4%) after 3 weeks.Amostras de matérias fecais de 119 búfalos clinicamente sadios, de 5 propriedades, foram colocadas em enriquecimento a 10% em infusão de cérebro e coração por 3 semanas e semeadas semanalmente em meio seletivo para Yersinia spp (Yersinis Selective Agar com Yersinia Antimicrobial Supplement) e em agar Mac Conckey. Yersinia pseudotuberculosis sorotipo Olll foi isolada somente em amostras de uma propriedade em que estava ocorrendo um surto de yersiniose. A bactéria foi recuperada de 21 amostras de um total de 25 amostras de fêmeas adultas sadias e de todas as 9 amostras de bezerros sadios. Y. pseudotuberculosis não foi isolada das demais propriedades, incluindo2 naquelas em que haviam sido diagnosticados surtos de yersiniose 1 e 5 anos antes da coleta. Dos 30 isolamentos, 14 (46,7%) foram isolados nos 2 meios de cultura, 1 (3,3%) somente em agar Mac Conckey e 15 (50%) somente em meio seletivo, demonstrando a maior eficiência deste meio para a identificação de animais portadores. Dos 15 isolamentos obtidos em Mac Conckey, 12 (80%) foram isolados após 1 semana de crioenriquecimento, 3 (20%) após 2 semanas e nenhum após 3 semanas. Dos 29 isolamentos obtidos em meio seletivo, 22 (75,1%) foram isoladosapós 1 semana, 6 (20,7%) após 2 semanas e 1 (3,4%) após 3 semanas

Livestock preference for endophyte-infected or endophyte-free Oxytropis sericea, Ipomoea carnea, and Ipomoea asarifolia

Fungal endophyte-infected forages have been shown to alter herbivore feeding preferences. The objective of this experiment was to compare the preference of cattle, sheep, and goats for plants containing (E+) and not containing (E-) fungal endophytes using freshly harvested Oxytropis sericea, Ipomoea carnea, and Ipomoea asarifolia. Goats and sheep rejected all forage choices regardless of endophyte status except for grass and alfalfa hay. Endophyte status had no influence on cattle forage preferences. Cattle rejected all Oxytropis sericea E+ and E- choices. Cattle discriminated between Ipomoea species, preferring Ipomoea carnea to Ipomoea asarifolia (P = 0.004). In all comparisons, Ipomoea carnea was selected over Ipomoea asarifolia. Cattle did not discriminate between E+ and E- plants of either species (P \u3e 0.33). Cattle preferred E+ Ipomoea carnea over E- Ipomoea asarifolia (P = 0.03), E- Ipomoea carnea over E- Ipomoea asarifolia (P = 0.003), E- Ipomoea carnea over E+ Ipomoea asarifolia (P = 0.001), and E+ Ipomoea carnea over E+ Ipomoea asarifolia (P = 0.01). Nutritional composition, including nonstructural carbohydrate concentrations, did not explain cattle preferences, as Ipomoea asarifolia contained higher total carbohydrate concentrations than did Ipomoea carnea. The presence of ergot and indole diterpene alkaloids in E+ Ipomoea asarifolia, or swainsonine in E+ Oxytropis sericea and E+ Ipomoea carnea did not influence cattle preference because cattle did not discriminate between E- and E+ plants. This study suggests that for these specific toxic plants, endophyte status plays no part in preferences of grazing cattle. For grazing animals, selection by livestock is related to forage scarcity or low nutrient content in the other available forage

Poisoning by Marsdenia hilariana and Marsdenia megalantha (Apocynaceae) in ruminants

AbstractNeurological signs were observed in cattle consuming the roots of Marsdenia hilariana and sheep consuming leaves of Marsdenia megalantha. Similar nervous signs to those observed in spontaneous poisoning were induced experimentally by the administration of roots of M. hilariana to goats, and by the administration of leaves and roots of M. megalantha to sheep. No lesions were observed at necropsies and on histological examination of the nervous system and other tissues

Detection and Characterization of Bovine Rumen Microorganisms Resistant to Sodium Fluoroacetate

Background: Poisoning of animals due to toxic plants is found in Brazil and other countries. One of the known toxic plants in Brazil, with the active ingredient sodium fluoroacetate (SF), is Palicourea marcgravii. Dehalogenases that inactivate the fluor-carbon bonds are enzymes found in microorganisms and may prevent intoxication. This study evaluated the occurrence of rumen microorganisms naturally resistant to SF.Materials, Methods & Results: Two samples of rumen fluid of cattle from the Experimental Farm of Federal University of Mato Grosso fed with Brachiaria sp. were obtained via fistula in flasks. An aliquot of 2 mL was placed in a microtube and centrifuged at 9000 g for 1 min. Then, the sample was inoculated into 2 tubes, one containing 100 µL of clarified rumen fluid in 2 mL of modified liquid culture medium (0.1% ammonium sulfate, 0.1% potassium phosphate monobasic, 0.05% sodium phosphate dibasic, 0.01% magnesium sulfate, 0.01% yeast extract, pH 7.0) and 0.4% of SF and the other sample containing 2 mL of liquid culture medium and 100 µL of clarified rumen fluid. The 2 samples were incubated at 40°C for 24 h. Dilutions were performed under the same conditions every 24 h until the attainment of microorganisms resistant to SF, and the finaldilution containing 50 µL of each sample was plated in the middle containing SF (0.4%) and incubated at 40°C for 24 h for the isolation of bacteria. The bacterial colonies resistant to SF were identified by morphological methods, stained, and subjected to DNA extraction sequencing using the universal primers 27f and 1492r (16S rDNA) for the identification of the bacterial genus using Blast DNA identity analysis. These bacteria were cultured with and without SF (0.4%), and the presence of fluoride ions was detected by an ion-selective electrode (fluoride) during incubation for 0, 30, 60, 90, and 120 min. Two resistant microorganisms were isolated, one was a Gram-positive coccus and the other was a Gram-positive rod. DNA sequencing identified these organisms as Enterococcus faecalis (98% identity Genbank 1358689) and Bacillus sp. (89% identity Genbank 1358671). Fluoride ions were detected more at 60-min incubation time in both E. faecalis (0.0560 ppm) and Bacillus sp. (0.0488 ppm). Bioassay protection tests were performed in mice ofthe following four groups: negative control (NC) with saline administration, positive control (PC) with administration of plant containing SF, Bacillus group (BG) with administration of plant containing SF plus Bacillus sp., and coccus group (CG) with administration of SF and E. faecalis. Clinical signs were recorded, and statistical analyses were performed to confirm the differences in the groups. Bioassay protection tests showed clinical signs of intoxication in the PC group (83.3%), BG group (100%), and CG group (16.6%) but not in the NC group (0%), with a statistical difference between GC and PC groups (P < 0.05).Discussion: Several environmental bacteria possessing dehalogenase activity have been described, such as Pseudomonas sp., Moraxella sp., and Burkholderia sp. and Pigmentiphaga kullae and Ancylobacter dichloromethanicus isolated from the rumen. No previous study has yet reported an association between dehalogenase activity and E. faecalis, and the protection assay has been observed only in the E. faecalis group. Similar results were observed in experimental intoxication in goats that had previously consumed SF, with the microorganisms identified being Pigmentiphaga kullae and Ancylobacter dichloromethanicus. E. faecalis, isolated from the bovine rumen, exhibited a dehalogenase activity, which could help control animal poisoning by plants containing SF

Arthrogryposis in Murrah buffaloes in southern Brazil

Congenital arthrogryposis is described in a Murrah buffalo herd. The disease was characterized by curvature and multiple articular rigidity of the hindlimbs or of all limbs without associated defects except for one case of brachygnatia. Histologically there was reduction of motor neurons from the ventral horns of the spinal cord and hypoplasia of the limb muscles. Analysis of the herd breeding records suggests that the disease is genetically transmitted by an autosomal recessive trait.Facultad de Ciencias Veterinaria

Congenital Cerebellar Cortical Degeneration in Holstein Cattle in Southern Brazil

A congenital progressive cerebellar disorder is described in Holstein calves. The clinical signs were progressive and were characterized by ataxia, hypermetria, a wide stance and fine head tremors. When the affected cattle were forced to run, the signs were exacerbated, leading to epileptiform attacks. Histological lesions consisted of a very selective cerebellar cortical degeneration, almost exclusively affecting the Purkinje cells. The disease affected 6 out of 200 Holstein calves from the same bull. However, results of mating tests of the bull with his daughters and granddaughters suggested that it was not hereditary (p = 0.0062) although an environmental–genetic interaction could not be ruled out.Facultad de Ciencias Veterinaria

Molecular prevalence of Coxiella burnetii in bulk-tank milk from bovine dairy herds :systematic review and meta-analysis

Coxiella burnetii is an obligate intracellular zoonotic bacterium that causes Q fever. Ruminants, including cattle, are broadly known to be reservoirs for this bacterium. Since 2006, many research groups have evaluated the herd-level prevalence of C. burnetii in cattle by molecular techniques on composite milk samples. This study explored the global C. burnetii herd-level prevalence from studies done on bovine bulk-tank milk (BTM) samples using PCR-based analysis. Also, moderators were investigated to identify sources of heterogeneity. Databases (CAB Abstracts, Medline via Ovid, PubMed, Web of Science and Google Scholar) were searched for index articles on C. burnetii prevalence in BTM samples by PCR published between January-1973 and November-2018. Numerous studies (1054) were initially identified, from which seventeen original publications were included in the meta-analysis based on the pre-defined selection criteria. These studies comprised 4031 BTM samples from twelve countries. A random-effects model was used because of considerable heterogeneity (I2 = 98%) to estimate the herd-level prevalence of C. burnetii as 37.0%(CI95%25.2–49.5%). The average herd size appeared to account for a high level of the heterogeneity. No other moderators (geographic location, gross national income or notification criteria for Q fever) seemed to be determinant. This systematic evaluation demonstrated a high molecular prevalence of C. burnetii in BTM samples both in European and non-European countries, evidencing a widespread herd-level circulation of this agent in bovine dairy farms around the world. Meta-regression showed herd size as the most relevant moderator with the odds of a BTM sample testing positive doubling with every unit increase