Surto de mastite bovina causada por Arcanobacterium pyogenes

An uncommon outbreak of mastitis caused by Arcanobacterium pyogenes in 26 cows is reported. The epidemiological findings, clinical signs, microbiological exams, somatic cell count, in vitro susceptibility profile of strains, efficacy of intramammary treatment and control measures were discussed. Florfenicol (96.2%), cefoperazona (92.3%), cefaloxin (84.6%) and ceftiofur (84.6%) were the most effective antimicrobials, and neomicin (27.0%) and enrofloxacin (17.4%) the least effective antimicrobials.

Breed and season influence on milk quality parameters and in mastitis occurrence

Os objetivos do presente estudo foram avaliar a performance das raças Jersey e Holandesa em diferentes condições de pluviosidade (estações seca e chuvosa) através do monitoramento de aspectos relacionados com a mastite subclínica (contagem de células somáticas, isolamento microbiológico, tipo de patógeno isolado), qualidade do leite (lactose, proteína, gordura e sólidos totais) e produção (media da produção de leite) de ambas as raças. O estudo foi conduzido em propriedade leiteira localizada no estado de São Paulo, Brasil. Oito visitas foram realizadas a propriedade, quatro em período de alta pluviosidade e outro em período de baixa pluviosidade. Amostras de leite foram colhidas de todos os animais para contagem eletrônica de células somáticas e determinação dos principais componentes do leite (proteína, gordura, sólidos totais, lactose). Gordura, proteína, sólidos totais e produção leiteira foram influenciadas tanto pela raça como pela estação, apresentando tendências similares para ambas raças em ambas estações. A contagem de células somáticas (CCS) apresentou resultados similares para ambas as raças. Vacas holandesas com infecção intramamária (IIM) apresentaram um maior aumento na CCS quando comparadas as vacas Jersey (P<0.001). Na estação seca, 53 animais tiveram IIM em pelo menos um mês do estudo. Destes, 32 eram da raça Holandesa e 21 da raça Jersey. Na estação chuvosa, 65 animais possuíram infecção intramamária, dos quais 43 eram da raça Holandesa e 22 da raça Jersey. A frequência de casos de IIM foi maior na estação chuvosa em comparação à estação seca. Vacas Jersey apresentaram uma menor chance de desenvolver sinais e sintomas de IIM em relação às vacas holandesas na estação chuvosa (razão de chances=0.52). O maior numero de casos de IIM na estação chuvosa pode ter contribuído para uma menor taxa de lactose no leite para ambas as raças, sendo que esta pode ser considerada como um indicador do status de IIM. Existiu uma prevalência de patógenos contagiosos durante todo o experimento. O modelo estatístico aplicado mostrou que patógenos ambientais foram mais frequentemente isolados da raça Jersey, independentemente do período do estudo. Aparentemente existem diferenças na resposta imune das raças Jersey e Holandesa.

Estudo dos métodos de rotina diagnóstica de mastite no leite de éguas

Routine diagnosis methods used in bovine mastitis were studied in 55 mares in lactation. The findings of strip cup test, California Mastitis Test-CMT, electronic somatic cell count-CCS, microbiological culture, and in vitro antimicrobial susceptibility profile of isolates were discussed. Streptococcus spp., Staphylococcus spp, and enterobacteria were the most common microorganisms isolated in health and CMT-positive mammary glands. Staphylococcus aureus and Arcanobacterium pyogenes were identified in two mares presenting clinical mastitis. Mean somatic cell count of eight mares without presence of microorganisms in milk was 247.57x10³/mL and 1.621,86x10³/mL in 47 mares with positive microbiological culture. Moderate concordance (63.8%) between positive reactions in CMT (1 to 3+) and microbiological culture was observed. Amicacin (78.9%), ceftiofur (74.7%), sulpha-trimetoprim (69,0%) and norfloxacin (69.0%), were the most effective drugs, while resistance of isolates was mainly observed against penicillin (64.8%), gentamycin (35.2%), azithromycin (35.2%), enrofloxacin (28.2%), and florfenicol (28.2%).

Relationship between teat-end condition, udder cleanliness and bovine subclinical mastitis

The aims of the present study were to relate intramammary infection (IMI) occurrence and somatic cell count (SCC) with teat-end condition (TEC) and udder cleanliness (UC). Milk samples from 1931 teats were evaluated according to the presence of IMI and SCC. Scores were applied to teats according to the TEC and to UC. Teats ends with a very rough ring had the largest number of IMI when compared to the other three categories, as well as animals with dirtier udders. The change in a TEC score increased by around 30% the chance of IMI. Also, the chance of the animal developing IMI increased by approximately 47% when the UC score increased. No significant association between both scores and quarter SCC was found. It can be concluded that animals with very rough teat end rings and very dirty udders have a greater predisposition to IMI. (C) 2011 Elsevier Ltd. All rights reserved.

Molecular detection of Streptococcus agalactiae in bovine raw milk samples obtained directly from bulk tanks

Mastitis is the most common infectious disease affecting dairy cattle; in addition, it remains the most economically important disease of dairy industries around the world. Streptococcus agalactiae, a contagious pathogen associated with subclinical mastitis, is highly infectious. This bacterium can cause an increase in bulk tank bacterial counts (BTBC) and bulk tank somatic cell counts (BTSCC). The microbiological identification of S. agalactiae in samples from bulk tanks is an auxiliary method to control contagious mastitis. Thus, there are some limitations for time-consuming cultures or identification methods and additional concerns about the conservation and transport of samples. Bulk tank samples from 247 dairy farms were cultured and compared through polymerase chain reaction (PCR), directed to 16S rRNA genes of S. agalactiae, followed by BTBC and S. agalactiae isolation. The mean value of BTBC was 1.08 x 10(6) CFU mL(-1) and the bacterium was identified through the microbiological method in 98 (39.7%; CI95% = 33.8-45.9%) and through PCR in 110 (44.5%; CI95% = 38.5-50.8%) samples. Results indicated sensitivity of 0.8571 +/- 0.0353 (CI95% = 0.7719-0.9196) and specificity of 0.8255 +/- 0.0311 (CI95% = 0.7549-0.8827). The lack of significant difference between microbiological and molecular results (kappa = 0.6686 +/- 0.0477 and CI95% = 0.5752-0.7620) indicated substantial agreement between the methods. This suggests that PCR can be used for bulk tank samples to detect contagious mastitis caused by S. agalactiae. (C) 2011 Elsevier Ltd. All rights reserved.

Analysis of the electrical conductivity in milking fractions as a mean for detecting and characterizing mastitis in goats

The aim of the work was to study the effect of milking fraction on electrical conductivity of milk (EC) to improve its use in dairy goat mastitis detection using automatic EC measurements during milking. The experiment was carried out on a group of 84 Murciano-Granadina goats (28 primiparous and 56 multiparous). Goats were in the fourth month of lactation. A linear mixed model was used to analyse the relationship between EC or somatic cell count (SCC) of gland milk and parity, mammary gland health status, analysed fraction (first 100 mL=F-1; machine milk=F-2; and stripping milk=F-3) and their first order interactions. Additionally, the mastitis detection characteristics (sensitivity, specificity, positive predictive value and negative predictive value) of SCC and EC were studied at different thresholds.All factors considered were significant for EC and SCC. EC decreased significantly as milking progressed (from F-1 to F-3) in both healthy and infected glands. EC was not significantly different between healthy and infected glands in F-1 and F-2 fractions, but EC of healthy glands (5.01 mS/cm) was significantly lower than in infected glands (5.03 mS/cm) at F-3.Mastitis detection characteristics of EC did not differ amongst studied fractions. The small significant difference of EC between healthy and infected glands obtained in F-3 fraction did not yield better sensitivity results compared to F-1 and F-2. The best EC mastitis detection characteristics were obtained at 5.20 mS/cm threshold (sensitivity of 70% and specificity of 50%). The best SCC mastitis detection characteristics were obtained at 300,000 cells/mL threshold and F-3 fraction (sensitivity of 85% and specificity of 65%).It was concluded that mastitis detection characteristics of EC were similar in the three milking fractions analysed, being slightly better for SCC in F-3 fraction. As shown in previous studies, there are no factors other than the mammary gland health status that affect milk EC and should be considered in the algorithms for mastitis detection to improve the results. (C) 2012 Elsevier B.V. All rights reserved.

Substituição do milho pelo triticale na alimentação de tilápias-do-nilo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Structural and ultrastructural characterization of buffalo fetus (Bubalus bubalis) ovarian germinative cells

The objective of the present study was to characterize ovogones, primary oocytes and preantral follicles of buffalo fetus in different ages of gestation. For this, 29 fetuses were collected from a slaughterhouse (Frigol, Brazil) and crown-rump lengths were measured to estimate the fetal age (0-3, 4-6, 7-10 months of gestation). The ovaries were removed and ovarian tissue was processed for classic histology and transmission eletron microscopy examination. The structural evaluation demonstrated that in the first period of the gestation (0-3 months) the buffalo fetus showed ovogones (in mitotic division) and in some cases, the primary oocytes surrounded by somatic cells. In the second period (4-6 months), it was verified that the preantral follicles were completely formed. In the last period (70 month to the end of gestation) the ovaries contained a large amount of preantral follicles, and in some fetuses, antral follicles were observed. The ultrastructural analysis of the ovogones, primary oocytes and preantral follicles showed that these cells have few organelles and the quantity of mitochondria, endoplasmatic reticulum and apparatus Golgi complex is increased as the germinative cells passing from one stage to another.

Estudo do leite de éguas sadias ou portadoras de mastite subclínica, pelo teste de Whiteside, análise microbiológica e contagem de células somáticas

Com o objetivo de identificar a microbiota existente no leite de éguas normais ou portadoras de mastite subclínica, coletaram-se amostras (10 a 15 ml) de leite de 38 animais, que foram examinadas pelo teste de Whiteside, após a homogeneização das amostras dos dois tetos de cada animal. Os resultados foram negativos. Os exames microbiológicos realizados em meios de ágar sangue bovino 10% e ágar MacConkey revelaram presença de bactérias do gênero Staphylococcus spp. e Streptococcus spp. A contagem de células somáticas de amostras individuais de cada teto revelou números superiores a 500.000 células/ml de leite em somente 9,3% das 73 amostras de leite examinadas. Os resultados sugerem a realização de novos estudos objetivando-se a padronização do número de células somáticas no leite de éguas.

Gonadal function arrest in fillies after birth, as reflected by steroid serum concentrations

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

Metabolic changes in Brycon cephalus (Teleostei, Characidae) during post-feeding and fasting

Metabolic changes during the transition from post-feeding to fasting were studied in Brycon cephalus, an omnivorous teleost from the Amazon Basin in Brazil. Body weight and somatic indices (liver and digestive tract), glycogen and glucose content in liver and muscle, as well as plasma glucose, free fatty acids (FFA), insulin and glucagon levels of B. cephalus, were measured at 0, 12, 24, 48, 72, 120, 168 and 336 h after the last feeding. At time 0 h (the moment of food administration, 09.00 h) plasma levels of insulin and glucagon were already high, and relatively high values were maintained until 24 h post-feeding. Glycemia was 6.42 +/- 0.82 mM immediately after food ingestion and 7.53 +/- 1.12 MM at 12 h. Simultaneously, a postprandial replenishment of liver and muscle glycogen reserves was observed. Subsequently, a sharp decrease of plasma insulin occurred, from 7.19 +/- 0.83 ng/ml at 24 h of fasting to 5.27 +/- 0.58 ng/ml at 48 h. This decrease coincided with the drop in liver glucose and liver glycogen, which reached the lowest value at 72 h of fasting (328.56 +/- 192.13 and 70.33 +/- 14.13 mumol/g, respectively). Liver glucose increased after 120 h and reached a peak 168 h post-feeding, which suggests that hepatic gluconeogenesis is occurring. Plasma FFA levels were low after 120 and 168 h and increased again at 336 h of fasting. During the transition from post-feeding to fast condition in B. cephalus, the balance between circulating insulin and glucagon quickly adjust its metabolism to the ingestion or deprivation of food. (C) 2002 Elsevier B.V. All rights reserved.

Search for Genomic Alterations in Monozygotic Twins Discordant for Cleft Lip and/or Palate

Phenotypically discordant monozygotic twins offer the possibility of gene discovery through delineation of molecular abnormalities in one member of the twin pair. One proposed mechanism of discordance is postzygotically occurring genomic alterations resulting from mitotic recombination and other somatic changes. Detection of altered genomic fragments can reveal candidate gene loci that can be verified through additional analyses. We investigated this hypothesis using array comparative genomic hybridization; the 50K and 250K Affymetrix GeneChip (R) SNP arrays and an Illumina custom array consisting of 1,536 SNPs, to scan for genomic alterations in a sample of monozygotic twin pairs with discordant cleft lip and/or palate phenotypes. Paired analysis for deletions, amplifications and loss of heterozygosity, along with sequence verification of SNPs with discordant genotype calls did not reveal any genomic discordance between twin pairs in lymphocyte DNA samples. Our results demonstrate that postzygotic genomic alterations are not a common cause of monozygotic twin discordance for isolated cleft lip and/or palate. However, rare or balanced genomic alterations, tissue-specific events and small aberrations beyond the detection level of our experimental approach cannot be ruled out. The stability of genomes we observed in our study samples also suggests that detection of discordant events in other monozygotic twin pairs would be remarkable and of potential disease significance.

Importância do Staphylococcus aureus nas mastites subclínicas: pesquisa de enterotoxinas e toxina do choque tóxico, e a relação com a contagem de células somáticas

O Staphylococcus aureus é um dos principais agentes das mastites consideradas contagiosas, apresentando elevada incidência na maioria dos rebanhos leiteiros em vários países. Além de perdas econômicas é importante salientar o aspecto de saúde pública para cepas produtoras de enterotoxinas e da toxina do choque tóxico. A enterotoxina A, relacionada com maior ênfase nos casos de toxinfecções alimentares, pode ser veiculada pelo leite cru, pasteurizado e subprodutos lácteos. A síndrome do choque tóxico é determinada mais freqüentemente pela toxina do choque tóxico, porém as enterotoxinas do tipo B e C também podem ser implicadas. O objetivo deste estudo foi verificar a ocorrência de S.aureus produtores de enteroxinas e da toxina do choque tóxico em amostras de leite de animais com mastite subclínica, e correlacionar estes resultados com a contagem de células somáticas; utilizando a técnica de celofane over agar para detecção da TNAase, kit comercial para identificação das enterotxinas e contagem eletrônica de células somáticas. Avaliod]MORENO, B.[u-se 209 amostras de leite oriundas de vacas com mastite subclínica por S.aureus, e dentre estas, 209 (98,86%) produziram TNAse, nove amostras (4,39%) foram produtoras de enterotoxinas, sendo que uma (0,49%) dentre elas foi produtora de EED, três (1,46%) de EEC, e três (1,46%) de EEB. em uma amostra (0,49%), detectou-se concomitantemente EEA e EEB e em outra EEB e EEC. A toxina do choque tóxico não foi encontrada nas cepas avaliadas neste estudo, assim como não houve aumento estatisticamente significativo, na contagem de células somáticas, das amostras de cepas produtoras de enteroxinas.

Morphological aspects of cluster formation in the germarium of the sugarcane borer Diatraea saccharalis Fabricius (Lepidoptera : Pyralidae)

Diatraea saccharalis F. is one of the greatest pests of the sugar cane culture. This report aimed to characterize the germanium region of the sugarcane borer by light and transmission electron microscopy, emphasizing the morphological steps of the ovarian cluster formation. In the germanium of this insect, four zones could be morphologically identified during the cluster formation. In the most apical end of each ovariole - Zone I - the germ line stem cells undergo complete mitotic division, originating the cystoblasts. In the Zone II, each cystoblast produces a group of eight cells, the cystocytes, which are interconnected by the ring canals. Clusters containing all the cystocytes in the meiosis, characterizes the Zone III. Germ cells with ultrastructural features of apoptosis are also detected in this Zone. In the Zone IV the cystocytes differentiate, morphologically, into one oocyte and seven nurse cells. Interstitial somatic cells and pre-follicle cells exhibit, in their cytoplasm, heterogeneous vacuoles containing degenerated cellular fragments, characterized as apoptotic bodies. Our results pointed out to the morphological evidences related with important control mechanisms for new clusters/follicles production and for the cellular arrangement into the germanium, resulting from the programmed cell death. We believe that the morphological characterization of ovarian cluster formation in D. saccharalis provided valuable information for the understanding of the initial steps of oogenesis and contributed for the knowledge of the cellular mechanisms related with the oocyte production and with reproduction in insects.

Desenvolvimento das gônadas de Dermatobia hominis (Diptera: Cuterebridae)

O trabalho descreve o desenvolvimento das gônadas do berne (D. hominis) durante o período pupal. As pupas desenvolvidas de larvas com peso superior a 650 mg, deram imagos fêmeas, enquanto que as desenvolvidas daquelas pesando entre 500 e 650 mg deram macho, tendo havido um erro ao redor de 5%. Até o oitavo dia de pupação os testículos crescem mais que os ovários; a partir daí diminui o desenvolvimento, parando de crescer entre o vigésimo e vigésimo quinto dias. A espermatogênese inicia por volta do sétimo dia de pupa quando é grande o número de espermatócitos. No décimo dia alguns testículos apresentam considerável número de espermátides e os espermatozóides começam a aparecer por volta do vigésimo dia. A espermiogênese desenvolve-se sem interrupção e ao final da pupação quase toda loja testicular está repleta de espermatózóides. Os machos começam a nascer dois dias antes das fêmeas. Nessas, os ovaríolos aparecem formados por volta do oitavo dia de pupa; os folículos se individualizam por volta do vigésimo dia de pupa onde se distingue os trofócitos com núcleos politênicos e citoplasmas bem basófilos, enquanto o ovócito tem citoplasma mais acidófilo e núcleo com cromatina bastante frouxa. A vitelogênese tem início ao redor do vigésimo quinto dia de pupa e se completa ao nascimento da imago. A ligação das gônadas com suas respectivas estruturas somáticas acontece ao redor do décimo terceiro dia de pupação.