Genetic variability of Mycoplasma synoviae detected in commercial layers in southeastern Brazil / Variabilidade genética de Mycoplasma synoviae detectado em poedeiras comerciais do sudeste do Brasil

Este estudo teve como objetivo caracterizar genótipos de M. synoviae circulantes em poedeiras comerciais, na Região Sudeste do Brasil. Para estabelecer a relação evolutiva entre as cepas de MS, foi analisada a sequência genética do gene vlhA de 11 cepas de MS identificadas no Rio de Janeiro e em São Paulo, de 10 outras cepas de MS identificadas no Brasil e cujas sequências foram depositadas no banco de dados GenBank, e da cepa vacinal MSH. O método da máxima verossimilhança e o modelo de Kimura com dois parâmetros foram utilizados para comparar as cepas. As sequências obtidas foram depositadas no Genbank, sob os números de acesso OP279775 a OP279785. Foi possível verificar a presença de diferentes cepas circulantes no Brasil, com alta similaridade entre as cepas do Rio de Janeiro pela análise do gene vlhA. As duas cepas paulistas detectadas no presente estudo possuem o baixo percentual (68%) de similaridade, demonstrando a variabilidade das cepas dessa localidade.

Proposal of an iELISA for Mycoplasma bovis diagnosis in dairy cattle and associated risk factors / [Proposta de um iELISA para diagnóstico de Mycoplasma bovis em bovinos leiteiros e fatores de risco associados]

Mycoplasma bovis is a highly contagious agent associated with several pathologies in cattle. The detection of reactive antibodies to M. bovis by Indirect Enzyme-Linked Immunosorbent Assay (iELISA) identifies if there was an exposure to the microorganism. The current study aimed to optimize an iELISA from M. bovis total cell antigen, applying it to bovine serum samples, and to evaluate risk factors. Serum samples were obtained from 400 cows from 17 herds from Southeast Brazil. In the optimization of iELISA, the following was established: 2 µg/mL of antigen, sera dilution 1:300, and conjugate dilution 1:15000. The frequency was 62.3% (249/400) of reactive animals and 100% (17/17) of reactive herds. Risk factors were: herds with more than 100 animals (OR= 3.1; CI= 95%); Holstein breed (OR= 72.5; CI= 95%); cows (OR= 29.7; CI= 95%); intensive breeding system (OR= 3.3; CI= 95%); associated small ruminant production (OR= 4.4; CI= 95%); milk production above 500L (OR= 2.9; CI= 95%); no quarantine (OR= 1.5; CI= 95%); mechanical milking (OR= 5.5; CI= 95%) and cases of mastitis (OR= 5.5; CI= 95%). The proposed iELISA was able to detect antibodies reactive to M. bovis in bovine serum. Knowledge of these risk factors can assist in the implementation of prophylactic measures.(AU)

Mycoplasma bovis é um agente altamente contagioso relacionado a várias patologias em bovinos. A detecção de anticorpos reativos a M. bovis por Ensaio de Imunoadsorção Enzimática Indireto (iELISA) identifica se houve exposição ao microrganismo. O presente estudo teve como objetivo otimizar um iELISA de antígeno celular total de M. bovis, aplicando-o a amostras de soro bovino, bem como avaliar fatores de risco. Amostras de soro foram obtidas de 400 vacas de 17 rebanhos da Região Sudeste do Brasil. Na otimização do iELISA foram obtidos: 2µg/mL de antígeno, diluição dos soros 1:300 e do conjugado 1:15000. A frequência de animais reativos foi de 62,3% (249/400) e de 100% (17/17) para os rebanhos. Os fatores de risco foram: rebanhos com mais de 100 animais (OR= 3,1; IC= 95%); raça Holandesa (OR= 72,5;IC= 95%); vacas (OR= 29,7;IC= 95%); sistema intensivo (OR= 3,3; C= 95%); produção de pequenos ruminantes (OR= 4,4;IC=95%); produção de leite acima de 500L (OR= 2,9;IC= 95%); sem quarentena (OR= 1,5;IC= 95%); ordenha mecânica (OR= 5,5;IC= 95%) e casos de mastite (OR= 5,5;IC= 95%). O iELISA proposto foi capaz de detectar anticorpos reativos a M. bovis no soro bovino. O conhecimento desses fatores de risco pode auxiliar na implementação de medidas profiláticas.(AU)

Occurrence of Avian Mycoplasmas in Free-Living Muscovy-Ducks (Cairina Moschata)

The present study aimed to investigate, by culture and PCR, the occurrence of Mollicutes, Mycoplasma gallisepticum and Mycoplasma synoviae in free-living Muscovy-ducks (Cairina moschata) from the Rio Zoo, RJ, Brazil. Tracheal swabs were obtained from 82 asymptomatic ducks and the samples were submitted to culture of mycoplasmas and PCR for identification of Mollicutes Class, Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS). Samples were also analyzed directly by PCR, without prior culture, for Mollicutes, MG and MS. Eighteen (18/82) Muscovy-ducks were positive for Mollicutes by culture, all isolates were confirmed as Mollicutes and seven were identified as MG. Of the samples analyzed directly by PCR, without prior culture, 17,1% (14/82) was positive for Mollicutes, being 35,7% (5/14) identified as MG and 21,4% (3/14) as MS. The occurrence of Mollicutes class bacteria was detected in Muscovy-ducks. MG and MS were identified in these animals suggesting the circulation of these agents in the Rio de Janeiro Zoo and may present a risk for the health status of the other birds.(AU)

Occurrence of Avian Mycoplasmas in Free-Living Muscovy-Ducks (Cairina Moschata)

The present study aimed to investigate, by culture and PCR, the occurrence of Mollicutes, Mycoplasma gallisepticum and Mycoplasma synoviae in free-living Muscovy-ducks (Cairina moschata) from the Rio Zoo, RJ, Brazil. Tracheal swabs were obtained from 82 asymptomatic ducks and the samples were submitted to culture of mycoplasmas and PCR for identification of Mollicutes Class, Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS). Samples were also analyzed directly by PCR, without prior culture, for Mollicutes, MG and MS. Eighteen (18/82) Muscovy-ducks were positive for Mollicutes by culture, all isolates were confirmed as Mollicutes and seven were identified as MG. Of the samples analyzed directly by PCR, without prior culture, 17,1% (14/82) was positive for Mollicutes, being 35,7% (5/14) identified as MG and 21,4% (3/14) as MS. The occurrence of Mollicutes class bacteria was detected in Muscovy-ducks. MG and MS were identified in these animals suggesting the circulation of these agents in the Rio de Janeiro Zoo and may present a risk for the health status of the other birds.

Eggshell apex abnormalities in a free-range hen farm with mycoplasma synoviae and infectious bronchitis virus in Rio de Janeiro state, Brazil

A farm with 3,000 free-range hens between 24 and 65 weeks of age was investigated. These hens were separated in small flocks of 400 to 700 birds, presenting 10 to 23% egg production reduction. Twenty serum samples were collected during the period of drop in egg production and three weeks later for the investigation of Mycoplasma synoviae (MS), M. gallisepticum (MG) and Infectious Bronchitis Virus (IBV) antibodies using ELISA. At the time of the second collection, egg production had resumed to normal levels; however, with 10.23% of the eggs showed eggshell abnormalities limited to the apex. Eggshell strength was significantly different between normal and those with eggshell apex abnormalities, but not other egg-quality parameters. ELISA tests showed that MS and IBV titers increased during the evaluated period. MS infection was confirmed by culture and by PCR of tracheal swabs. All samples were negative for MG by ELISA and PCR. Further studies with larger samples to ensure the occurrence of this disease in industrial layer flocks in Brazil are under way.

Eggshell apex abnormalities in a free-range hen farm with mycoplasma synoviae and infectious bronchitis virus in Rio de Janeiro state, Brazil

A farm with 3,000 free-range hens between 24 and 65 weeks of age was investigated. These hens were separated in small flocks of 400 to 700 birds, presenting 10 to 23% egg production reduction. Twenty serum samples were collected during the period of drop in egg production and three weeks later for the investigation of Mycoplasma synoviae (MS), M. gallisepticum (MG) and Infectious Bronchitis Virus (IBV) antibodies using ELISA. At the time of the second collection, egg production had resumed to normal levels; however, with 10.23% of the eggs showed eggshell abnormalities limited to the apex. Eggshell strength was significantly different between normal and those with eggshell apex abnormalities, but not other egg-quality parameters. ELISA tests showed that MS and IBV titers increased during the evaluated period. MS infection was confirmed by culture and by PCR of tracheal swabs. All samples were negative for MG by ELISA and PCR. Further studies with larger samples to ensure the occurrence of this disease in industrial layer flocks in Brazil are under way.(AU)

Principais alterações no leite por agentes causadores de mastite no rebanho caprino dos estados de Minas Gerais e Rio de Janeiro / Major changes in milk by mastitis causative agents in goat herd from the states of Minas Gerais and Rio de Janeiro, Brazil

A mastite subclínica caprina ocasiona prejuízos econômicos em decorrência do descarte, dos gastos com medidas terapêuticas e da redução da quantidade e qualidade do leite e seus derivados.Nesse estudo, 129 amostras de leite de cabra in natura, provenientes de 11 propriedades foram avaliadas pelo teste da caneca telada, California Mastitis Test (CMT), exame bacteriológico, pesquisa de Mycoplasma spp. e pela determinação dos parâmetros físico-químicos. No teste da caneca telada e no CMT, 3,1% e 4,6% das amostras foram positivas, respectivamente. No exame bacteriológico, 57,4% das amostras foram positivas e o patógeno mais frequente foi Staphylococcus coagulase negativa com 56% das cepas resistentes à penicilina e 100% de sensíveis à gentamicina. Mycoplasma spp. não foi identificado nas amostras. O diagnóstico da mastite subclínica pelo CMT e pelo exame bacteriológico diferiu de forma significativa e não houve associação entre o número de UFC/mL obtidas no exame microbiológico e o resultado do CMT (Qui-quadrado p 0,05). Com base nos resultados obtidos, recomenda-se a associação do exame bacteriológico quando na utilização do CMT para diagnóstico da mastite subclínica caprina.

Major changes in milk by mastitis causative agents in goat herd from the states of Minas Gerais and Rio de Janeiro, Brazil. Goat mastitis causes significant economic losses due to the discarding of milk, costs of drugs and veterinary care, reducing the quantity and quality of milk and dairy products. In this study, 129 raw milk samples from 11 goat farms were investigated by the Tamis test, California mastitis test (CMT), bacteriological exam, presence of Mycoplasma spp. and physicochemical parameters. Seven (4.6%) and four samples (3.1%) were positive by CMT and Tamis test respectively. Bacteriological exam was positive from 57.4% of samples and coagulase-negative Staphylococcus was the most frequent bacteria isolated showing 56% of the strains resistant to penicillin and no resistance to gentamicin. Negative results were obtained from traditional culture as well as by PCR for Mycoplasma spp. The diagnosis of mastitis, the bacteriological exam and the CMT results differed significantly and no association was observed (chi squared, p 0.05). The physicochemical parameters differed significantly (ANOVA, Tukey-Kramer, p < 0.05) among the herds. These results indicate the need to associate microbiological exam when the CMT is used for the diagnosis of goat mastitis.

Principais alterações no leite por agentes causadores de mastite no rebanho caprino dos estados de Minas Gerais e Rio de Janeiro / Major changes in milk by mastitis causative agents in goat herd from the states of Minas Gerais and Rio de Janeiro, Brazil

A mastite subclínica caprina ocasiona prejuízos econômicos em decorrência do descarte, dos gastos com medidas terapêuticas e da redução da quantidade e qualidade do leite e seus derivados.Nesse estudo, 129 amostras de leite de cabra in natura, provenientes de 11 propriedades foram avaliadas pelo teste da caneca telada, California Mastitis Test (CMT), exame bacteriológico, pesquisa de Mycoplasma spp. e pela determinação dos parâmetros físico-químicos. No teste da caneca telada e no CMT, 3,1% e 4,6% das amostras foram positivas, respectivamente. No exame bacteriológico, 57,4% das amostras foram positivas e o patógeno mais frequente foi Staphylococcus coagulase negativa com 56% das cepas resistentes à penicilina e 100% de sensíveis à gentamicina. Mycoplasma spp. não foi identificado nas amostras. O diagnóstico da mastite subclínica pelo CMT e pelo exame bacteriológico diferiu de forma significativa e não houve associação entre o número de UFC/mL obtidas no exame microbiológico e o resultado do CMT (Qui-quadrado p < 0,05). Os parâmetros físico-químicos diferiram significativamente entre os rebanhos (ANOVA, Tukey-Kramer, p < 0,05) e a gordura foi o constituinte que demonstrou maior amplitude, sendo que 63,4% dos rebanhos apresentaram os valores abaixo do exigido pela legislação brasileira. Não houve associação significativa entre a presença de mastite diagnosticada pelo exame bacteriológico e os valores obtidos para os parâmetros físico-químicos (t-Student p > 0,05). Com base nos resultados obtidos, recomenda-se a associação do exame bacteriológico quando na utilização do CMT para diagnóstico da mastite subclínica caprina.(AU)

Major changes in milk by mastitis causative agents in goat herd from the states of Minas Gerais and Rio de Janeiro, Brazil. Goat mastitis causes significant economic losses due to the discarding of milk, costs of drugs and veterinary care, reducing the quantity and quality of milk and dairy products. In this study, 129 raw milk samples from 11 goat farms were investigated by the Tamis test, California mastitis test (CMT), bacteriological exam, presence of Mycoplasma spp. and physicochemical parameters. Seven (4.6%) and four samples (3.1%) were positive by CMT and Tamis test respectively. Bacteriological exam was positive from 57.4% of samples and coagulase-negative Staphylococcus was the most frequent bacteria isolated showing 56% of the strains resistant to penicillin and no resistance to gentamicin. Negative results were obtained from traditional culture as well as by PCR for Mycoplasma spp. The diagnosis of mastitis, the bacteriological exam and the CMT results differed significantly and no association was observed (chi squared, p < 0.05). Fat was the constituent with more variations and 63.4% of the herds did not meet the minimum requirement according to Brazilian government criteria for this constituent. There was no significant association between mastitis and the physicochemical parameters (t-Student, p > 0.05). The physicochemical parameters differed significantly (ANOVA, Tukey-Kramer, p < 0.05) among the herds. These results indicate the need to associate microbiological exam when the CMT is used for the diagnosis of goat mastitis.(AU)