Leptospirose em reprodução animal: IV. Achados sorológicos em éguas de seis propriedades no Rio de Janeiro, Brasil (1993-1996)

From February 1993 until October 1996, 547 blood samples were collected from mares with reproductive problems in six farms of the state of Rio de Janeiro, Brazil, and tested by the microscopic agglutination test (MAT) with live antigens for antibodies to seven leptospira serovars. A total of 235 positive reactions (42.96%) at a minimum serum dilution of 1:100 were observed against one or more serovars, which in comparison to other studies developed in Brazil, may be considered as a high prevalence. On mares with anti-leptospiral antibodies, the predominant serovar was icterohaemorrhagiae, reactive on 102 (43.40%) samples, followed by 64 (27.23%) reactions against bratislava, and 34 (14.47%) against pomona. The high prevalence of antibodies to serovar icterohaemorrhagiae observed in this study could have been expected, because in Brazil about 36% of the population of the maintenance host of such strain, Rattus norvegicus, are leptospiral carriers, mainly to strains of the Icterohaemorrhagiae serogroup.De fevereiro de 1993 a outubro de 1996, 547 amostras sangüíneas foram colhidas de éguas com problemas reprodutivos de seis propriedades no Estado do Rio de Janeiro, Brasil, e testadas pela técnica da soroaglutinação microscópica (MAT) com antígenos vivos para anticorpos perante sete sorotipos de leptospiras. Um total de 235 reações positivas (42,96%) a um título mínimo de 100 foram observadas perante um ou mais sorotipos de leptospira, o que, em comparação com outros estudos já realizados no Brasil, pode ser considerado uma alta prevalência. Em éguas com anticorpos antileptospiras, o sorotipo predominante foi icterohaemorrhagiae, reativo em 102 (43,40%) amostras, seguido de 64 (27,23%) reações positivas para bratislava e 34 (14,47%) perante pomona

O uso de Elisa como ferramenta complementar para o controle da tuberculose bovina no Brasil

The detection of infected animals is one of the main factors involved in tuberculosis control and, with some variations, is performed through intradermal tuberculin tests. Nevertheless, skin test-negative animals may be infected and represent an important threat to bovine tuberculosis eradication programs. Despite this well-known phenomenon, ELISA testing did not become a routine in tuberculosis control programs. Our purpose was to describe field applications of ELISA in the detection of anergic animals in Rio de Janeiro, Brazil. From 18 herds involved on a tuberculosis control program, two presented skin test-negative infected animals what have delayed and compromised the success of the program, with severe economic losses. Infection in those animals was identified through ELISA and confirmed by isolation of M. bovis from lung lesions. Therefore they were considered to be the most probable source of continuing infection and responsible for the maintenance of the disease in their herds. Without the use of serological tests as ELISA those cows would probably stay in their herds perpetuating the disease and the eradication of the disease in those herds would become impossible. In conclusion, we suggest the use of ELISA as a valuable complementary tool in order to identify possible anergic cows that may be acting as reservoirs of the agent in the herd.A detecção de animais infectados é um dos mais importantes fatores envolvidos no controle da tuberculose e, com algumas variações, é realizado através de testes intradérmicos de tuberculinização. No entanto, animais negativos aos testes intradérmicos podem estar infectados e representam uma importante ameaça aos programas de erradicação da tuberculose. Apesar deste conhecido fenômeno, o uso de ELISA não é rotina nestes programas. Nosso objetivo foi o de descrever experiências do uso a campo de ELISA na detecção de animais anérgicos no Rio de Janeiro, Brasil. Dentre 18 rebanhos envolvidos em um programa de controle da tuberculose, dois apresentaram animais infectados negativos aos testes intradérmicos, o que atrasou e comprometeu o sucesso do programa, com severas perdas econômicas. A infecção nestes animais foi identificada através de ELISA e confirmada pelo isolamento de M.bovis nas lesões pulmonares. Desta forma foram considerados como a mais provável fonte de infecção e responsáveis pela manutenção da enfermidade nos rebanhos. Sem o uso de testes sorológicos como ELISA estes animais provavelmente permaneceriam nos rebanhos perpetuando a infecção e a erradicação da enfermidade seria impossível. Em conclusão, sugere-se o uso de ELISA como uma valiosa ferramenta complementar para identificar animais anérgicos que possam atuar como reservatórios do agente nos rebanhos

Comparison of cefoxitin disk diffusion test and mecA gene PCR results for methicillin resistance detection in Staphylococcus intermedius group isolates from canine origin in Brazil

The study evaluated cefoxitin disk diffusion tests breakpoints and their correlation to mecA gene PCR results for detecting Methicillin-resistant Staphylococcus intermedius Group (MRSP) isolates from dogs in Brazil. Agreement using proposed breakpoint (resistant < 30 mm) was encouraging. The current study reinforces that an epidemiological breakpoint can be established to predict presence of MRSP

Challenges on the Follow-Up Experimental Leptospiral Infection in Sheep

Background: Leptospirosis is currently a source of significant economic losses in the agribusiness; as such, experimental studies on this infection are required to develop a better understanding of the pathogenesis, treatment, and immunoprophylaxis of the disease. Sheep may represent a good model for ruminants in such models. Despite the extent of the studies that has been conducted thus far, researchers have yet to reach a consensus on the experimental practices to apply for leptospirosis in this animal species, and several gaps in understanding remain. To bridge these gaps, the present study aimed to assess the usage of several tools for the monitoring of experimental leptospirosis in sheep.Material, Methods & Results: Twelve Santa Ines sheep of different ages were each allocated to one of four groups (A, B, C, and D). The subjects in groups A, B, and C received different doses of Leptospira interrogans serogroup Icterohemorrhagiae by intraperitoneal route, 1x102, 1x105, and 1x108 respectively. Group D was the control. Hematological, biochemical and clinical parameters were evaluated daily. Serology by microscopic agglutination test (MAT) and PCR were performed to evaluate the infection status. The most remarkable clinical signs were fever (41ºC) and dehydration, and acute pain (cub). Two animals from Group C presented leukocytosis. Only those in Group C exhibited positive results according to serology, while positivity in PCR was observed in animals in groups A and C. The results of the experiment indicated that sheep may be experimentally infected and can, therefore, be used as a model for leptospirosis in ruminants. Clinical signs cannot be considered to represent a reliable parameter for evaluating the development of leptospirosis in experimentally infected sheep. We recommend the use of urine PCR and serology to confirm the infection in experimentally infected animals and daily complete blood count (CBC) as a follow-up tool.Discussion: It was observed that the clinical signs cannot be considered as a reliable parameter to evaluate the pathogenesis in experimentally infected ewes, being important to emphasize that the age of the animals does not seem to alter their susceptibility to the infection. This finding is in agreement with other experimental studies, which report that leptospirosis infection in ruminants occurs asymptomatic and subclinical. Hematological and biochemical tests proved to be adequate tools to monitor the experimental infection. Studies have shown that the complete blood count has been used to monitor the acute phase of leptospirosis and is effective in detecting anemia and leukocytosis with neutrophilia in ruminants. Despite the lack of clinical signs, the serological and molecular results confirmed the experimental infection. PCR has been used as an important tool in the diagnosis of leptospirosis. In addition, the current study is the first of its kind to use PCR to detect the carrier status in experimentally infected ewes. Despite this limitation, PCR was very effective in confirming the infection and should be considered for use in experimental studies. Sheep have been used as a good experimental model in several studies, sheep are relatively small compared to other ruminants and can be easily allocated in smaller pens and pens, facilitating the management of research and minimizing the costs of experimentation. In this context, we suggest that sheep represent a good model for the study of leptospirosis in ruminants and therefore a reliable protocol for experimental infection by leptospirosis is necessary

Detecção molecular de ovinos carreadores de Leptospira em ambiente tropical

The purpose of this study was to analyze the usefulness of PCR for the detection of leptospiral carriers in sheep under tropical field conditions. Two flocks, previously reported as seroreactive (A) and seronegative (B), were selected for this study. From those, the totality of animals of each flock, urine and vaginal fluid (VF)/semen were collected for bacteriological culture and PCR, as well as serum samples for serology. Serology confirmed the previous status of the two flocks. Culture was negative for all the samples. In PCR, animals of Flock A presented 26.7% (VF), 33.3% (semen) and 38.9% (urine) of positivity. Flock B presented 40.0% (VF), 33.3% (semen) and 5.6% (urine) of positivity by PCR. In conclusion, PCR was important to identify carriers of leptospires, including animals from a seronegative flock, what reinforces the advantages of the usage of this tool for the detection of carriers in sheep as part of control programs of leptospirosis under tropical field conditions.O objetivo do presente estudo foi analisar a aplicabilidade da PCR na detecção de ovinos carreadores de Leptospira em ambiente tropical. Brevemente, dois rebanhos ovinos, previamente reportados como sororeativo (A) e soronegativo (B) foram selecionados para este estudo. Da totalidade de animais de cada rebanho, amostras de urina e fluido vaginal (FV)/sêmen foram colhidas para cultura bacteriológica e PCR. Além disso, amostras de soro foram colhidas e utilizadas na sorologia (teste da soroaglutinação microscópica). Esta técnica confirmou o estado prévio dos dois rebanhos. Nenhuma amostra pura de leptospiras foi obtida no cultivo. Já na PCR, animais do Rebanho A apresentaram 26,7% (FV), 33,3% (sêmen) e 38,9% (urina) de amostras positivas. O Rebanho B apresentou 40,0% (FV), 33,3% (sêmen) e 5,6% (urina) de positividade pela PCR. Em conclusão, a PCR foi uma importante ferramenta na identificação de carreadores de leptospiras, incluindo animais do rebanho soronegativo, o que reforça as vantagens do uso desta técnica para a detecção de ovinos portadores como parte dos programas de controle da leptospirose em ambiente tropical.

OCORRÊNCIA DE ANTICORPOS CONTRA O HERPESVÍRUS EQUINO E VIRUS DA ARTERITE EQUINA EM REBANHOS EQUINOS DO ESTADO DO RIO DE JANEIRO

A infecção pelo herpesvírus equino (EHV) e o vírus da arterite equina (EAV) tem sido associada a perdas econômicas importantes para a equideocultura em nível mundial. Estudos sorológicos têm demonstrado a circulação destes agentes no Brasil. O presente trabalho teve como objetivo principal estudar a ocorrência de anticorpos específicos contra o EAV e EHV em cavalos oriundos de diferentes regiões do estado do Rio de Janeiro. Para este propósito, foram coletadas amostras de soro de 581 animais não vacinados e de 44 éguas provenientes de um plantel vacinado regularmente contra a rinopneunonite equina. Todas as amostras foram submetidas ao teste de soroneutralização para a pesquisa de anticorpos específicos contra cada um dos vírus. Os resultados demonstraram 29,6% (172/581) de animais soropositivos para o EHV (títulos entre 2 e ? 256) e 0,79% (05/630) para o EAV (títulos entre  2 e 4.096). Considerando a sorologia positiva em animais não imunizados, os achados demonstram a indução de anticorpos específicos após exposição natural aos respectivos vírus, indicando uma possível circulação desses agentes nos rebanhos analisados. Palavras-chave: anticorpos; EAV; EHV; equinos; soroneutralização.