Ehrlichiosis in Brazil

Ehrlichiosis is a disease caused by rickettsial organisms belonging to the genus Ehrlichia. In Brazil, molecular and serological studies have evaluated the occurrence of Ehrlichia species in dogs, cats, wild animals and humans. Ehrlichia canis is the main species found in dogs in Brazil, although E. ewingii infection has been recently suspected in five dogs. Ehrlichia chaffeensis DNA has been detected and characterized in mash deer, whereas E. muris and E. ruminantium have not yet been identified in Brazil. Canine monocytic ehrlichiosis caused by E. canis appears to be highly endemic in several regions of Brazil, however prevalence data are not available for several regions. Ehrlichia canis DNA also has been detected and molecularly characterized in three domestic cats, and antibodies against E. canis were detected in free-ranging Neotropical felids. There is serological evidence suggesting the occurrence of human ehrlichiosis in Brazil but its etiologic agent has not yet been established. Improved molecular diagnostic resources for laboratory testing will allow better identification and characterization of ehrlichial organisms associated with human ehrlichiosis in Brazil.

Occurrence and molecular characterization of Cryptosporidium spp. isolated from domestic animals in a rural area surrounding Atlantic dry forest fragments in Teodoro Sampaio municipality, State of São Paulo, Brazil

The aim of this study was to assess the occurrence of Cryptosporidium in domestic animals in rural properties surrounding rain forest fragments within the municipality of Teodoro Sampaio, southeastern Brazil. Conventional sucrose flotation method followed by molecular characterization of the parasites by sequencing PCR products amplified from SSU rRNA gene were used. Stool samples were collected from domestic animals raised as pets and livestock in all rural properties surrounding three forest fragments. Samples from cattle (197), equine (63), pigs (25), sheep (11), and dogs (28) were collected from 98 rural properties. The frequency of occurrence of Cryptosporidium within each animal species was 3.0% (6/197) among cattle and 10.7% (3/28) among dogs. Cryptosporidium was not detected in stool samples from equine, sheep, and pigs. All sequences obtained from the six samples of calves showed molecular identity with Cryptosporidium andersoni while all sequences from dog samples were similar to C. canis. The frequency of occurrence of Cryptosporidium in these domestic animal species was low. The absence of C. parvum in the present study suggests that the zoonotic cycle of cryptosporidiosis may not be relevant in the region studied. The presence of Cryptosporidium species seldom described in humans may be, otherwise, important for the wild fauna as these animals are a source of infection and dissemination of this protozoan to other animal species. The impact and magnitude of infection by C. andersoni in wild ruminants and C. canis in wild canids have to be assessed in future studies to better understand the actual importance of these species in this region.

Seroprevalence of Rickettsia bellii and Rickettsia felis in dogs, São José dos Pinhais, State of Paraná, Brazil

Brazilian spotted fever (BSF) is a vector-borne zoonosis caused by Rickettsia rickettsii bacteria. Dogs can be host sentinels for this bacterium. The aim of the study was to determine the presence of antibodies against Rickettsia spp. in dogs from the city of São José dos Pinhais, State of Paraná, Southern Brazil, where a human case of BSF was first reported in the state. Between February 2006 and July 2007, serum samples from 364 dogs were collected and tested at 1:64 dilutions by indirect immunofluorescence assay (IFA) against R. rickettsii and R. parkeri. All sera that reacted at least to one of Rickettsia species were tested against the six main Rickettsia species identified in Brazil: R. rickettsii, R. parkeri, R. bellii, R. rhipicephali, R. amblyommii and R. felis. Sixteen samples (4.4%) reacted to at least one Rickettsia species. Among positive animals, two dogs (15.5%) showed suggestive titers for R. bellii exposure. One sample had a homologous reaction to R. felis, a confirmed human pathogen. Although Rickettsia spp. circulation in dogs in the area studied may be considered at low prevalence, suggesting low risk of human infection, the present data demonstrate for the first time the exposure of dogs to R. bellii and R. felis in Southern Brazil.

New tick records in Rondônia, Western Brazilian Amazon

In the present study, we provide new tick records from Vilhena Municipality, in the Southeast of the State of Rondônia, Northern Brazil. Ticks collected from a capybara, Hydrochoerus hydrochaeris (Linnaeus), were identified as Amblyomma romitii Tonelli-Rondelli (1 female), and Amblyomma sp. (1 larva). Ticks collected from a harpy eagle, Harpia harpyja (Linnaeus), were identified as Amblyomma cajennense (Fabricius) (16 nymphs) and Haemaphysalis juxtakochi Cooley (1 nymph). Ticks collected from a yellow-footed tortoise, Chelonoidis denticulada (Linnaeus), were identified as Amblyomma rotundatum Koch (10 females, 2 nymphs), and Amblyomma sp. (2 larvae). The present record of A. romitii is the first in the State of Rondônia, and represents the southernmost record for this tick species, indicating that its distribution area is much larger than currently recognized. Although both A. cajennense and H. juxtakochi have been reported parasitizing various bird species, we provide the first tick records on a harpy eagle. A. rotundatum is widespread in the State of Rondônia, and has been previously reported on the yellow-footed tortoise. The present records increase the tick fauna of Rondônia to 26 species.

Prevalence of ehrlichial infection among dogs and ticks in Northeastern Brazil

This study investigated the epidemiology of canine ehrlichiosis in Northeastern Brazil, focusing the identification of the Ehrlichia species and vectors involved. Samples were collected from 472 domestic dogs residing in the health districts of Cajazeiras and Itapuã of Salvador city. The average prevalence of antibodies reactive to E. canis by immunofluorescent antibody test (IFAT) (titer > 1:80) was 35.6% (168/472). Blood samples from the E. canis-seropositive animals were tested by nested PCR in order to identify the Ehrlichia species responsible for the infection. Among the seropositives, 58 (34.5%) were found to be PCR-positive for E. canis. Ticks were found in 32 dogs. Nested-PCR analysis showed that 21.9% (7/32) of the Rhipicephalus sanguineus were infected by E. canis. In both dogs and Rhipicephalus sanguineus, nested-PCR for E. ewingii and E. chaffeensis was negative, with no amplification of DNA fragment.

Heartworm (Dirofilaria immitis) disease in a Brazilian oncilla (Leopardus tigrinus)

Heartworm disease is caused by the intravascular nematode Dirofilaria immitis, a pathogen of public health importance usually associated to domestic dogs and cats, and to a lesser extend to other mammal species. The oncilla (Leopardus tigrinus) is a threatened neotropic felid species that naturally occurs in Brazil. Here, we report the encounter of adult and larval stages of heartworms in a female specimen of L. tigrinus, probable of free-ranging origin, from Ubatuba, São Paulo, Brazil, which died showing clinical signals compatible with heartworm disease. This was the first reported case of D. immitis infection and associated disease in L. tigrinus, also suggesting that the oncilla acted as a definitive host for this parasite. The present findings confirmed D. immitis as a pathogenic agent for this felid species, thus supporting the recommendation for the inclusion of diagnostic testing for this pathogen in routine health screening procedures for captive and free-ranging oncillas in Brazil, especially in those localities where climate conditions support the occurrence of the parasite. Potential reservoirs as oncillas are established beyond the reach of veterinary care, thus representing a continuing risk for domestic animals and humans acquiring heartworm infection. We encourage further serologic and molecular studies aiming to establish D. immitis prevalences in L. tigrinus and other wild carnivores in the region of Ubatuba, as well as ecological and veterinary studies to access the role of this pathogen for the survival of this threatened felid species.

Spatial clustering analysis of the foot-and-mouth disease outbreaks in Mato Grosso do Sul state, Brazil - 2005

In the southern region of Mato Grosso do Sul state, Brazil, a foot-and-mouth disease (FMD) epidemic started in September 2005. A total of 33 outbreaks were detected and 33,741 FMD-susceptible animals were slaughtered and destroyed. There were no reports of FMD cases in other species than bovines. Based on the data of this epidemic, it was carried out an analysis using the K-function and it was observed spatial clustering of outbreaks within a range of 25km. This observation may be related to the dynamics of foot-and-mouth disease spread and to the measures undertaken to control the disease dissemination. The control measures were effective once the disease did not spread to farms more than 47 km apart from the initial outbreaks.

Study of infection by Rickettsiae of the spotted fever group in humans and ticks in an urban park located in the City of Londrina, State of Paraná, Brazil

INTRODUCTION: Spotted fevers are emerging zoonoses caused by Rickettsia species in the spotted fever group (SFG). Rickettsia rickettsii is the main etiologic agent of Brazilian spotted fever (BSF) and it is transmitted by Amblyomma spp. ticks. METHODS: The study aimed to investigate SFG rickettsiae in the Arthur Thomas Municipal Park in Londrina, PR, by collecting free-living ticks and ticks from capybaras and blood samples from personnel working in these areas. Samples from A. dubitatum and A. cajennense were submitted for PCR in pools to analyze the Rickettsia spp. gltA (citrate synthase gene). RESULTS: All the pools analyzed were negative. Human sera were tested by indirect immunofluorescence assay with R. rickettsii and R. parkeri as antigens. Among the 34 sera analyzed, seven (20.6%) were reactive for R. rickettsii: four of these had endpoint titers equal to 64, 2 titers were 128 and 1 titer was 256. None of the samples were reactive for R. parkeri. An epidemiological questionnaire was applied to the park staff, but no statistically significant associations were identified. CONCLUSIONS: The serological studies suggest the presence of Rickettsiae related to SFG that could be infecting the human population studied; however, analysis of the ticks collected was unable to determine which species may be involved in transmission to humans.

What are the similarities between stress, sudden cardiac death in Gallus gallus and sudden unexpected death in people with epilepsy

Individuals with epilepsy are at higher risk of sudden unexpected death in epilepsy (SUDEP), responsible for 7.5% to 17% of all deaths in epilepsy. Many factors are current associated with SUDEP and possible effect of stress and cardiac arrhythmia are still not clear. Sudden death syndrome (SDS) in chickens is a disease characterized by an acute death of well-nourished and seeming healthy Gallus gallus after abrupt and brief flapping of their wings, similar to an epileptic seizure, with an incidence estimated as 0.5 to 5% in broiler chickens. A variety of nutritional and environmental factors have been included: but the exactly etiology of SDS is unknown. Studies had suggested that the hearts of broiler chickens are considerably more susceptible to arrhythmias and stress may induce ventricular arrhythmia and thus, sudden cardiac death. In this way, SDS in Gallus gallus could be an interesting model to study SUDEP.

Flow cytometry as a tool in the evaluation of blood leukocyte function in Chelonia mydas (Linnaeus, 1758) (Testudines, Cheloniidae)

Chelonia mydas is a sea turtle that feeds and nests on the Brazilian coast and a disease called fibropapillomatosis is a threat to this species. Because of this, it is extremely necessary to determine a methodology that would enable the analysis of blood leukocyte function in these sea turtles. In order to achieve this aim, blood samples were collected from C. mydas with or without fibropapillomas captured on the São Paulo north coast. Blood samples were placed in tubes containing sodium heparin and were transported under refrigeration to the laboratory in sterile RPMI 1640 cell culture medium. Leukocytes were separated by density gradient using Ficoll-PaqueTM Plus, Amershan Biociences®. The following stimuli were applied in the assessment of leukocyte function: Phorbol Miristate-Acetate (PMA) for oxidative burst activity evaluation and Zymosan A (Saccharomyces cerevisiae) Bio Particles®, Alexa Fluor® 594 conjugate for phagocytosis evaluation. Three cell populations were identified: heterophils, monocytes and lymphocytes. Monocytes were the cells responsible for phagocytosis and oxidative burst.

Hematological profile of Chelonia mydas (Testudines, Cheloniidae) according to the severity of fibropapillomatosis or its absence

The green turtle Chelonia mydas feeds and nests in the Brazilian coastal area and is considered an endangered species by the World Conservation Union (IUCN 2009) and threatened by the Red List of Brazilian Fauna (Ministério do Meio Ambiente 2009). Fibropapillomatosis is a disease characterized by benign skin tumors (fibropapillomas), and it is one of the main threats to the survival of this species. Studies suggest the involvement of viruses as infectious agents associated with environmental and genetic factors. Blood samples were collected from 45 turtles captured in the coastal area of the state of Sao Paulo, Brazil. From these, 27 were affected by fibropapillomas and 18 were tumor free. Biometrical data on the turtles, size, location and quantity of tumors were recorded. The area occupied by fibropapillomas per animal was calculated and four groups were determined according to severity of the disease or its absence. The objective of the study was to compare hemogram results of the sea turtles classified in these four groups. The lowest hematocrit value was observed in severely affected animals. In the hemoglobin assay, the highest value was observed in the group of tumor free turtles and the lowest, in animals severely affected. Lymphocyte counts and curved carapace length were on the verge of statistical significance.

Infecção por C. psittaci: uma revisão com ênfase em psitacídeos

A clamidiose ou ornitose é uma doença infecciosa, causada pela bactéria Chlamydophila psittaci, que acomete aves e mamíferos. Trata-se de uma das principais zoonoses de origem aviária. A transmissão ocorre principalmente por inalação de secreções contaminadas. Os sinais clínicos mais comuns incluem alterações no sistema gastrointestinal, respiratório e ocular, porém é possível encontrar aves infectadas sem sinais aparentes, dificultando a identificação da doença. O diagnóstico definitivo em aves vivas pode ser difícil, devido às características da infecção pela bactéria. Há duas principais abordagens para o diagnóstico, a primeira envolve a detecção direta da bactéria e a segunda implica a detecção de anticorpos anti-Chlamydophila sp. O tratamento é longo e envolve o uso de tetraciclinas, quinolonas ou macrolídeos, durante 21-45 dias, dependendo da espécie e do fármaco de escolha. Atualmente, o Brasil não dispõe de medidas padronizadas que visam a guiar o clínico na identificação, manejo e tratamento para a doença. Tais medidas tornam-se necessárias, bem como a pesquisa de novos métodos diagnósticos e auxiliares para a doença.

Isolamento de Salmonella enterica em gambás (Didelphis aurita e Didelphis albiventris) do Estado de São Paulo, Brasil

No Brasil, não há relato de estudos de Salmonella em gambás, sendo assim, este trabalho tem por objetivo determinar a frequência de isolamento de Salmonella enterica em gambás (D. aurita e D. albiventris) no Estado de São Paulo. No período de janeiro de 2005 a dezembro de 2006, foram necropsiados 106 D. aurita e 40 D. albiventris e colhidos fragmentos de intestinos delgado, grosso e suabe da cloaca. As amostras foram plaqueadas diretamente em ágar Mac Conkey, paralelamente suspendidas nos caldos Rappaport-Vassiliadis e Tetrationato e posteriormente plaqueados em ágar XLT4. As colônias sugestivas de Salmonella foram confirmadas através de provas bioquímicas e sorotipagem. Encontrou-se Salmonella enterica em 17,0% (18/106) dos D. aurita. Destes, 50% apresentaram positividade no intestino delgado (ID), 88,9% no intestino grosso (IG) e 66,7% na cloaca. Da espécie S. enterica, as subespécies encontradas foram: diarizonae (11,1%) houtenae e enterica (5,5% cada um); enquanto da subespécie S. enterica enterica os sorotipos foram Newport (83,3%), Typhimurium e Cerro (5,5% cada um). Nos D. albiventris, 17,5% (7/40) eram positivos, sendo que se encontraram 42,8% no ID, 85,7% no IG e 71,4% na cloaca. O sorotipo mais prevalente também foi Newport (71,4%), seguido por Typhimurium, Bareilly e Thompson (14,3% cada um). Através dos resultados obtidos neste estudo pode-se comprovar a presença de Salmonella enterica no trato intestinal de gambás no Brasil.

Produção in vitro de embriões de ovinos: uma visão crítica do método e de seu resultado a campo

A metodologia de produção in vitro de embriões de ovinos implica no desenvolvimento de meios de maturação, fertilização e cultivo que permitam aumentar a taxa de clivagem e desenvolvimento, tanto para o investimento biotecnológico em programas comerciais, quanto para sua utilização em clonagem e transgenia dessa espécie animal. Do ponto de vista da pesquisa, os ovócitos podem ser obtidos pelas técnicas de punção e slicing a partir de ovários oriundos de matadouros, ou através de aspiração folicular por laparoscopia. Como vantagem, este método permite o uso de uma mesma doadora estimulada hormonialmente em intervalos periódicos, mantida sob rigoroso controle sanitário, o que é de vital importância para a produção de biofármacos em programas que utilisem os ovinos como modelo biológico. Por outro lado, em nosso país a demanda pela multiplicação de animais de alto valor genético, seja pela produtividade ou pelo elevado valor comercial dos mesmos, impõe o desenvolvimento, adaptação e otimização das diferentes metodologias desenvolvidas ao longo dos ultimos anos em laboratórios de referência mundiais. Nesse contexto, cresce de importância o perfeito conhecimento da fisiologia dessa espécie e das raças criadas em nosso país, e da problemática da produção in vitro de seus embriões. Respeitando essas premissas, gerar o desenvolvimento de protocolos que permitam não apenas aumentar a população de ovócitos passíveis de maturação in vitro, mas de sua competência ao desenvolvimento ao estágio de blastocisto, ou, alternativamente, sua transferência a receptoras em estágios precoces do desenvolvimento, evitando assim as conhecidas perdas durante o desenvolvimento in vitro, e o baixo percentual de gestações que chegam a termo, com cordeiro saudáveis. Trata-se de um desafio, que já apresenta os primeiros resultados em nosso país, tanto na produção comercial de embriões produzidos in vitro, quanto em programas de clonagem e transgenia.

Microbiological and histopathological aspects of canine pyometra

As pyometra is recognized as one of the main causes of disease and death in the bitch the purposes of this study were to evaluate microbiological and histopathological aspects of canine pyometra and to research the virulence factors of the E. coli isolates identifying possible risks to human health. The microbiological isolation from the intrauterine contents of 100 dogs with pyometra was carried out and the virulence factors in the E. coli strains were identified using PCR method. This study also consisted of the counting of microorganisms colonies forming units in samples of intrauterine content, tests of antimicrobial susceptibility of the E. coli isolates and the histological examination of the uterus. E. coli was the most prevalent microorganism isolated (76.6%) and 120 strains (79.5%) were positive for sfa, 86 (56.9%) were positive for cnf, 87 (57.6%) were positive for pap, 52 (34.4%) were positive for hly, 51 (33.8%) were positive for iuc and 5 (3.3%) were positive for afa genes. One observed more sensitivity of E. coli to norfloxacin, polimixin B, sulphazotrin, chloranfenicol and enrofloxacin. In 42% of the samples of uterine walls where microorganisms were isolated, the sizes of the areas of the inflammatory responses corresponded to 39-56%. Virulence factors were identified in 98.0% of the strains evaluated, demonstrating a high frequency of potentially pathogenic E. coli. It must be considered that dogs are animals that are living in close proximity to man for thousands of years and have an important role in the transmission of E. coli to other animals and to man.