Ecological implications on the aggregation of Amblyomma fuscum (Acari: Ixodidae) on Thrichomys laurentius (Rodentia: Echimyidae), in northeastern Brazil.

We investigated the Amblyomma fuscum load on a pullulating wild rodent population and the environmental and biological factors influencing the tick load on the hosts. One hundred and three individuals of Thrichomys laurentius were caught in an Atlantic forest fragment in northeastern Brazil, as part of a longitudinal survey on ticks infesting non-volant small mammals. Ticks (n = 342) were found on 45 individuals and the overall mean intensity of infestation was 7.6 ticks per infested rodent. Ticks were highly aggregated in the host population and the negative binomial distribution model provides a statistically satisfactory fit. The aggregated distribution was influenced by sex and age of the host. The microhabitat preference by T. laurentius probably increases contact opportunities between hosts and aggregated infesting stages of the ticks and represents important clues about the habitat suitability for A. fuscum.

Microbiologia de swabs retais e otológicos em carnívoros silvestres do zoológico do Parque Estadual de Dois Irmãos, Pernambuco / Microbiology of rectal and otologic swabs of wild carnivores from the Zoo of the Parque Estadual de Dois Irmãos, Pernambuco, Brazil

O estudo epidemiológico de patógenos em populações selvagens no ambiente in situ e ex situ é fundamental para implementação de programas de prevenção, controle e monitoramento de enfermidades e para elaboração de políticas públicas de saúde pública e animal. O estudo foi realizado no zoológico do Parque Estadual de Dois Irmãos no período de janeiro a julho de 2011 onde foram coletados swabs anais e otológicos referentes a 29 carnívoros silvestres cativos do zoológico. Dos swabs otológicos analisados, 1/29 (3,4%) foi positivo para Malassezia pachy dermatis no exame direto. No exame microbiológico dos swabs otológicos, observou-se maior freqüência para bactérias do gênero Bacillus 16/29 (55,2%), seguida de Sta phylococcus 15/29 (51,7%), Escherichia coli 7/29 (24,1%), Streptobacillus 1/29 (3,4%), Micrococcus 1/29 (3,4%) e Klebsiella 1/29 (3,4%). Com relação ao exame presuntivo para o gênero Salmonella a partir das amostras de swab retal, observou-se positividade para seis raposas (Cerdocyon thous) e um guaxinim (Procyon cancrivorus). O isolamento de Salmonella spp. em C. thous e em P. cancrivorus indica um risco à saúde pública, principalmente para os profissionais do zoológico que trabalham diretamente com esses animais. Essa pesquisa reforça a importância da criação de estratégias de vigilância epidemiológica voltadas para a prevenção, controle e monitoramento de potenciais reservatórios de agentes etiológicos de doenças infecciosas e parasitárias no ambiente dos zoológicos.

The epidemiological study of pathogens in wild populations in the environment in situ and ex situ is essential for implementation of prevention, control and monitoring of diseases and for development of public policies for public and animal health. The study was conducted at the Zoo of Parque Estadual de Dois Irmãos, Recife/PE, Brazil, from January to July 2011, where we collected anal and otological swabs from 29 Zoo's captive wild carnivores. The analysis of the otological swabs showed that 1/29 (3.4%) were positive for Malassezia pachydermatis on direct examination. In the microbiological examination of otologic swabs we found mainly bacteriae of the genus Bacillus 16/29 (55.2%), followed by Staphylococcus 15/29 (51.7%), Escherichia coli 7/29 (24.1%), Streptobacillus 1/29 (3.4%), Micrococcus 1/29 (3.4%) and Klebsiella 1/29 (3.4%). Regarding the presumptive test for the genus Sal monella from rectal swabs, positive samples were observed in six foxes (Cerdocyon thous) and a raccoon (Procyon cancrivorus). The isolation of Salmonella spp. in C. thous and P. can crivorus indicates risks to public health, especially for zoo professionals who work directly with these animals. This research reinforces the importance of establishing surveillance strategies aimed at prevention, control and monitoring of potential reservoirs of the etiologic agents of infectious and parasitic diseases in the environment of zoos.

Exposure of small mammals to ticks and rickettsiae in Atlantic Forest patches in the metropolitan area of Recife, North-eastern Brazil.

Between December 2007 and March 2009, small mammals were captured in 6 Atlantic Forest patches in Brazil. We assessed tick-host associations and whether they differ among forest strata, sites, seasons, and host age classes or between sexes. Moreover, we assessed the exposure of animals to Rickettsia spp. In total, 432 animals were captured and 808 ticks were found on 32·9% of them. Significant differences were found among host species, collection sites, and forest strata; microhabitat preference was a strong risk factor for tick infestation. The highest tick density rates were recorded in forest fragments settled in rural areas; 91·3% of the ticks were collected from animals trapped in these forest fragments. A high prevalence (68·8%) of antibodies to Rickettsia spp. was detected among animals. This study suggests that disturbed Atlantic Forest fragments provide an environment for ticks and small mammals, which are highly exposed to rickettsiae. It also indicates that forest patches settled in rural areas are usually associated with higher small mammal diversity as well as with higher tick density rates.