Xenodiagnosis in four domestic cats naturally infected by Leishmania infantum.

Leishmaniasis is a neglected tropical disease that continues to pose a serious public health problem. Albeit dogs have long been held as the major reservoirs of Leishmania infantum, the involvement of domestic cats in the zoonotic cycle of visceral leishmaniasis has gained prominence. Here, 240 cats were evaluated by clinical signs and haematological/biochemical changes compatible with leishmaniasis and were diagnosed by serological, molecular, and parasitological techniques. Thus, four cats naturally infected by L. infantum were submitted to xenodiagnosis. A total of 203 females of Lutzomyia longipalpis were subjected to feeding on four cats, with all females completing the blood meal. Parasitological and molecular assays were carried out to evaluate the presence of L. infantum in the sand flies' midgut. Promastigotes were observed in 10 females (6.5%) that fed on one cat, and L. infantum DNA was detected in 17 (8.4%) females that fed on two cats. Our results strengthen the evidence that naturally infected cats are capable of transmitting L. infantum to sand flies.

DNA extraction from individual Phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae) specimens: Which is the method with better results?

Phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae) are a group of small insects of great concern for Public Health. These dipterous are intensely studied worldwide due to their involvement in the transmission of several pathogens, mainly Leishmania spp. parasites. Nowadays, the molecular tools have been included in Phlebotomine sand flies studies and has shown to be powerful tools in bioecology studies of these dipterous. Thereby, when molecular approaches are employed, there is a great concern regarding the amount and quality of the DNA obtained for analysis. Here, seven methods of DNA extraction, between commercial kits and in house extraction protocols were evaluated. We considered measure of DNA concentration and purity ratios using a spectrophotometer to check the performance of each protocol. In addition, the quality evaluation of the DNA extracted was performed by endogenous gene PCR on samples. The results of the seven evaluated DNA extraction protocols and their implications are discussed.

Conjunctival swab PCR to detect Leishmania spp. in cats.

The relevance of the dog as a source of visceral leishmaniasis infection is known, but the role of cats as reservoir hosts for leishmaniasis is not yet fully clear. This study assessed the efficacy of conjunctival swab PCR (CS-PCR) in the detection of cats infected by Leishmania spp. The results were seven (13.5%) cats positive for Leishmania spp. in the PCR, in 52 cats tested from Pirassunuga-SP and Ilha Solteira-SP. From the city of Pirassununga - SP 28.6% (2/7) were positive and from the city of Ilha Solteira - SP 11.1% (5/45) were positive. The results showed that CS-PCR was capable of detecting cats infected by this protozoan. Conjunctival swab samples proved easier to perform in cats, which might facilitate studies on the frequency and distribution of feline leishmaniasis.

Serology, isolation, and molecular detection of Leptospira spp. from the tissues and blood of rats captured in a wild animal preservation centre in Brazil.

To elucidate the occurrence and epidemiology of leptospirosis in rats cohabitating with forest animals, 13 rats were captured at seven locations of the Centre for the Conservation of Wild Fauna (CCWF) in Sao Paulo state, Brazil, and samples of their blood, liver, and kidneys were collected. The diagnostic techniques utilized were the microscopic agglutination test (MAT), polymerase chain reaction (PCR) for Leptospira spp., and cultures of rat kidneys and liver in Fletcher's medium. The MAT results showed that 13 (100%) of the samples were reactive to 12 serovars among the 29 Leptospira spp. tested, and the Australis and Tarassovi serovars were the most frequently identified serovars. To research the agent in fragments of the liver and kidney, 13 samples from each tissue were cultured in Fletcher's medium, and the results revealed seven positive samples (53.8%; three from the kidneys and four from the livers). The analysis of the blood samples by PCR for Leptospira spp. showed that six animals (46.1%) were positive, whereas the analysis of the organs (kidneys and liver) by PCR revealed that nine animals (69.2%) were positive, and the culture of the organs revealed four positive animals (30.8%). These results suggest that the presence of Leptospira spp. infection in rats at the study site and the knowledge of the serovars that exist in this environment are important for the epidemiological comprehension of the disease and for the identification of control measures that should be considered to reduce the risk of transmission of the disease through this animal reservoir.