Isolamento e caracterização molecular de Leptospira sp. em animais silvestres do Semiárido da Paraíba.

Abstract

Leptospirosis is a zoonotic bacterial disease that is among the most widespread globally, affecting domestic animals, wild and humans. This infection is caused by pathogenic species of Leptospira sp., Which can penetrate the host through intact or damaged skin, by direct contact with the urine of an infected animal or through contaminated water. The occurrence of leptospirosis is linked to environmental factors and the presence of reservoir animals, and for the control of the disease a crucial step is the identification of these hosts that are sources of infection, which are responsible for spreading the agent in the environment. A series of studies carried out in the Semi-arid region of the Northeast allow for an understanding of the occurrence of leptospirosis in several species of domestic animals, however there is a gap about knowledge in wild species, as well as their role in the disease transmission cycle. Therefore, the objective was to investigate the occurrence of Leptospira sp. in the species teiú (Tupinambis merianae) and gambá-de-orelha-branca (Didelphis albiventris) from the semiarid region of Paraíba. For this, the Brazilian Institute of the Environment and Renewable Natural Resources (IBAMA) authorized the capture of 12 teiús and 12 possums (protocol Nº57190-1). Samples of tissue from the reproductive tract, kidney, liver and bladder, in addition to urine, were collected for molecular detection (tissue from the central nervous system was still collected) and attempted isolation, and blood serum for serological testing. The molecular test performed was the polymerase chain reaction (PCR) and the serological test was the microscopic agglutination test (SAM), in an attempt to isolate were used the medium culture Fletcher, EMJH and EMJH enriched with antibiotics, in addition to the samples with amplification of DNA were subjected to genetic sequencing. In the teiús, six (50%) animals were found with anti-Leptospira sp. antibodies, the majority of the reactions for the serogroup Tarassovi (50%) and Pyrogenes (33,3%), the leptospiral DNA was detected in nine (75%) animals, and the genes from two samples (liver and urine) were sequenced and showed identity to Leptospira interrogans. In opossums, no anti-Leptospira sp. antibodies were found. In none of the serological samples, the leptospiric DNA was detected in the central nervous system (SNC) of five animals (41.7%), the gene from one of these samples was sequenced. and presented identity with Leptospira interrogans. In none of the species there was microbial growth in the cultured tissues. The results show that the Tupinambis merianae participate in the epidemiological cycle of leptospirosis in the Semiarid region, being a source of infection for domestic animals and humans. And the presence of Leptospira sp. no SNC of Didelphis albiventris does not yet allow characterizing this species as a reservoir with potential for agent transmission in the region, however it represents a location that needs to be further investigated. This shows a difficulty in controlling the disease in regions such as Northeastern Brazil, where there is a diversity of wild species, which through indirect contact has just disseminated the agent to other animals.