Sorovariedades de Leptospira sp. circulantes em duas espécies de peixes neotropicais em área lacustre maranhense, Brasil

Abstract

Leptospirosis is a zoonosis with a cosmopolitan distribution whose etiological agent can infect different animal species and accidentally infect humans. Despite the wide variety of hosts, there is a scarcity of studies on the occurrence of the disease in species living in aquatic habitats. In this sense, the objective was to diagnose the serovarities of Leptospira sp. circulating in two species of neotropical fish from the quilombola area of Maranhão. To this end, the study was divided into three stages: (i) bibliographical survey on the topic under study, with a search in the databases Pubmed, SciELO, Periódicos Capes, Catalog of Theses and Dissertations Capes, Theses and Dissertations of Postgraduate Programs graduation from the state of Maranhão, in addition to websites of Official Bodies, using Boolean connectors and signals as search strategies, according to the methodology of each database and also inclusion and exclusion criteria; (ii) field activity with the measurement of abiotic parameters (temperature, hydrogen potential and salinity) of the water in the fish capture environment, using a multiparameter instrument and capture of 42 fish specimens, 21 of which were Hoplerythrinus unitaeniatus (jeju) and 21 Cichlasoma bimaculatum (black acará). The captured fish were transported alive in isothermal boxes with water from the capture site, equipped with equipment to oxygenate the water, to the State University of Maranhão. In a laboratory environment, blood samples were collected by channeling branchial veins. The sera obtained were tested for anti-leptospira agglutinins against 25 serovars of the Leptospira sp. complex. using the microscopic seroagglutination technique; and, (iii) preparation of a guide on health and the environment in quilombola communities. As results of the first stage of the study, the bacteria identified in the bibliographical survey were total and thermotolerant coliforms, Escherichia coli, Salmonella spp., Aeromonas cavie, A. hydrophila, A. veroni biovar veron, A. schubertii, A. trota, Staphylococcus sp. and positive coagulase, Citrobacter sp. and Serratia odirifera. None of the bacteria identified in this survey are included in the list of notifiable diseases of the Ministry of Agriculture, Livestock and Supply and the World Organization for Animal Health. As for the second stage of the study, the sampled environment found characteristics favorable to the survival of Leptospira sp. such as the low speed of the water; pH of 7.31; and, temperatures of 28.3 °C. The total occurrence of anti-Leptospira agglutinins in the study was 80.95% (n=34/42) with titers ranging from 1:100 to 1:400. The serovarities of the Leptospira sp. The most frequent were: Pomona, Hebdomadis, Butembo, Copenhageni, Cynopteri, Panama, Sentot, Bratislava, Icteriohaemorragiae, Pomona variant Bubalinos, Pyrogenes, Whitcombi. Leptospirosis, an infectious disease documented worldwide in several animal species and in humans, infects native fish H. unitaeniatus and C. bimaculatum with high percentages of occurrence. Health education actions are needed with the quilombola community about the risks of using water and fishing resources from the flooded environment studied. It is also necessary to investigate the sources of infection for fish and apply appropriate measures to prevent leptospirosis in this geographic area. It is expected that the results obtained in this study and the guidance prepared in the third part stage of the study can help in the discussion and development of control strategies for leptospirosis in quilombola areas whose economy is based, above all, on artisanal fishing.