Ecoepidemiology of Leishmaniasis in the Chaco Region Argentina, with emphasis in Bio-control proposal by Bacteria native strains

ENRIQUE ALEJANDRO SZELAG; JUAN RAMÓN ROSA; LUIS ANTONIO MERINO; OSCAR DANIEL SALOMÓN

Belo Hotizonte

Workshop; Gnatwork workshop; 2019

Gnatwork, Pirbright intitute, London school of hygiene & tropical medicine

In the Argentinian Chaco Region, Tegumentary Leishmaniasis (TL) is reported since 1950, presenting sporadic outbreaks, with an increasing trend of incidence. Visceral Leishmaniasis human cases are not reported yet in the province, but the records of infected canines is growing, besides the vector was recorded in the area since 2010. In the Chaco province we found 20 out of the 38 Phlebotominae species recorded in Argentina, being Nysomyia neivai the most abundant species and considered responsible for the larger TL outbreaks in the country. A high heterogeneity of fauna abundance and distribution was reported at microfocal scales; these differences could be determined by the presence of entomopathogenic fungi, bacteria and protozoa that would act on the Phlebotominae populations, and thereby affecting the transmission of the disease. Based on this hypothesis, a project was started with the aim of isolating and identifying native strains of bacteria with entomopathogenic effect that could act as biocontrollers. Twenty Bacillus sp. isolates were obtained from soil samples, and identified by API-50CH and MALDI-TOF. The chitinolytic activity of each strain was determined in a minimal medium containing colloidal chitin and subsequently PCR was performed using 4 pairs of primers designed to detect the presence of coding genes from 4 families of chitinases. Eleven isolates presented ?in vitro? chitinase production while enzyme coding genes were detected in twelve of them. The entomopathogenic effect of these isolates is expected to be tested in experimental colonies of phlebotominae with the aim of developing biocontroller systems.