Banca de DEFESA: DAIANA SANTOS DE OLIVEIRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : DAIANA SANTOS DE OLIVEIRA
DATA : 22/09/2020
HORA: 14:00
LOCAL: Webconferência
TÍTULO:

Dynamics and diversity of Leptospira spp. of environmental samples and its implications in the transmission of leptospirosis in humans 

PALAVRAS-CHAVES:

Leptospirosis, isolation, physico-chemical, soil, sewage, environment, soroprevalence.

PÁGINAS: 119
GRANDE ÁREA: Ciências Biológicas
ÁREA: Microbiologia
RESUMO:

Leptospirosis is a zoonosis caused by a bacteria of the genus Leptospira. It affects more than one million people annually worldwide, causing approximately 60,000 deaths. Vulnerable urban populations, deprived of infrastructure and basic sanitation, are more exposed to this disease. In those settings, exposure to the environment contaminated by Leptospira is the main route of transmission. Previous studies have demonstrate the presence of pathogenic Leptospira species in environmental matrices. However, information on the dynamics and diversity of pathogenic Leptospira in different environmental matrices from urban areas is limited. Many studies are focused on the analysis of epidemiological and seroprevalence data in animals. However, most of these studies did not consider the environmental determinants and co-circulation of different serogroups / serovars. The present study aimed to characterize the presence, diversity, and dynamics of Leptospira species in different environmental niches, the physical and chemical environmental parameters that are associated with the presence and concentration of Leptospira in aquatic matrices and the epidemiological profile of individuals with the presence of anti-Leptospira antibodies. The research was carried out in five vulnerable urban communities in the city of Salvador-Ba, with lack of basic sanitation, where leptospirosis is endemic. Our results shown that sewage, pooled water and soil are important Leptospira's environmental reservoirs. qPCR positivity rate in sewage and pooled water samples was 36% and 34%, respectively. Positivity rate and concentration were higher in the rainy period, sugesting that rain plays an important role in pathogen dispersion and maintenance. Physical-chemical factors such as TDS (Total Dissolved Solids), salinity and pH were associated with the presence and concentration of the bacteria in the environment. Using isolation technique, we identified a diversity of Leptospira species in soil, including intermediate and pathogenic leptospires. However we were not able to identify the two more frequent leptospires related to human transmission (L. interrogans sorovar Copenhageni and L. Kirschneri sorovar Cynopteri). Moreover, our data suggest specific epidemiological patterns associated with the transmission of Copenhageni and Cynopteri. Future studies aimed at identifying the Cynopteri reservoir in urban communities are necessary. Thus, these data can assist in the development of more effective disease prevention strategies.

 

MEMBROS DA BANCA:
Externo ao Programa - 1213625 - CARLOS ROBERTO FRANKE
Interno - 249.563.328-58 - LEONARDO PAIVA FARIAS - USP
Externo ao Programa - 1675209 - MELISSA HANZEN PINNA VALENTIM
Presidente - 287831 - MITERMAYER GALVAO DOS REIS
Externo ao Programa - 1879071 - PAULA CARVALHAL LAGE VON BUETTNER RISTOW