Infectivity of Giardia duodenalis Cysts from UV Light-Disinfected Wastewater Effluent Using a Nude BALB/c Mouse Model.

Giardia duodenalis is a protozoan of public health interest that causes gastroenteritis in humans and other animals. In the city of Campinas in southeast Brazil, giardiasis is endemic, and this pathogen is detected at high concentrations in wastewater effluents, which are potential reservoirs for transmission. The Samambaia wastewater treatment plant (WWTP) in the city of Campinas employs an activated sludge system for sewage treatment and ultraviolet (UV) light for disinfection of effluents.

Comparison of methods for the enumeration of Clostridium perfringens spores in water.

Four methods for enumerating Clostridium perfringens spores in water were evaluated: (1) the IMM (Iron Milk Medium) method (MPN); (2) the LS (Lactose Sulfite Broth) method (MPN); (3) the m-CP (membrane filtration Clostridium perfringens Agar) method (membrane filtration); and (4) the TSC (Tryptose Sulfite Cycloserine Agar) method (membrane filtration). The performance of these methods was compared with that of the DRCM (Differential Reinforced Clostridium Medium) method (MPN) as adopted by CETESB (Brazil's Environmental Sanitation Technology Company) for the analysis of C. perfringens spores in water.

Cryptosporidium spp. and Giardia spp. in surface water supply of Campinas, southeast Brazil.

Surface water contaminated by domestic sewage discharges is a potential source of pathogens, including protozoa. During 2005-2006, the source water (Atibaia River) of the Surface Water Treatment Plant (WTP) of Campinas city, São Paulo, Brazil was sampled to obtain an assessment of Cryptosporidium oocyst and Giardia cyst concentrations. Calcium carbonate flocculation (CCF) and membrane filtration (MF) concentration techniques, with and without purification by immunomagnetic separation (IMS) were evaluated.

Microcystin production by a freshwater spring cyanobacterium of the genus Fischerella.

We investigated the production of a hepatotoxic, cyclic heptapeptide, microcystin, by a filamentous branched cyanobacterium belonging to the order Stigonematales, genus Fischerella. The freshwater Fischerella sp. strain CENA161 was isolated from spring water in a small concrete dam in Piracicaba, São Paulo State, Brazil, and identified by combining a morphological description with 16S rRNA gene sequencing and phylogenetic analysis.

First report of Cryptosporidium spp. oocysts in oysters (Crassostrea rhizophorae) and cockles (Tivela mactroides) in Brazil.

The consumption of oysters and cockles, which are usually eaten raw or lightly-cooked, can cause outbreaks of human diseases, especially if these shellfish are harvested from polluted areas. In Brazil data about the occurrence of pathogens, like hepatitis A virus, in shellfish have been reported but research on natural contamination for pathogenic protozoa is still non-existent. Cryptosporidium oocyst contamination of oysters (Crassostrea rhizophorae) and cockles (Tivela mactroides) was evaluated during two different periods in a coastal area from São Paulo, Brazil.

Comparison of two methodologies for detection of Giardia spp. cysts and Cryptosporidium spp. oocysts in activated sludge samples from a sewage treatment plant in the city of Campinas, São Paulo State, Brazil.

Giardia spp. and Cryptosporidium spp. are recognized worldwide as highly infectious protozoan parasites that can cause severe gastrointestinal disease in humans and animals.

Occurrence of Giardia cysts and Cryptosporidium oocysts in activated sludge samples in Campinas, SP, Brazil.

Giardia and Cryptosporidium have caused several outbreaks of gastroenteritis in humans associated with drinking water. Contaminated sewage effluents are recognized as a potential source of waterborne protozoa. Due to the lack of studies about the occurrence of these parasites in sewage samples in Brazil, we compared the efficiency of two procedures for concentrating cysts and oocysts in activated sludge samples of one sewage treatment plant.