Label-free detection and enumeration of Giardia cysts in agitated suspensions using in situ microscopy.

Laboratory procedures performed in water treatment studies frequently require the characterization of (oo)cyst suspensions. Standard methods commonly used are laborious, expensive and time-consuming, besides requiring well-trained personnel to prepare samples with fluorescent staining and perform analysis under fluorescence microscopy. In this study, an easy cost-effective in situ microscope was assessed to acquire images of Giardia cysts directly from agitated suspensions without using any chemical labels or sample preparation steps. An image analysis algorithm analyzes the acquired images, and automatically enumerates and provides morphological information of cysts within 10 min. The proposed system was evaluated at different cyst concentrations, achieving a limit of detection of ~30 cysts/mL. The proposed system overcomes cost, time and labor demands by standard methods and has the potential to be an alternative technique for the characterization of Giardia cyst suspensions in resource-limited facilities, since it is independent of experts and free of consumables.

Babesiosis caused by Babesia vogeli in dogs from Uberlândia State of Minas Gerais, Brazil.

Babesia is tick-transmitted protozoan parasites that infect mammalian hosts and have a major impact on farm and pet health-associated costs worldwide. This study aimed to test the prevalence of Babesia spp. infection in a small cohort of dogs at a veterinary hospital and to perform molecular characterization of the Babesia species causing the infection. For the PCR assay, 5 mL of blood was collected by venipuncture of the cephalic or radial veins in 300 dogs of different ages, sex, and breeds, which were presented to the veterinary hospital of the Federal University of Uberlândia between March 2015 and April 2016. In addition, a drop of blood was collected from the marginal blood vessels of the ear of dogs included in this study. Ninety-two (30.67%) were positive for Babesia spp., as determined by microscopic observation of the blood smear, revealing the presence of intra-erythrocyte merozoites. For molecular characterization by PCR, 17 samples were chosen from dogs who were tested positive for Babesia spp. by blood smears. Among them, B. vogeli was found to infect all 17 dogs, as determined by 99-100% sequence identity (closest GenBank match KT246307) using primers PIRO A/PIRO B. Our results indicate that the species observed in these dogs was B. vogeli.