The objective of this study was to evaluate the efficacy of a vaccine in the prevention of Giardia duodenalis infection in calves. Six 2-week old calves were vaccinated subcutaneously with a sonicated G. duodenalis trophozoite vaccine. Six 2-week old control calves received a subcutaneous injection of sterile phosphate-buffered-saline mixed with adjuvant. Injections were repeated after 28 days. Eleven days after the second injection, calves were challenged orally with 1x10(5) purified G. duodenalis cysts from a naturally infected calf. Throughout the study, fecal samples were collected at regular intervals and examined for the presence of G. duodenalis cysts. Blood samples were collected weekly until G. duodenalis challenge and bi-weekly following challenge. Calves were euthanized 14 days after challenge and G. duodenalis trophozoites within the small intestines were enumerated. Serum antibody titers were significantly higher in vaccinated compared to non-vaccinated calves. Vaccinated calves tended to excrete more G. duodenalis cysts in their feces than non-vaccinated calves. The number of trophozoites in the small intestine was not different between vaccinated and non-vaccinated calves. Changes consistent of moderate enteritis were found in the intestines of one vaccinated and one non-vaccinated calf. Despite a serological immune response following vaccination, this vaccine was not efficacious in preventing giardiasis or reducing cyst shedding in calves.
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http://dx.doi.org/10.1016/j.vetpar.2007.01.013 | DOI Listing |
Zoonoses Public Health
December 2024
Parasitology Reference and Research Laboratory, National Centre for Microbiology, Majadahonda, Madrid, Spain.
Introduction: Intestinal microeukaryote parasites are major contributors to the burden of diarrhoea in humans and domestic animals, but their epidemiology in wildlife is not fully understood. We investigated the frequency, genetic diversity and zoonotic potential of protists of animal and public health significance in free-ranging grey wolf (Canis lupus) populations in south-western Europe.
Methods: Individually formed faecal samples collected from necropsied wolves or scat trails in Italy (n = 47), Portugal (n = 43) and Spain (n = 225) during the period 2011-2023 were retrospectively analysed using molecular (PCR and Sanger sequencing) methods.
Food Sci Nutr
November 2024
Department of Pathobiology, Faculty of Veterinary Medicine Lorestan University Khorramabad Iran.
is a protozoan parasite that infects approximately one billion people worldwide. In this study, the effects of lycopene on experimental giardiasis in mice were investigated by evaluating cyst shedding rate, weight changes, duodenal antioxidant status, and histopathological alteration. Ninety-five male mice aged four to six weeks were divided into six groups of 15 and one group of 5 as the negative control.
View Article and Find Full Text PDFJ Water Health
November 2024
School of Public Health, University of São Paulo., Av. Dr Arnaldo 715, 1° floor, 01246-904 São Paulo, Brazil; NARA - Center for Research into Environmental Risk Assessment, Av. Dr Arnaldo 715, 1° floor, 01246-904 São Paulo, Brazil E-mail:
Our study investigated the presence of and in shallow wells used for drinking water (DW) in a rural area. Also, bovine feces were collected from their vicinity. Our findings highlight significant potential risks associated with these pathogens in DW sources.
View Article and Find Full Text PDFGut Pathog
November 2024
Parasitology Reference and Research Laboratory, Spanish National Centre for Microbiology, Health Institute Carlos III, Majadahonda, Spain.
Background: The ubiquitous protozoan parasite Giardia duodenalis is a major contributor to the global burden of diarrhoea, particularly in young children living in poor-resource regions. Although rarely mortal, giardiasis is associated with growth retardation and cognitive impairment in early childhood. Here we investigate the epidemiology of human giardiasis in Iranshahr (south-eastern Iran), a region where this information was previously lacking.
View Article and Find Full Text PDFParasit Vectors
November 2024
College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan, 450000, People's Republic of China.
Background: Giardia duodenalis is a common enteric protozoan parasite that is categorized into eight assemblages (A-H). In particular, assemblages A and B are zoonotic, capable of infecting both humans and animals worldwide, resulting in significant economic losses and public health challenges in epidemic regions. Thus, the development of rapid, accurate and non-laboratory-based diagnostic methods for infected animals is crucial for the effective prevention and control of giardiasis.
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