Corticosteroid therapy is known to be hazardous in patients with occult infection but the mechanism by which the host parasite relationship is altered by steroids is not known. We have used an intestinal protozoal parasite, Giardia muris, to examine the effects of corticosteroids on the number of parasites in the intestine in the course of a primary infection. A single injection of cortisone ac...

Giardia is a protozoan flagellate that was first observed by chymotrypsin and trypsin, producing two trophozoites (vegetative stage) from each cyst [6, 7]. The trophozoites replicate in Van Leeuwenhoek in 1681 and more fully described by Lamb in 1859. It was initially thought to be a commensal in humans, the crypts of the duodenum and upper jejunum and reproduce asexually by binary fission. Som...

We describe the synthesis of a novel hydrophilic derivative of a tetradentate β-diketone europium ligand that was used to prepare an immunoconjugate probe against Giardia lamblia cysts. We used a Gated Autosynchronous Luminescence Detector (GALD) to obtain high quality delayed luminescence images of cells 30-fold faster than ever previously reported.

Giardia and Cryptosporidium are the most frequent enteric protozoa causing gastroenteritis in humans worldwide. Intense recreational activity at Portuguese river beaches triggered the opportunity for a 2-year seasonal survey of 19 large river basin beaches. A total of 74 samples were collected and processed according to USEPA Method 1623 to detect Cryptosporidium and Giardia (oo)cysts. Faecal i...

In developing wastewater treatment regulations and guidelines for potable reuse, the reduction of pathogens is critical importance. draft regulations, state California has proposed overall process log values (LRVs) 20, 14, 15 respectively viruses, Giardia cysts, Cryptosporidium oocysts, direct reuse. meeting requirements, agencies have sought to obtain credit LRVs achieved consistently through ...

Expression of TSA 417, the predominant cysteine-rich variable surface protein of Giardia lamblia WB clone C6 trophozoites, did not change during encystation in vitro. However, in vitro excystation of cysts derived in vitro or in vivo consistently produced TSA 417 nonexpressing trophozoite populations, suggesting that completion of the life cycle leads to antigenic switching.

Bile salts and fatty acids stimulated differentiation of cultured Giardia lamblia trophozoites into water-resistant cysts at the slightly alkaline pH of the small intestinal lumen. Maximum encystation occurred at pH 7.8. Thus, specific small-intestinal factors may influence encystation in vivo as well as in vitro.

We present the case of a 32-year-old French man who presented with morning nausea, bloating, frequent flatulence, burping, occasional pyrosis, and alternating diarrhea and constipation two weeks after a trip to Morocco. The diagnosis was established by a parasitological stool exam that revealed cysts of Giardia lamblia. He was successfully treated with tinidazole.

A novel quantitative PCR (qPCR) for Giardia at the glutamate dehydrogenase (gdh) locus was developed and validated. The qPCR was used to screen a total of 3412 lamb faecal samples collected from approximately 1189 lambs at three sampling periods (weaning, post-weaning and pre-slaughter) from eight farms across South Australia (SA), New South Wales (NSW), Victoria (Vic) and Western Australia (WA...

Cysts of Giardia lamblia and Entamoeba histolytica and oocysts of Toxoplasma gondii and Cryptosporidium parvum are the infectious and sometimes diagnostic forms of these parasites. To discover the structural components of cyst and oocyst walls, we have developed strategies based upon a few simple assumptions. Briefly, the most abundant wall proteins are identified by monoclonal antibodies or ma...