Giardia duodenalis, Cryptosporidium spp. and Toxoplasma gondii are protozoan parasites that have been highlighted as emerging foodborne pathogens by the Food and Agriculture Organization of the United Nations and the World Health Organization. According to the European Food Safety Authority, 4786 foodborne and waterborne outbreaks were reported in Europe in 2016, of which 0.4% were attributed to parasites including Cryptosporidium, Giardia and Trichinella. Until 2016, no standardized methods were available to detect Giardia, Cryptosporidium and Toxoplasma (oo)cysts in food. Therefore, no regulation exists regarding these biohazards. Nevertheless, considering their low infective dose, ingestion of foodstuffs contaminated by low quantities of these three parasites can lead to human infection. To evaluate the risk of protozoan parasites in food, efforts must be made towards exposure assessment to estimate the contamination along the food chain, from raw products to consumers. This requires determining: (i) the occurrence of infective protozoan (oo)cysts in foods, and (ii) the efficacy of control measures to eliminate this contamination. In order to conduct such assessments, methods for identification of viable (i.e. live) and infective parasites are required. This review describes the methods currently available to evaluate infectivity and viability of G. duodenalis cysts, Cryptosporidium spp. and T. gondii oocysts, and their potential for application in exposure assessment to determine the presence of the infective protozoa and/or to characterize the efficacy of control measures. Advantages and limits of each method are highlighted and an analytical strategy is proposed to assess exposure to these protozoa.

Fungal respiratory colonization of cystic fibrosis (CF) patients emerges as a new concern; however, the heterogeneity of mycological protocols limits investigations. We first aimed at setting up an efficient standardized protocol for mycological analysis of CF sputa that was assessed during a prospective, multicenter study: "MucoFong" program (PHRC-06/1902). Sputa from 243 CF patients from seven centers in France were collected over a 15-month period and submitted to a standardized protocol based on 6 semi-selective media. After mucolytic pretreatment, sputa were plated in parallel on cycloheximide-enriched (ACT37), erythritol-enriched (ERY37), benomyl dichloran-rose bengal (BENO37) and chromogenic (CAN37) media incubated at 37 °C and on Sabouraud-chloramphenicol (SAB27) and erythritol-enriched (ERY27) media incubated at 20-27 °C. Each plate was checked twice a week during 3 weeks. Fungi were conventionally identified; time for detection of fungal growth was noted for each species. Fungal prevalences and media performances were assessed; an optimal combination of media was determined using the Chi-squared automatic interaction detector method. At least one fungal species was isolated from 81% of sputa. Candida albicans was the most prevalent species (58.8%), followed by Aspergillus fumigatus (35.4%). Cultivation on CAN37, SAB27, ACT37 and ERY27 during 16 days provided an optimal combination, detecting C. albicans, A. fumigatus, Scedosporium apiospermum complex and Exophiala spp. with sensitivities of 96.5, 98.8, 100 and 100%. Combination of these four culture media is recommended to ensure the growth of key fungal pathogens in CF respiratory specimens. The use of such consensual protocol is of major interest for merging results from future epidemiological studies.

Summary :Cryptosporidiosis emergence triggered the screening of many compounds for potential anti-cryptosporidial activity in which the majority were ineffective. The outbreak of cryptosporidiosis which occurred in Milwaukee in 1993 was not only the first significant emergence of Cryptosporidium spp. as a major human pathogen but also a huge waterborne outbreak thickening thousands of people from a major city in North America. Since then, outbreaks of cryptosporidiosis are regularly occurring throughout the world. New drugs against this parasite became consequently urgently needed. Among the most commonly used treatments against cryptosporidiosis are paromomycin, and azithromycin, which are partially effective. Nitazoxanide (NTZ)'s effectiveness was demonstrated in vitro, and in vivo using several animal models and finally in clinical trials. It significantly shortened the duration of diarrhea and decreased mortality in adults and in malnourished children. NTZ is not effective without an appropriate immune response. In AIDS patients, combination therapy restoring immunity along with antimicrobial treatment of Cryptosporidium infection is necessary. Recent investigations focused on the potential of molecular-based immunotherapy against this parasite. Others tested the effects of probiotic bacteria, but were unable to demonstrate eradication of C. parvum. New synthetic isoflavone derivatives demonstrated excellent activity against C. parvum in vitro and in a gerbil model of infection. Newly synthesized nitroor non nitro-thiazolide compounds, derived from NTZ, have been recently shown to be at least as effective as NTZ against C. parvum in vitro development and are promising new therapeutic agents.

A case of metronidazole- and albendazole-resistant giardiasis in a patient with the acquired immunodeficiency syndrome was successfully treated with nitazoxanide (1.5 g twice a day for 30 days). Animal studies and in vitro assays showed that the isolate was resistant to both metronidazole and albendazole and susceptible to nitazoxanide.

The effects of nitazoxanide and its metabolites, tizoxanide and tizoxanide glucuronide, on the development of the asexual and sexual stages of Cryptosporidium parvum in differentiated human enterocytic HCT-8 cells were evaluated in a quantitative alkaline phosphatase immunoassay. Nitazoxanide, tizoxanide and tizoxanide glucuronide were inhibitory for up to 46 h when added after sporozoite invasion (MIC50 1.2, 22.6 and 2.2 mg/L, respectively). Tizoxanide had only limited activity, but nitazoxanide and tizoxanide glucuronide strongly inhibited asexual and sexual stages, respectively.

Invasive Geotrichum clavatum fungal infections are extremely rare and unusual, occurring nearly exclusively in patients experiencing prolonged neutropenia during the treatment for acute myeloid leukaemia. Several groups of cases of fatal G. clavatum infection were reported in France between 2011 and 2012, but the ecological niche has not yet been identified. We report a case of a 32-year-old patient with acute myeloid leukaemia who developed G. clavatum sepsis with primary peritonitis, hepatic nodular lesions, and multivisceral failure during aplasia after induction followed by salvage chemotherapy. He was treated with voriconazole and is still alive 1 year after with controlled disease. We then discuss the epidemiological, clinical, and therapeutic features of these serious fungal infections compared to the published data.

Irritable bowel syndrome (IBS) is the most frequent functional gastrointestinal disorder. It is characterized by abdominal hypersensitivity, leading to discomfort and pain, as well as altered bowel habits. While it is common for IBS to develop following the resolution of infectious gastroenteritis [then termed postinfectious IBS (PI-IBS)], the mechanisms remain incompletely understood. Giardia duodenalis is a cosmopolitan water-borne enteropathogen that causes intestinal malabsorption, diarrhea, and postinfectious complications. Cause-and-effect studies using a human enteropathogen to help investigate the mechanisms of PI-IBS are sorely lacking. In an attempt to establish causality between giardiasis and postinfectious visceral hypersensitivity, this study describes a new model of PI-IBS in neonatal rats infected with G. duodenalis At 50 days postinfection with G. duodenalis (assemblage A or B), long after the parasite was cleared, rats developed visceral hypersensitivity to luminal balloon distension in the jejunum and rectum, activation of the nociceptive signaling pathway (increased c-fos expression), histological modifications (villus atrophy and crypt hyperplasia), and proliferation of mucosal intraepithelial lymphocytes and mast cells in the jejunum, but not in the rectum. G. duodenalis infection also disrupted the intestinal barrier, in vivo and in vitro, which in turn promoted the translocation of commensal bacteria. Giardia-induced bacterial paracellular translocation in vitro correlated with degradation of the tight junction proteins occludin and claudin-4. The extensive observations associated with gut hypersensitivity described here demonstrate that, indeed, in this new model of postgiardiasis IBS, alterations to the gut mucosa and c-fos are consistent with those associated with PI-IBS and, hence, offer avenues for new mechanistic research in the field.

We studied COVID-19 associated mucormycosis based on 17 cases reported nationwide and assessed the differences with India. They differed by frequencies of diabetes mellitus (47% in France versus up to 95% in India), hematological malignancies (35% versus 1%), anatomical sites (12% versus >80% rhino-orbito-cerebral) and prognosis (88% mortality versus <50%).