Interactions between free-living amoebae and Cryptosporidium parvum: an experimental study

Free-Living Amebae (FLA) and Cryptosporidium oocysts occasionally share the same environment. From 2004 to 2016, Cryptosporidium was responsible for 60% of 905 worldwide waterborne outbreaks caused by protozoan parasites. The aim of this study was to evaluate interactions between C. parvum oocysts and two common FLAs (Acanthamoeba castellanii and Vermamoeba vermiformis) in a water environment. Encystment and survival of FLAs were evaluated by microscopy using trypan blue vital coloration. Oocysts were numerated on microscopy. Interactions were studied over time in conditions both unfavorable and favorable to phagocytosis. Potential phagocytosis was directly evaluated by several microscopic approaches and indirectly by numeration of microorganisms and oocyst infectivity evaluation. Occasional phagocytosis of C. parvum by FLAs was documented. However, oocyst concentrations did not decrease significantly, suggesting resistance of oocysts to phagocytosis. A temporary decrease of oocyst infectivity was observed in the presence of A. castellanii. The effect of these interactions on C. parvum infectivity is particularly interesting. The biofilm condition could favor the persistence or even the proliferation of oocysts over time. This study demonstrated interactions between C. parvum and FLAs. Further knowledge of the mechanisms involved in the decrease of oocyst infectivity in the presence of A. castellanii could facilitate the development of new therapeutic approaches.

Saprochaete clavata Chorioretinitis in a Post-chemotherapy Immunocompromised 9-Year-Old Child

PURPOSE

To describe the management of bilateral chorioretinitis with Saprochaete clavata in a post-chemotherapy immunocompromised young patient.

METHOD

A retrospective case report.

RESULT

A 9-year-old boy treated with chemotherapy for type 2 acute myeloid leukaemia was diagnosed with Saprochaete clavata (formerly called Geotrichum clavatum) fungaemia. Systematic ocular examination revealed chorioretinitis of the left eye becoming bilateral within the next 3 days. Therapy was based on systemic administration of voriconazole, amphotericin B and flucytosine associated with granulocytic stimulation without stabilizing the ophthalmological situation. Bilateral intravitreal injections of amphotericin B were administered. Voriconazole residual blood concentration was monitored to adjust daily dose. Final best corrected visual acuity in the right eye was 20/50 and 20/20 in the left eye.

CONCLUSION

This is the first report of chorioretinitis with Saprochaete clavata. Because of its unpredictable pharmacokinetics, especially in pediatric population, therapeutic drug monitoring of voriconazole is essential to control fungal infection.

Genetic diversity of Cryptosporidium spp. in non-human primates in rural and urban areas of Ethiopia

Non-Human Primates (NHPs) harbor Cryptosporidium genotypes that can infect humans and vice versa. NHPs Chlorocebus aethiops and Colobus guereza and humans have overlapping territories in some regions of Ethiopia, which may increase the risk of zoonotic transmission of Cryptosporidium. This cross-sectional study examined the molecular prevalence and subtypes of Cryptosporidium spp. from 185 fecal samples of Chlorocebus aethiops and Colobus guereza in rural and urban areas in Ethiopia. Samples were tested for Cryptosporidium infection using nested polymerase chain reaction (PCR), and subtypes were determined by sequencing a fragment of the 60-kDa glycoprotein gene (gp60). Of the 185 samples, fifty-one (27.56%) tested positive for Cryptosporidium infection. The species detected were C. parvum (n = 34), C. hominis (n = 12), and C. cuniculus (n = 3). Mixed infection with C. parvum and C. hominis were detected in 2 samples. Four C. hominis family subtypes (Ia, Ib, Id, and Ie) and one C. parvum family subtype (IIa) were identified. C. hominis IaA20 (n = 7) and C. parvum IIaA17G1R1 (n = 6) were the most prevalent subtypes detected. These results confirm that Chlorocebus aethiops and Colobus guereza can be infected with diverse C. parvum and C. hominis subtypes that can also potentially infect humans. Additional studies could help to understand the role of NHPs in the zoonotic transmission of Cryptosporidium in Ethiopia.

A summary of cryptosporidiosis outbreaks reported in France and overseas departments, 2017–2020

Cryptosporidium is a known foodborne pathogen, ranked fifth out of 24 among foodborne parasites in terms of importance and a cause of many cryptosporidiosis outbreaks worldwide. In France, very few outbreaks were reported before 2017, and data recently obtained by the Expert Laboratory of the Cryptosporidiosis National Reference Center (CNR-LE-Cryptosporidiosis) have shown that outbreaks are in fact common and frequently underreported. In this work, we aim to report the characteristics of outbreaks detected in France during the period 2017–2020 and present a summary of investigations carried out by the CNR-LE-Cryptosporidiosis. During the study period, there were eleven cryptosporidiosis outbreaks, including three with no identified origin. Among the eight identified outbreaks: six were due to water contamination (five tap water and one recreational water), one was due to direct contact with infected calves, and one was due to consumption of contaminated curd cheese. Among these outbreaks, five of them exceeded one hundred cases. Recent results obtained by the CNR-LE-Cryptosporidiosis revealed the multiannual occurrence of Cryptosporidium outbreaks in France. Waterborne outbreaks were more frequently detected, while foodborne outbreaks which are more difficult to detect were likely underreported.

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Massive Cryptosporidium outbreaks were detected in France recently.

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Waterborne origin appeared predominant.

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Foodborne origin is probably strongly neglected.

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Develop adapted monitoring and preventing strategies could reduce cryptosporidiosis

Cryptosporidiosis outbreak in Amazonia, French Guiana, 2018

BACKGROUND

Cryptosporidiosis outbreaks in South America are poorly documented. In March 2018, 51 cases of cryptosporidiosis were reported in Maripasoula, a village located in a remote forest area along the border between Surinam and French Guiana.

METHOD

To identify the origin of the epidemic, we performed epidemiological, microbiological, and environmental investigations. Only the cases involving diarrhoea and Cryptosporidium-positive stool were considered as bona fide, while cases involving diarrhoea and close contact with a confirmed case were classified as "possible".

RESULTS

We identified 16 confirmed cases and 35 possible ones. Confirmed cases comprised nine children (median age of 18 months, range: 6-21), one immunocompromised adult and six soldiers. One child required a hospitalisation for rehydration. All 16 Cryptosporidium stools were PCR positive, and sequencing of the gp60 gene confirmed only one Cryptosporidium hominis subtype IbA10G2. Tap water consumption was the only common risk factor identified. Contamination of the water network with Cryptosporidium parvum subtype IIdA19G2 was found.

CONCLUSION

Water quality is a major public health issue in Amazonian French Guiana, especially for population at risk (children, people with comorbidity, travelers). For them, alternative water supply or treatment should be implemented.

Epidemiological and clinical study of microsporidiosis in French kidney transplant recipients from 2005 to 2019: TRANS-SPORE registry

INTRODUCTION

Microsporidiosis is an emerging opportunistic infection in renal transplantation (RT) recipients. We aimed to describe its clinical presentation and treatment.

MATERIALS AND METHODS

We collected microsporidiosis cases identified in RT recipients between 2005 and 2019 in six French centers from the Crystal, Divat and Astre prospective databases.

RESULTS

We report 68 RT recipients with intestinal microsporidiosis; the patients were predominantly male (61.8%), with a median age of 58 (46-69) years. Infection occurred at a median time of 3 (0.8-6.8) years posttransplant. Only Enterocytozoon bieneusi was found. Microsporidiosis manifested as diarrhea (98.5% of patients) with weight loss (72.1%) and acute renal injury (57.4%) without inflammatory biological parameters. The therapeutic approaches were no treatment (N = 9), reduction of the immunosuppressive regimen (∆IS) (N = 22), fumagillin alone (N = 9), fumagillin and ∆IS (N = 19), and albendazole or nitazoxanide and ∆IS (N = 9). Overall clinical remission was observed in 60 patients (88.2%). We observed no acute kidney rejection, renal transplant failure, or death within 6 months after microsporidiosis.

CONCLUSION

E. bieneusi is an underestimated opportunistic pathogen in RT recipients, and infection with E. bieneusi leads to diarrhea with important dehydration and acute renal injury. The treatment is based on the reduction of the immunosuppressive regimen and the administration of fumagillin if available.

Molecular characterization of Cryptosporidium spp. from humans in Ethiopia

Data on the distribution and genotype of Cryptosporidium species is limited in Ethiopia. This study examined the presence and genetic diversity of Cryptosporidium species circulating in Ethiopian human population. Stool samples collected from patients who visited rural (n = 94) and urban (n = 93) health centers in Wurgissa and Hawassa district, respectively, were examined for the presence of Cryptosporidium spp. using microscopy, nested PCR and real-time PCR. To detect infection with PCR, analysis of 18S ribosomal RNA was performed. Subtyping was performed by sequencing a fragment of GP60 gene. The overall prevalence of infection was 46% (n = 86) by microscope and PCR. When 48 (out of 86) PCR positive samples were genotyped, two species were identified: C. parvum (n = 40) and C. hominis (n = 8). When 15 of the 40 C. parvum isolates were subtyped, zoonotic subtypes of IIaA14G1R1 (n = 1), IIaA15G2R1 (n = 1), IIaA16G1R1 (n = 2), IIaA16G3R1 (n = 2), IIaA17G1R1 (n = 1), IIaA19G1R1 (n = 1), IIaA20G1R1 (n = 3), IIaA22G1R1 (n = 1), IIaA22G2R1 (n = 1), IIdA23G1 (n = 1) and IIdA24G1 (n = 1) were identified. When 6 of the 8 C. hominis isolates were subtyped, subtypes IaA20 (n = 5), and IdA21(n = 1) were identified. This study suggests that C. parvum and C. hominis are causes of cryptosporidiosis in human in the Wurgissa district and Hawassa in Ethiopia. Zoonotic transmission might be the main route of transmission.

Comparative Performance of Eight PCR Methods to Detect Cryptosporidium Species

Diagnostic approaches based on PCR methods are increasingly used in the field of parasitology, particularly to detect Cryptosporidium. Consequently, many different PCR methods are available, both “in-house” and commercial methods. The aim of this study was to compare the performance of eight PCR methods, four “in-house” and four commercial methods, to detect Cryptosporidium species. On the same DNA extracts, performance was evaluated regarding the limit of detection for both C. parvum and C. hominis specificity and the ability to detect rare species implicated in human infection. Results showed variations in terms of performance. The best performance was observed with the FTD^® Stool parasites method, which detected C. parvum and C. hominis with a limit of detection of 1 and 10 oocysts/gram of stool respectively; all rare species tested were detected (C. cuniculus, C. meleagridis, C. felis, C. chipmunk, and C. ubiquitum), and no cross-reaction was observed. In addition, no cross-reactivity was observed with other enteric pathogens. However, commercial methods were unable to differentiate Cryptosporidium species, and generally, we recommend testing each DNA extract in at least triplicate to optimize the limit of detection.

Multicenter Comparative Study of Six Cryptosporidium parvum DNA Extraction Protocols Including Mechanical Pretreatment from Stool Samples

BACKGROUND

Nowadays, many commercial kits allow the detection of Cryptosporidium sp. in stool samples after deoxyribonucleic acid (DNA) extraction. Protocols of stool pretreatment have been proposed to optimize oocysts' DNA extraction. Among them, mechanical grinding was reported to improve the performance of Cryptosporidium oocysts' DNA extraction.

METHODS

A multicenter comparative study was conducted within the framework of the French National Reference Center-Expert Laboratory for Cryptosporidiosis. Six extraction systems (i.e., manual or automated) associated with various mechanical pretreatment protocols, were compared for the Cryptosporidium parvum oocyst' DNA extraction, before amplification using the same real-time PCR method targeting.

RESULTS

The sensitivity of real-time PCR assay was unequally impacted by the pretreatment/extraction protocol. We observed significant differences for the lowest concentrations of C. parvum oocysts (i.e., 0-94.4% and 33.3-100% respectively for 10 and 50 oocysts/mL). All in all, the protocol using Quick DNA Fecal/Soil Microbe-Miniprep® manual kit showed the best performances. In addition, optimal performances of mechanical pretreatment were obtained by combining a grinding duration of 60 s with a speed of 4 m/s using Fastprep24® with Lysing Matrix E®.

CONCLUSIONS

Sample pretreatment, as well as the extraction method, needs to be properly adapted to improve the diagnostic performances of the C. parvum DNA amplification methods.

Survival and infectivity of Toxoplasma gondii and Cryptosporidium parvum oocysts bioaccumulated by Dreissena polymorpha

AIMS

The study was aimed to understand the depuration process of Cryptosporidium parvum and Toxoplasma gondii oocysts by zebra mussel (Dreissena polymorpha), to consider the use of the zebra mussel as a bioremediation tool.

MATERIALS AND METHODS

Two experiments were performed: (i) individual exposure of mussel to investigate oocyst transfers between bivalves and water and (ii) in vivo exposure to assess the ability of the zebra mussel to degrade oocysts.

RESULTS

(i) Our results highlighted a transfer of oocysts from the mussels to the water after 3 and 7 days of depuration; however, some oocysts were still bioaccumulated in mussel tissue. (ii) Between 7 days of exposure at 1000 or 10 000 oocysts/mussel/day and 7 days of depuration, the number of bioaccumulated oocysts did not vary but the number of infectious oocysts decreased.

CONCLUSION

Results show that D. polymorpha can release oocysts in water via (pseudo)faeces in depuration period. Oocysts remain bioaccumulated and infectious oocyst number decreases during the depuration period in zebra mussel tissues. Results suggest a degradation of bioaccumulated C. parvum and T. gondii oocysts.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study highlighted the potential use of D. polymorpha as a bioremediation tool to mitigate of protozoan contamination in water resources.

Cryptosporidiosis after treatment with fingolimod: a case report and pharmacovigilance review

Background

Cryptosporidium sp. are common intracellular parasites responsible of severe diarrhea in T-cell-immunocompromised patients. We report the first case of a woman who contracted cryptosporidiosis after treatment with fingolimod, a drug labeled for multiple sclerosis and responsible for marked lymphopenia.

Case presentation

A 60-year-old woman was admitted for abdominal pain diarrhea and fever. The patient suffered from multiple sclerosis and had been treated with fingolimod from august 2017 to september 2018 time of occurrence of the first digestive symptoms. Stool culture was negative but parasitological examination was positive for Cryptosporidium sp. Blood biological examination profound lymphopenia of 240/mm³ [17 CD4/mm³ (7%) and 32 CD8/mm³ (14%)]. Fingolimod was stopped, and the patient was put on nitazoxanide 500 mg bid for 7 days. The diarrhea resolved and no relapse was observed. Six other cases were found in the Pharmacovigilance database.

Conclusion

Physicians should be aware of this association and screen for Cryptosporidium in cases of diarrhea in patients treated with fingolimod. Patients should be aware of this risk and advise to take appropriate measures to avoid such contamination.

Pneumocystis Infection Outbreaks in Organ Transplantation Units in France: A Nation-Wide Survey

The burden of nosocomial Pneumocystis infections in transplantation units in France was evaluated through a retrospective survey. Over 12 years, 16 outbreaks occurred, including 13 among renal transplant recipients (RTRs). We performed Pneumocystis jirovecii genotyping in 5 outbreaks, which suggested that specific strains may have been selected by RTRs.

Comparative Evaluation of Commercial Concentration Procedures for Human Intestinal Parasite Detection

BACKGROUND

Effective stool concentration is essential in microscopically based diagnosis of human intestinal parasite infections.

OBJECTIVE

To compare the performances of 4 concentration commercial kits and 1 homemade procedure in 96 clinical stool specimens that tested positive for the detection of 9 helminth and 8 protozoa parasites.

METHODS

The presence or absence of parasite forms was microscopically determined under conditions of standard practice. Also, we established the accuracies, concentration factors, and extraction yields.

RESULTS

No difference was observed between procedures for preconcentration specimens that tested positive. However, for preconcentration specimens that tested negative, we discovered that the homemade procedure was the most effective, and 2 of the 4 commercial kits were discovered to be satisfactory for routine applications.

CONCLUSIONS

For all parasites, procedures with biphasic solvents exhibited higher performances than organic solvent-free procedures. For the first time, the effectiveness of commercial concentration kits has been evaluated on several common stool parasites, and the results suggest that improvement of commercial procedures is possible.

Successful treatment of Trichosporon asahii fungemia with isavuconazole in a patient with hematologic malignancies

Trichosporon spp. are yeast-like microorganisms responsible for skin, urinary, pulmonary, or bloodstream infections. Due to intrinsic resistance to echinocandins, poor susceptibility to polyenes, and preferred occurrence in immunocompromised patients, such infections are often of poor prognosis. Yet no consensual therapeutic guidelines are presently available. Several clinical cases of Trichosporon infections have been successfully treated with azole therapy, including voriconazole which appeared frequently effective against Trichosporon both in vitro and in vivo. However, the low efficacy associated with some Trichosporon genotypes, complex pharmacokinetics, and the side effects of voriconazole represent limitations for its use and has prompted a search for other therapeutic options. Here, we report a case of T. asahii fungemia in a patient with B-cell acute lymphoblastic leukemia which was successfully treated with isavuconazole consecutive to stopping voriconazole therapy due to severe side effects. This observation suggests that isavuconazole with a similar spectrum to voriconazole, fewer pharmacology interactions, and side effects may be considered as a valuable therapeutic option against Trichosporon infections.

Correction: Octreotide modulates the expression of somatostatin receptor subtypes in inflamed rat jejunum induced by Cryptosporidium parvum

[This corrects the article DOI: 10.1371/journal.pone.0194058.].

8th European Conference on Rare Diseases & Orphan Products (ECRD 2016)

O1 The European Social Preferences Measurement (ESPM) study project: social cost value analysis, budget impact, commercial life cycle revenue management, and the economics of biopharmaceutical Research & Development (R&D)

Michael Schlander, Søren Holm, Erik Nord, Jeff Richardson, Silvio Garattini, Peter Kolominsky-Rabas, Deborah Marshall, Ulf Persson, Maarten Postma, Steven Simoens, Oriol de Solà Morales, Keith Tolley, Mondher Toumi, Harry Telser

O2 Newborn Screening: the potential and the challenges

James R Bonham

O3 Untreatable disease outcomes - how would we measure them?

Helmut Hintner, Anja Diem, Martin Laimer

O4 Taking Integrated Care Forward: Experiences from Canada to inspire service provision for people living with rare disease in Europe

Réjean Hébert

O5 Listening to the patient’s voice: social media listening for safety and benefits in rare diseases

Nabarun Dasgupta, Carrie E. Pierce, Melissa Jordan

O6 Via Opta: Mobile apps making visually impaired patients’ lives easier

Barbara Bori, Mohanad Fors, Emilie Prazakova

O7 A report of the IRDiRC “Small Population Clinical Trial” Task Force

Simon Day

O8 HAE patient identification and diagnosis: An innovative, ‘game changing’ collaboration

Thomas J. Croce Jr.

O9 Co-creating with the community: primary packaging & administration for people with haemophilia

Jonas Fransson, Philip Wood

O10 Go with Gaucher, taking forward the next generation. How to involve young people to create a new generation of patient advocates

Anne-Grethe Lauridsen, Joanne Higgs, Vesna Stojmirova Aleksovska

P1 ODAK – Orphan Drug for Acanthamoeba Keratitis

Christina Olsen, Ritchie Head, Antonio Asero, Vincenzo Papa, Christa van Kan, Loic Favennec, Silvana Venturella, Michela Salvador, Alan Krol

P5 Rare Navigators help people living with rare diseases to manage the social – and healthcare systems Stephanie J. Nielsen, Birthe B. Holm

P6 The eAcademy for Tay-Sachs & Sandhoff disease app

Daniel Lewi, Patricia Durão

P10 The role of a patient organisation in driving the research agenda in a rare disease

Heather Band, Andrea West

P13 Expertise for rare diseases mapped

Marinda J.A. Hammann, Marije C. Effing-Boele, Hanka K. Dekker

P14 The hidden costs of rare diseases: a feasibility study

Amy Hunter, Amy Simpson

P15 FDA’s new natural history grant program: support to build a solid foundation for development of products for rare diseases

Gumei Liu, Katherine Needleman, Debra Lewis, Gayatri Rao

P17 Understanding the wider impact of adrenal insufficiency: patient organisation involvement in the TAIN project

Amy Simpson, Amy Hunter, Martin J Whitaker

P20 Bridging the gaps between medical and social care for people living with a rare disease

Raquel Castro

Ruling out nosocomial transmission of Cryptosporidium in a renal transplantation unit: case report

Background

Cryptosporidium spp. is a ubiquitous parasite affecting humans as well as domestic and wild vertebrates, causing diarrhea in both immunocompetent and immunocompromised hosts worldwide. Its transmission occurs primarily by the fecal-oral route. In humans, C. parvum and C. hominis are the most prevalent species, whereas immunocompetent and immunocompromised individuals can also be infected by other zoonotic species. Renal transplant patients are prone to develop cryptosporidiosis, which can induce severe and life-threatening diarrhea.

Case presentation

We report here a series of nearly concomitant cases of acute symptomatic cryptosporidiosis in three renal transplant patients attending the Strasbourg University Hospital Nephrology Unit. The clinical presentation was persistent diarrhea and acute renal failure. The diagnosis was confirmed by microscopic stool examination using a modified Ziehl-Neelsen staining method and species identification by molecular tools. All patients were treated with nitazoxanide and recovered from diarrhea after 14 days of therapy.

Conclusion

Genotypic species identification was not consistent with an epidemic context, thus underlining the need for genotyping to monitor at risk patients.

Giardia duodenalis induces paracellular bacterial translocation and causes postinfectious visceral hypersensitivity

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.

Pilot-Scale Pulsed UV Light Irradiation of Experimentally Infected Raspberries Suppresses Cryptosporidium parvum Infectivity in Immunocompetent Suckling Mice

Cryptosporidium spp., a significant cause of foodborne infection, have been shown to be resistant to most chemical food disinfectant agents and infective for weeks in irrigation waters and stored fresh vegetal produce. Pulsed UV light (PL) has the potential to inactivate Cryptosporidium spp. on surfaces of raw or minimally processed foods or both. The present study aimed to evaluate the efficacy of PL on viability and in vivo infectivity of Cryptosporidium parvum oocysts present on raspberries, a known source of transmission to humans of oocyst-forming apicomplexan pathogens. The skin of each of 20 raspberries was experimentally inoculated with five 10-μl spots of an oocyst suspension containing 6 × 10(7) oocysts per ml (Nouzilly isolate). Raspberries were irradiated by PL flashes (4 J/cm(2) of total fluence). This dose did not affect colorimetric or organoleptic characteristics of fruits. After immunomagnetic separation from raspberries, oocysts were bleached and administered orally to neonatal suckling mice. Seven days after infection, mice were euthanized, and the number of oocysts in the entire small intestine was individually assessed by immunofluorescence flow cytometry. Three of 12 and 12 of 12 inoculated mice that received 10 and 100 oocysts isolated from nonirradiated raspberries, respectively, were found infected. Four of 12 and 2 of 12 inoculated mice that received 10(3) and 10(4) oocysts from irradiated raspberries, respectively, were found infected. Oocyst counts were lower in animals inoculated with 10(3) and 10(4) oocysts from irradiated raspberries (92 ± 144 and 38 ± 82, respectively) than in animals infected with 100 oocysts from nonirradiated raspberries (35,785 ± 66,221, P = 0.008). PL irradiation achieved oocyst reductions of 2 and 3 log for an inoculum of 10(3) and 10(4) oocysts, respectively. The present pilot-scale evaluation suggests that PL is an effective mode of decontamination for raspberries and prompts further applicability studies in industrial contexts.

Assessment of microscopic and molecular tools for the diagnosis and follow-up of cryptosporidiosis in patients at risk

Cryptosporidiosis is an important though underreported public health concern. Molecular tools might be helpful in improving its diagnosis. In this study, ZR Fecal DNA MiniPrep™ Kit (ZR) and NucliSens® easyMAG® (EM) were compared using four Cryptosporidium-seeded feces and 29 Cryptosporidium-positive stools. Thereafter, ZR was selected for prospective evaluation of Cryptosporidium detection by 18S rDNA and LAXER quantitative PCR (qPCR) in 69 stools from 56 patients after Cryptosporidium detection by glycerin, modified Ziehl-Neelsen (ZN) and auramine-phenol (AP) stainings. The combination of any of the two extraction methods with 18S qPCR yielded adequate detection of Cryptosporidium in seeded stools, but the ZR kit showed the best performance. All 29 Cryptosporidium-positive samples were positive with 18S qPCR, after both ZR and EM extraction. However, false-negative results were found with LAXER qPCR or nested PCR. Cryptosporidiosis was diagnosed in 7/56 patients. All the microscopic methods enabled the initial diagnosis, but Cryptosporidium was detected in 12, 13, and 14 samples from these seven patients after glycerin, ZN, and AP staining respectively. Among these samples, 14 and 12 were positive with 18S and LAXER qPCR respectively. In two patients, Cryptosporidium DNA loads were found to be correlated with clinical evolution. Although little known, glycerin is a sensitive method for the initial detection of Cryptosporidium. When combined with 18S qPCR, ZR extraction, which had not been evaluated so far for Cryptosporidium, was an accurate tool for detecting Cryptosporidium and estimating the oocyst shedding in the course of infection.

Protozoa interaction with aquatic invertebrate: interest for watercourses biomonitoring

Toxoplasma gondii, Cryptosporidium parvum, and Giardia duodenalis are human waterborne protozoa. These worldwide parasites had been detected in various watercourses as recreational, surface, drinking, river, and seawater. As of today, water protozoa detection was based on large water filtration and on sample concentration. Another tool like aquatic invertebrate parasitism could be used for sanitary and environmental biomonitoring. In fact, organisms like filter feeders could already filtrate and concentrate protozoa directly in their tissues in proportion to ambient concentration. So molluscan shellfish can be used as a bioindicator of protozoa contamination level in a site since they were sedentary. Nevertheless, only a few researches had focused on nonspecific parasitism like protozoa infection on aquatic invertebrates. Objectives of this review are twofold: Firstly, an overview of protozoa in worldwide water was presented. Secondly, current knowledge of protozoa parasitism on aquatic invertebrates was detailed and the lack of data of their biological impact was pointed out.

Effects of octreotide on jejunal hypersensitivity triggered by Cryptosporidium parvum intestinal infection in an immunocompetent suckling rat model

BACKGROUND

Similar to other bacterial or protozoan infections, human cryptosporidiosis may trigger postinfectious irritable bowel syndrome (IBS)-like symptoms, a condition in which enhanced visceral perception of pain during intestinal distension plays a pivotal role. In an immunocompetent suckling rat model which mimicks features of postinfectious IBS, Cryptosporidium parvum infection induces long-lasting jejunal hypersensitivity to distension in association with intestinal activated mast cell accumulation. The aim of the present study was to explore in this model whether octreotide, a somatostatin agonist analog, could prevent the development of jejunal hypersensitivity and intestinal mast cell/nerve fiber accumulation.

METHODS

Five-day-old Sprague-Dawley rats were infected with C. parvum and treated 10 days later with octreotide (50 g kg(-1) day(-1), i.p.) for 7 days.

KEY RESULTS

Compared with untreated infected rats, octreotide treatment of infected rats resulted in increased weight gain [day 23 postinfection (PI)], decreased food intake (day 16 PI), and a reduction in jejunal villus alterations (day 14 PI), CD3(+) IEL (day 37 PI) and mast cell (days 37 and 50 PI) accumulations, nerve fiber densities (day 50 PI), and hypersensitivity to distension (day 120 PI). In uninfected rats, the effects of octreotide treatment were limited to higher weight gain (days 16 and 23 PI) and decreased food intake (day 23 PI) compared with uninfected-untreated rats.

CONCLUSIONS & INFERENCES

Data confirms the relevance of the present rat model to postinfectious IBS studies and prompt further investigation of somatostatin-dependent regulatory interactions in cryptosporidiosis.

Intensive exploitation of a karst aquifer leads to Cryptosporidium water supply contamination

Groundwater from karst aquifers is an important source of drinking water worldwide. Outbreaks of cryptosporidiosis linked to surface water and treated public water are regularly reported. Cryptosporidium oocysts are resistant to conventional drinking water disinfectants and are a major concern for the water industry. Here, we examined conditions associated with oocyst transport along a karstic hydrosystem, and the impact of intensive exploitation on Cryptosporidium oocyst contamination of the water supply. We studied a well-characterized karstic hydrosystem composed of a sinkhole, a spring and a wellbore. Thirty-six surface water and groundwater samples were analyzed for suspended particulate matter, turbidity, electrical conductivity, and Cryptosporidium and Giardia (oo)cyst concentrations. (Oo)cysts were identified and counted by means of solid-phase cytometry (ChemScan RDI(®)), a highly sensitive method. Cryptosporidium oocysts were detected in 78% of both surface water and groundwater samples, while Giardia cysts were found in respectively 22% and 8% of surface water and groundwater samples. Mean Cryptosporidium oocyst concentrations were 29, 13 and 4/100 L at the sinkhole, spring and wellbore, respectively. Cryptosporidium oocysts were transported from the sinkhole to the spring and the wellbore, with respective release rates of 45% and 14%, suggesting that oocysts are subject to storage and remobilization in karst conduits. Principal components analysis showed that Cryptosporidium oocyst concentrations depended on variations in hydrological forcing factors. All water samples collected during intensive exploitation contained oocysts. Control of Cryptosporidium oocyst contamination during intensive exploitation is therefore necessary to ensure drinking water quality.

Ultra low κ PECVD Porogen Approach: Matrix Precursors Comparison and Porogen Removal Treatment Study

The introduction of new dielectrics into silicon chip interconnection technology is necessary to increase electrical performance. Sub-65nm technologies need κ values below 2.5 and the main way to reduce the dielectric constant is to introduce porosity. This work reports results concerning a two steps PECVD porogen approach to perform Ultra Low κ (κ <2.5). The first step is an hybrid material deposition: i.e. an a-SiOC:H matrix containing organic sacrificial inclusions (porogen phase). In the second step, the porogen is removed by a suitable curing to generate porosity. Two siloxane precursors (decamethylcyclopentasiloxane and diethoxymethylsilane) were evaluated as matrix precursors. Their influences, as well as O2 addition in plasma gas feed, in terms of cross-linking and incorporation were evaluated by FTIR analysis. Thermal anneal and UV treatment (thermally assisted) were evaluated as a curing second step. It allows to better understand this critical step which combines porogen removal and material cross-linking. By optimizing deposition and curing parameters, κ value lower than 2.4 were obtained.

Evaluation of water treatment plant UV reactor efficiency against Cryptosporidium parvum oocyst infectivity in immunocompetent suckling mice

AIM

To assess the efficiency of a medium-pressure UV reactor under full-scale water treatment plant (WTP) conditions on the infectivity of Cryptosporidium parvum oocysts in an Naval Medical Research Institute (NMRI) suckling mice infectivity model.

METHODS AND RESULTS

Six/seven-day-old mice were administered orally 2-10x10(4)Cryptosporidium parvum oocysts. Compared with nonirradiated oocysts, 40 mJ cm(-2) UV irradiation of ingested oocysts resulted 7 days later in a 3.4-4.0 log10 reduction in the counts of small intestine oocysts, using a fluorescent flow cytometry assay.

CONCLUSION

Present data extend to industrial conditions previous observations of the efficiency of UV irradiation against Cryptosporidium parvum oocyst in vivo development.

SIGNIFICANCE AND IMPACT OF THE STUDY

Present results suggest that in WTP conditions, a medium-pressure UV reactor is efficient in reducing the infectivity of Cryptosporidium parvum oocysts, one of the most resistant micro-organisms present in environmental waters.

In vitro efficacy of nitro- and halogeno-thiazolide/thiadiazolide derivatives against Sarcocystis neurona

Sarcocystis neurona is an obligate intracellular parasite that causes equine protozoal myeloencephalitis (EPM). The aim of this work was to document inhibitory activities of nitazoxanide (NTZ, [2-acetolyloxy-N-(5-nitro 2-thiazolyl) benzamide]) and new thiazolides/thiadiazolides on S. neurona in vitro development, and investigate their structure-activity relationships. S. neurona was grown in bovine turbinate cell cultures. At concentrations varying from 1.0 to 5.0mg/L, nitazoxanide and 21 of 32 second generation thiazolide/thiadiazolide agents exerted a > or =95% maximum inhibition on S. neurona development. Most active agents were either NO(2) or halogen substituted in position 5 of their thiazole moiety. In contrast, other 5-substitutions such as hydrogen, methyl, SO(2)CH(3), and CH(3) negatively impacted activity. Compared with derivatives with an acetylated benzene moiety, deacetylated compounds which most probably represent primary metabolites exhibited similar inhibitory activities. Present data provide the first evidence of in vitro inhibitory activities of nitazoxanide and new thiazolides/thiadiazolides on S. neurona development. Active halogeno-thiazolide/thiadiazolides may provide a valuable nitro-free alternative to nitazoxanide for EPM treatment depending on further evaluation of their in vivo activities.

[Troponin dosage in a patient with asymptomatic myocarditis due to trichinellosis]

Human trichinellosis is a potentially severe parasitic disease occurring after ingestion of undercooked meat infected with Trichinella sp. larvae. We report the case of a patient who ate an undercooked bear meat hunted in Canada; he presented with the usual symptoms of trichinellosis (i.e, facial oedema, myalgias and fever) complicated with an asymptomatic myocarditis. Myocarditis is a rare, but potentially lethal complication of trichinellosis. Myocarditis should be screened systematically even when specific symptoms are missing; dosage of troponin serum is a simple and reliable mean for such screening.

Duodenal intraepithelial T lymphocytes in patients with functional dyspepsia

AIM: To quantify the intraepithelial lymphocytes (IELs) and to document the membrane expression of CD4, CD8, TCRγδ and adhesion and/or activation-associated molecules (CD103, CD28, CD44, CD69, HLA-DR, CD95/Fas) in the duodenal mucosa of patients with functional dyspepsia (FD) in order to provide arguments for an immunological process in FD.

METHODS: Twenty-six FD patients according to Rome II criteria (20 were H pylori negative) were studied and compared to 12 healthy adults. IELs were isolated from five duodenal biopsy samples, then quantified by microscopy and flow cytometry while the membrane phenotypes were determined by cytofluorometry.

RESULTS: Duodenal histological examination was normal. In H pylori negative patients, the number of IELs was not different from that in healthy controls. Median percentage expression of CD4, CD8, or TCRγδ and CD103, CD44, CD28, CD69 on CD3+ IELs, among the adhesion/activation associated molecules tested, was not different from that in healthy controls. In contrast, the median percentage expression of CD95/Fas [22 (9-65) vs 45 (19-88), P = 0.03] and HLA-DR expressing CD3+ IELs [4 (0-30) vs 13 (4-42), P = 0.04] was significantly lower in the H pylori negative FD group than in healthy controls, respectively. The number of IELs was significantly greater in H pylori positive FD patients than in healthy controls [median ratiofor 100 enterocytes 27.5 (6.7-62.5) vs 10.8 (3-33.3), P = 0.02] due to a higher number of CD8+ CD3+ IELs.

CONCLUSION: In H pylori negative FD patients, the phenotypic characterization of IELs suggests that we cannot exclude a role of IELs in FD.

Leishmaniose cutanée au cours d'une polymyosite

INTRODUCTION

The prevalence of cutaneous leishmaniasis is increasing, especially in immunocompromized subjects.

CASE RECORD

We report a case of particular interest, where a patient with steroid refractory polymyositis developed cutaneous leishmaniasis. Clinical outcome was favorable after institution of intralesional antimony therapy.

DISCUSSION

Cutaneous leishmaniasis is still recognized to be an opportunistic infection. Its frequency is indeed higher in immunocompromized subjects, mainly HIV-infected patients. In our patient, both polymyositis and steroid therapy were predisposing factors of cutaneous leishmaniasis onset; prednisone therapy has been postulated to be associated with immune dysfunction leading to: reduced blood T cells' levels (CD4 et CD8) as well as decreased cytokine synthesis (e.g. interferon gamma).

Intérêt des prélèvements intraoculaires dans le diagnostic étiologique des uvéites présumées infectieuses

PURPOSE

To study the etiologic distribution of patients with presumed infectious uveitis who underwent ocular fluid analysis.

PATIENTS AND METHODS

We retrospectively analyzed vitreous and or aqueous humor samples of patients with presumed infectious uveitis, referred to the department of Ophthalmology of the University Hospital of Rouen, France, between January 1997 and June 2004. We excluded patients with postsurgical or endogenous endophthalmitis. We noted clinical features and intraocular sample analysis methods for each pathogen.

RESULTS

The study included 42 patients, 24 men and 18 women, aged between 6 and 79 years (mean, 39.5 years). Uveitis was unilateral in 88% of cases and bilateral in 12%. Posterior uveitis was predominant (52%), followed by panuveitis (24%), anterior (14%), and intermediate uveitis (10%). Aqueous humor and vitreous analysis confirmed etiological diagnosis for 13 of 41 patients (31%) and three of six cases (50%), respectively. Inflammation was controlled or stabilized in all cases. The most pejorative visual outcome was observed for candidiasis and viral retinitis. Positivity of intraocular samples was variable, depending on the suspected pathogen, with results similar to those reported in other studies.

DISCUSSION

Atypical features in potential infectious uveitis justify ocular paracentesis or vitrectomy, which are more efficient since molecular biological tools have become available. Sensitivity of aqueous humor analysis is high for posterior uveitis and suspicion of viral retinitis. New molecular variants applied to ocular samples will improve the etiological diagnosis of infectious uveitis, particularly for pathogens that are difficult to culture, such as fungi and bacteria.

Inhibitory activities of epidermal growth factor receptor tyrosine kinase-targeted dihydroxyisoflavone and trihydroxydeoxybenzoin derivatives on Sarcocystis neurona, Neospora caninum, and Cryptosporidium parvum development

Several gene sequences of parasitic protozoa belonging to protein kinase gene families and epidermal growth factor (EGF)-like peptides, which act via binding to receptor tyrosine kinases of the EGF receptor (EGFR) family, appear to mediate host-protozoan interactions. As a clue to EGFR protein tyrosine kinase (PTK) mediation and a novel approach for identifying anticoccidial agents, activities against Sarcocystis neurona, Neospora caninum, and Cryptosporidium parvum grown in BM and HCT-8 cell cultures of 52 EGFR PTK inhibitor isoflavone analogs (dihydroxyisoflavone and trihydroxydeoxybenzoine derivatives) were investigated. Their cytotoxicities against host cells were either absent, mild, or moderate by a nitroblue tetrazolium test. At concentrations ranging from 5 to 10 microg/ml, 20 and 5 analogs, including RM-6427 and RM-6428, exhibited an in vitro inhibitory effect of > or = 95% against at least one parasite or against all three, respectively. In immunosuppressed Cryptosporidium parvum-infected Mongolian gerbils orally treated with either 200 or 400 mg of agent RM-6427/kg of body weight/day for 8 days, fecal microscopic oocyst shedding was abolished in 6/10 animals (P of <0.001 versus untreated controls) and mean shedding was reduced by 90.5% (P of <0.0001) and 92.0% (P of <0.0001), respectively, higher levels of inhibition than after nitazoxanide (200 mg/kg/day for 8 days) or paromomycin (100 mg/kg/day for 8 days) treatment (55.0%, P of <0.001, and 17.5%, P of >0.05, respectively). After RM-6427 therapy (200 mg/kg/day for 8 days), the reduction in the ratio of animals with intracellular parasites was nearly significant in ileum (P = 0.067) and more marked in the biliary tract (P < 0.0013) than after nitazoxanide or paromomycin treatment (0.05 < P < 0.004). RM-6428 treatment at a regimen of 400 mg/kg/day for 12 days inhibited oocyst shedding, measured using flow cytometry from day 4 (P < 0.05) to day 12 (P < 0.02) of therapy, when 2/15 animals had no shedding (P < 0.0001) and 11/15 were free of gut and/or biliary tract parasites (P < 0.01). No mucosal alteration was microscopically observed for treated or untreated infected gerbils. To our knowledge, this report is the first to suggest that the isoflavone class of agents has the potential for anticoccidial therapy.

Efficacy of nitazoxanide and paromomycin in biliary tract cryptosporidiosis in an immunosuppressed gerbil model

OBJECTIVES

To evaluate the efficacy of nitazoxanide and paromomycin in biliary tract cryptosporidiosis in an immunosuppressed Mongolian gerbil (Meriones unguiculatus) model.

METHODS

Gerbils (1-month-old) were dexamethasone-immunosuppressed for 10 days and challenged orally with 10(5) Cryptosporidium parvum oocysts. From day 0 to day 12 post-infection, one group (n=14) was treated with 200 mg/kg/day nitazoxanide and another (n=15) with 100 mg/kg/day paromomycin. Infection and efficacy of nitazoxanide and paromomycin were assessed by measuring oocyst shedding in faeces, biliary tract and ileum histological examination.

RESULTS

In nitazoxanide-treated and paromomycin-treated groups as compared with untreated animals (P<0.05), oocyst shedding was partially suppressed in a similar manner (P>0.05). Parasites were present in histological sections of the ileal mucosa of 16/16 infected untreated animals versus 3/14 and 6/15 in the nitazoxanide-treated and the paromomycin-treated groups, respectively (P<0.05). In addition, gall bladder infection was less frequent in nitazoxanide-treated (2/14, P<0.01) and paromomycin-treated (5/15, P=0.07) animals than in untreated controls (9/16). No histological alteration of biliary mucosa was observed in both treated and untreated infected gerbils.

CONCLUSIONS

Present data support the efficacy of nitazoxanide and, to a lesser extent, paromomycin on biliary C. parvum infection in gerbils, and prompt further investigation of the potential clinical benefits of nitazoxanide in treating human biliary cryptosporidiosis.