High-resolution melting-curve (HRM) analysis for C. meleagridis identification in stool samples.

BACKGROUND: Cryptosporidiosis represents a major public health problem. This infection, caused by a protozoan parasite of the genus Cryptosporidium, has been reported worldwide as a frequent cause of diarrhoea. In the immunocompetent host, the typical watery diarrhea can be self-limiting. However, it is severe and chronic, in the immunocompromised host and may cause death. Cryptosporidium spp. are coccidians, which complete their life cycle in both humans and animals. The two species C. hominis and C. parvum are the major cause of human infection. Compared to studies on C. hominis and C. parvum, only a few studies have developed methods to identify C. meleagridis. AIM: To develop a new real time PCR-coupled High resolution melting assay allowing the detection for C. meleagridis, in addition of the other dominant species (C. hominis and C. parvum). METHODS: The polymorphic sequence on the dihydrofolate reductase gene (DHFR) of three species was sequenced to design primers pair and establish a sensitive real-time PCR coupled to a high-resolution melting-curve (HRM) analysis method, allowing the detection of Cryptosporidium sp. and discrimination between three prevalent species in Tunisia. We analyzed a collection of 42 archived human isolates of the three studied species. RESULTS: Real-time PCR coupled to HRM assay allowed detection of Cryptosporidium, using the new designed primers, and basing on melting profile, we can distinguish C. meleagridis species in addition to C. parvum and C. hominis. CONCLUSION: We developed a qPCR-HRM assay that allows Cryptosporidium genotyping. This method is sensitive and able to distinguish three Cryptosporidium species.

[Abdomino-pelvic actinomycosis. Report of 2 cases]. / Actinomycose abdomino-pelvienne. A propos de deux cas.

Actinomycosis is a chronic, granulomatous, suppurative and fistulasing infection related to a gram-positive bacteria (actinomyces israeli). Cervico-facial actinomycosis is the most common localization. The prevalence of abdomino-pelvic actinomycosis is increasing mainly with the increase of the use of intrauterin device. Its clinical presentation is variable and may mimic cancer or tuberculosis. The diagnosis of abdomino-pelvic actinomycosis is hard and most of the cases are detected during surgical exploration. We report two cases of abdomino-pelvic actinomycosis; in the first case, the disease was extended to the caecum and the abdominal wall. The skin biopsies made the diagnosis of actinomycosis, avoiding surgery. In the second case, the diagnosis of actinomycosis is made post operatively because of high suspicion of pelvic cancer. Through these two observations, we review pathogenesis of the disease, its clinical aspects and its diagnostic and therapeutic means.