Immunofluorescence Assay and PCR Analysis of Cryptosporidium Oocysts and Species From Human Feacal Specimens

Background: Cryptosporidium spp. is a widespread protozoan parasite involving humans and animals. Objectives: This study was carried out to evaluate the immunofluorescence assay (IFA) and PCR results for more accurate diagnosis of faecal specimens. Patients and Methods: Forty six faecal human specimens of Cryptosporidium oocysts were examined by PCR and IFA in Calgary, Canada. In statistical analysis, sensitivity and positive predictive value were detected by IFA. Results: Among 46 faecal samples, 9 (19.6%) were IFA-positive and 10 (21.7%) PCR-positive. Faecal smears of both PCR- and IFA-positive shown that the reproducibility was 90.9% for PCR-DNA and 81.8% for IFA. In Our findings, PCR -DNA showed that diagnosis cryptosporidiosis 2.1% was more sensitive than IFA. Two different oocysts sizes were visualized by IF microscopy which belonged to different species. Furthermore, PCR analysis with primers against the 18S rRNA gene indicated two genotypes of C. hominis and C. parvum, 500-650 base pairs (bp). In this study, the golden standard was the PCR. In statistical analyses, IFA had positive predictive value (PPV) of 81.8% with 81.8% sensitivity, whereas negative predictive value (NPV) was 1% with 0.97% specificity. Conclusions: PCR showed more sensitivity than IFA for tracking Cryptosporidium oocysts as well as detection of species in faecal human specimens.Background: The brown-banded cockroach Supella longipalpa (F.) as a mechanical vector of pathogens and source of allergens has recently become widespread in the city of Ahvaz, southwestern Iran. Objectives: This research was done to evaluate the efficacy of a dust-formulation of Metarhizium anisopliae isolate IRAN 437C, as a common entomopathogenous fungus, against S. longipalpa. Materials and Methods: Conidia dust-formulations of M. anisopliae were prepared in proportions of 1%, 5%, 10%, 25%, 50% and 100% with bad wheat flour as the carrier. Cockroaches were exposed to surfaces treated with 1.5 mg/cm2 of the formulations under laboratory and semi-field conditions. Results: Cockroach mortality rates increased and survival times (ST50) decreased with an increased proportion of conidia from 1% to 100% but records taken for mortality and survival time from proportions of 25%, 50% and 100% were not significantly different. The mortality rates reached 100% and 90-100% in adults and nymphs, respectively on the seventh day. The lowest ST50 was related to the proportion of 100% (3 days). Probit analysis indicated LD50 and LD90 values of 1.7 × 106 and 1.7 × 107 conidia/cm2 for adults and these values changed to 4.5 × 106 and 2.9 × 107 for third and fourth instar nymphs at three days post exposure. Proportion of 25% caused mortality rates of 87%, 81% and 73% in adult, adult amp; nymph and nymph populations, respectively at four days after exposure under room conditions. Conclusions: Conidia dust-formulation of M. anospliae isolate IRAN 437C could present a promising alternative to control the brown-banded cockroach.