Cryptosporidium uses CSpV1 to activate host type I interferon and attenuate antiparasitic defenses.

Cryptosporidium infects gastrointestinal epithelium and is a leading cause of infectious diarrhea and diarrheal-related death in children worldwide. There are no vaccines and no fully effective therapy available for the infection. Type II and III interferon (IFN) responses are important determinants of susceptibility to infection but the role for type I IFN response remains obscure. Cryptosporidium parvum virus 1 (CSpV1) is a double-stranded RNA (dsRNA) virus harbored by Cryptosporidium spp. Here we show that intestinal epithelial conditional Ifnar1-/- mice (deficient in type I IFN receptor) are resistant to C. parvum infection. CSpV1-dsRNAs are delivered into host cells and trigger type I IFN response in infected cells. Whereas C. parvum infection attenuates epithelial response to IFN-γ, loss of type I IFN signaling or inhibition of CSpV1-dsRNA delivery can restore IFN-γ-mediated protective response. Our findings demonstrate that type I IFN signaling in intestinal epithelial cells is detrimental to intestinal anti-C. parvum defense and Cryptosporidium uses CSpV1 to activate type I IFN signaling to evade epithelial antiparasitic response.

A novel detection method of Cryptosporidium parvum infection in cattle based on Cryptosporidium parvum virus 1.

Cryptosporidium parvum is an important zoonotic parasite that causes significant economic loss in the animal husbandry industry, especially the cattle industry. As there is no specific vaccine or drug against Cryptosporidium, a rapid and accurate method for the detection of C. parvum is of great significance. In this study, colloidal gold strips were developed based on Cryptosporidium parvum virus 1 (CSpV1) for the detection of C. parvum infection in cattle fecal samples. The colloidal gold solution was prepared by reducing trisodium citrate and the CSpV1 #5 monoclonal antibody was labeled with colloidal gold. A polyclonal antibody against the CSpV1 capsid protein and an anti-mouse IgG antibody were coated on the colloidal gold strips for use in the test and control lines, respectively. Our results showed that the detection sensitivity in fecal samples was up to a 1:64 dilution. There was no cross-reaction with Cryptosporidium andersoni or Giardia in the fecal samples. The different preservation conditions (room temperature, 4°C, and 37°C) and preservation time (7, 30, 60, and 90 days) were analyzed. The data showed that the strips could be preserved for 90 days at 4°C and for 60 days at room temperature or 37°C. The colloidal gold strips were used to detect the samples of 120 clinical fecal in Changchun, China. The results indicated that the rate of a positive test was 5% (6/120). This study provides a rapid and accurate method for detecting C. parvum infection in cattle and humans.

[Cross-section study on co-infection of HIV and Cryptosporidium].

OBJECTIVE: To investigate the co-infection status of HIV and Cryptosporidium, and explore the influencing factors associated with the co-infection. METHODS: A total of 309 people with HIV positive in Fuyang City of Anhui Province were recruited and their fecal and blood samples were collected for examinations of Cryptosporidium spp. infection and the levels of hemoglobin, cytokines and CD4+/CD8+ T-lymphocytes. Meanwhile, the questionnaire survey was conducted. RESULTS: Among 302 people involved in fecal examinations, the infection rate of Cryptosporidium spp. was 8.28%, and the difference between infection rates of the male (13.49%) and the female (2.92%) was statistically significant (P < 0.05). The multivariate logistic regression model showed that 4 factors were significantly associated with the coinfection of HIV and Cryptosporidium spp, including male (OR = 6.700, 95% CI: 2.030, 22.114), younger than 42 years old (OR = 4.148, 95% CI: 1.348, 12.761), level of IL-2 below 77 pg/ml (OR = 0.226, 95%CI: 0.076, 0.674) and personal hygiene habits (OR = 0.324, 95% CI: 0.105, 0.994). CONCLUSION: The co-infection rate of Cryptosporidium spp. and HIV is high, the key targets of control are the people who are male, younger than 42 years old, with high level of IL2 and poor personal hygiene habits.

Orthoreovirus infection and concurrent cryptosporidiosis in rough green snakes (Opheodrys aestivus): pathology and identification of a novel orthoreovirus strain via polymerase chain reaction and sequencing.

Reoviruses are nonenveloped, segmented, double-stranded RNA viruses capable of infecting a wide range of invertebrate, vertebrate, fungus, and plant hosts. Though sporadic infection has been reported in a variety of reptilian species, infection of rough green snakes (Opheodrys aestivus) has not been previously described. Five wild-caught, adult rough green snakes were obtained by a zoological institution. Clinical deterioration was first noted in all snakes after 3 weeks in quarantine. Despite treatment, clinical decline progressed, and all 5 snakes died or were euthanized by 48 days post-arrival. Moderate, multifocal, acute, necrotizing hepatitis with hepatocellular syncytia was diagnosed in 1 snake. Two additional snakes had severe, diffuse, subacute to chronic pancreatitis. All 5 snakes had gastroenteric cryptosporidiosis. Electron microscopic examination of liver from the snake with hepatic lesions revealed scattered hepatocytes containing 1 or more intranuclear clusters of approximately 90 nm in diameter viral particles arranged in loose arrays. Polymerase chain reaction (PCR) amplification of a segment of the reovirus RNA-dependent RNA polymerase gene was performed on RNA extracted from tissues of all 5 snakes. PCR amplification of samples extracted from the snake with hepatic lesions resulted in a 109-base pair (bp) product. Phylogenetic analyses indicated the virus was a novel strain distinct from other reoviruses at a level consistent with species difference. The source of infection was unknown. PCR amplification of samples extracted from the other 4 snakes was negative.

Risks of recreational exposure to waterborne pathogens among persons with HIV/AIDS in Baltimore, Maryland.

OBJECTIVES: We assessed the prevalence of recreational activities in the waterways of Baltimore, MD, and the risk of exposure to Cryptosporidium among persons with HIV/AIDS. METHODS: We studied patients at the Johns Hopkins Moore Outpatient AIDS Clinic. We conducted oral interviews with a convenience sample of 157 HIV/AIDS patients to ascertain the sites used for recreational water contact within Baltimore waters and assess risk behaviors. RESULTS: Approximately 48% of respondents reported participating in recreational water activities (fishing, crabbing, boating, and swimming). Men and women were almost equally likely to engage in recreational water activities (53.3% versus 51.3%). Approximately 67% (105 of 157) ate their own catch or that of friends or family members, and a majority (61%, or 46 of 75) of respondents who reported recreational water contact reported consumption of their own catch. CONCLUSIONS: Baltimoreans with HIV/AIDS are engaging in recreational water activities in urban waters that may expose them to waterborne pathogens and recreational water illnesses. Susceptible persons, such as patients with HIV/AIDS, should be cautioned regarding potential microbial risks from recreational water contact with surface waters.

Detection of Cryptosporidium parvum in HIV-infected patients in Malaysia using a molecular approach.

This cross-sectional study determined the prevalence of cryptosporidiosis in HIV-infected patients using polymerase chain reaction (PCR). Stool specimens were collected from HIV infected patients who were admitted to Hospital Raja Perempuan Zainab II, Kota Bharu, Malaysia, for various indications from December 2004 to December 2005. A modified acid-fast stain was performed on the direct stool smears, then the stool specimens were further tested using nested PCR targeting the 18S rRNA gene of Cryptosporidium parvum, with a built-in internal control (IC). Out of 59 samples, 11 were positives. Nested PCR identified a total of nine samples (16%) compared to microscopy, which identified only three samples. All PCR negative results showed IC amplicons, suggesting that these samples were true negatives and were not due to inhibition of PCR. This study highlights the importance of molecular diagnosis in determining the true prevalence and epidemiology of C. parvum.

Prevalence of intestinal parasitic infestation in HIV/AIDS patients with diarrhea in Madurai City, South India.

The prevalence and pattern of parasitic infestation among 80 HIV/AIDS patients with diarrhea in Madurai, south India, was studied by microscopy. Eighty HIV-negative patients were used as controls. Intestinal parasites were detected in 31 HIV/AIDS patients (38.7%) and in 14 (17.5%) HIV-negative patients, a difference that was statistically significant (P < 0.05). In HIV/AIDS patients with diarrhea, protozoa accounted for the majority of diarrhea cases (Entamoeba spp. 37.5%, Cryptosporidium parvum 28.7%). It is therefore suggested that enteric infections are more common in HIV-infected patients than in HIV-negative persons in south India, and this may be due to differences in immunological profile, susceptibility as well as factors related to sanitation and the environment.

Mixed Cryptosporidium infections and HIV.

Mixed Cryptosporidium infections were detected in 7 of 21 patients with a diagnosis of rare Cryptosporidium canis or C. felis infections; 6 patients were infected with 2 Cryptosporidium spp. and 1 patient with 3 species. Mixed infections may occur more frequently than previously believed and should be considered when assessing cryptosporidiosis.

Cytomegalovirus and Cryptosporidium infections in AIDS: a necropsy study.

A case of coinfection of cytomegalovirus (CMV) and Cryptosporidium in an AIDS patient is reported. Chronic diarrhea was the presenting symptom. Etiologic agents were diagnosed only at postmortem evaluation. CMV intranuclear inclusions were seen in the terminal ileum, colon and vermiform appendix. Cryptosporidium oocysts were also present in the intestinal brush border of the colon. Improvement of diagnostic procedures such as colonic biopsy and the use of appropriate staining procedure for AIDS patients with diarrhea can help identify the cause of illness.