BACKGROUND: Diagnosis of Cryptosporidium species based on morphological characteristics is very limited and has no taxonomic value alone, and therefore the use of molecular methods removes these limitations to some extent. OBJECTIVES: The aim of this study was to determine the predominant Cryptosporidium genotypes in calves with diarrhea. METHODS: Study were conducted in calves aged less than 3 months for a period of 2 years. During the study period, 160 dung samples were collected from neonatal calves and examined first microscopically and then by molecular techniques. Stools were analyzed for the presence of Cryptosporidium oocysts by Sheather's Sugar Flotation Solution followed by Ziel-Neelsen staining method. DNA of parasite was extracted and multiplex nested-PCR protocol basis on the 18srRNA were done to identify three cattle-adapted species (C. andersoni, C. bovis and C. ryanae) plus the zoonotic species C. parvum. RESULTS: 110 fecal samples were collected from livestock in Alborz province and 50 fecal samples were collected from livestock in Shahroud city. Of the 160 animals examined, 90 were female and 70 were male. In total, out of 160 animals examined, 85 cases (53.12%) had diarrhea, of which 55 cases (34.37%) were positive using Ziel-Neelsen staining. Since all positive cases were related to diarrhea samples and related to calves under one month old, a significant relationship was observed between diarrhea status and the presence of this parasite (p < /em><0.05). In terms of seasonal distribution, no difference was observed in the rate of diarrhea and positive parasitic cases. The presence of 305 bp band in all Ziel-Neelsen positive samples confirmed the presence of C. parvum in all samples. CONCLUSIONS: Neonatal calves are more likely to be infected with Cryptosporidium parvum, as confirmed by the present study.

Serum retinol, retinyl palmitate, and total vitamin A concentrations, and jejunoileal morphology were examined in neonatal calves infected with Cryptosporidium parvum. Group-1 calves served as noninfected controls and, after an adjustment period, were given 50 ml of saline solution IV every 12 hours for 6 days. Group-2 calves were inoculated with 10(7) C parvum oocysts and, after the onset of diarrhea, were given 50 ml of saline solution IV every 12 hours for 6 days. Group-3 calves were inoculated with 10(7) C parvum oocysts and, after the onset of diarrhea, were treated with difluoromethylornithine (DFMO, 200 mg/kg of body weight IV, q 12 h) for 6 days. Group-4 calves were naturally infected with C parvum. Jejunoileal biopsy specimens were excised from calves of groups 1-3 at 3 and again at 15 to 16 days of age. During the course of diarrhea and 3 days after saline or DFMO administration, water-miscible retinyl palmitate was administered orally (2,750 micrograms/kg) to each calf in each group. Cryptosporidium parvum infection was associated with significant (P < 0.05) reduction in postadministration serum retinol, retinyl palmitate, and total vitamin A concentrations in calves of groups 2, 3, and 4. Cryptosporidium parvum infection caused significant (P < 0.05) reduction in villus height. Decreased villus height, villus blunting and fusion, and attenuation of the intestinal mucosa were associated with reduced absorption of vitamin A, as indicated by lower peak postadministration retinyl palmitate concentration in C parvum-infected calves. Intravenous administration of DFMO to group-3 calves did not improve retinol absorption. Vitamin A should be provided parenterally to young calves with enteric cryptosporidiosis in an attempt to avoid depletion of concurrent low liver vitamin A reserves.

The prevalence and intensity of Cryptosporidium infection were examined in 445 Holstein calves at 10 dairy farms in western Washington, near Seattle. Fifty-one percent (176) of calves in the 7- to 21-day-old age group (n = 342) were positive for oocysts in the feces by carbolfuchsin staining. Prevalence and intensity of infection were highest in calves 8 to 14 days old; prevalence was 60% in this group, and 48% of the Cryptosporidium-positive calves had oocyst shedding at a 4+ level. A seasonal pattern in prevalence was not evident.

Clinical signs of respiratory tract disease were observed in chickens that were inoculated intratracheally with 1 x 10(6) oocysts of Cryptosporidium baileyi at 2 or 14 days of age (10 chickens/group), but not in chickens inoculated at 28 or 42 days of age (10 chickens/group). Orally inoculated chickens in all age groups (10 chickens/group) did not develop clinical signs of disease. Orally and intratracheally inoculated chickens in all age groups were infected, as determined by the finding of cryptosporidia in tissue sections of the trachea, bursa of Fabricius, and cloaca, and by the recovery of oocysts from their feces. Chickens inoculated at 2 and 14 days of age excreted oocysts for a longer period and had greater numbers of cryptosporidia in their tissues, compared with chickens inoculated at 28 and 42 days of age.

The current research included examination of 100 fecal sample from bovine wascollected from AL-Qadisiyah province, from September 2018 until February 2019.TheMicroscopically result showed that oval or spherical shaped with dark pink color or redoocyst on blue ground and 30(30%) positive sample out 100 case . It was recorded thatthe maximum rate 41.66% (5/12) was seen in November, but the lowest rate 18.75%(3/16) was seen in the month of February with no significant differences at level(p&lt;0.05.) According to age the maximum rate of incidence 40%(14/35)was found inthe age group lower than a month, but the lowest incidence was seen in the group( &gt;1years). There is no significant differences at p&lt;0.05.between male and female. In thecurrently study the N-PCR in molecular investigation were used ,the positive samplewas18 (60%) out of 30 fecal sample. Sequencing of a fragment of the(18s rRNA) gene(834 bp) that separated from many distinct area in AL- Qadisiyah governmentrecorded (50%)6/12 sample related to NCBI &ndash; Blast Cryptosporidium parvum ,( 33.33%)4/12 sample display deep related to NCBI &ndash;Blast Cryptosporidium bovis (this firststudy reported C. bovis in Iraq ) , (16.66%) 2/12 sample showed closed related to NCBI&ndash;Blast Cryptosporidiumandersoni.

The aim of current study was investigate the isolation of Cryptosporidium oocystsfrom 93 fecal samples of infected slaughtered broiler chicken in local markets ofsome areas in Baghdad city, during the period from the beginning of November 2017to end of April 2018. In this study three diagnostic techniques used, flotation bySheather's sugar solution, isolation and measuring of Cryptosporidium oocysts (byocular micrometer). For conform that the isolated species of the parasite from infectedcases belong to the Cryptosporidium baileyi, experimental infection done in, broilerchicken chicks aged one week to study the histopathological lesion in infected organs(intestinal, trachea, and bursa of Fabricius). The results of calibration of isolatedoocysts, showed that the mean of measurement size of Cryptosporidium oocysts was6.2x 4.7 micrometers.

Fift y nine samples of feces were collected from broiler flocks farms located in Hama and Aleppo provinces of Syria, which suffered from diarrhea or respiratory problem or both. For the first time, this study confirmed the infection of the broiler flocks with Cryptosporidium in Syria with a rate of 8.4%. The infection has been demonstrated by detecting the Cryptosporidium oocysts in the fecal by using direct smear method and Formol-Ether concentration method, then stained by Kinyoun acid fast stain. The result of tests based on morphology and size of Cryptosporidium oocysts showed that the parasite is probably C. baileyi which ranged between (6 µm X 4 µm).