Publications

effect of cryptosporidium baileyi on broilers infected at 26 days of age.	cryptosporidium baileyi causes respiratory disease, pallor, death, and transient increased feed conversion (fc) and decreased body weight gain (bwg) when intratracheally (it) inoculated into young chicks. unlike the case for young chicks in previous studies, c. baileyi had no effect on fc, bwg, or mortality in it-inoculated 26-day-old chicks. results from two different histologic evaluations indicated that it inoculation with 10(4) oocysts caused higher epithelium lesion scores (p less than 0.05 ...	1990	2369384
experimental infections in domestic ducks with cryptosporidium baileyi isolated from chickens.	oral inoculation of 13 ducks (anas platyrhynchos) with 1 x 10(6) cryptosporidium baileyi oocysts produced patent infections but no clinical signs of disease. intratracheal inoculation of 13 ducks with 1 x 10(6) c. baileyi oocysts produced only mild clinical signs of respiratory disease, no deaths, and gross lesions of airsacculitis in only three ducks. the distribution of developmental stages of c. baileyi in ducks was similar to that observed in experimentally infected chickens and turkeys. res ...	1989	2522769
the pathogenicity of cryptosporidium parvum tyzzer, 1912 and c. baileyi current, upton et haynes, 1986 for chickens.	clinical symptoms and pathological-morphological changes in the respiratory tract of chickens inoculated with cryptosporidium parvum were described for the first time and compared with those induced by cryptosporidium baileyi. intratracheal inoculation with these two species caused symptoms of a respiratory tract disease in all chicken, but a disease of the digestive tract or death did not occur in any case. pathological and morphological changes were observed only in the respiratory system and ...	1989	2583611
apparent inability of cryptosporidium baileyi of chickens to infect poultry handlers in bangkok.		1989	2617628
interaction of reovirus and cryptosporidium baileyi in experimentally infected chickens.	no clinical signs, gross lesions, or increased mortality were observed in specific-pathogen-free chickens orally inoculated at 5 days of age with cryptosporidium baileyi, reovirus 2035, reovirus 2408, or combinations of these agents. weight gain of chickens inoculated with only reovirus 2408 was depressed 0-8 days postinoculation (pi) (p less than 0.01) but not for the 21-day period pi. weight gain of chickens inoculated with only reovirus 2035 was not affected. cryptosporidium baileyi infection ...	1988	2848481
experimental cryptosporidiosis and infectious bursal disease virus infection of specific-pathogen-free chickens.	specific-pathogen-free chickens orally inoculated at 4 days of age with a moderately pathogenic vaccine strain of infectious bursal disease virus (ibdv) and/or at 5 days of age with cryptosporidium baileyi oocysts remained free of overt clinical signs throughout a 16-day period postinoculation (pi). the prepatency period for c. baileyi oocyst shedding was shorter in chickens receiving higher numbers of oocysts, but once shedding was detected, there were no obvious differences in shedding pattern ...	1988	2849406
effect of broiler chicken age on susceptibility to experimentally induced cryptosporidium baileyi infection.	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 cry ...	1988	3178034
cultivation of cryptosporidium baileyi: studies with cell cultures, avian embryos, and pathogenicity of chicken embryo-passaged oocysts.	sporozoites of cryptosporidium baileyi did not undergo development in primary cell cultures from either avian or mammalian hosts, or in mammalian cell lines. oocysts of c. baileyi produced infections resulting in complete development to sporulated oocysts in chicken embryos and embryos of 8 other avian species examined. inoculation of 4 x 10(5) oocysts was not pathogenic for avian embryos as evidenced by the lack of gross lesions or death. oocysts obtained after c. baileyi had been passaged 10 t ...	1988	3357120
development of and serologic evaluation of acquired immunity to cryptosporidium baileyi by broiler chickens.	eighteen 2-wk-old broiler chickens that were inoculated orally with oocysts of cryptosporidium baileyi (group b) became infected, shed large numbers of oocysts in their feces on days 6 to 12 post inoculation (pi), and suddenly cleared the parasites from the mucosal epithelium of the bursa of fabricius (bf), cloaca, or both bf and cloaca on days 14 to 16 pi. eighteen uninoculated birds (group a) did not shed oocysts during this time period. five days after all birds in group b stopped shedding oo ...	1988	3405948
subclinical cryptosporidiosis of turkeys in iowa.	cryptosporidium oocysts were found in the feces of 16 of 20 (80%) 17-day-old and 38 of 100 (38%) 24-day-old turkeys in a healthy commercial flock in central iowa. mean dimensions of 50 oocysts were 4.5 x 5.3 micron. in experimentally inoculated turkeys and chickens, the parasites frequently infected the ceca, colon, and cloaca, but rarely infected the small intestine or bursa of fabricius. these data differ from published descriptions of cryptosporidium baileyi in chickens and turkeys. the resul ...	1988	3418465
cryptosporidium baileyi: effects of intra-abdominal and intravenous inoculation of oocysts on infectivity and site of development in broiler chickens.	developmental stages of cryptosporidium baileyi were observed on the epithelium of the larynx, trachea, primary and secondary bronchi, air sacs, bursa of fabricius, and cloaca of 12 chickens inoculated intra-abdominally with oocysts. all 12 birds inoculated intra-abdominally developed clinical signs of respiratory disease and had gross lesions of airsacculitis at necropsy. developmental stages of c. baileyi and clinical signs of disease were not observed in 12 chickens inoculated intravenously w ...	1987	3442534
chemoprophylaxis of cryptosporidiosis in chickens, using halofuginone, salinomycin, lasalocid, or monensin.	chemoprophylaxis of cryptosporidium baileyi infections was attempted by feeding 4 groups of chicks diets containing 3 mg of halofuginone/kg of feed, 60 mg of salinomycin/kg, 75 mg of lasalocid/kg, or 110 mg of monensin/kg. rations were fed 5 days before oral or intratracheal inoculation with oocysts and were continued for 20 days. none of the drugs prevented c baileyi infections. clinical signs of respiratory tract disease and gross lesions of airsacculitis were observed in intratracheally inocu ...	1987	3565889
in vitro excystation of cryptosporidium baileyi from chickens.	release of sporozoites from the oocysts of cryptosporidium baileyi is described from nomarski interference-contrast microscopy. just prior to excystation, the four sporozoites became motile and rearranged themselves within the oocyst. the sporozoites were then rapidly expelled through an opening that formed in the oocyst wall, and the residuum was either released or retained within the oocyst. excysted sporozoites were crescent shaped and measured 5.0-9.0 microns x 1.0-1.6 micron (mean = 6.8 x 1 ...	1987	3572840
experimental cryptosporidiosis in broiler chickens.	seven-day-old conventional broilers were inoculated either orally or intratracheally (it) with 2.5 x 10(5), 5.0 x 10(5), or 2.0 x 10(6) oocysts of cryptosporidium baileyi (32 birds for each dosage level per group; 192 birds total). thirty-two birds served as unninoculated controls. mean weekly weight gain and feed conversion were determined during a 5-week period. carcass pigment was graded using a roche color fan. fecal oocysts were calculated from random cage samples 6, 8, 11, 13, 15, 18, 20, ...	1987	3601855
experimental cryptosporidium baileyi infections in chickens and turkeys produced by ocular inoculation of oocysts.	developmental stages of cryptosporidium baileyi were observed on the conjunctival epithelium of 3 of 14 chicks and none of 7 turkeys following ocular inoculation of oocysts. no clinical signs of disease were observed in chicks or turkeys. all 14 chicks had developmental stages of c. baileyi in the cloaca, whereas 4 of the 7 turkeys were infected at this site.	1987	3619829
experimentally induced infections in turkeys with cryptosporidium baileyi isolated from chickens.	oocysts of cryptosporidium baileyi isolated from chickens were inoculated by different routes into 3 groups of turkey poults. intratracheal inoculation of oocysts produced clinical signs of respiratory tract disease, deaths, and gross lesions of airsacculitis. parasites developed in the microvillous border of the nasopharynx, larynx, trachea, bronchi, and air sacs. oral and intracloacal inoculations of oocysts caused no deaths or clinical signs of disease, but did produce patent infections. resp ...	1987	3826828
the life cycle of cryptosporidium baileyi n. sp. (apicomplexa, cryptosporidiidae) infecting chickens.	the life cycle and morphology of a previously undescribed species of cryptosporidium isolated from commercial broiler chickens is described. the prepatent period for cryptosporidium baileyi n. sp. was three days post oral inoculation (pi) of oocysts, and the patent period was days 4-24 pi for chickens inoculated at two days of age and days 4-14 for chickens inoculated at one and six months of age. during the first three days pi, most developmental stages of c. baileyi were found in the microvill ...	1986	3735157