• Korean Journal of Veterinary Service
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• v.18 no.2
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• pp.152-157
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• 1995

A total of 1050 layer and broiler chickens from 63 flocks of 21 poultry farms in South-Kyeonggi area, aged from 1 to 18 weeks, were investigated for the prevalence of Cryptosporidium baileyi infection from May 1992 to March 1993. The results have shown that 44 chickens(4.19%) were infected with C.(baileyi during the period of investigation) Fecal samples were treated by using Sheather's flotating technique and were examined under the light and phase contrast microscopy and then stained by Kinyoun method. Cryptosporidium oocysts were found in 35 out of 650 broilers(5.4%) and 9 out of 400 layer chickens(2.3%) aged mainly from 2 to 12 weeks. The regional infection rate were 4.7% in Pyeong-taek, 5.1% in An-sung and 2.3% in Yong-in, respectively. The average size of isolated oocyst was about $5.23{\times}4.92{\mu}m$ and the oocysts were orally inoculated into 2-day-old SPF chickens for the histological examination of oocyst in bursa of Fabricius. The study has concluded that C. baileyi infects chickens and oocysts were isolated in South-Kyeonggi area.

• Parasites, Hosts and Diseases
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• v.41 no.4
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• pp.197-201
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• 2003

The present study was undertaken to determine the viability and infectivity of oocysts of Cryptosporidium baileyi that had been stored from 1 to 40 months at $4^{\circ}C$ preserved in 2.5% potassium dichromate solution. Oocysts of C. baileyi were purified from the feces of experimentally infected chickens using discontinuous sucrose gradients. Subsequently, the purified oocysts were suspended in 2.5% potassium dichromate solution at a concentration of $1{\;}{\times}10^7$ organism/ml, and their viabilities were assessed by nucleic acid staining, histologic examination, and infectivity to 2-day-old chickens. All chickens inoculated with oocysts that had been stored for 1-18 months developed patent infections, while chickens infected with older oocysts remained uninfected. Between 5.8% and 82.2% of the oocysts, stored at $4^{\circ}C$ in 2.5% potassium dichromate solution, were found to be viable, as determined by nucleic acid staining. Parasite colonization in the bursa of Fabricius was detected in the microvillus border of bursal epithelium. The finding that C. baileyi oocysts remain infective to chickens for at least 18 months offers important time-saving advantages to investigators who frequently require large numbers of oocysts.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.575-582
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• 1999

Morphometrical analysis of chicken Cryptosporidium baileyi in various stages of life cycle in the bursa of Fabricius were carried out by electron microscope to establish a differential point for identification of C baileyi. By avidin-biotin complex method, protozoans of the bursa of Fabricius were identified Cryptosporidium spp. The size and area on each developmental stages of C baileyi, as measured by Morphomat 10 attached to electron microscope were as follows. Trophozoites' size with range of $3.21{\pm}0.70{\times}2.49{\pm}0.59{\mu}m$, area with range of $118.82{\pm}41.92{\mu}m^2$; meronts' size $3.99{\pm}1.07{\times}2.96{\pm}0.52{\mu}m$, area $210.11{\pm}57.11{\mu}m^2$; merozoites' size $1.98{\pm}0.43{\times}0.60{\pm}0.18{\mu}m$, area $24.10{\pm}5.97{\mu}m^2$; microgametes' size $1.36{\pm}0.83{\times}0.50{\pm}0.23{\mu}m$, area $20.23{\pm}6.73{\mu}m^2$; macrogametes' size $4.57{\pm}0.65{\times}4.02{\pm}0.55{\mu}m$, area $258.37{\pm}51.83{\mu}m^2$; oocytes' size $4.39{\pm}0.56{\times}3.44{\pm}0.50{\mu}m$, area $187.21{\pm}62.68{\mu}m^2$. In conclusion, the size and area on each developmental stages of Cryptosporidium baileyi is different from that of other Gryptosporidia spp. It suggests, with considering tissue tropism and life cycle, morphometrical analysis can be quite a good way to identify C baileyi.

• Parasites, Hosts and Diseases
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• v.36 no.4
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• pp.281-284
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• 1998

Humoral immune response of young chicks to Brucella abortus strain 1119-3 inoculation was monitored to verify the degree of immunosuppression caused by infection with Cryptosporidium baileyi. Young chicks (2-day-old) were orally inoculated each with $2{\times}10^6$ oocysts of C. baileyi, and then injected intramuscularly with 0.3 $m\ell$ B. abortus strain 1119-3 containing $1{\times}10^9$ living organisms on day 14 postinoculation (PI). Serum samples were tested by plate agglutination test on day 17 PI onwards at an interval of 3-6 days over a period of 36 days. Infected chicks with the coccidium showed significantly lower antibody titers than those of uninfected controls (P<0.05). These findings document that C. baileyi infection in early life stage may predispose chicks easily to other potential poultry diseases.

• Parasites, Hosts and Diseases
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• v.29 no.4
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• pp.315-324
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• 1991

Each of SPF chicken(Hi-Line strain, 2-day-old males) was inoculated with 2.5 or $5\times10^4$ oocysts by stomach tube. The oocyst was the medium type of Cryptosporidium previously isolated from Korean chicken origin, and passed in 2-day-old SPF chicken. The patterns of oocyst discharge were monitored daily, and in order to observe the ultrastructure of the developmental stages, the bursa of Fabricius of the chicken was examined by transmission electron microscopy (TEM) on the 12th day postinoculation. The prepatent period for 8 chicken was 5.9 days postinoculation on the average, and the patent period was 12.9 days. The number of oocysts discharged per day for the chicken was reached peak on day 12 postinoculation on the average. A large number of oocysts was found in fecal samples obtained from inoculated chicken on days 8~14 postinoculation. The ultrastructural feature of almost every developmental stage of the medium type from chicken was very similar to that of Cryptosporidium previously isolated from mammalia including human and birds except for the attachment site of C. tsuris to the mucus cell from mammalia, but dimension of the oocysts from fecal samples of the medium type was different from those of C. meleagridis and mammalia origin. The above results reveal that the medium type of Cryptosporidium of Korean chicken origin is identified as Cryptosporidium baileyi.

• Parasites, Hosts and Diseases
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• v.56 no.3
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• pp.281-285
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• 2018

Cryptosporidium is the most common protozoan that can infect a wide range of animals, including mammals and birds. Avian Cryptosporidium spp. can cause enteric and respiratory diseases which can be fatal in birds and some species are zoonotic. Companion birds have the potential as reservoir due to their close contact with humans. Pet shops are the major source of companion birds. However, few reports are available regarding Cryptosporidium spp. infection among companion birds kept in pet shops. The present study reports the prevalence and molecular characteristics of Cryptosporidium spp. among companion birds kept in pet shops in Japan. A total of 265 fresh fecal samples were obtained from birds kept in 4 pet shops; these birds belonged to 41 species in 3 bird orders. A nested polymerase chain reaction (PCR) assay targeting the small subunit rRNA gene was employed for the detection of Cryptosporidium spp. A total of 24 samples (9.1%) were positive, and Cryptosporidium spp. were detected from all pet shops. The prevalence of Cryptosporidium spp. in each of the bird orders was 6.5% (10/153) in Psittaciformes, 14.4% (13/90) in Passeriformes, and 4.5% (1/22) in Galliformes. Based on sequence analysis, 13 (54.2%) isolates were classified to C. galli, 8 (33.3%) were avian genotype III, and the remaining 3 (12.5%) were C. baileyi. No infection with zoonotic C. meleagridis and no coinfection with multiple Cryptosporidium spp. and/or genotypes were observed. The zoonotic potential of Cryptosporidium spp. infecting companion birds kept in pet shops in Japan is likely to be low.

• Parasites, Hosts and Diseases
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• v.34 no.4
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• pp.255-258
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• 1996

Eight 2-day-old SPF Chickens were each inoculated Orally With 3 Sing1e dose Of 5 × 105 oocysts of Cryptosporinium boilevi. and immunoglobulin G (IgG) antibody responses were chronologically measured by indirect immunofluorescent antibody (IFA) assay. Anti-C. bcileyi IgG antibody levels remained high (1 : 106.67 to 1:512.00) for at least 4 months with 330 days of a detectable period. Ten days after the negative conversion, each chicken was re-challenged with 1 × 107 oocysts of the same species. Subsequent infection in 340-day-old individuals caused sudden elevated IgG antibody levels and the titer peaked on day 28 postchallenge inoculation (PCI), at 1:1.024 with a 65 days of detection period. Chickens in primary infection showed oocyst shedding profiles. but did not exhibit any oocyst shedding before or after experimental reinfection.

• Parasites, Hosts and Diseases
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• v.36 no.2
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• pp.121-126
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• 1998

Hemagglutination-inhibition titers (log2) to Newcastle disease (ND) vims were chronologically observed in chicks, which were orally inoculated with 5 × 105 oocysts of Cwptospori,drum bcileyi at 2 days of age and subsequently vaccinated with inactivated ND virus at 4 and 21 days postinoculation. In general, the titers were considerably lower in the infected chicks than those in the uninfected control throughout the experimental period (p < 0.01), and rapid negative seroronversions were observed in the infected chicks. The titers reached a peak on weeks 2 and 4 post-booster-vaccination in the control and infected chicks, respectively. Thus, C. bciLeWi infection was shown to have an immunosuppressive effect on ND vaccination when the agent was given to 2-day-old chicks. It is suggested that C. bniLeWi infection in chicks may increase the host susceptibility to ND virus.

• Parasites, Hosts and Diseases
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• v.36 no.3
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• pp.203-206
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• 1998

Two-day-old commercial chicks were inoculated orally with 2 × 106 oocysts of Cwptosporinium bailevi and vaccinated with 103.5 EID50/head of a commercially available avian infectious bronchitis (IB) live virus vaccine at 4 and 14 days following inoculation. Chicks infected with C. baileyi were shown to have an immunosuppressive effect on IB virus. It is concluded that infection with the protozoon in early life may increase their susceptibility to IB.

• Parasites, Hosts and Diseases
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• v.36 no.1
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• pp.33-36
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• 1998

Hemagglutinin (HA) titers to SRBC were chronologically observed in chickens orally inoculated at 2 days of age with 5 × 105 oocysts of Cwptosporidium bniLeWi. All the infected chickens exhibited negligible HA titers by 44 days postinoculation (Pl) . The titers were elevated as time progressed. and peaked on day 52 Pl, declined gradually thereafter, and eventually reached to normal titers on day 92 Pl. On the contrary, the titers in uninfected chickens were higher in comparison with infected chickens during the experiment. Chickens infected with the protozoa showed normal oocyst shedding profiles during this period. These data suggest that C. bnilewi infection suppress development of humoral immunity to SRBC in chickens. It is possible that impairment of the bursa of Fabricius by cryptosporidiosis rendered chickens vulnerable to other pathogens.