Cross-transmission Studies Research Articles

Occurrence and phylogenetic analysis of avipoxvirus isolated from birds around Jammu.

Domesticated fowls, pigeons and turkey birds were screened for avipoxvirus infection from different areas in Jammu region. Based on typical pox lesions the overall occurrence in fowl was found to be 18.52%, 17.03% in pigeons and 57.14% in turkeys. Mortality recorded in chicks was 41.96%, 45.36% in squabs, 100% in poults, and 20.00% in adult turkeys. Both cutaneous and diphtheritic forms of the disease was observed of which the latter was particularly prevalent in young birds. One sample of putative fowlpox virus (FWPV) from skin lesions of a fowl, and two samples of putative pigeonpox virus (PGPV) from skin and diphtheritic lesions each were inoculated on chorio-allantoic membrane (CAM) of 10-12days old chicken embryonated eggs. A confirmatory diagnosis was made by PCR amplification of a highly conserved P4b gene locus detected in tissue samples from skin, diphtheritic membrane and virus inoculated CAM yielding a predicted 578bp product. Phylogenetic analysis based on the same P4b gene locus revealed FWPV and turkeypox virus (TKPV) to be 99% related and belonging to clade 1, while PGPV was found to belong to clade 2. All three isolates illustrate considerable heterogeneity within the conserved P4b gene locus. The study indicates that the closely related FWPV and TKPV isolates may have the potential of cross infection between fowls and turkeys and therefore cross transmission studies are suggested.

A new species of Giardia K\xfcnstler, 1882 (Sarcomastigophora: Hexamitidae) in hamsters

BackgroundGiardia spp. are flagellated protozoan parasites that infect humans and many other vertebrates worldwide. Currently seven species of Giardia are considered valid.ResultsHere, we report a new species, Giardia cricetidarum n. sp. in hamsters. Trophozoites of G. cricetidarum n. sp. are pear-shaped with four pairs of flagella and measure on average 14 μm (range 12–18 μm) in length and 10 μm (range 8–12 μm) in width. The trophozoites of the new species are generally larger and stouter than those of most of the other Giardia spp. and exhibit the lowest length/width ratio (c.1.40) of all recognized Giardia species. Cysts of G. cricetidarum n. sp. are ovoid and measure on average 11 μm (range 9–12 μm) in length and 10 μm (range 8–10 μm) in width and are indistinguishable from the cysts of other Giardia species. Molecular phylogenetic analyses based on beta-giardin, small subunit rRNA, and elongation factor-1 alpha loci all demonstrated that G. cricetidarum n. sp. is genetically distinct from all currently accepted Giardia spp. Investigation of the host range indicated that the new species was only found in hamsters (including Phodopus sungorus, P. campbelli and Mesocricetus auratus), while all the other described mammal-parasitizing species (G. muris, G. microti and G. intestinalis) each infect multiple hosts. Cross-transmission studies further demonstrated the apparent host specificity of G. cricetidarum n. sp. as it only infected hamsters. Trophozoites were found in high numbers in hamster intestines (5 × 105 – 5 × 106) and was rarely detected co-infecting with other Giardia spp. in the common hamster, suggesting it has some advantages in parasitizing hamsters.ConclusionsThis study has identified a new species of Giardia, which appears to be specific to hamsters, and together with the three other mammal-parasitizing Giardia species with different host ranges, may be able to be used as a model system for the study of evolutionary divergence of host parasitism strategies in Giardia.

Host specificity of turkey and chicken Eimeria: Controlled cross-transmission studies and a phylogenetic view

Protozoan parasites of the Eimeria genus have undergone extensive speciation and are now represented by a myriad of species that are specialised to different hosts. These species are highly host-specific and usually parasitise single host species, with only few reported exceptions. Doubts regarding the strict host specificity were frequent in the original literature describing coccidia parasitising domestic turkeys. The availability of pure characterised lines of turkey and chicken Eimeria species along with the recently developed quantitative PCR identification of these species allowed to investigate the issue of host specificity using well-controlled cross-transmission experiments. Seven species of gallinaceous birds (Gallus gallus, Meleagris gallopavo, Alectoris rufa, Perdix perdix, Phasianus colchicus, Numida meleagris and Colinus virginianus) were inoculated with six species and strains of turkey Eimeria and six species of chicken coccidia and production of oocysts was monitored. Turkey Eimeria species E. dispersa, E. innocua and E. meleagridis could complete their development in the hosts from different genera or even different families. Comparison of phylogenetic positions of these Eimeria species according to 18S rDNA and COI showed that the phylogeny cannot explain the observed patterns of host specificity. These findings suggest that the adaptation of Eimeria parasites to foreign hosts is possible and might play a significant role in the evolution and diversification of this genus.

Natural infection of Cryptosporidium muris in ostriches (Struthio camelus)

A total of 303 fecal samples were collected from ostriches (Struthio camelus) and 31 samples (10.2%) were Cryptosporidium-positive upon microscopic analysis. The infection rate was 27.6% in ostriches aged 16–60 days, 1.2% in those aged 61–180 days, and 20.4% in those aged >10 years. The Cryptosporidium-positive isolates were genotyped with a restriction fragment length polymorphism analysis and DNA sequence analysis of the small subunit (SSU) rRNA gene. The 22 isolates from ostriches aged >10 years were identified as Cryptosporidium muris, whereas the nine isolates from ostriches <180 days were Cryptosporidium baileyi. Ten of the 22 C. muris isolates were analyzed based on the actin and HSP70 genes, and the results were identical to those observed for the SSU rRNA gene. Cross-transmission studies demonstrated that the C. muris isolate infected BALB/c mice and Mongolian gerbils, but did not infect chickens. C. muris isolated in this study appears to be host-adapted, consistent with a previous multilocus sequence typing analysis. Further studies are required to understand the prevalence and transmission of Cryptosporidium spp. in ostriches in different geographic areas.

Some aspects of coccidiosis in sheep and goats

This paper provides a brief review of the widespread and economically important disease of coccidiosis. At one time, coccidia were considered to be virtually non pathogenic, but by the 1960s they were recognised to cause disease. Almost all young lambs and kids will be exposed and become infested during their early life and there are similarities and differences between the two host species. Coccidian species are mainly identified by their morphology and the predilection site within the host's alimentary tract. At one time, it was thought the species in goats and sheep were the same, but cross transmission studies have shown that the coccidia are host-specific. Currently, 11 coccidian species are recognised in sheep and nine in goats. Two sheep species are known to be highly pathogenic and these two parasites inhabit both the small and large intestine. Much less work has been undertaken on goat coccidia, although it is considered that several Eimeria species might be pathogenic. Often, clinical signs in sheep and goats are limited and mild, but it is common for animals to decrease their weight gain or even lose weight. The faeces may alter and there may be diarrhoea. Whilst there are production losses, there has been little quantification in sheep or goats. Moreover, infested animals appear more susceptible to other infections. Diagnosis is often more difficult than it seems. Because of problems, this has resulted in suggestions that the diagnosis of coccidiosis should be based on a number of parameters: epidemiology, clinical signs, oocyst counts in faecal samples, pathological findings and, finally, clinical response to treatment. There are several preparations licensed in the United Kingdom for sheep, but none for goats. There are also several management factors which can assist in control of the disease, but often medication has to be used to prevent the disease.

Prevalence of Cryptosporidium baileyi in ostriches (Struthio camelus) in Zhengzhou, China

Few data are available on the molecular characterization of Cryptosporidium spp. in ostriches. The objective of this study was to determine the prevalence of Cryptosporidium species or genotypes in ostriches. A total of 452 fecal samples from five farms, a zoo, and an animal rescue center in Zhengzhou, Henan Province, China were examined for Cryptosporidium oocysts by microscopy of wet mount of fecal materials concentrated by the Sheather's sugar flotation technique. Fifty-three samples were Cryptosporidium-positive from four farms, with an overall prevalence of 11.7%. The percentage of animals shedding oocysts was 0, 16.2%, 7.2%, and 0 in 1–3 weeks, 4–8 weeks, 3–12 months, and more than 12 months ostriches, respectively (χ2=17.74; ρ<0.01). PCR-restriction fragment length polymorphism (RFLP) analysis of the small subunit (SSU) rRNA gene of the 53 Cryptosporidium-positive samples showed the presence of only Cryptosporidium baileyi, which was confirmed by DNA sequencing of the SSU rRNA PCR products from 16 positive samples. Cross-transmission studies demonstrated that the C. baileyi isolate could infect chickens and quails. Thus, ostriches are commonly infected with C. baileyi that is genetically and biologically similar to C. baileyi found in other birds.

Multilocus phylogenetic analysis of Cryptosporidium andersoni (Apicomplexa) isolated from a bactrian camel (Camelus bactrianus) in China

This is the first report of cryptosporidiosis in a bactrian camel (Camelus bactrianus) in China. Two Cryptosporidium isolates derived from the same bactrian camel (3-year-old) in November 2005 and April 2006 were characterized using sequence and phylogenetic analysis of the small-subunit rRNA (18S rRNA), 70-kDa heat shock protein (HSP70), actin and Cryptosporidium oocyst wall protein (COWP) genes. The sequences of the 18S rRNA and COWP were identical to all other Cryptosporidium andersoni isolates although minor differences were noticed between the isolates and the USA isolate at the actin locus (99.2% of similarity). The sequence of the HSP70 was identical to the Japanese C. andersoni isolate, with a minor difference from the Australian C. andersoni isolate (99.7% of similarity). Cross-transmission studies demonstrated that the C. andersoni isolates did not infect immunosuppressed or immunocompetent Kun-ming mice, severe combined immunodeficiency mice, and immunosuppressed or immunocompetent calves. Among the C. andersoni isolates reported so far, only isolates from Japan could infect SCID mice. Thus, the C. andersoni isolates from the bactrian camel were biologically similar to most bovine C. andersoni isolates characterized so far, but are different from bovine isolates from Japan.

Cross-Transmission Studies with Eimeria arizonensis, E. arizonensis-like Oocysts and Eimeria langebarteli: Host Specificity at the Genus and Species Level within the Muridae

Cross-transmission experiments were done using sporulated oocysts of Eimeria arizonensis from Peromyscus truei and Peromyscus maniculatus, and oocysts of 2 putative species that resemble E. arizonensis, i.e., Eimeria albigulae from Neotoma albigula, and Eimeria onychomysis from Onychomys leucogaster. Oocysts of each species were inoculated into representatives of P. maniculatus and the latter 2 rodent species. Other experiments were conducted wherein oocysts of Eimeria langebarteli from Peromyscus leucopus were given to P. truei and P. maniculatus. Oocysts of E. arizonensis from P. truei and P. maniculatus could be transmitted only to P. maniculatus; likewise, oocysts of E. albigulae and E. onychomysis produced patent infections only in N. albigula and O. leucogaster, respectively. Oocysts of E. langebarteli from P. leucopus could be transmitted to P. truei, but not P. maniculatus. These results indicate that E. arizonensis, and the morphologically similar E. albigulae and E. onychomysis, are distinct species that are not transmissible between the genera of their respective hosts (Peromyscus, Neotoma, Onychomys), and that some isolates of E. langebarteli, reported from 6 species of Peromyscus and Reithrodontomys megalotis, may not always be infective to P. maniculatus.

Cross-transmission studies of Perkinsus karlssoni (Apicomplexa) from bay scallops Argopecten irradians to native Atlantic Canadian shellfish species

Cross-transmission studies of Perkinsus karlssoni (Apicomplexa) from bay scallops Argopecten irradians to native Atlantic Canadian shellfish species

Comparative morphological and cross transmission studies with bovine and deer babesias in Ireland

A babesia from wild sika deer in Ireland and Babesia capreoli from red deer in Scotland were isolated in experimental splenectomised sika deer and, together with B. divergens (the bovine piroplasm), they were compared in morphological, serological and transmission studies. Despite slight morphological differences, the Irish isolate was indistinguishable from B. capreoli, and B. divergens and B. capreoli seem to be closely related but distinct species. Important cross infection between deer and cattle with these species is unlikely to occur (even though they are both transmitted by the tick Ixodes ricinus). Infections of B. capreoli were established in sika deer with some difficulty; this suggests that parasite is not well-adapted to this introduced deer species. The low serological prevalence in sika compared with red deer supports this interpretation.

Zoonotic aspects of giardiasis: A review

Several studies suggested that some water-borne epidemics of giardiasis in the U.S.A. were of zoonotic origin. Also, cats and dogs were suspected of being sources of giardiasis for man. These observations have been partly supported by experimental cross-transmissions. However, there are also some indications that zoonotic giardiasis may not be common. The host-specificity of Giardia spp. is still controversial. To date, morphological characteristics can only differentiate three very basic types of Giardia: G. intestinalis, G. muris and G. agilis. Host-specific and morphometric criteria resulted in the description of more than 40 species of Giardia; many of them probably invalid. Only a few subtle antigenic differences among G. intestinalis(lamblia) strains have been observed. The comparison of isoenzymes and DNA banding patterns revealed 3 basic groups, not necessarily related to host origin. Further biochemical, immunological, genetic and cross-transmission studies in host and parasite populations are needed to better understand host-specificity of various Giardia isolates. At the present time one may only conclude that although mammals and man do not seem to possess their own unique species of Giardia, in reality the major methods of transmission of giardiasis probably remain basically host-specific.

Cross-transmission of Eimeria spp. (Protozoa, Apicomplexa) of rodents--a review.

A total of 169 cross-transmission attempts has been made with 44 (11.8%) of the 372 named species of Eimeria of rodents. Of these, 161 were rodent-to-rodent, 6 rodent-to-lagomorph, and 1 each rodent-to-carnivore and rodent-to-bird. None of the last three categories was successful. In the rodent-to-rodent combinations, 39 (80%) of the 49 attempts to transmit a coccidian species from one rodent species to another of the same genus were successful, and only 14 (12.5%) of the 112 attempts to transmit a coccidium to a rodent of a different genus were successful. Eight of the successful attempts were with E. chinchillae, which was the only truly euryxenous species of Eimeria in the group. Two successful attempts were between between the closely related rodent genera Spermophilus and Cynomys, and two were both of E. separata from Rattus norvegicus to some genetic strains but not to others of Mus musculus. One attempt with E. vermiformis from Mus musculus to Rattus norvegicus required treatment of the rat with the immunosuppressant dexamethasone to succeed. More cross-transmission studies are needed to determine the host spectra of the species of Eimeria and other coccidian genera, and to determine the roles of genetics and immunosuppression in their transmission.

Cryptosporidium infections in birds and mammals and attempted cross-transmission studies

Infections by Cryptosporidium were detected in association with clinical disease in 11 humans ( Homo sapiens), 19 calves ( Bos taurus), nine common quail ( Coturnix coturnix), six mallard ducks ( Anas platyrhynchos), five ring-necked pheasant ( Phasianus colchicus) and a single budgerigar ( Melopsittacus undulatus). Infections in mammals were accompanied by transient diarrhoea and anorexia, whereas infected birds exhibited clinical signs of respiratory distress. Repeated cross-transmission studies revealed apparent strain differences or differences in the host specificity of several mammalian and avian isolates for homologous vertebrate classes only. Oocysts from humans and calves were infective to mice, pigs or lambs, but not to chickens, whereas oocysts from quail and pheasant were infective to chickens, but not to mice.

Experimental Cryptosporidium parvum Infections in Chickens

Levine (1984, Journal of Protozoology 31: 9498) reviewed taxonomy and cross-transmission studies of members of the genus Cryptosporidium (Apicomplexa: Cryptosporidiidae). Based on the class of vertebrate that they infected, he considered that there were 4 valid species: Cryptosporidium muris Tyzzer, 1907, in mammals, C. crotali Triffit, 1925, in reptiles, C. meleagridis Slavin, 1955, in birds, and C. nasorum Hoover, Hoerr, Carlton, Hinsman, and Ferguson, 1981, in fish. However, Upton and Current (1985, Journal of Parasitology 71: 625-629) demonstrated, based on oocyst size, that both C. parvum Tyzzer, 1912, and C. muris Tyzzer, 1907, were present in dairy and beef cattle. These authors (Upton and Current, 1985, loc. cit.) considered C. parvum to be the causative agent in all welldocumented cases of mammalian cryptosporidiosis. Current et al. (1986, Journal of Protozoology 33: 289-296) described Cryptosporidium baileyi from chickens and considered this species responsible for causing cryptosporidiosis in chickens.

Seasonal Prevalence of Hematozoa in Willow Ptarmigan (Lagopus lagopus) from Northwestern British Columbia

juvenile and female ducks than in adults and males, respectively, in central Saskatchewan. But, susceptibility may vary for renal and intestinal coccidia. Tyzzeria pellerdyi oocysts obtained from Anas spp. in 1977 were used for cross-transmission studies. Oocysts were embedded in 2.0% agar blocks or suspended in 0.9% NaCl and administered per os to 12 domestic ducklings, A. platyrhynchos domestica, 1 to 2 mo of age. Three uninfected ducklings were kept isolated and served as controls. Feces were collected at 24-hr intervals for 14 days postinfection, but none of the ducks shed oocysts during this time period. This work was supported in part by NIH Grant RR 08012. s, A. platyrhynchos domestica, 1 to 2 mo age. Thr e u infected ducklings were kept

Trypanosoma cervi Kingston and Morton, 1975 from mule deer, Odocoileus hemionus, in Wyoming.

Mensural values of blood stream stages and cross-transmission studies defined the trypanosome species from mule deer, Odocoileus hemionus, as con-specific with Trypanosoma cervi, the trypanosome found in elk from the same locality. Trypanosomes were found in eight mule deer sampled in the spring and eight sampled in the winter in southeastern Wyoming.

The Coccidian Parasites (Protozoa, Sporozoa) of Rodents

The taxonomic scheme used in this text is based on Levine's previous classification of the Sporozoa and his system of uniform endings for names of higher taxa. Brief sections are presented on life cycle, general oocyst morphology, criteria for separation of species and pathogenicity. These are followed by a large section on systematics which for each species includes synonymy, a description, and the available information on sporulation time, schizogony and gametogony, prepatent period, type host, other hosts, location in the host, geographic distribution, pathogenicity, cross-transmission studies, and prevalence. Additional pertinent remarks are included for many of the species. In some instances new specific names are assigned to previously described coccidia. The species described are listed under the following genera: Eimeria, Isospora, Dorisiella, Wenyonella, Caryospora, Tyzzeria, Cryptosporidium, Klossia and Klossiella. A brief discussion section includes comments on the number of species of rodent coccidia in the various genera, relation of morphology of the oocyst of Eimeria to the host family, and cross-infection studies.

Trypanosomes and Haemobartonella in wild rodents in Illinois.

SYNOPSIS. Trypanosoma microti and Haemobartonella microti were found in 1 (17%) of 6 yellow‐bellied voles Microtus ochrogastev, and T. iowensis was found in 7 (11.5%) of 60 thirteen‐lined ground squirrels Spermophilus tridecemlineatus in Illinois. Reports of lewisi group trypanosomes from Microtus and Spermophilus are summarized. Those from different rodent host genera are considered to belong to different species. All of the 6 species named from the host genus Sperinophilus may belong to a single species; if so, their correct name would be T. otospermophili. However, until adequate cross transmission studies are carried out, it is considered preferable to retain the names originally assigned to the North American species.