Species Of Helminth Parasites Research Articles

Bis-acridines as lead antiparasitic agents: structure-activity analysis of a discrete compound library in vitro.

Parasitic diseases are of enormous public health significance in developing countries-a situation compounded by the toxicity of and resistance to many current chemotherapeutics. We investigated a focused library of 18 structurally diverse bis-acridine compounds for in vitro bioactivity against seven protozoan and one helminth parasite species and compared the bioactivities and the cytotoxicities of these compounds toward various mammalian cell lines. Structure-activity relationships demonstrated the influence of both the bis-acridine linker structure and the terminal acridine heterocycle on potency and cytotoxicity. The bioactivity of polyamine-linked acridines required a minimum linker length of approximately 10 A. Increasing linker length resulted in bioactivity against most parasites but also cytotoxicity toward mammalian cells. N alkylation, but less so N acylation, of the polyamine linker ameliorated cytotoxicity while retaining bioactivity with 50% effective concentration (EC(50)) values similar to or better than those measured for standard drugs. Substitution of the polyamine for either an alkyl or a polyether linker maintained bioactivity and further alleviated cytotoxicity. Polyamine-linked compounds in which the terminal acridine heterocycle had been replaced with an aza-acridine also maintained acceptable therapeutic indices. The most potent compounds recorded low- to mid-nanomolar EC(50) values against Plasmodium falciparum and Trypanosoma brucei; otherwise, low-micromolar potencies were measured. Importantly, the bioactivity of the library was independent of P. falciparum resistance to chloroquine. Compound bioactivity was a function of neither the potential to bis-intercalate DNA nor the inhibition of trypanothione reductase, an important drug target in trypanosomatid parasites. Our approach illustrates the usefulness of screening focused compound libraries against multiple parasite targets. Some of the bis-acridines identified here may represent useful starting points for further lead optimization.

Use of parasite tags in delineating stocks of white hake ( Urophycis tenuis) from the southern Gulf of St. Lawrence and Cape Breton Shelf

Protozoan and metazoan parasites were inventoried in 396 white hake ( Urophycis tenuis), 40–60 cm in length, collected from the southern Gulf of St. Lawrence (NAFO division 4T) and Cape Breton Shelf (NAFO subdivision 4Vn) between August 2001 and May 2003. Discriminant function analysis (DFA) of parasite abundances revealed that cysts of unknown etiology (“CUE”) in the gill filaments, and three species of parasitic helminth, the monogenean, Diclidophoroides maccallumi, and the nematodes, Capillaria gracilis and Hysterothylacium aduncum, were useful as markers for discriminating 4T hake found at depths of >100 m along the southern slope of the Laurentian Channel and in the Cape Breton Trough from those found in the shallower (<50 m) waters of St. Georges Bay in the southeastern Gulf. DFA of the southern Gulf samples yielded an overall correct classification rate of 78%, thereby supporting earlier tagging, meristic and morphometric studies which indicated that 4T hake are comprised of distinct deep-water (Channel) and shallow-water (Strait) stock components. DFA of all 4TVn samples, with the inclusion of a fifth marker, the acanthocephalan Echinorhynchus gadi, yielded correct classification rates of 66 and 76% for “channel” and “strait” hake, respectively, and 76% for 4Vn hake from Laurentian slope waters of the Cape Breton Shelf. Hence, parasite tags could be applied, together with other biological and/or genetic markers, in studies of migration and possible mixing of 4TVn stock components over-wintering in Laurentian slope waters.

THE COMPONENT HELMINTH COMMUNITY IN SIX SYMPATRIC SPECIES OF ARDEIDAE

We studied the helminth communities in 6 sympatric species of Ardeidae (Ixobrychus minutus (Linnaeus, 1766), Nycticorax nycticorax (Linnaeus, 1758), Bubulcus ibis (Linnaeus, 1758), Egretta garzetta (Linnaeus, 1766), Ardea cinerea (Linnaeus, 1758), and Ardea purpurea (Linnaeus, 1766)) from "La Albufera de Valencia," Spain. The survey revealed 13 species of helminth parasites: 5 digeneans, 2 cestodes, and 6 nematodes. The component helminth communities of the Ardeidae examined are depauperate and conform to the pattern typically found in isolationist communities, probably because of their high trophic dependence on a few prey species. Evenness was positively correlated with richness and abundance, but host body weight was not correlated with the number of helminth species or with the total number of helminths. Ardea cinerea is more heavily infected than E. garzetta by Apharyngostrigea cornu, and B. ibis is more heavily infected than both Ardea cinerea and E. garzetta by Desportesius spinulatus. Apharyngostrigea cornu was positively associated with Desmidocercella numidica and D. spinulatus in A. cinerea.

Helminths of Freshwater Fishes from the Metztitlán Canyon Reserve of the Biosphere, Hidalgo, Mexico

The occurrence of 6 species of helminth parasites (Clinostomum complanatum, Diplostomidae gen. sp., Posthodiplostomum minimum, Bothriocephalus acheilognathi, Glossocercus sp., Contracaecum sp.) is reported from 7 species of freshwater fishes (Chirostoma jordani, Astyanax mexicanus, Herichthys labridens, Oreochromis niloticus niloticus, Abramis brama, Cyprinus carpio carpio, and Poeciliopsis gracilis) in Metztitlan Lake (Laguna de Metztitlan), Reserva de la Biosfera Barranca de Metztitlan, Hidalgo, Mexico. Fish were collected between July 2002 and June 2003. The helminth fauna of H. labridens, an endangered species of Cichlidae, is described for the first time. Migratory birds of the families Ardeidae and Phalacrocoracidae appear to play an important role in the helminth species composition of fishes from Metztitlan Lake. All helminth species represent new records for this federally protected area of Hidalgo.

Helminth parasites in freshwater fish from the Papaloapan river basin, Mexico

A checklist based on previously published records and original data is presented for the helminth parasites reported in 35 fish species from nine families from the Rio Papaloapan basin, east Mexico. The checklist contains 85 taxa from 39 helminth families. Trematodes and nematodes were the most abundant taxonomic groups. The helminth fauna in the fish of the Papaloapan River basin predominantly consists of Neotropical species that are largely autogenic. The introduced species Centrocestus formosanus was the most widely distributed helminth, infecting 16 host species. Ten of the recorded helminth species have only been found in fish from the Papaloapan. This inventory contributes 157 new host records, and reports the presence of 30 helminth species in the Papaloapan for the first time . This inventory shows the richness of helminth parasite species in the fish of the Papaloapan River basin in comparison with the other hydrological basins in Mexico. It also demonstrates that this fauna is typically Neotropical and quite similar to that from the neighboring basins of the Grijalva-Usumacinta system and the Yucatan Peninsula. The data also suggest highly effective transmission between environments within the same basin and that the regional parasite fauna is strongly influenced by fish community composition.

Host specificity and the probability of discovering species of helminth parasites

Different animal species have different probabilities of being discovered and described by scientists, and these probabilities are determined to a large extent by the biological characteristics of these species. For instance, species with broader geographical ranges are more likely to be encountered by collectors than species with restricted distributions; indeed, the size of the geographical range is often the best predictor of a species' date of description. For parasitic organisms, host specificity may be similarly linked to the probability of a species being found. Here, using data on 170 helminth species parasitic in freshwater fishes, we show that host specificity is associated with the year in which the helminths were described. Helminths that exploit more host species, and to a lesser degree those that exploit a broader taxonomic range of host species, tend to be discovered earlier than the more host-specific helminths. This pattern was observed across all helminth species, as well as within the different helminth taxa (trematodes, cestodes, nematodes and acanthocephalans). Our results demonstrate that the parasite species known at any given point in time are not a random subset of existing species, but rather a biased subset with respect to the parasites' biological properties.

Infection status with helminthes in feral cats purchased from a market in Busan, Republic of Korea

The present study was performed to investigate the infection status with helminth in a group of feral cats in Korea. More than 29 helminth species including adults or eggs were detected in visceral and fecal samples of the examined cats. Among these were a host of nematodes, including toxocarids, Ancylostoma sp. and the larva of Anisakis simplex; trematodes, including Clonorchis sinensis, Paragonimus westermani, Eurytrema pancreaticum, Pharyngostomum cordatum, Metagonimus spp., Heterophyes nocens, Pygidiopsis summa, Heterophyopsis continua, Stictodora fuscata, Stictodora lari, Acanthotrema felis, Stellantchasmus falcatus, Centrocestus armatus, Procerovum varium, Cryptocotyle sp., Echinostoma revolutum, Echinostoma hortense, Echinochasmus japonicus, Stephanoprora sp., Plagiorchis muris, Neodiplostomum sp. and diplostomulum. We also detected a variety of cestodes, including Spirometra erinacei, Taenia taeniaeformis and unidentified species of tapeworm. We also found examples of the acanthocephalan, Bolbosoma sp. In our assessment of the stools, we detected at least 12 species of helminth eggs. These findings confirmed that feral cats in Korea are infected with a variety of helminth parasite species. Furthermore, among the helminths detected, E. pancreaticum, S. fuscata, S. lari, A. felis, S. falcatus, C. armatus, P. varium, Cryptocotyle sp., E. revolutum, E. japonicus, Stephanoprora sp., P. muris, Neodiplostomum sp. and Bolbosoma sp. represent helminth fauna which have not been reported previously in feral cats in the Republic of Korea.

Helminth parasites of &lt;i&gt;Clarias gariepinus&lt;/i&gt; (Teugels) in Zaria, Nigeria

A total of 240 Clarias gariepinus (Teugels) were randomly purchased from fish landings in Sabon-gari market, Zaria. The fish were examined parasitologically for gastrointestinal parasites. Five species of helminth parasites comprising 3 cestodes, 1 nematode and 1 acanthocephala were isolated from the fish. The cestodes and their prevalence were Anomotaenia sp. (2.5%), Monobothrium sp. (13.33%) and Polyonchobothrium clariae (1.67%). The nematode, Procamallanus laevionchus and the acanthocephalan, Neoechinorhynchus rutili had a prevalence of 0.83% and 0.83% respectively. Majority of the parasites were found in the intestine. Infection was limited to fish with length ranging from 30.0 – 39.9 cm (prevalence: 15.83%; mean intensity: 3.78) and 40.0 – 49.9 cm (prevalence: 3.33%; mean intensity: 2.5) Fish specimens that were lighter in weight (150.0 – 299.9 g) were free of infection, but those found with parasites weighed between 350.0 – 399.0 g (prevalence, 7.5%) and 450.0 – 500.0 g (prevalence 6.67%). There was no statistically significant difference (P > 0.05) in the infection of the male and female C. gariepinus. The study highlights the importance of changing feeding habit of C. gariepinus with age on the prevalence and intensity of gastrointestinal parasites, and parasitised male fish have lower condition factor than unparasitised ones. Key Words: Helminth, parasites, Clarias gariepinus, Zaria. Journal of Aquatic Sciences Vol.19(2) 2004: 71-76

HELMINTH COMMUNITIES OF THE LESSER SANDEEL AMMODYTES TOBIANUS L. OFF THE WEST COAST OF IRELAND

The helminth parasites present in 412 lesser sandeels (Ammodytes tobianus) taken from June 1996 to May 1997 from the Aran Islands on the west coast of Ireland were examined. Ten helminth parasite species were recorded, and more than 92% of the sandeels were infected with at least 1 helminth species. Seven of the species were digeneans, including Brachyphallus crenatus, Hemiurus communis, Derogenes varicus, Lecithaster gibbosus, Opechona bacillaris, Cryptocotyle lingua, and Galactosomum lacteum; 2 nematodes, including Hysterothylacium sp. and Contracaecum sp.; and 1 cestode, Scolex pleuronectis. Three of the 7 digenean species were either larvae or immature. Only 2 species, the digeneans G. lacteum and H. communis, had prevalences greater than 50%. The dominant species was G. lacteum, accounting for 67% of all parasites present. The relationship between spawned groups, host length, and season versus the abundance, prevalence, species richness, and the total number of parasites in the infracommunities was investigated. No difference was found between the parasite communities of the 2 spawning races of the host population. Mean abundance and prevalence of the different parasite species showed seasonal variation. Numbers of parasite species and numbers of parasites increased with fish length. The role of A. tobianus as an intermediate host for helminths was assessed; it was determined that most were infectious to birds or mammals, with the majority of the parasite species being autogenic (infectious to fish). The mean number of parasites per fish was nearly a quarter of the value recorded for A. tobianus in the North Sea, where a much higher intensity of infection was recorded.

Differential expression of AP-1 transcription factor genes c-fos and c-jun in the helminth parasites Taenia crassiceps and Taenia solium.

Homologues of c-fos and c-jun from total DNA of Taenia crassiceps and Taenia solium were cloned and sequenced. The amino acid alignment analysis revealed that c-fos DNAs from T. crassiceps and T. solium were highly homologous (96%), and both have high homology compared to several mammalian c-fos proteins (93% to mouse, 96% to rat and 86% to human). The c-jun protein alignment showed higher homology (T. crassiceps and T. solium have 98%), when compared with mouse, rat and human, being 92%, 98% and 93% respectively. RT-PCR amplification of the parasite's total RNA, showed that T. crassiceps expressed both AP-1 complex genes, while T. solium only expressed c-fos. Southern blot hybridization analysis confirmed the true origin of each amplified gene. AP-1 transcription gene expression is regulated by oestradiol in the same fashion as their mammalian counterparts only in T. crassiceps. To study if AP-1 genes are involved in a physiological function of the cyst, reproduction was studied in vitro. Oestradiol treatment stimulated reproduction in T. crassiceps but not in T. solium cysticerci. This is the first report of the detection and functionality of AP-1 transcription factor genes in any species of helminth parasite.

Quantitation of complement and leukocyte binding to a parasitic helminth species

Methods used to quantify complement deposition and cell adherence to parasitic helminths usually involve subjective visual comparisons of immunofluorescence or time-consuming manual counting of bound cells. Such targets are relatively large and, generally, few individual organisms can be analysed. More objective and efficient radiometric assays are available, but these also have considerable disadvantages. We have developed an improved immunofluorescence-based method for quantitation of complement deposition on viable third-stage larvae of the nematode Nippostrongylus brasiliensis (L3). A similar strategy was also applied to measuring leukocyte adherence to the parasite. Fluorescein isothiocyanate (FITC)-conjugated antibodies were used to detect complement on serum-treated larvae. The adherence of carboxyfluorescein diacetate succinimidyl ester (CFSE)-labelled mouse leukocytes to larvae was investigated using the same basic approach. Images of fluorescent larvae or fluorescent cells attached to larvae were generated with a Bio-Rad Molecular Imager FX and fluorescence intensity was quantified. Hundreds of larvae can be analysed simultaneously in multiple samples, and these strategies allow rapid and sensitive quantitation that is directly proportional to the amount of protein or the number of leukocytes added to cultures. These techniques may also be applicable to other large objects, organisms or biological surfaces.

Correlates of helminth community in the red-legged partridge (Alectoris rufa L.) in Spain.

Between 1992 and 1996, 587 wild red-legged partridges (Alectoris rufa) from 16 Spanish provinces were examined to study the variations of helminth communities in this game species across a broad geographical area. The survey revealed 13 species of helminth parasites. Dicrocoelium sp.. Rhabdometra nigropunctata, and Cheilospirura gruweli were the most common species, whereas Raillietina bolivari, Choanotaenia infundibulum, Tetrameres sp., and Capillaria anatis were the most rare. Subulura suctoria, Heterakis gallinarum, Heterakis tenuicaudata, Capillaria contorta, Trichostrongylus tenuis, and Raillietina tetragona occurred with intermediate frequencies. The abundance of C. gruweli, S. suctoria, H. tenuicaudata, T. tenuis, and R. tetragona was inversely correlated to latitude and directly correlated to yearly mean temperature, whereas the abundance of Dicrocoelium sp. was directly correlated to latitude and inversely correlated to yearly mean temperature. The abundance of R. tetragona was inversely correlated to latitude and yearly mean humidity. The number of helminths per partridge and the number of helminth species per partridge were lower in young birds than in adults. Partridge body condition was inversely correlated to abundance of C. contorta. Richer infracommunities were linked to richer component communities. At the infracommunity level, total number of helminths per partridge and number of helminth species per partridge were inversely correlated to latitude and directly correlated to yearly mean temperature. At the component community level, both species richness and diversity (Simpson's index) were inversely correlated to latitude and directly correlated to mean temperature. Across the broad geographical range of the study area, the helminth parasite communities of red-legged partridges had marked geographical variation in their structure. Our results suggest that this variation is determined by the distribution of both intermediate and definitive hosts. We discuss the implications of this variation for the hypothesis that supplementary releases of captive-bred partridges for sport hunting can affect the helminth fauna of wild red-legged partridges.

The occurrence of helminth parasites in barbel (Barbus plebejus escherichi Stendachner, 1897) of the Doganci (Bursa) Dam Lake, Turkey

The occurrence of helminth parasites of barbel in the Doganci Dam Lake was investigated monthly from December 1998 to November 1999. During this study a total of 47 barbell were caught and examined for helminth parasites. A total of 5 species of helminth parasites was found as follows. Dactylogyrus carpathicus (Monogenea) was observed on gills of the fish and Bothriocephalus acheilognathi, Caryophyllaeus laticeps (Cestoda) Allocreadium isoporum (Digenea) and Contracaecum sp (Nematoda) were present in the intestines and the abdominal cavity of fishes. D. carpathicus was the dominant parasite species found in barbel. A total of 117 parasites were recorded on 27 of the 47 fish examined. The overall prevalence of D. carpathicus was 57%. A. isoporum was the second most dominant parasite in this study. A total of 35 parasites were found in 9 of 47 fish examined and the total prevalence of A. isoporum was 19.1%. However B. acheliognathi were present only in very small numbers. Only seven B. acheliognathi were found in 4 of the 47 fish examined. Four fish were infected by C. laticeps and a total of 13 parasites was found. A single species of Nematoda, Contracaecum sp was observed in 5 of the 47 fish examined. A total of 25 parasites was recorded. The overall prevalence of Contracaecum sp was 27.2%. D. carpathicus and.A. isoporum were new records for the helminth fauna of Turkey.

The ecology of fish parasites with particular reference to helminth parasites and their salmonid fish hosts in Welsh rivers: A review of some of the central questions

The ecology of fish parasites with particular reference to helminth parasites and their salmonid fish hosts in Welsh rivers: A review of some of the central questions

The occurrence of Helminth fauna in sand goby (Gobius fluviatilis, Pallas, 1811) from lake Uluabat, Turkey

Helminth parasites of sand goby (Gobius fluviatilis Pallas, 1811) from Lake Uluabat were investigated on a monthly or bimonthly basis between April 1998 and November 1999. Four species of helminth parasites were recorded in 98 out of 134 fish: Gyrodactylus gobii Shul'man, 1953; Bothriocephalus acheilognathi Yamaguti, 1934; Ligula pavlovskii Dubinina, 1959 Eustrongylides excisus Jagerskiold, 1909. They were evaluated with respect to seasons and host size. While G. gobii appeared to infect the gills and the skin of host fish, B. acheilognathi established itself in the intestines, and E. excisus and L pavlovskii in the body cavity. A total of 789 specimens of G. gobii were detected especially on smaller host fish during the spring period (prevalence 25.3%, mean intensity 23.21 ±9.17 specimens/fish). Although 184 B. acheilognathi appeared on host fish of various sizes and in all seasons, the mean intensity of infection was relatively low (prevalence 34.3%, mean intensity 3.98 ± 3.15 specimens/fish). Concerning L. pavlovskii, the second cestode species, only 9 parasites were found in medium-sized host fish during the summer, autumn and winter (prevalence 3.7%, mean intensity 1.60 ± 0.89 specimens/fish). A total of 108 parasite specimens of E. excisus was found on 40 host fish in the summer and autumn (prevalence 29.8%, mean intensity 2.70 ± 2.29 specimens/fish). The present study gives the occurrence, density, seasonal changes, and parasite-host size relationship for a new locality - Lake Uluabat - as a contribution to the geographical distribution of G. gobii and E. excisus in sand goby.

Parasitic helminths of jumbo squid Dosidicus gigas (Cephalopoda: Ommastrephidae) in open waters of the central east Pacific

During 1981–1989, 849 jumbo squid, Dosidicus gigas, from four open ocean regions of the east Pacific (from 11°N to 22°S) were examined for parasitic helminths. The samples were collected from the Peruvian (9–21°S and 82–87°W), east equatorial (2°N–6°S and 84–87°W), west equatorial (1°N–3°S and 96–100°W) and Nicaraguan (9–11°N and 88–91°W) regions. Nine species of parasitic helminths were found, with a total prevalence of infection of 75.5%. Trematoda: metacercaria of Didymozoidae indet (prevalence: 13%, intensity: 1–35, abundance: 0.51); Cestoda: Pelichnibothrium speciosum (75.2%, 1–63 000, 664.5); Phyllobothrium sp. (1.2%, 1–2, 0.02); Tentacularia coryphaenae (6.6%, 1–5, 0.16); Nematoda: Anisakis simplex (9.2%, 1–16, 0.23); Anisakis physeteris (24.2%, 1–26, 1.22); Porrocaecum sp. (29.4%, 1–17, 0.30); Contracaecum sp. (0.5%, 1–41, 0.22); Spinitectus sp. (0.4%, 1–3, 0.01). All these parasites occurred in the larval stage. The composition of helminths and quantitative infection indexes were similar for males and females of similar mantle length (ML). Four size groups of Dosidicus were recognised. The helminths of the first size group, 30–89 mm ML comprised metacercaria of Didymozoidae and larvae of Porrocaecum sp. In the second size group, 90–139 mm ML, the prevalence of didymozoids increased to 47.5% and the majority of the parasite fauna (four species) occurred at this stage. All nine species were present in the third size group, 140–359 mm ML, but with a sharp decrease in the prevalence of didymozoids (5.8%). In the fourth size group, 360–431 mm ML, didymozoids were absent while the prevalence and intensity values for the other helminth species were maximal. The helminth fauna of similar sized squid (190–300 mm ML) from different regions was similar and the levels of infection corresponded closely. However, a comparison of ontogenetic infection dynamics between the Peruvian and east equatorial waters showed that the prevalence and intensity data for the main and secondary helminth species differed. This may support the hypothesis of isolated populations in these two regions. D. gigas is a paratenic (transport) host for the helminth species studied, with scombroid and xiphoid fishes, sharks and marine mammals as the definitive hosts.

Helminth parasites in six species of shorebirds (Charadrii) from the coast of Belize.

Thirteen species of helminth parasites were recovered from six species of charadriid shorebirds (Aves: Charadriiformes) from Belize: the ruddy turnstone, Arenaria interpres, the snowy plover, Charadrius alexandrinus, the semipalmated plover, C. semipalmatus, the killdeer, C. vociferus, the white-rumped sandpiper, Calidris fuscicollis, and the black-bellied plover, Pluvialis squatarola. Cestode species were predominant (N = 8), followed by trematode species (N = 3) and acanthocephala (N = 2). The trematode, Paramaritremopsis solielangi infected four of the six species of hosts. The cestodes, Nadejdolepis litoralis and N. paranitidulans infected three and two host species respectively. Helminth parasite species were contagious (clumped) and not evenly distributed among hosts. Twelve of the 13 species were generalists. The one specialist Microphallus kinsellae was recovered from one C. fuscicollis. Three of the four types of feeding guilds were present and in approximately the same number. All but M. kinsellae have been reported from other species of hosts, mostly from Eurasia and North America.

A preliminary survey of the ecto and endoparasites of the grasscutter (Thryonomys swinderianus Temminck): case study in Ekumfi, Cental Region of Ghana

Domestication and farming of grasscutter is gradually spreading throughout the country as an important source of protein to supplement grasscutter meat obtained from the wild, yet very little is known about their diseases. The present study attempts to throw some light on parasitic infestations capable of hindering grasscutter farming in Ghana. One hundred and fifty grasscutters (or cane rats) were examined within a period of seven months for ecto and endoparasites at Eisam in the Ekumfi District of Ghana. Four species of ticks namely: Rhipicephalus simpsoni, Ixodes aulacodi, Ixodes sp. and Hemaphysalis parmata were the ectoparasites found. The ticks were found on all body regions of the grasscutters. The anterior part of the body was found to have the highest tick infestation, whilst the posterior had the least. The probable season for site preference has been discussed. Six species of helminth parasites comprising 2 species of cestodes and 4 species of nematodes were found in various parts of the gut of the grasscutters. The cestodes were Furhmanella transvaalensis, Railettina mahonae and the nematodes were Longistriata spira, Trachypharynx natalensis, Paralibyostrongylus vondwei and Trichuris paravispicularis. This is the first report of R. mahonae as a parasite in the gut of the grasscutter. There was no significant difference in relative infestation between male and female grasscutters for any tick or helminth species. We hope that this study will encourage further research into other agents of grasscutter diseases to reduce mortality and thereby help to increase grasscutter meat production in the country. (Journal of the Ghana Science Association: 2001 3(3): 30-36)

Coexistence of helminth species in Lysapsus limellus (Anura: Pseudidae) from an Argentinean subtropical area: influence of biotic and abiotic factors.

The need for studies on helminth communities of South American amphibians was addressed by examining changes in composition and population dynamics of the helminth component and infracommunities in the frog Lysapsus limellus Cope, 1862, from 1994 to 1996. Two pond types were considered, one permanent and one semipermanent. The main goals of this study were (1) to investigate the relationships between pond type, season, study time, frog body size, and frog sex and the presence-absence and counts of helminth parasite species in the frog host, L. limellus, and (2) to examine the co-occurrence of the different parasite species in the frog host in terms of the structure, assembly, and dynamics of the helminth infracommunity. Parasite presence and absence were analyzed using logistic regression and parasite counts were analyzed using log-linear modeling. To examine the association between parasite species, a principal components analysis was carried out on the correlation matrix for the counts. The pattern of co-occurrences was also examined through a randomization test. The main results were as follows: (1) five parasite species were found in the infracommunity; (2) the pond type and the host size class were the principal factors related to the presence and absence of parasites for the three dominant species, while the year of study and the host sex were only important for one of the species; (3) for the parasite counts, many more factors were significant, with body size class and pond type always important factors for the three core species of the infracommunity, with season, year of study, and sex also sometimes important, and (4) strong associations were observed between some helminth species of the host from the permanent pond, but the same species did not co-occur in frogs in the semipermanent pond. The life histories of the five species can be considered as opportunistic or "r strategists."

Health Status of Northern Bobwhite Quail (Colinus virginianus) in Eastern Kansas

The health status of wild northern bobwhite quail (Colinus virginianus) from Lyon County, Kansas, was evaluated by conducting comprehensive health assessments on 25 birds. Gross lesions indicative of avian pox, ulcerative enteritis, and quail bronchitis were not present. Serologic tests for antibodies to Salmonella pullorum, Salmonella gallinarum, Pasteurella multocida, Mycoplasma gallisepticum, Mycoplasma synoviae, and avian adenoviruses were all negative. Intestinal coccidia (Eimeria spp.) were found in 36% of the birds. Only three species of helminth parasites were found: Dispharynx nasuta in two birds, Cyrnea colini in one bird, and larval Physaloptera sp. in four birds. Arthropod parasites (ticks, lice, mites, and/or chiggers) were present on 96% of the birds examined. Compared with wild bobwhite populations in the southeastern United States, the diversity, prevalence, and intensities of microbial and parasitic agents were low.