Cryptosporidium and cryptosporidiosis in man and animals

There has been an explosion of descriptions of new species of Cryptosporidium during the last two decades This has been accompanied by confusion regarding the criteria for species designation, largely because of the lack of distinct morphologic differences and strict host specificity among Cryptosporidium spp A review of the biologic species concept, the International Code of Zoological Nomenclature (ICZN), and current practices for Cryptosporidium species designation calls for the establishment of guidelines for naming Cryptosporidium species All reports of new Cryptosporidium species should include at least four basic components: oocyst morphology, natural host specificity, genetic characterizations, and compliance with the ICZN Altogether, 13 Cryptosporidium spp are currently recognized: C muris, C andersoni, C parvum, C hominis, C wrairi, C felis; and C cannis in mammals; C baileyi, C meleagridis, and C galli in birds; C serpentis and C saurophilum in reptiles; and C molnari in fish With the establishment of a framework for naming Cryptosporidium species and the availability of new taxonomic tools, there should be less confusion associated with the taxonomy of the genus Cryptosporidium The clarification of Cryptosporidium taxonomy is also useful for understanding the biology of Cryptosporidium spp, assessing the public health significance of Cryptosporidium spp in animals and the environment, characterizing transmission dynamics, and tracking infection and contamination sources

Cryptosporidium Taxonomy: Recent Advances and Implications for Public Health (Review)

Nematode Parasites of Vertebrates: Their Development and Transmission

This review summarizes data on the biogeography and dispersal of bacteria, microfungi and selected protists, such as dinoflagellates, chrysophytes, testate amoebae, and ciliates. Furthermore, it introduces the restricted distribution and dispersal of mosses, ferns and macrofungi as arguments into the discussion on the postulated cosmopolitism and ubiquity of protists. Estimation of diversity and distribution of micro-organisms is greatly disturbed by undersampling, the scarcity of taxonomists, and the frequency of misidentifications. Thus, probably more than 50% of the actual diversity has not yet been described in many protist groups. Notwithstanding, it has been shown that a restricted geographic distribution of micro-organisms occurs in limnetic, marine, terrestrial, and fossil ecosystems. Similar as, in cryptogams and macrofungi about, 30% of the extant suprageneric taxa, described and undescribed, might be morphological and/or genetic and/or molecular endemics. At the present state of knowledge, micro-organism endemicity can be proved/disproved mainly by flagship species, excluding sites (e.g., university ponds) prone to be contaminated by invaders. In future, genetic and molecular data will be increasingly helpful. The wide distribution of many micro-organisms has been attributed to their small size and their astronomical numbers. However, this interpretation is flawed by data from macrofungi, mosses and ferns, many of which occupy distinct areas, in spite of their minute and abundant means of dispersal (spores). Thus, I suggest historic events (split of Pangaea etc.), limited cyst viability and, especially, time as major factors for dispersal and provinciality of micro-organisms. Furthermore, the true number of species and their distribution can hardly be estimated by theories and statistics but require reliable investigations on the number of morphospecies in representative ecosystems. Generally, the doubts on Beijerinck's famous metaphor "in micro-organisms everything is everywhere" can be focussed on a simple question: If the world is teeming with cosmopolitan unicells, where is everybody?

Biogeography and Dispersal of Micro-organisms: A Review Emphasizing Protists

AMPHIBIAN DECLINES: THE CONSERVATION STATUS OF UNITED STATES SPECIES. Michael Lannoo (ed.). 2005. University of California Press, Berkeley. ISBN 0-520-235924. XXI + 1094 p. $95.00 (hard cover).—During the past decade and a half, much has been discussed and published on amphibian declines. The new information obtained created a novel field of research in herpetology. The starting point of this new field was the First World Congress of Herpetology, held in Canterbury, England, in 1989, when herpetologists found that the amphibian disappearances they had witnessed individually were not merely rare, local phenomena but rather appeared to be occurring around the globe. The relevance of amphibian declines can be measured not only by the scientific production but also by the extensive coverage by the popular press. The book ‘‘Amphibian Declines: The Conservation Status of United States Species’’ summarizes the advances of this new research field, mainly in the United States. This is an extraordinary book based on the experience of an impressive team of specialists on amphibian declines and conservation, primarily focused on species from the United States. Because North American herpetologists have accumulated detailed data on native amphibians over many years, this book is very thorough. The book is divided into two parts; part one is a collection of 52 essays on conservation written mainly by researchers with extensive experience in amphibian conservation. This first part is divided into an Introduction and chapters titled Declines, Causes, Conservation, Surveys and Monitoring, Education, and Perspective. Part two corresponds to the species accounts for Anura and Caudata. An amazing total of 215 contributors participated in the two parts of the book, producing more than a thousand pages of rich information on amphibian declines and conservation in United States. The essays vary in detail and breadth of coverage, and there is some overlap among some of them, but this is to be expected in a book written by so many scientists. In the Introduction there are five essays that provide a historical perspective on the conservation of amphibians. In the Declines chapter five essays give a historical perspective as well, but there is also specific information on the decline of cricket frogs (Acris crepitans) and a data-rich essay on the decline of the salamanders of the genus Plethodon. Together the essays address all of the relevant topics of conservation and decline in amphibians. For example, the first essay by Tim Halliday addresses the main reasons for amphibian declines, summarizing recent progress that is improving our understanding on the causal factors promoting it. He indicates habitat destruction, climate change, pollution, increased UV-B radiation, and disease as the main factors, but also calls attention to the synergistic action among some of these causes. The necessity of a more ample comprehension of the conservation status of other groups of organisms is also highlighted, given that declines may also be severe in other taxa, such as bivalves. The lack of data on distribution, population structure, and habitat of amphibians makes the task of protection more difficult. In the second essay, Martha L. Crump discusses why some species are in decline while others are not. She compares studies in different parts of the world and concludes that the patterns associated with declines in one assemblage are not necessarily repeated in other assemblages. She did not find a clear pattern of differences (in phylogeny, distribution, habitat, activity, diet, body size, skin characteristics, and life history traits) between declining and non-declining species. She concludes that some species are less able to cope with anthropogenic environmental changes. In Causes, 12 essays adequately cover the main causes that have been proposed or demonstrated to be involved in amphibian declines. Global warming, UV radiation, chemical pollution, parasites and malformations, habitat destruction or alteration, and commercial trade of amphibians are among the treated topics. However, in this chapter some essays are not related to the causes of decline per se, such as the essay on the Lucké renal adenocarcinoma in Northern Leopard Frogs (Lithobates pipiens). In this case there is no evidence that the carcinoma is a factor in frog population decline. In Conservation, 18 essays treat different aspects of amphibian conservation. There are essays on the conservation of specific taxa, such as one on the endangered Houston Toad (Anaxyrus houstonensis) that includes information on the major causes of decline and the politics that play an important role in conservation. The essay on fluctuations in the size of tiger salamander populations provides useful information for understanding the related natural and anthropogenic factors that affect this amphibian. The essay on the Texas spring and cave salamanders (Eurycea) shows that most species have restricted distributions and are threatened by human activities. The essay on the Southwestern desert bufonids indicates that, although these toads escaped the declines experienced by many anurans, some species are being eliminated from some areas as a result of habitat alteration. Two essays raise questions on taxonomic and systematic problems and the conservation status of the amphibians. They call attention to the necessity of clear and workable systems of classification to describe biodiversity, the importance of phylogenetic taxonomies, and the importance of conservation systematics in management and politics. The essay by Karen R. Lips and Maureen A. Donnelly is an exception in the book in that it aims to describe the nature, extent, and possible causes of amphibian declines in the tropics and not in United States. The limitation of this essay is the lack of data on tropical amphibian, which is not the authors’ fault (see below). Other essays in this chapter are on amphibian decline and management, landscape ecology, ecotoxicology, importance of museum collections in amphibian conservation, reserve network, population manipulations of imperiled species, exotic invading species of fish and amphibians and their impacts on the natural systems, and the importance of natural history in the conservation of amphibians. In the Surveys and Monitoring chapter, nine essays cover general and specific aspects, including methodological proposals. Some essays treat the distribution, decline, and monitoring of amphibians from specific places in the United States or from a general program, the North American

Amphibian Declines: The Conservation Status of United States Species

Parasites of Desmognathus brimleyorum (Caudata: Plethodontidae) from the Ouachita Mountains of Arkansas and Oklahoma

Cross-transmission experiments were performed using oocysts of an Eimeria arizonensis-like coccidian from Peromyscus leucopus and Peromyscus truei, an E. arizonensis-like coccidian from Reithrodontomys fulvescens, Eimeria baiomysis and Eimeria taylori from Baiomys taylori, Eimeria albigulae from Neotoma albigula, and Eimeria onychomysis from Onychomys spp., between representatives of the above host genera. The E. arizonensis-like coccidian from R. fulvescens infected Reithrodontomys megalotis, Reithrodontomys montanus, and Peromyscus leucopus. Oocysts of E. arizonensis from P. leucopus could be transmitted to both P. leucopus and R. megalotus. Oocysts of E. baiomysis and E. taylori infected only B. taylori. Oocysts of E. arizonensis from P. truei infected P. truei but not Neotoma mexicana or Onychomys leucogaster. Oocysts of E. albigulae from N. albigula were infective for N. mexicana but not for P. truei or O. leucogaster. Oocysts of E. onychomysis from Onychomys spp. infected O. leucogaster but not N. mexicana or P. truei. These results demonstrate that Peromyscus and Reithrodontomys, genera known to be related very closely evolutionarily, are capable of sharing E. arizonensis, whereas morphologically similar coccidians (E. albigulae, E. baiomysis, and E. onychomysis) from more distantly related hosts, are probably distinct and more stenoxenous. This also is the first report of coccidians infecting species of Reithrodontomys.

/pdf/cross-transmission-studies-with-eimeria-arizonensis-like-372684immi.pdf

Cross-transmission studies with Eimeria arizonensis-like oocysts (Apicomplexa) in New World rodents of the Genera baiomys, Neotoma, Onychomys, Peromyscus, and Reithrodontomys (Muridae).

A comparative study of endoparasites in three species of sympatric Bufo (Anura: Bufonidae), from Texas.

Three new species of Coccidia (Apicomplexa: Eimeriidae) are described from turtles in Texas, U.S.A. Oocysts of Eimeria texana sp.n. were found in 2/8 (25%) Texas cooters, Pseudemys texana, and are bent-cylindrical or elongate, 20.5 × 8.4 (17.6–23.2 × 7.2–9.0) μm (mean, range), with a smooth, thin, single-layered wall. A micropyle is absent but an oocyst residuum and polar granule are present. Sporocysts are ovoid, 8.1 × 4.7 (7.0–8.8 × 4.0–5.4) μm, with a Stieda body and sporocyst residuum. Oocysts of Eimeria cooteri sp.n. were recovered from 3/8 (37.5%) Pseudemys texana and are ellipsoid or bent-cylindrical, 25.9 × 10.9 (22.6–28.0 × 9.6–12.8) μm, with a single-layered wall. A polar granule and oocyst residuum are present but a micropyle is absent. Sporocysts are elongate, 14.9 × 5.3 (12.8–16.0 × 4.8–6.6) μm, with an elongate Stieda body capped by tiny knob-like thickenings and covered by a thin membrane; sporocyst residuum present. Oocysts of Eimeria stylosa sp.n. were harbored by 2/16 (12.5%) red-eared s...

The Coccidia (Apicomplexa: Eimeriidae) of Testudines, with descriptions of three new species

Fourteen amphibians (7 species) and 37 reptiles (25 species) collected from 3 sites in the Pastaza Province of the Republic of Ecuador were examined for helminths. A total of 6 (42.7%) individual amphibians and 18 (48.6%) individual reptiles were infected. Five (71.4%) of the amphibian species (4 frogs, 1 toad) and 10 (40.0%) of the reptile species (4 lizards, 6 snakes) were found to harbor 1 species of helminth; 1 amphibian species (14.3%) and 5 reptile species (13.2%) harbored 2 species of helminths each. One species of cestode and 16 species of nematodes, together representing 11 families, were found in the herpetofauna surveyed. Twenty-five new host and 15 new geographic records are documented. When compared to other South American countries, the majority of parasites reported herein for Ecuador have been reported previously in herpetofauna from Brazil.

https://bioone.org/journals/comparative-parasitology/volume-77/issue-1/4402.1/Helminth-Parasites-of-Selected-Amphibians-and-Reptiles-from-the-Republic/10.1654/4402.1.pdf

Chris T. McAllister

Papers

Parasites of Desmognathus brimleyorum (Caudata: Plethodontidae) from the Ouachita Mountains of Arkansas and Oklahoma

Cross-transmission studies with Eimeria arizonensis-like oocysts (Apicomplexa) in New World rodents of the Genera baiomys, Neotoma, Onychomys, Peromyscus, and Reithrodontomys (Muridae).

A comparative study of endoparasites in three species of sympatric Bufo (Anura: Bufonidae), from Texas.

The Coccidia (Apicomplexa: Eimeriidae) of Testudines, with descriptions of three new species

Helminth Parasites of Selected Amphibians and Reptiles from the Republic of Ecuador