Volume 57, Issue 4

Microscopy has traditionally been the most common method in parasitological studies, but in recent years molecular screening has become increasingly frequent to detect protozoan parasites in a wide range of vertebrate hosts and vectors. During routine molecular screening of apicomplexan parasites in reptiles using the 18S rRNA gene, we have amplified and sequenced Proteromonas parasites from three lizard hosts (less than 1% prevalence). We conducted phylogenetic analysis to confirm the taxonomic position and infer their relationships with other stramenopiles. Although our phylogeny is limited due to scarcity of molecular data on these protists, our results confirm they are closely related to Proteromonas lacertae. Our findings show that unexpected parasites can be amplified from host samples (blood and tissue) using general procedures to detect hemoparasites, and stress that positive PCR amplifications alone should not be considered as definitive proof of infection by particular parasites. Further validation by sequence confirmation and thorough phylogenetic assessment will not only avoid false positives and biased prevalence estimates but also provide valuable information on the biodiversity and phylogenetic relationships of other parasitic organisms. More generally, our results illustrate the perils of general diagnosis protocols in parasitological studies and the need of cross-validation procedures.

The life cycle, spore morphology, pathogenicity, tissue specificity, mode of transmission and small subunit rRNA (SSU-rRNA) gene sequence analysis of the five new microsporidian isolates viz., NIWB-11bp, NIWB-12n, NIWB-13md, NIWB-14b and NIWB-15mb identified from the silkworm, Bombyx mori have been studied along with type species, NIK-1s_mys. The life cycle of the microsporidians identified exhibited the sequential developmental cycles that are similar to the general developmental cycle of the genus, Nosema. The spores showed considerable variations in their shape, length and width. The pathogenicity observed was dose-dependent and differed from each of the microsporidian isolates; the NIWB-15mb was found to be more virulent than other isolates. All of the microsporidians were found to infect most of the tissues examined and showed gonadal infection and transovarial transmission in the infected silkworms. SSU-rRNA sequence based phylogenetic tree placed NIWB-14b, NIWB-12n and NIWB-11bp in a separate branch along with other Nosema species and Nosema bombycis; while NIWB-15mb and NIWB-13md together formed another cluster along with other Nosema species. NIK-1s_mys revealed a signature sequence similar to standard type species, N. bombycis, indicating that NIK-1s_mys is similar to N. bombycis. Based on phylogenetic relationships, branch length information based on genetic distance and nucleotide differences, we conclude that the microsporidian isolates identified are distinctly different from the other known species and belonging to the genus, Nosema. This SSU-rRNA gene sequence analysis method is found to be more useful approach in detecting different and closely related microsporidians of this economically important domestic insect.

While studying Myxobolus gill infections of cyprinid fishes, the authors found large, segmented plasmodia in three species: ide (Leuciscus idus), asp (Aspius aspius) and white bream (Blicca bjoerkna). As regards their size and morphology, the spores from these plasmodia corresponded to those of M. dujardini described from chub (Leuciscus cephalus). However, the 18S rDNA sequences of spores from the three cyprinids differed from those of M. dujardini. Based on molecular differences, this paper describes two new species: M. alvarezae sp. nov. from ide and asp, and M. sitjae sp. nov. from white bream. The two new species and M. dujardini had a similar tissue tropism, and infected the multilayered epithelium of the gill filaments. Histological examination of the infected filaments demonstrated that the large plasmodia with multiple buddings were formed from amalgamating small plasmodia. Besides carrying infection in the filamental epithelium, the three above fish species were infected by small intralamellar plasmodia as well. These plasmodia were filled by spores that resembled the roach parasite M. intimus both in morphology and seasonal development. The 18S rDNA sequences of ‘intimus-like’ spores from ide and asp differed only in some base pairs from spores found in the type host roach, and were identified as belonging to M. intimus. The spores found in white bream, however, showed 3.6-5.0% difference in DNA sequence from those of M. intimus; therefore, they have been described as M. eirasianus sp. nov. The aim of this paper was to demonstrate the importance of using molecular methods for separating and identifying morphologically corresponding or closely similar Myxobolus spp.

Mawsonascaris parva sp. nov. collected from the Arabian whipray Himantura randalli Last, Manjaji-Matsumoto et Moore (Rajiformes: Dasyatidae) off the coast of Iraq is described and illustrated using light and scanning electron microscopy. The new species differs from its congeners by its small body size (8.11–18.2 mm long), the absence of an intestinal caecum, the slightly unequal spicules (left and right spicule 1.08–2.50 mm and 0.98–2.01 mm long, respectively, representing 12.1–13.7% and 10.1–12.1% of body length), the number and arrangement of male caudal papillae (13–14 pairs in total, arranged as: 7–8 pairs of precloacal, 1 pair of double paracloacal and 5 pairs of postcloacal) and the presence of a single, median precloacal papilla. Thus, a total of six species of Mawsonascaris are now known and this is the first species of this genus recorded from species of Himantura.

A new nematode species, Philometroides acanthopagri sp. nov. (Philometridae), is described from gravid and subgravid specimens found in the musculature near pectoral fins and in nasal cavity of the yellowfin seabream Acanthopagrus latus (Houttuyn) (Sparidae, Perciformes) from marine waters off the coast of southern Iraq. Based on light and scanning electron microscopical examination, the new species differs from its congeners in a combination of morphological and biometrical features. It is the first species of Philometroides reported from a sparid fish and the first representative of this genus recorded from fishes in the Arabian Gulf. A key to Philometroides species parasitizing marine and brackish-water fishes is provided.

Ectoparasites are common on birds and in their nests. Amongst these parasites are diverse gamasid mite species that can lead to irritation, disease transmission and blood loss. Few studies of the ectoparasites of birds breeding in the High Arctic exist. The parasitic mite, Dermanyssus hirundinis, was found in nests of snow buntings Plectrophenax nivalis nivalis, both natural nests and within nesting boxes, on Spitsbergen. Densities per nest varied from sporadic to greater than 26,000 individuals. This is the northernmost observation of this parasite. The mite was present in new nests, nests constructed the previous year and nests not utilized the previous summer. The parasite survives at least 18 months without access to a blood meal and can tolerate the Arctic winter, surviving temperatures below −20°C. D. hirundinis is hence well adapted to arctic conditions. Only females were observed suggesting that this population is facultatively parthenogenetic.

A new quill mite species Syringophilopsis davidi sp. nov. (Prostigmata, Syringophilidae) parasitizing Greater Short-toed Lark Calandrella brachydactyla (Leisler) (Passeriformes, Alaudidae) in Egypt is described. This new species is distinguishable from S. tyranni Bochkov and Galloway by 10–13 chambers of the peritremal lateral branches, setae se located slightly anterior to c1, and by setae ag2 about twice longer than the genital setae. This is the first record of this genus from the hosts of the family Alaudidae and in the Arab Republic of Egypt.

Six species of 3 genera belonging to the fur mite family Listrophoridae were recorded on skins of South American rodents of the cricetid subfamily Sigmodontinae housed in the Bavarian State Collection of Zoology (Munich, Germany). Among them, Amlistrophorus geoxus sp. nov. from Geoxus valdivianus from Chile is described as a new for science, and males of Prolistrophorus amazonicus amazonicus Fain, 1971 are recorded for the first time. The full generic status for the subgenus Amlistrophorus of the genus Prolistrophorus proposed by Fain et al. (1996) is not supported, and Prolistrophorus musculinus Fain, 1973 stat. nov. (formerly a subspecies of P. amazonicus) from Mus musculus (Rodentia: Muridae) from Suriname is raised to species status. New hosts are recorded for the following species: Prolistrophorus argentinus (Hirst, 1921) from Holochilus brasiliensis and H. chacarius from Argentina, P. amazonicus from Calomys callosus from Argentina and Bolivia, C. laucha and C. musculinus from Argentina, P. akodon Fain and Lukoschus, 1982 from Akodon montensis from Argentina, P. nectomys Fain, 1971 from Nectomys palmipes from Peru and Melanomys caliginosus from Panama, and Sclerolistrophorus oxymycteris Fain, 1976 from Oryzomys laticeps from Brazil.

A new species of dajid isopod in the genus Aspidophryxus G.O. Sars, 1883 is described from three females and one male found infesting the lateral carapace of Heteromysis (Olivemysis) actiniae Clarke, 1955 (Mysidae: Heteromysinae) associated with the corkscrew anemone Bartholomea annulata (Lesuer, 1817) (Anthozoa: Aiptasiidae) from the British Virgin Islands. This is the first record of the genus from the western Atlantic; three other species are known from northern European waters, the central Atlantic and Japan, all on mysid hosts. The new species is the first dajid recorded from tropical Caribbean waters. A key to species in the genus and a list of all known hosts with parasite orientation are provided.

Trichinella larvae were detected in a marten (Martes martes) and a badger (Meles meles) in Poland. The animals were found dead following car accidents. All examined animals derived from the Mazurian Lake district, north-east Poland, near the village Kosewo Górne where Trichinella infection were earlier confirmed in wildlife; red foxes and wild boars. The muscle samples were examined by artificial pepsin-HCl digestion method. The parasites were identified as Trichinella britovi by multiplex polymerase chain reaction method. Larvae were found in two out of three martens and one out of seven examined badgers. This is the first report of the identification of Trichinella britovi larvae from martens and badgers in Poland.