Feline leishmaniasis has been reported in various parts of the world in recent years, occurring mainly in areas where zoonotic visceral leishmaniasis (VL) is endemic. The purpose of this study was to assess the occurrence of natural infection by Leishmania spp. in domestic cats (Felis catus) in the municipality of Teresina, Piauí state, Brazil, an endemic area of VL in Brazil. The prevalence of infection by Leishmania spp. in the population under study was 4% (3/83) in the enzyme-linked immunosorbent assay (ELISA) and 4% (3/83) by smear observation and isolation in a culture medium, using popliteal lymphnode sample. Only one of the three infected cats was positive for ELISA, also being positive for feline immunodeficiency virus. In the haematologic parameters, normocytic normochromic anaemia was the most common change, being present in the three infected animals. In the biochemical measurements also were observed alterations in infected animals. The Leishmania spp. strains isolated from the culture medium were characterized as L. infantum. The presence of L. infantum infection in cats in the city of Teresina, an area endemic for VL, suggests the possible involvement of these animals in the epidemiological chain of L. infantum in high-transmission areas.

The oyster Crassostrea gasar is a species widely used as food and a source of income for the local population of the estuaries of Northeast Brazil. Perkinsus marinus and Perkinsus olseni are deleterious parasites for oyster farming and were recently detected in Brazil. In this study, a histopathologic survey of the oyster C. gasar cultured in the estuary of the River Mamanguape (Paraíba State) was performed. Adult oysters were collected in December 2011 and March, May, August and October 2012 and processed for histology and Perkinsus sp. identification by molecular analyses. Histopathological analysis revealed the presence of parasitic organisms including viral gametocytic hypertrophy, prokaryote-like colonies, protozoans (Perkinsus sp. and Nematopsis sp.) and metazoans (Tylocephalum sp. and cestodes). Other commensal organisms were also detected (the protozoan Ancistrocoma sp. and the turbellarian Urastoma sp.). The protozoan parasite Perkinsus sp. had the highest overall prevalence among the symbiotic organisms studied (48·9%), followed by Nematopsis sp. (36·3%). The other organisms were only sporadically observed. Only the protozoan Perkinsus sp. caused alterations in the oysters’ infected organs. Molecular analyses confirmed the presence of P. marinus, P. olseni and Perkinsus beihaiensis infecting the oyster C. gasar. This is the first report of P. beihaiensis in this oyster species.

Epitrix species (Coleoptera: Chrysomelidae) feed mostly on plants from the family Solanaceae and some of them are major pests of potato crops. All Epitrix species are morphologically highly similar, which makes them difficult to identify and limits their study and management. Identification of species is mostly based on the observation of the genitalia and requires a high level of expertise. Here, we propose a tool to reliably identify all developmental stages of the most economically important Epitrix species feeding on potato in Europe and North America (Epitrix cucumeris, Epitrix similaris, Epitrix tuberis, Epitrix subcrinita and Epitrix hirtipennis). We first sequenced two DNA markers (mitochondrial cytochrome c oxidase I (COI) and nuclear internal transcribed spacer 2 (ITS2)) to test their effectiveness in differentiating among six Epitrix species (126 specimens). Morphospecies of Epitrix were well-differentiated by both DNA barcodes and no mitochondrial introgression was detected. Then, we developed an RFLP-based diagnostic method and showed that unambiguous species discrimination can be achieved by using the sole restriction enzyme TaqI on COI polymerase chain reaction products. The tool proposed here should improve our knowledge about Epitrix species biology, distribution and host range, three capacities that are particularly important in the detection and management of these pest species. Specifically, this tool should help prevent the introduction of E. tuberis and E. subcrinita in Europe and limit the spread of the recently introduced E. cucumeris and E. similaris, with minimal disruption to Solanaceae trade.

Melicertus kerathurus represents an economically important resource for fisheries and aquaculture. Seven microsatellite loci from 373 specimens of M. kerathurus collected in different parts of the Mediterranean and NE Atlantic were identified. Four of these microsatellites showed a moderate level of polymorphism, with 2 to 14 alleles per locus, whereas three had a monomorphic profile. Observed and expected heterozygosity ranged between 0.28 to0.64 and 0.28 to 0.65, respectively. Three microsatellite loci deviated from Hardy-Weinberg equilibrium in some populations, with a deficit of heterozygosity. Mean Fst values showed significant differentiation among sample sites analysed and indicate that these loci are useful for the study of genetic variation in this species. These results may supply functional information on the population genetic structure of Melicertus kerathurus, valuable for future sustainable management strategies.

We screened a population of the brackish water crustacean Gammarus duebeni from the Isle of Cumbrae for the presence of vertically transmitted microsporidia. We compared 2 screening techniques; light microscopy and PCR-based detection using generic 16S rDNA microsporidian primers. Fifty percent of females from this population tested positive for vertically transmitted microsporidia. The PCR screen was 100% efficient in comparison with existing LM based screening. In addition, the PCR screen produced bands of 2 sizes suggesting that more than 1 species of microsporidian was present. Sequencing revealed 2 distinct species of vertically transmitted microsporidia; 33% of females were infected with the feminizer Nosema granulosis and 17% were infected with a new species which we provisionally designate Microsporidium sp. On the basis of sequence information, we developed a discriminatory PCR–RFLP test based on MspI and HaeIII digests. This screen allows rapid detection and discrimination of vertically transmitted microsporidia in natural field populations. We applied the PCR–RFLP screen to a second G. duebeni population from the Isle of Man. This population also hosted these 2 parasite species. In total 45% of females harboured N. granulosis and 10% harboured Microsporidium sp. No dual-infected individuals were found in either population. The occurrence of 2 vertically transmitted parasites within a population has implications for our understanding of parasite–host relationships in the field and we discuss factors affecting the dynamics of parasite–parasite competition and coexistence.

The use of biofuels has been proposed as one possible substitute for fossil fuels, which contribute substantially to the increase in [CO2] in the atmosphere. However, increased harvesting of forest residues for biofuel might affect the availability of base cations, P and N, as well as the development, community dynamics and function of ectomycorrhizas. This in turn might influence nutrient uptake and tree growth. In this study we investigated the effects of repeated forest residue harvesting on ectomycorrhizal species colonizing spruce roots in the humus layer of a 35-yr-old forest. Harvesting significantly decreased the thickness of the humus layer as well as decreasing the numbers of ectomycorrhizal root tips both per metre root length and per unit humus volume. Changes in mycorrhizal community structure were studied by ITS typing with the use of PCR–RFLP analysis. In total, 19 different ITS types were found on two different sampling occasions (autumn and spring); 11 of these were common to both samplings. Nine of the ITS types were identified to at least the genus level by comparison with RFLP patterns of identified fruiting bodies or axenic cultures. Five species, Cortinarius sp. 2, Thelephora terrestris (Ehrenb.) Fr., Lactarius theiogalus (Bull.[ratio ]Fr.) S. F. Gray s.st. Neuhoff, Tylospora fibrillosa Donk and Tö-96-12, occurred on over 5% of the total sampled root tips. Together these five types colonized 63% of the mycorrhizas screened. A similarity index assessment showed no shift in mycorrhizal community structure as a result of harvesting. Our findings suggest that the repeated removal of forest residues might have a strong effect on the quantity and development of ectomycorrhizal roots in the organic horizon, but little effect on the species composition of the community.

In order to investigate the molecular taxonomy within Trypanosoma cruzi, the ribosomal small subunit (18S) gene was amplified by polymerase chain reaction (PCR) from a selection of 21 stocks and 3 outgroup taxa. Amplification products were digested with 10 restriction enzymes; restriction fragments were separated by polyacrylamide gel electrophoresis and profiles were visualized by silver staining. Upon analysis of such riboprint profiles, an estimate of pairwise phenetic distance between stocks of T. cruzi was calculated. Upon principal coordinate analysis of this data matrix, a tendency towards a bi-polar grouping of stocks was observed. These 2 groups were predominantly either zymodeme 1 stocks or zymodeme 2 stocks. The position of zymodeme 3 stocks remained intermediate between the 2 groups but did not form a coherent group by themselves. It would therefore appear premature to warrant division of T. cruzi into 2 discrete taxa or subspecies until the relationships of further zymodeme 3 stocks are elucidated.

To test the homogeneity of 18S sequences within Trypanosoma cruzi, riboprint profiles were separated by temperature gradient gel electrophoresis (TGGE). Upon interpretation of melting curves of fragments within a riboprint profile, there appeared to be two 18S sequence types within each stock examined. Two similar types were also observed within outgroup taxa Trypanosoma conorhini, Trypanosoma rangeli and Leishmania braziliensis. From DNA hybridization studies, these fragments were shown to have homology to the 18S V1 region. There are therefore two 18S V1 regions, differing in sequence, present in all taxa examined. When only a single 18S sequence is used to represent each taxa for phylogenetic inference, comparisons may be between paralogous and not orthologous copies of this region, such that, inferred relationships may merely reflect a gene history. This seriously questions the current molecular phylogeny of these protozoa using 18S data.