A new nematode species (Seuratoidea, Cucullanidae) parasitizing Parauchenipterus striatulus (Steindachner, 1876) (Pisces, Auchenipteridae) in Brazil

A new species of a cucullanid nematode is described, illustrated and compared with Cucullanus brevispiculus Moravec, Kohn & Fernandes, 1993 and C. rhamphichthydis Moravec, Kohn & Fernandes, 1997, two species previously reported as parasitizing freshwater fish in South America. The new species is characterized mainly by markedly short spicules, deirids and excretory pore situated posterior to the oesophago-intestinal junction, presence of strongly sclerotized plates in the oesophastome and oesophagus divided into two distinct portions.

In vitro interaction of Brazilian strains of the Nematode-trapping fungi Arthrobotrys spp. on Panagrellus sp. and Cooperia punctata

In vitro tests were carried out to verify the activity of 26 Brazilian isolates of predatory fungi of the genus Arthrobotrys on a free-living nematode (Panagrellus sp.) and on infective larvae of Cooperia punctata, a parasitic gastrointestinal nematode of cattle. The results showed that the free-living nematode Panagrellus sp. was the most preyed upon, compared to C. punctata, for all the fungal treatments. Also, variable predatory capacity was observed for different fungal isolates belonging to the same genus when applied to different nematode species.

Nematode Infections Are Risk Factors for Staphylococcal Infection in Children

Nematode infection may be a risk factor for pyogenic liver abscess in children and we hypothesized that the immunomodulation induced by those parasites would be a risk factor for any staphylococcal infection in children. The present study was designed to compare, within the same hospital, the frequency of intestinal nematodes and Toxocara infection in children with and without staphylococcal infections. From October 1997 to February 1998, 80 children with staphylococcal infection and 110 children with other diseases were submitted to fecal examination, serology for Toxocara sp., evaluation of plasma immunoglobulin levels, and eosinophil counts. Mean age, gender distribution, birthplace, and socioeconomic conditions did not differ significantly between the two groups. Frequency of intestinal nematodes and positive serology for Toxocara, were remarkably higher in children with staphylococcal infections than in the non-staphylococcal group. There was a significant correlation between intestinal nematodes or Toxocara infection and staphylococcal infection in children, reinforced by higher eosinophil counts and higher IgE levels in these children than in the control group. One possible explanation for this association would be the enhancement of bacterial infection by the immunomodulation induced by helminth infections, due to strong activation of the Th2 subset of lymphocytes by antigens from larvae and adult worms.

Pelecitus helicinus Railliet & Henry, 1910 (Filarioidea, Dirofilariinae) and Other Nematode Parasites of Brazilian Birds

We report Pelecitus helicinus Railliet & Henry, 1910 from 13 species of birds of 2 orders and 7 families, collected from the states of São Paulo and Mato Grosso, Brazil. All 13 constitute new host records for this nematode. In addition, we report the first record of Aprocta golvani Diaz-Ungria, 1963 from Brazil and Monasa nigrifrons (Bucconidae), as well as a number of other nematode records from Neotropical birds.

Polymerase chain reaction with lesion scrapping for the diagnosis of human American tegumentary leishmaniasis

The objective of this work was to compare the polymerase chain reaction (PCR) using lesion scrapping with other conventional techniques for the diagnosis of the American tegumentary leishmaniasis (ATL). For this, patients with cutaneous lesions suspected to be ATL were studied. The DNA was amplified with the MP1L/MP3H primers. From the 156 studied patients, 79 (50.6%) presented positive parasite direct search (PD), 81 (51.9%) had positive Montenegro skin test (MST), and 90 (57.7%) presented PD and/or MST positive. The PCR was positive in all of the positive-PD patients (100% sensitivity), in 91.1% of the positive PD and/or MST patients, and in 27.3% of the patients that presented negative PD and positive MST. The PCR positivity was similar to the PD (P = 0.2482) and inferior to the MST (P = 0.0455), and to the PD/MST association (P = 0.0133). The high PCR sensitivity, and positivity in those cases where the PD was negative, highlights the importance of this technique as an auxiliary tool for the diagnosis of ATL.

Prevalence and pathology of the nematode Heterakis gallinarum, the trematode Paratanaisia bragai, and the protozoan Histomonas meleagridis in the turkey, Meleagris gallopavo

The prevalence of infection and associated pathology induced by two helminth and one protozoan species infecting Brazilian turkeys are reported. The intestinal nematode Heterakis gallinarum appeared with a prevalence of 70% in the infected birds, without gross lesions when not associated to the protozoan Histomonas meleagridis. Histological findings in the ceca were represented by the presence of H. gallinarum worms, intense chronic diffuse inflammatory processes with mononuclear and polymorphonuclear (heterophils) leucocyte infiltrations. The prevalence of the protozoan H. meleagridis associated to H. gallinarum was of 2.5% and microscopic examination revealed a severe inflammatory process in the liver and cecum with the presence of small clear areas with round eosinophilic parasites. Gross lesions were absent in turkeys infected with the renal digenetic trematode Paratanaisia bragai; the parasite was prevalent in 20% of the cases and cross-sections of the kidneys showed a remarkable distension of the collecting ducts with several worms in the lumen. The walls of the ducts presented a discrete heterophilic infiltrate among mononuclear cells.

Lesion aspirate culture for the diagnosis and isolation of Leishmania spp. from patients with cutaneous leishmaniasis

The detection of Leishmania spp. in skin lesion aspirates, using a puncture technique, was evaluated in 76 patients with cutaneous leishmaniasis (CL) who were referred to a Leishmaniasis Reference Centre in Brazil. CL was defined based on skin lesions suggestive of the disease and on a positive result of the Montenegro skin test or Giemsa-stained imprints of biopsy fragments. The aspirates were cultured using a vacuum tube device containing culture medium and evaluated for the presence of Leishmania spp. The biphasic medium culture was examined once a week for three weeks. Promastigotes were observed in 53/76 (69.7%) cultures. Stained smears from 60 of the 76 patients were evaluated using PCR-RFLP to detect the conserved minicircle region of Leishmania spp. and to classify the parasite. Of these patients, 45 (75%) showed positive results in aspirate culture and 15 presented negative results. The PCR was positive in 80% (53/60) samples. The PCR-RFLP profile was determined in 49 samples, of which 45 (92%) showed a pattern compatible with Leishmania (Viannia) braziliensis. The aspirate culture is a sensitive and feasible method for diagnosing CL and may be routinely adopted by health services for L. (V.) braziliensis isolation and identification.

Angiostrongylus cantonensis (Nematode: Metastrongyloidea) in molluscs from harbour areas in Brazil

Angiostrongylus cantonensis is the most common aetiological agent of human eosinophilic meningoencephalitis. Following a report indicating the presence of this parasite in Brazil in 2007, the present study was undertaken to investigate the presence of A. cantonensis in the surrounding Brazilian port areas. In total, 30 ports were investigated and the following molluscs were identified: Achatina fulica, Belocaulus sp., Bradybaena similaris sp., Cyclodontina sp., Helix sp., Leptinaria sp., Melampus sp., Melanoides tuberculata, Phyllocaulis sp., Pomacea sp., Pseudoxychona sp., Rhinus sp., Sarasinula marginata, Streptaxis sp., Subulina octona, Succinea sp., Tomigerus sp., Wayampia sp. and specimens belonging to Limacidae and Orthalicinae. Digestion and sedimentation processes were performed and the sediments were examined. DNA was extracted from the obtained larvae and the internal transcribed spacer region 2 was analysed by polymerase chain reaction-restriction fragment length polymorphism after digestion with the endonuclease ClaI. Of the 30 ports investigated in this study, 11 contained molluscs infected with A. cantonensis larvae. The set of infected species consisted of S. octona, S. marginata, A. fulica and B. similaris. A total of 36.6% of the investigated ports were positive for A. cantonensis, indicating a wide distribution of this worm. It remains uncertain when and how A. cantonensis was introduced into South America.

Diagnostic challenges of single plaque-like lesion paucibacillary leprosy

The diagnosis of single-lesion paucibacillary leprosy remains a challenge. Reviews by expert dermatopathologists and quantitative polymerase chain reaction (qPCR) results obtained from 66 single-plaque biopsy samples were compared. Histological findings were graded as high (HP), medium (MP) or low (LP) probability of leprosy or other dermatopathy (OD). Mycobacterium leprae-specific genes were detected using qPCR. The biopsies of 47 out of 57 clinically diagnosed patients who received multidrug therapy were classified as HP/MP, eight of which were qPCR negative. In the LP/OD (n = 19), two out of eight untreated patients showed positive qPCR results. In the absence of typical histopathological features, qPCR may be utilised to aid in final patient diagnosis, thus reducing overtreatment and delay in diagnosis.

Complete genome sequence of Deltapapillomavirus 4 (bovine papillomavirus 2) from a bovine papillomavirus lesion in Amazon Region, Brazil

The complete genome sequence of bovine papillomavirus 2 (BPV2) from Brazilian Amazon Region was determined using multiple-primed rolling circle amplification followed by Illumina sequencing. The genome is 7,947 bp long, with 45.9% GC content. It encodes seven early (E1, E2,E4, E5, E6,E7, and E8) and two late (L1 and L2) genes. The complete genome of a BPV2 can help in future studies since this BPV type is highly reported worldwide although the lack of complete genome sequences available.

Validation of microsatellite markers for assisted selection of soybean resistance to cyst nematode races 3 and 14

The objective of this work was to validate microsatellite markers associated with resistance to soybean cyst nematode (Heterodera glycines Ichinohe) races 3 and 14, in soybean (Glycine max L.) genotypes, for use in marker-assisted selection (MAS) programs. Microsatellites of soybean linkage groups A2, D2 and G were tested in two populations, and their selection efficiencies were determined. The populations were 65 F2:3 families from Msoy8001 (resistant) x Conquista (susceptible) cross, and 66 F2:3 families of S5995 (resistant) x Renascença (susceptible) cross, evaluated for resistance to races 3 and 14, respectively. Families with female index up to 30% were considered moderately resistant. Markers of A2 and G linkage groups were associated with resistance to race 3. Markers Satt309 and GMENOD2B explained the greatest proportion of phenotypic variance in the different groups. The combinations Satt309+GMENOD2B and Satt309+Satt187 presented 100% selection efficiency. Resistance to race 14 was associated with markers of G linkage group, and selection efficiency in the Satt309+Satt356 combination was 100%. The selection differential obtained by phenotypic and marker assisted selection showed that both can result in similar gains.

Inheritance pattern and selection criteria for resistance to soybean cyst nematode races 3 and 9

The objective of this work was to determine soybean resistance inheritance to Heterodera glycines Ichinohe (soybean cyst nematode - SCN) races 3 and 9, as well as to evaluate the efficiency of direct and indirect selection in a soybean population of 112 recombinant inbred lines (RIL) derived from the resistant cultivar Hartwig. The experiment was conducted in a completely randomized design, in Londrina, PR, Brazil. The estimated narrow-sense heritabilities for resistance to races 3 and 9 were 80.67 and 77.97%. The genetic correlation coefficient (r g = 0.17; p<0.01) shows that some genetic components of resistance to these two races are inherited together. The greatest genetic gain by indirect selection was obtained to race 9, selecting to race 3 due to simpler inheritance of resistance to race 9 and not because these two races share common resistance genes. The resistance of cultivar Hartwig to races 3 and 9 is determined by 4 and 2 genes, respectively. One of these genes confers resistance to both races, explaining a fraction of the significant genetic correlation found between resistance to these SCN races. The inheritance pattern described indicates that selection for resistance to SCN must be performed for each race individually.

Inheritance of resistance to soybean cyst nematode races 3 and 14 in soybean RIL and F2 populations

The objective of this work was to evaluate the soybean inheritance of resistance to cyst nematode races 3 and 14. The following populations where evaluated: one population of recombinant inbred lines (RILs) [Hartwig (resistant) x Y23 (susceptible line)] for races 3, 14 and 9; one population of families F2:3 [M-SOY 8001 (resistant) x MB/BR 46 - Conquista (susceptible)] for race 3; and one population of families F2:3 [(S5995 (resistant) x BRSMG Renascença (susceptible)] for race 14. In RIL populations, four epistatic genes were identified which conditioned resistance to race 14, and three epistatic ones for resistance to races 3 and 9. The lack of one gene provided moderate resistance under all situations. The highest number of genes for resistance to race 14 points out that genes responsible for lower effects might be involved. In population F2:3 from M-SOY 8001 x MB/BR 46 - Conquista, one recessive gene for moderate resistance and two recessive genes complete resistance to race 3 were identified. Two recessive genes conditioning moderate resistance to race 14 were identified in population F2:3 from the crossing S5995 x BRSMG Renascença. These results will be useful in designing crossings, involving these parentals, with higher possibility to accumulating genes that provide resistance to several SCN races.

QTLs for resistance to soybean cyst nematode, races 3, 9, and 14 in cultivar Hartwig

The objective of this work was to identify major and minor-effect quantitative trait loci (QTL) for resistance to races 3, 9, and 14 of soybean cyst nematode (SCN) in Hartwig cultivar; to map new resistance QTLs for these races; and to check for the existence of epistatic interactions between QTLs. Cultivar Hartwig is an important resistance source to SCN. Recombinant inbred lines (RIL) obtained from a cross between 'Hartwig' (resistant) and Y23 (susceptible) were evaluated regarding resistance to the three races. New genomic regions for resistance to SCN were identified by microsatellites. Four QTLs, which explained between 12 and 34% of phenotypic variance, were detected for resistance to race 3 in linkage groups (LG) A2, G, J, and M. The QTL in LG G is also important for resistance to race 9. Epistatic interactions were detected between loci, which indicate resistance to races 9 and 14. There are high and low-effect resistance QTLs to SCN.

Nematode community, trophic structure and population fluctuation in soybean fields

Temporal (monthly in three fields for 12 months) and spatial (once in 23 fields during March-April) samplings were conducted in the major soybean (Glycine max)-growing region of the Brazilian Federal District. Fifty-three nematode genera were found in both samplings, but 13 were detected only by the temporal sampling, and one only by the spatial sampling. Fifty-three percent were plant-parasites, 35% were bacterivores, and about 12% were fungivores, predators and omnivores constituted the community that was dominated by the genera Helicotylenchus (40% of total abundance), Acrobeles (15%), Cephalobus (7.6%), Meloidogyne(5.6%) and Pratylenchus (4.9%). Heterodera glycines was not found in this study. There were no differences in ten ecological measurements [Ds, H', Es, T, FF/BF, (FF+BF)/PP, MI, PPI, mMI, and Dorylaimida (%)] between the two sampling types, but differences in indexes d and J'. Plant parasite populations dropped at the end of the crop cycle, remained at low levels during the dry season and the seedling period, then increased again in the crop-growing season. Fungivores maintained their low populations throughout the year, increasing only in June and July, the post-harvest period, when soil fungi decomposed root tissue. The population of bacterivores slightly declined during the dry season and the initial rainy season, but peaked in the middle of the rainy season, apparently associated with soil humidity. In the five most abundant nematodes, those of Acrobeles and Pratylenchus were more populous in wet soils, Cephalobus and Meloidogyne adapted well in dry soils, but Helicotylenchus survived abundantly in a wide range of soil moisture.