Small rodent communities and their associated damage to wheat-groundnut agriculture systems.

Rodents can cause significant damage to wheat-groundnut crops in developing countries, as well as to stored produce and infrastructure, affecting food security and income of small-holder farmers. Wheat (Triticum aestivum) and groundnuts (Arachis hypogea) are important cash crops for local farmers in Pakistan. Field experiments were performed to assess the extent of rodent damage to wheat-groundnut crops throughout their growth stages (i.e, germination, flowering/peg formation and maturity) in the agro-ecological zones of Pothwar Plateau, Pakistan. We used a quadrat method to record the number of damaged crop plants. On the basis of the trapping data four rodent species were captured from wheat-groundnut cropping systems which were responsible for causing damage, i.e., lesser bandicoot rat (Bandicota bengalensis) was the main species, followed by the short-tailed mole rat (Nesokia indica), the Indian gerbil (Tatera indica) and the bush rat (Golunda ellioti). In both crops, the maximum damage was recorded at crop maturity (10.7 and 14.4%, respectively). The lowest reported damage to wheat and groundnuts was at the germination stage (3.5% and 6.0%, respectively). The lower damage reported at germination could be due to availability of non-crop vegetation at field borders that may be a potential factor influencing damage. Our findings clearly show the considerable amount of damage caused by rodents to wheat-groundnut at maturity across all the agro-ecological zones of Pothwar and indicated that the small mammal composition was more related to maturity stage/season of crops, when the availability of food and climatic condition were favorable and having security under crop shelter. More detailed studies are needed to fully understand the population and breeding ecology of the relevant rodent pest species in relation to damage patterns to optimize management beyond individual structural measures.

Avian schistosomes and human cercarial dermatitis in a wildlife refuge in Mazandaran Province, northern Iran.

Each year, hundreds of aquatic migratory birds migrate from northern hemisphere to the Mazandaran Province, northern Iran. Little information is available on prevalence and density of schistosomes in water birds in Iran and around the world. The objectives of this study were to determine definitive and intermediate hosts of avian schistosomes as well as to assess human cercarial dermatitis (HCD) in a wildlife refuge in Mazandaran Province. Of 1106 examined people, 589 (53.2%) had maculopapular rashes mainly on feet but also on hand. The majority of cases were adults and local residents. Of 260 ducks, 41 (15.8%) were found to be infected with Trichobilharzia spp. eggs or adult worms. Prevalence was highest in Anas clypeata and Anas platyrhynchos, 79% and 18.9%, respectively. A total of 1.2% snails, examined by both shedding and crushing methods, were infected with furcocercariae belonging to avian schistosomes. The most frequently infected snail was Lymnaea gedrosiana (5.9%). Our results showed that cercarial dermatitis and avian schistosomiasis is a common and yet neglected disease in this area. Anas clypeata played the most important role in exposing snails to miracidia in ponds and paddy fields. Moreover, because of the high prevalence in ducks and high prevalence of HCD in the region, it is considered as a new endemic focus in Iran.

Molecular Characterization of Echinococcus granulosus from Hydatid Cysts Isolated from Human and Animals in Golestan Province, North of Iran.

BACKGROUND: The aim of the present study was to determine the molecular characteristics of Echinococcus granulosus from paraffin-embedded tissues of hydatid cysts isolated from human and protoscoleces of hydatid cysts from sheep, cattle and camel isolates using PCR- RFLP of ITS1- rDNA analysis in Golestan Province, northern Iran. METHODS: E. granulosus isolates from human patients infected with hydatid cyst and protoscoleces from hydatid cysts of sheep, cattle and camel isolates were collected from different hospitals and the abattoir throughout the Golestan Province. In all, 60 E. granulosus genomic DNA were extracted and examined by PCR - ITS1 of rDNA and amplified using BD1 / 4S and EGF1 / EGR2 primers, followed by RFLP using Alu1, Msp1 and TaqI restriction enzymes. RESULTS: The PCR-ITS1 products obtained from sheep, cattle and human isolates were similar to sheep strain (1000 bp and 391 bp). Majority of the camel samples yielded 295 bp DNA bands. RFLP -ITS1 of E. granulosus with Taq1 in human, sheep and cattle isolates showed similar patterns in the number and size of DNA. RFLP methods in camel isolates showed a different genotype, using Taq1, whereas no DNA bands were observed using Alu1 in camel and human isolates. Therefore, two clearly distinguishable banding patterns of E. granulosus were obtained with the three enzymes, which separating human, sheep and cattle isolates from the camel origin. CONCLUSION: The results indicate the possible of transmission of the G1 and G6 genotypes of E. granulosus between livestock animals and human in Golestan Province.

Molecular and Seroepidemiological Survey of Visceral Leishmaniasis among Humans and Domestic Dogs in Mazandaran Province, North of Iran.

BACKGROUND: New cases of visceral leishmaniasis (VL) have been reported recently in some parts of Mazandaran Province, north of Iran where the first human case of VL was reported in 1949. This study aimed to determine the present status of Leishmaniainfantum infection among humans and domestic dogs using serological and molecular methods in central parts of Mazandaran Province. METHODS: In this cross-sectional study, blood samples were randomly collected from 402 humans and forty-nine domestic dogs throughout 2009 and 2010 in the central part of Mazandaran Province including Semeskadeh and Kiakola districts where recent cases of human visceral leishmaniasis had been reported there. All the collected samples were tested by direct agglutination test (DAT) for the detection of anti-Leishmania infantum antibodies as well as convenience PCR assay on whole blood samples for detection of leishmanial infection and identification of Leishmania species. RESULTS: None of 402 collected human (402) and dog (49) blood samples showed anti Leishmaniainfantum antibodies at titers 1:3200 and 1:320 as cut-off values of DAT, respectively but only 2 of domestic dogs (4.1%) were found PCR-positive corresponding to L.infantum. CONCLUSION: This study confirms the circulation of L. infantum at least among domestic dogs and highlights the sporadic pattern of VL in the studied areas. Further investigations regarding to sand flies fauna and wild canines as reservoir hosts of the disease, are recommended.

Asymptomatic human carriers of Leishmania infantum: possible reservoirs for Mediterranean visceral leishmaniasis in southern Iran.

Over the last decade, the incidence of visceral leishmaniasis (VL) has increased in many districts of the province of Fars, in southern Iran. Recent epidemiological reports indicate that asymptomatic human infections with Leishmania infantum (the causative agent of VL throughout the Mediterranean basin) occur more frequently in Iran than was previously believed. Between 2004 and 2006, blood samples were collected from 802 apparently healthy subjects from communities, in the north-west and south-east of Fars province, where VL cases had been recorded. Each of these samples was tested for anti-Leishmania antibodies, in direct agglutination tests (DAT), and for L. infantum kinetoplast DNA, in PCR-based assays. Of the 426 subjects from north-western Fars, eight (1.9%) were found seropositive and 68 (16.0%) PCR-positive. The corresponding values for the 376 subjects from south-eastern Fars were lower, with five (1.3%) seropositive and 32 (8.5%) PCR-positive. Of the 100 PCR-positive subjects, 18 (18.0%) each lived in a household in which there had been a case of VL, and six (6.0%) had had VL themselves (in each case, more than a year before the blood sampling for the present study). Although 21 of the PCR-positives have now been followed-up for at least 18 months, none has developed symptomatic VL. Since positivity in the PCR-based assay probably indicated the presence of L. infantum amastigotes in the peripheral blood of 12.5% of the subjects, it is clear that asymptomatic human carriers of L. infantum are quite common in the study areas and probably act as reservoirs in the transmission of the parasite, to humans and to dogs, by sandflies.

Atypical presentation of Old-World cutaneous leishmaniasis, diagnosis and species identification by PCR.

BACKGROUND: The diagnosis of cutaneous leishmaniasis (CL) is traditionally based on microscopic demonstration of amastigote forms in tissue biopsies or smears. However, this method usually presents low sensitivity, and in atypical forms, CL may be overlooked because of similarity to other dermal diseases. Thus, it is necessary to apply specific diagnostic methods as polymerase chain reaction (PCR). OBJECTIVE: To evaluate the possible advantage of PCR in the diagnosis and species identification of CL in patients with atypical clinical presentation. METHODS: Fifty-one patients clinically suspected of CL with positive and negative controls were tested. After microscopic examination, extraction of DNA was performed on their smears and analysed by two specific PCR assays for diagnosis and species identification. For these methods, conserved and variable regions of kinetoplastic DNA (KDNA) of Leishmania species have been amplified, respectively. Atypical forms of CL were evaluated among PCR-positive patients. RESULTS: PCR results were positive in 37 out of 51 cases (72.5%), among whom microscopic examination revealed Leishmania amastigotes in only 3 (5.9%). Among these patients, 10 (27%) had atypical presentation of CL; using species-specific primers, 6 patients had Leishmania major, 3 had Leishmania tropica and 1 patient had no species diagnosis. None of the samples of other dermal diseases revealed positive results (specificity, 100%). All patients were successfully treated by CL-specific drug regimens. DISCUSSION: The results showed that KDNA PCR methods have a higher sensitivity compared with microscopic method. Moreover, PCR could identify the parasite species for specific therapy. Microscopic method had low sensitivity and less value in chronic and atypical CL cases.

An integrated pipeline for the development of novel panels of mapped microsatellite markers for Leishmania donovani complex, Leishmania braziliensis and Leishmania major.

A panel of microsatellites mapped to the Leishmania genome might make it possible to find associations between specific loci and phenotypic traits. To identify such loci, a Perl programme was written that scans the sequence of a genome and writes all loci containing microsatellites to a MySQL database. The programme was applied to the sequences of the L. braziliensis, L. infantum and L. major genomes. The database is publicly available over the internet: http://www.genomics.liv.ac.uk/tryps/resources.html 'Microsatellite Locus Extractor', and allows the selection of mapped microsatellites that meet user-defined criteria from a specified region of the selected genome. The website also incorporates a primer design pipeline that will design primers to amplify the selected loci. Using this pipeline 12 out of 17 primer sets designed against the L. infantum genome generated polymorphic PCR products. A tailed primer protocol was used to label all microsatellite primers with a single set of labelled primers. To avoid the culture of parasites prior to genotyping, sets of nested PCR primers were developed to amplify parasite DNA eluted from microscope slides. The limit of detection was approximately 1.6 parasite equivalents. However, only 6/56 DNA from slides stored at ambient temperature for over 6 months gave positive PCR results.