ABSTRACT
Plants are promising sources of agents useful for the control of vectors of human diseases including leishmaniasis. The effect of Ricinus communis [Euphorbiaceae] and Bougainvillea glabra [Nyctaginaceae] on transmission of leishmaniasis was investigated using them as diets for Phlebotomus papalasi to monitor their effect on life-history traits. P. papatasi were allowed to feed separately on both plants then offered a blood-meal. Fed-females were observed daily for egg-laying and subsequent developmental stages. P. papatasi was able to feed on B. glabra [29.41% females and 46.30% males] and R. communis [5.80% females and 10.43% males]. 34.28% of females died within 24-48 hours post-feeding on R. communis, whereas, it was 16.5% in females fed on B. glabra. Overall fecundity of surviving females was reduced compared to controls, reared on standard laboratory diet; however there was no effect on the sex ratio of progeny. Female P. papatasi in the control group had significantly longer life span compared to plant-fed group. Feeding on these plants not only decreased sand fly survival rates but incurred negative effects on fecundity. Findings indicate that planting high densities of R. communis and B. glabra in sand flies-endemic areas will reduce population sizes and reduce the risk of Leishmania major infections
Subject(s)
Plants, Medicinal/adverse effects , Psychodidae , Phlebotomus/parasitology , Fertility/physiology , Leishmania major/parasitologyABSTRACT
Cutaneous leishmaniasis [CL] is a neglected clinical form that is quite prevalent in Eastern North parts of the country in Sinai Peninsula. Leishmania tropica was identified by previous reports as the causative agent responsible for viscerotropic infections in-patients and experi-mental animals. Here, we reported the viscerotropic infections from naturally infected rodent Gerbillus pyramidum floweri collected from North-Sinai. Footpad and tail lesions, spleenomeg-aly, and malformed dark-colored spleen were the characteristic CL symptoms. The spleen of the rodent found positive to amastigote impression smear. ITS-1 DNA was sequenced and revealed 100% identity of the strain in the current study to the other L tropica sequences identified from the patients with the suspected CL and inhabited the same study area. The current findings confirmed the susceptibility of gerbil to L. tropica, and raise the concerns for the role of rodents as accidental host suffering the infections. The susceptibility of wild and experimental rodents to the same tropica strain was also investigated; BALB/c and G. pyramidum were more susceptible to L tropica [2433 +/- 4.37 and 25 +/- 4.58 days post-infection, respectively]. Similar viscero-tropic pathologies were reported in experimental infection of only golden hamster [" 120 days post-infection], and G p. floweri [ 160 days post-infection]
Subject(s)
Animals , Leishmaniasis, Cutaneous , Rodentia , Psychodidae , PhlebotomusABSTRACT
This study compared the cellular interactions of Spodopteralittoralis haemocytes with two virulence-different entomopathogenic fungi: Beauveriabassiana and Nomuraearileyi. Using light and transmission microscopy, five types of haemocytes namely, prohaemocytes [PRs], plasmatocytes [PLs], granulocytes [GRs], spherule cells [SPs] and oenocytoids [OEs] were identified in the 6[th] instar larvae. PRs and PLs were found in the haemopoietic tissue.Intra-haemocoelic injection of blastospores induced ultrastructural alterations in the cytoplasm and nucleiof circulating haemocytes of treated larvae. Different responses were observed in the populations of haemocyte types following injection with the tested fungi. The most important changes were the decrease of the numbers of GRs aiccompanied with increase inSPs at 12-48h following injection with B. bassiana, whereas,a decrease of PLs with a commitment increase inSPs and OEs were observed at most time intervals after injection with N. rileyi. Both fungi provoked a decrease of the total number of haemocytes at 48h followed by an increase at 72h post-injection. In vivo assay showed that the GRs and PLs actively phagocytised fungal blastospores. There was a time-dependent decrease and increase in the phagocytosis activity after injection of B. bassiana and N. Rileyi, respectively .In B. bassiana-injected insects, the numbers nodules increased significantly at 6-48h in comparison with the controls post-injection. In N. rileyi-injected insects, nodules increased significantly only at 72h post-injection.No cellular encapsulation was observed in any of the examined insects
Subject(s)
Beauveria/physiology , Hemocytes/ultrastructure , Microscopy, Electron , PhagocytosisABSTRACT
During entomological surveys conducted in Southern Sinai in the summers of 1997-1999, a clinically confirmed zoonotic cutaneous leishmaniasis [ZCL] case was encountered for the first time in Sheikh Atiya Village in June 1999. The parasite was isolated and identified as L. major using cellulose acetate electrophoresis. A total of 784 phlebotomine sand flies was collected. Sand fly species composition at Sheikh Atiya Village showed that P. papatasi and P. alexandri were the most abundant species in the area and each comprises about 47% of the collected files. P. sergenti and P. kazeruni occurred in very low numbers. All the female flies dissected [N = 304] were negative for any Leishmania-like flagellates. When the identified isolate was inoculated in the footpads of a clean laboratory colonized Acomys cahirinus dimidiatus, a lesion was developed on the site of inoculation nine months post-injection