Since 1996, there have been several case reports of autochthonous visceral leishmaniasis in Thailand. Here we report a case in a 52-year-old Thai male from northern Thailand, who presented with subacute fever, huge splenomegaly and pancytopenia. Bone marrow aspiration revealed numerous amastigotes within macrophages. Isolation of Leishmania LSCM1 into culture and DNA sequence analysis (ribosomal RNA ITS-1 and large subunit of RNA polymerase II) revealed the parasites to be members of the Leishmania enriettii complex, and apparently identical to L. martiniquensis previously reported from the Caribbean island of Martinique. This is the first report of visceral leishmaniasis caused by L. martiniquensis from the region. Moreover, the majority of parasites previously identified as “L. siamensis” also appear to be L. martiniquensis. Visceral leishmaniasis is a potentially life threatening parasitic disease that is found in many tropical and subtropical regions of the world. We report a case of visceral leishmaniasis in northern Thailand caused by a recently described new species of Leishmania parasite, Leishmania martiniquensis. By comparing DNA sequences from this parasite with those of other isolates, we show that this parasite is more widely spread than previously thought, with several other examples in Thailand, and possibly from Europe and the USA, as well as the original location in the Caribbean island of Martinique. This parasite appears to be an emerging pathogen, which, because it causes a potentially fatal disease, needs to be investigated in detail so that its transmission can be understood and control measures can be developed.
1 September 2015 in International Journal for Parasitology
An active case detection approach with PCR diagnosis was used in the Ho District of the Volta Region, Ghana that identified individuals with active cutaneous leishmaniasis. Three isolates were successfully cultured and DNA sequences from these were analysed (ribosomal RNA internal transcribed spacer 1; ribosomal protein L23a intergenic spacer; RNA polymerase II large subunit), showing them to be Leishmania, identical to each other but different from all other known Leishmania spp. Phylogenetic analysis showed the parasites to be new members of the Leishmania enriettii complex, which is emerging as a possible new subgenus of Leishmania parasites containing human pathogens.
The recent introduction of sachet water to consumers was to provide safe, hygienic and affordable instant drinking water to the public. Although this is a laudable idea current trends seem to suggest that sachet drinking water could be a route of transmission of enteric pathogens. To assess the safety of sachet drinking water. Twenty seven different brands of 500ml sachet water samples randomly selected and purchased from various vendors in Accra were subjected to microscopic examinations to determine the presence of parasitic protozoa. The study was carried out between January and May 2005. Seventy-seven percent of the samples contained infective stages of pathogenic parasitic organisms. Common pathogens identified include, Microsporidia sp 14/27 (51.2%), Cryptosporidium parvum 17/27 (63.0%), Cyclospora cayetenensis 16/27 (59.3%), Sarcocystis sp. 18/27 (66.7%). Rotifers 5/27 (18.5%), and Charcoat Leyden crystals 12/27 (44.4%). Ninety-three percent of the samples contained unidentified impurities/artifacts. 29.6% of the samples contained at least one type of parasite, 14.8% contained at least 2 types of parasites, 25.9% contained at least three types of parasites, while 29.6% contained four types of parasites. The study indicated the presence of contaminants of feacal and zoonotic origin in some of the sachet water examined. This has grim public health implications as the organisms identified can cause water related diseases which have serious complications in children and adults particularly immunocompromised individuals. Sachet water should be constantly monitored for its microbial quality.
Genetic and phylogenetic analysis was performed on 2 isolates of Leishmania using DNA sequence data from the RNA polymerase II large subunit gene and the ribosomal protein L23a intergenic sequence. This showed the isolates to represent 2 new species within the subgenus Leishmania (Mundinia). The addition of Leishmania (Mundinia) chancei and Leishmania (Mundinia) procaviensis creates a total of 6 named species to date within this recently described subgenus of parasitic protozoa, containing both human pathogens and nonpathogens. Their widespread geographical distribution, basal phylogenetic position within the genus Leishmania, and probable non–sand fly vectors make these L. (Mundinia) species of significant medical and biological interest.
Current treatment for HIV-1 largely relies on chemotherapy through the administration of antiretroviral drugs. While the search for anti-HIV-1 vaccine remain elusive, the use of highly active antiretroviral therapies (HAART) have been far-reaching and has changed HIV-1 into a manageable chronic infection. There is compelling evidence, including several side-effects of ARTs, suggesting that eradication of HIV-1 cannot depend solely on antiretrovirals. Gene therapy, an expanding treatment strategy, using RNA interference (RNAi) and programmable nucleases such as meganuclease, zinc finger nuclease (ZFN), transcription activator-like effector nuclease (TALEN), and clustered regularly interspaced short palindromic repeats/CRISPR-associated proteins (CRISPR–Cas9) are transforming the therapeutic landscape of HIV-1. TALENS and ZFNS are structurally similar modular systems, which consist of a FokI endonuclease fused to custom-designed effector proteins but have been largely limited, particularly ZFNs, due to their complexity and cost of protein engineering. However, the newly developed CRISPR–Cas9 system, consists of a single guide RNA (sgRNA), which directs a Cas9 endonuclease to complementary target sites, and serves as a superior alternative to the previous protein-based systems. The techniques have been successfully applied to the development of better HIV-1 models, generation of protective mutations in endogenous/host cells, disruption of HIV-1 genomes and even reactivating latent viruses for better detection and clearance by host immune response. Here, we focus on gene editing-based HIV-1 treatment and research in addition to providing perspectives for refining these techniques.