To gain new insights on the origin, evolution, and modes of dissemination of human T-cell leukemia virus type 1 (HTLV-1), we performed a molecular analysis of 58 new African HTLV-1 strains (18 from West Africa, 36 from Central Africa, and 4 from South Africa) originating from 13 countries. Of particular interest were eight strains from Pygmies of remote areas of Cameroon and the Central African Republic (CAR), considered to be the oldest inhabitants of these regions. Eight long-term activated T-cell lines producing HTLV-1 gag and env antigens were established from peripheral blood mononuclear cell cultures of HTLV-1 seropositive individuals, including three from Pygmies. A fragment of the env gene encompassing most of the gp21 transmembrane region was sequenced for the 58 new strains, while the complete long terminal repeat (LTR) region was sequenced for 9 strains, including 4 from Pygmies. Comparative sequence analyses and phylogenetic studies performed on both the env and LTR regions by the neighbor-joining and DNA parsimony methods demonstrated that all 22 strains from West and South Africa belong to the widespread cosmopolitan subtype (also called HTLV-1 subtype A). Within or alongside the previously described Zairian cluster (HTLV-1 subtype B), we discovered a number of new HTLV-1 variants forming different subgroups corresponding mainly to the geographical origins of the infected persons, Cameroon, Gabon, and Zaire. Six of the eight Pygmy strains clustered together within this Central African subtype, suggesting a common origin. Furthermore, three new strains (two originating from Pygmies from Cameroon and the CAR, respectively, and one from a Gabonese individual) were particularly divergent and formed a distinct new phylogenetic cluster, characterized by specific mutations and occupying in most analyses a unique phylogenetic position between the large Central African genotype (HTLV-1 subtype B) and the Melanesian subtype (HTLV-1 subtype C). We have tentatively named this new HTLV-1 genotype HTLV-1 subtype D. While the HTLV-1 subtype D strains were not closely related to any known African strain of simian T-cell leukemia virus type 1 (STLV-1), other Pygmy strains and some of the new Cameroonian and Gabonese HTLV-1 strains were very similar (>98% nucleotide identity) to chimpanzee STLV-1 strains, reinforcing the hypothesis of interspecies transmission between humans and monkeys in Central Africa.
The susceptibilities of different strains of inbred rats to infection with the human T-cell leukemia virus (HTLV-I) after inoculation of human HTLV-I producer cell lines were compared. The Fisher F344 and Brown Norway strains developed the highest antibody response to HTLV-I, while the Lewis and BB strains were low responders. Antibodies against the HTLV-I gag proteins, and env gp21 but not env gp46, were detected in Western blots with sera from HTLV-I-infected Fischer F344 and Brown Norway rats. These sera were inactive in an in vitro syncytium-formation inhibition test. The HTLV-I provirus was detected by polymerase chain reaction in all Fischer F344, and some Lewis and Brown Norway rats, but not in the BB, which lack CD8+ T lymphocytes. The most frequent locations of the HTLV-I provirus in the Fischer F344, Lewis and Brown Norway rats at 12 weeks after infection were the peripheral blood mononuclear cells (PBMC) and spinal cord. In a second experiment in Brown Norway rats, the provirus was again detected in the PBMC of rats at 12 weeks, but not at 22 weeks, and among the other organs tested at 22 weeks the sympathetic nerve ganglia were positive. It is concluded that HTLV-I infection occurs in adult rats, but is suppressed with time.
A study of simian T-cell leukemia virus type 1 (STLV-1) infection in a captive colony of 23 Macaca tonkeana macaques indicated that 17 animals had high human T-cell leukemia virus type 1 (HTLV-1) antibody titers. Genealogical analysis suggested mainly a mother-to-offspring transmission of this STLV-1. Three long-term T-cell lines, established from peripheral blood mononuclear cell cultures from three STLV-1-seropositive monkeys, produced HTLV-1 Gag and Env antigens and retroviral particles. The first complete nucleotide sequence of an STLV-1 (9,025 bp), obtained for one of these isolates, indicated an overall genetic organization similar to that of HTLV-1 but with a nucleotide variability for the structural genes ranging from 7.8 to 13.1% compared with the HTLV-1 ATK and STLV-1 PTM3 Asian prototypes. The Tax and Rex regulatory proteins were well conserved, while the pX region, known to encode new proteins in HTLV-1 (open reading frames I and II), was more divergent than that in the ATK strain. Furthermore, a fragment of 522 bp of the gp21 env gene from uncultured peripheral blood mononuclear cell DNAs from five of the STLV-1-infected monkeys was sequenced. Phylogenetic trees constructed with the long terminal repeat and env (gp46 and gp21) regions demonstrated that this new STLV-1 occupies a unique position within the Asian STLV-1 and HTLV-1 isolates, being, by most analyses, related more to the Australo-Melanesian HTLV-1 topotype than to any other Asian STLV-1. These data raise new hypotheses on the possible interspecies viral transmission between monkeys carrying STLV-1 and early Australoid settlers, ancestors of the present day Australo-Melanesian inhabitants, during their migrations from the Southeast Asian land mass to the greater Australian continent.
Tujuan Uji biokimia untuk identifi kasi Candida spp. memakan waktu dan menunjukkan hasil yang tidak dapat ditentukan. Metoda deteksi spesifi k untuk antibodi, antigen dan metabolit Candida spp. memiliki sensitivitas dan spesifi sitas yang rendah. Pada penelitian ini kami mengembangkan metoda diagnostik cepat, Uji Reaksi Rantai Polimerasa Multipleks (Multiplex-PCR) assay untuk identifi kasi Candida spp. Metode Lima isolate Candida spp. dibiak, diidentifi kasi menggunakan uji germ tub, dan kit API ® 20 C AUX (BioMerieux ® SA). Selanjutnya, DNA dipurifi kasi dengan kit QIAamp DNA mini (Qiagen ®) untuk uji Multiplex-PCR. Hasil Batas deteksi DNA dengan uji Multiplex-PCR assay dari C. albicans, C. tropicalis, C. parapsilosis, C. krusei dan C. glabrata berturut-turut adalah 4 pg, 0,98 pg, 0,98 pg, 0,5 pg and 16 pg Uji ini lebih sensitif daripada biakan karena Multiplex-PCR dapat mendeteksi 2.6-2.9 x 100 CFU/ml, sementara biakan hanya 2.6-2.9 x 102 CFU/ml. Kesimpulan Multiplex PCR menunjukkan sensitivitas yang lebih tinggi dari biakan. Uji ini dapat direkomendasikan sebagai uji yang sensitive dan spesifi k untuk identifi kasi Candida spp.
Rapid development and advancement of bioresearch at a university's laboratories can have both positive and negative implications for public health and the environment. Many research activities in which biological materials have been created, modified, stored, and manipulated require safety procedures to keep the negative effects on humans and the environment as low as possible. The Occupational Health, Safety and Environmental (OHS&E) Department of the University of Indonesia (UI) is trying to increase the awareness and responsibility of its university members and laboratory staffs who work with biohazard materials by creating a biorisk checklist. The checklist was developed based on WHO guidelines and the National University of Singapore (NUS) Laboratory Manual, which contains 311 questions about the management, administration, and handling of various hazards, recombinant experiments, and animal and plant experiments. A gap analysis was run against the checklist in 14 laboratories at the University of Indonesia Salemba campus, which daily works with highly infectious pathogens and high-risk agents. Overall result showed that none of these laboratories had met all of the checklist items, and there were only 2 laboratories that had implemented more than half of the items. This checklist was proven to be a simple tool for assessing laboratories that handle and store biohazard materials, and it could be used as a monitoring tool for biorisk programs as well. It also could be further developed as a laboratory software application to increase its effectiveness and its accuracy.
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