A Gram-stain-negative, rod-shaped bacterium (strain K-39 T) was isolated from the thermophilic phase of the composting process for oyster mushroom substrate preparation. The strain grew at 40-80 6C (optimum, 65-75 6C), at pH 5-9 (optimum, pH 7), in media containing up to 1.5 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain K-39 T formed a distinct lineage within the genus Thermus. Its closest cultivated relative was Thermus islandicus PRI 3838 T (96.8 % similarity). The DNA G+C content of strain K-39 T was 71.3 mol%. The new strain could be differentiated from the related taxa by not being able to hydrolyse starch. The predominant fatty acids of strain K-39 T were iso-C 17 : 0 and anteiso-C 17 : 0. Strain K-39 T contained a lower amount of the fatty acid iso-C 15 : 0 as compared to related species of the genus Thermus. The predominant respiratory quinone of the new isolate was menaquinone MK-8. On the basis of a taxonomic study using a polyphasic approach, strain K-39 T is considered to represent a novel species of the genus Thermus, for which the name Thermus composti sp. nov. is proposed. The type strain is K-39 T (5DSM 21686 T 5NCAIM B 02340 T). The genus Thermus was established by Brock & Freeze (1969) with the description of Thermus aquaticus. Nine further species have been described (Bjornsdottir et al., 2009; Zhang et al., 2010), originating from natural and artificial thermal environments such as hydrothermal areas, hot water taps, self-heating compost piles and rock surfaces (da Costa et al., 2006). In a recent article, Vajna et al. (2010) investigated the microbiota during oyster mushroom (Pleurotus ostreatus) substrate preparation. The preparation had three main stages: (1) wheat straw supplemented with alfalfa was chopped, moistened and kept in heaps for composting for 7 days with daily mixing, during which the inside temperature rose to 70-75 u C; (2) the partially composted substrate was packed into tunnels for pasteurization (65 u C for 18 h); (3) it was conditioned (48 u C for 48 h), and left to cool to approximately 25 u C. During that study several strains were isolated from the thermophilic phase (70-75 u C). One strain gave low pairwise similarity values of partial 16S rRNA gene sequences to recognized members of the genus Thermus. This paper describes the detailed taxonomic characterization of strain, K-39 T , which represents a novel species of the genus Thermus. Strain K-39 T was isolated with the use of the standard dilution plating technique on oat flake medium (DSMZ Medium 189) incubated at 60 u C. The reference strains used in this study for side by side analyses, Thermus arciformis TH92 T (5JCM 15153 T) and Thermus islandicus PRI 3838 T (5DSM 21543 T) were obtained from the Japan Collection of Microorganisms (JCM) and the Deutsche Sammlung von Micro-organismen und Zellkulturen (DSMZ), respectively. Strain K-39 T was maintained on R2A medium (DSMZ Medium 830); subcultivation for detailed taxonomical analyses was performed at 65 u C. Colony morphol...

Frequencies of genetic polymorphisms of the three most frequent HIV-1 resistance-conferring alleles playing an important role in HIV-1 pathogenesis were analysed in Vlach Gypsy populations living in Hungary, as the largest minority. Mutations in the encoding genes, such as CCR5-∆32, CCR2-64I and SDF1-3'A are shown to result in protective effects against HIV-1 infection and disease progression. 560 samples collected from Vlach Gypsy individuals living in 6 North-East Hungarian settlements were genotyped by PCR-RFLP method. Overall allele frequencies of CCR5-∆32, CCR2-64I and SDF1-3'A were found as 0.122, 0.186 and 0.115 respectively. All the observed genotype frequencies were in accordance with Hardy-Weinberg equilibrium . In regions, however, Vlach Gypsies live in majority and in ethnically homogenous communities, a higher CCR5-∆32 mutations were found, with allele frequencies of 0.148 and 0.140 respectively, which are remarkably higher than those in general Hungarian people, and ten times higher than in regions of North-Western India from where present day Hungarian Gypsies originated in the Middle Ages. In the background of this higher CCR5-∆32 allele frequency in the population analysed in our study a genetic founder effect could be assumed. Allele frequency of CCR2-64I was found to be among the highest in Europe. SDF1-3'A allele frequency in Vlach Gypsies was significantly lower than in ethnic Hungarians. 63% of the total 560 individuals tested carried at least one of the mutations studied. These results could partially explain the low incidence of HIV/AIDS among Vlach Gypsies in Hungary.

Thiolated pyrimidine derivatives have been synthetized and their antiretroviral effect against human immunodeficiency virus type 1 (HIV-1IIIB) and HIV-1 chimeric pseudovirions have been quantitatively determined in cell-based viral infectivity assays including syncytium inhibition assay as well as a single-cycle viral infection assay on HeLaCD4-LTR/ß-gal cells. Pseudotype virions prepared bearing HIV-1 envelope preference for CCR5 coreceptor, CXCR4 coreceptor or for both, respectively, with a HIV-1 core containing luciferase reporter gene were able to infect susceptible cells but are replication defective so unable to replicate in the cells . Data indicate that thiolated pyrimidine derivatives inhibited effectively virally induced cell fusion in vitro as well as infectivity of primary HIV-1IIIB strain and HIV-1 pseudovirions using chemokine receptors CCR5 or CXCR4 or both for virus entry a dose dependent manner. Inhibition was selective, depended on the pseudovirus coreceptor preference. Our results suggest that some of these sulfur containing pyrimidines interact with redoxactive -SH groups required for successful HIV entry, including a redox active disulfide in the CD4 molecule as well as -SH groups in HIV viral envelope gp120. This mode of action is unique representing a new class of potential HIV entry inhibitors.

Mutations in the HIV-1 pol gene associated with resistance to antiretroviral drugs in therapy-naïve Hungarian individuals transmitted as primary infection by their foreign sexual partners originated from African, Asian and other European countries had been analyzed. Drug resistance genotyping of HIV RT and PR genes were performed where mutations of 72 codons - among them 64 specific resistance codons representing 6 nucleoside reverse transcriptase inhibitor (NRTIs), 2 non-nucleoside reverse transcriptase inhibitor (NNRTIs) and 6 proteinase inhibitor (PRIs) drugs - had been analyzed by Truegene HIV-1 Genotyping kit and OpenGene Sequencing System. Viral variants harboring resistance mutations in the po l gene were detected in 14% of the subjects. The highest rate of resistance to a single class of inhibitors was detected towards PR inhibitors (12%), followed by NRTI (8%) and NNRTI (5%). On the contrary, 25% of viruses transmitted by homosexual activity contained mutations led to resistance to NNRT. Viruses from 11 percent of cases were resistant to 2 classes of inhibitors, and 7 percent to three classes of inhibitors. Based upon sequence data non-B subtypes and CRFs were detected in more than 71% of cases. HIV-1 C (10.7%), HIV-F1 (7.2%) and HIV-1 G (3.6%) were detected as the more frequent subtypes. Among the HIV-1 recombinant viruses CRF02_AG variants were found more frequently (28.5%) followed by CRF06_cpx (17.8%) indicating penetration of non-B subtypes and recombinant African variants into Hungary, which raises serious clinical and public health consequences.

Antiretroviral effect of thiolated nucleotide 4-thio-uridylate (S 4 UMP, designated as UD29) against human immunodeficiency virus type 1 (HIV-1) have been quantitatively determined in cell-based viral infectivity assays. In syntitium inhibition assay on MT-2 human T-cell line UD29 prevented cell fusion and formation of syntitia induced by HIV-1 IIIB with IC 50 values of 11.7 µg/ml. In a single-cycle viral infection assay (MAGI assay) UD29 proved to have a potent inhibitory effect against HIV-1 IIIB on HeLaCD4-LTR/b-gal cells, which was dose dependent with IC 50 values of 4.75 µg/ml and IC 90 of 39.7 µg/ml. UD29 showed a most prominent antiviral effect when administered 30 min prior HIV-1 infection. As HIV entry requires thiol/disulfide exchange process, results suggest that reactive -SH group of enol-form of the thiolated nucleotide may interfere with the function of cell surface proteins. UD29 cannot penetrate into cells and may have an interactive role in redox processes active in viral entry.