An imbalance in the bacterial species resulting in the loss of intestinal homeostasis has been described in inflammatory bowel diseases (IBD) and irritable bowel syndrome (IBS). In this prospective study, we investigated whether IBD and IBS patients exhibit specific changes in richness and distribution of fecal and mucosal-associated microbiota. Additionally, we assessed potential 16S rRNA gene amplicons biomarkers for IBD, IBS, and controls (CTRLs) by comparison of taxonomic composition. The relative abundance of bacteria, at phylum and genus/species levels, and the bacterial diversity were determined through 16S rRNA sequence-based fecal and mucosal microbiota analysis. Linear discriminant analysis effect size (LEfSe) was used for biomarker discovery associated to IBD and IBS as compared to CTRLs. In fecal and mucosal samples, the microbiota richness was characterized by a microbial diversity reduction, going from CTRLs to IBS to IBD. β-diversity analysis showed a clear separation between IBD and CTRLs and between IBD and IBS with no significant separation between IBS and CTRLs. β-diversity showed a clear separation between mucosa and stool samples in all the groups. In IBD, there was no difference between inflamed and not inflamed mucosa. Based upon the LEfSe data, the Anaerostipes and Ruminococcaceae were identified as the most differentially abundant bacterial taxa in CTRLs. Erysipelotrichi was identified as potential biomarker for IBS, while Gammaproteobacteria, Enterococcus, and Enterococcaceae for IBD. This study provides an overview of the alterations of microbiota and may aid in identifying potential 16S rRNA gene amplicons mucosal biomarkers for IBD and IBS.
16 January 2015 in Journal of Experimental & Clinical Cancer Research
Classical Kaposi’s Sarcoma (cKS) is a rare vascular tumor, which develops in subjects infected with Human Herpesvirus-8 (HHV-8). Beside the host predisposing factors, viral genetic variants might possibly be related to disease development. The aim of this study was to identify HHV-8 variants in patients with cKS or in HHV-8 infected subjects either asymptomatic or with cKS-unrelated cutaneous lymphoproliferative disorders. The VR1 and VR2 regions of the ORF K1 sequence were analyzed in samples (peripheral blood and/or lesional tissue) collected between 2000 and 2010 from 27 subjects with HHV-8 infection, established by the presence of anti-HHV-8 antibodies. On the basis of viral genotyping, a phylogenetic analysis and a time-scaled evaluation were performed. Two main clades of HHV-8, corresponding to A and C subtypes, were identified. Moreover, for each subtype, two main clusters were found distinctively associated to cKS or non-cKS subjects. Selective pressure analysis showed twelve sites of the K1 coding gene (VR1 and VR2 regions) under positive selective pressure and one site under negative pressure. Thus, present data suggest that HHV-8 genetic variants may influence the susceptibility to cKS in individuals with HHV-8 infection.
1 December 2014 in Asian Pacific Journal of Tropical Medicine
Chikungunya virus is a mosquito-transmitted alphavirus that causes chikungunya fever, a febrile illness associated with severe arthralgia and rash. Chikungunya virus is transmitted by culicine mosquitoes; Chikungunya virus replicates in the skin, disseminates to liver, muscle, joints, lymphoid tissue and brain, presumably through the blood. Phylogenetic studies showed that the Indian Ocean and the Indian subcontinent epidemics were caused by two different introductions of distinct strains of East/Central/South African genotype of CHIKV. The paraphyletic grouping of African CHIK viruses supports the historical evidence that the virus was introduced into Asia from Africa. Phylogenetic analysis divided Chikungunya virus isolates into three distinct genotypes based on geographical origins: the first, the West Africa genotype, consisted of isolates from Senegal and Nigeria; the second contained strains from East/Central/South African genotype, while the third contained solely Asian. The most recent common ancestor for the recent epidemic, which ravaged Indian Ocean islands and Indian subcontinent in 2004 - 2007, was found to date in 2002. Asian lineage dated about 1952 and exhibits similar spread patterns of the recent Indian Ocean outbreak lineage, with successive epidemics detected along an eastward path. Asian group splitted into two clades: an Indian lineage and a south east lineage. Outbreaks of Chikungunya virus fever in Asia have not been associated necessarily with outbreaks in Africa. Phylogenetic tools can reconstruct geographic spread of Chikungunya virus during the epidemics wave. The good management of patients with acute Chikungunya virus infection is essential for public health in susceptible areas with current Aedes spp activity.
1 March 2016 in Travel Medicine and Infectious Disease