Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases
-
Infect. Genet. Evol. · Mar 2013
Genetic variations of PD1 and TIM3 are differentially and interactively associated with the development of cirrhosis and HCC in patients with chronic HBV infection.
Cooperation or interaction of programmed cell death-1 (PD-1) and T cell immunoglobulin and mucin domain-containing molecule-3 (Tim-3) molecules is more relevant than either molecule alone to immune dysfunction in chronic viral infection and cancers. This study simultaneously investigated polymorphisms at PD1 +8669 and TIM3 -1516 loci in 845 hepatitis B virus (HBV) chronically infected patients [151 asymptomatic carriers, 202 chronic hepatitis, 221 cirrhosis and 271 hepatocellular carcinoma (HCC)], 141 HBV infection resolvers and 318 healthy controls. ⋯ The combined carriage of PD1 +8669 AA/TIM3 -1516 GT or TT was higher in cirrhosis and HCC pooled patients than in patients without cirrhosis (OR, 2.326; P=0.020) and in HCC patients than in cirrhosis patients (OR, 2.232; P=0.013). These data suggest that PD1 and TIM3 polymorphisms may differentially and interactively predispose cirrhosis and HCC in chronic HBV infection.
-
Infect. Genet. Evol. · Jul 2012
Molecular investigations of chikungunya virus during outbreaks in Orissa, Eastern India in 2010.
Chikungunya virus (CHIKV), an arthritogenic alphavirus, is transmitted to humans by mosquitoes of genus Aedes, mainly Aedes aegypti and Aedes albopictus. The resurgence of CHIKV in different parts of India is a point of major public health concern. In 2010, chikungunya outbreaks with high epidemic magnitude were recorded in coastal areas of Orissa, Eastern India, affecting more than 15,000 people coupled with severe arthralgia and prolonged morbidites. ⋯ Phylogenetic analysis revealed that the CHIKV strains involved in the outbreak belonged to the Indian Ocean Lineage (IOL) group within the East, Central and South African (ECSA) genotype. Genetic characterization of envelope glycoprotein (E1 and E2) genes revealed that all the CHIKV isolates from Orissa had the E1-A226V mutation that enhances viral dissemination and transmissibility by A. albopictus mosquitoes along with E2-L210Q and E2-I211T mutations, which play an epistatic role with E1-A226V mutation in adaptation of CHIKV to A. albopictus by increasing its midgut infectivity, thereby favoring its vectorial capacity. Our results showed the involvement of A. albopictus vector in the recent outbreaks in Orissa and circulation of IOL strains of ECSA genotype of CHIKV with E1-A226V, E2-L210Q and E2-I211T mutations in vectors and patients serum.
-
Infect. Genet. Evol. · Jun 2012
ReviewEmergence and treatment of multidrug resistant (MDR) and extensively drug-resistant (XDR) tuberculosis in South Africa.
Drug resistant tuberculosis (TB) has reached alarming proportions in South Africa, draining valuable resources that are needed to fight drug susceptible TB. It is currently estimated that 9.6% of all TB cases have multi-drug resistant (MDR)-TB, thereby ranking South Africa as one of the highest MDR-TB burden countries in the world. Molecular epidemiological studies have demonstrated the complexity of the epidemic and have clearly shown that the epidemic is driven by transmission as a consequence of low cases detection and diagnostic delay. ⋯ Failure to achieve cure may be explained from DNA sequencing results which have demonstrated mutations in 7 genes encoding resistance to at least 8 anti-TB drugs. This review shows how molecular epidemiology has provided novel insights into the MDR-TB epidemic in South Africa and thereby has highlighted the challenges that need to be addressed regarding the diagnosis and treatment of MDR-TB. An important step towards for curbing this epidemic will be collaboration between clinicians, laboratories and researchers to establish scientific knowledge and medical expertise to more efficiently guide public health policy.
-
Infect. Genet. Evol. · Dec 2011
Genetic polymorphism of interleukin-16 influences susceptibility to HBV-related hepatocellular carcinoma in a Chinese population.
Interleukin-16 (IL16) as a multifunctional cytokine, plays a key role in inflammatory and autoimmune diseases as well as tumour growth and progression. Recently, genetic polymorphisms of IL16 have been reported to be associated with susceptibility to a range of cancers. This study was undertaken to investigate the IL16 gene polymorphisms and determine whether these genetic factors are related to the occurrence of hepatocellular carcinoma (HCC) in a Chinese population. ⋯ This study showed that the genotypes and allele of IL16 SNPs were associated with chronic HBV infection and HCC. However, further investigation with a larger sample size and haplotype analysis with other SNPs may be required to validate the genetic effects of the IL16 polymorphisms on chronic HBV infection and HCC.
-
Infect. Genet. Evol. · Oct 2011
SARS-Coronavirus ancestor's foot-prints in South-East Asian bat colonies and the refuge theory.
One of the great challenges in the ecology of infectious diseases is to understand what drives the emergence of new pathogens including the relationship between viruses and their hosts. In the case of the emergence of SevereAcute Respiratory Syndrome Coronavirus (SARS-CoV), several studies have shown coronavirus diversity in bats as well as the existence of SARS-CoV infection in apparently healthy bats, suggesting that bats may be a crucial host in the genesis of this disease. To elucidate the biogeographic origin of SARS-CoV and investigate the role that bats played in its emergence, we amplified coronavirus sequences from bat species captured throughout Thailand and assessed the phylogenetic relationships to each other and to other published coronavirus sequences. ⋯ These findings illustrate the importance of the host phylogeny and the host/pathogen ecological interactions in the description and the understanding of pathogen emergence. The host's phylogeny, biogeography and behaviour, combined with already described roles of pathogen plasticity and anthropic changes are likely to be co-factors of disease emergence. Elucidating the common ancestor of Hipposideridae and Rhinolophidae is key to understanding the evolutionary history of actual betacoronaviruses and therefore to get an insight of the deep origin of SARS-CoV.