Common variants in CLDN2 and MORC4 genes confer disease susceptibility in patients with chronic pancreatitis

A recent Genome-wide Association Study (GWAS) identified association with variants in X-linked CLDN2 and MORC4 and PRSS1-PRSS2 loci with Chronic Pancreatitis (CP) in North American patients of European ancestry. We selected 9 variants from the reported GWAS and replicated the association with CP in Indian patients by genotyping 1807 unrelated Indians of Indo-European ethnicity, including 519 patients with CP and 1288 controls. The etiology of CP was idiopathic in 83.62% and alcoholic in 16.38% of 519 patients. Our study confirmed a significant association of 2 variants in CLDN2 gene (rs4409525—OR 1.71, P = 1.38 x 10-09; rs12008279—OR 1.56, P = 1.53 x 10-04) and 2 variants in MORC4 gene (rs12688220—OR 1.72, P = 9.20 x 10-09; rs6622126—OR 1.75, P = 4.04x10-05) in Indian patients with CP. We also found significant association at PRSS1-PRSS2 locus (OR 0.60; P = 9.92 x 10-06) and SAMD12-TNFRSF11B (OR 0.49, 95% CI [0.31–0.78], P = 0.0027). A variant in the gene MORC4 (rs12688220) showed significant interaction with alcohol (OR for homozygous and heterozygous risk allele -14.62 and 1.51 respectively, P = 0.0068) suggesting gene-environment interaction. A combined analysis of the genes CLDN2 and MORC4 based on an effective risk allele score revealed a higher percentage of individuals homozygous for the risk allele in CP cases with 5.09 fold enhanced risk in individuals with 7 or more effective risk alleles compared with individuals with 3 or less risk alleles (P = 1.88 x 10-14). Genetic variants in CLDN2 and MORC4 genes were associated with CP in Indian patients

Cloning and Characterization of lin Genes Responsible for the Degradation of Hexachlorocyclohexane Isomers by Sphingomonas paucimobilis Strain B90

Hexachlorocyclohexane (HCH) has been used extensively against agricultural pests and in public health programs for the control of mosquitoes. Commercial formulations of HCH consist of a mixture of four isomers, α, β, γ, and δ. While all these isomers pose serious environmental problems, β-HCH is more problematic due to its longer persistence in the environment. We have studied the degradation of HCH isomers by Sphingomonas paucimobilis strain B90 and characterized the lin genes encoding enzymes from strain B90 responsible for the degradation of HCH isomers. Two nonidentical copies of the linA gene encoding HCH dehydrochlorinase, which were designated linA1 and linA2, were found in S. paucimobilis B90. The linA1 and linA2 genes could be expressed in Escherichia coli, leading to dehydrochlorination of α-, γ-, and δ-HCH but not of β-HCH, suggesting that S. paucimobilis B90 contains another pathway for the initial steps of β-HCH degradation. The cloning and characterization of the halidohydrolase (linB), dehydrogenase (linC and linX), and reductive dechlorinase (linD) genes from S. paucimobilis B90 revealed that they share ∼96 to 99% identical nucleotides with the corresponding genes of S. paucimobilis UT26. No evidence was found for the presence of a linE-like gene, coding for a ring cleavage dioxygenase, in strain B90. The gene structures around the linA1 and linA2 genes of strain B90, compared to those in strain UT26, are suggestive of a recombination between linA1 and linA2, which formed linA of strain UT26

Hexachlorocyclohexane-degrading bacterial strains Sphingomonas paucimobilis B90A, UT26 and Sp+, having similar lin genes, represent three distinct species, Sphingobium indicum sp. nov., Sphingobium japonicum sp. nov. and Sphingobium francense sp. nov., and reclassification of [Sphingomonas] chungbukensis as Sphingobium chungbukense comb. nov.

Three strains of Sphingomonas paucimobilis, B90A, UT26 and Sp+, isolated from different geographical locations, were found to degrade hexachlorocyclohexane. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these strains do not fall in a clade that includes the type strain, Sphingomonas paucimobilis ATCC 29837T, but form a coherent cluster with [Sphingomonas] chungbukensis IMSNU 11152T followed by Sphingobium chlorophenolicum ATCC 33790T. The three strains showed low DNA–DNA relatedness values with Sphingomonas paucimobilis ATCC 29837T (8–25 %), [Sphingomonas] chungbukensis IMSNU 11152T (10–17 %), Sphingobium chlorophenolicum ATCC 33790T (23–54 %) and Sphingomonas xenophaga DSM 6383T (10–28 %), indicating that they do not belong to any of these species. Although the three strains were found to be closely related to each other based on 16S rRNA gene sequence similarity (99·1–99·4 %), DNA–DNA relatedness (19–59 %) and pulsed-field gel electrophoresis (PFGE) patterns indicated that they possibly represent three novel species of the genus Sphingobium. The three strains could also be readily distinguished by biochemical tests. The three strains showed similar polar lipid profiles and contained sphingoglycolipids. The strains differed from each other in fatty acid composition but contained the predominant fatty acids characteristic of other Sphingobium species. A phylogenetic study based on 16S rRNA gene sequences showed that [Sphingomonas] chungbukensis IMSNU 11152T formed a cluster with members of the genus Sphingobium. Based on these results, it is proposed that strains B90A, UT26 and Sp+, previously known as Sphingomonas paucimobilis, are the type strains of Sphingobium indicum sp. nov. (=MTCC 6364T=CCM 7286T), Sphingobium japonicum sp. nov. (=MTCC 6362T=CCM 7287T) and Sphingobium francense sp. nov. (=MTCC 6363T=CCM 7288T), respectively. It is also proposed that [Sphingomonas] chungbukensis be transferred to Sphingobium chungbukense comb. nov