Simultaneous detection of variable number tandem repeats, single nucleotide polymorphisms, and allelic imbalance in the thymidylate synthase gene enhancer region using denaturing high-performance liquid chromatography

In 2011, in Bangladesh, 11 anthrax outbreaks occurred in six districts of the country. Different types of samples were collected from May to September in the six districts where anthrax had occurred in order to detect and type Bacillus anthracis (B. anthracis) strains. Anthrax was detected in 46.6% of the samples analysed, in particular in soils, but also in bone samples, water, animal feed, and rumen ingesta of dead animals. Canonical single nucleotide polymorphisms (CanSNPs) analysis showed that all the isolates belonged to the major lineage A, sublineage A.Br.001/002 of China and Southeast Asia while the multi-locus variable number of tandem repeats (VNTRs) analysis (MLVA) with 15 VNTRs demonstrated the presence of five genotypes, of which two resulted to be new genotypes. The single nucleotide repeats (SNRs) analysis showed 13 SNR types; nevertheless, due to its higher discriminatory power, the presence of two isolates with different SNR-type polymorphisms was detected within two MLVA genotypes. This study assumes that soil is not the only reason for the spread of the disease in Bangladesh; contaminated feed and water can also play an important role in the epidemiology of anthrax. Possible explanations for these epidemiological relationships are discussed.

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Molecular characteristics of Brucella melitensis isolates from humans in Qinghai Province, China

Infectious Diseases of Poverty ◽

10.1186/s40249-021-00829-0 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Zhi-Jun Zhao ◽

Ji-Quan Li ◽

Li Ma ◽

Hong-Mei Xue ◽

Xu-Xin Yang ◽

...

Keyword(s):

Tandem Repeats ◽

Brucella Melitensis ◽

Draft Genome ◽

Geographic Origin ◽

Variable Number ◽

Human Brucellosis ◽

Molecular Characteristics ◽

Whole Genome ◽

Qinghai Province ◽

Variable Number Tandem Repeats

Abstract Background The prevalence of human brucellosis in Qinghai Province of China has been increasing rapidly, with confirmed cases distributed across 31 counties. However, the epidemiology of brucellosis transmission has not been fully elucidated. To characterize the infecting strains isolated from humans, multiple-locus variable-number tandem repeats analysis (MLVA) and whole-genome single-nucleotide polymorphism (SNP)-based approaches were employed. Methods Strains were isolated from two males blood cultures that were confirmed Brucella melitensis positive following biotyping and MLVA. Genomic DNA was extracted from these two strains, and whole-genome sequencing was performed. Next, SNP-based phylogenetic analysis was performed to compare the two strains to 94 B. melitensis strains (complete genome and draft genome) retrieved from online databases. Results The two Brucella isolates were identified as B. melitensis biovar 3 (QH2019001 and QH2019005) following conventional biotyping and were found to have differences in their variable number tandem repeats (VNTRs) using MLVA-16. Phylogenetic examination assigned the 96 strains to five genotype groups, with QH2019001 and QH2019005 assigned to the same group, but different subgroups. Moreover, the QH2019005 strain was assigned to a new subgenotype, IIj, within genotype II. These findings were then combined to determine the geographic origin of the two Brucella strains. Conclusions Utilizing a whole-genome SNP-based approach enabled differences between the two B. melitensis strains to be more clearly resolved, and facilitated the elucidation of their different evolutionary histories. This approach also revealed that QH2019005 is a member of a new subgenotype (IIj) with an ancient origin in the eastern Mediterranean Sea.

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Effect of P450 Oxidoreductase Polymorphisms on the Metabolic Activities of Ten Cytochrome P450s Varied by Polymorphic CYP Genotypes in Human Liver Microsomes

Cellular Physiology and Biochemistry ◽

10.1159/000490934 ◽

2018 ◽

Vol 47 (4) ◽

pp. 1604-1616 ◽

Cited By ~ 8

Author(s):

Yan Fang ◽

Na Gao ◽

Xin Tian ◽

Jun Zhou ◽

Hai-Feng Zhang ◽

...

Keyword(s):

Gene Polymorphisms ◽

High Performance ◽

Liver Microsomes ◽

Nucleotide Polymorphisms ◽

Liquid Chromatograph ◽

Single Nucleotide ◽

P450 Oxidoreductase ◽

Human Livers ◽

Metabolic Activities ◽

The Impact

Background/ Aims: Little is known about the effect of P450 oxidoreductase (POR) gene polymorphisms on the activities of CYPs with multiple genotypes. Methods: We genotyped 102 human livers for 18 known POR single nucleotide polymorphisms (SNPs) with allelic frequencies greater than 1% as well as for 27 known SNPs in 10 CYPs. CYP enzyme activities in microsomes prepared from these livers were determined by measuring probe substrate metabolism by high performance liquid chromatograph. Results: We found that the effects of the 18 POR SNPs on 10 CYP activities were CYP genotype-dependent. The POR mutations were significantly associated with decreased overall Km for CYP2B6 and 2E1, and specific genotypes within CYP1A2, 2A6, 2B6, 2C8, 2D6 and 2E1 were identified as being affected by these POR SNPs. Notably, the effect of a specific POR mutation on the activity of a CYP genotype could not be predicted from other CYP genotypes of even the same CYP. When combining one POR SNP with other POR SNPs, a hitherto unrecognized effect of multiple-site POR gene polymorphisms (MSGP) on CYP activity was uncovered, which was not necessarily consistent with the effect of either single POR SNP. Conclusions: The effects of POR SNPs on CYP activities were not only CYP-dependent, but more importantly, CYP genotype-dependent. Moreover, the effect of a POR SNP alone and in combination with other POR SNPs (MSGP) was not always consistent, nor predictable. Understanding the impact of POR gene polymorphisms on drug metabolism necessitates knowing the complete SNP complement of POR and the genotype of the relevant CYPs.

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Slipped-Strand Mispairing at Noncontiguous Repeats in Poecilia reticulata: A Model for Minisatellite Birth

Genetics ◽

10.1093/genetics/155.3.1313 ◽

2000 ◽

Vol 155 (3) ◽

pp. 1313-1320 ◽

Cited By ~ 2

Author(s):

John S Taylor ◽

Felix Breden

Keyword(s):

Tandem Repeat ◽

Poecilia Reticulata ◽

Tandem Repeats ◽

Phylogenetic Reconstruction ◽

Variable Number ◽

Repeat Motif ◽

Raw Material ◽

Direct Repeats ◽

Mt Dna ◽

Variable Number Tandem Repeats

Abstract The standard slipped-strand mispairing (SSM) model for the formation of variable number tandem repeats (VNTRs) proposes that a few tandem repeats, produced by chance mutations, provide the “raw material” for VNTR expansion. However, this model is unlikely to explain the formation of VNTRs with long motifs (e.g., minisatellites), because the likelihood of a tandem repeat forming by chance decreases rapidly as the length of the repeat motif increases. Phylogenetic reconstruction of the birth of a mitochondrial (mt) DNA minisatellite in guppies suggests that VNTRs with long motifs can form as a consequence of SSM at noncontiguous repeats. VNTRs formed in this manner have motifs longer than the noncontiguous repeat originally formed by chance and are flanked by one unit of the original, noncontiguous repeat. SSM at noncontiguous repeats can therefore explain the birth of VNTRs with long motifs and the “imperfect” or “short direct” repeats frequently observed adjacent to both mtDNA and nuclear VNTRs.

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