Displaying all 4 publications

Abstract:
Sort:
  1. Tang SS, Carlin NI, Talukder KA, Cam PD, Verma NK
    BMC Microbiol, 2016 Jun 27;16(1):127.
    PMID: 27349637 DOI: 10.1186/s12866-016-0746-z
    BACKGROUND: Shigella spp. are the primary causative agents of bacillary dysentery. Since its emergence in the late 1980s, the S. flexneri serotype 1c remains poorly understood, particularly with regard to its origin and genetic evolution. This article provides a molecular insight into this novel serotype and the gtrIC gene cluster that determines its unique immune recognition.

    RESULTS: A PCR of the gtrIC cluster showed that serotype 1c isolates from different geographical origins were genetically conserved. An analysis of sequences flanking the gtrIC cluster revealed remnants of a prophage genome, in particular integrase and tRNA(Pro) genes. Meanwhile, Southern blot analyses on serotype 1c, 1a and 1b strains indicated that all the tested serotype 1c strains may have had a common origin that has since remained distinct from the closely related 1a and 1b serotypes. The identification of prophage genes upstream of the gtrIC cluster is consistent with the notion of bacteriophage-mediated integration of the gtrIC cluster into a pre-existing serotype.

    CONCLUSIONS: This is the first study to show that serotype 1c isolates from different geographical origins share an identical pattern of genetic arrangement, suggesting that serotype 1c strains may have originated from a single parental strain. Analysis of the sequence around the gtrIC cluster revealed a new site for the integration of the serotype converting phages of S. flexneri. Understanding the origin of new pathogenic serotypes and the molecular basis of serotype conversion in S. flexneri would provide information for developing cross-reactive Shigella vaccines.

    Matched MeSH terms: Multigene Family/genetics*
  2. Khosravi Y, Tay ST, Vadivelu J
    J Med Microbiol, 2011 Jul;60(Pt 7):988-994.
    PMID: 21436370 DOI: 10.1099/jmm.0.029868-0
    In this study, 90 non-replicate imipenem-resistant Pseudomonas aeruginosa (IRPA) Malaysian isolates collected between October 2005 and March 2008 were subjected to a screening test for detection of the integron and the gene cassette. Class 1 integrons were detected in 54 IRPA clinical isolates, whilst three isolates contained class 2 integrons. Analysis of the gene cassettes associated with the class 1 integrons showed the detection of accC1 in isolates carrying bla(IMP-7) and aacA7 in isolates carrying bla(VIM-2). aadA6 was detected in two isolates carrying bla(IMP-4). Using random amplification of polymorphic DNA analysis, 14 PCR fingerprint patterns were generated from the 32 isolates carrying metallo-β-lactamase (MBL) genes (35.5 %), whilst 20 patterns were generated from the 58 non-MBL gene isolates (64.4 %). Based on the differences in the fingerprinting patterns, two clusters (A and B) were identified among the MBL-producing isolates. Cluster A comprised 18 isolates (56 %) carrying the bla(VIM) gene, whereas cluster B comprised 14 (44 %) isolates carrying the bla(IMP) gene. The non-MBL isolates were divided into clusters C and D. Cluster C comprised 22 non-MBL isolates harbouring class 1 integrons, whilst cluster D consisted of three isolates carrying class 2 integrons. These findings suggest that the class 1 integron is widespread among P. aeruginosa isolated in Malaysia and that characterization of cassette arrays of integrons will be a useful epidemiological tool to study the evolution of multidrug resistance and the dissemination of antibiotic resistance genes.
    Matched MeSH terms: Multigene Family/genetics
  3. Hua ZS, Wang YL, Evans PN, Qu YN, Goh KM, Rao YZ, et al.
    Nat Commun, 2019 10 08;10(1):4574.
    PMID: 31594929 DOI: 10.1038/s41467-019-12574-y
    Several recent studies have shown the presence of genes for the key enzyme associated with archaeal methane/alkane metabolism, methyl-coenzyme M reductase (Mcr), in metagenome-assembled genomes (MAGs) divergent to existing archaeal lineages. Here, we study the mcr-containing archaeal MAGs from several hot springs, which reveal further expansion in the diversity of archaeal organisms performing methane/alkane metabolism. Significantly, an MAG basal to organisms from the phylum Thaumarchaeota that contains mcr genes, but not those for ammonia oxidation or aerobic metabolism, is identified. Together, our phylogenetic analyses and ancestral state reconstructions suggest a mostly vertical evolution of mcrABG genes among methanogens and methanotrophs, along with frequent horizontal gene transfer of mcr genes between alkanotrophs. Analysis of all mcr-containing archaeal MAGs/genomes suggests a hydrothermal origin for these microorganisms based on optimal growth temperature predictions. These results also suggest methane/alkane oxidation or methanogenesis at high temperature likely existed in a common archaeal ancestor.
    Matched MeSH terms: Multigene Family/genetics
  4. Harano K, Harano T
    Rinsho Byori, 2010 Apr;58(4):325-31.
    PMID: 20496759
    Hb and gene analyses of a Malaysian mother and her two daughters with microcytic anemia living in Japan were performed. Hb analyses of their hemolysates by IEF and DEAE-HPLC revealed high values of Hb A2 and HbF, but abnormal Hbs such as Hb E and Hb Constant Spring, which cause beta- and alpha-thalassemia traits, were not detected. From these data, they were suspected to be beta-thalassemia carriers. The thalassemic mutations commonly found in the Asian area by ARMS and nucleotide sequencing methods were not detected, and the frameworks of the beta-globin gene and the haplotypes of the beta-like globin gene cluster between the mother and daughters were not identical. These results led us to conclude that there was a beta(0)-thalassemia mutation with a large deletion from the beta-globin gene beyond the 3'beta/BamHI polymorphic site 3' downstream to the beta-globin gene. However, the range of the deletion from the beta-like globin gene cluster has not yet been completed in detail. Recently, there have been many foreigners mainly from Asian countries in Japan. We may encounter people with the rare type thalassemic mutation described in the text besides the mutations frequently found in Asian countries.
    Matched MeSH terms: Multigene Family/genetics
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links