Displaying publications 1 - 20 of 175 in total

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  1. Mining the genome of Bacillus velezensis FS26 for probiotic markers and secondary metabolites with antimicrobial properties against aquaculture pathogens
    Sam-On MFS, Mustafa S, Mohd Hashim A, Yusof MT, Zulkifly S, Malek AZA, et al.
    Microb Pathog, 2023 Aug;181:106161.
    PMID: 37207784 DOI: 10.1016/j.micpath.2023.106161
    Bacillus velezensis FS26 is a bacterium from the genus Bacillus that has been proven as a potential probiotic in aquaculture with a good antagonistic effect on Aeromonas spp. and Vibrio spp. Whole-genome sequencing (WGS) allows a comprehensive and in-depth analysis at the molecular level, and it is becoming an increasingly significant technique in aquaculture research. Although numerous probiotic genomes have been sequenced and investigated recently, there are minimal data on in silico analysis of B. velezensis as a probiotic bacterium isolated from aquaculture sources. Thus, this study aims to analyse the general genome characteristics and probiotic markers from the B. velezensis FS26 genome with secondary metabolites predicted against aquaculture pathogens. The B. velezensis FS26 genome (GenBank Accession: JAOPEO000000000) assembly proved to be of high quality, with eight contigs containing 3,926,371 bp and an average G + C content of 46.5%. According to antiSMASH analysis, five clusters of secondary metabolites from the B. velezensis FS26 genome showed 100% similarity. These clusters include Cluster 2 (bacilysin), Cluster 6 (bacillibactin), Cluster 7 (fengycin), Cluster 8 (bacillaene), and Cluster 9 (macrolactin H), which signify promising antibacterial, antifungal, and anticyanobacterial agents against pathogens in aquaculture. The probiotic markers of B. velezensis FS26 genome for adhesion capability in the hosts' intestine, as well as the acid and bile salt-tolerant genes, were also detected through the Prokaryotic Genome Annotation System (Prokka) annotation pipeline. These results are in agreement with our previous in vitro data, suggesting that the in silico investigation facilitates establishing B. velezensis FS26 as a beneficial probiotic for use in aquaculture.
    Matched MeSH terms: Genome, Bacterial
  2. Whole-Genome Sequencing of Pseudomonas koreensis Isolated from Diseased Tor tambroides
    Kho CJY, Lau MML, Chung HH, Chew IYY, Gan HM
    Curr Microbiol, 2023 Jun 25;80(8):255.
    PMID: 37356021 DOI: 10.1007/s00284-023-03354-5
    Unlike environmental P. koreensis isolated from soil, which has been studied extensively for its role in promoting plant growth, pathogenic P. koreensis isolated from fish has been rarely reported. Therefore, we investigated and isolated the possible pathogen that is responsible for the diseased state of Tor tambroides. Herein, we reported the morphological and biochemical characteristics, as well as whole-genome sequences of a newly identified P. koreensis strain. We assembled a high-quality draft genome of P. koreensis CM-01 with a contig N50 value of 233,601 bp and 99.5% BUSCO completeness. The genome assembly of P. koreensis CM-01 is consists of 6,171,880 bp with a G+C content of 60.5%. Annotation of the genome identified 5538 protein-coding genes, 3 rRNA genes, 54 tRNAs, and no plasmids were found. Besides these, 39 interspersed repeat and 141 tandem repeat sequences, 6 prophages, 51 genomic islands, 94 insertion sequences, 4 clustered regularly interspaced short palindromic repeats, 5 antibiotic-resistant genes, and 150 virulence genes were also predicted in the P. koreensis CM-01 genome. Culture-based approach showed that CM-01 strain exhibited resistance against ampicillin, aztreonam, clindamycin, and cefoxitin with a calculated multiple antibiotic resistance (MAR) index value of 0.4. In addition, the assembled CM-01 genome was successfully annotated against the Cluster of Orthologous Groups of proteins database, Gene Ontology database, and Kyoto Encyclopedia of Genes and Genome pathway database. A comparative analysis of CM-01 with three representative strains of P. koreensis revealed that 92% of orthologous clusters were conserved among these four genomes, and only the CM-01 strain possesses unique elements related to pathogenicity and virulence. This study provides fundamental phenotypic and genomic information for the newly identified P. koreensis strain.
    Matched MeSH terms: Genome, Bacterial
  3. Complete genome sequence of Aquitalea pelogenes USM4 (JCM19919), a polyhydroxyalkanoate producer
    Wan JH, Ng LM, Neoh SZ, Kajitani R, Itoh T, Kajiwara S, et al.
    Arch Microbiol, 2023 Jan 16;205(2):66.
    PMID: 36645481 DOI: 10.1007/s00203-023-03406-1
    Polyhydroxyalkanoate (PHA) is a type of biopolymer produced by most bacteria and archaea, resembling thermoplastic with biodegradability and biocompatibility features. Here, we report the complete genome of a PHA producer, Aquitalea sp. USM4, isolated from Perak, Malaysia. This bacterium possessed a 4.2 Mb circular chromosome and a 54,370 bp plasmid. A total of 4067 predicted protein-coding sequences, 87 tRNA genes, and 25 rRNA operons were identified using PGAP. Based on ANI and dDDH analysis, the Aquitalea sp. USM4 is highly similar to Aquitalea pelogenes. We also identified genes, including acetyl-CoA (phaA), acetoacetyl-CoA (phaB), PHA synthase (phaC), enoyl-CoA hydratase (phaJ), and phasin (phaP), which play an important role in PHA production in Aquitalea sp. USM4. The heterologous expression of phaC1 from Aquitalea sp. USM4 in Cupriavidus necator PHB-4 was able to incorporate six different types of PHA monomers, which are 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), 4-hydroxybutyrate (4HB), 5-hydroxyvalerate (5HV), 3-hydroxyhexanoate (3HHx) and isocaproic acid (3H4MV) with suitable precursor substrates. This is the first complete genome sequence of the genus Aquitalea among the 22 genome sequences from 4 Aquitalea species listed in the GOLD database, which provides an insight into its genome evolution and molecular machinery responsible for PHA biosynthesis.
    Matched MeSH terms: Genome, Bacterial*
  4. Fulltext The population genomic legacy of the second plague pandemic
    Gopalakrishnan S, Ebenesersdóttir SS, Lundstrøm IKC, Turner-Walker G, Moore KHS, Luisi P, et al.
    Curr Biol, 2022 Nov 07;32(21):4743-4751.e6.
    PMID: 36182700 DOI: 10.1016/j.cub.2022.09.023
    Human populations have been shaped by catastrophes that may have left long-lasting signatures in their genomes. One notable example is the second plague pandemic that entered Europe in ca. 1,347 CE and repeatedly returned for over 300 years, with typical village and town mortality estimated at 10%-40%.1 It is assumed that this high mortality affected the gene pools of these populations. First, local population crashes reduced genetic diversity. Second, a change in frequency is expected for sequence variants that may have affected survival or susceptibility to the etiologic agent (Yersinia pestis).2 Third, mass mortality might alter the local gene pools through its impact on subsequent migration patterns. We explored these factors using the Norwegian city of Trondheim as a model, by sequencing 54 genomes spanning three time periods: (1) prior to the plague striking Trondheim in 1,349 CE, (2) the 17th-19th century, and (3) the present. We find that the pandemic period shaped the gene pool by reducing long distance immigration, in particular from the British Isles, and inducing a bottleneck that reduced genetic diversity. Although we also observe an excess of large FST values at multiple loci in the genome, these are shaped by reference biases introduced by mapping our relatively low genome coverage degraded DNA to the reference genome. This implies that attempts to detect selection using ancient DNA (aDNA) datasets that vary by read length and depth of sequencing coverage may be particularly challenging until methods have been developed to account for the impact of differential reference bias on test statistics.
    Matched MeSH terms: Genome, Bacterial
  5. Fulltext International links between Streptococcus pneumoniae vaccine serotype 4 sequence type (ST) 801 in Northern European shipyard outbreaks of invasive pneumococcal disease
    Gladstone RA, Siira L, Brynildsrud OB, Vestrheim DF, Turner P, Clarke SC, et al.
    Vaccine, 2022 Feb 11;40(7):1054-1060.
    PMID: 34996643 DOI: 10.1016/j.vaccine.2021.10.046
    BACKGROUND: Pneumococcal disease outbreaks of vaccine preventable serotype 4 sequence type (ST)801 in shipyards have been reported in several countries. We aimed to use genomics to establish any international links between them.

    METHODS: Sequence data from ST801-related outbreak isolates from Norway (n = 17), Finland (n = 11) and Northern Ireland (n = 2) were combined with invasive pneumococcal disease surveillance from the respective countries, and ST801-related genomes from an international collection (n = 41 of > 40,000), totalling 106 genomes. Raw data were mapped and recombination excluded before phylogenetic dating.

    RESULTS: Outbreak isolates were relatively diverse, with up to 100 SNPs (single nucleotide polymorphisms) and a common ancestor estimated around the year 2000. However, 19 Norwegian and Finnish isolates were nearly indistinguishable (0-2 SNPs) with the common ancestor dated around 2017.

    CONCLUSION: The total diversity of ST801 within the outbreaks could not be explained by recent transmission alone, suggesting that harsh environmental and associated living conditions reported in the shipyards may facilitate invasion of colonising pneumococci. However, near identical strains in the Norwegian and Finnish outbreaks does suggest that transmission between international shipyards also contributed to those outbreaks. This indicates the need for improved preventative measures in this working population including pneumococcal vaccination.

    Matched MeSH terms: Genome, Bacterial
  6. Fulltext Limitation of nutrients stimulates musty odor production by Streptomyces sp. isolated from a tropical environment
    Shudirman S, Abang Kassim A, Shamsol Anuar NS, Utsumi M, Shimizu K, Muhammad Yuzir MA, et al.
    J Gen Appl Microbiol, 2021 Jul 31;67(3):92-99.
    PMID: 33642451 DOI: 10.2323/jgam.2020.08.001
    Musty odor production by actinomycetes is usually related to the presence of geosmin and 2-methylisoborneol (2-MIB), which are synthesized by enzymes encoded by the geoA and tpc genes, respectively. Streptomyces spp. strain S10, which was isolated from a water reservoir in Malaysia, has the ability to produce geosmin when cultivated in a basal salt (BS) solid medium, but no 2-MIB production occurred during growth in BS medium. Strain S10 could produce higher levels of geosmin when the phosphate concentration was limited to 0.05 mg/L, with a yield of 17.53 ± 3.12 ✕ 105 ng/L, compared with growth in BS medium. Interestingly, 2-MIB production was suddenly detected when the nitrate concentration was limited to 1.0 mg/L, with a yield of 1.4 ± 0.11 ✕ 105 ng/L. Therefore, it was concluded that phosphate- and nitrate-limiting conditions could induce the initial production of geosmin and 2-MIB by strain S10. Furthermore, a positive amplicon of geoA was detected in strain S10, but no tpc amplicon was detected by PCR analysis. Draft genome sequence analysis showed that one open reading frame (ORF) contained a conserved motif of geosmin synthase with 95% identity with geoA in Streptomyces coelicolor A3 (2). In the case of the tpc genes, it was found that one ORF showed 23% identity to the known tpc gene in S. coelicolor A3(2), but strain S10 lacked one motif in the N-terminus.
    Matched MeSH terms: Genome, Bacterial/genetics
  7. A stop-gain mutation in sigma factor SigH (MAB_3543c) may be associated with tigecycline resistance in Mycobacteroides abscessus
    Lee CL, Ng HF, Ngeow YF, Thaw Z
    J Med Microbiol, 2021 Jul;70(7).
    PMID: 34236301 DOI: 10.1099/jmm.0.001378
    Introduction. Tigecycline is currently acknowledged to be one of the most effective antibiotics against infections caused by Mycobacteroides abscessus.Gap statement. The genetic determinants of tigecycline resistance in M. abscessus are not well understood.Aim. In this study, we characterized a tigecycline-resistant M. abscessus mutant, designated CL7, to identify the potential resistance mechanism.Methodology. CL7 was characterized using antimicrobial susceptibility testing, whole-genome sequencing, PCR and RT-qPCR. For biological verification, gene overexpression assays were carried out.Results. Whole-genome sequencing and the subsequent gene overexpression assays showed that CL7 harboured a stop-gain mutation in MAB_3543 c, which may be responsible for the tigecycline resistance phenotype. This gene encodes an orthologue of SigH, which is involved in the positive regulation of physiological stress response and is negatively regulated by the RshA anti-sigma factor in Mycobacterium tuberculosis. We hypothesized that the MAB_3543 c mutation may disrupt the interaction between SigH and RshA (MAB_3542 c). RT-qPCR analyses revealed the upregulation of MAB_3543 c and other key stress response genes, which has previously been shown to be a hallmark of SigH-RshA bond disruption and tigecycline resistance.Conclusion. The MAB_3543c mutation may represent a novel determinant of tigecycline resistance in M. abscessus. The findings of this study will hopefully contribute to our knowledge of potential tigecycline resistance mechanisms in M. abscessus, which may lead to better diagnostics and treatment modalities in the future.
    Matched MeSH terms: Genome, Bacterial
  8. Genomic analysis revealing the resistance mechanisms of extended-spectrum β-lactamase-producing Klebsiella pneumoniae isolated from pig and humans in Malaysia
    Mobasseri G, Thong KL, Teh CSJ
    Int Microbiol, 2021 May;24(2):243-250.
    PMID: 33469786 DOI: 10.1007/s10123-021-00161-5
    Extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae has been associated with a wide range of infections in humans and animals. The objective of this study was to determine the genomic characteristics of two multiple drug resistant, ESBLs-producing K. pneumoniae strains isolated from a swine in 2013 (KP2013Z28) and a hospitalized patient in 2014 (KP2014C46) in Malaysia. Genomic analyses of the two K. pneumoniae strains indicated the presence of various antimicrobial resistance genes associated with resistance to β-lactams, aminoglycosides, colistin, fluoroquinolones, phenicols, tetracycline, sulfonamides, and trimethoprim, corresponding to the antimicrobial susceptibility profiles of the strains. KP2013Z28 (ST25) and KP2014C46 (ST929) harbored 5 and 2 genomic plasmids, respectively. The phylogenomics of these two Malaysian K. pneumoniae, with other 19 strains around the world was determined based on SNPs analysis. Overall, the strains were resolved into five clusters that comprised of strains with different resistance determinants. This study provided a better understanding of the resistance mechanisms and phylogenetic relatedness of the Malaysian strains with 19 strains isolated worldwide. This study also highlighted the needs to monitor the usage of antibiotics in hospital settings, animal husbandry, and agricultural practices due to the increase of β-lactam, aminoglycosides, tetracycline, and colistin resistance among pathogenic bacteria for better infection control.
    Matched MeSH terms: Genome, Bacterial
  9. Fulltext Genomic epidemiology of tuberculosis in eastern Malaysia: insights for strengthening public health responses
    Bainomugisa A, Meumann EM, Rajahram GS, Ong RT, Coin L, Paul DC, et al.
    Microb Genom, 2021 05;7(5).
    PMID: 33945455 DOI: 10.1099/mgen.0.000573
    Tuberculosis is a leading public health priority in eastern Malaysia. Knowledge of the genomic epidemiology of tuberculosis can help tailor public health interventions. Our aims were to determine tuberculosis genomic epidemiology and characterize resistance mutations in the ethnically diverse city of Kota Kinabalu, Sabah, located at the nexus of Malaysia, Indonesia, Philippines and Brunei. We used an archive of prospectively collected Mycobacterium tuberculosis samples paired with epidemiological data. We collected sputum and demographic data from consecutive consenting outpatients with pulmonary tuberculosis at the largest tuberculosis clinic from 2012 to 2014, and selected samples from tuberculosis inpatients from the tertiary referral centre during 2012-2014 and 2016-2017. Two hundred and eight M. tuberculosis sequences were available for analysis, representing 8 % of cases notified during the study periods. Whole-genome phylogenetic analysis demonstrated that most strains were lineage 1 (195/208, 93.8 %), with the remainder being lineages 2 (8/208, 3.8 %) or 4 (5/208, 2.4 %). Lineages or sub-lineages were not associated with patient ethnicity. The lineage 1 strains were diverse, with sub-lineage 1.2.1 being dominant (192, 98 %). Lineage 1.2.1.3 isolates were geographically most widely distributed. The greatest diversity occurred in a border town sub-district. The time to the most recent common ancestor for the three major lineage 1.2.1 clades was estimated to be the year 1966 (95 % HPD 1948-1976). An association was found between failure of culture conversion by week 8 of treatment and infection with lineage 2 (4/6, 67 %) compared with lineage 1 strains (4/83, 5 %) (P<0.001), supporting evidence of greater virulence of lineage 2 strains. Eleven potential transmission clusters (SNP difference ≤12) were identified; at least five included people living in different sub-districts. Some linked cases spanned the whole 4-year study period. One cluster involved a multidrug-resistant tuberculosis strain matching a drug-susceptible strain from 3 years earlier. Drug resistance mutations were uncommon, but revealed one phenotype-genotype mismatch in a genotypically multidrug-resistant isolate, and rare nonsense mutations within the katG gene in two isolates. Consistent with the regionally mobile population, M. tuberculosis strains in Kota Kinabalu were diverse, although several lineage 1 strains dominated and were locally well established. Transmission clusters - uncommonly identified, likely attributable to incomplete sampling - showed clustering occurring across the community, not confined to households or sub-districts. The findings indicate that public health priorities should include active case finding and early institution of tuberculosis management in mobile populations, while there is a need to upscale effective contact investigation beyond households to include other contacts within social networks.
    Matched MeSH terms: Genome, Bacterial
  10. Fulltext Characterization of multidrug-resistant Acinetobacter baumannii strain ATCC BAA1605 using whole-genome sequencing
    Ten KE, Md Zoqratt MZH, Ayub Q, Tan HS
    BMC Res Notes, 2021 Mar 04;14(1):83.
    PMID: 33663564 DOI: 10.1186/s13104-021-05493-z
    OBJECTIVE: The nosocomial pathogen, Acinetobacter baumannii, has acquired clinical significance due to its ability to persist in hospital settings and survive antibiotic treatment, which eventually resulted in the rapid spread of this bacterium with antimicrobial resistance (AMR) phenotypes. This study used a multidrug-resistant A. baumannii (strain ATCC BAA1605) as a model to study the genomic features of this pathogen.

    RESULTS: One circular chromosome and one circular plasmid were discovered in the complete genome of A. baumannii ATCC BAA1605 using whole-genome sequencing. The chromosome is 4,039,171 bp long with a GC content of 39.24%. Many AMR genes, which confer resistance to major classes of antibiotics (beta-lactams, aminoglycosides, tetracycline, sulphonamides), were found on the chromosome. Two genomic islands were predicted on the chromosome, one of which (Genomic Island 1) contains a cluster of AMR genes and mobile elements, suggesting the possibility of horizontal gene transfer. A subtype I-F CRISPR-Cas system was also identified on the chromosome of A. baumannii ATCC BAA1605. This study provides valuable genome data that can be used as a reference for future studies on A. baumannii. The genome of A. baumannii ATCC BAA1605 has been deposited at GenBank under accession no. CP058625 and CP058626.

    Matched MeSH terms: Genome, Bacterial/genetics
  11. Whole genome strategies and bioremediation insight into dehalogenase-producing bacteria
    Oyewusi HA, Wahab RA, Huyop F
    Mol Biol Rep, 2021 Mar;48(3):2687-2701.
    PMID: 33650078 DOI: 10.1007/s11033-021-06239-7
    An integral approach to decoding both culturable and uncultured microorganisms' metabolic activity involves the whole genome sequencing (WGS) of individual/complex microbial communities. WGS of culturable microbes, amplicon sequencing, metagenomics, and single-cell genome analysis are selective techniques integrating genetic information and biochemical mechanisms. These approaches transform microbial biotechnology into a quick and high-throughput culture-independent evaluation and exploit pollutant-degrading microbes. They are windows into enzyme regulatory bioremediation pathways (i.e., dehalogenase) and the complete bioremediation process of organohalide pollutants. While the genome sequencing technique is gaining the scientific community's interest, it is still in its infancy in the field of pollutant bioremediation. The techniques are becoming increasingly helpful in unraveling and predicting the enzyme structure and explore metabolic and biodegradation capabilities.
    Matched MeSH terms: Genome, Bacterial
  12. Fulltext Genome sequence of an uncharted halophilic bacterium Robertkochia marina with deciphering its phosphate-solubilizing ability
    Lam MQ, Chen SJ, Goh KM, Abd Manan F, Yahya A, Shamsir MS, et al.
    Braz J Microbiol, 2021 Mar;52(1):251-256.
    PMID: 33141351 DOI: 10.1007/s42770-020-00401-2
    The wide use of whole-genome sequencing approach in the modern genomic era has opened a great opportunity to reveal the prospective applications of halophilic bacteria. Robertkochia marina CC-AMO-30DT is one of the halophilic bacteria that was previously taxonomically identified without any inspection on its biotechnological potential from a genomic aspect. In this study, we present the whole-genome sequence of R. marina and demonstrated the ability of this bacterium in solubilizing phosphate by producing phosphatase. The genome of R. marina has 3.57 Mbp and contains 3107 predicted genes, from which 3044 are protein coding, 52 are non-coding RNAs, and 11 are pseudogenes. Several phosphatases such as alkaline phosphatases and pyrophosphatases were mined from the genome. Further genomic study (phylogenetics, sequence analysis, and functional mechanism) and experimental data suggested that the alkaline phosphatase produced by R. marina could potentially be utilized in promoting plant growth, particularly for plants on saline-based agricultural land.
    Matched MeSH terms: Genome, Bacterial*
  13. Fulltext Whole-genome comparative analysis of Malaysian Burkholderia pseudomallei clinical isolates
    Ghazali AK, Eng SA, Khoo JS, Teoh S, Hoh CC, Nathan S
    Microb Genom, 2021 02;7(2).
    PMID: 33565959 DOI: 10.1099/mgen.0.000527
    Burkholderia pseudomallei, a soil-dwelling Gram-negative bacterium, is the causative agent of the endemic tropical disease melioidosis. Clinical manifestations of B. pseudomallei infection range from acute or chronic localized infection in a single organ to fulminant septicaemia in multiple organs. The diverse clinical manifestations are attributed to various factors, including the genome plasticity across B. pseudomallei strains. We previously characterized B. pseudomallei strains isolated in Malaysia and noted different levels of virulence in model hosts. We hypothesized that the difference in virulence might be a result of variance at the genome level. In this study, we sequenced and assembled four Malaysian clinical B. pseudomallei isolates, UKMR15, UKMPMC2000, UKMD286 and UKMH10. Phylogenomic analysis showed that Malaysian subclades emerged from the Asian subclade, suggesting that the Malaysian strains originated from the Asian region. Interestingly, the low-virulence strain, UKMH10, was the most distantly related compared to the other Malaysian isolates. Genomic island (GI) prediction analysis identified a new island of 23 kb, GI9c, which is present in B. pseudomallei and Burkholderia mallei, but not Burkholderia thailandensis. Genes encoding known B. pseudomallei virulence factors were present across all four genomes, but comparative analysis of the total gene content across the Malaysian strains identified 104 genes that are absent in UKMH10. We propose that these genes may encode novel virulence factors, which may explain the reduced virulence of this strain. Further investigation on the identity and role of these 104 proteins may aid in understanding B. pseudomallei pathogenicity to guide the design of new therapeutics for treating melioidosis.
    Matched MeSH terms: Genome, Bacterial
  14. Fulltext Metabolic potential of the moderate halophile Yangia sp. ND199 for co-production of polyhydroxyalkanoates and exopolysaccharides
    Romero Soto L, Thabet H, Maghembe R, Gameiro D, Van-Thuoc D, Dishisha T, et al.
    Microbiologyopen, 2021 01;10(1):e1160.
    PMID: 33650793 DOI: 10.1002/mbo3.1160
    Yangia sp. ND199 is a moderately halophilic bacterium isolated from mangrove samples in Northern Vietnam, which was earlier reported to grow on several sugars and glycerol to accumulate poly(hydroxyalkanoates) (PHA). In this study, the potential of the bacterium for co-production of exopolysaccharides (EPS) and PHA was investigated. Genome sequence analysis of the closely related Yangia sp. CCB-M3 isolated from mangroves in Malaysia revealed genes encoding enzymes participating in different EPS biosynthetic pathways. The effects of various cultivation parameters on the production of EPS and PHA were studied. The highest level of EPS (288 mg/L) was achieved using sucrose and yeast extract with 5% NaCl and 120 mM phosphate salts but with modest PHA accumulation (32% of cell dry weight, 1.3 g/L). Growth on fructose yielded the highest PHA concentration (85% of CDW, 3.3 g/L) at 90 mM phosphate and higher molecular weight EPS at 251 mg/L yield at 120 mM phosphate concentration. Analysis of EPS showed a predominance of glucose, followed by fructose and galactose, and minor amounts of acidic sugars.
    Matched MeSH terms: Genome, Bacterial/genetics
  15. Fulltext Statistical Optimisation of Phenol Degradation and Pathway Identification through Whole Genome Sequencing of the Cold-Adapted Antarctic Bacterium, Rhodococcus sp. Strain AQ5-07
    Lee GLY, Zakaria NN, Convey P, Futamata H, Zulkharnain A, Suzuki K, et al.
    Int J Mol Sci, 2020 Dec 09;21(24).
    PMID: 33316871 DOI: 10.3390/ijms21249363
    Study of the potential of Antarctic microorganisms for use in bioremediation is of increasing interest due to their adaptations to harsh environmental conditions and their metabolic potential in removing a wide variety of organic pollutants at low temperature. In this study, the psychrotolerant bacterium Rhodococcus sp. strain AQ5-07, originally isolated from soil from King George Island (South Shetland Islands, maritime Antarctic), was found to be capable of utilizing phenol as sole carbon and energy source. The bacterium achieved 92.91% degradation of 0.5 g/L phenol under conditions predicted by response surface methodology (RSM) within 84 h at 14.8 °C, pH 7.05, and 0.41 g/L ammonium sulphate. The assembled draft genome sequence (6.75 Mbp) of strain AQ5-07 was obtained through whole genome sequencing (WGS) using the Illumina Hiseq platform. The genome analysis identified a complete gene cluster containing catA, catB, catC, catR, pheR, pheA2, and pheA1. The genome harbours the complete enzyme systems required for phenol and catechol degradation while suggesting phenol degradation occurs via the β-ketoadipate pathway. Enzymatic assay using cell-free crude extract revealed catechol 1,2-dioxygenase activity while no catechol 2,3-dioxygenase activity was detected, supporting this suggestion. The genomic sequence data provide information on gene candidates responsible for phenol and catechol degradation by indigenous Antarctic bacteria and contribute to knowledge of microbial aromatic metabolism and genetic biodiversity in Antarctica.
    Matched MeSH terms: Genome, Bacterial*
  16. Fulltext Comparative genome analyses of Mycobacteroides immunogenum reveals two potential novel subspecies
    Choo SW, Rishik S, Wee WY
    Microb Genom, 2020 12;6(12).
    PMID: 33295861 DOI: 10.1099/mgen.0.000495
    Mycobacteroides immunogenum is an emerging opportunistic pathogen implicated in nosocomial infections. Comparative genome analyses may provide better insights into its genomic structure, functions and evolution. The present analysis showed that M. immunogenum has an open pan-genome. Approximately 36.8% of putative virulence genes were identified in the accessory regions of M. immunogenum. Phylogenetic analyses revealed two potential novel subspecies of M. immunogenum, supported by evidence from ANIb (average nucleotide identity using blast) and GGDC (Genome to Genome Distance Calculator) analyses. We identified 74 genomic islands (GIs) in Subspecies 1 and 23 GIs in Subspecies 2. All Subspecies 2-harboured GIs were not found in Subspecies 1, indicating that they might have been acquired by Subspecies 2 after their divergence. Subspecies 2 has more defence genes than Subspecies 1, suggesting that it might be more resistant to the insertion of foreign DNA and probably explaining why Subspecies 2 has fewer GIs. Positive selection analysis suggest that M. immunogenum has a lower selection pressure compared to non-pathogenic mycobacteria. Thirteen genes were positively selected and many were involved in virulence.
    Matched MeSH terms: Genome, Bacterial
  17. Draft genome sequence of Parvularcula flava strain NH6-79 T, revealing its role as a cellulolytic enzymes producer
    Abdul Karim MH, Lam MQ, Chen SJ, Yahya A, Shahir S, Shamsir MS, et al.
    Arch Microbiol, 2020 Nov;202(9):2591-2597.
    PMID: 32607725 DOI: 10.1007/s00203-020-01967-z
    To date, the genus Parvularcula consists of 6 species and no potential application of this genus was reported. Current study presents the genome sequence of Parvularcula flava strain NH6-79 T and its cellulolytic enzyme analysis. The assembled draft genome of strain NH6-79 T consists of 9 contigs and 7 scaffolds with 3.68 Mbp in size and GC content of 59.87%. From a total of 3,465 genes predicted, 96 of them are annotated as glycoside hydrolases (GHs). Within these GHs, 20 encoded genes are related to cellulosic biomass degradation, including 12 endoglucanases (5 GH10, 4 GH5, and 3 GH51), 2 exoglucanases (GH9) and 6 β-glucosidases (GH3). In addition, highest relative enzyme activities (endoglucanase, exoglucanase, and β-glucosidase) were observed at 27th hour when the strain was cultured in the carboxymethyl cellulose/Avicel®-containing medium for 45 h. The combination of genome analysis with experimental studies indicated the ability of strain NH6-79 T to produce extracellular endoglucanase, exoglucanase, and β-glucosidase. These findings suggest the potential of Parvularcula flava strain NH6-79 T in cellulose-containing biomass degradation and that the strain could be used in cellulosic biorefining process.
    Matched MeSH terms: Genome, Bacterial/genetics*
  18. Fulltext Analysis of Salmonella enterica serovar Enteritidis isolates from chickens and chicken meat products in Malaysia using PFGE, and MLST
    Zakaria Z, Hassan L, Sharif Z, Ahmad N, Ali RM, Husin SA, et al.
    BMC Vet Res, 2020 Oct 17;16(1):393.
    PMID: 33069231 DOI: 10.1186/s12917-020-02605-y
    BACKGROUND: Salmonella is a very important foodborne pathogen causing illness in humans. The emergence of drug-resistant strains also constitutes a serious worry to global health and livestock productivity. This study investigated Salmonella isolates from chicken and chicken meat products using the phenotypic antimicrobial screening as well as the molecular characteristics of Salmonella isolates. Upon serotyping of the isolates, the antimicrobial susceptibility profiling using a panel of 9 commonly used antimicrobials was done. Subsequently, the molecular profiles of all the isolates were further determined using Pulsed Field Gel Electrophoresis (PFGE) and the Whole Genome Multi-Locus Sequence Type (wgMLST) analysis in order to obtain the sequence types.

    RESULTS: The PFGE data was input into FPQuest software, and the dendrogram generated was studied for possible genetic relatedness among the isolates. All the isolates were found to belong to the Salmonella Enteritidis serotype with notable resistance to tetracycline, gentamycin, streptomycin, and sulfadimidine. The S. Enteritidis isolates tested predominantly subtyped into the ST11 and ST1925, which was found to be a single cell variant of ST11. The STs were found to occur in chicken meats, foods, and live chicken cloacal swabs, which may indicate the persistence of the bacteria in multiple foci.

    CONCLUSION: The data demonstrate the presence of S. Enteritidis among chickens, indicating its preference and reservoir status for enteric Salmonella pathogens.

    Matched MeSH terms: Genome, Bacterial
  19. Genome Mining Reveals the Biosynthetic Pathways of Polyhydroxyalkanoate and Ectoines of the Halophilic Strain Salinivibrio proteolyticus M318 Isolated from Fermented Shrimp Paste
    Van Thuoc D, Loan TT, Trung TA, Van Quyen N, Tung QN, Tien PQ, et al.
    Mar Biotechnol (NY), 2020 Oct;22(5):651-660.
    PMID: 32827070 DOI: 10.1007/s10126-020-09986-z
    Salinivibrio proteolyticus M318, a halophilic bacterium isolated from fermented shrimp paste, is able to produce polyhydroxyalkanoate (PHA) from different carbon sources. In this study, we report the whole-genome sequence of strain M138, which comprises 2 separated chromosomes and 2 plasmids, and the complete genome contains 3,605,935 bp with an average GC content of 49.9%. The genome of strain M318 contains 3341 genes, 98 tRNA genes, and 28 rRNA genes. The 16S rRNA gene sequence and average nucleotide identity analysis associated with morphological and biochemical tests showed that this strain has high homology to the reference strain Salinivibrio proteolyticus DSM 8285. The genes encoding key enzymes for PHA and ectoine synthesis were identified from the bacterial genome. In addition, the TeaABC transporter responsible for ectoine uptake from the environment and the operon doeABXCD responsible for the degradation of ectoine were also detected. Strain M318 was able to produce poly(3-hydroxybutyrate) [P(3HB)] from different carbon sources such as glycerol, maltose, glucose, fructose, and starch. The ability to produce ectoines at different NaCl concentrations was investigated. High ectoine content of 26.2% of cell dry weight was obtained by this strain at 18% NaCl. This report provides genetic information regarding adaptive mechanisms of strain M318 to stress conditions, as well as new knowledge to facilitate the application of this strain as a bacterial cell factory for the production of PHA and ectoine.
    Matched MeSH terms: Genome, Bacterial/genetics
  20. Fulltext A novel strain of acetic acid bacteria Gluconobacter oxydans FBFS97 involved in riboflavin production
    Noman AE, Al-Barha NS, Sharaf AM, Al-Maqtari QA, Mohedein A, Mohammed HHH, et al.
    Sci Rep, 2020 08 11;10(1):13527.
    PMID: 32782276 DOI: 10.1038/s41598-020-70404-4
    A novel bacterial strain of acetic acid bacteria capable of producing riboflavin was isolated from the soil sample collected in Wuhan, China. The isolated strain was identified as Gluconobacter oxydans FBFS97 based on several phenotype characteristics, biochemicals tests, and 16S rRNA gene sequence conducted. Furthermore, the complete genome sequencing of the isolated strain has showed that it contains a complete operon for the biosynthesis of riboflavin. In order to obtain the maximum concentration of riboflavin production, Gluconobacter oxydans FBFS97 was optimized in shake flask cultures through response surface methodology employing Plackett-Burman design (PBD), and Central composite design (CCD). The results of the pre-experiments displayed that fructose and tryptone were found to be the most suitable sources of carbon and nitrogen for riboflavin production. Then, PBD was conducted for initial screening of eleven minerals (FeSO4, FeCl3, KH2PO4, K2HPO4, MgSO4, ZnSO4, NaCl, CaCl2, KCl, ZnCl2, and AlCl3.6H2O) for their significances on riboflavin production by Gluconobacter oxydans strain FBFS97. The most significant variables affecting on riboflavin production are K2HPO4 and CaCl2, the interaction affects and levels of these variables were optimized by CCD. After optimization of the medium compositions for riboflavin production were determined as follows: fructose 25 g/L, tryptone 12.5 g/L, K2HPO4 9 g/L, and CaCl2 0.06 g/L with maximum riboflavin production 23.24 mg/L.
    Matched MeSH terms: Genome, Bacterial
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