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  1. Ng LM, Sudesh K
    J Biosci Bioeng, 2016 Nov;122(5):550-557.
    PMID: 27132174 DOI: 10.1016/j.jbiosc.2016.03.024
    Aquitalea sp. USM4 (JCM 19919) was isolated from a freshwater sample at Lata Iskandar Waterfall in Perak, Malaysia. It is a rod-shaped, gram-negative bacterium with high sequence identity (99%) to Aquitalea magnusonii based on 16S rRNA gene analysis. Aquitalea sp. USM4 also possessed a PHA synthase gene (phaC), which had amino acid sequence identity of 77-78% to the PHA synthase of Chromobacterium violaceum ATCC12472 and Pseudogulbenkiania sp. NH8B. PHA biosynthesis results showed that wild-type Aquitalea sp. USM4 was able to accumulate up to 1.5 g/L of poly(3-hydroxybutyrate), [P(3HB)]. The heterologous expression of the PHA synthase gene of Aquitalea sp. USM4 (phaCAq) in Cupriavidus necator PHB(-)4 had resulted in PHA accumulation up to 3.2 g/L of P(3HB). It was further confirmed by (1)H nuclear magnetic resonance (NMR) analysis that Aquitalea sp. USM4 and C. necator PHB(-)4 transformant were able to produce PHA containing 3-hydroxyvalerate (3HV), 4-hydroxybutyrate (4HB) and 3-hydroxy-4-methylvalerate (3H4MV) monomers from suitable precursor substrates. Interestingly, relatively high PHA synthase activity of 863 U/g and 1402 U/g were determined in wild-type Aquitalea sp. USM4 and C. necator PHB(-)4 transformant respectively. This is the first report on the member of genus Aquitalea as a new PHA producer as well as in vitro and in vivo characterization of a novel PHA synthase from Aquitalea sp. USM4.
  2. Zain NA, Ng LM, Foong CP, Tai YT, Nanthini J, Sudesh K
    Curr Microbiol, 2020 Mar;77(3):500-508.
    PMID: 31893298 DOI: 10.1007/s00284-019-01852-z
    A novel polyhydroxyalkanoate (PHA)-producing bacterium, Jeongeupia sp. USM3 (JCM 19920) was isolated from the limestone soil at Gua Tempurung, Perak, Malaysia. This is the first report on the complete genome sequence for the genus Jeongeupia. This genome consists of a circular chromosome with a size of 3,788,814 bp and contains 3557 genes. Two PHA synthase (phaC) genes encoding for the key enzyme in the polymerization of PHA monomers and other PHA-associated genes were identified from the genome. Phylogenetic analysis of the PhaC protein sequences has revealed that both PhaC1 and PhaC2 of Jeongeupia sp. USM3 are categorized as Class I PHA synthases with 56% similarity to each other. Both of the PHA synthase genes of this isolate were cloned and heterologously expressed in a PHA mutant strain Cupriavidus necator PHB-4. The ability of the transformants to accumulate PHA showed that both PhaC1 and PhaC2 were functional.
  3. 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.
  4. Lim WY, Hss AS, Ng LM, John Jasudass SR, Sararaks S, Vengadasalam P, et al.
    BMC Fam Pract, 2018 07 19;19(1):120.
    PMID: 30025534 DOI: 10.1186/s12875-018-0808-4
    BACKGROUND: To evaluate the effectiveness of a structured prescription review and prescriber feedback program in reducing prescribing errors in government primary care clinics within an administrative region in Malaysia.

    METHODS: This was a three group, pragmatic, cluster randomised trial. In phase 1, we randomised 51 clinics to a full intervention group (prescription review and league tables plus authorised feedback letter), a partial intervention group (prescription review and league tables), and a control group (prescription review only). Prescribers in these clinics were the target of our intervention. Prescription reviews were performed by pharmacists; 20 handwritten prescriptions per prescriber were consecutively screened on a random day each month, and errors identified were recorded in a standardised data collection form. Prescribing performance feedback was conducted at the completion of each prescription review cycle. League tables benchmark prescribing errors across clinics and individual prescribers, while the authorised feedback letter detailed prescribing performance based on a rating scale. In phase 2, all clinics received the full intervention. Pharmacists were trained on data collection, and all data were audited by researchers as an implementation fidelity strategy. The primary outcome, percentage of prescriptions with at least one error, was displayed in p-charts to enable group comparison.

    RESULTS: A total of 32,200 prescriptions were reviewed. In the full intervention group, error reduction occurred gradually and was sustained throughout the 8-month study period. The process mean error rate of 40.7% (95% CI 27.4, 29.5%) in phase 1 reduced to 28.4% (95% CI 27.4, 29.5%) in phase 2. In the partial intervention group, error reduction was not well sustained and showed a seasonal pattern with larger process variability. The phase 1 error rate averaging 57.9% (95% CI 56.5, 59.3%) reduced to 44.8% (95% CI 43.3, 46.4%) in phase 2. There was no evidence of improvement in the control group, with phase 1 and phase 2 error rates averaging 41.1% (95% CI 39.6, 42.6%) and 39.3% (95% CI 37.8, 40.9%) respectively.

    CONCLUSIONS: The rate of prescribing errors in primary care settings is high, and routine prescriber feedback comprising league tables and a feedback letter can effectively reduce prescribing errors.

    TRIAL REGISTRATION: National Medical Research Register: NMRR-12-108-11,289 (5th March 2012).
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