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Detection of leptospira species in environmental samples by amplification of 16s rrna and rpoβ genes

Mohd Nasir Mohd Desa

Sains Malaysiana, 2018;47:1795-1800.

This study attempted to identify and determine distribution of Leptospira spp. in environmental samples using 16S
rRNA and rpoβ genes amplification. The samples were collected from high risk areas in Selangor, Malaysia. A total of
105 environmental samples consisting of soil and water were subjected to direct DNA extraction and PCR reaction. PCR
products were analysed using gel electrophoresis and subjected to sequence analysis. Thirteen out of 105 (12.38%)
samples were amplified for 16S rRNA with an expected amplicon size of 330 bp, while 50 out of 105 (47.62%) samples
showed amplification using rpoβ primers, but were not of expected size. Of the 13 16S rRNA amplified samples, only 5
were identified as Leptospira in the gene sequence analysis and clustered under uncultured group via phylogenetic tree.
This study showed the DNA-based approach using PCR and sequence analysis is able to detect the presence of Leptospira,
although environmental samples may contain diverse microbial populations that may complicate the detection. Overall,
the study suggested the importance of surveillance for Leptospira from environmental samples.
Comparison of susceptibility test methods to detect penicillin susceptibility in Streptococcus pneumoniae isolates

Mohd Nasir MD, Parasakthi N

Malays J Pathol, 2004 Jun;26(1):29-33.
PMID: 16190104

The increasing prevalence of penicillin-resistant Streptococuus pneumoniae urges for fast and accurate susceptibility testing methods. This study evaluated the comparability of three commonly used techniques; disk diffusion, E-test and agar dilution, to detect penicillin susceptibility in clinical isolates of S. pneumoniae. Fifty pneumococcal isolates, obtained from patients at the University of Malaya Medical Centre, were selected to include both penicillin-susceptible strains and those that had decreased susceptibility (resistant and intermediate) to penicillin. The minimum inhibitory concentration (MIC) values of penicillin to serve as the reference was determined by the agar dilution method in which, based on the MIC breakpoints recommended by the National Committee for Clinical Laboratory Standards (NCCLS), 27 strains had decreased susceptibility to penicillin with 17 strains resistant and 10 intermediate. Comparing to the agar dilution method, oxacillin disk diffusion test detected all strains with decreased penicillin susceptibility as such while E-test showed a close agreement of susceptibility (92%) of the isolates to penicillin. This confirmed that oxacillin is a good screening test for S. pneumoniae isolates with decreased susceptibility to penicillin while E-test is very reliable for rapid and accurate detection of penicillin susceptibility.
Fulltext Antinociceptive activity of methanolic extract of melastoma malabathricum l.leaves and mechanisms of action in experimentalanimals

Erman Shah Jaios, Suzanah Abdul Rahman, Mooi, Ching Siew, Arifah Abdul Kadir, Mohd Nasir Mohd Desa, Zainul Amirudin Zakaria

International Journal of Allied Health Sciences, 2017;1(1):1-1.
MyJurnal

Objectives/Research Problem:Melastoma malabathricum L., (Melastomaceae) is a medicinally important plant known as “Senduduk”. Traditionally, the leaves are used to relieve diverse pain-related ailments. Present study aims to examine the antinociceptive activity of methanolic extract of M. malabathricum (MEMM) leaves and its fractions via in vivo models of nociception.

Materials and Method: Extracts (100, 250, 500 mg/kg) were administered orally 60 minutes prior to subjection to the respective test, n=6/group. Evaluation of MEMM antinociceptive activity; chemically (acetic acid-induced abdominal constriction; ACT, formalin-induced paw licking test; FT) and thermally (hot plate test; HT) models of nociception and elucidation of mechanisms of action involved; role of opioid, vanilloid receptors, glutamatergic system and NO/cGMP pathway were determined. Continuously, MEMM, partitioned into three fractions: petroleum ether (PEMM), ethyl acetate (EAMM), and aqueous (AQMM) extracts and determine the most potent fraction. Therefore, experiment ED50 and its 95% confidence intervals (CI) values were conducted, and ACT was used to screen. Calculation, obtained, PEMM, the most effective was further used to assess the antinociceptive properties. Phytochemical screening, HPLC and GC-MS analysis were performed.

Results and Discussion: First stage, MEMM exhibited significant (P
Nasal colonisation, antimicrobial susceptibility and genotypic pattern of Staphylococcus aureus among agricultural biotechnology students in Besut, Terengganu, east coast of Malaysia

Zarizal S, Yeo CC, Faizal GM, Chew CH, Zakaria ZA, Jamil Al-Obaidi MM, et al.

Trop Med Int Health, 2018 08;23(8):905-913.
PMID: 29873865 DOI: 10.1111/tmi.13090

BACKGROUND: This study aimed to profile the antimicrobial susceptibility and presence of resistance and virulence genes of methicillin-susceptible Staphylococcus aureus (MSSA) and MRSA nasal carriage, by means of genotypic analyses, in students of a tertiary institution in the state of Terengganu, east coast of Malaysia.
METHODS: A total of 370 agricultural biotechnology students from Universiti Sultan Zainal Abidin in Besut, Terengganu, were enrolled in this study. Antimicrobial susceptibility profiles were evaluated by standard methods. PCR detection of resistance and virulence genes was performed on S. aureus that were methicillin-resistant, macrolide-lincosamide-streptogramin B (MLSB )-positive phenotype and/or positive for the leukocidin (pvl) gene followed by staphylococcal cassette chromosome mec (SCCmec), staphylococcal protein A (spa) and accessory gene regulator (agr) typing.
RESULTS: One hundred and nineteen of 370 students carried S. aureus (32%); 18 of the isolates were MRSA (15%). Erythromycin resistance was detected in 20% (24/119) of which 15% (18/119) were MRSA and 5% (6/119) MSSA. Among the 24 erythromycin-resistant isolates, D-test was positive in 29% (7/24) displaying inducible MLSB , whereas the remaining 71% (17/24) showed constitutive MLSB phenotypes. Nine (7.6%) of 119 isolates were pvl positive: 44% MRSA (4/9) and 56% MSSA (5/9). Staphylococcal surface protein sasX gene was present in 92% of MRSA and 8% of MSSA isolates. The majority of MRSA isolates were agr type I (15/18; 83%). Five spa types identified with spa t037 were predominant, followed by spa types (t304 and t8696) as newly reported Malaysian MRSA in a community setting.
CONCLUSION: The presence of MRSA with SCCmec of hospital-associated features and globally recognised spa types in community setting is worrisome. Furthermore, the presence of MLSB strains among multidrug-resistant (MDR) S. aureus with sasX as well as pvl-positive isolates highlights the potential risk of a community setting in facilitating the dissemination of both virulence and resistance determinants.