1.Biofilm forming ability of intermediate and saprophytic Leptospira on abiotic and biotic surfaces
Kasing Apun ; Jennifer Jalan ; Chai Fung Pui ; Lesley Maurice Bilung ; Hashimatul Fatma Hashim ; Anisa Aina Nadiah Md Ahsan ; Rennielyn Rupert
Malaysian Journal of Microbiology 2018;14(4):313-319
Aims:
Leptospira spp. has the ability to develop biofilm communities and this attribute is an essential factor to leptospiral pathogenesis. This study aims to assess and quantify the biofilm forming ability of intermediate and saprophytic Leptospira strains.
Methodology and results:
The biofilm assay was quantified on microtitre polystyrene plates (abiotic) and wood chips (Jelutong Paya hardwood) over a duration of 11 days. Phase contrast light microscope was used to assess the structure of the on the surface. The biofilm production on wood chips surface were approximately one times higher than on polystyrene plate surface indicating Leptospira strains were capable of forming higher quantity of biofilm on biotic surface compared to abiotic surface by both intermediate and saprophytic Leptospira. A significant difference (p<0.05) exists in biofilms produced by Leptospira on wood surface which formed more biofilm than on polystyrene surface. The strongest biofilm producer is intermediate strain G14 with OD600 of 2.283±0.180 and OD600 of 2.333±0.037, on polystyrene and wood surface, respectively. Visualisation of biofilm by phase-contrast microscopy of two representative strains correlated with the OD values and the colour intensity of stained microtitre plates and wood surfaces. The biofilm formed comprises of a three-step process are adherence (1 th to 24 th h), maturation (6t h to 7 th day) and detachment (9 th to 11 th day) of biofilms.
Conclusion, significance and impact of study
The contact time of intermediate pathogenic strains was faster compared to saprophytic strain, indicating the biofilm forming ability is related to the level of pathogenicity of Leptospira strains.
2.Investigation of genetic diversity of Plasmodium knowlesi kelch13-propeller region in Sabah, Malaysia
Jennifer Kui Ling Chee ; Eric Tzyy Jiann Chong ; Ping-Chin Lee
Malaysian Journal of Microbiology 2023;19(no.6):602-609
Aims:
The kelch13 gene mutations of Plasmodium falciparum is associated with delayed parasite clearance after artemisinin-based combination therapy (ACT). It is unclear for P. knowlesi that is predominantly reported in Sabah. Therefore, this study aims to analyse the diversity of the P. knowlesi kelch13 gene in five divisions of Sabah.
Methodology and results: :
Ninety-five blood samples infected with P. knowlesi were obtained. The DNA of P. knowlesi samples was extracted and the kelch13 gene was amplified. The amplicons were cloned and sequenced. The
sequencing data were aligned and analysed using MEGA 11 and DnaSP v6 software. A phylogenetic tree was constructed using the Neighbour-joining approach, which showed a diverse clade of P. knowlesi in Sabah, with a nucleotide diversity (π) of 0.451 and a haplotype diversity of 0.947. The deduced amino acid sequences were classified into 14 haplotypes, providing evidence of distinct P. knowlesi lineages in Sabah. When compared to P. falciparum, the kelch13 sequences of P. knowlesi exhibited a higher π of 0.490 and haplotype diversity of 1.000, and similar mutations that conferred drug resistance to ACT in P. falciparum were detected in P. knowlesi in this study.
Conclusion, significance and impact of study:
The kelch13 gene of P. knowlesi isolates in Sabah has high nucleotide and haplotype diversities. Additionally, mutations conferring drug resistance to ACT in P. falciparum were identified in P. knowlesi in Sabah. The findings in this study can be used to better understand the emergence of drug resistance of P.
knowlesi in Sabah.
3.Relationship between Psychosocial Risk Factors and Work-Related Musculoskeletal Disorders among Public Hospital Nurses in Malaysia.
Nur Azma AMIN ; Rusli NORDIN ; Quek Kia FATT ; Rahim M NOAH ; Jennifer OXLEY
Annals of Occupational and Environmental Medicine 2014;26(1):23-23
OBJECTIVE: This study examined the relationships between psychosocial work factors and risk of WRMSDs among public hospital nurses in the Klang Valley, Malaysia. METHODS: We conducted a cross-sectional study among 660 public hospital nurses. A self-administered questionnaire was used to collect data on the occurrence of WRMSDs according to body regions, socio-demographic profiles, occupational information and psychosocial risk factors. 468 questionnaires were returned (response rate of 71%), and 376 questionnaires qualified for subsequent analysis. Univariate analyses were applied to test for mean and categorical differences across the WRMSDs; multiple logistic regression was applied to predict WRMSDs based on the Job Strain Model's psychosocial risk factors. RESULTS: Over two thirds of the sample of nurses experienced discomfort or pain in at least one site of the musculoskeletal system within the last year. The neck was the most prevalent site (48.94%), followed by the feet (47.20%), the upper back (40.69%) and the lower back (35.28%). More than 50% of the nurses complained of having discomfort in region one (neck, shoulders and upperback) and region four (hips, knees, ankles, and feet). The results also revealed that psychological job demands, job strain and iso-strain ratio demonstrated statistically significant mean differences (p < 0.05) between nurses with and without WRMSDs. According to univariate logistic regression, all psychosocial risk factors illustrated significant association with the occurrence of WRMSDs in various regions of the body (OR: 1.52-2.14). Multiple logistic regression showed all psychosocial risk factors were significantly associated with WRMSDs across body regions (OR: 1.03-1.19) except for region 1 (neck, shoulders and upper back) and region 4 (hips, knees, ankles, and feet). All demographic variables except for years of employment were statistically and significantly associated with WRMSDs (p < 0.05). CONCLUSIONS: The findings indicated the high prevalence of WRMSDs in many body regions, and the risks of developing WRMSDs according to the various body regions were associated with important psychosocial risk factors based on the job strain model. These findings have implications for the management of WRMSDs among public hospital nurses in the Klang Valley, Malaysia.
Ankle
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Body Regions
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Cross-Sectional Studies
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Employment
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Foot
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Hospitals, Public*
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Knee
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Logistic Models
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Malaysia*
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Musculoskeletal System
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Neck
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Prevalence
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Risk Factors*
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Shoulder