Indoor air quality is an essential aspect for occupational health including in a densely populated university. This study aimed to assess the indoor airborne microorganisms via biochemical and molecular approaches in five enclosed workplaces, and their resistance towards six commonly used antibiotics. Cfu/dm2/h for five enclosed workplaces was determined using settle plate technique with 1/1/1 scheme and Gram staining was performed for all pure strains isolated. Two strains with the highest count and with different morphologies were identified using biochemical test as well as 16S rRNA amplification and direct sequencing. Minimum inhibitory concentration for antibiotics was carried out for these two strains. In this study, 27 microbial strains with different morphologies were obtained from all workplaces and 2 strains with the highest count were strain J in café and strain M in library, which were identified as Bacillus cereus and Staphylococcus cohnii, respectively. Both of them were highly susceptible to ampicillin and tetracycline. With resistance up to 0.78 µg/mL; B. cereus was less sensitive to kanamycin and neomycin whereas S. cohnii was less sensitive to streptomycin. In conclusion, antibiotics resistant B. cereus and S. cohnii were two of the microorganisms showing the most abundance in the café and library of a Malaysian public university, respectively. This study may serve as the baseline for the prescriptions of antibiotics to airborne microbial related infections especially to the community in the university who seek for medical treatments; particularly for respiratory and digestive infections which often associated with indoor microenvironment.
antibiotic resistance ; Bacillus cereus ; indoor air quality ; minimum inhibitory concentration ; Staphylococcus cohnii

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.