Aims: Pseudomonas has been associated with diseases occurring in people with weakened or compromised immune system after exposure to contaminated water. The diseases are commonly treated with antibiotics. However, the bacteria had developed resistances to commonly used antibiotics making treatment a difficult task. Therefore, the continuous surveillance of susceptibility of Pseudomonas especially for the human pathogen P. aeruginosa to commonly clinical and aquaculture farming used antibiotics is important to ensure that serious infections remain susceptible to those antibiotics. Methodology and results: In this study, the bacteria were screened from water, sediment and fish from rivers and aquaculture farms around Kuching, Sarawak. A total number of 38 presumptive P. aeruginosa were isolated using CHROMagar TM Pseudomonas and subjected to a series of biochemical tests. Out of all the isolates tested, only two isolates designated as AS-R10(S) and BK2-OLT2(S) fulfilled the biochemical characteristics of P. aeruginosa. 16S rRNA gene sequencing further confirmed these two isolates as P. aeruginosa based on their 100% similarity with P. aeruginosa strain GD1 and P. aeruginosa strain PA1201 in NCBI database. These two isolates were tested for their susceptibilities against nine common antibiotics used in both clinical and aquaculture farming nowadays: imipenem, piperacillin, meropenem, amikacin, gentamicin, ciprofloxacin, ceftazidime, tobramycin and norfloxacin according to CLSI standard using disk diffusion method. Conclusion, significance and impact of study The two isolates exhibited total susceptibility to all the antibiotics analysed, suggesting the effectiveness of the antimicrobial agents towards P. aeruginosa isolated from aquaculture and water environment in the study area.

Aims: Arbuscular mycorrhizal (AM) fungi or previously known as the vesicular-arbuscular mycorrhizal (VAM) fungi, is a type of endomycorrhiza that closely associates with most species of plants. Meanwhile, they significantly improve the nutrients uptake in exchange of photosynthates and decrease the stress caused by both biotic and abiotic factors through symbiosis relationship. However, the understanding of indigenous AM fungi species present in its host plants are comparatively inadequate, hence this research study concentrated on indigenous AM fungi population in some selected plants that contribute to agricultural sector in Malaysia and phytochemical properties of soil that affect the colonization rate of AM fungi. Methodology and results: Bamboo, banana, coconut, sugarcane, papaya, lemongrass, pandan and tapioca plant were selected in this study. The soil and plant roots were sampled and the fungi spores were extracted by applying Wet sieves and decantation techniques then further purified by sucrose density centrifugation. Genera Glomus, Funneliformis, Rhizophagus, Acaulospora and Dentiscutata were isolated and Glomus was determined as the dominant genera followed by Acaulospora in these selected plants. Soil pH were found to be significantly affecting the AM fungi population and the root colonization percentage of AM fungi in the plants analysed. Conclusion, significance and impact of study From this study, tapioca recorded the highest percentage of AM fungi root colonization rate with 20.00% in root while banana recorded the lowest rate of 3.33% only. Based on this study, tapioca is recommended for the propagation of AM fungi for biofertilizer usage in agricultural sector in future.

Aims: Pigments have a large and growing market in the world. Drawbacks in their production such as raw materials availability and low productivity prompt the search for fermentation routes for industrial production. A carotenoid-producing yeast identified as Rhodotorula mucilaginosa was isolated in our laboratory. The aim of this study was to investigate the growth and carotenoid production capacity of the yeast. Methodology and results: A cost-effective substrate of sago starch hydrolysate (SSH) derived from sago fiber waste was used for the fermentation. The fermentation was carried out for 96 h at 27 °C in batch mode. The biomass produced during 5 days of fermentation was 9.6 g/L, which contained a carotenoid concentration of 8.1 mg/L and a specific yield of 845.9 g/g. Conclusion, significance and impact of study The results demonstrated the capacity of R. mucilaginosa yeast to produce carotenoids and its potential for larger-scale production.

Aims: Aquaculture has grown tremendously in Malaysia over the past decades. However, guaranteeing aquaculture sustainability is a big challenge in terms of maintaining continuous output with a safe environment. Furthermore, the cultured species should be free from antibiotic resistance bacterial and antibiotic residue. This study aimed to monitor the existence and prevalence of antibiotic resistant bacteria associated with aquaculture farms in Sarawak. Methodology and results: Samples of water, sediment and fish were collected from five aquaculture farms within Sarawak. The samples were plated on trypticase soy agar and incubated at 28 °C for 24 h. A total of 204 bacterial isolates were isolated and analysed by (GTG)5-fingerprinting to determine genetic similarity among the bacterial isolates, so that representatives could be selected from similar clonal isolates. Based on the (GTG)5 profiles, 50 representative isolates were chosen for species identification using 16S rRNA sequencing. The identified bacteria were tested against 25 antibiotics using standard disk diffusion method. The 16S rRNA analysis revealed that the isolates constitute of 14 genera of bacteria including Bacillus (38%), Exiguobacterium (16%), Enterobacter (14%), Aeromonas (6%), Acinetobacter (4%), Citrobacter (4%), Staphylococcus (4%), Achromobacter (2%), Chitinophaga (2%), Fictibacillus (2%), Plesiomonas (2%), Pseudomonas (2%), Pseudoxanthomonas (2%) and Stenotrophomonas (2%). The antibiotic resistance analysis revealed that the highest percentage of resistance was recorded against streptomycin (75.0%), followed by ampicillin (66.0%), ceftriaxone (50.0%), rifampin (43.3%), aztreonam (36.8%) and ceftazidime (31.6%). Resistance to more than two antibiotics was observed in 40.0% of isolates with an overall multiple antibiotic resistant (MAR) index ranging from 0 to 0.79. Conclusion, significant and impact of study The variability of antibiotic resistance patterns exhibited by different bacterial species suggests a dependence on selective pressures exhibited in different geographical locations. Our results show that the occurrence of MAR bacteria in an aquaculture environment with unknown history of antibiotics usage in the aquaculture system is possible, indicating a need to continuously monitor the presence of antibiotic resistant bacteria in the aquaculture system.
Drug Resistance, Microbial ; Aquaculture ; Malaysia