ABSTRACT
Microalgae play an important function in aquatic environments by serving as the energy foundation of the food chain for all aquatic species. Microalgae produce a wide range of bioproducts, including polysaccharides, lipids, pigments, proteins, vitamins, bioactive chemicals, and antioxidants. In this study, a dataset of identification of three microalgae isolated from freshwater riverine areas at Glami Lemi River, Malaysia is presented. The identification data was acquired using molecular identification using the PCR method and morphological observation. The morphological observation of the microalgae isolates, GL01, GL02, and GL03, showed the closest features and characteristics with Chlorella sp., Ankinstrodesmus sp., and Tetradesmus (Scenedesmus) sp., respectively. The sequence similarity analysis of partial 18s rDNA gene using BLASTn identified the three microalgae species as Chlorella sorokiniana for isolate GL01, Ankistrodesmus fusiformis for isolate GL02, and Tetradesmus obliquus for isolate GL03. Both morphological observation and molecular identification were in agreement in the determination of the species. This is the first report on the three microalgae species isolated from this area.
ABSTRACT
Vibrio is the most common bacterium associated with diseases in crustaceans. Outbreaks of vibriosis pose a serious threat to shrimp production. Therefore, antibiotics are commonly used as preventative and therapeutic measures. Unfortunately, improper use of antibiotics leads to antibiotic resistance. Nevertheless, information on the occurrence of Vibrio spp. and antibiotic use in shrimp, particularly in Malaysia, is minimal. This study aimed to provide information on the occurrence of Vibrio spp., its status of antibiotic resistance and the plasmid profiles of Vibrio spp. isolated from cultured shrimp in Peninsular Malaysia. Shrimp were sampled from seven farms that were located in different geographical regions of Peninsular Malaysia. According to the observations, 85% of the shrimp were healthy, whereas 15% were unhealthy. Subsequently, 225 presumptive Vibrio isolates were subjected to biochemical tests and molecular detection using the pyrH gene. The isolates were also tested for antibiotic susceptibility against 16 antibiotics and were subjected to plasmid profiling. Eventually, 13 different Vibrio spp. were successfully isolated and characterized using the pyrH gene. They were the following: V. parahaemolyticus (55%), V. communis (9%), V. campbellii (8%), V. owensii (7%), V. rotiferianus (5%), Vibrio spp. (4%), V. alginolyticus (3%), V. brasiliensis (2%), V. natriegens (2%), V. xuii (1%), V. harveyi (1%), V. hepatarius (0.4%) and P. damselae (3%). Antibiotic susceptibility profiles revealed that all isolates were resistant to penicillin G (100%), but susceptible to norfloxacin (96%). Furthermore, 16% of the isolates revealed MAR of less than 0.2, while 84% were greater than 0.2. A total of 125 isolates harbored plasmids with molecular weights between 1.0 and above 10 kb, detected among the resistant isolates. The resistant isolates were mediated by both chromosomal and plasmid factors. These findings support the use of surveillance data on the emerging patterns of antimicrobial-resistance and plasmid profiles of Vibrio spp. in shrimp farms. The findings from this study can be used to develop a better disease management strategy for shrimp farming.
ABSTRACT
Vibriosis accounts for 66.7% of diseases reported in groupers' cultures and affects almost all stages of growth. The disease could lead up to mortality up to 50% mortality, and it was reported that high stocking density and poor fish handling were among the factors that contributed to the disease dissemination. V. harveyi has been reported to be among the causative agent and has caused acute mortality in cage groupers. In this study, we report the genome of V. harveyi VH1 isolated from a diseased tiger grouper Epinephelus fuscoguttatus, reared in a cage farm located in the coastal area of Langkawi.
