Vibrio parahaemolyticus is a causative agent of foodborne outbreaks associated with the consumption of raw or under-cooked seafood. This study aimed to quantify and detect the occurrence of V. parahaemolyticus in freshwater fish by performing Most Probable Number (MPN) method in combination with Polymerase Chain Reaction (PCR). In this study, a total of 20 red tilapia (Oreochromis sp.) were collected from nearby local wet markets. Polymerase Chain Reaction (PCR) assay targeting the toxR gene in V. parahaemolyticus was performed, with the expected DNA amplification size of 368 bp. MPN analysis showed that the estimated microbial load of V. parahaemolyticus were more than 1100 MPN/g. The result of the PCR assay confirmed the presence of V. parahaemolyticus in 90% of the isolates. This positive detection elucidated the presence of food-borne bacteria in freshwater fish from local wet-market which may affect not only the health of fish stocks but also raise public health concerns.
Listeria spp. and Salmonella spp. are capable of causing food-borne outbreaks and diseases in humans. This study aimed to quantify and detect the occurrence of Listeria monocytogenes and Salmonella Typhimurium in fruit juices by utilizing Most Probable Number (MPN) in combination with Polymerase Chain Reaction (PCR). In this study, a total of 50 fruit juice samples, consisting of orange, papaya, watermelon, honeydew and apple were collected from Kota Samarahan and Kuching. Specific Polymerase Chain Reaction (PCR) assay targeting the virulence gene, hlyA gene in L. monocytogenes and fliC gene in S. Typhimurium was performed, with the expected size of 730 bp and 559 bp, respectively. MPN analysis showed that the estimated microbial loads of Listeria spp. and Salmonella spp. in all samples were more than 1100 MPN/g. However, based on the PCR analysis, none of the samples (0%) were positive for L. monocytogenes or S. Typhimurium. This study presented as a preliminary food safety screening for the occurrence of Listeria spp. and Salmonella spp. from retailed fruit juices. Hygienic practices and food safety measures should be adhered by all food vendors and restaurants in order to avoid foodborne disease outbreaks in the future.
The epidermal mucus of fish contains antimicrobial agents that act as biological defence against disease. This study aims to identify antibacterial activity and protein concentration of epidermal mucus of Barbodes everetti, a Bornean endemic freshwater fish. The epidermal mucus was extracted with 3% acetic acid, 0.85% sodium chloride and crude solvents. The mucus activity against eight strains of human pathogenic bacteria, including Bacillus cereus ATCC 33019, Escherichia coli O157:H7, Listeria monocytogenes ATCC 7644, Pseudomonas aeruginosa ATCC 27853, Salmonella braenderup ATCC BAA 664, Salmonella typhimurium, Staphylococcus aureus ATCC 25933, and Vibrio cholerae, were tested. The acetic acid mucus extract of B. everetti was able to inhibit five strains of bacteria and show no activity toward E. coli O157:H7, B. cereus ATCC 33019 and L. monocytogenes ATCC 7644. Moreover, the highest protein concentration was quantified in crude extract, followed by aqueous and acetic acid extracts. This study provides a preliminary knowledge on the activity of epidermal mucus of B. everetti towards five out of the eight human pathogens tested, therefore it may contain potential sources of novel antibacterial components which could be further extracted for the production of natural antibiotics towards human-related pathogenic bacteria.
Yeast growth and biomass production are greatly influenced by the length of the
incubation period during cultivation. Therefore, this study was conducted to
investigate the growth kinetics of five Lipomyces starkeyi strains as determined by
biomass production. The five L. starkeyi strains, namely L. starkeyi ATCC 12659, L.
starkeyi MV-1, L. starkeyi MV-4, L. starkeyi MV-5 and L. starkeyi MV-8, were inoculated
in sterilized Yeast Malt broth, and, incubated for 192 hr at ambient temperature.
Biomass yields were assessed and calculated gravimetrically every 24 hr. Results
indicated that the optimal biomass production of L. starkeyi ATCC 12659, L. starkeyi
MV-1, L. starkeyi MV-4, L. starkeyi MV-5 and L. starkeyi MV-8 were at 120, 168, 144,
168 and 120 hr, with the concentrations of 6.64, 6.43, 9.78, 11.23 and 8.56 g/L,
respectively. These results indicate that each L. starkeyi strain requires specific
incubation period for the optimum production of fungal biomass. Therefore, by
cultivating each L. starkeyi strain at the predetermined incubation period, biomass
yields could significantly be improved for further downstream applications such as
single cell protein and lipid production.