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@#Introduction: The outbreaks of foodborne diseases have been linked to the consumption of contaminated seafood. This research aims to screen the bacteria from the sea cucumbers Acaudina molpadioides collected from Pulau Langkawi. Methods: A total of 22 sea cucumber samples were collected randomly from Pulau Langkawi, Kedah, Malaysia. The samples were isolated and identified for the presence of bacteria using the conventional culture-based method. Presumptive bacteria colonies were subjected to various biochemical and antimicrobial susceptibility tests. Results: There were no bacterial growth in Hektoen Enteric (HE) agar and Thiosulphate-Citrate-Bile Salt (TCBS) agar. Positive samples were isolated from MacConkey (MAC) agar with 6 samples were Staphylococcus spp. (27.27%), 14 samples were Proteus spp. (63.63%) and 2 samples were Bacillus spp. (9.01%). Among these isolates, highest resistance was found against Ampicillin (45%) followed by Tetracycline (40%). Conclusion: The results indicate that the sea cucumbers Acaudina molpadioides were contaminated with potential bacteria. There is a need for adequate consumer protection measures.
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@#Introduction: This study reported the concentration of bacterial and fungal bioaerosol at an animal house and hospital laboratories with the aim to compare the concentration levels at library and administrative offices. The bioaerosol levels between mid-shift (afternoon) were also compared to the concentration measured during pre-shift (morning). Methods: The NIOSH 0800 method utilising microbiological air sampler collecting airborne bacterial and fungal samples via impaction technique on Nutrient agar (NA) and Sabouraud Dextrouse agar (SDA) as culture medium, respectively. Sampling was done twice daily; before (pre-shift) and during working (mid-shift) hour. Results: The highest bacteria and fungi concentration was recorded at the animal house with median concentration of 2477 CFU/ m3 (IQR=121-2477) and 791 CFU/m3 (IQR = 379-2081), respectively. Higher-risked workplaces such as animal house and hospital laboratories have significantly higher bioaerosol concentrations compared to control workplaces such as library and administrative offices (p<0.05). Interestingly, there were significantly higher fungi concentrations during the pre-shift compared to the mid-shift, for both high risk and control workplaces. Conclusion: Animal research room had exceeded the recommended bioaerosol level of 500 CFU/m3, but all the other sites had concentrations below the recommended level. Appropriate control measures should be adhered such as practicing hygiene practices and housekeeping to minimise the bioaerosol exposure among the workers and occupants.
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Aims: Postbiotic metabolites are metabolic compounds produced by probiotic lactic acid bacteria. These compounds produced by Lactobacillus sp. have been shown to be effective substitutes for in-feed antibiotic in livestock due to their broad inhibitory activity. Therefore, the aim of this study was to determine the effects of various carbon and nitrogen sources on the bacteriocin-inhibitory activity of postbiotic metabolites produced by Lactobacillus plantarum I-UL4. Methodology and results: The effects of various combinations of carbon and nitrogen sources on the bacteriocininhibitory activity (expressed as modified bacteriocin activity, MAU/mL) of postbiotic metabolites produced by L. plantarum I-UL4 were determined in basal media without micronutrients. The combination of glucose (20 g/L) and yeast extract (22 g/L) gave the best bacteriocin-inhibitory activity as compared to other combinations. Maximum bacteriocininhibitory activity of 1440 MAU/mL was achieved when 36.20 g/L of yeast extract was added as the sole nitrogen source in modified de Man, Rogosa and Sharpe (MRS) medium. The glucose concentration was further optimised to enhance the bacteriocin-inhibitory activity of the postbiotic metabolites. Lower bacteriocin-inhibitory activity was observed at 5, 10, 15 and 40 g/L in comparison to 20 g/L of glucose. Conclusion, significance and impact of study: Maximum bacteriocin-inhibitory activity of postbiotic metabolites was achieved at 1440 MAU/mL when 20 g/L of glucose and 36.20 g/L of yeast extract were added as the sole carbon and nitrogen sources respectively in the modified MRS medium. Optimisation of other micronutrients present in MRS media is necessary to further enhance the bacteriocin-inhibitory activity of postbiotic metabolites produced by L. plantarum IUL4.
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LactobacillusABSTRACT
<p><b>OBJECTIVE</b>To determine lethal median dose (LD50) and histopathological toxicity of water extract of Holothuria atra (H. atra) in mice.</p><p><b>METHODS</b>The behavioral changes, mortality and histopathology examination on liver were assessed in mice 14 d after the administration (i.p.) of H. atra water extract. Seven doses (10, 20, 30, 50, 100, 150 and 200 mg/kg) of H. atra were used. The control group was treated with normal saline.</p><p><b>RESULTS</b>In the acute study in mice, the water extracts of H. atra caused dose-dependent general behavior adverse affects and mortality. The main behavioral sign of toxicity was hypoactivity, noticed immediately after administration of the extract which was more obvious at the higher doses and persisted until death. Mortality increased with increasing doses, the calculated LD50 was 41 mg/kg in mice. The liver toxicity was confirmed by histopathological examination, which indicated the presence of abnormal hepatocytes with a distorted shape and undefined cell lining as well as enlarged nuclei in low doses groups. High doses groups indicated a more prominent distortion of the polyhedral hepatocytes with undefined cell lining, massive cytoplasm, pyknotic, karyorhexis and karyolytic nuclei (necrosis of hepatocytes). Control group showed polyhedral hepatocytes with defined cell lining arranged in cords and normal round nuclei, with granular cytoplasm.</p><p><b>CONCLUSIONS</b>Because of the relatively low LD50 value in the acute study in mice, it may be concluded that the H. atra water extract is toxic.</p>
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Objective: To determine lethal median dose (LD