No abstract

Homalomena cochinchinensis Engl. is a rare species which is found in Southern China, Cambodia, Laos and Vietnam and its chemical constituents and bioactivity have not been determined yet. In this study, we identified 32 and 38 compounds in acetone extracts of H. cochinchinensis aerial part and rhizome, respectively via gas chromatography mass spectrometry (GC/MS). The main constituents of acetone extract of the aerial part were 3-((4Z,7Z)-Heptadeca-4,7-dien-1-yl)phenol (18.73%); cis-9,cis-12-Octadecadienoic acid (12.04%); linolenic acid (11.08%); n-Hexadecanoic acid (10.13%); (Z)-3-(Heptadec-10-en-1-yl)phenol (7.09%); ?-Sitosterol (5.58%) and linalool (5.56%). On the other hand, acetone extract of rhizome contained linalool (28.42%); 1,2,3-Propanetriol, 1-acetate (10.13%); 3-((4Z,7Z)-Heptadeca-4,7-dien-1-yl)phenol (5.28%); 3-Buten-2-one, 3-methyl-4-(1,3,3-trimethyl-7-oxabicyclo[4.1.0]heptan-1-yl)- (5.28%) and 4-(2,6,6-Trimethyl-cyclohex-1-enyl)-butyric acid (4.54%). Furthermore, this study has also proved the antibacterial activity of acetone extracts from the aerial part and the rhizome of this species for the first time using disk diffusion method. The results showed that the extract of the aerial part could inhibit the growth of 5 out of a total 6 bacterial strains, including Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis and Staphylococcus aureus; while the susceptible strains to the rhizome extract were 5 strains, such as B. cereus, E. coli, P. aeruginosa, Salmonella typhimurium and S. aureus. The findings suggest the further application of this species in pharmacology and medicine.

In this study, a total of 228 raw meat samples (pork: 76, beef: 76, chicken: 76) and 301 raw seafood samples (fish: 199, shrimp: 67, squid: 35) were collected randomly at traditional markets in Ho Chi Minh City (Vietnam). In meat, the ratio of Salmonella spp. was 70.61% (161/228). Among the contaminated meat samples, pork was infected with a ratio of 90.79 % (69/76) while the contamination ratios in beef and chicken were 43.42% (33/76) and 77.63% (59/76), respectively. Salmonella contamination was detected in fish (40.20%), shrimp (7.46%) and squid (17.14%). Because of sulfonamide group is used in Salmonella treatment, the study focused on sulfonamide resistance. In fresh seafood comparison, there were 32.56%, 40% and 10% Salmonella showing resistance to sulfamethoxazol in fish, squid and shrimp, respectively. In fresh meat comparison, there were 31.58%, 16.67% and 55.56% Salmonella showing resistance to sulfamethoxazol in pork, beef and chicken, respectively. Interestingly, there were 21 serovars including 19 identified serovars including S. Kentucky (8), S. Agona (2), S. Infanis (4), S. Saintpaul (1), S. Indiana (1), S. Braenderup (1), S. Potsman (2) and 2 unidentified serovars showing different phenotype to this antibiotic. Among the 21 serovars, only 23.81% strains carried both genes (sul1, sul2). For the sul1 gene, 61.9% strains were presented while sul2 occupied at a lower rate than sul1 with the rate of 52.38%. The study is very interesting and useful to go more functional analysis in sulfonamide resistance.

In this study, the sensory, microbiological, and biochemical qualities were used to examine the quality of Pacific white shrimps (Litopenaeus vannamei) preserved at 0°C during a 10-day period. The sensory quality was evaluated by a quality index (QI) that resulted from a quality index method (QIM) scheme. Meanwhile, the total viable count (TVC) and K-value were used to assess the microbiological and biochemical qualities of the shrimp. On day 9, the results from TVC and QIM have shown that the shrimp showed signs of spoilage, corresponding to a log CFU/g of 6.4 and a QI of 21.37, which is unacceptable to consumers. The QI increased linearly with storage days therefore the remaining shelf-life of the shrimp was estimated from a linear regression equation. In particular, this study found a linear relationship between QI, K-value, and hypoxanthine content. Furthermore, hypoxanthine itself could be considered as an independent quality index like the K-index. In conclusion, the quality of Pacific white shrimp was categorized into four different classes: excellent, good, acceptable, and moderately acceptable, based on its sensory and biochemical quality indicators.

In the study, about 695 samples comprising (fish powder: 320 samples, blood meal: 41 samples, bone meal: 123 samples), finished feed (pellets of pig feed: 213 samples) were collected and detected by polymerase chain reaction (PCR). Isolation prevalence in fish powder, blood meal, bone meal, finished feed was 23(7.19 %), 9 (21.95%), 48 (39.67%), 2 (0.94%) respectively. These Salmonella showed different antibiotic sensitivities to erythromycin, ampicillin, penicillin, ciprofloxacin. However, all these strains were inhibited with plantaricin produced by Lactobacillus plantarum PN05 isolated in Coryandrium sativum. Our findings highlighted a potential public health hazard and warned human the outbreaks of human salmonellosis with high resistance due to the consumption of contaminated feed and also suggested the prevention by plantaricin of Lactobacillus plantarum PN05.