Detection of Enterotoxin Genes (seg, seh and sei) in Staphylococcus aureus Milk Isolates from Cow with Subclinical Mastitis

Enterotoxigenic Staphylococcus aureus can be isolated from various sources and are responsible for food poisoning in addition to many suppurative infections. In the present study, from 82 physically normal milk samples from cattle subclinical mastitis 33(40.24%) were isolated to S. aureus. Out of these, 22 (66.66%) S. aureus isolates had either one or more enterotoxin genes. Both seg and sei enterotoxin genes were carried by 19 (57.5%) S.aureus isolates while only three (9.09%) isolates were positive for seh gene. This study showed the evidence of presence of enterotoxin genes seg, seh, and sei in S. aureus isolates from subclinical mastitis. The presence of these enterotoxigenic S. aureus strains in milk indicates potential public health concern

Identification of Soluble Epoxide Hydrolase Inhibitors from the Seeds of Passiflora edulis Cultivated in Vietnam

Soluble epoxide hydrolases (sEH) are enzymes present in all living organisms, metabolize epoxy fatty acids to 1,2-diols. sEH in the metabolism of polyunsaturated fatty acids plays a key role in inflammation. In addition, the endogenous lipid mediators in cardiovascular disease are also broken down to diols by the action of sEH that enhanced cardiovascular protection. In this study, sEH inhibitory guided fractionation led to the isolation of five phenolic compounds trans-resveratrol (1), trans-piceatannol (2), sulfuretin (3), (+)-balanophonin (4), and cassigarol E (5) from the ethanol extract of the seeds of Passiflora edulis Sims cultivated in Vietnam. The chemical structures of isolated compounds were determined by the interpretation of NMR spectral data, mass spectra, and comparison with data from the literature. The soluble epoxide hydrolase (sEH) inhibitory activity of isolated compounds was evaluated. Among them, trans-piceatannol (2) showed the most potent inhibitory activity on sEH with an IC₅₀ value of 3.4 µM. This study marks the first time that sulfuretin (3) was isolated from Passiflora edulis as well as (+)-balanophonin (4), and cassigarol E (5) were isolated from Passiflora genus.

Prevalence of seg, seh and sei Genes among Clinical and Nasal Staphylococcus aureus Isolates in Palestine.

Aims: To investigate the presence of the staphylococcal enterotoxin genes seg, seh and sei among clinical and nasal isolates. Place and Duration of Study: Department of Biology and Biotechnology, An-Najah N. University, Palestine, in 2011. Methodology: A total 124 S. aureus isolates were collected, forty three were nasal and 81 were clinical isolates. PCR technique was used to detect enterotoxin genes seg, seh and sei, mecA gene and analysis of SCCmec types. Enterotoxigenic strains were also typed using coagulase typing kit. Results: Fifty two (41.9%) isolates were positive for one or more of these enterotoxin genes. The prevalence of toxin genes among S. aureus isolated from nasal swabs 25/43 (58.1%) was higher than those isolated from clinical samples 27/81 (33.3%). Combination of the toxin genes was noted only in MSSA isolate from both nasal swabs and clinical samples. Distribution of toxin genes in MSSA isolates was higher (49.5%) than those in MRSA isolates (21.2%). SCCmec typing showed that the MRSA enterotoxigenic strain were belonged to types II, III and IVa. MRSA strains were found to belong to coagulase serotypes II, III and VII, while MSSA strains were belonged to serotypes II-VII. In nasal samples, 16/25 (64.0%) of enterotoxigenic strains showed the genotype seg+/sei+, while in clinical samples 1/27 (3.7%), 1/27 (3.7%) and 3/27 (11.1%) of enterotoxigenic strains showed the genotypes seg+/seh+, seg+/sei+ and seg+/seh+/sei+, respectively. This study showed that the majority of the isolates 42/124 (33.9%) were seg+, while none of nasal strains harbored seh gene. Conclusion: The prevalence of seg, seh and sei genes in the S. aureus isolated from nasal swabs differed significantly from those obtained from clinical samples, as well as the prevalence of the same genes in MSSA differed significantly from those in MRSA. In addition, S. aureus isolates from clinical and nasal swabs could serve as a possible reservoir of newly described seg, seh and sei genes.