Use Of A Bacteriophage Cocktail In Combination With Modified Atmosphere Packaging To Control Escherichia Coli O157:H7 Contamination On Fresh-Cut Green Leafy Vegetables

The 2006 multi-state Escherichia coli O157:H7 (EHEC) outbreak linked to bagged spinach raised concerns about the safety of fresh produce. One novel approach to control foodborne pathogens is lytic bacteriophages, which does not affect the produce microflora. The objectives of this study were; 1) to test and verify the efficacy of a phage cocktail against EHEC in a laboratory medium, 2) to determine the effectiveness of the phage cocktail on fresh-cut leafy greens, and 3) to test and compare the effectiveness of the phage cocktail against EHEC on fresh-cut green leafy vegetables stored under air and modified air (low O2/high CO2) conditions. The efficacy of the phage cocktail was determined against a nalidixic acid resistant (NalR) EHEC strain in Tryptic Soy Broth (TSB). Next, pieces (~2x2 cm2) of leafy greens inoculated with 4.50 log EHEC NalR/cm2 and air-dried were sprayed with 6.50 log phage cocktail/cm2. Samples were stored at 4 or 10°C for 15 days under atmospheric or modified (5% O2/35% CO2/60% N2) air. The recovered EHECs were enumerated on MacConkey agar supplemented with 25 μg/ml Nal. Phage treatment resulted in 6 log reduction (P\u3c0.05) of EHEC NalR in TSB. At 4°C under air, the phage cocktail significantly (P\u3c0.05) lowered the EHEC NalR counts in one day by 1.19, 3.21, and 3.25 log units on spinach, green leaf, and romaine lettuce, respectively. When stored under modified atmosphere, the reductions in EHEC NalR concentrations were 2.18, 3.50, and 3.13 logs. At 10°C, EHEC reductions under air were 1.99, 3.90, and 3.99 logs, and under modified air were 3.08, 3.89, and 4.34 logs on spinach, green leaf, and romaine lettuce, respectively. The results of this study suggest that bacteriophages may be used successfully for controlling/reducing pathogenic bacterial presence and/or growth on fresh produce stored under modified atmosphere packaging

Leaf Hexane Extracts of Two Turkish Fig (Ficus carica L.) Cultivars Show Cytotoxic Effects on a Human Prostate Cancer Cell Line

The world-famous Turkish fig, grown in Aydin, is also used for the treatment of various diseases with its leaves and latex. Studies have shown that fig leaf has antioxidant, antiviral, antidiabetic, antimicrobial, and anticancer effects. The objective of the study is to examine the anticarcinogenic and antimicrobial effects of nonpolar extracts from the leaves of two fig cultivars (Sari Lop and Aydin Black) that are the most widely grown in Aydin. The fig leaves collected in the summer of 2017 were dried in shade at room temperature and crumbled. The n-hexane extracts of the dried fig leaves obtained with manual soxhlet and semi-automated soxhlet apparatus were applied on PC3 human prostate cancer cell line for 24h. The antimicrobial activities of the extracts were examined on Escherichia coli and Bacillus cereus using disc and agar well diffusion methods. As a result, antimicrobial activity of the n-hexane extracts on the bacteria was not detected at the highest dose tested (100 mg/ml). The n-hexane extracts showed cytotoxic effect on PC3 cells in a dose-dependent fashion and caused close to 100% death at 1000 μg/ml. No significant difference was observed between the cytotoxic effects of n-hexane extracts of two fig cultivars and the extraction methods (P>0.05)

Variation Analysis in Premenopausal and Postmenopausal Breast Cancer Cases

Menopausal status affects the prognoses and consequences of breast cancer. Therefore, this retrospective study aimed to reveal the molecular variation profile differences in breast cancer patients according to their menopausal status, with the hypothesis that the molecular variation profiles will be different at premenopausal and postmenopausal ages. Breast cancer patients (n = 254) who underwent molecular subtyping and QIAseq Human Breast Cancer NGS Panel screening between 2018 and 2022 were evaluated retrospectively. Their menopausal status was defined by age, and those aged 50 years and above were considered postmenopausal. Of the subjects, 58.66% (n = 149) were premenopausal and 41.34% (n = 105) were postmenopausal. The mean age at the time of diagnosis for all patients was 49.31 ± 11.19 years, with respective values of 42.11 ± 5.51 and 59.54 ± 9.01 years for the premenopausal and postmenopausal groups, respectively (p = 0.000). Among premenopausal patients, the percentages of patients in BCa subtypes (luminal A, luminal B-HER2(−), luminal B-HER2(+), HER2 positive, and triple-negative) were determined to be 34.90%, 8.05%, 26.17%, 10.74%, and 20.13%, respectively, while in the postmenopausal group, these values were 39.05%, 16.19%, 24.76%, 6.67%, and 13.33%, respectively (p > 0.05). Considering menopausal status, the distribution of hormone receptors in premenopausal patients was ER(+)/PgR(+) 63.76%, ER(−)/PgR(−) 23.49%, ER(+)/PgR(−) 10.74%, and ER(−)/PgR(+) 2.01%, respectively, while in postmenopausal women, this distribution was observed to be 74.29%, 23.81%, 1.90% and 0.00% in the same order (p = 0.008). The most frequently mutated gene was TP53 in 130 patients (51.18%), followed by PIK3CA in 85 patients (33.46%), BRCA2 and NF1 in 56 patients (22.05%), PTEN in 54 patients (21.26%), and ATR and CHEK2 in 53 patients (20.87%). TP53, PIK3CA, NF1, BRCA2, PTEN, and CHEK2 mutations were more frequently observed in premenopausal patients, while TP53, PIK3CA, BRCA2, BRCA1, and ATR mutations in postmenopausal patients. These findings contribute to a deeper understanding of the underlying causes of breast cancer with respect to menopausal status. This study is the first from Turkey that reflects the molecular subtyping and somatic mutation profiles of breast cancer patients according to menopausal status

Dimeric DNA Aptamer Complexes for High-capacity–targeted Drug Delivery Using pH-sensitive Covalent Linkages

Treatment with doxorubicin (Dox) results in serious systemic toxicities that limit effectiveness for cancer treatment and cause long-term health issues for cancer patients. We identified a new DNA aptamer to prostate-specific membrane antigen (PSMA) using fixed sequences to promote Dox binding and developed dimeric aptamer complexes (DACs) for specific delivery of Dox to PSMA+ cancer cells. DACs are stable under physiological conditions and are internalized specifically into PSMA+ C4-2 cells with minimal uptake into PSMA-null PC3 cells. Cellular internalization of DAC was demonstrated by confocal microscopy and flow cytometry. Covalent modification of DAC with Dox (DAC-D) resulted in a complex with stoichiometry ~4:1. Dox was covalently bound in DAC-D using a reversible linker that promotes covalent attachment of Dox to genomic DNA following cell internalization. Dox was released from the DAC-D under physiological conditions with a half-life of 8 hours, sufficient for in vivo targeting. DAC-D was used to selectively deliver Dox to C4-2 cells with endosomal release and nuclear localization of Dox. DAC-D was selectively cytotoxic to C4-2 cells with similar cytotoxicity as the molar equivalent of free-Dox. In contrast, DAC-D displayed minimal cytotoxicity to PC3 cells, demonstrating the complex displays a high degree of selectivity for PSMA+ cells. DAC-D displays specificity and stability features that may be useful for improved delivery of Dox selectively to malignant tissue in vivo