In recent years, the overuse of antibiotics has become very serious. Many pathogenic bacteria have become resistant to them, with serious potential health consequences. Thus, it is urgent that we develop new antibiotic drugs. Antimicrobial peptides (AMPs) are important endogenous antibacterial molecules that contribute to immunity. Most have spectral antibacterial properties and do not confer drug resistance. In this paper, an 11-residue peptide (LFcinB18–28) with a sequence of KCRRWQWRMKK was modified by amino acid substitution to form a symmetrical amino acid sequence. The antibacterial activities and mechanisms of action of engineered peptides including KW-WK (KWRRWQWRRWK), FP-PF (FPRRWQWRRPF), FW-WF (FWRRWQWRRWF), and KK-KK (KKRRWQWRRKK) were investigated. The four engineered peptides could more effectively inhibit bacteria than the original peptide, LFcinB18–28. This suggested that a symmetrical amino acid sequence might enhance the antibacterial activity of AMPs. However, only peptides KW-WK, FP-PF, and KK-KK were safe; FW-WF displayed hemolytic activity. The engineered peptides shared cationic and amphipathic characteristics that facilitated interactions with the anionic microbial membranes, leading to disruption of membrane integrity and permeabilizing microbial membranes, resulting in cell death. Therefore, a symmetrical amino acid sequence and related structural parameters offer an alternative approach to the design of AMPs. This will provide a scientific basis for the design and synthesis of new AMPs.

The aim of the present study was to estimate the prevalence of Salmonella and investigate the dominant serovars distribution in raw beef and to screen the isolated serovars for the prescense of beta-lactamases and virulence genes. A total of 150 samples of raw beef sold at butcher shops (n = 75) and supermarkets (n = 75) in Karachi city were collected (50 samples each from muscles, lymph nodes, and minced beef). The samples were cultured according to the ISO-6579-1guidlines. The overall prevalence of Salmonella strains was found to be 21.34%. A total of 56 isolates of Salmonella belonging to four serogroups (Salmonella Pullorum, Salmonella Enteritidis, Salmonella Typhimurium and Salmonella Choleraesuis) were isolated from beef muscles (12%), lymph nodes (24%) and minced beef (28%) samples collected from butcher shops (av. 21.34%). No Salmonella was detected in beef samples collected from supermarkets. S. Enteritidis contamination was highest (37.5%), followed by S. Choleraesuis (30.4%), S. Pullorum (19.6%) and S. Typhimurium (12.5 %). Antibiotic susceptibility testing revealed that Salmonella isolates were highly resistant to Oxytetracycline (90%), Ampicillin (90.5%), Amoxicillin (81.1%), Tetracycline (76%), Neomycin, (79.8%) and Ciprofloxacin (61.4%). The Salmonella isolates examined were more susceptible to the Cephalosporin antibiotics such as Cefixime (43.2%), Cefepime (48.2) and Cefoxitin (49.8%). PCR based screening of blaTEM, blaCTX-M and blaSHV revealed that blaCTX-M and blaTEM were the dominant resistant genes in S. Enteritidis and S. Typhimurium followed by S. Pullorum and S. Choleraesuis whereas blaSHV was the least detected beta-lactamase in Salmonella isolates. Virulence genes screening revealed that at least five genes were present in all the serovars, highest being present in S. Enteritidis (12/17) and S. Typhimurium (12/17). S. Cholerasuis (5/17) carried the least number of virulence genes followed by S. Pullorum (6/17). The present data suggest that beef samples from butcher shops of Karachi city are heavily contaminated with MDR Salmonella. The presence of resistance and virulence genes in MDR strains of Salmonella may play a significant role in transmission and development of Salmonella infection in humans.

Diet has a significant impact on fecal microbiota, which in turn plays an important role in human health. To evaluate the impact of dietary habits on fecal microbiota, we investigated the fecal microbial composition in vegetarians and omnivores using 16S rRNA gene sequencing, and estimated the correlation between fecal microbiota, body mass and diet. The dietary data showed that vegetarians consumed more plant-based foods rich in dietary fiber, omnivores consumed more animal-based foods rich in fat and overweight and obese people consumed more high-energy foods. Compared to omnivores, vegetarians had greater richness and diversity in their fecal microbiota. The Firmicutes/Bacteroidetes ratio was lower and the Prevotella/Bacteroides ratio was higher in vegetarians. The meat intake correlated positively with the proportion of Bacteroides and negatively with the proportion of Prevotella. The composition and diversity in fecal microbiota in the normal weight group, overweight group and obesity group were similar to that of vegetarians and omnivores, respectively. This paper revealed the distinctive characteristics of fecal microbiota in vegetarians and omnivores. The omnivorous diet contained more fat, which reduced the fecal microbial diversity, and was more likely to lead to being overweight or obese.

This study aims to evaluate the reproducibility and validity of a semi-quantitative food frequency questionnaire (SQFFQ) developed for vegetarians and omnivores in Harbin, China. Participants (36 vegetarians and 64 omnivores) administered SQFFQ at baseline (SQFFQ1) and six months later (SQFFQ2) to assess the reproducibility. The 24 h recalls (24 HRs) for three consecutive days were completed between the administrations of two SQFFQs to determine the validity. For reproducibility, Pearson correlation coefficients between SQFFQ1 and SQFFQ2 for vegetarians and omnivores were 0.45~0.88 and 0.44~0.84, respectively. For validity, unadjusted Pearson correlation coefficients were 0.46~0.83 with an average of 0.63 and 0.43~0.86 with an average of 0.61, respectively; energy-adjusted Pearson correlation coefficients were 0.43~0.82 with an average of 0.61 and 0.40~0.85 with an average of 0.59, respectively. Majority of the correlation coefficients for food groups and macronutrients decreased or remained unchanged after energy adjustment. Furthermore, all correlations were statistically significant (p < 0.05). Bland–Altman plots also showed reasonably acceptable agreement between the two methods. In conclusion, the SQFFQ developed in this study has reasonably acceptable reproducibility and validity.

Jujube wine production faces the technical challenge of excessive methanol formation due to the high pectin content of the raw material. This study systematically compared five pre-fermentation treatments (pectinase, chitosan, bentonite, gelatin, and diatomite) for their effects on the methanol content and overall quality of jujube wine, aiming to identify an adsorbent pretreatment strategy that effectively reduces methanol levels while preserving wine quality. Using pectinase treatment as a reference control (representing conventional industrial pectin degradation), the results showed that all adsorbent treatments reduced the pectin content in jujube juice, thereby influencing methanol generation in the fermented wine. Notably, chitosan pretreatment exhibited the most pronounced methanol reduction (113.35 mg/L), which was 59.20% lower than that of the pectinase reference group (277.65 mg/L), and remained far below the methanol limits stipulated by Chinese, EU, and OIV standards (≤400 mg/L). This effectiveness is attributed to the positively charged nature of chitosan, which efficiently removes negatively charged pectin through electrostatic adsorption, thereby blocking methanol formation at the source. Chitosan treatment also resulted in the highest alcohol content (5.82%) and significantly reduced organic acid levels but concurrently led to a slight decrease in some key aroma esters. However, sensory evaluation revealed that jujube wine produced from the chitosan-pretreated juice maintained a harmonious overall taste profile, with an overall score comparable to that of the pectinase reference group. In comparison, bentonite and gelatin showed moderate effectiveness, while diatomite performed poorly. Notably, although pectinase treatment yielded the lowest pectin content, it paradoxically resulted in the highest methanol levels, highlighting the critical mechanism of pectin degradation (rather than removal) promoting methanol formation. In conclusion, chitosan was recommended as an effective pre-fermentation treatment strategy for producing jujube wine with a significantly reduced methanol risk. This study provided a theoretical basis and technical reference for the safe, high-quality industrial production of jujube wine.

Background: Data on the nutritional adequacy of unsupplemented vegetarians in Northeast China are limited. Methods: We compared dietary intake, body composition, and serum biomarkers among vegans, lacto-ovo-vegetarians, and omnivores. This cross-sectional study included 356 adults (all diet ≥ 2 years, no supplements). Dietary intake was assessed using a validated semi-quantitative FFQ, body composition by BIA, and serum biomarkers. Kruskal–Wallis tests with Bonferroni correction were used. Results: Vegans had lower BMI (22.0 vs. 24.6 kg/m²), body fat (24.5% vs. 28.0%), and visceral fat (0.65 vs. 1.05 L) than omnivores (all p < 0.002). Vegans consumed more fiber (38.5 vs. 18.0 g/d) and vitamin C (180 vs. 85 mg/d), but less vitamin B₁₂ (0.3 vs. 4.2 μg/d), vitamin D (0.5 vs. 3.2 μg/d), calcium (520 vs. 720 mg/d), iodine (65 vs. 130 μg/d), and selenium (45 vs. 85 μg/d). Serum vitamin B₁₂, 25-(OH)D, ferritin, and selenium were significantly lower in vegans, while homocysteine was higher. The proportion of vegans with dietary intake below the recommendation reached 100% for vitamin B₁₂ and 97% for vitamin D, whereas omnivores showed excessive sodium (75%) and SFA (70%) intake. Conclusions: In this Northeast China cohort, unsupplemented vegetarian diets offered favorable macronutrient profiles and body composition but were associated with a high prevalence of dietary intakes below recommendations for vitamin B₁₂, vitamin D, iodine, selenium, zinc, and calcium. These findings underscore the need for targeted supplementation and food fortification strategies for individuals adhering to plant-based diets without supplement use in this region.