Corrigendum to Application of natural antimicrobials in food preservation: Recent views [Food Control 126 (2021) 108066]

In vitro phytochemical analysis and antibacterial and antifungal efficacy assessment of ethanolic and aqueous extracts of Rumex nervosus leaves against selected bacteria and fungi

Background and Aim

Scientists are interested in identifying natural antibiotic substitutes that are effective against drug-resistant pathogenic microbes and spoilage fungi to counter pathogens and reduce the major public health problem of antibiotic residues in animal products. This study aimed to evaluate the antimicrobial activity of Rumex nervosus leaves (RNLs) as a medicinal herb against four bacterial and two fungal strains using absolute ethanol, 50% ethanol, and aqueous extracts.

Materials and Methods

The antimicrobial activities of various RNL extracts against selected microbes were evaluated using the disk diffusion antibiotic susceptibility test, minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), minimum fungicidal concentrations, and the poisoned food technique.

Results

The absolute ethanol RNL extract showed the best bacteriostatic/bactericidal activity against Salmonella Typhimurium, Escherichia coli, and Staphylococcus aureus (MIC/MBC: 0.20/0.40, 0.20/0.40, and 0.32/0.65 mg/mL, respectively). The diameter of the zone of inhibition was larger (p < 0.05) for the 100% ethanol RNL extract (8.17 mm) against Salmonella Typhimurium, the 50% ethanol-RNL extract (11.5 mm) against E. coli, and the aqueous RNL extract (14.0 mm) against S. aureus than for any other bacterial isolate. The aqueous RNL extract strongly (p < 0.0001) inhibited the mycelial growth of Aspergillus fumigatus (100%) and Aspergillus niger (81.4%) compared with the control.

Conclusion

The results of this study suggest that RNL is a promising new natural antimicrobial agent for food preservation. To date, most research on the antimicrobial properties of natural herbs has been conducted in vitro, with few exceptions in vivo and intervention-based research.

Bacteriological Quality and Antimicrobial Susceptibility Patterns Among Raw Milk Producers and Vendors in Gomole District, Borena Zone, Southern Ethiopia

Background and Aim

Milk consumption plays a great role in the nutrition of consumers and the income of producers as well as vendors, but their bacteriological quality causes loss of those benefits. Hence, the aim of this study was to determine the bacteriological quality, associated factors and antimicrobial susceptibility pattern among raw milk of producers and vendors in Gomole district, Borena zone, South Ethiopia, from March 1 to April 30, 2019.

Methods

A cross-sectional study was conducted on 130 purposively selected study participants. Pretested structured questionnaires and observation checklists were used to collect data. Then, 15 to 20 mL of milk samples were collected from producers and vendors for laboratory analysis. Standard plate count agar and eosin methylene blue agar were used for total bacterial count and total coliform count, respectively. Bacterial isolation from poor-quality milk was performed with biochemical tests and antimicrobial susceptibility tests using Kirby Bauer’s disk diffusion method. After completeness checking, the data were analyzed by Statistical Package for the Social Sciences version 21. Chi-square (χ²) was used to analyze association factors, and a p value <0.05 was considered statistically significant.

Results

The overall means ± standard deviation of the total bacterial count (TBC) and total coliform count (TCC) were 7.75 ± 0.882 and 6.69 ± 1.545 log10 CFU/mL, respectively. The mean TBC was significantly different between producers’ and vendors’ milks t = 2.1 (P < 0.001). The proportions of raw milk TBC and TCC of poor quality were 90% and 80%, respectively. Poor hand washing practices before milking, water source and cleanliness of milk containers were associated with poor milk quality. The isolated bacteria were E. coli (30.8%), S. aureus (17.9%) and Salmonella spp. Out of the bacterial isolates, 80.4% were extensive drug resistant, 14.3% were multidrug resistant, and 5.4% were resistant against all antimicrobials used in this study.

Conclusion

Ensuring proper hygienic practices during milking, storage and transportation to reduce milk contamination.