Simango C
Department of Medical Laboratory Technology, University of Zimbabwe Medical School, Avondale, Harare, Zimbabwe.
J Trop Med Hyg. 1995 Dec;98(6):465-8.
This study was carried out to investigate the survival rates of strains of enteropathogenic Escherichia coli in lactic and acetic acids and to compare them with their survival rates in sour porridge. The fermented and unfermented porridges were prepared in the laboratory. The fermented porridge had both lactic and acetic acids; unfermented porridge was adjusted to the pH of sour porridge with lactic and acetic acids. The sour porridge, the unfermented porridge adjusted to the pH of sour porridge with lactic and acetic acids and the unfermented porridge were inoculated with six strains of enteropathogenic E. coli. The inoculated porridges had a final concentration of 10(6)-10(7) colony-forming units (c.f.u.) per ml of food. Few of the strains of enteropathogenic E. coli were detected 48 hours after inoculation in sour porridge. All the strains were detected 48 hours after inoculation in unfermented porridges adjusted to the pH of sour porridge with lactic and acetic acids but decreased in numbers of surviving cells by about 2 log10 c.f.u. per ml of food. All the strains survived in unfermented porridge for 48 hours and increased in numbers. These results show that lactic and acetic acids have antimicrobial properties but they are not as effective as sour porridge in inhibiting the growth and survival of enteropathogenic E. coli. The inhibitory property of sour porridge is due to a combination of many substances including lactic and acetic acids.
本研究旨在调查肠致病性大肠杆菌菌株在乳酸和乙酸中的存活率，并将其与在酸粥中的存活率进行比较。在实验室制备了发酵粥和未发酵粥。发酵粥中同时含有乳酸和乙酸；未发酵粥用乳酸和乙酸调节至酸粥的pH值。将六种肠致病性大肠杆菌菌株接种到酸粥、用乳酸和乙酸调节至酸粥pH值的未发酵粥以及未发酵粥中。接种后的粥每毫升食物中的最终浓度为10(6)-10(7)菌落形成单位（c.f.u.）。接种后48小时，在酸粥中几乎检测不到肠致病性大肠杆菌菌株。在用乳酸和乙酸调节至酸粥pH值的未发酵粥中，接种后48小时所有菌株均被检测到，但每毫升食物中存活细胞数量减少了约2个对数10 c.f.u.。所有菌株在未发酵粥中存活48小时且数量增加。这些结果表明，乳酸和乙酸具有抗菌特性，但在抑制肠致病性大肠杆菌的生长和存活方面不如酸粥有效。酸粥的抑制特性归因于包括乳酸和乙酸在内的多种物质的组合。
