Antibacterial action on pathogenic bacterial spore by green tea catechins

Abstract

Antibacterial effects of catechins, the major green tea polyphenols, were studied using Clostridium and Bacillus spores. Incubation with crude catechins decreased the number of C botulinum and C butyricum spores but not B cereus spores. Furthermore, the effects of six catechin derivatives on spores were investigated. (−)-Epicatechin gallate (ECg), (−)-epigallocatechin (EGC), (−)-epigallocatechin gallate (EGCg) and (+)-gallocatechin gallate (GCg) were more effective in decreasing C botulinum and C butyricum spore numbers than (+)-catechin (C) and (−)-epicatechin (EC). The vegetative growth of C botulinum and B cereus was inhibited by crude extracts of the catechins. Specifically, purified GCg and EGCg inhibited the vegetative growth of C botulinum and B cereus. The inhibitory effect of ECg on B cereus was similar to that of GCg. However, toxin-production by B cereus was not inhibited by catechin. Damage to the membrane of C butyricum spores by catechin derivatives was shown using fluorescent microscopy. This study shows that low concentrations of catechins, although requiring a long exposure time, inhibited the growth of bacterial spores. However, the effects of the purified derivatives of the catechins were not the same and GCg and EGCg were found to be the most potent. Spores that are generally resistant to many disinfectants were sensitive to catechins.

Modified Green Tea Polyphenols, EGCG-S and LTP, Inhibit Endospore in Three <i>Bacillus</i> spp.

“…TEM and SEM studies indicated that the lipid based green tea polyphenols destroyed the surface of the spores of B. cereus which supports the finding by Hara-Kudo's group [28]. The concentrations (1% and 5%) used in this study displayed a very high percentage of inhibition.…”

“…For 5% LTP, treatment for 5, 10, 15 and 30 min, the percentage of viability were 7.92% ± 0.021%, 7.32% ± 0.051%, 0.13% ± 0.002%, and 0% ± 0% respectively. 1% EGCG-S for 5 to 30 min yielded an average percentage of inhibition ranging 80.98% -99.73% and 5% EGCG-S for 5 to 30 min yielded a Figure 6(A) revealed that EGCG was working in a mechanism that was leading to destruction of the spore coat of the endospore and agglutination of spores as reported [28]. Images in Figure 6(B) clearly demonstrated that the spore coats were completely destroyed in most of the endospores after treated with 1% EGCG-S.…”

“…Green tea catechins have shown inhibitory effects on the vegetative growth of the spore forming bacteria like C. botulinum and B. cereus [28]. There are also reports indicating that EGCG can work on the heat resistant spores in B. stearothermophilus, C. thermoaceticum [29].…”

“…There are also reports indicating that EGCG can work on the heat resistant spores in B. stearothermophilus, C. thermoaceticum [29]. Hara-Kudo's group suggested that GTP is able to damage the spore membrane [28].…”

Inhibitory Effects of Natural Additives on Pathogenic Microorganisms Growth during Storage of Commercial Chicken

“…녹차에서 추출된 카테킨은 에피카테킨 (epicatechin (EC)), 에피갈로카테킨(epigallocatechin (EGC)), 에피카 테킨갈레이트(epicatechin gallate (ECG)) 및 에피갈로카테킨 갈레 이트(epigallocatechin gallate (EGCG))의 4 종류로 나눠지는데 이 중 EGCG가 전체 카테킨의 40~50%를 차지하며, 녹차의 폴리페 놀 중 EGCG가 강력한 항균 효과가 있다고 보고되었고 (13,14), 마늘 또한 닭고기 소세지 저장기간 동안 산화방지 및 미생물 생 장 억제 효과가 있다고 알려졌다 (15)(16)(17) …”