title: Tea polyphenols inactivate Cronobacter sakazakii isolated from powdered infant formula.
abstract: This study evaluated the antimicrobial activity of tea polyphenols (TP) against 4 Cronobacter sakazakii strains with different sequence types (ST) isolated from powdered infant formula (PIF). The results showed that in normal saline, 5mg/mL of TP (pH 3.44) could eliminate approximately 7.0 log cfu/mL of C. sakazakii within 1 h; in rehydrated PIF, after acidification with HCl (pH 3.55), TP showed a stronger antibacterial activity compared with the controls (malic acid, ascorbic acid, and citric acid). Further, some differences were obvious in tolerance to TP between C. sakazakii strains with different ST. The tolerance of C. sakazakii CE1 (ST4) to TP was found to be greater than that of the other 3 C. sakazakii strains (ST1, ST8, and ST64). The results of recovered test and transmission electron microscope analysis revealed that the action of TP against C. sakazakii was an irreversible bactericidal process caused by leakage of cytoplasm. Taken together, these results indicated that TP had an effective bactericidal effect against C. sakazakii, and provided a new idea for preventing and inactivating C. sakazakii in PIF.
authors.affiliation: Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin 150030, China.
authors.forename: R
authors.initials: R
authors.lastname: Li
authors.affiliation: Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin 150030, China.
authors.forename: P
authors.initials: P
authors.lastname: Fei
authors.affiliation: National Research Center of Dairy Engineering and Technology, Northeast Agricultural University, Harbin 150086, China; Synergetic Innovation Center of Food Safety and Nutrition, Northeast Agricultural University, Harbin 150030, China.
authors.forename: C X
authors.initials: CX
authors.lastname: Man
authors.affiliation: Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin 150030, China.
authors.forename: B B
authors.initials: BB
authors.lastname: Lou
authors.affiliation: Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin 150030, China.
authors.forename: J T
authors.initials: JT
authors.lastname: Niu
authors.affiliation: Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin 150030, China.
authors.forename: J
authors.initials: J
authors.lastname: Feng
authors.affiliation: Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin 150030, China.
authors.forename: L H
authors.initials: LH
authors.lastname: Sun
authors.affiliation: Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin 150030, China.
authors.forename: M Y
authors.initials: MY
authors.lastname: Li
authors.affiliation: Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin 150030, China; National Research Center of Dairy Engineering and Technology, Northeast Agricultural University, Harbin 150086, China; Synergetic Innovation Center of Food Safety and Nutrition, Northeast Agricultural University, Harbin 150030, China. Electronic address: yujun_jiang@163.com.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Jiang
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D028241:Camellia sinensis / Q000737:chemistry*; D019343:Citric Acid; D044083:Cronobacter sakazakii / Q000187:drug effects* / Q000302:isolation & purification*; D005516:Food Microbiology; D006801:Humans; D007223:Infant; D041943:Infant Formula / Q000382:microbiology*; D059808:Polyphenols / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D059808:Polyphenols; D019343:Citric Acid
keywords: Cronobacter sakazakii; inactivation; powdered infant formula; tea polyphenols