Jiang X, Doyle M P
Center for Food Safety and Quality Enhancement, University of Georgia, Griffin 30223-1797, USA.
J Food Prot. 1998 Aug;61(8):929-33. doi: 10.4315/0362-028x-61.8.929.
The effect of temperature (4 to 42 degrees C), NaCl concentration (0.5 to 7.5%), NaNO2 concentration (0 to 400 micrograms/ml), water activity (aw level of 0.6 to 0.995), pH (3.5 to 7.3) and urea (8 mM) on the survival and growth of Helicobacter pylori in a nutrient-rich laboratory culture medium was investigated. Under microaerobic conditions (5% O2, 10% CO2, and 85% N2), the organism grew well in brain heart infusion broth supplemented with 7% horse serum and antibiotics (BHI-HS-TVA) in a temperature range of 30 to 37 degrees C with agitation. H. pylori (initial population of ca. 5 x 10(3) CFU/ml) survived for 14 days at 4 degrees C, for 2 days at 25 degrees C, and for less than 1 day at 40 and 42 degrees C. The optimal NaCl concentration for growth of H. pylori was 0.5 to 1.0%; 2.0% NaCl inhibited growth. Up to 400 micrograms of NaNO2 per ml did not prevent growth. The minimum aw (adjusted with glycerol) and pH (acidified with HCl) for growth of H. pylori was 0.98 and 4.5, respectively. The addition of urea to broth greatly enhanced the growth of H. pylori at both pH 4.5 and 5.5. Although H. pylori did not grow at pH 3.5, the presence of urea in broth enhanced its survival. Considering the apparent fastidious conditions for growth of H. pylori in BHI-HS-TVA broth, H. pylori is unlikely to grow well, if at all, in most foods. The bacterium may, however, survive for extended periods of time in low acid-high moisture environments under refrigerated storage.
研究了温度（4至42摄氏度）、氯化钠浓度（0.5至7.5%）、亚硝酸钠浓度（0至400微克/毫升）、水分活度（aw值为0.6至0.995）、pH值（3.5至7.3）和尿素（8毫摩尔）对幽门螺杆菌在营养丰富的实验室培养基中存活和生长的影响。在微需氧条件下（5%氧气、10%二氧化碳和85%氮气），该菌在添加7%马血清和抗生素的脑心浸液肉汤（BHI-HS-TVA）中，于30至37摄氏度的温度范围内振荡培养时生长良好。幽门螺杆菌（初始菌量约为5×10³CFU/毫升）在4摄氏度下存活14天，在25摄氏度下存活2天，在40和42摄氏度下存活不到1天。幽门螺杆菌生长的最佳氯化钠浓度为0.5至1.0%；2.0%的氯化钠抑制生长。每毫升高达400微克的亚硝酸钠并不妨碍生长。幽门螺杆菌生长的最低水分活度（用甘油调节）和pH值（用盐酸酸化）分别为0.98和4.5。向肉汤中添加尿素极大地增强了幽门螺杆菌在pH值4.5和5.5时的生长。尽管幽门螺杆菌在pH值3.5时不生长，但肉汤中尿素的存在提高了其存活率。考虑到幽门螺杆菌在BHI-HS-TVA肉汤中生长的明显苛刻条件，幽门螺杆菌在大多数食物中不太可能生长良好，即便能生长也很有限。然而，该菌在冷藏储存的低酸高水分环境中可能会长期存活。
