Saravia Marta Estela, Nelson-Filho Paulo, da Silva Raquel Assed Bezerra, Faria Gisele, Rossi Marcos Antonio, Ito Izabel Yoko
National University of Tucumán, Tucumán, Argentina.
J Dent Child (Chic). 2008 Jan-Apr;75(1):29-32.
Employing microbial culture, the purpose of this study was to assess in vitro the viability of Streptococcus mutans on toothbrush bristles relative to the drying time.
Forty-five toothbrushes were soaked in a suspension containing S. mutans (ATCC 25175) in a 1,720.000 cfu/mL concentration (0.5 McFarland scale) for 4 minutes, rinsed in sterile tap water, and assigned to 9 groups. Group 1 toothbrushes were immediately incubated in CaSaB CaSaB (bacitracin sucrose broth-selective enrichment broth) culture medium for 4 days. Toothbrushes from groups 2 to 9 were kept at room temperature for 4, 8, 12, 24, 36, 48, 60, and 72 hours, respectively, and subsequently incubated in CaSaB culture medium.
It was observed that micro-organisms were present on toothbrushes of groups 1 to 3, ranging from 50 to 100+ cfu. From the 12-hour drying period on, there was no growth of S. mutans. Regarding the S. mutans cfu, the results were expressed in scores and submitted to the Kruskal Wallis statistical test. It was observed that groups 1 to 3 were similar to each other (P>.05) and differed significantly (P<.001) from other groups, which, in turn, behaved similarly (P>0.05). From the 12-hour drying period on, there was a statistically significant decrease in the number of S. mutans cfu (P<.01).
It may be concluded that Streptococcus mutans remained viable on the toothbrushes' bristles for up to 8 hours.
本研究采用微生物培养法，旨在体外评估变形链球菌在牙刷刷毛上的生存能力与干燥时间的关系。
45支牙刷浸泡于含有浓度为1,720,000 cfu/mL（0.5麦氏比浊标准）的变形链球菌（ATCC 25175）的悬液中4分钟，用无菌自来水冲洗后，分为9组。第1组牙刷立即置于CaSaB（杆菌肽蔗糖肉汤 - 选择性增菌肉汤）培养基中培养4天。第2至9组的牙刷分别在室温下放置4、8、12、24、36、48、60和72小时，随后置于CaSaB培养基中培养。
观察到第1至3组的牙刷上存在微生物，菌落形成单位（cfu）为50至100+。从干燥12小时起，变形链球菌未生长。关于变形链球菌的cfu，结果以评分表示，并进行Kruskal Wallis统计检验。观察到第1至3组彼此相似（P>0.05），与其他组有显著差异（P<0.001），而其他组之间表现相似（P>0.05）。从干燥12小时起，变形链球菌的cfu数量有统计学显著下降（P<0.01）。
可以得出结论，变形链球菌在牙刷刷毛上可存活长达8小时。
