Abstract：
OBJECTIVE: The aim of the present study is to evaluate the probiotic effect of Lactobacillus acidophilus and Lactobacillus rhamnosus on clinical isolates of Mutans Streptococci (MS) and antibiotic susceptibility of these strains to commonly used antibiotics in dentistry.
METHODS: Plaque samples from permanent first molars were collected and transferred aseptically onto Mitis-Salivarius agar and incubated at 37°C for 24 hours in the presence of 5-10% CO2. Mutans streptococci colonies were identified biochemically using Hi-Strep identification kit. The inhibitory activity of the clinical strains of MS on Lactobacilli was investigated using agar-overlay interference technique. Positive inhibition was appreciated as a clear zone around the Lactobacilli. Disk diffusion assay was done as described by CLSI M100-S25 for antibiotic susceptibility. The zone of growth inhibition caused by Lactobacilli and antibiotics on MS clinical strains was measured directly using a vernier caliper. Statistical analysis was done using independent t-test.
RESULTS: Mutans streptococci exhibited positive inhibition with both the probiotic strains and L. acidophilus showed more zones of inhibition than L. rhamnosus. Antibiotic susceptibility of clinical strains of MS showed sensitivity to penicillin and vancomycin, however, tetracycline and erythromycin showed very few resistant strains. The highest zone of inhibition was shown by cephalothin followed by penicillin, tetracycline, ciprofloxacin, erythromycin, and vancomycin.
CONCLUSIONS: L. rhamnosus and L. acidophilus have strong inhibitory effects on clinical strains of MS. Lactobacillus acidophilus showed a higher zone of inhibition. All the clinical strains of MS were sensitive to penicillin and vancomycin. The highest zone of inhibition was shown by cephalothin.
CONCLUSIONS: Dental caries remains silent epidemic and increasing antibiotic resistance is another major challenge that threatens the world. Newer methods such as whole-bacteria replacement therapy using probiotics for decreasing harmful oral pathogens and reducing the intake of antibiotics must be explored. More researches to promote use of probiotics should be initiated due to its possible preventive and health maintenance benefits providing an end to new cavities and antibiotic resistance.
METHODS: Plaque samples from permanent first molars were collected and transferred aseptically onto Mitis-Salivarius agar and incubated at 37°C for 24 hours in the presence of 5-10% CO2. Mutans streptococci colonies were identified biochemically using Hi-Strep identification kit. The inhibitory activity of the clinical strains of MS on Lactobacilli was investigated using agar-overlay interference technique. Positive inhibition was appreciated as a clear zone around the Lactobacilli. Disk diffusion assay was done as described by CLSI M100-S25 for antibiotic susceptibility. The zone of growth inhibition caused by Lactobacilli and antibiotics on MS clinical strains was measured directly using a vernier caliper. Statistical analysis was done using independent t-test.
RESULTS: Mutans streptococci exhibited positive inhibition with both the probiotic strains and L. acidophilus showed more zones of inhibition than L. rhamnosus. Antibiotic susceptibility of clinical strains of MS showed sensitivity to penicillin and vancomycin, however, tetracycline and erythromycin showed very few resistant strains. The highest zone of inhibition was shown by cephalothin followed by penicillin, tetracycline, ciprofloxacin, erythromycin, and vancomycin.
CONCLUSIONS: L. rhamnosus and L. acidophilus have strong inhibitory effects on clinical strains of MS. Lactobacillus acidophilus showed a higher zone of inhibition. All the clinical strains of MS were sensitive to penicillin and vancomycin. The highest zone of inhibition was shown by cephalothin.
CONCLUSIONS: Dental caries remains silent epidemic and increasing antibiotic resistance is another major challenge that threatens the world. Newer methods such as whole-bacteria replacement therapy using probiotics for decreasing harmful oral pathogens and reducing the intake of antibiotics must be explored. More researches to promote use of probiotics should be initiated due to its possible preventive and health maintenance benefits providing an end to new cavities and antibiotic resistance.
摘要：
目的：本研究的目的是评价嗜酸乳杆菌和鼠李糖乳杆菌对临床分离的变形链球菌(MS)的益生作用及其对牙科常用抗菌药物的敏感性。
方法:收集来自永久性第一磨牙的菌斑样品并无菌转移到Mitis-Salivarius琼脂上,并在5-10%CO2存在下在37°C下孵育24小时。使用Hi-Strep鉴定试剂盒生化鉴定突变链球菌菌落。使用琼脂覆盖干扰技术研究了MS临床菌株对乳杆菌的抑制活性。阳性抑制被认为是乳杆菌周围的清晰区域。如CLSIM100-S25所述进行圆盘扩散测定以用于抗生素敏感性。使用游标卡尺直接测量MS临床菌株上由乳杆菌和抗生素引起的生长抑制区域。使用独立t检验进行统计学分析。
结果：变形链球菌对益生菌菌株均表现出阳性抑制，而嗜酸乳杆菌比鼠李糖乳杆菌表现出更多的抑制区。MS临床菌株的抗生素敏感性显示对青霉素和万古霉素的敏感性，然而,四环素和红霉素的耐药菌株很少。最高的抑制区域是头孢菌素，其次是青霉素，四环素,环丙沙星,红霉素,和万古霉素.
结论：L.鼠李糖和嗜酸乳杆菌对临床菌株有很强的抑制作用。嗜酸乳杆菌显示出更高的抑制区。所有MS临床菌株均对青霉素和万古霉素敏感。最高的抑制区由头孢菌素显示。
结论：龋齿仍然是无声的流行，增加抗生素耐药性是威胁世界的另一个主要挑战。必须探索新的方法，例如使用益生菌的全细菌替代疗法，以减少有害的口腔病原体并减少抗生素的摄入。应该开始更多的研究来促进益生菌的使用，因为它可能具有预防和健康维护的益处，可以终止新的龋齿和抗生素耐药性。
方法:收集来自永久性第一磨牙的菌斑样品并无菌转移到Mitis-Salivarius琼脂上,并在5-10%CO2存在下在37°C下孵育24小时。使用Hi-Strep鉴定试剂盒生化鉴定突变链球菌菌落。使用琼脂覆盖干扰技术研究了MS临床菌株对乳杆菌的抑制活性。阳性抑制被认为是乳杆菌周围的清晰区域。如CLSIM100-S25所述进行圆盘扩散测定以用于抗生素敏感性。使用游标卡尺直接测量MS临床菌株上由乳杆菌和抗生素引起的生长抑制区域。使用独立t检验进行统计学分析。
结果：变形链球菌对益生菌菌株均表现出阳性抑制，而嗜酸乳杆菌比鼠李糖乳杆菌表现出更多的抑制区。MS临床菌株的抗生素敏感性显示对青霉素和万古霉素的敏感性，然而,四环素和红霉素的耐药菌株很少。最高的抑制区域是头孢菌素，其次是青霉素，四环素,环丙沙星,红霉素,和万古霉素.
结论：L.鼠李糖和嗜酸乳杆菌对临床菌株有很强的抑制作用。嗜酸乳杆菌显示出更高的抑制区。所有MS临床菌株均对青霉素和万古霉素敏感。最高的抑制区由头孢菌素显示。
结论：龋齿仍然是无声的流行，增加抗生素耐药性是威胁世界的另一个主要挑战。必须探索新的方法，例如使用益生菌的全细菌替代疗法，以减少有害的口腔病原体并减少抗生素的摄入。应该开始更多的研究来促进益生菌的使用，因为它可能具有预防和健康维护的益处，可以终止新的龋齿和抗生素耐药性。
