■铜绿假单胞菌是犬外耳炎的主要原因。恩诺沙星通常局部应用于治疗这种疾病,尽管顽固性和复发性感染很常见。有证据表明,暴露于蓝光(400-470nm)对铜绿假单胞菌和其他微生物具有杀菌作用。
■在本研究中,我们测试了蓝光(375-450nm)的杀生物效果,单独或与恩诺沙星联合使用,针对来自外耳炎犬的6株铜绿假单胞菌(其中5株对恩诺沙星具有抗性)。
■用蓝光处理浮游细胞培养物导致所有七个测试菌株的集落形成单位(CFU)显着降低(p<0.5)。在某些情况下低于检测限。在暴露于405nm波长的光后观察到最大的杀菌效果(p<0.05)。暴露于蓝光20分钟通常导致铜绿假单胞菌比恩诺沙星治疗更多的减少,和联合治疗通常导致最大的CFU减少。对这些菌株的基因组序列的分析确定恩诺沙星抗性可能是GyrB中S466F取代的结果。然而,基因型与蓝光治疗易感性之间没有明显关联.
■这些结果表明,蓝光处理,特别是在405nm波长下,尤其是与恩诺沙星联合治疗,可能是由铜绿假单胞菌引起的其他顽固的犬外耳炎的有效治疗方法。它还可以提供扩展恩诺沙星治疗的有用性的方法,否则恩诺沙星治疗作为唯一的治疗剂将是无效的。
UNASSIGNED: Pseudomonas aeruginosa is a leading cause of canine otitis externa.
Enrofloxacin is often applied topically to treat this condition, although recalcitrant and recurring infections are common. There is evidence that exposure to blue light (400-470 nm) has a bactericidal effect on P. aeruginosa and other microorganisms.
UNASSIGNED: In the present study, we tested the biocidal effect of blue light (375-450 nm), alone or in combination with
enrofloxacin, against six isolates of P. aeruginosa from dogs with otitis externa (5 of which were resistant to
enrofloxacin).
UNASSIGNED: Treatment of planktonic cell cultures with blue light resulted in significant (p < 0.5) reductions in Colony Forming Units (CFU) for all seven strains tested, in some cases below the limit of detection. The greatest bactericidal effect was observed following exposure to light at 405 nm wavelength (p < 0.05). Exposure to blue light for 20 min usually resulted in a greater reduction in Pseudomonas aeruginosa than enrofloxacin treatment, and combination treatment typically resulted in the largest reductions in CFU. Analysis of the genome sequences of these strains established that
enrofloxacin resistance was likely the result of a S466F substitution in GyrB. However, there was no clear association between genotype and susceptibility to blue light treatment.
UNASSIGNED: These results suggest that blue light treatment, particularly at 405 nm wavelength, and especially in combination with enrofloxacin therapy, could be an effective treatment for otherwise recalcitrant canine otitis externa caused by Pseudomonas aeruginosa. It may also provide a way of extending the usefulness of
enrofloxacin therapy which would otherwise be ineffective as a sole therapeutic agent.