Conner-Kerr T A, Sullivan P K, Gaillard J, Franklin M E, Jones R M
Department of Physical Therapy, School of Allied Health Sciences, East Carolina University, Greenville, NC 27858, USA.
Ostomy Wound Manage. 1998 Oct;44(10):50-6.
Wound infections produced by antibiotic-resistant bacterial strains are particularly difficult to manage. This study examined the effectiveness of ultraviolet (UV) light treatment in killing antibiotic-resistant strains of Staphylococcus aureus and Enterococcus faecalis in vitro. Between 2 and 5 replications of each organism at 10(8) organisms/ml were prepared and plated on sheep blood agar medium and treated with UV light (254 nm, 15.54 mW/cm2 output). Irradiation times were 0, 2, 5, 8, 15, 30, 45, 60, 90 or 120 seconds. Bacterial cultures were then incubated at 35 degrees C for 24 hours. Kill rates were 99.9 percent for the methicillin-resistant strain of S. aureus (MRSA) at 5, 8, 15, 30, 45, 60 seconds and 100 percent at 90 and 120 seconds. Kill rates were 99.9 percent at 5, 8, 15, 30 seconds for vancomycin-resistant E. faecalis (VRE) and 100 percent at 45, 60, 90, 120 seconds. Similar results were found with UV light treatment of the antibiotic-susceptible strains of S. aureus and E. faecalis. A significant difference in kill rates at 30 seconds of UV exposure was detected between the antibiotic-resistant strain of S. aureus and the antibiotic-resistant strain of E. faecalis (Student's t test, p < 0.01). Significant differences were also detected in the kill rates at 30 second exposure times for the antibiotic-susceptible strains of S. aureus and E. faecalis. These findings suggest that the Enterococcal bacteria is more susceptible to the killing effects of UV. This data also suggests that UV light at 254 nm is bactericidal for antibiotic-resistant strains of S. aureus and E. faecalis at times as short as 5 seconds and that the enterococcal bacteria is more susceptible to the killing effects of UV. With recommended patient treatment times for infected wounds being significantly longer than 5 seconds, this data indicates that patient treatment times need to be re-examined.
由耐抗生素细菌菌株引起的伤口感染特别难以处理。本研究检测了紫外线（UV）光疗法在体外杀灭耐抗生素金黄色葡萄球菌和粪肠球菌菌株的有效性。将每种微生物以10⁸个/ml的浓度进行2至5次重复培养，接种于羊血琼脂培养基上，并用紫外线（254nm，输出功率15.54mW/cm²）进行处理。照射时间分别为0、2、5、8、15、30、45、60、90或120秒。然后将细菌培养物在35℃下孵育24小时。耐甲氧西林金黄色葡萄球菌（MRSA）菌株在照射5、8、15、30、45、60秒时的杀灭率为99.9%，在90和120秒时为100%。耐万古霉素粪肠球菌（VRE）在照射5、8、15、30秒时的杀灭率为99.9%，在45、60、90、120秒时为100%。对金黄色葡萄球菌和粪肠球菌的抗生素敏感菌株进行紫外线光疗法也得到了类似结果。在照射30秒时，耐抗生素金黄色葡萄球菌菌株和耐抗生素粪肠球菌菌株之间的杀灭率存在显著差异（学生t检验，p<0.01）。在照射30秒时，金黄色葡萄球菌和粪肠球菌的抗生素敏感菌株的杀灭率也存在显著差异。这些发现表明肠球菌对紫外线的杀伤作用更敏感。该数据还表明，254nm的紫外线在短至5秒的时间内对耐抗生素金黄色葡萄球菌和粪肠球菌菌株具有杀菌作用，并且肠球菌对紫外线的杀伤作用更敏感。鉴于推荐的感染伤口患者治疗时间明显长于5秒，该数据表明需要重新审视患者的治疗时间。
