Wiegand Cornelia, Abel Martin, Ruth Peter, Elsner Peter, Hipler Uta-Christina
Department of Dermatology, University Hospital Center Jena, Jena, Germany.
Skin Pharmacol Physiol. 2015;28(3):147-58. doi: 10.1159/000367632. Epub 2015 Jan 20.
Wound infection plays an important role in compromised wound healing. A high bioburden impairs healing and leads to formation of a chronic wound. Distinctly higher pH values were observed in chronic wounds compared to acute wounds. However, there is only limited knowledge of pH dependency on the antibacterial efficacy of common antimicrobial substances.
This study investigated the pH influence on the antimicrobial efficacy of povidone (PVP)-iodine, silver nitrate, chlorhexidine, octenidine and polihexanide against Staphylococcus aureus and Pseudomonas aeruginosa using the agar diffusion test and microplate laser nephelometry.
The bactericidal activity of chlorhexidine and octenidine was mainly pH-independent in a pH range of 5.0-9.0. In contrast, polihexanide showed a significant efficacy increase at a higher pH. It was also found that the influence of the pH on antiseptics differs among species of bacteria. For instance, S. aureus exhibited an increasing sensitivity against silver nitrate with rising pH whereas the effect on P. aeruginosa was found to be distinctly decreased. The antimicrobial effect of PVP-iodine was strongly diminished with rising pH.
The shift towards higher pH values in chronic wounds compared to acute wounds makes it imperative to know whether the antimicrobial efficacy of applied antimicrobial substances is altered by different pH levels. The results suggest that application of polihexanide might be advantageous for the management of wound infections, as both S. aureus and P. aeruginosa exhibited an increased susceptibility with rising pH.
伤口感染在受损伤口愈合中起重要作用。高生物负荷会损害愈合并导致慢性伤口形成。与急性伤口相比，慢性伤口的pH值明显更高。然而，关于pH值对常见抗菌物质抗菌效果的依赖性，目前了解有限。
本研究使用琼脂扩散试验和微孔板激光散射比浊法，研究了pH值对聚维酮碘、硝酸银、氯己定、奥替尼啶和聚己缩胍对金黄色葡萄球菌和铜绿假单胞菌抗菌效果的影响。
在5.0 - 9.0的pH范围内，氯己定和奥替尼啶的杀菌活性主要与pH值无关。相比之下，聚己缩胍在较高pH值时显示出显著的效果增强。还发现pH值对防腐剂的影响因细菌种类而异。例如，金黄色葡萄球菌对硝酸银的敏感性随pH值升高而增加，而对铜绿假单胞菌的影响则明显降低。聚维酮碘的抗菌效果随pH值升高而显著降低。
与急性伤口相比，慢性伤口的pH值向更高值转变，这使得了解所应用抗菌物质的抗菌效果是否会因不同的pH水平而改变变得至关重要。结果表明，应用聚己缩胍可能对伤口感染的管理有利，因为金黄色葡萄球菌和铜绿假单胞菌对其敏感性均随pH值升高而增加。
