Departments of Ophthalmology and Visual Sciences, Texas Tech University Health Sciences Center, School of Medicine, Lubbock, TX, USA.
Departments of Molecular Microbiology and Immunology, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
Int Wound J. 2017 Feb;14(1):79-84. doi: 10.1111/iwj.12554. Epub 2015 Dec 28.
For proper wound healing, control of bacteria or bacterial infections is of major importance. While caring for a wound, dressing material plays a key role as bacteria can live in the bandage and keep re-infecting the wound. They do this by forming biofilms in the bandage, which slough off planktonic bacteria and overwhelm the host defense. It is thus necessary to develop a wound dressing that will inhibit bacterial growth. This study examines the effectiveness of a polyurethane foam wound dressing bound with polydiallyl-dimethylammonium chloride (pDADMAC) to inhibit the growth of bacteria in a wound on the back of a mouse. This technology does not allow pDADMAC to leach away from the dressing into the wound, thereby preventing cytotoxic effects. Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii were chosen for the study to infect the wounds. S. aureus and P. aeruginosa are important pathogens in wound infections, while A. baumannii was selected because of its ability to acquire or upregulate antibiotic drug resistance determinants. In addition, two different isolates of methicillin-resistant S. aureus (MRSA) were tested. All the bacteria were measured in the wound dressing and in the wound tissue under the dressing. Using colony-forming unit (CFU) assays, over six logs of inhibition (100%) were found for all the bacterial strains using pDADMAC-treated wound dressing when compared with control-untreated dressing. The CFU assay results obtained with the tissues were significant as there were 4-5 logs of reduction (100%) of the test organism in the tissue of the pDADMAC-covered wound versus that of the control dressing-covered wound. As the pDADMAC cannot leave the dressing (like other antimicrobials), this would imply that the dressing acts as a reservoir for free bacteria from a biofilm and plays a significant role in the development of a wound infection.
为了实现适当的伤口愈合，控制细菌或细菌感染至关重要。在护理伤口时，敷料材料起着关键作用，因为细菌可以生活在绷带中，并不断重新感染伤口。它们通过在绷带中形成生物膜来实现这一点，生物膜会脱落浮游细菌并使宿主防御系统不堪重负。因此，有必要开发一种能够抑制细菌生长的伤口敷料。本研究考察了一种与聚二烯丙基二甲基氯化铵（pDADMAC）结合的聚氨酯泡沫伤口敷料抑制小鼠背部伤口中细菌生长的效果。这种技术不会使 pDADMAC 从敷料中渗出到伤口中，从而防止细胞毒性作用。选择金黄色葡萄球菌、铜绿假单胞菌和鲍曼不动杆菌感染伤口，是因为它们是伤口感染的重要病原体，而不动杆菌则因其能够获得或上调抗生素药物耐药决定因素而被选中。此外，还测试了两种不同的耐甲氧西林金黄色葡萄球菌（MRSA）分离株。所有细菌都在伤口敷料中和敷料下的伤口组织中进行了测量。使用集落形成单位（CFU）测定法，与对照未处理的敷料相比，使用 pDADMAC 处理的伤口敷料对所有细菌菌株的抑制率超过 6 个对数级（100%）。组织中 CFU 测定法的结果非常显著，因为在 pDADMAC 覆盖的伤口组织中，测试菌的减少量为 4-5 个对数级（100%），而对照敷料覆盖的伤口组织中的减少量则为 4-5 个对数级（100%）。由于 pDADMAC 不能离开敷料（就像其他抗菌剂一样），这意味着敷料充当生物膜中游离细菌的储库，并在伤口感染的发展中起着重要作用。
