Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK.
Microbiology Department, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK.
J Med Microbiol. 2022 May;71(5). doi: 10.1099/jmm.0.001517.
Diabetic foot infection (DFI) is the main reason for diabetes-related hospitalisation and is a major cause of diabetes-related amputation. DFIs are often complicated by ischaemia in the affected limb, the presence of polymicrobial biofilms and increasingly the occurrence of antibiotic resistant bacteria. Antibiotic loaded beads could inhibit the growth of polymicrobial DFI communities with differing compositions . This study investigates the efficacy of antibiotic loaded calcium sulfate beads (Stimulan Rapid Cure, Biocomposites Ltd., UK) against polymicrobial DFI communities and individual bacterial strains derived from DFIs. Debrided tissue obtained from the base of infected diabetic foot ulcers was homogenised and spread over the surface of Columbia blood agar (CBA) and fastidious anaerobe agar (FAA) plates. Calcium sulfate beads containing a combination of vancomycin and gentamicin were then placed on the surface of the agar and following incubation, zones of inhibition (ZOI) were measured. For individual bacterial strains isolated from the infected tissue, calcium sulfate beads containing vancomycin, gentamicin, flucloxacillin or rifampicin and beads containing a combination of vancomycin and gentamicin or flucloxacillin and rifampicin were tested for their ability to inhibit growth. Calcium sulfate beads loaded with a combination of vancomycin and gentamicin were able to inhibit bacterial growth from all polymicrobial tissue homogenates tested, with ZOI diameters ranging from 15 to 40 mm. In the case of individual bacterial strains, beads containing combinations of vancomycin and gentamicin or flucloxacillin and rifampicin were able to produce ZOI with Gram-positive facultatitive anaerobic strains such as and , Gram-negative facultative anaerobic strains such as and obligate anaerobic strains such as even where acquired resistance to one of the antibiotics in the combination was evidenced. The local use of calcium sulfate beads containing a combination of two antibiotics demonstrated high efficacy against polymicrobial DFI communities and individual DFI bacterial strains in zone of inhibition tests. These results show promise for clinical application, but further research and clinical studies are required.
糖尿病足感染（DFI）是导致糖尿病住院的主要原因，也是导致糖尿病相关截肢的主要原因。DFI 常伴有受累肢体缺血、多微生物生物膜的存在，以及越来越多的抗生素耐药菌。载抗生素珠粒可以抑制具有不同组成的多微生物 DFI 群落的生长。本研究调查了载抗生素硫酸钙珠粒（Stimulan Rapid Cure，Biocomposites Ltd.，英国）对多微生物 DFI 群落和源自 DFI 的单个细菌菌株的疗效。从感染性糖尿病足溃疡的底部获得清创组织，将其均质化并涂在哥伦比亚血琼脂（CBA）和苛养厌氧菌琼脂（FAA）平板表面。然后将载有万古霉素和庆大霉素的硫酸钙珠粒置于琼脂表面，孵育后测量抑菌区（ZOI）。对于从感染组织中分离出的单个细菌菌株，测试了载有万古霉素、庆大霉素、氟氯西林或利福平的硫酸钙珠粒以及载有万古霉素和庆大霉素或氟氯西林和利福平组合的珠粒抑制生长的能力。载有万古霉素和庆大霉素组合的硫酸钙珠粒能够抑制所有测试的多微生物组织匀浆中的细菌生长，ZOI 直径范围为 15 至 40mm。对于个别细菌菌株，载有万古霉素和庆大霉素或氟氯西林和利福平组合的珠粒能够产生 ZOI，对革兰氏阳性兼性厌氧菌菌株如 、革兰氏阴性兼性厌氧菌菌株如 、甚至对组合中一种抗生素产生获得性耐药的专性厌氧菌菌株 也是如此。局部使用载有两种抗生素组合的硫酸钙珠粒在抑菌试验中对多微生物 DFI 群落和单个 DFI 细菌菌株表现出高效。这些结果为临床应用提供了希望，但需要进一步的研究和临床研究。
