Fallon M T, Shafer W, Jacob E
Atlanta VA Medical Center Research Service, Emory University, Atlanta, Georgia, USA.
J Surg Res. 1999 Sep;86(1):97-102. doi: 10.1006/jsre.1999.5686.
In a previous study, the topical administration of biodegradable, controlled-release poly-(dl-lactide-co-glycolide) cefazolin microspheres could effectively prevent surgical wound infections with a sensitive strain of Staphylococcus aureus in an experimental animal model. The objective of the current study was to evaluate and compare the efficacy of topical antibiotic therapy with cefazolin microspheres to systemic cefazolin therapy for the treatment of experimental rat surgical wounds contaminated with a methicillin-resistant strain of S. aureus (MRSA).
A local infection model in rats was used. MRSA was used to infect pockets surgically produced in the paraspinous muscles. Groups of rats received either topical cefazolin microspheres, topical cefazolin powder, parenteral cefazolin, or no treatment. Feces were cultured to evaluate the effect of antibiotic therapy on gut flora.
The rate of clinical wound infection following topical application of cefazolin microspheres (13%) was significantly lower than the 53% infection rate observed in rats who had received a 2-week course of systemic cefazolin therapy (P = 0.046). Moreover, single-dose topical antibiotic therapy with cefazolin microspheres completely eradicated MRSA from the wounds of 7 of 15 (47%) animals. There was no statistically significant difference, however, in the rate of clinical wound infection between rats whose wounds were treated topically with free cefazolin powder and those treated with systemic cefazolin (P = 0.12). Importantly, selection of antibiotic-resistant bacteria was associated with systemic but not local cefazolin therapy.
The results of this study suggest that topical antibiotic therapy with controlled-release cefazolin microspheres may be effective for the prevention of wound infection with both methicillin-sensitive and methicillin-resistant strains of S. aureus in selected surgical procedures that are at high risk of developing postoperative wound infection.
在之前的一项研究中，局部应用可生物降解的控释聚（dl-丙交酯-共-乙交酯）头孢唑林微球能够在实验动物模型中有效预防由敏感金黄色葡萄球菌引起的手术伤口感染。本研究的目的是评估并比较头孢唑林微球局部抗生素治疗与全身性头孢唑林治疗对感染耐甲氧西林金黄色葡萄球菌（MRSA）的实验大鼠手术伤口的疗效。
采用大鼠局部感染模型。用MRSA感染在椎旁肌中手术形成的腔隙。大鼠分组后分别接受局部应用头孢唑林微球、局部应用头孢唑林粉末、胃肠外给予头孢唑林或不进行治疗。对粪便进行培养以评估抗生素治疗对肠道菌群的影响。
局部应用头孢唑林微球后的临床伤口感染率（13%）显著低于接受为期2周全身性头孢唑林治疗的大鼠的感染率（53%）（P = 0.046）。此外，15只动物中有7只（47%）接受单剂量头孢唑林微球局部抗生素治疗后伤口中的MRSA被完全清除。然而，局部应用游离头孢唑林粉末治疗的大鼠与接受全身性头孢唑林治疗的大鼠的临床伤口感染率之间无统计学显著差异（P = 0.12）。重要的是，抗生素耐药菌的选择与全身性而非局部头孢唑林治疗相关。
本研究结果表明，在有术后伤口感染高风险的特定外科手术中，采用控释头孢唑林微球进行局部抗生素治疗可能对预防甲氧西林敏感和耐甲氧西林金黄色葡萄球菌引起的伤口感染均有效。
