Marchese Anna, Gualco Laura, Debbia Eugenio A, Schito Gian Carlo, Schito Anna Maria
Sezione di Microbiologia, Di.S.C.A.T., University of Genoa, Genoa, Italy.
Int J Antimicrob Agents. 2003 Oct;22 Suppl 2:53-9. doi: 10.1016/s0924-8579(03)00230-9.
The aim of this study was to reassess the activity of fosfomycin against recently isolated uropathogens circulating in Italy and to evaluate the effect of fosfomycin resistance on the expression of several virulence traits using the rare mutant strains. In vitro activity of fosfomycin was evaluated using 441 Gram-negative organisms isolated from patients with uncomplicated urinary tract infections (UTIs). Fosfomycin was the most active antibiotic against Escherichia coli (99% susceptibility). The activity against Proteus mirabilis was more potent than that of co-trimoxazole and nitrofurantoin (87.5, 67 and 0% susceptibility, respectively). The other microorganisms, accounting for about 7% of all pathogens tested, showed variable susceptibilities to fosfomycin. Compared with susceptible strains, fosfomycin-resistant mutants showed a reduced rate of growth and were impaired in their ability to adhere to uroepithelial cells and to urinary catheters. They were also more resistant to UV irradiation and to phage T7 and showed diminished rates of colicin synthesis and transfer of plasmids.
本研究的目的是重新评估磷霉素对意大利近期分离出的尿路病原体的活性，并使用罕见突变菌株评估磷霉素耐药性对几种毒力特征表达的影响。使用从单纯性尿路感染（UTIs）患者中分离出的441株革兰氏阴性菌评估了磷霉素的体外活性。磷霉素是对大肠杆菌最具活性的抗生素（敏感性为99%）。对奇异变形杆菌的活性比对复方新诺明和呋喃妥因更强（敏感性分别为87.5%、67%和0%）。其他微生物约占所有测试病原体的7%，对磷霉素表现出不同的敏感性。与敏感菌株相比，磷霉素耐药突变体的生长速率降低，黏附于尿路上皮细胞和尿管的能力受损。它们对紫外线照射和噬菌体T7也更具抗性，并且大肠菌素合成速率和质粒转移速率降低。
