Staphylococcus epidermidis strains isolated from breast milk of women suffering infectious mastitis: potential virulence traits and resistance to antibiotics
Staphylococcus epidermidis strains isolated from breast milk of women suffering infectious mastitis: potential virulence traits and resistance to antibiotics
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DOI：
10.1186/1471-2180-9-82
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发表时间：
2009-05-07
期刊：
影响因子：
4.2
通讯作者：
Rodriguez, Juan M.
中科院分区：
文献类型：
--
作者：
Delgado, Susana;Arroyo, Rebeca;Rodriguez, Juan M.
背景：虽然金黄色葡萄球菌被认为是感染性乳腺炎的主要病原，但最近的研究表明凝固酶阴性葡萄球菌（CNS）也可能在感染性乳腺炎中发挥重要作用。这项工作的目的是从哺乳期乳腺炎妇女的乳汁中分离葡萄球菌，选择和表征CNS分离株，并将这些特性与从健康妇女乳汁中分离的CNS菌株所显示的特性进行比较。结果：采集30例妇女乳汁，检出细菌27例，其中表皮葡萄球菌26例，金黄色葡萄球菌8例。从乳腺炎妇女乳汁中分离得到270株葡萄球菌，其中200株经表型分析、种特异性PCR和PCR测序鉴定为表皮葡萄球菌。采用脉冲场凝胶电泳（PFGE）进行基因分型。将表皮葡萄球菌菌株的PFGE谱与105株健康妇女乳汁分离株的PFGE谱进行比较。从76个不同的PFGE谱中选择一个代表来研究毒力因子的发生率和抗生素耐药性。从乳乳中分离的菌株中，含有与生物膜相关的icaD基因并对oxacillin、红霉素、克林霉素和莫匹罗星耐药的菌株数量显著高于其他菌株。结论：表皮葡萄球菌可能是哺乳期妇女感染性乳腺炎的常见原因，但在很大程度上被低估了。从患有乳腺炎的妇女的乳汁中分离出的菌株对多种抗生素的耐药性和形成生物膜的能力较高，这可能解释了这种传染病的慢性和/或复发性。
Background: Although Staphylococcus aureus is considered the main etiological agent of infectious mastitis, recent studies have suggested that coagulase-negative staphylococci (CNS) may also play an important role in such infections. The aims of this work were to isolate staphylococci from milk of women with lactational mastitis, to select and characterize the CNS isolates, and to compare such properties with those displayed by CNS strains isolated from milk of healthy women.Results: The milk of 30 women was collected and bacterial growth was noted in 27 of them, of which Staphylococcus epidermidis was isolated from 26 patients and S. aureus from 8. Among the 270 staphylococcal isolates recovered from milk of women with mastitis, 200 were identified as Staphylococcus epidermidis by phenotypic assays, species-specific PCR and PCR sequencing. They were typified by pulsed field gel electrophoresis (PFGE) genotyping. The PFGE profiles of the S. epidermidis strains were compared with those of 105 isolates from milk of healthy women. A representative of the 76 different PFGE profiles was selected to study the incidence of virulence factors and antibiotic resistance. The number of strains that contained the biofilm-related icaD gene and that showed resistance to oxacillin, erythromycin, clindamycin and mupirocin was significantly higher among the strains isolated from mastitic milk.Conclusion: S. epidermidis may be a frequent but largely underrated cause of infectious mastitis in lactating women. The resistance to diverse antibiotics and a higher ability to form biofilms found among the strains isolated from milk of women suffering mastitis may explain the chronic and/or recurrent nature of this infectious condition.