金黄色葡萄球菌和凝固酶阴性葡萄球菌浮游细胞与生物膜细胞的抗菌药物耐药谱
Antimicrobial Resistance Profile of Planktonic and Biofilm Cells of Staphylococcus aureus and Coagulase-Negative Staphylococci.
作者信息
de Oliveira Adilson, Cataneli Pereira Valéria, Pinheiro Luiza, Moraes Riboli Danilo Flávio, Benini Martins Katheryne, Ribeiro de Souza da Cunha Maria de Lourdes
机构信息
Departamento de Microbiologia e Imunologia, Instituto de Biociências, UNESP-Univ Estadual Paulista, Rua Professor Doutor Antonio Celso Wagner Zanin, s/n, Botucatu, São Paulo-CEP 18618-689, Brazil.
Departamento de Anatomia Patológica, Instituto Lauro de Souza Lima, Bauru 17034-971, Brazil.
出版信息
Int J Mol Sci. 2016 Sep 1;17(9):1423. doi: 10.3390/ijms17091423.
The objective of the present study was to determine the antimicrobial resistance profile of planktonic and biofilm cells of Staphylococcus aureus and coagulase-negative staphylococci (CoNS). Two hundred Staphylococcus spp. strains were studied, including 50 S. aureus and 150 CoNS strains (50 S. epidermidis, 20 S. haemolyticus, 20 S. warneri, 20 S. hominis, 20 S. lugdunensis, and 20 S. saprophyticus). Biofilm formation was investigated by adherence to polystyrene plates. Positive strains were submitted to the broth microdilution method to determine the minimum inhibitory concentration (MIC) for planktonic and biofilm cells and the minimal bactericidal concentration for biofilm cells (MBCB). Forty-nine Staphylococcus spp. strains (14 S. aureus, 13 S. epidermidis, 13 S. saprophyticus, 3 S. haemolyticus, 1 S. hominis, 3 S. warneri, and 2 S. lugdunensis) were biofilm producers. These isolates were evaluated regarding their resistance profile. Determination of planktonic cell MIC identified three (21.4%) S. aureus strains that were resistant to oxacillin and six (42.8%) that were resistant to erythromycin. Among the CoNS, 31 (88.6%) strains were resistant to oxacillin, 14 (40%) to erythromycin, 18 (51.4%) to gentamicin, and 8 (22.8%) to sulfamethoxazole/trimethoprim. None of the planktonic isolates were resistant to vancomycin or linezolid. MICs were 2-, 4-, 8-, and up to 16-fold higher for biofilm cells than for planktonic cells. This observation was more common for vancomycin and erythromycin. The MBCB ranged from 8 to >256 µg/mL for oxacillin, 128 to >128 µg/mL for vancomycin, 256 to >256 µg/mL for erythromycin and gentamicin, >64 µg/mL for linezolid, and 32/608 to >32/608 µg/mL for sulfamethoxazole/trimethoprim. The results showed considerably higher MICs for S. aureus and CoNS biofilm cells compared to planktonic cells. Analysis of MBCM confirmed that even high concentrations of vancomycin were unable to eliminate the biofilms of S. aureus and CoNS species. Linezolid was the most effective drug in inhibiting staphylococci in the biofilm, without an increase in the MIC, when compared to planktonic cells. None of the isolates were resistant to this drug.
本研究的目的是确定金黄色葡萄球菌和凝固酶阴性葡萄球菌（CoNS）浮游细胞和生物膜细胞的抗菌药物耐药谱。研究了200株葡萄球菌属菌株，包括50株金黄色葡萄球菌和150株CoNS菌株（50株表皮葡萄球菌、20株溶血葡萄球菌、20株华纳葡萄球菌、20株人葡萄球菌、20株路邓葡萄球菌和20株腐生葡萄球菌）。通过聚苯乙烯平板黏附法研究生物膜形成情况。对阳性菌株采用肉汤微量稀释法测定浮游细胞和生物膜细胞的最低抑菌浓度（MIC）以及生物膜细胞的最低杀菌浓度（MBCB）。49株葡萄球菌属菌株（14株金黄色葡萄球菌、13株表皮葡萄球菌、13株腐生葡萄球菌、3株溶血葡萄球菌、1株人葡萄球菌、3株华纳葡萄球菌和2株路邓葡萄球菌）为生物膜产生菌。对这些分离株的耐药谱进行了评估。浮游细胞MIC测定结果显示，3株（21.4%）金黄色葡萄球菌菌株对苯唑西林耐药，6株（42.8%）对红霉素耐药。在CoNS中，31株（88.6%）菌株对苯唑西林耐药，14株（40%）对红霉素耐药，18株（51.4%）对庆大霉素耐药，8株（22.8%）对磺胺甲恶唑/甲氧苄啶耐药。所有浮游分离株均对万古霉素或利奈唑胺不耐药。生物膜细胞的MIC比浮游细胞高2倍、4倍、8倍，最高达16倍。这种现象在万古霉素和红霉素中更为常见。苯唑西林的MBCB范围为8至>256μg/mL，万古霉素为128至>128μg/mL，红霉素和庆大霉素为256至>256μg/mL，利奈唑胺>64μg/mL，磺胺甲恶唑/甲氧苄啶为32/608至>32/608μg/mL。结果显示，与浮游细胞相比，金黄色葡萄球菌和CoNS生物膜细胞的MIC显著更高。MBCM分析证实，即使高浓度的万古霉素也无法消除金黄色葡萄球菌和CoNS菌株的生物膜。与浮游细胞相比，利奈唑胺是抑制生物膜中葡萄球菌最有效的药物，且MIC没有增加。所有分离株均对该药物不耐药。
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