PBP2a的错义突变与非洲耐甲氧西林金黄色葡萄球菌（MRSA）对头孢洛林和头孢比普的敏感性降低有关。
Missense mutations of PBP2a are associated with reduced susceptibility to ceftaroline and ceftobiprole in African MRSA.
作者信息
Schaumburg Frieder, Peters Georg, Alabi Abraham, Becker Karsten, Idelevich Evgeny A
机构信息
Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
Institute of Medical Microbiology, University Hospital Münster, Münster, Germany.
出版信息
J Antimicrob Chemother. 2016 Jan;71(1):41-4. doi: 10.1093/jac/dkv325. Epub 2015 Oct 5.
OBJECTIVES
Ceftaroline and ceftobiprole are new cephalosporins, which are active against MRSA by inhibiting PBP2a. Recently, high rates of resistance to ceftaroline were reported from Ghana. The objective of this study was to assess rates of resistance to ceftaroline and ceftobiprole in MRSA from Africa and to describe potential missense mutations of PBP2a.
METHODS
MRSA isolates derived from Staphylococcus aureus colonization (n = 37) and infection (n = 23) and were collected in Côte d'Ivoire (n = 17), DR Congo (n = 6), Gabon (n = 21) and Nigeria (n = 16). The MICs were determined by the broth microdilution method. The mecA gene was sequenced and missense mutations were associated with the corresponding MLST ST.
RESULTS
In total, 16.7% (n = 10) and 15% (n = 9) of isolates were resistant to ceftaroline and ceftobiprole, respectively. The corresponding MICs of ceftaroline and ceftobiprole correlated significantly (r = 0.92). Isolates belonging to ST241 harboured a triple mutation of PBP2a (N146K-N204K-G246E), which was associated with high rates of resistance to ceftaroline (90.9%) and ceftobiprole (81.8%).
CONCLUSIONS
Resistances to ceftaroline and ceftobiprole were only detected in Nigeria and were associated with ST241 and a triple mutation of PBP2a.
目的
头孢洛林和头孢比普是新型头孢菌素，通过抑制PBP2a对耐甲氧西林金黄色葡萄球菌（MRSA）具有活性。最近，加纳报告了对头孢洛林的高耐药率。本研究的目的是评估非洲MRSA对头孢洛林和头孢比普的耐药率，并描述PBP2a的潜在错义突变。
方法
从金黄色葡萄球菌定植（n = 37）和感染（n = 23）中分离出MRSA菌株，这些菌株分别来自科特迪瓦（n = 17）、刚果民主共和国（n = 6）、加蓬（n = 21）和尼日利亚（n = 16）。采用肉汤微量稀释法测定最低抑菌浓度（MIC）。对mecA基因进行测序，并将错义突变与相应的多位点序列分型（MLST）ST相关联。
结果
总的来说，分别有16.7%（n = 10）和15%（n = 9）的分离株对头孢洛林和头孢比普耐药。头孢洛林和头孢比普的相应MIC显著相关（r = 0.92）。属于ST241的分离株携带PBP2a的三重突变（N146K-N204K-G246E），这与对头孢洛林（90.9%）和头孢比普（81.8%）的高耐药率相关。
结论
仅在尼日利亚检测到对头孢洛林和头孢比普的耐药性，且与ST241和PBP2a的三重突变有关。
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