Carriage trends and fitness cost of MDROs in Lebanese nursing homes.
Carriage trends and fitness cost of MDROs in Lebanese nursing homes.
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DOI：
10.3855/jidc.9996
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发表时间：
2018-02-22
影响因子：
1.9
通讯作者：
Daoud, Ziad
中科院分区：
文献类型：
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作者：
Challita, Caren;Hafza, Nourhane;Daoud, Ziad
前言：多药耐药微生物（MDRO）的出现对医学治疗的有效性提出了挑战。黎巴嫩疗养院的居民发现MDR肠杆菌科的粪便携带率很高。以前的研究声称，具有抗性基因的细菌会经历适应性成本。本研究评估MDR大肠杆菌和肺炎克雷伯菌的竞争性增长。方法：粪便拭子收集，在连续6个月，从10个老人居住在黎巴嫩养老院。对所有分离株进行API 20 E（bioMerieux，Marcy L'埃托伊莱，法国）和抗菌药物敏感性（Kirby-Bauer法）检测。表型上，使用EDTA、PBA、氯唑西林和DDST（Biorad，Hercules，USA）检测ESBL（超广谱β-内酰胺酶）、MBL（金属β-内酰胺酶）、AmpC和KPC（肺炎克雷伯菌碳青霉烯酶）。选择产ESBL的E.埃希菌和pneumoniae进行多重PCR分析。结果：在117株分离株中，E.大肠埃希菌（71.8%）、产ESBL菌（7.7%）和产AmpC酶菌（5.1%）。用大肠大肠杆菌种内试验中，敏感分离株的竞争力超过所有其他菌株，其次是ESBL，AmpC和OXA-48（苯唑西林）生产者。种间测定表明产ESBL的K. pneumoniae在敏感E.杆菌而产ESBL的E. coli需要2个敏感K.结论：本研究突出了耐药大肠埃希菌。埃希菌和pneumoniae的频率在敏感分离株的存在下降低，支持适应性成本假设。因此，繁殖肠道植物群的竞争性补充物种将确保进一步采取措施对抗MDRO。
INTRODUCTION: Nowadays, medical treatments efficiency is challenged by multi drug resistant organisms (MDROs). Lebanese nursing homes' residents revealed high fecal carriage rates of MDR Enterobacteriacea. Previous studies claim that bacteria with resistant genes experience fitness cost. This study assesses the competitive growth of MDR Escherichia coli and Klebsiella pneumoniae.METHODOLOGY: Fecal swabs were collected, during six consecutive months, from ten elderly residing in a Lebanese nursing home. All isolates were subject to API 20E (bioMerieux, Marcy L' Etoile, France) and antimicrobial susceptibility (Kirby-Bauer method) testing. Phenotypically, ESBL (extended spectrum beta-lactamase), MBL (metallo beta-lactamase), AmpC and KPC (Klebsiella pneumoniae carbapenemase) were detected using EDTA, PBA, cloxacillin, and DDSTs (Biorad, Hercules, USA). Selected ESBL producing E. coli and K. pneumoniae underwent multiplex PCR analysis. Intra and inter-species in-vitro competition assays were conducted in multiple combinations.RESULTS: Among 117 collected isolates, E. coli was predominant (71.8%); 7.7% were ESBL and 5.1% AmpC producers. With E. coli intra-species assays, sensitive isolates out-competed all others, followed by ESBL, AmpC, and OXA-48 (oxacillin) producers. Inter-species assays, demonstrated a decreased fitness of ESBL producing K. pneumoniae in presence of sensitive E. coli. While out-competing ESBL producing E. coli required 2 sensitive K. pneumoniae isolates.CONCLUSION: This study highlights resistant E. coli and K. pneumoniae frequency decrease in presence of sensitive isolates, endorsing the fitness cost hypothesis. Hence, competing supplementary species reproducing gut flora, would ensure further steps in the fight against MDROs.