Gajdács Márió, Kárpáti Krisztina, Nagy Ádám László, Gugolya Máté, Stájer Anette, Burián Katalin
1Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, Tisza Lajos krt 63., 6720 Szeged, Hungary.
2Institute of Medical Microbiology, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4., 1089 Budapest, Hungary.
Acta Microbiol Immunol Hung. 2021 Sep 14. doi: 10.1556/030.2021.01487.
Bacteria can enhance their survival by attaching to inanimate surfaces or tissues, and presenting as multicellular communities encased in a protective extracellular matrix called biofilm. There has been pronounced interest in assessing the relationship between the antibiotic resistant phenotype and biofilm-production in clinically-relevant pathogens. The aim of the present paper was to provide additional experimental results on the topic, testing the biofilm-forming capacity of Escherichia coli isolates using in vitro methods in the context of their antibiotic resistance in the form of a laboratory case study, in addition to provide a comprehensive review of the subject. In our case study, a total of two hundred and fifty (n = 250) E. coli isolates, originating from either clean-catch urine samples (n = 125) or invasive samples (n = 125) were included. The colony morphology of isolates were recorded after 24h, while antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method. Biofilm-formation of the isolates was assessed with the crystal violet tube-adherence method. Altogether 57 isolates (22.8%) isolates were multidrug resistant (MDR), 89 isolates (35.6%) produced large colonies (>3 mm), mucoid variant colonies were produced in 131 cases (52.4%), and 108 (43.2%) were positive for biofilm formation. Biofilm-producers were less common among isolates resistant to third-generation cephalosporins and trimethoprim-sulfamethoxazole (P = 0.043 and P = 0.023, respectively). Biofilms facilitate a protective growth strategy in bacteria, ensuring safety against environmental stressors, components of the immune system and noxious chemical agents. Being an integral part of bacterial physiology, biofilm-formation is interdependent with the expression of other virulence factors (especially adhesins) and quorum sensing signal molecules. More research is required to allow for the full understanding of the interplay between the MDR phenotype and biofilm-production, which will facilitate the development of novel therapeutic strategies.
细菌可通过附着于无生命表面或组织来提高其生存能力，并以包裹在称为生物膜的保护性细胞外基质中的多细胞群落形式存在。人们对评估临床相关病原体中抗生素耐药表型与生物膜形成之间的关系有着浓厚兴趣。本文的目的是提供关于该主题的更多实验结果，以实验室案例研究的形式，在体外方法测试大肠杆菌分离株生物膜形成能力的同时，结合其抗生素耐药性情况，此外还对该主题进行全面综述。在我们的案例研究中，共纳入了250株大肠杆菌分离株，它们分别来自清洁中段尿样本（n = 125）或侵入性样本（n = 125）。24小时后记录分离株的菌落形态，同时使用 Kirby - Bauer 纸片扩散法进行抗菌药物敏感性测试。采用结晶紫试管黏附法评估分离株的生物膜形成情况。共有57株分离株（22.8%）为多重耐药（MDR），89株（35.6%）产生大菌落（>3 mm），131例（52.4%）产生黏液样变异菌落，108株（43.2%）生物膜形成呈阳性。在对第三代头孢菌素和甲氧苄啶 - 磺胺甲恶唑耐药的分离株中，生物膜产生菌较少见（分别为P = 0.043和P = 0.023）。生物膜为细菌提供了一种保护性生长策略，确保其免受环境应激源、免疫系统成分和有害化学物质的侵害。作为细菌生理学的一个组成部分，生物膜形成与其他毒力因子（尤其是黏附素）和群体感应信号分子的表达相互依存。需要更多研究来全面了解多重耐药表型与生物膜形成之间的相互作用，这将有助于开发新的治疗策略。
