Dairy Bacteriology Section, Southern Regional Station, ICAR-National Dairy Research Institute, Adugodi, Bengaluru, 560 030, Karnataka, India.
Antimicrobial Laboratory, ICAR-National Institute of Veterinary Epidemiology and Disease Informatics, Yelahanka, Bengaluru, 560064, Karnataka, India.
Microb Pathog. 2024 Oct;195:106905. doi: 10.1016/j.micpath.2024.106905. Epub 2024 Sep 3.
Antibiotic resistance poses a persistent threat to modern medicine due to the emergence of novel antibiotic-resistant strains. Therefore, a timely understanding of antibiotic resistance and the virulence biology of pathogenic bacteria, particularly those of public health significance, is crucial for implementing effective mitigation strategies. This study aimed to investigate the virulence profiles of ten S. aureus isolates (NDa to NDj) and ten E. coli isolates (ND1 to ND10) originating from livestock and poultry, and to assess how various cell surface properties and biofilm formation abilities influence antibiotic resistance phenotypes. Antibiotic resistance profiling through phenotypic (AST) and genotypic methods (PCR) confirmed that NDa to NDe were methicillin-resistant S. aureus (MRSA) and ND1 to ND5 were extended-spectrum β-lactamase (ESBL) producing E. coli isolates. Virulence properties such as hemolytic activity, coagulase activity, and nuclease activity were found to be independent of the antibiotic resistance phenotype in S. aureus. In contrast, biofilm formation phenotype was observed to influence antibiotic resistance phenotypes, with MRSA and ESBL E. coli isolates demonstrating higher biofilm formation potency. Chemical and enzymatic analysis of S. aureus and E. coli biofilms revealed proteins and polysaccharides as major components, followed by nucleic acids. Furthermore, cell surface properties such as auto-aggregation and hydrophobicity were notably higher in isolates with strong to medium biofilm-forming capabilities (ESBL and MRSA isolates), corroborated by genomic confirmation of various genes associated with biofilm, adhesion, and colonization. In conclusion, this study highlights that surface hydrophobicity and biofilm formation ability of MRSA (NDa to NDe) and ESBL E. coli (ND1 to ND5) isolates may influence antibiotic resistance phenotypes.
由于新型抗生素耐药菌株的出现，抗生素耐药性对现代医学构成了持续威胁。因此，及时了解抗生素耐药性和致病菌（特别是对公共卫生具有重要意义的致病菌）的毒力生物学特性，对于实施有效的缓解策略至关重要。本研究旨在调查 10 株来自家畜和家禽的金黄色葡萄球菌（NDa 至 NDe）和 10 株大肠杆菌（ND1 至 ND10）的毒力特征，并评估各种细胞表面特性和生物膜形成能力如何影响抗生素耐药表型。通过表型（AST）和基因型方法（PCR）进行抗生素耐药性分析，证实 NDa 至 NDe 是耐甲氧西林金黄色葡萄球菌（MRSA），ND1 至 ND5 是产生扩展谱β-内酰胺酶（ESBL）的大肠杆菌。在金黄色葡萄球菌中，溶血活性、凝固酶活性和核酸酶活性等毒力特性与抗生素耐药表型无关。相比之下，生物膜形成表型被观察到会影响抗生素耐药表型，MRSA 和 ESBL 大肠杆菌分离株表现出更高的生物膜形成能力。金黄色葡萄球菌和大肠杆菌生物膜的化学和酶分析表明，蛋白质和多糖是主要成分，其次是核酸。此外，具有较强至中等生物膜形成能力的分离株（ESBL 和 MRSA 分离株）的细胞表面特性，如自动聚集和疏水性明显更高，这与与生物膜、粘附和定植相关的各种基因的基因组确证相吻合。总之，本研究表明，MRSA（NDa 至 NDe）和 ESBL 大肠杆菌（ND1 至 ND5）分离株的表面疏水性和生物膜形成能力可能影响抗生素耐药表型。
