Role of antibiotic stress in phenotypic switching to persister cells of antibiotic-resistant Staphylococcus aureus
Year: 2020
Type: article
Abstract: Purpose This study was designed to evaluate phenotypic and genotypic properties of persister cells formed by Staphylococcus aureus ATCC 15564 (SAWT), oxacillin-induced S. aureus (SAOXA), ciprofloxacin-induced S. aureus (SACIP), and clinically isolated multidrug-resistant S. aureus CCARM 3080 (SAMDR). Methods The dose-dependent biphasic killing patterns were observed for SAWT, SAOXA, SACIP, and SAMDR in response to twofold minimum inhibitory concentrate (MIC) of ciprofloxacin. The surviving cells of SAWT, SAOXA, SACIP, and SAMDR after twofold MIC of ciprofloxacin treatment were analyzed using a metabolic-based assay to estimate the fractions of persister cells. Results The least persister formation was induced in SACIP after twofold MIC of ciprofloxacin treatment, showing 58% of persistence. The lowest fitness cost of resistance was observed for the recovered persister cells of SACIP (relative fitness = 0.95), followed by SAMDR (relative fitness = 0.70), while the highest fitness cost was observed for SAWT (relative fitness = 0.26). The mRNA transcripts were analyzed by RT-PCR assay in recovered persister cells pre-incubated with ciprofloxacin. The highest expression levels of stress-related genes (dnaK and groEL) and efflux pump-related genes (mepR, norA, and norB) were observed in the recovered persister cells of SAOXA and SAMDR. Conclusion This study provides valuable information for understanding crosstalk between antibiotic resistance, tolerance, and persistence in different antibiotic-resistant S. aureus strains.
Source: Annals of Microbiology
Authors: Jirapat Dawan, Shuai Wei, Juhee Ahn
Institutions: Kangwon National University, Guangdong Ocean University
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $1,990
Awards: G2303457584, G6568154175
OpenAlex ID: W3030341380