Related Experiment Videos

Daptomycin-resistant Staphylococcus capitis: Mechanisms, molecular epidemiology, and clinical aspects

Junxiong Zhang1, Zhengan Wang2, Chao Gu3

  • 1Department of Microbiology Laboratory, Xihu District Center for Disease Control and Prevention (Health Supervision Institute), Hangzhou, Zhejiang, China; Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China; Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.

Journal of Global Antimicrobial Resistance
|June 24, 2026
PubMed
Abstract

Insights

Methicillin-resistant Staphylococcus capitis (MRSC) shows high susceptibility to daptomycin (DAP), with one resistant strain identified. Novel mutations in mprF confer DAP resistance and increase susceptibility to beta-lactams, offering treatment insights.

Area of Science:

  • Clinical Microbiology
  • Infectious Diseases
  • Antimicrobial Resistance

Background:

  • Coagulase-negative staphylococci, particularly Staphylococcus epidermidis, are significant nosocomial pathogens.
  • Staphylococcus capitis is an emerging pathogen with increasing clinical and epidemiological relevance.
  • Limited data exists on daptomycin (DAP) resistance in methicillin-resistant S. capitis (MRSC).

Purpose of the Study:

  • To investigate DAP susceptibility among clinical MRSC isolates.
  • To identify molecular mechanisms underlying DAP resistance in MRSC.
  • To explore potential cross-resistance patterns with other antibiotics.

Main Methods:

  • Analysis of 101 clinical MRSC strains collected between 2018-2020.
  • Determination of minimum inhibitory concentrations (MICs) using agar dilution and broth microdilution.
  • Multilocus sequence typing (MLST) for molecular characterization.
  • Whole-genome sequencing to identify resistance-associated mutations.

Main Results:

  • 99.01% of MRSC strains were DAP-susceptible; 0.99% (1/101) were resistant (MIC=4 µg/mL).
  • Reduced susceptibility (MIC > 0.5 µg/mL) was observed in 48.51% of strains.
  • Dominant sequence types (STs) were ST1, ST6, and ST3; ST6 strains showed higher DAP susceptibility than ST1.
  • No cross-resistance between DAP and vancomycin or teicoplanin was found.
  • The DAP-resistant strain harbored novel mutations: mprF-A784L and yycF-H120P.
  • Complementation of mprF restored DAP resistance and increased beta-lactam susceptibility (seesaw effect).

Conclusions:

  • This study provides crucial in vitro DAP activity data for S. capitis.
  • Novel mprF mutations are identified as key determinants of DAP resistance in MRSC.
  • The observed 'seesaw effect' on beta-lactam susceptibility offers valuable insights for MRSC infection treatment strategies.
Keywords:
DaptomycinMethicillin-resistant Staphylococcus capitisSeesaw effectmprF

Related Concept Videos

Clinical Significance of Antibiotic Resistance01:25

Clinical Significance of Antibiotic Resistance

Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...
Mechanism of Antibiotic Resistance in MRSA01:25

Mechanism of Antibiotic Resistance in MRSA

Antibiotic resistance in bacteria arises when microorganisms evolve the ability to withstand drugs designed to kill them or inhibit their growth, rendering once-effective treatments useless. This phenomenon, driven by genetic change and selection under antibiotic exposure, poses a profound threat to modern medicine. Mechanisms include drug-inactivating enzymes (e.g., β-lactamases), efflux pumps that eject antibiotics, mutations altering antibiotic targets, decreased drug uptake, and acquisition...
Staphylococcal Skin Infections01:29

Staphylococcal Skin Infections

Staphylococcus aureus is a Gram-positive coccus that resides harmlessly on the skin and mucous membranes of healthy individuals. When the skin barrier is breached, it can shift from a commensal to an opportunistic pathogen. This transition is facilitated by surface adhesins, such as clumping factor B and S. aureus surface protein G (SasG), which bind to structural proteins, including loricrin and cytokeratin, in the damaged epidermis. Protein A, another key factor, binds the Fc region of...
Inhibitors of Bacterial Protein Synthesis01:25

Inhibitors of Bacterial Protein Synthesis

Aminoglycosides constitute a highly potent class of bactericidal antibiotics that exert their antimicrobial effects by targeting the bacterial ribosome, specifically disrupting protein synthesis. These polycationic molecules consist of amino-modified sugars linked via glycosidic bonds to an aminocyclitol core such as 2-deoxystreptamine or streptamine. Their strong positive charges facilitate tight binding to the negatively charged phosphate backbone of ribosomal RNA (rRNA), primarily at the 16S...
Development of Antibiotic Resistance01:30

Development of Antibiotic Resistance

Antibiotic resistance is a major public health concern that arises when bacteria evolve mechanisms to withstand the effects of antibiotic treatments. This resistance can be intrinsic, acquired through genetic mutations, or transferred between bacteria via horizontal gene transfer. The development of antibiotic resistance poses significant challenges in treating bacterial infections and necessitates ongoing research to develop new therapeutic strategies.Intrinsic resistance occurs when bacterial...
Bacterial Meningitis II: Pathophysiology01:26

Bacterial Meningitis II: Pathophysiology

Bacterial meningitis typically begins when pathogens such as Neisseria meningitidis and Streptococcus pneumoniae colonize the nasopharynx and invade the bloodstream. This process is facilitated by bacterial virulence factors, such as polysaccharide capsules, which resist phagocytosis and complement-mediated killing. Less commonly, bacteria reach the central nervous system via contiguous spread from infections like otitis media or sinusitis, through congenital or acquired dural defects, or...