Related Experiment Video

Updated: May 14, 2026

Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
14:04

Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria

Published on: May 8, 2013

[Clinical microbiological investigation of vancomycin intermediate Staphylococcus aureus during glycopeptide therapy]

Hirofumi Toda1, Toshihiro Yamaguchi, Takayuki Miyara

  • 1Department of Clinical Laboratory, Kinki University Hospital.

Kansenshogaku Zasshi. the Journal of the Japanese Association for Infectious Diseases
|February 2, 2013
PubMed

Insights

Three vancomycin-intermediate Staphylococcus aureus (VISA) strains were identified without common resistance genes. Cell wall thickening was noted, with some strains reversing susceptibility, suggesting vancomycin may help manage MRSA infections by limiting cell wall thickening.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Antimicrobial Resistance

Background:

  • Vancomycin is a critical antibiotic for treating serious Staphylococcus aureus infections, including methicillin-resistant Staphylococcus aureus (MRSA).
  • Emergence of vancomycin resistance in Staphylococcus aureus poses a significant threat to public health.
  • Understanding the mechanisms and characteristics of vancomycin-intermediate Staphylococcus aureus (VISA) is crucial for effective treatment strategies.

Observation:

  • Three distinct VISA strains (VISA-1, VISA-2, VISA-3) were isolated from patients with infective endocarditis, pneumonia, and spondylitis.
  • These VISA isolates lacked the vanA, vanB, vanC1, and vanC2/C3 genes, indicating alternative resistance mechanisms.
  • Consistent cell wall thickening was observed in all isolated VISA strains.

Findings:

  • VISA-1 and VISA-3 exhibited identical pulsed-field gel electrophoresis (PFGE) patterns to the original MRSA strains from the respective patients.
  • After prolonged incubation, VISA-2 and VISA-3 demonstrated a reversion of vancomycin susceptibility.
  • Cell wall thickening remained consistent in all VISA strains even after extended culture periods.

Implications:

  • The study highlights VISA strains with unique genetic profiles and persistent cell wall alterations.
  • The observed reversion of susceptibility in some strains suggests dynamic resistance mechanisms.
  • Vancomycin's role in managing MRSA infections may involve mitigating cell wall thickening, a key factor in VISA development.

More Related Videos

Improved Enzyme Protection Assay to Study Staphylococcus aureus Internalization and Intracellular Efficacy of Antimicrobial Compounds06:36

Improved Enzyme Protection Assay to Study Staphylococcus aureus Internalization and Intracellular Efficacy of Antimicrobial Compounds

Published on: September 8, 2021

A Novel Method to Determine the Longitudinal Antibacterial Activity of Drug-Eluting Materials06:18

A Novel Method to Determine the Longitudinal Antibacterial Activity of Drug-Eluting Materials

Published on: March 3, 2023

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...
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 Gram-positive Cell Wall Synthesis01:23

Inhibitors of Gram-positive Cell Wall Synthesis

Bacterial cell walls are typically rigid structures composed mainly of peptidoglycan, a mesh-like polymer that provides mechanical strength and maintains cell shape. The synthesis of peptidoglycan is a crucial process in bacterial growth and serves as a primary target for many antibiotics.Mechanism of Action of Beta-Lactam AntibioticsBeta-lactam antibiotics, such as penicillin, inhibit peptidoglycan synthesis in actively growing cells. These antibiotics share a characteristic four-membered...
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...
Automated Microbial Diagnostics01:24

Automated Microbial Diagnostics

Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe...
Antimicrobial Effectiveness01:28

Antimicrobial Effectiveness

The effectiveness of antimicrobial agents depends on various factors influencing their ability to eliminate microbial populations. Larger microbial populations require more time for complete eradication, emphasizing the importance of population size analysis when evaluating antimicrobial efficacy.Microbial resistance to antimicrobial agents varies significantly. Highly resilient microorganisms include endospores, gram-negative bacteria, and non-enveloped viruses, while prions are exceptionally...