Related Experiment Video

Updated: Sep 23, 2026

Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus
09:03

Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus

Published on: September 5, 2013

Alterations in phage-typing patterns in vancomycin-intermediate Staphylococcus aureus

John E Gustafson1, Frances G O'Brien1, Geoffrey W Coombs1

  • 1Department of Biology, New Mexico State University, Las Cruces, NM 88003-8001, USA 2Gram-positive Bacteria Typing and Research Unit, Curtin University of Technology, and Royal Perth Hospital, Perth 6845, Western Australia 3Microbiology Group, Department of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA.

Journal of Medical Microbiology
|July 18, 2003
PubMed

Insights

Phage-typing and SmaI RFLPs were used to analyze vancomycin-intermediate Staphylococcus aureus (VISA) strains. SmaI RFLPs showed strain relatedness, but phage-typing did not, indicating potential issues in epidemiological studies.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Epidemiology

Background:

  • Vancomycin-intermediate Staphylococcus aureus (VISA) poses a significant challenge in healthcare settings.
  • Accurate strain typing is crucial for understanding the epidemiology of antibiotic-resistant bacteria.

Purpose of the Study:

  • To evaluate the utility of phage-typing and SmaI chromosomal RFLPs for assessing strain relatedness between VISA and their susceptible parent strains.
  • To determine if these methods accurately reflect clonal relationships in vitro-selected VISA.

Main Methods:

  • Analysis of 12 vancomycin-intermediate Staphylococcus aureus (VISA) strains and their 7 vancomycin-susceptible parent strains.
  • Application of phage-typing and SmaI chromosomal Restriction Fragment Length Polymorphism (RFLP) analysis.

Main Results:

  • SmaI RFLP analysis revealed clear clonal relationships between isogenic parent and VISA strains, with generally no observed alterations.
  • Phage-typing profiles frequently differed between parent and VISA strains, with some VISA strains becoming untypable.
  • Observed discrepancies suggest cell wall alterations in VISA strains affecting phage receptor sites.

Conclusions:

  • SmaI RFLP is a reliable method for determining strain relatedness between isogenic VISA and susceptible Staphylococcus aureus.
  • Phage-typing alone may lead to inaccurate epidemiological conclusions due to VISA-induced alterations.
  • Combined use of genotypic and phenotypic methods is recommended for accurate epidemiological assessments of VISA strains.

More Related Videos

Atomic Force Microscopy Combined with Infrared Spectroscopy as a Tool to Probe Single Bacterium Chemistry08:51

Atomic Force Microscopy Combined with Infrared Spectroscopy as a Tool to Probe Single Bacterium Chemistry

Published on: September 15, 2020

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...
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...
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...