Related Experiment Video

Updated: Aug 24, 2026

Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus
10:39

Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus

Published on: March 10, 2017

Nucleotide substitutions in Staphylococcus aureus strains, Mu50, Mu3, and N315

Toshiko Ohta1, Hideki Hirakawa, Kazuya Morikawa

  • 1Institute of Basic Medical Sciences, University of Tsukuba, 1-1-1 Tennohdai, Tukuba, Ibaraki 305-8575, Japan. tohta@sakura.cc.tsukuba.ac.jp

DNA Research : an International Journal for Rapid Publication of Reports on Genes and Genomes
|May 15, 2004
PubMed

Insights

Genetic differences in Staphylococcus aureus strains Mu50 and N315 were identified, revealing key variations in transport, carbohydrate metabolism, and RNA synthesis genes. These genetic changes likely explain Mu50

Area of Science:

  • Microbiology
  • Genomics
  • Molecular Biology

Background:

  • Staphylococcus aureus strains Mu50 and Mu3 exhibit a unique phenotype with thickened cell walls and moderate vancomycin resistance.
  • The N315 strain, a methicillin-resistant S. aureus (MRSA) prototype, carries the mecA gene but remains methicillin susceptible.

Purpose of the Study:

  • To investigate and compare the genetic sequences of S. aureus strains Mu50, Mu3, and N315.
  • To identify specific genetic diversities contributing to the distinct characteristics of strain Mu50.

Main Methods:

  • Comparative genomic analysis of S. aureus strains Mu50, N315, and Mu3.
  • Re-sequencing of 362 open reading frames (ORFs) identified as diverse between Mu50 and N315.
  • Categorization and analysis of fixed genetic diversities, including nucleotide substitutions, frame shifts, and truncations.

Main Results:

  • 213 ORFs showed diversity between Mu50 and N315; 9 ORFs were diverse between Mu50 and Mu3.
  • Fixed genetic diversities in 174 ORFs were analyzed, with significant proportions found in transport (14.9%), carbohydrate metabolism (5.7%), and RNA synthesis (9.6%) categories.
  • These functional gene categories are implicated as decisive factors for Mu50's thickened cell wall and vancomycin resistance.

Conclusions:

  • Specific genetic variations in S. aureus strains directly correlate with phenotypic traits like vancomycin resistance and cell wall thickness.
  • Comparative genomics is crucial for understanding the molecular basis of bacterial phenotypes and resistance mechanisms.
  • The identified gene diversities provide insights into the evolution and adaptation of Staphylococcus aureus.

More Related Videos

A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues07:10

A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues

Published on: February 19, 2019

Related Concept Videos

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...
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...
Mismatch Repair01:36

Mismatch Repair

Overview
Mismatch Repair01:20

Mismatch Repair

Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
Mutations in Microorganisms01:18

Mutations in Microorganisms

Mutations are heritable changes in an organism’s genome involving alterations in the base sequence of DNA or RNA. These changes can influence cellular processes and phenotypic traits, potentially transforming the unaltered wild type into a mutant form. Such changes, termed forward mutations, are pivotal in shaping the genetic diversity of organisms.RNA viruses exhibit the highest mutation rates due to the absence of robust proofreading mechanisms during genome replication. In contrast,...