Related Experiment Video

Updated: Jun 16, 2026

A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues
07:10

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

Published on: February 19, 2019

Virulence properties of methicillin-susceptible Staphylococcus aureus food isolates encoding Panton-Valentine

Mert Sudagidan1, Ali Aydin

  • 1Biotechnology and Bioengineering Central Research Laboratory, Izmir Institute of Technology, Gulbahce Campus, Urla, 35430 Izmir, Turkey. msudagidan@yahoo.com.tr

International Journal of Food Microbiology
|February 13, 2010
PubMed

Insights

Three Panton-Valentine Leukocidin (PVL)-positive methicillin-susceptible Staphylococcus aureus (MSSA) strains were identified in Turkish food samples. These antibiotic-susceptible strains possessed specific virulence genes but did not form biofilms.

Area of Science:

  • Microbiology
  • Food Safety
  • Molecular Epidemiology

Background:

  • Panton-Valentine Leukocidin (PVL) is a key virulence factor in Staphylococcus aureus, often associated with community-acquired infections.
  • Methicillin-susceptible Staphylococcus aureus (MSSA) strains carrying PVL genes are less common than their methicillin-resistant counterparts (MRSA).
  • The presence and characteristics of PVL-positive MSSA in food matrices require further investigation for potential public health implications.

Purpose of the Study:

  • To isolate and characterize Panton-Valentine Leukocidin (PVL)-positive methicillin-susceptible Staphylococcus aureus (MSSA) strains from food samples.
  • To determine the genetic relatedness, virulence gene content, antibiotic susceptibility, and biofilm formation capabilities of these strains.

Main Methods:

  • Isolation of Staphylococcus aureus strains from food samples.
  • Characterization using Multi-Locus Sequence Typing (MLST), spa typing, and Pulsed-Field Gel Electrophoresis (PFGE).
  • Detection of virulence factor genes (including lukS-PV and lukF-PV) and antibiotic susceptibility testing against 21 antibiotics.
  • Assessment of biofilm formation capacity.

Main Results:

  • Three PVL-positive MSSA strains (M1-AAG42B, PY30C-b, YF1B-b) were identified.
  • All strains were susceptible to all tested antibiotics and were mecA-negative.
  • The strains belonged to the same clonal type (ST152) and spa type (t355), with identical PFGE patterns, indicating genetic relatedness.
  • Positive results for alpha- and beta-haemolysin, protease, and lukED genes were observed; other tested virulence genes were absent.
  • None of the strains exhibited biofilm formation.

Conclusions:

  • This study reports the presence of PVL-positive MSSA strains in food samples from Turkey, highlighting a potential food safety concern.
  • The characterized strains, while PVL-positive, showed a non-virulent profile regarding antibiotic resistance and biofilm formation.
  • Further research is needed to understand the prevalence and transmission dynamics of such strains in the food chain.

More Related Videos

Quantifying the Cytotoxicity of Staphylococcus aureus Against Human Polymorphonuclear Leukocytes12:27

Quantifying the Cytotoxicity of Staphylococcus aureus Against Human Polymorphonuclear Leukocytes

Published on: January 3, 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...
Determinants of Bacterial Pathogenicity and Virulence01:20

Determinants of Bacterial Pathogenicity and Virulence

Pathogenic bacteria employ a variety of strategies to establish infections, including the secretion of extracellular enzymes that act as potent virulence factors. These enzymes facilitate bacterial colonization of host tissues and help evade immune surveillance. By targeting structural components of host tissues and interfering with immune mechanisms, these enzymes play a pivotal role in disease progression.Extracellular Enzymes Facilitating Tissue Invasion: Several bacterial pathogens secrete...
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...
Regulation of Bacterial Virulence01:28

Regulation of Bacterial Virulence

Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
Defense Against Bacterial Pathogens01:31

Defense Against Bacterial Pathogens

The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism.
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...