Related Experiment Video

Updated: May 28, 2026

Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
14:04

Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria

Published on: May 8, 2013

Staphylococcus haemolyticus as an important hospital pathogen and carrier of methicillin resistance genes

E M Barros1, H Ceotto, M C F Bastos

  • 1Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.

Journal of Clinical Microbiology
|October 7, 2011
PubMed

Insights

Most Staphylococcus haemolyticus clinical isolates showed high rates of methicillin resistance and multiresistance. The study identified prevalent staphylococcal cassette chromosome mec element (SCCmec) types, highlighting significant diversity in resistance mechanisms.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Clinical Science

Background:

  • Staphylococcus haemolyticus is a significant opportunistic pathogen.
  • Understanding its antibiotic resistance is crucial for infection control.
  • Methicillin resistance in staphylococci poses a major public health threat.

Purpose of the Study:

  • To characterize the antibiotic resistance patterns of clinical Staphylococcus haemolyticus isolates.
  • To identify the molecular mechanisms conferring methicillin resistance, including SCCmec types.
  • To assess the genetic diversity among resistant isolates.

Main Methods:

  • Phenotypic antibiotic susceptibility testing was performed.
  • Molecular methods, including PCR, were used to detect the mecA gene and SCCmec types.
  • Pulsed-field gel electrophoresis (PFGE) was employed for strain typing.

Main Results:

  • 87% of isolates were methicillin-resistant Staphylococcus haemolyticus (MRSH) due to the presence of the mecA gene.
  • Staphylococcal cassette chromosome mec element (SCCmec) type V was the most common (55%), with only one isolate harboring SCCmec type IV.
  • 75% of isolates exhibited multidrug resistance phenotypes.
  • Pulsotype analysis revealed considerable genetic diversity among the isolates.

Conclusions:

  • Clinical isolates of Staphylococcus haemolyticus frequently exhibit methicillin resistance and multidrug resistance.
  • SCCmec type V is a predominant mobile genetic element associated with MRSH in this cohort.
  • The high diversity of strains suggests multiple independent acquisitions of resistance determinants or successful dissemination of diverse clones.

More Related Videos

Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus10:39

Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus

Published on: March 10, 2017

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...
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...
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...
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...