Related Experiment Video

Updated: Sep 13, 2026

Implementation of a Permeable Membrane Insert-based Infection System to Study the Effects of Secreted Bacterial Toxins on Mammalian Host Cells
09:25

Implementation of a Permeable Membrane Insert-based Infection System to Study the Effects of Secreted Bacterial Toxins on Mammalian Host Cells

Published on: August 19, 2016

Some pharmacological properties of the alpha-toxin of staphylococcus pyogenes

D A BROWN, B N PRICHARD, J P QUILLIAM

    British Journal of Pharmacology and Chemotherapy
    |March 1, 1959
    PubMed

    Insights

    Staphylococcus pyogenes alpha-toxin causes persistent gut contracture, blocked by antitoxin. Several drugs, notably papaverine and pethidine, can reduce or abolish this effect.

    Area of Science:

    • Microbiology
    • Pharmacology
    • Gastroenterology

    Background:

    • Staphylococcus pyogenes alpha-toxin is a potent exotoxin.
    • The physiological effects of alpha-toxin on gastrointestinal smooth muscle are not fully understood.

    Purpose of the Study:

    • To investigate the effects of Staphylococcus pyogenes alpha-toxin on isolated rabbit jejunum and guinea-pig ileum.
    • To determine the efficacy of antitoxin and various pharmacological agents in modulating the alpha-toxin-induced contracture.

    Main Methods:

    • Isolated rabbit jejunum and guinea-pig ileum preparations were exposed to alpha-toxin.
    • The effects of antitoxin and various drugs (papaverine, pethidine, mepyramine, etc.) on alpha-toxin-induced contracture were assessed.
    • Gut-stimulant activity and haemolytic units of alpha-toxin samples were compared.

    Main Results:

    • Alpha-toxin induced a persistent, irreversible contracture of isolated gut preparations.
    • Antitoxin prevented the contracture if added before, but not after, alpha-toxin.
    • Papaverine and pethidine were highly effective in abolishing or reducing the contracture, while other agents showed varying degrees of efficacy.

    Conclusions:

    • Staphylococcus pyogenes alpha-toxin elicits a sustained contractile response in the gut, potentially through mechanisms not immediately neutralized by antitoxin.
    • Pharmacological agents like papaverine and pethidine demonstrate significant potential in mitigating the effects of alpha-toxin on gastrointestinal motility.
    Keywords:
    MICROCOCCUS PYOGENES

    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

    Bacterial Toxins01:12

    Bacterial Toxins

    Bacterial toxins are sophisticated virulence factors that enable pathogenic bacteria to interact with, invade, and damage host tissues. These toxins fall broadly into two types: protein exotoxins, which are secreted into the environment and target specific host receptors, and lipopolysaccharide endotoxins, which are structural components of the bacterial outer membrane released primarily during bacterial lysis or membrane shedding. Exotoxins generally act more selectively, binding to cell...
    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...
    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...
    Streptococcal Pharyngitis01:27

    Streptococcal Pharyngitis

    Streptococcal pharyngitis, commonly known as “strep throat,” is an acute infection of the oropharyngeal tissues caused by the Gram‑positive Group A Streptococcus (Streptococcus pyogenes). Transmission occurs primarily through respiratory droplets expelled during coughing, sneezing, or talking.Mechanisms of Host Entry and Immune EvasionUpon entering the host, S. pyogenes adheres to the mucosal epithelial cells of the pharynx via surface proteins, notably lipoteichoic acid and the antiphagocytic...
    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...