Related Experiment Video

Updated: Aug 18, 2026

Using the Overlay Assay to Qualitatively Measure Bacterial Production of and Sensitivity to Pneumococcal Bacteriocins
06:05

Using the Overlay Assay to Qualitatively Measure Bacterial Production of and Sensitivity to Pneumococcal Bacteriocins

Published on: September 30, 2014

A bacteriocin produced by certain M-type 49 Streptococcus pyogenes strains when incubated anaerobically

J R Tagg, S A Skjold

    The Journal of Hygiene
    |October 1, 1984
    PubMed

    Insights

    Group A streptococci produce bacteriocins, like streptococcin A-FF22 (SA-FF22), under anaerobic conditions. This study identifies a new bacteriocin, SA-M49, aiding in strain differentiation.

    Area of Science:

    • Microbiology
    • Bacteriology
    • Molecular Biology

    Background:

    • Group A Streptococcus (GAS) M-type 49 strains are significant human pathogens.
    • Bacteriocin production is a key characteristic used for typing and epidemiological studies of bacteria.
    • Previous studies focused on aerobic conditions for bacteriocin detection, potentially missing anaerobic production.

    Purpose of the Study:

    • To investigate bacteriocin production in M-type 49 group A streptococci under anaerobic conditions.
    • To characterize the novel bacteriocin produced by these strains.
    • To evaluate the utility of bacteriocin production for differentiating M-type 49 GAS strains.

    Main Methods:

    • P-typing of 75 M-type 49 group A streptococci strains under aerobic and anaerobic conditions.
    • Isolation and partial purification of the bacteriocin using freeze-thaw elution, ammonium sulfate precipitation, and Sephadex chromatography.
    • Analysis of molecular weight, heat stability, and inhibitory spectra of the purified bacteriocin.
    • Comparison of the novel bacteriocin with streptococcin A-FF22 (SA-FF22).

    Main Results:

    • Anaerobic incubation induced bacteriocin production in 28% of M-type 49 strains.
    • A novel bacteriocin, SA-M49, was isolated and characterized as a heat-stable proteinaceous molecule (approx. 8000 Da).
    • SA-M49 exhibited identical inhibitory spectra and cross-immunity to SA-FF22.
    • SA-M49 production was consistent within outbreaks and useful for differentiating strains of phage subtypes II, III, and VI.

    Conclusions:

    • Anaerobic conditions are crucial for detecting bacteriocin production in certain M-type 49 group A streptococci.
    • SA-M49 is a distinct bacteriocin with properties similar to SA-FF22.
    • Bacteriocin P-typing under anaerobic conditions can serve as a valuable tool for epidemiological surveillance and strain discrimination of M-type 49 GAS.

    More Related Videos

    A Method to Assess Bacteriocin Effects on the Gut Microbiota of Mice07:54

    A Method to Assess Bacteriocin Effects on the Gut Microbiota of Mice

    Published on: July 25, 2017

    Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/4306:06

    Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43

    Published on: September 11, 2020

    Related Concept Videos

    Bacterial Phylum Actinobacteria01:30

    Bacterial Phylum Actinobacteria

    Coryneform bacteria are gram-positive, aerobic, nonmotile rods that exhibit irregular, club-shaped, or V-shaped arrangements. Their V-shape results from snapping division, where the inner cell wall layer forms the cross-wall, while the outer layer remains intact until it ruptures on one side, causing the daughter cells to bend away.The primary genera are Corynebacterium and Arthrobacter. Corynebacterium includes diverse species, ranging from saprophytes to pathogens like Corynebacterium...
    Bacterial Phylum Tenericutes01:24

    Bacterial Phylum Tenericutes

    The phylum Tenericutes, which includes the single class Mollicutes, comprises bacteria that lack cell walls. The term "Mollicutes" derives from the Latin word mollis, meaning "soft." These organisms are among the smallest known and are commonly referred to as mycoplasmas due to the prominence of the genus Mycoplasma, which includes well-known human pathogens. Despite their inability to stain gram-positively (a result of their lack of cell walls), mycoplasmas are phylogenetically related to the...
    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...
    Inhibitors of Gram-positive Cell Wall Synthesis01:23

    Inhibitors of Gram-positive Cell Wall Synthesis

    Bacterial cell walls are typically rigid structures composed mainly of peptidoglycan, a mesh-like polymer that provides mechanical strength and maintains cell shape. The synthesis of peptidoglycan is a crucial process in bacterial growth and serves as a primary target for many antibiotics.Mechanism of Action of Beta-Lactam AntibioticsBeta-lactam antibiotics, such as penicillin, inhibit peptidoglycan synthesis in actively growing cells. These antibiotics share a characteristic four-membered...
    Inhibitors of Bacterial Protein Synthesis01:25

    Inhibitors of Bacterial Protein Synthesis

    Aminoglycosides constitute a highly potent class of bactericidal antibiotics that exert their antimicrobial effects by targeting the bacterial ribosome, specifically disrupting protein synthesis. These polycationic molecules consist of amino-modified sugars linked via glycosidic bonds to an aminocyclitol core such as 2-deoxystreptamine or streptamine. Their strong positive charges facilitate tight binding to the negatively charged phosphate backbone of ribosomal RNA (rRNA), primarily at the 16S...
    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...