Related Experiment Video

Updated: May 30, 2026

Phage-Mediated Genetic Manipulation of the Lyme Disease Spirochete Borrelia burgdorferi
09:01

Phage-Mediated Genetic Manipulation of the Lyme Disease Spirochete Borrelia burgdorferi

Published on: September 28, 2022

[Interaction of plague microbe strains varying in plasmid composition with the fleas Xenopsylla cheopis (Roths.

G A Voronova, E G Tokmakova, S V Balakhonov

    Meditsinskaia Parazitologiia I Parazitarnye Bolezni
    |July 30, 2011
    PubMed

    Insights

    The proventricular block in fleas by Yersinia pestis does not guarantee pathogen transmission. Avirulent strains lacking key plasmids still formed blocks but failed to transmit plague effectively.

    Area of Science:

    • Microbiology
    • Vector-borne diseases
    • Infectious disease transmission

    Background:

    • Yersinia pestis, the causative agent of plague, is transmitted by fleas.
    • The formation of a proventricular block in fleas is a key factor in plague transmission.
    • Plasmid composition of Yersinia pestis influences its virulence and interaction with vectors.

    Purpose of the Study:

    • To investigate the role of specific Yersinia pestis plasmids in proventricular block formation and transmission by Xenopsylla cheopis fleas.
    • To compare the transmission efficiency of virulent and avirulent Yersinia pestis strains in fleas.
    • To assess the impact of Yersinia pestis infection on flea mortality rates.

    Main Methods:

    • Infection of Xenopsylla cheopis fleas with two Yersinia pestis strains differing in plasmid content (virulent I-2638 with four plasmids, avirulent I-3480 lacking pCad and pPst).
    • Assessment of proventricular block formation in fleas.
    • Evaluation of plague transmission efficiency by infected fleas.
    • Monitoring of flea survival rates.

    Main Results:

    • Both virulent and avirulent Yersinia pestis strains formed proventricular blocks in fleas with similar frequency.
    • Fleas infected with the avirulent strain failed to transmit the pathogen, indicating block formation does not equate to transmission.
    • Flea mortality rates were similar for both strains but higher in spring than in summer, with males dying more frequently than females.

    Conclusions:

    • Proventricular block formation by Yersinia pestis in fleas is not a reliable indicator of plague transmission.
    • Specific plasmids (pCad, pPst) are not essential for block formation but may influence transmission efficiency.
    • Environmental factors (season) and flea sex impact flea mortality during Yersinia pestis infection.

    More Related Videos

    'Bioluminescent' Reporter Phage for the Detection of Category A Bacterial Pathogens11:31

    'Bioluminescent' Reporter Phage for the Detection of Category A Bacterial Pathogens

    Published on: July 8, 2011

    Feeding of Ticks on Animals for Transmission and Xenodiagnosis in Lyme Disease Research08:23

    Feeding of Ticks on Animals for Transmission and Xenodiagnosis in Lyme Disease Research

    Published on: August 31, 2013

    Related Concept Videos

    Plague01:24

    Plague

    Plague is a highly virulent zoonotic disease caused by Yersinia pestis, a Gram-negative, facultatively anaerobic coccobacillus. This pathogen primarily circulates among rodent populations and is transmitted to humans through the bite of infected fleas. Additional transmission routes include direct contact with infected animal tissue or inhalation of respiratory droplets from individuals with pneumonic plague. These multiple transmission pathways highlight the bacterium’s potential for rapid...
    Bacterial Phylum Spirochaetes01:30

    Bacterial Phylum Spirochaetes

    Spirochetes, unique bacteria in the phylum Spirochaetes, are gram-negative, motile, tightly coiled, slender, and flexible. They inhabit aquatic sediments and animals, with some causing diseases like syphilis. Spirochetes are classified into eight genera based on habitat, pathogenicity, phylogeny, and characteristics.Their distinctive motility arises from endoflagella, located within the cell’s periplasm. These endoflagella anchor at the cell poles and extend along the cell length, encased by a...
    Bacterial Phylum Chlamydiae01:29

    Bacterial Phylum Chlamydiae

    The phylum Chlamydiae or Chlamydiota is composed of a single order, Chlamydiales. This phylum consists entirely of obligate intracellular parasites that infect eukaryotic hosts. While human pathogens within this group have been studied extensively, the phylum encompasses many species capable of interacting with various eukaryotic organisms. Members of Chlamydiae are typically small cocci, approximately 0.5 μm in diameter, and exhibit a distinctive developmental cycle. As is characteristic of...
    Microbial Interactions: Parasitism01:22

    Microbial Interactions: Parasitism

    Parasitism is a form of microbial interaction in which parasitic microbes exploit a host organism for nutrients and shelter, often at the host's expense. Unlike mutualistic relationships, where both organisms benefit, parasitism benefits only the parasite and harms the host.Classification of ParasitesMicrobial parasites are broadly classified based on their location relative to the host.Ectoparasites remain on the host’s surface, such as the skin or outer tissues, drawing nutrients...
    Inhalation Anthrax01:25

    Inhalation Anthrax

    Anthrax is a zoonotic disease caused by Bacillus anthracis, a Gram-positive, spore-forming bacterium. It primarily affects herbivorous animals but can be transmitted to humans through skin contact, ingestion, or inhalation of spores.Cutaneous anthrax, the most common form, typically results from direct contact with bacterial spores through skin abrasions and is generally less severe. Gastrointestinal anthrax results from eating undercooked or contaminated meat. It affects the mouth, throat, or...
    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...