2,772views
00:00 / 00:00
Bacteriology
Bacterial structure and functions
Staphylococcus epidermidis
Staphylococcus aureus
Staphylococcus saprophyticus
Streptococcus viridans
Streptococcus pneumoniae
Streptococcus pyogenes (Group A Strep)
Streptococcus agalactiae (Group B Strep)
Enterococcus
Clostridium perfringens
Clostridium botulinum (Botulism)
Clostridium difficile (Pseudomembranous colitis)
Clostridium tetani (Tetanus)
Bacillus cereus (Food poisoning)
Listeria monocytogenes
Corynebacterium diphtheriae (Diphtheria)
Bacillus anthracis (Anthrax)
Nocardia
Actinomyces israelii
Escherichia coli
Salmonella (non-typhoidal)
Salmonella typhi (typhoid fever)
Pseudomonas aeruginosa
Enterobacter
Klebsiella pneumoniae
Shigella
Proteus mirabilis
Yersinia enterocolitica
Legionella pneumophila (Legionnaires disease and Pontiac fever)
Serratia marcescens
Bacteroides fragilis
Yersinia pestis (Plague)
Vibrio cholerae (Cholera)
Helicobacter pylori
Campylobacter jejuni
Neisseria meningitidis
Neisseria gonorrhoeae
Moraxella catarrhalis
Francisella tularensis (Tularemia)
Bordetella pertussis (Pertussis/Whooping cough)
Brucella
Haemophilus influenzae
Haemophilus ducreyi (Chancroid)
Pasteurella multocida
Mycobacterium tuberculosis (Tuberculosis)
Mycobacterium leprae
Mycobacterium avium complex (NORD)
Mycoplasma pneumoniae
Chlamydia pneumoniae
Chlamydia trachomatis
Borrelia burgdorferi (Lyme disease)
Borrelia species (Relapsing fever)
Leptospira
Treponema pallidum (Syphilis)
Rickettsia rickettsii (Rocky Mountain spotted fever) and other Rickettsia species
Coxiella burnetii (Q fever)
Ehrlichia and Anaplasma
Gardnerella vaginalis (Bacterial vaginosis)
Borrelia species (Relapsing fever)
0 / 6 complete
of complete
2022
2021
2020
2019
2018
animal transmission p. 147
lice p. 158
Alexandru Duhaniuc, MD
Kaylee Neff
Borrelia is a genus of spirochetes, which are long, thin, spiral shaped bacteria, that spin or twist to move around.
The genus has two major groups. The first one is associated with Lyme disease and the most common species is Borrelia burgdorferi.
The second group is associated with relapsing fever and the most common species are Borrelia hermsii, Borrelia turicatae, Borrelia parkeri and Borrelia recurrentis.
Of the second group, the first three species cause tick-borne relapsing fever, while Borrelia recurrentis causes louse-borne relapsing fever.
By the way, you may know this already, but “louse” is actually singular for “lice” - so body lice are the vector that transmits Borrelia recurrentis.
Now, all Borrelia species have an outer membrane that contains a substance similar to lipopolysaccharides, an inner membrane, and a layer of peptidoglycan in a periplasmic space, which is the space between the inner and the outer membrane.
Since the peptidoglycan layer is thin, it doesn’t retain the purple dye used during Gram staining, so they’re classified as Gram-negative.
However, they can’t be easily visualized with Gram staining. Instead, they’re best seen with the Wright or Giemsa stain, which make the bacteria appear purple, and with dark-field microscopy, which make the bacteria appear white against a dark background.
Now, Borrelia species are motile, which means they can move around using long, thin filaments called endoflagella, which are located in their periplasmic space.
The filaments rotate in this space, between the outer membrane and the peptidoglycan layer, propelling the bacterium forward in a corkscrew-like motion.
Finally, the bacteria can be cultivated on Barbour-Stoenner-Kelly medium or by intraperitoneal inoculation of immature laboratory mice, but these tests are not widely available.
Now, Borrelia can enter the body one of two ways, depending on the type of relapsing fever.
So, in tick-borne relapsing fever, or TBRF, the bacteria enters the bloodstream through the bite of an infected tick.
Borrelia species are gram-negative spirochetes that cause relapsing fever. The characteristic feature of relapsing fever is the cyclical pattern of fever and afebrile periods. Transmission of Borrelia to humans generally occurs through the bite of an infected vector, commonly a tick or a louse. Lyme disease is the most common presentation of Borreliosis. Symptoms can include fever, headache, myalgia, and arthralgia. Borrelia burgdorferi is the primary causative agent of Lyme disease. Untreated Lyme disease can lead to neurologic sequelae, including meningitis and encephalitis.
Copyright © 2023 Elsevier, except certain content provided by third parties
Cookies are used by this site.
USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.