Effects of penicillin, ceftriaxone, and doxycycline on morphology of Borrelia burgdorferi

Abstract

Antibiotic therapy with penicillin, doxycycline, and ceftriaxone has proven to be effective for the treatment of Lyme borreliosis. In some patients, however, it was noticed that borreliae can survive in the tissues in spite of seemingly adequate therapy. For a better understanding of this phenomenon, we investigated the different modes of degeneration of Borrelia burgdorferi suspensions during a 96-h exposure to various antibiotics. By dark-field microscopy and ultrastructural investigations, increasing blebbing and the gradual formation of granular and cystic structures could be followed during the exposure time. Although antibiotic concentrations at the MIC at which 90% of organisms are inhibited after 72 h were 80% or even greater, motile organisms were still present after incubation with penicillin and doxycycline but not after incubation with ceftriaxone. By transmission electron microscopy, intact spirochetal parts, mostly situated in cysts, were seen up to 96 h after exposure with all three antibiotics tested. According to experiences from studies with other spirochetes it is suggested that encysted borreliae, granules, and the remaining blebs might be responsible for the ongoing antigenic stimulus leading to complaints of chronic Lyme borreliosis.Borrelia burgdorferi, the pathogenic agent of Lyme borreliosis, has been recognized as a bacterium that is susceptible to antibiotics. The long-term persistence of these bacteria in tissues, despite adequate treatment of infected patients, has been indicated to be responsible for late complications and a chronic course of disease (17,26,28). The withdrawal of borreliae, or parts of them, into privileged or secluded sites, where they are further inaccessible to antibiotics, raises the question of whether antibiotics themselves can be made responsible for transforming the organism into a persistent, viable, or nonviable but antigenically potent form.Immobilization of bacteria has been seen as a result of incubation with antibiotics in vitro (21). By light microscopy, Preac-Mursic et al. (29) observed blebs, spherical structures, and granules in B. burgdorferi cultures during incubation with antibiotics. In ultrastrucutral studies the action of penicillin on cultures of Borrelia hermsii has been investigated (3).Penicillin, doxycycline, and ceftriaxone are the most preferred antibiotics for treating Lyme borreliosis. Although certain differences in the actions of these antimicrobial agents have been evaluated, they seem to be equally effective (34).Culture experiments were carried out to investigate the actions of these antibiotics on the motility, morphology, and survival of B. burgdorferi during exposure to antibiotic solutions. The course and mode of degeneration of these spirochetes were recorded on a videomicroscope and were photographed with an electron microscope. MATERIALS AND METHODSCulture experiments. Three strains of B. burgdorferi sensu lato, B31 (ATCC 35219) and two isolates from erythema migrans lesions on the skin of patients in Vienna, isolates hig...

Vancomycin Reduces Cell Wall Stiffness and Slows Swim Speed of the Lyme Disease Bacterium

“…Although doxycycline acts through inhibition of protein synthesis (15,16), amoxicillin and cefuroxime axetil both interfere with cell wall synthesis (17,18). The cell wall in bacteria is a prime target for antibiotics, since it is the main structural component of the cell and is composed of peptidoglycan, a network of glycan strands connected by peptide cross-links whose molecular constitutents are not found in eukaryotes (Fig.…”

Destruction of spirochete Borrelia burgdorferi round-body propagules (RBs) by the antibiotic Tigecycline

“…Penicillin, among many other ''unfavorable growth conditions,'' induces RBs (3,6,(10)(11)(12)(13)15). That penicillin does not cure either of the two ''Great Imitators'' (Lyme disease and syphilis) is widely accepted in Russian medical literature.…”

“…Transition from one growth medium to a second of different viscosity or temperature stimulates the formation of RBs. Starvation, threat of desiccation, exposure to oxygen gas, total anoxia and/or sulfide may induce RB formation (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13). RBs revert to the active helical swimmers when favorable conditions that support growth return (3)(4)(5).…”

In Vitro Activities of Fluoroquinolones against the SpirocheteBorrelia burgdorferi

“…Although the spectrum of antimicrobial agents active against Borrelia burgdorferi in vitro has been enlarged, therapeutic failures and a protracted course of the disease continue to be problems for clinicians in the management of patients suffering from chronic Lyme disease (12). A major consideration in selecting appropriate agents for the treatment of Lyme borreliosis remains the knowledge of the in vitro antimicrobial susceptibility of B. burgdorferi (2).…”