National Library of Medicine: IGM Selected Full Records Screen
Selected full citations from 12 MEDLINE records
Date: Sun, 09 Apr 2000
From: Kathleen Dickson
Organization: SeCT Lyme Support Group
TITLE:
Serum-starvation-induced changes
in protein synthesis and morphology of Borrelia burgdorferi.
AUTHORS:
Alban PS; Johnson PW; Nelson DR
AUTHOR AFFILIATION:
Department of Biochemistry, Microbiology,
and Molecular Genetics, University of Rhode Island, Kingston 02881, USA.
SOURCE:
Microbiology 2000 Jan;146 ( Pt
1):119-27
CITATION IDS:
PMID: 10658658 UI: 20121745
ABSTRACT:
It has been demonstrated previously
that motile Borrelia burgdorferi cells transform into non-motile cyst-forms
when incubated for several weeks in BSKII (a complex medium) lacking rabbit
serum. B. burgdorferi cells cannot synthesize fatty acids de novo and serum
is thought to provide a source of fatty acids and lipids. When B. burgdorferi
cells were serum-starved in defined RPMI medium, -90% of the cells formed
spherical cysts within 48 h. Cyst formation was inhibited by tetracycline.
Cyst opening and recovery of vegetative cells was rapidly induced by the
addition of either BSKII or rabbit serum. The percentage of viable cells
recovered from cysts ranged from 2.9% to 52-5%. Viability was inversely
proportional to cyst age. Protein synthesis by B. burgdorferi during serum
starvation was examined by labelling cells with Tran35S-Label and analysing
the labelled proteins by two-dimensional gel electrophoresis and fluorography.
The synthesis of over 20 proteins was induced during serum starvation.
Western blots of proteins from vegetative cells and cysts probed with sera
from either B. burgdorferi-infected humans or monkeys revealed that several
cyst proteins were antigenic. These data suggest that cells of B. burgdorferi,
although possessing a small genome and extremely limited biosynthetic capabilities,
rapidly respond to conditions of serum starvation by inducing changes in
protein synthesis and cell morphology. This study may help explain how
cells of B. burgdorferi can survive periods of nutrient deprivation in
different hosts and host tissues.
Transformation of cystic forms
of Borrelia burgdorferi to normal, mobile spirochetes.
AUTHORS:
Brorson O; Brorson SH
AUTHOR AFFILIATION:
Dept. of Microbiology, Ulleval
University Hospital, Oslo, Norway.
SOURCE:
Infection 1997 Jul-Aug;25(4):240-6
CITATION IDS:
PMID: 9266264 UI: 97411286
ABSTRACT:
The purpose of this study was to
evaluate the behaviour of Borrelia burgdorferi under controlled conditions.
The occurrence of cystic forms of Borrelia burgdorferi in vitro was noted,
and these cysts were able to be transformed to normal, mobile spirochetes.
B. burgdorferi was cultivated in a commercial culture medium without serum.
The spirochetes multiplied only slowly in this medium, and transformation
to encysted forms was observed after 1 week. When these cysts were transferred
to the same culture medium with rabbit serum, the encysted forms developed
into regular, mobile spirochetes after 6 weeks, and their regeneration
time was normal. Examination of these cysts in the transmission electron
microscope revealed transverse fission inside the cysts. It is probable
that similar phenomena may occur in vivo under conditions unfavourable
for spirochetes. These observations may help to explain why diagnosis and
treatment of B. burgdorferi infections in humans can be difficult.
Animal
Borrelia burgdorferi/growth & development
Cell Membrane/ultrastructure
Cell Movement
Culture Media
Flagella/ultrastructure
Human
Microscopy/methods
Microscopy, Electron
Rabbits
Reference Values
1997/07
1997/01 00:00
PUBLICATION TYPES:
JOURNAL ARTICLE
CAS REGISTRY NUMBERS:
0 (Culture Media)
LANGUAGES:
Eng
TITLE:
Effects of penicillin, ceftriaxone,
and doxycycline on morphology of Borrelia burgdorferi.
AUTHORS:
Kersten A; Poitschek C; Rauch S;
Aberer E
AUTHOR AFFILIATION:
Department of Dermatology, University
of Vienna, Austria.
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 survival 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.
[The cytoarchitectonics of hard
chancre in rabbits with experimental syphilis exposed to soliusul'fon and
cefamezine]
VERNACULAR TITLE:
Tsitoarkhitektonika tverdogo shankra
u krolikov s eksperimental'nym sifilisom pri vozdeistvii soliusul'fonom
i tsefamezinom.
AUTHORS:
Delektorskii VV; Romanenko VN;
Gupalo LA; Balakishieva FI
SOURCE:
Vestn Dermatol Venerol 1990;(4):32-6
CITATION IDS:
PMID: 2202167 UI: 90357885
ABSTRACT:
Twenty rabbits were infected with
Treponema pallidum suspension. Ten animals were injected with solusulfone,
the rest with cefamezin. Specific features of syphilis induced by a pool
of Treponemas are described, such as T. pallidum ultrastructure, formation
of a specific granule, form of the agent aggression. Solusulfone treatment
was associated with activation of phagocytosis, that manifested by a shift
of the incomplete/complete phagocytosis ratio towards the reaction completion;
however, intact T. pallidum were detectable even in 72 hrs after the drug
injection. Cefamezin had no effect on the cysts and cyst-like formations
at the beginning of the treatment course but these forms of the agent were
already undetectable in 48 hours.
MAIN MESH HEADINGS:
Cefazolin/*therapeutic use
Chancre/*pathology
Sulfones/*therapeutic use
Syphilis/*pathology
ADDITIONAL MESH HEADINGS:
Animal
Biopsy
Chancre/drug therapy
Chancre/microbiology
Drug Screening
English Abstract
Microscopy, Electron
Phagocytosis/drug effects
Rabbits
Skin/drug effects
Skin/ultrastructure
Time Factors
Treponema pallidum/drug effects
Treponema pallidum/ultrastructure
1990/01
1990/01 00:00
Spirochaetes were isolated from
rectal biopsies of three patients and successfully cultured. Enzymatic
reactions and electron microscopy revealed spirochaetes resembling Brachyspira
aalborgi. Examination of ultrathin sections of centrifugates of cultured
spirochaetes yielded unusual cyst-like structures with an outer double
membrane containing spirochaetes in different developmental stages. The
protoplasmic cylinders seemed to originate from a large electron-dense
focus in the cyst-like structures. The axial fibrils occurred as loosely
distributed solitary structures in the cyst-like structures. Cysts were
not found in the biopsy tissue. The encystment of the spirochaetes could
be related to their protection, multiplication, spread and transmission.