All Posts Tagged With: "borrelia burgdorferi"

Link: http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=21113897&retmode=ref&cmd=prlinks

Excerpt:

Infectious diseases can affect the previously healthy adolescent as well as
severely immuno-compromised intensive care unit patients. The effects may be
merely annoying, but in many cases they can become life-threatening. The
immediate impact of infectious diseases on everyday life can be seen with
Helicobacter pylori, which infects more than 50% of the global population,
or Borrelia burgdorferi, which causes a major tick-borne disease in Europe
and America. On the other hand, in less-developed countries, infections
causing diarrhea are still among the most important causes of death –
especially in children. Research in Medical Microbiology ranges from
attempts to better understand the physiology and ecology of the causative
agents to epidemiological typing of clinical isolates. It covers the mutual
interactions of pathogenic microbes as well as the interplay between
microorganism and host. Among the most pressing problems in medical
microbiology is the emerging of antibiotic resistances. In recent years,
both Gram-positive bacteria – with the first description of vancomycin
resistant Staphylococcus aureus – as well as Gram-negative species – e.g.
with the emergence of extended spectrum beta-lactamases – have seen new and
dramatic occurrences of resistance.
Consequently, the detection and characterization of new antimicrobial
compounds is, more than ever, an important task. All these topics are
covered by the research articles compiled in this Special Issue of the
Journal of Basic Microbiology. Further, the publication of this Special
Issue should underline the importance of “Basic Microbiology” for “Medical
Microbiology”: The sometimes existing gap between basic research and
application needs to be bridged urgently and in a time-saving manner as
often as possible. We are convinced that only combined efforts of experts in
both areas will allow us to tackle future’s problems in infectious diseases
efficiently ((c) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).

Link: http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=21223661&retmode=ref&cmd=prlinks

Excerpt:

OBJECTIVE: To understand the carrying status of Borrelia burgdorferi in
ticks from the mountain areas from six representative provinces, including
Jilin, Shanxi, Gansu, Qinghai, Guizhou and Hunan in China. 

METHODS: Flagging and
trapping methods were used to collect ticks in forest area and culture
medium was used to isolate the pathogen. Nested-PCR was used to detect the
germ-carrying rate of ticks. 

RESULTS: More than 2200 ticks from six
representative provinces were collected and 1000 ticks were used to isolate
the pathogen. 13 Lyme disease spirochetes from ixodes persulcatus in
Changbai, Jilin province and 9 Lyme disease spirochetes from ixodes
granulatus in Daozhen, Guizhou province were identified. There were 1255
ticks used for PCR testing.
Specific fragments of the Borrelia burgdorferi in ticks were found from the
six representative provinces in China. The carrier rate was higher in Jilin
(Changbai 27.08%, Tonghua 20.41%), Qinghai (Huzhu 25.06%, Huangnan 21.11%)
and Guizhou (Daozhen 25.63%), than in Shanxi (Yuanqu 4.72%, Jiaocheng
3.64%). Result from the sequence analysis showed that the genotype belong to
Borrelia garinii in Jilin, Qinghai, Gansu, Shanxi provinces but Borrelia
valaisiana in Guizhou and Hunan provinces. 

CONCLUSION: Our data showed that there existed Lyme disease spirochetes in
all the six representative provinces in China, but the carrying rates of
ticks were different. Borrelia garinii was found in Shanxi province, and
Borrelia valaisiana in Hunan province.

Link: http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=20941513&retmode=ref&cmd=prlinks

Excerpt:

Invasive species, including pathogens, can have important effects
on local ecosystems, including indirect consequences on native
species. This study focuses on the effects of an invasive plant
pathogen on a vertebrate community and Ixodes pacificus, the
vector of the Lyme disease pathogen (Borrelia
burgdorferi) in California. Phytophthora ramorum, the causative
agent of sudden oak death, is a non-native pathogen killing trees
in California and Oregon. We conducted a multi-year study using a
gradient of SOD-caused disturbance to assess the impact on the
dusky-footed woodrat (Neotoma fuscipes) and the deer mouse
(Peromyscus maniculatus), two reservoir hosts of B. burgdorferi,
as well as the impact on the Columbian black-tailed deer
(Odocoileus hemionus
columbianus) and the western fence lizard (Sceloporus
occidentalis), both of which are important hosts for I. pacificus
but are not pathogen reservoirs.
Abundances of P. maniculatus and S. occidentalis were positively
correlated with greater SOD disturbance, whereas N. fuscipes
abundance was negatively correlated. We did not find a change in
space use by O. hemionus. 
Our data show
that SOD has a positive impact on the density of nymphal ticks,
which is expected to increase the risk of human exposure to Lyme
disease all else being equal. A positive correlation between SOD
disturbance and the density of nymphal ticks was expected given
increased abundances of two important hosts: deer mice and
western fence lizards. However, further research is needed to
integrate the direct effects of SOD on ticks, for example via
altered abiotic conditions with host-mediated indirect effects

Excerpt:

Among the 20 tick species described in Switzerland, Ixodes ricinus, the most
frequent one, is implicated in the transmission of pathogenic agents. Lyme
borreliosis and tick-borne encephalitis (TBE) are the major tick-borne
diseases transmitted to human. 
**Presently 5 Borrelia species, belonging to the group Borrelia burgdorferi,
are recognized as human pathogens**. 
The risks of infection depend on the stage of the vector, the multiple
hosts, the pathogenic agent, as well as human behavior in nature. 
The detection of other pathogenic agents in ticks: Anaplasma, Babesia and
Rickettsia predispose to infections or co-infections. Results of
sero-epidemiologic studies suggest human infections. Active surveillance by
physicians is necessary and clinical studies are required to evaluate the
importance of these infections in Switzerland.

Link: http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=21188224&retmode=ref&cmd=prlinks

Excerpt:

Lyme neuroborreliosis or “neurological Lyme disease” was evidenced in 2 of
23 patients submitted to strict criteria for case selection of the Centers
for Disease Control and Prevention employing a two-tier test to detect
antibodies to Borrelia burgdorferi at a single institution. One patient had
symptomatic polyradiculoneuritis, dysautonomia, and serological evidence of
early infection; and another had symptomatic small fiber sensory neuropathy,
distal polyneuropathy, dysautonomia, and serological evidence of late
infection. In the remaining patients symptoms initially ascribed to Lyme
disease were probably unrelated to B. burgdorferi infection. Our findings
suggest early susceptibility and protracted involvement of the nervous
system most likely due to the immunological effects of B. burgdorferi
infection, although the exact mechanisms remain uncertain.

Link: http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=21177909&retmode=ref&cmd=prlinks

Excerpt:

In North America, Lyme borreliosis (LB) is a tick-borne disease caused by
infection with the spirochete Borrelia burgdorferi. We studied the genetic
diversity of LB spirochetes in north-coastal Californian residents.
Spirochete DNA was detected in 23.7% (27/114) of study subjects using a PCR
protocol optimized for increased sensitivity in human sera. Californians
were most commonly infected with B. burgdorferi ospC genotype A, a globally
widespread spirochete associated with high virulence in LB patients.
Sequence analysis of rrf-rrl and p66 loci in 11% (3/27) of PCR-positive
study subjects revealed evidence of infection with an organism closely
related to B. bissettii. This spirochete, heretofore associated with LB only
in Europe, is widely distributed among ticks and wildlife in North America.
Further molecular testing of sera from residents in LB-endemic areas is
warranted to enhance our understanding of the geographic distribution and
frequency of occurrence of B. bissettii-like infections.

Link: http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=21173795&retmode=ref&cmd=prlinks

Excerpt:

Background A 71-year-old woman presented to a rheumatologist with what she
believed to be a 2-year history of Lyme disease, progressing from erythema
migrans to Lyme arthritis.Investigations History, physical examination and
serologic testing confirmed the diagnosis of Lyme disease.Diagnosis Lyme
disease.Management The patient refused antibiotic therapy during the first 2
years of her illness. During the next 2 years, she consulted a
rheumatologist, but declined antibiotic therapy. She continued to have
recurrent episodes of arthritis, following which she was successfully
treated with doxycycline, given initially for 2 weeks, with a second, 4-week
cycle administered 2 months later.
This case illustrates the natural history of untreated Lyme disease, which
is rarely observed in most patients since diagnosis almost always leads to
successful antibiotic treatment. Furthermore, this case also demonstrates
that infection with Borrelia burgdorferi can persist for years in untreated
patients; however, antibiotic therapy is still likely to be effective,
despite long-term infection.

Link: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0015830

Excerpt:

The Lyme disease spirochete Borrelia burgdorferi dramatically upregulates
outer surface protein C (OspC) in response to fresh bloodmeal during
transmission from the tick vector to a mammal, and abundantly produces the
antigen during early infection. As OspC is an effective immune target, to
evade the immune system B. burgdorferi downregulates the antigen once the
anti-OspC humoral response has developed, suggesting an important role for
OspC during early infection.

Methodology/Principal Findings

In this study, a borrelial mutant producing an OspC antigen with a
5-amino-acid deletion was generated. The deletion didn’t significantly
increase the 50% infectious dose or reduce the tissue bacterial burden
during infection of the murine host, indicating that the truncated OspC can
effectively protect B. burgdorferi against innate elimination. 
However, the deletion greatly impaired the ability of B. burgdorferi to
disseminate to remote tissues after inoculation into mice.

Conclusions/Significance

The study indicates that OspC plays an important role in dissemination of B.
burgdorferi during mammalian infection.

Link: http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.1001144

Excerpt:

If insufficiently treated, Lyme borreliosis can evolve into an
inflammatory disorder affecting skin, joints, and the CNS. Early
innate immunity may determine host responses targeting infection.
Thus, we sought to characterize the immediate cytokine storm
associated with exposure of PBMC to moderate levels of live
Borrelia burgdorferi. Since
Th17 cytokines are connected to host defense against
extracellular bacteria, we focused on interleukin (IL)-17 and
IL-22. Here, we report that, despite induction of inflammatory
cytokines including IL-23, IL-17 remained barely detectable in
response to B. burgdorferi. In contrast, T cell-dependent
expression of IL-22 became evident within 10 h of exposure to the
spirochetes. This dichotomy was unrelated to interferon-? but to
a large part dependent on caspase-1 and IL-1 bioactivity derived
from monocytes. In fact, IL-1? as a single stimulus induced IL-22
but not IL-17. Neutrophils display antibacterial activity against
B. burgdorferi, particularly when opsonized by antibodies. Since
neutrophilic inflammation, indicative of IL-17 bioactivity, is
scarcely observed in Erythema migrans, a manifestation of skin
inflammation after infection, protective and antibacterial
properties of IL-22 may close this gap and serve essential
functions in the initial phase of spirochete infection.

Link: http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=20974828&retmode=ref&cmd=prlinks

Excerpt:

Bacterial lipoproteins are a set of membrane proteins with many
different functions. Due to this broad-ranging functionality
these proteins have a considerable significance on many
phenomenon from cellular physiology through to cell division and
virulence. Here, we give a general overview of lipoprotein
biogenesis and highlight examples of the roles of lipoproteins in
bacterial disease caused by a selection of medically relevant
Gram negative and Gram positive pathogens; Mycobacterium
tuberculosis, Streptococcus pneumoniae, Borrelia burgdorferi and
Neisseria meningitidis. Lipoproteins have been shown to play key
roles in the adhesion to host cells, the modulation of
inflammatory processes and translocation of virulence factors
into host cells. As such, a number of lipoproteins have been
shown to be potential vaccines. This review provides a summary of
some of the reported roles of lipoproteins and of how this
knowledge has been exploited in some cases for the generation of
novel countermeasures to bacterial diseases.