Link: http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.1002079

Excerpt:

Using a yeast surface display approach, 
a tick gut protein named TRE31 was identified to interact with BBE31. 
Silencing tre31 also decreased the B. burgdorferi burden in the tick 
hemolymph. Delineating the specific spirochete and arthropod ligands 
required for B. burgdorferi movement in the tick may lead to new 
strategies to interrupt the life cycle of the Lyme disease agent.

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).

Excerpt:

A new study led by researchers at the University of Copenhagen has confirmed that vitamin D plays an important role in activating immune defenses against infectious diseases like flu.

Vitamin D deficiency has already been linked to a wide spectrum of diseases including heart disease, cancer, diabetes, depression, autoimmune disease and many others.

The study published in the latest edition of Nature Immunology discovers that activation of T-cells to fight infections needs definite help from vitamin D.

Carsten Geisler and colleagues, study authors, explained the role vitamin D plays in the immune responses as follows.

First when the naive T cell recognizes foreign invaders like bacteria or viruses with T cell receptor (TCR), it sends activating signals (1) to the vitamin D receptor gene. The VDR gene then starts producing DVR protein, which binds vitamin D in the T cell (3) and becomes activated. Then the vitamin D bound and activated DVR gets into the cell nucleus and activates the gene for PLC-gamma1 (5), which in turn produces PLC-gamma1 protein (6) and “the T cells can get started”.

Results

We demonstrate that B. garinii OspA serotype 4 (ST4) PBi resist complement-mediated killing by binding of FHL-1. To identify the primary ligands of FHL-1 four CspA orthologs from B. garinii ST4 PBi were cloned and tested for binding to human CFH and FHL-1. Orthologs BGA66 and BGA71 were found to be able to bind both complement regulators but with different intensities. In addition, all CspA orthologs were tested for binding to mammalian and avian CFH. Distinct orthologs were able to bind to CFH of different animal origins.

Conclusions

B. garinii ST4 PBi is able to evade complement killing and it can bind FHL-1 to membrane expressed proteins. Recombinant proteins BGA66 can bind FHL-1 and human CFH, while BGA71 can bind only FHL-1. All recombinant CspA orthologs from B. garinii ST4 PBi can bind CFH from different animal origins. This partly explains the wide variety of animals that can be infected by B. garinii

Excerpt:

The number of known Bartonella species is rapidly growing. Some of them are responsible for distinct infectious diseases and show different prevalence and antibiotic susceptibility profiles. Not only have some vectors of Bartonella not been fully characterized, but also intermediate hosts are actually much more numerous and diverse than previously thought. Among these, dogs differ from cats because they tend to suffer an overt disease similar to humans, thus providing the base for a useful animal indicator and research model. Among the debilitating conditions with an unclear impact on the course of these infections, specific conditions (e.g., homelessness, alcoholism) have been linked to a much higher prevalence and to high risk of unfavorable outcome. Due to the limited arsenal of antibiotics effective in vivo on this peculiar intracellular pathogen, the risk/benefit balance of antibiotic therapy is sometimes difficult to draw. In this evolving picture, the recent discoveries of new species highlights the importance of basic molecular biology resources that would bring major public health benefits if available in endemic areas, and specifically in many areas of Peru and Bolivia.

Methods.Separate serum sets from LD patients and control subjects were tested independently at 2 medical centers using whole‐cell enzyme immunoassays and IgM and IgG immunoblots, with recombinant VlsE added to the IgG blots. The results from both centers were combined, and a new second‐tier IgG algorithm was developed.

Results.With standard 2‐tiered IgM and IgG testing, 31% of patients with active erythema migrans (stage 1), 63% of those with acute neuroborreliosis or carditis (stage 2), and 100% of those with arthritis or late neurologic involvement (stage 3) had positive results. Using new IgG criteria, in which only the VlsE band was scored as a second‐tier test among patients with early LD (stage 1 or 2) and 5 of 11 IgG bands were required in those with stage 3 LD, 34% of patients with stage 1, 96% of those with stage 2, and 100% of those with stage 3 infection had positive responses. Both new and standard testing achieved 100% specificity.

Conclusions.Compared with standard IgM and IgG testing, the new IgG algorithm (with VlsE band) eliminates the need for IgM testing; it provides comparable or better sensitivity, and it maintains high specificity.

Received 27 May 2009; accepted 10 August 2009; electronically published 30 November 2009.

Reprints or correspondence: Dr. John A. Branda, Clinical Microbiology Laboratory, GRB 526, Massachusetts General Hospital, Boston, MA 02114 (branda.john@mgh.harvard.edu).

• Presented in part: 45th Annual Meeting of the Infectious Diseases Society of America, San Diego, CA, 4-7 October 2007; and 11th International Conference on Lyme Borreliosis and Other Tick‐Borne Diseases, Irvine, CA, 19-22 October 2008.

http://www.journals.uchicago.edu/doi/abs/10.1086/648674 Clinical Infectious Diseases 2010;50:000-000 © 2009 by the Infectious Diseases Society of America. All rights reserved. 1058-4838/2010/5001-00XX$15.00 DOI: 10.1086/648674 MAJOR ARTICLE

2‐Tiered Antibody Testing for Early and Late Lyme Disease Using Only an Immunoglobulin G Blot with the Addition of a VlsE Band as the Second‐Tier Test

John A. Branda,¹

Maria E. Aguero‐Rosenfeld,^3,4

Mary Jane Ferraro,^1,2

Barbara J. B. Johnson,⁵

Gary P. Wormser,⁴ and

Allen C. Steere²

Departments of ¹Pathology and ²Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts; Departments of ³Pathology and ⁴Medicine, Division of Infectious Diseases, New York Medical College, Valhalla, New York; ⁵Division of Vector‐Borne Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado

Passage through Ixodes scapularis ticks enhances the virulence of a weakly pathogenic isolate of Borrelia burgdorferi.

Adusumilli S, Booth CJ, Anguita J, Fikrig E. Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America; Section of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America; Department of Veterinary and Animal Sciences, University of Massachusetts at Amherst, Amherst, Massachusetts, United States of America.

Lyme disease is the most common tick-borne illness in the United States. In this paper we explore the contribution of Ixodes scapularis ticks to the pathogenicity of Borrelia burgdorferi in mice. Previously we demonstrated that an isolate of B. burgdorferi sensu stricto (designated N40), passaged 75 times in vitro (N40-75), was infectious but no longer able to cause arthritis and carditis in C3H mice. We now show that N40-75 spirochetes can readily colonize I. scapularis and multiply during tick engorgement. Remarkably, tick-transmitted N40-75 spirochetes cause disease in mice. N40-75 spirochetes isolated from these animals also retained their pathogenicity when subsequently administered to mice via syringe inoculation. Array analysis revealed that several genes associated with virulence, including bba25, bba65, bba66, bbj09 and bbk32 had higher expression levels in the tick-passaged N40-75 spirochete. These data suggest that transmission of a high-passage attenuated isolate of B. burgdorferi by the arthropod vector results in generation of spirochetes that have enhanced pathogenesis in mice. PMID: 19822652 [PubMed – as supplied by publisher]=

Passage through Ixodes scapularis ticks enhances the virulence of a weakly
pathogenic isolate of Borrelia burgdorferi.

Adusumilli S, Booth CJ, Anguita J, Fikrig E.

Section of Infectious Diseases, Department of Internal Medicine, Yale University
School of Medicine, New Haven, Connecticut, United States of America; Section of
Comparative Medicine, Yale University School of Medicine, New Haven,
Connecticut, United States of America; Department of Veterinary and Animal
Sciences, University of Massachusetts at Amherst, Amherst, Massachusetts, United
States of America.Lyme disease is the most common tick-borne illness in the United States. In this
paper we explore the contribution of Ixodes scapularis ticks to the
pathogenicity of Borrelia burgdorferi in mice. Previously we demonstrated that
an isolate of B. burgdorferi sensu stricto (designated N40), passaged 75 times
in vitro (N40-75), was infectious but no longer able to cause arthritis and
carditis in C3H mice. We now show that N40-75 spirochetes can readily colonize
I. scapularis and multiply during tick engorgement. Remarkably, tick-transmitted
N40-75 spirochetes cause disease in mice. N40-75 spirochetes isolated from these
animals also retained their pathogenicity when subsequently administered to mice
via syringe inoculation. Array analysis revealed that several genes associated
with virulence, including bba25, bba65, bba66, bbj09 and bbk32 had higher
expression levels in the tick-passaged N40-75 spirochete. These data suggest
that transmission of a high-passage attenuated isolate of B. burgdorferi by the
arthropod vector results in generation of spirochetes that have enhanced
pathogenesis in mice.

http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=19822652&retmode=ref&cmd=prlinks
PMID: 19822652  [PubMed – as supplied by publisher]