LymeNet Newsletter Volume 2 Issue 20

Volume: 2
Issue: 20
Date: 02-Dec-94

Table of Contents:

I. NIAID: Summary Of Second Consultation On Chronic LD II. NIAID: Recent Projects at Rocky Mountain Labs III. ANTIMICROB AGENTS CHEMOTHER: In vitro activity of vancomycin against the spirochete Borrelia burgdorferi IV. About The LymeNet Newsletter

Newsletter:

*********************************************************************** * The National Lyme Disease Network * * LymeNet Newsletter * ***********************************************************************

IDX# Volume 2 - Number 20 - 12/02/94 IDX# INDEX IDX# IDX# I. NIAID: Summary Of Second Consultation On Chronic LD IDX# II. NIAID: Recent Projects at Rocky Mountain Labs IDX# III. ANTIMICROB AGENTS CHEMOTHER: In vitro activity of IDX# vancomycin against the spirochete Borrelia burgdorferi IDX# IV. About The LymeNet Newsletter IDX#

I. NIAID: Summary Of Second Consultation On Chronic LD --------------------------------------------------------- Sender: Edward McSweegan <[email protected]>

On October 18, NIAID convened a second informal meeting on chronic Lyme disease (LD). The discussion focused on possible clinical trial designs for chronic LD, infectious and non-infectious aspects of chronic LD, and potentially important co-infecting microorganisms in some cases of chronic LD. The meeting also served to provide the NIAID with a better understanding of the biomedical, logistical and analytical issues involved in carrying out a treatment trial for chronic LD. As noted at the first meeting on January 31, a fundamental question about chronic LD is whether the lingering signs and symptoms of post-treatment LD are due to persistent infection by Borrelia burgdorferi or to non-infectious sequelae. Furthermore, if persistent infection is common, is it antibiotic-responsive? The answers to these questions are critical to guiding the care and treatment of patients with evidence of chronic LD.

For purposes of the meeting, the term Post-Lyme Disease Syndrome (PLDS) was used to describe a condition of chronic or intermittent signs and symptoms coincident with the time of infection and persisting for six months to years despite documentation of appropriate antibiotic therapy. PLDS was further characterized by symptoms of cognitive disturbances (encephalopathy), chronic fatigue and malaise, headache, and joint and muscle pain. The PLDS concept was useful for discussing chronic LD and for outlining various etiologic considerations, including; persistent infection, incorrect diagnosis, slow resolution of signs and symptoms, residual damage from infection, re-infection, unmasking of a prior pathology, and a post-infectious immune or inflammatory process.

Given the varied clinical presentations and possible etiologies associated with PLDS, most of the meeting participants concluded that an initial trial should focus on a well-defined patient population with probable infection that might respond to antibiotics. The use of an antibiotic-responsive or microbiologic case definition in an antibiotic treatment trial would also simplify entry criteria, endpoint and outcome measures, and reduce the necessary study size. Entry criteria for such a treatment trial might include objective measures such as positive serologies, a history of tick bite or EM rash, compatible clinical signs and symptoms, repetitive positive PCRs, positive culture, and severe fatigue (> 6 months) after appropriate antibiotic therapy.

The use of a placebo was also thought by many participants to be essential in measuring the efficacy of an antibiotic treatment. The use of a double-blind, randomized, placebo-controlled trial would allow investigators to determine if the antibiotic-treated group improved significantly over the placebo group. Subsequent to such a determination it would be possible to ask other questions about optimal treatment duration, optimal drug route and optimal drug choice.

The meeting participants noted, however, that it would be unacceptable to enroll a placebo group into a treatment trial, based on their likelihood of being infected, without eventually treating them as aggressively as the antibiotic-treated group. Various approaches, such as a cross-over and parallel track trial designs, were discussed as ways of ensuring proper patient care throughout the duration of a treatment study.

An initial well-designed treatment trial involving a select population of PLDS patients would provide new information about treating chronic LD and suggest additional avenues of patient care and research. Most investigators recognized that in the absence of a sufficient number of infected patients who had never been treated, no particular group of LD patients would be uniform and ideal for a given treatment trial. It was also noted that a patient group with probable infection represented only the apex of a pyramid of PLDS patients with varying clinical presentations and possible etiologies. However, the intention of a first treatment trial would be to ask treatment and diagnostic questions in one well-defined patient group in the hope that the resulting answers could eventually be applied to others.

A report of the October 18 meeting will be presented to the NIAID Council at its next meeting in February 1995.

Chronic Lyme Disease: Clinical Trial Considerations --------------------------------------------------- Chairman - Steve Schutzer, M.D., Dept. of Medicine, UMDNJ. Med. Sch. Janice I. Beers, J.D., L.D. Assoc. of the U.S. William Blackwelder, Ph.D., Chief, Biometry, DMID/NIAID, NIH Carl Brenner, L.D. Coalition of NY Patricia Coyle, M.D., Dept. of Neurology, SUNY George Curlin, M.D., Deputy Director, DMID/NIAID, NIH Raymond Dattwyler, M.D., Div. Allergy, Rheum. & Clinical Immuno. SUNY Sch. of Med. Charlene DeMarco, M.D., Private Practice David Dennis, M.D., Div. Vector-Borne Inf. Dis., CDC/NCID Jesse Goodman, M.D., Div. of Medicine, U. of Minnesota Stephen Heyse, M.D., Director, OPECA/NIAMS, NIH Benjamin Luft, M.D., Div. of Inf. Dis., SUNY Sch. of Med. Robin McKenzie, M.D., Lab. Clin. Invest., NIAID, NIH David H. Persing, M.D., Lab. Med. Patho., Mayo Foundation Robert Quackenbush, Ph.D., Chief, BMB/DMID/NIAID, NIH Alfred J. Saah, M.D., School of Hygiene & Pub. Hlth, Johns Hopkins U. Susana Serrate-Sztein, Ph.D., NIAMS, NIH
Janice M. Soreth, M.D., Div. Anti-Infective Drug Prod., NIH Allen Steere, M.D., N.E. Med. Ctr., Rheumatology/Immunology David L. Weld, Exec. Dir., American Lyme Disease Foundation Inc. Edward McSweegan, Ph.D., NIAID

CONTACT: Edward McSweegan, Ph.D. Lyme Disease Program Officer National Institute of Allergy and Infectious Diseases Solar Bldg., Rm. 3A34 Bethesda, MD 20892-7630 301-496-7728 301-402-2508 (fax) [email protected]

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II. NIAID: Recent Projects at Rocky Mountain Labs --------------------------------------------------- Sender: Edward McSweegan <[email protected]>

TITLE: MOLECULAR BASIS FOR INFECTION BY BORRELIA BURGDORFERI ABSTRACT:

The objectives of this project are to (1) use recombinant DNA techniques to express specific antigens of Borrelia burgdorferi to improve the serodiagnosis of Lyme disease, (2) characterize at the molecular level, isolates of the Lyme disease spirochete from a wide range of biological and geographical sources, and (3) to use animal models to help understand the pathogenesis of Lyme disease and to examine serological responses to infection. During the last year we entered into a collaboration with Korean scientists to examine the potential for human Lyme disease in Korea. Lyme disease spirochetes, Borrelia burgdorferi sensu lato, were identified and characterized for the first time from Korea. Four isolates, designated Konkuk-1, Konkuk-2, Kangwon-3, and KM-4 were made from midgut suspensions of three Ixodes ticks and heart tissue from one mouse, Apodemus agrarius, collected from Chungbuk and Kangwon Provinces. The four Korean isolates and B. burgdorferi sensu lato from other geographic areas and biological sources were
compared using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) for protein profiles, Western immunoblot analysis for reactivities with monoclonal and polyclonal antibodies, and agarose gel electrophoresis for plasmid profiles. Two typing schemes using the polymerase chain reaction (PCR) identified three of the isolates as members of group VS461 and one, Kangwon-3, as B. garinii. These results demonstrate the potential for human Lyme disease to occur in some provinces of Korea. Previous studies have demonstrated that the urinary bladder is a consistent source for isolating the Lyme disease spirochete, Borrelia burgdorferi, from both experimentally infected and naturally exposed rodents. We examined histopathological changes in the urinary bladder of different types of rodents experimentally infected with Lyme spirochetes, including BALB/c mice (Mus musculus), nude mice (M. musculus), white-footed mice (Peromyscus leucopus), and grasshopper mice (Onychomys leucogaster). Animals
were inoculated intraperitoneally, subcutaneously, or intranasally with low-passaged spirochetes, high-passaged spirochetes, or phosphate-buffered saline. At various times following inoculation, animals were sacrificed and approximately one-half of each urinary bladder and kidney were cultured separately in BSK-II medium while the other half of each organ was prepared for histological examination. Spirochetes were cultured from the urinary bladder of all 35 mice inoculated with low-passaged spirochetes while we were unable to isolate spirochetes from any kidneys of the same mice. The pathological changes observed most frequently in the urinary bladder of the infected mice were the presence of lymphoid aggregates, vascular changes including an increase in the number of vessels and thickening of the vessel walls, and perivascular infiltrates. Our results demonstrate that nearly all individuals (93%) of the four types of mice examined had a cystitis associated with spirochetal infection.

TITLE: PATHOGENESIS OF INFECTION WITH THE LYME DISEASE SPIROCHETE, BORRELIA BURGDORFERI ABSTRACT: Our broad objective is to understand the means by which Borrelia burgdorferi establishes an infection: transmission cycle between the tick vector and mammalian reservoir host, both of which are needed to maintain the spirochete in nature. The following research efforts relate to this goal. l. Outer surface protein variation. The outer membrane of B. burgdorferi contains several abundant proteins (Osps) that are variable in size and expression and of unknown function. It is likely that the different Osps confer distinct properties on the spirochete that are pertinent to the disparate environments in which it must survive. Rosa and Hogan have identified homologous recombination between DSP genes in natural populations of B. burgdorferi in ticks. Dr. Margolis has also determined that transcriptional regulation or mRNA stability is responsible for different patterns of Osp synthesis among clonal variants. He has
cloned an osp gene that is variably expressed in B. burgdorferi in culture and is investigating the sequences and factors involved in the regulation of its expression. 2. Linear plasmid replication. An understanding of the unusual linear structure of the Borrelia chromosome and plasmids is of intrinsic interest and practical merit. Dr. Tilly has isolated homologs of heat shock genes that are involved in plasmid replication in other systems. These genes are induced by a temperature upshift as would be experienced upon transfer from a tick to a mammal. She has isolated and sequenced the gene of the Borrelia IHF homolog, another candidate gene that may be involved in linear plasmid replication, and is characterizing its biological activities in E. coli. She has identified unique concatemeric or circular forms of the linear plasmids that could represent replication intermediates.

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III. ANTIMICROB AGENTS CHEMOTHER: In vitro activity of vancomycin against the spirochete Borrelia burgdorferi ------------------------------------------------------------------- AUTHORS: Dever LL, Jorgensen JH, Barbour AG REFERENCE: Antimicrob Agents Chemother; 1993: 37, 1115-1121 ABSTRACT:

Borrelia burgdorferi, a spirochete and the causative agent of Lyme disease, has been reported to be susceptible to a variety of antimicrobial agents. In this investigation, the action of vancomycin, a glycopeptide antibiotic not previously known to have activity against spirochetes, against borrelias was examined. The in vitro activity of vancomycin against a variety of strains of B. burgdorferi and one strain of Borrelia hermsii was determined by use of a microdilution MIC method (L.L. Dever, J.H. Jorgensen, and A.G. Barbour, J. Clin. Microbiol. 30:2692-2697, 1992). MICs ranged from 0.5 to 2 micrograms/ml. MICs of the glycopeptides ristocetin and teicoplanin and the lipopeptide daptomycin against strain B31 of B. burgdorferi were all > or = 8 micrograms/ml. Subsurface plating, time- kill studies, synergy studies, and electron microscopy were used to investigate further the activity of vancomycin against B31. The MBC of vancomycin was 2 micrograms/ml. Time-kill curves demonstrated > or = 3-log10-unit (99.9%) killing of the final
inoculum after 72 h by vancomycin concentrations twice the MIC. Synergy between vancomycin and penicillin was demonstrated at concentrations one-fourth the MIC of each drug. In electron microscopy, B31 cells exposed to vancomycin showed a disruption of cellular integrity and were indistinguishable from those exposed to penicillin. These studies demonstrate another class of microorganisms susceptible in vitro to vancomycin.

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