scholarly journals Deletion of BBA64, BBA65, and BBA66 Loci Does Not Alter the Infectivity of Borrelia burgdorferi in the Murine Model of Lyme Disease

2008 ◽  
Vol 76 (11) ◽  
pp. 5274-5284 ◽  
Author(s):  
Mahulena Maruskova ◽  
J. Seshu
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Murine Model ◽  
Profile Analysis ◽  
Mammalian Host ◽  
Triple Mutant ◽  
Environmental Signals ◽  
Significant Difference ◽  
Clonal Isolate

ABSTRACT Borrelia burgdorferi, the causative agent of Lyme disease, alters its gene expression in response to highly disparate environmental signals encountered in its tick vector versus vertebrate hosts. Whole-genome transcriptional profile analysis of B. burgdorferi, propagated in vitro under mammalian-host-specific conditions, revealed significant upregulation of several linear plasmid 54 (lp54)-encoded open reading frames (ORFs). Among these ORFs, BBA64, BBA65, and BBA66 have been shown to be upregulated in response to multiple mammalian-host-specific signals. Recently, we determined that there was no significant difference in the ability of BBA64− mutant to infect C3H/HeN mice compared to its isogenic control strains, suggesting that B. burgdorferi might utilize multiple, functionally related determinants to establish infection. We further generated BBA65− and BBA66− single mutants in a noninfectious, lp25− clonal isolate of B. burgdorferi strain B31 (ML23) and complemented them with the minimal region of lp25 (BBE22) required for restoring the infectivity. In addition, we generated a BBA64− BBA65− BBA66− triple mutant using an infectious, clonal isolate of B. burgdorferi strain B31 (5A11) that has all of the infection-associated plasmids. There were no significant differences in the ability to isolate viable spirochetes from different tissues of C3H/HeN mice infected via intradermal needle inoculation with either the individual single mutants or the triple mutant compared to their respective isogenic parental strains at days 21 and 62 postinfection. These observations suggest that B. burgdorferi can establish infection in the absence of expression of BBA64, BBA65, and BBA66 in the murine model of Lyme disease.

scholarly journals Role of the BBA64 Locus of Borrelia burgdorferi in Early Stages of Infectivity in a Murine Model of Lyme Disease

2007 ◽  
Vol 76 (1) ◽  
pp. 391-402 ◽  
Author(s):  
Mahulena Maruskova ◽  
M. Dolores Esteve-Gassent ◽  
Valerie L. Sexton ◽  
J. Seshu
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Immunoblot Analysis ◽  
Open Reading Frames ◽  
Mammalian Host ◽  
Environmental Signals ◽  
Significant Difference ◽  
Linear Plasmid 54

ABSTRACT Borrelia burgdorferi, the causative agent of Lyme disease, undergoes rapid adaptive gene expression in response to environmental signals encountered during different stages of its life cycle in the arthropod vector or the mammalian host. Among all the plasmid-encoded genes of B. burgdorferi, several linear plasmid 54 (lp54)-encoded open reading frames (ORFs) exhibit the greatest differential expression in response to mammalian host-specific temperature, pH, and other uncharacterized signals. These ORFs include members of the paralogous gene family 54 (pgf 54), such as BBA64, BBA65, and BBA66, present on lp54. In an attempt to correlate transcriptional up-regulation of these pgf 54 members to their role in infectivity, we inactivated BBA64 and characterized the phenotype of this mutant both in vitro and in vivo. There were no major differences in the protein profiles between the BBA64 mutant and the control strains, while immunoblot analysis indicated that inactivation of BBA64 resulted in increased levels of BBA65. Moreover, there was no significant difference in the ability of the BBA64 mutant to infect C3H/HeN mice compared to that of its parental or complemented control strains as determined by culturing of viable spirochetes from infected tissues. However, enumeration of spirochetes using quantitative real-time PCR revealed tissue-specific differences, suggesting a minimal role for BBA64 in the survival of B. burgdorferi in select tissues. Infectivity analysis of the BBA64 mutant suggests that B. burgdorferi may utilize multiple determinants to establish infection in mammalian hosts.

scholarly journals Efficacy of an Evernimicin (SCH27899) In Vitro and in an Animal Model of Lyme Disease

2001 ◽  
Vol 45 (3) ◽  
pp. 936-937 ◽  
Author(s):  
Charles S. Pavia ◽  
Gary P. Wormser ◽  
John Nowakowski ◽  
Anthony Cacciapuoti
Keyword(s):  
Animal Model ◽  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Antibiotic Treatment ◽  
Murine Model ◽  
C3h Mice

ABSTRACT The MICs of evernimicin at which 90% of Borrelia burgdorferi patient isolates were inhibited ranged from 0.1 to 0.5 μg/ml. Evernimicin was as effective as ceftriaxone againstB. burgdorferi in a murine model of experimental Lyme disease. As assessed by culturing the urinary bladders of infected C3H mice, no live Borrelia isolates were recoverable following antibiotic treatment.

scholarly journals The Borrelia burgdorferi Glycosaminoglycan Binding Protein Bgp in the B31 Strain Is Not Essential for Infectivity despite Facilitating Adherence and Tissue Colonization

2017 ◽  
Vol 86 (2) ◽  
Author(s):  
Samantha Schlachter ◽  
Janakiram Seshu ◽  
Tao Lin ◽  
Steven Norris ◽  
Nikhat Parveen
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Binding Protein ◽  
Mammalian Host ◽  
Infection Model ◽  
Binding Assays ◽  
Content Type ◽  
Mouse Infection Model ◽  
Successful Infection

ABSTRACTThe Lyme disease-causing organismBorrelia burgdorferiis transmitted into the mammalian host by an infected-tick bite. Successful infection relies on the ability of this extracellular pathogen to persist and colonize different tissues.B. burgdorferiencodes a large number of adhesins that are able to interact with host ligands to facilitate adherence and tissue colonization. Multiple glycosaminoglycan binding proteins present inB. burgdorferioffer a degree of redundancy of function during infection, and this highlights the importance of glycosaminoglycans as host cell receptors for spirochete adherence. Of particular interest in this study isBorreliaglycosaminoglycan binding protein (Bgp), which binds to heparin-related glycosaminoglycans. The properties of abgptransposon mutant and atrans-complemented derivative were compared to those of the wild-typeB. burgdorferiin thein vitrobinding assays and in infection studies using a C3H/HeJ mouse infection model. We determined that the loss of Bgp impairs spirochete adherence, infectivity, and tissue colonization, resulting in a reduction of inflammatory manifestations of Lyme disease. Although Bgp is not essential for infectivity, it is an important virulence factor ofB. burgdorferithat allows adherence and tissue colonization and contributes to disease severity.

scholarly journals Decorin-Binding Protein A (DbpA) of Borrelia burgdorferi Is Not Protective When Immunized Mice Are Challenged via Tick Infestation and Correlates with the Lack of DbpA Expression by B. burgdorferi in Ticks

2000 ◽  
Vol 68 (8) ◽  
pp. 4759-4764 ◽  
Author(s):  
Kayla E. Hagman ◽  
Xiaofeng Yang ◽  
Stephen K. Wikel ◽  
George B. Schoeler ◽  
Melissa J. Caimano ◽  
...  
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Murine Model ◽  
Blood Meal ◽  
Tick Infestation ◽  
Ixodes Scapularis ◽  
Binding Protein ◽  
Protein A ◽  
Lyme Disease Vaccine

ABSTRACT Previous studies showed that decorin-binding protein A (DbpA) ofBorrelia burgdorferi was a protective immunogen in the murine model of Lyme borreliosis when mice were challenged (needle inoculated) intradermally with in vitro-cultivated spirochetes. In the present study, DbpA-immunized C3H/HeJ mice were not protected from infection when infested with Ixodes scapularis nymphs harboring virulent B. burgdorferi 297. This lack of protection correlated with the failure to detect DbpA on B. burgdorferi in ticks, suggesting that DbpA is not available as a target for bactericidal antibodies in serum when B. burgdorferi-infected ticks take their blood meal from an immunized host. The failure of DbpA immunization to protect tick-challenged mice contradicts the results of earlier needle inoculation vaccination experiments and suggests that DbpA may not be suitable as a Lyme disease vaccine.

scholarly journals Function of theBorrelia burgdorferiFtsH Homolog Is Essential for Viability bothIn VitroandIn Vivoand Independent of HflK/C

mBio ◽  
2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Chen-Yi Chu ◽  
Philip E. Stewart ◽  
Aaron Bestor ◽  
Bryan Hansen ◽  
Tao Lin ◽  
...  
Keyword(s):  
Lyme Disease ◽  
Membrane Proteins ◽  
Borrelia Burgdorferi ◽  
Cellular Response ◽  
Protein Transport ◽  
Protein Quality ◽  
Laboratory Culture ◽  
Biologically Active ◽  
Infectious Cycle

ABSTRACTIn many bacteria, the FtsH protease and its modulators, HflK and HflC, form a large protein complex that contributes to both membrane protein quality control and regulation of the cellular response to environmental stress. Both activities are crucial to the Lyme disease pathogenBorrelia burgdorferi, which depends on membrane functions, such as motility, protein transport, and cell signaling, to respond to rapid changes in its environment. Using an inducible system, we demonstrate that FtsH production is essential for both mouse and tick infectivity and forin vitrogrowth ofB. burgdorferi. FtsH depletion inB. burgdorfericells resulted in membrane deformation and cell death. Overproduction of the protease did not have any detectable adverse effects onB. burgdorferigrowthin vitro, suggesting that excess FtsH does not proteolytically overwhelm its substrates. In contrast, we did not observe any phenotype for cells lacking the protease modulators HflK and HflC (ΔHflK/C), although we examined morphology, growth rate, growth under stress conditions, and the complete mouse-tick infectious cycle. Our results demonstrate that FtsH provides an essential function in the life cycle of the obligate pathogenB. burgdorferibut that HflK and HflC do not detectably affect FtsH function.IMPORTANCELyme disease is caused byBorrelia burgdorferi, which is maintained in nature in an infectious cycle alternating between small mammals andIxodesticks.B. burgdorferiproduces specific membrane proteins to successfully infect and persist in these diverse organisms. We hypothesized thatB. burgdorferihas a specific mechanism to ensure that membrane proteins are properly folded and biologically active when needed and removed if improperly folded or dysfunctional. Our experiments demonstrate that FtsH, a protease that fulfills this role in other microorganisms, is essential toB. burgdorferiviability. Cells depleted of FtsH do not survive in laboratory culture medium and cannot colonize mice or ticks, revealing an absolute requirement for this protease. However, the loss of two potential modulators of FtsH activity, HflK and HflC, does not detectably affectB. burgdorferiphysiology. Our results provide the groundwork for the identification of FtsH substrates that are critical for the bacterium’s viability.

An enhanced GFP reporter system to monitor gene expression in Borrelia burgdorferi

Microbiology ◽  
2003 ◽  
Vol 149 (7) ◽  
pp. 1819-1828 ◽  
Author(s):  
James A. Carroll ◽  
Philip E. Stewart ◽  
Patricia Rosa ◽  
Abdallah F. Elias ◽  
Claude F. Garon
Keyword(s):  
Gene Expression ◽  
Borrelia Burgdorferi ◽  
Fluorescent Protein ◽  
Regulation Of Gene Expression ◽  
Epifluorescence Microscopy ◽  
Reporter System ◽  
Environmental Signals ◽  
Gfp Reporter ◽  
Green Fluorescent

Borrelia burgdorferi regulates genes in response to a number of environmental signals such as temperature and pH. A green fluorescent protein (GFP) reporter system using the ospC, ospA and flaB promoters from B. burgdorferi B31 was introduced into infectious clonal isolates of strains B31 and N40 to monitor and compare gene expression in response to pH and temperature in vitro. GFP could be assayed by epifluorescence microscopy, immunoblotting or spectrofluorometry and was an accurate reporter of target gene expression. It was determined that only 179 bp 5′ of ospC was sufficient to regulate the reporter gfp in vitro in response to pH and temperature in B. burgdorferi B31. The loss of linear plasmid (lp) 25, lp28-1, lp36 and lp56 had no effect on the ability of B. burgdorferi B31 to regulate ospC in response to pH or temperature. The amount of OspC in N40 transformants was unaffected by changes in pH or temperature of the culture medium. This suggests that regulation of gene expression in response to pH and temperature may vary between these two B. burgdorferi strains.

scholarly journals Expression of a luxS Gene Is Not Required for Borrelia burgdorferi Infection of Mice via Needle Inoculation

2003 ◽  
Vol 71 (5) ◽  
pp. 2892-2896 ◽  
Author(s):  
Anette Hübner ◽  
Andrew T. Revel ◽  
Dena M. Nolen ◽  
Kayla E. Hagman ◽  
Michael V. Norgard
Keyword(s):  
Quorum Sensing ◽  
Borrelia Burgdorferi ◽  
Mammalian Host ◽  
Wild Type ◽  
Sensing System ◽  
Autoinducer 2 ◽  
Sensing Systems ◽  
Quorum Sensing System ◽  
Culture Supernatants

ABSTRACT The luxS gene product is an integral component of LuxS/autoinducer-2 (AI-2) quorum-sensing systems in bacteria. A putative luxS gene was expressed at comparable levels by Borrelia burgdorferi strain 297 cultivated either in vitro or in dialysis membrane chambers implanted in rat peritoneal cavities. Although the borrelial luxS gene functionally complemented a LuxS deficiency in Escherichia coli DH5α, AI-2-like activity could not be detected within B. burgdorferi culture supernatants or concentrated cell lysates. Finally, a luxS-deficient mutant of B. burgdorferi was infectious at wild-type levels when it was intradermally needle inoculated into mice, indicating that expression of luxS probably is not required for infectivity but, at the very least, is not essential for mammalian host adaptation. Our findings also challenge the notion that a LuxS/AI-2 quorum-sensing system is operative in B. burgdorferi.

scholarly journals Evaluation of RevA, a Fibronectin-Binding Protein of Borrelia burgdorferi, as a Potential Vaccine Candidate for Lyme Disease

2013 ◽  
Vol 20 (6) ◽  
pp. 892-899 ◽  
Author(s):  
Angela M. Floden ◽  
Tammy Gonzalez ◽  
Robert A. Gaultney ◽  
Catherine A. Brissette
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Passive Immunization ◽  
Surface Protein ◽  
Surface Expression ◽  
Content Type ◽  
Good Target ◽  
Potential Vaccine ◽  
Mammalian Infection

ABSTRACTPrevious studies indicated that the Lyme disease spirocheteBorrelia burgdorferiexpresses the RevA outer surface protein during mammalian infection. As an adhesin that promotes bacterial interaction with fibronectin, RevA appears to be a good target for preventive therapies. RevA proteins are highly conserved across all Lyme borreliae, and antibodies against RevA protein are cross-reactive among RevA proteins from diverse strains. Mice infected withB. burgdorferimounted a rapid IgM response to RevA, followed by a strong IgG response that generally remained elevated for more than 12 months, suggesting continued exposure of RevA protein to the immune system. RevA antibodies were bactericidalin vitro. To evaluate the RevA antigen as a potential vaccine, mice were vaccinated with recombinant RevA and challenged withB. burgdorferiby inoculation with a needle or by a tick bite. Cultured tissues from all treatment groups were positive forB. burgdorferi. Vaccinated animals also appeared to have similar levels ofB. burgdorferiDNA compared to nonvaccinated controls. Despite its antigenicity, surface expression, and the production of bactericidal antibodies against it, RevA does not protect againstBorrelia burgdorferiinfection in a mouse model. However, passive immunization with anti-RevA antibodies did prevent infection, suggesting the possible utility of RevA-based immunotherapeutics or vaccine.

scholarly journals Borrelia burgdorferi Alters Its Gene Expression and Antigenic Profile in Response to CO2 Levels

2006 ◽  
Vol 189 (2) ◽  
pp. 437-445 ◽  
Author(s):  
Jenny A. Hyde ◽  
Jerome P. Trzeciakowski ◽  
Jonathan T. Skare
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Borrelia Burgdorferi ◽  
Growth Conditions ◽  
Etiologic Agent ◽  
Complex Life Cycle ◽  
Mammalian Host ◽  
Transcriptional Level ◽  
Virulence Determinants

ABSTRACT The etiologic agent of Lyme disease, Borrelia burgdorferi, must adapt to the distinct environments of its arthropod vector and mammalian host during its complex life cycle. B. burgdorferi alters gene expression and protein synthesis in response to temperature, pH, and other uncharacterized environmental factors. The hypothesis tested in this study is that dissolved gases, including CO2, serve as a signal for B. burgdorferi to alter protein production and gene expression. In this study we focused on characterization of in vitro anaerobic (5% CO2, 3% H2, 0.087 ppm O2) and microaerophilic (1% CO2, 3.48 ppm O2) growth conditions and how they modulate protein synthesis and gene expression in B. burgdorferi. Higher levels of several immunoreactive proteins, including BosR, NapA, DbpA, OspC, BBK32, and RpoS, were synthesized under anaerobic conditions. Previous studies demonstrated that lower levels of NapA were produced when microaerophilic cultures were purged with nitrogen gas to displace oxygen and CO2. In this study we identified CO2 as a factor contributing to the observed change in NapA synthesis. Specifically, a reduction in the level of dissolved CO2, independent of O2 levels, resulted in reduced NapA synthesis. BosR, DbpA, OspC, and RpoS synthesis was also decreased with the displacement of CO2. Quantitative reverse transcription-PCR indicated that the levels of the dbpA, ospC, and BBK32 transcripts are increased in the presence of CO2, indicating that these putative borrelial virulence determinants are regulated at the transcriptional level. Thus, dissolved CO2 may be an additional cue for borrelial host adaptation and gene regulation.

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