The role of deer in facilitating the spatial spread of the pathogen Borrelia burgdorferi

2010 ◽  
Vol 4 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Matthew Hartfield ◽  
K. A. Jane White ◽  
Klaus Kurtenbach
Keyword(s):  
Borrelia Burgdorferi ◽  
Spatial Spread

scholarly journals Spatial spread of the West Africa Ebola epidemic

2016 ◽  
Vol 3 (8) ◽  
pp. 160294 ◽  
Author(s):  
Andrew M. Kramer ◽  
J. Tomlin Pulliam ◽  
Laura W. Alexander ◽  
Andrew W. Park ◽  
Pejman Rohani ◽  
...  
Keyword(s):  
West Africa ◽  
Sierra Leone ◽  
Ebola Virus ◽  
Emerging Diseases ◽  
Relative Probability ◽  
Effective Response ◽  
Spatial Spread ◽  
Force Of Infection ◽  
International Border

Controlling Ebola outbreaks and planning an effective response to future emerging diseases are enhanced by understanding the role of geography in transmission. Here we show how epidemic expansion may be predicted by evaluating the relative probability of alternative epidemic paths. We compared multiple candidate models to characterize the spatial network over which the 2013–2015 West Africa epidemic of Ebola virus spread and estimate the effects of geographical covariates on transmission during peak spread. The best model was a generalized gravity model where the probability of transmission between locations depended on distance, population density and international border closures between Guinea, Liberia and Sierra Leone and neighbouring countries. This model out-performed alternative models based on diffusive spread, the force of infection, mobility estimated from cell phone records and other hypothesized patterns of spread. These findings highlight the importance of integrated geography to epidemic expansion and may contribute to identifying both the most vulnerable unaffected areas and locations of maximum intervention value.

scholarly journals Borrelia burgdorferi Resistance to a Major Skin Antimicrobial Peptide Is Independent of Outer Surface Lipoprotein Content

2009 ◽  
Vol 53 (10) ◽  
pp. 4490-4494 ◽  
Author(s):  
Amit Sarkar ◽  
Kit Tilly ◽  
Philip Stewart ◽  
Aaron Bestor ◽  
James M. Battisti ◽  
...  
Keyword(s):  
Borrelia Burgdorferi ◽  
Antimicrobial Peptide ◽  
Immune Evasion ◽  
Essential Role ◽  
Potential Role ◽  
Innate Immune ◽  
Initial Stage ◽  
Mammalian Infection ◽  
Innate Immune Evasion

ABSTRACT We hypothesize a potential role for Borrelia burgdorferi OspC in innate immune evasion at the initial stage of mammalian infection. We demonstrate that B. burgdorferi is resistant to high levels (>200 μg/ml) of cathelicidin and that this antimicrobial peptide exhibits limited binding to the spirochetal outer membrane, irrespective of OspC or other abundant surface lipoproteins. We conclude that the essential role of OspC is unrelated to resistance to this component of innate immunity.

scholarly journals CsrA (BB0184) Is Not Involved in Activation of the RpoN-RpoS Regulatory Pathway in Borrelia burgdorferi

2014 ◽  
Vol 82 (4) ◽  
pp. 1511-1522 ◽  
Author(s):  
Zhiming Ouyang ◽  
Jianli Zhou ◽  
Michael V. Norgard
Keyword(s):  
Gene Expression ◽  
Borrelia Burgdorferi ◽  
Animal Studies ◽  
Expression System ◽  
Regulatory Pathway ◽  
Content Type ◽  
Mouse Tissues ◽  
Differential Gene ◽  
Carbon Storage Regulator

ABSTRACTBorrelia burgdorferiencodes a homologue of the bacterial carbon storage regulator A (CsrA). Recently, it was reported that CsrA contributes toB. burgdorferiinfectivity and is required for the activation of the central RpoN-RpoS regulatory pathway. However, many questions concerning the function of CsrA inB. burgdorferigene regulation remain unanswered. In particular, there are conflicting reports concerning the molecular details of how CsrA may modulaterpoSexpression and, thus, how CsrA may influence the RpoN-RpoS pathway inB. burgdorferi. To address these key discrepancies, we examined the role of CsrA in differential gene expression in the Lyme disease spirochete. Upon engineering an induciblecsrAexpression system inB. burgdorferi, controlled hyperexpression of CsrA in a merodiploid strain did not significantly alter the protein and transcript levels ofbosR,rpoS, and RpoS-dependent genes (such asospCanddbpA). In addition, we constructed isogeniccsrAmutants in two widely used infectiousB. burgdorferistrains. When expression ofbosR,rpoS,ospC, anddbpAwas compared between thecsrAmutants and their wild-type counterparts, no detectable differences were observed. Finally, animal studies indicated that thecsrAmutants remained infectious for and virulent in mice. Analyses ofB. burgdorferigene expression in mouse tissues showed comparable levels ofrpoStranscripts by thecsrAmutants and the parental strains. Taken together, these results constitute compelling evidence that CsrA is not involved in activation of the RpoN-RpoS pathway and is dispensable for mammalian infectious processes carried out byB. burgdorferi.

scholarly journals Role of Migratory Birds in Introduction and Range Expansion of Ixodes scapularis Ticks and of Borrelia burgdorferi and Anaplasma phagocytophilum in Canada

2008 ◽  
Vol 74 (6) ◽  
pp. 1780-1790 ◽  
Author(s):  
N. H. Ogden ◽  
L. R. Lindsay ◽  
K. Hanincová ◽  
I. K. Barker ◽  
M. Bigras-Poulin ◽  
...  
Keyword(s):  
Borrelia Burgdorferi ◽  
Range Expansion ◽  
Anaplasma Phagocytophilum ◽  
Migratory Birds ◽  
Ixodes Scapularis ◽  
Intergenic Spacer ◽  
Infection Prevalence ◽  
Eastern Canada ◽  
Wide Range

ABSTRACT During the spring in 2005 and 2006, 39,095 northward-migrating land birds were captured at 12 bird observatories in eastern Canada to investigate the role of migratory birds in northward range expansion of Lyme borreliosis, human granulocytic anaplasmosis, and their tick vector, Ixodes scapularis. The prevalence of birds carrying I. scapularis ticks (mostly nymphs) was 0.35% (95% confidence interval [CI] = 0.30 to 0.42), but a nested study by experienced observers suggested a more realistic infestation prevalence of 2.2% (95% CI = 1.18 to 3.73). The mean infestation intensity was 1.66 per bird. Overall, 15.4% of I. scapularis nymphs (95% CI = 10.7 to 20.9) were PCR positive for Borrelia burgdorferi, but only 8% (95% CI = 3.8 to 15.1) were positive when excluding nymphs collected at Long Point, Ontario, where B. burgdorferi is endemic. A wide range of ospC and rrs-rrl intergenic spacer alleles of B. burgdorferi were identified in infected ticks, including those associated with disseminated Lyme disease and alleles that are rare in the northeastern United States. Overall, 0.4% (95% CI = 0.03 to 0.41) of I. scapularis nymphs were PCR positive for Anaplasma phagocytophilum. We estimate that migratory birds disperse 50 million to 175 million I. scapularis ticks across Canada each spring, implicating migratory birds as possibly significant in I. scapularis range expansion in Canada. However, infrequent larvae and the low infection prevalence in ticks carried by the birds raise questions as to how B. burgdorferi and A. phagocytophilum become endemic in any tick populations established by bird-transported ticks.

scholarly journals The role of Borrelia burgdorferi outer surface proteins

2012 ◽  
Vol 66 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Melisha R. Kenedy ◽  
Tiffany R. Lenhart ◽  
Darrin R. Akins
Keyword(s):  
Borrelia Burgdorferi ◽  
Outer Surface ◽  
Surface Proteins ◽  
Outer Surface Proteins

Reservoir Role of Lizard Psammodromus algirus in Transmission Cycle of Borrelia burgdorferi Sensu Lato (Spirochaetaceae) in Tunisia

2006 ◽  
Vol 43 (4) ◽  
pp. 737-742 ◽  
Author(s):  
Najla Dsouli ◽  
Hend Younsi-kabachii ◽  
Danièle Postic ◽  
Said Nouira ◽  
Lise Gern ◽  
...  
Keyword(s):  
Borrelia Burgdorferi ◽  
Transmission Cycle ◽  
Psammodromus Algirus
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