scholarly journals Lyme disease ecology in San Luis Obispo County: The role of the western gray squirrel

2015 ◽  
Author(s):  
Ryan William Baker-Branstetter
Keyword(s):  
Lyme Disease ◽  
Disease Ecology ◽  
Gray Squirrel ◽  
San Luis ◽  
Western Gray Squirrel

scholarly journals Serum Complement Sensitivity as a Key Factor in Lyme Disease Ecology

1998 ◽  
Vol 66 (3) ◽  
pp. 1248-1251 ◽  
Author(s):  
Klaus Kurtenbach ◽  
Henna-Sisko Sewell ◽  
Nick H. Ogden ◽  
Sarah E. Randolph ◽  
Patricia A. Nuttall
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Lyme Borreliosis ◽  
Disease Ecology ◽  
Specific Pattern ◽  
Serum Complement ◽  
Key Factor ◽  
Species Specific

ABSTRACT The sensitivity of Borrelia burgdorferi sensu lato to animal sera was analyzed. Complement-mediated borreliacidal effects were observed with particular combinations of host serum andBorrelia genospecies. The species-specific pattern of viability and/or lysis is highly consistent with the pattern of reservoir competence of hosts for B. burgdorferi sensu lato, suggesting a key role of complement in the global ecology of Lyme borreliosis.

scholarly journals Impact of the experimental removal of lizards on Lyme disease risk

2011 ◽  
Vol 278 (1720) ◽  
pp. 2970-2978 ◽  
Author(s):  
Andrea Swei ◽  
Richard S. Ostfeld ◽  
Robert S. Lane ◽  
Cheryl J. Briggs
Keyword(s):  
Lyme Disease ◽  
Disease Ecology ◽  
Disease Risk ◽  
Large Fraction ◽  
Host Community ◽  
Deer Mice ◽  
Infection Prevalence ◽  
Alternate Host ◽  
Experimental Removal ◽  
Tick Infection

The distribution of vector meals in the host community is an important element of understanding and predicting vector-borne disease risk. Lizards (such as the western fence lizard; Sceloporus occidentalis ) play a unique role in Lyme disease ecology in the far-western United States. Lizards rather than mammals serve as the blood meal hosts for a large fraction of larval and nymphal western black-legged ticks ( Ixodes pacificus —the vector for Lyme disease in that region) but are not competent reservoirs for the pathogen, Borrelia burgdorferi . Prior studies have suggested that the net effect of lizards is to reduce risk of human exposure to Lyme disease, a hypothesis that we tested experimentally. Following experimental removal of lizards, we documented incomplete host switching by larval ticks (5.19%) from lizards to other hosts. Larval tick burdens increased on woodrats, a competent reservoir, but not on deer mice, a less competent pathogen reservoir. However, most larvae failed to find an alternate host. This resulted in significantly lower densities of nymphal ticks the following year. Unexpectedly, the removal of reservoir-incompetent lizards did not cause an increase in nymphal tick infection prevalence. The net result of lizard removal was a decrease in the density of infected nymphal ticks, and therefore a decreased risk to humans of Lyme disease. Our results indicate that an incompetent reservoir for a pathogen may, in fact, increase disease risk through the maintenance of higher vector density and therefore, higher density of infected vectors.

The role of mining and agricultural activity in creating coexisting but divergent soils, San Luis Valley, Colorado, USA

Geoderma ◽  
2009 ◽  
Vol 148 (3-4) ◽  
pp. 384-391 ◽  
Author(s):  
S.W. Blecker ◽  
S.C. Connolly ◽  
G.E. Cardon ◽  
E.F. Kelly
Keyword(s):  
Agricultural Activity ◽  
San Luis Valley ◽  
San Luis

Sex, attitudes, and the assibilation of /r/ among young people in San Luis Potosí, Mexico

1989 ◽  
Vol 1 (3) ◽  
pp. 269-283 ◽  
Author(s):  
Dorothy A. Rissel
Keyword(s):  
Young People ◽  
Language Change ◽  
Young Men ◽  
Women's Speech ◽  
San Luis ◽  
San Luis Potosi ◽  
Gender Display ◽  
Sex Attitudes ◽  
San Luis Potosí

ABSTRACTThis article analyzes the assibilation of /r/ among young people in San Luis Potosí, Mexico, in light of previous research on women's speech in language change. It is demonstrated that assibilation, an innovation known to have first appeared in the speech of women of the middle and upper social echelons, is closely associated with sex, sociocultural level, and attitude toward traditional male and female roles. These attitudes are suggested as a factor that plays an important role in the dynamics of the change, showing opposite effects among young men and women. That is, young men with traditional attitudes assibilate least, whereas young women with traditional attitudes assibilate most frequently. Parallels between this study and one of a similar innovation in Argentinian Spanish suggest a generalized pattern of change in which variables introduced by women of the middle and upper social echelons become markers of gender display in the lower classes, where they grow to be favored by women and avoided by men. The discovery of the role of attitude toward traditional sex roles in this pattern of change is unique to the present study.

scholarly journals The OspE-Related Proteins Inhibit Complement Deposition and Enhance Serum Resistance ofBorrelia burgdorferi, the Lyme Disease Spirochete

2011 ◽  
Vol 79 (4) ◽  
pp. 1451-1457 ◽  
Author(s):  
Melisha R. Kenedy ◽  
Darrin R. Akins
Keyword(s):  
Lyme Disease ◽  
Mutant Strain ◽  
Membrane Attack Complex ◽  
Factor H ◽  
Serum Resistance ◽  
Complement Components ◽  
Complement Inhibitors ◽  
Related Proteins ◽  
Complement Deposition

ABSTRACTBorrelia burgdorferi, the Lyme disease spirochete, binds the host complement inhibitors factor H (FH) and FH-like protein 1 (FHL-1). Binding of FH/FHL-1 by theB. burgdorferiproteins CspA and the OspE-related proteins is thought to enhance resistance to serum-mediated killing. While previous reports have shown that CspA confers serum resistance inB. burgdorferi, it is unclear whether the OspE-related proteins are relevant inB. burgdorferiserum resistance when OspE is expressed on the borrelial surface. To assess the role of the OspE-related proteins, we overexpressed them in a serum-sensitive CspA mutant strain. OspE overexpression enhanced serum resistance of the CspA-deficient organisms. Furthermore, FH was more efficiently bound to theB. burgdorferisurface when OspE was overexpressed. Deposition of complement components C3 and C5b-9 (the membrane attack complex), however, was reduced on the surface of the OspE-overexpressing strain compared to that on the CspA mutant strain. These data demonstrate that OspE proteins expressed on the surface ofB. burgdorferibind FH and protect the organism from complement deposition and subsequent serum-mediated destruction.

scholarly journals Seasonal Prevalence of Lyme Disease Spirochetes in a Heterothermic Mammal, the Edible Dormouse (Glis glis)

2014 ◽  
Vol 80 (12) ◽  
pp. 3615-3621 ◽  
Author(s):  
Joanna Fietz ◽  
Jürgen Tomiuk ◽  
Franz-Rainer Matuschka ◽  
Dania Richter
Keyword(s):  
Lyme Disease ◽  
Reservoir Host ◽  
Glis Glis ◽  
Content Type ◽  
Transmission Cycle ◽  
Western Germany ◽  
Edible Dormice ◽  
Study Sites ◽  
Reservoir Hosts

ABSTRACTIn Europe, dormice serve as competent reservoir hosts for particular genospecies of the tick-borne agent of Lyme disease (LD) and seem to support them more efficiently than do mice or voles. The longevity of edible dormice (Glis glis) and their attractiveness for ticks may result in a predominance of LD spirochetes in ticks questing in dormouse habitats. To investigate the role of edible dormice in the transmission cycle of LD spirochetes, we sampled skin tissue from the ear pinnae of dormice inhabiting five different study sites in south western Germany. Of 501 edible dormice, 12.6% harbored DNA of LD spirochetes. Edible dormice were infected most frequently with the pathogenic LD spirocheteBorrelia afzelii. The DNA ofB. gariniiandB. bavariensiswas detected in ca. 0.5% of the examined individuals. No spirochetal DNA was detectable in the skin of edible dormice until July, 6 weeks after they generally start to emerge from their obligate hibernation. Thereafter, the prevalence of spirochetal DNA in edible dormice increased during the remaining period of their 4 to 5 months of activity, reaching nearly 40% in September. Males were more than four times more likely to harbor LD spirochetes than females, and yearlings were almost twice more likely to be infected than adults. The seasonality of the prevalence of LD spirochetes in edible dormice was pronounced and may affect their role as a reservoir host in respect to other hosts.

New Size Records for the Western Gray Squirrel

The Murrelet ◽  
1973 ◽  
Vol 54 (2) ◽  
pp. 20
Author(s):  
Frederick T. Crase
Keyword(s):  
Gray Squirrel ◽  
Western Gray Squirrel
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