Borrelia Sequences Associated with Birds and Ticks

Sequence data from various Borrelia genospecies prepared in FASTA format

Bird and Tick Infection and Infestation data

These data represent all birds, Ixodes pacificus nymphs, and Ixodes pacificus larvae sampled in the associated study, and what Borrelia genospecies were found in each sample

<i>Borrelia burgdorferi</i> Sensu Lato Spirochetes in Wild Birds in Northwestern California: Associations with Ecological Factors, Bird Behavior and Tick Infestation

<div><p>Although <i>Borrelia burgdorferi</i> sensu lato (s.l.) are found in a great diversity of vertebrates, most studies in North America have focused on the role of mammals as spirochete reservoir hosts. We investigated the roles of birds as hosts for subadult <i>Ixodes pacificus</i> ticks and potential reservoirs of the Lyme disease spirochete <i>B. burgdorferi</i> sensu stricto (s.s.) in northwestern California. Overall, 623 birds representing 53 species yielded 284 <i>I. pacificus</i> larvae and nymphs. We used generalized linear models and zero-inflated negative binomial models to determine associations of bird behaviors, taxonomic relationships and infestation by <i>I. pacificus</i> with borrelial infection in the birds. Infection status in birds was best explained by taxonomic order, number of infesting nymphs, sampling year, and log-transformed average body weight. Presence and counts of larvae and nymphs could be predicted by ground- or bark-foraging behavior and contact with dense oak woodland. Molecular analysis yielded the first reported detection of <i>Borrelia bissettii</i> in birds. Moreover, our data suggest that the Golden-crowned Sparrow (<i>Zonotrichia atricapilla</i>), a non-resident species, could be an important reservoir for <i>B. burgdorferi</i> s.s. Of 12 individual birds (9 species) that carried <i>B. burgdorferi</i> s.l.-infected larvae, no birds carried the same genospecies of <i>B. burgdorferi</i> s.l. in their blood as were present in the infected larvae removed from them. Possible reasons for this discrepancy are discussed. Our study is the first to explicitly incorporate both taxonomic relationships and behaviors as predictor variables to identify putative avian reservoirs of <i>B. burgdorferi</i> s.l. Our findings underscore the importance of bird behavior to explain local tick infestation and <i>Borrelia</i> infection in these animals, and suggest the potential for bird-mediated geographic spread of vector ticks and spirochetes in the far-western United States.</p></div

Body weight as a null model for presence or absence of tick infestation and <i>B</i>. <i>burgdorferi</i> s.l. infection in birds.

<p>Graphs depict: (a) larvae per bird by log(average body weight), (b) nymphs per bird by log(average body weight), and (c) bird infection by log(average body weight). Each data point represents one bird species. One outlier point in plot (a) represents Lark Sparrows (<i>Chondestes grammacus</i>). The solid line is a regression on all species, while the dotted-line is a regression on zero-truncated data (species with positive results only).</p

Summary of <i>Ixodes pacificus</i> infestation on birds, <i>Borrelia burgdorferi</i> s.l. (BBSL) infection in bird blood, and number of BBSL infected larvae by bird species.

<p>Summary of <i>Ixodes pacificus</i> infestation on birds, <i>Borrelia burgdorferi</i> s.l. (BBSL) infection in bird blood, and number of BBSL infected larvae by bird species.</p

Summary of <i>B</i>. <i>burgdorferi</i> s.l. genospecies found in birds.

<p>Numbers in bold with an asterisk (*) indicate matching genospecies between individual bird and hosted ticks, for the indicated category. Acronyms in table are: BBSL, <i>B</i>. <i>burgdorferi</i> s.l; BBSS, <i>B</i>. <i>burgdorferi</i> sensu stricto; BBIS, <i>B</i>. <i>bissettii</i>; BBSL(un), undifferentiated genospecies in the <i>B</i>. <i>burgdorferi</i> sensu lato complex that are neither BBSS nor BBIS; and BBSLmix, any combination of BBSL(un), BBSS, and BBIS detected in a single sample.</p><p>Summary of <i>B</i>. <i>burgdorferi</i> s.l. genospecies found in birds.</p

Summary of <i>B</i>. <i>burgdorferi</i> s.l. genospecies found in <i>I</i>. <i>pacificus</i> nymphs removed from birds.

<p>Numbers in <b>bold</b> with an asterisk (*) indicate matching genospecies between individual bird and hosted ticks, for the indicated category. Acronyms in table are: BBSL, <i>B</i>. <i>burgdorferi</i> s.l; BBSS, <i>B</i>. <i>burgdorferi</i> sensu stricto; BBIS, <i>B</i>. <i>bissettii</i>; BBSL(un), undifferentiated genospecies in the <i>B</i>. <i>burgdorferi</i> sensu lato complex that are neither BBSS nor BBIS; and BBSLmix, any combination of BBSL(un), BBSS, and BBIS detected in a single sample.</p><p>Summary of <i>B</i>. <i>burgdorferi</i> s.l. genospecies found in <i>I</i>. <i>pacificus</i> nymphs removed from birds.</p

Bird infection and tick infestation modeling goals and best supported models, based on AIC and AICc values.

<p>Bird infection and tick infestation modeling goals and best supported models, based on AIC and AICc values.</p

Prevalence (by %) of infection of birds, <i>I</i>. <i>pacificus</i> larvae and nymphs with different genospecies of <i>Borrelia</i>.

<p>Prevalence (by %) of infection of birds, <i>I</i>. <i>pacificus</i> larvae and nymphs with different genospecies of <i>Borrelia</i>.</p

Summary of <i>B</i>. <i>burgdorferi</i> s.l. genospecies found in <i>I</i>. <i>pacificus</i> larvae removed from birds.

<p>Numbers in <b>bold</b> with an asterisk (*) indicate matching genospecies between individual bird and hosted ticks, for the indicated category. Acronyms in table are: BBSL, <i>B</i>. <i>burgdorferi</i> s.l; BBSS, <i>B</i>. <i>burgdorferi</i> sensu stricto; BBIS, <i>B</i>. <i>bissettii</i>; BBSL(un), undifferentiated genospecies in the <i>B</i>. <i>burgdorferi</i> sensu lato complex that are neither BBSS nor BBIS; and BBSLmix, any combination of BBSL(un), BBSS, and BBIS detected in a single sample.</p><p>Summary of <i>B</i>. <i>burgdorferi</i> s.l. genospecies found in <i>I</i>. <i>pacificus</i> larvae removed from birds.</p