title: Remarkable diversity of tick or mammalian-associated Borreliae in the metropolitan San Francisco Bay Area, California.
abstract: The diversity of Lyme disease (LD) and relapsing fever (RF)-group spirochetes in the metropolitan San Francisco Bay area in northern California is poorly understood. We tested Ixodes pacificus, I. spinipalpis, and small mammals for presence of borreliae in Alameda County in the eastern portion of San Francisco Bay between 2009 and 2012. Analyses of 218 Borrelia burgdorferi sensu lato (Bb sl) culture or DNA isolates recovered from host-seeking I. pacificus ticks revealed that the human pathogen Bb sensu stricto (hereinafter, B. burgdorferi) had the broadest habitat distribution followed by B. bissettii. Three other North American Bb sl spirochetes, B. americana, B. californiensis and B. genomospecies 2, also were detected at lower prevalence. OspC genotyping of the resultant 167 B. burgdorferi isolates revealed six ospC alleles (A, D, E3, F, H and K) in I. pacificus. A novel spirochete belonging to the Eurasian Bb sl complex, designated CA690, was found in a questing I. spinipalpis nymph. Borrelia miyamotoi, a relapsing-fever (RF) group spirochete recently implicated as a human pathogen, was detected in 24 I. pacificus. Three rodent species were infected with Bb sl: the fox squirrel (Sciurus niger) with B. burgdorferi, and the dusky-footed wood rat (Neotoma fuscipes) and roof rat (Rattus rattus) with B. bissettii. Another spirochete that clustered phylogenetically with the Spanish R57 Borrelia sp. in a clade distinct from both the LD and RF groups infected some of the roof rats. Together, eight borrelial genospecies were detected in ticks or small mammals from a single Californian county, two of which were related phylogenetically to European spirochetes.
authors.affiliation: Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720, USA; Alameda County Vector Control Services District, Alameda, CA 94502, USA. Electronic address: natfed511@gmail.com.
authors.forename: Natalia
authors.initials: N
authors.lastname: Fedorova
authors.affiliation: Alameda County Vector Control Services District, Alameda, CA 94502, USA.
authors.forename: Joyce E
authors.initials: JE
authors.lastname: Kleinjan
authors.affiliation: Alameda County Vector Control Services District, Alameda, CA 94502, USA.
authors.forename: David
authors.initials: D
authors.lastname: James
authors.affiliation: Alameda County Vector Control Services District, Alameda, CA 94502, USA.
authors.forename: Lucia T
authors.initials: LT
authors.lastname: Hui
authors.affiliation: Sunol, CA 94586, USA.
authors.forename: Hans
authors.initials: H
authors.lastname: Peeters
authors.affiliation: Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720, USA.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Lane
mesh_terms: D000818:Animals; D001096:Arachnid Vectors / Q000382:microbiology*; D003411:Arvicolinae; D001483:Base Sequence; D001898:Borrelia / Q000235:genetics / Q000302:isolation & purification*; D025065:Borrelia burgdorferi / Q000235:genetics / Q000302:isolation & purification; D004197:Disease Reservoirs; D005838:Genotype; D006801:Humans; D018884:Ixodes / Q000382:microbiology*; D008193:Lyme Disease / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D008969:Molecular Sequence Data; D009758:Nymph; D010802:Phylogeny; D051381:Rats; D012061:Relapsing Fever / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D012495:San Francisco / Q000453:epidemiology; D012589:Sciuridae; D017422:Sequence Analysis, DNA
keywords: Borrelia burgdorferi sensu lato; Borrelia miyamotoi; Ixodes; Rodents; osp C