RESUMO
To determine if the range of deer ticks in Maine had expanded, we conducted a multitarget serosurvey of domestic dogs (Canis lupus familiaris) in 2007. An extension of exposure to Borrelia burgdorferi to the northern border and local transmission of Anaplasma phagocytophilum throughout southern areas was found.
Assuntos
Anaplasmose/diagnóstico , Doenças do Cão/diagnóstico , Doença de Lyme/veterinária , Anaplasma phagocytophilum/imunologia , Anaplasmose/epidemiologia , Animais , Borrelia burgdorferi/imunologia , Doenças do Cão/epidemiologia , Cães , Doença de Lyme/diagnóstico , Doença de Lyme/epidemiologia , Maine/epidemiologia , Fatores de RiscoRESUMO
The recent range expansion of Ixodes scapularis has been accompanied by the emergence of Borrelia burgdorferi. The development of genetic diversity in B. burgdorferi at these sites of emergence and its relationship to range expansion is poorly understood. We followed colonization of I. scapularis on a coastal Maine island over a 17-year period. B. burgdorferi's emergence was documented, as was expansion of ospC strain diversity. Ticks collected from rodents and vegetation were examined for the presence of B. burgdorferi. Sequencing and reverse line blot were used to detect B. burgdorferi ospC major groups (oMG). No I. scapularis were found until year four of the study, after which time they increased in abundance. No B. burgdorferi was detected by darkfield microscopy in I. scapularis until 10 years into the study, when 4% of adult ticks were infected. Seven years later, 43% of adult ticks were infected. In 2003, one oMG accounted for 91% of B. burgdorferi strains. This "founder" strain persisted in 2005, but by 2007 was a minority of the 7 oMGs present. Given the island's isolation, gene flow by avian introduction of multiple strains is suggested in the development of B. burgdorferi oMG diversity.
Assuntos
Borrelia burgdorferi/genética , Variação Genética , Genótipo , Ixodes/microbiologia , Animais , Antígenos de Bactérias/genética , Antígenos de Bactérias/metabolismo , Oceano Atlântico , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Regulação Bacteriana da Expressão Gênica/fisiologia , Geografia , Maine/epidemiologia , Roedores/parasitologia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/veterinária , Fatores de TempoRESUMO
Borrelia garinii is the most neurotropic of the genospecies of B. burgdorferi sensu lato that cause Lyme disease in Europe, where it is transmitted to avian and mammalian reservoir hosts and to humans by Ixodes ricinus. B. garinii is also maintained in an enzootic cycle in seabirds by I. uriae, a tick found at high latitudes in both the Northern and Southern Hemispheres. To determine whether B. garinii is present in seabird ticks on the Atlantic Coast of North America, we examined 261 I. uriae ticks by polyclonal antiborrelial fluorescent antibody. Ten of 61 ticks from Gull Island, Newfoundland, were positive for borreliae by this screen. Amplicons of DNA obtained by PCR that targeted the B. garinii rrs-rrla intergenic spacer were sequenced and matched to GenBank sequences for B. garinii. The potential for introduction of this agent into the North American Lyme disease enzootic is unknown.