All Posts Tagged With: "Rickettsia species"

Excerpt:

In this study, we evaluated Amblyomma americanum (lone star tick)
in Mississippi for the presence of Ehrlichia chaffeensis,
causative agent of human monocytic ehrlichiosis; Ehrlichia
ewingii, causative agent of human and canine granulocytic
ehrlichiosis; Borrelia lonestari, putative agent of southern
tick-associated rash illness; Francisella tularensis, the agent
of tularemia; and Rickettsia spp., particularly R. amblyommii, a
suspected pathogen. We collected adult A. americanum from four
regions of Mississippi: Northeast, Northwest, Southeast, and
East. Of the ticks collected, 192 were dissected and DNA was
extracted for nested polymerase chain reaction (PCR) assays to
detect the above bacteria. In all, 3% of tick extracts had
evidence of Borrelia sp., 4% for E. chaffeensis, 6% for E.
ewingii, and 44% for a Rickettsia species. As determined by
sequencing, most Rickettsia spp. were R. amblyommii. In addition,
extracts from 42 pools (total of 950) of larval A. americanum
collected in Southwest Mississippi were tested for the presence
of E. chaffeensis and Rickettsia species. Of these extracts from
pools, nine of 37 (24%) were PCR positive for a Rickettsia sp.,
most often, R. amblyommii; none had evidence of E. chaffeensis,
supporting the ability of lone star ticks to transovarially
transmit R. amblyommii, but not E. chaffeensis. This study
demonstrates E.

Among the various species of hard ticks, Ixodes ricinus is the most frequently
found tick throughout Europe. As with other ixodid ticks, the developmental
cycle runs through three stages. In each stage a blood meal is required in order
to develop to the next stage. Ixodes ricinus has been found to feed on more than
300 different vertebrate species. Usually, larval ticks feed on small mammals
such as mice and become infected with various microorganisms and viruses, of
which some are substantial pathogens to humans. The pathogens remain in the tick
during molting and are thus transstadially transmitted to the next developmental
stage. Pathogens transmitted to humans are the agents of Lyme borreliosis, the
tick-borne encephalitis virus, Rickettsia species, Anaplasma phagocytophilum,
occasionally Francisella tularensis, and protozoal Babesia species. Within the
scope of an EU project Ixodes ricinus ticks from all federal states of Austria
were searched by means of PCR methods for bacterial pathogens such as Anaplasma
phagocytophilum, Borrelia burgdorferi sensu lato, Coxiella burnetii, Ehrlichia
spp., Francisella tularensis, Rickettsia spp., and protozoal Babesia.
Additionally, the prevalence of Bartonella spp. in this tick species was also
determined. Besides the singular detection of Coxiella burnetii and Francisella
tularensis in one tick collection site the overall prevalence of Anaplasma
phagocytophilum, borreliae, rickettsae and babesiae in Ixodes ricinus amounted
to 15%, 14%, 6% and surprising 36% and 51%, respectively. Bartonellae were
detected in about 7%.

Among the various species of hard ticks, Ixodes ricinus is the most frequently found tick throughout Europe. As with other ixodid ticks, the developmental cycle runs through three stages. In each stage a blood meal is required in order to develop to the next stage. Ixodes ricinus has been found to feed on more than 300 different vertebrate species. Usually, larval ticks feed on small mammals such as mice and become infected with various microorganisms and viruses, of which some are substantial pathogens to humans. The pathogens remain in the tick during molting and are thus transstadially transmitted to the next developmental stage. Pathogens transmitted to humans are the agents of Lyme borreliosis, the tick-borne encephalitis virus, Rickettsia species, Anaplasma phagocytophilum, occasionally Francisella tularensis, and protozoal Babesia species. Within the scope of an EU project Ixodes ricinus ticks from all federal states of Austria were searched by means of PCR methods for bacterial pathogens such as Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, Coxiella burnetii, Ehrlichia spp., Francisella tularensis, Rickettsia spp., and protozoal Babesia. Additionally, the prevalence of Bartonella spp. in this tick species was also determined. Besides the singular detection of Coxiella burnetii and Francisella tularensis in one tick collection site the overall prevalence of Anaplasma phagocytophilum, borreliae, rickettsae and babesiae in Ixodes ricinus amounted to 15%, 14%, 6% and surprising 36% and 51%, respectively. Bartonellae were detected in about 7%. Continued