Minimum Infection Rate of Ambylomma americanum (Acari: Ixodidae) by Ehrlichia chaffeensis (Rickettsiales: Ehrlichieae in Southern Indiana

Burket, Christopher T.; Vann, Carolyn N.; Pinger, Robert R.; Chatot, Clare L.; Steiner, Fresia E.

doi:10.1093/jmedent/35.5.653

Cited by 39 publications

(29 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In those studies, the prevalence of infected ticks was reported to be 0 to 29% in the United States (2,4,22,26). The results of our current study, however, suggest that the prevalence rates of positive ticks may be greater if this nested RT-PCR is used.…”

Section: Discussioncontrasting

confidence: 69%

Sensitive Detection of Ehrlichia chaffeensis in Cell Culture, Blood, and Tick Specimens by Reverse Transcription-PCR

Felek¹,

Ünver²,

Stich

et al. 2001

J Clin Microbiol

View full text Add to dashboard Cite

Ehrlichia chaffeensis is an obligatory intracellular bacterium of monocytes and macrophages and the etiologic agent of human monocytic ehrlichiosis, an emerging zoonosis. The Lone Star tick (Amblyomma americanum) has been implicated as the primary vector of E. chaffeensis. The present study examined the sensitivity of the nested reverse transcription (RT)-PCR based on the 16S rRNA gene relative to that of the nested PCR for detection of E. chaffeensis in infected DH82 cells, experimentally infected dog peripheral blood mononuclear cells, or experimentally infected A. americanum tick samples. The RT-PCR was found to be approximately 100 times more sensitive than the PCR for detection of E. chaffeensis regardless of the nature of the specimens. Thus, this RT-PCR is useful for detection of E. chaffeensis when a high sensitivity is required. Positive results by RT-PCR also imply the presence of viable pathogens. This is the first demonstration of RNA of E. chaffeensis in infected blood and acquisition-fed male, nymphal, and larval A. americanum ticks.

show abstract

Section: Discussioncontrasting

confidence: 69%

Sensitive Detection of Ehrlichia chaffeensis in Cell Culture, Blood, and Tick Specimens by Reverse Transcription-PCR

Felek¹,

Ünver²,

Stich

et al. 2001

J Clin Microbiol

View full text Add to dashboard Cite

show abstract

“…By contrast, the MIR of adult ticks collected at the same location was 3.5% (258). In general, infection prevalences appear to be lower among nymphal ticks than among adults, and failure to detect E. chaffeensis in nymphs collected at sites with confirmed infections in adult A. americanum has been described by several investigators (10,43).…”

Section: Tick Vectorsmentioning

confidence: 92%

“…chaffeensis has been detected in female and male lone star ticks collected in Alabama, Arkansas, Connecticut, Georgia, Florida, Indiana, Kansas, Kentucky, Maryland, Missouri, North Carolina, New Jersey, Rhode Island, and Virginia (10,43,135,170,235,256,257,278). Infection prevalences presumably vary intrinsically across location, sampling period, and life stage of Amblyomma ticks tested and extrinsically with the assaying method (e.g., numbers of ticks sampled, sampling methods, and sensitivity of the assay), making generalizations difficult.…”

Section: Tick Vectorsmentioning

confidence: 99%

“…As with many other tick-transmitted pathogens, infections of tick populations may appear spatially or temporally discontinuous, and wide variations in infection prevalences can be expected among ticks collected from closely spaced geographic locales (43,278) or among ticks collected at the same site during different years (256). In this context, infection may not always be evident among ticks at a specific location at a particular time of sampling (43,278).…”

Section: Tick Vectorsmentioning

confidence: 99%

See 1 more Smart Citation

Ehrlichia chaffeensis: a Prototypical Emerging Pathogen

2003

View full text Add to dashboard Cite

Ehrlichia chaffeensis is an obligately intracellular, tick-transmitted bacterium that is maintained in nature in a cycle involving at least one and perhaps several vertebrate reservoir hosts. The moderate to severe disease caused by E. chaffeensis in humans, first identified in 1986 and reported for more than 1,000 patients through 2000, represents a prototypical “emerging infection.” Knowledge of the biology and natural history of E. chaffeensis, and of the epidemiology, clinical features, and laboratory diagnosis of the zoonotic disease it causes (commonly referred to as human monocytic ehrlichiosis [HME]) has expanded considerably in the period since its discovery. In this review, we summarize briefly the current understanding of the microbiology, pathogenesis, and clinical manifestations associated with this pathogen but focus primarily on discussing various ecological factors responsible for the recent recognition of this important and potentially life-threatening tick-borne disease. Perhaps the most pivotal element in the emergence of HME has been the staggering increases in white-tailed deer populations in the eastern United States during the 20th century. This animal serves as a keystone host for all life stages of the principal tick vector (Amblyomma americanum) and is perhaps the most important vertebrate reservoir host for E. chaffeensis. The contributions of other components, including expansion of susceptible human populations, growth and broadening geographical distributions of other potential reservoir species and A. americanum, and improvements in confirmatory diagnostic methods, are also explored

show abstract

“…Most E. chaffeensis-specific PCR assays reported to date are based on nested primer sets that anneal to the 16S rRNA gene (16S rDNA) [5][6][7][8][9][10][11]. These nested PCR assays have been used extensively to detect the pathogen in mammals and pools of naturally exposed ticks.…”

Section: Introductionmentioning

confidence: 99%

Development of a p28-based PCR assay for Ehrlichia chaffeensis

Wagner

Bremer

Rikihisa

et al. 2004

Molecular and Cellular Probes

View full text Add to dashboard Cite

Detection of Ehrlichia chaffeensis is necessary to study interactions between the parasite and its vertebrate and invertebrate hosts. The purpose of this study was to develop a sensitive, specific PCR assay for E. chaffeensis based on the outer membrane protein gene, p28. Candidate primer sets were identified and ranked based on annealing scores, similarities to three major p28 sequence clusters, dissimilarity to E. canis p30, an ortholog of p28, and the proximities of flanking primer sequences for nested PCR. The relative sensitivities of five optimized single-step and two nested PCR assays were determined, and the most sensitive assay was found to be a single-step PCR that was as much as 1000-fold more sensitive than a standard 16S rDNA-based nested PCR assay. This p28-based PCR assay amplified the target amplicon from isolates representative of all three major clusters of known p28 sequences, and this assay did not amplify template prepared from either of the two species most closely related to E. chaffeensis, E. canis and E. muris. These results indicate that this sensitive, specific and isolate-universal single-step PCR assay will be a useful tool in characterizing the transmission of this important zoonotic pathogen.

show abstract

Minimum Infection Rate of Ambylomma americanum (Acari: Ixodidae) by Ehrlichia chaffeensis (Rickettsiales: Ehrlichieae in Southern Indiana

Cited by 39 publications

References 10 publications

Sensitive Detection of Ehrlichia chaffeensis in Cell Culture, Blood, and Tick Specimens by Reverse Transcription-PCR

Sensitive Detection of Ehrlichia chaffeensis in Cell Culture, Blood, and Tick Specimens by Reverse Transcription-PCR

Ehrlichia chaffeensis: a Prototypical Emerging Pathogen

Development of a p28-based PCR assay for Ehrlichia chaffeensis

Contact Info

Product

Resources

About