Environmental Public Health Commons^™

Beta Interferon-Mediated Activation Of Signal Transducer And Activator Of Transcription Protein 1 Interferes With Rickettsia Conorii Replication In Human Endothelial Cells, Punsiri M. Colonne, Marina Eremeeva, Sanjeev K. Sahni

Marina E. Eremeeva

Infection of the endothelial cell lining of blood vessels with Rickettsia conorii, the causative agent of Mediterranean spotted fever, results in endothelial activation. We investigated the effects of R. conorii infection on the status of the Janus kinase (JAK)-signal transducer and activator of transcription protein (STAT) signaling pathway in human microvascular endothelial cells (HMECs), the most relevant host cell type, in light of rickettsial tropism for microvascular endothelium in vivo. R. conoriiinfection induced phosphorylation of STAT1 on tyrosine 701 and serine 727 at 24, 48, and 72 h postinfection in HMECs. Employing transcription profile analysis and neutralizing …

Rickettsia Felis In Cat Fleas, Ctenocephalides Felis Parasitizing Opossums, San Bernardino County, California, Kyle F. Abramowicz, J. W. Wekesa, C. N. Nwadike, Maria L. Zambrano, Sandor E. Karpathy, D. Cecil, J. Burns, Renjie Hu, Marina Eremeeva

Marina E. Eremeeva

Los Angeles and Orange Counties are known endemic areas for murine typhus in California; however, no recent reports of flea-borne rickettsioses are known from adjacent San Bernardino County. Sixty-five opossums (Didelphis virginiana) were trapped in the suburban residential and industrial zones of the southwestern part of San Bernardino County in 2007. Sixty out of 65 opossums were infested with fleas, primarily cat fleas, Ctenocephalides felis (Bouché, 1835). The flea minimum infection rate with Rickettsia felis was 13.3% in pooled samples and the prevalence was 23.7% in single fleas, with two gltA genotypes detected. In spite of historic …

Eschar-Associated Spotted Fever Rickettsiosis, Bahia, Brazil, Nanci Silva, Marina Eremeeva, Tatiana Rozental, Guilherme S. Ribeiro, Christopher D. Paddock, Eduardo Antonio G. Ramos, Alexsandra R.M. Favacho, Mitermayer G. Reis, Gregory A. Dasch,, Elba R.S. De Lemos, Albert I. Ko

Marina E. Eremeeva

In Brazil, Brazilian spotted fever was once considered the only tick-borne rickettsial disease. We report eschar-associated rickettsial disease that occurred after a tick bite. The etiologic agent is most related to Rickettsia parkeri, R. africae, and R. sibirica and probably widely distributed from São Paulo to Bahia in the Atlantic Forest.

Emergence Of A Novel Human Ehrlichia-Muris Like Organism In North America – Wisconsin And Minnesota, Bobbi S. Pritt, Lynne M. Sloan, Diep K. Hoang-Johnson, Ulrike G. Munderloh, Susan M. Paskewitz, Kristina M. Mcelroy, Jevon D. Mcfadden, Matthew J. Binnicker, David F. Neitzel, Gongping Liu, William L. Nicholson, Curtis M. Nelson, Joni J. Franson, Scott A. Martin, Scott A. Cunningham, Christopher R. Steward, Kay Bogumill, Mary E. Bjorgaard, Jeffrey P. Davis, Jennifer H. Mcquiston, David M. Warshauer, Mark P. Wilhelm, Robin Patel, Vipul A. Trivedi, Marina Eremeeva

Marina E. Eremeeva

Background: Ehrlichiosis is a clinically important, emerging zoonosis. Only Ehrlichia chaffeensis and E. ewingii have been thought to cause ehrlichiosis in humans in the United States. Patients with suspected ehrlichiosis routinely undergo testing to ensure proper diagnosis and to ascertain the cause.

Methods: We used molecular methods, culturing, and serologic testing to diagnose and ascertain the cause of cases of ehrlichiosis.

Results: On testing, four cases of ehrlichiosis in Minnesota or Wisconsin were found not to be from E. chaffeensis or E. ewingii and instead to be caused by a newly discovered ehrlichia species.

All patients had fever, …

Rocky Mountain Spotted Fever In Panama: A Cluster Description, Maribel Tribaldos, Yamitzel Zaldivar, Sergio Bermudez, Franklyn Samudio, Yaxelis Mendoza, Alexander A. Martinez, Rodrigo Villalobos, Marina Eremeeva, Christopher D. Paddock, Kathleen Page, Rebecca E. Smith, Juan Miguel Pascale

Marina E. Eremeeva

Rocky Mountain spotted fever (RMSF) is a tick-borne infection caused by Rickettsia rickettsii. We report a cluster of fatal cases of RMSF in 2007 in Panama, involving a pregnant woman and two children from the same family. The woman presented with a fever followed by respiratory distress, maculopapular rash, and an eschar at the site from which a tick had been removed. She died four days after disease onset. This is the second published report of an eschar in a patient confirmed by PCR to be infected with R. rickettsii. One month later, the children presented within days of one …