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Full-Text Articles in Environmental Health and Protection

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, R. Hu, Marina E. Eremeeva Dec 2012

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, R. Hu, Marina E. Eremeeva

Environmental Health Sciences Faculty Publications

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 records of murine …


Rickettsia Felis In Ctenocephalides Felis From Guatemala And Costa Rica, Adriana Troyo, Danilo Alvarez, Lizeth Taylor, Gabriela Abdalla, Olger Calderon-Arguedas, Maria L. Zambrano, Gregory A. Dasch, Kim A. Lindblade, Laya Hun, Marina Eremeeva, Alejandra Estevez Jun 2012

Rickettsia Felis In Ctenocephalides Felis From Guatemala And Costa Rica, Adriana Troyo, Danilo Alvarez, Lizeth Taylor, Gabriela Abdalla, Olger Calderon-Arguedas, Maria L. Zambrano, Gregory A. Dasch, Kim A. Lindblade, Laya Hun, Marina Eremeeva, Alejandra Estevez

Environmental Health Sciences Faculty Publications

Rickettsia felis is an emerging human pathogen associated primarily with the cat flea Ctenocephalides felis. In this study, we investigated the presence of Rickettsia felis in C. felis from Guatemala and Costa Rica. Ctenocephalides felis were collected directly from dogs and cats, and analyzed by polymerase chain reaction for Rickettsia-specific fragments of 17-kDa protein, OmpA, and citrate synthase genes. Rickettsia DNA was detected in 64% (55 of 86) and 58% (47 of 81) of flea pools in Guatemala and Costa Rica, respectively. Sequencing of gltA fragments identified R. felis genotype URRWXCal2 in samples from both countries, and genotype Rf2125 in …


Calcium Montmorillonite Clay Reduces Urinary Biomarkers Of Fumonisin B₁ Exposure In Rats And Humans, Abraham Robinson, Natalie M. Johnson, A. Strey, John F. Taylor, Alicia Marroquin-Cardona, N. J. Mitchell, Evans Afriyie-Gyawu, Nii-Ayi Ankrah, Jonathan H. Williams, Jia-Sheng Wang, Pauline E. Jolly, R. J. Nachman, Timothy D. Phillips Jan 2012

Calcium Montmorillonite Clay Reduces Urinary Biomarkers Of Fumonisin B₁ Exposure In Rats And Humans, Abraham Robinson, Natalie M. Johnson, A. Strey, John F. Taylor, Alicia Marroquin-Cardona, N. J. Mitchell, Evans Afriyie-Gyawu, Nii-Ayi Ankrah, Jonathan H. Williams, Jia-Sheng Wang, Pauline E. Jolly, R. J. Nachman, Timothy D. Phillips

Environmental Health Sciences Faculty Publications

Fumonisin B1 (FB1) is often a co-contaminant with aflatoxin (AF) in grains and may enhance AF’s carcinogenicity by acting as a cancer promoter. Calcium montmorillonite (i.e. NovaSil, NS) is a possible dietary intervention to help decrease chronic aflatoxin exposure where populations are at risk. Previous studies show that an oral dose of NS clay was able to reduce AF exposure in a Ghanaian population. In vitro analyses from our laboratory indicated that FB1 (like aflatoxin) could also be sorbed onto the surfaces of NS. Hence, our objectives were to evaluate the efficacy of NS clay to reduce urinary FB1 in …


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 Jan 2012

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 Jan 2012

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 …