A novel spotted fever group Rickettsia infecting Amblyomma parvitarsum (Acari: Ixodidae) in highlands of Argentina and Chile

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• 作者：Maria Ogrzewalska^a ; ^b ; ^{maria.ogrzewalska@fiocruz.ioc.br" class="auth_mail" title="E-mail the corresponding author} ; Fernanda A. Nieri-Bastos^a ; Arlei Marcili^c ; ^d ; Santiago Nava^e ; Daniel Gonz&aacute ; lez-Acuñ ; a^f ; Sebasti&aacute ; n Muñ ; oz-Leal^a ; ^f ; Ignacio Ruiz-Arrondo^g ; José ; M. Venzal^h ; Atilio Mangold^e ; Marcelo B. Labruna^a
• 关键词：Spotted fever group ; Rickettsia ; Amblyomma parvitarsum ; Argentina ; Chile
• 刊名：Ticks and Tick-borne Diseases
• 出版年：2016
• 出版时间：April 2016
• 年：2016
• 卷：7
• 期：3
• 页码：439-442
• 全文大小：385 K

文摘

The tick m>Amblyomma parvitarsumm> (Acari: Ixodidae) has established populations in Andean and Patagonic environments of South America. For the present study, adults of m>A. parvitarsumm> were collected in highland areas (elevation >3500 m) of Argentina and Chile during 2009–2013, and tested by PCR for rickettsial infection in the laboratory, and isolation of rickettsiae in Vero cell culture by the shell vial technique. Overall, 51 (62.2%) out of 82 m>A. parvitarsumm> adult ticks were infected by spotted fever group (SFG) rickettsiae, which generated DNA sequences 100% identical to each other, and when submitted to BLAST analysis, they were 99.3% identical to corresponding sequence of the m>ompAm> gene of m>Rickettsiam> sp. strain Atlantic rainforest. Rickettsiae were successfully isolated in Vero cell culture from two ticks, one from Argentina and one from Chile. DNA extracted from the third passage of the isolates of Argentina and Chile were processed by PCR, resulting in partial sequences for three rickettsial genes (m>gltAm>, m>ompBm>, m>ompAm>). These sequences were concatenated and aligned with rickettsial corresponding sequences available in GenBank. Phylogenetic analysis revealed that the m>A. pavitarsumm> rickettsial agent grouped under high bootstrap support in a clade composed by the SFG pathogens m>R. sibiricam>, m>R. africaem>, m>R. parkerim>, m>Rickettsiam> sp. strain Atlantic rainforest, and two unnamed SFG agents of unknown pathogenicty, m>Rickettsiam> sp. strain NOD, and m>Rickettsiam> sp. strain ApPR. The pathogenic role of this m>A. parvitarsumm> rickettsia cannot be discarded, since several species of tick-borne rickettsiae that were considered nonpathogenic for decades are now associated with human infections.