Rickettsia felis inXenopsylla cheopis, Java, Indonesia

Abstract

Rickettsia typhi and R. felis, etiologic agents of murine typhus and fleaborne spotted fever, respectively, were detected in Oriental rat fleas (Xenopsylla cheopis) collected from rodents and shrews in Java, Indonesia. We describe the first evidence of R. felis in Indonesia and naturally occurring R. felis in Oriental rat fleas.M urine typhus (endemic typhus, fleaborne typhus), caused by Rickettsia typhi, is transmitted to humans by infected fleas and is relatively common wherever susceptible rodent hosts reside (1). Fleaborne spotted fever (cat flea typhus), caused by Rickettsia felis, is another zoonotic disease carried by fleas and appears to have an equally wide, cosmopolitan distribution; human infections with R. felis have a clinical syndrome similar to that of murine typhus (1-4). The cat flea, Ctenocephalides felis, has been identified as the primary arthropod vector of R. felis in North and South America (United States, Mexico, Peru, Brazil), Europe (Spain, France, United Kingdom, Cyprus), Africa (Gabon, Ethiopia), Asia (Thailand, Afghanistan, Israel), Australia, and New Zealand (1,5-10). We describe the first evidence of R. felis in Indonesia and apparent natural infections of R. felis in the Oriental rat flea, Xenopsylla cheopis, implicating this flea species for the first time as a potential vector for fleaborne spotted fever. The StudySamples of X. cheopis were collected from 39 live-captured, peridomestic rodents and shrews from 3 localities in Malang, East Java, Indonesia, during an epidemiologic study conducted in 1994 (11). In this study the fleas were reidentified by using morphologic criteria, stored in fresh 70% ethanol, and subsequently evaluated for the presence of rickettsial DNA. DNA sample preparations were derived from triturates of 103 individual fleas in 100 µL PrepManUltra sample preparation reagent (Applied Biosystems, Foster City, CA, USA). DNA preparations of 1 to 5 fleas collected from the same rodent were pooled for testing. Reaction mixtures for the quantitative real-time PCR (qPCR) assays had a total volume of 25 µL and contained 3 µL DNA template. The master mixes were prepared for the 17-kDa Rickettsia-, R. typhi-and R. felis-specific qPCR assays in a separate, clean (DNA-free) room as previously described (6,12). The primer and probe sequences for the 17-kDa Rickettsia-specific and R. felis-specific assays have been reported (6,11). The R. typhi forward (Rt557F: 5′-TGG TAT TAC TGC TCA ACA AGC T-3′) and reverse (Rt678R: 5′-CAG TAA AGT CTA TTG ATC CTA CAC C-3′) primers and probe (Rt640BP: 5′-TET-CGC GAT CGT TAA TAG CAG CAC CAG CAT TAT CGC G-DABCYL-3′) sequences are listed here. Included in each run were 3 negative controls (GIBCO Ultrapure DNA-free distilled water, Invitrogen Corporation, Grand Island, NY, USA), 1 produced in the clean room and 2 in a biosafety cabinet in another laboratory where DNA templates were added. A TOPO TA plasmid (Invitrogen Corporation) that contained the target sequence at 10 3 copies for each assay was used as a positive control. qPCR reactions w...

Molecular Detection of Rickettsia felis in Different Flea Species from Caldas, Colombia

“…With a larger sample of X. cheopis and other flea species, it would be of interest to test for the presence of coinfection with R. felis and R. typhi in the same positive fleas, because it was previously reported in experimental works 42 and under natural conditions. 22,43,44 The analysis of the sequence electropherograms showed lack of ambiguity in the nucleotide assignments for all samples included. Because the PCR products were derived from pools in which several members could be positive, the clean sequence reads suggest that the amplified fragments were highly conserved and/or that only one flea in each pool was positive for a single Rickettsia.…”

Rickettsial Infections in Southeast Asia: Implications for Local Populace and Febrile Returned Travelers

“…R. felis infections produce a clinical syndrome similar to that of murine typhus. 35 Given the clinical similarities, some authors believe that previously reported outbreaks of murine typhus infections may have been caused by the more recently recognized R. felis.…”

“…32,33 Infection of rat flea Xenopsylla cheopis with R. felis has also been found in Indonesia, which increases the possibility of human infections with R. felis in the region, although no clinical case has been reported to date. 35,37 Ectoparasite field surveys of villages in Laos and Malaysian Borneo of domestic animals also showed significantly high overall R. felis DNA detection rates of 76.6% and 74.4%, respectively. 36 However, in contrast, another study in peninsula Malaysia showed a lower rate (2.9%) of R. felis DNA detection.…”

“…[26][27][28][29] Socioeconomically, agricultural, plantation, or forest workers in Thailand, Malaysia, and Indonesia were frequently affected by scrub typhus and SFGR infections. 21 [32][33][34][35][36][37][38] Rodents were found to be important reservoirs for SFGR and murine typhus; high seropositive rates (up to 39.1% for SFGR) were observed in some parts of rural Indonesia. 32,33 Infection of rat flea Xenopsylla cheopis with R. felis has also been found in Indonesia, which increases the possibility of human infections with R. felis in the region, although no clinical case has been reported to date.…”

Molecular Detection of Rickettsia felis, Bartonella henselae, and B. clarridgeiae in Fleas from Domestic Dogs and Cats in Malaysia

“…21 Human and animal infections of R. felis and bartonellae have been reported in Southeast Asia. 16,[22][23][24] This study is the second study in Southeast Asia that investigated the prevalence of R. felis and bartonellae in flea samples. Compared with the previous study, 16 a larger number of fleas examined in this study were positive for B. henselae and B. clarridgeiae .…”