Spotted fever rickettsioses in southern and eastern Europe

Fatal Israeli spotted fever in a UK traveler to South Portugal

A 63-year-old previously healthy woman developed a severe systemic infection 5 days after returning from a holiday to Southern Portugal. She subsequently died, and polymerase chain reaction of a blood sample was positive for Rickettsia conorii ssp israeliensis. The prevalence of severe forms of this illness in the Mediterranean Basin is discussed.

Antimicrobial prevention and therapy for travelers' infection

International journeys are increasing and more than 70 million people from industrialized countries cross the borders of tropical countries every year. More than 50% of them will suffer from some form of infectious illness, ranging from mild travelers' diarrhea to severe dengue fever to fatal malaria, with a wide spectrum of microbiological entities. Travel-related respiratory infections, including TB, and sexually transmitted infections are also increasingly reported. Awareness of travel-related risk is not always adequate among international travelers. Specific training on travel medicine-related issues, as well as better diagnostic facilities for imported diseases, is crucial for physicians and nurses in industrialized countries.

Transposon insertion reveals pRM, a plasmid of Rickettsia monacensis

Until the recent discovery of pRF in Rickettsia felis, the obligate intracellular bacteria of the genus Rickettsia (Rickettsiales: Rickettsiaceae) were thought not to possess plasmids. We describe pRM, a plasmid from Rickettsia monacensis, which was detected by pulsed-field gel electrophoresis and Southern blot analyses of DNA from two independent R. monacensis populations transformed by transposon-mediated insertion of coupled green fluorescent protein and chloramphenicol acetyltransferase marker genes into pRM. Two-dimensional electrophoresis showed that pRM was present in rickettsial cells as circular and linear isomers. The 23,486-nucleotide (31.8% G/C) pRM plasmid was cloned from the transformant populations by chloramphenicol marker rescue of restriction enzyme-digested transformant DNA fragments and PCR using primers derived from sequences of overlapping restriction fragments. The plasmid was sequenced. Based on BLAST searches of the GenBank database, pRM contained 23 predicted genes or pseudogenes and was remarkably similar to the larger pRF plasmid. Two of the 23 genes were unique to pRM and pRF among sequenced rickettsial genomes, and 4 of the genes shared by pRM and pRF were otherwise found only on chromosomes of R. felis or the ancestral group rickettsiae R. bellii and R. canadensis. We obtained pulsed-field gel electrophoresis and Southern blot evidence for a plasmid in R. amblyommii isolate WB-8-2 that contained genes conserved between pRM and pRF. The pRM plasmid may provide a basis for the development of a rickettsial transformation vector.