Aurélie Renvoisé

Q fever in France, 1985-2009.

To assess Q fever in France, we analyzed data for 1985–2009 from the French National Reference Center. A total of 179,794 serum samples were analyzed; 3,723 patients (one third female patients) had acute Q fever. Yearly distribution of acute Q fever showed a continuous increase. Periodic variations were observed in monthly distribution during January 2000–December 2009; cases peaked during April–September. Q fever was diagnosed more often in patients in southeastern France, where our laboratory is situated, than in other areas. Reevaluation of the current positive predictive value of serologic analysis for endocarditis was performed. We propose a change in the phase I (virulent bacteria) immunoglobulin G cutoff titer to >1,600. Annual incidences of acute Q fever and endocarditis were 2.5/100,000 persons and 0.1/100,000 persons, respectively. Cases and outbreaks of Q fever have increased in France.

Coxiella burnetii DNA, But Not Viable Bacteria, in Dairy Products in France

Transmission by the oral route of Coxiella burnetii is controversial. Our objective was to evaluate dairy products in the transmission of Q fever. Pasteurized, unpasteurized, and thermized dairy products were tested for C. burnetii by using a quantitative polymerase chain reaction specific for IS1111 and IS30A spacers, culturing in human embryonic lung fibroblasts cells, and inoculation into BALB/c mice. We tested 201 products and C. burnetii was identified in 64%. Cow milk origin products were more frequently positive than goat or ewe products (P = 0.006 and P = 0.0001, respectively), and industrial food was more frequently positive than artisanal food (P < 0.0001). Food made from unpasteurized milk contained higher bacteria concentrations than food made from pasteurized milk (P = 0.02). All cultures were negative and mice did not show signs of illness. Farm animals are highly infected in France but consumption of cheese and yogurt does not seem to pose a public health risk for transmission of Q fever.

Rickettsia felis Infection in Man, France

To the Editor: In August 2008, a 64-year-old man was admitted to the Salon-de-Provence Hospital, France. He had fever (39°C) and a maculopapular rash. No eschars or adenopathy were noted. The patient had a relatively mild illness; the only abnormal laboratory values were elevated aminotransferase levels (aspartate aminotransferase 85 U/L and alanine aminotransferase 135 U/L). The man was an agricultural worker who had originated from Algeria but at this time lived in a shelter in southern France. His potential for contact with dogs in his environment was noted, but no history of flea exposure was elicted. This disease was postulated to be rickettsiosis because no other cause for his fever and rash was evident. Doxycycline was then administered, and the patient rapidly improved. Serum testing at the Unite des Rickettsies (Marseilles, France), using a multiple-antigen immunofluorescent assay (1), showed the following titers: spotted fever group (SFG) (e.g., Rickettsia felis, R. conorii, R. aeschlimannii, R. massiliae) 1,024 and 512 for immunoglobulin (Ig) G and IgM, respectively, and typhus group 512 and 256 for IgG and IgM, respectively. Serum was tested by real-time PCR by using a probe that enabled screening for spotted fever and a probe specific for R. felis; results were negative. A Western blot with cross-adsorption (2) showed R. felis as the causative agent (Figure). At a follow-up visit 3 months later, the patient had no signs or symptoms. Rickettsiae were first described in the cat flea (Ctenocephalides felis) in 1918 and tentatively named R. ctenocephali. However, this work was overlooked until 1990, when an ELB agent was found in C. felis fleas by electron microscopy (3); the agent was demonstrated to be a Rickettsia-like organism. Results of subsequent studies were controversial because of suspected contamination of cultures. The species R. felis was formally validated by molecular criteria in 2001, and the reference strain was isolated in 2002 (4). R. felis has been demonstrated to belong to the SFG (5). R. felis is distributed worldwide (Technical Appendix), although it has not been found in the northern, coldest regions. The vectors described include fleas, ticks, and mites; however, the only currently recognized vector is the C. felis flea (6). The reported hosts for these vectors are mainly cats, dogs, and rodents. R. felis is the only SFG species that is transmitted by fleas. Studies have confirmed that R. felis in C. felis flea populations is mostly maintained by transstadial and transovarial transmission (7). Levels of R. felis infestation in C. felis fleas are variable, and the specific mechanisms of maintenance within each flea remain unknown. Prevalence is increased by fleas feeding on mammalian hosts infected with R. felis. Nevertheless, the precise relationship between the vector and the host remains unknown, and the mechanisms of rickettsial replication have not yet been examined (7). We searched PubMed and found reports (case reports and seroprevalence studies) of 68 R. felis infections. Cases have been reported in the Americas, Asia, Tunisia, and Europe (Technical Appendix). Such clinical cases rarely occur in warm countries, unlike the worldwide distribution of the bacteria, mentioned above. Reports of human infection with R. felis are rare, but the organism is frequently isolated from fleas. We summarized the available clinical findings for 34 persons infected with R. felis: 32 had fever; 24, cutaneous rash (mostly maculopapular); 4, cutaneous eschar; 5, neurologic signs; 7, digestive symptoms; 3, cough without pneumonia; and 2, pneumonia. Clinical findings for R. felis are often confused with those found for patients with murine typhus or other febrile illnesses, and they appear to be more complex and more severe than initially thought. R. felis infections can be diagnosed by serologic testing (1), molecular analysis, or a combination of each. Several molecular methods for detection of R. felis have focused on the presence of several genes, but real-time PCR assays are becoming increasingly useful (8). Serologic profiles for R. felis infections differ; cross-reactions with SFG rickettsiae as well as with SFG rickettsiae and R. typhi have been observed, but a lack of cross-reactions has also been observed (9). It has been noted (10) that when cross-reactions were observed between R. felis and both R. conorii and R. typhi, the infection was probably related to R. felis. When cross-reactions were observed between R. felis and only R. typhi, the causative agent was most probably of the typhus group. R. felis infections occur globally and are linked to the worldwide distribution of vectors, but the occurrence is relatively rare when compared with the high frequency of R. felis infections related to flea infestation. Human infections remain poorly characterized and are apparently underappreciated, possibly because of the lack of specific signs and symptoms. Further characterization of the interactions between R. felis and fleas could elucidate the particular epidemiology and pathology of flea-borne spotted fever. Figure Western blot after cross-adsorption with (left to right) Rickettsia conorii, R. massiliae, R. felis, and R. aeschlimannii. When cross-adsorption is performed with R. felis, the specific antigen-corresponding line disappears, which indicates R. felis as ...

Diagnosis of rickettsioses from eschar swab samples, Algeria.

To the Editor: Tick-borne rickettsioses are zoonoses caused by intracellular bacteria belonging to the spotted fever group rickettsiae (1). The main clinical signs are high fever, maculopapular rash, and an inoculation eschar at the site of the tick bite (corresponding to the portal of entry of rickettsiae into the host). Recently, several rickettsioses were diagnosed by using swab samples from skin lesions (2,3). In an animal model, as long as eschars were present, rickettsial DNA was detected (2). Our aim was to evaluate the advantage of skin swab samples for diagnosis of rickettsial diseases in a country where rickettsioses are endemic (4).

Intracellular Rickettsiales: Insights into manipulators of eukaryotic cells

The order Rickettsiales comprises obligate intracellular bacteria that are the ancestors of modern eukaryotes. These bacteria infect various vectors and hosts, with some species being pathogenic to man. Rickettsiales have small, degraded genomes and provide a paradigm for increased pathogenicity despite gene loss; significant levels of genetic exchange occur between bacteria that infect the same host and with the eukaryotic hosts themselves. Crosstalk between host and bacteria appears to be mediated by a Type IV secretion system and proteins containing eukaryotic-like repeat motifs. Rickettsiales also manipulate host reproduction and induce host resistance to viruses. Manipulation of its host by Rickettsiales has long been misunderstood because of technical difficulties, but recent advances in understanding bacterial-eukaryotes interactions have been made and are reviewed here.

Strikes, flooding, rats, and leptospirosis in Marseille, France

OBJECTIVES The aim of this study was to examine the mechanisms by which weather conditions, the incidence of Leptospira in reservoir populations, and various socio-ecological factors are driving the emergence of leptospirosis in Marseille, France. METHODS Over the last 30 years our laboratory has surveyed all human cases of leptospirosis in Marseille using clinical, epidemiological, serological, and molecular tools. Data for the weather conditions in Marseille were collected from the official meteorological station, and garbage management strikes were monitored through the local press. Rats were trapped in alleys near to where the patients may have acquired leptospirosis. RESULTS Three new cases of autochthonous leptospirosis are reported. The global tendency for rainfall showed a slight increase over the period under analysis. The index case of leptospirosis occurred after a heavy rainfall with flooding. Over the last 10 years Marseille has undergone 82 days of garbage management strikes. Leptospira DNA was detected in two of 11 rats. CONCLUSIONS The emergence of leptospirosis has become a public health problem in Marseille, and is associated with a combination of heavy rainfall and garbage collection strikes in which garbage is left on the street and thereby contributes to the expansion of the rat population on the surface.

Old and new tick-borne rickettsioses

The field of rickettsiology is rapidly evolving. Rickettsiae are small Gram-negative bacteria that can be transmitted to humans by arthropods. In most cases they are transmitted transovarially in the arthropod; human beings are incidental hosts. In recent years the use of cell culture and molecular biology has profoundly changed our knowledge of rickettsiae and has led to the description of several new species. New rickettsial diseases have been found in three main situations: firstly, in places where no new species have been identified, typical rickettsial symptoms have been observed (Japan, China); secondly, typical rickettsioses have been found to be caused by different organisms - in such cases a new Rickettsia species has been misdiagnosed as a previously identified bacterium (for example, R. parkeri was confused with R. rickettsii); thirdly, atypical clinical symptoms have been found to be caused by rickettsial organisms such as R. slovaca. These findings challenge the old dogma that only one tick-borne rickettsiosis is prevalent in one geographical area. Many Rickettsia spp. have been identified in ticks, but have not yet been implicated in human pathology. These rickettsiae should be considered as potential pathogens. All known or suspected rickettsial diseases should be treated (including in children) with doxycycline.

Actinomyces massiliensis sp. nov., isolated from a patient blood culture.

Gram-positive, non-spore-forming rods (strain 4401292(T)) were isolated from a human blood sample. Based on cellular morphology and the results of biochemical tests, this strain was tentatively identified as belonging to an undescribed species of the genus Actinomyces. Phylogenetic analysis based on 16S rRNA gene sequence comparison showed that the bacterium was related closely to Actinomyces gerencseriae (95.1 % 16S rRNA gene sequence similarity), Actinomyces israelii (95.2 %), Actinomyces oricola (95.2 %), Actinomyces ruminicola (93.3 %) and Actinomyces dentalis (91.4 %). The predominant fatty acids were C18 : 1omega9c and C16 : 0. On the basis of phenotypic data and phylogenetic inference, the novel species Actinomyces massiliensis sp. nov. is proposed; the type strain is 4401292(T) (=CSUR P18(T)=CCUG 53522(T)).

Actinomyces timonensis sp. nov., isolated from a human clinical osteo-articular sample

Gram-positive, non-spore-forming rods were isolated from a human osteo-articular sample (strain 7400942(T)). Based on cellular morphology and the results of biochemical analysis, this strain was tentatively identified as a novel species of the genus Actinomyces. Phylogenetic analysis based on 16S rRNA gene sequence comparisons showed that the bacterium was closely related to the type strain of Actinomyces denticolens (96.9 % 16S rRNA gene sequence similarity). A comparison of biochemical traits showed that strain 7400942(T) was distinct from A. denticolens in a number of characteristics, i.e. in contrast with A. denticolens, strain 7400942(T) was negative for nitrate reduction and for beta-galactosidase, alpha-glucosidase and alanine arylamidase activities, it was positive for acid production from N-acetylglucosamine, melezitose and glycogen, and it was negative for acid production from turanose. Matrix-assisted laser-desorption/ionization time-of-flight MS protein analysis confirmed that strain 7400942(T) represents a novel species, as scores obtained for its spectra were significant (>2.2) only with strain 7400942(T). On the basis of phenotypic data and phylogenetic inference, it is proposed that this strain should be designated Actinomyces timonensis sp. nov.; the type strain is strain 7400942(T) (=CSUR P35(T)=CCUG 55928(T)).

A case of rickettsialpox in Northern Europe

We report the first case of rickettsialpox caused by Rickettsia akari in the Netherlands. The diagnosis was suspected based on clinical grounds and was confirmed by Western blot analysis with cross-adsorption. Because the arthropod vector (Liponyssoides sanguineus) is ubiquitous, we suspect that the disease is under-diagnosed in non-endemic areas.