M. Clerc

Chlamydial infections in duck farms associated with human cases of psittacosis in France.

Five severe cases of psittacosis in individuals associated with duck farms were notified in France between January and March 2006. Diagnostic examination included serology and/or molecular detection by PCR from respiratory samples. As a consequence, we investigated all duck flocks (n=11) that were housed in the three farms where human infections occurred. While serology by complement fixation test was negative for all samples, cloacal and/or tracheal chlamydial excretion was detected by PCR in all three units. Notably, one duck flock was tested strongly positive in 2 of the 3 affected farms, and Chlamydophila (C.) psittaci strains were isolated from cloacal and/or tracheal swab samples from both farms. Human samples and duck isolates exhibited the same PCR-RFLP restriction pattern, which appeared to be an intermediate between genotypes A and B. Analysis of ompA gene sequences and comparison to those of the type strains showed that the isolates could not be strictly assigned to any of the generally accepted genotypes of C. psittaci. Further analysis by MLVA of the PCR-positive human samples revealed two distinct patterns, which were related to previously isolated C. psittaci duck strains.

Activity of moxifloxacin against the urogenital mycoplasmas Ureaplasma spp., Mycoplasma hominis and Mycoplasma genitalium and Chlamydia trachomatis

The activity of moxifloxacin was compared with that of other antimicrobial agents against 54 strains of Ureaplasma spp., 54 strains of Mycoplasma hominis, 14 strains of Mycoplasma genitalium, and 44 strains of Chlamydia trachomatis. Moxifloxacin inhibited 90% of all isolates at a concentration </=1 mg/L, being the most active compound against C. trachomatis and sharing the highest activity with garenoxacin and gemifloxacin against mycoplasmas. Moxifloxacin killed the 30 mycoplasma isolates tested at a concentration </=1 mg/L, except those resistant to fluoroquinolone. Thus, moxifloxacin has attracted interest as a potential therapy for mycoplasmal or chlamydial urogenital infections.

First case of Chlamydia trachomatis L2b proctitis in a woman

Since 2003, outbreaks of lymphogranuloma venereum (LGV) have been reported in European countries, North America, and Australia. Current LGV cases have been caused by Chlamydia trachomatis serovar L2. This sexually transmitted infection is predominantly found among men who have sex with men, specifically men who are seropositive for human immunodeficiency virus and have clinical signs of proctitis. The current outbreak has been almost exclusively attributed to a new variant, designated L2b. Although urogenital cases of LGV have been described in the heterosexual population, we report the first case of C. trachomatis L2b proctitis in a woman.

Rectal lymphogranuloma venereum surveillance in France 2004-2005

Lymphogranuloma venereum (LGV) is a sexually transmitted infection (STI) caused by Chlamydia trachomatis strains belonging to the L1, L2 or L3 genotype. An alert about an outbreak of LGV among MSM in the Netherlands was published in January 2004. The first cases of rectal LGV in France were retrospectively diagnosed in March 2004 and sentinel surveillance for LGV was implemented in April 2004. Most of the participating centres were located in the cities of Paris and Bordeaux. Only confirmed rectal LGV cases were included in the surveillance. Rectal specimens from men that were found to be positive for C trachomatis by PCR were sent to the National Reference Centre for Chlamydia infection for genotyping. Simple epidemiological data provided by clinicians and genotyping results were sent to the Institut de Veille Sanitaire (InVS) where data were anonymously recorded. A total of 328 C. trachomatis rectal strains isolated in men were genotyped by the end of December 2005. Of these, 244 (74%) were LGV strains belonging to the L2 genotype. No L1 or L3 C. trachomatis genotype was found. Diagnosis was made retrospectively for 46 cases. The median age of patients with LGV was 39 years. HIV status was known for 96 patients: 82/96 (85%) were HIV-infected. Most LGV cases were diagnosed in the Paris area (92%). Among the remaining 26% C. trachomatis strains, genotypes Da and G were the most frequent. As with syphilis in recent years, the emergence of LGV in Europe is mainly affecting HIV-infected MSM. The screening and treatment of STIs should be included in the clinical follow-up of all HIV-infected MSM.

Rectal lymphogranuloma venereum, France.

To the Editor: Lymphogranuloma venereum (LGV), a sexually transmitted disease (STD) caused by Chlamydia trachomatis serovars L1, L2, or L3, is prevalent in tropical areas but occurs sporadically in the western world, where most cases are imported (1). LVG commonly causes inflammation and swelling of the inguinal lymph nodes, but it can also involve the rectum and cause acute proctitis, particularly among men who have sex with men. However, LGV serovars of C. trachomatis remain a rare cause of acute proctitis, which is most frequently caused by Neisseria gonorrhoeae or by non-LGV C. trachomatis (2). In 1981, in a group of 96 men who have sex with men with symptoms suggestive of proctitis in the United States, Quinn et al. found that 3 of 14 C. trachomatis infections were caused by LGV serovar L2 (3). In France, 2 cases of rectal LGV were reported in an STD clinic in Paris from 1981 to 1986 (4). In 2003, an outbreak of 15 rectal LGV cases was reported among men who have sex with men in Rotterdam; 13 were HIV-infected, and all reported unprotected sex in neighboring countries, including Belgium, France, and the United Kingdom (5). At the same time, a rise in C. trachomatis proctitis (diagnosed by using polymerase chain reaction [PCR]; [Cobas Amplicor Roche Diagnostic System, Meylan, France]) was detected in 3 laboratories in Paris and in the C. trachomatis national reference center located in Bordeaux. To identify the serovars of these C. trachomatis spp., all stored rectal specimens were analyzed by using a nested omp1 PCR-restriction fragment length polymorphism assay. The amplified DNA product was digested by restriction enzymes. Analysis of digested DNA was performed by electrophoresis. Patterns were compared visually with reference patterns (6). From January 1, 2003, to March 31, 2004, a total of 44 of 124 male rectal swabs were positive for C. trachomatis. Of those, 38 were identified as belonging to the L2 serotype, which confirms the diagnosis of rectal LGV. Epidemiologic information was retrospectively obtained by clinicians through review of medical records, telephone interview, or both. A complete history was available for 14 of the 38 cases. All 14 men reported unprotected anal sex with anonymous male sex partners in France, and none reported a stay in an LGV-endemic area. Their mean age was 40 years (31–50); 8 were HIV-infected, and 9 had another concomitant STD. The mean duration of symptoms before LGV diagnosis was 50 days (range 11–120 days). All 14 patients had symptoms of acute proctitis, including rectal pain, discharge, and tenesmus, and 3 (all HIV-infected) had fever. Deep, extended rectal ulcerations were reported in 8 patients, 3 of whom were HIV-infected and had lesions suggestive of rectal carcinoma. In 1 patient in whom a late diagnosis was made 4 months after the onset of symptoms, a rectal tumorlike stricture was observed. All 14 patients were treated with tetracycline for a mean duration of 16 days (range 10–60 days). An information campaign among microbiologists and clinicians and a sentinel LGV surveillance system were launched in April 2004. Subsequently, LGV was diagnosed in 65 additional male patients, some retrospectively. In total, rectal LGV was diagnosed in 103 patients from July 2002 to August 2004 (Figure). Figure Number of rectal lymphogranuloma venereum cases diagnosed in men in France, July 2002–August 2004. Prompt diagnosis and treatment is indeed paramount to prevention and control. Diagnosis may be further hampered because rectal LGV may mimic other conditions such as rectal carcinoma or Crohn disease. Treatment duration should be no shorter than 21 days, and follow-up examinations should be conducted until all signs and symptoms have resolved (7,8). If left untreated, rectal LGV could lead to serious complications such as rectal stricture (1). If recently exposed to infection, sexual contacts should receive prophylactic treatment to prevent reinfection and to eliminate a potential reservoir. The emergence of rectal LGV, characterized by deep mucosal ulcerations and frequently occurring in HIV-infected men who have sex with men, is a serious concern for the gay community in Europe.

Screening of Volunteer Students in Yaounde (Cameroon, Central Africa) for Chlamydia trachomatis Infection and Genotyping of Isolated C. trachomatis Strains

ABSTRACT The prevalence of Chlamydia trachomatis infection was 3.78% out of 1,277 volunteer students screened by direct fluorescence assay and Cobas Amplicor PCR. The infection was associated with the nonuse or inconsistent use of condoms in women (P = 0.026) and a previous sexually transmitted infection in men (P = 0.023). The most frequent genotypes determined by sequencing the omp1 genes of 25 clinical isolates were E (44%) and F (20%), and some strains harbored mutations, but E genotype strains did not.

Culture-Negative Endocarditis Due to Chlamydia pneumoniae

ABSTRACT We report on the case of a 54-year-old woman diagnosed as having culture-negative endocarditis (clinical and histopathologic evidence compatible with a recent episode of endocarditis). The responsibility of Chlamydia pneumoniae in this episode of endocarditis was suggested by a serological study and was then confirmed by the positive results of PCR and in situ hybridization tests with aortic and mitral valves tissues. To our knowledge, this is the first case of endocarditis due to C. pneumoniae confirmed by molecular biology-based techniques.

Effects of antibiotics on Chlamydia trachomatis viability as determined by real-time quantitative PCR.

The objective of this study was to determine the effect of antibiotics on Chlamydia trachomatis viability by using a quantitative real-time PCR assay that measured DNA replication and mRNA transcription of the structural omp1 and omp2 genes, 16S rRNA and the groEL1 gene with and without antibiotics. Ofloxacin, moxifloxacin, azithromycin and doxycycline were tested against the serovar D and L2 reference strains and a derivative mutant resistant to fluoroquinolones, L2-OFXR, obtained by in vitro selection. Using DNA quantification, the antibiotic MIC was calculated when the number of DNA copies was equal to that of the chlamydial inoculum at time zero. This method allowed the easy determination of MICs by DNA quantification of the four selected genes and gave similar results to those obtained by immunofluorescence staining without biased interpretation. By using cDNA quantification, the lowest antibiotic concentration for which no RNA was transcribed corresponded to the minimum bactericidal concentration. C. trachomatis still transcribed the16S rRNA and groEL1 genes, even at concentrations well above the MIC, showing a bacteriostatic effect for all antibiotics tested. This method allows the study of antibiotic activity on growth and viability of C. trachomatis by DNA and RNA quantification at the same time without additional cell-culture passaging.

MLVA subtyping of genovar E Chlamydia trachomatis individualizes the Swedish variant and anorectal isolates from men who have sex with men.

This study describes a new multilocus variable number tandem-repeat (VNTR) analysis (MLVA) typing system for the discrimination of Chlamydia trachomatis genovar D to K isolates or specimens. We focused our MLVA scheme on genovar E which predominates in most populations worldwide. This system does not require culture and therefore can be performed directly on DNA extracted from positive clinical specimens. Our method was based on GeneScan analysis of five VNTR loci labelled with fluorescent dyes by multiplex PCR and capillary electrophoresis. This MLVA, called MLVA-5, was applied to a collection of 220 genovar E and 94 non-E genovar C. trachomatis isolates and specimens obtained from 251 patients and resulted in 38 MLVA-5 types. The genetic stability of the MLVA-5 scheme was assessed for results obtained both in vitro by serial passage culturing and in vivo using concomitant and sequential isolates and specimens. All anorectal genovar E isolates from men who have sex with men exhibited the same MLVA-5 type, suggesting clonal spread. In the same way, we confirmed the clonal origin of the Swedish new variant of C. trachomatis. The MLVA-5 assay was compared to three other molecular typing methods, ompA gene sequencing, multilocus sequence typing (MLST) and a previous MLVA method called MLVA-3, on 43 genovar E isolates. The discriminatory index was 0.913 for MLVA-5, 0.860 for MLST and 0.622 for MLVA-3. Among all of these genotyping methods, MLVA-5 displayed the highest discriminatory power and does not require a time-consuming sequencing step. The results indicate that MLVA-5 enables high-resolution molecular epidemiological characterisation of C. trachomatis genovars D to K infections directly from specimens.

Evaluation of the combination of the NucliSENS easyMAG® and the EasyQ® applications for the detection of Mycoplasma pneumoniae and Chlamydia pneumoniae in respiratory tract specimens

Mycoplasma pneumoniae and Chlamydia pneumoniae are respiratory tract pathogens frequently involved in community-acquired pneumonia, but are fastidious microorganisms. Their direct detection mainly requires molecular amplification techniques. A nucleic acid extraction system, NucliSENS easyMAG®, and a real-time nucleic acid sequence-based amplification (NASBA) technique, NucliSENS EasyQ®, were recently developed by bioMérieux to detect both bacteria. The aim of our study was to compare the easyMAG/EasyQ combination with our in-house combination, MagNA Pure extraction (Roche) and real-time polymerase chain reaction (PCR), to detect both bacteria in respiratory tract specimens. The analytical specificities of both combinations were similar. A higher analytical sensitivity was found for C. pneumoniae using the easyMAG/EasyQ combination, since the easyMAG/EasyQ system detected nucleic acid extracts 106 times more diluted than the in-house combination. Both combinations were equivalent when detecting M. pneumoniae in positive respiratory tract samples. Finally, the easyMAG/EasyQ combination is a potential useful tool for the detection of both bacteria regarding sensitivity, specificity, monitoring, and standardization of the procedure.