Arabella Touati

The spread of Mycoplasma pneumoniae is polyclonal in both an endemic setting in France and in an epidemic setting in Israel.

Mycoplasma pneumoniae infections occur both endemically and epidemically, and macrolide resistance has been spreading for 10 years worldwide. A substantial increased incidence of M. pneumoniae infections has been reported in several countries since 2010. Whether this increased incidence is attributed to different or to the same M. pneumoniae genotype is unknown. We have developed a multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) for the molecular typing of M. pneumoniae isolates. In this study, the MLVA typing method was modified and validated to be applicable directly to respiratory tract specimens without culture. This method was applied to 34 M. pneumoniae-positive specimens received at the Bordeaux Hospital, France, between 2007 and 2010 in an endemic setting, and to 63 M. pneumoniae-positive specimens collected during an epidemic surge of M. pneumoniae infections in 2010 in Jerusalem, Israel. The M. pneumoniae endemic spread was shown to be polyclonal in France, with 15 MLVA types identified. Strikingly, the Israeli epidemic surge was also a multi-clonal phenomenon, with 18 circulating MLVA types. The macrolide resistance-associated substitution, A2058G, was found in 22% of the Israeli patients. Macrolide-resistant M. pneumoniae belonged to four MLVA types, the MLVA type Z being the most frequent one. An association between the MLVA type Z and macrolide resistance might exist since macrolide resistance was present or generated during the course of illness in all patients infected with this MLVA type. In conclusion, the discriminatory power of the MLVA showed that the spread of M. pneumoniae strains in France in an endemic setting was polyclonal as well as the surge of M. pneumoniae infections in Israel in 2010.

Direct Detection of Macrolide Resistance in Mycoplasma genitalium Isolates from Clinical Specimens from France by Use of Real-Time PCR and Melting Curve Analysis

ABSTRACT Mycoplasma genitalium is a sexually transmitted organism commonly treated with azithromycin. However, macrolide resistance has been reported and is associated with point mutations in the 23S rRNA gene. To evaluate the prevalence of macrolide resistance in M. genitalium isolates from clinical specimens from France, we first used a previously reported high-resolution melting assay. Because susceptible and resistant M. genitalium isolates were hardly discriminated in M. genitalium-positive clinical specimens, we developed a new molecular assay for the rapid detection of macrolide resistance. An assay using real-time PCR based on fluorescence resonance energy transfer (FRET) coupled with melting curve analysis was designed. The assay was first validated on characterized macrolide-resistant M. genitalium isolates and then applied to 202 urogenital M. genitalium-positive specimens collected from 178 patients from France in 2011 and 2012. Resistant genotypes were confirmed by 23S rRNA gene sequencing. Among the 202 M. genitalium-positive specimens, 155 were amplified, demonstrating a sensitivity of 76.7%. A substitution in the 23S rRNA gene was found in 14.2% of the patient samples. Nine and six patients had M. genitalium isolates with a substitution at positions 2059 and 2058, respectively. In four cases, a mixed population of wild-type and mutated M. genitalium isolates was observed. The prevalence of M. genitalium macrolide resistance has been stable in France since its detection in 2006. Our FRET PCR assay is able to discriminate between wild-type and resistant genotypes directly from clinical specimens. This assay will allow clinicians to shorten the time to the initiation of effective disease treatment.

The increased incidence of Mycoplasma pneumoniae in France in 2011 was polyclonal, mainly involving M. pneumoniae type 1 strains

An increased incidence of Mycoplasma pneumoniae infections was reported in 2011 in two cities in France, Bordeaux and Caen. Two complementary molecular typing methods, PCR-RFLP on adhesin P1 and multilocus variable number tandem repeat analysis (MLVA), were used to determine whether this phenomenon was clonal. In 2011, the percentage of M. pneumoniae-positive patients doubled in both cities compared with 2010. Macrolide resistance remained stable at 8.3% of patients. Eighteen MLVA types were identified among 94 M. pneumoniae-positive specimens, demonstrating that the phenomenon was multiclonal. Types P, J, U, X and E were the most frequent and 81.6% of the strains were adhesin P1 type 1.

Evaluation of five commercial real-time PCR assays for detection of Mycoplasma pneumoniae in respiratory tract specimens.

ABSTRACT The performances of five commercial TaqMan real-time PCR assays for the detection of Mycoplasma pneumoniae in respiratory tract specimens were evaluated in comparison with an in-house real-time PCR. All kits allowed prompt and specific results, validated by the use of an internal control. The Nanogen kit showed the best clinical sensitivity.

Prevalence of Mycoplasma pneumoniae-associated respiratory tract infections in hospitalized children: results of a 4-year prospective study in Tunis

Specific microbiologic, molecular, and serologic assays are hardly available in Tunis to confirm a suspected infection of Mycoplasma pneumoniae (MP). These diagnosis methods were used for the first time in a Tunisian prospective study to estimate the prevalence of MP infection in children and to evaluate their usefulness for diagnosis. A total of 540 children hospitalized in Tunis for lower respiratory tract infections (LRTIs) between 2005 and 2009 and 580 clinical specimens were investigated for the presence of MP by culture and by end-point polymerase chain reaction (PCR) targeting the P1 and the 16S rRNA genes. Real-time PCR was also used for MP detection on 158 respiratory samples. A total of 525 serum samples were tested for detection of MP-specific IgM and IgG. The P1 adhesin type and the antibiotic susceptibility testing were determined for the 9 clinical strains isolated during the study period. MP was detected in 33 (5.7%) clinical samples. Specific MP seropositivity was confirmed in 54 serum samples (10.3%), among which 19 (3.6%) were indicative of acute MP infection. MP infection was confirmed in 39 (7.2%) patients: 24 positive by PCR and/or culture, 10 serologically positive only, and 5 confirmed positive by both methods. MP infections occurred throughout the year with a slight decrease in autumn. The 9 MP isolates were susceptible to erythromycin, tetracycline, and ciprofloxacin, and all belonged to type I. The prevalence of MP infection in children with LRTI was 7.2% between 2005 and 2009, in Tunisia. Combination of direct detection and serology was required to enhance the clinical sensitivity of MP detection in clinical specimens.

Changing Pattern of Chlamydia trachomatis Strains in Lymphogranuloma Venereum Outbreak, France, 2010-2015.

We describe a change in the molecular epidemiology of Chlamydia trachomatis strains involved in an outbreak of rectal lymphogranuloma venereum in France during January 2010–April 2015. Until 2012, the C. trachomatis L2b strain predominated; however, starting in 2013, most cases involved the L2 strain. We also identified 4 genetic L2b ompA variants.

Phenotypic and molecular characterization of β-lactams resistance in commensal Neisseria strains isolated from neutropenic patients in Tunisia

We aimed to determine the frequency and the molecular basis of β-lactams resistance in a total of 44 commensal Neisseria strains. Bacterial identification was performed using standard biochemical tests. Genetic diversity of penA gene was studied by penA fingerprinting. Commensal Neisseria strains were represented essentially by Neisseria subflava biovar perflava (75%). Four strains (9%) were β-lactamase producers and had the blaTEM gene. TEM-type β-lactamase was characterized by blaTEM gene sequencing. PenA fingerprinting gave 32 patterns with MspI and 19 patterns with TaqI. Our strains presented an important frequency of β-lactamase production as well as a high rate of reduced susceptibility to β-lactams with an extensive genetic diversity in the penA gene polymorphism.

Surface lipoproteome of Mycoplasma hominis PG21 and differential expression after contact with human dendritic cells

AIM To assess the lipoproteins that are involved in the interaction between Mycoplasma hominis and human dendritic cells. MATERIALS & METHODS The surface lipoproteome of M. hominis PG21 was characterized by using Triton X-114 extraction and LC-MS/MS identification. The transcriptional changes in lipoprotein genes upon contact with human dendritic cells were determined by using reverse transcription quantitative PCR after identification of reference genes suitable for normalization. RESULTS A large-scale overexpression of lipoprotein genes was observed with 21 upregulated transcripts. Seven genes of unknown function were M. hominis species specific and six genes were putatively associated with increased nutrient capture from the host cell and adhesion. CONCLUSION M. hominis regulates lipoprotein gene expression and may use species-specific mechanisms during the host colonization process.

Mycoplasma pneumoniae Monoclonal P1 Type 2c Outbreak, Russia, 2013

To the Editor: Mycoplasma pneumoniae is a major cause of respiratory infections among children and young adults and is responsible for up to 40% of all community-acquired pneumonia. In 2011, an epidemic of M. pneumoniae infection was reported in several countries in Europe and Asia and in Israel that primarily involved adhesin P1 type 1 strains and only a few P1 type 2 strains (1,2). The spread of M. pneumoniae was polyclonal (1–3), except in a few semiclosed settings, such as schools (4). Recently, a new adhesin P1 type 2 variant, named 2c, was reported (5,6) and accounted for 8.3% of 96 M. pneumoniae–positive samples in Germany (7).

Dual infection with Bordetella pertussis and Mycoplasma pneumoniae in three infants: case reports

Studying pertussis-like respiratory infections, we report the cases of three infants with evidence of both Bordetella pertussis and Mycoplasma pneumoniae. Bordetella infection was identified by the real-time polymerase chain reaction (RT-PCR) of nasopharyngeal specimens. Neither B. pertussis nor B. parapertussis were recovered on the culture of nasopharyngeal aspirates (NPAs) from any subjects. M. pneumoniae etiology was diagnosed by culture and RT-PCR. The evolution was fatal for all of the subjects. We conclude that, among patients with Bordetella infection, co-infection with another respiratory pathogen is often probable, and these mixed infections might cause a more severe form of illness, sometimes leading to death.