Haemophilus spp., an emerging multidrug-resistant sexually transmitted pathogen

OBJECTIVES

To describe the characteristics of patients with a positive urethral sample for Haemophilus spp.

MATERIAL AND METHODS

We performed a retrospective study from January 2018 to July 2019 at the Bordeaux university hospital (France) of all urethral samples positive for Haemophilus spp.

RESULTS

Haemophilus spp. was isolated in 10 urethral samples from nine patients. The mean age was 33.8 years. Most patients reported having unprotected sex. Haemophilus parainfluenzae was isolated in nine samples, and Haemophilus influenzae in one sample. Antibiotic susceptibility tests were performed in five samples; Haemophilus spp. was always resistant to amoxicillin and tetracycline. One patient had persistent symptoms after treatment for a multidrug-resistant Haemophilus parainfluenzae strain.

CONCLUSION

Haemophilus spp. is a rare pathogen of urethritis. Its responsibility should be considered in case of persistent symptoms. The emergence of multidrug-resistant Haemophilus spp. is becoming problematic.

MOLECULAR TYPING OF MYCOBACTERIUM KANSASII — A GLOBAL PERSPECTIVE

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Observational study of anorectal Chlamydia trachomatis infections in France through the lymphogranuloma venereum surveillance network, 2010-2015

The objective of this article is to describe the epidemiology of lymphogranuloma venereum (LGV) and non-LGV Chlamydia trachomatis anorectal infections in France and to examine the characteristics of the affected populations via a voluntary sentinel surveillance system for LGV between 2010 and 2015. Anorectal samples positive for C. trachomatis (CT) were sent by the participating laboratories to the National Reference Center for CT for LGV identification. Biological and clinical data were collected by biologists and clinicians. There were 1740 LGV episodes and 2248 non-LGV episodes. Continuous monitoring highlighted a sharp increase in the number of LGV and non-LGV anorectal infections, which were 2.3-fold and 6.5-fold, respectively. Most of the infections occurred in men who have sex with men. LGV patients were older than non-LGV patients and were more frequently human immunodeficiency virus (HIV)-positive compared to non-LGV patients. Anorectal LGV was significantly associated with residence in Paris, HIV co-infection, concurrent syphilis and bloody anal discharge. Undocumented patient characteristics were strongly associated with anorectal LGV. The anorectal LGV epidemic is poorly controlled in France. Early detection and prompt treatment of patients and their sexual partners are required to prevent transmission in the context of pre-exposure prophylaxis (PrEP) for HIV infection.

Impact of the introduction of a nucleic acid amplification test for Clostridium difficile diagnosis on stool rejection policies

Background

The change from non-molecular to nucleic acid amplification tests (NAATs) is known to increase the detection of Clostridium difficile infection (CDI); however, the impact on stool rejection policies in clinical laboratories is unclear. The current guidelines have reinforced the importance of respecting strict conditions for performing tests on stool samples for CDI diagnosis. The purpose of this study was to estimate whether the implementation of molecular tests has resulted in changes in stool rejection policies between clinical laboratories that introduced NAATs and those that did not.

Results

A survey was conducted to evaluate the change in the number of stool samples rejected and the rejection criteria among 12 hospital laboratories in southwestern France before and after the switch from non-molecular tests to NAATs using retrospective data from June 1 till September 30, 2013 and the same period 2014. Four laboratories introduced NAATs as a second or third step in the process. A total of 1378 and 1297 stools samples were collected in 2013 and 2014, respectively. The mean number of rejected stool samples significantly increased (p < 0.001, Chi square test), with a total of 99 (7.1%) and 147 (11.3%) specimens rejected in 2013 and 2014, respectively. Notably, these laboratories had more stringent criteria and were no longer testing the stool samples of patients with CDI-positive results within 7 days. In contrast, there was a significant decrease in the rate of rejected stool samples (p < 0.001, Chi square test) in the five laboratories that did not adopt NAATs and a less stringent stool rejection policy.

Conclusion

Nucleic acid amplification test implementation improved compliance with recommended stool rejection policies. Laboratories should follow the recommended laboratory algorithm for the CDI diagnosis combined with the correct stool rejection policy.

Electronic supplementary material

The online version of this article (10.1186/s13099-018-0245-x) contains supplementary material, which is available to authorized users.

Infective endocarditis caused by Streptococcus tigurinus-like organisms

Streptococcus species are important causes of infective endocarditis but species identification remains challenging. We report two cases of infective endocarditis due to Streptococcus tigurinus-like organisms, which were first identified by 16S ribosomal RNA gene sequence analysis and subsequently confirmed using phylogeny based on the analysis of the shetA gene encoding exfoliative toxin.

The L2b real-time PCR targeting the pmpH gene of Chlamydia trachomatis used for the diagnosis of lymphogranuloma venereum is not specific to L2b strains

The French Reference Centre for chlamydiae uses two real-time PCRs targeting the pmpH gene of Chlamydia trachomatis to differentiate between L strains and variant L2b, responsible for a lymphogranuloma venereum outbreak in Europe. We compared the results obtained for 122 L2b C. trachomatis-positive specimens, using the two real-time PCRs, with the sequencing of the ompA gene. Only 91 specimens were confirmed as L2b. Our results demonstrate that the lymphogranuloma venereum outbreak is no longer dominated by the variant L2b, and that many L-positive specimens were misidentified as L2b with the method used, which raises the question of its specificity.

Screening for Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium should it be integrated into routine pregnancy care in French young pregnant women?

Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium screening during pregnancy is not performed routinely in France. We conducted the first prospective study in 1004 women attending for routine antenatal care to determine the prevalence and risk factors for these bacterial infections. The overall prevalence of C. trachomatis, N. gonorrhoeae, and M. genitalium infections was 2.5%, 0%, and 0.8%, respectively. In patients aged 18-24 years, the prevalence increased to 7.9% for C. trachomatis and to 2.4% for M. genitalium. C. trachomatis infection was associated with age ≤24 years or being single or having more than 5 sexual partners in a lifetime. M. genitalium infection was more frequent in patients aged ≤24 years or who had a history of abortion or their first sexual intercourse after 20 years of age. The high prevalence of C. trachomatis in pregnant women aged ≤24 years, mostly asymptomatic, suggests that systematic screening could be beneficial.

Development of a real-time PCR targeting the yidC gene for the detection of Mycoplasma hominis and comparison with quantitative culture

Mycoplasma hominis is an opportunistic human mycoplasma species that can be either commensal or pathogenic. Its detection by culture is considered to comprise the reference technique. Previously reported PCR techniques target the 16S rRNA or the gap gene, although sequence variations among clinical isolates may lead to variations in clinical sensitivity. The present study aimed to develop a specific TaqMan quantitative real-time PCR assay, targeting a gene conserved in all M. hominis isolates, and to compare it with quantitative culture. With the knowledge of the M. hominis PG21 genome sequence, the yidC gene, encoding a membrane protein translocase, was chosen as target. Its intraspecies heterogeneity was checked at the nucleotide level using 31 reference or clinical strains. The limit of detection, the analytical specificity and the reproducibility of the assay were assessed. Moreover, PCR and culture results were compared using 153 urogenital specimens. The limit of detection was seven copies/μL. The analytical specificity was 100%, with good inter- and intra-assay reproducibility. Among the 153 urogenital specimens, the yidC PCR and culture allowed detection of 55 and 45 M. hominis-positive samples, respectively. Comparison of the bacterial load among the 45 specimens found to be M. hominis-positive by both techniques revealed a statistically significant association between the quantitative results obtained. In conclusion, we developed a specific, sensitive and reproducible real-time PCR to detect all M. hominis clinical isolates. This PCR was shown to have higher sensitivity than culture, although both methods were correlated for quantification of M. hominis loads in urogenital specimens.

Detection and susceptibility testing of Mycoplasma amphoriforme isolates from patients with respiratory tract infections

Three isolates of Mycoplasma amphoriforme, a new Mycoplasma species rarely described to date, were obtained from respiratory tract specimens from two children and one adult with respiratory tract infections. Molecular methods were required to distinguish them from Mycoplasma pneumoniae. MICs of macrolides, tetracyclines and fluoroquinolones were identical to those for M. pneumoniae, except for that of ciprofloxacin, which was slightly more potent against M. amphoriforme. M. amphoriforme could possibly have been involved in one case of severe respiratory infection with sepsis, but further studies are needed to specify its role as a potential respiratory tract pathogen.

[Thyroglobulin mRNA detection in the follow-up of thyroid carcinomas]

The follow-up of differentiated carcinomas is based on the detection of thyroglobulin (Tg) in the serum. Tg assays are immunoassays that may be hampered by autoantibodies directed against Tg. To avoid this problem some authors advocated the use of mRNA extraction and RT-PCR amplification. Quantitative methods have been developed to achieve a good analytical sensitivity. These techniques may then be alternative to the Tg assay when anti-Tg antibodies are present in the serum should it be proven they display pronostic values reliable enough for clinical diagnosis use.