Clinical microbiologyClinical sources and antimicrobial susceptibility of Prevotella timonensis at the university hospital of Montpellier, France
Introduction
The Prevotella genus was created in 1990 by Shah and Collins, who described obligatory anaerobic Gram-negative rods bacteria [1]. Prevotella species have been isolated from different human samples (oral, respiratory tract, gut, urogenital tract etc.) and are considered to be a part of the normal microbiota. They have been involved in oral and non-oral infections such as bacteraemia, cervical abscesses, meningitis, and liver and spleen abscesses either alone or with other aerobic or anaerobic species [1,2]. Among anaerobes, Prevotella are known to be frequent producers of beta-lactamases, hydrolysing penicillins and some cephalosporins. Previous studies on the susceptibility profile of Prevotella species in Europe show differences between species and the need to monitor their antimicrobial resistances [1,3]. However, identification at the species level is difficult due to lack of specific phenotypic and biochemical traits and a continuous description of novel species. 16S rRNA gene sequence analysis is still the gold standard technic for their identification [4], however, it is time-consuming and expensive. Matrix-assisted desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) is a good alternative with a continuously updated database allowing accurate and fast identification [5,6].
Prevotella timonensis was first described in 2007, isolated from a breast abscess of a 40-year-old woman [2]. To the best of our knowledge, there are no other studies covering this species. In this study we report the prevalence of P. timonensis recovered between January 2007 and November 2016 at the University Hospital of Montpellier, South of France, by 1) describing their clinical sources, associated microbiota and involvement in infectious processes, and 2) performing antimicrobial susceptibility testing on the majority of the isolates.
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Bacterial isolates and identification
All clinical isolates identified as Prevotella timonensis at the University hospital of Montpellier between January 2007 and November 2016 have been included in this study. Until June 2015, identifications were performed by 16S rRNA sequence analysis as previously described [7], and has concerned 39 isolates. During that period not all Prevotella isolates were identified at the species level, therefore we may have missed some P. timonensis isolates. 26 isolates from this period were still
Results and discussion
A total of 84 Prevotella timonensis clinical isolates were isolated in our hospital during the study period (39 before June 2015 and 45 after). Isolation frequency of this species has substantially increased since we use the mass spectrometry for identification, representing 6.3% of the Prevotella strains isolated in the last six months of this study.
All isolates identified using 16S rRNA sequence analysis, and still viable after storage at −80 °C (n = 26) were identified at the species level
Conclusion
To our knowledge, this is the first retrospective study on clinical isolates of P. timonensis. It has been isolated from a variety of clinical sources, but with a predominance of genital and wound samples. They have been consistently recovered in a mixed microbiota and their involvement in infectious processes remains questionable. The identification of this species has been greatly facilitated by MALDI-TOF MS and the ENRIA database seems to be a more reliable choice. P. timonensis antibiotic
Ethical approval
Not required.
Funding
None.
Competing interests
None declared.
Acknowledgements
We thank Amélie Mauger, Raymonde Devigne, Kathija Mechalik, Laetitia Esquerre and Mathieu Puig for their technical assistance. We also thank the European Society of Clinical Microbiology and Infectious Diseases Study Group for Anaerobic Infections (ESGAI) for its involvement in this study.
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