Session: EV006 Bacteroides and other anaerobes
Category: 3b. Resistance surveillance & epidemiology: Gram-negatives
22 April 2017, 08:45 - 15:30 EV0045
Prevotella timonensis: a study on seventy-seven strains isolated since 2007 at the university hospital of Montpellier, France
Salim Aberkane1, Anne-Laure Michon2, Chrislène Laurens3, Nicolas Bouzinbi4, Anaïs Suzanne Christiane Appelgren5, Marie-Noëlle Didelot6, Christian Carriere3, Sylvain Godreuil3, Hélène Jean-Pierre*3
1Chu Arnaud de Villeneuve; Hôpital Arnaud de Villeneuve; Microbiologie-Virologie
2Centre Hospitalier Régional Universitaire (Chru) de Montpellier; Hôpital Arnaud de Villeneuve; Bactériologie
3Centre Hospitalier Régional Universitaire (Chru) de Montpellier; Hôpital Arnaud de Villeneuve; Département de Bactériologie-Virologie
4Chu Arnaud de Villeneuve; Microbiologie-Virologie
5University Hospital of Montpellier; Bacteriology-Virology
6Chu Montpellier; Hôpital Arnaud de Villeneuve; Laboratoire de Bactériologie
Background: Prevotella spp. are obligatory anaerobic Gram-negative bacilli bacteria. They have been isolated from different human samples and are considered to be a part of the normal flora. They have also been involved in clinical infections. They are known to be frequently producers of beta- lactamases that can hydrolyse penicillins and cephalosporins which can be an issue in the infection therapeutic management. Previous studies report a high prevalence of Prevotella species producing beta-lactamases in Europe. However, their difficult species identification due to lack of characteristic phenotypic and biochemical traits remains an issue. Prevotella timonensis was first described in 2007, isolated from a breast abscess of a 40-year-old woman. To the best of our knowledge, there have been no other studies covering this species. In this study we report a list of clinicaly recovered isolates of P. timonensis at the University Hospital of Montpellier, South of France. Material/methods: All isolates identified as P. timonensis between January 2007 and November 2016 (ongoing study) have been investigated whether they were involved in an infection process and identified with which bacteria they were recovered. All isolates have been identified to the species level using the matrix-assisted desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) using both the standard and the The European Network for the Rapid Identification of Anaerobes (ENRIA) databases. Most of isolates were previously identified using a 16S rRNA gene sequence analysis for there has been no specific specter for P. timonensis in the MALDI-TOF database until June 2015. Susceptibility testing was performed for fifty isolates according to the standards of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) 2016. Resistance rates were calculated using the EUCAST 2016 breakpoints. β-lactamase production was investigated for the same fifty isolates using the chromogenic cephalosporin disk test.
Results: A total of seventy-seven P. timonensis have been recovered, mostly isolated from cutaneous/soft tissues (45.45%), semen (27.27%) and bone (14.28%) samples, 55.85% were part of an infectious process. A higher MALDI-TOF identification score was noticed with the ENRIA database. All isolates were recovered from multimicrobial samples. 45.45% of the tested isolates were resistant to clindamycin and 2.27% were resistant to metronidazole. β-lactamase production was noticed for 54.55% of the tested isolates.
Conclusions: This study emphasises the necessity of species identification of Prevotella timonensis strains and antibiotic susceptibility testing as they are often involved in infectious processes and can be resistant to clinically used antibiotics. The MALDI-TOF seems to be a good alternative to the 16S rRNA gene sequence analysis with a continuously updated database allowing an accurate and fast identification.