Background: Macrolide and fluoroquinolone resistance is alarmingly emerging in M. genitalium worldwide. This article provides the first estimates of the current prevalence of macrolide and fluoroquinolone resistance–mediating mutations in Barcelona, Spain, and identifies risk factors associated with the acquisition of these resistances.
Methods: The study was conducted retrospectively with specimens submitted between February 2013 and March 2014 to the microbiology department of the Vall d'Hebron Hospital, Barcelona, where M. genitalium was detected using nucleic acid amplification methods. DNA sequencing of 23S ribosomal RNA gene and parC was performed in the Statens Serum Institut, Copenhagen, to detect genotypic macrolide and fluoroquinolone resistance markers, respectively.
Results: Macrolide resistance–mediating mutations were detected in 35% (95% confidence interval, 24%-47%) of the M. genitalium–positive episodes, whereas 8% (95% confidence interval, 3%-17%) carried fluoroquinolone resistance mutations. Of them, three cases harbored multidrug resistance to both classes of antibiotics. Men who had sex with men (P = 0.002) and treatment with azithromycin within the previous 12 months (P = 0.006) were strongly associated with macrolide resistance.
Conclusion: The widespread appearance of resistances, also in Spain, makes imperative the implementation of combined diagnostic-resistance detection assays for M. genitalium to facilitate the optimization of antibiotic treatment in the management of nongonococcal urethritis and potentially reduce the transmission of resistances.
Macrolide resistance is highly prevalent in M. genitalium in Spain, and men who had sex with men and patients having received previous azithromycin are strongly associated with these resistances. Additionally, an alarming rate of fluoroquinolone resistance and the first multidrug resistances are detected.
From the *Sexually Transmitted Infections Unit Vall d'Hebron-Drassanes, Vall d'Hebron Hospital, University of Barcelona, Barcelona, Spain; †Microbiology Department, Vall d'Hebron Hospital, Universitat Autònoma de Barcelona, Barcelona, Spain; and ‡Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark
M-J.B. and M.F-H. contributed equally to this article.
The authors thank the Statistics and Bioinformatics Unit of the Research Institute of the Hospital Vall d'Hebron (VHIR) for the statistics support. The authors also thank Susanne Cramer Larsson and Christina Norgaard for the excellent technical assistance in identifying resistance mutations. The authors sincerely appreciate the dedication of the laboratory and clinical staff (especially Maider Arando, Pere Armengol, and Marti Vall), which made this research possible.
Conflict of interest and sources of funding: None of the authors have any conflicts of interest to disclose, but Statens Serum Institut performed M. genitalium mutations detection as a paid diagnostic service.
Correspondence: Antonia Andreu, MD, PhD, Microbiology Department, Hospital Vall d'Hebron, Passeig Vall d'Hebron 119-129, 08035 Barcelona, Spain. E-mail: firstname.lastname@example.org.
Received for publication December 28, 2016, and accepted March 20, 2017.