Antibiotic selection may contribute to increases in macrolide-resistant Treponema pallidum

Area of Science:

• Microbiology
• Infectious Diseases
• Antimicrobial Resistance

Background:

• Macrolide antibiotics are crucial for treating Treponema pallidum infections.
• Emergence of macrolide resistance in Treponema pallidum poses a significant public health threat.
• Understanding the prevalence and genetic basis of macrolide resistance is essential for effective treatment strategies.

Purpose of the Study:

• To investigate the presence and evolution of the 23S rRNA mutation conferring macrolide resistance in Treponema pallidum.
• To determine if macrolide resistance is emerging in multiple Treponema pallidum strains.
• To assess the association between prior macrolide exposure and the likelihood of infection with resistant strains.

Main Methods:

• Screening of 58 Treponema pallidum isolates (2001-2005) for the 23S rRNA mutation.
• Utilizing an unrelated sequence to differentiate between Treponema pallidum strains.
• Statistical analysis to evaluate trends in resistance and risk factors.

Main Results:

• The prevalence of macrolide-resistant Treponema pallidum strains showed a statistically significant increase over the study period (P=.006).
• Patients with a history of macrolide use in the preceding year had a 2.2-fold increased risk of harboring a resistant strain (P=.02).
• The identified macrolide-resistant strains were genetically distinct, indicating resistance is not confined to a single strain lineage.

Conclusions:

• Macrolide resistance in Treponema pallidum is an increasing concern, driven by the emergence of resistance in multiple strains.
• Antibiotic pressure from macrolide use appears to be a significant factor contributing to the rise of resistant strains.
• Continued surveillance and development of alternative treatment options are necessary to combat Treponema pallidum macrolide resistance.