Related Experiment Video
Updated: Jun 18, 2025
Gastric Mucosa Quantitative Polymerase Chain Reaction Analysis for Detecting Helicobacter pylori and Antibiotic Resistance
Published on: March 7, 2025
The Crisis of Macrolide Resistance in Pneumococci in Latin America
Carolina Viteri-Dávila1, Diana Morales-Jadán1, Aidan Creel2
1One Health Research Group, Universidad de Las Américas, Quito, Ecuador.
Abstract:
Macrolide antibiotics are recommended for the treatment of pneumococcal pneumonia and invasive pneumococcal disease (IPD). Prior to 2000, ∼10% of Streptococcus pneumoniae strains isolated from IPD cases in Latin American countries were resistant to macrolides. The mechanism of resistance to macrolides was associated mainly with the efflux pump known as the macrolide efflux genetic assembly, since most pneumococcal strains carried the mef(A/E) gene, whereas <6% strains carried both the methylase gene ermB and mef(A/E). In the first decade of this century, a significant increase in the prevalence of macrolide resistance was observed in pneumococcal strains in both Mexico and Peru. Approximately 30% of S. pneumoniae strains in these countries were already resistant to erythromycin, while the prevalence in Colombia, Argentina, and Brazil remained below 10%. During the last decade, we have been experiencing a worrisome increase in pneumococcal strains carrying resistance to macrolides, with a prevalence of up to 80% for resistance to erythromycin. The mechanism for disseminating macrolide resistance has evolved. Currently, more than 55% of invasive S. pneumoniae macrolide-resistant strains carry both the ermB and the mef(A/E)/mel genes. Lessons learned from the current macrolide resistance crisis in Latin America can inform interventions in other regions.
Insights
Macrolide resistance in Streptococcus pneumoniae is increasing in Latin America. The primary resistance mechanism has shifted from efflux pumps to include methylase genes, impacting treatment efficacy.
Area of Science:
- Microbiology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Macrolide antibiotics are crucial for treating pneumococcal pneumonia and invasive pneumococcal disease (IPD).
- Prior to 2000, macrolide resistance in Streptococcus pneumoniae was low in Latin America, primarily mediated by the mef(A/E) gene.
- A concerning rise in macrolide resistance has been observed in recent decades.
Purpose of the Study:
- To analyze the evolution and mechanisms of macrolide resistance in Streptococcus pneumoniae in Latin America.
- To highlight the changing prevalence and genetic basis of macrolide resistance.
Main Methods:
- Review of epidemiological data on macrolide-resistant Streptococcus pneumoniae strains.
- Analysis of genetic mechanisms conferring macrolide resistance, including mef(A/E) and ermB genes.
Main Results:
- Macrolide resistance prevalence increased significantly in Mexico and Peru during the first decade of the 21st century.
- Erythromycin resistance rates reached up to 80% in the last decade.
- The prevalence of strains carrying both ermB and mef(A/E)/mel genes has increased to over 55%.
Conclusions:
- The prevalence and mechanisms of macrolide resistance in Streptococcus pneumoniae have evolved significantly in Latin America.
- The increasing prevalence of dual resistance mechanisms poses a challenge to antibiotic treatment.
- Lessons from this crisis can inform global strategies to combat antimicrobial resistance.
