Geographic divergence of methicillin-resistant Staphylococcus aureus ST5-SCCmecI in the aftermath of a major earthquake and tsunami: impact of a plasmid harboring heavy metal resistance genes

Autores organización

• 

  Jinnethe Cristina Reyes Manrique

  Autor

• 

  Lina Paola Carvajal Ortiz

  Autor

• 

  Sandra Liliana Rincon Nuñez

  Autor

Autores

• Martínez J.R.W.
• Alcalde-Rico M.
• Jara-Videla E.
• Ríos R.
• Diaz L.
• Quesille-Villalobos A.
• Riquelme-Neira R.
• Rivas L.
• Moustafa A.M.
• Hanson B.
• Undurraga E.A.
• Olivares-Pacheco J.
• García P.
• Araos R.
• Planet P.J.
• Arias C.A.
• Munita J.M.

Unidades de investigación

• Unidad de Genética y Resistencia Antimicrobiana UGRA

Resumen

Methicillin-resistant Staphylococcus aureus (MRSA) is a major public health menace. The global spread of MRSA is characterized by successive waves of epidemic clones dominating specific geographical regions. The acquisition of genes encoding resistance to heavy metals (HMRGs) is thought to be a key feature in the geographic divergence of MRSA. However, the cause-effect relationship between the presence of HMRGs and the divergence of MRSA clones remains to be clarified. In this study, we assessed the role that HMRGs may have played in the evolutionary divergence of the MRSA ST5-SCCmecI lineage in Latin America. We conducted a genomic characterization of 113 MRSA clinical isolates from six Latin American healthcare centers, including 53 isolates collected from two cities in Chile (Santiago and Concepción). We found a plasmid (pSCL4752) harboring arsenic, cadmium, and mercury resistance genes in 65% (n = 71) of the ST5-SCCmecI isolates. We also observed a geographic divergence associated with the presence of pSCL4752 in Chilean isolates, with a higher frequency in isolates from Concepción (88%) compared to Santiago (29%). Interestingly, a molecular clock analysis revealed that this divergence occurred in the aftermath of an 8.8 Mw earthquake and tsunami that struck the Concepción area in 2010. Moreover, our results demonstrate that the carriage of pSCL4752 can be beneficial or detrimental for ST5-SCCmecI isolates, depending on the environmental availability of these heavy metals. Our results suggest that the divergence of the ST5-SCCmecI MRSA lineage in Latin America could have been fostered by environmental disasters and influenced by the presence/absence of HMRGs harbored in a plasmid. Copyright © 2025 Martínez et al.

Keywords

• Anti-Bacterial Agents; Chile; Earthquakes; Humans; Metals, Heavy; Methicillin-Resistant Staphylococcus aureus; Plasmids; Staphylococcal Infections; Tsunamis; arsenic; cadmium; cephalosporin derivative; ciprofloxacin; clindamycin; cotrimoxazole; erythromycin; fosfomycin; gentamicin; heavy metal; linezolid; penicillin derivative; quinolone derivative; rifampicin; tetracycline; tetracycline derivative; vancomycin; virulence factor; antiinfective agent; heavy metal; aminoglycoside resistance; antibiotic resistance; antibiotic sensitivity; Article; bacterial virulence; bacterium identification; bacterium isolation; bioinformatics; broth dilution; chromosomal mapping; controlled study; DNA extraction; earthquake; epidemic doubling time; evolutionary adaptation; gene mutation; genetic variability; geographic distribution; methicillin resistant Staphylococcus aureus; minimum inhibitory concentration; multilocus sequence typing; nonhuman; phylogenetic tree; phylogenomics; phylogeny; real time p