Maria Soledad Ramirez

 

Photograph of Maria Soledad Ramirez Identification and characterization of antibiotic resistance mechanisms, their dissemination, evolution and impact in morbidity and mortality of bacterial infections

We are in the midst of a dramatic antibiotic resistance outbreak that has spread across the world. The World Health Organization has recently identified this problem as a public health priority (http://www.who.int/drugresistance). Research on the different causes of antibiotic resistance in clinical and non-clinical environments is urgently required to develop strategies to contain or overcome this problem. Our laboratory focuses on identifying mechanisms of antibiotic resistance, and understanding their evolution, means of dissemination across different genera, and impact in the morbidity and mortality of bacterial infections.

We place special emphasis on Acinetobacter baumannii, an important cause of high mortality nosocomial infections worldwide. A. baumannii’s infections are becoming increasingly difficult to treat, and in some cases they are untreatable as there are no antibacterial options left. The rapid increase in antibiotic resistance is due to the extreme genome plasticity of A. baumannii. Therefore, understanding of the molecular mechanisms by which this bacterium acquires and exchanges genetic information is to understand the physiology and virulence of this bacterium to devise new treatments.

Considering that A. baumannii is one of the most troublesome pathogens for its remarkable capability to acquire antibiotic resistance, explore the genetic basis of the antibiotic resistance; its acquisition and its dissemination will help to clarify the mechanisms that are playing a role not only in the development of antibiotic resistance, but also in the acquisition of the new determinants that allow A. baumannii to survive in extreme environments and drives to genome diversification.



Selected publications (Click for full list)

Mezcord, V., Escalante, J., Nishimura, B., Traglia, G. M., Sharma, R., Valle, Q., . . . Ramirez, M. S. (2023). Induced Heteroresistance in Carbapenem-Resistant Acinetobacter baumannii (CRAB) via Exposure to Human Pleural Fluid (HPF) and Its Impact on Cefiderocol Susceptibility. Int J Mol Sci, 24(14). doi:10.3390/ijms241411752

Mezcord, V., Wong, O., Pasteran, F., Corso, A., Tolmasky, M. E., Bonomo, R. A., & Ramirez, M. S. (2023). Role of beta-lactamase inhibitors on cefiderocol activity against carbapenem-resistant Acinetobacter species. Int J Antimicrob Agents, 61(1), 106700. doi:10.1016/j.ijantimicag.2022.106700

Ngo, D., Magana, A. J., Tran, T., Sklenicka, J., Phan, K., Eykholt, B., . . . Tolmasky, M. E. (2023). Inhibition of Enzymatic Acetylation-Mediated Resistance to Plazomicin by Silver Ions. Pharmaceuticals (Basel), 16(2). doi:10.3390/ph16020236

Nishimura, B., Escalante, J., Mezcord, V., Tuttobene, M. R., Subils, T., Actis, L. A., . . . Ramirez, M. S. (2023). Human serum albumin-induced modification of Ton-B-dependent receptor expression in cefiderocol-exposed carbapenem-resistant Acinetobacter baumannii. Int J Antimicrob Agents, 62(5), 106950. doi:10.1016/j.ijantimicag.2023.106950

Rodriguez, C., Ramlaoui, D., Georgeos, N., Gasca, B., Leal, C., Subils, T., . . . Ramirez, M. S. (2023a). Antimicrobial activity of the Lacticaseibacillus rhamnosus CRL 2244 and its impact on the phenotypic and transcriptional responses in carbapenem resistant Acinetobacter baumannii. Sci Rep, 13(1), 14323. doi:10.1038/s41598-023-41334-8

Rodriguez, C., Ramlaoui, D., Georgeos, N., Gasca, B., Leal, C., Subils, T., . . . Ramirez, M. S. (2023b). Phenotypic and transcriptional analysis of the antimicrobial effect of lactic acid bacteria on carbapenem-resistant Acinetobacter baumannii: Lacticaseibacillus rhamnosus CRL 2244 an alternative strategy to overcome resistance?". Res Sq. doi:10.21203/rs.3.rs-3151881/v1

Solar Venero, E. C., Galeano, M. B., Luqman, A., Ricardi, M. M., Serral, F., Fernandez Do Porto, D., . . . Tribelli, P. M. (2023). Fever-like temperature impacts on Staphylococcus aureus and Pseudomonas aeruginosa interaction, physiology, and virulence both in vitro and in vivo. bioRxiv. doi:10.1101/2023.03.21.529514

Traglia, G., Ramirez, M. S., & Tolmasky, M. E. (2023). Role of Xer site-specific recombination in the genesis of pJHCMW1: an evolutionary hypothesis. J Glob Antimicrob Resist, 34, 199-201. doi:10.1016/j.jgar.2023.07.017

Traglia, G. M., Pasteran, F., Escalante, J., Nishimura, B., Tuttobene, M. R., Subils, T., . . . Ramirez, M. S. (2023). Genomic Comparative Analysis of Two Multi-Drug Resistance (MDR) Acinetobacter baumannii Clinical Strains Assigned to International Clonal Lineage II Recovered Pre- and Post-COVID-19 Pandemic. Biology (Basel), 12(3). doi:10.3390/biology12030358

Traglia, G. M., Rodriguez, C., Leal, C., Gasca, B., Aziz, A., Lopez, C., . . . Ramirez, M. S. (2024). Draft genome sequence of Lacticaseibacillus rhamnosus CRL 2244, a strain with strong killing effect on carbapenem-resistant Acinetobacter baumannii. Microbiol Resour Announc, 13(1), e0089223. doi:10.1128/mra.00892-23