María Soledad Ramírez

Contact Information

Office: DBH 117A

Phone: 657-278-4562


María Soledad Ramírez



PhD, University of Buenos Aires, Argentina

MSc, University of Buenos Aires, Argentina

Research Areas

Molecular mechanisms of antibiotic resistance, their dissemination, evolution, as well as impact in the morbidity and mortality of bacterial infections.

Courses Regularly Taught

General Microbiology, Advances in Microbiology


First case of human infection due to Pseudomonas fulva, an environmental bacteria isolated from cerebrospinal fluid. Almuzara M.N., Vazquez M.,Tanaka N.,Turco M.,Ramirez M.S.,Lopez E.L.,Pasteran F., Rapoport M., Procopio A., Vay C.A. J. Clinical Microbiology. 2010. 48:660-664 .

Novel insights about class 2 integrons from experimental and genomic epidemiology.Ramírez M.S, Piñeiro S., Integron Argentinian Collaborative Group, Centrón D. Antimicrob Agents Chemother 54:139213-08.

A naturally competent Acinetobacter baumannii clinical isolate as a convenient model for genetic studies. Ramirez M.S., Don M., Merkier A.K., Bistué A.J., Zorreguieta A., Centrón D., Tolmasky M.E.. J Clin Microbiol. 2010. 48: 1488-1490.

Tn7::In2-8 dispersion in multidrug resistance isolates of Acinetobacter baumannii from Chile.Ramírez M.S., Bello H., González Rocha G., Márquez C., Centrón D. RAM. 2010. 42:138-140 .

Reservoir of antimicrobial resistance determinants associated to horizontal gene transfer in clinical isolates of the genus Shewanella. Ramírez M.S., Merkier A.K., Almuzara M., Vay C., Centrón D. Antimicrob Agents Chemother . 2010. 54:4516-4517.

Aminoglycoside modifying enzymes. Ramirez M.S., Tolmasky M.E. Drug Resistance Updates 2010. 13:151-171.

Increasing frequency of class 1 and 2 integrons in multidrug resistant clones of Acinetobacter baumannii reveals the need for continuous molecular surveillance. Ramírez M.S., Stietz M.S., Vilacoba E., Jeric E.P., Limansky A.S., Catalano C., Centrón D. Int J Antimicrob Agents. 2011. 37:175-177

Genomic Analysis of Acinetobacter baumannii A118 by Comparison of Optical Maps: Identification of Structures Related to its Susceptibility Phenotype. RamirezM.S ., AdamsM.D., BonomoR.A., CentrónD., and Tolmasky M.E. Antimicrob Agents Chemother . 2011. 55:1520-1526.

First Case of Fulminant Sepsis due to Wohlfahrtiimonas chitiniclastica. Almuzara M.N., Palombarani S., Tuduri A., Figueroa S., Gianecini A., Sabater L., Ramírez M.S., Vay C.A. J Clin Microbiol. 2011. 49:2333-2335.

Acinetobacter baumannii is able to gain and maintain a plasmid harbouring In35 found inEnterobacteriaceae isolates from Argentina. Ramírez M.S., Merkier A.K., Quiroga M.P., Centrón D. Current Microbiology. 2012. 64: 211-213.

Class 2 integrons dissemination among multidrug resistance (MDR) clones of Acinetobacter baumannii. Ramírez M.S., Morales A., Vilacoba E., Marquez C., Bello H., Argentinian Integron Study Group, Centrón D. Current Microbiology. 2012. 64: 290-293.

Recurrent Urinary Infection with Bifidobacterium scardovii. Barberis C., Cittadini R., Almuzara M., Feinsilberg A., Famiglietti A., Ramírez M.S., Vay C. J. Clinical Microbiol. 2012. 50:1086-1088.

Multidrug resistant (MDR) Klebsiella pneumoniae clinical isolates: a zone of high heterogeneity (HHZ) as a tool for epidemiological studies. Ramírez, M.S., Xie G., Marshall S., Hujer K., Chain P., Bonomo R.A., Tolmasky M.E. Clin Microbiol Infect. 2012. 18: E254-E258.

Class 1 integrons in environments with different degrees of urbanization. Nardelli M., Scalzo P.M., Ramírez M.S., Quiroga M.P., Cassini M.H., Centrón D. PLoS One. 2012. 7: e39223.

Transposons and integrons in colistin resistant clones with epidemic or sporadic behavior. Arduino S., Quiroga M.P., Ramírez M.S., Merkier A.K., Errecalde L., Di Martino A., Smayevsky J., Kaufman S., Centrón D. J Med Microbiol. 2012. 61:1417-20.

First Report of an Extensive Drug-Resistant VIM-2 Metallo-β-Lactamase-ProducingBrevundimonas diminuta Clinical Isolate. Almuzara M., Barberis C., Rodriguez C., Famiglietti A., Ramírez M. S., Vay C.. J. Clin Microbiol. 2012. 50:2830-2832.

Achromobacter xylosoxidans : An Emerging Pathogen Carrying Different Elements Involved In Horizontal Genetic Transfer. Traglia G.M., Almuzara M., Merkier A.K., Adams C., Galanternik L., Vay C., Centrón D., Ramírez M.S. Current Microbiol. 2012. 65:673-678.

Internalization of locked nucleic acids/DNA hybrid oligomers into Escherichia coli. Traglia G.M., Davies Sala C., Fuxman Bass J.I., Soler-Bistué A.J.C., Zorreguieta A., Ramírez M.S.,Tolmasky M.E. Biores Open Access. 2012. 1: 260-263.

First Isolation of Kerstersia gyorium from a Patient with Cholesteatomatous Chronic Otitis Media. Almuzara M., Barberis C., Traglia G., Martinez Ordoñez A., Famiglietti A., Ramirez M.S., Vay C. J. Clinical Microbiol. 2012. 50: 3809-3811.

Emergence and spread of tet(B)::ISCR2 plasmid-borne in minocycline resistanceAcinetobacter baumannii isolates. Vilacoba E., Almuzara M., Gulone. L, Traglia G., Figueroa S.A., Sly G., Fernández A., Centrón D., Ramírez M.S. Antimicrob Agents Chemother. 2013. 57: 651-654

Acinetobacter baumannii extensively drug resistant lineages in Buenos Aires hospitals differ from the international clones I-III, and emerge from their susceptible ancestors. Stietz M.S.,Ramírez M.S., Vilacoba E., Merkier A.K., Limansky A.S., Centrón D., Catalano M. Infect Genet Evol. 2013. 14C: 294-301.

 Spreading of AbaR-type genomic islands in multidrug resistance Acinetobacter baumannii strains belonging to other than the prevalent clonal complexes. Ramírez M.S., Vilacoba E., Stietz M.S., Merkier A.K., Limansky A.S., Márquez C., Catalano M., Bello H., Centrón. Current Microbiology. 2013: 67: 9-14.

OXA-258 from Achromobacter ruhlandii: a Species Specific Marker. Papalia M., Almuzara M., Cejas D., Traglia G., Ramirez M.S., Galanternik L., Vay C., Gutkind G., Radice M. J. Clinical Microbiol. 2013. 51: 1602-1605.

Genome Sequences of two Klebsiella pneumoniae isolates from different geographical regions: Argentina (JHCK1) and the United States (VA360). Xie G., Ramirez M.S., Marshall S., Hujer K., Chien-Chi Lo, Johnson S., Po-E Li, Davenport K., Endimiani A., Bonomo R., Tolmasky M., Chain P. 2013. 2013. Genome Announcements, 1(2). doi:pii: e00168-13. 10.1128/genomeA.00168-13.

Intra-abdominal Infections Due to Comamonas kerstersii. Almuzara M., Cittadini R., Vera Ocampo C., Bakai R., Traglia G., Ramirez M.S., Del Castillo M., Vay C. 2013. J. Clinical Microbiol. 2013. 51: 1998-2000.

Rise and dissemination of aminoglycoside resistance: the aac(6')-Ib paradigm.  Ramírez M.S., Nikolaidis N., Tolmasky M.E. Frontiers in Antimicrobials, Resistance and Chemotherapy. 2013. doi: 10.3389/fmicb.2013.00121: 1-13

Distribution of allelic variants of the chromosomal gene bla OXA-114-like in Achromobacter xylosoxidans clinical isolates. 2013. Traglia G., Almuzara M., Merkier A.K., Papalia M., Radice M., Vay C., Centrón D., Ramírez M.S . Current Microbiol. 2013. 67:596-600.

Actinobaculum schaalii causing urinary tract infections: report of four cases from Argentina. Barberis C., Cittadini R., del Castillo M., Acevedo P., García Roig C., Ramírez M.S., Pérez S. Almuzara M., Vay C. J. Infection in Developing Countries. 2013. 8:240-244.

A cointegrate-like plasmid that facilitates dissemination by conjugation of the extended spectrum β-lactamase CTX-M-17. Lin D., Ramírez M.S., Tran T., Tolmasky M.E. Antimicrob Agents and Chemother. 2013. 57: 5191-5192

Bacteremia caused by an Acinetobacter junii strain harboring class 1 integron and diverse DNA mobile elements. 2013. Traglia G.M., Almuzara M., Vilacoba E., Tuduri A., Neumann G., Pallone E., Centrón D., Ramírez M.S. J Infect Dev Ctries 2014. 8: 666-669.

Outbreak of extensively drug-resistant Acinetobacter baumannii indigo-pigmented strains. Vilacoba, E., Almuzara M., Gulone L., Rodriguez R, Pallone E., Bakai R., Centrón D, Ramírez M.S. J. Clinical Microbiol. 2013. 51: 3726-3730.

Streptococcus lutetiensis Bacteremia. First Clindamycin Resistant Isolate Carrying lnuB Gene. Almuzara M., Bonofiglio L., Cittadini R., Vera Ocampo C., Montilla A., Del Castillo M.,Ramirez M.S., Mollerach M., Vay C.. J. Clinical Microbiol. 2013. 51: 4259-4261.

Presence of OXA-type enzymes in Achromobacter insuavis and A. dolens. Traglia G.M., Papalia M., Almuzara M., Gutkind G., Centrón D., Vay C., Radice, Ramírez M.S. Accepted to be published in Current Microbiol 2014.

Inhibition of Aminoglycoside 6'-N-Acetyltransferase Type Ib by Zinc: Reversal of Amikacin Resistance in Acinetobacter baumannii and Escherichia coli by a Zinc Ionophore. Lin D., Tran T., Alam J., Herron S., Ramírez M.S., Tolmasky M.E. Accepted to be published in Antimicrob Agents and Chemother 2014.

Comparison of the Bruker MALDI-TOF Mass Spectrometry system and conventional phenotypic methods for identification of Gram-positive rods. Barberis C., Almuzara M., Join-Lambert O., Ramírez M.S., Famiglietti A., Vay C. PloS One. 2014 Sep 3;9(9):e106303. doi: 10.1371/journal.pone.0106303. eCollection 2014.

Genome Sequences of Two Carbapenemase-Resistant Klebsiella pneumoniae ST258 Isolates. Ramírez M.S., Xie G, Johnson S., Davenport K., van Duin D., Perez F., Bonomo R., Chain P., and Tolmasky M.E.. Genome Announc. 2014 2(3). pii: e00558-14. doi: 10.1128/genomeA.00558-14.

Whole-Genome Sequence Analysis of the Naturally Competent Acinetobacter baumanniiClinical Isolate A118. Traglia G.M., Chua K., Centrón D., Tolmasky M.E., Ramírez M.S.Genome Biol Evol. 6(9):2235-9. doi: 10.1093/gbe/evu176.

Plasmid-mediated antibiotic resistance and virulence in Gram-negatives: the Klebsiella pneumoniae paradigm. Ramirez M.S., Traglia G.M., Lin D.L., Tran T., Tolmasky M.E. Microbiology Spectrum, in press.

Draft Genome Sequence of an of extensively drug-resistant Acinetobacter baumannii indigo-pigmented strain. TragliaG.M., VilacobaE., AlmuzaraM., DianaL., Iriarte A., CentrónD.,Ramírez M.S.. Genome Announcements October 2014. 2: 6 e01146-14

Draft Genome Sequence of an international clonal lineage 1 (ICL1) Acinetobacter baumanniiStrain from Argentina. Vilacoba E., Déraspe M., Traglia G.M., Roy P.H., Ramírez M.S., Centrón D. Genome Announcements. 2014. 2(6). pii: e01190-14. doi: 10.1128/genomeA.01190-14.

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