1221. Genetic Characteristics of Healthcare-Associated Methicillin-Resistant Staphylococcus aureus (HA-MRSA) Belonging to Clonal Complex 5 (CC5) in Latin-America
Session: Poster Abstract Session: Healthcare Epidemiology: MSSA, MRSA and Other Gram Positive Infections
Friday, October 5, 2018
Room: S Poster Hall
Background: MRSA are responsible for a high proportion of healthcare-associated infections. HA-MRSA is multidrug resistant, and infections occur most frequently among inpatients, for example, those who have undergone invasive medical procedures or those aged 50 to 60 years and older. Dominance of multidrug-resistant CC5 (Chilean and New York/Japan clones) was prevalent in infections in Latin America with the notable exception of Colombia and Ecuador where USA300-LV isolates dominate. We performed genetic characterization of HA-MRSA-CC5 isolates recovered from infections in 9 countries (12 hospitals).

Methods: Species identification of S. aureus and presence of mecA were performed by PCR. We determined MICs to common anti-MRSA antibiotics and performed screening for VISA phenotype. Molecular characterization included detection of lukSF-PV and SCCmec typing. PFGE and MLST were performed in selected MRSA isolates with susceptibility patterns typical of the Chilean (ST5-MRSA-I) and USA300-LV (ST8-MRSA-IV) lineages.

Results: A total of 665 S. aureus isolates were prospectively recovered from 592 patients. A high frequency of methicillin resistance (> 40%) was observed in all countries (62%, 55%, 44% and 40% in BRA, PER, CHI and ARG, respectively). Decreased susceptibility to VAN was not observed and VAN MIC90 was 1 µg/ml. In PER and CHI, the overwhelming majority of isolates (89%) belonged to the Chilean/Cordobes clone (CC5) with susceptibility patterns typical of this lineage (Resistance to ß-Lactams, MLSB-type, quinolones and aminoglycosides). The New York/Japan clone (ST5-MRSA-II) was predominant in Brazil, replacing the prevalent hospital-associated Brazilian (ST239-MRSA-III) lineage. Most Argentinian MRSA isolates exhibiting a CA (ST5-IV) pattern, previously described in this country.

Conclusion: A variety of MRSA genetic lineages are circulating in Latin America with geographic clustering and clonal replacement. Dissemination of the CA-USA300-LV has not occurred beyond the northern region of the subcontinent.

Jinnethe Reyes, PhD1,2, Lina P Carvajal, BSc2, Rafael Rios, MSc2, Aura Echeverri, MSc2, Sandra Rincon, MSc2, Jose M Munita, MD1,3, Truc Tran, PharmD1, Diana Panesso, PhD1, Cesar Arias, MD, PhD, FIDSA1,2 and Lorena Diaz, PhD1,2, (1)Center for Antimicrobial Resistance and Microbial Genomics (CARMiG), University of Texas McGovern Medical School, Houston, TX, (2)Molecular Genetics and Antimicrobial Resistance Unit - International Center for Microbial Genomics, Universidad El Bosque, Bogota, Colombia, (3)3Genomics and Resistant Microbes (GeRM) Group, Clinica Alemana de Santiago, Universidad del Desarrollo School of Medicine, Santiago, Chile


J. Reyes, None

L. P. Carvajal, None

R. Rios, None

A. Echeverri, None

S. Rincon, None

J. M. Munita, Pfizer: Grant Investigator , Research grant .

T. Tran, None

D. Panesso, None

C. Arias, Merck & Co., Inc.: Grant Investigator , Research support . MeMed: Grant Investigator , Research support . Allergan: Grant Investigator , Research support .

L. Diaz, None

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