Profile and evolution of resistance to beta-lactams and vancomycin in Staphylococcus aureus isolated from blood culture

• Grant number: 20/04599-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): September 01, 2020
• Effective date (End): August 31, 2022
• Field of knowledge: Biological Sciences - Microbiology - Biology and Physiology of Microorganisms
• Principal Investigator: Maria de Lourdes Ribeiro de Souza da Cunha
• Grantee: Guilherme de Lima Brenno
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

We continue to fail to contain the spread of resistance genes, which already pose a threat to the health of populations. Currently, multidrug-resistant microorganisms are already responsible for infectious conditions acquired in the community. An important example are MRSA (Methicillin-resistant Staphylococcus aureus), which represent a serious risk to public health worldwide, due to the rapid spread and diversification of pandemic clones with increasing antimicrobial resistance. MRSA are one of the main causes of nosocomial or healthcare-related infections (Healthcare-associated [HA] -MRSA), and their prevalence is increasing in community-associated infections (Community-associated [CA] -MRSA). MRSA is generated when methicillin-sensitive S. aureus (MSSA) acquires the methicillin resistance gene, mecA, exogenously transported by a mobile genetic element, mec staphylococcal chromosomal cassette (SCCmec). Resistance in S. aureus is not restricted to methicillin and other beta-lactams. In the last few years, a slow and progressive increase in low-level resistance to vancomycin has been observed, leading to failure of MRSA treatment. There is also an increase in the report of S. aureus that is intermediate sensitive or even resistant to vancomycin. Currently, recently developed drugs such as 5th generation cephalosporins can treat these resistant staphylococci, but there are already reports of reduced sensitivity to them. In view of the rapid acquisition of resistance and the high rate of infections and mortality caused by these microorganisms, studies with a significant number of samples are essential, covering long periods to assess the evolution of resistance for control and therapy. proper. Therefore, the study will aim to characterize the profile and evolution of resistance to beta-lactams and vancomycin in S. aureus isolated from blood cultures, as well as resistance to ceftaroline (fifth-generation cephalosporin).