Staphylococcus epidermidis and Staphylococcus haemolyticus: detection of biofilm, toxins genes, antimicrobial resistance and clonal typing in isolates from blood cultures

• Grant number: 11/15396-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2012
• End date: February 28, 2014
• Field of knowledge: Biological Sciences - Microbiology - Biology and Physiology of Microorganisms
• Principal Investigator: Maria de Lourdes Ribeiro de Souza da Cunha
• Grantee: Luiza Hubinger
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Staphylococcus epidermidis and Staphylococcus haemolyticus, belonging to coagulase-negative staphylococcus group (CoNS), are the species of Staphylococcus genus most isolated from hospital bacteremias. They live symbiotically with their host, and can cause opportunist infections, mainly in immunocompromised individuals. The extensive and indiscriminate use of antibiotics is selecting resistant strains, as oxacilin, whose mechanism of resistance is often due to mecA gene, contained in a mobile genetic element, Staphylococcal Cassette Chromosome mec. Reduced susceptibility to vancomycin in CoNS, frequent in S. haemolyticus, is one of the main problems of selection of resistant strains, since this is one of the latest treatment options available. The mechanisms of this resistance range from thickening of the cell wall of bacteria to the product of genes van, received from enterococci. To verify if microorganisms involved in cross-transmission events, such as antimicrobial resistance, have possible clonal relationship, it has been increasingly important genotyping of isolates by PFGE. Among the major virulence factors of the CoNS, are the staphylococcal toxins, characterized as superantigens, stimulating continuously the immune system, and considered a major cause of food poisoning. The polysaccharide PIA, encoded by the ica operon and produced by S. haemolyticus and S. epidermidis especially, is very important component in biofilm formation on medical devices, and acts hindered the action of the host immune system. Contribute significantly to the pathogenicity of Staphylococcus infections, besides enterotoxins and biofilm, the production of hemolysins, capable of causing direct injury to the outer membrane of target cells. This study aims to study the pathogenic profile of S. epidermidis and S. haemolyticus from patients hospitalized at the Hospital das Clínicas, Faculdade de Medicina de Botucatu (FMB-HC) for resistance to oxacillin by real-time searching of mecA, characterization of SCCmec, reduced susceptibility to vancomycin genotype and phenotypically, and clonal profile of resistant strains, genes encoding enterotoxins, hemolysins, and genes responsible for the production of biofilms in real-time.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PINHEIRO, LUIZA; BRITO, CARLA IVO; DE OLIVEIRA, ADILSON; FACCIOLI MARTINS, PATRICIA YOSHIDA; PEREIRA, VALERIA CATANELI; RIBEIRO DE SOUZA DA CUNHA, MARIA DE LOURDES. Staphylococcus epidermidis and Staphylococcus haemolyticus: Molecular Detection of Cytotoxin and Enterotoxin Genes. TOXINS, v. 7, n. 9, p. 3688-3699, SEP 2015. (11/15396-1)

PINHEIRO, LUIZA; BRITO, CARLA IVO; DE OLIVEIRA, ADILSON; PEREIRA, VALERIA CATANELI; RIBEIRO DE SOUZA DA CUNHA, MARIA DE LOURDES. Staphylococcus epidermidis and Staphylococcus haemolyticus: detection of biofilm genes and biofilm formation in blood culture isolates from patients in a Brazilian teaching hospital. DIAGNOSTIC MICROBIOLOGY AND INFECTIOUS DISEASE, v. 86, n. 1, p. 11-14, SEP 2016. (11/15396-1)

PINHEIRO, LUIZA; BRITO, CARLA IVO; PEREIRA, VALERIA CATANELI; OLIVEIRA, ADILSON; BARTOLOMEU, ARIANE ROCHA; CAMARGO, CARLOS HENRIQUE; RIBEIRO SOUZA CUNHA, MARIA LOURDES. Susceptibility Profile of Staphylococcus epidermidis and Staphylococcus haemolyticus Isolated from Blood Cultures to Vancomycin and Novel Antimicrobial Drugs over a Period of 12 Years. MICROBIAL DRUG RESISTANCE, v. 22, n. 4, p. 283-293, JUN 2016. (11/15396-1)