Project description:This study aims to determine the epidemiology of Enterobacteriaceae resistant to antibiotics of last resort in pregnant women in labour at a tertiary hospital, Pretoria, South Africa. Rectal swabs shall be used to screen for colonisation with CRE and colistin-resistant Enterobacteriales in pregnant women during labour. Carbapenem and colistin-resistant Enterobacterales can cause the following infections: bacteraemia; nosocomial pneumonia; urinary tract infections, and intra-abdominal infections. Due to limited treatment options, infections caused by these multidrug-resistant organisms are associated with a mortality rate of 40-50%. Screening for colonisation of carbapenem-resistant Enterobacteriaceae (CRE) and colistin-resistant Enterobacteriaceae will help implement infection and prevention measures to limit the spread of these multidrug-resistant organisms.
Project description:Neutrophil lysis after phagocytosis is a process potentially important in the pathogenesis of community-associated methicillin-resistant S. aureus (CA-MRSA) infection. The mechanism for this process is not currently known. Therefore, to better understand CA-MRSA virulence we used human oligonucleotide microarrays to investigate the mechanism underlying enhanced PMN lysis that occurs after phagocytosis of CA-MRSA. In order to examine the effect of S. aureus on the neutrophil transcriptome and to elucidate any possible differences in this effect between hospital- and community-associated S. aureus, we performed microarray expression analysis on human neutrophils treated with hospital- and community-associated S. aureus.
2010-06-01 | GSE16837 | GEO
Project description:MRSA outbreak in a tertiary neonatal intensive care unit in Iceland
Project description:Methicillin-resistant Staphylococcus aureus (MRSA) is the causative agent of serious hospital- and community-associated infections. Due to the global rise in community-associated MRSA, the respective lineages are increasingly introduced into hospitals. This raises the question whether and, if so, how they adapt to this new environment. The present study was aimed at investigating how MRSA isolates of the USA300 lineage, infamous for causing infections in the general population, have adapted to the hospital environment. To this end, a collection of community- and hospital-associated USA300 isolates was compared by RNA-sequencing. Here we report that merely 460 genes were differentially expressed between these two epidemiologically distinct groups, including genes for virulence factors, oxidative stress responses and the purine, pyrimidine and fatty acid biosynthetic pathways. Differentially regulated virulence factors included leukotoxins and phenol-soluble modulins, implicated in staphylococcal escape from immune cells. We therefore investigated the ability of the studied isolates to survive internalization by human neutrophils. This showed that the community-associated isolates have the highest neutrophil-killing activity, while the hospital-associated isolates are better adapted to intra-neutrophil survival. Importantly, the latter trait protects internalized staphylococci against a challenge with antibiotics. We therefore conclude that prolonged intra-neutrophil survival serves as a relatively simple early adaptation of S. aureus USA300 to the hospital environment where antibiotic pressure is high.