title: In vivo sortase A and clumping factor A mRNA expression during Staphylococcus aureus infection.
abstract: The Staphylococcus aureus cell surface protein clumping factor A (ClfA) and the enzyme sortase A (SrtA), which attach surface proteins to the cell wall, have both been shown to be virulence factors in models of septic arthritis and sepsis. The mRNA levels of clfA, srtA and the putative housekeeping gene gyrase B (gyrB) in S. aureus were determined using real-time PCR during the course of sepsis/septic arthritis. Expression was measured in joints, being a target of localized infection, and in kidneys, representing a systemic compartment. In infected kidneys, the mRNA levels of clfA, srtA and gyrB were all decreasing over time, from day 3 of infection to day 14. The transcript numbers of clfA and srtA decreased faster in septic mice than in mice with a non-septic disease. The mRNA levels of clfA and gyrB in joints, though, were increasing during the course of infection. These differences suggest that the specific tissue environment is decisive for the differentiation of staphylococci. Also, there was a negative relationship between bacterial load in a tissue and the numbers of clfA, srtA and gyrB transcripts per colony-forming unit. Possibly enters the majority of bacteria a metabolically dormant steady state at high bacterial loads.
authors: Department of Rheumatology and Inflammation Research, Göteborg University, Guldhedsgatan 10, Göteborg, Sweden. elisabet.josefsson@rheuma.gu.se
authors: Elisabet
authors: E
authors: Josefsson
authors: Malgorzata
authors: M
authors: Kubica
authors: Piotr
authors: P
authors: Mydel
authors: Jan
authors: J
authors: Potempa
authors: Andrej
authors: A
authors: Tarkowski
mesh_terms: D019881:Aminoacyltransferases / Q000096:biosynthesis*; D000818:Animals; D001170:Arthritis, Infectious / Q000382:microbiology; D001426:Bacterial Proteins / Q000096:biosynthesis*; D003030:Coagulase / Q000096:biosynthesis*; D015169:Colony Count, Microbial; D003546:Cysteine Endopeptidases / Q000096:biosynthesis*; D027081:DNA Gyrase / Q000096:biosynthesis; D005260:Female; D020869:Gene Expression Profiling; D007596:Joints / Q000382:microbiology; D007668:Kidney / Q000382:microbiology; D008297:Male; D051379:Mice; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018805:Sepsis / Q000382:microbiology; D013203:Staphylococcal Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000737:chemistry / Q000235:genetics*; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins; C515944:ClfA protein, Staphylococcus aureus; D003030:Coagulase; D012333:RNA, Messenger; D019881:Aminoacyltransferases; C120542:sortase A; D003546:Cysteine Endopeptidases; D027081:DNA Gyrase