The expression of small regulatory RNAs in clinical samples reflects the different life styles of Staphylococcus aureus in colonization vs. infection.
Small RNAs (sRNAs) are involved in the post-transcriptional regulation of metabolic pathways and in responses to stress and virulence. We analyzed the expression levels of five sRNAs of Staphylococcus aureus during human colonization or infection. Total RNA was isolated from nasal carriers, abscesses and cystic fibrosis patients (20 subjects per condition). The expression levels of the sRNAs were measured in the clinical samples and compared with those of the corresponding strains grown in vitro. Five sRNAs were encoded and expressed in all clinical strains in vitro. In vivo, the global expression of the five sRNAs was extremely variable in the abscessed patients, more homogeneous in the cystic fibrosis patients, and highly uniform in the nasal carrier samples. The expression levels of the sRNAs in vivo resembled those obtained at exponential phase or late exponential phase of growth in vitro, for three and one sRNA respectively; while for one sRNA, the expression was always higher in vivo as compared to in vitro growth. The in vitro conditions do not uniformly mimic the in vivo conditions for sRNA expression. Nasal colonization is associated with a unique expression pattern of sRNA that might reflect the commensalism of S. aureus in this niche.
Department of Immunology and Pathogen Biology, Medical school of Xi'an Jiaotong University, Xi'an, Shaanxi province, China.
Juan
J
Song
Claire
C
Lays
François
F
Vandenesch
Yvonne
Y
Benito
Michèle
M
Bes
Yonglie
Y
Chu
Gérard
G
Lina
Pascale
P
Romby
Thomas
T
Geissmann
Sandrine
S
Boisset
D000038:Abscess / Q000382:microbiology*; D003550:Cystic Fibrosis / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D012329:RNA, Bacterial / Q000378:metabolism*; D058727:RNA, Small Untranslated / Q000378:metabolism*; D013203:Staphylococcal Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000235:genetics* / Q000378:metabolism
D012329:RNA, Bacterial; D058727:RNA, Small Untranslated