The expression of Panton-Valentine leukocidin gene and its correlation with agrA among different clinical isolates of Staphylococcus aureus / 中华检验医学杂志

ABSTRACT

Objective To investigate the correlation between expression of Panton-Valentine leukocidin gene and accessory gene regulator among different clinical isolates of Staphylococcus aureus.Methods All non-duplicate Staphylococcus aureus clinical isolates were isolated from various clinical specimens of the patients at 4 hospitals from January 2003 to December 2010.Panton-Valentine leukocidin genes among Staphylococcus aureus clinical isolates were detected by PCR and DNA sequencing.The expressions of lukS-PV and agrA were determined by real-time PCR.Results Ninty-six S.aureus isolates including 58 hospital-acquired and 28 community-acquired isolates were positive for PVL genes,among which 54 from blood,33 from pus and 9 from sputum.Ten isolates cannot be classified due to lack of information.Sixty-seven and 29 PVL-positive isolates were isolated from the specimens of adults and children.The median relative quantities of lukSmRNA of the isolates from pus and blood were 1.500 and 0.818.The quantity of lukSmRNA among the isolates from pus was significantly higher than that from blood (U =634,P =0.025).The median relative quantities of lukSmRNA of the isolates from children and adults were 1.292 and 0.540,respectively.The quantity of lukSmRNA among the isolates from children was significantly higher than that from adults (U =660,P =0.013).The median relative quantities of lukSmRNA among community-acquired and hospital-acquired isolates were 1.034 and 0.536,respectively.The quantity of lukSmRNA among community-acquired isolates was significantly higher than that from hospital-acquired isolates (U =338,P =0.012).The correlation coefficients between lukSmRNA and agrAmRNA of total isolates,pus isolates and blood isolates were 0.592 (P ＜ 0.01),0.810 (P ＜ 0.0l) and 0.543 (P ＜0.01),respectively.While the correlation coefficients of those among the isolates from children and adults were 0.804 (P ＜ 0.01) and 0.476 (P ＜ 0.01).The correlation coefficients of those among the isolates from community-acquired and hospital-acquired isolates were 0.767 (P ＜ 0.01) and 0.556 (P＜0.01).Conclusions The quantity of lukSmRNA of Staphylococcus aureus isolates from pus was significantly higher than that from blood.The agr may have positive regulation effect on the expression of lukS/F-PV,especially among the isolates from pus and children.(Chin J Lab Med,2013,36313-317)