Staphylococcus lugdunensis感染症：鼠径部における高頻度の保菌

Staphylococcus lugdunensis infections: high frequency of inguinal area carriage.

抄録

手術方法の変更に伴い，当院形成外科の検体からStaphylococcus lugdunensisが分離される割合が著しく増加した．そこで，これらのS. lugdunensis株の由来を調査したところ，ドレーン保菌や手術部位感染の場合，術前に陰部を剃毛していた場合には，患者の皮膚細菌に由来する可能性が高いことが判明した．陰部結核の仮説を検証するために，鼠径部の皮膚細菌叢におけるS. lugdunensisの保菌率を評価した．その結果，140人の受診者のうち22％がこの部位にS. lugdunensisを保有しており，両鼠径部での保有が多いことが分かった（保有者の68％）．臨床株（n＝18）と常在株（n＝53）を含む全集団の遺伝子構造を調べた結果，本種の多様性は低く，35％の距離で分岐する2大グループで構成されていることが明らかとなった．また，臨床用株と常在菌の区別は，特に特徴的なものはなかった．また，β-lactamase産生株のみが均質であり，β-lactamase陽性株8株のうち6株は同一のパルスフィールドゲル電気泳動パターンを示した．

Following a change in surgical practice, we noted that the rate at which Staphylococcus lugdunensis was isolated from samples from the plastic surgery unit of our hospital increased considerably. We investigated the sources of these S. lugdunensis strains, and we found that in the case of drain colonization or surgical site infection, the strain was more likely to have come from the patient's skin bacteria when the pubic site had been shaved preoperatively. To test the hypothesis of pubic site colonization, we evaluated the prevalence of S. lugdunensis carriage among the cutaneous flora of the inguinal area. We found that 22% of 140 incoming patients carried S. lugdunensis in this area and that carriage at both inguinal folds was frequent (68% of carriers). A study of the genetic structure of the total population, including the clinical (n = 18) and the commensal (n = 53) strains, revealed that the diversity of the species was low and that the population was composed of two major groups that diverged at a distance of 35%. No particular characteristics made it possible to distinguish between clinical and commensal strains. Only isolates producing beta-lactamase were homogeneous; six of the eight beta-lactamase-positive strains displayed the same pulsed-field gel electrophoresis pattern.