Department of Hepatobiliary Surgery, Qianfoshan Hospital Affiliated to Shandong University, Jinan, Shandong 250014, China.
Chin Med J (Engl). 2012 Jul;125(14):2417-21.
Liver transplantation is the most effective treatment for patients with end-stage liver failure, however infection after transplantation is a serious clinical complication. The purpose of this research was to investigate the molecular epidemiology and the influence of multidrug-resistant Gram-positive infection in patients, following liver transplantation, to provide reference for clinical treatment and prevention of Gram-positive bacterial infection.
We isolated and detected bacteria from phlegm, throat swabs, urine, wound or wound secretions, blood, and fecal samples from 221 liver transplant patients in our hospital from January 2007 to April 2010. All isolated bacterial strains were identified and tested by minimal inhibitory concentration (MIC) drug-sensitive detection using the BioMerieux ATB bacterial identification instrument and repetitive extragenic palindromic-polymerase chain reaction (REP-PCR) detection of bacterial homology. Risk factors were calculated by multivariate Logistic regression analysis.
We collected 250 specimens from 221 patients hospitalized following liver transplantation surgery, of which 29 patients developed multiple infections. Sixty-five Gram-positive bacterial strains were isolated from different specimens from 53 infectious patients. We detected 29 multidrug-resistant Gram-positive strains from 29 patients (44.62%), including 20 Staphylococcus aureus (S. aureus) strains (68.97%) and nine Enterococcus strains (31.03%). All 20 S. aureus strains were highly resistant to aminoglycosides (gentamicin), cephalosporins (cefoxitin), quinolones (ciprofloxacin and levofloxacin), lincomycins (clindamycin), penicillin, and erythromycin. The resistance rate reached 100% in some cases. The S. aureus strains were highly sensitive to vancomycin and oxazolidinone (linezolid), with MIC50 < 2 µg/ml for both. The nine Enterococci strains were also highly resistant to aminoglycosides, quinolones, and penicillins, and highly sensitive to vancomycin (MIC50 < 2 µg/ml) and oxazolidinone (MIC50 < 1 µg/ml). Using REP-PCR detection, S. aureus was divided into five genotypes with 14 B-type strains. Enterococcus was divided into 11 genotypes, with two D-type strains, two G-type strains, and two K-type strains. The risk factors for Gram-positive bacterial infection in patients following liver transplantation were preoperative use of antibiotics (OR = 3.949, P = 0.004), high intra-operative blood input (OR = 1.071, P = 0.005), and postoperative renal failure (OR = 5.427, P = 0.043).
S. aureus and Enterococcus were the main pathogens causing infection following liver transplantation in patients with drug-resistant Gram-positive bacterial infection. The isolated strains were resistant to multiple antibiotics. B-type S. aureus strains were predominant. Reasonable use of antibiotics, decreasing intra-operative blood input, and preventing post-operative renal failure may reduce Gram-positive bacterial infections and the appearance of drug-resistant strains following liver transplantation.
肝移植是治疗终末期肝功能衰竭患者的最有效方法，但是移植后感染是一种严重的临床并发症。本研究的目的是研究分子流行病学以及多药耐药革兰氏阳性感染对肝移植患者的影响，为革兰氏阳性细菌感染的临床治疗和预防提供参考。
我们从 2007 年 1 月至 2010 年 4 月在我院接受肝移植手术的 221 例患者的痰、咽拭子、尿液、伤口或伤口分泌物、血液和粪便样本中分离并检测细菌。使用生物梅里埃公司的 ATB 细菌鉴定仪和重复回文外扩增聚合酶链反应（REP-PCR）检测细菌同源性，对所有分离的细菌菌株进行鉴定和最小抑菌浓度（MIC）药敏检测。通过多变量 Logistic 回归分析计算危险因素。
我们从 221 例住院肝移植手术后的患者中采集了 250 份标本，其中 29 例患者发生了多种感染。从 53 例感染患者的不同标本中分离出 65 株革兰氏阳性细菌。我们从 29 名患者（44.62%）中检测到 29 株多药耐药革兰氏阳性菌株，包括 20 株金黄色葡萄球菌（S. aureus）和 9 株肠球菌。所有 20 株金黄色葡萄球菌对氨基糖苷类（庆大霉素）、头孢菌素（头孢西丁）、喹诺酮类（环丙沙星和左氧氟沙星）、林可酰胺类（克林霉素）、青霉素和红霉素均高度耐药。某些情况下，耐药率达到 100%。金黄色葡萄球菌对万古霉素和唑烷酮（利奈唑胺）高度敏感，MIC50 均<2µg/ml。9 株肠球菌也对氨基糖苷类、喹诺酮类和青霉素高度耐药，对万古霉素（MIC50 < 2µg/ml）和唑烷酮（MIC50 < 1µg/ml）高度敏感。使用 REP-PCR 检测，金黄色葡萄球菌分为 5 种基因型，其中 B 型 14 株。肠球菌分为 11 种基因型，其中 D 型 2 株，G 型 2 株，K 型 2 株。肝移植术后革兰氏阳性细菌感染患者的危险因素是术前使用抗生素（OR=3.949，P=0.004）、术中高输血量（OR=1.071，P=0.005）和术后肾衰竭（OR=5.427，P=0.043）。
金黄色葡萄球菌和肠球菌是导致肝移植术后患者发生耐药革兰氏阳性细菌感染的主要病原体。分离株对多种抗生素具有耐药性。B 型金黄色葡萄球菌菌株占优势。合理使用抗生素、减少术中输血量和预防术后肾衰竭可能会减少肝移植术后革兰氏阳性细菌感染和耐药菌株的出现。
