Vega Silvio, Dowzicky Michael J
Complejo Hospitalario Metropolitano, Caja del Seguro Social, Panama City, Panama.
Pfizer Inc, Collegeville, PA, 19426, USA.
Ann Clin Microbiol Antimicrob. 2017 Jul 12;16(1):50. doi: 10.1186/s12941-017-0222-0.
The in vitro activity of tigecycline and comparator agents was evaluated against Gram-positive and Gram-negative isolates collected in Latin American centers between 2004 and 2015 as part of the Tigecycline Evaluation and Surveillance Trial (T.E.S.T.) global surveillance study.
Minimum inhibitory concentrations (MICs) were determined using the broth microdilution methodology according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Antimicrobial susceptibility was determined using CLSI breakpoints, except for tigecycline for which the US Food and Drugs Administration breakpoints were used.
A total of 48.3% (2202/4563) of Staphylococcus aureus isolates were methicillin-resistant S. aureus (MRSA). All MRSA isolates were susceptible to linezolid and vancomycin, and 99.9% (2199/2202) were susceptible to tigecycline. Among Streptococcus pneumoniae isolates, 13.8% (198/1436) were penicillin-resistant; all were susceptible to linezolid and vancomycin, and 98.0% (194/198) were susceptible to tigecycline. Susceptibility was >99.0% for linezolid and tigecycline against Enterococcus faecium and Enterococcus faecalis isolates. A total of 40.8% (235/576) E. faecium and 1.6% (33/2004) E. faecalis isolates were vancomycin-resistant. Among the Enterobacteriaceae, 36.3% (1465/4032) of Klebsiella pneumoniae isolates, 16.4% (67/409) of Klebsiella oxytoca isolates and 25.4% (1246/4912) of Escherichia coli isolates were extended-spectrum β-lactamase (ESBL) producers. Of the ESBL-producing K. pneumoniae and E. coli isolates, susceptibility was highest to tigecycline [93.4% (1369/1465) and 99.8% (1244/1246), respectively] and meropenem [86.9% (1103/1270) and 97.0% (1070/1103), respectively]. A total of 26.7% (966/3613) of Pseudomonas aeruginosa isolates were multidrug-resistant (MDR). Among all P. aeruginosa isolates, susceptibility was highest to amikacin [72.8% (2632/3613)]. A total of 70.3% (1654/2354) of Acinetobacter baumannii isolates were MDR, and susceptibility was highest to minocycline [88.3% (2079/2354) for all isolates, 86.2% (1426/1654) for MDR isolates]. Tigecycline had the lowest MIC (2 mg/L) among A. baumannii isolates, including MDR isolates.
This study of isolates from Latin America shows that linezolid, vancomycin and tigecycline continue to be active in vitro against important Gram-positive organisms such as MRSA, and that susceptibility rates to meropenem and tigecycline against members of the Enterobacteriaceae, including ESBL-producers, were high. However, we report that Latin America has high rates of MRSA, MDR A. baumannii and ESBL-producing Enterobacteriaceae which require continued monitoring.
作为替加环素评估与监测试验（T.E.S.T.）全球监测研究的一部分，对2004年至2015年间在拉丁美洲各中心收集的革兰氏阳性和革兰氏阴性分离株进行了替加环素及对照药物的体外活性评估。
根据临床和实验室标准协会（CLSI）指南，采用肉汤微量稀释法测定最低抑菌浓度（MIC）。除替加环素采用美国食品药品监督管理局的标准外，抗菌药物敏感性根据CLSI标准判定。
金黄色葡萄球菌分离株中，共有48.3%（2202/4563）为耐甲氧西林金黄色葡萄球菌（MRSA）。所有MRSA分离株对利奈唑胺和万古霉素敏感，99.9%（2199/2202）对替加环素敏感。在肺炎链球菌分离株中，13.8%（198/1436）对青霉素耐药；所有菌株对利奈唑胺和万古霉素敏感，98.0%（194/198）对替加环素敏感。利奈唑胺和替加环素对粪肠球菌和屎肠球菌分离株的敏感性>99.0%。共有40.8%（235/576）的屎肠球菌分离株和1.6%（33/2004）的粪肠球菌分离株对万古霉素耐药。在肠杆菌科中，36.3%（1465/4032）的肺炎克雷伯菌分离株、16.4%（67/409）的产酸克雷伯菌分离株和25.4%（1246/4912）的大肠埃希菌分离株为超广谱β-内酰胺酶（ESBL）生产者。在产ESBL的肺炎克雷伯菌和大肠埃希菌分离株中，对替加环素的敏感性最高[分别为93.4%（1369/1465）和99.8%（1244/1246）]，对美罗培南的敏感性次之[分别为86.9%（1103/1270）和97.0%（1070/1103）]。共有26.7%（966/3613）的铜绿假单胞菌分离株为多重耐药（MDR）。在所有铜绿假单胞菌分离株中，对阿米卡星的敏感性最高[72.8%（2632/3613）]。共有70.3%（1654/2354）的鲍曼不动杆菌分离株为MDR，对米诺环素的敏感性最高[所有分离株为88.3%（2079/2354），MDR分离株为86.2%（1426/1654）]。在鲍曼不动杆菌分离株中，包括MDR分离株，替加环素的MIC最低（2mg/L）。
这项对拉丁美洲分离株的研究表明，利奈唑胺、万古霉素和替加环素在体外对MRSA等重要革兰氏阳性菌仍有活性，对包括产ESBL菌在内的肠杆菌科细菌，美罗培南和替加环素的敏感率较高。然而，我们报告拉丁美洲的MRSA、MDR鲍曼不动杆菌和产ESBL肠杆菌科细菌的发生率较高，需要持续监测。
