Rodríguez-Guerrero Enrique, Callejas-Rodelas Juan Carlos, Navarro-Marí José María, Gutiérrez-Fernández José
Laboratory of Microbiology, Virgen de las Nieves University Hospital & ibs.Granada-Instituto de Investigación Biosanitaria de Granada, Avda. de las Fuerzas Armadas 2, 18014 Granada, Spain.
Department of Microbiology, School of Medicine, University of Granada & ibs.Granada-Instituto de Investigación Biosanitaria de Granada, Avenida de la Investigación 11, 18016 Granada, Spain.
Microorganisms. 2022 Mar 14;10(3):611. doi: 10.3390/microorganisms10030611.
Beta-lactamase (BL) production is a major public health problem. Although not the most frequent AmpC type, AmpC-BL is increasingly isolated, especially plasmid AmpC-BL (pAmpC-BL). The objective of this study was to review information published to date on pAmpC-BL in and and on the epidemiology and detection methods used by clinical microbiology laboratories, by performing a systematic review using the MEDLINE PubMed database. The predictive capacity of a screening method to detect AmpC-BL using disks with cloxacillin (CLX) was also evaluated by studying 102 clinical isolates grown in CHROMID ESBL medium with the addition of cefepime (FEP), cefoxitin (FOX), ertapenem (ETP), CLX, and oxacillin with CLX. The review, which included 149 publications, suggests that certain risk factors (prolonged hospitalization and previous use of cephalosporins) are associated with infections by pAmpC-BL-producing microorganisms. The worldwide prevalence has increased over the past 10 years, with a positivity rate ranging between 0.1 and 40%, although AmpC was only detected when sought in a targeted manner. CMY-2 type has been the most prevalent pAmpC-BL-producing microorganism. The most frequently used phenotypic method has been the double-disk synergy test (using CLX disks or phenyl-boronic acid and cefotaxime [CTX] and ceftazidime) and the disk method combined with these inhibitors. In regard to screening methods, a 1-µg oxacillin disk with CLX showed 88.9% sensitivity, 100% specificity, 100% positive predictive value (PPV), 98.9% negative predictive value (NPV), and 98.9% validity index (VI). This predictive capacity is reduced with the addition of extended-spectrum beta-lactamases, showing 62.5% sensitivity, 100% specificity, 100% PPV, 93.5% NPV, and 94.1% VI. In conclusion, there has been a worldwide increase in the number of isolates with pAmpC-BL, especially in Asia, with CMY-2 being the most frequently detected pAmpC-BL-producing type of microorganism. Reduction in its spread requires routine screening with a combination of phenotypic methods (with AmpC inhibitors) and genotypic methods (multiplex PCR). In conclusion, the proposed screening technique is an easy-to-apply and inexpensive test for the detection of AmpC-producing isolates in the routine screening of multidrug-resistant microorganisms.
β-内酰胺酶（BL）的产生是一个重大的公共卫生问题。虽然不是最常见的AmpC类型，但AmpC-BL的分离越来越多，尤其是质粒AmpC-BL（pAmpC-BL）。本研究的目的是通过使用MEDLINE PubMed数据库进行系统评价，回顾迄今为止发表的关于日本和韩国pAmpC-BL以及临床微生物实验室使用的流行病学和检测方法的信息。通过研究在添加头孢吡肟（FEP）、头孢西丁（FOX）、厄他培南（ETP）、氯唑西林（CLX）和含CLX的苯唑西林的CHROMID ESBL培养基中培养的102株临床分离株，还评估了使用含氯唑西林（CLX）纸片检测AmpC-BL的筛选方法的预测能力。该评价纳入了149篇出版物，表明某些危险因素（长期住院和先前使用头孢菌素）与产pAmpC-BL微生物感染有关。在过去10年中，全球患病率有所上升，阳性率在0.1%至40%之间，尽管只有在有针对性地寻找时才检测到AmpC。CMY-2型一直是最常见的产pAmpC-BL微生物。最常用的表型方法是双纸片协同试验（使用CLX纸片或苯硼酸与头孢噻肟[CTX]和头孢他啶）以及与这些抑制剂联合的纸片法。关于筛选方法，含CLX的1μg苯唑西林纸片显示出88.9%的敏感性、100%的特异性、100%的阳性预测值（PPV）、98.9%的阴性预测值（NPV）和98.9%的有效性指数（VI）。添加超广谱β-内酰胺酶后，这种预测能力降低，敏感性为62.5%，特异性为100%，PPV为100%，NPV为93.5%，VI为94.1%。总之，全球产pAmpC-BL的分离株数量有所增加，尤其是在亚洲，CMY-2是最常检测到的产pAmpC-BL微生物类型。减少其传播需要结合表型方法（使用AmpC抑制剂）和基因型方法（多重PCR）进行常规筛选。总之，所提出的筛选技术是一种易于应用且成本低廉的检测方法，用于在多重耐药微生物的常规筛选中检测产AmpC的分离株。
