Department of Medical Laboratory Sciences, College of Health Sciences, Wollo University, Dessie, Ethiopia.
Department of Bacteriology and Mycology, Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
PLoS One. 2020 Nov 12;15(11):e0241984. doi: 10.1371/journal.pone.0241984. eCollection 2020.
Extended spectrum Beta-lactamases (ESBLs) and AmpC beta-lactamases (AmpC) are the common enzymes produced by gram negative bacilli, which are their main mechanisms of resistance to all generations of cephalosporins. Hence, this study aimed to determine the magnitude of ESBLs and AmpC producing gram negative bacilli (GNB) isolated from clinical specimens at International clinical Laboratories in Addis Ababa, Ethiopia.
A cross sectional study was conducted from January to May 2018. From different clinical specimens, 338 GNB were isolated and characterized. Bacterial species identification, antimicrobial susceptibility testing and screening for ESBLs and AmpC production were performed using Phoenix automated system (BD phoenix100). ESBLs production was confirmed using a combination disc method. All Cefoxitin resistant and confirmed ESBLs producing GNB were confirmed for AmpC beta-lactamases production by AmpC confirmatory Neo-Sensitabs discs (ROSCO tablet). Data were analyzed using SPSS version 20 software.
E. coli 66.0% (224/338) followed by K. pneumoniae 12.1% (41/338) were GNB most frequently isolated. The overall magnitude of ESBLs producing GNB was 38.8% (131/338) and the extent of AmpC beta-lactamase producing GNB was 2.4% (8/338). Majority of ESBLs and AmpC beta-lactamases producing GNB were isolated from urine specimens 47.5% (116/338). Ampicillin (75.4%), amoxicillin with clavulanic acid (64.0%) and sulfamethoxazole-trimethoprim (55.6%) were most the antibiotics to which resistance was most commonly found. The multidrug resistance (MDR) level of GNB was 74.0% (250/338). Of ESBLs and AmpC beta-lactamases producing GNB, 99.3% were MDR (p < 0.05).
The high magnitude of ESBLs and AmpC beta-lactamases producing GNB calls the needs of strong intervention to minimize further occurrence and spread of such GNB. More importantly, the MDR level was high which suggests continuous monitoring & reviewing of antimicrobial policy in hospitals and the country at large.
超广谱β-内酰胺酶（ESBLs）和 AmpC 型β-内酰胺酶（AmpC）是革兰氏阴性杆菌产生的常见酶，是其对所有代头孢菌素产生耐药性的主要机制。因此，本研究旨在确定埃塞俄比亚亚的斯亚贝巴国际临床实验室从临床标本中分离出的产 ESBLs 和 AmpC 革兰氏阴性杆菌（GNB）的比例。
这是一项在 2018 年 1 月至 5 月进行的横断面研究。从不同的临床标本中分离出 338 株 GNB 并进行鉴定。采用 Phoenix 自动化系统（BD phoenix100）进行细菌种属鉴定、药敏试验以及 ESBLs 和 AmpC 产生的筛选。采用联合纸片法确认 ESBLs 的产生。所有头孢西丁耐药且确认为 ESBLs 产生的 GNB 均通过 AmpC 确证性 Neo-Sensitabs 纸片（ROSCO 纸片）确认为 AmpCβ-内酰胺酶产生。使用 SPSS 20 软件进行数据分析。
最常分离到的革兰氏阴性杆菌是大肠埃希菌（66.0%，224/338），其次是肺炎克雷伯菌（12.1%，41/338）。产 ESBLs 的 GNB 总体比例为 38.8%（131/338），产 AmpCβ-内酰胺酶的 GNB 比例为 2.4%（8/338）。大多数 ESBLs 和 AmpCβ-内酰胺酶产生的 GNB 是从尿液标本中分离出来的（47.5%，116/338）。氨苄西林（75.4%）、阿莫西林克拉维酸（64.0%）和磺胺甲恶唑-甲氧苄啶（55.6%）是最常见的耐药抗生素。革兰氏阴性杆菌的多重耐药（MDR）率为 74.0%（250/338）。产 ESBLs 和 AmpCβ-内酰胺酶的 GNB 中，99.3%为 MDR（p<0.05）。
产 ESBLs 和 AmpCβ-内酰胺酶的 GNB 比例较高，需要采取强有力的干预措施，以尽量减少此类 GNB 的进一步发生和传播。更重要的是，MDR 水平较高，这表明需要持续监测和审查医院乃至全国的抗菌药物政策。
