Extended-spectrum Beta-lactamase and AmpC Beta-lactamase producing gram negative bacilli isolated from clinical specimens at International Clinical Laboratories, Addis Ababa, Ethiopia

Abstract

Background : For Gram negative pathogens, production of beta-lactamase (β-lactamases) enzymes are the main mechanisms of resistance for most antimicrobial drugs. Of these β-lactamases, Extended spectrum Beta-lactamases (ESBL) and AmpC β-lactamases (AmpC) are the commonest enzymes produced by gram negative bacilli which are main mechanisms for the resistance all generations of cephalosporins. This study was therefore, aimed to assess the magnitude of ESBL and AmpC producing gram negative bacilli (GNB) isolated from clinical specimens at International clinical Laboratories, Addis Ababa, Ethiopia. Methods: A cross sectional study was conducted between January to May 2018. From different clinical specimens, 338 GNB were isolated. Bacterial species identification, antimicrobial susceptibility testing and β-lactamases screening were performed using phoenix automated system (BD phoenix 100 ). Cefoxitin resistant bacteria were confirmed for AmpC β-lactamases production by AmpC confirmatory disc. ESBLs production was confirmed using a combination disc method. Data were analyzed using SPSS version 20 software. Results: The predominant GNB was E. coli 66.0% (224/338) followed by K. pneumoniae 12.1% (41/338). The overall magnitude of ESBL producing GNB was 38.8% (131/338) while AmpC β-lactamases producing GNB was 2.4% (8/338). The majority of ESBLs and AmpC β-lactamases producing GNB were isolated from urine specimen 47.5% (116/338). Ampicillin (75.4%), amoxicillin with clavulanic acid (64.0%) and sulfamethoxazole-trimethoprim (55.6%) were most common resistance antibiotics. Multidrug resistance (MDR) level was 73.7% (249/338). Of ESBLs and AmpC β-lactamases producing GNB, 99.3% were MDR (P < 0.05). Conclusion: The magnitude of ESBL and AmpC β-lactamases producing GNB were significantly high which is worrying that needs intervention to minimize further occurrence and spread of such GNB. The MDR level was high which suggests continuous monitoring & reviewing of antimicrobial policy in hospitals and the country at large. Keywords: Extended spectrum β-lactamase, AmpC β-lactamase, Multidrug Resistance, Gram negative bacilli, Addis Ababa, Ethiopia

Characterization of Salmonella enterica serovar Isangi from South Africa, 2020-2021

“…ESBLs and AmpC are enzymes that confer resistance against most beta-lactam antibiotics, including penicillins, and cephalosporins, with ESBLs comprising of isolates that exhibit co-resistance to other classes of antibiotics such as aminoglycosides, uoroquinolones and sulfonamides. ESBLs can be inhibited by β-lactamase inhibitors such as clavulanic acid, while AmpC activity is not affected by ESBL inhibitors [4]. Although ESBL-production is predominantly associated with other species in the Enterobacteriaceae family, the emergence of ESBLs in Salmonella Isangi has become increasingly more prevalent in South Africa [2].…”