Co-production of ESBL and AmpC β-Lactamases in Clinical Isolates of A. baumannii and A. lwoffii in a Tertiary Care Hospital From Northern India

Abstract

Background: Acinetobacter baumannii is an important cause of health care associated infections which are difficult to control and treat, because of widespread antimicrobial resistance which is possessed by this organism. Aims:The aim of the present study was to know the prevalence of ESBLs and AmpC β-lactamases in clinical isolates of Acinetobacter spp. which were cultured from various clinical specimens by using different phenotypic methods. Settings and Design:Study was conducted over a period of one year at the Microbiology Department of a tertiary care teaching hospital. A total of 100 consecutive, non-duplicate strains of Acinetobacter species which were isolated from various clinical samples were included. Materials and Methods:All the isolates were identified by standard microbiological procedures and antimicrobial susceptibility testing was done by Kirby-Bauer disc diffusion technique. Isolates which showed reduced susceptibilities to third generation cephalosporins were tested for ESBL production by CLSI double disc synergy method and also by using sulbactam as an inhibitory agent. Isolates which showed reduced susceptibilities to cefoxitin were tested for AmpC detection by doing AmpC disc test.Statistical Analysis: SPSS, version 17 was used to calculate p-value. If the p-value was <0.05, it was considered to be significant. Results:Out of 100 isolates, 82 were Acinetobacter baumannii and 18 were Acinetobacter lwoffii. ESBL were mentioned in 4% of the Acinetobacter isolates and in 77% of the isolates by using clavulanic acid and sulbactam as inhibitory agents respectively. AmpC β-lactamase production was detected in 60% isolates of Acinetobacter spp. Co-production of both ESBL and AmpC enzymes were seen in 29% of the Acinetobacter strains. Conclusion:Failure in detecting β-lactamases contributes to their uncontrolled spread and therapeutic failures. Hence, these β-lactamases should be detected routinely and they should be reported to clinicians in time, so that inappropriate use of antibiotics can be stopped in time.Pooja Singla 1 , Rama SiKKa 2 , antaRiKSh DeeeP 3 , DeeP gagneja 4 , Uma ChaUDhaRy 5 InTRODuCTIOnMembers of the genus Acinetobacter, in particular, Acinetobacter baumannii, are being reported increasingly as the causative agents of numerous hospital outbreaks which occur in several countries. They are responsible for causing a number of nosocomial infections like septicaemia, pneumonia, wound sepsis, endocarditis, meningitis and urinary tract infections (UTIs), especially in intensive care settings [1]. The infections caused by these organisms are often extremely difficult for clinicians to treat, because of the widespread resistance of these bacteria to the major groups of antibiotics like aminoglycosides, fluoroquinolones, ureidopenicillins and third generation cephalosporins. Moreover, the ability of resistant strains of A. baumannii to survive for prolonged periods in the hospital environment, contributes significantly to antimicrobial resistance, thereby posing a difficult chall...

Antibacterial Activity of Aqueous Garlic Extract on Beta-Lactamase Producing Acinetobacter Isolates From Skin and Soft Tissue Infections

“…The presence of beta-lactamase enzyme was confirmed based on phenotypic tests, and the results were in agreement with the study carried out by Singla et al [8]. None of the isolates were pure ESBL producers.…”

“…None of the isolates were pure ESBL producers. The production rate of AmpC alone and co-production rate of ESBL and AmpC beta-lactamases were in accordance with the study carried out by Singla et al [8]. The prevalence rate of MBL producers in Acinetobacter species was well-corroborated with similar studies conducted in India [24,25].…”

“…They lack inhibition by the commercially available beta-lactam inhibitors; clavulanic acid, sulbactam, and tazobactam [7]. Often coexistence of multiple beta-lactamase enzymes in a single isolate is observed, which further complicates treatment options [8].…”

High antimicrobial resistant rates among Gram-negative pathogens in intensive care units

“… 31 The extensive use of these agents also promotes the emergence of extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase producing isolates. 32 The dissemination of K. pneumoniae and E. coli isolates harboring diverse resistant beta-lactamase resistance genes has been studied previously, which revealed resistance to cephalosporins and other antimicrobial classes. 33 , 34 …”

Detection and genotype analysis of AmpC β-lactamase in Klebsiella pneumoniae from tertiary hospitals

“…In Portugal, 104/124 (83.9%) of Enterobacteriaceae isolates that were resistant to third generation cephalosporins were also resistant to fourth generation cephalosporins (10). In comparison with ESBL-producing gram-negative bacilli, AmpC β-lactamase-producing strains show more extensive antibiotic resistance; 29% of Acinetobacter strains, for example, were found to produce both ESBL and AmpC enzymes (11). To be more specific, the majority of Acinetobacter baumannii isolates were producers of carbapenemase and metallo-β-lactamase (12).…”