Prevalence of Extended Spectrum Beta-lactamase and Carbapenemase Producers in Gram Negative Bacteria causing Blood Stream Infection in Intensive Care Unit Patients

Abstract

Introduction: Blood Stream Infections (BSI) in Intensive Care Unit (ICU) patients at initial stages are acute infections which might even become life threatening. In developing countries, increasing antimicrobial resistance and emergence of Extended Spectrum Beta-Lactamases (ESBL) and carbapenemase has also added an extra burden on physicians. Aim: To study the prevalence of emergence of ESBL and carbapenemase producing Gram Negative Bacteria (GNB) causing BSI in ICU patients. Materials and Methods: The present cross-sectional study was conducted on 1537 blood samples which were received in duration of two years from 2018 to 2020 in the Department of Microbiology, Maharishi Markandeshwar Institute of Medical Sciences and Research (MMIMSR), Mullana, Haryana, India from various ICUs. A 5-7 mL of blood was aseptically added to BACTEC bottles and bottles after proper labeling were inserted into the machine and incubated upto five days. 0.1 mL of broth from positively flagged bottles was cultured on Blood and MacConkey Agar. These plates were incubated at 37o C for 24 hours and processed as per standard microbiological procedures. Data was entered locally and calculated on the Microsoft Excel database. Results: Among 1537 samples, 263 (17.11%) samples were flagged positive by BACTEC system. On culture out of 263 samples, 51 (19.40%) were Gram Positive Cocci (GPC), 21 (07.98%) were Candida spp. and 191 (72.62%) were GNB. Among 191 Gram negative isolates, Escherichia coli 64 (33.51%) was the predominant organism followed by Klebsiella spp. 60 (31.41%). For all gram negative isolates, meropenem was the most sensitive drug followed by imipenem. Tigecycline (81.25%) was the second most effective drug against Acinetobacter baumannii. ESBL detection was done by Combine Disc Test on 124 samples (Escherichia coli and Klebsiella spp.) which showed Klebsiella spp. 25(20.16%) as the highest ESBL producing organism The rate of carbapenemase producer was 20 (10.45%) among all the gram negative isolates. Conclusion: For BSI in ICU patients, culture and sensitivity along with screening for prevalence of ESBL and carbapenemase producers should be done prior to starting antibiotics

Keywords

• combined disc test
• escherichia coli
• modified carbapenem inactivation method