Background The existence of multidrug-resistant organisms, including extended-spectrum beta-lactamases (ESBLs), is on rise across the globe and is becoming a severe problem. Knowledge of the prevalence and antibiogram profile of such isolates is essential to develop an appropriate treatment methodology. This study aimed to study the prevalence of Gram-negative isolates exhibiting ESBL at a tertiary care hospital and study their antibiogram profile. Methods A cross-sectional study was conducted at Shahid Gangalal National Heart Centre, Kathmandu, Nepal, from June 2018 to November 2018. A total of 770 clinical samples were collected and identified using the conventional biochemical tests following the Clinical and Laboratory Standard Institute (CLSI) guidelines. Antimicrobial susceptibility testing (AST) was performed using the standardized Kirby-Bauer disk diffusion method. The screening test for ESBL producers was performed as recommended by the CLSI and the confirmatory test was performed phenotypically using the E-test. Results Out of the 92 isolates, 84 (91.3%) were multidrug-resistant, and 47 (51.1%) were found to be potential ESBL producers. Of these, 16 isolates were confirmed ESBL producers by the E-test. Escherichia coli and Klebsiella pneumoniae were the predominant isolates and were also the major ESBL producers. Besides polymyxin B (100% sensitive), meropenem and imipenem showed high efficacy against the ESBL producers. Conclusion Multidrug resistance was very high; however, ESBL production was low. Polymyxin B and carbapenems are the choice of drugs against ESBL producers but should be used only as the last line drugs.

Background and Objectives: Carbapenems have been the choice of antibiotics for the treatment of infections caused by multidrug-resistant bacteria. The main objective of this study was to determine the prevalence of carbapenemase (blaVIM and bla ) producing isolates among Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter baumannii. Materials and Methods: A total of 1,151 clinical samples were collected from the patients visiting Annapurna Neurological Institute and Allied Science and Annapurna Research Centre, Kathmandu, between June 2017 and January 2018. Antibiotic susceptibility testing (AST) was performed on the Enterobacteriaceae, P. aeruginosa and A. baumannii isolates using the Kirby-Bauer disk diffusion method. The modified Hodge test (MHT) was performed on the carbapenem-resistant isolates to confirm carbapenemase production. DNA was extracted and then screened for blaVIM and blaIMP genes by multiplex PCR. Results: Of the total 1,151 clinical samples, 253 (22.0%) showed positive growth. Of them, 226 (89.3%) were identified as Enterobacteriaceae, P. aeruginosa, and A. baumannii. Among the 226 isolates, 106 (46.9%) were multidrug-resistant. Out of the 106, 97 (91.5%) isolates showed resistance to at least one of the carbapenem used. Among the 97 carbapenem-resistant isolates, 67 (69.1%) showed the modified Hodge test (MHT) positive results. bla isolates respectively using multiplex PCR assay. Conclusion: This study determined a high prevalence of MDR and carbapenem resistance among Enterobacteriaceae, P. aeruginosa, and A. baumannii as detected by the presence of blaVIM and blaIMP genes. This study recommends the use of rapid and advanced diagnostic tools along with conventional phenotypic detection methods in the clinical settings for early detection and management of drug-resistant pathogens to improve treatment strategies.

Aim Although carbapenem is the last-resort drug for treating drug-resistant Gram-negative bacterial infections, prevalence of carbapenem-resistant bacteria has substantially increased worldwide owing to irrational use of antibiotics particularly in developing countries like Nepal.  Therefore, this study was aimed to determine the prevalence of carbapenemase-producing K. pneumoniae and to detect the carbapenemase genes (blaNDM-2 and blaOXA-48) in at a tertiary care hospital in Nepal. Materials and methods A hospital-based cross-sectional study was carried out from June 2018 to January 2019 at the Microbiology Laboratory of Annapurna Neurological Institute and Allied Sciences, Kathmandu, Nepal. Different clinical samples were collected and cultured in appropriate growth media. Biochemical tests were performed for the identification of K. pneumoniae. Antibiotic susceptibility testing (AST) was performed by the Kirby–Bauer disc diffusion method. The modified Hodge test (MHT) was performed to detect carbapenemase producers. The plasmid was extracted by the modified alkaline hydrolysis method. Carbapenemase-producing K. pneumoniae were further confirmed by detecting blaNDM-2 and blaOXA-48 genes by PCR using specific forward and reverse primers followed by gel electrophoresis. Results Out of the total 720 samples, 38.9% (280/720) were culture positive. K. pneumoniae was the most predominant isolate 31.4% (88/280). Of 88 K. pneumoniae isolates, 56.8% (50/88) were multi-drug resistant (MDR), and 51.1% (45/88) were MHT positive. Colistin showed the highest sensitivity (100%; 88/88), followed by tigecycline (86.4%; 76/88). blaNDM-2 and blaOXA-48 genes were detected in 24.4% (11/45) and 15.5% (7/45) of carbapenemase-producing K. pneumoniae isolates, respectively. Conclusion The rate of MDR and carbapenemase production was high in the K. pneumoniae isolates. Colistin and tigecycline could be the drug of choice for the empirical treatments of MDR and carbapenemase-producing K. pneumoniae. Our study provides a better understanding of antibiotic resistance threat and enables physicians to select the most appropriate antibiotics.

Carbapenemases are the enzymes that catalyze β–lactam groups of antibiotics. The carbapenemase producers are resistant to β–lactam antibiotics and are usually multidrug-resistant bacteria challenging widely used therapeutics and treatment options. Therefore, the detection of carbapenemase activity among clinical isolates is of great therapeutic importance. We aimed to study the MDR and carbapenemase-producing Klebsiella pneumoniae and Pseudomonas aeruginosa isolated from various clinical samples at a tertiary care hospital in Nepal. A total of 3,579 clinical samples were collected from the patients visiting the Department of Microbiology, B&B Hospital, Gwarko, Lalitpur. The samples were processed to isolate K. pneumoniae and P. aeruginosa and then subjected to antibiotic susceptibility testing (AST) by the Kirby-Bauer disk diffusion method. Phenotypic detection of carbapenemase activity was performed in the imipenem-resistant isolates by the modified Hodge test (MHT). Of the total samples, 1,067 (29.8%) samples showed significant growth positivity, out of which 190 (17.3%) isolates were K. pneumoniae and 121 (11.3%) were P. aeruginosa. Multidrug resistance was seen in 70.5% of the K. pneumoniae isolates and 65.3% of the P. aeruginosa isolates. Carbapenemase production was confirmed in 11.9%, and 12.2% of the imipenem-resistant K. pneumoniae and P. aeruginosa isolates, respectively, by the MHT. This study determined the higher prevalence of MDR among K. pneumoniae and P. aeruginosa; however, carbapenemase production was relatively low.