Antibiogram of Escherichia coli and Klebsiella pneumoniae Urinary Isolates and Susceptibility of Amikacin in Extended-spectrum Beta-Lactamase Producers

Urinary tract infections (UTIs) are predominantly caused by bacteria, with Escherichia coli and Klebsiella pneumoniae being predominant causative agents. This retrospective study evaluated the antibiotic susceptibility profiles of E. coli and K. pneumoniae isolates obtained from urine culture of patients with UTI symptoms presenting at the Pradyumna Bal Memorial Hospital, Kalinga Institute of Medical Sciences, Bhubaneswarr, Odisha. With increasing antibiotic resistance, particularly in bacterial strains that synthesize extended-spectrum beta-lactamases (ESBLs), identifying effective treatment options is crucial. From January to November 2023, 1,798 urine cultures were analyzed using the VITEK 2 Compact System, revealing E. coli 432 (60%) and K. pneumoniae 239 (33.2%) as the predominant pathogens. E. coli isolates exhibited high susceptibility to fosfomycin (98.6%), nitrofurantoin (80%), and amikacin (75.8%). K. pneumoniae showed high susceptibility to fosfomycin (73.9%) and amikacin (50.2%) but significantly lower susceptibility to nitrofurantoin (17.2%). Approximately 307 (58.03%) isolates were ESBL-synthesizing E. coli (57.9%) and K. pneumoniae (42.01%). ESBL synthesizing E. coli and K. pneumoniae were highly susceptible to fosfomycin (71.5%) and amikacin (62.4%). Our results emphasize the need to consider local resistance patterns when choosing empirical antimicrobial treatments for UTIs. Although fosfomycin demonstrated the highest sensitivity, being a reserve drug requires cautious use. Amikacin, with its favorable susceptibility profile is a valuable alternative especially for UTIs caused by ESBL-synthesizing, nitrofurantoin-resistant, and fosfomycin-resistant K. pneumoniae and E. coli, and offers a potential single-dose treatment option. This targeted approach can help preserve last-resort antibiotics in more critical cases.