Viral Vadwai, Vidya Nerurkar, Mamta Kumari, Uma Ramesh, Sunanda Dey and Bibhu Ranjan Das
Aim: To perform a retrospective analysis to assess the antimicrobial resistance pattern of gram positive- and negative- organisms involved in causing bloodstream infections. Antimicrobial susceptibility was performed using broth microdilution methodologies and results were interpreted using Clinical and Laboratory Standards Institute guidelines.
Results: This study included 1825 gram-positive and 2986 gram-negative isolates. Twenty-nine percent (108/372) of the Staphylococcus aureus isolates were methicillin resistant with high rate of susceptibility for glycopeptides (>95%). Among the Enterococcus species, 12.1% (18/154) isolates were vancomycin resistant; also conferring resistance to linezolid (3.3%, 5/154). Most gram negative organisms recorded high level resistance to cephalosporins (>70%), fluoroquinolones (>50%) and β-lactum agents (>65%). Extended-spectrum β-lactamases (ESBLs) were reported among 52.8% (346/655) of Escherichia coli; and of these, 5.3% (18/346) isolates conferred carbapenem resistance. Similarly, reduced carbapenem susceptibility was reported against Acinetobacter spp. (62-83%; [Acinetobacter baumannii, ~85%]) and Pseudomonas spp. (62%; [Pseudomonas aeroginosa, <50%]).
Conclusion: Thus, glycopeptides and carbapenems retain high antimicrobial activity against most gram positive- and gram negative- pathogens.