Antibiotic Resistance Pattern of Isolates in Intensive Care Unit and Source of Nosocomial Infection in a Tertiary Care Hospital, Dhaka, Bangladesh

Background: Infections with resistance bacteria threatens the effectiveness of antibiotic treatment with increased morbidity, mortality and hospital costs. Rapid emergence of multi-drug resistance necessitates monitoring microbial isolates with their resistance pattern. During 2015-16, this study conducted in Square hospital ICU to see pattern of pathogens, their antimicrobial resistance and presence of MRSA, ESBL and CRE in nosocomial infections. Methods: Specimens from ICU patients processed for isolation, identification, tested antimicrobial resistance and production of ESBL, CRE and MRSA following standard methods. Admitted patients were monitored and data analyzed for pattern of hospital-acquired infections. Results: Of 2,447 pathogens, majority yielded from tracheal aspirates (37%) compared to others. Among pathogens, Klebsiella were 21.6%, E. coli 12%, Pseudomonas 9.9% and Acinatobacterspp 9.8%; while Staphylococci were 8.3%, Enterococci 3.4%, Pneumococci 2% and Candida were 13%. Overall 78% E. coli were resistant to multiple drugs; of which 82% resistant to cefuroxime, 75% to amoxiclav and ciprofloxacin each, 69% to cefixime, 67% to ceftriaxone and 66% to cefepime. Majority Klebsiella were resistant to common antibiotics, except meropenem (50%). About 40% Pseudomonas and Acinatobacter were resistant to common antibiotics except colistin and polymyxin B. About 58% of E. coli and 24% Klebsiella produced ESBL, with 48% resistant to carbapenem. Penicillin and amoxicillin resistance were 90% among gram positive bacteria and MRSA Producing Staphylococci was 47% with no resistance to vancomycin. Among 277 hospital-acquired infections, Ventilator associated pneumonia (VAP) was 56% followed by 23.1% UTI and 10.5% BSI. Conclusion: Emergence of MDR bacteria among ICU patients is a global problem as they contract hospital-acquired infections more commonly from foci within hospitals. Higher prevalence of MDR infection in ICU of SHL is not an exception. Challenges remain in treating patients with CRE, ESBL and MRSA infections. Strengthening antimicrobial stewardship, monitoring effectiveness of antibiotic usage and infection control program could reduce this critical problem.