- Poster presentation
- Open Access
Changing patterns of microbial resistance in an Indian cancer hospital ICU
© Biomed central limited 2006
- Published: 21 March 2006
- Klebsiella Pneumoniae
To analyse the pattern of microbial isolates and antibiotic sensitivity with time, changing antibiotic prescription and improved infection control.
A 550-bed tertiary referral cancer center with 11 ICU and 10 HDU beds. In 2004–05, the ICU had 640 admissions, with a mean APACHE II score of 15. Prospectively collected microbial culture and sensitivity data sent from the ICU over 34 months (between September 2002 and June 2005) was retrospectively analysed with respect to microbial isolates and antibiotic sensitivity. Data between September 2002 and December 2003 (P1) was compared with that from January 2004 and June 2005 (P2). Between the two periods, empirical use of third-generation cephalosporins was curtailed, with an increase in use of piperacillin-tazobactam and carbapenems, and emphasis was laid on handwashing and other infection control measures.
In P1, 622 (43.1%) of 1443 culture samples in 330 patients were positive and grew 750 organisms. In P2, 1807 culture samples were sent in 445 patients, of which 577 (32%) were positive and grew 664 organisms. There were fewer polymicrobial isolates in P2 (12% vs 16%, P = 0.01). There was no difference in the number of Gram-negative bacteria (GNB) (77% vs 80%), but there were fewer Gram-positive bacteria (GPB) (14% vs 19%, P = 0.01) and more fungi (5.7% vs 3.5%, P = 0.04). The major GNB grown were similar between the two periods with the largest being Pseudomonas aeruginosa (PA) followed by Klebsiella pneumoniae (KP) and Escherichia coli (EC). There was a reduction in the proportion of MRSA in P2 (12% vs 8%, P = 0.01) and a trend towards an increase in Acinetobacter (12% vs 9%) and candida spp. (5.4% vs 3.4%, both P > 0.05). There was a significant decrease in MRSA from thoracic isolates in P2 (36% vs 3% P = 0.0004). In P2, resistance of PA to ciprofloxacin reduced from 61% to 37%, and to ceftazidime from 81% to 65% (P < 0.001 for both). However, resistance to imipenem and meropenem increased from 49% to 61%, and from 32% to 56%, respectively (P < 0.01). Seventy-one percent of KP and 68% of the EC strains were resistant to ceftazidime in P2 (vs 53% [P = 0.030] and 60% [P > 0.05], respectively, in P1), probably reflecting an increase in ESBLs. Sixteen percent of KP and 14% EC strains were resistant to meropenem, versus 6.3% (P = 0.003) and 6% (P > 0.05), respectively, in P1. VRE (four cases) was observed in the ICU for the first time ever in P2. Overall, most GNB in P2 were sensitive to ciprofloxacin (65%), followed by the carbapenems (62%) and piperacillin-tazobactam (50%).
There is high incidence of resistant organisms in our ICU. Reduced use of cephalosporins has resulted in a significantly increased sensitivity of GNB to ciprofloxacin; however, resistance to the carbapenems has increased. Infection control measures may have helped reduce GPB infections. Monitoring changing trends in bacterial resistance can help rationalize empirical antibiotic therapy in the ICU.