Relationship between piperacillin-tazobactam consumption and bacterial resistance in Colombian hospitals. Atime-series analysis,20042007

Abstract number: P751

Buitrago G., Alvarez C.A., Leal A.L., Castillo J.S., Martinez J., Sanchez R., Cortes J.A., Jimenez A., Chaves O., Meneses A.F.

Objectives: Determine the relationship between the piperacillin-tazobactam (TZP) consumption and resistance of Pseudomonas aeruginosa and Klebsiella pneumoniae to this antibiotic in three high complexity hospitals from Colombia.

Methods: Ecological time series study to relate the effect of TZP consumption in P. aeruginosa and K. pneumoniae resistance. Monthly hospital consumption of TZP was collected in three hospitals of two cities in Colombia (Bogota and Cucuta). Antibiotic consumption was grouped as the number of defined daily doses (DDD) per 100 bed-days (World Health Organization) each month between January 2004 and December 2007 (48 periods). P. aeruginosa and K. pneumoniae resistance to TZP was determined as the proportion of resistant isolates reported by hospital laboratory, data was analyzed in Whonet 5.4® (Geneva, WHO). Resistance proportions were translated to odds and log transformed (ln[R/(1 - R)]). Univariate monthly series per hospital were performed for consumption and resistance (ARIMA – Box Jenkins). The relationship between both variables was explored using transfer function models per institution. All time series analysis were done in SCA (Villa Park, USA).

Results: Average monthly consumption of TZP was 1.36 DDD per 100 bed-days. In the three hospitals there was an upward trend in TZP consumption for study period. There was an absolute increase of 0.56, 1.81 and 3.33 DDD per 100 bed-days for each hospital. Monthly average resistance proportion in each hospital was 13.9, 19 and 36.8% for K. pneumoniae and 4.7, 24.4 and 37.1% for P. aeruginosa. Univariate consumption analysis shows an increase. Transfer function in the six models evidence consistency between the statistical association of TZP consumption and the expression of resistance to this antibiotic for K. pneumoniae and P. aeruginosa (Figure 1).

Conclusions: There is consistent relationship between TZP consumption and resistance of K. pneumoniae and P. aeruginosa to this drug. TZP consumption can explain until 20% of resistance found in P. aeruginosa and 12% in K. pneumoniae. Remaining unexplained resistance can be related to other uncontrolled factors not considered in the models.

Session Details

Date: 16/05/2009
Time: 00:00-00:00
Session name: 19th European Congress of Clinical Microbiology and Infectious Diseases
Location: Helsinki, Finland, 16 - 19 May 2009
Presentation type:
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