[Antibiotic consumption and antimicrobial susceptibility evolution in the Centro Hospitalario Pereira Rossell in methicillin resistant Staphylococcus aureus era].

Introduction: In the past few years, an increase in methicillin resistant-not multiresistant Staphylococcus aureus was observed in Uruguay among children with community acquired infections. Recommendations for empiric antibiotic treatment required adjustments and new national guidelines were recommended in July 2004. Adherence to these guidelines was indirectly performed by monitoring antibiotic consumption and antimicrobial susceptibility patterns in Uruguay.

Objective: To describe and compare antibiotic consumption and antimicrobial susceptibility of Staphylococcus aureus in a Pediatric Hospital of the Centro Hospitalario Pereira Rossell (PH-CHPR) between 2001 and 2006.

Methods: Antibiotic consumption in hospitalized children was calculated using the Defined Daily Dose per 100 bed-days (DDD/100). Reference values were obtained from the World Health Organization Collaborating Center for Drug Statistics Methodology of. Consumption. Data were obtained using the WinPharma programme of the Pharmacy Department of CHPR. The fraction of annual occupancy of hospital beds was obtained from the Statistic Division of CHPR. Antibiotic consumption was evaluated between 2001 and 2006 and expressed as DDD/100 and percent change. Antimicrobial susceptibility was evaluated using CHPR's Microbiology Laboratory data during the same time period.

Results: After 2003 a significant increase in consumption of clindamycin, ceftriaxone, trimethoprim-sulphamethoxazole, cefuroxime, vancomycin and gentamycin was observed, except for cephradine. Consumption of clindamycin, ceftriaxone and trimethoprim-sulphamethoxazole showed the highest increase (6.15%; 1.44% and 1.17% respectively). Detection of Staphylococcus aureus increased significantly mostly from skin and soft tissue infections. Oxacillin susceptibility of S. aureus strains obtained from different sites had a significant and persistent decrease after 2003 (from 81 % during year 2001 to 40% in year 2006 (p < 0.05). Susceptibility to others antibiotics did not decrease. Between 2004 and 2006 the "D effect" decreased from 28% to 21 %. Antimicrobial susceptibility patterns did not differ by site of infection.

Conclusions: Methicillin resistant-not multiresistant Staphylococcus aureus has established itself as a regular community pathogen in Uruguayan children. Changes in antimicrobial consumption patterns reflect the impact of this pathogen in clinical practice and the overall adherence to new recommendations. This change was not associated with an increase in antibiotic resistance. Clindamycin is an alternative treatment although Clindamycin inducible resistance is a worry. Continuous monitoring of antibiotic consumption and local susceptibility patterns are required to promote rational use of antibiotics.