RESUMEN
OBJECTIVE: Ceftazidime-avibactam (CZA) is a good option for Gram-negative bacilli infections that produce carbapenemase Classes A (especially blaKPC) and D (blaOXA). However, it is unknown whether it would have an impact on metallo-ß-lactamases (blaMBL) selection. The aim of the study was to compare carbapenem and CZA Klebsiella pneumoniae (KPN) susceptibility profiles for a period of two years following the introduction of CZA. METHODS: The study was conducted in a 36-bed adult ICU of a tertiary hospital in Buenos Aires, Argentina. Antimicrobial consumption was expressed as days of treatment per 100 patients-day (DOT). RESULTS: A total of 123 KPN strains in the first year and 172 in the second year were analyzed. An alarming decrease in carbapenem susceptibility was detected in the second year (OR 0.5 [0.3-0.8] p<.001). In parallel, there was a decrease in CZA susceptibility (OR 0.5 [0.3-0.9] p<.05). These findings were linked to a rise in blaMBL-KPN (32.1% vs. 45.1%, OR 1.7 [1.1-2.9], p <.04) during the second year. This new KPN susceptibility profile promoted an increment in CZA (1.0 DOT vs. 6.6 DOT, OR 6.6 [4.9-9.1] p<.001) and aztreonam (0.3 DOT vs. 4.1 DOT, OR 16.3 [9.1-29.3] p<.001) consumption. Thus, there was a decrease in carbapenem prescription (17.8 DOT vs. 15.4 DOT, OR 0.8 [0.8-0.9] p<.001). CONCLUSIONS: There was an escalation of blaMBL-KPN rate two years after CZA introduction, leading to a decrease in CZA and carbapenem susceptibility and an increase in CZA and aztreonam prescriptions.
Asunto(s)
Antibacterianos , Compuestos de Azabiciclo , Ceftazidima , Combinación de Medicamentos , Unidades de Cuidados Intensivos , Infecciones por Klebsiella , Klebsiella pneumoniae , Pruebas de Sensibilidad Microbiana , beta-Lactamasas , Ceftazidima/farmacología , Ceftazidima/uso terapéutico , Compuestos de Azabiciclo/uso terapéutico , Compuestos de Azabiciclo/farmacología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/genética , Argentina , Humanos , Antibacterianos/uso terapéutico , Antibacterianos/farmacología , beta-Lactamasas/genética , Infecciones por Klebsiella/tratamiento farmacológico , Infecciones por Klebsiella/microbiología , Carbapenémicos/farmacología , Carbapenémicos/uso terapéutico , Centros de Atención TerciariaRESUMEN
Fluoroquinolone resistance is a growing problem that has only recently emerged in S. agalactiae. Between 2005-2007, WHONET--Argentina network evaluated levofloxacin susceptibility in 1128 clinical S. agalactiae isolates, 10 (0.9%) of which proved to be resistant. Nine of them had come from 5 hospitals (in Buenos Aires City and 4 Argentinean provinces) and recovered from urine (n=7) and vaginal screening cultures (n=2). Three strains were also resistant to macrolides, lincosamides and B streptogramins due to the ermA gene. All nine fluoroquinolone-resistant isolates bore the same two mutations, Ser79Phe in ParC and Ser81Leu in GyrA proteins. Genetic relationships were analyzed by Apal-PFGE and two clones were determined, A (n=6) and B (n=3). To our knowledge, these are the first fluoroquinolone-resistant S. agalactiae isolates detected in Latin America.