The objectives of this study were to establish the extended spectrum β-lactamases (ESBL), in nosocomial bacilli Gram negative and to compare three methods for the detection of ESBL.
Materials and methods.
201 microorganisms were studied isolated of patients with nosocomial infections at the Hospital San Jerónimo (HSJ) of Montería during the years 2001 and 2002. To detect the presence of ESBL was taking account the hydrolytic activity upon ceftazidime, that measured the synergism of the clavulanic acid in combination with ceftazidime. To compare the methods of detection of ESBL, were used those proposed by the National Committee for Clinical Laboratory Standards (NCCLS) disk diffusion, the Minimal inhibitory Concentration (MIC90
) and the combination disk method of Jarlier.
The results showed that 86 (43%) of 201 germs were ESBL producers. ESBL were observed in 24 (63%) of 38 Acinetobacter baumannii
, 11 (61%) of 18 Enterobacter
spp, 17 (46%) of 37 Klebsiella pneumoniae
, 22 (38%) of 58 Pseudomonas aeruginosa
, 5 (31%) of 16 Proteus mirabilis
and 7 (20.5%) of 34 Escherichia coli
. The comparison of the detection methods did not show differences between them (p>0.05). The results show a high prevalence of ESBL (43%) in the nosocomial bacilli Gram negative at the HSJ of Montería.
The study was able to show the importance of the methods for detection of ESBL as support to establish the correct antimicrobial therapy in nosocomial germs and upon this base to suggest the implementation of measures of surveillance that prevent and to reduce the dissemination of ESBL at this hospital.