Introduction: The emergence and propagation of multi-resistant
bacteria in the hospital environment have become serious
epidemiological and therapeutic problems. It is essential to update
data regarding the susceptibility to the most commonly used
antibiotics in each hospital, allowing obtaining specific resistance
patterns to define the antibiotic therapy.
Objectives: This study aims to establish a profile of susceptibility
vs. resistance for different microorganisms isolated during 3 years
(2009-2011) using 3300 clinical isolates of different biological
samples obtained from different hospital units belonging to Centro
Hospitalar de Trás-os-Montes e Alto Douro (CHTMAD).
Methods: Identification and susceptibility tests were done using
microdilution plate method and results were submitted to principal
component analysis (PCA).
Results: Methicillin resistant Staphylococcus aureus (MRSA),
Enterococcus faecium and coagulase negative Staphylococcus (CNS)
seem to be the most concerning Gram positive microorganisms. For
Gram negative species, despite the high resistance presented by
Enterobacteriaceae producing extended-spectrum beta-lactamases
(ESBL) to b-lactamic antibiotics, imipenem is still a good
therapeutic option, as well as fosfomycin (for urinary infection).
Stenotrophomonas maltophilia, Pseudomonas aeruginosa MR
and Acinetobacter baumannii, are progressively acquiring higher
resistance to these antibiotics, mainly to imipenem, cotrimoxazol
and even aminoglycosides (tobramycin and gentamycin).
Conclusions: Overall, the developed resistance seems to be directly
associated with antibiotics use and, therefore, studies centered
in multi-resistance to antibiotics are crucial to establish dynamic
protocols adequate to specific resistance vs. susceptibility profiles
