Multicenter study of isolated micro-organisms resistant to antimicrobials in 10 Portuguese hospitals in 1994.


  • J M Cristino Hospital de Santa Maria, Lisboa.
  • E Calado
  • I M Calheiros
  • D Costa
  • M N Costa
  • J Diogo
  • M L Felicio
  • M L Ferro
  • J C Da Fonseca
  • M A Guimarães
  • L Lito
  • J Marques
  • M T Marques
  • F Martins
  • M A Pais
  • M Pinto
  • M H Ramos
  • G Ribeiro
  • L A Rodrigues
  • M J Salgado
  • J Simões
  • M D Sobral
  • C Toscano



In 1994, Microbiology Laboratories of ten Portuguese hospitals analysed isolated microorganisms found in blood and urine samples and studied antimicrobial susceptibilities of the most frequent bacterial pathogens. From 63780 blood samples, the most frequent were Staphylococcus spp. and from 69189 urine samples significant numbers of Escherichia coli, Enterococcus spp., Pseudomonas aeruginosa and Candida spp. were isolated. Escherichia coli strains (c.7000) revealed a low percentage of resistance to antibiotics with the exceptions of ampicillin (48%) and co-trimoxazol (25%). Klebsiella pneumoniae isolates (c.2000) revealed important resistance to ampicillin (98%), cephalotin (31%), co-trimoxazol (38%) and gentamicin (28%), while values for 3rd generation cephalosporins varied among hospitals, with several strains showing phenotype of extended-spectrum beta-lactamase. A great variation in resistance values of P. aeruginosa (c.4000) was found in relation to the antibiotics as well as to the hospitals. Resistance to methicillin in S. aureus (c.6000) was high, reaching an average of 47%, and it was even higher with S. epidermidis (c.3000) and S. haemolyticus (c.650). Only vancomycin was always active against these strains. In E. faecalis (c.2500) resistance was of 2% to ampicillin, 35% to gentamicin, 45% to streptomycin and 1% to vancomycin. E. faecium isolates (c.300) showed the most worrying results with 70% resistance to ampicillin, 42% to gentamicin, 59% to streptomycin and 9% (30 strains isolated in 5 hospitals) to vancomycin. Vancomycin resistant strains were also resistant to all other antibiotics.


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How to Cite

Cristino JM, Calado E, Calheiros IM, Costa D, Costa MN, Diogo J, Felicio ML, Ferro ML, Da Fonseca JC, Guimarães MA, Lito L, Marques J, Marques MT, Martins F, Pais MA, Pinto M, Ramos MH, Ribeiro G, Rodrigues LA, Salgado MJ, Simões J, Sobral MD, Toscano C. Multicenter study of isolated micro-organisms resistant to antimicrobials in 10 Portuguese hospitals in 1994. Acta Med Port [Internet]. 1996 Jun. 30 [cited 2024 Apr. 20];9(4-6):141-50. Available from:



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