Confronto dell'Antibioticoresistenza di Pseudomonas aeruginosa verso tutti gli altri batteri Gram negativi non fermentanti il glucosio: risultati di uno studio osservazionale condotto su isolati da matrici ambientali di un policlinico universitario romano.

[Autom. eng. transl.] OBJECTIVES: In Italy the phenomenon of antibiotic resistance has assumed alarming dimensions; in fact, the epidemiological data collected at European level show that Italy is among the countries with higher frequencies of antibiotic-resistant microorganisms and also among those with the highest consumption. An observational study, lasting 6 years (September 2004-September 2010), was conducted to compare the anti-antibiotic resistance of Pseudomonas aeruginos with that of other gram-negative non-fermenting glucose bacteria (BGNnF), all isolated from different aqueous matrices from wards to medium and high risk of a University Hospital in Rome. METHODS: The susceptibility of isolates to 19 antibiotics individually and to two, three and four antibiotics was tested simultaneously. The strains were subjected to resistance studies with miniaturized automatic systems (ATB PSE 5, Bio-Merieux). The chi-square test (chi2) was used to evaluate the association between the P. antibiotics resistance and that of the BGNnF; the statistical significance was set at a value of p <0.05. RESULTS: 2,016 samples were taken and analyzed, of which 116 were positive: 40 (34.5%) for the presence of P. aeruginosa and 76 (65.5%) of BGNnF. A statistically significant association of P. aeruginosa resistance (p <0.001) with BGNnF was detected with the following antibiotics: Amikacin (chi2 = 18.56), Ampicillin-sulbactam (chi2 = 25.37), Colistin (chi2 = 40.65), Cotrimoxazole (chi2 = 54.01), Gentamicin (chi2 = 25.72) and Tobramycin (chi2 = 23.17); on the other hand, there is no statistically significant association with Imipenem (chi2 = 0.37; p = 0.539), Meropenem (chi2 = 1.64; p = 0.199), Ceftazidime (chi2 = 1.04; p = 0,30) and Cefepima (chi2 = 0,02; p = 0,877), considered last generation antibiotics. CONCLUSIONS: The above results suggest that isolated P. aeruginosa strains are still susceptible to the latest antibiotics; this confirms the importance of a prudent and "judicious" use of the latter. Understanding the role of environmental microbial ecology and antibiotic resistance profiles could help predict and control the development and evolution of future resistance even in clinical strains. Therefore, it would be advisable to continue to monitor the evolution of this phenomenon constantly, with predetermined time frames, integrating the best scientific evidence relating to the environmental strains with those concerning the clinical strains, to protect the hygiene of the environment and, at the same time , patient safety.