Evaluation of the ciprofloxacin effect on resistant isolates of Pseudomonas aeruginosa in In-vitro and In-vivo

Introdu ction. Pseudomona I infections freque nt ly responds poorly to co nve ntio na l the rapy. Ciprotloxacin,a bacteriocidal 4-q uinolone , bas a higb activity aga ins t a broad spectrum of bacte ria including Pse udomona s aer uginosa. Materials and Methods. l IZ resistant isol a tes of P.aeru ginosa were co llecte d from five hospi tals in Tehra n. Afte r co nfirming them by the mos t spe cifi c ba cte riol ogical te sts such as cultured on Skim milk agar a nd e tc, th e efficacy of ciprofloxac in e va lua te d in compa riso n with 11 other antipseudorn onal antibiotics on 103 co nfi rmed res istan t isol at es. Su sce ptibility tests were performed by disk-diffusion (BAUER-KIRBY) a nd Micro dilu tio n broth methods. The th era peut ic effects of ciprotloxacin in compariso n with the ot hers we re st udied in experimenta l infe ctio us mo del, T he ED50 were de termined by spe r rna n-Ka rbe rs me th od. Results. Ci protloxacin was th e most active agent against a ll isolates of P.a e r uginosa tha t tes te d in in-vitro. The geometr ic mean(GM) MICs a nd range s o f c ip rotloxac in was I a nd < O.OIS to Z 1/g1ml. In- vivo protective effica cy of cip ro tl oxac in by intravenusf lV) injectio n was higher than th os e of the ot he r a ge nts te sted in a mouse mode l of int ra peritone ally inocul at ed infec tio n caused by P.aeruginos a. Other agents did no t exhib it co mparable to th at o f ciprofl oxacin in the same model of infe ct io n caused by P.a e r uginosa. Conclution, The susce ptibility p rofile of individual isol ates of each hospital diffe rs o nly a little , but differs more th an the ot he rs. Thus, tr eatment p rograms of infec t io us dise ases must be designe d best o n th e individual hospital to control th e a ntibio tic resi stance.