From the Department of Genetics, Research Center, Kelman University of Medical Sciences, Kerman,I.R.Iran , shakibaie@arg3.uk.ac.ir
Abstract: (5175 Views)
Pseudomonas aeruginosa is a leading cause of bum infections, and antibiotic-
resistant strains of this bacterium are emerging due to extensive application
of antibiotics in the bum unit of hospitals. In this study 50 strains of P. aeruginosa
were isolated from bum patients infected with this micro-organism in the bum
unit of a general hospital in Kerman, Iran over one year [May 1999-ApriI2000].
Sensitivity/ resistance of the isolates for antibiotics and metals was determined
by MIC test. 46% of the isolates were resistant to ciprofioxacin, kanamycin (K),
gentamicin (Gm), tetracycline (Te) and chloramphenicol ( c ). 35% were resistant
to amikacin (AN), ceftriaxone (Ceft), and cefotaxime (CTX), and 10% were resistant
to imipenem (Imp) and piperacillin (PIP). The isolates exhibited varied
MIC's to metal ions. 87% were sensitive to cadmium (Cd), 62% to lead (Pb),
91 % to mercury (Hg), 54% to zinc (Zn), 85% to chromium (Cr), and 83% to
arsenate (Ars). Among them, strain 16 was found to be resistant to Pb, Cr, and Zn
as well as Te, C, Gm, and K. Conjugation and transformation experiments revealed
the transfer of Ter, Cr, Krand Gmr along with Pbr to a sensitive strain of P.
aeruginosa PTCC1074.1 (Rif) but not to E. coli K12 HB101.1(Rifr). Subsequent
plasmid isolation and agarose gel electrophoresis (0.7%) confirmed the
presence of three-plasmid bands in strain 16 and the transconjugant. Furthermore,
strain 16 accumulated a maximum amount of Pb (50µM) within 60 min. and
reached a plateau afterwards.