ABSTRACT
Irrational use of antibiotics has fueled a major increase in prevalence of multi drug resistant pathogens, leading some to speculate that we are nearing the end of antibiotic era. The assessment of the activity of an antibiotic is crucial to the successful outcome of antimicrobial therapy. The objective of the study is to evaluate the resistance pattern between cefixime [a third generation cephalosporin] of 5micro g and cefepime [a fourth generation cephalosporin] of 30 micro g, on a total of 138 different clinical isolates namely as; Escherichia coli [30%], Staphylococcus aureus [30%], Salmonella typhi [14%], Klebsiella pneumoniae [13%] and Pseudomonas aeruginosa [13%]. The isolates were collected over a period of one year [January 2008 to January 2009] from pathological laboratories of different hospitals in Karachi, Pakistan, which comprised of 59 urine, 30 skin pus, 29 ear pus, 15 blood and 5 stool samples. In-vitro antibiotic sensitivity was performed by disk diffusion or Bauer-Kirby method using 0.5 McFarland standard. Cefepime showed good sensitivity of about 92.6% against Escherichia coli, 85% against Staphylococcus aureus, 94% against Klebsiella pneumoniae, 77.77% against Pseudomonas aeruginosa and 65% against Salmonella typhi. Cefixime showed least sensitivity against Pseudomonas aeruginosa [16.66%] and maximum effectiveness against Salmonella typhi [90%]. Results of the study indicate that cefepime is more effective for the treatment of infections caused by the above pathogens except for Salmonella typhi. It is concluded that in the face of continuing development of resistance, considerable effort will be required to maintain the effectiveness of these drug groups