An in vitro evaluation of antibiotic combinations for urinary tract infections in patients with diabetes mellitus.

This prospective in-vitro study evaluates the synergistic potential of various antibiotic combinations against resistant pathogens isolated from urinary tract infections (UTIs) in patients with diabetes mellitus. Antibiotic combinations using the microtiter checkerboard method showed that overall, synergy could be seen in 41.86%-67.44% cases amongst the five different antibiotic combinations studied against the four predominant resistant pathogens namely Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella ozaenae. The checkerboard synergy studies showed that 69.23% of the S. aureus strains tested were synergistically inhibited by the combination of ofloxacin + cefotaxime [OF+CF], 83.33% of the E. coli strains and 75% of the K. ozaenae strains were synergistically inhibited by the combination of amikacin + cefotaxime [AK+CF], while 58.33% of the P. aeruginosa strains were synergistically inhibited by the combination of amikacin + piperacillin [AK+PP].

Antibiotic combinations in polymicrobic diabetic foot infections.

OBJECTIVE: The aim of this study was to evaluate synergistic potential of antibiotic combinations against pathogenic microorganisms isolated from patients with diabetic foot wounds. RESEARCH DESIGN AND METHODS: 272 diabetic foot patients were studied prospectively over a two-year period. Tissue curettage samples from ulcer base were processed microbiologically to isolate aerobic as well as anaerobic pathogens. [775 isolates] Antibiotic susceptibility testing [MIC/MBC], from amongst these organisms revealed 75 multiresistant organisms, of which only 69 strains could be further studied to assess synergistic effect of various antibiotic combinations by the microtitre checkerboard assay technique. RESULTS: The checkerboard synergy studies showed that overall, synergy could be demonstrated in 21.74% to 59.57%. Amongst the 14 combinations tested, it was found that four combinations could be of worthwhile clinical significance, namely Amikacin/Piperacillin [AK + PP] [77.50%]; Ampicillin-Sulbactum/Piperacillin [AS + PP] [76.92%]; Ampicillin Sulbactum/Cefoperazone [AS + CP] [74.47%], and Ofloxacillin/Cefotaxime [OF + CT] [71.43%]. CONCLUSIONS: Amikacin/Piperacillin is a combination that has been proven to be of synergistic potential. This study not only confirms this observation but also showed that Ampitum-Sulbactum in combination with either Piperacillin or Cefoperazone was equally efficacious. Furthermore, it was also observed that Ofloxacillin/Cefotaxime combination could be almost equally useful. The study thus emphasizes that antibiotic combinations which are synergistic can be of great clinical significance in the management of patients with diabetic foot infections.

Diabetic foot infections: a study of microorganisms associated with the different Wagner grades.

Patients with diabetes foot infections were evaluated over a two year period to assess the bacteriological spectrum in the different Wagner's grades of foot wounds. Most of the diabetic foot wounds were found to be polymicrobic in nature with an average of 3.07 organisms isolated per case studied. Amongst a total of 775 clinical isolates, 71.09% were aerobic; whereas 28.91% were anaerobic pathogens. Gram-positive organisms like Staphylococcus spp. and Streptococcus spp. formed almost 50% of the clinical isolates in the first two grades and were reduced to less one-fourth of the total organisms in the last two grades. These was a significant increase in the gram-negative organisms and anaerobes in the last two grades.