Characterization of antibiotic resistance of Staphylococcus aureus isolated from patients with diabetic foot ulcers in Wasit Province

Diabetic foot ulcers are one of the most common public health issues worldwide, putting a social strain on those who suffer from them; chronic ulcers that lead to amputation are a severe disease that can reduce diabetic patients' quality of life. A total of seventy-five samples were collected from diabetic foot ulcer with age (30 - 89) years, during the period from 1st October 2020 to15th January 2021, admitted to Al-Karama teaching hospital and private clinics in Wasit province. The results revealed that the frequency among males 50 (67 %) more than female 25 (33 %).The sample distribution according to age it appears high (42.7 %) with group (50-59) years. The results shows that Gram negative bacteria reveals a high rate 57.4% (n=35) which includes K. pneumoniae that show a high percentage 24% (n=18), then E.coli 13.2% (n=10). followed, P.aeruginosa 4.0% (n=3) and P.mirabilis 2.7(n=2) and A.baumannii 2.7% (n=2). While Gram-positive bacteria recorded 42.6% (n=26) ,which include S. aureus was the most isolated bacteria in this study with percentage 33.3 % (n=25) followed by streptococcus group B 1.4% (n=1).
Methicillin resistant Staphylococcus aureus was recorded with 92.3 % in all isolates and results of MRSA isolates antibiotic susceptibility for S. aureus as shown: the maximum resistance level to the Oxacillin (100 %), penicillin (100 %), cefoxitin (92.3 % ), vancomycin (61.5 % ), clindamycin (61.5 % ), followed by gentamicin (53.8 %), erythromycin (53.8 %), while the lowest resistance with ciprofloxacin (38.4 %). The maximal S. aureus sensitivity has been to Trimethoprim-Sulfamethoxazole (57.8 %) , vancomycin (38.5 %) , ciprofloxacin (30.7 %) and gentamicin (34.6 %). DNA of twenty-five isolates S. aureus were extracted, also purity and concentration were confirmed with Nanodrop, the purity of the nucleic acid in the samples ranged between 1.8-2, while its concentration ranged from (50-360 mg / μl).
Resistance genes possessed by the S. aureus isolates were: mecA (96%), ermC (40%), msrA (8.0 %) and aac(6′)-aph(2″) (16 %). while ermA and vanA genes were absent among all isolates. In conclusion, the findings of the present study revealed that most studied isolates which had multiple antibiotic resistances.