Clinico-microbiological study and antimicrobial drug resistance profile of diabetic foot infections in North India.

The study was carried out in diabetic patients with foot ulcer to determine the microbiological profile of infected ulcer, antibiotic resistance of the isolates and to find out the potential risk factors for infection with multidrug resistance and the outcome of these infections. A detailed clinical history and physical examination was carried out in each patient. Pus samples for bacterial culture were collected from 102 patients admitted with diabetic foot infections. All patients had ulcer with Texas grades 1-3. Seventeen patients (16.6%) had coexisting osteomyelitis. Aerobic gram negative bacilli were tested for extended spectrum β lactamase (ESBL) production by phenotypic and genotypic methods. Staphylococcus isolates were tested for susceptibility to oxacillin and cefoxitin by disk method. Potential risk factors for MDRO positive samples were explored. Gram negative aerobes were most frequently isolated (63.8%), followed by gram positive aerobes (36.1%) and anaerobes (31.4%). Forty five percent of patients were positive for MDROs. ESBL production and methicillin resistant was noted in 68.5% and 43.2% of bacterial isolates respectively. 34.5% gram negative strains were positive for bla(CTX-M) gene followed by bla(SHV) (23%) and bla(TEM) (7.4%). Among the anaerobic organism 17(31.4%) from 54 patients, most commonly isolated were Peptostreptococcus sp. (35.2%). MDRO positive status was associated with the presence of neuropathy (P<0.001), osteomyelitis (P<0.03), and ulcer size >4 cm(2) (P<0.01) [corrected] but not with patients characteristic, ulcer type and type of diabetes, or duration of hospital stay. Poor glycemic control in 68.6% patients, duration of infection>1 month (36.2%) and ulcer size >4 cm(2) (75.4%) were independently associated with risk of MDR organisms infection.