A Clinico-microbiological Study of Diabetic Foot Ulcers in an Indian Tertiary Care Hospital

Abstract

OBJECTIVE -To determine the microbiological profile and antibiotic susceptibility patterns of organisms isolated from diabetic foot ulcers. Also, to assess potential risk factors for infection of ulcers with multidrug-resistant organisms (MDROs) and the outcome of these infections.RESEARCH DESIGN AND METHODS -Pus samples for bacterial culture were collected from 80 patients admitted with diabetic foot infections. All patients had ulcers with Wagner's grade 3-5. Fifty patients (62.5%) had coexisting osteomyelitis. Gram-negative bacilli were tested for extended spectrum ␤-lactamase (ESBL) production by double disc diffusion method. Staphylococcal isolates were tested for susceptibility to oxacillin by screen agar method, disc diffusion, and mec A-based PCR. Potential risk factors for MDRO-positive samples were explored.RESULTS -Gram-negative aerobes were most frequently isolated (51.4%), followed by gram-positive aerobes and anaerobes (33.3 and 15.3%, respectively). Seventy-two percent of patients were positive for MDROs. ESBL production and methicillin resistance was noted in 44.7 and 56.0% of bacterial isolates, respectively. MDRO-positive status was associated with presence of neuropathy (P ϭ 0.03), osteomyelitis (P ϭ 0.01), and ulcer size Ͼ4 cm 2 (P Ͻ 0.001) but not with patient characteristics, ulcer type and duration, or duration of hospital stay. MDRO-infected patients had poor glycemic control (P ϭ 0.01) and had to be surgically treated more often (P Ͻ 0.01). CONCLUSIONS -Infection withMDROs is common in diabetic foot ulcers and is associated with inadequate glycemic control and increased requirement for surgical treatment. There is a need for continuous surveillance of resistant bacteria to provide the basis for empirical therapy and reduce the risk of complications. Diabetes Care 29:1727-1732, 2006W orldwide, diabetic foot lesions are a major medical, social, and economic problem and are the leading cause of hospitalization for patients with diabetes. Infectious agents are associated with amputation of the infected foot if not treated promptly.Proper management of these infections requires appropriate antibiotic selection based on culture and antimicrobial susceptibility results; however, initial management comprises empirical antimicrobial therapy, which is often based on susceptibility data extrapolated from studies performed on general clinical isolates (1). Several studies found methicillin-resistant Staphylococcus aureus (MRSA) in as many as 15-30% of diabetic wounds (1-3). Infection with multidrug-resistant organisms (MDROs) may increase the duration of hospital stay and cost of management and may cause additional morbidity and mortality (4). Although increasing antimicrobial resistance is a pertinent problem in India, there is paucity of data on the frequency of MDRO infections and the outcome of such infections among diabetic foot ulcers in this region. The aim of this study was to determine the microbiological and antimicrobial susceptibility profile of organisms isolated from patients with diab...

Aerobic bacterial profile and antibiotic resistance in patients with diabetic foot infections

“…and Enterobacter spp. Although the fi ndings of our study are consistent with the results of previous studies showing that Gram-positive bacteria were predominant in diabetic foot infections (13) (22) , other studies have reported that Gram-negative bacteria were predominant in particular regions (23) (24) . These results suggest, in part, differences in the type and severity of infections (5) (25) .…”

Incidence of carbapenem-resistant <i> Pseudomonas aeruginosa</i> in diabetes and cancer patients

“…[2] In diabetic patients, foot infections are frequent; these infections are polymicrobial and there is a high incidence of multidrug-resistant P. aeruginosa reported from patients with type 2 diabetes mellitus. [8] We found 75% resistance to carbapenem amongst the P. aeruginosa isolates from such cases.…”

Diabetic foot ulcers and biofilm formation- The culprits

“…The prevalence of MRSA in our study was lower as compared to prior studies in which it ranged from 40%-69.8%. [21,25,26,28] However a similar prevalence of 12% was seen in a Malaysian study. [20] The MRSA displayed high level of resistance to clindamycin (80%), erythromycin (80%) and penicillin G (80%).…”

“…The predominance of Gram negative organisms has been noted in several studies. [4,25] However, certain studies (1,26,27) have established a higher proportion of Gram positive organisms.…”