Polymicrobial Nature of Chronic Diabetic Foot Ulcer Biofilm Infections Determined Using Bacterial Tag Encoded FLX Amplicon Pyrosequencing (bTEFAP)

Diabetic extremity ulcers are associated with chronic infections. Such ulcer infections are too often followed by amputation because there is little or no understanding of the ecology of such infections or how to control or eliminate this type of chronic infection. A primary impediment to the healing of chronic wounds is biofilm phenotype infections. Diabetic foot ulcers are the most common, disabling, and costly complications of diabetes. Here we seek to derive a better understanding of the polymicrobial nature of chronic diabetic extremity ulcer infections. spp. and against difficult to culture bacteria such as anaerobes. While PCR methods also have bias, further work is now needed in comparing traditional culture results to high-resolution molecular diagnostic methods such as bTEFAP

Macro-microcirculation in the lower extremities - possible relationship

Impaired blood supply is a significant risk factor for diabetic foot ulceration and gangrene. A possible relationship between peripheral macroangiopathy and the spectral components of microvascular skin blood flow in the lower extremities was tested in diabetic patients (DP) and non-diabetic subjects (C). Basal skin blood flow (BSBF) was recorded for 30 min at the right and left medial malleolus (predominantly nutritive capillary circulation) by laser Doppler flowmetry in 64 DP and 31 C. Its oscillatory components were analyzed using wavelet transform. Peripheral arterial obliterative disease (PAOD) was defined according to ankle/brachial index (ABI): PAOD+ (ABI < 0.9: 21 DP, 12 C), PAOD− (ABI 0.91–1.3: 43 DP, 19 C). No statistically significant differences in BSBF and its oscillatory components were observed between PAOD+ and PAOD−, neither in DP nor in C. In DP, the spectral component of microvascular flow associated with endothelial activity was in significant positive correlation with systolic pressures on brachial and dorsal pedal artery (p = 0.001 and 0.010, respectively). These results indicate that mean BSBF and its oscillatory components do not change with diabetic PAOD; however there is a strong correlation between systolic pressure and the oscillatory components of BSBF related to endothelial activity manifested in the frequency interval 0.0095–0.02 Hz

Skin Blood Flow in the Upper and Lower Extremities of Diabetic Patients with and without Autonomic Neuropathy

Background: Microvascular blood flow in the human skin is subject to rhythmic variations reflecting the influence of heartbeat, respiration, intrinsic myogenic activity, neurogenic factors and endothelial activity. The aim of our study was to test the hypothesis that basal skin blood flow (BSBF) and its dynamic components differ (1) among diabetic patients without autonomic neuropathy and with it and healthy control subjects, and (2) among the upper and lower extremities. Patients and Methods: BSBF at four recording sites with predominantly nutritive capillary circulation (right and left caput ulnae, right and left medial malleolus) was measured by laser Doppler flowmetry in 25 diabetic patients without cardiovascular autonomic neuropathy (D), 18 neuropathic diabetic patients (DAN) and 36 healthy controls (C). Wavelet transform was applied to the laser Doppler signal. Results: In absolute terms, mean flow, mean amplitude of the total spectrum and mean amplitudes at all frequency intervals were highest in C, followed by DAN and lowest in D. However, these differences were statistically significant only in the left arm. Within all three groups, mean flow and spectral amplitudes were significantly higher in the arms than in the legs, besides there was a significant difference between the two arms in D. Conclusion: We have confirmed the differences in BSBF among D, DAN and C, and demonstrated differences among the four recording sites which have not been previously described. The latter indicates an uneven progression of autonomic neuropathy and allows for speculation that the left arm is the latest to be affected