ارتباط الببتيد المضاد للميكروبات Human β Defensin بنوع العزلات البكتيرية لدى مرضى القدم السكري

Correlation of Antimicrobial Peptide Human β Defensin with The Type of Bacterial Isolates in Diabetic Foot Patients

Abstract

Diabetic foot ulcer (DFU) poses a growing global public health challenge, becoming a significant financial burden on every healthcare system worldwide. The risk of bacterial infection is elevated and highly associated with wound necrosis and poor clinical outcomes.
Human beta-defensin (HBD-2) is a soluble peptide with antimicrobial activities. The importance of defensins in DFU and their association with the type of bacterial infection and their effect on wound healing has been poorly described and still needs further investigation.
To the best of our knowledge, this is the 1st study in Iraq / Kerbala aimed to determine the serum level of beta-defensins in diabetic patients with foot ulcer and compare these levels with disease and healthy controls. In addition to studying the association of these levels with the type of bacterial infection and type of wound grade.
One hundred and forty-seven subjects were included in this study classified into three groups each group with 49 individuals, T2DM patients with DFU, T2DM without DFU, and healthy subjects. Both blood samples and DFU swabs (from DFU patients) were collected from October 2023 to January 2024 in Karbala Governorate, Iraq. Both age and sex were matched among the study groups. Blood samples were used to measure HbA1c, CBC count, and HBD-2. Swab samples were used to identify bacterial infection if present.
The mean age of participants was (55.73 ± 9.36), (57.43 ± 10.23) and (57.31 ± 10.27) for control, T2DM and DFU participants, respectively, and 59.9% of participants were males. Grade three was the most common type of grades among DFU patients (57.1%). A total of 69 bacteria were isolated from the swab samples; of them, 42 (60.9%) were gram-negative and 27 (39.1%) were gram-positive. The most common type of bacterial isolates was Staphylococcus aureus (23.18%) followed by Escherichia coli (15.9%).
No significant difference was observed in the mean level of serum HBD-2 among the three studied groups. However, a lower mean of HBD-2 was seen in DFU (1149.75 ± 870.66) followed by T2DM (1206.53 ± 692.78) in comparison to the highest concentration which was seen in the healthy group (1291.89 ± 882.35).
significantly higher mean level of HBD-2 was seen in grade one (2054.48 ± 1440.42) of the Wagner classification in comparison to other grades. Significant higher means were also seen in DFU patients with no growth (2401.47 ± 1658.51) in comparison to infected DFU, in patients infected with a single type of bacteria (1121.24 ± 645.92), and in patients with ulcers infected with gram-positive bacteria (1317.28 ± 733.98). The highest mean of HBD-2 was observed in patients infected with Staphylococcus aureus (1104.78 ± 730.92), followed by Escherichia coli (998.23 ± 620.09), and the lowest level was seen in patients infected with Proteus mirabilis (781.31 ± 426.75). Furthermore, the current study revealed significant differences in the mean level of HBD-2 according to glycemic control. A higher mean was observed in subjects with good glycemic control (1362.80 ± 970.98).
In conclusion, a decreased level of HBD-2 may reflect a dysregulated immune response associated with diabetic wound infection and impaired wound healing. The lower production of HBD-2 could be due to either hyperglycaemia. The mean level of HBD-2 was different in response to infection with different types of bacterial isolates.