العلاقة بين تعدد الأشكال الجيني Chemokine MCP-1 وشدة الاصابه بالعدوى البكتيرية الهوائية لدى مرضى الحروق

Relationship between Chemokine MCP-1 Gene Polymorphism and Severity of Aerobic Bacterial Infection in Burn Wound Patients

Abstract

Burn wound infections remain one of the most widespread bacterial infections in the world. These infections are predominantly caused by Pseudomonas aeruginosa. Following thermal injury, MCP-1, a myeloid-associated factor, is associated with worse clinical outcomes. The MCP-1 gene’s promoter region contains a functional genetic polymorphism at rs1024611 (-2518 A > G), which influences MCP-1 expression and associated to a number of inflammatory diseases.
A total of 83 swab samples were collected from both sex (44 males and 39 females), whose ages ranged from (1-60) years, attending to Imam Al-Hussein Medical City, Karbala, Iraq, during the period extending from August 2023 to December 2023. In addition, 70 blood samples were collected in an EDTA tube, divided into 35 samples from burn wound patients and 35 samples from apparently healthy individuals at an age range of (1-52) years old. Blood samples were used to detect the MCP-1 gene polymorphism. All bacterial isolates were subjected to cultural, microscopical, and biochemical examinations. The identification of these bacterial species and the antibiotic susceptibility test of Pseudomonas aeruginosa were confirmed by using the VITEK2 compact system. And MCP-1gene polymorphism was measured by amplification refractory mutational system (ARMS) by polymerase chain reaction technique.
The results showed that the percentage of burned males and females were 53.0% and 47.0% respectively. While in control (42.9%) as males and (57.1%) as females. Regarding sex, there were non significant differences (P=0.420) between the study’s groups. Rates of infection were higher in patients under the age of 11 compared to other age groups, and there were non significant differences (P=0.575) between the control and patient groups.
According to the type of burn, scald burns comprised the largest percentage of burn injuries (53%), followed by flame burns (41%), and electric burns (6.0%) had the lowest percentage of injuries.
In regards to the degrees of burn severity, the second degree constituted the most common of the cases (66.3%), while the third degree burned (25.3%), and the second +third degree constituted only (8.4%). The current study showed that Pseudomonas aeruginosa was the commonest burn wound isolate (31.43%), then Klebsiella pneumoniae (20.00%), followed by Escherichia coli (14.29%). Also, this study showed high resistance rates of Pseudomonas aeruginosa to all antibiotics (100%), except for the susceptibility (100%) to Colistin only.
Regarding the MCP-1 gene polymorphism (rs1024611), the present study showed that patients’ AA genotype was higher than that of controls’ (40.0% vs. 8.6%, respectively). The percentage of the AG genotype was found to be higher in the control group compared to the patient group (17.1% vs. 14.3%, respectively), However, GG genotype was higher percentage in controls than in patients (74.3% vs. 45.7%, respectively). There was a significant difference in genotypes (P=0.008) between cases and control groups. The “A” allele was increased in patients compared with control (47.2% vs. 17.2%, respectively), whereas the “G” allele was elevated in control compared with patients (82.8% vs. 52.8%, respectively). There were significant differences (P = 0.001) between them.
The result of this study has shown that the AA genotype was higher in patients compared to controls. Therefore, the MCP-1 gene (rs1024611) polymorphism may have a protective role in burn wound bacterial infection. In addition, Pseudomonas aeruginosa is the most prevalent bacteria in burned patients and susceptible to Colistin only.