The relation of bacteria and TLR4 gene polymorphisms in biofilm formation in infected patients – the case of Iraq / Thi-Qar City Hospital

The aim of the study was to investigate and evaluate the relationship between TLR4 rs 10759932, TLR4 rs 12377632 functional polymorphisms and the effect of bacteria on biofilm formation and susceptibility to infection. A case-control study including 250 samples suspected of bacterial biofilm infections were collected from Al-Rifai General Hospital, Thi-Qar city, Southern Iraq, between June 2023 and December 2023 from patients aged between 10 and 45 years. The current results showed that 100 (40.0%) samples were positive and 150 (60.0%) samples were negative for bacterial biofilm formation. These results show that the prevalence of bacterial biofilm is higher in Gram-negative bacteria compared to Gram-positive bacteria (66 (66.0%) vs. 34 (34.0%)). The frequency distribution of biofilm-containing bacterial isolates is as follows; 36 (36.0%) E. coli, 22 (22.0%) S. epidermidis, 12 (12.0%) S. aureus, 16 (16.0%) K. pneumoniae and 14 (14.0%) Proteus mirabilis were detected. In addition, these results showed that most of the biofilm-producing bacteria were isolated from patients with urinary tract infections. Bacterial biofilm positivity was more common in older patients (30 years and above). The available results regarding gender determined that the patient group consisted of 40 (40.0%) males and 60 (60.0%) females. Since 60 (60.0%) of the patients with bacterial biofilm came from urban areas, the prevalence of bacterial biofilm was found to be higher in urban areas compared to rural areas. Comparison of genotype and allele frequencies of TLR4-rs10759932 SNP and TLR4-rs12377632 SNP between patients with bacterial biofilm formation infection and healthy controls showed that homozygous CC and heterozygous TC genotypes are significant risk factors. As a result, patients with homozygous CC and heterozygous TC genotypes are more prone to develop the disease compared to other genotypes.