ObjectiveTo investigate the correlation between TLR5 rs5744174 gene polymorphism and Streptococcus pneumoniae pneumonia.MethodsOne-hundred and six patients with Streptococcus pneumoniae pneumonia admitted to this hospital from January 2014 to October 2018 were selected as an observation group, and 85 healthy subjects were selected as a control group during the same period. The clinical and pathological data of the subjects were collected, polymorphism of TLR5 rs5744174 gene was analyzed by PCR and sequencing, and the relationships between cell classification count, C-reactive protein (CRP) level in bronchoalveolar lavage fluid (BALF) and TLR5 rs5744174 gene polymorphism in the patients with Streptococcus pneumoniae pneumonia were analyzed.ResultsThere were significant differences in age, smoking, alcoholism, diabetes and the other general data between the observation group and the control group (P<0.05). The distribution of TLR5 rs5744174 genotype in the observation group and the control group was in accordance with Hardy-Weinberg equilibrium test level (χ2=16.89 for the observation group, χ2=10.76 for the control group, both P>0.05). There was no significant difference in the distribution frequency of TLR5 rs5744174 (C < T) genotype and allele between the two groups (P>0.05). There were significant differences in the proportion of diabetes mellitus among the three genotypes (CC, CT, TT) of the patients with Streptococcus pneumoniae pneumonia (P<0.05). The percentage of neutrophils and CRP levels in BALF were significantly different (P<0.05).ConclusionThe polymorphism of TLR5 rs5744174 gene may not be related to the occurrence of Streptococcus pneumoniae pneumonia, but is related to the proportion of complicated diabetes mellitus, the percentage of neutrophils and the level of CRP in patients with Streptococcus pneumoniae pneumonia, which may affect the degree of inflammation.