Association of Genotyping of Bacillus cereus with Clinical Features of Post-Traumatic Endophthalmitis

Bacillus cereus is the second most frequent cause of post-traumatic bacterial endophthalmitis. Although genotyping of B. cereus associated with gastrointestinal infections has been reported, little is known about the B. cereus clinical isolates associated with post-traumatic endophthalmitis. This is largely due to the limited number of clinical strains available isolated from infected tissues of patients with post-traumatic endophthalmitis. In this study, we report successful isolation of twenty-four B. cereus strains from individual patients with different disease severity of post-traumatic endophthalmitis. Phylogenetic analysis showed that all strains could be categorized into three genotypes (GTI, GTII and GTIII) and the clinical score showed significant differences among these groups. We then further performed genotyping using the vrrA gene, and evaluated possible correlation of genotype with the clinical features of B. cereus–caused post-traumatic endophthalmitis, and with the prognosis of infection by conducting follow-up with patients for up to 2 months. We found that the disease of onset and final vision acuity were significantly different among the three groups. These results suggested that the vrrA gene may play a significant role in the pathogenesis of endophthalmitis, and genotyping of B. cereus has the potential for predicting clinical manifestation and prognosis of endophthalmitis. To the best of our knowledge, this is the first report of isolation of large numbers of clinical isolates of B. cereus from patients with endophthalmitis. This work sets the foundation for future investigation of the pathogenesis endophthalmitis caused by B. cereus infection.