Streptococcus angriness isolated from Patients with Acute Infection following Surgical Tooth Extraction


  • Hiyam Faez Ahmed Ministry of Agriculture, Department of Veterinary, Veterinary Education Hospital, Babylon, Iraq
  • Ilham A. Bunyan Department of Microbiology, College of Medicine, University of Babylon, Iraq



Acute inflammation, Surgical tooth extraction, virulence factors, biofilm, Streptococcus anginosus


In this study, 250 individuals with acute infection following surgical tooth extraction were treated at a Hilla dental clinic and cultivated at 37°C for 18–24 hours. They cultured on several selective medium at 37°C for 18–24 hours. Identification of Streptococcus anginosus was based on colonial morphology, microscopically, and biochemical tests, and all scientific specimens were successful cultures. Of 250 specimens, only 25(10%) were biochemically identified as Strep. anginosus, while 225(90%) were associated with other microorganisms. Hemolysin-producing Strep. anginosus isolates have been studied. 10(66.66%) isolates produced hemolysin in blood agar that formed a clearance sector around the colonies and a streak on the plate after 24 hours of incubation at 37°C. Strep. anginosus isolates were also tested for siderophores production, 5(33.33%) Strep. anginosus isolates produce siderophores. All bacterial isolates provide protease to hydrolyze protein. After 24 hours of incubation, all Strep. anginosus isolates were able to hydrolyze protein using protease enzyme (100%) when tested using M9 (supported by 20% glucose and 1% csaien). Adding 3ml of 5% Trichloroacetic acid gave the colony a clean hallo. Quantitative biofilm development tests were performed in a microtiter using Trypticase Soy Broth with 1% glucose. To improve accuracy, this assay was done three times. All Strep. anginosus isolates were biofilm former (100%), 12/15(80%) were strong biofilm formers, and 3/15 (20%) were mild biofilm formers. However, the antibiotic disc diffusion test using six clinically important antibiotics showed that most Strep. anginosus isolates were extremely resistant to the antibiotics, especially the ?-lactams, including Amoxicillin 13(86.6%), Cefixime 12(80%), Ceftriaxone 12(80%), Meropenem, 11(73.33%) Cefotaxime 10(66.66%), and Imipenem 9(60%).