College of Science, University of Mustansiriyah discussed a master dissertation on the effect of temperature and pH on Gene expression of the toxin-antitoxin system of Klebsiella pneumoniae bacteria by the postgraduate student, Ms. Fatima Jaafar Hassan.

The dissertation demonstrated collecting (70) isolates of Klebsiella pneumoniae bacteria from various medical conditions, including urinary tract infections, blood, sputum, wounds, burns and ear secretions, diagnosing the bacteria using the (VITEK2) system, evaluating the isolates and testing them on aspects of resistance to antibiotics, sensitivity to them and composition, biofilm and viscosity in light of different temperatures and pH values, as well as evaluating the Gene expression of the type II toxin-antitoxin system using (RT-PCR) technology.

The dissertation indicated that most clinical isolates of Klebsiella pneumoniae bacteria possess multiple resistance to antibiotics and produce a biofilm, and that temperature and pH clearly affect the effectiveness of antibiotics against bacteria, especially cefotaxime, which increased its activity in alkaline conditions, and tetracycline, which showed high activity in acidic conditions not to mention, the expression levels of type II toxin-antitoxin systems (hipB antitoxin, mqsR toxin, relE toxin) are affected by temperature and pH values.

The dissertation concluded that the studied systems exert an important role in antibiotic resistance and biofilm formation and that Klebsiella pneumoniae bacteria have the ability to adapt to various environmental conditions by modifying the gene expression of the toxin-antitoxin system, which makes them resistant to antibiotics.