Acute lung infection induced by Extended Spectrum β-Lactamases (ESBL) producing isolates was determined by measuring inflammatory mediators; malondialdehyde (MDA), myeloperoxidase (MPO) and nitric oxide (NO). The mice were randomly divided into three groups of 20 animals each. All mice were given 104 c.f.u. ml-1 of the test organism intranasally in a volume of 50 µl while holding the mouse in an upright position without any anaesthesia. Group A received an intraperitoneal injection of an antibiotic, imipenem at a dose of 20 mg ml-1/ 25 g body weight which was administered 48 h post infection, Group B received only normal saline orally while group C, control-mice did not receive any treatment. The animals were sacrificed by cervical dislocation; lungs were removed aseptically and examined for various inflammatory mediators. The MDA, NO and MPO estimations in the lung homogenates in each group was measured and compared. Group treated with imipenem recorded lower absorbance values when compared with group treated with normal saline. The different parameters were statistically significant since the P-values were less than 0.05.

Keywords: Isolates, malondialdehyde, myeloperoxidase, nitric oxide, inflammation, imipenem