Antibacterial activity of Klebsiella pneumoniae isolated from pneumonia patients

Bacterial samples were collected from 100 patients suffering from chest (respiratory tract) infections, particularly pneumonia, admitted in Baghdad hospitals (Al-Yarmouk Teaching Hospital and Al-Karama Teaching Hospital) between January 2023 and March 2023. The patients were of both genders: males 51/100 (51%) and females 49/100 (49%). Sputum from infected patients was collected in sterile containers and then inoculated onto MacConkey through a swab containing crystal violet medium. The samples were inoculated onto the nutrient agar medium and incubated at 37°C for 24–48 hours. The basic biochemical tests diagnosed bacterial isolates. The results showed Pseudomonas aeruginosa (39/100, 39%), Klebsiella pneumoniae (34/100, 34%), and Acinetobacter baumanii were (27/100, 27%) were isolated from respiratory tract infected patients who presented as outpatients and inpatients. These isolates were cultured on Mueller–Hinton agar medium to study their antibiotic resistance. The results of the antibiotic susceptibility test showed that K. pneumoniae were resistant to Piperacillin (PRL) 100 μg (31/34, 91.18%), Augmentin (AUG) 30 μg (28/34, 82.35%), Aztreonam (ATM) 30 μg (24/34, 70.59%), Imipenem (IMI) 10 μg (26/34, 76.47%), Meropenem (MRP) 10 μg (28/34, 82.35%), Vancomycin (VA) 30 μg (24/34, 70.59%), Ceftriaxone (CRO) 30 μg (24/34, 70.59%), Cefotaxime (CTX) 30 μg (26/34, 76.48%), Ceftazidime (CAZ) 30 μg (20/34, 58.82%), Cefepime (FEP) 30 μg (19/34, 55.89%), Azithromycin (AZM) 15 μg (22/34, 64.70%), Gentamycin (CN) 10 μg (25/34, 73.53%), Tetracycline (TE) 30 μg (23/34, 67.68%), Amikacin (AK) 30 μg (21, 61.77%), and Sulfamethoxazole (SMX) 100 μg (23/34, 67.68%). The aim of this study was to determine the effectiveness of antibiotics used in killing or inhibiting bacterial growth, and to study bacterial resistance to these antibiotics to reduce unnecessary antibiotics that lead to increased bacterial resistance through antibiotics for a cure.