Molecular Detection of Psts Antibiotic-Resistant Gene in Pseudomonas aeruginosa Isolates

Abstract Background: Otitis media is a very common infection among people of different age groups. Objective: The goal of the current work was to determine the existence of PstS gene among Pseudomonas aeruginosa isolates recovered from otitis media cases in Iraqi patients. Materials and Methods: A total of 100 ear swabs were collected from patients suffering from otitis media attending the ENT outpatient clinic at Baghdad Teaching Hospital from July 2022 to the end of December 2022. The age range was 18-75 years. Detection of morphology and biochemical testing by Vitek 2 system. The antibiotic sensitivity test of the bacteria spp. was the detection of 18 antibiotics for different types using Vitek2 system. Identify the genes for antibiotic resistance mechanisms. DNA was extracted from samples, and resistance genes PstS were amplified using polymerase chain reaction (PCR). Results: This study showed 80 out of 100 swabs revealed Pseudomonas aeruginosa isolates, and 71 (89%) isolates out of these 80 exhibited PstS genes. Age groups of the patients were 38-47, 48-57, and 58-67 years with percentages of 22.5%, 25%, and 25%, respectively. The highest resistance percentages of strains to tested antibiotics were for Ceftoriaxone, Cefpodoxime (100%), and the lowest resistant percentage was 22.5% for colistin, which determined the relationship between the presence of Psts and resistance to 18 antibiotics for different types. Colistin was the most effective antibiotic and can be considered as the drug of choice against Pseudomonas aeruginosa . Conclusions: Pseudomonas aeruginosa isolates recovered from patients suffering otitis media show the prevalence rate appears to be higher among the elderly and high virulence and antibiotic resistance due to the presence of PstS antibiotic resistance gene and ability to form biofilms, thus aggressive antimicrobial therapy is highly recommended in such conditions.