Assessing the Impact of Antibiotics on Resistant Strains of Pseudomonas aeruginosa

Pseudomonas aeruginosa is a Gram-negative opportunistic bacillus capable of causing severe infections, such as ventilator-associated pneumonia, sepsis, urinary tract infections, gastrointestinal tract infections, skin infections, and bone-joint infections. P. aeruginosa rapidly develops antibiotic resistance during infection and treatment, making it a significant clinical challenge. Twenty-eight isolates of suspected P. aeruginosa were obtained from clinical specimens, and standard biochemical and culture techniques were used to identify the isolates. The VITEK 2 compact system was used for identification and antibiotic susceptibility tests; further confirmation of isolates was achieved using the 16S rRNA gene. Growth curves were generated using a 96-well microtiter plate for four selected strains under normal and antibiotic stress conditions. The VITEK 2 compact system and molecular diagnostic confirmation showed that 20 isolates were P. aeruginosa. Four isolates were selected to represent varying resistance profiles: A2 (susceptible control), A3 and A4 (resistant to all tested antibiotics), and A9 (resistant to three antibiotics, Piperacillin/tazobactam, Ceftazidime and Cefepime). Growth curve analysis demonstrated a steady increase in A2 over time, statistical comparisons were performed One way ANOVA and Tukey’s test. Wherein A9 exhibited the most significant growth inhibition (p < 0.001), followed by A4 and A3 (p < 0.001) and (p= 0.016) respectively. Suggesting a potential antibiotic synergy effect. In conclusion, this study underscores the resilience of multidrug-resistant P. aeruginosa strains, which exhibited the ability to resist despite repeated exposure to a diverse array of antibiotics. These findings highlight the urgent need for further molecular investigations into the mechanisms of resistance.