Combination of several therapeutic drugs with tetracycline to combat highly drug resistant urinary tract infection pathogens

Abstract

Urinary tract infection (UTI) is one of the most frequent bacterial infections worldwide. Presently, the most crucial factor of treating UTI is antibiotic resistance. The overutilization of antibiotics has become the greatest pitfall of modern public health development process. This study was aimed to find out a combination of drug with tetracycline to combat UTI pathogens- Klebsiella pneumoniae & Pseudomonas aeruginosa. A number of 90 samples were collected, of them 47 (52.22%) were K. pneumoniae and 43 (47.78%) were P. aeruginosa. They were further categorized into multidrug resistant (MDR), extensively drug resistant (XDR) and pan drug resistant (PDR) pathogens. A total of 11 antibiotics were trialed in combination with tetracycline against these two pathogens. Antibiotic susceptibility test (disk diffusion method) was done for primary screening and minimum inhibitory concentration (MIC) test was done for more accurate results. A fractional inhibitory concentration (FIC) index was calculated to evaluate the effect of combined drugs. A value of <0.5 indicates synergistic effect and more than 4 shows antagonism. Among all the combined drug trials, tetracycline-amoxicillin with clavulanic acid and tetracycline-chloramphenicol showed great efficiency. Moreover, tetracycline-amoxicillin with clavulanic acid and tetracycline-chloramphenicol both combinations had FIC index value of 0.3278 and 0.3785 respectively, indicating that both of them had synergistic effect. A further extension of validation by in vivo animal model study needs to be performed to know whether the combination is suitable for human.