UTIs are a group of inflammatory diseases that involve urinary tract and are found to affect all individuals irrespective of age and gender. Symptoms of UTI include pain during urination, flanking pain, hematuria, fever as well as nausea although the disease may be asymptomatic as well . Although the present study included more males, generally UTIs are much more prevalent among females due, in part, to the anatomical differences between two genders . Among gram-negative bacteria, E. coli was the predominant pathogen responsible for UTI in present exploration followed by Klebsiella spp. and Proteus spp. It is already well established that E. coli is the most frequently isolated pathogen from UTI cases followed by Klebsiella spp. [5, 15].
Gram-negative pathogens demonstrated complete resistance against AMP and AMC in present investigation both of which are β-lactam antibiotics. A high degree of resistance was measured against CAZ, CIP, CTX, NA and NOR, two of which are β-lactams. Previously, a substantial amount of resistance has been reported against β-lactam antibiotics by some of the gram-negative pathogens in other populations which is in accordance with our findings, although some differences also exist possibly due to differential geographical distribution of pathogens and varying antibiotic susceptibility profiles across the globe [16, 17]. E. coli was established as being resistant completely against AMP, AMC, CIP, CTX, NA and NOR, three of which are β-lactam antibiotics whereas considerable degree of resistance was documented against CAZ, SCF and SXT, two of which are β-lactams. Earlier, a similar pattern of resistance of E. coli strains was reported against AMP, AMC, CIP and CTX in Sudanese population . Furthermore, comparable degree of resistance of E. coli was reported against CAZ, CIP and NA in a study from Uganda . This signifies that majority of the β-lactams are becoming ineffective for administration to UTI patients over time and rationally devised and planned strategies are required to minimize further spread of resistance among pathogenic bacteria.
The most effective drugs against gram-negative bacteria isolated here were AK, FOS, IPM and MEM while F and TZP were also documented as being effective, though to a lesser extent. Similar observations regarding efficacy of these antibiotics have been reported earlier though the exact percentage of sensitivity of gram-negative pathogens varied somewhat [19, 20]. Against E. coli strains isolated in the present study, AK, F, FOS, IPM and MEM were very much effective and TZP was also effective, but to a lesser degree. Similar to our observations, E. coli was reported as being particularly sensitive to all of these antibiotics in a Russian study conducted in recent times . Analogous observations were also reported formerly in an Iraqi population with a difference that TZP was not very effective in their study subjects . Together, these observations imply that FOS is one of the best drugs of choice for treatment of UTIs particularly when E. coli is the etiological agent. Carbapenems are also efficacious for treatment of UTIs and hence, must be recommended over other less operative antibiotics.
Molecular analysis was done due to its superiority over phenotypic methods so as to detect ESBL producing bacteria and it was revealed that approximately half of the isolates were possessing blaTEM and blaCTX−M genes making them ESBL-producers. An elevated prevalence rate has previously been reported for blaCTX−M genes in another Pakistani study . A UK-based investigation also stated similarly higher prevalence of ESBL genes amongst children . In a different population, ESBL genes have been reported as being less prevalent among pathogens in comparison with our observations . This highlights the fact that ESBL prevalence is dissimilar from region to region and country to country pointing towards global differences. We documented comparatively higher positivity rate for blaCTX−M than for blaTEM amongst all pathogenic isolates except for Proteus vulgaris which can be explained as chance observation based on the low number of Proteus vulgaris isolates which were only three. Gender-based differences in the prevalence rate for blaCTX−M and blaTEM were not statistically significant and could not be ascertained with meticulousness and certainty due to small sample size. The higher prevalence of blaCTX−M is in line with the observations in an Irani as well as an Egyptian cohort [26, 27]. Several anthropogenic factors serve as determinants of ESBL prevalence rate among different populations accounting for the similarities as well as disparities observed in different studies. Additionally, inclusion of a larger dataset may provide more valuable and reliable information as the sample size was limited for the present study.