Comparative in vitro activity of ciprofloxacin and levofloxacin against isolated uropathogens in Ghana: a pilot study

Introduction Studies on urinary tract infections (UTIs) in West Africa from 1990 to 2012 have showed moderate to high antimicrobial resistance to commonly prescribed antibiotics. Fluoroquinolones have been the main stay in the management of UTIs, but recent reports show emergence of resistance. Levofloxacin and ciprofloxacin still remain the commonest fluoroquinolones prescribed for UTIs in many settings. objective: this study sought to compare activity of ciprofloxacin and levofloxacin against clinical isolates obtained from patients with suspected UTI at the Ghana Police Hospital. Methods Midstream urine samples from 153 suspected UTI patients who visited the Ghana Police Hospital from July 2016 to March 2017 were examined. Urine samples were cultured and isolates identified by standard biochemical and serological methods. The Kirby-Bauer disc diffusion method was used to determine susceptibility of isolates to ciprofloxacin and levofloxacin. Results UTI prevalence was significantly (p < 0.05) higher among female patients (74.5%) than male patients (25.5%). Clinical uropathogens isolated from urine samples were Escherichia coli (28.1%), Coliform spp (43.2%), Klebsiella spp (26.1%) and Staphylococcus aureus (2.6%). Overall sensitivity of the uropathogens to ciprofloxacin and levofloxacin were 77.1% and 62.8%, respectively. Staphylococcus aureusshowed greater resistance to levofloxacin (75%) compared to ciprofloxacin (25%). All Gram-negative isolates showed a higher sensitivity to ciprofloxacin compared to levofloxacin: Escherichia coli; 69.8% vrs 62.8%, Coliform spp; 80.3% vrs 65.2%, and Klebsiella spp; 80% vrs 62.5%. Conclusion This study revealed emergence of resistance of uropathogens to quinolones. The isolates showed higher sensitivity to ciprofloxacin compared to levofloxacin. Rational prescribing and use of these fluoroquinolones following local susceptibility data is thus recommended.


Introduction
Urinary tract infection (UTI) is one of the commonly reported microbial infections at healthcare settings. UTI can affect all ages and both sexes, although prevalence is known to be higher amongst females [1]. Reports suggest that there could be spontaneous resolution of UTI (rates between 50 -70%) without any pharmacologic intervention [2]. Effective management of UTI would usually require the use of antimicrobial agents. However, reports show increasing resistance among certain urinary pathogens (uropathogens) to some commonly used antimicrobial agents. A number of studies report resistance of uropathogens to some first line antibiotic therapy: 10 -20% for trimethoprim and sulfamethoxazole (TMP-SMX), 40% for ampicillin, 15 -20% for nitrofurantoin and less than 10% for the fluoroquinolones [2][3][4][5].
Among the various antimicrobials used in the treatment of UTIs, the fluoroquinolones remain the preferred class. This is due to the fact that fluoroquinolones have high bacteriologic and clinical cure rates, low resistance rates, and few adverse drug reactions [6,7].
Fluoroquinolones are bactericidal antibiotics that target specifically DNA gyrase of the microorganism. Amongst the most frequently prescribed fluoroquinolones for empirical treatment of UTIs are ciprofloxacin and levofloxacin [3,8,9]. Ciprofloxacin, a secondgeneration fluoroquinolone, has greater activity against Gramnegative bacteria compared to nalidixic acid (a first-generation quinolone). Levofloxacin, a third-generation fluoroquinolone, is known to have broad spectrum of activity against Gram-positive and Gram-negative bacteria, and atypical pathogens [10]. Despite the preference for fluoroquinolones in the management of UTIs, there are current reports that suggest emergence of uropathogen resistance to commonly prescribed fluoroquinolones [11,12]. Data from Ghana and elsewhere show that isolated uropathogens have higher resistance to ciprofloxacin compared to levofloxacin [13][14][15].
As a result of this, healthcare professionals in Ghana may sometimes prescribe levofloxacin instead of ciprofloxacin (which is first-line treatment)for uncomplicated UTI. Two recent studies at a secondary level quasi-government hospital in Ghana showed that isolated uropathogen exhibited 35.9 % resistance to ciprofloxacin [16] and 51.6% resistance to levofloxacin [17]. Data from the latter study showed that levofloxacin resistance among uropathogens was on the rise. Therefore, the current study sought to compare the susceptibility of uropathogens (clinical isolates) to levofloxacin and ciprofloxacin concurrently.   [21]. Other studies elsewhere have also showed that the prevalence of UTI in females is higher than in males [22,23]. Factors such as hormonal changes during pregnancy, anatomical difference between the male and female urethra, proximity of the male and female urethra to anal opening, poor personal hygiene, some cultural practices among women and the absence of prostatic secretion in females could be underlying factors for the moderately high UTI prevalence observed among females than their male counterparts [23]. The age range with the highest infection, 49.7%, was in patient within 20-39 years.
Those with ages less than 20 years had the lowest infection (13.7%). The high rate of UTI among the age category 20-39 years could be due to the high incidence of sexual activity and/or multiple sex partners known to be associated with that age group [24]. UTI among patients within the age range of 40-59 (12.6%) and above 60 years (15%) observed in this study could be due to factors such as prostatic enlargement in males, reduced ambulation, catheterization, diabetes mellitus and weak bladder sphincters [25]. respectively. The level of resistance to these two fluoroquinolones were higher than the 10% resistance observed in a similar study in United States of America [5], but lower than findings from the study in India [35]. Further analysis of results also showed that, resistance of levofloxacin and ciprofloxacin to uropathogens in this study was lower than fluoroquinolone resistance (> 50%) reported after a recent nationwide antimicrobial resistance surveillance in Ghana [33]. Findings from this study (emerging resistance to fluoroquinolones) tend to agree with conclusions from a systematic review and meta-analysis of UTIs in West Africa from 1990 to 2012 by Bernabe et al [36].

Competing interests
The authors declare no competing interests.