Abstract
Background:
The rapid emergence of multidrug-resistant (MDR) Escherichia coli has become a major global health concern, limiting the effectiveness of conventional antimicrobial therapy. Medicinal plants such as Hibiscus rosa-sinensis and rose (Rosa species) contain bioactive phytochemicals with known antimicrobial properties and may act as antibiotic adjuvants against resistant bacteria.
Aim:
To evaluate the antibiotic adjuvant potential of Hibiscus rosa-sinensis and rose leaves extracts against multidrug-resistant Escherichia coli isolates.
Materials and Methods:
This hospital-based prospective study was conducted in the Department of Microbiology and included 51 clinical isolates of Escherichia coli obtained from urine, sputum, wound swab, and blood samples. Antimicrobial susceptibility testing was performed using the Kirby–Bauer disc diffusion method according to CLSI guidelines. Isolates resistant to one or more antibiotics were further tested for synergistic antibacterial activity using leaf extracts of Hibiscus rosa-sinensis and rose prepared by Soxhlet extraction. Sterile discs impregnated with 15 µL of extract (40 mg/mL) were combined with resistant antibiotics and tested on Mueller–Hinton agar. Enhancement in the zone of inhibition was compared with antibiotics alone.

Results:
Among the 51 E. coli isolates, 35 (68.63%) demonstrated resistance to one or more antibiotics. Most resistant isolates were obtained from urine samples [30 (85.72%)]. The resistance was highest against ampicillin [28 (80%)], followed by ofloxacin [26 (74.28%)], cefotaxime [24 (68.57%)], cotrimoxazole [21 (60%)], and cefuroxime [21 (60%)]. After using extract of Hibiscus and rose leaves along with the previously resistant antibiotics , we found an increase in the antibacterial activity of certain antibiotics like cefotaxime, ceftazidime, piperacillin, and ceftazidime–clavulanic acid. But with Levofloxacin which showed synergistic increase in sensitivity with rose leaf extract only, whereas amikacin showed enhancement in the zone size with Hibiscus rosa-sinensis extract..
Conclusion:
The increased in the zone size of antibiotics after adding Hibiscus rosa-sinensis and rose leaf extracts demonstrated that both the plant extract has a significant antibiotic adjuvant activity against multidrug-resistant Escherichia coli. and could serve as promising natural adjuncts in combating antimicrobial resistance. This enhancement may be due to the presence of phytocompounds including phenols, tannins and flavonoids constituents which is responsible for antibacterial activities of these plants.