Plasmid Profiles of Multidrug Resistant Uropathogens and Antibacterial Efficacy of Leaf Extracts of Luffa cylindrica

Abstract

This study analyzes the antibacterial activity of Luffa cylindrica leaf extracts, the plasmid profile and molecular characterization of MDR Uropathogenic bacteria obtained from patients from selected hospitals in Asaba. Two hundred (200) samples of urine were collected, microscopic examinations, cultures, and susceptibility tests were performed. Bacterial isolates that exhibited resistance to three or more classes of antibiotics were defined, for the purpose of this study, as Multidrug-Resistant (MDR) uropathogens. Molecular identification was performed using 16S rRNA sequencing, while plasmid extraction and curing analyses were used to determine the role of plasmid-mediated resistance. Series of quantitative and qualitative tests were conducted in order to assess the phytochemistry of the leaf extracts, and the antibacterial properties of the extracts were characterized using the agar-well diffusion method, along with a determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Among the 200 specimens tested, 62 (31%) tested positive in cultures, producing 70 isolates, including Staphylococcus aureus (40%), Escherichia coli (28.6%), Klebsiella pneumonia (18.6%), Proteus mirabilis (7.1%), and Pseudomonas aeruginosa (5.7%). 76% of the isolates were multi-drug resistant (MDR) and Pseudomonas aeruginosa and Proteus mirabilis had 100% resistance. Molecular identification based on 16S rRNA gene sequencing revealed that the isolates were closely related to Escherichia coli, Enterobacter cloacae, and other clinically relevant bacterial species. However, confirmation of uropathogenicity would require further characterization of specific virulence determinants associated with urinary tract infections. All MDR strains had large plasmids (>10 kbp) and in the strains from which plasmids were removed, resistance was decreased, indicating that the resistance was from plasmids. The phytochemical analysis showed that the leaves tested positive for alkaloids, flavonoids, phenols, saponins, tannins, terpenoids, glycosides and steroids. Inhibitory zones of 24-34 mm were produced from ethanolic extracts which also had significant antibacterial activity with Minimum inhibitory concentrations (MICs) of the ethanolic extract ranged from 103.75 ± 4.78 to 310 ± 8.16 mg/mL. Although antibacterial activity was observed, these MIC values are relatively high compared with conventional antibiotics such as ciprofloxacin, suggesting that further purification of active phytochemical constituents may be required to achieve clinically relevant potency. The results suggest that the Luffa cylindrica leaf-extracts have antibacterial qualities and can be used as alternative treatments for resistant strains of uropathogens.