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This study investigates the bulb extracts of Crinum jagus for antimicrobial activities. The bulb samples were dried, ground and subjected to successive extraction using hexane, ethylacetate and methanol. The extracts were screened for activity against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi, Klebisidlae pneumonae, Candida albicans, Aspergillus niger, Penicillium notatum and Rhizopus stolonifer at concentrations between 6.25 and 200 mg/ml. Antimicrobial assays werecarried out using agar diffusion method. The Minimum Inhibitory Concentration (MIC) of the extracts was determined. The percentage yields obtained for the hexane, ethylacetate and methanol extracts of the bulbs are 0.28 %, 0.44% and 24.68 % respectively. Results showed that the methanolic extract had better antibacterial and antifungal activities than the other extracts. The methanol extract showed the highest antibacterial activity against S. aureus with a zone of inhibition of 28 mm at 200 mg/ml. Also, the methanol extract showed the highest antifungal activities against C. albicans, A. niger and P. notatum with a zone of inhibition of 20 mm at 200 mg/ml. The hexane and ethylacetate extracts had no activity against the microorganisms at 6.25 mg/ml.The methanol extract had the lowest Minimum Inhibitory Concentration (MIC) of 2.50 mg/ml against S. aureus, E. coli, B. subtilis, P. aeruginosa and S. typhi. The methanol extract could be a source of potent antimicrobial compounds. [ABSTRACT FROM AUTHOR]

Plants have been used in ethno-medicine for ages in the treatment of various diseases. In the current study, the leaves of C. jagus are investigated for antimicrobial activities. The leaves were dried and extracted successively with hexane, ethylacetate and methanol. The concentrated extracts were screened for activity against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi, Klebisidlae pneumonae, Candida albicans, Aspergillus niger, Penicillium notatum and Rhizopus stolonifer at concentrations between 6.25 and 200 mg/ml using the agar diffusion method. The Minimum Inhibitory Concentration (MIC) was also determined. The percentage yields obtained were 0.92 %, 1.20 % and 25.2 % for the hexane, ethylacetate and methanol extracts respectively. The zones of inhibition of the organisms by the extracts generally increased with the concentrations. The methanol extract showed the best activity of the three extracts tested. The methanol extract had values ranging between 20 mm and 26 mm against the bacteria at 200 mg/ml. This extract also showed values between 18 mm and 20 mm against the fungi at 200 mg/ml. The lowest MICs values (of 2.5 mg/ml) were obtained against S. aureus, E. coli, B. subtilis and S. typhi. The polar constituents in the leaves of the plant are likely responsible for the antimicrobial properties observed. None of the extracts showed activity comparable to those of the standard drugs, however the methanol extract showed some potential as a source of antimicrobial compounds [ABSTRACT FROM AUTHOR]

Antibiotics are often used to treat severe Vibrio infections, with third-generation cephalosporins and tetracyclines combined or fluoroquinolones alone being recommended by the US Centers for Disease Control and Prevention. Increases in antibiotic resistance of both environmental and clinical vibrios are of concern; however, limited longitudinal data have been generated among environmental isolates to inform how resistance patterns may be changing over time. Hence, we evaluated long-term trends in antibiotic resistance of vibrios isolated from Chesapeake Bay waters (Maryland) across two 3-year sampling periods (2009-2012 and 2019-2022). Vibrio parahaemolyticus ( n = 134) and Vibrio vulnificus ( n = 94) t ox R-confirmed isolates were randomly selected from both sampling periods and tested for antimicrobial susceptibility against eight antibiotics using the Kirby-Bauer disk diffusion method. A high percentage (94%-96%) of V. parahaemolyticus isolates from both sampling periods were resistant to ampicillin and only 2%-6% of these isolates expressed intermediate resistance or resistance to third-generation cephalosporins, amikacin, tetracycline, and trimethoprim-sulfamethoxazole. Even lower percentages of resistant V. vulnificus isolates were observed and those were mostly recovered from 2009 to 2012, however, the presence of multiple virulence factors was observed. The frequency of multi-drug resistance was relatively low (6%-8%) but included resistance against antibiotics used to treat severe vibriosis in adults and children. All isolates were susceptible to ciprofloxacin, a fluoroquinolone, indicating its sustained efficacy as a first-line agent in the treatment of severe vibriosis. Overall, our data indicate that antibiotic resistance patterns among V. parahaemolyticus and V. vulnificus recovered from the lower Chesapeake Bay have remained relatively stable since 2009.IMPORTANCE Vibrio spp. have historically been susceptible to most clinically relevant antibiotics; however, resistance and intermediate-resistance have been increasingly recorded in both environmental and clinical isolates. Our data showed that while the percentage of multi-drug resistance and resistance to antibiotics was relatively low and stable across time, some Vibrio isolates displayed resistance and intermediate resistance to antibiotics typically used to treat severe vibriosis (e.g., third-generation cephalosporins, tetracyclines, sulfamethoxazole-trimethoprim, and aminoglycosides). Also, given the high case fatality rates observed with Vibrio vulnificus infections, the presence of multiple virulence factors in the tested isolates is concerning. Nevertheless, the continued susceptibility of all tested isolates against ciprofloxacin, a fluoroquinolone, is indicative of its use as an effective first-line treatment of severe Vibrio spp. infections stemming from exposure to Chesapeake Bay waters or contaminated seafood ingestion., Competing Interests: The authors declare no conflict of interest.