In vitro Antibacterial Evaluation of Four Selected Medicinal Plants against Staphylococcus aureus Isolated from Bovine Mastitis in Mieso District West Hararghe Zone, Oromia Regional State, Ethiopia

Abstract

Background: Bovine mastitis is a major disease mostly caused by bacterial infection and associated with losses in the global dairy industry. Since mastitis-causing bacterial developing multidrug resistance to conventional antibiotics, there is an admirable supplementary study on medicinal plants to use them as an alternative therapy. This study aimed to evaluate the antibacterial activity and phytochemical screening of four selected medicinal plants against Staphylococcus aureus. Methods: An experimental study was done to evaluate the antibacterial activity of crude methanolic extracts of four traditionally used medicinal plants against S. aureus. Standard phytochemical screening tests were conducted to detect the bioactive principle of plants. Agar well diffusion assay was used to evaluate the antimicrobial activity of crude methanolic plant extract. The broth dilution method was also used to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of plant extracts. Results: The percentage yields obtained from the root of Clerodandrum myricoides, Kalanchoe densiflora, Kalanchoe marmorata and leaf of Kalanchoe marmorata and Datura stramonium were 22.6%, 37.2%, 51.6%, 32.3% and 50.7%, respectively. Phytochemical screening tests revealed the presence of secondary metabolites such as tannins, phenols, and steroids in all plant extract, except in D. stramonium, while others like alkaloids, flavonoids, quinones, and saponins were fairly detected in all samples. The agar well diffusion results showed significant (p < 0.05) differences in the mean zone of inhibition (ZOI) between each plant at different concentrations with significant potency comparable to gentamicin. C. myricoides and D. stramonium revealed the broadest spectrum of action yielding the highest ZOI (27.0 ± 0.58 mm), whereas K. marmorata leaf showed less activity with the lowest ZOI (22.3 ± 0.33 mm). The broth dilution method indicated that the MIC value of plant extracts against S. aureus ranged between 3.90 and 7.80 mg/ml while its corresponding MBC value ranged between 7.80 and 15.6 mg/ml. According to the MIC/MBC ratio, all tested plants (except K. densiflora) against standard S. aureus while C. myricoides and D. stramonium against clinical S. aureus isolate were determined to be bactericidal. Conclusion: This finding confirmed that all tested plants had a potential anti-staphylococcal effect. Thus, further study on in vivo experiments and cytotoxicity analyses must be conducted to suggest these plants as alternative mastitis treatments.

In vitro antibacterial activity of Bersama abyssinica Fresen crude extract against representative Gram‐positive and Gram‐negative bacterial isolates

“…Moreover, the plant demonstrates moderate antibacterial activity against E. coli and P. aeruginosa isolates. The present study's observed MIC values for plant crude extracts fall within the range or are less than those of other plant extracts reported from various nations (Manilal et al., 2020; Popović et al., 2015; Sama et al., 2015; Yirdaw & Kassa, 2023; Yusuf et al., 2022). The MIC of B. abyssinica extracts reported by Ameya et al.…”

“…The present study's observed MIC values for plant crude extracts fall within the range or are less than those of other plant extracts reported from various nations (Manilal et al, 2020;Popović et al, 2015;Sama et al, 2015;Yirdaw & Kassa, 2023;Yusuf et al, 2022). The MIC of B. abyssinica extracts reported by Ameya et al (2019) was significantly higher (12.5-25 mg/mL) than the current finding (0.78-3.12 mg/mL).…”

Eradication of Klebsiella pneumoniae pulmonary infection by silver oxytetracycline nano-structure

“…After the MIC determination of the AgNO 3 , OTC, AgNPs and Ag-OTC-Ns, aliquots of 10 µl samples from all the tubes which showed no visible bacterial growth, were seeded on Brain Heart Infusion Agar (BHI agar) plates and incubated for 24 h at 37 °C. When 99.9% of the bacterial population is killed at the lowest concentration of an antimicrobial agent, it is termed as the minimum bactericidal concentration (MBC) endpoint (Yusuf et al 2022). This was done by observing pre and post-incubated agar plates for the presence or absence of bacterial colonies.…”

Blunt Antibiotic Weapons Against Mastitis

“…The rise of antibiotic resistance hence needed a remedy in the form of some other alternatives besides conventional antibiotics and the best of these turned out to be plant extracts (Zaatout 2022). An important reason for using plant extracts was their easy availability and affordability (Rakholiya et al 2013;Yusuf et al 2022). This chapter aims to explain antibiotic resistance in some important pathogens of mastitis along with its causes, effects, and treatment.…”