There is a need for the screening more effective, affordable and readily available antimicrobial substances from local medicinal plants or herbs as the pathogenic bacteria are developing the resistance to common antibiotics. Guava (Psidium guajava L.) has antimicrobial activities and it is easily accessible to local populace in tropical region. Antimicrobial properties of guava extracts are attributed to the presence of different phytochemical constituents. The fact that phytochemicals’ constituents vary as a result of geographical locations and literatures about Ethiopian guava with respect to phytochemicals’ composition and content, and antimicrobial activities are hardly available, there is a need to analyze phytochemicals and antimicrobial properties of the Ethiopian guava from Oromia Regional State, Babile and Gursum Districts against Salmonella Typhi, Shigella boydii, Staphylococcus aureus and Enterococcus faecalis. Extraction was done by maceration. Qualitative analysis of phytochemicals was carried out using standard protocol and quantitative phytochemical determination was conducted using spectrophotometric and gravimetric methods. Antimicrobial activities were determined by disc diffusion and broth dilution method. Qualitative phytochemical analysis revealed the presence of alkaloids, saponin, steroids and tannin, but the absence of flavonoid and phlobatannin in all Babile and Gursum leaf and bark extracts. Gravimetric measurement showed the highest terpenoid content of 105.00 ± 8.66 mg extract/g of powder in Gursum leaf extract. Similarly, spectrophotometric measurement showed the highest total phenol content of 0.205 ± 0.01 mg/g of the extracts as Tannic Acid Equivalent in Gursum leaf extract. Antimicrobial activity tests revealed that Babile leaf extract showed the highest 13.0 ± 6.79 mm zone of inhibition against Shigella boydii compared to that of other guava extracts. Babile leaf extract showed the lowest 2.375 ± 0.177 mg/ml minimum inhibitory concentration against Shigella boydii, while Gursum leaf extract showed the lowest 1.875 ± 0.884 mg/ml MIC against Salmonella Typhi. Phytochemical analysis showed the presence of alkaloids, saponins, steroids and tannins in the all extracts, but the absence of flavonoids and phlobatannins in the all extracts and terpenoids in Babile extracts. The highest content of alkaloid and terpenoid (98.67 ± 14.43, 93.33 ± 8.82 mg extract/g of powder, respectively) were found in Babile leaf and Gursum bark extracts, respectively. Antimicrobial activity tests revealed that Babile leaf extracts showed higher zone of inhibition against all clinical isolates than that of Gursum leaf extracts, but Babile bark extracts showed lower zone of inhibition against all clinical isolates than that of Gursum bark extracts. Babile leaf extracts showed the highest zone of inhibition (13.0 ± 6.79 mm) against S. boydii, and Babile bark extracts showed the lowest Minimum Inhibitory Concentration (1.250 ± 0.001 mg/ml) against S. Typhi. Guava extracts from different location could be source of natural antimicrobial agents with different composition and content. In vivo antimicrobial activity, and isolation, identification and synergy of specific active compound that responsible for the antibacterial activity should be evaluated.

中文翻译：

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埃塞俄比亚奥罗米亚东部哈拉格的番石榴提取物的植物化学成分和抗菌特性

由于病原细菌正在发展对普通抗生素的抗性，因此需要从当地的药用植物或草药中筛选更有效，可负担且易于获得的抗菌物质。番石榴（Psidium guajava L.）具有抗菌活性，热带地区的当地居民很容易接近。番石榴提取物的抗菌特性归因于不同植物化学成分的存在。植物化学成分的变化是由于地理位置和有关埃塞俄比亚番石榴的植物成分和含量方面的文献而变化，而且几乎没有抗菌活性，因此有必要分析来自奥罗米亚州的埃塞俄比亚番石榴的植物化学成分和抗菌特性区域州，反对伤寒沙门氏菌，博伊氏志贺氏菌，金黄色葡萄球菌和粪肠球菌的巴比勒和古尔苏姆地区。通过浸渍进行提取。使用标准方案对植物化学物质进行定性分析，并使用分光光度法和重量分析法对植物化学成分进行定量测定。通过盘扩散和肉汤稀释法测定抗菌活性。定性植物化学分析显示，所有巴比利和古尔苏姆叶和树皮提取物中均存在生物碱，皂角苷，类固醇和单宁，但不存在类黄酮和间巴坦宁。重量分析显示古尔苏姆叶提取物中的最高萜类化合物含量为105.00±8.66 mg提取物/ g粉末。同样，分光光度法测定的最高总酚含量为0.205±0。菊苣叶提取物中的鞣酸当量为01 mg / g提取物。抗菌活性测试表明，与其他番石榴提取物相比，巴比叶提取物显示出对博伊氏志贺氏菌的最高抑制区为13.0±6.79 mm。巴比叶提取物对博伊氏志贺氏菌的最低抑菌浓度最低，为2.375±0.177 mg / ml，而古尔苏姆叶提取物对鼠伤寒沙门氏菌的最低抑菌浓度为1.875±0.884 mg / ml。植物化学分析显示，所有提取物中均存在生物碱，皂角苷，类固醇和单宁，但巴西比勒提取物中所有提取物和萜类化合物中均不存在类黄酮和苯巴比汀。巴比利叶和古尔苏姆树皮提取物中的生物碱和萜类化合物含量最高（分别为98.67±14.43、93.33±8.82 mg / g粉末）。抗菌活性测试表明，巴比勒叶提取物对所有临床分离株的抑制区均比古尔苏姆叶提取物的抑制区高，但巴比勒树皮提取物对所有临床分离株的抑制区均比古尔苏姆树皮提取物低。巴比叶提取物对博伊氏菌的抑制作用最高（13.0±6.79 mm），而巴比树皮提取物对鼠伤寒沙门氏菌的最低抑菌浓度最低（1.250±0.001 mg / ml）。来自不同位置的番石榴提取物可能是具有不同组成和含量的天然抗菌剂的来源。应评估体内的抗菌活性以及负责抗菌活性的特定活性化合物的分离，鉴定和协同作用。