Insects are excellent model organisms to examine the phenotypic variation of innate immunity. The innate immunity is the immediate response of invertebrates for protection against pathogens. In this study, we assessed the immune responses of Drosophila melanogaster and Drosophila ananassae against Staphylococcus aureus and Escherichia coli. It includes survival ability against infection, systemic pathogen load, and estimation of phenoloxidase activity, melanization reaction, the total number of hemocytes, quantification of fat, and the nitrite levels in adult flies and also the bacterial inhibitory effect of hemolymph. The results showed increased bacterial growth in D. ananassae compared to D. melanogaster. Due to bacterial infection, reduced fat accumulation was observed in both D. ananassae and D. melanogaster, which suggests a possible decline in physiological condition. Further, a significant elevation in phenoloxidase, nitrite levels and hemolymph reveals that bacterial cell growth was found to be inhibited due to the immune response of both Drosophila species. D. ananassae showed high sensitivity to bacterial infection, while D. melanogaster showed moderate sensitivity. The results have demonstrated the level of immunocompetence of laboratory stocks of D. melanogaster and D. ananassae against Gram-positive and Gram-negative bacteria.

中文翻译：

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评估果蝇和果蝇的抗菌免疫应答

昆虫是检查先天免疫表型变异的优秀模式生物。天生的免疫力是无脊椎动物对病原体的直接反应。在这项研究中，我们评估了果蝇果蝇和果蝇果蝇对金黄色葡萄球菌和大肠杆菌的免疫反应。它包括抵抗感染的生存能力，全身病原体负荷以及酚氧化酶活性，黑色素反应，血细胞总数，脂肪定量和成年果蝇中亚硝酸盐含量的估计，以及血淋巴的细菌抑制作用。结果表明，与D. ananassae相比，细菌的生长增加了。D.黑变种。由于细菌感染，在D. ananassae和D. melanogaster中均观察到脂肪堆积减少，这表明生理状况可能下降。此外，酚氧化酶，亚硝酸盐水平和血淋巴的显着升高表明，由于两种果蝇的免疫应答，细菌细胞的生长受到抑制。D. ananassae对细菌感染显示高敏感性，而D. melanogaster显示中等敏感性。结果证明了D. melanogaster和D. ananassae实验室储备液的免疫能力水平 对抗革兰氏阳性和革兰氏阴性细菌。