Insects exhibit a particular resistance to infections.The activation of the innate immune response of insects is involved in the recognition of the infectious nonself and subsequent activation of cellular and humoral reactions.In humoral reactions,insect antibacterial peptides and lysozyme are very important in resistance to infections.Housefly(Musca domestica) is one of the most important kinds of insects and it has strong ability to adapt to the adverse circumstances.It is of momentous theoretical and practical significance to research the immunity system of housefly.The methods of inducement of housefly larvae were firstly studied.Then an antibacterial protein,whose molecular weight is 28kDa,was purified from housefly larvae,induced by 30% H2O2,through saltout,Sephadex G25 column,Sephadex G75 column and CMSepharose Fast Flow column.This antibacterial peptide had activities against most of Gram positive and Gram negative bacteria.

Objective:To compare clinical features of patients with pyogenic liver abscesses with and without septated lobulations.Methods:Patients diagnosed to have pyogenic liver abscesses who were treated in our hospital from January 2011 to March 2021 were enrolled into this retrospective study. There were 203 males and 132 females, with age of (56±14) years old. The patients were divided into two groups by findings on computed tomography and ultrasound into the septated lobulation group ( n=68) and the non-septated lobulation group ( n=267). The clinical data of these patients were compared. Results:In the septated lobulation group, the neutrophil count was 9.17(5.97, 12.33)×10 9/L and the TBil was 17.65(11.92, 27.84) μmol/L. These were significantly higher than the corresponding figures of 7.81(5.42, 10.81)×10 9/L, 12.90(9.00, 19.68) μmol/L, respectively in the non-septated lobulation group ( P<0.05). The difference in the maximum diameters of the septated lobulation group was also significantly larger than the non-septated lobulation group ( P=0.032). Additionally, pus culture showed the proportion of Klebsiella pneumoniae positive patients in the septated lobulation group was significantly higher than that in the non-septated lobulation group [41.18% (28/68) vs. 25.84% (69/267), P=0.013]. The use of fluoroquinolones in patients in the septated lobulation group was higher than that in the non-septated lobulation group [20.59% (14/68) vs. 10.11% (27/267), χ 2=5.54, P=0.019]. Conclusion:Compared to patients without septated lobulations, those with septated lobulations had a larger diameter of abscesses, a higher positive rate of Klebsiella pneumoniae on pus culture and a higher proportion of patients receiving fluoroquinolones.