Enhancing the Decomposition of Paper Cups Using Galleria Mellonella and Eisenia Fetida

The composition of paper cups creates a challenge for the recycling industry,as the paperboard–plastic film composite is hard to separate.Therefore,paper cups are sent to landfills or waste incinerators.This study explores the combined use of red worms(Eisenia fetida)and Greater wax moth(Galleria mellonella)in the biodegradation of paper cups.The study investigates the conditions and combinations that promote using Eisenia fetida and Galleria mellonella for degrading paper cups.The study considered the influence of environmental temperature,the presence of food waste,varying the number of Eisenia fetida worms,and the presence of a Galleria mellonella growth-slowing agent on the degradation process.To achieve the study objectives,the study followed a quantitative approach.The study monitored the degradation of paper cup cuts that were placed in jars containing different combinations of Eisenia fetida worms,Galleria mellonella larvae,food waste,bedding material,and Galleria mellonella growth-slowing agents.The study found that the best operating temperature is 30oC.The study found that using food waste improves the performance of Eisenia fetida worms and Galleria mellonella larvae significantly.The study found that adding a Galleria mellonella growth-slowing agent slightly enhances the degradation of the paper cup.Finally,a numerical model was obtained to simulate the paper cup degradation efficiency.

Pathogenicity of bacterium, Xenorhabdus nematophila isolated from entomopathogenic nematode (Steinernema carpocapsae) and its secretion against Galleria mellonella larvae

The entomopathogenic bacterium, Xenorhabdus nematophila was isolated from the hemolymph of Galleria mel- lonella infected with Steinernema carpocapsae. The bacterial cells and its metabolic secretions have been found lethal to the Galleria larvae. Toxic secretion in broth caused 95% mortality within 4 d of application whereas the bacterial cells caused 93% mortality after 6 d. When filter and sand substrates were compared, the later one was observed as appropriate. Similarly, bacterial cells and secretion in broth were more effective at 14% moisture and 25 °C temperature treatments. Maximum insect mortality (100%) was observed when bacterial concentration of 4×106 cells/ml was used. Similarly, maximum bacterial cells in broth (95%) were penetrated into the insect body within 2 h of their application. However, when stored bacterial toxic secretion was applied to the insects its efficacy declined. On the other hand, when the same toxic secretion was dried and then dissolved either in broth or water was proved to be effective. The present study showed that the bacterium, X. nematophila or its toxic secretion can be used as an important component of integrated pest management against Galleria.

Evaluation of Antimycobacterial Activity of Higenamine Using Galleria mellonella as an In Vivo Infection Model

The Phytochemical investigation on MeOH extract on the bark of Aristolochia brasiliensis Mart.&Zucc(Aristolochi-aceae)led to the isolation of major compound(1)as light brown grainy crystals.The compound was identified as 1-(4-hydroxybenzyl)-1,2,3,4-tetrahydroisoquinoline-6,7-diol(higenamine)on the basis of spectroscopic analysis,including 1D and 2D NMR spectroscopy.The compound was evaluated for its antimycobacterial activity against Mycobacterium indicus pranii(MIP),using Galleria mellonella larva as an in vivo infection model.The survival of MIP infected larvae after a single dose treatment of 100 mg/kg body weight of higenamine was 80%after 24 h.Quantitatively the compound exhibited a dose dependent activity,as evidenced by the reduction of colony density from 10^(5) to 10^(3) CFU for test concentrations of 50,100,150 and 200 mg/kg body weight respectively.The IC50 value for higenamine was 161.6 mg/kg body weight as calculated from a calibration curve.Further analysis showed that,a complete inhibition of MIP in the G.mellonella could be achieved at 334 mg/kg body weight.Despite the fact that MIP has been found to be highly resistant against isoniazid(INH)in an in vitro assay model,in this study the microbe was highly susceptible to this standard anti-TB drug.The isolation of higenamine from the genus Aristolochia and the method used to evaluate its in vivo antimycobacterial activity in G.mellonella are herein reported for the first time.

取食天然饲料与人工饲料的大蜡螟Galleria mellonella的生长发育差异比较

在温度为35±1℃、相对湿度为65±5％及全黑暗的条件下,对取食天然饲料和人工饲料的大蜡螟Galleria mellonella(L.)的生长发育进行了观察。在天然饲料中,以中蜂巢脾为食的大蜡螟生长发育最好,意蜂巢脾次之,蜂蜡不能很好地使大蜡螟完成发育。试验采用来源广泛且价格低廉的麸糠、面粉和玉米粉为主要原料配制成人工饲料供大蜡螟取食,与供食中蜂巢脾的大蜡螟比较,蛹重、成虫寿命、产卵量均无显著差异,但幼虫历期明显缩短6.8天。

Observations of Embryonic Changes in Middle and Late Stages of the Greater Wax Moth, <i>Galleria mellonella</i>(Lepidoptera: Pyralidae)

The embryogenesis of lepidopteran insects has morphogenetic events accompanying the blastokinesis movements (anatrepsis and katatrepsis) in early and late stages, respectively. Katatrepsis is related to embryonic movement with yolk mass and regression of amnioserosa folds in the second half of the development cycle. The whole mount method and differential interference contrast microscopy (DIC) were used for analysing the embryonic developmental changes. Those changes in the middle and late embryonic periods were described and divided into eight stages: 1) Completion of segmentation and differentiation of cephalic and thoracic appendages (32 - 40 hours post-oviposition h. PO);2) Expanded growth of cephalo-gnathal and abdominal parts (41 - 60 h. PO);3) Completion of thoracic appendages and appearance of pleuropodia, katatrepsis (60 - 70 h. PO);4) Pre-revolution morphogenetic movement of the cephalo-gnathal region (71 - 80 h. PO);5) revolution of the embryo (81 - 100 h. PO);6) Beginning of dorsal closure (101 - 115 h. PO);7) completion of dorsal closure (116 - 120 h. PO);and 8) full-grown embryo just before hatching (121 - 144 h. PO).

Genomics,transcriptomics,and peptidomics of the greater wax moth Galleria mellonella neuropeptides and their expression in response to lead stress

Neuropeptides are crucial in regulation of a rich variety of developmental,physiological,and behavioral functions throughout the life cycle of insects.Using an integrated approach of multiomics,we identified neuropeptide precursors in the greater wax moth Galleria mellonella,which is a harmful pest of honeybee hives with a worldwide distribution.Here,a total of 63 and 67 neuropeptide precursors were predicted and annotated in the G.mellonella genome and transcriptome,in which 40 neuropeptide precursors were confirmed in the G.mellonella peptidome.Interestingly,we identified 12 neuropeptide precursor genes present in G.mellonella but absent in honeybees,which may be potential novel pesticide target sites.Honeybee hives were contaminated with heavy metals such as lead,enabling its bioaccumulation in G.mellonella bodies through the food chain,we performed transcriptome sequencing to analyze the effects of Pb stress on the mRNA expression level of G.mellonella neuropeptide precursors.After treatment by Pb,the expression of neuropeptide F1 was found to be significantly downregulated,implying that this neuropeptide might be associated with responding to the heavy metal stress in G.mellonella.This study comprehensively identified neuropeptide precursors in G.mellonella,and discussed the effects of heavy metals on insect neuropeptides,with the example of G.mellonella.The results are valuable for future elucidation of how neuropeptides regulate physiological functions in G.mellonella and contribute to our understanding of the insect's environmental plasticity and identify potential new biomarkers to assess heavy metal toxicity in insects.

Characterization of bacteriophage BUCT631 lytic for K1 Klebsiella pneumoniae and its therapeutic efficacy in Galleria mellonella larvae

Severe infections caused by multidrug-resistant Klebsiella pneumoniae(K.pneumoniae)highlight the need for new therapeutics with activity against this pathogen.Phage therapy is an alternative treatment approach for multidrug-resistant K.pneumoniae infections.Here,we report a novel bacteriophage(phage)BUCT631 that can specifically lyse capsule-type K1 K.pneumoniae.Physiological characterization revealed that phage BUCT631 could rapidly adsorb to the surface of K.pneumoniae and form an obvious halo ring,and it had relatively favorable thermal stability(4–50C)and pH tolerance(pH?4–12).In addition,the optimal multiplicity of infection(MOI)of phage BUCT631 was 0.01,and the burst size was approximately 303 PFU/cell.Genomic analysis showed that phage BUCT631 has double-stranded DNA(total length of 44,812 bp)with a G t C content of 54.1%,and the genome contains 57 open reading frames(ORFs)and no virulence or antibiotic resistance related genes.Based on phylogenetic analysis,phage BUCT631 could be assigned to a new species in the genus Drulisvirus of the subfamily Slopekvirinae.In addition,phage BUCT631 could quickly inhibit the growth of K.pneumoniae within 2 h in vitro and significantly elevated the survival rate of K.pneumoniae infected Galleria mellonella larvae from 10%to 90%in vivo.These studies suggest that phage BUCT631 has promising potential for development as a safe alternative for control and treatment of multidrug-resistant K.pneumoniae infection.

Passive vectoring of entomopathogenic fungus Beauveria bassiana among the wax moth Galleria mellonella larvae by the ectoparasitoid Habrobracon hebetor females

Females of the ectoparasitoid Habrobracon hebetor attack and envenomate numerous host individuals during oviposition. The vectoring of the entomopathogenic fungus Beauveria bassiana during the adhesion stage by ectoparasitoid females among the wax moth larvae Galleria mellonella was explored under laboratory conditions. Vectoring occurred both from infected parasitoids to wax moth larvae and from infected to healthy wax moth larvae by parasitoids. The efficacy of vectoring in both cases was dose dependent. Parasitoid females were unable to recognize infected larvae in a labyrinth test. In addition, the presence of H. hebetor females significantly （1.5-13 fold） increased the mycoses level in clusters of G. mellonella, with 40% of the larvae infected with ftmgal conidia. Envenomation by H. hebetor increased conidia germination on the cuticles of the wax moth larvae by 4.4 fold. An enhanced germination rate （2 fold） was registered in the n- hexane epicuticular extract of envenomated larvae compared to that of healthy larvae. Both envenomation and mycoses enhanced the phenoloxidase （PO） activity in the integument of G. mellonella and, in contrast, decreased the encapsulation rate in hemolymphs. We hypothesize that changes in the integument property and inhibition of cellular immunity provide the highest infection efficacy of entomopathogenic fungi with H. hebetor.

Effects of food quality on trade-offs among growth, immunity and survival in the greater wax moth Galleria mellonella

The resources available to an individual in any given environment are finite, and variation in life history traits reflect differential allocation of these resources to competing life functions. Nutritional quality of food is of particular importance in these life history decisions. In this study, we tested trade-offs among growth, immunity and survival in 3 groups of greater wax moth （Galleria mellonella） larvae fed on diets of high and average nutritional quality. We found rapid growth and weak immunity （as measured by encapsulation response） in the larvae of the high-energy food group. It took longer to develop on food of average nutritional quality. However, encapsulation response was stronger in this group. The larvae grew longer in the low-energy food group, and had the strongest encapsulation response. We observed the highest survival rates in larvae of the low-energy food group, while the highest mortality rates were observed in the high-energy food group. A significant negative correlation between body mass and the strength of encapsulation response was found only in the high-energy food group revealing significant competition between growth and immunity only at the highest rates of growth. The results of this study help to establish relationships between types of food, its nutritional value and life history traits of G. mellonella larvae.

Immunity of the greater wax moth Galleria mellonella

Investigation of insect immune mechanisms provides important information concerning innate immunity, which in many aspects is conserved in animals. This is one of the reasons why insects serve as model organisms to study virulence mechanisms of human pathogens. From the evolutionary point of view, we also learn a lot about host-pathogen interaction and adaptation of organisms to conditions of life. Additionally, insect-derived antibacterial and antifungal peptides and proteins are considered for their potential to be applied as alternatives to antibiotics. While Drosophila melanogaster is used to study the genetic aspect of insect immunity, Galleria mellonella serves as a good model for biochemical research. Given the size of the insect, it is possible to obtain easily hemolymph and other tissues as a source of many immune-relevant polypeptides. This review article summarizes our knowledge concerning G. mellonella immunity. The best-characterized immune-related proteins and peptides are recalled and their short characteristic is given. Some other proteins identified at the mRNA level are also mentioned. The infectious routes used by Galleria natural pathogens such as Bacillus thuringiensis and Beauveria bassiana are also described in the context of host-pathogen interaction. Finally, the plasticity of G. mellonella immune response influenced by abiotic and biotic factors is described.

聚苯乙烯降解菌的筛选鉴定及降解特性研究

石油基废弃塑料造成的环境污染已成为人类难以解决的问题,而现有的处理方式既耗能又容易造成二次污染。研究发现,大蜡螟幼虫肠道内存在降解塑料的细菌,可有效加快塑料的降解,分离纯化其肠道内菌株具有极高的研究价值。因此,使用生活中常见的聚苯乙烯(PS)包装盒作为唯一食物来源喂食大蜡螟幼虫,富集大蜡螟幼虫肠道内的PS降解菌;经解剖、培养、分离,最终获得4株菌株(PD-1、PD-2、PD-3和PD-4)。将各菌株接种至以PS薄膜为唯一碳源的基础盐培养基(MSM培养基)并测定了其降解率。结果表明,PD-1对PS薄膜降解率最高,为1.8%。对PD-1进行菌株形态观察、生理生化测定及系统发育树构建,鉴定PD-1为肠杆菌科克雷伯氏菌属(Klebsiella)。同时,采用紫外或硝酸对PS薄膜进行了预处理,以期提高菌株降解率。结果表明,PD-1降解硝酸预处理的PS薄膜的降解率为2.5%,而对紫外预处理的PS薄膜的降解率为0.8%,PS薄膜经硝酸预处理后更易被PD-1降解。

噬菌体PCCM_KpP1172的鉴定及其对大蜡螟幼虫碳青霉烯耐药高毒力肺炎克雷伯菌感染的疗效评估

背景碳青霉烯耐药的高毒力肺炎克雷伯菌感染发生率逐年增加,临床治疗困难,死亡率高。使用具有高裂解能力的噬菌体治疗细菌感染是颇具前景的治疗方法。目的针对碳青霉烯耐药高毒力肺炎克雷伯菌分离一株新型裂解性T7噬菌体,对该分离株进行生物学特性测定和基因组学测序分析,为临床开展噬菌体治疗提供可应用的噬菌体资源。方法从肺部感染患者的痰液中分离出肺炎克雷伯菌,通过细菌鉴定、药敏分析、全基因组测序和PCR检测验证菌株的毒力基因与耐药基因,以此株肺炎克雷伯菌为宿主菌,在污水中分离出一株裂解性噬菌体,命名为PCCM_KpP1172。测定该噬菌体生物学特性,分析其基因组序列,并通过大蜡螟幼虫感染模型检测该噬菌体的治疗效果。结果该株肺炎克雷伯菌基因组分析存在耐药基因与毒力基因rmpA2、rmpA、iroN、icu。以此菌株为宿主菌分离到新型肺炎克雷伯菌噬菌体,命名为PCCM_KpP1172,在宿主菌菌苔上可形成完全透明的噬菌斑并伴晕圈;透射电镜下呈现有尾噬菌体目短尾病毒科病毒的典型形态特征;一步生长曲线显示其潜伏期为15 min,最佳感染复数(multiplicity of infection,MOI)为0.0001,对ST11KL64型肺炎克雷伯菌有广泛裂解范围。基因组分析显示,该噬菌体为双链DNA(总长度为40222 bp),G+C含量为53%,基因组包含49个开放阅读框(open reading frames,ORF),无毒力或抗生素耐药性相关基因。基于系统发育分析,该噬菌体可归属于有尾噬菌体目Studiervirinae亚科Przondovirus属的一个新种。此外,噬菌体PCCM_KpP1172可在体外3 h内有效抑制碳青霉烯耐药肺炎克雷伯菌的生长,并能提高宿主菌感染的大蜡螟幼虫存活率(P<0.01)。结论本研究针对碳青霉烯耐药的高毒力肺炎克雷伯菌分离并鉴定了一株新的T7噬菌体PCCM_KpP1172,具有高裂解力,无耐药基因和毒力基因,对大蜡螟幼虫感染模型具有良好治疗效果。

五株临床分离肠炎沙门氏菌同源性及耐药与毒力特征分析

肠炎沙门氏菌是一种重要的食源性致病菌,多重耐药以及高致病性菌株的出现对临床感染及治疗造成严重负担。为了探究临床分离肠炎沙门氏菌菌株的遗传进化关系及其耐药性和毒力特征,该研究对5株临床来源的肠炎沙门氏菌进行了全基因组测序(whole genome sequencing,WGS),并对其抗生素耐药性和毒力进行了表征。基于WGS生物信息学分析表明5株沙门氏菌均为肠炎血清型,ST型为ST11。cgSNP系统发育分析表明,5株肠炎沙门氏菌中菌株48A和公共数据库中一株分离自鸡的菌株聚类在一起,其余4株菌与公共数据库中的临床分离株有较近的进化关系。微量肉汤稀释法测定结果表明,5株菌株均为抗生素耐药菌株,其中抗4株菌为多重耐药菌,并且菌株33A对黏菌素和多黏菌素B具有耐药性。运动能力、生物被膜形成能力和对大蜡螟幼虫的致死率均表明菌株48A的毒力最强,但该菌株对Caco-2细胞的黏附和侵袭能力并不强。研究结果表明,肠炎沙门氏菌48A是一株高毒力菌株且可能是食品来源,菌株33A具有多黏菌素耐药性,应引起重视。该研究结果可为临床耐药肠炎沙门氏菌的溯源及治疗提供参考。

大蜡螟性肽受体基因GmelSPR克隆及表达分析

交配是昆虫繁衍的重要方式,雌性交配后会显现出一系列保护后代而产生的行为,SPR则是重要的交配行为调控受体基因。本研究根据前期转录组SPR基因数据信息,利用RT-PCR扩增出大蜡螟SPR基因的完整CDS序列,命名为GmelSPR(GenBank登录号:OR347698)。生物信息学分析显示该基因编码区全长1263 bp,编码420个氨基酸,预测分子量48.70718 kDa,理论等电点8.70,有7个跨膜螺旋区,具有典型G蛋白偶联受体蛋白特征。系统进化树比对结果显示大蜡螟GmelSPR与螟蛾科昆虫脐橙螟Amyelois transitella、印度谷螟Plodia interpunctella置信度较高。大蜡螟不同状态、不同组织中表达分析表明,未交尾雌蛾、雄蛾和已交尾雌蛾、雄蛾GmelSPR均在头部较高表达,且在未交尾雌蛾、雄蛾中表达量均高于已交尾雌蛾、雄蛾。本研究克隆了大蜡螟SPR基因,克隆结果表明GmelSPR与螟蛾科昆虫亲缘较近;表达谱分析则显示GmelSPR可能参与大蜡螟交配行为,为进一步研究大蜡螟中SPR基因功能奠定基础。

顺-3-己烯醇乙酸酯对大蜡螟的驱避作用

利用植物挥发物监测和调控害虫行为已逐渐成为害虫绿色防控的重要途径。顺-3-己烯醇乙酸酯广泛存在于瓜果及绿色植物的叶片中,具有环境友好、无残留的优点。大蜡螟是养蜂产业中常见的害虫,严重影响蜂产业和蜜蜂资源保护。为生产中应用顺-3-己烯醇乙酸酯调控大蜡螟的行为控制其对蜂群的危害提供依据,为开发新型昆虫行为调控剂以及大蜡螟的绿色防控提供支持,利用Y-型嗅觉仪研究大蜡螟不同虫态的个体对不同浓度、同一浓度不同剂量顺-3-己烯醇乙酸酯的行为趋性。结果表明,大蜡螟幼虫对顺-3-己烯醇乙酸酯表现出显著的负趋性,浓度为0.5 mol/L时,大蜡螟幼虫总选择率为79.33%,并表现为极显著的负趋性;雄成虫对顺-3-己烯醇乙酸酯的选择率为8.33%,具有显著的负趋性;不同剂量的顺-3-己烯醇乙酸酯对大蜡螟成虫的选择行为影响不显著,但对幼虫均具有明显的驱避效果。

皮炎外瓶霉黑色素的致病力:基于大蜡螟感染模型的评估

目的 采用大蜡螟-皮炎外瓶霉模型评估皮炎外瓶霉黑色素的致病力。方法 采用“共生法”恢复皮炎外瓶霉白化株黑色素的生成,使用皮炎外瓶霉白化株、色素株及色素恢复株构建大蜡螟感染模型,观察最佳感染浓度下各组大蜡螟生存曲线、外观表现及组织病理学变化情况。结果 采用“共生法”可以恢复皮炎外瓶霉白化株黑色素的生成,孢子浓度10^(7)/mL为大蜡螟-皮炎外瓶霉模型的最佳感染浓度。观察终点时,白化株组存活率低于色素株组、色素恢复株组,生存曲线差异具有统计学意义(色素株组与白化株组:χ^(2)=6.11,P=0.013;色素恢复株组与白化株组:χ^(2)=6.37,P=0.010),而色素株组与色素恢复株组生存曲线的差异无统计学意义(χ^(2)=0.01,P=0.940)。组织病理学检查显示,与白化株相比,皮炎外瓶霉色素株及色素恢复株可吸引更多大蜡螟血细胞聚集,形成更大的感染性结节。结论 在蜡螟感染模型中,皮炎外瓶霉白化株表现出比色素株更强的致病力,恢复白化株黑色素的生成,可以逆转白化株致病力。

取食不同聚乙烯材料对大蜡螟种群延续的影响

取食聚乙烯材料对大蜡螟种群延续的影响直接决定了大蜡螟取食并生物降解废弃聚乙烯塑料应用的可行性,为验证该影响规律,以农业中常用降解新膜(JJXM)、PE新膜(PEXM)、农田残留滴灌带(FDGD)、农田残膜(NTCM)为不同聚乙烯材料食物,人工饲料(RGSL,对照组)做对比,恒温30℃、相对湿度(RH)60%±10%RH条件下连续饲养大蜡螟两个世代。结果表明:取食不同聚乙烯材料较RGSL首先显著降低了大蜡螟取食量,进而显著降低了大蜡螟蛹重蛹长、成虫体重体长、产卵量、孵化率;第二代取食不同聚乙烯材料量均较第一代增加,而蛹重、蛹长、成虫体重、孵化率均低于第一代(P>0.05);不同聚乙烯材料处理产卵量由高到低依次为NTCM、FDGD、PEXM、JJXM;5龄期大蜡螟幼虫在不同聚乙烯处理条件下较RGSL处理总历期有缩短的趋势。

聚乙烯高效降解复合菌系的构建及其降解特性研究

【目的】聚乙烯塑料的稳定性及与日俱增的使用量为生态环境带来严重“白色污染”,其风化形成的微塑料为生物健康安全带来严重威胁的难题亟待解决。【方法】通过选择与纯培养技术分离大蜡螟幼虫消化道内潜在的聚乙烯微生物降解资源,通过菌株比例复配构建高效降解复合菌系,通过质控回收评估其降解能力,使用光镜与扫描电镜验证其降解性能,通过红外光谱、凝胶渗透色谱、气质联用与液质联用等技术手段探究聚乙烯的微生物降解特性。【结果】共分离出13株可降解聚乙烯微生物;首次发现Debaryomyces hansenii具有高效降解聚乙烯的能力;构建出一组由真菌与细菌组成的聚乙烯高效降解复合菌系,相较于单菌复合菌系的降解性能提升了3.3倍,其降解效率高达0.9367 mg/d远高于现有研究水平;光镜与扫描电镜发现聚乙烯薄膜降解后表面存在生物膜附着痕迹与明显孔洞;红外光谱显示降解液中存在多个新官能团,凝胶渗透色谱结果显示降解后聚乙烯微塑料分子量降低;气质与液质联用结果表明降解液中出现了酰胺类、氨基酸类、烯烃类、醇类、酮醛类等生物活性成分,以及大分子烷烃类物质等。【结论】研究挖掘了聚乙烯的微生物降解资源,构建出了高效降解复合菌系,探究了微生物的降解特性,为聚乙烯的微生物降解提供了数据支撑与可行方案。

金黄色葡萄球菌噬菌体裂解酶Lys239表达纯化及活性分析

为获得具有高效裂解活性的金黄色葡萄球菌噬菌体裂解酶,将测序后的噬菌体全基因序列在GenBank数据库中进行比对,找出裂解酶基因序列,对其克隆后在BL21(DE3)中表达蛋白并纯化,选择大蜡螟幼虫作为模型模拟体内细菌感染以探究其抑菌效果。结果显示,裂解酶合成基因构建到载体pET22b中,得到重组质粒pET22b-lys239。并将重组质粒转入BL21(DE3)感受态细胞后诱导其表达,经纯化验证后,获得浓度为2μg/μL的具有裂解活性的裂解酶Lys239。大蜡螟幼虫体内细菌感染试验结果显示,Lys239处理组存活率明显高于对照组,血淋巴负荷测定显示各处理组与对照组差异极显著(P<0.01)且Lys239浓度越高,对于金黄色葡萄球菌抑制效果越显著。说明重组表达的裂解酶Lys239具有良好的抑菌效果,可作为一种潜在的新型抑菌剂。

植物药组方MYF-20的抗马拉色菌活性及初步作用机制探究

目的以糠秕马拉色菌(Malassezia furfur)为目标菌株,对本实验室研发的植物药组方MYF-20的乙醇提取物进行抗菌活性及初步作用机制研究。方法采用改良CLSI-M27A法确定组方对马拉色菌的最小抑菌浓度,电导率法以及扫描电镜形态学观察研究MYF-20对马拉色菌细胞完整性的影响,铜皂法检测组方对马拉色菌脂肪酶活性影响,构建大蜡螟感染模型评价MYF-20的体内药效。结果MYF-20对马拉色菌的最小抑菌浓度为7.83 mg/mL(生药干重),MYF-20处理后,菌液相对电导率显著上升(P<0.01);扫描电镜证实了菌体芽孢断裂、细胞破裂内陷的发生;脂肪酶活性被显著抑制(P<0.01)。大蜡螟体内实验证明,MYF-20可以显著提高大蜡螟马拉色菌感染模型的存活率与黑化健康评分,降低体内真菌负荷(P<0.01)。结论MYF-20对马拉色菌在体内外均具有强抗菌活性,可通过多途径发挥其抑菌功能,具有成为抗马拉色菌植物类新药的一定潜力。