细菌天然群体感应信号分子抑制剂研究进展

长期抗生素滥用导致了多重耐药菌株及其超级细菌的出现,由密度感应系统调控的生物被膜的形成和成熟是造成细菌感染的机制之一。自然界存在的生物活性物质能够淬灭密度感应系统,这些生物活性物质被称为群体感应信号分子抑制剂(quorum sensing inhibitor,QSI)。近年来,群体感应抑制剂成为细菌抗感染药物开发的靶点,有必要对细菌群体感应信号分子抑制剂种类、作用机制进行研究,本文综述了细菌天然群体感应信号分子抑制剂,干扰群体感应系统,从而治疗细菌感染。绝大多数原核生物能够产生群体感应抑制剂,这被认为是安全的。动物、豆类、传统的药用植物、海洋生物均能产生群体感应抑制剂。这些天然抑制剂可能替代传统抗生素,具有广阔的研究和应用前景。     

不同来源白色念珠菌的基因型及耐药性分析

为了研究不同来源白色念珠菌的基因型及耐药性情况,试验对患病鸡、鸭、鹅进行白色念珠菌的分离,用特异性引物扩增分离株的25S rDNA分析其基因型,用抗真菌药物伊曲康唑、制霉菌素、两性霉素B等对分离株进行耐药性分析。结果显示：从鸡、鸭、鹅中分离得到三株白色念珠菌CaJ、CaY和CaE,其基因型分别为 A型、A型和B型,耐药性试验结果显示三株分离株对制霉菌素和两性霉素B均表现出了较高的敏感性,但对其它药物表现出不同程度的耐药性。说明部分药物临床中可能使用过多,来自不同家禽的白色念珠菌在耐药性方面有所不同。     

野鸡白色念珠菌病的诊治

从某野鸡场送检的病死野鸡病料中,分离到白色念珠菌,通过发病情况、临床检查、病原学检查等,综合诊断该群野鸡所患为白色念珠菌病。经综合治疗,取得了满意的效果。     

肉鸽白色念珠菌病的诊治

念珠菌病又叫鹅口疮或霉菌性口炎,主要是由白色念珠菌所致禽上消化道的一种细菌病,特征是上消化道黏膜形成白色的假膜和溃疡。此菌广泛存在于自然界,能在健康的畜禽及人的口腔、上呼吸道和肠道等处寄居,主要引起幼龄禽如鸡、鸽等发病。     

信鸽白色念珠菌病的诊治

念珠菌病又叫鹅疮或霉菌性口炎,主要是由白色念珠菌致禽上消化的一种细菌病,特征是上消化道黏膜形成白色的假膜和溃疡.此菌广泛存在于自然界,能在健康的畜禽及人的口腔、上呼吸道和肠道等处寄居,主要引起幼龄禽如鸡、鸽等发病.     

鸡白色念珠菌病的诊治

2012年10月,南宁市郊某养鸡专业户饲养的肉用麻鸡出现逐渐消瘦、死亡的情况。经临床症状观察、结合剖检的病变特点和实验室检验结果,诊断为鸡白色念珠菌病。笔者对病鸡鸡群采取综合防治措施,使病情得到了控制。     

肉鸽白色念珠菌病的诊断与防制

1病原学本病的病原是类酵母状的真菌,称为白色念珠菌。在病变组织、渗出物及普通培养基上能产生芽生孢子和假菌丝,不形成有性孢子。出芽细胞呈卵圆形,直径2~4微米,培养基上菌落呈白色金属光泽。菌体小而椭圆,能够长芽,伸长而形成假菌丝。革兰氏染色阳性,但着色不甚均匀。白色念珠菌在自然界     

维生素C对酮康唑抑制白色念珠菌的影响研究

为研究酮康唑治疗畜禽真菌感染过程中能否给与维生素C辅助治疗,体外测试了添加维生素C后白念珠菌对酮康唑的敏感性。结果发现,维生素C能显著抑制酮康唑对白色念珠菌的敏感性,为科学治疗畜禽机会性真菌临床感染提供了依据。     

犬猫白色念珠菌病的防治措施

白色念珠菌病又名霉菌性口炎,俗称“鹅口疮”,是由白色念珠菌引起的一种真菌病。其主要特征为口腔和咽喉等黏膜形成局部溃疡,表面覆有黄白色的假膜,严重时内脏器官可形成脓肿、肉芽肿以及坏死灶等。该病呈世界性分布,犬、猫、家畜、禽类等各种动物均可感染,且幼畜更为多发。     

微生物细胞交流的方式——群体感应

在细菌和真菌中普遍存在着被称为群体感应的细胞与细胞之间的交流.介绍了群体感应概念、机制及其应用.     

Candida albicans infection in free-living populations of hihi (stitchbird; Notiomystis cincta)

Abstract

AIM: To describe the occurrence of candidiasis in hihi (stitch-bird; Notiomystis cincta) nestlings, and investigate the carriage and impact of Candida albicans infection in a free-living population of hihi.

METHODS: Mortality of nestlings was investigated in a reintroduced population of the endangered, endemic hihi at Zealandia: Karori Sanctuary, Wellington, New Zealand. Oral and faecal samples were collected from live hihi nestlings, for microbiological examination, between October 2008 and April 2009. All hihi that died and could be recovered were submitted to the New Zealand Wildlife Health Centre (NZWHC) at Massey University, for post-mortem examination. The results were compared with data obtained retrospectively from the National Wildlife Mortality (NWM) database for two other reintroduced populations of hihi on Mokoia and Tiritiri Matangi Islands.

RESULTS: Fifty chicks fledged from 82 eggs hatched during the 2008–2009 breeding season at Zealandia: Karori Sanctuary. Thirty-four live nestlings were sampled from 11 nests, and C. albicans was isolated from gastrointestinal swabs of 13 live nestlings from four nest sites. Eight (62%) of those nestlings survived to fledge, compared with 17/21 (81%) of those that tested negative (p=0.254; Fisher's exact test). Of the 32 hihi nestlings that died during the period of the study, 25 were recovered for necropsy. Histopathological examination revealed candidiasis was a factor in the deaths of four nestlings. An adult hihi that died during the period of the study at Zealandia: Karori Sanctuary was also found to have candidiasis. Retrospective analysis of data from the NWM database revealed candidiasis was also a factor in the deaths of five nestlings aged between 1 and 10 days from Mokoia Island, and of three nestlings <5 days old and one adult from Tiritiri Matangi Island.

CONCLUSIONS: Candida albicans was isolated from 38% of hihi nestlings sampled in this study, and vertical transmission of this organism from parent to offspring is likely to occur. Some colonised nestlings developed ventriculitis associated with Candida spp., but survival to fledging was not significantly different between nestlings that tested positive or negative, although the fate of birds following fledging was unknown.     

雉鸡口角炎白色念珠菌病的诊断及病原ITS序列测定

2009年7月广东顺德某珍禽场种雏鸡出现单侧口角炎,从发生口角炎的230日龄的公雉鸡口角病灶中分离到1株酵母样菌,经鉴别培养、生化试验、动物接种试验和ITS序列测定,鉴定为致病性白色念珠菌,其序列与常见的引发幼龄雉鸡嗉囊炎的白色念珠菌高度同源。     

鸽白色念珠菌药物敏感性及ITS1和Als1序列分析

为研究防控集约化养殖场鸽嗉囊炎,本研究对鸽白色念珠菌(C.Albicans)PGG菌株进行了6种抗真菌药物的药敏试验,并进行ITS1和Als1序列测序及分析。结果表明,C.Albicans对常用抗真菌药两性霉素B、咪康唑、氟康唑、酮康唑、伊曲康唑和制霉菌素均敏感;PGG菌株的ITS1序列约243 bp,Als1序列980 bp,分析比对表明C.Albicans PGG的Als1序列(JQ034421)与人源白色念珠菌株SC5314的Als1序列(XM 712984)的同源性为99%。     

奶牛乳房炎白色念珠菌的分离鉴定及生物学特性研究

试验旨在了解宁夏地区奶牛真菌性乳房炎的发生情况,为诊断和治疗真菌性奶牛乳房炎提供有效依据。采集宁夏周边地区各奶牛场使用抗生素治疗无效的乳房炎奶样,对奶样中的真菌进行分离鉴定,并对分离菌进行生物学特性研究。通过选择性培养基从乳房炎奶样中获得真菌,进一步应用生物化学和分子生物学手段鉴定出样品中的真菌为白色念珠菌。通过溶血性、磷脂酶活性及产膜等方面的研究,证实其具有不同毒力,分离菌株对试验动物有较强的致病性。同时,采用药敏纸片法对分离株进行药敏试验,结果显示,菌株对临床常用抗生素耐药,对临床常用抗真菌药物敏感。结果表明,宁夏地区真菌性乳房炎奶样中分离出的致病菌均为白色念珠菌,感染率为43%,分离株具有较强的毒力,对常用抗生素耐药,对抗真菌药物和中药敏感。     

Isolation,Identification and Analysis of Biological Characteristics of Candida albicans in Bouine Mastitis

The study was aimed to learn the infection of dairy cows with fungi in Ningxia and take effective measures to prevent and control the fungi infection. Milk samples were collected from dairy cows that did not respond to antibiotics in Ningxia, fungi in milk samples were separated and identified, and the biological characteristics of isolated bacteria were analyzed. Milk samples infected by fungus were screened out using fungal selective medium. The yeast pathogen was shown to be Candida albicans by biochemistry and molecular biology methods. Determination of enzyme activity and biofilm-forming tests confirmed that it had different levels of virulence with strong pathogenicity to experimental animals. Drug sensitive test was carried out by K-B programe, the results showed that the isolates were resistant to clinical commonly used antibiotics, and were sensitive to clinical common antifungal drugs. The fungal mastitis was caused by Candida albicans in Ningxia, the ratio of fungal infection was 43%. Candida albicans had strong virulence and were resistant to common antibiotic and sensitivity to antifungal drugs and traditional Chinese medicine.     

白色念珠菌和鼠伤寒沙门氏菌的荧光标记及其对细胞粘附作用的影响

比较了几种荧光染料标记白色念殊菌和鼠伤寒沙门氏菌的效果及其对病菌生长和与Hela细胞粘附能力的影响，旨在为建立简便有效的荧光标记方法奠定基础。将2种致病菌分别在添加了罗丹明B、荧光素Na盐或吖啶橙的LB培养液，37℃条件下培养1d，结果发现这2种致病菌都可以被荧光素Na盐标记，鼠伤寒沙门氏菌还可以被罗丹明B标记，但这2种致病菌都不能在吖啶橙中生长。测定致病菌荧光强度发现，随罗丹明B标记剂量的增加，致病菌荧光强度增强，而荧光素Na盐小剂量组处理的致病菌荧光强度最强。此外还发现，致病菌与Hela细胞的粘附不受荧光标记的影响。     

肉桂醛、柠檬醛对犬白色念珠菌黏附力及超微结构的影响

根据先前的研究,肉桂醛和柠檬醛都有较好的抗真菌活性。本研究对肉桂醛、柠檬醛在真菌黏附口腔黏膜上皮以及对犬白色念珠菌超微结构的影响进行探索。结果表明,药物处理组白色念珠菌黏附率显著下降。扫描电镜显示,经过药物处理的犬白色念珠菌细胞表面粗糙、皱缩、萎陷、外膜空洞、胞浆内容物流出。透射电镜下,细胞普遍发生细胞壁增厚,质壁分离,萎陷,胞浆内容物外流等损伤。     

卵黄抗体对鸽毛滴虫与白色念珠菌感染的治疗效果

旨在研究鸽毛滴虫与白色念珠菌二联卵黄抗体制备方法和评价其临床效果。利用临床分离的白色念珠菌与毛滴虫制备二联灭活疫苗,免疫产蛋母鸡获得高水平抗体,采取低温冻干技术制备成卵黄抗体粉。建立ELISA抗体检测法测定卵黄抗体水平,确保质量可控;以分离的肉鸽毛滴虫、白色念珠菌制备发病模型,评价卵黄抗体的保护效果。结果表明：二次免疫后,卵黄中毛滴虫抗体和白色念珠菌抗体OD值达到高峰,分别为0.90和0.66,抗体维持时间达到2个月。卵黄抗体按1 g·只^-1口服饲喂5 d后,肉鸽口腔和嗉囊病变评分与感染对照组相比显著降低（P<0.05）,与甲硝唑、制霉菌素无差异;此外,毛滴虫、白色念珠菌病原载量极显著降低（P<0.01）。研制的鸽毛滴虫与白色念珠菌二联卵黄抗体可以替代甲硝唑和制霉菌素,为肉鸽的健康养殖提供一种新的抗菌素替代产品。     

畜禽消化道细菌群体感应及相关调控技术研究进展

群体感应是一种微生物细胞间的通讯机制,它在细菌毒力因子表达、生物发光、孢子形成、生物膜形成等方面起关键调控作用。近年来陆续发现畜禽消化道菌群同样存在有群体感应现象。鉴于消化道菌群对畜禽消化、生理代谢、免疫功能等的重要作用,针对畜禽消化道细菌群体感应进行研究及调控对于提高畜禽生产水平及保障畜禽健康等均具有重要的意义。本文简述了细菌群体感应的分类及作用,介绍了国内外学者对不同畜禽消化道中细菌群体感应的研究发现,归纳并总结了当前细菌群体感应相关的调控手段及其可能机制,以期为畜禽养殖中消化道细菌群体感应的研究及相关应用提供参考依据。     

大熊猫铜绿假单胞菌呼吸道感染继发白色念珠菌性肠炎的诊治

报道了1只大熊猫呼吸道感染,继发肠炎的病例。介绍了其病史,血液学变化和临床症状。经过微生物培养和鉴定,确诊呼吸道感染的致病菌为铜绿假单胞菌,继发性肠炎的致病菌为白色念珠菌。根据药物敏感试验结果,选用阿奇霉素和环丙沙星治愈呼吸道感染;选用氟康唑和金双歧,治愈继发性肠炎。并讨论了铜绿假单胞菌和白色念珠菌的发病原因,总结了临床用药的经验。