红色毛癣菌菌株的特异性PCR鉴定方法研究

目的建立一种快速的红色毛癣菌分子生物学鉴定方法。方法根据红色毛癣菌保守区域-真菌核糖体DNA（rDNA）的转录间隔区（ITS）设计特异性引物,采用上游：ITS19865＇GAC ACC AAG AAA AAA TTC TCT GAA GA3＇,下游：ITS24415＇GTC CTG AGG GCG CTG AA3＇为引物对45株红色毛癣菌、5株须癣毛癣菌和1株紫色毛癣菌菌株的DNA进行PCR扩增,观察产物电泳带型的差异。结果 45株红色毛癣菌均能扩增出目的片段,5株须癣毛癣菌和1株紫色毛癣菌均无目的片段扩增出。结论红色毛癣菌可用特异引物PCR方法快速鉴定。     

20例儿童脓癣临床特征分析

目的 探讨分析儿童脓癣的临床特征,以提高临床医师对儿童脓癣的认识。方法 回顾性分析2017—2022年我院确诊的20例儿童脓癣患儿的临床资料、治疗和预后。结果 20例脓癣中,单发脓肿型17例,多发毛囊炎型3例。19例饲养过猫、犬或兔子,1例有足癣接触史。经口服盐酸特比萘芬片联合口服糖皮质激素和抗生素再辅以外用药物治疗,所有患儿在6～12周内临床治愈。1例有胃部不适,余未见不良反应。3例伴有癣菌疹。结论 儿童脓癣临床表现有时不典型,容易误诊。真菌荧光染色直接镜检阳性率高。脓癣培养的病原真菌以犬小孢子菌最常见,其次为须癣毛癣菌。盐酸特比萘芬片治疗脓癣预后较好,安全有效。     

更正声明

本刊2020年10月出版的第15卷第5期刊登的“湖北省及周边地区625例头癣病原菌分析”一文中存在错误,表1中须癣毛癣菌引起两例黄癣,实际为须癣毛癣菌引起的脓癣。经作者仔细核查原始资料发现这两例须癣毛癣菌所致的儿童“黄癣”,临床表现有似黄癣痂样改变,经菌种鉴定为须癣毛癣菌,结合患者有与兔接触史,应诊断为脓癣。黄癣由许兰毛癣菌引起,此两例患者应归入脓癣中。表中脓癣列“12(16.00),4(5.33),39(52.00),4(5.33),13(17.33),3(4.00),0,0,75(14.79)”更正为“12(15.58),4(5.19),41(53.25),4(5.19),13(16.88),3(3.90),0,0,77(15.19)”;黄癣列“1(33.33),3(0.59)”更正为“1(100),1(0.20)”;χ^2值列“93.258”更正为“177.61”。特此更正。     

须癣毛癣菌致成人眉区脓癣1例

报告1例由须癣毛癣菌引起的眉毛区域脓癣。患者女性,46岁,左眉部周围红斑1个月。致病菌株经真菌学鉴定为须癣毛癣菌。给予盐酸特比萘芬250mg/d口服,硝酸舍他康唑软膏外用,治疗1个月后皮损完全愈合。     

应用CLSI M38-A2方案测定须癣毛癣菌对抗真菌药物敏感性

目的:对我国代表地区须癣毛癣菌临床分离株作抗真菌药物敏感性测定,进一步验证CLSI的M38-A2方案.方法:选取我国南北方8个省市地区经表型和分子生物学鉴定的趾间型毛癣菌38株和苯海姆节皮菌6株,采用M38-A2方案测定氟康唑、伊曲康唑、伏立康唑、特比萘芬、灰黄霉素、联苯苄唑、环吡酮胺和阿莫罗芬等8种常见抗真菌药物的最小抑菌浓度(minimal inhibitory concentration,MIC).结果:氟康唑、伊曲康唑、伏立康唑、特比萘芬、灰黄霉素、联苯苄唑、环吡酮胺和阿莫罗芬对趾间型毛癣菌株的MIC值(μg/mL)范围分别为0.25-32、0.0312-1、0.0156-0.0625、0.000937-0.00781、0.0625-1、0.0312-2、1-2、0.00781-0.0625;对苯海姆节皮菌株的MIC值(μg/mL)范围分别为≥64、2、0.25-0.5、0.000937-0.00381、1、2-4、1-2、0.0312-0.0625.不同抗真菌药物对趾间型毛癣菌及苯海姆节皮菌的药敏有明显差别(P<0.001);趾间型毛癣菌和苯海姆节皮菌对伊曲康唑、灰黄霉素、环吡酮胺、伏立康唑和氟康唑的药敏差异有统计学意义,对特比萘芬、阿莫罗芬和联苯苄唑的药敏差异无统计学意义.结论:趾间型毛癣菌和苯海姆节皮菌之间对伊曲康唑、灰黄霉素、环吡酮胺、伏立康唑和氟康唑的药敏有明显差异.M38-A2方案有较好的重复性和稳定性,适合用来体外测定须癣毛癣菌对抗真菌药物的敏感性.     

须癣毛癣菌的形态学及分子生物学鉴定

目的对临床上分离自人(36株)及狐狸(5株)的须癣毛癣菌菌株进行新的分类系统鉴定,并检测传统的分类方法是否能满足临床鉴定需要。方法①观察原鉴定为须癣毛癣菌菌株在沙氏培养基、1%蛋白胨培养基、溴甲酚紫乳固体葡萄糖琼脂培养基(BCP-MSG)和显微镜下形态学及尿素酶、毛发穿孔等生理学试验表现。②通过ITS区段和LSU区段分子生物学序列分析进行新的分类系统的菌种分型,并对传统形态学和生理学鉴定方法进行检测。结果①41株须癣毛癣菌形态学及生理学试验符合须癣毛癣菌(38株)和红色毛癣菌(3株)菌落的特点。②ITS区段序列分析发现ITS区段能将须癣毛癣菌和红色毛癣菌准确的鉴定到种,但无法明确其种内分型;而LSU区段序列分析可对36株(36/38)须癣毛癣菌有性型做出明确的鉴定。结论传统实验室鉴定方法仍具有其有效性及可靠性。通过分子生物学鉴定,临床分离的须癣毛癣菌皆为指(趾)间毛癣菌(38/38),而LSU区段的序列分析鉴定狐狸源性菌株皆属于本海姆节皮菌,有别于大多数人源性菌株有性型为万博节皮菌,对于须癣毛癣菌的菌种鉴定更优于ITS区段,但分子生物学试验还需结合形态学的观察,才能够对菌种做出正确的鉴定。     

迁延性黑点癣1例

目的报道病程30余年、由紫色毛癣菌感染所致成人黑点癣1例。方法对头发及鳞屑标本进行多次真菌直接镜检和培养,对病原菌进行形态学鉴定和药物敏感性试验。结果鉴定为紫色毛癣菌。体外药敏试验该菌对特比萘芬、伊曲康唑敏感。结论本病例证实为紫色毛癣菌感染导致黑点癣,患者经口服伊曲康唑和局部治疗痊愈。     

麻类织物对须癣毛癣菌生长抑制作用的研究

目的通过分析汉麻、亚麻和苎麻对须癣毛癣菌生长的影响,探讨麻类织物对浅部真菌的抑制作用。方法实验采用振荡法。将3种麻类织物分别与须癣毛癣菌混合培养,对照组为棉布组,3d后分别取培养液稀释5倍后涂布培养皿,计算各自的菌落数和抑菌率并进行统计分析。结果麻类织物组菌落数明显少于对照组棉布组(P<0.01),3种麻类织物对须癣毛癣菌的抑菌率均高于60%,但3种麻类织物的抑菌率之间无明显差异(P<0.01)。结论3种麻类织物均可显著抑制须癣毛癣菌的生长,麻类织物有可能用来预防由须癣毛癣菌引起的足癣、股癣等浅部真菌病。     

蒺藜TTS-12对须癣毛癣菌的体内外抗菌活性研究

为考察天然产物蒺藜TTS-12对须癣毛癣菌的体外和体内抗菌活性,本研究采用CLSI的M38-A2方案对须癣毛癣菌进行最小抑菌和杀菌浓度的检测,选取多重指标考察TTS-12对须癣毛癣菌的抑菌作用;建立豚鼠感染须癣毛癣菌豚鼠体癣模型,分组给药观察低、中、高剂量蒺藜TTS-12凝胶剂对豚鼠体癣模型在背部病变程度评分,病灶皮肤真菌培养阴性率,病灶皮肤病理变化的影响。结果发现,TTS-12对须癣毛癣菌的标株菌株的MIC值为1μg/mL,MFC为8μg/mL,其还能够显著抑制须癣毛癣菌的菌丝生长,浓度为4μg/mL的TTS-12作用15天时,菌丝生长抑制率已经高于60%,且对须癣毛癣菌的孢子萌发抑制作用呈时间和浓度依赖性。动物实验中,低、中、高剂量蒺藜TTS-12凝胶剂均能显著降低背部病变程度评分(P<0.01),中、高剂量能增高病灶皮肤真菌培养阴性率(P<0.05),病灶皮肤HE染色切片表明高剂量组棘层肥厚降低,背部炎症减弱,使角质层恢复正常。以上结果表明蒺藜TTS-12在体外抗须癣毛癣菌和豚鼠体癣模型中均有较好的活性。     

枯草芽孢杆菌JA抗菌物特性的研究及抗菌肽的分离纯化

枯草芽孢杆菌JA分泌物中具有抑菌作用的粗提液通过DEAESepharose FF、SOURCE 15 PHE、Sephacry1 S200HR和反相HPLC多步柱层析分离纯化后,获得3种对水稻纹枯和小麦赤霉病菌均有抑菌作用的抗菌肽AFP1、AFP2和AFP3。MALDITOF质谱法测得其分子量分别为1462.645D、1476.390D和1490.530D。氨基酸组成分析结果表明,AFP1和AFP3由苏氨酸、异亮氨酸、酪氨酸、脯氨酸等多种氨基酸组成。目标产物热稳定性好、对蛋白酶有一定的耐受性,推断很可能是低分子量的环状脂肽。     

Antimicrobial bioassay of Colchicum luteum Baker

The methanolic extract of the corms of Colchicum luteum Baker (Liliaceae) and its subsequent fractions in different solvent systems were screened for antibacterial and antifungal activities. The crude extract and all the fractions demonstrated moderate to excellent antifungal activities against tested pathogens in antifungal bioassay. Excellent antifungal activity was shown against trichophyton longifusus, up to 75%, and microsporum canis, up to 85%, while the crude extract and subsequent fractions showed mild to moderate activities in an antibacterial bioassay with maximum antibacterial activity 58% against Bacillus subtilis.     

Antibacterial potentiality of Argemone mexicana solvent extracts against some pathogenic bacteria

The sensitivity of two Gram positive (Staphylococcus aureus and Bacillus subtilis) and two Gram negative (Escherichia coli and Pseudomonas aeruginosa) pathogenic multi-drug resistant bacteria was tested against the crude extracts (cold aqueous, hot aqueous, and methanol extracts) of leaves and seeds of Argemone mexicana L. (Papaveraceae) by agar well diffusion method. Though all the extracts were found effective, yet the methanol extract showed maximum inhibition against the test microorganisms followed by hot aqueous extract and cold aqueous extract.     

Antimicrobial activity of new phorbins from Jatropha curcas Linn. (Euphorbiaceae) leaves

The crude methanol extract of Jatropha curcas leaves exhibited activity against Staphylococcus aureus, Bacillus subtilis, Mycobacterium phlei, Candida albicans, and Trichophyton mentagrophytes but was inactive against Escherichia coli, Pseudomonas aeruginosa, and Saccharomyces cerevisiae. In a bioassay-directed fractionation, two new phorbins were isolated and analysed by spectroscopic methods. Isolate 1 was characterized as an analogue of pheophytin b with a phytyl moiety containing three double bonds which are at positions P2/P3, P6/P7, and P10/P11. Compound 2 was characterized as methyl pheophorbide a with 132-OH and 17- and 17(1)-CH3 moieties. It is active against Serratia marcescens.     

In vitro antibacterial activity of a 7-O-beta-D-glucopyranosyl-nutanocoumarin from Chaptalia nutans (Asteraceae)

Ethanolic crude extracts from the roots of Chaptalia nutans, traditionally used in Brazilian folk medicine, were screened against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa by using the disk diffusion test technique. S. aureus with 14 mm inhibition zone was considered susceptible. E. coli and P. aeruginosa without such a zone were considered resistant. As a result of this finding, the ethanolic crude extract was fractionated on silica gel column chromatography into five fractions. The ethyl acetate fraction was active against S. aureus and Bacillus subtilis. Further column chromatography separation of the ethyl acetate fraction afforded 30 fractions, which were assayed against S. aureus. Fractions 16 and 17 showed inhibition zones with S. aureus, indicating the presence of active compounds, and were subjected to purification by repeated preparative thin layer chromatography. The pure compound 7-O-beta-D-glucopyranosyl-nutanocoumarin inhibited B. subtilis and S. aureus at concentrations of 62.5 g/ml and 125 g/ml, respectively. The antibacterial property of C. nutans appears to have justified its use for the treatment of wounds, which are contaminated through bacterial infections.     

Antimicrobial activity of Wedelia trilobata crude extracts.

A biological screening of activity against Gram-positive and Gram-negative bacteria, yeasts, and fungi of crude extracts from Wedelia trilobata is reported. The n-hexane extract showed antibacterial activity against Bacillus subtilis, Mycobacterium smegmatis, Staphylococcus aureus, and Staphylococcus epidermidis (Gram-positive bacteria); along with Proteus vulgaris, Pseudomonas aeruginosa, Salmonella group C, Salmonella paratyphi, and Shigella sonnei (Gram-negative bacteria). The ethyl acetate extract was active only against Salmonella group C; and the aqueous extract was inactive against the tested bacteria. None of the tested extracts showed biological activity against the yeasts (Candida albicans, Candida tropicalis, Rhodotorula rubra) or the fungi (Aspergillus flavus, Aspergillus niger, Mucor sp., Trichophyton rubrum).     

Developmental modulation of deoxyribonucleic acid-binding proteins of Bacillus subtilis during sporulation stages

The isolation of deoxyribonucleic acid (DNA)-binding proteins from various stages of growth and sporulation of Bacillus subtilis is described. After adsorption and elution from phosphocellulose, the proteins were fractionated according to their ability to adsorb to denatured calf thymus DNA-cellulose or native B. subtilis DNA-cellulose. The proteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and purification was monitored by a nitrocellulose filter binding assay. Approximately 1% of the proteins in the crude extract adsorbed to denatured calf thymus DNA-cellulose and 0.1% adsorbed to native B. subtilis DNA-cellulose. Each class of proteins varied qualitatively and quantitatively as sporulation proceeded. Several proteins from the exponential phase of growth that bound to denatured DNA were lost by T(0), whereas at T(5) new polypeptides appeared. Fewer changes in the profile of proteins with affinity for native DNA were observed between exponential phase and T(0); however, the dominant species in these eluates were clearly different.     

Transformation of Bacillus subtilis and Escherichia coli by a hybrid plasmid pCD1.

The gene thyP3 from Bacillus subtilis bacteriophage phi 3T was cloned in the plasmid pMB9. The resulting chimeric plasmid, pCD1, is effective in transforming both Escherichia coli and Bacillus subtilis to thymine prototrophy. The activity of the thyP3 gene product, thymidylate synthetase, was assayed and found to be 9 times greater in a transformed strain of Escherichia coli than in a phi 3T lysogen of Bacillus subtilis. The physical location of restriction sites has been determined for two related plasmids pCD1 and pCD2. Hybridization studies clearly indicate that the plasmid gene responsible for Thy+ transformation is the gene from the bacteriophage phi 3T. The lack of restriction in this transformation process is consistent with our previous studies using bacterial DNA in heterospecific exchanges indicating that the nucleotide sequence surrounding the gene is the dominant factor in determining interspecific transformation.     

Whole-genome sequences of Bacillus subtilis and close relatives

We sequenced four strains of Bacillus subtilis and the type strains for two closely related species, Bacillus vallismortis and Bacillus mojavensis. We report the high-quality Sanger genome sequences of B. subtilis subspecies subtilis RO-NN-1 and AUSI98, B. subtilis subspecies spizizenii TU-B-10(T) and DV1-B-1, Bacillus mojavensis RO-H-1(T), and Bacillus vallismortis DV1-F-3(T).     

Identification and purification of a calcium-binding protein from Bacillus subtilis

A Ca(2+)-binding protein was identified in Bacillus subtilis in the log phase of growth. The molecular mass of this protein is about 38 kDa as estimated by polyacrylamide gel electrophoresis in the presence of SDS and by gel filtration. The protein was found to be resistant 10 min at 65 degrees C and was purified about 400 times, starting from heated crude extract, by conventional procedures. This novel protein is able to bind Ca2+ in the presence of an excess of MgCl2 and KCl both in solution and after SDS gel electrophoresis and electrotransfer. Since an impairment of the Ca2+ intake, in Bacillus subtilis, results in an impairment of chemotactic behavior (Matsushita, T. et al (1988) FEBS lett. 236, 437-440), 38 kDa protein may be involved in the regulation of chemotaxis.     

水稻稻瘟病拮抗菌L1鉴定及抑菌特性的初步研究

本研究对水稻稻瘟病菌的拮抗菌L1形态、生理生化特性等进行测定, 结果发现其为杆状细胞、革兰氏阳性、菌落不规则有褶皱、好氧生长、颜色较深等, 初步鉴定为枯草芽孢杆菌; 拮抗菌L1培养5 d的发酵液抑菌活性最高, 抑菌率为74.57%; 拮抗菌L1对水稻稻瘟病菌的拮抗活性物质对温度不敏感; 拮抗菌L1的发酵液用硫酸铵梯度沉淀法提取粗蛋白, 在50%~60%硫酸铵饱和度下沉淀的粗蛋白质对水稻稻瘟病菌抑菌效果最好, 平均抑菌半径达0.51 cm。