苏芸金杆菌的一个新血清型

苏芸金杆菌云南变种(Bacillus thurtngtensts subsp. Yunnanensis)113菌株的H-抗原和 H-抗血清均与已知苏芸金杆菌H一血清型l到19的所有参考标准菌株的H一抗血清和H一抗原不发生交叉凝集反应。113菌株的生化反应结果与所有参考标准菌株也不相同。此外,113菌株对致倦库蚊(Culex pipiens var. quinquefaseiatces)(双翅目)(Bombyx mori) (鳞翅目)幼虫均无毒性。 因此,113菌株是一个新血清型20,即苏芸金杆菌云南变种,血清型20(Bacillus thuringiensis subsp. Yunnanensis H20)。     

球形芽孢杆菌LP1-G的发酵特性及杀蚊活性*

球形芽孢杆菌（Ｂａｃｉｌｌｕｓ ｓｐｈａｅｒｉｃｕｓ）ＬＰ１－Ｇ菌株在ＭＢＳ培养基上能正常生长、发育,产生位于芽孢孢外膜外的伴孢晶体。其产生的４１．９和５１．２ｋＤ二元毒素蛋白合成于芽孢形成期,另一分子量约为４９ｋＤ蛋白和二元毒素同期合成,并随着芽孢的释放而被降解。生物测定结果表明该菌株在营养体生长阶段对致倦库蚊幼虫无毒,孢子囊初期毒力较高,并在整个芽孢形成期都维持较高的毒力水平。其全发酵液对敏感和抗性库蚊幼虫都具有中等的毒杀作用,对３～４龄幼虫４８ｈ的ＬＣ_５０。值分别为０．１１３和０．１     

从湖北神农架原始森林土壤中分离的高毒力苏云金芽孢杆菌

从神农架原始森林土壤中分离出苏云金芽孢杆菌 9株。经过生理生化和血清学鉴定 ,此 9株苏云金芽孢杆菌分属于H7、H6和H14。生物测定结果表明 :两株H7型菌株对棉铃虫幼虫有较高的毒力 ;另两株对致倦库蚊幼虫和白纹伊蚊幼虫有很强的毒杀作用 ,此两株属苏云金芽孢杆菌H14。     

樱桃根癌土壤杆菌及其对土壤杆菌素84敏感性的研究

从山东、河北、辽宁等地樱桃园的樱桃冠瘿瘤和土壤样品中分离到46株根瘤土壤杆菌。经鉴定有4株是Agrobacteriumtumefaciens（原生物型1）,其余42株是A.rhizogenes（原生物型2）。这些菌株所诱导的冠瘿瘤中均合成胭脂碱（nopaline）,属胭脂碱型Ti质粒的根癌土壤杆菌,并对放射土壤杆菌K84菌株所产生的土壤杆菌素84敏感。由于K84菌株对含胭脂碱Ti质粒的根癌土壤杆菌有很好的抑制效果,因此,用K84菌株防治樱桃根癌病是有应用前景的．     

一株对棉铃虫高效的苏云金杆菌

１９７９年从舍蝇（Ｍｕｓｃａｖｉｃｉｎａ）幼虫中分离出一株能够形成伴孢晶体的芽孢杆菌７９００７。该菌具有苏云金杆菌天门变种（７２１６）的典型特征。血清型属Ｈ_{３ａ－３ｂ},但培养特征,生化特征与知的Ｈ_{３ａ－３ｂ}的戈尔斯德变种（ＨＤ－１）、天门变种（７２１６）略有不同,特别是对棉铃虫的毒力大大高于巳知的菌株,预示着将成为我国防治棉铃虫的一株高效菌。     

我国葡萄根癌土壤杆菌的生化型与质粒类型的初步研究

从我国内蒙古、辽宁、吉林、北京、山东等地采集的49份葡萄冠瘿标本中,分离到根痛土壤杆菌(Agrobacterium tumefactens)67株,经鉴定有生化1型21株,生化II型4株,生化III型42株。葡萄根癌土壤杆菌中以生化ill型占优势。生化111型有97％、生化I型有24％的菌株能使葡萄或向日葵致瘤。鉴定了2S株生化l型和生化[I]型菌株所致冠瘿中的opines,其中有2株生化III型菌株合成nopaline,3株生化III型菌株合成精氨酸,其余菌株合成octopine。     

苏芸金杆菌的一个新血清型

从土壤中分离出一株产生伴孢晶体的芽孢杆菌。该菌株具有苏芸金杆菌的典型特征,严生不规则型晶体,鞭毛抗原及生化反应与已知的苏芸金杆菌21个血清型不㈤,不产生β-外毒素。对棉铃虫、粘虫、大蜡螟及尖音库蚊幼虫均无毒性,是一个新血清型(H22),定名为苏芸金杆菌山东变种(Bacillus thuringiensis serovar shandongiensis, H22)。     

球形芽孢杆菌C_3－41对致倦库蚊的毒效及在蚊体内的再循环

球形芽抱杆菌Ｃ３－４１菌株（Ｂａｃｉｌｌｕｓｓｐｈａｅｒｉｃｕｓ　Ｃ３－４１）对致倦库蚊（Ｃｕｌｅｘｑｕｉｎｑｕｅｆａ－ｓｃｉａｔｕｓ）幼虫有很高毒效,对２龄和３—４龄幼虫的半致死剂量（ＬＤ５０）分别为６３．１和８９．７芽孢／蚊幼虫。处理浓度越高,取食时间越长,蚊幼虫取食到的杀蚊活性物质量越多,死亡率越高。当蚊幼虫取食互致死剂量杀蚊活性物质后,球形芽孢杆菌在感染的活幼虫体内不增殖;但当蚊幼虫取食致死剂量杀蚊活性物质后,蚊幼死亡,球形芽抱杆菌在死蚊幼虫体内增殖明显,６天内芽抱从感染初期的１．８６×１０２／蚊幼虫增加到１．５９×１０６／蚊幼虫。芽抱在死蚊幼虫体内能正常荫发、生长、产孢和形成毒素。增殖的芽抱同样对致倦库蚊幼虫有较高毒力。     

中国毛白杨根癌土壤杆菌的类型和对土壤杆菌素敏感性的研究

从我国北方8个毛白杨根癌病发病苗圃分离到根癌土壤杆菌(Agrobacterlum tume[actena)8株。经质粒型、生物型、寄主范匿和对土壤秆菌素agfocin 84和D286的敏感性测定,证明5株系nopaline质粒型,其中生物I型2株,生物|I型2株,I—II中间型1株,3株系agroplne质粒型,其中生物I型2株,生物II型1株。所有分离菌株均系宽寄主群,其中1株经回接能侵染单子叶植物美人蕉(Canna inaiea),水仙(Narcissus)和吊兰(Chlorophytum)。分离菌株中,5株nopaIine质粒型菌榫对土壤杆菌素84敏感,3株agropine质粒和3株生物I型nopali 质粒菌株对土壤杆菌素])286敏感。在温室中,合并使用两种土壤杆菌素产生菌——放射土壤杆菌(A．Radiobaccer)K84和D286的菌体悬浮液,预浸毛白杨和向目荚幼苗根部 或与致病的毛白杨根癌土壤杆菌共接种枝茎,降低根瘟病诱发率达94％以上。表明放射土壤扦菌K84和D286可以控制毛白杨根癌病。     

我国部分地区土壤中的苏芸金芽孢杆菌和球形芽孢杆菌

从云南、贵州、四川和陕西4省的土壤中分离到大量苏芸金芽孢杆菌(Bacillus thuringie—nsis)和球形芽孢杆菌(Bacillus sphaeticus)菌株。血清型分析表明,苏芸金芽孢杆菌分离株分属于23个血清型中的13个血清型,另有近20％的自凝型菌株及部分与所有标准菌抗血清无反应的菌株。对该两种昆虫病原细菌的生态分布规律进行了分析。研究了全部苏芸金芽孢杆菌分离株对鳞翅目、鞘翅目及双翅目的6种昆虫的毒力特性、伴孢晶体与芽孢的形态,以及晶体蛋白质成分。观察和测定了球形芽孢杆菌分离株的形态和毒力,并分析了部分菌株的晶体蛋白质成分。得到22株高效苏芸金芽孢杆菌和2株高效球形芽孢杆菌。证明苏芸金芽孢杆菌是典型的土壤微生物类群,我国西南地区土壤中的苏芸金芽孢杆菌资源十分丰富。     

Larval susceptibility of the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae), to Bacillus thuringiensis H serovars isolated in Japan

A total of 1700 Japanese strains of Bacillus thuringiensis, belonging to at least 47 H serogroups, were examined for insecticidal activity against larvae of the diamondback moth, Plutella xylostella. The high-level toxicity was associated with 612 isolates (36.0%). Of these, 608 isolates (99.3%) fell into 13 H serogroups belonging to the low-numbered H serotypes, H1-H10. Conversely, most isolates belonging to the high-numbered serotypes (>H10) had little or no larvicidal activity; only one isolate of the serovar japonensis H23 was active. P xylostella larvae were susceptible to 89.8% of the serovar morrisoni H8a:8b strains and 85.7% of galleriae H5a:5b strains. High values of 60-80% were also obtained in six serovars (thuringiensis H1, alesti H3a:3c, kurstaki H3a:3b:3c, kenyae H4a:4c, aizawai H7, and tolworhi H9), while relatively low values of <60% in two other common serovars, sotto H4a:4b and darmstadiensis H10a:10b. Five selected isolates, belonging to H serovars other than kurstaki and aizawai, were 10-60 times less toxic than the reference strain HD-1 (serovar kurstaki). Parasporal inclusion proteins of these strains were immunologically unrelated to those of the strain HD-1 and the aizawai type strain.     

Identification of Flagellar (H) antigenci subfactors in Bacillus thuringiensis H serotypes 10, 18, and 24 isolated in Japan

A total of 95 Bacillus thuringiensis strains isolated from Japan and belonging to H serotypes 10, 18 and 24, were examined for their H antigenic subfactors. Of 84 H serotype 10 isolates, 83 were identified as the H serotype 10a: 10b (serovar darmstadiensis ) and only one isolate was assigned to the II serotype 10a: 10c (serovar londrina ). Among five isolates belonging to the H serotype 18, three were allocated to the H serotype 18a: 18b (serovar kumamotoensis ), while two isolates did not react to antisera against the two known H antigenic subfactors, 18b and 18c. All of the six H serotype 24 isolates were assigned to the H serotype 24a: 24b (serovar neoleonensis ).     

Production of heat-stable exotoxin by Bacillus thuringiensis and related bacteria

Heat-stable exotoxin production by 740 strains of Bacillus thuringiensis and related bacteria was investigated using the housefly, Musca domestica, from the following viewpoints: (1) the relation-ship between B. thuringiensis flagellar (H) serotypes and exotoxin production and (2) the exotoxin production by Bacillus species other than B. thuringiensis. Of 437 isolates belonging to 11 serotypes of B. thuringiensis which had been confirmed to produce parasporal inclusions, 35 isolates belonging to serotypes 1, 3a:3b, 4a:4c, and 10 produced heat-stable exotoxin. Exotoxin was not detected in the isolates of serotypes 3a, 4a:4b, 5a:5b, 5a:5c, 6, 7, and 8a:8b. No heat-stable exotoxin was demonstrated in 28 acrystalliferous isolates which possessed H antigens of B. thuringiensis serotypes 1, 3a, 4a:4b, 4a:4c, 5a:5c, 6, 7, 10, 11a:11c, and 12. A total of 270 B. cereus isolates which did not possess B. thuringiensis H antigen were examined and three isolates were found to produce heat-stable exotoxin. No heat-stable exotoxin was produced by B. subtilis (two strains), B. natto (one strain), and B. megaterium (two strains). These results indicate that the heat-stable exotoxin production in B. thuringiensis is a strain-specific property rather than a serotype(subspecies)-specific property.     

Investigation of the cyt gene in Bacillus thuringiensis and the biological activities of Bt isolates from the soil of China

The presence of cyt genes was investigated in 80 type strains of Bacillus thuringiensis and 143 isolates obtained from soil samples of China by PCR amplification using two pairs of primers for the cyt1 and cyt2 genes. Three type strains of serotypes H11ac, H14 and H36, eight isolates belonging to H3, H14, H18 and H21, and one isolate of unknown serotype harbored cyt genes. We also tested the cytolytic activity for mammal cells, the hemolytic activity for sheep erythrocytes and insecticidal activity against mosquitoes of five isolates that contained cyt genes but did not belong to B. thuringiensis serovar israelensis. The protein profiles of the five isolates were different from those of the type strains of B. thuringiensis serovar israelensis, and among the five isolates, only Y-5 showed mosquitocidal activity against larvae of Culex quinquefasciatus. All five of the isolates exhibited hemolytic activity, but only three could cause the cell death of A549 cells. The cytopathological changes induced by NX-4 in some A549 cells were characterized with cell-ballooning.     

Specific Strains of Bacteroides Species in Human Fecal Flora as Measured by Deoxyribonucleic Acid Homology

Membrane competition homology experiments were used to compare Bacteroides uniformis and Bacteroides vulgatus isolates obtained from fecal samples from different individuals and isolates obtained from fecal samples of single individuals. Isolates of B. uniformis, when isolated from different individuals, had interstrain deoxyribonucleic acid homology values that ranged from 63 to 95%, with most of the values being in the 70 to 85% range. When isolates obtained from a single individual were compared, each species was represented by one or two groups of very closely related organisms, with each group having essentially 100% interstrain homology. When strains from two groups were compared with each other, the homology values were in the same range as when organisms were isolated from different individuals. Isolates which have nearly 100% homology with each other persisted in fecal samples collected over a 5- to 6-month period. It appears that the colon of each person may be populated by bacterial strains that are specific for that individual. Somatic antigen serotyping has been used as an indicator for specific Escherichia coli strains in fecal samples. Two isolates having the same O, K, and H antigens had 99% homology, but when only O and H antigens were in common, the homology values were in the 70 to 85% range. It seems that isolates of a given serotype, when isolated from a single individual, may represent a unique strain, but isolates of a given serotype, when isolated from different individuals, probably do not.     

Genetic characterization of Listeria monocytogenes food isolates and pathogenic potential within serovars 1/2a and 1/2b

A total of 39 Listeria monocytogenes strains isolated from raw milk, smoked meat, chicken carcass and reference strains, belonging to serovars 1/2a, 4a, 1/2b, 3b and 4b, were analysed by RAPD and by polymorphisms of the virulent genes inlAB and iap. Ten isolates, belonging to serovars 1/2a and 1/2b and, collected from raw milk and smoked meat, were further tested for pathogenicity by IP injection into mice. The clustering of the 39 L. monocytogenes strains in 3 groups at 0.45 similarity level, based on molecular typing, was observed. Distribution of serovars in these clusters was in agreement with the proposed three Listeria monocytogenes lineages. Within serovar 1/2b, the 50% lethal dose (LD50) ranged from 8.4 x 10(4) to 1.7 x 10(6) cfu.ml(-1). One of the serovar 1/2b strains, isolated from smoked meat, exhibited the lowest virulence potential evaluated by LD50 and by mean time to death (MTD) and, from this point of view, was completely different from the other strains. Our results suggest the existence of heterogeneity in virulence levels within serovars 1/2a and 1/2b. However, when comparing the isolates based on genotyping, virulence indicators and food origin, no relation could be assessed.     

2017–2019年我国南方地区高致病性H5N6亚型禽流感病毒血凝素蛋白分子特征分析

【背景】自2014年以来,H5N6禽流感病毒在我国家禽和活禽市场持续进化,成为人类和动物健康的重大威胁。【目的】对2017-2019年中国南方地区93株高致病性H5N6禽流感病毒的HA基因进行分子进化分析。【方法】接种9-11日龄鸡胚分离核酸检测阳性的H5N6标本,运用下一代测序平台对病毒分离物进行全基因组测序,从NCBI和GISAID数据库下载参考序列,利用BLAST、MEGA6.1及Clustal X等软件进行序列分析。【结果】2017-2019年,从189份江苏省H5亚型禽类/环境标本和1名H5N6患者咽拭子标本中共分离到43株病毒,完成了33株H5N6病毒的全基因组测序。下载网上同时期中国其他地区流行的H5N6毒株序列,对总计93株H5N6病毒的HA基因进行分子进化分析。93株H5N6病毒中有78株属于Clade 2.3.4.4h,9株病毒属于Clade 2.3.4.4e,4株H5N6病毒属于Clade 2.3.4.4b,1株属于Clade 2.3.4.4f,1株属于Clade 2.3.4.4g。所有93株病毒HA蛋白的裂解位点含有多个碱性氨基酸,表明它们都属于高致病性禽流感病毒。所有93株病毒HA蛋白的Q222和G224位氨基酸没有发生突变,保留了禽类受体α2-3半乳糖苷唾液酸(SAα2-3Gal)结合特性;158位点丧失糖基化,同时124位出现一个新的潜在糖基化位点。【结论】2017-2019年间中国南方地区H5N6病毒进化活跃,具有明显的基因多样性,需要加强对病毒分子进化的监测。     

Isolation of a non-insecticidal Bacillus thuringiensis strain belonging to serotype H8a8b

Bacillus thuringiensis strains non-toxic to Lepidoptera, Bombyx mori and Diptera, Culex pipiens pallens larvae were isolated from Korean soil samples during an investigation of B. thuringiensis isolates highly toxic to insect pests. One of these isolates, NTB-88, produces parasporal inclusions about 138 kDa in size and is non-toxic to 19 insect species of three orders, Lepidoptera, Diptera and Coleoptera, even though it is highly susceptible to tryptic cleavage. Study of flagellar (H) antibodies of 33 B. thuringiensis strains revealed that NTB-88 has an H antigen identical with that of subsp. morrisoni (serotype 8a8b). Comparison of parasporal inclusion proteins and plasmid DNA patterns of strain NTB-88 with B. thuringiensis subsp. morrisoni HD-12 and B. thuringiensis subsp. morrisoni PG-14 showed that the isolate is a novel non-insecticidal B. thuringiensis strain belonging to serotype 8a8b.     

Characterization and pathogenic evaluation of Bacillus thuringiensis and Bacillus sphaericus isolates from Argentinean soils

Eighty soil samples of different origin (from urban, agricultural, forested and horticultural areas) which had not previously been treated with bioinsecticides, were collected and examined to investigate the presence of Bacillus thuringiensis and B. sphaericus. From a total of 1473 bacterial isolates examined by differential staining techniques and growth on nutrient agar with the addition of penicillin and streptomycin, 31 (2.1%) strains of Bacillus sphaericus and 25 (1.6%) strains of Bacillus thuringiensis were isolated. These strains were tested for their pathogenicity against Diptera (Culex quinquefasciatus) and Lepidoptera (Anticarsia gemmatalis and Spodoptera frugiperda). Seven strains of Bacillus thuringiensis subspecies kurstaki were found to be pathogenic to Spodoptera frugiperda and twenty-two strains showed a pathological effect against Anticarsia gemmatalis. None of the strains of Bacillus thuringiensis nor the Bacillus sphaericus investigated, showed pathogenic activity against Culex quinquefasciatus. The strains of Bacillus thuringiensis were characterized serologically as belonging to six serotypes (darmstadiensis, entomocidus, kurstaki, muju, sotto and xianguangiensis). One strain seemed to be a new serotype. The electrophoretic profiles of the strains of Bacillus thruringiensis showed bands of 130 kDa similar to those found in strains pathogenic against Lepidoptera. Some physicochemical characteristics were also studied in the soil samples, in order to relate them to the presence or absence of these Bacillus species.     

球形芽孢杆菌C3—41二元毒素基因在苏云金芽孢杆菌以色列亚种中的？…

球形芽孢杆菌Ｃ３－４１是我国分离的一株对蚊幼虫有毒杀作用的高毒力菌株,对库蚊、按蚊幼虫的毒性高于２３６２菌株,Ｓｏｕｔｈｅｒｎ杂交证明Ｃ３－４１总ＤＮＡ中３．５ＫｂＨｉｎｄＩＩＩ片段上带有４１．９和５１．４ｋＤ二元毒素基因。