Studies on bacterial flora in the population of the fall webworm, Hyphantria cunea Drury. (Lep., Arctiidae)

Abstract:  In this study, the bacterial flora of Hyphantria cunea Drury. (Lep., Arctiidae) were investigated during three hazelnut seasons from 1998 to 2000. Four different bacteria were found in dead and living larvae. They were isolated and identified as Bacillus thuringiensis , Escherichia freundii , Micrococcus sp. and Streptococcus sp. Laboratory experiments carried out to determine the insecticidal activities of these isolates showed that E. freundii and Micrococcus sp. did not have any insecticidal effect on second – third instar larvae of H. cunea . However, B. thuringiensis and Streptococcus sp. had 56 and 38% effects, respectively. Crystals and spores from B. thuringiensis were also purified and the crystals, spores and crystals–spore mixture were tested separately against the larvae of H. cunea . It was found that the insecticidal activities of the crystals, spores and crystal–spore mixture were 37.5, 25 and 62.5%, respectively, on second – third instar larvae of H. cunea . These results indicate that the crystal–spore mixture has 6.5% more insecticidal effect than that of the vegetative cells of the B. thuringiensis isolate.     

Insecticidal effects of some biological agents on Agelastica alni (Coleoptera: Chrysomelidae)

The alder leaf beetle (Agelastica alni L., Coleoptera: Chrysomelidae) causes approximately 10% of total economic damage to hazelnut product per year in Turkey. A. alni larvae are susceptible to several pathogens indigenous to the area in which these insects occur in Turkey. In the present study, in order to find a more effective and safer biological control agent against this common pest, we evaluated the various biological agents’ insecticidal activity during the four hazelnut seasons from 2002 to 2005 on the larvae of the alder leaf beetle collected from the vicinity of Trabzon, Turkey. The tested agents are 25 insect-originating bacteria, 2 bacterial toxins and 1 viral preparation. The results showed that the highest insecticidal activity was obtained by bacterial isolates at 1.8 × 10⁹ bacteria/mL dose, within ten days on the larvae of A. alni. These are 90% for Bacillus thuringiensis biovar tenebrionis (4AA1), Bacillus sphaericus (Ar4, isolated from Anoplus roboris L., Col.: Curculionidae), and Bacillus thuringiensis (Mm2, isolated from Melolontha melolontha L., Col.: Scarabaeidae). Our results indicate that these isolates may be valuable as biological control agent.     

Isolation and insecticidal effects of some bacteria from Euproctis chrysorrhoea L. (Lepidoptera: Lymantriidae)

In this study, we investigated the bacterial pathogens of Euproctis chrysorrhoea and tested for their insecticidal activities. Based on colony color and morphology, four isolates were determined. According to morphological, physiological and biochemical characters of the isolates, they were identified as Enterobacter aerogenes, Lactobacillus sp., Bacillus thuringiensis and Micrococcus luteus. The insecticidal effects of these bacterial isolates on third-fourth instar larvae of Euproctis chrysorrhoea were investigated. The highest insecticidal effect determined on this pest is 68% with Bacillus thuringiensis. The effects of the other isolates are 45% with Enterobacter aerogenes, 15% Micrococcus luteus and 0% with Lactobacillus sp.     

Distribution of genes encoding putative virulence factors and fragment length polymorphisms in the vrrA gene among Brazilian isolates of Bacillus cereus and Bacillus thuringiensis

One hundred twenty-one strains of the Bacillus cereus complex, of which 80 were isolated from a variety of sources in Brazil, were screened by PCR for the presence of sequences (bceT, hblA, nheBC, plc, sph, and vip3A) encoding putative virulence factors and for polymorphisms in variable-number tandem repeats (VNTR), using a variable region of the vrrA open reading frame as the target. Amplicons were generated from isolates of B. cereus and Bacillus thuringiensis for each of the sequences encoding factors suggested to play a role in infections of mammals. Intriguingly, the majority of these sequences were detected more frequently in Bacillus thuringiensis than in B. cereus. The vip3A sequence, which encodes an insecticidal toxin, was detected exclusively in B. thuringiensis. VNTR analysis demonstrated the presence of five different fragment length categories in both species, with two of these being widely distributed throughout both taxa. In common with data generated from previous studies examining European, Asian, or North American populations, our investigation of Brazilian isolates supports the notion that B. cereus and B. thuringiensis should be considered to represent a single species.     

A Bacillus thuringiensis S-layer protein involved in toxicity against Epilachna varivestis (Coleoptera: Coccinellidae)

The use of Bacillus thuringiensis as a biopesticide is a viable alternative for insect control since the insecticidal Cry proteins produced by these bacteria are highly specific; harmless to humans, vertebrates, and plants; and completely biodegradable. In addition to Cry proteins, B. thuringiensis produces a number of extracellular compounds, including S-layer proteins (SLP), that contribute to virulence. The S layer is an ordered structure representing a proteinaceous paracrystalline array which completely covers the surfaces of many pathogenic bacteria. In this work, we report the identification of an S-layer protein by the screening of B. thuringiensis strains for activity against the coleopteran pest Epilachna varivestis (Mexican bean beetle; Coleoptera: Coccinellidae). We screened two B. thuringiensis strain collections containing unidentified Cry proteins and also strains isolated from dead insects. Some of the B. thuringiensis strains assayed against E. varivestis showed moderate toxicity. However, a B. thuringiensis strain (GP1) that was isolated from a dead insect showed a remarkably high insecticidal activity. The parasporal crystal produced by the GP1 strain was purified and shown to have insecticidal activity against E. varivestis but not against the lepidopteran Manduca sexta or Spodoptera frugiperda or against the dipteran Aedes aegypti. The gene encoding this protein was cloned and sequenced. It corresponded to an S-layer protein highly similar to previously described SLP in Bacillus anthracis (EA1) and Bacillus licheniformis (OlpA). The phylogenetic relationships among SLP from different bacteria showed that these proteins from Bacillus cereus, Bacillus sphaericus, B. anthracis, B. licheniformis, and B. thuringiensis are arranged in the same main group, suggesting similar origins. This is the first report that demonstrates that an S-layer protein is directly involved in toxicity to a coleopteran pest.     

Characterization of a highly pathogenic<Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> strain isolated from common cockchafer,<Emphasis Type="Italic">Melolontha melolontha</Emphasis>

A bacterial isolate (Mm2) of Melolontha melolontha was identified and characterized. Based on various morphological, physiological, biochemical and molecular characteristics, it was identified as Bacillus thuringiensis subsp. tenebrionis. This isolate was compared to the reference strains by electron microscopy, SDS-PAGE analysis, plasmid pattern, cry gene content and insecticidal activity. Cells of the isolate harbored flat square inclusions containing a protein component of approximately equal to65 kDa. After trypsin digestion of solubilized crystals, SDS-PAGE resolved a unique proteinase-resistant peptide of approximately equal to 50 kDa. Plasmid pattern showed similar bands to those of the reference strain, PCR analysis showed that the isolate has cry3 gene. Toxicity tests (against 5 coleopteran species) showed 80 % insecticidal activity against the larvae of M. melolontha. The isolate Mm2 may be valuable as biological control agent for M. melolontha and other coleopteran insects.     

特异性杀虫基因Bt cry3A在桑粒肩天牛幼虫两种肠道常驻内生菌中的转化和表达

[目的]将特异性杀虫毒蛋白基因Bt cry3A转入桑粒肩天牛(Apriona germari Hope,Ag)幼虫肠道常驻内生菌中,构建能在天牛幼虫肠道中定殖并表达特异性杀虫基因Bt cry3A的工程菌.[方法]以传统方法和16S rDNA分子生物学分析等方法分离、鉴定Ag幼虫肠道优势的常驻内生菌,从中筛选出适合转化的候选菌株.利用电转化技术将含有对鞘翅目昆虫具专一性毒力Bt cry3A基因的Escherichia coli-Bacillus thuringiensis穿梭表达质粒pHT305a和pHT7911分别转入Ag幼虫肠道常驻内生菌短短芽孢杆菌(Brevibacillus brevis Ag12,Ag12)和苏云金芽孢杆菌(Bacillus thuringiensis Ag13,Ag13)中.[结果]从Ag幼虫肠道共分离获得18个不同种的可培养细菌菌株,并从中选取菌株Ag12和Ag13作为出发菌株转入Bt cry3A基因.经质粒稳定性试验、转化子生长特性测试、伴胞晶体电镜检测、毒蛋白SDS-PAGE分析、工程菌定殖性分析以及生物毒力测试,结果显示cry3A基因已经成功转入Ag幼虫的常驻内生菌短短芽孢杆菌和苏云金芽孢杆菌中,并且工程菌Ag12-305a、Ag13-305a、Ag 12-7911和Ag13-7911都能在天牛幼虫肠道内稳定生长、繁殖并表达分子量约65kDa的伴孢晶体杀虫蛋白Cry3A.[结论]Bt cry3A基因已成功转入桑粒肩天牛幼虫肠道优势常驻内生菌中,获得了四株能在桑粒肩天牛幼虫肠道内定殖,并能表达目的杀虫基因Btcry3A的转基因工程菌.     

Molecular cloning of the 130-kilodalton mosquitocidal delta-endotoxin gene of Bacillus thuringiensis subsp. israelensis in Bacillus sphaericus

A 3.7-kilobase (kb) XbaI fragment harboring the cryIVB gene (L. Thorne, F. Garduno, T. Thompson, D. Decker, M. A. Zounes, M. Wild, A. M. Walfield, and T. J. Pollock, J. Bacteriol. 166:801-811, 1986) which encoded a 130-kilodalton (kDa) mosquitocidal toxin from a 110-kb plasmid of Bacillus thuringiensis subsp. israelensis 4Q2-72 was cloned into pUC12 and transformed into Escherichia coli. The clone with a recombinant plasmid (designated pBT8) was toxic to Aedes aegypti larvae. The fragment (3.7 kb) was ligated into pBC16 (tetracycline resistant [Tcr]) and transformed by the method of protoplast transformation into Bacillus sphaericus 1593 and 2362, which were highly toxic to Anopheles and Culex mosquito larvae but less toxic to Aedes larvae. After cell regeneration on regeneration medium, the Tcr plasmids from transformants (pBTC1) of both strains of B. sphaericus were prepared and analyzed. The 3.7-kb XbaI fragment from the B. thuringiensis subsp. israelensis plasmid was shown to be present by agarose gel electrophoresis and Southern blot hybridization. In addition, B. sphaericus transformants produced a 130-kDa mosquitocidal toxin which was detected by Western (immuno-) blot analysis with antibody prepared against B. thuringiensis subsp. israelensis 130-kDa mosquitocidal toxin. The 50% lethal concentrations of the transformants of strains 1593 and 2362 against A. aegypti larvae were 2.7 X 10(2) and 5.7 X 10(2) cells per ml, respectively. This level of toxicity was comparable to the 50% lethal concentration of B. thuringiensis subsp. israelensis but much higher than that of B. sphaericus 1593 and 2362 (4.7 X 10(4) cells per ml) against A. aegypti larvae.(ABSTRACT TRUNCATED AT 250 WORDS)     

Identification of quorum-quenching N-acyl homoserine lactonases from Bacillus species

A range of gram-negative bacterial species use N-acyl homoserine lactone (AHL) molecules as quorum-sensing signals to regulate different biological functions, including production of virulence factors. AHL is also known as an autoinducer. An autoinducer inactivation gene, aiiA, coding for an AHL lactonase, was cloned from a bacterial isolate, Bacillus sp. strain 240B1. Here we report identification of more than 20 bacterial isolates capable of enzymatic inactivation of AHLs from different sources. Eight isolates showing strong AHL-inactivating enzyme activity were selected for a preliminary taxonomic analysis. Morphological phenotypes and 16S ribosomal DNA sequence analysis indicated that these isolates probably belong to the species Bacillus thuringiensis. Enzymatic analysis with known Bacillus strains confirmed that all of the strains of B. thuringiensis and the closely related species B. cereus and B. mycoides tested produced AHL-inactivating enzymes but B. fusiformis and B. sphaericus strains did not. Nine genes coding for AHL inactivation were cloned either by functional cloning or by a PCR procedure from selected bacterial isolates and strains. Sequence comparison of the gene products and motif analysis showed that the gene products belong to the same family of AHL lactonases.     

Expression of the mosquitocidal toxins of Bacillus sphaericus and Bacillus thuringiensis subsp. israelensis by recombinant Caulobacter crescentus, a vehicle for biological control of aquatic insect larvae.

In the quest for effective control of mosquitoes, attention has turned increasingly to strains of the bacteria Bacillus sphaericus and Bacillus thuringiensis subsp. israelensis, which produce potent toxins with specific mosquitocidal activities. However, sedimentation of the bacterial spores limits the duration of effective control after field application of these bacilli. We describe here the cloning of genes encoding the 51.4- and 41.9-kDa toxins from B. sphaericus 2297, the 100-kDa toxin from B. sphaericus SSII-1, and the 130-kDa toxin from B. thuringiensis subsp. israelensis into the broad-host-range plasmid pRK248 and the transfer of these genes for expression in Caulobacter crescentus CB15. The recombinant C. crescentus cells were shown to be toxic to mosquito larvae. Caulobacter species are ubiquitous microorganisms residing in the upper regions of aquatic environments and therefore provide the potential for prolonged control by maintaining mosquitocidal toxins in larval feeding zones.     

Isolation, geographical diversity and insecticidal activity of Bacillus thuringiensis from soils in Spain

Bacillus thuringiensis is a spore-forming bacterium showing the unusual ability to produce endogenous crystals during sporulation that are toxic for some pest insects. This work was performed to study the composition, ecological distribution and insecticidal activity of isolates of this entomopathogenic bacterium from the Spanish territory. Using a standard isolation method, B. thuringiensis was isolated from 115 out of 493 soil samples collected in the Iberian Peninsula and the Canary and Balearic Archipelagos. The percentages of samples with B. thuringiensis were 31.7, 27.6 and 18.5 and the B. thuringiensis index 0.065, 0.067 and 0.11 for the Iberian Peninsula, Canary and Balearic Archipelagos, respectively. The prairies were shown to be the worst source of B. thuringiensis while forests, urban and agricultural habitats showed similar percentages. Strain classification based on H-antigen agglutination showed a great diversity among the Spanish isolates, which were distributed among 24 subspecies, including three new ones andaluciensis, asturiensis and palmanyolensis. We differentiated 65 different protein profiles of spore-crystal mixtures by sulfate-polyacrylamide gel electrophoresis and we selected 109 isolates representative of these profiles to evaluate their insecticidal activity against insects from the Orders Orthoptera, Dictyoptera, Coleoptera, Lepidoptera and Diptera. We found variable percentages of isolates active against Coleoptera and Lepidoptera, one isolate highly active against mosquito larvae and for the first time, three isolates active against cockroaches and locusts.     

The bacterium, Lysinibacillus sphaericus, as an insect pathogen

Since the first bacteria with insecticidal activity against mosquito larvae were reported in the 1960s, many have been described, with the most potent being isolates of Bacillus thuringiensis or Lysinibacillus sphaericus (formerly and best known as Bacillus sphaericus). Given environmental concerns over the use of broad spectrum synthetic chemical insecticides and the evolution of resistance to these, industry placed emphasis on the development of bacteria as alternative control agents. To date, numerous commercial formulations of B. thuringiensis subsp. israelensis (Bti) are available in many countries for control of nuisance and vector mosquitoes. Within the past few years, commercial formulations of L. sphaericus (Ls) have become available. Because Bti has been in use for more than 30 years, its properties are well know, more so than those of Ls. Thus, the purpose of this review is to summarise the most critical aspects of Ls and the various proteins that account for its insecticidal properties, especially the mosquitocidal activity of the most common isolates studied. Data are reviewed for the binary toxin, which accounts for the activity of sporulated cells, as well as for other toxins produced during vegetative growth, including sphaericolysin (active against cockroaches and caterpillars) and the different mosquitocidal Mtx and Cry toxins. Future studies of these could well lead to novel potent and environmentally compatible insecticidal products for controlling a range of insect pests and vectors of disease.     

Screening and identification of polyhydroxyalkanoates producing bacteria and biochemical characterization of their possible application

Polyhydroxyalkanoates (PHAs) accumulating bacteria were isolated under various selective conditions such as pH, salt concentrations and types of heavy metal. Fifty strains of bacterial isolates were found to belong to Bacillus, Proteus, Pseudomonas, Aeromonas, Alcaligenes and Chromobacterium, based on phenotypical features and genotypic investigation. Only twenty five bacterial isolates were selected and observed for the production of PHAs. Interestingly, bacteria belonging to Firmucutes Bacillus sp. produced a high amount of PHAs. The maximum PHAs were accumulated by B. licheniformis PHA 007 at 68.80% of dry cell weight (DCW). Pseudomonas sp., Aeromonas sp., Alcaligenes sp. and Chromobacterium sp. were recorded to produce a moderate amount of PHAs, varying from 10.00-44.32% of DCW. The enzymatic activity was preliminarily analyzed by the ratio of the clear zone diameter to colony diameter. Bacillus gave the highest ratio of hydrolysis zone which corresponds to the highest hydrolytic enzyme activities. Bacillus licheniformis PHA 007 had the highest lipase and protease activity at 2.1 and 5.1, respectively. However, the highest amylase activity was observed in Bacillus sp. PHA 023 at 1.4. Determination of metabolic characteristics was also investigated to check for their ability to consume a wide range of substrates. Bacillus, Aeromonas sp. and Alcaligenes sp. had great ability to utilize a variety of substrates. To decrease high PHA cost, different sources of cheap substrates were tested for the production of PHAs. Bacillus cereus PHA 008 gave the maximal yield of PHA production (64.09% of DCW) when cultivated in anaerobically treated POME. In addition, the accumulation of PHA copolymers such as 3-hydroxyvalerate and 3-hydroxyhexanoate was also observed in Bacillus and Pseudomomas sp. strain 012 and 045, respectively. Eight of the nine isolates accumulated a significant amount of PHAs when inexpensive carbon sources were used as substrates. Here it varied from 1.69% of DCW by B. licheniformis PHA 007 to 64.09% of DCW by B. cereus PHA 008.     

Isolation of endospore-forming bacilli toxic to Culiseta longiareolata (Diptera: Culicidae) in Jordan

Ten of 80 endospore-forming bacilli, isolated from various habitats of Jordan, were found to be highly toxic to the 4th instar larvae of Culiseta longiareolata (Macquart). The bacilli were identified into the following species and strains: Bacillus sphaericus (H6), B. sphaericus (H9a, 9b), B. cereus Frankland and Frankland, B. brevis Migula and B. megaterium Bary. Bacillus cereus comprised 50% of the isolates. The toxic concentrations of these isolates against C. longiareolata ranged between 1.2 x 10(7) and 1.1 x 10(9) viable spores ml-1.     

Insecticidal bacteria isolated from predatory larvae of the antlion species Myrmeleon bore (Neuroptera: Myrmeleontidae)

Various bacterial species were isolated from the crop (digestive organ) of the antlion species Myrmeleon bore and tested for their insecticidal activity against caterpillars by injection. Sixty-eight isolates from the antlion crop were grouped into twenty-four species based on homologies of 16S rRNA gene sequences and biochemical properties. Isolated Bacillus cereus, Bacillus sphaericus, Morganella morganii, Serratia marcescens and a Klebsiella species killed 80% or more cutworms when injected at a dose of 5x10(5)cells per insect. In addition, cutworms killed by these isolates resembled observations made of caterpillars attacked by antlions. A culture-independent analysis showed that the isolated bacterial species are likely to be frequently present in the antlion crop. These results suggest that insecticidal microorganisms associate with antlions, and may promote the death of prey.     

Genetic differentiation between sympatric populations of Bacillus cereus and Bacillus thuringiensis

Little is known about genetic exchanges in natural populations of bacteria of the spore-forming Bacillus cereus group, because no population genetics studies have been performed with local sympatric populations. We isolated strains of Bacillus thuringiensis and B. cereus from small samples of soil collected at the same time from two separate geographical sites, one within the forest and the other at the edge of the forest. A total of 100 B. cereus and 98 B. thuringiensis strains were isolated and characterized by electrophoresis to determine allelic composition at nine enzymatic loci. We observed genetic differentiation between populations of B. cereus and B. thuringiensis. Populations of a given Bacillus species--B. thuringiensis or B. cereus--were genetically more similar to each other than to populations of the other Bacillus species. Hemolytic activity provided further evidence of this genetic divergence, which remained evident even if putative clones were removed from the data set. Our results suggest that the rate of gene flow was higher between strains of the same species, but that exchanges between B. cereus and B. thuringiensis were nonetheless possible. Linkage disequilibrium analysis revealed sufficient recombination for B. cereus populations to be considered panmictic units. In B. thuringiensis, the balance between clonal proliferation and recombination seemed to depend on location. Overall, our data indicate that it is not important for risk assessment purposes to determine whether B. cereus and B. thuringiensis belong to a single or two species. Assessment of the biosafety of pest control based on B. thuringiensis requires evaluation of the extent of genetic exchange between strains in realistic natural conditions.     

Screening of cry gene contents of Bacillus thuringiensis strains isolated from avocado orchards in Mexico, and their insecticidal activity towards Argyrotaenia sp. (Lepidoptera: Tortricidae) larvae

Aims:  To screen for Bacillus thuringiensis strains from avocado orchards in two Mexican states with lepidopteran-specific cry gene content and evaluate their insecticidal activity against Argyrotaenia sp., an undescribed species present in avocado orchards.
Methods and Results:  Lepidopteran-active cry 1, cry 2 and cry 9 genes were detected by PCR analysis in 37 isolates. cry 1 genes were more frequent in Michoacán, but were undetected in Nayarit isolates. cry 9 and cry 2 genes were detected in isolates from both states, although cry 2 genes were less frequent. A variety of crystal shapes were observed among the isolates. According to gene profile, eight isolates were selected and tested against 2-day old Argyrotaenia sp. larvae. Standard strain HD-125 caused the highest mortality followed by strain MR-26 from Michoacán at a concentration of 500 μg ml⁻¹, respectively.
Conclusions:  Bacillus thuringiensis strains isolated from avocado orchards exhibit a low toxic activity towards Argyrotaenia sp. larvae, in spite of their specific cry gene content.
Significance and Impact of the Study:  Toxic activity of B. thuringiensis is not necessarily related to insect pest habitat and neither to specific cry gene content associated to other lepidopterans.     

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。     

Novel Bacillus thuringiensis binary insecticidal crystal proteins active on western corn rootworm, Diabrotica virgifera virgifera LeConte

A new family of insecticidal crystal proteins was discovered by screening sporulated Bacillus thuringiensis cultures for oral activity against western corn rootworm (WCR) larvae. B. thuringiensis isolates PS80JJ1, PS149B1, and PS167H2 have WCR insecticidal activity attributable to parasporal inclusion bodies containing proteins with molecular masses of ca. 14 and 44 kDa. The genes encoding these polypeptides reside in apparent operons, and the 14-kDa protein open reading frame (ORF) precedes the 44-kDa protein ORF. Mutagenesis of either gene in the apparent operons dramatically reduced insecticidal activity of the corresponding recombinant B. thuringiensis strain. Bioassays performed with separately expressed, biochemically purified 14- and 44-kDa polypeptides also demonstrated that both proteins are required for WCR mortality. Sequence comparisons with other known B. thuringiensis insecticidal proteins failed to reveal homology with previously described Cry, Cyt, or Vip proteins. However, there is evidence that the 44-kDa polypeptide and the 41.9- and 51.4-kDa binary dipteran insecticidal proteins from Bacillus sphaericus are evolutionarily related. The 14- and 44-kDa polypeptides from isolates PS80JJ1, PS149B1, and PS167H2 have been designated Cry34Aa1, Cry34Ab1, and Cry34Ac1, respectively, and the 44-kDa polypeptides from these isolates have been designated Cry35Aa1, Cry35Ab1, and Cry35Ac1, respectively.     

Identification of entomopathogenic Bacillus isolated from Simulium (Diptera, Simuliidae) larvae and adults.

Entomopathogenic bacteria isolated from Simulium larvae and adults from breeding sites in the states of S?o Paulo and Rio de Janeiro, Brazil, were identified as 18 strains of Bacillus thuringiensis and one of B. sphaericus. Most of these strains were serotyped according to their flagellar antigens. However, nine of the B. thuringiensis samples, could not be serotyped and were designated as "autoagglutinating"; they were also shown to be toxic in preliminary tests against Aedes aegypti larvae. Additionally, B. sphaericus was also shown to be toxic towards Culex quinquefasciatus larvae.