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1.
PLoS Pathog ; 19(12): e1011859, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38060601

RESUMO

Microsporidia are a group of obligate intracellular parasites that infect almost all animals, causing serious human diseases and major economic losses to the farming industry. Nosema bombycis is a typical microsporidium that infects multiple lepidopteran insects via fecal-oral and transovarial transmission (TOT); however, the underlying TOT processes and mechanisms remain unknown. Here, we characterized the TOT process and identified key factors enabling N. bombycis to invade the ovariole and oocyte of silkworm Bombyx mori. We found that the parasites commenced with TOT at the early pupal stage when ovarioles penetrated the ovary wall and were exposed to the hemolymph. Subsequently, the parasites in hemolymph and hemolymph cells firstly infiltrated the ovariole sheath, from where they invaded the oocyte via two routes: (I) infecting follicular cells, thereby penetrating oocytes after proliferation, and (II) infecting nurse cells, thus entering oocytes following replication. In follicle and nurse cells, the parasites restructured and built large vacuoles to deliver themselves into the oocyte. In the whole process, the parasites were coated with B. mori vitellogenin (BmVg) on their surfaces. To investigate the BmVg effects on TOT, we suppressed its expression and found a dramatic decrease of pathogen load in both ovarioles and eggs, suggesting that BmVg plays a crucial role in the TOT. Thereby, we identified the BmVg domains and parasite spore wall proteins (SWPs) mediating the interaction, and demonstrated that the von Willebrand domain (VWD) interacted with SWP12, SWP26 and SWP30, and the unknown function domain (DUF1943) bound with the SWP30. When disrupting these interactions, we found significant reductions of the pathogen load in both ovarioles and eggs, suggesting that the interplays between BmVg and SWPs were vital for the TOT. In conclusion, our study has elucidated key aspects about the microsporidian TOT and revealed the key factors for understanding the molecular mechanisms underlying this transmission.


Assuntos
Bombyx , Nosema , Animais , Humanos , Vitelogeninas/metabolismo , Esporos Fúngicos/metabolismo , Nosema/metabolismo , Bombyx/metabolismo
2.
BMC Womens Health ; 24(1): 141, 2024 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-38402149

RESUMO

OBJECTIVE: Understanding HPV vaccination willingness and its influencing factors among female sex workers (FSWs) in entertainment venues in an urban area of Guangxi, China. METHODS: From 15 August to 15 October 2022, FSWs in entertainment venues with commercial sex trade in an urban area of Guangxi were selected as the study subjects for the questionnaire survey using the method of intentional sampling. The questionnaire based on the information-motivation-behavior (IMB) skills model was used to collect the basic characteristics, HPV and HPV vaccine-related information and cognition, motivation to vaccinate, behavioral skills and willingness to vaccinate from the research targets. A multifactor logistic regression model was used to analyze the factors influencing the research targets' willingness to receive HPV vaccination. RESULTS: Of the 921 research targets, 712 (77.31%) were willing to receive HPV vaccination. The higher the level of knowledge regarding HPV and HPV vaccine-related information, the higher the motivation for HPV vaccination. In addition, the higher the behavioral skills score, the higher the willingness of FSWs in entertainment venues to receive HPV vaccination (P<0.001). FSWs in entertainment venues with lower venue grades [OR(95% CI)=0.693 (0.539, 0.891), P=0.004] were more reluctant to receive HPV vaccination. Those who favored the effectiveness of the vaccine in preventing the disease [OR(95% CI)=2.144 (1.449, 3.174), P<0.001] and those who had heard of HPV vaccine [OR(95% CI)=2.105 (1.451, 3.054), P<0.001], were able to perceive the benefits of HPV vaccination [OR(95% CI)=1.134 (1.045, 1.230), P=0.002]. These individuals acquired greater behavioral skills i.e., self-decision making for HPV vaccination [OR(95% CI)=1.130 (1.008, 1.267), P=0.036] and self-efficacy [OR(95% CI)=1.135 (1.081, 1.191), P<0.001] and they were more willing to receive HPV vaccine. CONCLUSIONS: There was a relatively high HPV vaccination willingness among FSWs in entertainment venues in an urban area of Guangxi, China. Attention should be focused on introducing the benefits of primary prevention measures such as the HPV vaccine for individuals and behavioral skills for HPV vaccination in order to increase their willingness to be vaccinated thus increasing their HPV vaccination rate.


Assuntos
Infecções por Papillomavirus , Vacinas contra Papillomavirus , Profissionais do Sexo , Humanos , Feminino , Trabalho Sexual , Motivação , Infecções por Papillomavirus/prevenção & controle , China , Inquéritos e Questionários , Vacinas contra Papillomavirus/uso terapêutico , Vacinação , Conhecimentos, Atitudes e Prática em Saúde , Aceitação pelo Paciente de Cuidados de Saúde
3.
Small ; 19(48): e2303864, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37525330

RESUMO

Silicon (Si) is regarded as one of the most promising anode materials for high-performance lithium-ion batteries (LIBs). However, how to mitigate its poor intrinsic conductivity and the lithiation/delithiation-induced large volume change and thus structural degradation of Si electrodes without compromising their energy density is critical for the practical application of Si in LIBs. Herein, an integration strategy is proposed for preparing a compact micron-sized Si@G/CNF@NC composite with a tight binding and dual-encapsulated architecture that can endow it with superior electrical conductivity and deformation resistance, contributing to excellent cycling stability and good rate performance in thick electrode. At an ultrahigh mass loading of 10.8 mg cm-2 , the Si@G/CNF@NC electrode also presents a large initial areal capacity of 16.7 mA h cm-2 (volumetric capacity of 2197.7 mA h cm-3 ). When paired with LiNi0.95 Co0.02 Mn0.03 O2 , the pouch-type full battery displays a highly competitive gravimetric (volumetric) energy density of ≈459.1 Wh kg-1 (≈1235.4 Wh L-1 ).

4.
BMC Microbiol ; 23(1): 334, 2023 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-37951859

RESUMO

BACKGROUND: Enterocytozoon bieneusi, Encephalitozoon spp., Cryptosporidium spp., and Giardia duodenalis (G. intestinalis) are enteric pathogens that cause diarrhea in pigs. This study aimed to determine the prevalence of these enteric parasites and their coinfection with E. bieneusi in diarrheic pigs in Southwest China (Chongqing and Sichuan) using nested polymerase chain reaction (nPCR) based methods. RESULTS: A total of 514 fecal samples were collected from diarrheic pigs from 14 pig farms in Chongqing (five farms) and Sichuan (nine farms) Provinces. The prevalence of Encephalitozoon spp., Cryptosporidium spp. and G. duodenalis was 16.14% (83/514), 0% (0/514), and 8.95% (46/514), respectively. Nested PCR revealed 305 mono-infections of E. bieneusi, six of E. cuniculi, two of E. hellem, and nine of G. duodenalis and 106 concurrent infections of E. bieneusi with the other enteric pathogens. No infections of E. intestinalis and Cryptosporidium species were detected. The highest coinfection was detected between E. bieneusi and E. cuniculi (10.5%, 54/514), followed by E. bieneusi and G. duodenalis (5.8%, 30/514) and E. bieneusi and E. hellem (2.9%, 15/514). E. bieneusi was the most frequently detected enteric pathogen, followed by E. cuniculi, G. duodenalis and E. hellem. There was a significant age-related difference in the prevalence of E. cuniculi in fattening pigs (χ2 = 15.266, df = 3, P = 0.002) and G. duodenalis in suckling pigs (χ2 = 11.92, df = 3, P = 0.008) compared with the other age groups. Sequence analysis of the ITS region of Encephalitozoon species showed two genotypes (II and III) for E. cuniculi and one (TURK1B) for E. hellem. Only G. duodenalis assemblage A was identified in all nested PCR-positive samples. E. bieneusi was found more often than other enteric pathogens. CONCLUSIONS: This study showed that E. bieneusi, Encephalitozoon spp. [E. cuniculi and E. hellem] and G. duodenalis were common enteric parasites in diarrheic pigs in Chongqing and Sichuan Provinces. In case of both mono-infection and coinfection, E. bieneusi was the most common enteric pathogen in diarrheic pigs. Thus, it may be a significant cause of diarrhea in pigs. Precautions should be taken to prevent the spread of these enteric parasites.


Assuntos
Coinfecção , Criptosporidiose , Cryptosporidium , Encephalitozoon , Enterocytozoon , Giardia lamblia , Giardíase , Microsporidiose , Animais , Suínos , Giardia lamblia/genética , Giardíase/epidemiologia , Giardíase/veterinária , Giardíase/parasitologia , Enterocytozoon/genética , Criptosporidiose/epidemiologia , Criptosporidiose/parasitologia , Cryptosporidium/genética , Coinfecção/epidemiologia , Coinfecção/veterinária , Microsporidiose/epidemiologia , Microsporidiose/veterinária , China/epidemiologia , Genótipo , Fezes/parasitologia , Diarreia/epidemiologia , Diarreia/veterinária
5.
Can J Microbiol ; 69(3): 136-145, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36638365

RESUMO

Cordyceps farinosa, an entomopathogenic fungus, infects and leads to high mortality of Thitarodes armoricanus larvae, which die soon after the infection of C. farinose, usually before the colonization of Ophiocordyceps sinensis owing to competitive inhibition and fruiting body formation. Therefore, monitoring C. farinosa in the O. sinensis cultivation environment is critical for minimizing the C. farinosa infection-induced losses. In this study, we initially designed a PCR primer pair (Tar-1F/Tar-1R) through open reading frame prediction and homology comparison of the C. farinosa genome sequence. This primer pair can detect both C. farinosa and Samsoniella hepiali. To further distinguish, primers (ITS5-172/ITS4-95) were then designed to selectively amplify the large ribosomal subunit sequences in the C. farinosa genome. All these primers were applied in combination for detection of C. farinosa in soil samples. The sensitivity reached a detection limit of 1 × 106 spores/g soil. In addition, these primers can detect the presence of C. farinosa in dead T. armoricanus larval samples. This newly established rapid detection method provides important information for C. farinosa control during O. sinensis cultivation.


Assuntos
Cordyceps , Mariposas , Animais , Cordyceps/genética , Mariposas/microbiologia , Larva/microbiologia , Reação em Cadeia da Polimerase/métodos
6.
J Invertebr Pathol ; 198: 107937, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37209810

RESUMO

Bombyx mori nucleopolyhedrovirus (BmNPV) poses a significant threat to sericulture production, and traditional sanitation practices remain the main strategy for controlling BmNPV infection. Although RNAi targeting BmNPV genes engineered into transgenic silkworms has shown to be a promising approach in reducing viral infection, it cannot block viral entry into host cells. Therefore, there is an urgent need to develop new effective prevention and control measures. In this study, we screened a monoclonal antibody 6C5 that potently neutralizes BmNPV infection by clamping the internal fusion loop of the BmNPVglycoprotein64 (GP64). Furthermore, we cloned the VH and VL fragments of mAb-6C5 from the hybridoma cell, and the eukaryotic expression vector of scFv6C5 was constructed to anchor the antibody on the cell membrane. The GP64 fusion loop antibody-expressing cells exhibited a reduced capacity for BmNPV infection. The results from our study provide a novel BmNPV control strategy and lay the foundation for the future development of transgenic silkworms with improved antiviral efficacy.


Assuntos
Bombyx , Nucleopoliedrovírus , Animais , Nucleopoliedrovírus/genética , Animais Geneticamente Modificados , Interferência de RNA , Membrana Celular
7.
Int J Mol Sci ; 24(12)2023 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-37373428

RESUMO

Melanin is a complex natural pigment that is widely present in fungi. The mushroom Ophiocordyceps sinensis has a variety of pharmacological effects. The active substances of O. sinensis have been extensively studied, but few studies have focused on the O. sinensis melanin. In this study, the production of melanin was increased by adding light or oxidative stress, namely, reactive oxygen species (ROS) or reactive nitrogen species (RNS), during liquid fermentation. Subsequently, the structure of the purified melanin was characterized using elemental analysis, ultraviolet-visible absorption spectrum, Fourier transform infrared (FTIR), electron paramagnetic resonance (EPR), and pyrolysis gas chromatography and mass spectrometry (Py-GCMS). Studies have shown that O. sinensis melanin is composed of C (50.59), H (6.18), O (33.90), N (8.19), and S (1.20), with maximum absorbance at 237 nm and typical melanin structures such as benzene, indole, and pyrrole. Additionally, the various biological activities of O. sinensis melanin have been discovered; it can chelate heavy metals and shows a strong ultraviolet-blocking ability. Moreover, O. sinensis melanin can reduce the levels of intracellular reactive oxygen species and counteract the oxidative damage of H2O2 to cells. These results can help us to develop applications of O. sinensis melanin in radiation resistance, heavy metal pollution remediation, and antioxidant use.


Assuntos
Agaricales , Cordyceps , Cordyceps/química , Melaninas/química , Espécies Reativas de Oxigênio , Peróxido de Hidrogênio
8.
Bull Entomol Res ; 112(4): 502-508, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35382911

RESUMO

Nosema bombycis is a destructive and specific intracellular parasite of silkworm, which is extremely harmful to the silkworm industry. N. bombycis is considered as a quarantine pathogen of sericulture because of its long incubation period and horizontal and vertical transmission. Herein, two single-chain antibodies targeting N. bombycis hexokinase (NbHK) were cloned and expressed in fusion with the N-terminal of Slmb (a Drosophila melanogaster FBP), which contains the F-box domain. Western blotting demonstrated that Sf9-III cells expressed NSlmb-scFv-7A and NSlmb-scFv-6H, which recognized native NbHK. Subsequently, the NbHK was degraded by host ubiquitination system. When challenged with N. bombycis, the transfected Sf9-III cells exhibited better resistance relative to the controls, demonstrating that NbHK is a prospective target for parasite controls and this approach represents a potential solution for constructing N. bombycis-resistant Bombyx mori.


Assuntos
Bombyx , Nosema , Animais , Bombyx/genética , Drosophila melanogaster , Hexoquinase/metabolismo , Estudos Prospectivos
9.
Can J Microbiol ; 66(6): 401-412, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32160477

RESUMO

Fusarium wilt is a devastating soil-borne disease mainly caused by highly host-specific formae speciales of Fusarium spp. Antagonistic microorganisms play a very important role in Fusarium wilt control. Isolation of potential biocontrol strains has become increasingly important. Bacterial strain SEM-2 was isolated from the high-temperature stage of silkworm excrement composting. SEM-2 exhibited a considerable antagonistic effect against Fusarium graminearum mycelial growth and spore germination. The results of pot experiments suggested that SEM-2 has a better inhibitory effect on the early stage of disease occurrence. The green fluorescent protein labelled SEM-2 coated on the surface of tomato seeds colonised the roots of tomato plants in 15 days. Genome sequencing identified SEM-2 as a new strain of Bacillus subtilis, and genome annotation and analysis determined gene clusters related to the biosynthesis of antimicrobials, such as bacillaene, fengycin, bacillibactin, subtilosin A, surfactin, and bacilysin. Interestingly, liquid chromatography - quadrupole time-of-flight mass spectrometry revealed that metabolites in pathways associated with the synthesis of secondary metabolites and antibiotics were highly differentially expressed. These findings may help to explain the mode of action of B. subtilis SEM-2 against Fusarium spp.


Assuntos
Antibiose , Bacillus subtilis/fisiologia , Bombyx/microbiologia , Fusarium/crescimento & desenvolvimento , Genoma Bacteriano/genética , Doenças das Plantas/prevenção & controle , Solanum lycopersicum/microbiologia , Animais , Anti-Infecciosos/metabolismo , Bacillus subtilis/química , Bacillus subtilis/genética , Bacillus subtilis/isolamento & purificação , Agentes de Controle Biológico , Cromatografia Líquida , Fezes/microbiologia , Espectrometria de Massas , Família Multigênica/genética , Doenças das Plantas/microbiologia , Sementes/microbiologia
10.
J Invertebr Pathol ; 170: 107322, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31901433

RESUMO

Microsporidia are a fascinating phylum of obligate intracellular pathogens with unique infection processes and complicated life cycles. Microsporidian life cycles can be divided roughly into intracellular and extracellular stages. Currently, research on their life cycles were mainly explored by morphology because there are few molecular markers available with which to distinguish the different life stages. In this study, we generated H20, a monoclonal antibody (MAb) to label mature spores of Nosema bombycis. Immunofluorescence assays showed that the target protein of H20, which is highly stable and was barely affected by alkali and sodium dodecyl sulfate (SDS) treatments, was located on the mature spore surface. Western blot analysis showed that spore wall protein 26 (SWP26) was the likely target of H20. This MAb can specifically identify mature spores in a complex biological sample based on immunological detection of the parasite.


Assuntos
Nosema/isolamento & purificação , Esporos Fúngicos/isolamento & purificação , Anticorpos Antifúngicos/análise , Anticorpos Monoclonais/análise , Antígenos de Fungos/análise , Western Blotting , Técnica Indireta de Fluorescência para Anticorpo , Técnicas In Vitro
11.
J Invertebr Pathol ; 169: 107310, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31862268

RESUMO

Nosema bombycis is an obligate intracellular pathogen that can be transmitted vertically from infected females to eggs, resulting in congenital infections in embryos. Here we investigated the proliferation characteristics of N. bombycis in silkworm embryos using a histopathological approach and deep RNA sequencing. We found that N. bombycis proliferated mainly around yolk granules at the early stage of the embryonic development, 1-2 days post oviposition (dpo). At 4-6 dpo, a portion of N. bombycis in different stages adjacent to the embryo were packaged into the newly formed intestinal lumen, while the remaining parasites continued to proliferate around yolk granules. In the newly hatched larvae (9 dpo), the newly formed spores accumulated in the gut lumen and immediately were released into the environment via the faeces. Transcriptional profiling of N. bombycis further confirmed multiplication of N. bombycis throughout every stage of embryonic development. Additionally, the increased transcriptional level of spore wall proteins and polar tube proteins from 4 dpo indicated an active formation of mature spores. Taken together, our results have provided a characterization of the proliferation of this intracellular microsporidian pathogen in congenitally infected embryos leading to vertical transmission.


Assuntos
Bombyx/microbiologia , Interações Hospedeiro-Patógeno , Nosema/fisiologia , Animais , Bombyx/embriologia , Bombyx/crescimento & desenvolvimento , Embrião não Mamífero/microbiologia , Larva/crescimento & desenvolvimento , Larva/microbiologia , RNA-Seq
12.
Microb Ecol ; 77(3): 651-663, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30178387

RESUMO

Bacillus sp. 7PJ-16, an endophytic bacterium isolated from a healthy mulberry stem and previously identified as Bacillus tequilensis 7PJ-16, exhibits strong antifungal activity and has the capacity to promote plant growth. This strain was studied for its effectiveness as a biocontrol agent to reduce mulberry fruit sclerotiniose in the field and as a growth-promoting agent for mulberry in the greenhouse. In field studies, the cell suspension and supernatant of strain 7PJ-16 exhibited biocontrol efficacy and the lowest disease incidence was reduced down to only 0.80%. In greenhouse experiments, the cell suspension (1.0 × 106 and 1.0 × 105 CFU/mL) and the cell-free supernatant (100-fold and 1000-fold dilution) stimulated mulberry seed germination and promoted mulberry seedling growth. In addition, to accurately identify the 7PJ-16 strain and further explore the mechanisms of its antifungal and growth-promoting properties, the complete genome of this strain was sequenced and annotated. The 7PJ-16 genome is comprised of two circular plasmids and a 4,209,045-bp circular chromosome, containing 4492 protein-coding genes and 116 RNA genes. This strain was ultimately designed as Bacillus subtilis based on core genome sequence analyses using a phylogenomic approach. In this genome, we identified a series of gene clusters that function in the synthesis of non-ribosomal peptides (surfactin, fengycin, bacillibactin, and bacilysin) as well as the ribosome-dependent synthesis of tasA and bacteriocins (subtilin, subtilosin A), which are responsible for the biosynthesis of numerous antimicrobial metabolites. Additionally, several genes with function that promote plant growth, such as indole-3-acetic acid biosynthesis, the production of volatile substances, and siderophores synthesis, were also identified. The information described in this study has established a good foundation for understanding the beneficial interactions between endophytes and host plants, and facilitates the further application of B. subtilis 7PJ-16 as an agricultural biofertilizer and biocontrol agent.


Assuntos
Antibiose , Bacillus subtilis/genética , Endófitos/genética , Morus/microbiologia , Doenças das Plantas/prevenção & controle , Ascomicetos/fisiologia , Bacillus subtilis/fisiologia , Bacteriocinas/genética , Bacteriocinas/metabolismo , Agentes de Controle Biológico/isolamento & purificação , Agentes de Controle Biológico/metabolismo , Endófitos/isolamento & purificação , Endófitos/fisiologia , Frutas/microbiologia , Genoma Bacteriano , Genômica , Peptídeos Cíclicos/genética , Peptídeos Cíclicos/metabolismo , Doenças das Plantas/microbiologia
13.
J Invertebr Pathol ; 168: 107260, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31622597

RESUMO

Nosema bombycis is a pathogen of the silkworm that belongs to the microsporidia, a group of obligate intracellular parasites related to fungi. N. bombycis infection causes the disease pébrine in silkworms. Insects utilize hemolymph melanization as part of the innate immune response to fight against pathogens, and melanization relies on a serine protease-mediated prophenoloxidase (PPO) activation cascade that is tightly regulated by serine protease inhibitors (serpins). Previous studies showed that N. bombycis infection suppressed silkworm hemolymph melanization, however the mechanism has not been elucidated. We hypothesize that N. bombycis can secret serpins (NbSPNs) to inhibit host serine proteases in the PPO activation cascade, thus suppressing phenoloxidase (PO) activity and the consequent melanization. We demonstrated in this study that N. bombycis infection suppressed silkworm PO activity and melanization and we identified the expression of N. bombycis serpin 6 (NbSPN6) in the hemolymph of the infected host. When recombinant NbSPN6 was added to normal hemolymph, PO activity was inhibited in a dose-dependent manner. Moreover, in vivo analysis by RNA interference technology showed that when NbSPN6 expression is blocked, the inhibitory effects on PO activity can be reversed and the proliferation of N. bombycis within host can be suppressed. These results demonstrated the indispensable role of NbSPN6 in successful pathogen infection. To further elucidate the molecular basis of NbSPN6 suppressing host defense, we determined that the host serine protease prophenoloxidase-activating enzyme (PPAE) is the direct target of NbSPN6 inhibition. Taken together, our novel study is the first to elucidate the molecular mechanism of pathogen-derived serpin inhibiting hemolymph melanization and, thus, regulating host innate immune responses. This study may also provide novel strategies for preventing microsporidia infection.


Assuntos
Bombyx/microbiologia , Nosema/metabolismo , Serina Endopeptidases/metabolismo , Serpinas/metabolismo , Animais , Bombyx/imunologia , Bombyx/metabolismo , Expressão Gênica , Hemolinfa/imunologia , Hemolinfa/metabolismo , Interações Hospedeiro-Parasita , Imunidade Inata , Proteínas de Insetos/metabolismo , Melaninas/imunologia , Melaninas/metabolismo , Nosema/genética , Serina Proteases/metabolismo , Serpinas/genética
14.
J Invertebr Pathol ; 164: 59-65, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31039370

RESUMO

Nosema bombycis, the pathogen of silkworm pébrine, causes enormous economic losses to sericulture. As such, quarantine of commercial silkworm eggs represents an important safeguard to the silkworm industry. Here, we established a user-friendly detection system based on a nucleic acid lateral flow strip (NAFLS) that combines polymerase chain reaction (PCR) and a colloidal gold strip. PCR primers were designed based on the sequence of LSU rDNA of N. bombycis and has favourable specificity for common microsporidian isolates in silkworms. The forward and reverse primers were labeled on the 5' end with biotin and carboxyfluorescein (FAM), respectively. Genomic DNA was extracted from egg samples and was used as a template for PCR, followed by subsequent detection by NALFS. The detection limit of purified N. bombycis genomic DNA was 1 pg, 100× more sensitive than that of agarose gel electrophoresis (AGE). Furthermore, the sensitivity of detection of simulated "infected" silkworm eggs was 10-100× higher than that of AGE. NALFS detected infection in 27 of 29 samples of silkworm eggs oviposited by female moths infected in lab; ≥2% infected eggs per batch are detected as positive, while ≥40% infected eggs per batch are required for detection by AGE. Collectively, NALFS is easy to use and has great potential for widespread use in the detection of N. bombycis in silkworm egg production.


Assuntos
Bombyx/microbiologia , Microsporidiose/diagnóstico , Nosema/isolamento & purificação , Animais , Óvulo/microbiologia , Patologia Molecular/métodos
15.
Biotechnol Lett ; 39(6): 857-864, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28247198

RESUMO

OBJECTIVE: To develop a reliable and easy to use expression system for antibiotic production improvement of Streptomyces. RESULTS: A two-compound T7 RNA polymerase-dependent gene expression system was developed to fulfill this demand. In this system, the T7 RNA polymerase coding sequence was optimized based on the codon usage of Streptomyces coelicolor. To evaluate the functionality of this system, we constructed an activator gene overexpression strain for enhancement of actinorhodin production. By overexpression of the positive regulator actII-ORF4 with this system, the maximum actinorhodin yield of engineered strain was 15-fold higher and the fermentation time was decreased by 48 h. CONCLUSION: The modified two-compound T7 expression system improves both antibiotic production and accelerates the fermentation process in Streptomyces. This provides a general and useful strategy for strain improvement of important antibiotic producing Streptomyces strains.


Assuntos
Antibacterianos/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , Streptomyces/metabolismo , Proteínas Virais/metabolismo , Antraquinonas/análise , Antraquinonas/metabolismo , Antibacterianos/análise , Biotecnologia , Clonagem Molecular , RNA Polimerases Dirigidas por DNA/genética , Fermentação , Streptomyces/enzimologia , Streptomyces/genética , Proteínas Virais/genética
16.
Wei Sheng Wu Xue Bao ; 56(3): 406-17, 2016 Mar 04.
Artigo em Zh | MEDLINE | ID: mdl-27382784

RESUMO

OBJECTIVE: To determine the functions of gouC and gouD in gougerotin biosynthesis, disruption of these two genes was performed. As gougerotin producing strain Streptomyces graminearus lacks efficient genetic manipulation system, the gene cluster for gougerotin biosynthesis was heterologously expressed in Streptomyces coelicolor M1146 to facilitate genetic manipulations of gouC and gouD. METHODS: By using fosmid D6-4H containing the complete gougerotin biosynthetic gene cluster, gouC and gouD were disrupted by PCR-targeting method to generate pGOUe-ΔC and pGOUe-ΔD. Both pGOUe-ΔC and pGOUe-ΔD were introduced into Streptomyces coelicolor M1146 by intergeneric conjugation, thus gouC and gouD disrpution mutants (Ml146-GOUe-AC and M1146-GOUe-ΔD) were obtained. The gougerotin production of M1146-GOUe-ΔC and M1146-GOUe-ΔD were assayed by HPLC analysis. The intermediates accumulated in these mutants were purified and subjected to MS and NMR analyses for structure determinations. Bioassay of these intermediates against tumor cell line were also carried out. RESULTS: Disruption mutants of gouC and gouD failed to produce gougerotin and the mutants accumulated different gougerotin intermediates, which lost their ability to inhibit cancer cell proliferation. CONCLUSION: gouC and gouD are key structual genes in the biosynthesis of gougerotin peptidyl moieties. This study will pave the way for the elucidation of gougerotin biosynthetic pathway.


Assuntos
Proteínas de Bactérias/metabolismo , Vias Biossintéticas , Streptomyces/metabolismo , Proteínas de Bactérias/genética , Estrutura Molecular , Família Multigênica , Nucleosídeos de Pirimidina/biossíntese , Nucleosídeos de Pirimidina/química , Streptomyces/química , Streptomyces/genética , Streptomyces coelicolor/genética , Streptomyces coelicolor/metabolismo
17.
Appl Environ Microbiol ; 80(2): 714-22, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24242236

RESUMO

Gougerotin is a peptidyl nucleoside antibiotic. It functions as a specific inhibitor of protein synthesis by binding ribosomal peptidyl transferase and exhibits a broad spectrum of biological activities. gouR, situated in the gougerotin biosynthetic gene cluster, encodes a TetR family transcriptional regulatory protein. Gene disruption and genetic complementation revealed that gouR plays an important role in the biosynthesis of gougerotin. Transcriptional analysis suggested that GouR represses the transcription of the gouL-to-gouB operon consisting of 11 structural genes and activates the transcription of the major facilitator superfamily (MFS) transporter gene (gouM). Electrophoresis mobility shift assays (EMSAs) and DNase I footprinting experiments showed that GouR has specific DNA-binding activity for the promoter regions of gouL, gouM, and gouR. Our data suggested that GouR modulates gougerotin production by coordinating its biosynthesis and export in Streptomyces graminearus.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Streptomyces/genética , Streptomyces/metabolismo , Sequência de Bases , Sítios de Ligação , Desoxirribonuclease I/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Regulação Bacteriana da Expressão Gênica , Teste de Complementação Genética , Dados de Sequência Molecular , Família Multigênica , Mutação , Óperon , Regiões Promotoras Genéticas , Transporte Proteico , Nucleosídeos de Pirimidina/biossíntese , Nucleosídeos de Pirimidina/genética , Transativadores/genética
18.
RSC Adv ; 14(1): 463-477, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38173595

RESUMO

In this study, using density functional and Boltzmann transport theories, we systematically investigated the effects of tensile and compressive strains on the elastic properties, phonon dispersion relation, electronic structure, and transport properties of the half-Heusler compound BiBaK. We calculated the elastic constants and phonon dispersion curves for BiBaK, which demonstrated its mechanical and thermodynamic stability, respectively, under different isotropic strains. Further, calculations showed that the electronic structure and energy bandgap of BiBaK changed with the application of isotropic strain. A high power factor and low thermal conductivity are key to improving the performance of thermoelectric materials. The figure of merit of BiBaK is 0.6 when it is unstrained and reaches a maximum value of 0.93 at -9% compressive strain and a temperature of 1200 K, indicating that under isotropic compressive strain, BiBaK compounds are efficient thermoelectric materials for high-temperature applications.

19.
Microbiol Resour Announc ; 13(7): e0030624, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-38842340

RESUMO

Streptomyces sp. F41 is a potent insecticidal metabolite producing actinomycetes isolated from the topsoil, and the complete genome sequence was determined. The genome consists of 8,343,496 bp, with 7,221 genes and a GC content of 71.84%.

20.
Microbiol Spectr ; 12(1): e0301423, 2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-38014967

RESUMO

IMPORTANCE: The multiplex-crRNA CRISPR/Cas12a detection method saves hands-on time, reduces the risk of aerosol pollution, and can be directly applied to detecting silkworms infected with Nosema bombycis. This study provides a new approach for the inspection and quarantine of silkworm pébrine disease in sericulture and provides a new method for the detection of other pathogens.


Assuntos
Bombyx , Microsporidiose , Nosema , Animais , Sistemas CRISPR-Cas , RNA Guia de Sistemas CRISPR-Cas , Nosema/genética
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