RESUMO
BACKGROUND: Corynebacterium spp. are widely disseminated in the environment, and they are part of the skin and mucosal microbiota of animals and humans. Reports of human infections by Corynebacterium spp. have increased considerably in recent years and the appearance of multidrug resistant isolates around the world has drawn attention. OBJECTIVES: To describe a new species of Corynebacterium from human tissue bone is described after being misidentified using available methods. METHODS: For taxonomic analyses, phylogenetic analysis of 16S rRNA and rpoB genes, in silico DNA-DNA hybridization, average nucleotide and amino acid identity, multilocus sequence analysis, and phylogenetic analysis based on the complete genome were used. FINDINGS: Genomic taxonomic analyzes revealed values of in silico DNA-DNA hybridization, average nucleotide and amino acids identity below the values necessary for species characterization between the analyzed isolates and the closest phylogenetic relative Corynebacterium aurimucosum DSM 44532T. MAIN CONCLUSIONS: Genomic taxonomic analyzes indicate that the isolates analyzed comprise a new species of the Corynebacterium genus, which we propose to name Corynebacterium hiratae sp. nov. with isolate 332T (= CBAS 826T = CCBH 35,014T) as the type strain.
Assuntos
Infecções por Corynebacterium , Corynebacterium , DNA Bacteriano , Filogenia , RNA Ribossômico 16S , Corynebacterium/genética , Corynebacterium/classificação , Corynebacterium/isolamento & purificação , Humanos , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Infecções por Corynebacterium/microbiologia , Osso e Ossos/microbiologia , Tipagem de Sequências Multilocus , Genoma Bacteriano , Técnicas de Tipagem Bacteriana , Hibridização de Ácido NucleicoRESUMO
This study reports the virome investigation of pollinator species and other floral visitors associated with plants from the south of Bahia: Aphis aurantii, Atrichopogon sp., Dasyhelea sp., Forcipomyia taiwana, and Trigona ventralis hoozana. Studying viruses in insects associated with economically important crops is vital to understand transmission dynamics and manage viral diseases that pose as threats for global food security. Using literature mining and public RNA next-generation sequencing data deposited in the NCBI SRA database, we identified potential vectors associated with Malvaceae plant species and characterized the microbial communities resident in these insects. Bacteria and Eukarya dominated the metagenomic analyses of all taxon groups. We also found sequences showing similarity to elements from several viral families, including Bunyavirales, Chuviridae, Iflaviridae, Narnaviridae, Orthomyxoviridae, Rhabdoviridae, Totiviridae, and Xinmoviridae. Phylogenetic analyses indicated the existence of at least 16 new viruses distributed among A. aurantii (3), Atrichopogon sp. (4), Dasyhelea sp. (3), and F. taiwana (6). No novel viruses were found for T. ventralis hoozana. For F. taiwana, the available libraries also allowed us to suggest possible vertical transmission, while for A. aurantii we followed the infection profile along the insect development. Our results highlight the importance of studying the virome of insect species associated with crop pollination, as they may play a crucial role in the transmission of viruses to economically important plants, such as those of the genus Theobroma, or they will reduce the pollination process. This information may be valuable in developing strategies to mitigate the spread of viruses and protect the global industry.
Assuntos
Viroma , Vírus , Humanos , Abelhas , Animais , Filogenia , Insetos , Vírus/genética , Produtos AgrícolasRESUMO
Non-diphtheria Corynebacterium species (NDC) belonging to the human skin and mucosa microbiota are frequently neglected as contaminants. However, reports of human infections by Corynebacterium spp. have increased considerably in recent years. In this study, a group of six NDC isolates of urine (n = 5) and sebaceous cyst (n = 1) from two South American countries were identified at genus level or misidentified based on API® Coryne and genetic/molecular analyses. The 16S rRNA (99.09-99.56%) and rpoB (96.18-97.14%) gene sequence similarities of the isolates were higher when compared with Corynebacterium aurimucosum DSM 44532 T. Multilocus sequence analysis (MLSA) indicated that these six NDC isolates compose a distinctive phylogenetic clade. Genome-based taxonomic analysis with the whole-genome sequences was able to separate these six isolates from other known Corynebacterium type strains. Average nucleotide identity (ANI), average amino acid identity (AAI), and digital DNA-DNA hybridization (dDDH) values between closely related type strains and the six isolates were considerably lower than the currently recommended threshold values for species circumscription. Phylogenetic and genomic taxonomy analyses indicated these microorganisms as a novel Corynebacterium species, for which we formally propose the name Corynebacterium guaraldiae sp. nov. with isolate 13T (= CBAS 827T = CCBH 35012T) as type strain.
Assuntos
Corynebacterium , DNA , Humanos , Análise de Sequência de DNA , Filogenia , RNA Ribossômico 16S/genética , Corynebacterium/genética , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Ácidos Graxos/química , Hibridização de Ácido NucleicoRESUMO
BACKGROUND: Allergen-specific immunotherapy (AIT) is the only disease-modifying treatment approach to change disease-causing allergens. Hypoallergenic derivatives show promise as potential therapeutics, amongst which BTH2 was designed to induce tolerance against Blomia tropicalis allergy. Our aim was to investigate the hypoallergenicity and immunoregulatory activity of BTH2 in vitro and its therapeutic potential in a mouse model of AIT. METHODS: Recombinant Blo t 5 and Blo t 21 allergens and their hybrid derivatives (BTH1 and BTH2) were expressed and purified. IgE binding capacity was tested by ELISA using sera from Brazilian, Colombian, and Ecuadorian subjects. Secretion of cytokines in supernatants from human cell cultures was measured following stimulation with the four recombinants and controls. The capacity of BTH2 to ameliorate allergic airway inflammation induced by B. tropicalis extract was evaluated in a murine model of AIT. RESULTS: rBlo t 5 and rBlo t 21 were identified as major allergens in Latin American patients, and BTH2 had the lowest IgE binding. In vitro stimulation of human cells induced greater levels of IL-10 and IFN-γ and reduced the secretion of Th2 cytokines. BTH2 ameliorated allergic airway inflammation in B. tropicalis-challenged A/J mice, as evidenced by the histopathological and humoral biomarkers: decreased Th2 cytokines and cellular infiltration (especially eosinophils), lower activity of eosinophil peroxidase, an increase in IgG blocking antibodies and strong reduction of mucus production by goblet cells. CONCLUSIONS: Our study shows that BTH2 represents a promising candidate for the treatment of B. tropicalis allergy with hypoallergenic, immune regulatory and therapeutic properties. Further pre-clinical studies are required in murine models of chronic asthma to further address the efficacy and safety of BTH2 as a vaccine against B. tropicalis-induced allergy.
Assuntos
Hipersensibilidade , Humanos , Camundongos , Animais , Modelos Animais de Doenças , Hipersensibilidade/terapia , Alérgenos , Inflamação , Citocinas , Dessensibilização Imunológica , Imunoglobulina ERESUMO
BACKGROUND: Allergen-specific immunotherapy (AIT) is the only clinical approach that can potentially cure some allergic diseases by inducing immunological tolerance. Dermatophagoides pteronyssinus is considered as the most important source of mite allergens worldwide, with high sensitization rates for the major allergens Der p 1, Der p 2 and Der p 23. The aim of this work is to generate a hypoallergenic hybrid molecule containing T-cell epitopes from these three major allergens. METHODS: The hybrid protein termed Der p 2231 containing T-cell epitopes was purified by affinity chromatography. The human IgE reactivity was verified by comparing those with the parental allergens. The hybrid was also characterized immunologically through an in vivo mice model. RESULTS: The hybrid rDer p 2231 stimulated in peripheral blood mononuclear cells (PBMCs) isolated from allergic patients with higher levels of IL- 2, IL-10, IL-15 and IFN-γ, as well as lower levels of IL-4, IL-5, IL-13, TNF-α and GM-CSF. The use of hybrid molecules as a therapeutic model in D. pteronyssinus allergic mice led to the reduction of IgE production and lower eosinophilic peroxidase activity in the airways. We found increased levels of IgG antibodies that blocked the IgE binding to the parental allergens in the serum of allergic patients. Furthermore, the stimulation of splenocytes from mice treated with rDer p 2231 induced higher levels of IL-10 and IFN-γ and decreased the secretion of IL-4 and IL-5, when compared with parental allergens and D. pteronyssinus extract. CONCLUSIONS: rDer p 2231 has the potential to be used in AIT in patients co-sensitized with D. pteronyssinus major allergens, once it was able to reduce IgE production, inducing allergen-specific blocking antibodies, restoring and balancing Th1/Th2 immune responses, and inducing regulatory T-cells.
Assuntos
Antígenos de Dermatophagoides , Epitopos de Linfócito T , Hipersensibilidade , Animais , Humanos , Camundongos , Alérgenos , Antígenos de Dermatophagoides/imunologia , Antígenos de Dermatophagoides/farmacologia , Antígenos de Dermatophagoides/uso terapêutico , Proteínas de Artrópodes , Dermatophagoides pteronyssinus , Epitopos de Linfócito T/química , Epitopos de Linfócito T/uso terapêutico , Hipersensibilidade/tratamento farmacológico , Imunoglobulina E , Interleucina-10 , Interleucina-4 , Interleucina-5 , Leucócitos Mononucleares , Pyroglyphidae , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Imunoterapia/métodosRESUMO
Successful research in the wide-ranging field of allergy is usually achieved by definition not only of physicochemical and immunological properties of natural, but also recombinant allergens. Blomia tropicalis mite is a well-known source for various groups of hypersensitivity-causing proteins. The goal of the present work was to produce, purify and characterise by in silico, biochemical and immunological methods the recombinant group-12 allergen of B. tropicalis. The recombinant Blo t 12 aggregation capacity as well as the affinity to antibodies from BALB/c immunised mice and B. tropicalis-sensitised human donors were investigated through in silico analyses, dynamic light scattering, SDS-PAGE, ELISA and Western blot. The presence of Blo t 12 within B. tropicalis extracts was also determined by ELISA and Western blot. High concentrations of dimeric rBlo t 12 were detected through SDS-PAGE next to other aggregates and the results were confirmed by data from DLS and Western blot. The YITVM peptide was predicted to be the most aggregation-prone region. The IgE-reactivity of rBlo t 12 was not completely abolished by aggregate formation but it was significantly decreased compared to rBlo t 5, or B. tropicalis extracts. Natural Blo t 12 may naturally dimerises, but it was detected in non-delipidified B. tropicalis extracts in low amounts. Given that this allergen may be a specific marker for B. tropicalis allergy, the recombinant Blo t 12 herein obtained is characterised as a mid-tier allergen in Brazilian atopic patients and may be useful for the improvement in precision allergy molecular diagnostic applications.
Assuntos
Alérgenos/isolamento & purificação , Ácaros/metabolismo , Alérgenos/genética , Alérgenos/imunologia , Animais , Escherichia coli/genética , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Proteínas RecombinantesRESUMO
An 11-year-old male mixed-breed cat, with exclusively indoor life, presented 3 cough episodes after the owners tested positive by RT-PCR for SARS-CoV-2. The house is inhabited by 5 people (3 adults and 2 children), and 2 of the adults have shown mild symptoms associated with throat discomfort. The cat was vaccinated, had no history of any previous disease, and tested negative for feline coronavirus (FCoV), feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). Rectal sample collected from the cat was positive for SARS-CoV-2 by RT-PCR. Viral genome sequences recovered from human and cat samples showed an average 99.4% sequence identity. This is the first report of genome sequences of SARS-CoV-2 recovered from a cat and its owner in Latin America.
Assuntos
COVID-19 , Doenças do Gato , Gatos/virologia , SARS-CoV-2/isolamento & purificação , Animais , COVID-19/veterinária , Doenças do Gato/virologia , Humanos , Vírus da Imunodeficiência Felina , América Latina , Vírus da Leucemia Felina , MasculinoRESUMO
Toxocariasis, a natural helminth infection of dogs and cats caused by Toxocara canis and T. cati, respectively, that are transmitted to mammals, including humans. Infection control is based currently on periodic antihelmintic treatment and there is a need for the development of vaccines to prevent this infection. MATERIALS AND METHODS: Eight potential vaccine candidate T. canis recombinant proteins were identified by in silico (rTcGPRs, rTcCad, rTcVcan, rTcCyst) and larval proteomics (rTES26, rTES32, rMUC-3 and rCTL-4) analyses. Immunogenicity and protection against infectious challenge for seven of these antigens were determined in a murine model of toxocariasis. C57BL/6 female mice were immunized with each of or combinations of recombinant antigens prior to challenge with 500 T. canis embryonated eggs. Levels of specific antibodies (IgG, IgG1, IgG2a and IgE) in sera and cytokines (IL-5, INF-ɣ and IL-10) produced by antigens-stimulated splenocytes, were measured. Presence of specific antibodies to the molecules was measured in sera of T. canis-seropositive dogs and humans. RESULTS: All seven molecules were immunogenic in immunized mice; all stimulated significantly elevated levels of specific IgG, IgG1 or IgG2a and six were associated with elevated levels of specific IgE; all induced elevated production of IFN- ɣ and IL-10 by splenocytes, but only the in silico-identified membrane-associated recombinants (rTcCad, rTcVcan, and rTcCyst) induced significantly increased IL-5 production. Vaccination with two of the latter (rTcCad and rTcVcan) reduced larval loads in the T. canis challenged mice by 54.3% and 53.9% (P < 0.0001), respectively, compared to unimmunized controls. All seven recombinants were recognized by T. canis-seropositive dog and human sera. CONCLUSION: The identification of vaccine targets by in silico analysis was an effective strategy to identify immunogenic T. canis proteins capable of reducing larval burdens following challenge with the parasite. Two recombinant proteins, rTcCad and rTcVcan, were identified as promising vaccine candidates for canine toxocariasis.
Assuntos
Doenças do Gato , Doenças do Cão , Toxocara canis , Toxocaríase , Animais , Gatos , Modelos Animais de Doenças , Cães , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Recombinantes/genética , Toxocaríase/prevenção & controleRESUMO
Introduction: Allergic illnesses are one of the most prevalent immunological disorders worldwide and house dust mites are important triggers of these diseases. Allergen-specific immunotherapy (AIT) is an alternative treatment to pharmacotherapy and among its technologies, recombinant hypoallergenic derivatives have shown promising features, turn them into safer and more efficient allergy vaccines.Areas covered: Patents and scientific publications referring to advances in the design of Dermatophagoides spp. hypoallergenic molecules. Data were obtained from the Espacenet® and PubMed websites, using different key terms, advanced tools and Boolean operators for searches. The retrieved data were then descriptively analyzed, taking into consideration clinical targets, geographical, temporal, collaborative, and different classification aspects of the productions.Expert opinion: Joint advances of molecular biology, genetic engineering, and bioinformatics technologies led to progresses in the design of Dermatophagoides spp. hypoallergenic derivatives. Collaborative networks seem to be an interesting way not only to improve technologies in AIT but also to boost the number of patents, publications, and grants for researchers. The observed trend for the use of hypoallergenic hybrid molecules was a fundamental AIT advance and this type of molecule appears to be a more attractive product for companies and more convenient, efficient, and safer allergy immunotherapy for patients.
Assuntos
Dessensibilização Imunológica/métodos , Hipersensibilidade/terapia , Pyroglyphidae/imunologia , Alérgenos/imunologia , Animais , Humanos , Hipersensibilidade/imunologia , Patentes como AssuntoRESUMO
Corynebacterium diphtheriae, Corynebacterium ulcerans and Corynebacterium pseudotuberculosis constitute a group of potentially toxigenic microorganisms that are related to different infectious processes in animal and human hosts. Currently, there is a lack of information on the prevalence of disease caused by these pathogens, which is partially due to a reduction in the frequency of routine laboratory testing. In this study, a multiplex polymerase chain reaction (mPCR) assay that can simultaneously identify and determine the toxigenicity of these corynebacterial species with zoonotic potential was developed. This assay uses five primer pairs targeting the following genes: rpoB (Corynebacterium spp), 16S rRNA (C. ulcerans and C. pseudotuberculosis), pld (C. pseudotuberculosis), dtxR (C. diphtheriae) and tox [diphtheria toxin (DT) ]. In addition to describing this assay, we review the literature regarding the diseases caused by these pathogens. Of the 213 coryneform strains tested, the mPCR results for all toxigenic and non-toxigenic strains of C . diphtheriae, C. ulcerans and C. pseudotuberculosis were in 100% agreement with the results of standard biochemical tests and PCR-DT. As an alternative to conventional methods, due to its advantages of specificity and speed, the mPCR assay used in this study may successfully be applied for the diagnosis of human and/or animal diseases caused by potentially toxigenic corynebacterial species.