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1.
Int J Syst Evol Microbiol ; 70(11): 5734-5739, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32941130

RESUMO

Novel catalase-negative, Gram-stain-positive, beta-haemolytic, coccus-shaped organisms were isolated from Chacoan peccaries that died from respiratory disease. The initial API 20 Strep profiles suggested Streptococcus agalactiae with acceptable identification scores, but the 16S rRNA gene similarity (1548 bp) to available sequences of streptococci was below 98 %. Next taxa of the genus Streptococcus, displaying highest similarities to the strains from this study, were S. bovimastitidis NZ1587T (97.5 %), S. iniae ATCC 29178T (97.5 %), S. hongkongensis HKU30T (97.4 %), S. parauberis DSM 6631T (97.1 %), S. penaeicida CAIM 1838T (97.1 %), S. pseudoporcinus DSM 18513T (97.0 %), S. didelphis DSM 15616T (96.6 %), S. ictaluri 707-05T (96.6 %), S. uberis JCM 5709T (96.5 %) and S. porcinus NCTC 10999T (96.4 %). All other Streptococcus species had sequence similarities of below 96.4 %. A sodA gene as well as whole genome-based core genome phylogeny of three representative strains and 145 available Streptococcus genomes confirmed the unique taxonomic position. Interstrain average nucleotide identity (ANI) and amino acid identity (AAI) values were high (ANI >96 %; AAI 100%), but for other streptococci clearly below the proposed species boundary of 95-96 % (ANI <75 %; AAI <83 %). Results were confirmed by genome-to-genome distance calculations. Pairwise digital DNA-DNA hybridization estimates were high (>90 %) between the novel strains, but well below the species boundary of 70 % for closely related Streptococcus type strains (23.5-19.7 %). Phenotypic properties as obtained from extended biochemical profiles and MALDI-TOF mass spectrometry supported the outstanding rank. Based on the presented molecular and physiological data of the six strains, we propose a novel taxon for which we suggest the name Streptococcus catagoni sp. nov. with the type strain 99-1/2017T (=DSM 110457T=CCUG 74072T) and five reference strains.


Assuntos
Artiodáctilos/microbiologia , Infecções Bacterianas/veterinária , Filogenia , Sistema Respiratório/microbiologia , Infecções Respiratórias/veterinária , Streptococcus/classificação , Animais , Animais de Zoológico/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Feminino , Genes Bacterianos , Alemanha , Masculino , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Infecções Respiratórias/microbiologia , Análise de Sequência de DNA , Streptococcus/isolamento & purificação
2.
Res Vet Sci ; 132: 426-438, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32777539

RESUMO

The current work investigated the discriminatory potential of MALDI-TOF MS fingerprinting towards most-relevant major (Streptococcus agalactiae, S. dysgalactiae, S. uberis) and minor (S. canis, S. parauberis, S. salivarius, S. equinus and S. gallolyticus) streptococci involved in bovine mastitis (BM), in comparison to 16S rRNA gene sequencing (GS)-based identification. The MALDI-TOF MS-generated spectral fingerprints were recruited for eliciting a detailed proteomic map that demonstrated clear variability for inter- and intra-species-specific biomarkers. Besides, a phyloproteomic dendrogram was evolved and comparatively analyzed against the phylogenetic one obtained from 16S rRNA GS in order to assess the differentiation of streptococci of bovine origin based on variability of protein fingerprints versus the variation of 16S rRNA gene homology. Results showed that the discrimination of BM-implicated streptococci can be obtained by both approaches; however MALDI-TOF MS was superior, achieving more variability at both intra- and sub-species levels. MALDI-TOF MS spectral analytics revealed that Streptococcus spp. exhibited three genus-specific biomarkers (peaks with m/z values at 2112, 4452 and 5955) and all streptococci exhibited spectral variability at both species and subspecies levels. Remarkably, MALDI-TOF MS fingerprinting was found to be at least as robust as 16S rRNA GS-based identification, allowing much cheaper and faster analysis, and additionally exhibiting high reliability for characterization of BM-implicated streptococci, thus proving to be a powerful tool that can be used independently within dairy diagnostics.


Assuntos
Mastite Bovina/microbiologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/veterinária , Infecções Estreptocócicas/veterinária , Streptococcus/fisiologia , Animais , Bovinos , Impressões Digitais de DNA/veterinária , Feminino , Filogenia , RNA Ribossômico 16S/análise , Análise de Sequência de RNA/veterinária , Infecções Estreptocócicas/microbiologia , Streptococcus/classificação , Streptococcus/isolamento & purificação
3.
Niger J Clin Pract ; 23(7): 900-905, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32620717

RESUMO

Objectives: This study aims to investigate the effects of various mouthwashes on bacteremia development following a debonding process, which is performed after orthodontic treatment. Subjects and Methods: The study included patients who received fixed orthodontic treatment and were indicated for debonding. A total of 40 patients in four groups were selected for the study; no mouthwash (Group 1), mouthwash containing 0.12% chlorhexidine-gluconate (Group 2), mouthwash containing essential-oils (Group 3), and mouthwash containing 7.5% povidone-iodine (Group 4). Before (T0) and following (T1) the debonding procedure, blood samples were obtained from the patients. Then, the blood samples were placed in blood culture bottles to investigate bacterial growth. Results: Based on the results of the study, it was determined that the blood samples obtained at T0did not indicate any bacterial growth. Furthermore, it was observed that the blood samples obtained at T1included Streptococcus viridans, Streptococcus oralis, Streptococcus mutans, and Staphylococcus aereus growth, respectively, in 4 patients from Group 1 while Streptococcus salivarius growth was observed in 1 patient from Group 3 in addition to Streptococcus mitis growth in 1 patient from Group 4. No bacterial growth was observed in Group 2. While the results obtained between Group 1 and Group 2 were statistically significant, no statistically significant difference was observed between other groups. Conclusions: Finally, it was determined that the mouthwash 0.12% chlorhexidine-gluconate was statistically significant in comparison to the control group. It can be concluded that this mouthwash can be used to decrease bacterial density in oral flora before debonding procedures.


Assuntos
Anti-Infecciosos Locais/farmacologia , Bacteriemia/tratamento farmacológico , Clorexidina/análogos & derivados , Antissépticos Bucais/farmacologia , Staphylococcus/efeitos dos fármacos , Streptococcus/efeitos dos fármacos , Adulto , Clorexidina/farmacologia , Descolagem Dentária , Feminino , Humanos , Masculino , Staphylococcus/classificação , Staphylococcus/isolamento & purificação , Streptococcus/classificação , Streptococcus/isolamento & purificação , Resultado do Tratamento
4.
Int J Syst Evol Microbiol ; 70(7): 4098-4104, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32539911

RESUMO

A new α-haemolytic streptococcal strain has been isolated from the dental plaque of a teenager with Down syndrome. Genetic and taxonomic analyses place this Streptococcus within the oralis group. It is a Gram-stain-positive, non-motile, non-spore-forming spherical alpha-haemolytic coccus arranged in chains, and it ferments a large number of monosaccharides and disaccharides, as well as polymeric carbohydrates. It differs biochemically from closely related species of Streptococcus due to its production of α-galactosidase, ß-galactosidase and N-acetyl-ß-d-glucosaminidase and by the absence of arginine dihydrolase deiminase and IgA1-protease. It grows in a temperature range of 25 to 40 °C (optimal growth temperature at 37 °C) and in a pH range of 4.5 to 8 (optimal pH at 7.0). A phylogenetic analysis based on its 16S and 23S rRNA gene sequences placed it close to Streptococcus dentisani CECT 7747T. The ANIb and ANIm values were 93.19 and 93.61 %, respectively, both below the accepted threshold to designate it as a new species of bacteria. A phylogenetic tree based on its core genome placed it close to Streptococcus oralis subsp. dentisani strain CECT 7747T with a distance in the expanded core phylogeny of 0.1298. The in silico DNA-DNA hybridization value was 52.2 % with respect to the closest species, S. oralis subsp. dentisani CECT 7747T. Based on these data, a new species of bacteria within the genus Streptococcus, family Streptococcaceae and order Lactobacillales is described, for which the name of Streptococcus downii sp. nov. is proposed (type strain CECT 9732T=CCUG 73139T).


Assuntos
Placa Dentária/microbiologia , Síndrome de Down , Boca/microbiologia , Filogenia , Streptococcus/classificação , Adolescente , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Humanos , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , Análise de Sequência de DNA , Streptococcus/isolamento & purificação
5.
Acta Vet Scand ; 62(1): 26, 2020 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-32493395

RESUMO

BACKGROUND: Streptococcus halichoeri infections have been reported in grey seals, a European badger, a Stellar sea lion and humans, but its presence in companion and fur animals is unknown. Since 2010, S. halichoeri-like bacteria (SHL) have been isolated from fur animals and dogs in Finland. Our aim was to retrospectively investigate laboratory records for SHL from canine and fur animal infections, characterize the isolates and compare their genetic relatedness in relation to three reference strains: CCUG 48324T, originating from a grey seal, and strains 67100 and 61265, originally isolated from humans. RESULTS: A total of 138 and 36 SHLs from canine and fur animal infections, respectively, were identified in the laboratory records. SHL was commonly associated with skin infections, but rarely as the only species. A set of 49 canine and 23 fur animal SHLs were further characterized. MALDI-TOF confirmed them as being S. halichoeri. The growth characteristics were consistent with the original findings, but isolates were catalase positive. In total, 17 distinct API 20 Strep patterns were recorded among all 75 isolates tested, of which pattern 5563100 was the most common (n = 30). Antimicrobial resistance to erythromycin and clindamycin was common in canine isolates, but rare in fur animal isolates. Three clusters were observed by PFGE, and 16S rRNA sequencing revealed 98.1-100% similarities with the human strains and 98.1-99.5% with the seal strain. A phylogenetic tree of concatenated 16S rRNA and rpoB revealed closely related isolates with two clades. Fifteen canine isolates were identical to the human strains based on concatenated 16S rRNA and rpoB sequencing. CONCLUSIONS: Streptococcus halichoeri appears to be quite a common bacterial species in the skin of dogs and fur animals. The clinical significance of S. halichoeri is uncertain, as it was rarely isolated as a monoculture. No apparent temporal or spatial clustering was detected, but isolates from different sources were genetically very similar. Because many canine isolates were genetically similar to the human reference strains, transmission between dogs and humans may be possible. WGS sequencing of strains from different sources is needed to further investigate the epidemiology and virulence of S. halichoeri.


Assuntos
Doenças do Cão/microbiologia , Raposas , Vison , Cães Guaxinins , Infecções Estreptocócicas/veterinária , Streptococcus/genética , Animais , Cães , Filogenia , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Estudos Retrospectivos , Streptococcus/química , Streptococcus/classificação , Streptococcus/fisiologia
6.
Georgian Med News ; (298): 49-53, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32141848

RESUMO

Chronic and recurrent tonsillitis associated with tonsillitis recurrence, which can greatly affect the quality of life of the patient. Among the causes of chronic infection and resistance to antibiotic treatment are the formation of biofilms in the respiratory tract in respiratory infections. The purpose of the study is to identify the ability to biofilm strains of streptococci on the surface of the epithelial tissue of the oropharynx isolated from patients with recurrent tonsillitis. Clinical strains of Streptococcus spp bacteria obtained from the oropharynx of 22 children with recurrent tonsillitis were investigated. The biofilm formation ability was studied by growing bacteria on 96-well plates. It was found that 9 (40.09%) strains out of 22 had film-forming ability, among which 1 (4.54%) strains showed strong film-forming, 4 (18.18%) strains-moderate, 4 strain (18.138%). - weak film formation and in 13strains (59.09%) this ability was absent. Studies of the intensity of biofilm formation over three days of cultivation showed a tendency to increase the rate of optical density (OD) in the line: 0,1691±0,019 on the first day (24 h); 0,2159±0,029 in the second (48 h) and in the third - 0,3156±0,055. The degree of severity of the film-forming ability of the studied strains of streptococci isolated from patients with recurrent tonsillitis showed an increase in the optical density (OD) over three days of cultivation, with it fluctuating within 0,1407

Assuntos
Infecções Estreptocócicas/diagnóstico , Streptococcus/isolamento & purificação , Tonsilite/microbiologia , Antibacterianos/uso terapêutico , Biofilmes , Criança , Humanos , Qualidade de Vida , Recidiva , Infecções Estreptocócicas/tratamento farmacológico , Streptococcus/classificação , Streptococcus/patogenicidade , Tonsilectomia/métodos , Tonsilite/diagnóstico , Tonsilite/cirurgia
7.
J Med Microbiol ; 69(4): 576-586, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32125264

RESUMO

Introduction. In some species, the population structure of pathogenic bacteria is clonal. However, the mechanisms that determine the predominance and persistence of specific bacterial lineages of group C Streptococcus remain poorly understood. In Brazil, a previous study revealed the predominance of two main lineages of Streptococcus dysgalactiae subsp. equisimilis (SDSE).Aim. The aim of this study was to assess the virulence and fitness advantages that might explain the predominance of these SDSE lineages for a long period of time.Methodology. emm typing was determined by DNA sequencing. Adhesion and invasion tests were performed using human bronchial epithelial cells (16HBE14o-). Biofilm formation was tested on glass surfaces and the presence of virulence genes was assessed by PCR. Additionally, virulence was studied using Caenorhabditis elegans models and competitive fitness was analysed in murine models.Results. The predominant lineages A and B were mostly typed as emm stC839 and stC6979, respectively. Notably, these lineages exhibited a superior ability to adhere and invade airway cells. Furthermore, the dominant lineages were more prone to induce aversive olfactory learning and more likely to kill C. elegans. In the competitive fitness assays, they also showed increased adaptability. Consistent with the increased virulence observed in the ex vivo and in vivo models, the predominant lineages A and B showed a higher number of virulence-associated genes and a superior ability to accumulate biofilm.Conclusion. These results suggest strongly that this predominance did not occur randomly but rather was due to adaptive mechanisms that culminated in increased colonization and other bacterial properties that might confer increased bacteria-host adaptability to cause disease.


Assuntos
Biodiversidade , Infecções Estreptocócicas/microbiologia , Streptococcus/patogenicidade , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Brasil , Caenorhabditis elegans , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Streptococcus/classificação , Streptococcus/genética , Streptococcus/isolamento & purificação , Virulência
8.
PLoS One ; 15(3): e0229417, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32134941

RESUMO

Streptococcus pneumoniae infections are one of the major causes of morbility and mortality worldwide. Although vaccination and antibiotherapy constitute fundamental and complementary strategies against pneumococcal infections, they present some limitations including the increase in non-vaccine serotypes and the emergence of multidrug-resistances, respectively. Ribosomally-synthesized antimicrobial peptides (i.e. bacteriocins) produced by Lactic Acid Bacteria (LAB) may represent an alternative or complementary strategy to antibiotics for the control of pneumococal infections. We tested the antimicrobial activity of 37 bacteriocinogenic LAB, isolated from food and other sources, against clinical S. pneumoniae strains. Streptococcus infantarius subsp. infantarius LP90, isolated from Venezuelan water-buffalo milk, was selected because of its broad and strong anti-pneumococcal spectrum. The in vitro safety assessment of S. infantarius LP90 revealed that it may be considered avirulent. The analysis of a 19,539-bp cluster showed the presence of 29 putative open reading frames (ORFs), including the genes encoding 8 new class II-bacteriocins, as well as the proteins involved in their secretion, immunity and regulation. Transcriptional analyses evidenced that the induction factor (IF) structural gene, the bacteriocin/IF transporter genes, the bacteriocin structural genes and most of the bacteriocin immunity genes were transcribed. MALDI-TOF analyses of peptides purified using different multichromatographic procedures revealed that the dairy strain S. infantarius LP90 produces at least 6 bacteriocins, including infantaricin A1, a novel anti-pneumococcal two-peptide bacteriocin.


Assuntos
Antibacterianos/metabolismo , Bacteriocinas/genética , Bacteriocinas/metabolismo , Infecções Pneumocócicas/metabolismo , Streptococcus/efeitos dos fármacos , Streptococcus/isolamento & purificação , Sequência de Aminoácidos , Antibacterianos/administração & dosagem , Antibacterianos/isolamento & purificação , Bacteriocinas/administração & dosagem , Bacteriocinas/isolamento & purificação , Humanos , Infecções Pneumocócicas/genética , Infecções Pneumocócicas/microbiologia , Streptococcus/classificação
9.
Int J Syst Evol Microbiol ; 70(4): 2611-2615, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32160144

RESUMO

Five strains of an unidentified Gram-positive, catalase-negative, chain-forming coccus-shaped organism recovered from sheep in Scotland were characterized using phenotypic and molecular taxonomic methods. Based on morphological and biochemical criteria, the strains were tentatively identified as streptococci but they did not appear to correspond to any recognised species of the genus. Comparative 16S rRNA gene sequencing showed the strains were highly related to each other and confirmed their placement in the genus Streptococcus, with a maximum nucleotide identity of around 97 % to extant species. Best matches were with Streptococcus hillyeri followed by Streptococcus porci. Average nucleotide identity and in silico DNA-DNA hybridization values determined from whole-genome sequence were also consistent with the group representing a novel species. Best matches, again seen to S. hillyeri, followed by S. porci and S. plurextorum, were below accepted cut-off values for species delineation. Based on biochemical criteria and molecular genetic evidence, it is proposed that the unknown isolates from sheep be assigned to a new species of the genus Streptococcus as Streptococcus caledonicus sp. nov. The type strain of Streptococcus caledonicus is S784/96/1T=CCUG 73951T=NCTC 14363T.


Assuntos
Filogenia , Pleura/microbiologia , Ovinos/microbiologia , Streptococcus/classificação , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Escócia , Análise de Sequência de DNA , Streptococcus/isolamento & purificação
10.
J Dairy Sci ; 103(5): 4717-4731, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32171518

RESUMO

Mastitis is an important constraint to milk production in pastoralist camel (Camelus dromedarius) herds in Kenya. The objective of this study was to investigate the prevalence, risk factors, and bacterial panorama of subclinical mastitis (SCM) in pastoralist camel herds in Isiolo County, Kenya. Furthermore, antimicrobial susceptibility in udder pathogens was studied. A cross-sectional sample of 206 camels from 20 milking herds was screened using the California Mastitis Test (CMT), and quarter milk was subjected to bacterial culturing. Isolates were confirmed using MALDI-TOF mass spectrometry analysis, and antimicrobial susceptibility was determined using the broth microdilution method. Interviews focusing on herd management were conducted with camel owners. Subclinical mastitis, defined as a CMT score ≥ 3 (scale 1 to 5) and absence of clinical symptoms in the udder, were present in all visited herds. On the individual level, 46% of the camels had at least 1 quarter affected with SCM, and on the quarter level the prevalence was 26%. Intramammary infections (IMI) were common; out of 798 quarter milk samples, 33% yielded conclusive bacterial growth. The sensitivity and specificity of CMT for correctly identifying quarters with IMI were 82% and 92%, respectively. The most prevalent pathogen was Streptococcus agalactiae (72% of IMI-positive quarters), followed by non-aureus staphylococci (19%) and Staphylococcus aureus (13%). Antimicrobial susceptibility testing revealed that only a low proportion (4.9%) of Strep. agalactiae isolates was sensitive to tetracycline. For Staph. aureus, 59.1% of isolates exhibited sensitivity to penicillin. Skin lesions on the teats or udder were a risk factor for SCM. Increased age, parity, and stage of lactation were associated with increased risk of both SCM and IMI. Older camels with a blind teat or a previous history of mastitis were more likely to be infected with Strep. agalactiae. Hygiene routines for milking were largely absent in the observed herds, and knowledge of adequate milk handling was limited. The poor udder health is likely to depend on multiple factors, most prominently the within-herd maintenance of contagious udder pathogens, in combination with difficult sanitary conditions and lack of awareness among camel keepers. This study showed that in pastoralist camel herds around Isiolo town, SCM and IMI specifically caused by Strep. agalactiae are common udder health problems and are associated with increasing age, parity, and stage of lactation, and skin lesions on the teats and udder. Resistance to tetracycline in Strep. agalactiae was common. Control strategies specifically targeting SCM and adapted to pastorally managed camel herds need to be developed to reduce disease, combat antimicrobial resistance, and improve the livelihoods of pastoralists.


Assuntos
Antibacterianos/farmacologia , Camelus/microbiologia , Farmacorresistência Bacteriana , Mastite/veterinária , Leite/microbiologia , Infecções Estafilocócicas/veterinária , Streptococcus/classificação , Animais , Estudos Transversais , Feminino , Geografia , Higiene , Quênia/epidemiologia , Lactação , Glândulas Mamárias Animais/microbiologia , Mastite/epidemiologia , Mastite/microbiologia , Leite/metabolismo , Prevalência , Fatores de Risco , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/classificação , Streptococcus agalactiae/classificação , Tetraciclina/farmacologia
11.
Pediatrics ; 145(4)2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32156773

RESUMO

CONTEXT: Pneumococcal conjugate vaccines (PCVs) (pneumococcal 13-valent conjugate vaccine [PCV-13] and pneumococcal 10-valent conjugate vaccine [PCV-10]) are available for prevention of pneumococcal infections in children. OBJECTIVE: To determine the vaccine effectiveness (VE) of PCV-13 and PCV-10 in preventing invasive pneumococcal disease (IPD) and acute otitis media (AOM) in children <5 years. DATA SOURCES: Systematic searches of Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, Web of Science, and Cochrane. STUDY SELECTION: Eligible studies examined the direct effectiveness and/or efficacy of PCV-10 and PCV-13 in reducing the incidence of disease in healthy children <5 years. DATA EXTRACTION: Two reviewers independently conducted data extraction and methodologic quality assessment. RESULTS: Significant effectiveness against vaccine-type IPD in children ≤5 years was reported for ≥1 dose of PCV-13 in the 3 + 1 (86%-96%) and 2 + 1 schedule (67.2%-86%) and for PCV-10 for the 3 + 1 (72.8%-100%) and 2 + 1 schedules (92%-97%). In children <12 months of age, PCV-13 VE against serotype 19A post-primary series was significant for the 3 + 1 but not the 2 + 1 schedule. PCV-10 crossprotection against 19A was significant in children ≤5 years with ≥1 dose (82.2% and 71%). Neither PCVs were found effective against serotype 3. PCV-13 was effective against AOM (86%; 95% confidence interval [CI]: 61 to 94). PCV-10 was effective against clinically defined (26.9%; 95% CI: 5.9 to 43.3) and bacteriologically confirmed AOM (43.3%; 95% CI: 1.7 to 67.3). LIMITATIONS: Because of the large heterogeneity in studies, a meta-analysis for pooled estimates was not done. CONCLUSIONS: Both PCVs afford protection against pneumococcal infections, with PCV-10 protecting against 19A IPD, but this VE has not been verified in the youngest age groups.


Assuntos
Otite Média/prevenção & controle , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/uso terapêutico , Doença Aguda , Pré-Escolar , Intervalos de Confiança , Humanos , Esquemas de Imunização , Lactente , Sorotipagem , Streptococcus/classificação , Vacinas Conjugadas/uso terapêutico
12.
Microbiol Immunol ; 64(2): 113-122, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31750556

RESUMO

Streptococcus dysgalactiae subsp. equisimilis (SDSE) causes severe invasive streptococcal infections, especially in elderly people. Between 2013 and 2018, 88 streptococci were isolated from clinical blood culture in a hospital in Toyama prefecture, Japan. The collection included six Group A SDSE (ASD) strains, which are rarely isolated. Multilocus sequence typing categorized five of the six strains into ST128 and the remaining strain into a new type. Maximum-likelihood phylogenetic analysis revealed that the six ASD strains had highly similar genome sequences. Bayesian analysis indicated that the most recent common ancestor of the strains appeared 39 years ago. The ASD strains possessed carbohydrate synthase genes that are conserved in Streptococcus pyogenes strains, whereas one strain featured a different arrangement of the gene cluster. The carbohydrate synthase genes varied by Lancefield type (A, C, and G).


Assuntos
Infecções Estreptocócicas , Streptococcus/genética , Idoso , Teorema de Bayes , Sangue/microbiologia , Metabolismo dos Carboidratos/genética , DNA Bacteriano , Resistência Microbiana a Medicamentos/genética , Genoma Bacteriano , Humanos , Japão/epidemiologia , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Filogenia , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/microbiologia , Streptococcus/classificação , Streptococcus/efeitos dos fármacos , Streptococcus/isolamento & purificação , Fatores de Virulência/genética , Sequenciamento Completo do Genoma
13.
J Dairy Sci ; 103(1): 128-140, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31677843

RESUMO

The dairy farm environment influences the raw milk microbiota and consequently affects milk processing. Therefore, it is crucial to investigate farm management practices such as the bedding materials. The aim of this study was to evaluate the effect of recycled manure solids (RMS) as bedding material on bulk tank milk and microbiological implications for cheese quality. Bulk tank samples were collected from 84 dairy farms using RMS or straw bedding. The use of RMS did not influence thermophilic and mesophilic aerobic viable counts from spores. However, straw-milk samples gave higher values for mesophilic anaerobic spore-forming bacteria (0.44 log cfu/mL) than RMS-milk samples (0.17 log cfu/mL). The presence of thermoresistant lactic acid bacteria was not increased in milk from farms using RMS. Nevertheless, taxonomic profiles of thermoresistant bacteria isolated were different between the 2 types of milk. More Enterococcus faecalis and Streptococcus spp. were identified in RMS-milk samples. Thermoresistant enterococci and streptococci could easily end up in cheese. Therefore, milk proteolytic activities of these isolates were tested. Neither Streptococcus spp. nor Enterococcus faecium isolates exhibited proteolytic activities, whereas 53% of E. faecalis showed some. Also, only 1 vancomycin-resistant enterococcus was detected. Survival of selected RMS-milk samples isolates (3 E. faecalis and 1 Streptococcus thermophilus) was evaluated during a model Cheddar cheese manufacture. Although those strains survived well, they did not modify the acidification curve of milk. However, they might cause organoleptic defects during cheese maturing.


Assuntos
Bactérias/classificação , Roupas de Cama, Mesa e Banho/veterinária , Queijo/normas , Leite/microbiologia , Animais , Bactérias/isolamento & purificação , Roupas de Cama, Mesa e Banho/microbiologia , Queijo/microbiologia , Enterococcus/classificação , Enterococcus/isolamento & purificação , Fazendas , Microbiologia de Alimentos , Esterco/microbiologia , Reciclagem , Streptococcus/classificação , Streptococcus/isolamento & purificação , Termotolerância
14.
Infect Dis (Lond) ; 52(1): 54-57, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31621444

RESUMO

Background: Invasive infections with non-beta-haemolytic streptococci (NBHS) is quite common and presents the clinicians with difficulties regarding which patients are at risk for infective endocarditis (IE). The HANDOC score was developed to identify patients with NBHS bacteraemia who are at low risk of IE. This study was conducted to validate HANDOC in an external cohort.Methods: Patients with NBHS in blood cultures between March and September 2016 in a Danish centre were included as part of an on-going study. Patient characteristics were collected to classify bacteria according to Dukés criteria and the components of the HANDOC score were collected retrospectively from the patients' medical records.Results: 68 patients were included in the cohort, of which 16 fulfilled Dukés criteria for IE. All patients with IE (16 of 16) had a HANDOC score above the predefined cut-off. Cases of IE were found in patients with. Streptococcus mitis, Streptococcus bovis, Streptococcus mutans, Streptococcus anginosus, and Streptococcus sanguinis group streptococci. The HANDOC score thus had a sensitivity of 100% and a specificity of 62% in this cohort.Conclusions: HANDOC has a sensitivity of 100% and a relatively high specificity (62%) also in a prospectively enrolled cohort of patients from another country than its origin. This indicates that HANDOC can be implemented in clinical practice to identify patients with a low risk of IE in whom echocardiography can be omitted.


Assuntos
Bacteriemia/diagnóstico , Endocardite Bacteriana/diagnóstico , Infecções Estreptocócicas/diagnóstico , Streptococcus/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Bacteriemia/microbiologia , Hemocultura , Estudos de Coortes , Dinamarca , Endocardite Bacteriana/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Infecções Estreptocócicas/microbiologia , Streptococcus/classificação
15.
BMC Bioinformatics ; 20(Suppl 19): 703, 2019 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-31870283

RESUMO

BACKGROUND: Group B streptococcus (GBS) is an important pathogen that is responsible for invasive infections, including sepsis and meningitis. GBS serotyping is an essential means for the investigation of possible infection outbreaks and can identify possible sources of infection. Although it is possible to determine GBS serotypes by either immuno-serotyping or geno-serotyping, both traditional methods are time-consuming and labor-intensive. In recent years, the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been reported as an effective tool for the determination of GBS serotypes in a more rapid and accurate manner. Thus, this work aims to investigate GBS serotypes by incorporating machine learning techniques with MALDI-TOF MS to carry out the identification. RESULTS: In this study, a total of 787 GBS isolates, obtained from three research and teaching hospitals, were analyzed by MALDI-TOF MS, and the serotype of the GBS was determined by a geno-serotyping experiment. The peaks of mass-to-charge ratios were regarded as the attributes to characterize the various serotypes of GBS. Machine learning algorithms, such as support vector machine (SVM) and random forest (RF), were then used to construct predictive models for the five different serotypes (Types Ia, Ib, III, V, and VI). After optimization of feature selection and model generation based on training datasets, the accuracies of the selected models attained 54.9-87.1% for various serotypes based on independent testing data. Specifically, for the major serotypes, namely type III and type VI, the accuracies were 73.9 and 70.4%, respectively. CONCLUSION: The proposed models have been adopted to implement a web-based tool (GBSTyper), which is now freely accessible at http://csb.cse.yzu.edu.tw/GBSTyper/, for providing efficient and effective detection of GBS serotypes based on a MALDI-TOF MS spectrum. Overall, this work has demonstrated that the combination of MALDI-TOF MS and machine intelligence could provide a practical means of clinical pathogen testing.


Assuntos
Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Streptococcus/classificação , Aprendizado de Máquina , Sorotipagem
16.
Vet Res ; 50(1): 94, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31727180

RESUMO

Although Streptococcus suis has attracted public attention as a major swine and human pathogen, this bacterium has also been isolated from other animals, including ruminants. However, recent taxonomic studies revealed the existence of other species that were previously identified as S. suis, and some of these isolates were reclassified as the novel species Streptococcus ruminantium. In Japan, biochemically identified S. suis is frequently isolated from diseased ruminants; however, such isolates have not yet been identified accurately, and their aetiological importance in ruminants is unclear. Therefore, to understand the importance of S. suis and S. suis-like bacteria in ruminants, we reclassified S. suis isolates from ruminants according to the updated classification and investigated their genetic diversity. Although both S. suis and S. ruminantium were isolated from healthy and diseased ruminants, most of the isolates from diseased animals were S. ruminantium, implying that S. ruminantium is more likely to be associated with ruminant disease than S. suis. However, the ruminant S. suis and S. ruminantium isolates from diseased animals were classified into diverse genotypes rather than belonging to certain clonal groups. Genome sequence analysis of 20 S. ruminantium isolates provided information about the antibiotic resistance, potential virulence, and serological diversity of this species. We further developed an S. ruminantium-specific PCR assay to aid in the identification of this bacterium. The information obtained and the method established in this study will contribute to the accurate diagnosis of ruminant streptococcal infections.


Assuntos
Variação Genética , Genótipo , Infecções Estreptocócicas/veterinária , Streptococcus suis/genética , Streptococcus/genética , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Doenças das Cabras/epidemiologia , Doenças das Cabras/microbiologia , Cabras , Japão/epidemiologia , Prevalência , Ovinos , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/microbiologia , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/microbiologia , Streptococcus/classificação , Streptococcus suis/classificação
17.
Nat Commun ; 10(1): 4927, 2019 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-31666527

RESUMO

Raman optical spectroscopy promises label-free bacterial detection, identification, and antibiotic susceptibility testing in a single step. However, achieving clinically relevant speeds and accuracies remains challenging due to weak Raman signal from bacterial cells and numerous bacterial species and phenotypes. Here we generate an extensive dataset of bacterial Raman spectra and apply deep learning approaches to accurately identify 30 common bacterial pathogens. Even on low signal-to-noise spectra, we achieve average isolate-level accuracies exceeding 82% and antibiotic treatment identification accuracies of 97.0±0.3%. We also show that this approach distinguishes between methicillin-resistant and -susceptible isolates of Staphylococcus aureus (MRSA and MSSA) with 89±0.1% accuracy. We validate our results on clinical isolates from 50 patients. Using just 10 bacterial spectra from each patient isolate, we achieve treatment identification accuracies of 99.7%. Our approach has potential for culture-free pathogen identification and antibiotic susceptibility testing, and could be readily extended for diagnostics on blood, urine, and sputum.


Assuntos
Antibacterianos/uso terapêutico , Bactérias/classificação , Infecções Bacterianas/diagnóstico , Aprendizado Profundo , Análise Espectral Raman/métodos , Bactérias/química , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/microbiologia , Técnicas de Tipagem Bacteriana , Candida/química , Candida/classificação , Enterococcus/química , Enterococcus/classificação , Escherichia coli/química , Escherichia coli/classificação , Humanos , Klebsiella/química , Klebsiella/classificação , Modelos Logísticos , Staphylococcus aureus Resistente à Meticilina/química , Staphylococcus aureus Resistente à Meticilina/classificação , Testes de Sensibilidade Microbiana , Redes Neurais de Computação , Análise de Componente Principal , Proteus mirabilis/química , Proteus mirabilis/classificação , Pseudomonas aeruginosa/química , Pseudomonas aeruginosa/classificação , Salmonella enterica/química , Salmonella enterica/classificação , Análise de Célula Única , Staphylococcus aureus/química , Staphylococcus aureus/classificação , Streptococcus/química , Streptococcus/classificação , Máquina de Vetores de Suporte
18.
PLoS One ; 14(10): e0223719, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31639136

RESUMO

A genotypic characterization of Streptococcus uberis isolated from clinical mastitis (CM) in dairy cows, and the association of Strep. uberis genotypes and antimicrobial susceptibility (AMS) was performed. A total of 89 isolates identified as Strep. uberis from 86 dairy cows with CM in 17 dairy herds of Southeastern Brazil were genotyped using random amplified polymorphic DNA (RAPD) analysis. After genotyping, two clusters (I and II) were created according to RAPD types. A commercial broth microdilution test was used to determine the susceptibility of Strep. uberis isolates to 8 antimicrobials (ampicillin, ceftiofur, cephalothin, erythromycin, penicillin, penicillin+novobiocin, pirlimycin and tetracycline). For each antimicrobial, we determined the minimal inhibitory concentrations that inhibit 50% (MIC50) and 90% (MIC90) of Strep. uberis strains. Differences in AMS among genotypic clusters were evaluated using mixed regression models. Overall, a great polymorphism (56 RAPD-types) was found among Strep. uberis isolates, although a higher genetic similarity (based on the PCR bands features) was observed within herds after genotypic clustering. No differences in AMS were observed among clusters. Strep. uberis isolated from bovine CM were resistant to most antimicrobials, with the exception of cephalothin and penicillin+novobiocin.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Mastite Bovina/microbiologia , Infecções Estreptocócicas/veterinária , Streptococcus/classificação , Streptococcus/genética , Animais , Bovinos , Feminino , Genes Bacterianos , Genótipo , Testes de Sensibilidade Microbiana , Filogenia , Streptococcus/efeitos dos fármacos
19.
Curr Microbiol ; 76(12): 1531-1536, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31570960

RESUMO

A novel facultative anaerobic, Gram-stain-positive coccus, strain JS71T, was isolated from the human subgingival dental plaque of a periodontitis lesion. Phylogenetic analysis based on the 16S ribosomal RNA gene (16S rDNA) revealed that the strain belonged to the genus Streptococcus. The 16S rDNA sequence had high similarity with Streptococcus rubneri DSM 26920T (98.6%), Streptococcus parasanguinis ATCC 15912T (98.5%), and Streptococcus australis CCUG 45919T (98.3%). The genome of strain JS71T was 2,009,592 bp in length. The DNA G+C content of the strain was 42.1 mol%. Average nucleotide identity values between strain JS71T and S. rubneri DSM 26920T, S. parasanguinis ATCC 15912T, and S. australis CCUG 45919T were 88.9%, 80.8%, and 92.4%, respectively. Genome-to-genome distance values between strain JS71TS. rubneri DSM 26920T, S. parasanguinis ATCC 15912T, and S. australis CCUG 45919T were 36.5% (34-39%), 26.3% (23.9-28.7%), and 48.0% (45.4-50.6%), respectively. The major fatty acids of the strain were C16:0 (39.7%), C18:1 ω6c/C18:1 ω7c (15.5%), and C18:0 (10.4%). Based on these results, strain JS71T (= KCOM 2890T = JCM 33454T) should be a novel species of the genus Streptococcus, for which the name Streptococcus koreensis sp. nov. is proposed.


Assuntos
Placa Dentária/microbiologia , Periodontite/microbiologia , Streptococcus/classificação , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Genoma Bacteriano/genética , Humanos , Hibridização de Ácido Nucleico , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Especificidade da Espécie , Streptococcus/química , Streptococcus/citologia , Streptococcus/genética
20.
mBio ; 10(5)2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31481387

RESUMO

From a common ancestor, Streptococcus pneumoniae and Streptococcus mitis evolved in parallel into one of the most important pathogens and a mutualistic colonizer of humans, respectively. This evolutionary scenario provides a unique basis for studies of both infection-associated properties and properties important for harmonious coexistence with the host. We performed detailed comparisons of 60 genomes of S. pneumoniae, S. mitis, Streptococcus pseudopneumoniae, the three Streptococcus oralis subspecies oralis, tigurinus, and dentisani, and Streptococcus infantis Nonfunctional remnants of ancestral genes in both S. pneumoniae and in S. mitis support the evolutionary model and the concept that evolutionary changes on both sides were required to reach their present relationship to the host. Confirmed by screening of >7,500 genomes, we identified 224 genes associated with virulence. The striking difference to commensal streptococci was the diversity of regulatory mechanisms, including regulation of capsule production, a significantly larger arsenal of enzymes involved in carbohydrate hydrolysis, and proteins known to interfere with innate immune factors. The exclusive presence of the virulence factors in S. pneumoniae enhances their potential as vaccine components, as a direct impact on beneficial members of the commensal microbiota can be excluded. In addition to loss of these virulence-associated genes, adaptation of S. mitis to a mutualistic relationship with the host apparently required preservation or acquisition of 25 genes lost or absent from S. pneumoniae Successful adaptation of S. mitis and other commensal streptococci to a harmonious relationship with the host relied on genetic stability and properties facilitating life in biofilms.IMPORTANCE Streptococcus pneumoniae is one of the most important human pathogens but is closely related to Streptococcus mitis, with which humans live in harmony. The fact that the two species evolved from a common ancestor provides a unique basis for studies of both infection-associated properties and properties important for harmonious coexistence with the host. By detailed comparisons of genomes of the two species and other related streptococci, we identified 224 genes associated with virulence and 25 genes unique to the mutualistic species. The exclusive presence of the virulence factors in S. pneumoniae enhances their potential as vaccine components, as a direct impact on beneficial members of the commensal microbiota can be excluded. Successful adaptation of S. mitis and other commensal streptococci to a harmonious relationship with the host relied on genetic stability and properties facilitating life in biofilms.


Assuntos
Hibridização Genômica Comparativa , Genes Bacterianos/genética , Genoma Bacteriano/genética , Streptococcus/genética , Fatores de Virulência/genética , Fatores de Virulência/isolamento & purificação , Evolução Biológica , Endocardite/microbiologia , Humanos , Streptococcus/classificação , Streptococcus/fisiologia , Streptococcus mitis/genética , Streptococcus oralis/genética , Streptococcus pneumoniae/genética , Simbiose , Virulência/genética
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