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1.
Res Vet Sci ; 138: 109-115, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34126449

RESUMO

Streptococcus agalactiae (GBS) is an important pathogen that has increasingly received attention for its role in invasive infections and its broad host range. Research on the regulation of gene expression could illuminate GBS pathogenesis. We previously identified a novel transcriptional regulator XtgS, which is a negative regulator of GBS pathogenicity. Here, we demonstrate that XtgS overexpression significantly attenuated GBS virulence in zebrafish infection tests, and XtgS indirectly downregulated the transcription of two iron transport systems based on the results of transcriptomic analysis, electrophoretic mobility shift assays (EMSAs) and lacZ fusion assays. Subsequent studies verified that the inactivation of iron transport system 1 resulted in GBS excessive iron accumulation and attenuated virulence. Thus, we infer that the downregulation of iron transport system 1 caused by XtgS overexpression probably attenuates bacterial virulence, which partially clarifies the mechanism by which XtgS alleviates the pathogenesis. These findings provide new insights into the relationship between exogenous transcriptional regulation and bacterial virulence.


Assuntos
Proteínas de Bactérias/genética , Doenças dos Peixes/microbiologia , Ferro/metabolismo , Infecções Estreptocócicas/veterinária , Streptococcus agalactiae/genética , Streptococcus agalactiae/patogenicidade , Fatores de Transcrição/genética , Peixe-Zebra , Animais , Proteínas de Bactérias/metabolismo , Infecções Estreptocócicas/microbiologia , Fatores de Transcrição/metabolismo , Virulência/genética
2.
Ann R Coll Surg Engl ; 103(7): e223-e226, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34192495

RESUMO

Hip disarticulation is the removal of the entire lower limb through the hip joint by detaching the femur from the acetabulum. This major ablative procedure is rarely performed for infection but may be required in severe necrotising fasciitis. We present a single centre retrospective review of all cases of emergency hip disarticulations in patients with necrotising fasciitis between 2010 and 2020. All five patients included in the review presented with acute lower limb pain and sepsis. Three patients had comorbidities predisposing them to necrotising fasciitis. Three were deemed to be high risk and two were at intermediate risk of developing necrotising fasciitis. There were two deaths in the postoperative period. Of the three survivors, two required revision surgery for a completion hindquarter amputation and one for flap closure. All three survivors had good functional outcomes after discharge from hospital. Despite its associated morbidity, emergency amputation of the entire lower limb is a life-saving treatment in cases of rapidly progressing necrotising fasciitis and should be considered as a first-line option in managing this condition.


Assuntos
Desarticulação/métodos , Tratamento de Emergência/métodos , Fasciite Necrosante/cirurgia , Articulação do Quadril/cirurgia , Sepse/prevenção & controle , Infecções Estreptocócicas/cirurgia , Adulto , Idoso de 80 Anos ou mais , Fasciite Necrosante/complicações , Fasciite Necrosante/microbiologia , Fasciite Necrosante/mortalidade , Feminino , Mortalidade Hospitalar , Hospitais de Distrito/estatística & dados numéricos , Hospitais Gerais/estatística & dados numéricos , Humanos , Extremidade Inferior , Masculino , Estudos Retrospectivos , Sepse/microbiologia , Índice de Gravidade de Doença , Infecções Estreptocócicas/complicações , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/mortalidade , Streptococcus/isolamento & purificação , Resultado do Tratamento
3.
Medicine (Baltimore) ; 100(25): e26387, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34160417

RESUMO

RATIONALE: Group B Streptococcus (GBS) remains a principal pathogen causing neonatal sepsis and meningitis, particularly in premature infants with relatively insufficient immunity. Recurrence may occur uncommonly, largely associated with subclinical mucosal persistence or repetitive exposure to exogenous sources. White matter injury (WMI) including cystic periventricular leukomalacia (PVL) has been associated with intrauterine infection/inflammation, and neonatal infection as a more significant predictor including postnatal sepsis and recurrent infection, even without microbial neuroinvasion. Furthermore, clinical and experimental evidence of WMI by some bacteria other than GBS without central nervous system invasion has been reported. However, there is little evidence of WMI associated with neonatal GBS sepsis in the absence of meningitis in the literature. PATIENT CONCERNS: A newborn at 30+4 weeks' gestation with low birthweight presented with 2 episodes (with a 13-day interval with no antibiotic therapy) of neonatal sepsis culture-proven for GBS with early-onset presentation after clinical chorioamnionitis via vertical GBS transmission and the associated conditions including prematurity-related neonatal immunodeficiency and persistent mucosal GBS carriage after the first antibiotic treatment. The perinatal GBS infection was complicated by progressive WMI presenting with ventriculomegaly and cystic PVL without a definite evidence of meningitis, intraventricular hemorrhage, and documented cerebral hypoxia or hypoperfusion conditions including septic shock. DIAGNOSES: Recurrent group B streptococcal sepsis and cystic PVL with ventriculomegaly. INTERVENTIONS: Two episodes of GBS sepsis were treated with 15-day parenteral antibiotic therapy, respectively. OUTCOMES: Resolution of the recurrent GBS sepsis without further relapses, however, complicated by WMI and subsequent about 6 months delay in motor development at 12 months' corrected age. LESSONS: This case suggests WMI associated with GBS bacteremia without central nervous system entry by viable GBS and also shows that in premature infants, intrauterine GBS infection with no interventions may lead to extensive and persistent GBS colonization, early-onset and recurrent GBS disease, and WMI. Postnatal as well as intrauterine infection/inflammation controls with maternal prophylaxis may be pivotal for prevention and limiting the magnitude of neurologic injury.


Assuntos
Leucomalácia Periventricular/microbiologia , Sepse Neonatal/microbiologia , Complicações Infecciosas na Gravidez/microbiologia , Infecções Estreptocócicas/complicações , Streptococcus agalactiae/isolamento & purificação , Administração Intravenosa , Antibacterianos/administração & dosagem , Corioamnionite/diagnóstico , Corioamnionite/microbiologia , Deficiências do Desenvolvimento/diagnóstico , Deficiências do Desenvolvimento/microbiologia , Quimioterapia Combinada/métodos , Feminino , Humanos , Hidrocefalia/diagnóstico , Hidrocefalia/microbiologia , Lactente , Recém-Nascido de Baixo Peso , Recém-Nascido , Recém-Nascido Prematuro , Transmissão Vertical de Doenças Infecciosas , Leucomalácia Periventricular/diagnóstico , Leucomalácia Periventricular/patologia , Imageamento por Ressonância Magnética , Masculino , Idade Materna , Sepse Neonatal/diagnóstico , Sepse Neonatal/terapia , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Recidiva , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/transmissão , Substância Branca/diagnóstico por imagem , Substância Branca/microbiologia , Substância Branca/patologia , Adulto Jovem
5.
Fish Shellfish Immunol ; 115: 70-74, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34089887

RESUMO

The polymerization of monomeric antigens can be a strategy to overcome the low immunogenicity of subunit vaccines. IMX313 is a hybrid oligomerization domain of chicken C4bp, and has been demonstrated to have potent activity as adjuvants for the fused antigens in mammals. In the present study, we investigated whether the oligomerization of α-enolase of Streptococcus iniae by fusion with IMX313 affected on antibody induction and on protection against S. iniae infection in olive flounder (Paralichthys olivaceus). The oligomerization of S. iniae enolase by fusion with IMX313 (enolase-IMX313) was verified by non-reducing PAGE, and the antibody titer against enolase in olive flounder immunized with enolase-IMX313 was significantly higher than that in fish immunized with enolase alone. Furthermore, although the survival of olive flounder immunized with enolase alone was low, fish immunized with enolase-IMX313 showed much higher survival (RPS 50%) in accordance with higher serum antibody titer, suggesting that fusion of antigens with IMX313 can be an effective way to enhance protective efficacy of subunit vaccines in olive flounder.


Assuntos
Formação de Anticorpos , Proteínas de Bactérias/genética , Doenças dos Peixes/imunologia , Linguados , Fosfopiruvato Hidratase/genética , Infecções Estreptocócicas/veterinária , Streptococcus iniae/genética , Animais , Anisóis , Proteínas Aviárias/genética , Proteínas de Bactérias/metabolismo , Doenças dos Peixes/microbiologia , Longevidade , Proteínas Adaptadoras de Sinalização NOD/genética , Fosfopiruvato Hidratase/metabolismo , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/microbiologia , Streptococcus iniae/enzimologia , Triazinas , Triazóis
6.
Med J Aust ; 215(1): 36-41, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34091892

RESUMO

OBJECTIVE: To quantify the burden of invasive group A Streptococcus (GAS) disease in Western Australia during 2000-2018. DESIGN, SETTING: Population-based data linkage study: Hospital Morbidity Data Collection (HMDC; all WA public and private hospital records), PathWest pathology data (government-owned pathology services provider), and death registrations. PARTICIPANTS: People with invasive GAS disease, defined by an isolate from a normally sterile site (PathWest) or a hospital-based principal ICD-10-AM diagnosis code (HMDC). MAIN OUTCOME MEASURES: Incidence of invasive GAS disease; median length of hospital stay; all-cause mortality. RESULTS: We identified 2237 cases of GAS disease during 2000-2018; 1283 were in male patients (57%). 1950 cases had been confirmed by GAS isolates from normally sterile tissues (87%; including 1089 from blood [56% of cases] and 750 from tissue [38%]). The age-standardised incidence increased from 2.0 (95% CI, 1.4-2.7) cases per 100 000 population in 2000 to 9.1 (95% CI, 7.9-10.2) cases per 100 000 in 2017 (by year, adjusted for age group and sex: incidence rate ratio [IRR], 1.09; 95% CI, 1.08-1.10). Incidence was consistently higher among Indigenous than non-Indigenous Australians (year-adjusted IRR, 13.1; 95% CI, 11.3-15.1). All-cause 30-day mortality was 5% (116 deaths), and 90-day mortality 7% (156 deaths); 30-day mortality, adjusted for age group and sex, was not statistically significantly different for cases involving Indigenous or non-Indigenous patients (adjusted odds ratio, 0.8; 95% CI, 0.6-1.1). CONCLUSIONS: The incidence of invasive GAS disease in WA increased between 2000 and 2018, particularly among Indigenous Australians. Mandatory notification of invasive GAS disease would therefore be appropriate. The social determinants of differences in incidence should be addressed, and other relevant host, pathogen, and health system factors investigated.


Assuntos
Grupo com Ancestrais Oceânicos/estatística & dados numéricos , Infecções Estreptocócicas/epidemiologia , Streptococcus pyogenes , Adolescente , Adulto , Fatores Etários , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/mortalidade , Austrália Ocidental/epidemiologia , Adulto Jovem
7.
J Zoo Wildl Med ; 52(2): 755-762, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34130423

RESUMO

A multiparous pygmy hippopotamus (Choeropsis liberiensis) dam produced three consecutive calves that died acutely at 13-15 wk of age from bacterial sepsis, for which diagnostic and therapeutic intervention was not possible. Streptococcus iniae (Cases 1 and 3), Escherichia coli (Case 2), and an unidentified member of the family Pasteurellaceae (Case 1) were identified in postmortem tissues through bacterial culture followed by standard and molecular identification methods. After the loss of two calves, a series of vaccinations were administered to the dam during the third pregnancy to enhance transplacental and colostral transfer of antibodies to the calf. The third calf did not survive, and the source of the bacterial infection in these three calves was undetermined. Prior to and after the birth of the fourth calf, nutritional and nutraceutical supplements were provided to the dam and calf. Additionally, pest control around the barn was enhanced. The fourth calf survived. Pygmy hippopotamus calves at the age of 13-15 wk may have increased susceptibility to bacterial infection, possibly due to waning maternally derived immunity. The findings in these cases, combined with a previous association of S. iniae in pygmy hippopotamus deaths, suggest that this bacterium is an especially important pathogen of the endangered pygmy hippopotamus.


Assuntos
Artiodáctilos , Infecções Bacterianas/veterinária , Endotoxemia/veterinária , Infecções por Escherichia coli/veterinária , Sepse/veterinária , Infecções Estreptocócicas/veterinária , Criação de Animais Domésticos , Animais , Animais de Zoológico , Infecções Bacterianas/prevenção & controle , Vacinas Bacterianas/imunologia , Endotoxemia/microbiologia , Escherichia coli , Infecções por Escherichia coli/patologia , Feminino , Masculino , Sepse/microbiologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/patologia , Streptococcus iniae
8.
J Zoo Wildl Med ; 52(2): 858-862, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34130437

RESUMO

A 1-y-old female southern tamandua (Tamandua tetradactyla) presented with vomiting, hyporexia, and neurologic signs. Magnetic resonance imaging revealed contrast-enhancing material within the lateral and fourth ventricles and a T2 hyperintense cerebellar lesion, consistent with meningoencephalitis. The tamandua rapidly declined and was euthanatized. On gross postmortem exam, the tamandua had diffusely injected leptomeninges, opaque fluid in the fourth ventricle, and subdural brainstem and spinal cord hemorrhage. Histologically, there was regionally hemorrhagic and multifocal fibrinosuppurative meningoencephalomyelitis, ventriculitis, choroid plexitis, cerebellar folia necrosis, ependymitis, radiculoneuritis, and abundant intralesional gram-positive cocci. Streptococcus equi ssp. zooepidemicus was cultured from brain, cardiac blood clot, and multiple samples of horsemeat collected from the animal's diet. This is the first report of streptococcal meningoencephalomyelitis in a southern tamandua. The route of infection was likely gastrointestinal inoculation, which may have implications for the routine practice of feeding diets containing raw meat to insectivores.


Assuntos
Ração Animal/microbiologia , Encefalomielite/veterinária , Insetívoros , Carne/microbiologia , Infecções Estreptocócicas/veterinária , Streptococcus equi/isolamento & purificação , Animais , Dieta/veterinária , Encefalomielite/microbiologia , Encefalomielite/patologia , Evolução Fatal , Feminino , Microbiologia de Alimentos , Cavalos , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/patologia
10.
Int J Mol Sci ; 22(11)2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-34072443

RESUMO

As an important zoonotic pathogen, Streptococcus suis (S. suis) infection has been reported to be a causative agent for variety of diseases in humans and animals, especially Streptococcal toxic shock-like syndrome (STSLS), which is commonly seen in cases of severe S. suis infection. STSLS is often accompanied by excessive production of inflammatory cytokines, which is the main cause of death. This calls for development of new strategies to avert the damage caused by STSLS. In this study, we found for the first time that Baicalein, combined with ampicillin, effectively improved severe S. suis infection. Further experiments demonstrated that baicalein significantly inhibited the hemolytic activity of SLY by directly binding to SLY and destroying its secondary structure. Cell-based assays revealed that Baicalein did not exert toxic effects and conferred protection in S. suis-infected cells. Interestingly, compared with ampicillin alone, Baicalein combined with ampicillin resulted in a higher survival rate in mice severely infected with S. suis. At the same time, we found that baicalein can be combined with meropenem against MRSA. In conclusion, these results indicate that baicalein has a good application prospect.


Assuntos
Antibacterianos/farmacologia , Flavanonas/farmacologia , Infecções Estreptocócicas/microbiologia , Streptococcus suis/efeitos dos fármacos , Animais , Antibacterianos/química , Citocinas/biossíntese , Modelos Animais de Doenças , Farmacorresistência Bacteriana/efeitos dos fármacos , Quimioterapia Combinada , Flavanonas/química , Hemólise/efeitos dos fármacos , Interações Hospedeiro-Patógeno , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Conformação Molecular , Infecções Estreptocócicas/tratamento farmacológico , Infecções Estreptocócicas/metabolismo , Infecções Estreptocócicas/patologia , Relação Estrutura-Atividade
11.
Res Vet Sci ; 137: 201-207, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34020335

RESUMO

Streptococcus suis is an important zoonotic pathogen that leads to huge economic losses in the swine industry. Because of the enormous genetic and phenotypic diversity within S. suis, it is necessary to develop effective vaccines to control this zoonotic pathogen. SBP2' is a major pili subunit in S. suis that belongs to an srtBCD pili cluster and has already been reported to be associated with the pathogenesis of this bacterium. In this study, we aimed to evaluate the immunogenicity and protective ability of SBP2'. The rSBP2' protein was expressed by an Escherichia coli expression system and emulsified with Montanide ISA 201 adjuvant to prepare the subunit vaccine. Through active immune assays, the results showed that rSBP2' exhibited good immunogenicity and could protect mice from a lethal dose challenge. Additionally, the qRT-PCR data showed that the transcription levels of cytokines associated with systemic symptoms caused by S. suis were decreased, indicating that immunization with rSBP2' could protect the host from cytokine storms caused by S. suis. Furthermore, the passive immune assay showed that the humoral immunity induced by rSBP2' played an important role against S. suis infection. Taken together, SBP2' could provide proper immune protection against S. suis challenge and could be a candidate for S. suis subunit vaccine. The results of this study could provide new ideas for the development of effective vaccines against S. suis.


Assuntos
Fímbrias Bacterianas/imunologia , Imunogenicidade da Vacina , Infecções Estreptocócicas/prevenção & controle , Vacinas Estreptocócicas/imunologia , Streptococcus suis/imunologia , Animais , Escherichia coli/genética , Camundongos , Camundongos Endogâmicos ICR , Sorogrupo , Infecções Estreptocócicas/microbiologia , Streptococcus suis/genética , Vacinas Sintéticas/imunologia
12.
BMC Infect Dis ; 21(1): 463, 2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-34020607

RESUMO

BACKGROUND: Streptococcus pyogenes causes a profound global burden of morbidity and mortality across its diverse clinical spectrum. To support a new controlled human infection ('challenge') model seeking to accelerate S. pyogenes vaccine development, we aimed to develop an accurate and reliable molecular method for quantifying bacterial load from pharyngeal swabs collected during experimental human pharyngitis. METHODS: Combined sequential RNA + DNA extraction from throat swabs was compared to traditional separate RNA-only and DNA-only extractions. An emm-type specific qPCR was developed to detect the emm75 challenge strain. Results from the qPCR were compared to culture, using throat swab samples collected in a human challenge study. RESULTS: The qPCR was 100% specific for the emm75 challenge strain when tested against a panel of S. pyogenes emm-types and other respiratory pathogens. Combined RNA + DNA extraction had similar yield to traditional separate extractions. The combined extraction method and emm75 qPCR had 98.8% sensitivity compared to culture for throat swabs collected from challenge study participants. CONCLUSIONS: We have developed a reliable molecular method for measuring S. pyogenes bacterial load from throat swabs collected in a controlled human infection model of S. pyogenes pharyngitis. TRIAL REGISTRATION: NCT03361163 on 4th December 2017.


Assuntos
Antígenos de Bactérias/genética , Carga Bacteriana , Proteínas da Membrana Bacteriana Externa/genética , Faringite/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/genética , Adulto , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Seguimentos , Voluntários Saudáveis , Humanos , RNA Bacteriano/genética , RNA Bacteriano/isolamento & purificação , Sensibilidade e Especificidade , Streptococcus pyogenes/classificação , Streptococcus pyogenes/isolamento & purificação
13.
BMC Infect Dis ; 21(1): 408, 2021 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-33941088

RESUMO

BACKGROUND: In non-pregnant adults, the incidence of invasive Group B Streptococcus (GBS) disease is continuously increasing. Elderly and immunocompromised persons are at increased risk of infection. GBS commonly colonizes the vaginal tract, though data on colonization in the elderly are scarce. It is unknown whether the prevalence of GBS colonization is increasing in parallel to the observed rise of invasive infection. We conducted a three-year (2017-2019) prospective observational cross-sectional study in two teaching hospitals in Switzerland to determine the rate of GBS vaginal colonization in women over 60 years and i) to compare the proportions of known risk factors associated with invasive GBS diseases in colonized versus non-colonized women and ii) to evaluate the presence of GBS clusters with specific phenotypic and genotypic patterns in this population. METHODS: GBS screening was performed by using vaginal swabs collected during routine examination from women willing to participate in the study and to complete a questionnaire for risk factors. Isolates were characterized for antibiotic resistance profile, serotype and sequence type (ST). RESULTS: The GBS positivity rate in the elderly was 17% (44/255 positive samples), and similar to the one previously reported in pregnant women (around 20%). We could not find any association between participants' characteristics, previously published risk factors and GBS colonization. All strains were susceptible to penicillin, 22% (8/36) were not susceptible to erythromycin, 14% (5/36) were not susceptible to clindamycin and 8% (3/36) showed inducible clindamycin resistance. Both M and L phenotypes were each detected in one isolate. The most prevalent serotypes were III (33%, 12/36) and V (31%, 11/36). ST1 and ST19 accounted for 11% of isolates each (4/36); ST175 for 8% (3/36); and ST23, ST249 and ST297 for 6% each (2/36). Significantly higher rates of resistance to macrolides and clindamycin were associated with the ST1 genetic background of ST1. CONCLUSIONS: Our findings indicate a similar colonization rate for pregnant and elderly women. TRIAL REGISTRATION: Current Controlled Trial ISRCTN15468519 ; 06/01/2017.


Assuntos
Infecções Estreptocócicas/microbiologia , Streptococcus agalactiae/efeitos dos fármacos , Streptococcus agalactiae/isolamento & purificação , Vagina/microbiologia , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Estudos Transversais , Farmacorresistência Bacteriana/efeitos dos fármacos , Feminino , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Gravidez , Prevalência , Estudos Prospectivos , Sorogrupo , Infecções Estreptocócicas/epidemiologia , Streptococcus agalactiae/classificação , Streptococcus agalactiae/genética , Suíça/epidemiologia
14.
PLoS One ; 16(4): e0248201, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33914767

RESUMO

Streptococcus pyogenes or group A Streptococcus (GAS) is a leading cause of bacterial pharyngitis, skin and soft tissue infections, life-threatening invasive infections, and the post-infectious autoimmune syndromes of acute rheumatic fever and post-streptococcal glomerulonephritis. Genetic manipulation of this important pathogen is complicated by resistance of the organism to genetic transformation. Very low transformation efficiency is attributed to recognition and degradation of introduced foreign DNA by a type I restriction-modification system encoded by the hsdRSM locus. DNA sequence analysis of this locus in ten GAS strains that had been previously transformed with an unrelated plasmid revealed that six of the ten harbored a spontaneous mutation in hsdR, S, or M. The mutations were all different, and at least five of the six were predicted to result in loss of function of the respective hsd gene product. The unexpected occurrence of such mutations in previously transformed isolates suggested that the process of transformation selects for spontaneous inactivating mutations in the Hsd system. We investigated the possibility of exploiting the increased transformability of hsd mutants by constructing a deletion mutation in hsdM in GAS strain 854, a clinical isolate representative of the globally dominant M1T1 clonal group. Mutant strain 854ΔhsdM exhibited a 5-fold increase in electrotransformation efficiency compared to the wild type parent strain and no obvious change in growth or off-target gene expression. We conclude that genetic transformation of GAS selects for spontaneous mutants in the hsdRSM restriction modification system. We propose that use of a defined hsdM mutant as a parent strain for genetic manipulation of GAS will enhance transformation efficiency and reduce the likelihood of selecting spontaneous hsd mutants with uncharacterized genotypes.


Assuntos
Proteínas de Bactérias/genética , Enzimas de Restrição-Modificação do DNA/genética , Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/genética , Transformação Genética , Regulação Bacteriana da Expressão Gênica , Loci Gênicos , Humanos , Modelos Moleculares , Mutação , Streptococcus pyogenes/patogenicidade , Virulência
15.
Fish Shellfish Immunol ; 113: 162-175, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33857622

RESUMO

Streptococcosis and motile aeromonad septicemia (MAS) are well-known diseases in tilapia culture, which cause mass mortality with significant economic losses. The development of feed-based bivalent vaccines in controlling these diseases has been initiated, however, the mechanisms of immunities and cross-protection in fish remain unclear. This study was conducted to assess the immuno-protective as well as the cross-protective efficacy of a newly developed feed-based bivalent vaccine against Streptococcus and Aeromonas infections in red hybrid tilapia. A total of five groups of fish were vaccinated orally through two different techniques; bivalent vaccine (inactivated Streptococcus iniae and Aeromonas hydrophila) sprayed on feed pellets (BS group); bivalent vaccine (inactivated S. iniae and A. hydrophila) incorporated in feed (BI group); monovalent inactivated S. iniae and A. hydrophila vaccine separately incorporated into feed as monovalent S. iniae (MS group) and monovalent A. hydrophila (MA group); and control group (without vaccine). The feed-based vaccine was delivered orally at 5% of body weight for five consecutive days. The booster doses were given in the same manner on weeks 2 and 6. Serum and skin mucus samples were collected to assess the IgM responses using indirect ELISA. The first administration of the feed-based vaccine stimulated the IgM levels that lasted until week 3, while the second booster ensured that the IgM levels remained high for a period of 16 weeks in the BI, MS and MA groups. The BI group developed a strong and significantly (P < 0.05) higher systemic and mucosal IgM responses against both S. iniae and A. hydrophila and also cross-protective antigen S. agalactiae and A. veronii compared to the BS and control groups. Quantitative real-time PCR results also showed that the relative expressions of IL-8, INF-γ and IgM in the BI immunized fish spleen, head kidney and hindgut exhibited various significant (P < 0.05) rising trends following both the vaccination and the challenge phase. On weeks 10, all fish were challenged through the intraperitoneal route, where relative percent survivals (RPS) of 82.22 ± 3.85% when challenged with S. iniae, 77.78 ± 3.85% when challenged with A. hydrophila and 77.78 ± 3.85% when co-challenged with both S. iniae and A. hydrophila were observed in the BI group, which were significantly higher (P < 0.05) compared to the other groups. The BI group also showed significantly (P < 0.05) higher partial cross-protections following challenges with S. agalactiae (RPS at 60.00 ± 6.67%) and A. veronii (RPS at 57.78 ± 7.70%). This study demonstrated that immunization with feed-based BI vaccine elicited immune responses that were capable of protecting red hybrid tilapia against streptococcosis and MAS.


Assuntos
Vacinas Bacterianas/imunologia , Ciclídeos/imunologia , Infecções por Bactérias Gram-Negativas/imunologia , Vacinas Combinadas/imunologia , Animais , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/veterinária , Vacinas Estreptocócicas/imunologia , Vacinas de Produtos Inativados/imunologia
16.
Fish Shellfish Immunol ; 113: 79-85, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33812989

RESUMO

Bacterial infections cause huge losses to aquaculture globally, and increased antibiotic resistance means that alternative methods of reducing mortality from bacterial diseases are required. We compared the resistance of Juvenile olive flounders, Paralichthys olivaceus, to Streptococcus iniae between those reared in biofloc and seawater conditions for ten months. Experimental fish were challenged with S. iniae at concentrations of 0, 3.36 × 106, 3.36 × 107, 3.36 × 108, and 3.36 × 109 colony forming units (CFU)/g fish for 96 h to evaluate the difference in S. iniae susceptibility of flounders reared in biofloc and seawater. The 96 h lethal concentration 50% (LC50) of fish injected with S. iniae was 2.41 × 109 CFU/g fish in biofloc and 1.51 × 108 CFU/g fish in seawater. Hematological parameters such as hemoglobin and hematocrit significantly decreased when fish were challenged by S. iniae. Plasma components such as calcium, glucose, cholesterol, total protein, GOT, GPT, and ALP were significantly altered by S. iniae infection and acetylcholinesterase activity was significantly inhibited. These results indicate that S. iniae infection affects the survival rates, hematological parameters, and neurotransmitter levels of flounders reared in biofloc and seawater, and that S. iniae susceptibility was higher in flounders reared in seawater than those reared in biofloc.


Assuntos
Aquicultura/instrumentação , Doenças dos Peixes/mortalidade , Linguados , Testes Hematológicos/veterinária , Neurotransmissores/metabolismo , Água do Mar/química , Infecções Estreptocócicas/veterinária , Animais , Doenças dos Peixes/microbiologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/mortalidade , Streptococcus iniae/fisiologia , Taxa de Sobrevida
17.
Molecules ; 26(7)2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33915741

RESUMO

As an important zoonotic pathogen, Streptococcus suis (S. suis) can cause a variety of diseases both in human and animals, especially Streptococcal toxic shock-like syndrome (STSLS), which commonly appears in severe S. suis infection. STSLS is often accompanied by excessive production of inflammatory cytokines, which is the main cause of host death. Therefore, it is urgent to find a new strategy to relieve the damage caused by STSLS. In this study, we found, for the first time, that apigenin, as a flavonoid compound, could combine with ampicillin to treat severe S. suis infection. Studies found that apigenin did not affect the growth of S. suis and the secretion of suilysin (SLY), but it could significantly inhibit the hemolytic activity of SLY by directly binding to SLY and destroying its secondary structure. In cell assays, apigenin was found to have no significant toxic effects on effective concentrations, and have a good protective effect on S. suis-infected cells. More importantly, compared with the survival rate of S. suis-infected mice treated with only ampicillin, the survival rate of apigenin combined with an ampicillin-treated group significantly increased to 80%. In conclusion, all results indicate that apigenin in combination with conventional antibiotics can be a potential strategy for treating severe S. suis infection.


Assuntos
Ampicilina/farmacologia , Antibacterianos/farmacologia , Apigenina/farmacologia , Infecções Estreptocócicas/tratamento farmacológico , Infecções Estreptocócicas/microbiologia , Streptococcus suis/efeitos dos fármacos , Ampicilina/química , Ampicilina/uso terapêutico , Animais , Antibacterianos/química , Apigenina/química , Apigenina/uso terapêutico , Sítios de Ligação , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Citocinas/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Eritrócitos/efeitos dos fármacos , Proteínas Hemolisinas/antagonistas & inibidores , Proteínas Hemolisinas/química , Interações Hospedeiro-Patógeno , Humanos , Mediadores da Inflamação/metabolismo , Camundongos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Ligação Proteica , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/metabolismo , Relação Estrutura-Atividade , Resultado do Tratamento
18.
Undersea Hyperb Med ; 48(1): 97-102, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33648039

RESUMO

The term "intracranial abscess" (ICA) includes cerebral abscess, subdural empyema, and epidural empyema, which share many diagnostic and therapeutic similarities and, frequently, very similar etiologies. Infection may occur and spread from a contiguous infection such as sinusitis, otitis, mastoiditis, or dental infection; hematogenous seeding; or cranial trauma. In view of the high morbidity and mortality of ICA and the fact that hyperbaric oxygen therapy (HBO2) is relatively non-invasive and carries a low complication rate, the risk-benefit ratio favors adjunct use of HBO2 therapy in selected patients with intracranial abscess.


Assuntos
Abscesso Encefálico/terapia , Oxigenação Hiperbárica/métodos , Abscesso Encefálico/diagnóstico por imagem , Abscesso Encefálico/etiologia , Empiema Subdural/diagnóstico por imagem , Empiema Subdural/etiologia , Empiema Subdural/terapia , Abscesso Epidural/diagnóstico por imagem , Abscesso Epidural/etiologia , Abscesso Epidural/terapia , Humanos , Seleção de Pacientes , Medição de Risco , Infecções Estreptocócicas/microbiologia
19.
Cochrane Database Syst Rev ; 3: CD004406, 2021 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-33728634

RESUMO

BACKGROUND: Antibiotics provide only modest benefit in treating sore throat, although their effectiveness increases in people with positive throat swabs for group A beta-haemolytic streptococci (GABHS). It is unclear which antibiotic is the best choice if antibiotics are indicated. This is an update of a review first published in 2010, and updated in 2013, 2016, and 2020. OBJECTIVES: To assess the comparative efficacy of different antibiotics in: (a) alleviating symptoms (pain, fever); (b) shortening the duration of the illness; (c) preventing clinical relapse (i.e. recurrence of symptoms after initial resolution); and (d) preventing complications (suppurative complications, acute rheumatic fever, post-streptococcal glomerulonephritis). To assess the evidence on the comparative incidence of adverse effects and the risk-benefit of antibiotic treatment for streptococcal pharyngitis. SEARCH METHODS: We searched the following databases up to 3 September 2020: CENTRAL (2020, Issue 8), MEDLINE Ovid (from 1946), Embase Elsevier (from 1974), and Web of Science Thomson Reuters (from 2010). We also searched clinical trial registers on 3 September 2020. SELECTION CRITERIA: Randomised, double-blind trials comparing different antibiotics, and reporting at least one of the following: clinical cure, clinical relapse, or complications and/or adverse events. DATA COLLECTION AND ANALYSIS: Two review authors independently screened trials for inclusion and extracted data using standard methodological procedures as recommended by Cochrane. We assessed the risk of bias of included studies according to the methods outlined in the Cochrane Handbook for Systematic Reviews of Interventions, and used the GRADE approach to assess the overall certainty of the evidence for the outcomes. We have reported the intention-to-treat analysis, and also performed an analysis of evaluable participants to explore the robustness of the intention-to-treat results. MAIN RESULTS: We included 19 trials reported in 18 publications (5839 randomised participants): six trials compared penicillin with cephalosporins; six compared penicillin with macrolides; three compared penicillin with carbacephem; one compared penicillin with sulphonamides; one compared clindamycin with ampicillin; and one compared azithromycin with amoxicillin in children. All participants had confirmed acute GABHS tonsillopharyngitis, and ages ranged from one month to 80 years. Nine trials included only, or predominantly, children. Most trials were conducted in an outpatient setting. Reporting of randomisation, allocation concealment, and blinding was poor in all trials. We downgraded the certainty of the evidence mainly due to lack of (or poor reporting of) randomisation or blinding, or both; heterogeneity; and wide confidence intervals. Cephalosporins versus penicillin We are uncertain if there is a difference in symptom resolution (at 2 to 15 days) for cephalosporins versus penicillin (odds ratio (OR) for absence of symptom resolution 0.79, 95% confidence interval (CI) 0.55 to 1.12; 5 trials; 2018 participants; low-certainty evidence). Results of the sensitivity analysis of evaluable participants differed (OR 0.51, 95% CI 0.27 to 0.97; 5 trials; 1660 participants; very low-certainty evidence). We are uncertain if clinical relapse may be lower for cephalosporins compared with penicillin (OR 0.55, 95% CI 0.30 to 0.99; number needed to treat for an additional beneficial outcome (NNTB) 50; 4 trials; 1386 participants; low-certainty evidence). Very low-certainty evidence showed no difference in reported adverse events. Macrolides versus penicillin We are uncertain if there is a difference between macrolides and penicillin for resolution of symptoms (OR 1.11, 95% CI 0.92 to 1.35; 6 trials; 1728 participants; low-certainty evidence). Sensitivity analysis of evaluable participants resulted in an OR of 0.79, 95% CI 0.57 to 1.09; 6 trials; 1159 participants). We are uncertain if clinical relapse may be different (OR 1.21, 95% CI 0.48 to 3.03; 6 trials; 802 participants; low-certainty evidence).  Azithromycin versus amoxicillin Based on one unpublished trial in children, we are uncertain if resolution of symptoms is better with azithromycin in a single dose versus amoxicillin for 10 days (OR 0.76, 95% CI 0.55 to 1.05; 1 trial; 673 participants; very low-certainty evidence). Sensitivity analysis for per-protocol analysis resulted in an OR of 0.29, 95% CI 0.11 to 0.73; 1 trial; 482 participants; very low-certainty evidence). We are also uncertain if there was a difference in relapse between groups (OR 0.88, 95% CI 0.43 to 1.82; 1 trial; 422 participants; very low-certainty evidence). Adverse events were more common with azithromycin compared to amoxicillin (OR 2.67, 95% CI 1.78 to 3.99; 1 trial; 673 participants; very low-certainty evidence). Carbacephem versus penicillin There is low-certainty evidence that compared with penicillin, carbacephem may provide better symptom resolution post-treatment in adults and children (OR 0.70, 95% CI 0.49 to 0.99; NNTB 14.3; 3 trials; 795 participants). Studies did not report on long-term complications, so it was unclear if any class of antibiotics was better in preventing serious but rare complications.  AUTHORS' CONCLUSIONS: We are uncertain if there are clinically relevant differences in symptom resolution when comparing cephalosporins and macrolides with penicillin in the treatment of GABHS tonsillopharyngitis. Low-certainty evidence in children suggests that carbacephem may be more effective than penicillin for symptom resolution. There is insufficient evidence to draw conclusions regarding the other comparisons in this review. Data on complications were too scarce to draw conclusions. These results do not demonstrate that other antibiotics are more effective than penicillin in the treatment of GABHS pharyngitis. All studies were conducted in high-income countries with a low risk of streptococcal complications, so there is a need for trials in low-income countries and Aboriginal communities, where the risk of complications remains high.


Assuntos
Antibacterianos/uso terapêutico , Faringite/tratamento farmacológico , Infecções Estreptocócicas/tratamento farmacológico , Streptococcus pyogenes , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Amoxicilina/efeitos adversos , Amoxicilina/uso terapêutico , Ampicilina/efeitos adversos , Ampicilina/uso terapêutico , Antibacterianos/efeitos adversos , Azitromicina/efeitos adversos , Azitromicina/uso terapêutico , Cefalosporinas/efeitos adversos , Cefalosporinas/uso terapêutico , Criança , Pré-Escolar , Clindamicina/efeitos adversos , Clindamicina/uso terapêutico , Humanos , Lactente , Macrolídeos/efeitos adversos , Macrolídeos/uso terapêutico , Pessoa de Meia-Idade , Penicilinas/efeitos adversos , Penicilinas/uso terapêutico , Faringite/microbiologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Infecções Estreptocócicas/microbiologia , Sulfonamidas/efeitos adversos , Sulfonamidas/uso terapêutico , Adulto Jovem
20.
Vet Res ; 52(1): 49, 2021 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-33743838

RESUMO

Streptococcus suis is one of the most important bacterial swine pathogens affecting post-weaned piglets, causing mainly meningitis, arthritis and sudden death. It not only results in severe economic losses but also raises concerns over animal welfare and antimicrobial resistance and remains an important zoonotic agent in some countries. The definition and diagnosis of S. suis-associated diseases can be complex. Should S. suis be considered a primary or secondary pathogen? The situation is further complicated when referring to respiratory disease, since the pathogen has historically been considered as a secondary pathogen within the porcine respiratory disease complex (PRDC). Is S. suis a respiratory or strictly systemic pathogen? S. suis is a normal inhabitant of the upper respiratory tract, and the presence of potentially virulent strains alone does not guarantee the appearance of clinical signs. Within this unclear context, it has been largely proposed that co-infection with some viral and bacterial pathogens can significantly influence the severity of S. suis-associated diseases and may be the key to understanding how the infection behaves in the field. In this review, we critically addressed studies reporting an epidemiological link (mixed infections or presence of more than one pathogen at the same time), as well as in vitro and in vivo studies of co-infection of S. suis with other pathogens and discussed their limitations and possibilities for improvement and proposed recommendations for future studies.


Assuntos
Coinfecção/veterinária , Infecções Estreptocócicas/veterinária , Streptococcus suis/fisiologia , Doenças dos Suínos/microbiologia , Animais , Coinfecção/complicações , Coinfecção/microbiologia , Coinfecção/virologia , Infecções Estreptocócicas/microbiologia , Sus scrofa , Suínos
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