RESUMEN
Neonatal porcine diarrhea (NPD) is a current problem on pig farms and is caused by several enteropathogens. Among them, Clostridioides difficile stands out due to its importance in piglets and zoonotic potential. A non-toxigenic strain of C. difficile (NTCD), named Z31, was previously tested in hamster and piglet experimental models as a strategy to prevent C. difficile infection (CDI). To evaluate the capacity of the strain Z31 to prevent CDI and NPD in one-day-old piglets on a commercial farm, 90 piglets from 16 litters received 1 × 106 spores of Z31 while 84 animals from the same litters served as controls. Animals were clinically evaluated, and fecal samples were collected 24 h after administration and submitted to A/B toxin detection and isolation of C. difficile. Stool samples were also submitted to rotavirus, Escherichia coli, and Clostridium perfringens detection. Administration of Z31 reduced the incidence of CDI in treated animals (7.8%) when compared to the control group (25.0%; P = 0.003). In animals that developed CDI, the intensity of diarrhea was lower in those that received Z31 than in the control group. Neonatal porcine diarrhea was reduced in treated animals when compared to untreated animals (P < 0.001). The present study suggests that Z31 can potentially be used to prevent CDI in piglets on commercial farms.
Asunto(s)
Clostridioides difficile/fisiología , Clostridioides difficile/patogenicidad , Infecciones por Clostridium/prevención & control , Diarrea/veterinaria , Enfermedades de los Porcinos/microbiología , Animales , Animales Recién Nacidos , Derrame de Bacterias , Infecciones por Clostridium/microbiología , Clostridium perfringens/aislamiento & purificación , Diarrea/microbiología , Diarrea/prevención & control , Escherichia coli Enterotoxigénica/aislamiento & purificación , Granjas , Heces/microbiología , Porcinos , Enfermedades de los Porcinos/prevención & controlRESUMEN
Four strains of a previously unknown, catalase-negative, facultatively anaerobic, gram-positive, rod-shaped organism originating from humans were characterized by biochemical, chemical, and molecular taxonomic methods. The four strains phenotypically closely resembled one another, and although they possessed characteristics consistent with membership in the genus Actinomyces, they differed from all previously recognized species of this genus. The results of comparative 16S rRNA gene sequencing studies demonstrated that the unknown human bacterium was phylogenetically a member of the genus Actinomyces. Within the genus Actinomyces, the unidentified bacterium formed a loose, but statistically significant, association with a subgroup which included Actinomyces bovis, the type species of the genus. 16S rRNA sequence divergence values of > 6%, however, unequivocally demonstrated that the unidentified bacterium represents a new subline of the genus Actinomyces. A new species, Actinomyces graevenitzii, is proposed for the four new isolates. The type strain of A. graevenitzii is CCUG 27294.
Asunto(s)
Actinomyces/clasificación , Actinomyces/aislamiento & purificación , Actinomicosis/microbiología , Actinomyces/genética , ADN Bacteriano/análisis , ADN Ribosómico/análisis , Humanos , Datos de Secuencia Molecular , FilogeniaRESUMEN
A systematic phylogenetic analysis of the genus Actinomyces was performed. The 16S rRNA gene sequences of 13 Actinomyces species, an unnamed Actinomyces strain (ATCC 49338), and an Actinomyces-like isolate from sea mammals were determined. Comparative sequence analysis with closely related taxa revealed phylogenetic diversity and internal structure within the genus Actinomyces. In addition, some members of other genera (viz., the genera Arcanobacterium, Mobiluncus, and Rothia) were shown to be phylogenetically intermixed with the Actinomyces species. It was evident from both distance and tree topology considerations that the genus Actinomyces is in urgent need of taxonomic revision and requires subdivision into several genera. Based on the results of the present study it is proposed that Actinomyces bernardiae and Actinomyces pyogenes be assigned to the genus Arcanobacterium as Arcanobacterium bernardiae comb. nov. and Arcanobacterium pyogenes comb. nov., respectively. In addition, a new species, Arcanobacterium phocae, is proposed for Actinomyces-like bacteria isolated from seals.
Asunto(s)
Actinomycetaceae/clasificación , Actinomycetaceae/genética , ADN Bacteriano/análisis , ARN Ribosómico 16S/genética , Técnicas Bacteriológicas , Medios de Cultivo/metabolismo , Datos de Secuencia Molecular , Filogenia , Homología de Secuencia de Ácido NucleicoRESUMEN
Over a 5-year period, six isolates of a previously unknown nonlipophilic coryneform bacterium were isolated from human clinical specimens. The most characteristic phenotypic reactions of these isolates included slow fermentative acid production from glucose but no acid production from maltose and sucrose and a strongly positive CAMP reaction. Chemotaxonomic investigations revealed that meso-diaminopimelic acid and mycolic acids were present, that palmitic, oleic, and stearic acids were the predominant cellular fatty acids, and that the G + C content was 62 to 64 mol%, characteristics which are consistent with assignment to the genus Corynebacterium. Phenotypically, the unknown coryneform bacterium could be readily differentiated from all other Corynebacterium species. A 16S rRNA gene sequence analysis and quantitative DNA-DNA hybridization experiments demonstrated unambiguously that the unknown coryneform bacterium is a member of the genus Corynebacterium and is genotypically distinct from all other members of this genus. Based on phenotypic and genotypic findings, a new species, Corynebacterium coyleae sp.nov., is proposed. The type strain of C coylease is strain DSM 44184 (= CCUG 35014).
Asunto(s)
Infecciones por Corynebacterium/microbiología , Corynebacterium/aislamiento & purificación , Adulto , Anciano , Técnicas Bacteriológicas , Composición de Base , Corynebacterium/química , Corynebacterium/genética , Corynebacterium/metabolismo , Medios de Cultivo/metabolismo , Ácido Diaminopimélico/análisis , Ácidos Grasos/análisis , Femenino , Fermentación , Glucosa/metabolismo , Humanos , Masculino , Maltosa/metabolismo , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Ácidos Micólicos/análisis , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S/genética , Homología de Secuencia de Ácido Nucleico , Sacarosa/metabolismoRESUMEN
Phenotypic and phylogenetic studies were performed on a Gram-negative obligately anaerobic rod-shaped bacterium isolated from two sea mammals. 16S rRNA gene sequence analysis demonstrated the bacterium represents a hitherto unknown line of descent peripherally associated to the fusobacteria and low G+C relatives. Based on the result of the phylogenetic analysis and phenotypic criteria, it is proposed that the bacterium should be assigned to a new genus, Cetobacterium ceti gen. nov., sp. nov. The type strain of Cetobacterium ceti sp. nov. is NCFB 3026.
Asunto(s)
Delfines/microbiología , Bacterias Anaerobias Gramnegativas/clasificación , Ballenas/microbiología , Animales , Antibacterianos/farmacología , Composición de Base , Secuencia de Bases , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/genética , Farmacorresistencia Microbiana , Bacterias Anaerobias Gramnegativas/genética , Bacterias Anaerobias Gramnegativas/aislamiento & purificación , Bacterias Anaerobias Gramnegativas/fisiología , Datos de Secuencia Molecular , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Homología de Secuencia de Ácido NucleicoRESUMEN
CDC coryneform group A-3 and A-4 bacteria were defined by Hollis and Weaver in 1981, but their taxonomic position is still unclear. By using biochemical and chemotaxonomical methods, four clinical strains belonging to CDC coryneform groups A-3 (n = 2) and A-4 (n = 2) were studied and could be assigned to the genus Cellulomonas, resulting in the first description of Cellulomonas strains isolated from clinical specimens. CDC coryneform group A-3 and A-4 strains were compared with the type strains of the seven species constituting the genus Cellulomonas at present as well as with the closely related species Oerskovia turbata, Oerskovia xanthineolytica, and Jonesia denitrificans, but their biochemical patterns were not compatible with the patterns of any of those species. Almost the entire sequences of the 16S rRNA genes of one representative strain of both CDC taxa were determined, and comparative sequence analysis confirmed the placement of the CDC coryneform group A-3 and A-4 strains studied in the Cellulomonas-Oerskovia subbranch of the actinomycetes. Both CDC taxa exhibited > 99% base pair homology within their 16S rDNAs. On the basis of phenotypic and molecular data, we formally propose a new species, Cellulomonas hominis sp. nov., for the CDC coryneform group A-3 bacteria examined. The type strain is DSM 9581. The precise taxonomic status of the CDC coryneform group A-4 strains studied remains to be established by quantitative DNA-DNA hybridizations.
Asunto(s)
Actinomycetales/clasificación , Actinomycetales/genética , Actinomycetales/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Secuencia de Bases , Cartilla de ADN/genética , ADN Bacteriano/genética , ADN Ribosómico/genética , Farmacorresistencia Microbiana , Genes Bacterianos , Humanos , Datos de Secuencia Molecular , Fenotipo , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Homología de Secuencia de Ácido Nucleico , Especificidad de la EspecieRESUMEN
Biochemical, chemotaxonomic, and molecular methods were used to establish the precise taxonomic position of the Centers for Disease Control (CDC) coryneform group 2 bacteria. The results of a comparative 16S rRNA sequence analysis demonstrated that the CDC coryneform group 2 bacteria constitute a distinct species within the genus Actinomyces. Actinomyces pyogenes was found to be the closest genealogical relative of the CDC coryneform group 2 bacteria, although these taxa were readily distinguished from each other and other Actinomyces spp. by using phenotypic criteria. On the basis of our findings we propose the name Actinomyces bernardiae sp. nov. for the CDC coryneform group 2 bacteria. The type strain is DSM 9152 (CCUG 33419).
Asunto(s)
Actinomyces/clasificación , Actinomycetales/clasificación , Secuencia de Bases , Centers for Disease Control and Prevention, U.S. , Datos de Secuencia Molecular , ARN Ribosómico 16S/química , ARN Ribosómico 16S/genética , Estados UnidosRESUMEN
It is theorized that charcoal hemoperfusion and hemodialysis with a highly permeable membrane should be synergistic in the management of fulminant hepatic failure. Previous studies have shown marked differences between these two treatments in their effects in the various biochemical abnormalities of this serious clinical problem. Survival rates in patients treated with charcoal hemoperfusion approximate the rates in those treated with hemodialysis with a highly permeable membrane but are only slightly better than in untreated cases. The excellent recovery of two patients with fulminant viral hepatitis in stage III and IV coma treated with this combined regimen indicates that further studies should be done to confirm this thesis.
Asunto(s)
Hemoperfusión , Hepatitis Viral Humana/terapia , Diálisis Renal , Adulto , Carbón Orgánico , Femenino , Humanos , Masculino , Ensayo de MaterialesAsunto(s)
Azatioprina/uso terapéutico , Ciclosporinas/uso terapéutico , Trasplante de Riñón , Azatioprina/administración & dosificación , Ensayos Clínicos como Asunto , Ciclosporinas/administración & dosificación , Esquema de Medicación , Estudios de Seguimiento , Rechazo de Injerto/efectos de los fármacos , Humanos , Prednisona/administración & dosificación , Prednisona/uso terapéuticoRESUMEN
Resting electrocardiograms were recorded in 18 male adult rats injected subcutaneously with two doses of isoproterenol (200 mg.kg-1 body weight) 10 days before the animals were submitted to the ajmaline test (1 mg.kg-1 body weight iv). After the ajmaline test all rats were killed and the hearts examined histologically. Electrocardiographic changes were detected at rest in 72% of the isoproterenol injected rats: pathological Q waves, lengthening of the QRS complex, and QRS abnormality were found in 50%, 44%, and 44% of these animals respectively. Ajmaline induced similar changes in both control and isoproterenol treated rats (P wave enlargement (p less than 0.01 and p less than 0.001 respectively), increased PR interval (p less than 0.003 and p less than 0.001 respectively), and increased QaT interval (p less than 0.001 in both groups]. However, ajmaline caused an increase in heart rate only in isoproterenol treated rats (p less than 0.05). A pronounced increase in PR interval, not observed in control rats, was detected in one of five isoproterenol injected rats with a normal resting ECG but showing microscopical cardiac lesions. Apical aneurysm of the left ventricle was found in 16% of isoproterenol injected rats. A mononuclear inflammatory reaction was observed in 13 (72%) of the isoproterenol injected rats and was multifocal in at least three regions of the myocardium in six (46%) and disseminated throughout the myocardium in seven (53%) of these animals. When the electrocardiographic and pathological findings were compared, the ECG changes were found to have a 91% sensitivity, 83% specificity, and 91% positive predictive value.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Cardiomiopatías/diagnóstico , Electrocardiografía , Miocardio/patología , Ajmalina/farmacología , Animales , Cardiomiopatías/inducido químicamente , Cardiomiopatías/patología , Cardiomiopatías/fisiopatología , Corazón/efectos de los fármacos , Corazón/fisiopatología , Isoproterenol , Masculino , Ratas , Sensibilidad y EspecificidadRESUMEN
A retrospective study of the medical records of our hospital from 1965 to 1985 was carried out to characterize for the first time chronic Chagas' heart disease in the elderly (more than 70 years old). A total of 25 patients (mean age = 76) were suitable for the study. Congestive heart failure, sudden cardiac death, thromboembolism and atypical chest pain were found in 68, 16, 8 and 8% of cases, respectively. Ventricular premature contractions (60%), right bundle branch block (32%), left anterior hemiblock (28%), atrial fibrillation (28%) and right bundle branch block associated with left anterior hemiblock (20%) were the ECG changes most frequently found. A morphological study was performed on 8 (32%) patients. All of them showed cardiac abnormalities, with apical aneurism being detected in 100% of cases. At autopsy, pulmonary embolism was observed in 3(37%) of these patients who presented with congestive heart failure, ventricular premature contractions and/or intraventricular conduction defect and/or atrial fibrillation. Thus, the characteristics of chronic Chagas' heart disease in the elderly are similar to those found in middle-aged patients. We suggest that these patients are important for the study of the pathogenesis of chronic Chagas' heart disease because they may have less aggressive pathophysiologic mechanisms than middle-aged patients.