RESUMEN

OBJECTIVE: The aim of this study was to investigate the value of next-generation sequencing for the diagnosis of Streptococcus suis meningitis. METHODS: Patients with meningitis in the Department of Neurology of the Hainan General Hospital were recruited and divided into a next-generation sequencing group and a control group. In the next-generation sequencing group, we used the next-generation sequencing method to detect the specific pathogenic bacteria in the patients. In the control group, we used the cerebrospinal fluid bacterial culture method to detect the specific pathogenic bacteria in the patients. RESULTS: A total of 28 participants were recruited for this study, with 14 participants in each group. The results showed similarities in both the average age and average course of the disease between the two groups (p>0.05). The white blood cell count, percentage of neutrophils, and level of C-reactive protein in the next-generation sequencing group were significantly higher than those in the control group (p<0.05). There were similarities in both the temperature and intracranial pressure between the two groups (p>0.05). In the next-generation sequencing group, all patients (100%) were detected as having had the S. suis meningitis infection by next-generation sequencing, while only 6 (43%) patients in the control group had been detected as having the S. suis meningitis infection by cerebrospinal fluid bacterial culture. CONCLUSIONS: The positive detection rate of S. suis by the next-generation sequencing method was significantly higher compared with using a cerebrospinal fluid bacterial culture. Therefore, the next-generation sequencing method is valuable for the diagnosis of S. suis meningitis and is worthy of clinical application.

Asunto(s)

Meningitis Bacterianas , Infecciones Estreptocócicas , Streptococcus suis , Humanos , Streptococcus suis/genética , Meningitis Bacterianas/diagnóstico , Meningitis Bacterianas/microbiología , Infecciones Estreptocócicas/diagnóstico , Neutrófilos , Secuenciación de Nucleótidos de Alto Rendimiento

RESUMEN

Streptococcus suis (S. suis) is a zoonotic pathogen that primarily inhabits the upper respiratory tract of pigs. Therefore, pigs that carry these pathogens are the major source of infection. Most patients are infected through contact with live pigs or unprocessed pork products and eating uncooked pork. S. Suis mainly causes sepsis and meningitis. The disease has an insidious onset and rapid progress. The patient becomes critically ill and the mortality is high. In this case report, we described a rare case of S. suis isolated from a middle-aged woman in Jinhua City, Zhejiang Province, China, who did not have any contact with live pigs and had not eaten uncooked pork. S. Suis was isolated from both the patient's blood and cerebrospinal fluid samples.

Asunto(s)

Meningitis , Sepsis , Infecciones Estreptocócicas , Animales , China , Humanos , Meningitis/diagnóstico , Meningitis/etiología , Meningitis/microbiología , Persona de Mediana Edad , Carne de Cerdo , Sepsis/diagnóstico , Sepsis/etiología , Sepsis/microbiología , Infecciones Estreptocócicas/líquido cefalorraquídeo , Infecciones Estreptocócicas/complicaciones , Infecciones Estreptocócicas/microbiología , Infecciones Estreptocócicas/transmisión , Streptococcus suis/genética , Porcinos

RESUMEN

Streptococcus suis is one of most important pathogens in the swine industry worldwide. Despite its importance, studies of S. suis characterization in South America are still rare. This study evaluates S. suis isolates from distinct Brazilian states, from 1999 to 2004, and its molecular and serological characterization. A total of 174 isolates were studied. S. suis identification was confirmed by PCR and isolates were further serotyped and genotyped by SE-AFLP and amplification of virulence markers. Serotype 1, 2, 3, 4, 7, 18, 22 and 32 were identified among the studied isolates, and only 4% were characterized as non-typeable. The mrp+/epf+/sly+ genotype was the most frequent. The SE-AFLP analysis resulted in 29 patterns distributed in three main clusters with over 65% of genetic similarity. Isolates presented a slight tendency to cluster according to serotype and origin; however, no further correlation with virulence genotypes was observed.(AU)

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Streptococcus suis é um dos patógenos de maior importância para indústria suinícola mundial. Apesar de sua importância, a caracterização de isolados de S. suis na América do Sul ainda é pouco descrita. O presente estudo descreve a avaliação de isolados de S. suis provenientes de diferentes Estados brasileiros, e sua caracterização sorológica e molecular. Foram avaliados 174 isolados de S. suis e os mesmos foram submetidos a SE-AFLP e pesquisa de marcadores de virulência. Os sorotipos 1, 2, 3, 4, 7, 18, 22 e 32 foram identificados dentre os isolados estudados e apenas 4% foram caracterizados como não tipáveis. O perfil de virulência mrp+/epf+/sly+ foi o mais frequente. A análise do SE-AFLP resultou em 29 perfis distribuídos em três grupos principais com mais de 65% de similaridade genética. Os isolados apresentaram tendência de se agrupar segundo origem e sorotipo; no entanto, não foi observada correlação entre os grupamentos e os perfis de virulência.(AU)

Asunto(s)

Animales , Serotipificación/veterinaria , Streptococcus suis/clasificación , Streptococcus suis/genética , Streptococcus suis/virología , Porcinos/virología , Virulencia

RESUMEN

Streptococcus suis is one of most important pathogens in the swine industry worldwide. Despite its importance, studies of S. suis characterization in South America are still rare. This study evaluates S. suis isolates from distinct Brazilian states, from 1999 to 2004, and its molecular and serological characterization. A total of 174 isolates were studied. S. suis identification was confirmed by PCR and isolates were further serotyped and genotyped by SE-AFLP and amplification of virulence markers. Serotype 1, 2, 3, 4, 7, 18, 22 and 32 were identified among the studied isolates, and only 4% were characterized as non-typeable. The mrp+/epf+/sly+ genotype was the most frequent. The SE-AFLP analysis resulted in 29 patterns distributed in three main clusters with over 65% of genetic similarity. Isolates presented a slight tendency to cluster according to serotype and origin; however, no further correlation with virulence genotypes was observed.(AU)

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Streptococcus suis é um dos patógenos de maior importância para indústria suinícola mundial. Apesar de sua importância, a caracterização de isolados de S. suis na América do Sul ainda é pouco descrita. O presente estudo descreve a avaliação de isolados de S. suis provenientes de diferentes Estados brasileiros, e sua caracterização sorológica e molecular. Foram avaliados 174 isolados de S. suis e os mesmos foram submetidos a SE-AFLP e pesquisa de marcadores de virulência. Os sorotipos 1, 2, 3, 4, 7, 18, 22 e 32 foram identificados dentre os isolados estudados e apenas 4% foram caracterizados como não tipáveis. O perfil de virulência mrp+/epf+/sly+ foi o mais frequente. A análise do SE-AFLP resultou em 29 perfis distribuídos em três grupos principais com mais de 65% de similaridade genética. Os isolados apresentaram tendência de se agrupar segundo origem e sorotipo; no entanto, não foi observada correlação entre os grupamentos e os perfis de virulência.(AU)

Asunto(s)

Animales , Streptococcus suis/clasificación , Streptococcus suis/genética , Streptococcus suis/virología , Serotipificación/veterinaria , Virulencia , Porcinos/virología

RESUMEN

Streptococcus suis is an emerging zoonotic pathogen that causes septicemia, meningitis, arthritis, and pneumonia in swine and humans. The present study aimed to characterize the genetic diversity of S. suis serotype 2 isolated from pigs showing signs of illness in Brazil using pulsed-field gel electrophoresis (PFGE), single-enzyme amplified fragment length polymorphism (SE-AFLP), and profiling of virulence-associated markers. A total of 110 isolates were studied, 62.7% of which were isolated from the central nervous system and 19.1% from the respiratory tract. Eight genotypes were obtained from the combination of virulence genes, with 43.6% and 5.5% frequencies for the mrp (+) /epf (+) /sly (+) and mrp (-) /epf (-) /sly (-) genotypes, respectively. The presence of isolates with epf gene variation with higher molecular weight also appears to be a characteristic of Brazilian S. suis serotype 2. The PFGE and SE-AFLP were able to type all isolates and, although they presented a slight tendency to cluster according to state and year of isolation, it was also evident the grouping of different herds in the same PFGE subtype and the existence of isolates originated from the same herd classified into distinct subtypes. No further correlation between the isolation sites and mrp/epf/sly genotypes was observed.

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Streptococcus suis est un agent pathogène zoonotique en émergence responsable de septicémies, des méningites, d'arthrites, et de pneumonies chez les porcs et les humains. La présente étude visait à caractériser la diversité génétique de souches de S. suis sérotype 2 isolées au Brésil de porcs montrant des signes de maladie à l'aide des techniques suivantes : électrophorèse en champs pulsés (PFGE), polymorphisme des fragments amplifiés par un enzyme unique (SE-AFLP), et profilage des marqueurs de virulence. Un total de 110 isolats a été étudié, 62,7 % isolats provenant du système nerveux central et 19,1 % du tractus respiratoire. Huit génotypes furent obtenus de la combinaison de gènes de virulence, avec des fréquences de 43,6 % et 5,5 % pour les génotypes mrp+/epf+/sly+ et mrp−/epf−/sly−, respectivement. La présence d'isolats avec la variation du gène epf et un poids moléculaire plus élevé semble être également une caractéristique de S. suis sérotype 2 d'origine brésilienne. Les méthodes PFGE et SE-AFLP ont été en mesure de permettre le typage de tous les isolats et, bien qu'il y avait une légère tendance à se regrouper selon l'état et l'année d'isolement, il était également évident qu'il y avait du regroupement d'isolats provenant de différents troupeaux dans le même sous-type de PFGE et de l'existence d'isolats provenant du même troupeau classifiés dans des sous-types différents. Aucune autre corrélation entre le site d'isolement et les génotypes de mrp/epf/sly ne fut observée.(Traduit par Docteur Serge Messier).

Asunto(s)

Variación Genética , Infecciones Estreptocócicas/veterinaria , Streptococcus suis/genética , Enfermedades de los Porcinos/microbiología , Animales , Brasil , Marcadores Genéticos , Serogrupo , Infecciones Estreptocócicas/epidemiología , Infecciones Estreptocócicas/microbiología , Streptococcus suis/patogenicidad , Porcinos , Enfermedades de los Porcinos/epidemiología , Transcriptoma , Virulencia

RESUMEN

The characteristics of 29 Chilean field strains of Streptococcus suis recovered between 2007 and 2011 from pigs with clinical signs at different farms were studied. Serotyping with use of the coagglutination test revealed that all but 1 strain belonged to serotype 6; the remaining strain was serotype 22. All the serotype-6 strains were suilysin (hemolysin)-negative; in addition, they were found to be genotypically homogeneous by enterobacterial repetitive intergenic consensus sequence-based polymerase chain reaction (ERIC-PCR) and sensitive to ampicillin, ceftiofur, penicillin, and trimethoprim/sulfamethoxazole. The results indicate that, in contrast to what is generally observed in other countries, a single clone of S. suis was isolated from diseased pigs in the central region of Chile.

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Les caractéristiques de 29 souches de Streptococcus suis d'origine chilienne provenant de porcs malades, dont la plupart d'entre elles n'ont aucun lien épidémiologique, ont été étudiées. Toutes les souches ont montré appartenir au sérotype 6 sauf 1, qui a été caractérisée comme étant un sérotype 22. De plus, toutes les souches du sérotype 6 se sont révélées négatives pour la production de suilysine (hémolysine). Avec l'utilisation d'un test PCR ciblant des séquences consensus intergéniques répétées d'entérobactéries (ERIC-PCR), toutes les souches de sérotype 6 testées se sont avérées être génétiquement homogènes. Finalement, ces souches se sont montrées sensibles à l'ampicilline, au ceftiofur, à la pénicilline ainsi qu'à l'association triméthoprime-sulfaméthoxazole. Les résultats indiquent que, contrairement à ce qui a déjà été observé dans d'autres pays, un seul clone de S. suis est majoritairement isolé chez des porcs malades dans la région centrale du Chili.(Traduit par les auteurs).

Asunto(s)

Infecciones Estreptocócicas/veterinaria , Streptococcus suis/genética , Enfermedades de los Porcinos/microbiología , Animales , Chile/epidemiología , Variación Genética , Ratones , Serogrupo , Infecciones Estreptocócicas/epidemiología , Infecciones Estreptocócicas/microbiología , Porcinos , Enfermedades de los Porcinos/epidemiología

RESUMEN

Cyclic diadenosine monophosphate is a recently identified signaling molecule. It has been shown to play important roles in bacterial pathogenesis. SSU98_1483 (ssDacA), which is an ortholog of Listeria monocytogenes DacA, is a putative diadenylate cyclase in Streptococcus suis serotype 2. In this study, we determined the enzymatic activity of ssDacA in vitro using high-performance liquid chromatography and mass spectrometry. Our results showed that ssDacA was a diadenylate cyclase that converts ATP into cyclic diadenosine monophosphate in vitro. The diadenylate cyclase activity of ssDacA was dependent on divalent metal ions such as Mg(2+), Mn(2+), or Co(2+), and it is more active under basic pH than under acidic pH. The conserved RHR motif in ssDacA was essential for its enzymatic activity, and mutation in this motif abolished the diadenylate cyclase activity of ssDacA. These results indicate that ssDacA is a diadenylate cyclase, which synthesizes cyclic diadenosine monophosphate in Streptococcus suis serotype 2.

Asunto(s)

Adenosina Trifosfato/química , Adenilil Ciclasas/química , Proteínas Bacterianas/química , Fosfatos de Dinucleósidos/química , Streptococcus suis/enzimología , Adenosina Trifosfato/metabolismo , Adenilil Ciclasas/genética , Adenilil Ciclasas/metabolismo , Secuencias de Aminoácidos , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Cationes Bivalentes , Cobalto/química , Cobalto/metabolismo , Fosfatos de Dinucleósidos/biosíntesis , Pruebas de Enzimas , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Concentración de Iones de Hidrógeno , Magnesio/química , Magnesio/metabolismo , Manganeso/química , Manganeso/metabolismo , Datos de Secuencia Molecular , Mutación , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Serogrupo , Streptococcus suis/clasificación , Streptococcus suis/genética

Asunto(s)

Infecciones Estreptocócicas/microbiología , Streptococcus suis/aislamiento & purificación , Antibacterianos/uso terapéutico , Argentina , Humanos , Masculino , Persona de Mediana Edad , Peritonitis/diagnóstico , Peritonitis/tratamiento farmacológico , Peritonitis/microbiología , Infecciones Estreptocócicas/diagnóstico , Infecciones Estreptocócicas/tratamiento farmacológico , Streptococcus suis/clasificación , Streptococcus suis/genética , Resultado del Tratamiento

Asunto(s)

Meningitis Bacterianas/diagnóstico , Meningitis Bacterianas/microbiología , Infecciones Estreptocócicas/diagnóstico , Infecciones Estreptocócicas/microbiología , Streptococcus suis/aislamiento & purificación , Chile/epidemiología , Femenino , Humanos , Masculino , Meningitis Bacterianas/epidemiología , Persona de Mediana Edad , Infecciones Estreptocócicas/epidemiología , Streptococcus suis/genética

Asunto(s)

Femenino , Humanos , Masculino , Persona de Mediana Edad , Meningitis Bacterianas/diagnóstico , Meningitis Bacterianas/microbiología , Infecciones Estreptocócicas/diagnóstico , Infecciones Estreptocócicas/microbiología , Streptococcus suis/aislamiento & purificación , Chile/epidemiología , Meningitis Bacterianas/epidemiología , Infecciones Estreptocócicas/epidemiología , Streptococcus suis/genética

RESUMEN

Streptococcus suis is a swine pathogen and also a zoonotic agent. The formation of biofilms allows S. suis to become persistent colonizers and resist clearance by the host immune system and antibiotics. In this study, biofilm forming potentials of various S. suis strains were characterized by confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM) and tissue culture plates stained with crystal violet. In addition, the effects of five antimicrobial agents on biofilm formation were assayed in this study. S. suis produced biofilms on smooth and rough surface. The nutritional contents including glucose and NaCl in the growth medium modulated biofilm formation. There was a significant difference in their biofilm-forming ability among all 46 S. suis strains. The biofilm-forming potential of S. suis serotype 9 was stronger than type 2 and all other types. However, biofilm formation was inhibited by five commonly used antimicrobial agents, penicillin, erythromycin, azithromycin, ciprofloxacin, and ofloxacin at subinhibitory concentrations, among which inhibition of ciprofloxacin and ofloxacin was stronger than that of other three antimicrobial agents.Our study provides a detailed analysis of biofilm formation potential in S. suis, which is a step towards understanding its role in pathogenesis, and eventually lead to a better understanding of how to eradicate S. suis growing as biofilms with antibiotic therapy.

Asunto(s)

Humanos , Animales , Antibacterianos/análisis , Biopelículas , Sistema Inmunológico , Huésped Inmunocomprometido , Microscopía Electrónica de Rastreo/métodos , Farmacorresistencia Microbiana/genética , Porcinos , Streptococcus suis/genética , Streptococcus suis/aislamiento & purificación , Métodos , Sus scrofa , Virulencia

RESUMEN

The postantibiotic effects (PAEs) and postantibiotic sub-MIC effects (PA SMEs) of tilmicosin, erythromycin and tiamulin on erythromycin-susceptible and erythromycin-resistant strains of Streptococcus suis (M phenotype) were investigated in vitro. Tilmicosin and tiamulin induced significantly longer PAE and PA SME against both erythromycin-susceptible and erythromycin-resistant strains than did erythromycin. The durations of PAE and PA SMEs were proportional to the concentrations of drugs used for exposure. The PA SMEs were substantially longer than PAEs on S. suis (P<0.05) regardless of the antimicrobial used for exposure. The results indicated that the PAE and PA SME could help in the design of efficient control strategies for infection especially caused by erythromycin-resistant S. suis and that they may provide additional valuable information for the rational drug use in clinical practice.

Asunto(s)

Animales , Antibacterianos/análisis , Antibacterianos/efectos adversos , Susceptibilidad a Enfermedades , Farmacorresistencia Microbiana , Técnicas In Vitro , Infecciones Estreptocócicas , Porcinos , Streptococcus suis/crecimiento & desarrollo , Streptococcus suis , Streptococcus suis/genética , Streptococcus suis/aislamiento & purificación , Medios de Cultivo , Métodos , Fenotipo , Reacción en Cadena de la Polimerasa/métodos , Muestreo , Métodos

RESUMEN

Streptococcus suis is considered one of the most important bacterial swine pathogens worldwide. The distribution of the 35 described serotypes in diseased animals may vary in different regions. Data regarding S. suis isolation from pigs in South America is not available. In the present study, 51 isolates of S. suis recovered in pure culture or as the predominant species from diseased animals in Brazil, were analyzed. These isolates were classified as serotypes 2 (58.8%), 3 (21.5%), 7 (13.7%), 1 (3.9%), and 14 (2%). Serotype 2 isolates were further studied for their production of virulence-related proteins muramidase-released protein (MRP), extracellular factor (EF), and suilysin. In addition, the genetic diversity was studied by randomly amplified polymorphic DNA. All but 1 of the serotype 2 isolates showed a clonal distribution of an atypical phenotype (MRP+, EF*, suilysin+), different from the known European (MRP+, EF+, suilysin+), and North American (MRPv, EF-, suilysin-), phenotypes.

Asunto(s)

Antígenos Bacterianos , Proteínas Bacterianas/metabolismo , Proteínas Hemolisinas/metabolismo , Infecciones Estreptocócicas/veterinaria , Streptococcus suis/clasificación , Enfermedades de los Porcinos/microbiología , Animales , Cápsulas Bacterianas , Brasil , Compuestos Orgánicos , Fenotipo , Técnica del ADN Polimorfo Amplificado Aleatorio/veterinaria , Serotipificación/veterinaria , Infecciones Estreptocócicas/microbiología , Streptococcus suis/genética , Streptococcus suis/patogenicidad , Virulencia