Sepsis neonatal temprana, incidencia y factores de riesgo asociados en un hospital público del occidente de México / Early neonatal sepsis, incidence and associated risk factors in a public hospital in western Mexico

Background: Early neonatal sepsis (EOS) is the second leading cause of death in the first week of life. Epidemiology differs in developed and developing countries. Aim: To describe the epidemiology of EOS among newborn patients in a public hospital in western Mexico. Methods: A prospective cohort study was performed in newborns of Nuevo Hospital Civil de Guadalajara "Dr. Juan I Menchaca". EOS was diagnosed with blood cultures or cultures of cerebrospinal fluid within the first 72 h of life. We analyzed risk factors (RF) by multivariate analysis with logistic regression. Results: We identified an EOS incidence of 4.7 events per 1,000 live births. Seventy two percent of the isolated bacteria were gram negative bacilli. Factors associated with EOS were maternal age ≤ 15 years (OR 3.50; 95% CI 1.56-7.85), rupture of membranes > 18 h (OR 2.65; 95% CI 1.18-5.92), maternal fever (OR 6.04; 95% CI 1.54-23.6), birth weight ≤ 2,500 g (OR 4.82; 95% CI 2.38-9.75) and gestational age < 37 weeks (OR 3.14; 95% CI 1.58-6.22). Conclusions: In addition to the RF known for EOS an independent association was observed with maternal age ≤ 15 years.

Introducción: La sepsis neonatal temprana (SNT) es la segunda causa de muerte en la primer semana de vida; la epidemiología difiere en países desarrollados y en vías de desarrollo. Objetivo: Describir la epidemiología de SNT en recién nacidos (RN) de un hospital público del occidente de México. Material y Métodos: Estudio de cohorte prospectivo en RN del Nuevo Hospital Civil de Guadalajara "Dr. Juan I Menchaca". Se diagnosticó SNT con cultivos de sangre o líquido cefalorraquídeo en las primeras 72 h de vida. Se indagaron factores de riesgo (FR) mediante análisis multivariado con regresión logística. Resultados: La incidencia de SNT fue de 4,7 eventos por 1.000 RN vivos. El 72% de las bacterias aisladas correspondió a bacilos gramnegativos. Los factores asociados a SNT fueron la edad materna ≤ 15 años (OR 3,50; IC 95% 1,56-7,85), ruptura de membranas > 18 h (OR 2,65; IC 95% 1,18-5,92), fiebre materna (OR 6,04; IC 95%1,54-23,6), peso al nacimiento ≤ 2.500 g (OR 4,82; IC 95% 2,38-9,75) y edad gestacional < 37 semanas (OR 3,14; IC 95% 1,58-6,22). Conclusiones: Además de los FR ya conocidos para SNT se observó asociación independiente con edad materna ≤ 15 años.

Evaluation of cytokines produced by β-hemolytic streptococcus in acute pharyngotonsillitis / Avaliação das citosinas produzidas por estreptococos β-hemolíticos em faringotonsilites agudas

INTRODUCTION: The most common pathogen in bacterial pharyngotonsillitis is group A β-hemolytic streptococcus, although groups B, C, F,and G have also been associated with pharyngotonsillitis.OBJECTIVE: To assess the levels of the cytokines TNF-α, IL-6,IL-4, and IL-10 in bacterial pharyngotonsillitis caused by group A and non-A (groups B, C, F and G) β-hemolytic streptococcus.METHODS: The study was conducted at a pediatric emergency care unit. The sample comprised children (5-9 years old) with acute bacterial pharyngotonsillitis diagnosed between December of 2011 and May of 2012. The research involved collection of blood samples from the patients, enzyme-linked immunosorbent assay detection of TNF-α, IL-6,IL-4, and IL-10, and collection of two oropharyngeal swabs for bacterial isolation. Additionally, the medical history of the study participants was also collected.RESULTS: In the studied group (mean age: 5.93 years), higher pharyngotonsillitis incidence was observed in the female gender (64.76%). Higher incidence of tonsillar exudates was observed with groups A and C. No statistically significant differences in cytokine levels were observed among groups. However, the group A and the control group showed a difference in the IL-6 level (p = 0.0016).CONCLUSIONS: The Groups A and C showed higher cytokine levels than the Groups B and control, suggesting similar immunological patterns.

INTRODUÇÃO: O patógeno mais comumente associado à faringotonsilite bacteriana é o estreptococo β-hemolítico do grupo A, a despeito dos grupos B, C, F e G terem também sido associados com a faringotonsilite.OBJETIVO: Determinar os níveis das citosinas TNF-α, IL-6, IL-4, e IL-10 na faringotonsilite bacteriana causada pelos estreptococos β-hemolíticos do grupo A e não-A (grupos B, C, F e G).MÉTODO: O estudo foi conduzido em uma emergência pediátrica. A amostra estudada compreendeu crianças (entre 5 e 9 anos) com faringotonsilite aguda bacteriana diagnosticada entre dezembro de 2011 e maio de 2012. A pesquisa envolveu a coleta de amostras sanguíneas dos pacientes, a detecção, através do ELISA, de TNF-α, IL-6, IL-4, and IL-10, além da coleta de dois swabs orofaríngeos para isolamento bacteriano. Adicionalmente foi coletada a história médica dos participantes do estudo.RESULTADOS: No grupo estudado (idade média: 5,93 anos), a maior incidência de faringotonsilite foi observada no gênero feminino (64,76%). Foram detectadas maiores incidências de exsudatos tonsilares nos grupos A e C. Não foram observadas diferenças estatisticamente significantes dos níveis de citosinas entre os grupos. Porém os grupos A e o controle mostraram diferença nos níveis de IL-6 (p = 0.0016).CONCLUSÕES: Os grupos A e C mostraram maiores níveis de citosinas que os grupos B e o controle, sugerindo mecanismos imunológicos similares.

Perfiles genéticos de Streptococcus uberis aislados de mastitis bovina / Genetic patterns of Streptococcus uberis isolated from bovine mastitis

El objetivo del presente estudio fue evaluar las relaciones genotípicas entre 40 Streptococcus uberis aislados de mastitis bovina mediante la técnica de electroforesis de campos pulsantes (pulsed-field gel electrophoresis [PFGE]). Además, se investigó la asociación entre los patrones de PFGE y los perfiles de virulencia. Los aislamientos mostraron 17 patrones de PFGE. Se encontraron diferentes cepas dentro de los tambos y en los distintos tambos, y un bajo número de aislamientos dentro del mismo tambo compartieron un perfil idéntico de PFGE. No se encontró ninguna asociación entre los patrones de PFGE y los perfiles de virulencia. Sin embargo, la detección de cepas particulares en algunos tambos podría indicar que algunas de ellas son más virulentas que otras. Sería importante avanzar en las investigaciones para identificar nuevos genes relacionados con la virulencia que podrían contribuir a la capacidad infecciosa de estas cepas

The aim of this study was to evaluate the genotypic relationships among 40 Streptococcus uberis isolated from bovine mastitis by using pulsed-field gel electrophoresis (PFGE). Additionally, the association between PFGE patterns and virulence profiles was investigated. The isolates exhibited 17 PFGE patterns. Different strains were found within and among herds; however, a low number of isolates within the same herd shared an identical PFGE type. No association between PFGE patterns and virulence profiles was found. However, the detection of specific strains in some herds could indicate that some strains are more virulent than others. Further research needs to be undertaken to elucidate new virulence-associated genes that might contribute to the capability of these strains to produce infection

Is Streptococcus pseudopneumoniae a neglected respiratory pathogen.

Streptococcus pseudopneumoniae is a member of Viridans streptococci, associated with chronic obstructive lung disease and lower respiratory infection. It is non-capsulated, bile insoluble and optochin susceptible in ambient air but intermediate or resistant in 5%CO2. But, its role as a pathogen is yet to be established. The objective of the study was to detect the prevalence and to determine the clinical significance of S.pseudopneumoniae in sputum samples. The study period was 5 months. Good quality sputum samples (>25 neutrophils and <10 epithelial cells/LPF) of patients suspected of LRTIs, were inoculated onto chocolate agar. Alpha haemolytic colonies were identified by testing for capsule by India ink preparation, bile solubility and optochin susceptibility in ambient air and 5%CO2. Antibiotic sensitivity testing was done by Kirby-Bauer's disc diffusion method. Out of 66 alpha haemolytic colonies, 4 were S.pseudopneumoniae, 17 were S.pneumoniae and 45 were other Viridans streptococci. Antibiotic sensitivity patterns of S.pseudopneumoniae and S.pneumoniae were analyzed. S.pseudopneumoniae is misinterpreted as S.pneumoniae unless specifically looked for. As there is scant information available, studies have to be encouraged for better determination of clinical importance of S.pseudopneumoniae. This will help in right diagnosis and successful treatment.

Metabolitos de bacterias lácticas antagónicos al crecimiento de microorganismos cariogénicos / Antagonistic activity of lactic acid bacteria metabolites toward cariogenic microorganisms growth

Aislar, purificar y conservar cepas de Streptococcus spp. y lactobacillus spp. de la cavidad bucal y enfrentarlas "in vitro" a bacterias lácticas. Materiales y métodos: se seleccionaron individuos con caries y se recolectaron muestras de saliva. Para recuperar Streptococcus spp. se empleó el medio Mitis Salivarius (Difco, Detroit, MI, Estados Unidos) y para Lactobacillus spp. se usó Rogosa (Blokar Diagnostics, Beauvais, Francia). Como cepas productoras de bacteriocinas se utilizaron 7 cepas de Lactococcus lactis subsp. lactis, 2 de Leuconostoc mesenteroides y 1 de Lactococcus lactis subsp. diacetylactis. La actividad antagónica de las bacterias lácticas al crecimiento in vitro de bacterias cariogénicas se determinó con el método de difusión en agar. Resultado: el desarrollo y la multiplicación de las cepas de Streptococcus spp. de origen bucal ensayadas se vieron afectados por la presencia de metabolitos generados por las cepas de Lactococcus lactis subsp. lactis. Conclusión: el crecimiento de las cepas de Streptococcus subsp. fue inhibido por efecto de L. lactis subsp. lactis...

A study on ß-defensin-2 and histatin-5 as a diagnostic marker of early childhood caries progression

BACKGROUND: Recently, a continuous growth of interest has been observed in antimicrobial peptides (AMPs) in the light of an alarming increase in resistance of bacteria and fungi against antibiotics. AMPs are used as biomarkers in diagnosis and monitoring of oral cavity pathologies. Therefore, the determination of specific protein profiles in children diagnosed with early childhood caries (ECC) might be a basis for effective screening tests and specialized examinations which may enable progression of disease. METHODS: The objective of the studies was to determine the role of histatin-5 and ß-defensing-2 as a diagnostic marker of early childhood caries progression. In this work, results of concentration determination of two salivary proteins (histatin-5 and ß-defensin-2) were presented. In addition, bacterial profiles from dental plaque in various stages of ECC and control were marked. The assessment of alteration in the concentration of these two proteins in a study group of children with various stages of ECC and a control group consisting of children with no symptoms was performed by enzyme-linked immunosorbent assays. RESULTS: The statistical analysis showed a significant increase in the concentration of histatin-5 and ß-defensin-2 in the study group compared to the control group and correlated with the progression of the disease. CONCLUSIONS: The confirmation of concentration changes in these proteins during the progression of dental caries may discover valuable disease progression biomarkers.

Perfil fitoquímico e determinação da atividade antimicrobiana de Syzygium cumini (L. ) Skeels (Myrtaceae) frente a microrganismos bucais / Phytochemical profile and determination of antimicrobial activity of Syzygiumcumini (L. ) Skeels (Myrtaceae) against oral microorganisms

RESUMO Este estudo teve como objetivo determinar o perfil fitoquímico e avaliar a atividade antimicrobiana in vitro do extrato etanólico da casca do caule de Syzygium cumini(L.) Skeels frente a microrganismos bucais. O perfil fitoquímico do extrato foi traçado através da determinação espectrofotométrica quantitativa para verificar o teor de taninos, flavonóides, saponinas e polifenóis. A atividade antimicrobiana foi determinada através da Concentração Inibitória Mínima (CIM), por meio da técnica de microdiluição em caldo, utilizando-se as seguintes linhagens de microrganismos: Streptococcus mutans (25175), Streptococcus oralis (10557) e Candida albicans (10231). Uma quantidade apreciável de fitocontituintes foi observada, especialmente de taninos (100,58 ± 1,81). Os extratos apresentaram atividade antimicrobiana inibindo o crescimento das linhagens em estudo, destacando-se essa atividade sobre o crescimento de C. albicans (CIM=250 µg/mL). Já as CIMs para Streptococcus foram baixas. Diante dos resultados expostos, pode-se concluir que o perfil fitoquímico foi traçado e que, dentre os microrganismos testados, o extrato etanólico da casca de S. cumini apresentou forte potencial de inibição sobre o crescimento de C. albicans e fraca inibição frente aos Streptococcus testados. Este estudo sugere que mais pesquisas devem ser realizadas dando continuidade à bioprospecção, por meio de análises experimentais com essa espécie vegetal, objetivando, no futuro, que essa planta possa ser utilizada clinicamente para tratar candidose bucal.

ABSTRACT This study aimed to determine the phytochemical profile and to evaluate the in vitro antimicrobial activity of the ethanol extract of stem bark of Syzygium cumini (L.) Skeels against oral microorganisms. The phytochemicalprofile of the extract was traced through a quantitative spectrophotometric determination in order to check the tannin, flavonoids, saponins, and polyphenols content. The antimicrobial activity was determined through minimum inhibitory concentration (MIC) by the broth microdilution technique, using the following strains of microorganisms: Streptococcus mutans (25175), Streptococcus oralis (10557) and Candida albicans (10231). An appreciable amount of fitocontituintes was observed, particularly the tannin (100.58 ± 1.81). The extracts showed antimicrobial activity, inhibiting the growth of the strains under study, with this activity being more intense on the growth of C. albicans ( MIC = 250 mg / mL). On the other hand, the MICs of the Streptococcus were low. In face of the mentioned results, we can conclude that the phytochemical profile was traced and that, among the tested microorganisms, the ethanol extract of S. cumini bark showed strong potential to inhibit the growth of C. albicans and weak inhibition against the Streptococcus tested. This study suggests that more research should be done by proceeding with the bioprospecting, through experimental tests with this plant`s species, aiming that in the future this substance can be used clinically for the treatment of oral candidiasis.

Prevalence of Group A beta- hemolytic streptococcal carriers in school going children.

Group A Streptococci (GAS) are one of the common pathogens responsible for causing tonsillitis and pharyngitis in both children and young adults. The asymptomatic pharyngeal carriage of GAS in children may lead to spread of respiratory infection in the community. Children aged 5 to 15 years with no signs and symptoms of upper respiratory tract infections and no history of antibiotic therapy within last two weeks were included in study. Throat swabs collected were cultured on blood agar. GAS was identified by conventional method and serogrouped using latex agglutination assay. GAS was isolated from 7 children, out of 250 children. The carrier rate was 3.6% which correlated well with other South Asian studies. Our study showed the importance of surveillance programme to keep carriers in check.

Infecciones invasivas por estreptococos de los grupos A, C y G en la Argentina / Invasive infectios due to group A, C and G streptococci in Argentina

Streptococcus pyogenes (estreptococo beta-hemolítico del grupo A) (SGA) y Streptococcus dysgalactiae subsp. equisimilis, (estreptococos beta-hemolíticos grupos C y G) (SDSE) son capaces de provocar enfermedades graves como la fascitis necrotizante y el síndrome de shock tóxico estreptocócico (SSTE) y de causar complicaciones posinfecciosas. El objetivo de este trabajo fue presentar resultados de un estudio multicéntrico y compararlo con diferentes estudios descriptivos previos sobre infecciones invasivas por estreptococos beta-hemolíticos de los grupos A, C y G, también realizados en la Argentina. Se incluyeron 54 pacientes de 0 a 15 años con infecciones invasivas por SGA (N=50) o SDSE (N=4) en forma prospectiva entre julio de 2011 y junio de 2012 en 28 centros de 17 ciudades argentinas. Se aisló S. pyogenes en 28 pacientes que presentaron bacteriemia, 6 de ellas sin foco. Cuatro pacientes (7,4%) presentaron SSTE, en todos los casos por S. pyogenes. La mortalidad fue del 2,0% para SGA. La evolución de los pacientes fue peor en los tres estudios anteriores respecto del actual: mayor porcentaje de casos de SSTE (diferencias no significativas) y mayor mortalidad (diferencia significativa respecto de dos estudios previos). Es probable que la morbimortalidad haya decrecido en esta última década en la Argentina posiblemente debido al uso temprano de clindamicina en las infecciones invasivas por S. pyogenes y SDSE, aunque no se puede descartar la diferente circulación de cepas virulentas. Esta apreciación además está sesgada por la inclusión de pacientes de distintos centros con diferentes formas de presentación inicial (AU)

Streptococcus pyogenes (group A ß-hemolytic streptococcus (GAS)) and Streptococcus dysgalactiae subsp. equisimilis (group C and G ß-hemolytic streptococcus (GCGS)) may cause severe diseases such as necrotizing fasciitis and streptococcal toxic shock syndrome (STSS) as well as postinfectious complications. The aim of this report was to present the results of a multicenter study and compare them with the results of different previous descriptive studies on invasive infections due to beta-hemolytic streptococcus groups A, C, and G that were also conducted in Argentina. Forty-five patients between 0 and 15 years of age with invasive infections due to GAS (N=50) or GCGS (N=4) were prospectively included in the study between July 2011 and June 2012 from 28 centers in 17 Argentine cities. S. pyogenes was isolated in 28 patients who presented with bacteremia, without a focus in six. Four patients (7.4%) had STSS, due to S. pyogenes in all of them. In patients with GAS, mortality rate was 2.0%. Outcome of the patients was worse in previous studies than in the present one: Percentages of cases with STSS (no significant difference) and mortality (significant difference) were higher. It is probable that over the last decade morbidity and mortality have decreased in Argentina, possibly due to the early use of clindamycin in invasive infections due to S. pyogenes and GCGS, although a different circulation of virulent strains cannot be ruled out. Additionally, this observation is biased by the inclusion of patients from different centers with different presentations at onset (AU)

Streptococcus gallolyticus subsp. pasteurianus en líquido cefalorraquídeo de un paciente pediátrico / [Streptococcus gallolyticus subsp. pasteurianus isolated from cerebrospinal fluid in a pediatric patient].

Streptococcus gallolyticus subsp. pasteurianus is known to cause bacterial meningitis in adults, and most of the few pediatric cases observed occurred in neonates. We report the case of a 9-month old boy with a history of repeated hospitalizations due to respiratory diseases, who presented meningitis and bacteremia by Streptococcus gallolyticus subsp. pasterianus. To our knowledge, this is the first reported case in Santa Fe to this date.

Cerebritis bifrontal y absceso cerebral por Streptococcus del grupo anginosus, en paciente previamente sano: Caso clínico / Bifrontal cerebritis and brain abscess caused by Sreptococcus anginosus group: Report of one case

The etiology of brain abscesses is mostly polymicrobial. Streptococci and anaerobic bacteria are the most commonly isolated pathogens. We report a previously healthy female without predisposingfactors, presenting with a bifrontal cerebritis caused by a Streptococcus anginosus group infection. The patient developed a brain abscess and a subdural collection with severe intracranial hypertension offatal evolution. The etiologic diagnosis was made culturing the material obtained from the subdural collection. It is presumed that, within the Streptococcus anginosus group, Streptococus intermedius could have been the causing bacteria, given its central nervous system tissue tropism and its predisposition to form brain abscesses.

Bacterial diversity in the saliva of patients with different oral hygiene indexes

The objective of the present study was to evaluate the bacterial diversity in the saliva of patients with different oral hygiene indexes using of two 16S rRNA gene libraries. Each library was composed of samples from patients with different averages of the differentiated Silness-Löe biofilm index: the first library (A) with an index between 1.0 and 3.0 (considered a high index) and the second library (B) between 0 and 0.5 (considered a low index). Saliva DNA was extracted and the 16S rRNA gene was amplified and cloned. The obtained sequences were compared with those stored at NCBI and RDP GenBank. The saliva of patients with high index presented five known genera - Streptococcus, Granulicatella, Gemella, Veillonella and Peptostreptococcus - and 33.3% of nonculturable bacteria grouped into 23 operational taxonomic units (OTUs). The saliva of patients with low index differed significantly from the first library (p=0.000) and was composed of 42 OTUs distributed into 11 known genera - Streptococcus, Granulicatella, Gemella, Veillonella, Oribacterium, Haemophilus, Escherichia, Neisseria, Prevotella, Capnocytophaga, Actinomyces - including 24.87% of nonculturable bacteria. It was possible to conclude that there is greater bacterial diversity in the saliva of patients with low dental plaque in relation to patients with high dental plaque.

O objetivo do presente estudo foi avaliar a diversidade bacteriana da saliva de pacientes com diferentes índices de higiene bucal através da construção de duas bibliotecas do gene 16S rRNA. Cada biblioteca foi composta por amostras de saliva de pacientes com índice de biofilme dental de Silness-Löe diferenciado, sendo a primeira (A) com índice de 1,0 a 3,0 (denominada de alto índice) e a segunda (B), entre 0 a 0,5 (denominada de baixo índice). O DNA da saliva foi extraído e o gene 16S rRNA foi amplificado, clonado e sequenciado. As sequências obtidas foram comparadas com aquelas armazenadas no GenBank do NCBI e RDP. A saliva de pacientes com alto índice de biofilme dental apresentou cinco gêneros conhecidos: Streptococcus, Granulicatella, Gemella, Veillonella e Peptostreptococcus e 33,3% de bactérias não-cultivadas, agrupados em 23 unidades taxonômicas operacionais (UTOs). A saliva de pacientes com baixo índice de biofilme dental, foi diferente significativamente da primeira (p=0,000) e foi composta de 42 UTOs, distribuídas em 11 gêneros conhecidos: Streptococcus, Granulicatella, Gemella, Veillonella, Oribacterium, Haemophilus, Escherichia, Neisseria, Prevotella, Capnocytophaga, Actinomyces, além de 24,87% de bactérias não-cultivadas. Pode-se concluir que existe maior diversidade bacteriana na saliva de pacientes com baixo índice de biofilme dental em relação a pacientes com alto índice de biofilme dental.

Microbial colonization in orthodontic mini-implants

Peri-implant inflammation contributes for loss of secondary stability of orthodontic mini-implants. The investigation of microbial colonization in this area would benefit its control, and consequently favor the long-term success of mini-implants. Therefore, the aim of this study was to determine the establishment and the evolution of microbial colonization process in orthodontic mini-implants for 3 months, since the time of their installation. One-hundred and fifty samples collected from 15 mini-implants were investigated from baseline up to 3 months. The biological material was obtained from peri-implant area using paper points. Nonspecific, Streptococcus spp, Lactobacillus casei and Candida spp colonizations were analyzed by cell growth methods. Porphyromonas gingivalis colonization was observed by 16S rDNA-directed polymerase chain reaction. Data from cell growth were submitted to the Wilcoxon sign rank test and results from molecular analysis were presented in a descriptive way. There was no significant difference in the microbial colonization among the examined time intervals, except for Streptococcus spp, between baseline and 24 h, which characterized the initial colonization in this time interval. Lactobacillus casei and Candida spp colonizations were insignificant. No Porphyromonas gingivalis was detected among the analyzed samples. The microbial colonization of mini-implants did not significantly change during the study. However, it should be monitored by orthodontists, since it is an important factor for mini-implants success.

A inflamação peri-implantar contribui para a perda da estabilidade secundária dos mini-implantes ortodônticos. A investigação da colonização microbiana desta área beneficiaria o seu controle e, consequentemente, favoreceria o sucesso dos mini-implantes a longo prazo. Portanto, o objetivo dos autores foi determinar o estabelecimento e evolução do processo de colonização microbiana em mini-implantes ortodônticos por três meses desde a instalação. Cento e cinquenta amostras coletadas de 15 mini-implantes foram investigadas desde o tempo inicial até 3 meses. O material biológico foi obtido da área peri-implantar com auxílio de cones de papel absorvente. As colonizações inespecíficas de Streptococcus spp, Lactobacillus casei e Candida spp foram analisadas por métodos de crescimento celular. A colonização por Porphyromonas gingivalis foi observada por meio da reação em cadeia da polimerase 16S rDNA. Os dados do crescimento celular foram submetidos ao teste de Wilcoxon sign rank e os resultados da biologia molecular foram apresentados de modo descritivo. Não houve diferença estatisticamente significante da colonização microbiana entre os intervalos de tempo avaliados, exceto para Streptococcus spp entre os tempos inicial e 24 h, o que caracterizou o início da colonização neste intervalo de tempo. As colonizações por Lactobacillus casei e Candida spp foram insignificantes. Não foi detectada a presença de Porphyromonas gingivalis nas amostras analisadas. A colonização microbiana nos mini-implantes não se alterou significativamente durante o estudo. No entanto, deve ser monitorada por ortodontistas, uma vez que é um fator importante para o sucesso dos mini-implantes.

Phenotypic and genotypic characterization of Streptococcus uberis isolated from bovine subclinical mastitis in Argentinean dairy farms

The aim of this study was to investigate the phenotypic and genotypic characteristics of Streptococcus uberis isolated from subclinical mastitis (SCM) cases, and to examine the possible association between both characteristics. A total of 32 S. uberis were isolated from 772 quarter milk samples (SCM > 250,000 cells/ml) collected from 195 cows selected randomly from 18 dairy farms located in Argentina. The S. uberis strains were characterized phenotypically by the presence of virulence factors as plasminogen activator factor (PAF), hyaluronidase (HYA), capsule (CAP) and CAMP factor, and were further characterized genotypically by pulsed-field gel electrophoresis (PFGE). S. uberis strains expressed plasminogen activator factor, hyaluronidase or capsule (65.5 %, 56.3 %, 59.4 %, respectively), but only 25 % of isolates were CAMP factor positive. Thirteen different virulence profiles were identified on the basis of the combination of virulence factors. Eighteen PFGE patterns with 90% of similarity were identified among 32 S. uberis. A great diversity of virulence profiles and PFGE patterns were present among dairy farms. S. uberis strains with the same PFGE pattern showed different virulence profiles. Bovine S. uberis strains causing SCM included in the present study showed heterogeneity in regard to their phenotypic and genotypic characteristics, and the PFGE patterns are not associated with the virulence profiles.

Caracterización fenotípica y genotípica de Streptococcus uberis aislados de mastitis bovina subclínica en tambos de Argentina. El objetivo de este estudio fue investigar las características fenotípicas y genotípicas de Streptococcus uberis aislados de casos de mastitis subclínica (MSC) y examinar la posible asociación entre ambas características. Un total de 32 cepas de S. uberis fueron aisladas de 772 muestras de leche de cuartos mamarios (MSC > 25 0000 células/ml) colectadas de 195 vacas seleccionadas al azar pertenecientes a 18 tambos lecheros localizados en Argentina. Las cepas de S. uberis fueron caracterizadas fenotípicamente sobre la base de la presencia de factores de virulencia tales como el factor activador del plasminógeno (FAP), la hialuronidasa (HIA), la cápsula (CAP) y el factor CAMP. Además, fueron caracterizadas genotípicamente por electroforesis de campos pulsados (PFGE). Las cepas de S. uberis expresaron el factor activador del plasminógeno, la hialuronidasa o la cápsula (65,5 %, 56,3 % y 59,4 %, respectivamente), pero solo el 25 % fueron CAMP positivas. Sobre la base de la combinación de los factores de virulencia se identificaron 13 perfiles de virulencia diferentes. Asimismo, se identificaron 18 patrones de PFGE con un 90 % de similitud entre las 32 cepas de S. uberis. Se presentó una gran diversidad de perfiles de virulencia y patrones de PFGE entre los tambos. Cepas con el mismo patrón de PFGE presentaron perfiles de virulencia diferentes. Las cepas de S. uberis causantes de MSC en bovinos incluidas en el presente estudio mostraron heterogeneidad con respecto a sus características fenotípicas y genotípicas, y los patrones de PFGE no estuvieron asociados con los perfiles de virulencia.

Hydrophobicity test in mutans Streptococci

Kinetic hydrophobic measurements were performed by confronting 40 mutans streptococci from thirty 10- to 20-year-old patients with 200 ml hexadecane (Sigma). Fourteen patients had high dental caries risk (Group A), dmft + DMFT >5 with 3 or more active caries, and 16 had low dental caries risk (Group B), dmft + DMFT <3 without active caries. Twenty bacteria from Group A and 20 bacteria from Group B were typed using De La Higuera's procedure and confirmed by API strip (bio- Merieux). From the 14 patients in Group A we obtained 12 S. mutans (8 hydrophobic/ 4 non-hydrophobic), 5 S. sobrinus (4 hydrophobic/ 1 non-hydrophobic) and 3 S. rattus (hydrophobic). From the 16 patients in Group B we obtained 11 Streptococcus mutans (10 non-hydrophobic/ 1 hydrophobic), 7 Streptococcus sobrinus (6 non-hydrophobic/ 1 hydrophobic) and 2 Streptococcus rattus (hydrophobic). Patients with high dental caries risk have a higher prevalence of hydrophobic bacteria than patients with low dental caries risk (p=0.0003). All typed S. rattus were hydrophobic.

Con el objeto de evaluar una posible relacion entre hidrofobicidad y caries dental, se estudiaron 40 cepas de Streptococcus grupo mutans provenientes de 30 pacientes de entre 10 y 20 anos, 14 pacientes con tres o mas caries activas e indice ceod mas CPOD > 5 (Grupo A) y 16 pacientes sin caries activas, con ceod mas CPOD < 3 (Grupo B). Las cepas fueron aisladas a partir de muestras de saliva en AMS-BT y tipificadas por pruebas bioquimicas y API-strep realizandose la medicion cinetica de hidrofobicidad, enfrentandolas con 200 ml de hexadecano (Sigma). En el grupo A se caracterizaron 12 cepas Streptococcus mutans: 8 hidrofobicas y 4 no hidrofobicas, 5 cepas de Streptococcus sobrinus: 4 hidrofobicas y 1 no hidrofobica y 3 cepas Streptococcus rattus hidrofobicas. En el grupo B, se caracterizaron 11 cepas de S. mutans, 10 no hidrofobicas y 1 hidrofobica, 7 cepas de S. sobrinus: 6 no hidrofobicas y 1 hidrofobica y 2 cepas de S. rattus hidrofobicas. Todos los pacientes del grupo A presentaron al menos 1 cepa hidrofobica. En las cepas aisladas de estos pacientes se demostro la existencia de una alta prevalencia de Streptococcus grupo mutans con caracteristicas hidrofobicas p=0,0003. Estos resultados indicarian la relacion entre la capacidad de adherencia a hexadecano y caries activa. Todas las cepas tipificadas como S. rattus fueron hidrofobicas independientemente del grupo de origen.

The effect of mango and neem extract on four organisms causing dental caries: Streptococcus mutans, Streptococcus salivavius, Streptococcus mitis, and Streptococcus sanguis: an in vitro study.

BACKGROUND AND OBJECTIVES: Chewing twigs of the mango or neem tree is a common way of cleaning the teeth in the rural and semi-urban population. These twigs are also believed to possess medicinal properties. The present study was conducted to evaluate the antimicrobial effects of these chewing sticks on the microorganisms Streptococcus mutans , Streptococcus salivarius , Streptococcus mitis , and Streptococcus sanguis which are involved in the development of dental caries. An additional objective was to identify an inexpensive, simple, and effective method of preventing and controlling dental caries. MATERIALS AND METHODS: The sticks were sun dried, ground into a coarse powder, and weighed into 5 gm, 10 gm, and 50 gm amounts. These were added to 100 ml of deionized distilled water. After soaking for 48 h at 4 degrees C, the water was filtered. The filtrate was inoculated onto blood agar plates containing individual species of microorganisms and incubated at 37 degrees C for 48 h. Results: Mango extract, at 50% concentration, showed maximum zone of inhibition on Streptococcus mitis . Neem extract produced the maximum zone of inhibition on Streptococcus mutans at 50% concentration. Even at 5% concentration neem extract showed some inhibition of growth for all the four species of organisms. INTERPRETATION AND CONCLUSION: A combination of neem and mango chewing sticks may provide the maximum benefit. We recommend the use of both the chewing sticks.

Estreptococos cariogénicos predominantes, niveles de infección e incidencia de caries en un grupo de escolares: estudio exploratorio / Predominant cariogenic Streptococcus, infection level and caries incidence in a group of schoolchildren: en exploratory study

Objetivo: Estudiar la distribución de estreptococos cariogénicos, niveles de infección y su asociación con la incidencia de caries. Metodología: Sesenta escolares (8 y 10 años), seguidos durante 18 meses. Se registró caries, niveles bacterianos de estreptococos en muestras de placa; por medio de análisis bioquímico se hizo la tipificación bacteriana, se calculó la incidencia de caries en el molar muestreado. Resultados: El 80 por ciento de los estreptococos correspondieron al grupo mutans (40 por ciento S. sobrinus, 32 por ciento S. mutans, 5 por ciento S. rattus y 3 por ciento S. cricetus). El 20 por ciento restante correspondió a otros estreptococos (S. salivarius, S. mitis y S. sanguis). El 55 por ciento de los niños presentó conteos 105 ufc/mL en placa y el 30 por ciento desarrolló caries en el molar estudiado. Un modelo de regresión logística múltiple de pasos sucesivos mostró asociación entre la bacteria predominante y los niveles de infección (P < 0.01). No se demostró asociación entre bacteria predominante e incidencia de caries (P > 0.05). Sin embargo con el mismo modelo ponderado según los niveles de infección, mostró una asociación significativa (P < 0.0018). Conclusión: La asociación de cepas de estreptococos con la incidencia de caries en niños es dependiente del nivel de infección

Aumento en la prevalencia de estreptococos beta hemoliticos en hisopados faringeos en Buenos Aires / High prevalence of beta hemolytic streptococci isolated from throat swabs in Buenos Aires

El estreptococo beta hemolítico grupo A (EBHGA) es el agente bacteriano más frecuentemente aislado en casos de faringoamigdalitis. Otros estreptococos beta hemolíticos no A también pueden producir esta enfermedad. Ante el elevado número de aislamientos obtenidos en el año 2004 decidimosrealizar un estúdio con el objeto de evaluar la prevalência de estos microorganismos durante um períodod de 5 años. Se incluyeron todos los cultivos de hisopados faríngeos que se realizaron con idéntica metodologia. Se considero ninõs a los comprendidos entre 6 meses y 18 años de edad, y adultos a los mayores de 18 años. Los aislamientos fueron identificados según la metodologia habitual. La determinación de grupo se realizo mediante la aglutinación con partículas de látex. La recuperación de EBHGA fue significativamente mayor enniños en relación a los adultos. En el año 2004 se obtuvo una recuperación significamente mayor de EBHGA, EBHGC y EBHGG en niños y de EBHGA y EBHGG en adultos respecto respecto de los años anteriores. El aislamiento de EBHGG fue mayor en adultos. El 18.9% y el 55.8% de los estreptococos beta hemolíticos aislados en niños y adultos espectivamente no pertenecieron al grupo A. El incremento en la prevalência de estreptococos betahemolíticos refuerza la buena práctica de realizar cultivos en adultos y niños así como la correcta búsqueda en el laboratório de bacteriología de los estreptococos beta hemolíticos no pertenecientes al grupo A.