Structural and biochemical characterization of a nucleotide hydrolase from Streptococcus pneumonia.

In this report, we structurally and biochemically characterized the unknown gene product SP1746 from Streptococcus pneumoniae serotype 4. Various crystal structures of SP1746 in the apo form and in complex with different nucleotides were determined. SP1746 is a globular protein, which belongs to the histidine-aspartate (HD) domain superfamily with two Fe3+ ions in the active site that are coordinated by key active site residues and water molecules. All nucleotides bind in a similar orientation in the active site with their phosphate groups anchored to the diiron cluster. Biochemically, SP1746 hydrolyzes different nucleotide substrates. SP1746 most effectively hydrolyzes diadenosine tetraphosphate (Ap4A) to two ADPs. Based on the aforementioned data, we annotated SP1746 as an Ap4A hydrolase, belonging to the YqeK family. Our in vitro data indicate a potential role for SP1746 in regulating Ap4A homeostasis, which requires validation with in vivo experiments in bacteria in the future.

Serotipos y resistencia antimicrobiana de Streptococcus pneumoniae en población pediátrica china: una revisión de alcance

Esta revisión tuvo como propósito explorar la distribución de serotipos y la resistencia antimicrobiana de Streptococcus pneumoniae en la población pediátrica de China a partir de literatura publicada en los últimos seis años. Se realizó una revisión de alcance a partir de PubMed y dos bases de datos de China: CNKI y WanFang Data. Del total de 196 artículos extraídos, se seleccionaron 14 estudios para esta revisión. Hay 13 artículos que analizan la distribución de serotipos de Streptococcus pneumoniae; los serotipos más frecuentemente registrados son: 19F, 19A, 23F, 14 y 6B. Hay 11 artículos que analizan la resistencia antimicrobiana de Streptococcus pneumoniae, la prevalencia de no susceptibles a la penicilina se encuentra en el rango de 0 % a 95,7 %. Los aislados son muy resistentes a eritromicina, clindamicina, tetraciclina y trimetoprima-sulfametoxazol; son resistentes a penicilina en meningitis neumocócica pero son sensibles a penicilina en otras enfermedades neumocócicas, además, son muy sensibles a levofloxacina, vancomicina y Linezolid. Se concluye que la vacuna antineumocócica conjugada 13 tiene alta cobertura en los serotipos de Streptococcus pneumoniae en los niños de China continental, por eso se recomienda su inclusión en el programa de vacunación infantil; al mismo tiempo, se debe tener en cuenta la aparición de la sustitución de serotipos. Por eso, se deben incluir más pacientes pediátricos o niños en las investigaciones, especialmente los menores de cinco años. Es necesaria una vigilancia de alta calidad a largo plazo sobre la distribución de serotipos y resistencia antimicrobiana de Streptococcus pneumoniae para el desarrollo de la prevención de enfermedades neumocócicas.

This review aimed to explore the serotype distribution and antimicrobial resistance of Streptococcus pneumoniae in the Chinese pediatric population based on literature published in the last six years. A scoping review was performed using PubMed and two Chinese databases: CNKI and WanFang Data. Of the total of 196 articles extracted, 14 studies were selected for this review. There are 13 articles that analyze the distribution of Streptococcus pneumoniae serotypes, the most frequently registered serotypes are: 19F, 19A, 23F, 14 and 6B. There are 11 articles that analyze the antimicrobial resistance of Streptococcus pneumoniae, the prevalence of non-susceptible to penicillin is in the range of 0% to 95.7%. Isolates are highly resistant to erythromycin, clindamycin, tetracycline, and trimethoprim-sulfamethoxazole; they are resistant to penicillin in pneumococcal meningitis but are sensitive to penicillin in other pneumococcal diseases, in addition, they are very sensitive to levofloxacin, vancomycin and Linezolid. It is concluded that the pneumococcal conjugate vaccine 13 has high coverage in Streptococcus pneumoniae serotypes in children from mainland China, therefore its inclusion in the childhood vaccination program is recommended; at the same time, the occurrence of serotype substitution should be taken into account. Therefore, more pediatric patients or children should be included in research, especially those under five years of age. Long-term, high-quality surveillance of the serotype distribution and antimicrobial resistance of Streptococcus pneumoniae is necessary for the development of pneumococcal disease prevention.

Encapsulated saponin by ferritin nanoparticles attenuates the murine pneumococcal pneumonia.

Streptococcus pneumonia is classified as a gram-positive bacterial pathogen that causes asymptomatic or symptomatic respiratory infections. This study aimed to evaluate the effects of designed encapsulated saponin by ferritin nanoparticles in the healing progression of experimental bacterial pneumonia. The saponin encapsulated by ferritin followed the disassembly-reassembly process. Pneumonia was induced by the preparation of Streptococcus pneumonia. A total of 50 NMRI mice were divided into control, pneumonia, pneumonia + ferritin, pneumonia + saponin, and pneumonia + encapsulated saponin by ferritin nanoparticles (Nano Saponin) groups. ELISA, Real-time PCR, and Western blotting were used to measure sera IL-4 level, tumor necrosis factor-alpha (Tnf-α), and protein cyclooxygenase-2 (COX-2) gene expression, respectively. COX-2 protein expression, Tnf-α gene expression, and serum levels of IL-4 reduced compared to the pneumonia group. The histopathology results revealed that the rates of inflammation, mucus secretion, pulmonary hemorrhage, thickening of the alveoli wall, and secretion of inflammatory cells were lower in the Nano Saponin group than in the other groups. This study suggests that Glycyrrhiza glabra saponin and encapsulated saponin by ferritin nanoparticles oral consumption with anti-Tnf-α effect besides decreasing protein expression of COX-2 allows mice with pneumonia to recover.

A Rare Case of Streptococcus Pneumoniae Causing Malignant Otitis Externa Complicated by Skull Base Osteomyelitis.

Skull base osteomyelitis is an aggressive infection involving bones of the skull. It is a rare complication of malignant otitis externa, caused by the contiguous spread of the infection. Patients are mostly elderly with comorbidities that compromise immunity. It is atypical for Streptococcus species to be encountered in basilar skull osteomyelitis. Here we present the case of an 80-year-old male with multiple comorbidities including diabetes mellitus with a two-month history of right ear pain associated with occasional discharge and diminished hearing who was found to have bacteremia and basilar skull osteomyelitis with Streptococcus pneumoniae isolated from blood and otorrhea fluid cultures. This unusual presentation of S. pneumoniae related skull base osteomyelitis could be attributed to an undiagnosed pancreatic cancer at the time of presentation. Malignant otitis externa can progress into invasive disease in the head and neck; almost all cases tend to be caused by Pseudomonas aeruginosa but unusual cases, such as this, can be caused by Streptococcus pneumoniae.

Comportamiento de las neumonías graves en el Hospital Pediátrico Borrás-Marfán. 2015-2019 / Behavior of severe pneumonia at Borrás-Marfán pediatric hospital. 2015-2019

Introducción: Las neumonías constituyen un grave problema de salud al ser causa frecuente de morbilidad y mortalidad infantil en el mundo. Objetivo: Describir el comportamiento de las neumonías graves en un grupo de pacientes ingresados en la Unidad de Terapia Intensiva Pediátrica (UTIP) del Hospital Pediátrico Docente Borrás-Marfán. Material y Métodos: Se realizó un estudio observacional, descriptivo, retrospectivo, en 223 pacientes que ingresaron en el servicio de terapia intensiva mencionado, entre agosto de 2015 y diciembre de 2019, con diagnóstico de neumonía grave. Se caracterizó la muestra según variables demográficas, complicaciones, procederes invasivos realizados, aislamiento microbiológico, antibióticos utilizados y estadía en el servicio. Para el análisis de los resultados se empleó la estadística descriptiva. Resultados: El grupo de edades más representativo fue el de 1-4 años, con un ligero predominio de varones. Las complicaciones más frecuentes fueron el derrame pleural, el neumatocele y el neumotórax. Requirieron toracocentesis el 40,81 por ciento de los casos y pleurotomía el 33,18 por ciento. El principal germen aislado fue el Streptococcus Pneumoniae y la mayoría de los pacientes necesitaron dos antibióticos para el tratamiento. Conclusiones: En el período estudiado, la principal complicación de la neumonía fue el derrame pleural y se realizó toracocentesis y pleurotomía en aproximadamente la mitad de los casos con buenos resultados. El uso de dos antibióticos en la mayoría de los pacientes según los protocolos establecidos resultó efectivo(AU)

Introduction: Pneumonia is a serious health problem because it is a frequent cause of infant morbidity and mortality worldwide. Objective: To describe the behavior of severe pneumonia in a group of patients admitted to the Pediatric Intensive Care Unit (PICU) of Borrás-Marfán Pediatric Hospital. Material and Methods: An observational, descriptive and retrospective study was conducted in 223 patients with the diagnosis of severe pneumonia admitted to the aforementioned intensive care service from August 2015 to December 2019. The sample was characterized according to demographic variables, complications, invasive procedures performed, microbiological isolation, type of antibiotics used, and the number of days spent in the hospital. Descriptive statistics was used for the analysis of results. Results: The most representative age group was 1-4 years, with a slight predominance of males. The most frequent complications were pleural effusion, pneumatocele and pneumothorax. In this group, 40.81 percentof the cases required thoracentesis and 33.18 percent underwent pleurotomy. The main isolated germ was the Streptococcus Pneumoniae and most of the patients needed treatment with two antibiotics. Conclusions: During the period studied, the principal complication of pneumonia was the pleural effusion. Approximately half of the cases underwent thoracentesis and pleurotomy and good results were achieved. The use of two antibiotics according to established protocols were effective, too(AU)

Reversion of Pneumolysin-Induced Executioner Caspase Activation Redirects Cells to Survival.

Apoptosis is an indispensable mechanism for eliminating infected cells and activation of executioner caspases is considered to be a point of no return. Streptococcus pneumoniae, the most common bacterial pathogen causing community-acquired pneumonia, induces apoptosis via its pore-forming toxin pneumolysin, leading to rapid influxes of mitochondrial calcium [Ca2+]m as well as fragmentation, and loss of motility and membrane potential, which is accompanied by caspase-3/7 activation. Using machine-learning and quantitative live-cell microscopy, we identified a significant number of alveolar epithelial cells surviving such executioner caspase activation after pneumolysin attack. Precise single-cell analysis revealed the [Ca2+]m amplitude and efflux rate as decisive parameters for survival and death, which was verified by pharmacological inhibition of [Ca2+]m efflux shifting the surviving cells towards the dying fraction. Taken together, we identified the regulation of [Ca2+]m as critical for controlling the cellular fate under pneumolysin attack, which might be useful for therapeutic intervention during pneumococcal infection.

Incidence and Risk of Pneumococcal Pneumonia in Adults with Distinct Underlying Medical Conditions: A Population-Based Study.

PURPOSE: This study investigated the incidence of pneumococcal pneumonia requiring hospitalisation among middle-aged and older adults with and without specific underlying medical conditions, evaluating the influence of these conditions in the risk of developing pneumonia. METHODS: Population-based prospective cohort study included 2,025,730 individuals ≥ 50 years around Catalonia, Spain. The Catalonian information system for the development of research in primary care (SIDIAP) was used to establish baseline characteristics of the cohort (comorbidities and underlying medical conditions). Hospitalisations from pneumococcal pneumonia occurred among cohort members between 01/01/2015 and 31/12/2015 were collected from hospital discharge codes of 68 reference Catalonian hospitals. Cox regression was used to estimate the association between baseline conditions and the risk of developing pneumonia. RESULTS: Global incidence rate (IR) of hospitalised pneumococcal pneumonia was 82.8 cases per 100,000 persons-year. Maximum IRs (per 100,000 persons-year) emerged among persons with haematological neoplasia (837.4), immunodeficiency (709.2), HIV infection (474.7), severe renal disease (407.5) and chronic pulmonary disease (305.7). In the multivariable analyses, apart from increasing age, HIV infection (hazard ratio [HR] 6.78), haematological neoplasia (HR 6.30), prior all-cause pneumonia (HR 5.27), immunodeficiency (HR 4.57) and chronic pulmonary disease (HR 2.89) were the conditions most strongly associated with an increasing risk. Pneumococcal vaccination did not emerge associated with a reduced risk in our study population (nor PPsV23 neither PCV13). CONCLUSION: Old age, immunocompromising conditions and chronic pulmonary/respiratory disease are major risk factors for pneumococcal pneumonia in adults. Our data underline the need for better prevention strategies in these persons.

Co infection of respiratory syncytial viruses (RSV) and streptococcus pneumonia modulates pathogenesis and dependent of serotype and phase variant.

Streptococcus pneumoniae (pneumococcus) is touted to be the generally found pathogen in patients with respiratory issues and there is an epidemiologic linkage present between Respiratory syncytial virus (RSV). This study aim at investigating the interaction between RSV and two serotypes of S. pneumoniae using a distinct animal model and a well-established colonizing pneumococcal strain. Phase variants phenotype of each strain was determined under oblique light. Co infection model was developed using BALB/c mice housed in a BSL-2 facility. Coinfection experiments were performed and number of bacterial colonies was quantified and phase determination was evaluated. RSV was detected in sample through real-time quantitative PCR. Adherence assays were performed to determine adherence of Spn strains and its knock out ΔNanA to nasopharyngeal carcinoma (NPC) epithelial CNE3 cell line. The biofilm viability was determined and phase composition was counted using plate count. Neuraminidase activity was measured in fluorometircassessed using 2'-(4-methylumbelliferyl)-α-D-N-acetylneuraminic acid (MUAN) as substrate as described in earlier literature. The GraphPad Software version 5.01 i.e., GraphPad Prism was used to conduct the statistical analysis. The extent of bacterial colonization was increased significantly (p < 0.05), when the mice were co infected. Nasal epithelium remained intact in mock sample with features of a thick mucociliary border. A small percentage of pneumococci exhibit phase variation between opaque phase and transparent phase. The percentage adherent of both phase were not found to be varying significantly within serotype but it was seen that nonpathogenic type 27 was more adherent. Biofilm formation was selectively more for transparent phase from a mixed-phase inoculum. Adherence of both phase variant of S. pneumoniae to nasopharyngeal epithelial cells 2 h post infection expressed as the percentage of adherent bacteria relative to the inoculum. In absence of viral infection, the nasal colonization of the opaque and the transparent variant was increased many folds, which was a significant differences. The extent of nasal colonization by the ΔNanA mutant strain were significantly reduced post-bacterial infection for both type of wild-type (P < 0.05). The findings explore insights into the interactions occurring between S. pneumoniae and RSV during respiratory infections and pneumococcal acquisition, indicate that pneumococcal serotypes have different ability to cause infection as well as co infections and potentially follow an unappreciated mechanism. Much more research work is needed to further understand the minutiae of this interaction within co-infection process.

Comparison of the virulence of Streptococcus pneumoniae in ICR mouse stocks of three different origins.

Streptococcus pneumoniae causes many people to suffer from pneumonia, septicemia, and other diseases worldwide. To identify the difference in susceptibility of and treatment efficacy against S. pneumoniae in three ICR mouse stocks (Korl:ICR, A:ICR, and B:ICR) with different origins, mice were infected with 2 × 106, 2 × 107, and 2 × 108 CFU of S. pneumoniae D39 intratracheally. The survival of mice was observed until three weeks after the infection. The three stocks of mice showed no significant survival rate difference at 2 × 106 and 2 × 107 CFU. However, the lung and spleen weight in the A:ICR stock was significantly different from that in the other two stocks, whereas the liver weight in B:ICR stock was significantly lower than that in the other two stocks. Interestingly, no significant CFU difference in the organs was observed between the ICR stocks. The level of interferon gamma inducible protein 10 in Korl:ICR was significantly lower than that in the other two stocks. The level of granulocyte colony stimulating factor in B:ICR was significantly lower than in the other two stocks. However, tumor-necrosis factor-alpha and interleukin-6 levels showed no significant difference between the ICR stocks. In the vancomycin efficacy test after the S. pneumoniae infection, both the single-dose and double-dose vancomycin-treated groups showed a significantly better survival rate than the control group. There was no significant survival difference between the three stocks. These data showed that Korl:ICR, A:ICR, and B:ICR have no susceptibility difference to the S. pneumoniae D39 serotype 2.

Enfermedad neumocócica invasiva en menores de cinco años en Cienfuegos (2009-2015) / Invasive pneumococcal disease in children younger than five years in Cienfuegos (2009-2015)

RESUMEN Fundamento: Desde hace más de una década, la dirección política del país, el sistema de salud y la industria biotecnológica, han otorgado máxima prioridad al proyecto cubano de desarrollo de un candidato vacunal conjugado heptavalente contra los neumococos. El Hospital Pediátrico de Cienfuegos es uno de los centros centinelas para la introducción de dicha vacuna. Objetivo: describir las características clínicas, epidemiológicas y de laboratorio en los pacientes diagnosticados con enfermedad neumocócica invasiva. Métodos: estudio descriptivo, con los pacientes menores de cinco años egresados con diagnóstico de enfermedad neumocócica invasiva. Se analizó edad, sexo, forma de presentación, días previos al ingreso con síntomas, localización del lugar donde se realizó el aislamiento, hospitalización en unidad de cuidados intensivos, mes de ingreso y serotipo aislado. Resultados: predominaron los menores de sexo masculino (60 %). La forma de presentación predominante fue la neumonía, con el 77,7 % de los casos y 66 aislamientos por hemocultivos. El mayor número de casos se concentró en los meses de invierno, y la mayoría de los aislamientos se reportaron en los serotipos 14, 19A y 19F. Un total de 62 pacientes estuvieron ingresado en la Unidad de Cuidados Intensivos. Conclusión: la enfermedad neumocócica invasiva presenta elevada incidencia en menores de cinco años, y es la neumonía la forma de presentación más frecuente con predominio del Serotipo 14.

ABSTRACT Foundation: For more than a decade, the political leadership of the country, the health system and the biotechnology industry have given top priority to the Cuban development project of a heptavalent conjugate vaccine candidate against pneumococci. The Pediatric Hospital of Cienfuegos is one of the sentinel centers for the introduction of this vaccine. Objective: to describe the clinical, epidemiological and laboratory characteristics in patients diagnosed with invasive pneumococcal disease. Methods: a descriptive study with patients younger than five years with a diagnosis of invasive pneumococcal disease. The variables analyzed were: Age, sex, form of presentation, days prior admission with symptoms, location of isolation, hospitalization in intensive care unit, month of admission and isolated serotype. Results: male infants predominated (60%). The predominant presentation was pneumonia, with 77.7% of the cases and 66 isolations by blood cultures. The largest number of cases was concentrated in the winter months, and most of the isolations were reported in serotypes 14, 19A and 19F. A total of 62 patients were admitted to the Intensive Care Unit. Conclusion: invasive pneumococcal disease has a high incidence in children younger than five years, and pneumonia is the most frequent presentation with predominance of Serotype 14.