In vitro antibacterial activities of silver nanoparticles synthesised using the seed extracts of three varieties of Phoenix dactylifera / Atividades antibacterianas in vitro de nanopartículas de prata sintetizadas usando extratos de sementes de três variedades de Phoenix dactylifera

Green synthesis of silver nanoparticles (AgNPs) is an ecofriendly, cost-effective and promising approach for discovery of novel therapeutics. The aim of the current work was to biogenic synthesize, characterize AgNPs using seed extracts of three economically important varieties of date palm (Iklas, Irziz and Shishi), and assess their anti-pathogenic bacterial activities. AgNPs were synthesised then characterised using electron microscopy and Fourier transform infrared analyses. The bactericidal activities of AgNPs against five different bacterial pathogens, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae, were determined in vitro. In particular, changes in membrane integrity of virulent bacterial strains in response to AgNPs were investigated. Results of lactate dehydrogenase, alkaline phosphatase activity assays, and measurement of membrane potential revealed that the cytotoxic effects of the AgNPs were mainly centred on the plasma membrane of bacterial cells, leading to loss of its integrity and eventually cell death. In conclusion, green synthesis of AgNPs is an efficient, cost-effective and promising strategy to combat virulent antibiotic-resistant strains.

A síntese verde de nanopartículas de prata (AgNPs) é uma abordagem ecologicamente correta, econômica e promissora para a descoberta de novas terapêuticas. O objetivo do presente trabalho foi sintetizar biogênica, caracterizar AgNPs usando extratos de sementes de três variedades economicamente importantes de tamareira (Iklas, Irziz e Shishi) e avaliar suas atividades bacterianas antipatogênicas. AgNPs foram sintetizados e caracterizados usando microscopia eletrônica e análise de infravermelho por transformada de Fourier. As atividades bactericidas de AgNPs contra cinco diferentes patógenos bacterianos, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Staphylococcus aureus resistente à meticilina e Streptococcus pneumoniae, foram determinadas in vitro. Em particular, foram investigadas alterações na integridade da membrana de cepas bacterianas virulentas em resposta a AgNPs. Os resultados da lactato desidrogenase, dos ensaios da atividade da fosfatase alcalina e da medição do potencial de membrana revelaram que os efeitos citotóxicos dos AgNPs estavam principalmente centrados na membrana plasmática das células bacterianas, levando à perda de sua integridade e, eventualmente, à morte celular. A síntese verde de AgNPs é uma estratégia eficiente, econômica e promissora para combater cepas virulentas resistentes a antibióticos.

Clinical and microbiological characteristics of community-acquired pneumonia associated with Streptococcus pneumoniae in adult patients in Mexico / Características clínicas y microbiológicas de la neumonía adquirida en la comunidad asociada con Streptococcus pneumoniae en pacientes adultos en México

The aim of this study was to assess the risk factors and clinical and microbiological characteristics of community-acquired pneumonia (CAP) in adult patients in Mexico. Streptococcus pneumoniae classified as the causative agent of CAP in adult patients and patients with invasive S. pneumoniae isolates presented to three tertiary teaching hospitals during the 15-year study period were selected. Serotyping and susceptibility testing were performed for all included isolates. Clinical and demographic data were recorded. A total of 96 patients infected with S. pneumoniae (71 with CAP, 25 with invasive disease) were included. The CAP group involved more males (74.6%) than the invasive disease group (p = 0.03). Head trauma was more common in the CAP group (21.1%) than in the invasive disease group (4.0%; p = 0.03). The most prevalent serotype was 19A, followed by serotypes 3 and 23F. After the introduction of the heptavalent conjugated pneumococcal vaccine (PCV7), the prevalence of included serotypes declined significantly; no such change was found after the introduction of the PCV13 vaccine, including in the prevalence of serotype 19A. Susceptibility to all antimicrobials tested except vancomycin declined over the study period. In conclusion, head trauma was the most common comorbidity in the CAP group. The most prevalent serotype was 19A. Decreased susceptibility to most antimicrobials tested was observed.

El objetivo de este estudio fue evaluar los factores de riesgo y las características clínicas y microbiológicas de la neumonía adquirida en la comunidad (NAC) en pacientes adultos en México. Se seleccionaron pacientes adultos con NAC con Streptococcus pneumoniae como agente causal y pacientes con aislamientos invasivos de S. pneumoniae que concurrieron a tres hospitales de enseñanza de tercer nivel durante el período de estudio de 15 anos (2000-2015). Se realizaron pruebas de serotipificación y sensibilidad con todos los aislados incluidos. Se colectaron los datos clínicos y demográficos. Se incluyeron en total 96 pacientes infectados con S. pneumoniae (71 con NAC y 25 con enfermedad invasiva). El grupo con NAC incluía más varones (74,6%) que el grupo de enfermedad invasiva (p = 0,03). El traumatismo craneoencefálico fue más frecuente en el grupo NAC (21,1%) queen el grupo con enfermedad invasiva (4,0%; p = 0,03). El serotipo más frecuente fue 19A, seguido de los serotipos 3 y 23F. Después de la introducción de la vacuna antineumocócica conjugada heptavalente (PCV7), la prevalencia de los serotipos incluidos en aquella disminuyó significativamente; no sucedió lo mismo después de la introducción de la PCV13, incluso en relación con la prevalencia del serotipo 19A. La sensibilidad a todos los antimicrobianos evaluados, excepto la vancomicina, disminuyó durante el período de estudio. En conclusión, el traumatismo craneoencefálico fue la comorbilidad más frecuente en el grupo con NAC. El serotipo más frecuente fue el 19A, y se observó disminución de la sensibilidad a la mayoría de los antimicrobianos probados a lo largo del período considerado.

Antimicrobial susceptibility and fluctuations in clonal complexes of serogroup 6 Streptococcus pneumoniae isolates collected from children in Beijing, China, between 1997 and 2016

ABSTRACT This study examined the antimicrobial susceptibility patterns and clonal complex (CC) characteristics of serogroup 6 Streptococcus pneumoniae isolates collected from children in Beijing, China, between 1997 and 2016. Serotypes were determined using the Quellung reaction, and the antimicrobial susceptibility profiles of the isolates were determined using the disc-diffusion method or by E-test. Sequence types (STs) were assigned based on multilocus sequence typing. A total of 250 isolates were examined, with 55.2%, 30.0%, 12.8%, and 2.0% of isolates identified as serotypes 6A, 6B, 6C, and 6D, respectively. All of the isolates were susceptible to levofloxacin and vancomycin, and the non-suceptibitility rate to penicillin was 41.6%. Eighty-two distinct STs, assigned to 13 CCs and 28 singletons, were identified. CC982 was the most prevalent CC amongst serotype 6A isolates (34%), followed by CC9789 and CC3173. Amongst serotype 6B isolates, CC90 and CC4542 were the most common, accounting for 25.3% and 14.7% of isolates respectively. Over the study period, the prevalence of CC982, CC4542, and CC4536 isolates showing susceptibility to penicillin and cefuroxime decreased, and the proportion of CC3173, CC9789, CC855, and CC902 isolates showing non-susceptibility to these two antibiotics increased.

Resistencia antibiótica y distribución de serotipos en cepas neumocócicas invasivas en adultos hospitalizados en Lima, Perú / Antibiotic resistance and distribution of serotypes of invasive pneumococcal strains isolated from hospitalized adults in Lima, Peru

RESUMEN Objetivos. Describir las características clínicas, resistencia antibiótica y distribución de serotipos de cepas causantes de enfermedad neumocócica invasiva (ENI) en adultos. Materiales y métodos. Estudio tipo serie de casos. Se recolectaron cepas de neumococo de pacientes adultos hospitalizados con ENI en cinco hospitales nacionales y dos laboratorios de Lima durante los años 2009-2011. Resultados. Se estudiaron datos de 43 pacientes con ENI, el 58,2% fueron mayores de 60 años. Los diagnósticos fueron neumonía 39,5%, meningitis 30,2%, bacteriemia 13,9%, peritonitis 11,6%, artritis séptica 4,8%. El porcentaje de fallecidos fue 28,9%, de los cuales el 72,7% fueron mayores de 60 años. Las cepas de neumococo presentaron la siguiente resistencia: penicilina 0% en cepas no meningitis y 30,8% en cepas meningitis; ceftriaxona 4,5% y 16,7% de resistencia intermedia en cepas no meningitis y cepas meningitis respectivamente; 69% a trimetoprim/sulfametoxazol y 35,7% a eritromicina. Los serotipos más comunes fueron 19F, 23F, 6B, 14 y 6C. El porcentaje de cepas vacunales fue 44,2% para la vacuna conjugada siete-valente (PCV7) y para la PCV10, 51,2% para PCV13 y 60,4% para la vacuna polisacárida veintitrés-valente (PPV23). Conclusiones. El neumococo es un patógeno relevante en adultos, en especial en los adultos mayores, debido a su elevada mortalidad.

ABSTRACT Objectives. To describe the clinical characteristics, antibiotic resistance, and distribution of serotypes of bacterial strains that cause invasive pneumococcal disease (IPD) in adults. Materials and methods. Case series. Pneumococcal strains were isolated from 2009 to 2011 from hospitalized adult patients with IPD in five hospitals and two laboratories located in Lima. Results. The analysis of data from 43 patients with IPD indicated that 58.2% were older than 60 years. The most common complications were pneumonia (39.5%), meningitis (30.2%), bacteremia (13.9%), peritonitis (11.6%), and septic arthritis (4.8%). The mortality rate was 28.9%, and 72.7% of cases involved patients older than 60 years. The pneumococcal strains were resistant to the following antibiotics: penicillin, 0% and 30.8% in non-meningitis and meningitis strains, respectively; ceftriaxone, 4.5% and 16.7% in non-meningitis and meningitis strains, respectively; trimethoprim/sulfamethoxazole, 69.0%; and erythromycin, 35.7%. The most common serotypes were 19F, 23F, 6B, 14, and 6C. The percentage of vaccine strains was 44.2% for the 7-valent conjugate pneumococcal vaccine (PCV7) and PCV10, 51.2% for PCV13, and 60.4% for the 23-valent polysaccharide vaccine (PPV23). Conclusions. Pneumococcus is an important pathogen in adults, particularly in older adults, owing to its high mortality rate.

Molecular characterization of non-vaccine Streptococcus pneumoniae serotypes 11A, 15 B/C and 23A recovered from invasive isolates in Colombia / Caracterización molecular de los serotipos no vacunales 11A, 15 B/C y 23A de Streptococcus pneumoniae recuperados de aislamientos invasivos en Colombia

Resumen Introduction: A total of 192 invasive Streptococcus pneumoniae isolates, from serotypes 11A, 15B/C and 23A (not included in the conjugated vaccines), were collected in Colombia between 1994 and 2014 as part of the activities of the Network surveillance system for the causative agents of pneumonia and meningitis (SIREVA II). Objective: To determine the molecular characteristics ofinvasive S. pneumoniaeisolates from serotypes 11A, 15B/C and 23A in Colombia from 1994 to 2014. Materials and methods: The molecular characterization of the isolates was carried out through Pulse-Field Gel Electrophoresis (PFGE) and Multilocus Sequence Typing (MLST). Results: Serotype 11A showed one clonal group represented by ST62. Serotype 15B/C was composed of three groups associated with Netherlands15B-37 ST199 (28.75%), ST8495 (18.75%), and SLV (Single-Locus Variant) of ST193 (21.25%). Isolates from serotype 23A were gathered in three clonal groups, with70.21% closely related toST42, 17.02% to Colombia23F-ST338, and6.38% to Netherlands15B-37 ST199. Conclusion: Clones Colombia23F-ST338 andNetherlands15B-ST199 covered more serotypes than those previously found by other authors, including serotype 23A. These analyses reveal the importance of capsular switching in the spreading of successful clones among non-vaccine serotypes causing invasive pneumococcal disease.

Abstract Introducción. En Colombia se recolectaron 192 aislamientos invasivos de Streptococcus pneumoniae de los serotipos 11A, 15B/C y 23A (no incluidos en las vacunas conjugadas) entre 1994 y 2014, como parte de las actividades del Sistema de Redes de Vigilancia de los Agentes Responsables de Neumonías y MeningitisBacterianas (SIREVA II). Objetivo. Determinar las características moleculares de aislamientosinvasivos de los serotipos11A, 15B/C y 23A de S. pneumoniae recolectados en Colombia entre 1994 y 2014. Materiales y métodos. La caracterización molecular de los aislamientos se hizo medianteelectroforesis en gel de campo pulsado (Pulse-Field Gel Electrophoresis, PFGE) y por tipificación de secuencias multilocus (Multilocus Sequence Typing, MLST). Resultados. El serotipo 11A mostró un grupo clonal representadopor el ST62, en tanto que el serotipo15B/C se distribuyó en tres grupos asociados conlos clones Netherlands15B-37 ST199 (28,75 %), ST8495 (18,75 %) y SLV (variante en un solo locus) de ST193 (21,25 %). Los aislamientos con serotipo 23A se agruparon en tres gruposclonales; 70,21 % de ellos estaban estrechamente relacionadoscon elST42, 17,02 % con elColombia23F-ST338, y 6,38 % con el Netherlands15B-37 ST199. Conclusión. Los clones Colombia23F-ST338 y Netherlands15B-ST199 encontrados en este estudio abarcaronmás serotipos de los reportados previamente por otros autores, incluido el serotipo23A. Estos análisis revelan laimportancia de la conmutación(switching) capsular en la expansión de clones exitosos entre los serotipos no vacunales como causa de enfermedad invasiva neumocócica.

Serotype changes and antimicrobial nonsusceptibility rates of invasive and non-invasive Streptococcus pneumoniae isolates after implementation of 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) in Bulgaria

Abstract The 10-valent pneumococcal conjugate vaccine (PCV10) has been included in Bulgarian Childhood Immunization Program since 2010. This study aimed to assess serotype distribution and antimicrobial resistance of 198 invasive and non-invasive Streptococcus pneumoniae strains that had been isolated in Bulgaria during 2011-2016 from patients with invasive (IPD) and non-invasive (NIPD) pneumococcal diseases. The most common invasive serotypes were 3 (10.1%), 19F (4.0%), and 7F (3.0%). A significant decrease in the proportion of invasive vaccine types (VTs) from 64.2% to 35.2% was found in comparison with pre-vaccine era. The most common serotypes among middle ear fluids were 3, 19A and 19F (5.6% each), and VTs fell down from 66.4% to 40.0% in post-PCV10 period. Among respiratory isolates, the most prevalent serotypes were some emergent serotypes such as 15A/B/C (5.0%), 19A, and 6C (4.0% each). VTs decreased significantly (16.3%) among vaccinated children compared to unvaccinated children and adults (44.0%). Two non-VTs (19A and 6C) have increased significantly more (p < 0.05) in vaccinated children than in unvaccinated patients. The rates of antibiotic nonsusceptible S. pneumoniae in Bulgaria remained high in post-PCV10 era. Among all source of isolates, antimicrobial nonsusceptibility rates were: oral penicillin - 46.5%, trimethoprim-sulfamethoxazole - 45.4%, erythromycin - 43.9%, tetracycline - 37.4%, and multidrug-resistance (MDR) was 44%. The most common MDR serotypes were 19F, 19A, 6A/C, 15A/B/C and 23A. Our results proved that PCV10 vaccination substantially reduced VTs pneumococcal IPD and NIPD. There has been a shift in the distribution of S. pneumoniae serotypes mostly in vaccinated children but also in the whole population and strong serotype-specific antibiotic resistance was observed after vaccine implementation. Therefore, it is important to continue monitoring serotype changes and pneumococcal resistance among all patient ages in addition to aid in determining the long-term effectiveness of PCV10 interventions.

Antimicrobial and molecular interaction studies on derivatives of curcumin against Streptococcus pneumoniae which caused pneumonia

Background: The antimicrobial properties and molecular interaction analysis of curcumin and its derivatives against three different strains of Streptococcus pneumoniae (Penicillin-susceptible, Penicillin-intermediate and Penicillin-resistant) are studied. Results: These properties were analyzed based on the measurement of the inhibition zone, minimum inhibitory concentration (MIC), and rate of kill revealed that curcumin monoglucoside, curcumin diglucoside and curcumin possessed strong antimicrobial properties even on the Penicillin-resistant strains. Additionally, the molecular docking simulation analyses against Penicillin Binding Protein of S. pneumoniae also confirm that these compounds docked at the active site of the enzyme. Further, the molecular dynamics simulation validates the conformational stability of the docked ligand-protein complexes in the dynamic environment. Conclusion: curcumin monoglucoside, curcumin diglucoside and curcumin can be prescribed for treatment against Penicillin-resistant S. pneumoniae.

Serotype Distribution and Antimicrobial Susceptibilities of Invasive Streptococcus pneumoniae Isolates from Adults in Korea from 1997 to 2012

In Republic of Korea, a 7-valent pneumococcal conjugated vaccine (PCV7) was licensed for use in infants in 2003, and 13-valent PCV (PCV13) replaced it since 2010. We investigated trends in serotype distribution and antibiotic susceptibility of pneumococcal isolates from adult patients with invasive pneumococcal diseases (IPD). Invasive pneumococcal isolates from adult patients of ≥ 16 years of age were collected from 1997 to 2012. Serotypes of the isolates were determined by the Quellung reaction. Distribution of serotypes was analyzed according to the vaccine types. Antibiotic susceptibility was tested by using E-test strips. A total of 272 invasive pneumococcal isolates were included. The most common serotypes were serotype 19F (8.5%, 23/272), and serotype 3 (8.1%, 22/272), and 24.6% (67/272) of the isolates were of non-vaccine serotypes. Of the 272 isolates, 2.6% (7/272) were penicillin MICs of ≥ 4 µg/mL. The proportion of the PCV13 serotypes decreased from 63.3% (50/79) in 1997-2003 to 48.6% (17/35) in 2011-2012, whereas that of non-vaccine serotypes was 26.6% (21/79) and 25.7% (9/35), respectively, for the same periods. The proportion of the PCV13 serotypes showed a decreasing trend among adult patients with IPD over the study period.

In vitro antimicrobial activity of Luffa operculata / Atividade antimicrobiana in vitro da Luffa operculata

INTRODUCTION:Luffa operculata is probably one of the most popular herbal medicines used in the treatment of rhinitis and rhinosinusitis. However, its specific mechanism of action is still unknown.OBJECTIVE: To evaluate in vitro antibacterial activity of L. operculata against three ordinary agents of upper respiratory tract infection: Staphylococcus aureus, Streptococcus pneumoniae and Streptococcus pyogenes.METHODS: Different concentrations of L. operculata alcoholic extract were applied to bacterial broth containing reference and community strains of the three described agents. After a 24-h incubation period, the bacterial culture turbidity was measured. The samples were then inoculated onto Mueller-Hinton and human blood agar plates. Bacterial growth was analyzed after 24- and 48-h incubation period. The test was considered negative when there was no environmental turbidity, confirmed by the absence of bacterial growth into the inoculated plates. Tests were considered positive when either turbidity changes were observed on the bacterial broth or when bacterial growth was detected on inoculated plates. Appropriate statistical analysis of the data was performed.RESULTS:L. operculata extracts showed antibacterial activity mainly to S. pyogenes followed by S. pneumoniae and S. aureus.CONCLUSIONS:L. operculata extract showed promising antibacterial activity in vitro against the studied agents.

INTRODUÇÃO: A Luffa operculataé, provavelmente, o fitoterápico mais utilizado no tratamento das rinites e rinossinusites. Apesar de amplamente utilizada pela população, seus mecanismos de ação ainda não estão completamente estabelecidos.OBJETIVO: Avaliar a atividade antimicrobiana in vitroda Luffa operculataem agentes causadores de infecções de vias aéreas superiores: Staphylococcus aureus, Streptococcus pneumoniaee Streptococcus pyogenes.MÉTODOS: Foram utilizadas diferentes concentrações de extrato alcoólico de Luffa operculataem caldo de bactérias dos agentes avaliados. Após incubação de 24 horas foi realizada a leitura de turvação do meio, e posteriormente, semeadura em placas de ágar-sangue e ágar Muller-Hinton, após 24 e 48 horas de incubação. Foram considerados testes negativos aqueles em que não houve a turvação do meio, confirmados pela ausência do crescimento das bactérias nas semeaduras. Foram considerados positivos os testes que apresentaram turvação do caldo ou positividade nas semeaduras de 24 ou 48 horas. Os resultados foram submetidos à análise estatística pertinente.RESULTADOS: Os extratos de Luffa operculataapresentaram atividade antimicrobiana, especialmente para Streptococcus pyogenes, seguido dos Streptococcus pneumoniaee Sthaphylococcus aureus.CONCLUSÃO: O extrato de Luffa operculataapresentou promissora atividade antimicrobiana in vitrocontra os agentes estudados.

Functional low vision in adults from Latin America: findings from population-based surveys in 15 countries / Baja visión funcional en adultos de América Latina: resultados de las encuestas poblacionales realizadas en 15 países

OBJECTIVE: To review data on functional low vision (FLV) (low vision-visual acuity (VA) < 6/18 (<20/60) to > perception of light (PL+) in the better eye-that is untreatable and uncorrectable) in adults aged 50 years or older from published population-based surveys from 15 countries in Latin America and the Caribbean. METHODS: Data from 15 cross-sectional, population-based surveys on blindness and visual impairment (10 national and five subnational) covering 55 643 people > 50 years old in 15 countries from 2003 to 2013 were reanalyzed to extract statistics on FLV. Eleven of the studies used the rapid assessment of avoidable blindness (RAAB) method and four used the rapid assessment of cataract surgical services (RACSS) method. For the 10 national surveys, age-and sex-specific prevalence of FLV was extrapolated against the corresponding population to estimate the total number of people > 50 years old with FLV. RESULTS: Age- and sex-adjusted prevalence of FLV in people > 50 years old ranged from 0.9% (Guatemala, Mexico, and Uruguay) to 2.2% (Brazil and Cuba) and increased by age. The weighted average prevalence for the 10 national surveys was 1.6%: 1.4% in men and 1.8% in women. For all 10 national studies, a total of 509 164 people > 50 years old were estimated to have FLV. Based on the 910 individuals affected, the main causes of FLV were age-related macular degeneration (weighted average prevalence of 26%), glaucoma (23%), diabetic retinopathy (19%), other posterior segment disease (15%), non-trachomatous corneal opacities (7%), and complications after cataract surgery (4%). CONCLUSIONS: FLV is expected to rise because of 1) the exponential increase of this condition by age, 2) increased life expectancy, and 3) the increase in people > 50 years old. These data can be helpful in planning and developing low vision services for the region; large countries such as Brazil and Mexico would need more studies. Prevention is a major strategy to reduce FLV, as more than 50% of it is preventable.

OBJETIVO: Analizar los datos de las encuestas poblacionales publicadas provenientes de 15 países de América Latina y el Caribe sobre baja visión funcional (BVF) (baja visión, desde una agudeza visual [AV] inferior a 6/18 [20/60] hasta > percepción de luz (PL+), en el mejor ojo, no tratable ni corregible) en adultos de 50 años de edad o mayores. MÉTODOS: Con objeto de extraer información estadística en materia de BVF, se volvieron a analizar los datos de 15 encuestas transversales poblacionales sobre ceguera y deficiencia visual realizadas del 2003 al 2013 (10 a escala nacional y cinco subnacio-nales) que abarcaron a 55 643 personas de > 50 años de edad en 15 países. Once de los estudios emplearon el método de Evaluación Rápida de la Ceguera Evitable y cuatro utilizaron el método de Evaluación Rápida de de Catarata y Servicios Quirúrgicos. Al analizar las 10 encuestas nacionales, se extrapoló la prevalencia específica por edad y sexo de la BVF frente a la población correspondiente, con objeto de calcular el número total de personas de > 50 años de edad con BVF. RESULTADOS: La prevalencia de la BVF ajustada por edad y sexo en personas de > 50 años de edad varió desde 0,9% (en Guatemala, México y Uruguay) a 2,2% (en Brasil y Cuba) y aumentó con la edad. La prevalencia promedio ponderada en las 10 encuestas nacionales fue de 1,6%: 1,4% en hombres y 1,8% en mujeres. Al considerar los 10 estudios nacionales en su conjunto, se calcularon un total de 509 164 personas de > 50 años de edad con BVF. Con base en las 910 personas afectadas, las principales causas de BVF fueron la degeneración macular relacionada con la edad (prevalencia promedio ponderada de 26%), el glaucoma (23%), la retinopatía diabética (19%), otras enfermedades del segmento posterior del ojo (15%), las opacidades corneales no tracomatosas (7%) y las complicaciones posteriores a la cirugía de la catarata (4%). CONCLUSIONES: Se prevé que la BVF aumente como consecuencia de 1) el aumento exponencial de esta afección con la edad, 2) la mayor esperanza de vida, y 3) el aumento de personas de > 50 años de edad. Estos datos pueden ser útiles para planificar y extender los servicios de atención a la disminución de la agudeza visual en la Región; países extensos, como Brasil y México, requerirían nuevos estudios. La prevención constituye una estrategia muy importante para reducir la BVF, ya que más de 50% de los casos se pueden prevenir.

Serotype distribution and antimicrobial resistance of Streptococcus pneumoniae causing noninvasive diseases in a Children's Hospital, Shanghai

Background: Streptococcus pneumoniae, which cause noninvasive pneumococcal diseases, severely impair children's health. This study analyzed serotype distribution and antimicrobial resistance of S. pneumoniae from January 2012 to December 2012 in a Children's Hospital, Shanghai. Methods: A total of 328 pneumococcal isolates were serotyped by multiplex sequential PCR and/or capsule-quellung reaction. The minimum inhibitory concentrations for 11 antimi- crobial agents were determined by broth microdilution method. Results: Among 328 strains, 19F (36.3%), 19A (13.4%), 6A (11.9%), 23F (11.0%), 14 (5.8%), 6B (5.2%), and 15B/C (4.3%) were the most common serotypes. The coverage rates of 7-, 10-, and 13-valent conjugate vaccines (PCV7, PCV10, and PCV13) were 58.2%, 58.2%, and 84.1%, respectively. Out of the isolates, 26 (7.9%) strains were penicillin resistant. Most of the strains displayed high resistance rate to macrolides (98.5% to erythromycin, 97.9% to azithromycin, and 97.0% to clindamycin). Conclusions: The potential coverage of PCV13 is higher than PCV7 and PCV10 because of the emergence of 19A and there should be long-term and systematic surveillance for non-vaccine serotypes. .

Detection of the Efflux-Mediated Erythromycin Resistance Transposon in Streptococcus pneumoniae

BACKGROUND: The present analysis focuses on phenotypic and genotypic characterizations of efflux-mediated erythromycin resistance in Streptococcus pneumoniae due to an increase in macrolide resistance in S. pneumoniae worldwide. METHODS: We investigated the prevalence of efflux-mediated erythromycin resistance and its relevant genetic elements from 186 specimens of S. pneumonia isolated from clinical and normal flora from Tehran, Iran. The presence of erythromycin resistance genes was tested by PCR with two sets of primers, specific for erm(B) and mef(A/E), and their genetic elements with tetM, xis, and int genes. Isolates were typed with the BOX PCR method and tested for resistance to six antibiotics. RESULTS: Antibiotic susceptibility tests revealed that 100% and 47% isolates were resistant to tetracycline and erythromycin, respectively. The erythromycin and clindamycin double-disc diffusion test for macrolide-lincosamide-streptograminB (MLSB) resistance phenotype showed 74 (84%) isolates with the constitutive MLSB phenotype and the remaining with the M phenotype. BOX PCR demonstrated the presence of 7 types in pneumococci with the M phenotype. Fourteen (16%) isolates with the M phenotype harbored mef(A/E), tetM, xis, and int genes. CONCLUSIONS: The present results suggest dissemination of polyclonal groups of S. pneumoniae with the M phenotype carrying resistance genes attributed to transposon 2009.

Infecciones invasivas con bacteriemia por Streptococcus pneumoniae en niños: ¿qué pasó en los últimos 5 años? / Invasive infections with bacteremia due to Streptococcus pneumoniae in children: What has happened over the past 5 years?

Introducción: Las infecciones por Streptococcus pneumoniae (Spn) constituyen enfermedades de alta prevalencia y representan una de las principales causas de morbimortalidad en pediatría. La resistencia antibiótica de S. pneumoniae es variable según las características del huésped, serotipos predominantes y la circulación de clones determinados. El objetivo del estudio fue evaluar las características de los niños con infecciones invasivas con bacteriemia por Spn, la sensibilidad a los antibióticos betalactámicos (penicilina y ceftriaxona) de las cepas, los serotipos identificados y la frecuencia de los serotipos en el período pre-vacunación universal para neumococo (2008 ­ 2011) versus pos vacunal (2012 ­ 2013). Material y métodos: estudio prospectivo. Se incluyeron todos los <18 años internados con documentación de Spn en hemocultivos en el Hospital de Pediatría J. P. Garrahan en el periodo 2008-2013.Se utilizó el programa Epi info versión 3.2.2 (Epi Info 7).Resultados: se incluyeron 171 pacientes, con 52,6% de varones, mediana de edad de 31 meses (RIC 12-61); 116 niños tenían co-morbilidad asociada (67,8%). Las formas clínicas de infección más frecuentes fueron neumonía (n: 68; 39,8%), supuración pleuropulmonar en 12,3% (n:21) y fiebre sin foco clínico en 18,7% (n: 32). La mortalidad fue del 8,2% (n: 14). Todos los aislamientos de Spn fueron sensibles a la penicilina y a las cefalosporinas de tercera generación. No se identificaron Spn con sensibilidad disminuida a los betalactámicos. Los serotipos predominantes fueron el 14, 1, 6A, 7F, 12F, 19A y 23F. Se identificaron serotipos incluidos en la vacuna neumocóccica 13­ V (VNC13) en el período pre vacunal en el 71.1% (n:74) versus 59.7% (n:40) en el período pos vacunal; dicha diferencia no fue estadísticamente significativa. Conclusiones: la mayoría de los pacientes con infecciones invasivas por Spn incluidos en este estudio presentaban enfermedades subyacentes. En el periodo observado no se identificaron cepas de Spn con sensibilidad disminuida a los beta- lactámicos. Aunque la incorporación de la vacuna VNC13 es reciente, la frecuencia de identificación de serotipos incluidos en la VNC-13 disminuyó un 11,4% en relación al periodo pre vacunal (71,1% vs 59,7%) (AU)

Introduction: Infections due to Streptococcus pneumoniae (Spn) are highly prevalent diseases that account for one of the main causes of morbidity and mortality in pediatrics. Resistance to antibiotics of S. pneumoniae is variable according to host characteristics, predominant serotypes, and circulation of dominant clones. The aim of this study was to assess the characteristics of children with invasive infections and bacteremia due to Spn, sensitivity of the strains to beta-lactam antibiotics (penicillin and ceftriaxone), the identified serotypes, and the incidence of serotypes in the pre-universal vaccination for pneumococcus period (2008 ­ 2011) versus the post-vaccination period (2012 ­ 2013). Material and methods: A prospective study. All children <18 years of age with documented Spn in hemocultures admitted to the Pediatric Hospital J. P. Garrahan between 2008 and 2013 were included. Epi info 3.2.2 (Epi Info 7) was used for statistical analysis. Results: We included 171 patients, 52.6% of whom were boys, with a mean age of 31 months (IQR 12-61); 116 children had associated comorbidities (67.8%). The most common clinical manifestations of infection were pneumonia (n: 68; 39.8%), inflammatory-purulent pleuropulmonary disease (n:21; 12.3%), and fever without a clinical focus (n: 32; 18.7%). Mortality was 8.2% (n: 14). All Spn isolates were sensitive to penicillin and third-generation cephalosporins. No Spn with reduced sensitivity to beta-lactams were found. Predominant serotypes were 14, 1, 6A, 7F, 12F, 19ª, and 23F. Serotypes included in the pneumococcal vaccine 13­ V (VNC13) were identified in the pre-vaccination period in 71.1% (n:74) versus 59.7% (n:40) in the post-vaccination period; this difference was not statistically significant. Conclusions: The majority of patients with invasive infections due to Spn included in this study had underlying diseases. In the study period no strains of Spn with diminished sensitivity to beta-lactams were observed. Although the VNC13 vaccine has been recently incorporated, the incidence of identification of serotypes included in the VNC-13 vaccine has decreased 11.4% compared to the pre-vaccine period (71.1% vs 59.7%)

Differentiation of Haemonchus placei from Haemonchus contortus by PCR and by morphometrics of adult parasites and third stage larvae / Identificação de Haemonchus placei e Haemonchus contortus por PCR e por análise morfológica de parasitas adultos e larvas infectantes

Molecular and morphological methods were evaluated to distinguish between Haemonchus contortus and Haemonchus placei species. A total of 141 H. contortus and 89 H. placei male adult specimens collected from artificially infected lambs were identified individually by PCR analysis, using a species-specific primer pair. These PCR results were used as gold standard for Haemonchus spp. identification. Haemonchus placei presented higher mean spicule and barb lengths than H. contortus (P<0.05). However, some measurements overlapped. For this reason, a discriminate function did not allow the correct identification of 13 H. contortus and one H. placei specimen. The sheath tail length of the third stage larvae (L3), which comprises the distance between the tip of the larval tail and the end of the sheath tail, were measured. Only three of the 485 H. placei larvae (0.619%) had a sheath tail shorter than 85 µm, while only four of the 500 H. contortus larvae (0.8%) presented a sheath tail longer than 85 µm. The results indicated that 6.09% of the male adult specimens would be misclassified based on the discriminate function, while only 0.71% of infective larvae would be misclassified. Therefore, identification of L3 can be used as the first method to indicate the presence of H. placei and/or H. contortus in a population of domestic ruminants.

Métodos moleculares e morfológicos foram avaliados para a identificação de Haemonchus contortus e Haemonchus placei. No total, 141 H. contortus e 89 H. placei machos adultos, obtidos de cordeiros artificialmente infectados, foram identificados individualmente por PCR com o emprego de um par de “primers” espécie-específico. Esses resultados da análise por PCR foram considerados como padrão para a identificação das espécies de Haemonchus. Haemonchus placei apresentou valores médios de espículos e ganchos superiores aos de H. contortus (P<0,05). Entretanto, houve sobreposição de alguns valores. Por essa razão, a função discriminante não permitiu a identificação correta de 13 exemplares de H. contortus e de um, de H. placei. Foi medida a cauda da bainha de larvas infectantes (L3), que compreende a distância entre a ponta da cauda da larva e a ponta da cauda da bainha. Apenas três das 485 L3 de H. placei (0,619%) apresentaram a cauda da bainha com medida inferior a 85 µm e somente em quatro das 500 L3 de H. contortus (0,8%) essa medida foi superior a 85 µm. Os resultados demonstraram que 6,09% dos machos adultos seriam identificados erroneamente com base na função discriminante, enquanto a identificação incorreta de L3 seria de apenas 0,71%. Portanto, a identificação de L3 pode ser utilizada como método inicial para indicar a presença de H. placei e/ou H. contortus em uma população de ruminantes domésticos.

Prevalencia de Streptococcus pneumoniae serotipo 19A antes y después de la introducción de la vacuna conjugada heptavalente en México / Prevalence of Streptococcus pneumoniae serotype 19A before and after the introduction of the heptavalent conjugate vaccine in Mexico

Objetivo. Conocer la prevalencia de S. pneumoniae serotipo 19A (Spn19A) antes y después de la introducción de la vacuna conjugada heptavalente (PCV7) en México. Material y métodos. Estudio descriptivo realizado con la información sobre vigilancia de enfermedades causadas por neumococos, generada por la red Sireva. Se realizó un análisis de regresión lineal con la proporción de cepas de Spn19A por año, en dos periodos. Los datos se analizaron con el paquete estadístico SPSS v.18. Resultados. Durante el periodo 2000-2012 se recuperaron 1 825 cepas de S. pneumoniae causantes de infección en población pediátrica, de las cuales 225/12.3% fueron Spn19A, y de éstos, 75/6.3% se aislaron en el periodo 2000-2008 y 150/23.6% en el periodo 2009-2012. La resistencia antimicrobiana post-vacunal aumentó para todos los fármacos, excepto a vancomicina. Conclusión. Se observó que la frecuencia de este serotipo y la resistencia a antimicrobianos aumentó posterior a la introducción de la PCV7.

Objective. To determine the prevalence of S. pneumoniae serotype 19A (Spn19A), before and after the introduction of heptavalent pneumococcal conjugate vaccine (PCV7) in Mexico. Materials and methods. Descriptive study carried out in Mexico with surveillance information of pneumococcal disease, generated from the Sireva network. We performed lineal regression analysis with the proportion of Spn19A by year in two study periods. Data were analyzed using SPSS v.18 software. Results. A total of 1825 S. pneumoniae strains causing infection in pediatric population were recovered in the period 2000-2012, 225/12.3% were Spn19A, and of these, 75/6.3% were isolated in 2000-2008 and 150/23.6% in 2009-2012. There was an increase in antimicrobial resistance post-vaccination for all drugs except vancomycin. Conclusion. It was observed that the frequency of this serotype and antimicrobial resistance increased after the introduction of PCV7.

Bacteremic pneumococcal pneumonia: serotype distribution, antimicrobial susceptibility, severity scores, risk factors, and mortality in a single center in Chile

AIMS: Bacteremic pneumococcal pneumonia (BPP) is a severe condition. To evaluate seasonal distribution, mortality, serotype frequencies, antimicrobial susceptibility, and different severity scores among patients with BPP. PATIENTS AND METHODS: Patients were identified by laboratory data and restricted to adulthood. Standard methods were used for serotyping and antimicrobial susceptibility. Risk factors were analyzed by univariate and multivariate methods. Severity scores (APACHE II, CURB-65 and CAP PIRO) were compared using ROC curves. RESULTS: Sixty events of community-acquired BPP occurred between 2005 and 2010. A seasonal pattern was detected. Mean age was 72.1 years old (81.4% >60 years). All had a predisposing factor. Previous influenza (3.3%) or pneumococcal immunization (1.7%) was infrequent. Admission to critical units was required by 51.7%. Twenty-two serotypes were identified among 59 strains. Only one strain had intermediate resistance to penicillin (1.7%). In-hospital mortality reached 33.3%. Multivariate analysis identified a CAP PIRO score>3 (OR 29.7; IC95 4.7-187), age >65 years (OR 42.1; IC95 2.2-796), and a platelet count<100,000/μL (OR 10.9; IC95 1.2-96) as significant independent factors associated with death. ROC curve analysis did not reveal statistical differences between the three severity scores to predict death (AUC 0.77-0.90). The prognostic yield for all of them was limited (Positive Likelihood Ratio: 1.5-3.8). CONCLUSIONS: BPP had a high case-fatality rate in this group of adult patients with no association to resistant isolates, and a low immunization record. Three independent factors were related to death and the prognostic yield of different severity scores was low. .

Meningitis neumocócica en niños menores de 15 años: Dieciséis años de vigilancia epidemiológica en Misiones, Argentina / Pneumococcal meningitis in children under 15 years of age in Misiones (Argentina): Sixteen year's epidemiological surveillance

Se presentan en este trabajo los resultados de 16 años de vigilancia epidemiológica de meningitis neumocócica llevada a cabo en el Hospital Provincial de Pediatría de Misiones (Argentina), antes de la introducción de la vacuna conjugada al calendario nacional. En el período que va de enero de 1994 a diciembre de 2009 se diagnosticaron 167 casos de meningitis por Streptococcus pneumoniae en niños (1 mes-15 años). La tasa de ataque cada 100 000 niños varió entre 19,2 (1997) y 4,3 (2009), con una media de 10,6 y una tendencia en disminución (y = ""0,689x + 16,52). Esto fue a expensas del grupo de niños entre 1 y 11 meses (94/167, 56 %), en el que disminuyó de 146,6 a 34,8 casos cada 100 000 niños. El 30,7 % de los aislamientos (46/150) fueron resistentes a penicilina y el 16,7 % (25/150) no sensibles a cefotaxima. La resistencia a β-lactámicos se incrementó a partir de 1997 y comenzó a disminuir en 2005. Se detectaron 19 serotipos, predominó el 14 (32 %; 40/125). El 84,8 % de los aislamientos quedaron circunscriptos a nueve serotipos: 14, 5, 1, 7F, 18C, 6B, 9N, 9V y 4. La cobertura teórica en los niños < 2 años y > 2 años fue de 84,1 % (74/88) y 83,8 % (31/37) con la vacuna 10-valente, y de 89,8 % (79/88) y 83,8 % (31/37) con la vacuna 13-valente, respectivamente. La resistencia a penicilina estuvo circunscripta a 8 serotipos (14, 6B, 6A, 9V, 4, 23B, 1 y 19A), y la no sensibilidad a cefotaxima a 3 serotipos (14, 9V y 1), el más importante fue en ambos casos el serotipo 14. Este estudio permitirá evaluar el impacto de la implementación de las vacunas conjugadas en nuestra zona.

We report the results of pneumococcal meningitis surveillance conducted at the Provincial Pediatric Hospital of Posadas, Misiones (Argentina), before the conjugate vaccine was introduced into the national vaccination schedule. Between January 1994 and December 2009, 167 cases of Streptococcus pneumoniae meningitis were diagnosed in children aged 1 month to 15 years. The attack rate/100,000 children ranged from 19.2 (1997) to 4.3 (2009), with a mean of 10.6 and a tendency to decrease (y=""0.689x+16.52). The number of cases per 100,000 children decreased from 146.6 to 34.8 and particularly involved the group of children aged 1 to 11 months (94/167, 56%). Thirty point seven percent (30.7%) (46/150) of the isolates were resistant to penicillin whereas 16.7% (25/150) were non-susceptible to cefotaxime. β-lactam resistance increased as from 1997 and began to decline in 2005. Nineteen serotypes were detected; type 14 was predominant and accounted for 32% (40/125). Eighty four point eight percent (84.8%) of the isolates were circumscribed to nine serotypes: 14, 5, 1, 7F, 18C, 6B, 9N, 9V and 4. Theoretical coverage for patients aged <2 years and >2 years was 84.1% (74/88) and 83.8% (31/37) for the 10-valent vaccine and 89.8 % (79/88) and 83.8% (31/37) for the 13-valent vaccine respectively. Penicillin resistance was restricted to 8 serotypes (14, 6B, 6A, 9V, 4, 23B, 19A1) and nonsusceptibility to cefotaxime was circumscribed to 3 serotypes (14, 9V and 1). This study will allow to evaluate the impact of the implementation of conjugate vaccines on our area.

Antimicrobial resistance in streptococcus pneumoniae: mechanisms and current epidemiology

Infections caused by Streptococcus pneumoniae are a worrisome public health problem worldwide. Young children and the elderly are the main age groups affected and the highest burden of the disease is found in developing countries. Pneumococcal infections cause 11% of the total infant deaths, representing the leading cause of child death currently preventable by vaccination. Epidemiologic information about pneumococci in Brazil is somehow restricted, but available data reinforce the worrisome occurrence of pneumococcal diseases, which are commonly treated empirically. Limitations in the diagnostic methods, along with the severity of disease contribute to this behavior. Thus, surveillance studies are crucial to define the prevalence of resistant strains both globally and in a particular region, as these strains may compromise empirical therapeutic choices. However, although different clones of penicillin non-susceptible pneumococci are internationally distributed, and considering diseases other than meningitis, the prevalence of resistance to penicillin is quite low, making this old, safe, and inexpensive drug an attractive first choice to treat pneumococcal infections. The widespread use of conjugate vaccines among children, influencing the circulation of resistant clones and the distribution of serotypes reinforces the need of surveillance studies to define the prevalence of resistance

Distribution of Serotypes and Antibiotic Susceptibility Patterns Among Invasive Pneumococcal Diseases in Saudi Arabia

BACKGROUND: Streptococcus pneumoniae causes life-threatening infections such as meningitis, pneumonia, and febrile bacteremia, particularly in young children. The increasing number of drug-resistant isolates has highlighted the necessity for intervening and controlling disease. To achieve this, information is needed on serotype distribution and patterns of antibiotic resistance in children. METHODS: All cases of invasive pneumococcal disease (IPD) in children aged less than 15 yr recorded at King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia, were reviewed for serotyping and antibiotic susceptibility. Isolates were collected from 78 consecutive patients with IPD between 2009 and 2012. All collected isolates were subjected to serotyping by co-agglutination, sequential multiplex PCR, and single PCR sequetyping as previously described. RESULTS: The most frequently isolated IPD serotypes were 23F, 6B, 19F, 18C, 4, 14, and 19A, which are listed in decreasing order and cover 77% of total isolates. The serotype coverage for the pneumococcal conjugate vaccine (PCV)7, PCV10, and PCV13 was 77%, 81%, and 90%, respectively. Results from sequential multiplex PCR agreed with co-agglutination results. All serotypes could not be correctly identified using single PCR sequetyping. Minimum inhibitory concentration showed that 50 (64%) isolates were susceptible to penicillin, whereas 70 (90%) isolates were susceptible to cefotaxime. CONCLUSIONS: The most common pneumococcal serotypes occur with frequencies similar to those found in countries where the PCV has been introduced. The most common serotypes in this study are included in the PCVs. Addition of 23A and 15 to the vaccine would improve the PCV performance in IPD prevention.

Resistencia antibiótica de streptococcus pneumoniae en portadores nasofaríngeos sanos de siete regiones del Perú / Antibiotic resistance of streptococcus pneumoniae among healthy nasopharyngeal carriers in seven regions of Peru

Objetivos. Determinar el patrón de susceptibilidad antibiótica de cepas de Streptococcus pneumoniae aisladas de portadores nasofaríngeos sanos menores de 2 años de siete regiones del Perú. Materiales y métodos. Entre el 2007 y 2009 se tomaron muestras de hisopado nasofaríngeo a 2123 niños sanos entre 2 y 24 meses de edad en los consultorios de crecimiento y desarrollo (CRED) y vacunación de hospitales y centros de salud de Lima, Piura, Cusco, Abancay, Arequipa, Huancayo, e Iquitos. Se determinó la resistencia a diez antibióticos mediante la prueba de disco-difusión de las cepas de neumococo aisladas. Resultados. Se aislaron 572 cepas. Se encontró altas tasas de resistencia a cotrimoxazol (58%); penicilina (52,2% no-sensibles); tetraciclina (29,1%); azitromicina (28,9%), y eritromicina (26,3%). La resistencia a cloranfenicol fue baja (8,8%). Se encontró 29,5% de multirresistencia. La resistencia a la azitromicina y a la penicilina fue diferente en las siete regiones (p<0,05), hallándose el mayor porcentaje de cepas no-sensibles a penicilina en Arequipa (63,6%), mientras que el menor fue en Cusco (23,4%). Conclusiones. Los elevados niveles de resistencia encontrados para penicilina, cotrimoxazol y macrólidos en cepas de neumococo aisladas de portadores sanos en todas las regiones estudiadas, y su asociación con uso previo de antibióticos, representan un importante problema de salud pública en nuestro país. Esto resalta la necesidad de implementar, a nivel nacional, estrategias para disminuir el uso irracional de antibióticos, sobre todo en la población pediátrica. Es necesario complementar los datos de resistencia a penicilina con la determinación de la concentración mínima inhibitoria para hacer las recomendaciones terapéuticas respectivas.

Objectives. To determine the pattern of antibiotic susceptibility of isolated Streptococcus pneumoniae strains of healthy nasopharyngeal carriers younger than 2 years in seven regions of Peru. Materials and methods. Between 2007 and 2009, nasopharyngeal swab samples were collected among 2123 healthy children aged 2-24 months in growth and development medical practices (CRED) and vaccination offices of hospitals and health centers in Lima, Piura, Cusco, Abancay, Arequipa, Huancayo, and Iquitos. The resistance to ten antibiotics through disk diffusion sensitivity testing of isolated pneumococcus strains was determined. Results. 572 strains were isolated. High rates of resistance to co-trimoxazole (58%), penicillin (52.2% non-sensitive); tetracycline (29,1%); azithromycin (28,9%), and erythromycin (26,3%). Resistance to chloramphenicol was low (8.8%). Multiresistance was found at 29.5%. Resistance to azithromycin and penicillin was different in all seven regions (p<0,05), the highest percentage of non-sensitive strains being found in Arequipa (63,6%), whereas the lowest percentage was found in Cusco (23.4%). Conclusions. High levels of resistance found to penicillin, co-trimoxasole and macrolides in isolated pneumococcus strains of healthy carriers in all studied regions, and their association to a previous use of antibiotics, represent a significant public health problem in our country. This emphasizes the need to implement nationwide strategies to reduce the irrational use of antibiotics, especially among children. It is necessary to complement data of resistance to penicillin with the determination of minimal inhibitory concentration to make proper therapeutic recommendations.