Posición condilar y espacio articular témporomandibular valorado con tomografía Cone beam / Condylar position and Temporomandibular Joint Space analysis with Cone-beam tomography

Resumen Objetivo. Comparar posición condilar y espacio articular en articulación témporo-mandibular, en pacientes con y sin disfunción témporo-mandibular mediante tomografía Cone Beam. Métodos. Criterios diagnósticos de investigación para trastornos témporo-mandibulares Eje II, n=50 pacientes ambos sexos, edad comprendida 18 - 27 años. Muestra aleatoria n= 50 pacientes equivalente a 100 articulaciones, se obtuvo: n=25 pacientes sin disfunción témporo-mandibular, considerados asintomáticos 25 con y sin disfunción témporo-mandibulares, considerados sintomáticos. Mediante tomografía Cone Beam de articulación témporo-mandibular boca abierta - boca cerrada se avaluó de forma manual los espacios interarticulares. Resultados. El espacio condilar anterior en pacientes con y sin disfunción témporo-mandibular no presentó diferencia significativa, p=0,30. La posición condilar tampoco mostró diferencia significativa p=0,58. En pacientes con y sin disfunción témporo-mandibular (sintomáticos) la posición central y posterior del cóndilo (35,2%), pacientes con y sin disfunción témporo-mandibular (asintomáticos) la posición anterior y central fue más significativa (37,0%); seguido de la posición posterior del cóndilo (26,1%). Conclusión. No existe diferencia significativa en la posición condilar y el espacio interarticular en pacientes sintomáticos y asintomáticos.

Abstract Aim. To compare the condylar position and joint space of the temporomandibular join in individuals with and without temporomandibular dysfunction, using cone beam computed tomography (CBCT). Methods. Research Diagnostic Criteria for Temporomandibular Disorders Axis II (n= 50) patients both sexes, age 18 - 27 years. Random sample (n=50) patients equivalent to 100 joints, obtaining: n-25 patients without temporomandibular dysfunction, considered asymptomatic and 25 patients with and without temporomandibular dysfunction, considered symptomatic. By tomography Cone Beam of open mouth temporomandibular joint - closed mouth was manually evaluated the interarticular spaces. Results. The anterior condylar position space and condylar position not significantly different in induvials with and without temporomandibular dysfunction temporomandibular disorders p=0,30 and p=0,58, respectively. Conclusions. There is no significant difference in the condylar position and intraarticular.

[Distribution of phylogenetic groups, virulence factors and antimicrobial susceptibility in strains of uropathogenic Escherichia coli]. / Distribución de grupos filogenéticos, factores de virulencia y susceptibilidad antimicrobiana en cepas de Escherichia coli uropatógena.

BACKGROUND: The difference between the pathogenic isolates and commensals of Escherichia coli is based on their phylogenetic antecedents. In Venezuela there are few studies that describe the pathogenic potential of phylogenetic groups in E. coli. AIMS: Relate antimicrobial susceptibility, distribution of phylogenetic groups and virulence genes in strains of uropathogenic E. coli (ECUP) isolated from patients with UTI. METHODS: We studied 17 ECUP strains, isolated from adult patients hospitalized in two health institutions. The susceptibility to 8 antibiotics was determined by the broth microdilution (MDC) method. Extended spectrum ß-lactamases (ESBL) and carbapenemases were phenotypically detected. The phylogenetic groups and the detection of the virulence genes were determined by PCR. RESULTS: All strains synthesized ESBL and of these, 41% were associated with the production of a carbapenemases (KPC or MBL). The phylogroup B2 (41%) was the most predominant. The most frequent virulence genes were fimH and fyuA with 82% each. Only one strain from group F was positive to the 6 genes studied. DISCUSSION: The diversity of associations between virulence genes and resistance profiles in the ECUP are evolving continuously, their distribution in the different phylogenetic groups depends to a large extent on the clinical epidemiological characteristics of the study groups.

Distribución de grupos filogenéticos, factores de virulencia y susceptibilidad antimicrobiana en cepas de Escherichia coli uropatógena / Distribution of phylogenetic groups, virulence factors and antimicrobial susceptibility in strains of uropathogenic Escherichia coli

Resumen Introducción: La diferencia entre los aislados patógenos y comensales de Escherichia coli se fundamenta en sus antecedentes filogenéticos. En Venezuela son escasos los estudios que describen el potencial patogénico de los grupos filogenéticos en E. coli. Objetivo: Relacionar la susceptibilidad antimicrobiana, distribución de los grupos filogenéticos y genes de virulencia en cepas de E. coli uropatógena (ECUP) aisladas de pacientes con infección del tracto urinario. Materiales y Métodos: Se estudiaron 17 cepas de ECUP, aisladas de pacientes adultos hospitalizados en dos instituciones de salud. La susceptibilidad frente a ocho antimicrobianos se determinó por el método de microdilución en caldo (MDC). Las β-lactamasas de espectro extendido (BLEE) y carbapenemasas fueron detectadas fenotípicamente. Los grupos filogenéticos y la detección de los genes de virulencia se determinaron por reacción de polimerasa en cadena. Resultados: Todas las cepas sintetizaban BLEE y de éstas, 41% se asoció a la producción de una carbapenemasa (KPC o MBL). El filogrupo B2 (41%) fue predominante. Los genes de virulencia más frecuentes fueron fimH y fyuA con 82% cada uno. Sólo un aislado clasificado en el filogrupo F fue positivo al conjunto de seis genes estudiados. Discusión: La diversidad de asociaciones entre genes de virulencia y perfiles de resistencia, en las cepas ECUP evolucionan continuamente. Además, su distribución en los distintos grupos filogenéticos depende en gran medida de las características clínico epidemiológicas de los grupos de estudios.

Abstract Background: The difference between the pathogenic isolates and commensals of Escherichia coli is based on their phylogenetic antecedents. In Venezuela there are few studies that describe the pathogenic potential of phylogenetic groups in E. coli. Aims: Relate antimicrobial susceptibility, distribution of phylogenetic groups and virulence genes in strains of uropathogenic E. coli (ECUP) isolated from patients with UTI. Methods: We studied 17 ECUP strains, isolated from adult patients hospitalized in two health institutions. The susceptibility to 8 antibiotics was determined by the broth microdilution (MDC) method. Extended spectrum β-lactamases (ESBL) and carbapenemases were phenotypically detected. The phylogenetic groups and the detection of the virulence genes were determined by PCR. Results: All strains synthesized ESBL and of these, 41% were associated with the production of a carbapenemases (KPC or MBL). The phylogroup B2 (41%) was the most predominant. The most frequent virulence genes were fimH and fyuA with 82% each. Only one strain from group F was positive to the 6 genes studied. Discussion: The diversity of associations between virulence genes and resistance profiles in the ECUP are evolving continuously, their distribution in the different phylogenetic groups depends to a large extent on the clinical epidemiological characteristics of the study groups.

Microfiltraciones entre ionómero de vidrio y resina compuesta en lesiones clase-V no cariosas / Microfiltration between glass ionomer and composite resin in non-carious class-V injuries / Microfiltrações entre ionômeros de vidro e resina composta em lesões não cariosas de classe V

No se han establecido estándares para el tratamiento de cavidades cervicales no cariosas; un biomaterial adecuado permitirá buena adaptación y longevidad de la restauración. Objetivo: Determinar la microfiltración en cavidades clase V no cariosas restauradas con ionómero de vidrio y resina nanoparticulada. Materiales y métodos: Cavidades clase V realizadas en la superficie vestibular de 80 premolares sanos (1,5 mm de pro-fundidad x 3 mm de altura en sentido ocluso- gingival x 2 mm de ancho en sentido mesio-distal) se restauraron aleatoriamente con dos biomateriales (n = 40): 1) ionómero de vidrio y 2) resina de nano relleno. Después, los especímenes fueron aislados con barniz y sumergidos en azul de metileno por 24 horas. Posteriormente, las muestras se sometieron 500 ciclos de termociclado por 8 horas y 45 minutos con cambios térmicos de 37°, 72° y 75°C, cada ciclo con una duración de 17 segundos. Las muestras fueron lavadas con agua destilada y seccionadas longitudinalmente para determinar el grado de microfiltración utilizando un estereoscopio (Leica M60, Biosystems). Los datos categóricos se analizaron con el test Chi2 en SPSS 24®. Resultados: Se pudo apreciar que la filtración es significativamente menor en resina que con ionómeros de vidrio (p < 0,001). Sin embargo, ninguno de los materiales de restauración probados fue capaz de sellar los márgenes o las paredes de los dientes completamente. Conclusión: como resultado del presente experimento se determina que las restauraciones de clase V obturadas con resina de nano relleno presentan menor microfiltración marginal que las restauradas con ionómero de vidrio.

No standards have been established for the treatment of non-carious cervical cavities; a suitable biomaterial will allow good adaptation and longevity of the restoration. Objective: To determine microfiltration in non-car-ious class V cavities restored with glass ionomer and nanoparticulate resin. Materials and methods: Class V cavities made on the vestibular surface of 80 healthy premolars (1.5 mm deep x 3 mm high in the occlusion-gin-gival direction x 2 mm wide in the mesio-distal direction) were randomly restored with two biomaterials (n = 40): 1) glass ionomer and 2) nano-filled resin. Then, the specimens were isolated with varnish and immersed in methylene blue for 24 hours. Subsequently, the samples were subjected to 500 cycles of thermocycling for 8 hours and 45 minutes with thermal changes of 37°, 72° and 75° C, each cycle with a duration of 17 seconds. The samples were washed with distilled water and sectioned longitudinally to determine the degree of micro-filtration using a stereoscope (Leica M60 Biosystems). Categorical data were analyzed with the Chi2 test in SPSS 24®. Results: It was observed that filtration is significantly lower in resin than in those restored with glass ionomers (p < 0.001). However, none of the restoration materials tested were able to seal the margins or walls of the teeth completely. Conclusion: As a result of the present experiment, it is determined that class V resto-rations sealed with nano-filled resin have less marginal microfiltration than those restored with glass ionomer.

Ainda não foram estabelecidos padrões para o tratamento de cavidades cervicais não cariosas; um biomate-rial adequado permitirá boa adaptação e longevidade da restauração. Objetivo: Determinar a microfiltração em cavidades não cariosas da classe V restauradas com ionômero de vidro e resina nanoparticulada. Materi-ais e métodos: Cavidades de classe V feitas na superfície vestibular de 80 pré-molares saudáveis (1,5 mm de profundidade x 3 mm de altura na direção oclusão-gengival x 2 mm de largura na direção mesio-distal) foram restaurados aleatoriamente com dois biomateriais (n = 40): 1) ionômero de vidro e 2) resina nano-híbrida. Em seguida, as amostras foram isoladas com verniz e imersas em azul de metileno por 24 horas. Posteriormente, as amostras foram submetidas a 500 ciclos de termociclagem por 8 horas e 45 minutos com alterações tér-micas de 37°, 72° e 75° C, cada ciclo com duração de 17 segundos. As amostras foram lavadas com água destilada e seccionadas longitudinalmente para determinar o grau de microfiltração usando um estereoscópio (Leica M60, Biosystems). Os dados categóricos foram analisados com o teste Chi2 no SPSS 24®. Resul-tados: Observou-se que a filtração é significativamente menor na resina do que nos ionômeros de vidro (p <0,001). No entanto, nenhum dos materiais de restauração testados foram capazes de selar completamente as margens ou paredes dos dentes. Conclusão: como resultado do presente experimento, determina-se que restaurações de classe V seladas com resina nano-preenchida possuem menos microfiltração marginal do que aquelas restauradas com ionômero de vidro.

Seroprevalence and molecular detection of Toxoplasma gondii among donors in a blood bank in Cúcuta, Colombia Introduction: Toxoplasma gondii infection / Seroprevalencia y detección molecular de Toxoplasma gondii en donantes de un banco de sangre de Cúcuta, Colombia

Introduction: Toxoplasma gondii infection manifests differently in humans according to their immunity ranging from asymptomatic profiles to severe disease. There are multiple transmission mechanisms including blood transfusions, but little is known about the frequency of T. gondii infection in Colombia's blood banks. Objective: To determine the prevalence of T. gondii infection in blood donors of a blood bank in the city of Cúcuta by serological and molecular diagnostic techniques. Materials and methods: We identified IgG and IgM antibodies against T. gondii by immunoassay in serum from 348 donors. The frequency of T. gondii DNA was determined by polymerase chain reaction (PCR) in whole blood from seropositive donors and relevant variables were analyzed based on the information obtained from surveys during blood donor selection. Results: Out of the 348 enrolled donors, 134 (38.5%) showed IgG antibodies against T. gondii; two of them (0.6%) had both IgG and IgM, and in two of them (1.5%), parasite DNA was detected in blood samples. A bivariate analysis indicated an association between seropositivity to T. gondii and being over 26 years of age (p=0.020). Conclusions: The prevalence of T. gondii infection found in the blood donors of this study suggests a significant exposure to the infectious agent that becomes relevant when parasitemia is detected.

Introducción. La infección por Toxoplasma gondii puede presentarse en los humanos con un amplio rango de manifestaciones que van desde el estado asintomático hasta la enfermedad grave, según el estado inmunológico del individuo. Los mecanismos de transmisión incluyen la transfusión sanguínea, pero poco se sabe sobre la frecuencia del parásito en los bancos de sangre de Colombia. Objetivo. Determinar la prevalencia de la infección con T. gondii en donantes de un banco de sangre de Cúcuta mediante técnicas de diagnóstico serológico y molecular. Materiales y métodos. Se determinaron los anticuerpos IgG e IgM contra T. gondii mediante un inmunoensayo en suero en 348 donantes. Se determinó la frecuencia de ADN de T. gondii utilizando la reacción en cadena de la polimerasa (PCR) en sangre total de donantes seropositivos y se analizaron las variables de interés con base en la información obtenida durante la selección de donantes. Resultados. De los 348 donantes participantes, 134 (38,5 %) presentaron anticuerpos IgG contra T. gondii; dos (0,6 %) de ellos presentaron tanto IgG como IgM y, en dos (1,5 %), se detectó ADN del parásito en la sangre. Un análisis bivariado evidenció una asociación entre la seropositividad para T. gondii y tener más de 26 años de edad (p=0,020). Conclusiones. La prevalencia de la infección con T. gondii encontrada en los donantes de sangre sugiere una exposición significativa al agente, la cual adquiere relevancia al detectarse la parasitemia.

Seroprevalencia y detección molecular de Toxoplasma gondii en donantes de un banco de sangre de Cúcuta, Colombia / Seroprevalence and molecular detection of Toxoplasma gondii among donors in a blood bank in Cúcuta, Colombia

Resumen Introducción. La infección por Toxoplasma gondii puede presentarse en los humanos con un amplio rango de manifestaciones que van desde el estado asintomático hasta la enfermedad grave, según el estado inmunológico del individuo. Los mecanismos de transmisión incluyen la transfusión sanguínea, pero poco se sabe sobre la frecuencia del parásito en los bancos de sangre de Colombia. Objetivo. Determinar la prevalencia de la infección con T. gondii en donantes de un banco de sangre de Cúcuta mediante técnicas de diagnóstico serológico y molecular. Materiales y métodos. Se determinaron los anticuerpos IgG e IgM contra T. gondii mediante un inmunoensayo en suero en 348 donantes. Se determinó la frecuencia de ADN de T. gondii utilizando la reacción en cadena de la polimerasa (PCR) en sangre total de donantes seropositivos y se analizaron las variables de interés con base en la información obtenida durante la selección de donantes. Resultados. De los 348 donantes participantes, 134 (38,5 %) presentaron anticuerpos IgG contra T. gondii; dos (0,6 %) de ellos presentaron tanto IgG como IgM y, en dos (1,5 %), se detectó ADN del parásito en la sangre. Un análisis bivariado evidenció una asociación entre la seropositividad para T. gondii y tener más de 26 años de edad (p=0,020). Conclusiones. La prevalencia de la infección con T. gondii encontrada en los donantes de sangre sugiere una exposición significativa al agente, la cual adquiere relevancia al detectarse la parasitemia.

Abstract Introduction: Toxoplasma gondii infection manifests differently in humans according to their immunity ranging from asymptomatic profiles to severe disease. There are multiple transmission mechanisms including blood transfusions, but little is known about the frequency of T. gondii infection in Colombia's blood banks. Objective: To determine the prevalence of T. gondii infection in blood donors of a blood bank in the city of Cúcuta by serological and molecular diagnostic techniques. Materials and methods: We identified IgG and IgM antibodies against T. gondii by immunoassay in serum from 348 donors. The frequency of T. gondii DNA was determined by polymerase chain reaction (PCR) in whole blood from seropositive donors and relevant variables were analyzed based on the information obtained from surveys during blood donor selection. Results: Out of the 348 enrolled donors, 134 (38.5%) showed IgG antibodies against T. gondii; two of them (0.6%) had both IgG and IgM, and in two of them (1.5%), parasite DNA was detected in blood samples. A bivariate analysis indicated an association between seropositivity to T. gondii and being over 26 years of age (p=0.020). Conclusions: The prevalence of T. gondii infection found in the blood donors of this study suggests a significant exposure to the infectious agent that becomes relevant when parasitemia is detected.

Molecular typing, antibiotic resistance profiles and biocide susceptibility in Salmonella enterica serotypes isolated from raw chicken meat marketed in Venezuela.

INTRODUCTION: Salmonella is a common bacterial cause of foodborne diarrhea worldwide. The purpose of this study was to characterize antimicrobial resistance and susceptibility to biocides in Salmonella enterica serotypes isolated from raw chicken meat, as well as to study the genetic relationship between strains and virulence profiles. METHODS: Nine Salmonella enterica strains (5 S. Heidelberg; 2 S. Enteritidis; 1 S. Typhimurium and 1 S. Meleagridis) recovered from raw chicken meat marketed in the urban area of Mérida, Venezuela, were studied. Phenotypic characterization was based on antimicrobial susceptibility testing as well as detection of extended-spectrum ß-lactamases (ESBLs) by double-disc synergy. The susceptibility to biocides was determined using the dilution-neutralization methods. The detection of quinolone resistance-determining regions of gyrA, gyrB, and parC genes, bla ESBLs genes, plasmid-mediated quinolone resistance determinants and virulence genes (invA and spvC) was carried out by PCR. All strains were typed using PFGE. RESULTS: Multidrug-resistance was evident in 6 of 9 strains studied. However, all Salmonella serotypes were susceptible to the tested biocides. Genotypic characterization determined that 5 strains harbored the bla CTXM-2, 4 bla TEM-1 and 3 qnrB19 genes. All strains were positive for the invA gene. The spvC gene was detected in 4 of them. PFGE grouped Salmonella strains into 4 different patterns that represented individual serotypes. CONCLUSIONS: This study provides valuable information on antibiotic resistance, biocide susceptibility profiles, virulence gene content and genetic diversity of Salmonella enterica serotypes isolated from raw chicken meat marketed in Venezuela, and evidenced a health risk for consumers.

Resurgence of Vaccine-Preventable Diseases in Venezuela as a Regional Public Health Threat in the Americas.

Venezuela's tumbling economy and authoritarian rule have precipitated an unprecedented humanitarian crisis. Hyperinflation rates now exceed 45,000%, and Venezuela's health system is in free fall. The country is experiencing a massive exodus of biomedical scientists and qualified healthcare professionals. Reemergence of arthropod-borne and vaccine-preventable diseases has sparked serious epidemics that also affect neighboring countries. In this article, we discuss the ongoing epidemics of measles and diphtheria in Venezuela and their disproportionate impact on indigenous populations. We also discuss the potential for reemergence of poliomyelitis and conclude that action to halt the spread of vaccine-preventable diseases within Venezuela is a matter of urgency for the country and the region. We further provide specific recommendations for addressing this crisis.

Comparación y evaluación de métodos cuantitativos para determinar la susceptibilidad antimicrobiana de cepas del complejo Mycobacterium abscessus / Comparison and Evaluation of Quantitative Methods for Determining Antimicrobial Susceptibility of Complex Mycobacterium Abscessus Strains / Comparação e avaliação de métodos quantitativos para determinar a susceptibilidade antimicrobiana de cepas do complexo Mycobacterium abscessos

Resumen Introducción: el complejo Mycobacterium abscessus incluye especies patógenas emergentes multirresistentes, lo cual limita las opciones terapéuticas para tratar las infecciones causadas por dichos microorganismos. En este estudio se compararon las concentraciones inhibitorias mínimas (CIM) obtenidas mediante dos métodos cuantitativos, se establecieron los puntos de corte empleados en el micrométodo colorimétrico (MMC) y se evaluó la susceptibilidad antimicrobiana. Materiales y métodos: la CIM de nueve antibióticos fue determinada mediante el MMC y la microdilución en caldo (MDC) para 19 cepas del complejo M. abscessus. El test F de Snedecor se utilizó para establecer la diferencia significativa de las CIM entre los dos métodos y se determinaron los puntos de corte mediante la técnica de distribución de la probabilidad para el MMC. Resultados: se encontró una correlación de los resultados de la CIM del 50% entre MMC y MDC para los antibióticos ensayados. Probablemente esta discrepancia en los resultados se deba a diferencias en algunos parámetros técnicos de cada procedimiento. Todas las cepas fueron sensibles a la amikacina y resistentes a meropenem y ampicilina-sulbactam. Independientemente de la especie del complejo M. abscessus, las fluoroquinolonas mostraron una baja actividad inhibitoria (0-25%) sobre los aislados clínicos, resultados que son similares a los reportados por otros autores. Conclusión: Los patrones de multirresistencia observados en las cepas analizadas sugieren la necesidad de utilizar las pruebas de susceptibilidad como herramientas que permitan orientar y optimizar las conductas terapéuticas en infecciones producidas por M. abscessus.

Abstract Introduction: The Mycobacterium abscessus complex includes multidrug resistant emerging pathogens, which limit therapeutic options for treating infections caused by these microorganisms. In this study, the minimum inhibitory concentrations (MICS) obtained by 2 quantitative methods were compared, the cut-off points used in the colorimetric micromethod (CMM) were established and the antimicrobial susceptibility was evaluated. Materials and Methods: The MIC for nine antibiotics was determined by CMM and broth microdilution (BMD) for 19 strains of M. abscessus complex. The Snedecor F test was used to establish the significant difference in the CIM between the methods, cutoff points were determined by the probability distribution method for the CMM. Discussion: A correlation of 50% between CMM and BMD for antibiotics tested was found. Probably, this discrepancy in the results is due to differences in some technical parameters of each procedure. All strains were susceptible to amikacin and were resistant to meropenem and ampicillin-sulbactam. Independently of the species of M. abscessus complex, fluoroquinolones showed a low inhibitory activity (0-25%) on clinical isolates, results that are similar to those reported by other authors. Conclussion: The Multidrug resistance patterns observed in the strains tested suggest the need for susceptibility testing as tools to guide and optimize the therapeutic behavior in infections caused by M. abscessus.

Resumo Introdução: o complexo Mycobacterium abscessus inclui espécies patógenas emergentes multirresistentes, o qual limita as opções terapêuticas para tratar as infeções causadas por estes microrganismos. Neste estudo compararam-se as concentrações inibitórias mínimas (CIMS) obtidas mediante 2 métodos quantitativos, se estabeleceram os pontos de corte empregados no micrométodo colorimétrico (MMC) e se avaliou a susceptibilidade antimicrobiana. Materiais e métodos: a CIM de 9 antibióticos foi determinada mediante o MMC e microdiluição em caldo (MDC) para 19 cepas do complexo M. abscessus. O teste F de Snedecor utilizou-se para estabelecer a diferença significativa das CIMS entre os dois métodos e determinaram-se os pontos de corte mediante a técnica de distribuição da probabilidade para o MMC. Resultados: se encontrou uma correlação dos resultados da CIM do 50% entre MMC e MDC para os antibióticos testados. Provavelmente, esta discrepância nos resultados se deve a diferenças em alguns parâmetros técnicos de cada procedimento. Todas as cepas foram sensíveis à amikacina e resistentes a meropenem e ampicilina-sulbactam. Independentemente da espécie do complexo M. abscessos, as fluoroquinolonas mostraram uma baixa atividade inibitória (0-25%) sobre os isolados clínicos, resultados que são similares aos reportados por outros autores. Conclussão: Os patrões de multirresistência observados nas cepas analisadas, sugerem a necessidade de utilizar as provas de susceptibilidade como ferramentas que permitam orientar e otimizar as condutas terapêuticas em infeções produzidas por M. abscessus.

Prevalence of Fecal Carriage of CTX-M-15 Beta-Lactamase-Producing Escherichia coli in Healthy Children from a Rural Andean Village in Venezuela.

OBJECTIVES: Antimicrobial resistant extended-spectrum-ß-lactamase-producing Enterobacteriaceae (ESBL-PE) have been shown to be present in healthy communities. This study examined healthy children from the rural Andean village of Llano del Hato, Mérida, Venezuela, who have had little or no antibiotic exposure to determine the prevalence of fecal carriage of ESBL-producing Escherichia coli (ESBL-EC). METHODS: A total of 78 fecal samples were collected in healthy children aged from 1 to 5 years. ESBL-EC were selected in MacConkey agar plates with cefotaxime and further confirmed by the VITEK 2 system. ESBL were phenotypically detected and presence of bla genes and their variants were confirmed by molecular assays. Determination of phylogenetic groups was performed by PCR amplification. Risk factors associated with fecal carriage of ESBL-EC-positive isolates were analyzed using standard statistical methods. RESULTS: Of the 78 children studied, 27 (34.6%) carried ESBL-EC. All strains harbored the blaCTX-M-15 allele. Of these, 8 were co-producers of blaTEM-1, blaTEM-5, blaSHV-5 or blaSHV-12. Co-resistance to aminoglycosides and/or fluoroquinolones was observed in 9 strains. 51.9% of ESBL-EC isolates were classified within phylogroup A. A significant, positive correlation was found between age (≥2.5 - ≤5 years), food consumption patterns and ESBL-EC fecal carriage. CONCLUSION: This is the first study describing the high prevalence of fecal carriage of ESBL-EC expressing CTX-M-15- among very young, healthy children from a rural Andean village in Venezuela with scarce antibiotic exposure, underlining the importance of this population as a reservoir.

Molecular characterisation of multidrug-resistant pneumococcal clones colonising healthy children in Mérida, Venezuela.

Genetic mechanisms of resistance, clonal composition and the occurrence of pili were analysed in 48 multidrug-resistant (MDR) pneumococci isolated from healthy children in Mérida, Venezuela. Intermediate resistance to penicillin was related to variations in pbp2b and pbp2x. High-level resistance to penicillin as well as low susceptibility to cephalosporins and carbapenems were associated with alterations in pbp1a, pbp2b and pbp2x. Non-ß-lactam resistance was associated with Tn3872, Tn5253, Tn6002 and Tn2010 transposons. Macrolide-resistant strains carried ermB or mefE, but not mefA. Tetracycline- and chloramphenicol-resistant pneumococci carried tetM and cat, respectively. MDR pneumococci were related to six clonal complexes (CCs), largely CC156 or CC15. Limited diversity in pbp2a,2b,2x-RFLP profiles within each clone was observed. Conversely, detection of non-ß-lactam resistance and transposons revealed clear genetic diversity within clones. A group of non-typeable/cpsA-negative pneumococci related to the null capsule clade 1 (NCC1) carrying a Tn2009 element was found. Each NCC1-related strain showed a novel MLST allelic combination and a different pbp2a,2b,2x-RFLP profile. PI-1 (pilus type 1 rrgC gene) was present in most of the MDR pneumococci and its occurrence was commonly homogeneous within each clone. PI-1 was present in all CC242 and CC320 pneumococci, whereas it was absent in all CC37, CC81 and NCC1 isolates. CC156 and CC15 isolates showed variations in the occurrence of PI-1. Both PI-1 and the islet for pilus type 2 were present in CC320 isolates. We provide useful data to follow the evolution of clonal composition, mechanisms of antibiotic resistance and the occurrence of pili among pneumococci circulating in Mérida.

Diversidad genética de cepas extraintestinales de Escherichia coli productoras de las betalactamasas TEM, SHV y CTX-M asociadas a la atención en salud / Genetic diversity of extraintestinal Escherichia coli strains producers of beta-lactamases TEM, SHV and CTX-M associated with healthcare

RESUMEN Introducción. En Venezuela existen pocos reportes que describan las bases genéticas del potencial patogénico y filogenético de las cepas de Escherichia coli provenientes de hospitales. Objetivo. Determinar la diversidad genética de cepas extraintestinales de E. coli productoras de las betalactamasas TEM, SHV y CTX-M asociadas a la atención de salud. Materiales y métodos. Se estudió una colección de 12 cepas extraintestinales de E. coli con sensibilidad disminuida a las cefalosporinas de amplio espectro. La sensibilidad antimicrobiana se determinó por concentración inhibitoria mínima. La detección de los grupos filogenéticos, de los factores de virulencia y de los genes que codifican la resistencia antimicrobiana se hizo mediante la técnica de reacción en cadena de la polimerasa y la relación clonal se estableció mediante reacción en cadena de la polimerasa de elementos palindrómicos extragénicos repetitivos (Repetitive Element Palindromic-PCR, rep-PCR). Resultados. Todas las cepas analizadas presentaron resistencia a las cefalosporinas, y resistencia conjunta a quinolonas y aminoglucósidos. La distribución filogenética evidenció que los grupos A y B1 fueron los más frecuentes, seguidos por D y B2; en este último, se detectaron todos los factores de virulencia evaluados, y el gen más frecuente fue el fimH. En todas las cepas analizadas, se encontró bla CTX-M, con predominio de las bla CTX-M-8, y en dos de estas cepas se evidenció la presencia simultánea de bla CTX-M-9, variantes bla CTX-M-65 y bla CTX-M-147. Conclusión. Las cepas estudiadas demostraron diversidad genética y albergaron diferentes genes de virulencia y betalactamasas de espectro extendido (BLEE) sin predominio de ningún filogrupo en particular. Este estudio constituye el primer reporte de la variante bla CTX-M-65 en Venezuela y de la variante bla CTX-M-147 en el mundo, en cepas no relacionadas genéticamente aisladas de hospitales, situación que merece atención y la racionalización del uso de los antimicrobianos.

ABSTRACT Introduction: There are few reports from Venezuela describing the genetic basis that sustains the pathogenic potential and phylogenetics of Escherichia coli extraintestinal strains isolated in health care units. Objective: To establish the genetic diversity of extraintestinal E. coli strains producers of beta-lactamases TEM, SHV and CTX-M associated with healthcare. Materials and methods: We studied a collection of 12 strains of extraintestinal E. coli with diminished sensitivity to broad-spectrum cephalosporins. Antimicrobial susceptibility was determined by minimum inhibitory concentration. We determined the phylogenetic groups, virulence factors and genes encoding antimicrobial resistance using PCR, and clonal characterization by repetitive element palindromic-PCR rep-PCR. Results: All strains showed resistance to cephalosporins and joint resistance to quinolones and aminoglycosides. The phylogenetic distribution showed that the A and B1 groups were the most frequent, followed by D and B2. We found all the virulence factors analyzed in the B2 group, and fimH gene was the most frequent among them. We found bla CTX-M in all strains,with a higher prevalence of bla CTX-M-8; two of these strains showed coproduction of bla CTX-M-9 and were genetically identified as bla CTX-M-65 and bla CTX-M-147 by sequencing. Conclusion: The strains under study showed genetic diversity, hosting a variety of virulence genes, as well as antimicrobial resistance with no particular phylogroup prevalence. This is the first report of bla CTX-M alleles in Venezuela and in the world associated to non-genetically related strains isolated in health care units, a situation that deserves attention, as well as the rationalization of antimicrobials use.

[Clinical and microbiological study of catheter-associated urinary tract infections in internal medicine services of a Venezuelan university hospital]. / Estudio clínico y microbiológico de la infección urinaria asociada a catéter, en los servicios de medicina interna de un hospital universitario venezolano.

OBJECTIVES: To determine the clinical and microbiological characteristics of catheter-associated urinary tract infections (CA-UTI) in patients admitted to the Internal Medicine services of the Hospital Universitario de Los Andes (HULA), Mérida, Venezuela and to establish the clonal distribution of multi-resistant Enterobacteriaceae that produce this infection. MATERIALS AND METHODS: Seventy-three adult patients with bladder catheterization were studied between January and July 2015. The microbiological processing of the urine samples was performed using conventional and automatized methods. Extended- spectrum beta-lactamase (ESBL) and carbapenemase were detected phenotypically. Clonal classification was determined using repetitive element sequence-based PCR. RESULTS: A total of 53.4% of the patients were male, and the average age was 50.6 years. The average time the catheter remained in the patient was 10.9 ± 6.5 days and 54.8% of patients had positive urine cultures. Yeasts were the main etiological agent (44.7%), followed by enterobacteria (29.8%). Enterobacteria, Pseudomonas aeruginosa, and Acinetobacter baumannii produced ESBL and carbapenemase associated with other resistance markers. Two clonal groups were identified in multi-resistant Escherichia coli and Klebsiella pneumoniae strains that circulated in the shock trauma unit in the adult emergency department. CONCLUSIONS: The findings in this study show the need to adopt strict criteria justifying the use of bladder catheterization and its duration, as well as the implementation of programs to prevent and control the spread of multi-resistant bacterial clones in patients with CA-UTI in the HULA Internal Medicine department.

[Genetic diversity of extraintestinal Escherichia coli strains producers of beta-lactamases TEM, SHV and CTX-M associated with healthcare].

INTRODUCTION: There are few reports from Venezuela describing the genetic basis that sustains the pathogenic potential and phylogenetics of Escherichia coli extraintestinal strains isolated in health care units. OBJECTIVE: To establish the genetic diversity of extraintestinal E. coli strains producers of betalactamases TEM, SHV and CTX-M associated with healthcare. MATERIALS AND METHODS: We studied a collection of 12 strains of extraintestinal E. coli with diminished sensitivity to broad-spectrum cephalosporins. Antimicrobial susceptibility was determined by minimum inhibitory concentration. We determined the phylogenetic groups, virulence factors and genes encoding antimicrobial resistance using PCR, and clonal characterization by repetitive element palindromic-PCR rep-PCR. RESULTS: All strains showed resistance to cephalosporins and joint resistance to quinolones and aminoglycosides. The phylogenetic distribution showed that the A and B1 groups were the most frequent, followed by D and B2. We found all the virulence factors analyzed in the B2 group, and fimH gene was the most frequent among them. We found blaCTX-M in all strains,with a higher prevalence of blaCTX-M-8; two of these strains showed coproduction of blaCTX-M-9 and were genetically identified as blaCTXM-65 and blaCTX-M-147 by sequencing. CONCLUSION: The strains under study showed genetic diversity, hosting a variety of virulence genes, as well as antimicrobial resistance with no particular phylogroup prevalence. This is the first report of blaCTX-M alleles in Venezuela and in the world associated to non-genetically related strains isolated in health care units, a situation that deserves attention, as well as the rationalization of antimicrobials use.

Estudio clínico y microbiológico de la infección urinaria asociada a catéter, en los servicios de medicina interna de un hospital universitario venezolano / Clinical and microbiological study of catheter-associated urinary tract infections in internal medicine services of a Venezuelan university hospital

RESUMEN Objetivos Determinar las características clínicas y microbiológicas de las infecciones del tracto urinario asociadas a catéter (ITUAC) en pacientes hospitalizados en los servicios de Medicina Interna del Hospital Universitario de Los Andes (HULA), Mérida, Venezuela y establecer la distribución clonal de Enterobacteriaceae multirresistentes productoras de esta infección. Materiales y métodos Se estudiaron 73 pacientes adultos con cateterismo vesical, durante enero a julio de 2015. El procesamiento microbiológico de las muestras de orina se realizó por métodos convencionales y automatizados. Las β-lactamasas de espectro extendido (BLEE) y carbapenemasas fueron detectadas fenotípicamente. La tipificación clonal se determinó por la amplificación de secuencias repetitivas por PCR. Resultados El 53,4% de los pacientes eran varones, con una edad media de 50,6 años. El promedio de permanencia del catéter fue de 10,9 + 6,5 días/paciente. El 54,8% de los pacientes tuvo urocultivos positivos. Las levaduras fueron el principal agente etiológico (44,7%), seguido por las enterobacterias (29,8%). Las enterobacterias, Pseudomonas aeruginosa y Acinetobacter baumannii produjeron BLEE y carbapenemasas asociadas a otros marcadores de resistencia. Dos grupos clonales fueron identificados en cepas de E. coli y K. pneumoniae multirresistentes, los cuales circularon en la unidad de trauma shock de la emergencia de adulto. Conclusiones Los hallazgos de este estudio permiten evidenciar la necesidad de adoptar estrictos criterios que justifiquen el uso del catéter vesical y la duración del mismo, así como el implementar programas para prevenir y controlar la diseminación de clonas bacterianas multirresistentes en pacientes con ITUAC en los servicios de medicina interna del HULA.

ABSTRACT Objectives To determine the clinical and microbiological characteristics of catheter-associated urinary tract infections (CA-UTI) in patients admitted to the Internal Medicine services of the Hospital Universitario de Los Andes (HULA), Mérida, Venezuela and to establish the clonal distribution of multi-resistant Enterobacteriaceae that produce this infection. Materials and Methods Seventy-three adult patients with bladder catheterization were studied between January and July 2015. The microbiological processing of the urine samples was performed using conventional and automatized methods. Extended- spectrum beta-lactamase (ESBL) and carbapenemase were detected phenotypically. Clonal classification was determined using repetitive element sequence-based PCR. Results A total of 53.4% of the patients were male, and the average age was 50.6 years. The average time the catheter remained in the patient was 10.9 ± 6.5 days and 54.8% of patients had positive urine cultures. Yeasts were the main etiological agent (44.7%), followed by enterobacteria (29.8%). Enterobacteria, Pseudomonas aeruginosa, and Acinetobacter baumannii produced ESBL and carbapenemase associated with other resistance markers. Two clonal groups were identified in multi-resistant Escherichia coli and Klebsiella pneumoniae strains that circulated in the shock trauma unit in the adult emergency department. Conclusions The findings in this study show the need to adopt strict criteria justifying the use of bladder catheterization and its duration, as well as the implementation of programs to prevent and control the spread of multi-resistant bacterial clones in patients with CA-UTI in the HULA Internal Medicine department.

Biochemical Characterization of ß-Lactamases from Mycobacterium abscessus Complex and Genetic Environment of the ß-Lactamase-Encoding Gene.

The objectives of this study were to determine the kinetic parameters of purified recombinant BlaMab and BlaMmas by spectrophotometry, analyze the genetic environment of the blaMab and blaMmas genes in both species by polymerase chain reaction and sequencing, furthermore, in silico models of both enzymes in complex with imipenem were obtained by modeling tools. Our results showed that BlaMab and BlaMmas have a similar hydrolysis behavior, displaying high catalytic efficiencies toward penams, cephalothin, and nitrocefin; none of the enzymes are well inhibited by clavulanate. BlaMmas hydrolyzes imipenem at higher efficiency than cefotaxime and aztreonam. BlaMab and BlaMmas showed that their closest structural homologs are KPC-2 and SFC-1, which correlate to the mild carbapenemase activity toward imipenem observed at least for BlaMmas. They also seem to differ from other class A ß-lactamases by the presence of a more flexible Ω loop, which could impact in the hydrolysis efficiency against some antibiotics. A -35 consensus sequence (TCGACA) and embedded at the 3' end of MAB_2874, which may constitute the blaMab and blaMmas promoter. Our results suggest that the resistance mechanisms in fast-growing mycobacteria could be probably evolving toward the production of ß-lactamases that have improved catalytic efficiencies against some of the drugs commonly used for the treatment of mycobacterial infections, endangering the use of important drugs like the carbapenems.

Evaluation of Two Supplemented Culture Media for Long-Term, Room-Temperature Preservation of Streptococcus pneumoniae Strains.

OBJECTIVE: To produce two supplemented agar types in order to store pneumococci for several months at room temperature. METHODS: Todd-Hewitt/Hemoglobin/Yeast/Charcoal/Agar (TH-HYC) and Todd-Hewitt/Skim-Milk/Yeast/Charcoal/Agar (TH-SYC) were used to prepare two supplemented agar types. Nineteen pneumococci isolated from patients or asymptomatic carriers displaying diverse serotypes and multilocus sequence types (MLST) were subcultured and stored onto supplemented agar types, in four different tests, at room temperature. FINDINGS: At the end of all tests (4-6 months) all noncontaminated subcultures were viable and maintained all phenotypic characteristics. Survival-time curves revealed a slow decrease of viable CFU over time on agar types, but at the end the number of viable CFU was satisfactory (≥2+ of growth). Decreasing of CFU was significantly higher for clinical versus nasopharyngeal isolates. Subcultures contamination rates were 6.25% and 14.58% after 2 and 6 months of storage, respectively. CONCLUSION: TH-HYC and TH-SYC agar types allowed the viability of pneumococci with several serotypes, MLST, and genetic profiles, after 6 months of storage at room temperature. We consider that these agar types are a valid alternative to preserve pneumococci over an extended period, especially when methods as cryopreservation or lyophilization are not available, and are useful for transporting strains between laboratories.

Nosocomial outbreak of extended-spectrum ß-lactamase-producing Enterobacter ludwigii co-harbouring CTX-M-8, SHV-12 and TEM-15 in a neonatal intensive care unit in Venezuela.

Enterobacter spp. have emerged as an important group of pathogens linked to outbreaks in neonatal intensive care units (NICUs), usually involving strains expressing extended-spectrum ß-lactamases (ESBLs). The aim of this study was to describe the first nosocomial bloodstream infection outbreak caused by Enterobacter ludwigii co-harbouring CTX-M-8, SHV-12 and TEM-15 in a NICU in a Venezuelan hospital. Initial bacterial identification was achieved by VITEK®2 system and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (VITEK® MS) and was subsequently confirmed by nucleotide sequencing of the 16S rDNA gene and hsp60 genotyping. Antimicrobial susceptibility testing was determined by AST-GN-299 VITEK®2 system cards and Etest strips. Isolates were typed by repetitive element sequence-based PCR (rep-PCR). Detection of blaESBL genes was carried out by molecular methods. Plasmid analysis included Southern blot and restriction pattern analysis, with transferability of resistance genes being assessed by conjugation. ESBL-producing E. ludwigii isolates were recovered from three neonates with bloodstream infection from the NICU in a 21-day period. rep-PCR fingerprints were indistinguishable among all of the isolates, strongly suggesting spread of a clonal strain. All isolates carried an ca. 56kb conjugative plasmid harbouring the blaCTX-M-8, blaSHV-12 and blaTEM-15 genes. Considering that isolation of ESBL-producing E. ludwigii remains an unusual phenomenon, not previously reported in Venezuela, the results of this study reveal the potential role of E. ludwigii as an emerging pathogen and highlight the importance of microbiological surveillance and judicious antibiotic use as measures to curb the emergence and spread of ESBL-producing bacteria.

Posición condilar y espacio articular témporomandibular valorado con tomografía Cone beam

Objetivo. Comparar posición condilar y espacio articular en articulación témporo-mandibular, en pacientes con y sin disfunción témporo-mandibular mediante tomografía Cone Beam. Métodos. Criterios diagnósticos de investigación para trastornos témporo-mandibulares Eje II, n=50 pacientes ambos sexos, edad comprendida 18 - 27 años. Muestra aleatoria n= 50 pacientes equivalente a 100 articulaciones, se obtuvo: n=25 pacientes sin disfunción témporo-mandibular, considerados asintomáticos 25 con y sin disfunción témporo-mandibulares, considerados sintomáticos. Mediante tomografía Cone Beam de articulación témporo-mandibular boca abierta - boca cerrada se avaluó de forma manual los espacios interarticulares. Resultados. El espacio condilar anterior en pacientes con y sin disfunción témporo-mandibular no presentó diferencia significativa, p=0,30. La posición condilar tampoco mostró diferencia significativa p=0,58. En pacientes con y sin disfunción témporo-mandibular (sintomáticos) la posición central y posterior del cóndilo (35,2%), pacientes con y sin disfunción témporo-mandibular (asintomáticos) la posición anterior y central fue más significativa (37,0%); seguido de la posición posterior del cóndilo (26,1%). Conclusión. No existe diferencia significativa en la posición condilar y el espacio interarticular en pacientes sintomáticos y asintomáticos.

Aim. To compare the condylar position and joint space of the temporomandibular join in individuals with and without temporomandibular dysfunction, using cone beam computed tomography (CBCT). Methods. Research Diagnostic Criteria for Temporomandibular Disorders Axis II (n= 50) patients both sexes, age 18 - 27 years. Random sample (n=50) patients equivalent to 100 joints, obtaining: n-25 patients without temporomandibular dysfunction, considered asymptomatic and 25 patients with and without temporomandibular dysfunction, considered symptomatic. By tomography Cone Beam of open mouth temporomandibular joint - closed mouth was manually evaluated the interarticular spaces. Results. The anterior condylar position space and condylar position not significantly different in induvials with and without temporomandibular dysfunction temporomandibular disorders p=0,30 and p=0,58, respectively. Conclusions. There is no significant difference in the condylar position and intraarticular.

Molecular mechanisms of clarithromycin resistance in Mycobacterium abscessus complex clinical isolates from Venezuela.

In this study, 26 clinical isolates of Mycobacterium abscessus complex strains were characterised using available identification algorithms for the three species (M. abscessus, M. massiliense and M. bolletii) and the genotypic characteristics of clarithromycin (CLR) resistance were determined. Strains were identified by PCR restriction fragment length polymorphism analysis of the hsp65 and erm(41) gene sequences. Susceptibility to CLR was determined by the broth microdilution method. The mechanism of resistance to this macrolide was evaluated by sequencing the erm(41) and rrl genes. Mutations and/or deletions associated with resistance to CLR as determined in this study were those that have been previously described. No constitutive resistance to CLR was found, however 35% (9/26) of the M. abscessus complex strains tested had a functional inducible erm(41) gene. Based on sequencing of this gene, the strains of M. abscessus were separated into six sequevars, of which only two are consistent with those previously reported. In conclusion, we demonstrated that the low percentage of strains with a resistant phenotype to CLR was due only to an inducible resistance mechanism conferred by the erm(41) gene and not to mutations in the rrl gene. CLR can still be useful for treatment in some Venezuelan patients infected with a member of the M. abscessus group, but drug resistance testing and/or molecular analysis must precede the prescription of this antibiotic.