Resumen Introducción. El tratamiento de las infecciones urinarias constituye un reto creciente por el aumento de Escherichia coli proveniente de la comunidad multirresistente a los medicamentos. Objetivo. Caracterizar aislamientos de E. coli multirresistente causantes de infecciones urinarias adquiridas en la comunidad en Cumaná, Venezuela, y detectar los posibles riesgos de infección por aislamientos productores de betalactamasas de espectro extendido (BLEE). Materiales y métodos. Se incluyeron todos los pacientes atendidos en la consulta externa de urología y en urgencias del Hospital de Cumaná entre enero y junio de 2014 y que evidenciaban infecciones urinarias. La detección de los genes blaTEM, blaSHV y blaCTX-M se hizo mediante la reacción en cadena de la polimerasa (PCR). Resultados. Se encontró una alta prevalencia de E. coli multirresistente a los medicamentos (25,2 %), con 20,4 % de aislamientos productores de BLEE y una gran frecuencia de resistencia simultánea a trimetoprim-sulfametoxazol, fluoroquinolonas y aminoglucósidos (66,7 %) comparados con los no productores (2,4 %). En el 65,4 % de los aislamientos resistentes, se encontró el gen blaTEM; en 34,6 %, el blaCTX-M, y en 23,1 %, el blaSHV. Los genes blaCTX-M detectados pertenecían a los grupos CTX-M-1 y CTX-M-2. Se demostró la transferencia in vitro de plásmidos por conjugación en 17 de los 26 aislamientos productores de BLEE. Los tres tipos de genes detectados se transfirieron a los transconjugantes. La edad mayor de 60 años, las infecciones urinarias con complicaciones y el uso previo de catéter, predispusieron a la infección por cepas de E. coli productoras de BLEE. Conclusiones. La gran frecuencia de aislamientos multirresistentes productores de BLEE debería alertar a las autoridades sanitarias para tomar medidas que reduzcan el riesgo de epidemias causadas por este tipo de bacterias en la comunidad.

Abstract Introduction: The treatment of urinary tract infections has become more challenging due to the increasing frequency of multidrug-resistant Escherichia coli in human populations. Objective: To characterize multidrug-resistant E. coli isolates causing community-acquired urinary tract infections in Cumaná, Venezuela, and associate possible risk factors for infection by extended-spectrum beta-lactamases (ESBL)-producing isolates. Materials and methods: We included all the patients with urinary tract infections attending the urology outpatient consultation and emergency unit in the Hospital de Cumaná, Estado Sucre, Venezuela, from January through June, 2014. blaTEM, blaSHV and blaCTX-M genes detection was carried out by PCR. Results: We found a high prevalence of multidrug-resistant E. coli (25.2%) with 20.4% of the isolates producing ESBL. The ESBL-producing isolates showed a high frequency (66.7%) of simultaneous resistance to trimethoprim-sulphamethoxazole, fluoroquinolones and aminoglycosides compared to non-producing isolates (2.4%). Of the resistant isolates, 65.4% carried the blaTEM gene, 34.6% the blaCTX-M and 23.1% the blaSHV. The blaCTX-M genes detected belonged to the CTX-M-1 and CTX-M-2 groups. Plasmid transfer was demonstrated by in vitro conjugation in 17 of the 26 ESBL-producing isolates. All three genes detected were transferred to the transconjugants. Age over 60 years, complicated urinary tract infections and previous use of a catheter predisposed patients to infection by ESBL-producing E. coli. Conclusions: The high frequency of multidrug-resistant ESBL-producing isolates should alert the regional health authorities to take measures to reduce the risk of outbreaks caused by these types of bacteria in the community.

ABSTRACT Multidrug resistance (MDR), virulence and transferable elements potentiate Pseudomonas aeruginosa's role as an opportunistic pathogen creating a high risk for public health. In this study, we evaluated the possible association of multidrug resistance, virulence factors and integrons with intrahospital P. aeruginosa strains isolated from patients at Cumana hospital, Venezuela. Relevant clinical-epidemiological data were collected to study 176 strains (2009-2016) isolated from different hospital units. Bacterial resistance was classified as susceptible, low-level resistant (LDR), multidrug resistant (MDR) and extensively drug-resistant (XDR). Most strains produced pyoverdine, DNase, gelatinase and hemolysin. Around 73% of the strains showed some type of movement. MDR and XDR strains increased from 2009 (24.2% and 4.8%, respectively) to 2016 (53.1% and 18.8%); while LDR decreased from 64.5% to 6.3%. The exoU and exoS genes were found in a significant number of strains (38.1 and 7.4%, respectively). Class I integrons were detected in 35.8% of the strains and the frequency was associated with resistance (42.9, 22.4, 41.4 and 61.9%, for susceptible, LDR, MDR and XDR, respectively). The MDR/XDR strains were positively associated with hemolysins and exoU, but negatively associated with bacterial twitching. MDR/XDR phenotypes were also associated with the Intensive Care Unit (ICU), septicemia, bronchial infection and diabetic foot ulcers, as well as long hospital stay (≥10 days) and previous antimicrobial treatment. High frequency of MDR/XDR strains and their association with class I integrons and virulence factors can increase the infection potential, as well as morbidity and mortality of patients attending this hospital and could spread infection to the community, creating a health risk for the region.

Background: Enterobacteria resistant to quinolones is increasing worldwide, including Venezuela. The mechanism for this resistance could be due to genes included in the chromosome or in transmissible plasmids. Aim: To evaluate the resistance to quinolones, coded by qnr genes present in enterobacteria species, isolated in the University Hospital of Cumana, Venezuela. Methods: Antimicrobial susceptibility tests to quinolones, beta-lactams and aminoglycosides were carried out to all the isolates. The presence of qnr genes were determined by PCR. The isolates carrying the qnr genes were used for bacterial conjugation tests to determine the presence of transferable plasmids. Antimicrobial susceptibility tests and PCR were carried out in the transconjugants to verify the transfer of the genes. Results: High levels of antimicrobial resistance to quinolones and beta-lactams were found among the isolates. We found that 33.6% of the isolates carry the qnrB gene and 0.9% qnr A gene. Of the 23 transconjugants, 20 showed to have qnrB gene, but none qnrA. Discussion: We concluded that the high frequency of qnr genes found in the enterobacteria isolates and their presence on transferable plasmids, complicate the use of quinolones for the treatment of bacterial infections, thus, a treatment plan should be designed with the rational use and the rotation of different types of antimicrobials, in order to avoid the selection of increasingly resistant strains.

Resumen Introducción: La resistencia de enterobacterias a quinolonas se ha difundido por el mundo, fenómeno presente también en Venezuela. El mecanismo de esta resistencia pudiera estar mediado por genes incluidos en el cromosoma bacteriano o transmitirse en el interior de plásmidos. Objetivo: Evaluar la resistencia a quino-lonas, codificada por genes qnr, presentes en cepas de enterobacterias, aisladas en el Hospital Universitario de Cumaná, Venezuela. Métodos: A las cepas obtenidas se les realizaron pruebas de susceptibilidad antimicrobiana a quinolonas, β-lactámicos y aminoglucósidos. La presencia del gen qnr se determinó por RPC. Las enterobacterias portadoras del gen qnr fueron sometidas al proceso de conjugación bacteriana para comprobar su capacidad de transferencia. A las transconjugantes obtenidas se les realizó pruebas de susceptibilidad antimicrobiana y RPC para comprobar la transferencia de los genes. Resultados: Se encontraron elevados porcentajes de resistencia antimicrobiana a quinolonas y betalactámicos. El 33,6% de las cepas eran portadoras del gen qnrB, y 0,9% del gen qnrA. Se obtuvieron 23 cepas transconjugantes; de éstas, 20 portaban el gen qnrB, no se observó la presencia de qnrA. Discusión: En conclusión, el elevado porcentaje de genes qnr encontrado en las enterobacterias aisladas, y comprobada la presencia de éstos en plásmidos transferibles, complica la aplicación de tratamientos basados en quinolonas y fluoroquinolonas, por lo que es recomendable el uso racional de estos antimicrobianos, y proponer la rotación de la terapia antimicrobiana, a fin de evitar la selección de cepas resistentes.

Introducción. Escherichia coli es uno de los principales agentes causales del síndrome diarreico agudo. Objetivo. Identificar grupos clonales de E. coli enteropatógena en 485 casos de diarrea aguda en niños entre 0 y 10 años de edad atendidos en centros de salud de los municipios de Arismendi, Benítez y Sucre del estado Sucre, Venezuela, entre marzo y diciembre de 2011. Materiales y métodos. Previo consentimiento informado, se recolectaron muestras fecales y se identificó E. coli mediante coprocultivo estándar y serología con antisueros polivalentes y monovalentes. Se aisló el ADN y se amplificaron los genes eae (intimina) y bfpA (bundlina) mediante dos pruebas de reacción en cadena de la polimerasa (PCR) múltiples. Resultados. En 39,6 % de los coprocultivos se determinó la presencia de infección bacteriana. La prevalencia de E. coli fue de 54,7 %; 82,9 % de estas cepas fue positivo por serología para los serogrupos y el serotipo evaluados, principalmente en niños entre los 0 y los 2 años (37,9 %). El 48,6 % de las cepas de E. coli amplificaron para el gen eae y, de estas, 58,8 % se clasificó como cepas de E. coli enteropatógena típica ( eae + y bfp +). El ECEP II fue el serogrupo más frecuente (38,7 %), con predominio de bacterias E. coli enteropatógenas típicas (60 %). El alelo β de la intimina fue el más identificado (74,5 %) en las cepas positivas para el gen eae . Solo se identificaron cuatro cepas con el serotipo O157:H7 utilizando antisueros, las cuales no amplificaron mediante PCR para los genes eae y bfpA . Conclusiones. Este estudio demostró la importancia de aplicar pruebas moleculares en la identificación de las cepas de E. coli causantes de diarrea de diversa gravedad.

Introduction: Diarrheagenic Escherichia coli is an important causative agent of acute diarrheic syndrome. Objective: To identify clonal groups of enteropathogenic E. coli (EPEC), in 485 children with acute diarrhea aged 0 to 10 years attending health care centers in Arismendi, Benítez and Sucre municipalities, Sucre state, Venezuela, from March to December, 2011. Materials and methods: After obtaining the informed consent, stool samples were collected. Escherichia coli was identified using standard coproculture methods and serology with polyvalent and monovalent antisera. DNA was isolated, and eae (intimin) and bfpA (bundlin) genes were amplified through two multiplex polymerase chain reactions (PCR). Results: The presence of bacterial infection was determined in 39.6% of coprocultures. The prevalence of E. coli was 54.7%; 82.9% of these isolates were positive by serology for the evaluated serogroups and serotypes, which were mostly identified in children between 0 and 2 years (37.9%); 48.6% of E. coli strains amplified the eae gene; of these, 58.8% were classified as typical EPEC ( eae + y bfp +). EPEC II was the most common serogroup (38.7%), with predominance of typical EPEC (60%). In positive strains for eae gene, the β intimin allele was the most frequently identified (74.5%). Only four strains with O157:H7 serotype were identified, which showed no PCR amplification of the eae and bfpA genes. Conclusion: This study showed the importance of molecular tests to identify diarrheagenic E. coli strains causing clinical conditions of varying severity.

A pesar de la importancia de las especies del complejo Enterobacter cloacae como patógeno nosocomial, poco se conoce sobre la frecuencia de cada especie/genotipo. Aquí se describe una cepa de E. hormaechei subsp. hormaechei aislada de una secreción bronquial de un paciente internado en la Unidad de Cuidados Intensivos del Hospital General de Cumaná, Venezuela, quien murió producto de complicaciones de su infección. La identificación molecular fue hecha por secuenciación del gen ARNr 16S y porcomparación con las secuencias del GenBank. Esta cepa mostró resistencia a múltiples familias de antibióticos (MDR) y se detectaron los genes blaKPCyblaVIMpor PCR. Este es el primer reporte de E. hormaechei en Venezuela.

Besides the importance of Enterobacter cloacae species complex as a nosocomial pathogen, little is known about the frequency of each species/genotype. Here, we describe a strain of E. hormaechei subsp. hormaechei isolated from a bronchial secretion of a patient, in the Intensive Care Unit at the General Hospital of Cumaná, Venezuela, who died due to complications of his infection. The molecular identification was done by sequencing the 16S rRNA gene and comparing it to sequences from the GenBank. This strain showed resistance to multiple families of antibiotics (MDR), and the genes blaKPC and blaVIM were detected by PCR. This is the first time E. hormaechei has been identified in Venezuela.

Las infecciones por Klebsiella pneumoniae, constituyen un problema creciente en los centros hospitalarios. El objetivo de la presente investigación fue evaluar la resistencia a los aminoglucósidos, así como la presencia de genes que codifican enzimas modificadoras de aminoglucósidos (EMA) en aislados intrahospitalarios de Klebsiella pneumoniae. Se analizaron 56 cepas provenientes de pacientes con diagnóstico de infección intrahospitalaria del Hospital Universitario “Antonio Patricio de Alcalá”, durante el periodo enero-septiembre de 2008. Se determinó la susceptibilidad antimicrobiana mediante los métodos de difusión y dilución en agar, siguiendo los lineamientos del Instituto de Estándares Clínicos y de Laboratorio. Se empleó la técnica de la reacción en cadena de la polimerasa (PCR) para detectar los genes que codifican EMA. Se encontró resistencia a gentamicina y tobramicina en el 33,9% y 35,7%, respectivamente. Los fenotipos de resistencia a aminoglucósidos más frecuentes fueron I (ANGMKTob) y II (GMKTob). Se identificaron los genes aadA (21,4%), aac(3)-IIa (16,1%), aadB (14,3%), aac (6`)-Ib (3,6%) y aph (3`)-Ia (1,8%). En 10 cepas se observó la presencia de más de un gen y en 13 cepas se correlacionó el fenotipo con los genes encontrados. La resistencia a los aminoglucósidos en los aislados evaluados se debe, principalmente, a enzimas de tipo acetiltransferasas.

Klebsiella pneumoniae infection is a growing problem in hospitals. The objective of this study was to evaluate resistance to aminoglycosides and detection of genes encoding for aminoglycoside modifying enzymes (AME) in hospital isolates of K. pneumoniae. Fifty-six isolates from patients with diagnosis of nosocomial infection at the University Hospital Antonio Patricio de Alcala, during the period January to September 2008 were included for study. Antimicrobial susceptibility was determined by the methods of diffusion and agar dilution, following the Institute for Clinical and Laboratory Standards Guidelines. Genes encoding AME were determined by the polymerase chain reaction procedure. Resistance results for Gentamycin were 33.9% and for Tobramycin 35.7%. Aminoglycoside resistance phenotypes most frequently identified were I (ANGMKTob) and II (GMKTob). The genes involved were aadA (21.4%), aac(3)-IIa (16.1%), aadB (14.3%), aac (6`)-Ib (3.6%) y aph (3`)-Ia (1.8%) For 10 of the isolates studied more than one gene was identified. In 13 isolates the phenotype corresponded to the genes found. Aminoglycoside resistance in the isolates studied is mainly due to the presence of acetyltransferase enzymes.

The enzymatic modification of aminoglycosides by aminoglycoside-acetyltransferases (AAC), aminoglycoside-adenyltransferases (AAD), and aminoglycoside-phosphotransferases (APH), is the most common resistance mechanism in P. aeruginosa and these enzymes can be coded on mobile genetic elements that contribute to their dispersion. One hundred and thirty seven P. aeruginosa isolates from the University Hospital, Cumana, Venezuela (HUAPA) were evaluated. Antimicrobial susceptibility was determined by the disk diffusion method and theaac, aadB and aph genes were detected by PCR. Most of the P. aeruginosa isolates (33/137) were identified from the Intensive Care Unit (ICU), mainly from discharges (96/137). The frequency of resistant P. aeruginosaisolates was found to be higher for the aminoglycosides tobramycin and amikacin (30.7 and 29.9%, respectively). Phenotype VI, resistant to these antibiotics, was the most frequent (14/49), followed by phenotype I, resistant to all the aminoglycosides tested (12/49). The aac(6´)-Ib,aphA1 and aadB genes were the most frequently detected, and the simultaneous presence of several resistance genes in the same isolate was demonstrated. Aminoglycoside resistance in isolates ofP. aeruginosa at the HUAPA is partly due to the presence of the aac(6´)-Ib, aphA1 andaadB genes, but the high rates of antimicrobial resistance suggest the existence of several mechanisms acting together. This is the first report of aminoglycoside resistance genes in Venezuela and one of the few in Latin America.

En un paciente masculino de 83 años, que ingresó al Hospital de Cumaná, Venezuela, con diagnóstico de infección urinaria severa, antecedentes de hospitalización y diferentes tratamientos antimicrobianos durante largos periodos de tiempo, se aisló una cepa de Enterobacter cloacae, la cual evidenció resistencia a múltiples tipos de antibióticos (solo sensible a gentamicina) y con fenotipo de carbapenemasas de tipo serina y metalobetalactamasa. Los genes blaVIM-2 y blaKPC fueron detectados en esta cepa. Este representa el primer reporte de una especie de Enterobacteriaceae productora simultánea de carbapenemasa KPC y metalobetalactamasa VIM en Venezuela. Esto tiene un gran impacto clínico y epidemiológico en la región por la posibilidad de transferencia de estos genes a otras cepas de Enterobacter u otras especies bacterianas causantes de infecciones, por medio de elementos móviles.

An 83-year-old male patient is admitted to the central hospital in Cumaná, Venezuela with severe urinary infection, history of hospitalizations and prolonged antimicrobial treatments. A strain of Enterobacter cloacae was isolated showing resistance to multiple types of antibiotics (only sensitive to gentamicin), with phenotype of serine- and metallo-carbapenemases. Both, blaVIM-2 and blaKPC genes were detected in the isolate. This is the first report of an Enterobacteriaceae species producing both KPC carbapenemase and VIM metallo carbapenemase in Venezuela. This finding has a great clinical and epidemiological impact in the region, because of the feasibility of transferring these genes, through mobile elements to other strains of Enterobacter and to other infection-causing species of bacteria.

Un total de 1.203 individuos de cuatro poblaciones rurales y dos zonas urbanas de Cumaná, estado Sucre, Venezuela, se incluyeron en un estudio comparativo de parasitosis intestinales. Previa información y consentimiento se recolectaron muestras fecales que fueron procesadas por examen coproparasitológico, método de Kato cualitativo, Ritchie, tinción de Zielh Neelsen y cultivo en agar. El 77,8% de los individuos resultaron parasitados, hallándose diferencias entre éstos con el tipo de población evaluada (χ2=75,1; p<0,001). En las zonas rurales predominó el poliparasitismo y en las urbanas el monoparasitismo, hallándose diferencias significativas (χ2=136,1; p<0,001). En ambas zonas fue mas frecuente en el sexo femenino. La edad arrojó asociación significativa, según el tipo de población siendo más prevalente el parasitismo en los niños de 0 a7 años en zonas rurales y 8 a14 años en urbanas (χ2=22,6; p<0,004). Se diagnosticaron más especies en las zonas rurales siendo Blastocystis spp. (protozoario) y Trichuris trichiura (helminto) las de mayor prevalencia. Blastocystis spp. estuvo asociado con otros protozoarios. Los helmintos asociados fueron T. trichiura y Ascaris lumbricoides en los dos tipos de poblaciones. La alta frecuencia de parasitosis intestinales en las poblaciones evaluadas, demostró la exposición de los habitantes a mecanismos comunes de contaminación.

Abstract: We carried out a comparative study of intestinal parasites in 1.200 individuals from four rural and two urban populations located at Cumana, Sucre State, Venezuela. After previously obtaining their informed consent, we collected fecal samples that were processed by a coproparasitological examination, qualitative Kato’s method, Ritchie, Ziehl-Neelsen stain, and agar culture. Results showed that 77.8% of the individuals were parasitized, and that there were differences according to the type of population being evaluated (χ2=136.1; p<0.001). In both rural an urban areas predominated polyparasitism and monoparasitism respectively, finding significant differences (χ2=136.1; p<0.001). In both areas it was more frequent in females. Age showed a significant association and parasites were most prevalent in children 0 to 7 years old in rural areas and 8 to 14 years old in urban areas (χ2=22.6; p<0.004). More species were diagnosed in rural areas and Blastocytiis spp. (protozoa) and Trichuris trichuira (helminth) were the most prevalent. Blastocyttis spp. was associated with other protozoa. Associated helminths were T. trichuria and Ascaris lumbricoides in both types of populations. The high frequency of intestinal parasites in the populations evaluated shows the exposure of the inhabitants to common contamination mechanisms.

Clinical strains of Enterobacter were isolated from Cumana's Central Hospital in Venezuela, and classified as E. cloacae (21), E. aerogenes(7), E. intermedium (1), E. sakazakii (1) and three unclassified. The strains showed high levels of resistance, especially to SXT (58.1%), CRO (48.8%), CAZ (46.6%), PIP (46.4%), CIP (45.2%) and ATM (43.3%). This is the first report for South America of blaVIM-2 in two E. cloacae and one Enterobacter sp., which also showed multiple mechanisms of resistance. Both E. cloacaeshowed blaTEM-1, but only one showed blaCTX-M-15 gene, while no blaSHV was detected.

Cepas clínicas de Enterobacter fueron aisladas del Hospital central de Cumaná en Venezuela, y se clasificaron como E. cloacae (21), E. aerogenes(7), E. intermedium (1), E. sakazakii (1) y 3 sin clasificar. Las cepas mostraron altos niveles de resistencia, especialmente a SXT (58.1%), CRO (48.8%), CAZ (46.6%), PIP (46.4%), CIP (45.2%) and ATM (43.3%). Este es el primer reporte de América del Sur de blaVIM-2 en dos cepas de E. cloacae y una de Enterobacter sp., las cuales también mostraron múltiples mecanismos de resistencia. Ambas especies de E. cloacae mostraron genes blaTEM-1, pero solo una mostro el gen blaCTX-M-15, mientras que blaSHV no fue detectado.

Esta investigación planteó detectar por nested PCR Entamoeba histolytica y E. dispar en niños del Hospital “Dr. Luis Razetti” de Barcelona, estado Anzoátegui y su asociación con síntomas clínicos. De 1.141 muestras fecales evaluadas parasitológicamente por microscopía convencional, 150 fueron positivas a E. histolytica en niños de 0-10 años y de ambos sexos. Se obtuvo información de signos, síntomas y reporte parasitólogico completo de cada uno de los pacientes y se realizó nested PCR para identificar E. histolytica y E. dispar. Los resultados de la microscopía convencional demostraron una frecuencia de diagnóstico de E. histolytica del 13,2%. En el 79,3% de estas positivas se reportó esta especie como único patógeno. Sin embargo, la nested PCR evidenció que sólo 28,0% (42/150) de las mismas presentaron infecciones por Entamoeba, evidenciándose un elevado sobrediagnóstico de E. histolytica. Además se identificaron 9,3% infecciones por E. histolytica, 4,0% E. dispar, y 4,7%infecciones mixtas. La diarrea fue el síntoma más común, seguido de dolor abdominal y fiebre. La presencia de sangre demostró asociación estadísticamente significativa con E. histolytica, pero también se reportó en infecciones por E. dispar. Este estudio demuestra que las técnicas moleculares complementarias a los métodos convencionales, permiten la identificación correcta de especies de Entamoeba, contribuyendo con una mejor evaluación epidemiológica de estos parásitos y la aplicación adecuada del tratamiento

The aim of this study was to identify the presence of Entamoeba histolytica and E. dispar by nested PCR in children attending the “Dr. Luis Razetti” Hospital, Barcelona, Anzoátegui State. Of the 1,141 fecal samples coproparasitologically evaluated by conventional microscopy, 150 were diagnosed positive for E. histolytica in 0-10 year-old-children, of both sexes. The signs, symptoms and a full coproparasitological report were obtained from all of these and nested PCR was performed to identify E. histolytica and E. dispar. The conventional microscopy results showed a diagnostic frequency of E. histolytica in 13.2% of the cases, of which 79.3% were positive only for this pathogen. However, nested PCR showed that of these, only 28% (42/150) were actually infected by Entamoeba spp., revealing a high over-diagnosis of E. histolytica. We also identified 9.3% E. histolytica, 4% E. dispar and 4.7% mixed infections. Diarrhea was the most common symptom, followed by abdominal pain and fever. Bloody stools were statistically associated with E. histolytica, but were also found for E. dispar infections. This study demonstrates that molecular techniques complementary to conventional methods enable the correct identification of Entamoeba spp., thus contributing to an improved epidemiological assessment of these parasites and implementation of the appropriate treatment

INTRODUÇÃO: Na Venezuela, síndrome da diarreia aguda (SDA) é a principal causa de mórbi-mortalidade, muitas vezes envolvem o gênero Salmonella. Infecções por Salmonella são associadas com gastroenterite aguda, uma das mais comuns intoxicações alimentares causada pelo consumo de água e alimentos contaminados, principalmente carne. MÉTODOS: Métodos convencionais e moleculares foram usados para detectar cepas de Salmonella em 330 amostras de fezes de indivíduos com SDA de diferentes idades e ambos os sexos. A reação em cadeia da polimerase (PCR) foi utilizada para a caracterização molecular de genes Salmonella invA, sefA e fliC para identificar o gênero e os sorotipos Enteritidis e Typhimurium, respectivamente. RESULTADOS: A maior frequência de indivíduos com SDA foi encontrada em crianças de 0-2 (39,4%) anos, e a frequência total de culturas de fezes positiva foi de 76,9%. Um total de 14 (4,2%) cepas foram bioquímica e imunologicamente identificados como Salmonella enterica subsp. enterica, dos quais 7 foram classificados como pertencentes ao sorotipo Enteritidis, Typhimurium sorotipo 4 e 3 para outros sorotipos. Cepas S. enterica foram distribuídas mais frequentemente em grupos de 3-4 e 9-10 anos de idade. CONCLUSÕES: O método de caracterização molecular usada provou ser altamente específico para tipificar as estirpes dos S. enterica usando tanto DNA extraído de colônias isoladas e direta e caldos de enriquecimento seletivo inoculados com amostras fecais, o que representa uma ferramenta complementar para a detecção e identificação de bactérias que causam a SDA.

INTRODUCTION:In Venezuela, acute diarrheic syndrome (ADS) is a primary cause of morbi-mortality, often involving the Salmonella genus. Salmonella infections are associated with acute gastroenteritis, one of the most common alimentary intoxications, and caused by the consumption of contaminated water and food, especially meat. METHODS: Conventional and molecular methods were used to detect Salmonella strains from 330 fecal samples from individuals of different ages and both sexes with ADS. Polymerase chain reaction (PCR) was used for the molecular characterization of Salmonella, using invA, sefA, and fliC genes for the identification of this genus and the serotypes Enteritidis and Typhimurium, respectively. RESULTS: The highest frequency of individuals with ADS was found in children 0-2 years old (39.4%), and the overall frequency of positive coprocultures was 76.9%. A total of 14 (4.2%) strains were biochemically and immunologically identified as Salmonella enterica subsp. enterica, of which 7 were classified as belonging to the Enteritidis serotype, 4 to the Typhimurium serotype, and 3 to other serotypes. The S. enterica strains were distributed more frequently in the age groups 3-4 and 9-10 years old. CONCLUSIONS: The molecular characterization method used proved to be highly specific for the typing of S. enterica strains using DNA extracted from both the isolated colonies and selective enrichment broths directly inoculated with fecal samples, thus representing a complementary tool for the detection and identification of ADS-causing bacteria.

In Venezuela, a total of 363,466 malaria cases were reported between 1999-2009. Several states are experiencing malaria epidemics, increasing the risk of vector and possibly transfusion transmission. We investigated the risk of transfusion transmission in blood banks from endemic and non-endemic areas of Venezuela by examining blood donations for evidence of malaria infection. For this, commercial kits were used to detect both malaria-specific antibodies (all species) and malaria antigen (Plasmodium falciparum only) in samples from Venezuelan blood donors (n = 762). All samples were further studied by microscopy and polymerase chain reaction (PCR). The antibody results showed that P. falciparum-infected patients had a lower sample/cut-off ratio than Plasmodium vivax-infected patients. Conversely, a higher ratio for antigen was observed among all P. falciparum-infected individuals. Sensitivity and specificity were higher for malarial antigens (100 and 99.8%) than for antibodies (82.2 and 97.4%). Antibody-positive donors were observed in Caracas, Ciudad Bolívar, Puerto Ayacucho and Cumaná, with prevalences of 1.02, 1.60, 3.23 and 3.63%, respectively. No PCR-positive samples were observed among the donors. However, our results show significant levels of seropositivity in blood donors, suggesting that more effective measures are required to ensure that transfusion transmission does not occur.

Para determinar la relación entre parámetros hematológicos, parasitemia y episodios maláricos, se evaluaron 59 individuos de ambos sexos, infectados con Plasmodium vivax y 30 controles del estado Sucre. Se extrajeron muestras de sangre por punción venosa y del lóbulo de la oreja el día del diagnóstico, a los 8 y 30 días postdiagnosis. Se realizó hematología completa, diagnóstico microscópico y molecular (PCR) y grado de parasitemia. Se encontraron diferencias significativas por sexo para la hemoglobina, eritrocitos y hematocrito (p < 0,01 en los tres análisis). Estos valores en los hombres disminuyeron para el día 8 del tratamiento con respecto al día 0 (p < 0,001; p = 0,006 y p = 0,025, respectivamente). En las mujeres, se observaron diferencias sólo entre los controles y los pacientes a las fechas de muestreo para hemoglobina y hematocrito (p < 0,001). El número promedio de los leucocitos para el día diagnóstico se ubicó dentro de los parámetros de referencia, pero significativamente por debajo (p < 0,001) de los del grupo control y de los obtenidos para durante y después del tratamiento. Los valores de eosinófilos se observaron por encima de los parámetros normales en los controles y los pacientes durante y después del tratamiento. Se observó trombocitopenia el día diagnóstico, pero a la semana del tratamiento los valores aumentaron significativamente (p < 0,001). La correlación de los parámetros evaluados con la parasitemia demostró una relación negativa con las plaquetas, y una positiva con la diferencia de plaquetas entre el día diagnóstico y día 8 de tratamiento (p = 0,014). Esta diferencia fue el único parámetro que se correlacionó con los episodios maláricos (p = 0,040). La trombocitopenia demostró ser un indicador de malaria aguda.

In order to determine the relationship between hematological parameters, parasitaemia and malaria episodes, we evaluated 59 individuals of both sexes, infected with Plasmodium vivax and 30 controls from Sucre state. Blood samples were obtained by venous puncture and from the earlobe at day of diagnosis, 8 and 30 days post-diagnosis. We carried out hematological analysis, microscopic and molecular (PCR) diagnosis and the parasitaemia was calculated. There were significant differences by sex for hemoglobin, erythrocytes and hematocrit (p < 0,01 in all three analysis). These values in males, decreased by day 8 with respect to day 0 (p < 0,001; p = 0,006 y p = 0,025, respectively). In females, significant differences were only seen in hemoglobin and hematocrit between controls and patients (p < 0,001). The average number of leucocytes at the day of diagnosis was within the reference values, but slightly lower compared to the controls and the samples during and after the treatment. The average proportion of eosinophils was higher than normal for both, controls and patients, during and after the treatment. Thrombocytopenia was observed at diagnosis, but a week after, the values increased significantly (p < 0,001). There was an inverse relationship between parasitaemia and platelet count and a direct relationship between the first and hemoglobin at day 0, as well as with the difference in platelet counts between day 0 and day 8 (p = 0,044 y p = 0,014, respectively). This difference was the only parameter related to the number of malaria episodes (p = 0,040). Thrombocytopenia showed to be an indicator of acute malaria.

El Virus de la Necrosis Infecciosa Hipodérmica y Hematopoyética (IHHNV) es un virus que causa altas mortalidades en Litopenaeus stylirostris y el síndrome de la deformidad del rostro (RDS) en L. vannamei. Con el fin de determinar la presencia del IHHNV en camarones cultivados asintomáticos, se analizaron muestras de camarones cultivados L. vannamei de cinco granjas camaroneras localizadas en el oriente y occidente de Venezuela. Se analizaron un total de 90 muestras por granja, de tres tallas: PL8-PL15, juveniles de 5-6 g y de 12 a 15 g de peso. El ADN total fue extraído de muestras homogeneizadas de pleópodos, mediante el uso de kit comerciales. La detección del IHHNV fue realizado, tanto por hibridación mediante “Dot Blot” como por PCR utilizando los kits de Diagxotics ShrimpProbe y ShrimPCaRe Simplex, respectivamente. Se detectó un total de siete muestras positivas, provenientes de cuatro (B, C, D y E) de las cinco granjas camaroneras estudiadas, variando las prevalencias entre 1,1 y 3,3% por granja. Todas las muestras positivas correspondieron a individuos de 5 a 6 g de peso. La técnica diagnóstica por PCR fue más sensible para la detección del IHHNV que la hibridación por “Dot Blot”. La presencia del IHHNV en camarones asintomáticos y a bajos niveles de prevalencia puede implicar que las poblaciones de camarones utilizadas para cultivo en Venezuela son resistentes o en todo caso tolerantes a este virus.

The Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) is a pathogen that may cause high mortalities in Litopenaeus stylirostris and the Runt Deformity Syndrome (RDS) in L. vannamei. In order to detect the presence of IHHNV in asymptomatic, cultivated shrimp, it were analyzed shrimp samples of cultivated L. vannamei from 5 farms located in the east and west costs of Venezuela. A total of 90 samples per farm were analyzed, using three sizes: PL8-PL15, juveniles of 5-6 g and of 12-15 g of weight. The DNA was extracted from homogenized samples of pleopods, using commercial kits. The detection of IHHNV was carried out by both dot blot hybridization and PCR using the Diagxotics kits ShrimpProbe and ShrimPCaRe Simplex, respectively. A total of 7 positive samples from 4 (B, C, D and E) of the 5 shrimp farms studied were detected. The prevalence in the farms ranged from 1.1 to 3.3%. All positive samples corresponded to individuals of 5 to 6 g of weight. PCR was a more sensitive technique than the dot blot hybridization. The presence of IHHNV in asymptomatic shrimp at low values of prevalence could imply that the shrimp populations used for culture in Venezuela are resistant or at least tolerant to this viral pathogen.