Abstract Introduction. In Mexico, 85 % of the crops are white maize, 10 % white yellow and 5 % other colors. Biochemical studies of pigmented native maize have been carried out, but there is little information on colour-improved maize. Objective. To evaluate the phytochemical content and antimicrobial capacity of two pigmented maize hybrids grown at the Tecnológico Nacional de México-Valle del Yaqui. Materials and methods. Extraction of biocompounds from a portion of the maize grains grown in southern Sonora, Mexico, during the summer-winter 2020 cycle was performed on red and purple maize hybrids. A thirty-part solution of ethanol, acetic acid and water was used. Proximal composition, anthocyanin, polyphenol and flavonoid content were determined by standardized methods. Antioxidant capacity was determined by ABTS (2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid)) and DPPH (2,2-diphenyl-1-picrylhydrazyl) methodologies. In addition, antimicrobial capacity and minimum inhibitory concentration were determined. Results. Purple maize showed higher content of anthocyanins (340.98±5.21 mg/100 g) and polyphenols (173.68±24.23 mg gallic acid/100 g) compared to red maize. Flavonoids are more abundant in purple maize (575.10±27.88 mg quercetin/100 g). Both maize hybrids exhibited more than 50 % antioxidant capacity against ABTS and DPPH radicals. Regarding antimicrobial activity, higher inhibition was observed for Escherichia coli and Salmonella (18 % and 47 %), and lower for Staphylococcus aureus and Shigella (19 % and 34 %) compared to gentamicin. Conclusion. Purple maize showed higher content of anthocyanins, polyphenols and flavonoids. Both hybrids had an antioxidant capacity higher than 50 %. Antimicrobial activity was higher against E. coli and Salmonella, than against S. aureus and Shigella.

Resumen Introducción. En México, el 85 % de las siembras son maíces blancos, el 10 % amarillo blancos y el 5 % de otros colores. Se han realizado estudios bioquímicos de maíces nativos pigmentados, pero existe poca información en maíces mejorados en color. Objetivo. Evaluar el contenido de fitoquímicos y capacidad antimicrobiana de dos híbridos de maíz pigmentado cultivados en el Tecnológico Nacional de México, Valle del Yaqui. Materiales y métodos. En granos de híbridos de maíz de color rojo y morado se realizaron las extracciones de biocompuestos a partir de una porción del maíz cultivado en el sur de Sonora, México, durante el ciclo verano-invierno 2020. Se utilizó una solución de etanol, ácido acético y agua en una proporción de treinta partes. La composición proximal, contenido de antocianinas, polifenoles y flavonoides se determinaron mediante métodos estandarizados. La capacidad antioxidante se evaluó mediante las metodologías ABTS (2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid)) y DPPH (2,2-difenil-1-picrilhidracilo). Además, se determinó la capacidad antimicrobiana y la concentración mínima inhibitoria. Resultados. El maíz morado presentó mayor contenido de antocianinas (340,98±5,21 mg/100 g) y polifenoles (173,68±24,23 mg de ácido gálico/100 g), en comparación con el maíz rojo. Los flavonoides son más abundantes en el maíz morado (575,10±27,88 mg de quercetina/100 g). Ambos híbridos de maíz exhibieron una capacidad antioxidante superior al 50 % frente a los radicales ABTS y DPPH. Respecto a la actividad antimicrobiana, se observó mayor inhibición para Escherichia coli y Salmonella (18 % y 47 %), y menor para Staphylococcus aureus y Shigella (19 % y 34 %) en comparación con la gentamicina. Conclusión. El maíz morado mostró mayor contenido de antocianinas, polifenoles y flavonoides. Ambos híbridos tuvieron una capacidad antioxidante mayor al 50 %. La actividad antimicrobiana fue mayor contra E. coli y Salmonella, que contra S. aureus y Shigella.

Resumen La bacteria Escherichia coli causa la colibacilosis en animales de granja que actúan como reservorios de cepas patógenas. La resistencia antimicrobiana de E. coli productor de betalactamasas de espectro extendido [BLEE] es un grave problema de salud pública y se puede atribuir a factores relacionados con el consumo de alimentos y el contacto con animales domésticos. El objetivo de este estudio fue determinar la presencia y patrones de resistencia antimicrobiana de E. coli BLEE aislado en muestras fecales provenientes de bovinos productores de leche de la provincia de Pichincha. Se analizaron un total 182 muestras de heces de bovinos: 112 muestras de bovinos faenados en el Camal Metropolitano de la provincia de Pichincha y 70 muestras de la colección de la Unidad de Investigación de Enfermedades Transmitidas por Alimentos y Resistencias a los Antimicrobianos [UNIETAR], se realizó el aislamiento de E. coli BLEE, la identificación bioquímica y pruebas de resistencia a los principales antibióticos utilizados. Se logró identificar 93 muestras positivas a E. coli BLEE (51 %), el análisis fenotípico reveló que los antibióticos amoxicilina más ácido clavulánico, cefepime, ceftazidima, ciprofloxacina, amikacina y tetraciclina presentaron porcentajes de resistencia mayores al 80 %. Además, se observó una baja resistencia a la nitrofurantoína, cefoxitin y ertapenem, mientras que ningún aislado fue resistente a la tigeciclina. El 100 % de los aislados presentaron fenotipos de multirresistencia y el patrón más frecuente estuvo compuesto por 7 familias de antibióticos. En conclusión, estos resultados sugieren que E. coli originaria de bovinos lecheros podría ser un reservorio de genes BLEE.

Abstract Escherichia coli causes colibacillosis in farm animals that act as reservoirs for pathogenic strains. Antimicrobial resistance of E. coli producing Extended Spectrum Beta-lactamases [ESBL] is a serious public health problem that can be attributed to factors related to food consumption and contact with domestic animals. This study aimed to determine the presence and patterns of antimicrobial resistance of ESBL E. coli isolated from fecal samples from dairy cattle in the Pichincha province. A total of 182 bovine feces samples were analyzed, 112 samples from cattle slaughtered at the official slaughterhouse in Quito-Pichincha province, and 70 samples from the collection of the Foodborne Diseases and Antimicrobial Resistance Research Unit [UNIETAR]. The isolation of ESBL E. coli, biochemical identification, and resistance tests using the main antibiotics were carried out at UNIETAR. It was possible to identify 93 positive samples for ESBL E. coli (51%), phenotypic analysis revealed that antibiotics such as amoxicillin plus clavulanic acid, cefepime, ceftazidime, ciprofloxacin, amikacin, tetracycline, presented resistance higher than 80%. Furthermore, low resistance to nitrofurantoin, cefoxitin, and ertapenem was observed, while no isolate was resistant to tigecycline. One hundred percent of the isolates presented multi-resistance phenotypes, with the most frequent pattern being composed of 7 families of antibiotics. In conclusion, these results suggest that E. coli from dairy cattle origin could be an important reservoir of ESBL genes.

Abstract Introduction. Rectal perforation due to blunt trauma is rare and associated with pelvic fractures. Signs of necrotizing fasciitis in lower limbs have been reported in non-traumatic rectal perforations, in most cases associated with high mortality. Case report. A 36-year-old man presents blunt abdomino-pelvic trauma and perforation of the lower rectum. Surgical management by intestinal diversion and pelvic fixation is performed. 4 days after admission, evolves with over-infected scrotal hematoma, hemodynamic instability, signs of necrotizing fasciitis and septic shock. Results. A sample for culture was taken from a scrotal hematoma that reported E. coli. Pathology of scrotal debridement reported coagulation necrosis in the entire specimen. Discussion. Digital rectal examination should always be performed in the presence of subcutaneous emphysema on physical examination or CT scan for early and multidisciplinary diagnosis and surgical management as appropriate. Conclusion. The presence of subcutaneous emphysema should raise the suspicion of rectal perforation. There are few reports of rectal perforation due to blunt trauma and fasciitis, so the associated mortality is not precisely known.

Resumen Introducción. La perforación del recto por trauma cerrado es poco frecuente y se asocia a fracturas pélvicas. En pacientes con perforaciones de recto no traumáticas se ha reportado fascitis necrosante en miembros inferiores, en la mayoría de los casos asociada a alta mortalidad. Caso clínico. Hombre de 36 años con trauma cerrado abdomino-pélvico y perforación de recto inferior, quien recibió manejo quirúrgico mediante derivación intestinal y fijación pélvica. Evolucionó con hematoma escrotal sobreinfectado, inestabilidad hemodinámica, signos de fascitis necrosante y choque séptico 4 días posterior a su ingreso. Resultados. Se tomó muestra para cultivo del hematoma escrotal que reportó E. coli. La patología del desbridamiento escrotal informó necrosis de coagulación en toda la muestra. Conclusión. El tacto rectal debe realizarse siempre ante la presencia de enfisema subcutáneo al examen físico o en la tomografía, para un diagnóstico temprano y manejo quirúrgico multidisciplinario oportuno, según el caso. La presencia de enfisema subcutáneo debe aumentar la sospecha de perforación de recto. Hay pocos reportes de fascitis secundaria a perforación de recto por trauma cerrado, por lo que no se conoce con precisión la mortalidad asociada.

Abstract Surveillance indicators of the quality of water for human consumption in the Amazon were analysed from 2016 to 2020 using 185,528 samples from 11 microregions. Of the samples analysed, 93.20% were from urban areas, 66.65% were from the public water supply system (WSS), 31.02% were from the Collective Alternative Solution-CAS, and 2.33% from the Individual Alternative Solution-IAS. There was an increase in the number of records by the WSS, with a downwards trend and fluctuations in records for the CAS and the IAS. The quality indicators of chemical and physical parameters for urban areas were higher than those for rural areas and traditional communities. Most of the samples presented pH values below the recommended level. In the quantification of microbiological parameters, a higher presence of total coliforms and E. coli was identified in samples from rural areas and in traditional communities. In conclusion, there were inadequacies in the chemical, physical and microbiological parameters as well as problems related to the supply, storage and surveillance of water distributed for human consumption. These findings indicate the need to build an agenda for public management to address water insecurity and its likely effects on food insecurity in the region. 201 202 185528 185 528 185,52 1 microregions 9320 93 20 93.20 6665 66 65 66.65 WSS , (WSS) 3102 31 02 31.02 SolutionCAS, SolutionCAS Solution CAS, Solution-CAS 233 2 33 2.33 SolutionIAS. SolutionIAS IAS Solution-IAS communities level E conclusion region 18552 18 52 185,5 932 9 93.2 666 6 66.6 (WSS 310 3 0 31.0 23 2.3 1855 5 185, 93. 66. 31. 2.

Resumo Analisaram-se indicadores de vigilância da qualidade da água para consumo humano no Amazonas, de 2016 a 2020, utilizando 185.528 amostras provenientes de 11 microrregiões. Das amostras analisadas, 93,20% são da área urbana, 66,65% provinham do sistema público (SAA), 31,02% da Solução Alternativa Coletiva (SAC) e 2,33% da Solução de Alternativa Individual (SAI). Observou-se aumento do número de registros pelo SAA, com tendência de queda e oscilações de registros para a SAC e a SAI. Os indicadores de qualidade dos parâmetros químicos e físicos da área urbana foram superiores aos das áreas rurais e de comunidades tradicionais. A maior parte das amostras apresentou valores de pH abaixo do recomendado. Na quantificação dos parâmetros microbiológicos, identificou-se maior presença de coliformes totais e E.coli na área rural e em comunidades tradicionais. Em conclusão, verificaram-se inadequações nos parâmetros químicos, físicos e microbiológicos, assim como problemas relativos ao abastecimento, armazenamento e à vigilância da água distribuída para consumo humano. Tais achados indicam a necessidade de construir uma agenda, pela gestão pública, para o enfrentamento da insegurança hídrica e seus prováveis efeitos sobre a insegurança alimentar existente na região. Analisaramse Analisaram se Amazonas 201 2020 185528 185 528 185.52 1 microrregiões analisadas 9320 93 20 93,20 6665 66 65 66,65 SAA , (SAA) 3102 31 02 31,02 (SAC 233 2 33 2,33 SAI . (SAI) Observouse Observou tradicionais recomendado microbiológicos identificouse identificou Ecoli E coli conclusão verificaramse verificaram abastecimento agenda pública região 202 18552 18 52 185.5 932 9 93,2 666 6 66,6 (SAA 310 3 0 31,0 23 2,3 (SAI 1855 5 185. 93, 66, 31, 2,

Abstract This research allowed us to understand the physical-chemical and microbiological quality of rainwater collected in the downtown area and Medrano neighborhood of the city of Quibdó - Chocó. This population has a high precipitation rate which ranges from 1500mm/year and 8500mm/year, both currently and in the future, although this situation contrasts with the low drinking water coverage, which is only 28.5%. To carry out this study, 5 sampling points were identified, and 4 samples were collected at each point with a periodicity of 1 weekly sampling for 4 weeks, for a total of 20 representative samples. The selected roof tops coverings were made of zinc, asbestos cement, and mantle, and are located in areas of high vehicular and pedestrian activity. The collected samples were analyzed in an accredited laboratory for this purpose. The parameters evaluated for rainwater quality were: apparent color, real color, conductivity, pH, total alkalinity, nitrites, nitrates, total coliforms, and Escherichia Coli. The result of the microbiological analyzes was POSITIVE in 100% of the cases, while 15% of the physical analyses and 34% of the chemical analyses also yielded negative results. Due to the presence mainly of colony-forming units of Escherichia Coli and total coliforms, it was concluded that rainwater in the downtown area and Medrano neighborhood of the city of Quibdó - Chocó, does 5not meet the standards established in the evaluated parameters and required by the regulations, which means that it is not safe for human consumption due to its level of contamination.

Resumen Esta investigación permitió conocer la calidad físico - química y microbiológica del agua lluvia recolectada en la Zona Centro y barrio Medrano de la ciudad de Quibdó - Chocó. Esta población presenta una alta tasa de precipitación la cual oscila entre 1500mm/año y 8500mm/año, tanto en la actualidad como en el futuro, aunque esta situación contraste con la baja cobertura de agua potable que tan solo es del 28,5%. Para realizar dicho estudio se identificaron 5 puntos de muestreo, en cada punto se recolectaron 4 muestras con una periodicidad de 1 muestreo semanal durante 4 semanas, para un total de 20 muestras representativas; las cubiertas seleccionadas fueron de zinc, asbesto cemento y manto; además, están ubicadas en zonas de alta actividad vehicular y peatonal. Las muestras recolectadas fueron analizadas en un laboratorio acreditado para tal fin. Los parámetros evaluados de la calidad del agua lluvia fueron; color aparente, color real, conductividad, pH, alcalinidad total, nitritos, nitratos, Coliformes totales y Escherichia Coli. El resultado de los análisis microbiológicos fue negativo en el 100% de los casos, mientras que el 15% de los análisis físicos y el 34% de los análisis químicos también arrojaron resultados negativos. Debido a la presencia principalmente de unidades formadoras de colonia de Escherichia Coli y Coliformes totales, se concluyó que el agua lluvia en la zona centro y el barrio Medrano de la ciudad de Quibdó - Chocó, no cumple con los estándares establecidos en los parámetros evaluados y requeridos por la norma, lo que significa que no es segura para el consumo humano debido al nivel de contaminación que presenta.

ABSTRACT: The Amazonian manatee (Trichechusinunguis) is an aquatic mammal threatened with extinction. However, few studies have investigated the pathogens in this species, which may affect both animal and human health. This study aimed to evaluate the frequency, distribution, and patterns of antimicrobial susceptibility of Staphylococcus spp. and Escherichiacoli colonizing the nasal and rectal cavities of Amazonian manatees kept in captivity at the National Institute for Amazonian Research (INPA) in the state of Amazonas, Brazil. Rectal and nasal swabs from 44 manatees of different ages were used in this study. The genus Staphylococcus was isolated from the nasal swabs of 32 (72.7%) animals, with two individuals harboring more than one species of Staphylococcus. S. sciuri was the most commonly isolated species. Resistance to penicillin was observed in 13 (40.6%) isolates, more frequent than the other antimicrobials tested (P = 0.01). E. coli was isolated from the rectal swabs of all animals, with phylogroup B1 being the most frequent among the strains obtained (P = 0.0008). Four isolates (6.8%) were positive for virulence factors, three of which were classified as enterotoxigenicE. coli (ETEC) and one as enteropathogenicE. coli (EPEC). To our knowledge, this is the first study to evaluate Staphylococcus spp. and E. coli in Amazonian manatee samples. This study revealed nasal colonization by Staphylococcus spp., mainly S. sciuri, and diarrheagenicE. coli isolates, including antimicrobial-resistant strains. ABSTRACT Trichechusinunguis (Trichechusinunguis extinction However health frequency distribution spp INPA (INPA Amazonas Brazil 4 3 72.7% 727 72 7 (72.7% animals S 1 40.6% 406 40 6 (40.6% P 0.01. 001 0.01 . 0 01 0.01) E B 0.0008. 00008 0.0008 0008 0.0008) 6.8% 68 8 (6.8% factors enterotoxigenicE ETEC (ETEC enteropathogenicE EPEC. EPEC (EPEC) knowledge samples diarrheagenicE antimicrobialresistant resistant 72.7 (72.7 40.6 (40.6 00 0.0 0000 0.000 000 6.8 (6.8 (EPEC 72. (72. 40. (40. 0. 0.00 6. (6. (72 (40 (6 (7 (4 (

RESUMO: O peixe-boi amazônico (Trichechus inunguis) é um mamífero aquático ameaçado de extinção. Apesar disso, poucos estudos investigaram patógenos nessa espécie que podem impactar a saúde animal e humana. O objetivo deste estudo foi avaliar a frequência, distribuição e padrões de suscetibilidade antimicrobiana de Staphylococcus sp. e Escherichia coli pertencentes à microbiota nasal e retal de peixes-bois da Amazônia mantidos em cativeiro no Instituto Nacional de Pesquisas da Amazônia (INPA) (Amazonas, Brasil). Foram utilizados suabes retais e nasais de 44 peixes-boi de diferentes idades. O gênero Staphylococcus foi isolado do swab nasal de 32 (72,7%) animais, sendo que dois indivíduos apresentaram mais de uma espécie de Staphylococcus. S. sciuri foi a espécie mais comumente isolada. A resistência à penicilina foi observada em 13 (40,6%) isolados, sendo mais frequente do que os outros antimicrobianos testados (P = 0,01). Escherichia coli foi isolada dos suabes retais de todos os animais, sendo o filogrupo B1 o mais frequente entre as cepas obtidas (P = 0,0008). Quatro isolados (6,8%) foram positivos para fatores de virulência, três dos quais foram classificados como E. coli enterotoxigênica (ETEC) e um isolado como E. coli enteropatogênica (EPEC). Este é o primeiro estudo a avaliar Staphylococcus spp. e E. coli de amostras de peixe-boi da Amazônia. O estudo revelou colonização nasal por Staphylococcus sp., principalmente S. sciuri, e por isolados diarreiogênicos de E. coli, incluindo cepas resistentes a antimicrobianos. RESUMO peixeboi peixe boi Trichechus inunguis extinção disso humana frequência sp peixesbois peixes bois INPA (INPA Amazonas, Amazonas (Amazonas Brasil. Brasil . Brasil) 4 peixesboi idades 3 72,7% 727 72 7 (72,7% animais S 1 40,6% 406 40 6 (40,6% P 0,01. 001 0,01 0 01 0,01) B 0,0008. 00008 0,0008 0008 0,0008) 6,8% 68 8 (6,8% virulência E ETEC (ETEC EPEC. EPEC (EPEC) spp 72,7 (72,7 40,6 (40,6 00 0,0 0000 0,000 000 6,8 (6,8 (EPEC 72, (72, 40, (40, 0, 0,00 6, (6, (72 (40 (6 (7 (4 (

Abstract: Lactic acid bacteria (LAB) are generally regarded as safe microorganisms with great potential for biopreservation. As biopreservative agents, LAB can be applied as viable cultures for the production of antimicrobial compounds or exploiting chemical agents. LAB are known for the production of a variety of antagonistic compounds, among them bacteriocins, and their antimicrobial potential is defined by the combined action of metabolites on non-desired bacteria. This work evaluates the antimicrobial activity of 7 strains of LAB isolated from raw milk and Paraguay cheese: Enterococcus faecium (M6A y M6B), Lactobacillus fermentum (M16A y M17A), Lactobacillus rhamnosus (M17B) and Lactobacillus plantarum (M18 y M21) against E. coli , S. aureus and L. monocytogenes .

Resumen: Las bacterias ácido lácticas (BAL) son microorganismos generalmente considerados como seguros y poseen una gran capacidad para la bioconservación. Como agentes bioconservantes, las BAL pueden aplicarse como cultivos viables para la producción de compuestos antimicrobianos o explotando agentes químicos. Las BAL son conocidas por la producción de una variedad de compuestos antagónicos, entre ellos la bacteriocinas, y su potencial antimicrobiano está definido por la acción combinada de los metabolitos sobre bacterias no de- seadas. En este trabajo se evalúa la actividad antimicrobiana de 7 cepas de BAL aisladas de leche cruda y queso Paraguay: Enterococcus faecium (M6A y M6B), Lactobacillus fermentum (M16A y M17A), Lactobacillus rhamnosus (M17B) y Lactobacillus plantarum (M18 y M21) frente a E. coli , S. aureus y L. monocytogenes.

Abstract This study analyzed the impact of leachate from a temporary landfill on soil microbial diversity in Tingo María, Huánuco region, Peru. Three treatments were used: untreated soil (S), addition of stream water (T0), leachate (T1), and leachate treated by coagulation and flocculation (T2), with 828.5 ml/week added in three weekly doses. Soil samples were collected from the Reserved Forest of the Universidad Nacional Agraria de la Selva. Twenty-one randomly distributed soil samples were taken and homogenized for analysis. Soil quality parameters measured included sand, clay, silt, texture, pH, organic matter, nitrogen, phosphorus and potassium. As for microorganisms, viable aerobes, lactobacilli, actinomycetes, fungi, nitrogen-fixing bacteria, and Escherichia coli were quantified using specific culture and counting methods for each of them. To evaluate the impact of the leachate on microbial diversity, equity indices (Shannon and inverse Simpson), dominance indices (complementary Simpson and Berger Parker) and the percentage composition of each microorganism per treatment were used. An ANOVA was performed to estimate differences in microbial diversity, with a Tukey test at a significance level of α = 0.05. The study showed that leachates affect soil microbial diversity, reducing equity and increasing the dominance of certain species such as E. coli. They also alter physicochemical parameters, decreasing organic matter and nitrogen but increasing other elements such as phosphorus and potassium. This could have implications for soil health and functionality.

Resumen En un experimento a escala piloto desarrollado en Brasil, se cultivaron juveniles de tilapia genéticamente mejorada en efluente de tanque séptico seguido de laguna de alta tasa (LAT). Durante las 22 semanas de la investigación se evaluó la combinación de tres tasas de aplicación superficial de nitrógeno amoniacal total (NAT) (0,6; 1,2 y 2,4 kg NAT.ha-1.d-1) y tres densidades de cultivo (3; 6 y 12 peces.m-2). Los tanques de cultivo funcionaron como unidades de pulimento para tratamiento de las aguas residuales, adicionando (con los mejores resultados, alcanzados con la menor densidad de cultivo y 1,2 kg NAT.ha-1.d-1) las siguientes eficiencias de remoción adicionales a las obtenidas mediante el uso de la LAT: 78,3% para nitrógeno total Kjeldahl; 89,1% para nitrógeno amoniacal; 63,9% para fósforo total; 57,2% para demanda química de oxígeno; 2,36 unidades logarítmicas para E. coli. La productividad de los peces se estimó del orden de 2,67 ton.ha-1 para cultivo durante seis meses por año para climas templados, utilizando la población de plancton natural del agua residual doméstica tratada como la única fuente de alimento.

Abstract In a pilot-scale experiment carried out in Brazil, genetically improved farmed tilapia juveniles were reared in septic tank-high rate algal pond (HRAP) effluent. The combination of three total ammonia nitrogen (TAN) surface loading rates (0.6; 1.2 and 2.4 kg TAN.ha-1.d-1) and three fish stocking densities (3; 6 and 12 fish.m-2) was evaluated during a 22-week research. The fish rearing tanks worked as wastewater treatment polishing units, adding (as the best results, achieved with the lowest fish stocking density and 1.2 kg TAN.ha-1.d-1) the following removal figures on top of those achieved at the HRAP: 78.3% total Kjeldahl nitrogen; 89.1% ammonia nitrogen; 63.9% total phosphorous; 57.2% chemical oxygen demand; 2.36 log units E. coli. Fish productivity was estimated at 2.67 ton.ha-1 for fish culture over six month per year in a temperate climate region, using the domestic treated wastewater natural plankton population as the only food source.

Abstract: Bacteremia is a major cause of morbidity and mortality in patients with cancer and episodes of high-risk febrile neutropenia (HRFN). Objective: To identify the frequency of microorganisms isolated from blood cultures (BC) and their antimicrobial resistance (R) profile in children with HRFN, compared with the same data from previous studies of the same group. Method: Prospective, multicenter, epidemiological surveillance study of microorganisms isolated from BC in patients under 18 years of age, from 7 PINDA network hospitals, between 2016 and 2021. Results: 284 episodes of HRFN with positive BC were analyzed out of 1091 enrolled episodes (26%). Median age 7.2 years [3.0-12.3]. The main isolates were gram-negative bacilli (GNB) 49.2%, gram-positive cocci (GPC) 43.8%, and fungi 3.6%. The most frequently isolated microorganisms were viridans group Streptococci (VGS) (25.8%), Escherichia coli (19.8%), Pseudomonas spp. (11.2%), Klebsiella spp. (10.9%), and coagulase negative Staphylococci (CoNS) (10.9%). There was an increase in R to third-generation cephalosporins (p = 0.011) in GNB and to oxacillin in CoNS (p = 0.00), as well as a decrease in R to amikacin in non-fermenting GNB (p = 0.02) and to penicillin in VGS (p = 0.04). Conclusion: VGS is the main agent isolated in BC from pediatric patients with cancer and episodes of HRFN, followed by E. coli, Pseudomonas spp., and Klebsiella spp. Having epidemiological surveillance of microorganisms isolated from BC and their antimicrobial R profile is essential to favor the rational use of antimicrobials.

Resumen: Las bacteriemias son una causa importante de morbimortalidad en pacientes con cáncer y episodios de neutropenia febril de alto riesgo (NFAR). Objetivo: Determinar la frecuencia de microorganismos aislados de hemocultivos (HC) y su perfil de resistencia (R) antimicrobiana en niños con NFAR, comparado con iguales datos de estudios previos del mismo grupo. Material y Método: Estudio prospectivo, multicéntrico, de vigilancia epidemiológica de microorganismos aislados de HC en pacientes menores de 18 años, en siete hospitales de la red PINDA, 2016-2021. Resultados: Se analizaron 284 episodios de NFAR con HC positivos de 1091 episodios enrolados (26%). Mediana de edad 7,2 años [3,0-12,3]. Los aislados principales fueron bacilos gramnegativos (BGN) 49,2%, cocáceas grampositivas (CGP) 43,8% y hongos 3,6%, con mayor frecuencia de Streptococcus grupo viridans (SGV) (25,8%), Escherichia coli (19,8%), Pseudomonas spp. (11,2%), Klebsiella spp. (10,9%) y Staphylococcus coagulasa negativa (SCN) (10,9%). Hubo aumento de R a cefalosporinas de tercera generación en enterobacterales (p = 0,011) y de R a oxacilina en SCN (p = 0,00), así como disminución de R a amikacina en BGN no fermentadores (p = 0,02) y de R a penicilina en SGV (p = 0,04). Conclusión: SGV es el principal agente aislado en HC de pacientes pediátricos con cáncer y episodios de NF, seguido de E. coli, Pseudomonas spp. y Klebsiella spp. Contar con vigilancia epidemiológica de microorganismos aislados de HC y su perfil de R antimicrobiana es esencial para favorecer el uso racional de antimicrobianos.

Resumen Las infecciones por Entamoeba se producen en todo el mundo, con mayor frecuencia en países de bajo nivel socioeconómico y salud pública deficiente. Dado que se ha reconocido a Entamoeba histolytica como la única especie patógena del género, es importante realizar un diagnóstico diferencial respecto de otras especies de Entamoeba morfológicamente idénticas. Este estudio tuvo como objetivos determinar la prevalencia de especies de Entamoeba en 2 poblaciones de Argentina, realizar su diagnóstico diferencial por PCR y caracterizar los aislados de Entamoeba secuenciando un fragmento del gen SSU ARNr. Se obtuvieron 493 muestras fecales seriadas de individuos de las provincias de Buenos Aires (n=210) y Misiones (n=283). Las muestras se examinaron por métodos convencionales (sedimentación de formalina-etil acetato y flotación de Willis) y mediante PCR específicas para diferenciar especies de Entamoeba. Los aislamientos de Entamoeba se caracterizaron por secuenciar un fragmento del gen SSU ARNr. La prevalencia general de la infección por Entamoeba fue del 12,4% y fue mayor en Buenos Aires que en Misiones (14,8 vs. 10,6%). Se informó por primera vez un caso de Entamoeba histolytica en Buenos Aires, confirmado por PCR y análisis de secuencia. Además, se registraron nuevos datos genéticos sobre Entamoeba coli y Entamoeba dispar. El análisis filogenético reveló una congruencia entre las características morfológicas y las secuencias del gen SSU ARNr. A través de este estudio, hemos sumado información acerca de la distribución de estas especies en nuestro país y en la región de las Américas.

Abstract Entamoeba infections occur worldwide, with higher frequency in countries of low socioeconomic status and poor public health. Since Entamoeba histolytica has long been recognized as the only pathogenic species, making a differential diagnosis of other morphologically identical Entamoeba is important. This study aimed to determine the prevalence of Entamoeba species in two populations from Argentina, make a differential diagnosis by PCR and characterize Entamoeba isolates at the SSU rRNA gene. A total of 493 serial fecal samples were obtained from individuals in the provinces of Buenos Aires (n=210) and Misiones (n=283). Samples were examined by conventional methods (formalin-ethyl acetate and Willis flotation) and specific PCRs to differentiate Entamoeba species. Entamoeba isolates were characterized by sequencing a fragment of the SSU rRNA gene. The overall prevalence of Entamoeba infection was 12.4%, being more prevalent in Buenos Aires than in Misiones (14.8% vs. 10.6%). A case of E. histolytica confirmed by PCR and sequence analysis was reported for the first time in Buenos Aires. Moreover, new genetic data on Entamoeba coli and Entamoeba dispar were recorded. The phylogenetic analysis revealed a congruence between morphological characteristics and SSU rRNA gene sequences. This study increases the amount of information on the distribution of these species in Argentina and the region of the Americas.

Biologically active compounds in most spices possess antimicrobial and other important biomedical properties. There have been huge demands for natural immunity boosters (spices and herbs), considering the recent global pandemic and challenges relating to drug-resistant pathogens. This study was designed to compare the efficacy of ginger, garlic and turmeric spices against some pathogenic microorganisms. Aqueous extraction of spices, antimicrobial sensitivity and minimum inhibitory concentration tests were done using standard microbiological methods. Bioactive compounds were estimated using the gas chromatography-mass spectrometry (GC-MS) method. Aqueous extracts of ginger inhibited the growth of all test isolates except Streptococcus pneumoniae, with inhibition zones ranging between 0.9 mm and 13.5 mm. Escherichia coli, S. pneumoniae and Haemophilus influenzae were resistant to turmeric extracts, while the extract of garlic inhibited only four of the test pathogens. Inhibition zones for turmeric ranged between 4.4 mm and 10.9 mm, while those for garlic were between 4.7 mm and 11.5 mm. All the spice extracts did not inhibit microbial growth at 10-40%. An antibiotic spectrum indicated that Bacillus sp. was resistant to all but one, nitrofurantoin, which also inhibited the growth of almost all pathogens, except H. influenzae, with zones ranging between 10.5 mm and 11.6 mm. All test pathogens were resistant to cloxacillin except E. coli (10.6 mm). The major phyto-active compounds present in ginger are 2-Butanone,4-(4-hydroxy-3-methoxyphenyl), 1,3-Cyclohexadiene and 1-(4-Hydroxy-3-methoxyphenyl). SIGNIFICANCE: Conclusively, ginger, turmeric and garlic have varied inhibitory activities against diverse organisms, indicating their antimicrobial properties; however, ginger showed a higher inhibitory effect and more diverse antimicrobial property amongst selected isolates. Furthermore, certain bioactive compounds of biomedical importance were present. We therefore recommend the use of these spices as alternative natural food preservatives against spoilage organisms, as well as potential natural sources for bioactive compounds in drug development against pathogens.

FtsZ is a bacterial divisome protein responsible for Z-ring formation in cytokinesis. Characterization of Escherichia coli FtsZ protein oligomers (EcFtsZ) in native conditions is defiance because the protein is found as a multi-oligomer in self-association-dissociation equilibrium. We characterize the trimeric state of EcFtsZ through native PAGE, gel filtration chromatography and sucrose gradient techniques combined with chemical cross-linking. The filtration results indicate that the EcFtsZ trimer has a molecular mass of 131 kDa and a filtration friction coefficient (Rs/Rmin) equal to 1.9, while the theoretical filtration friction coefficient (fn/f1) calculated for a linear trimer yielded a value equal to 1.8 very close to the experimental value. On the other side, formaldehyde-crosslinked EcFtsZ showed a band 128 kDa recognized by anti-FtsZ antibodies, and a sedimentation friction coefficient (Smax/S20,w) equal to 1.9, while the theoretical sedimentation friction coefficient (Sn/S1) calculated for a triangular trimer was equal to the experimental value. These results suggest that EcFtsZ has two homotrimeric structures (linear and triangular). Finally, we report the aggregation of EcFtsZ at micromolar concentrations of Capsaicin without GTP and Mg2+.

La FtsZ es una proteína del divisoma bacteriano responsable de la formación del anillo Z en la citocinesis. La caracterización de los oligómeros de la proteína FtsZ de Escherichia coli (EcFtsZ) en su estado nativo es un desafío porque la proteína se encuentra como un multioligómero en equilibrio de autoasociación-disociación. Nosotros caracterizamos el estado trimérico de la EcFtsZ a través de técnicas de PAGE nativo, cromatografía de filtración en gel y gradiente de sacarosa combinada con entrecruzamiento químico. Los resultados por filtración indican que el trímero de EcFtsZ tiene una masa molecular de 131 kDa y un coeficiente de fricción por filtración (Rs/Rmin) igual a 1.9, mientras que el coeficiente de fricción por filtración teórico (fn/f1) calculado para un trímero lineal arrojó un valor igual a 1.8 que está muy cercano al valor experimental. Por otro lado, la EcFtsZ entrecruzada con formaldehído presentó una banda de 128 kDa reconocida por anticuerpos anti-FtsZ y un coeficiente de fricción por sedimentación (Smax/S20,w) igual a 1.9, mientras que el coeficiente de fricción por sedimentación teórico (Sn/S1) calculado para un trímero triangular resultó igual a valor experimental. Estos resultados sugieren que la EcFtsZ tiene dos estructuras homotriméricas (lineal y triangular). Finalmente, reportamos la agregación de la EcFtsZ a concentraciones micromolares de Capsaicina sin GTP y Mg2+.

Abstract: Bacteremia is a major cause of morbidity and mortality in patients with cancer and episodes of high-risk febrile neutropenia (HRFN). Objective: To identify the frequency of microorganisms isolated from blood cultures (BC) and their antimicrobial resistance (R) profile in children with HRFN, compared with the same data from previous studies of the same group. Method: Prospective, multicenter, epidemiological surveillance study of microorganisms isolated from BC in patients under 18 years of age, from 7 PINDA network hospitals, between 2016 and 2021. Results: 284 episodes of HRFN with positive BC were analyzed out of 1091 enrolled episodes (26%). Median age 7.2 years [3.0-12.3]. The main isolates were gram-negative bacilli (GNB) 49.2%, gram-positive cocci (GPC) 43.8%, and fungi 3.6%. The most frequently isolated microorganisms were viridans group Streptococci (VGS) (25.8%), Escherichia coli (19.8%), Pseudomonas spp. (11.2%), Klebsiella spp. (10.9%), and coagulase negative Staphylococci (CoNS) (10.9%). There was an increase in R to third-generation cephalosporins (p = 0.011) in GNB and to oxacillin in CoNS (p = 0.00), as well as a decrease in R to amikacin in non-fermenting GNB (p = 0.02) and to penicillin in VGS (p = 0.04). Conclusion: VGS is the main agent isolated in BC from pediatric patients with cancer and episodes of HRFN, followed by E. coli, Pseudomonas spp., and Klebsiella spp. Having epidemiological surveillance of microorganisms isolated from BC and their antimicrobial R profile is essential to favor the rational use of antimicrobials.

Resumen: Las bacteriemias son una causa importante de morbimortalidad en pacientes con cáncer y episodios de neutropenia febril de alto riesgo (NFAR). Objetivo: Determinar la frecuencia de microorganismos aislados de hemocultivos (HC) y su perfil de resistencia (R) antimicrobiana en niños con NFAR, comparado con iguales datos de estudios previos del mismo grupo. Material y Método: Estudio prospectivo, multicéntrico, de vigilancia epidemiológica de microorganismos aislados de HC en pacientes menores de 18 años, en siete hospitales de la red PINDA, 2016-2021. Resultados: Se analizaron 284 episodios de NFAR con HC positivos de 1091 episodios enrolados (26%). Mediana de edad 7,2 años [3,0-12,3]. Los aislados principales fueron bacilos gramnegativos (BGN) 49,2%, cocáceas grampositivas (CGP) 43,8% y hongos 3,6%, con mayor frecuencia de Streptococcus grupo viridans (SGV) (25,8%), Escherichia coli (19,8%), Pseudomonas spp. (11,2%), Klebsiella spp. (10,9%) y Staphylococcus coagulasa negativa (SCN) (10,9%). Hubo aumento de R a cefalosporinas de tercera generación en enterobacterales (p = 0,011) y de R a oxacilina en SCN (p = 0,00), así como disminución de R a amikacina en BGN no fermentadores (p = 0,02) y de R a penicilina en SGV (p = 0,04). Conclusión: SGV es el principal agente aislado en HC de pacientes pediátricos con cáncer y episodios de NF, seguido de E. coli, Pseudomonas spp. y Klebsiella spp. Contar con vigilancia epidemiológica de microorganismos aislados de HC y su perfil de R antimicrobiana es esencial para favorecer el uso racional de antimicrobianos.

Abstract The present study sought to evaluate the antimicrobial and anti-adherent potential of Eucalyptus radiata essential oil against food-borne strains of Escherichia coli. The study was performed using the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). In addition, the disk diffusion technique was used to evaluate the association of Eucalyptus radiata essential oil with synthetic antimicrobials. The Minimum Inhibitory Adherence Concentration (MIC) was also performed. The results revealed that E. radiata showed antimicrobial activity against the E. coli strains tested, with MIC values ranging from 500 μg/mL to 1000 μg/mL and MBC values ranging from 500 μg/mL to 1,024 μg/mL. As for the associations, it was observed that E. radiata oil exhibited a synergistic effect for some antibiotics, especially Ceftriaxone, with greater interference from the essential oil. Furthermore, it was effective in inhibiting the adherence of bacterial strains of E. coli, showing a more significant antibiofilm effect than the antibacterial agent 0.12% chlorhexidine digluconate. In summary, the essential oil of E. radiata showed antimicrobial potential against strains of E. coli of food origin, and can therefore, through in-depth studies, be used alone or in association with synthetic antimicrobials to combat infections caused by this pathogen. antiadherent anti adherent foodborne borne (MIC MBC. . (MBC) addition E tested 50 μgmL μg mL 100 1024 1 024 1,02 associations antibiotics Ceftriaxone Furthermore 012 0 12 0.12 digluconate summary origin therefore indepth depth studies pathogen (MBC 5 10 102 02 1,0 01 0.1 1, 0.

Resumo O presente estudo buscou avaliar o potencial antimicrobiano e antiaderente do óleo essencial de Eucalipto radiata frente às cepas de veiculação alimentar de Escherichia coli. O estudo foi realizado usando a Concentração Inibitória Mínima (CIM) e Concentração Bactericida Mínima (CBM). Além disso, a técnica de difusão em disco foi usada para avaliar a associação do óleo essencial de Eucalipto radiata com antimicrobianos sintéticos. A Concentração Inibitória Mínima de Aderência (CIMA) também foi realizada. Os resultados revelaram que E. radiata apresentou atividade antimicrobiana contra as cepas de E. coli testadas, com valores de CIM variando entre 500 μg/mL a 1000 μg/mL e valores de CBM variando entre 500 μg/mL a 1,024 μg/mL. Quanto às associações, observou-se que o óleo de E. radiata exibiu efeito sinérgico para alguns antibióticos, sobretudo a Ceftriaxona, apresentando maior interferência do óleo essencial. Além disso, foi eficaz na inibição a aderência das cepas bacterianas de E. coli, mostrando um efeito antibiofilme mais significativo que o agente antibacteriano digluconato de clorexidina a 0.12%. Em resumo, o óleo essencial de E. radiata apresentou potencial antimicrobiano contra cepas de E. coli de origem alimentar, podendo assim, mediante estudos aprofundados, ser utilizado isoladamente ou em associação com antimicrobianos sintéticos para combater infecções causadas por esse patógeno. (CIM CBM. . (CBM) disso CIMA (CIMA realizada E testadas 50 μgmL μg mL 100 1024 1 024 1,02 associações observouse observou se antibióticos Ceftriaxona 012 0 12 0.12% resumo assim aprofundados patógeno (CBM 5 10 102 02 1,0 01 0.12 1, 0.1 0.