Flow-through Gas Phase Photocatalysis Using TiO2 Nanotubes on Wirelessly Anodized 3D-Printed TiNb Meshes.

In this work, for the first time 3D Ti-Nb meshes of different composition, i.e., Ti, Ti-1Nb, Ti-5Nb, and Ti-10 Nb, were produced by direct ink writing. This additive manufacturing method allows tuning of the mesh composition by simple blending of pure Ti and Nb powders. The 3D meshes are extremely robust with a high compressive strength, giving potential use in photocatalytic flow-through systems. After successful wireless anodization of the 3D meshes toward Nb-doped TiO2 nanotube (TNT) layers using bipolar electrochemistry, they were employed for the first time for photocatalytic degradation of acetaldehyde in a flow-through reactor built based on ISO standards. Nb-doped TNT layers with low concentrations of Nb show superior photocatalytic performance compared with nondoped TNT layers due to the lower amount of recombination surface centers. High concentrations of Nb lead to an increased number of recombination centers within the TNT layers and reduce the photocatalytic degradation rates.

Earliest directly dated rock art from Patagonia reveals socioecological resilience to mid-Holocene climate.

The timing for the evolution of the capacity to inscribe the landscape with rock art has global relevance. While this was an in-built capacity when Homo sapiens first colonized the Americas, the heterogeneous distribution of rock art shows that it was a facultative behavior arising under unknown socioecological conditions. Patagonia was the last region to be explored by humans. While its rock art is globally important, it remains largely undated by absolute methods. We report the earliest set of directly radiocarbon-dated rock art motifs from the archaeological site Cueva Huenul 1 (northwestern Patagonia, Argentina), starting at 8.2 thousand years before the present (ka B.P.), predating previous records by several millennia, and encompassing over 3 ka (~130 human generations). This mid-Holocene "rock art emergence" phase overlaps with extremely arid conditions and a human demographic stasis. We suggest that this diachronic rock art emerged as part of a resilient response to ecological stress by highly mobile and low-density populations.

Chemical composition and antifungal activity of Capsicum pepper aqueous extracts against plant pathogens and food spoilage fungi.

Capsicum pepper is a rich source of phytochemical compounds such as capsaicinoids, phenols, flavonoids, and so forth. Due to their antimicrobial and antioxidant potential all of these compounds have been assessed and used for both human and plant health benefits. Herein, three fresh varieties of Capsicum annuum (Cacho de Cabra, Bell pepper, and Hungarian Wax varieties) and one fresh and ripe variety of C. baccatum (Cristal) were evaluated. Capsaicin, dihydrocapsaicin, nordihydrocapsaicin and the phenolic content of Capsicum spp. extracts were characterised. The antifungal potential of capsaicinoids and antioxidant activities, and the ecotoxicity of each Capsicum spp. extract, using the model Galleria mellonella, were also evaluated. Phytochemical analyses showed that the Cristal and Hungarian Wax varieties presented the highest amount of capsaicin, dihydrocapsaicin, and nordihydrocapsaicin; while Bell Pepper had the highest phenol content and antioxidant activity. Capsaicinoids' standards and Capsicum spp. extracts showed fungistatic activity against the fungal strains assessed. For the fungal strains assessed, the fungistatic activities of capsaicinoids' standards were higher than those observed in Capsicum spp. extracts. The Hungarian Wax extracts inhibited slightly the growth of Aspergillus niger MUM05.11 and Fusarium oxysporum MUM16.143. Similarly, A. niger, F. oxysporum, Rhizopus arrhizus MUM16.05 and Alternaria sp. UFRO17.178 had their growth retarded by the use of Cacho de Cabra and Cristal extracts. Noticeable changes were observed in the fungal strains' morphologies, such as the presence of fragile fungal structures, pigmentation loss, variation in the reproductive structures size and the conidia number. Capsicum extracts weaken the growth of fungi, indicating their fungistatic potential. Considering the fungistatic potential and non-ecotoxicity of these extracts, it is possible to suggest their use as a tool for pest management in the agri-food sector, controlling the growth and reproduction of fungi without posing a risk to non-target biodiversity.

Ultrathin TiO2 Coatings via Atomic Layer Deposition Strongly Improve Cellular Interactions on Planar and Nanotubular Biomedical Ti Substrates.

This work aims to investigate the chemical and/or structural modification of Ti and Ti-6Al-4V (TiAlV) alloy surfaces to possess even more favorable properties toward cell growth. These modifications were achieved by (i) growing TiO2 nanotube layers on these substrates by anodization, (ii) surface coating by ultrathin TiO2 atomic layer deposition (ALD), or (iii) by the combination of both. In particular, an ultrathin TiO2 coating, achieved by 1 cycle of TiO2 ALD, was intended to shade the impurities of F- and V-based species in tested materials while preserving the original structure and morphology. The cell growth on TiO2-coated and uncoated TiO2 nanotube layers, Ti foils, and TiAlV alloy foils were compared after incubation for up to 72 h. For evaluation of the biocompatibility of tested materials, cell lines of different tissue origin, including predominantly MG-63 osteoblastic cells, were used. For all tested nanomaterials, adding an ultrathin TiO2 coating improved the growth of MG-63 cells and other cell lines compared with the non-TiO2-coated counterparts. Here, the presented approach of ultrathin TiO2 coating could be used potentially for improving implants, especially in terms of shading problematic F- and V-based species in TiO2 nanotube layers.

Correction: Taguatagua 3: A new late Pleistocene settlement in a highly suitable lacustrine habitat in central Chile (34°S).

[This corrects the article DOI: 10.1371/journal.pone.0302465.].

Taguatagua 3: A new late Pleistocene settlement in a highly suitable lacustrine habitat in central Chile (34°S).

We present the results of the excavations and analyses of the diverse and exceptional archaeological assemblage of Taguatagua 3, a new late Pleistocene site located in the ancient Tagua Tagua lake in Central Chile (34°S). The anthropogenic context is constrained in a coherently dated stratigraphic deposit which adds new information about the mobility, subsistence strategies, and settlement of the early hunter-gatherers of southern South America. The age model constructed, as well as radiocarbon dates obtained directly from a combustion structure, indicate that the human occupation occurred over a brief time span around 12,440-12,550 cal yr BP. Considering taphonomic, geoarchaeological, lithic, archaeobotanical, and zooarchaeological evidence, as well as the spatial distribution combined with ethnographic data, we interpret Taguatagua 3 as a logistic and temporary camp associated mainly with gomphothere hunting and butchering. Nevertheless, several other activities were carried out here as well, such as hide and/or bone preparation, small vertebrate and plant processing and consumption, and red ochre grinding. Botanical and eggshell remains suggest that the anthropic occupation occurred during the dry season. Considering the contemporaneous sites recorded in the basin, we conclude that the ancient Tagua Tagua lake was a key location along the region's early hunter-gatherer mobility circuits. In this context, it acted as a recurrent hunting/scavenging place during the Late Pleistocene due to its abundant, diverse, and predictable resources.

Parenteral iron nutrition: Iron dextran-poloxamer thermosensitive hydrogel for prolonged intramuscular iron supplementation.

The objective of this study was to evaluate the potential of novel poloxamer thermosensitive hydrogels (PTHs) formulations for prolonged release of iron dextran particles (IDP) for intramuscular (IM) injection. The thermosensitive behaviour helps to avoid hepcidin overexpression and toxicity by releasing IDPs without iron accumulation in injection or deposit sites. We hypothesized that novel PTH formulation would prolong iron liberation compared to the commercial iron dextran formulation (FEDEX). PTHs loaded with IDPs were developed with increasing iron content (0.1, 0.2 and 0.4 g of iron/g of poloxamer) and characterized as a prolonged release IM iron supplement. The PTHs had a biocompatible pH for IM injection (6.4) and thermosensitive viscosity, increasing from ∼50 (4 °C) to ∼3000 mPa.s (37 °C). PTHs were successfully injected in the sol state (at 4 °C) into pork meat at 37 °C, transitioning to the gel state in situ (in ∼60-190 s). Structural characterization indicated that there were no PTH-IDP chemical interactions, suggesting that IDP entrapment in PTHs was physical upon gelation. In vitro release studies revealed that iron release from PTH (0.4 g of iron/g of poloxamer) reached 100 % by day 10, whereas 100 % release from FEDEX was complete in 4 h. This novel iron PTH formulation achieved a 60 times long iron release compared to the commercial product. In conclusion, the reported strategy shows adequate IDP entrapment/release properties for prolonged iron release following ex vivo IM injection using biocompatible materials. These results provide a strong basis for future preclinical evaluation to elucidate aspects such as drug release, local irritation, biocompatibility, and efficacy.

[Osteoarticular paleopathology in a Chinchorro body: report of one case]. / Paleopatología osteoarticular en Chinchorro: revisión de un caso y discusión sobre el autocuidado en la prehistoria de Arica, norte de Chile.

We report a severe osteo-arthropathy in a body of a Chinchorro adult mole exhumed from the pre-Hispanic site of Playa Miller 8, located in the city of Arica, on the northern coast of Chile. The advanced state of joint disease shows that the individual was cared by his social group, to be able to survive. This care was perpetuated in the postmortem treatment, applying red color to the body. Particular self-care social dynamics of Chinchorro society are inferred.

MALDI-TOF MS: A Quick Method to Detect the Susceptibility of Fusarium spp. Clinical Isolates to Amphotericin B.

Disseminated fusariosis is treated with amphotericin B and voriconazole. To determine adequate therapy, the minimal inhibitory concentration (MIC) is used. However, MIC analysis is based on visual observation and requires a long period of fungal incubation. The measure of the minimal profile change concentration (MPCC) using MALDI-TOF MS is a quick spectral method that has presented good results in determining the antimicrobial resistance of yeasts. However, there is a lack of information on filamentous fungi. In the present work, 13 Fusarium spp. clinical isolates and two reference strains were used. MIC was obtained according to the M38-A2 protocol of the Clinical Laboratory Standards Institute, while MPPC was obtained following the initial steps of the M38-A2 protocol. Both Biotyper and the Rstudio environment were used to analyze mass spectra. For some fungal strains, the data obtained from the software MALDI Biotyper Compass 4.1 led to fuzzy heatmaps resulting in difficult interpretation, while heatmaps obtained using Rstudio tools generated better MPCC resolutions. Herein, 86.6% of the AMB MPCC values were highly correlated with the gold-standard AMB MIC. MALDI-TOF MS is a prominent tool used to determine MPCCs quicker, cost-effectively, and more accurately for Fusarium spp. strains. However, better statistical analyses could help measure the technique's limit detection.

Antifungal Potential of Capsaicinoids and Capsinoids from the Capsicum Genus for the Safeguarding of Agrifood Production: Advantages and Limitations for Environmental Health.

Opportunistic pathogenic fungi arise in agricultural crops as well as in surrounding human daily life. The recent increase in antifungal-resistant strains has created the need for new effective antifungals, particularly those based on plant secondary metabolites, such as capsaicinoids and capsinoids produced by Capsicum species. The use of such natural compounds is well-aligned with the One Health approach, which tries to find an equilibrium among people, animals, and the environment. Considering this, the main objective of the present work is to review the antifungal potential of capsaicinoids and capsinoids, and to evaluate the environmental and health impacts of biofungicides based on these compounds. Overall, capsaicinoids and their analogues can be used to control pathogenic fungi growth in plant crops, as eco-friendly alternatives to pest management, and assist in the conservation and long-term storage of agrifood products. Their application in different stages of the agricultural and food production chains improves food safety, nutritional value, and overcomes antimicrobial resistance, with a lower associated risk to humans, animals, and the environment than that of synthetic fungicides and pesticides. Nevertheless, research on the effect of these compounds on bee-like beneficial insects and the development of new preservatives and packaging materials is still necessary.

Penicillium digitatum, First Clinical Report in Chile: Fungal Co-Infection in COVID-19 Patient.

Penicillium digitatum is one of the most important phytopathogens. It causes deterioration and rotting of citrus fruits, generating significant economic losses worldwide. As a human pathogen, it is extremely rare. We present a case of pulmonary co-infection in a patient diagnosed with pneumonia due to SARS-CoV-2. A 20-year-old female patient, primigravid, 36 weeks of gestation, without comorbidities, and diagnosed with severe pneumonia due to the SARS-CoV-2, showed rapid lung deterioration for which their pregnancy was interrupted by surgery. The patient was hospitalized in the Intensive Care Unit (ICU), connected to mechanical ventilation and receiving corticosteroids and antibiotics. The diagnosis of pulmonary fungal infection was made through bronchoalveolar lavage (BAL) culture, and the species identification was performed by sequencing of ß-tubulin. Phylogenetic analysis with related species was performed for the confirmation of species identification. Antifungal susceptibility tests were performed for itraconazole (4 µg/mL), voriconazole (2 µg/mL), and amphotericin B (2 µg/mL). The patient was successfully treated with itraconazole. This is the second worldwide report of pulmonary infection by P. digitatum and the first in Chile. Although it is a fungus that rarely infects humans, it could represent an emerging opportunistic fungal pathogen, with associated risk factors that should be considered in the differential diagnosis of Penicillium species isolated from infections in humans.

[Health properties and sensory quality of apple snack destined for school feeding]. / Propiedades saludables y calidad sensorial de snack de manzanas destinadas a alimentacion escolar.

An apple snack has been developed with the purpose of introducing foods derived from fruit to reduce obesity in school children of Santiago, Chile. Apple slices of the 'Fuji' variety were dehydrated, with skin included, at 60 degrees C for 4 h obtaining a product with 4.6 g/100 g of humidity and water activity (Aw) of 0.56. The apple snack presented 24.8 +/- 0.3 g/100 g b.s. of dietary fiber and 550.16 +/- 5.89 mgGAE/100 g b.s of polyphenols which converts into a healthy food, it also presents high antioxidant capacity measured by FRAP, with 0.59 mmolFe/100g. The sensory analysis done in school children between the ages of 8 and 12 years old indicates that the product presents high acceptability, is a crispy product, of a crunchy texture, with bittersweet flavor, so it is an alternative for school snacks.

Unraveling the polychromy and antiquity of the Pachacamac Idol, Pacific coast, Peru.

Pachacamac is the name of the 15th-16th century Inca sanctuary on the Peruvian coast as well as the name of one of the principal oracles of Inca divinities. This effigy would have been destroyed by Pizarro in 1533 during his visit to the great monumental complex, and as such the originality and antiquity of the wooden statue-the so-called Pachacamac Idol-have been the subject of much controversy and debate. We present here previously unpublished dates that confirm its manufacture during the Middle Horizon (AD 500-1000), as well as evidence of its original polychromy. Traces of colors were observed on its different sections with portable microscopy and analyses with two different X-Ray Fluorescence spectrometry techniques, leading to identification of yellow, white, and red mineral pigments, including the presence of cinnabar. Dated between the 8th and 9th centuries, the statue would have been worshipped for almost 700 years, from the time of its creation to the time of the Spanish conquest, when Pachacamac was a major place of pilgrimage. These data not only offer a new perspective on Pachacamac's emblematic sacred icon, but also on the colorful practices of the Pre-Hispanic Andes.

Calidad del sueño y sus alteraciones durante la Pandemia por COVID-19 en una región del norte de Chile

Introducción: Las alteraciones del sueño son prevalentes en la población. La pandemia por SARSCoV-2 y la implementación de medidas de confinamiento para combatir su propagación podrían favorecer el desarrollo de trastornos del sueño o empeorar los preexistentes. Objetivo: Evaluar la calidad de sueño y somnolencia diurna durante la pandemia en la región de Coquimbo, Chile mediante la aplicación de encuesta validada. Metodología: Estudio observacional, descriptivo y transversal de carácter analítico. Tamaño muestral de 1.074 participantes. Intervalo de confianza 95%, margen de error 3%. Recopilación a través de un cuestionario online que incluye el Índice de Pittsburgh (PSQI), y Escala de Epworth (ESEp), ambos autoaplicables y validados al español. Análisis con programa SPSS-26. Aprobado por Comité de Ética. Resultados: 80,1% presentó alteraciones en calidad de sueño (PSQI), y 50,2% tuvo algún grado de somnolencia diurna según ESEp. Las mujeres presentaron peor calidad de sueño y mayor somnolencia diurna que los hombres con una diferencia estadísticamente significativa. Discusión/conclusión: El sueño es una función de gran relevancia para los seres vivos y sus alteraciones pueden ocasionar consecuencias importantes para la salud, lo cual preocupa en un sistema sanitario ya sobrecargado, más aún en pandemia, por lo que resulta importante incentivar la toma de medidas como una buena higiene del sueño para mejorar la calidad de vida de la población.

Background: Sleep disorders are prevalent in the general population. The SARS-CoV-2 pandemic and the implementation of sanitary measures to combat its spread, could worst sleep disorders or worsen preexisting ones. Objective: Evaluate the quality of sleep and daytime sleepiness during the pandemic in the Coquimbo region, Chile through the application of a validated sleep survey. Methodology: Observational, descriptive and cross-sectional study. Sample size of 1,074 participants. Confidence interval 95%, error range 3%. The survey was performed through an online questionnaire, that includes the Pittsburgh Index (PSQI) and the Epworth Scale (ESEp), both self-applied and validated in Spanish. Analysis with SPSS-26 program. Approved by the Ethics Committee. Results: 80.1% presented alterations in sleep quality (PSQI), and 50.2% had daytime sleepiness according to ESSep. The women presented worse quality of sleep and more daytime sleepiness than the men, with a statistically significant difference. Discussion/conclusion: Sleep is a important function for humans and other beings, and its alterations can cause important consequences for health. It is an important factor for the already overloaded health system, even more so in a pandemic. It is important to taking of measures such as good sleep hygiene to improve the quality of life of the population.

Intervención educativa en una enfermedad desatendida: hidatidosis/ equinococosis quística en escolares del norte de Chile / Educational intervention in a neglected disease: hydatidosis/cystic echinococcosis in schoolchildren in northern Chile

INTRODUCCIÓN: La hidatidosis es una zoonosis cuyo control más eficiente y eficaz es la promoción en salud, especialmente en la población infante-juvenil. OBJETIVO: Medir el impacto de un programa de intervención educativa sobre hidatidosis en escolares del norte de Chile. MÉTODO: Estudio intervencional educativo con fases pre y post test en 3.145 estudiantes de educación preescolar, primaria y secundaria de tres comunas. Se definieron dimensiones, unidades educativas y sistemas de evaluación incorporados en las bases curriculares. Se calculó el puntaje de logro de respuestas correctas utilizando la prueba t. Se estimó el tamaño del efecto mediante d de Cohen y análisis de varianza mixto. RESULTADOS: Se encontraron diferencias estadísticamente significativas en la muestra total y en las variables género, comuna, procedencia rural-urbana y nivel de educación. Los puntajes post intervención fueron mayores y con tamaños de efecto grandes a excepción de los primeros niveles de educación. Se hallaron puntajes mayores post test y efectos de interacción con diferencias significativas en rural-urbano y en comuna anteriormente intervenida. La dimensión mejor evaluada fue "medidas de autocuidado" y la más baja "tenencia responsable de perros". CONCLUSIONES: El programa educativo fue efectivo al ser dirigido a grupos etarios, mediante métodos pedagógicos en las bases curriculares de los establecimientos educacionales.

BACKGROUND: Hydatidosis is a zoonosis whose most efficient and effective control is health promotion, especially in children and youth. AIM: To measure the impact of an educational intervention program on hydatidosis in schoolchildren in northern Chile. METHOD: Educational interventional study was performed with pre-post test phases in 3,145 students of preschool, primary and secondary education from three districts. Dimensions, educational units and evaluation systems were defined and incorporated into the curricular bases. The correct answer achievement score was calculated using the T-test. Effect size was estimated using Cohen's d and mixed analysis of variance. RESULTS: Statistically significant differences were found in the total sample and in variables such as gender, district, rural-urban origin and level of education. Post-intervention scores were higher than pre-intervention and with large effect sizes, except for the first levels of education. Higher post-test scores and interaction effects were found with significant differences in rural-urban and in a previously intervened district. The best evaluated dimension was "self-care measures" and the lowest was "responsibly keeping dogs". CONCLUSIONS: The educational program was effective when directed to age groups, through pedagogical methods in the curricular bases of educational facilities.

Omics for Precious Rare Biosamples: Characterization of Ancient Human Hair by a Proteomic Approach.

Omics technologies have far-reaching applications beyond clinical medicine. A case in point is the analysis of ancient hair samples. Indeed, hair is an important biological indicator that has become a material of choice in archeometry to study the ancient civilizations and their environment. Current characterization of ancient hair is based on elemental and structural analyses, but only few studies have focused on the molecular aspects of ancient hair proteins-keratins-and their conservation state. In such cases, applied extraction protocols require large amounts of raw hair, from 30 to 100 mg. In the present study, we report an optimized new proteomic approach to accurately identify archeological hair proteins, and assess their preservation state, while using a minimum of raw material. Testing and adaptation of three protocols and of nano liquid chromatography-tandem mass spectrometry (nanoLC-MS/MS) parameters were performed on modern hair. On the basis of mass spectrometry data quality, and of the required initial sample amount, the most promising workflow was selected and applied to an ancient archeological sample, dated to about 3880 years before present. Finally, and importantly, we were able to identify 11 ancient hair proteins and to visualize the preservation state of mummy's hair from only 500 µg of raw material. The results presented here pave the way for new insights into the understanding of hair protein alteration processes such as those due to aging and ecological exposures. This work could enable omics scientists to apply a proteomic approach to precious and rare samples, not only in the context of archeometrical studies but also for future applications that would require the use of very small amounts of sample.

Micro X-ray Fluorescence Study of Late Pre-Hispanic Ceramics from the Western Slopes of the South Central Andes Region in the Arica y Parinacota Region, Chile: A New Methodological Approach.

Archeological ceramic paste material typically consists of a mix of a clay matrix and various millimeter and sub-millimeter sized mineral inclusions. Micro X-ray fluorescence (XRF) is a standard compositional classification tool and in this work we propose and demonstrate an improved fluorescence map processing protocol where the mineral inclusions are automatically separated from the clay matrix to allow independent statistical analysis of the two parts. Application of this protocol allowed us to enhance the discrimination between different ceramic shards compared with the standard procedure of working with only the spatially averaged elemental concentrations. Using the new protocol, we performed an initial compositional classification of a set of 83 ceramic shards from the western slopes of the south central Andean region in the Arica y Parinacota region (Chile). Comparing the classifications obtained using the new versus the old (average concentrations only) protocols, we found that some samples were erroneously classified with the old protocol. From an archaeological perspective, a broad and heterogeneous regional sample set was used in this experimental study due to the fact that this was the first such analysis to be performed on ceramics from this region. This allowed a general overview to be obtained, however further work on more specific sample sets will be necessary to extract concrete archaeological conclusions.

Medical audit using the Ten Group Classification System and its impact on the cesarean section rate.

OBJECTIVE: The aim of this study is to implement the Ten Group Classification System (TGCS) and evaluate whether the introduction of the medical audit cycle reduces the cesarean section (CS) rate without increasing maternal-fetal risk. STUDY DESIGN: A prospective cohort study was performed including all women who gave birth during 21 months. The study was subdivided into three consecutive periods: (1) implementation of the TGCS identifying the major CS rate contributor groups (three months), (2) audit and report changes in the CS rates to the medical and midwifery staff according to the TGCS (6 months) and (3) discontinue interventions but continue auditing the CS rates (6 months). RESULTS: The first period CS rate of 36.8% was reduced to 26.5% after the introduction of interventions in the second period (RR 0.71 IC 0.63-0.81). After the intervention was stopped, the CS rate increased again to 31.8% (RR 1.19 IC 1.09-1.32). This is a decrease of 5.08% from the basal period (RR 0.86 IC 0.76-0.97). The asphyxia rate remained unchanged for the periods studied. CONCLUSION: Auditing through the TGCS and feedback is an effective, safe, and easy-to-implement strategy to reduce the CS rate. Its diffusion would allow reduction of the CS rates in countries as ours, and by means of the TGCS, figures can be compared within individual entities and others.

Paleopatología osteoarticular en Chinchorro: Revisión de un caso y discusión sobre el autocuidado en la prehistoria de Arica, norte de Chile / Osteoarticular paleopathology in a Chinchorro body: Report of one case

We report a severe osteo-arthropathy in a body of a Chinchorro adult mole exhumed from the pre-Hispanic site of Playa Miller 8, located in the city of Arica, on the northern coast of Chile. The advanced state of joint disease shows that the individual was cared by his social group, to be oble to survive. This care was perpetuated in the postmortem treatment, applying red color to the body. Particular self-care social dynamics of Chinchorro society are inferred.

[Molecular identification of aminoglycoside-modifying enzymes among strains of Enterococcus spp. isolated in hospitals of the VIII Region of Chile]. / Identificación molecular de enzimas modificantes de aminoglucósidos en cepas de Enterococcus spp. aisladas en hospitales de la Octava Región de Chile.

BACKGROUND: Infectious diseases produced by Enterococcus spp, must be treated with a synergistic combination between a penicillin and an aminoglycoside. High level resistance to aminoglycosides is a serious therapeutic problem, since it predicts the loss of synergistic activity of this antimicrobial combination. AIM: To investigate the presence of genes encoding aminoglycoside-modifying enzymes (AMEs) among strains of Enterococcus spp with high level of resistance to aminoglycosides. MATERIAL AND METHODS: The genes encoding some of the AMEs were investigated among 305 aminoglycoside-resistant strains of Enterococcus spp isolated in hospitals of the VIII region of Chile, by dot blot hybridization and Polymerase Chain Reaction (PCS). RESULTS: High level resistance to some aminoglycosides was observed in 104 strains (34.1 %) and 93 of these harbored at least one of the genes encoding the investigated AMEs. Three genes were detected: aac(6)Ie-aph(2")Ia (14.8%) encoding for the enzyme AAC(6)Ie-APH(2")Ia (resistance to all aminoglycosides, except streptomycin); aph(3)IIIa (26%), and ant(6)la (28.5%) encoding for the phosphorylating enzymes APH(3)Ilia (resistance to kanamycin, amikacin and neomycin), and ANT(6)-la (resistance only to streptomycin), respectively. None of the strains harbored the gene ant (4) which encode for the enzyme ANT (4). CONCLUSION: The low frequency of strains harbouring the bifunctional enzyme (<15%), conferring an extended resistance profile to aminoglycosides, allows us to propose the empirical use of aminoglycoside-aminocyclitols, associated to a penicillin, in the treatment of serious infections produced by species of enterococci.