Diseño de una estrategia de comunicación para la promoción del uso del etiquetado de advertencia en niños, niñas y adolescentes mexicanos.

OBJETIVO: Describir el proceso para diseñar una estrategia de comunicación con el fin de promover el uso del etiqueta-do frontal de advertencia (EFA) y la selección de alimentos saludables en niños, niñas y adolescentes (NNA) mexicanos. Material y métodos. Estudio de cuatro fases con esco-lares, adolescentes y cuidadores: 1) investigación formativa (18 grupos focales, n= 179); 2) talleres de cocreación con NNA (n= 33); 3) diseño de la estrategia, con base en el modelo de comportamiento COM-B; y 4) prueba piloto (seis grupos focales, n= 52). RESULTADOS: La estrategia de comunicación debería mejorar la comprensión del EFA y los conocimientos sobre la relación de los ingredientes críticos (calorías, grasas saturadas, grasas trans, sodio, edulcorantes y cafeína) y la enfermedad; asimismo, debería resaltar las consecuencias positivas de una alimentación saludable y las negativas del consumo excesivo de alimentos con sellos, así como destacar que los alimentos naturales tienen un menor costo y mejor calidad que los alimentos con sellos; se deben ofrecer sugerencias de preparaciones atractivas y saludables con alimentos naturales. Conclusión. La investigación formativa y la participación de NNA en la creación de la campaña fueron esenciales para diseñar una estrategia cultu-ralmente pertinente con potencial de impacto. El proceso y los resultados del estudio podrían informar sobre esfuerzos en contextos parecidos al de México.

A Facile High-Throughput Model of Surface-Independent Staphylococcus aureus Biofilms by Spontaneous Aggregation.

Many microbes in their natural habitats are found in biofilm ecosystems attached to surfaces and not as free-floating (planktonic) organisms. Furthermore, it is estimated that nearly 80% of human infections are associated with biofilms. Biofilms are traditionally defined as three-dimensional, structured microbial communities that are attached to a surface and encased in a matrix of exopolymeric material. While this view of biofilm largely arises from in vitro studies under static or flow conditions, in vivo observations have indicated that this view of biofilms is essentially true only for foreign-body infections on catheters or implants where biofilms are attached to the biomaterial. In mucosal infections such as chronic wounds or cystic fibrosis or joint infections, biofilms can be found unattached to a surface and as three-dimensional aggregates. In this work, we describe a high-throughput model of aggregate biofilms of methicillin-resistant Staphylococcus aureus (MRSA) using 96-well plate hanging-drop technology. We show that MRSA forms surface-independent biofilms, distinct from surface-attached biofilms, that are rich in exopolymeric proteins, polysaccharides, and extracellular DNA (eDNA), express biofilm-related genes, and exhibit heightened antibiotic resistance. We also show that the surface-independent biofilms of clinical isolates of MRSA from cystic fibrosis and central catheter-related infections demonstrate morphological differences. Overall, our results show that biofilms can form by spontaneous aggregation without attachment to a surface, and this new in vitro system can model surface-independent biofilms that may more closely mimic the corresponding physiological niche during infection.IMPORTANCE The canonical model of biofilm formation begins with the attachment and growth of microbial cells on a surface. While these in vitro models reasonably mimic biofilms formed on foreign bodies such as catheters and implants, this is not the case for biofilms formed in cystic fibrosis and chronic wound infections, which appear to present as aggregates not attached to a surface. The hanging-drop model of biofilms of methicillin-resistant Staphylococcus aureus (MRSA), the major causative organism of skin and soft tissue infections, shows that these biofilms display morphological and antibiotic response patterns that are distinct from those of their surface-attached counterparts, and biofilm growth is consistent with their in vivo location. The simplicity and throughput of this model enable adoption to investigate other single or polymicrobial biofilms in a physiologically relevant setting.

A rare neurological complication of tuberculosis: Transverse myelitis.

Acute transverse myelitis is a rare inflammatory demyelinating disorder characterized by relatively acute onset of motor, sensory, and autonomic dysfunction. Mycobacterium tuberculosis is a very rare cause of transverse myelitis. We present a patient with tuberculosis presenting with meningitis and transverse myelitis who had marked clinical improvement and neurologic recovery after treatment of tuberculosis and intravenous steroid pulses.

Antimicrobial and Antibiofilm Activity of Synergistic Combinations of a Commercially Available Small Compound Library With Colistin Against Pseudomonas aeruginosa.

Biofilm-associated Pseudomonas aeruginosa infections remain a significant clinical challenge since the conventional antibiotic treatment or combination therapies are largely ineffective; and new approaches are needed. To circumvent the major challenges associated with discovery of new antimicrobials, we have screened a library of compounds that are commercially available and approved by the FDA (Prestwick Chemical Library) against P. aeruginosa for effective antimicrobial and anti-biofilm activity. A preliminary screen of the Prestwick Chemical Library alone did not yield any repositionable candidates, but in a screen of combinations with a fixed sub-inhibitory concentration of the antibiotic colistin we observed 10 drugs whose bacterial inhibiting activity was reproducibly enhanced, seven of which were enhanced by more than 50%. We performed checkerboard assays of these seven drugs in combination with colistin against planktonic cells, and analysis of their interactions over the complete combination matrix using the Zero Interaction Potency (ZIP) model revealed interactions that varied from highly synergistic to completely antagonistic. Of these, five combinations that showed synergism were down-selected and tested against preformed biofilms of P. aeruginosa. Two of the five combinations were active against preformed biofilms of both laboratory and clinical strain of P. aeruginosa, resulting in a 2-log reduction in culturable cells. In summary, we have identified synergistic combinations of five commercially available, FDA-approved drugs and colistin that show antimicrobial activity against planktonic P. aeruginosa (Clomiphene Citrate, Mitoxantrone Dihydrochloride, Methyl Benzethonium Chloride, Benzethonium Chloride, and Auranofin) as well as two combinations (Auranofin and Clomiphene Citrate) with colistin that show antibiofilm activity.

High-throughput microarray for antimicrobial susceptibility testing.

We describe the development of a novel, high-throughput, nano-scale microarray platform for antimicrobial susceptibility testing (AST). The platform allows to process 480 samples at 50 nL volume on a single chip, analyze by fluorescence read-out with an easy dunk-and-rinse step, and the ability to process multiple samples and chips simultaneously. We demonstrate the applicability of this chip for culturing community acquired methicillin resistant Staphylococcus aureus (CA-MRSA), and perform AST against clinical isolates of CA-MRSA. The chip platform holds promise for an impact in microbial biotechnology as an attractive high-throughput, lower sample volume and quicker alternative to conventional AST such as the traditional broth microdilution or the newer automated systems.

nBioChip, a Lab-on-a-Chip Platform of Mono- and Polymicrobial Biofilms for High-Throughput Downstream Applications.

Current in vitro techniques for the culture of microorganisms, and particularly of delicate microbial biofilms, are still mostly limited to low-density plates and manual labor and are not amenable to automation and true high-throughput (HT) applications. We have developed a novel fully automated platform for the formation of mono- and polymicrobial biofilms of Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans at the nanoscale level. The nBioChip is robotically printed, robustly handled, and scanned using a standard microarray reader. Using this technique, hundreds to thousands of identical nanobiofilms encapsulated in hydrogel spots were cultured on microscope slides. The spots can withstand the washing steps involved in screening assays. The miniaturized biofilms demonstrated characteristics similar to those displayed by conventionally formed macroscopic biofilms, including (i) three-dimensional architectural features, (ii) synthesis of exopolymeric matrix material, and (iii) elevated resistance to antibiotic treatment. On the basis of our results, the nBioChip can generate reliable high-throughput antimicrobial susceptibility testing (HT-AST) in 12 to 18 h. The chip serves as a proof-of-concept universal platform for high-throughput drug screening and other downstream applications and furthers understanding of microbial interactions in mixed-species communities at the nanoscale level. IMPORTANCE With an estimated 80% of infections being associated with a biofilm mode of growth and the ensuing recalcitrance of these biofilms with respect to conventional antibiotic treatment leading to high mortality rates, there is a dire and unmet need for the development of novel approaches to prevent, treat, and control these infections. Both bacteria and fungi are capable of forming biofilms that are inherently fragile and often polymicrobial in nature, which further complicates treatment. In this work, we showcase a nanobiofilm chip as a convenient platform for culturing several hundreds of mono- or polymicrobial biofilms and for susceptibility testing. This platform enables true ultra-high-throughput screening for antimicrobial drug discovery or diagnostics or for addressing fundamental issues in microbiology.

Screening a Commercial Library of Pharmacologically Active Small Molecules against Staphylococcus aureus Biofilms.

It is now well established that bacterial infections are often associated with biofilm phenotypes that demonstrate increased resistance to common antimicrobials. Further, due to the collective attrition of new antibiotic development programs by the pharmaceutical industries, drug repurposing is an attractive alternative. In this work, we screened 1,280 existing commercially available drugs in the Prestwick Chemical Library, some with previously unknown antimicrobial activity, against Staphylococcus aureus, one of the commonly encountered causative pathogens of burn and wound infections. From the primary screen of the entire Prestwick Chemical Library at a fixed concentration of 10 µM, 104 drugs were found to be effective against planktonic S. aureus strains, and not surprisingly, these were mostly antimicrobials and antiseptics. The activity of 18 selected repurposing candidates, that is, drugs that show antimicrobial activity that are not already considered antimicrobials, observed in the primary screen was confirmed in dose-response experiments. Finally, a subset of nine of these drug candidates was tested against preformed biofilms of S. aureus We found that three of these drugs, niclosamide, carmofur, and auranofin, possessed antimicrobial activity against preformed biofilms, making them attractive candidates for repurposing as novel antibiofilm therapies.

Diente doble en dentición temporal: reporte de caso clínico / Double tooth in the temporary dentition: case report

The term double tooth corresponds to a binding dental anomaly and refers, therefore, to two teeth together, and includes gemination and fusion. Gemination is an attempt to divide a developing germ, without affecting the final number of pieces. Fusion is the pre-eruptive or embryological union of two adjacent tooth germs, resulting in a piece down in the formula of the arcade hit. Both anomalies show similar clinical features and can occur in both dentitions. This report presents a case of double tooth in mandibular anterior dentition, with diagnosis of dental fusion in a 4 years old patient, explains the features of the case and finally identifies the importance of differential diagnosis between fusion and gemination as pathological entities of similar clinical presentation which according to the literature, can involve almost the same teeth, with potential effects on permanent dentition.

Paclitaxel delivery from cobalt-chromium alloy surfaces using self-assembled monolayers.

Polymer-based platforms in drug-eluting stents (DESs) can cause adverse reactions in patients. Hence, the development of a polymer-free drug delivery platform may reduce adverse reactions to DES. In this study, the use of a polymer-free platform, self-assembled monolayers (SAMs), is explored for delivering an antiproliferative drug [paclitaxel (PAT)] from a stent material [cobalt-chromium ((Co-Cr) alloy]. Initially, carboxylic acid terminated phosphonic acid SAMs were coated on Co-Cr alloy. Two different doses (25 and 100 µg/cm²) of PAT were coated on SAM coated Co-Cr surfaces using a microdrop deposition method. Also, control experiments were carried out to coat PAT directly on Co-Cr surfaces with no SAM modification. The PAT coated specimens were characterized using the Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic force microscopy (AFM). FTIR spectra showed the successful deposition of PAT on SAM coated and control-Co-Cr surfaces. SEM images showed islands of high density PAT crystals on SAM coated surfaces, while low density PAT crystals were observed on control-Co-Cr alloy. AFM images showed molecular distribution of PAT on SAM coated as well as control-Co-Cr alloy surfaces. In vitro drug release studies showed that PAT was released from SAM coated Co-Cr surfaces in a biphasic manner (an initial burst release in first 7 days was followed by a slow release for up to 35 days), while the PAT was burst released from control-Co-Cr surfaces within 1-3 days. Thus, this study demonstrated the use of SAMs for delivering PAT from Co-Cr alloy surfaces for potential use in drug-eluting stents.

Stability of antibacterial self-assembled monolayers on hydroxyapatite.

Open fractures are common in battlefields, motor vehicle accidents, gunshot wounds, sports injuries, and high-energy falls. Such fractures are treated using hydroxyapatite (HA)-based bone graft substitutes. However, open fracture wounds are highly susceptible to bacterial infections. Hence, this study was focused on incorporating antibacterial properties to HA using silver (Ag) carrying self-assembled monolayers (SAMs). Also, the stability of Ag carrying SAMs on HA was investigated under sterilization and physiological conditions. Initially, the -COOH terminated phosphonic acid SAMs of two different chain lengths (11 carbon atoms - shorter chain and 16 carbon atoms - longer chain) were deposited on HA. Antibacterial SAMs (ASAMs) were prepared by chemically attaching Ag to shorter and longer chain SAMs coated HA. X-ray photoelectron spectroscopy, atomic force microscopy, and contact angle goniometry collectively confirmed the attachment of Ag onto SAMs coated HA. The bacterial adhesion study showed that the adherence of Staphylococcus aureus was significantly reduced on ASAMs coated HA when compared to control-HA. The stability studies showed that gas plasma, dry heat and autoclave degraded most of the ASAMs on HA. UV irradiation did not damage the shorter chain ASAMs as vigorously as other treatments, while it degraded the longer chain ASAMs completely. Ethylene oxide treatment did not degrade the longer chain ASAMs unlike all other treatments but it severely damaged the shorter chain ASAMs. Both shorter and longer chain ASAMs significantly desorbed from the HA surfaces under physiological conditions although longer chain ASAMs exhibited better stability than shorter chain ASAMs. This study demonstrated the potential for using ASAMs to provide antibacterial properties to HA and the need for developing techniques to improve stability of SAMs under sterilization and physiological conditions.