Time-kill Kinetics of a Novel Antimicrobial Silver Wound Gel Against Select Wound Pathogens.

UNLABELLED: New treatments are needed as infection risk associated with diabetic, venous, and pressure ulcers are becoming more prevalent as comorbidities of obesity, aging, and major disease. Postsurgical, burn, and immunocompromised patients are also at an increased risk of wounds and infection. Silver has been utilized in treating various wounds associated with infections and, although highly effective, caution is required for use beyond 2 weeks due to potential silver cytotoxicity. To overcome this obstacle, an antimicrobial wound gel (CelaCare Technologies, Inc, Dallas, TX) was designed to allow low concentrations of a proprietary silver salt combined with acemannan, which has been demonstrated to aid wound healing. MATERIALS AND METHODS: This study's objective was to determine the time-kill kinetics of the antimicrobial wound gel vs 4 commercial topical silver products against 6 common wound pathogens and Bacillus subtilis as a spore-forming bacteria. RESULTS: The antimicrobial wound gel achieved a 2.9 log reduction in growth of Pseudomonas aeruginosa within 30 minutes, a 2.3 log reduction in Streptococcus pyogenes within 8 hours, a 2.1 log reduction in methicillin-resistant Staphylococcus aureus within 48 hours, a 2.3 log reduction in S. aureus within 24 hours, a 4.1 log reduction in Escherichia coli within 30 minutes, a 2.9 log reduction in B. subtilis within 60 minutes, and a 3.4 log reduction in Candida albicans within 90 minutes. Overall, the antimicrobial wound gel demonstrated broad antimicrobial coverage against all wound pathogens evaluated, and it was comparable to, or better than, other tested topical silver products containing substantially higher silver concentrations. CONCLUSION: The broad-spectrum antimicrobial activity of the wound gel indicates it could become a product alternative to current commercial products.

Analysis of real time PCR amplification efficiencies from three genomic region of dengue virus.

Early diagnosis of dengue virus (DENV) infection represents a key factor in preventing clinical complications attributed to the disease. The aim of this study was to evaluate the amplification efficiencies of an in-house quantitative real time-PCR (qPCR) assay of DENV, using the non-structural conserved genomic region protein-5 (NS5) versus two genomic regions usually employed for virus detection, the capsid/pre-membrane region (C-prM) and the 3'-noncoding region (3'NC). One-hundred sixty seven acute phase serum samples from febrile patients were used for validation purposes. Results showed that the three genomic regions had similar amplification profiles and correlation coefficients (0.987-0.999). When isolated viruses were used, the NS5 region had the highest qPCR efficiencies for the four serotypes (98-100%). Amplification from acute serum samples showed that 41.1% (67/167) were positive for the universal assay by at least two of the selected genomic regions. The agreement rates between NS5/C-prM and NS5/3'NC regions were 56.7% and 97%, respectively. Amplification concordance values between C-prM/NS5 and NS5/3'NC regions showed a weak (kappa = 0.109; CI 95%) and a moderate (kappa = 0.489; CI 95%) efficiencies in amplification, respectively. Serotyping assay using a singleplex NS5-TaqMan format was much more sensitive than the C-prM/SYBR Green I protocol (76%). External evaluation showed a high sensitivity (100%), specificity (78%) and high agreement between the assays. According to the results, the NS5 genomic region provides the best genomic region for optimal detection and typification of DENV in clinical samples.

Analysis of real time PCR amplification efficiencies from three genomic region of dengue virus / Análisis de las eficiencias de amplificación por PCR en tiempo real de tres regiones genómicas del virus dengue

Early diagnosis of dengue virus (DENV) infection represents a key factor in preventing clinical complications attributed to the disease. The aim of this study was to evaluate the amplification efficiencies of an in-house quantitative real time-PCR (qPCR) assay of DENV, using the non-structural conserved genomic region protein-5 (NS5) versus two genomic regions usually employed for virus detection, the capsid/pre-membrane region (C-prM) and the 3’-noncoding region (3’NC). One-hundred sixty seven acute phase serum samples from febrile patients were used for validation purposes. Results showed that the three genomic regions had similar amplification profiles and correlation coefficients (0.987-0.999). When isolated viruses were used, the NS5 region had the highest qPCR efficiencies for the four serotypes (98-100%). Amplification from acute serum samples showed that 41.1% (67/167) were positive for the universal assay by at least two of the selected genomic regions. The agreement rates between NS5/C-prM and NS5/3’NC regions were 56.7% and 97%, respectively. Amplification concordance values between C-prM/NS5 and NS5/3’NC regions showed a weak (k= 0.109; CI 95%) and a moderate (k= 0.489; CI 95%) efficiencies in amplification, respectively. Serotyping assay using a singleplex NS5-TaqMan® format was much more sensitive than the C-prM/SYBR Green® I protocol (76%). External evaluation showed a high sensitivity (100%), specificity (78%) and high agreement between the assays. According to the results, the NS5 genomic region provides the best genomic region for optimal detection and typification of DENV in clinical samples.

El diagnóstico precoz de la infección por el virus dengue (DENV) constituye un elemento clave para la prevención de las complicaciones clínicas propias de la enfermedad. El objetivo del estudio fue evaluar la detección de DENV mediante un ensayo cuantitativo de PCR-tiempo real (qPCR), desarrollado localmente, utilizando la región no-estructural-5 (NS5), versus dos regiones tradicionalmente empleadas para la detección del virus, la región cápside/pre-membrana (C-prM), y la región noncodificante-3’ (3’NC). Se recolectaron 167 muestras de suero de pacientes en fase aguda de la enfermedad. Las tres regiones génicas tuvieron perfiles de amplificación/coeficientes de correlación similares (0,987-0,999). Sin embargo, la región NS5 tuvo la eficiencia de amplificación más elevada para los cuatro serotipos (98-100%). Durante el proceso de validación, 41,1% (67/167) de las muestras de suero resultaron positivas para DENV al menos por dos de las regiones genómicas empleadas. Los valores de concordancia entre las regiones NS5/C-prM y NS5/3’NC fueron de 56,7% y 97%, respectivamente. La concordancia fue débil entre las regiones NS5/C-prM (k= 0,109; CI 95%), sin embargo, fue moderada entre las regiones NS5/3’NC (k= 0,489; CI 95%). El ensayo de tipificación uniplex en formato NS5/TaqMan® mostró alta sensibilidad (100%) que el protocolo C-prM/SYBRGreen®-I (76%). La validación externa del ensayo mostró una alta sensibilidad (100%), especificidad (78%) y acuerdo alto entre los ensayos utilizados. De acuerdo a los resultados obtenidos, la región NS5 ofrece la mayor opción para la detección y serotipificación del DENV en muestras clínicas.

Identification of Aedes aegypti and its respective life stages by real-time polymerase chain reaction.

An Aedes aegypti-specific, fluorogenic probe hydrolysis (Taq-Man), polymerase chain reaction assay was developed for real-time screening using a field-deployable thermocycler. Laboratory-based testing of A. aegypti, A. aegypti (Trinidad strain), Culex pipiens, Culex quinquefasciatus, Anopheles stephensi, and Ochlerotatus taeniorhynchus individual adult mosquitoes and mixed pools (n = 10) demonstrated 100% concordance in both in vitro sensitivity (six of six samples) and specificity (10 of 10 samples). A single adult A. aegypti was identified in a pool of 100 non-A. aegypti mosquitoes. The limit of detection of A. aegypti egg pools was five individual eggs. Field testing was conducted in central Honduras. An A. aegypti and Culex spp. panel of individual and mixed pools (n = 30) of adult mosquitoes, pupae, and larvae demonstrated 100% concordance in sensitivity (22 of 22 samples) and 97% concordance in specificity (29 of 30 samples), with one false-positive result. Field testing of an A. aegypti and Culex spp. blind panel (n = 16) consisting of individual and mixed pools of adult mosquitoes, pupae, and larvae demonstrated 90% concordance in sensitivity (nine of 10 samples) and 88% concordance in specificity (14 of 16 samples).