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Escherichia coli is the most common microorganism causing nosocomial or community-acquired bacteremia, and extended-spectrum β-lactamase-producing Escherichia coli isolates are identified worldwide with increasing frequency. For this reason, it is necessary to evaluate potential new molecules like antimicrobial peptides. They are recognized for their biological potential which makes them promising candidates in the fight against infections. The goal of this research was to evaluate the potential of the synthetic peptide ΔM3 on several extended-spectrum β-lactamase producing E. coli isolates. The antimicrobial and cytotoxic activity of the peptide was spectrophotometrically determined. Additionally, the capacity of the peptide to interact with the bacterial membrane was monitored by fluorescence microscopy and infrared spectroscopy. The results demonstrated that the synthetic peptide is active against Escherichia coli isolates at concentrations similar to Meropenem. On the other hand, no cytotoxic effect was observed in HaCaT keratinocyte cells even at 10 times the minimal inhibitory concentration. Microscopy results showed a permeabilizing effect of the peptide on the bacteria. The infrared results showed that ΔM3 showed affinity for the lipids of the microorganism's membrane. The results suggest that the ∆M3 interacts with the negatively charged lipids from the E. coli by a disturbing effect on membrane. Finally, the secondary structure experiments of the peptide showed a random structure in solution that did not change during the interaction with the membranes. [ABSTRACT FROM AUTHOR]

We performed a meta-analysis of diagnostic data to evaluate the performance of Histoplasma antigen detection tests for diagnosing histoplasmosis. We included all studies involving human subjects that assessed the performance of any antigen detection test for histoplasmosis in urine or serum by carrying out an exhaustive and reproducible search of the literature between 1980 and 2014 from four databases. Quality of the articles was assessed, and meta-analysis was performed under the random effects model, calculating sensitivity, specificity, likelihood and odds ratios, and ROC curve using Meta- DiSc( es). Nine out of a total of 23 studies met strict quality criteria and were therefore included. The overall sensitivity for antigen detection in serum and urine was 81 % (95 % CI 78-83 %), while specificity was 99 % (95 % CI 98-99 %). Sensitivity for antigenuria and antigenemia was 79 % (95 % CI 76-82 %) and 82 % (95 % CI 79-85 %), respectively; specificity values were 99 % (95 % CI 98-100 %) in urine and 97 % (95 % CI 96-98 %) in serum. The positive and negative likelihood ratios were 49.5 (95 % CI 20.7-118.7) and 0.19 (95 % CI 0.14-0.26), respectively, while the diagnostic OR was 362 (95 % CI 121.2-1080.3) and area under the curve was 0.99. In conclusion, the performance of Histoplasma antigen detection assay of urine was not significantly different from that of blood, indicating that antigenuria and antigenemia have equal diagnostic value in histoplasmosis. [ABSTRACT FROM AUTHOR]