In vivo monitoring of Lactiplantibacillus plantarum in the nasal and vaginal mucosa using infrared fluorescence.

Lactic acid bacteria (LAB) of the genus Lactiplantibacillus have been explored as potential mucosal vaccine vectors due to their ability to elicit an immune response against expressed foreign antigens and to their safety. However, tools for monitoring LAB distribution and persistence at the mucosal surfaces are needed. Here, we characterize Lactiplantibacillus plantarum bacteria expressing the infrared fluorescent protein IRFP713 for exploring their in vivo distribution in the mucosa and potential use as a mucosal vaccine vector. This bacterial species is commonly used as a vaginal probiotic and was recently found to have a niche in the human nose. Three different fluorescent L. plantarum strains were obtained using the nisin-inducible pNZRK-IRFP713 plasmid which contains the nisRK genes, showing stable and constitutive expression of IRFP713 in vitro. One of these strains was further monitored in BALB/c mice using near-infrared fluorescence, indicating successful colonization of the nasal and vaginal mucosae for up to 72 h. This study thus provides a tool for the in vivo spatiotemporal monitoring of lactiplantibacilli, allowing non-invasive bacterial detection in these mucosal sites. KEY POINTS: • Stable and constitutive expression of the IRFP713 protein was obtained in different L. plantarum strains. • IRFP713+ L. plantarum 3.12.1 was monitored in vivo using near-infrared fluorescence. • Residence times observed after intranasal and vaginal inoculation were 24-72 h.

Identificación bacteriana directamente del hemocultivo mediante una técnica rápida de espectrometría de masas Matrix-Assisted Laser Desorption-Ionisation Time-of-Flight / Bacterial identification from blood cultures by a rapid Matrix-Assisted Laser Desorption-Ionisation Time-of-Flight mass spectrometry technique

Introducción La espectrometría de masas Matrix-Assisted Laser Desorption-Ionisation Time-of-Flight (MALDI-TOF) es una técnica rápida y fiable de identificación bacteriana. Métodos Se evalúa un método para identificación directa del hemocultivo fácil, rápido de realizar y de bajo coste. Resultados El porcentaje de identificaciones con (..) (AU)

Introduction Matrix-Assisted Laser Desorption-Ionisation Time-of-Flight (MALDI-TOF) Mass Spectrometry is rapid and accurate for the bacterial identification. Methods We have evaluated a less laborious and less time consuming method for microorganism identification directly from positive blood cultures. Results When we considered the scores (..) (AU)

[Bacterial identification from blood cultures by a rapid Matrix-Assisted Laser Desorption-Ionisation Time-of-Flight mass spectrometry technique]. / Identificación bacteriana directamente del hemocultivo mediante una técnica rápida de espectrometría de masas Matrix-Assisted Laser Desorption-Ionisation Time-of-Flight.

INTRODUCTION: Matrix-Assisted Laser Desorption-Ionisation Time-of-Flight (MALDI-TOF) Mass Spectrometry is rapid and accurate for the bacterial identification. METHODS: We have evaluated a less laborious and less time consuming method for microorganism identification directly from positive blood cultures. RESULTS: When we considered the scores ≥1.7 and ≥1.4 for acceptable identification of species and genus, the percentage of identification was 77.5% and 93.9%, respectively. CONCLUSIONS: This method is reliable, rapid and cost-effective for implementation in routine use in clinical microbiology laboratories.