Simultaneous Two- and Three-Photon Deep Imaging of Autofluorescence in Bacterial Communities.

The intrinsic fluorescence of bacterial samples has a proven potential for label-free bacterial characterization, monitoring bacterial metabolic functions, and as a mechanism for tracking the transport of relevant components through vesicles. The reduced scattering and axial confinement of the excitation offered by multiphoton imaging can be used to overcome some of the limitations of single-photon excitation (e.g., scattering and out-of-plane photobleaching) to the imaging of bacterial communities. In this work, we demonstrate in vivo multi-photon microscopy imaging of Streptomyces bacterial communities, based on the excitation of blue endogenous fluorophores, using an ultrafast Yb-fiber laser amplifier. Its parameters, such as the pulse energy, duration, wavelength, and repetition rate, enable in vivo multicolor imaging with a single source through the simultaneous two- and three-photon excitation of different fluorophores. Three-photon excitation at 1040 nm allows fluorophores with blue and green emission spectra to be addressed (and their corresponding ultraviolet and blue single-photon excitation wavelengths, respectively), and two-photon excitation at the same wavelength allows fluorophores with yellow, orange, or red emission spectra to be addressed (and their corresponding green, yellow, and orange single-photon excitation wavelengths). We demonstrate that three-photon excitation allows imaging over a depth range of more than 6 effective attenuation lengths to take place, corresponding to an 800 micrometer depth of imaging, in samples with a high density of fluorescent structures.

An Emergent Entity: Indolent Mucormycosis of the Paranasal Sinuses. A Multicenter Study

Abstract Introduction Indolent or chronic mucormycosis is a rare entity that affects both immunosuppressed and immunocompetent individuals. Additionally, its clinical evolution is nonspecific and there is no standardized treatment for this condition. Objective To describe the clinical characteristics and management of patients with indolent mucormycosis. Methods In the project of study with chart review in the Interinstitutional secondary care centers, patients with evidence of indolentmucormycosis, defined as pathological confirmation of nasal/paranasal sinus mucormycosis for more than 1 month, were included. All patients underwent complete laboratory workup, imaging studies, surgical treatment and adequate follow-up. No evidence of disease status was defined when patient had subsequent biopsies with no evidence of mucormycosis. Results We included seven patients, three female and four male subjects. The mean age was 53.14 years. Four patients were immunosuppressed and three immunocompetent. Among the immunosuppressed patients three had diabetes and one had dermatomyositis. The symptomswere nonspecific: facial pain/headache, mucoid discharge and cacosmiawere the ones most frequently reported. Maxillary sinus involvement was present in all patients. Two immunosuppressed subjects received amphotericin. Posaconazole was the only treatmentinoneimmunosuppressedpatient. Allimmunocompetent patientshadsingleparanasal sinus disease and received only surgical treatment. All patients are alive and free of disease. Conclusion Indolent mucormycosis is a new and emerging clinical entity in immunosuppressed and immunocompetent patients. Single paranasal sinus disease is a frequent presentation and should not be overlooked as a differential diagnosis in these patients. Immunocompetent patients should only be treated surgically. (AU)