Journal: Pneumonia

Article Title: Fluorescent antibody-based detection and ultrastructural analysis of Streptococcus pneumoniae in human sputum

doi: 10.1186/s41479-025-00157-z

Figure Lengend Snippet: In vitro and in vivo detection of pneumococci with fluorescently-labelled antibodies. Strain TIGR4 ( A ) was mixed with anti S4-A488 (green) antibody and observed under a epifluorescence microscope within five minutes. ( B ) Spn serotype 19F strain 4924 was cultured for four h in a 8-well slide and pneumococci attached to the substratum were stained with an anti S19-A555 (red) antibody and the DNA was stained with DAPI. ( C - D ) Human pharyngeal cells grown to confluence were inoculated with ( C ) strain D39 or ( D ) a mixture of strain D39 and strain TIGR4 and incubated for four hours. D39 was stained with S2-A555 (red) and TIGR4 was stained with S4-A488. In panel C, DNA was stained with TO-PRO-3, while in panel D, it was stained with DAPI. ( E - F ) C57BL/6 mice ( N = 11) were intranasally inoculated with serotype 19F strain EF3030. After 48 h, mice were euthanized, and the nasal bone was removed. Nasopharyngeal tissue was collected, sectioned (∼5 μm), or homogenized. Nasopharyngeal homogenate ( E ) or tissue sections ( F ) were stained with DAPI and with an anti S19-A555 antibody. Arrows point out Spn. In panels B-F, micrographs were obtained by confocal microscopy, and the projection of z-stacks is shown. ( G ) Nasopharyngeal homogenates were diluted and plated to obtain the bacterial density. The density in the plot was grouped according to whether the samples yielded a positive reaction with Spn-FLUO or were not detected (ND). Student t test, ** p = 0.01

Article Snippet: Confocal micrographs were obtained using a Nikon C2 laser scanning confocal microscopy system and analyzed using the Imaris software (Bitplane).

Techniques: In Vitro, In Vivo, Microscopy, Cell Culture, Staining, Incubation, Confocal Microscopy

Journal: Pneumonia

Article Title: Fluorescent antibody-based detection and ultrastructural analysis of Streptococcus pneumoniae in human sputum

doi: 10.1186/s41479-025-00157-z

Figure Lengend Snippet: Detection of S. pneumoniae with Spn-FLUO in mouse lung specimens. Balb/c mice were intranasally inoculated with strain TIGR4 or isogenic mutant Δ spxB Δ lctO and euthanized when deemed moribund, or after 96 h post-infection. Lungs were collected and homogenized. ( A ) Lung homogenates were diluted and plated to obtain the bacterial density. ( B ) Aliquots of lung homogenate were stained with Spn-FLUO and scored for the presence of pneumococci. Micrographs were obtained with a fluorescence microscope in the green channel. The top panel shows a representative specimen scored “+” with arrows pointing out S. pneumoniae , while the bottom panel shows a representative specimen that scored “+++”. ( C ) The density in the graphic was grouped according to the semiquantitative detection of S. pneumoniae with Spn-FLUO. Statistical significance of differences in bacterial density were determined using Student’s t-test ( A ) or one-way ANOVA followed by Dunnett’s multiple comparisons test ( C ). * p = 0.027, ** p = 0.0088, *** p = 0.0007

Article Snippet: Confocal micrographs were obtained using a Nikon C2 laser scanning confocal microscopy system and analyzed using the Imaris software (Bitplane).

Techniques: Mutagenesis, Infection, Staining, Fluorescence, Microscopy