Relevance of biofilms in pediatric tonsillar disease.

In this investigation, we study the relation between chronic inflammation of the tonsils, clinical features, and the presence of biofilms in the crypts in patients presenting with obstructive hypertrophy and recurrent upper airway pathology. Thirty-six patients who needed to undergo a tonsillectomy for obstructive reasons (aged 1 to 6 years), among which none of them had taken any antibiotics 30 days prior to surgery, were included. Samples were examined with hematoxylin-eosin and Gram staining, fluorescent microscopy, and confocal laser microscopy. The predominance of symptoms were those related to obstructive pathology rather than infection (p < 0.01). All patients had tonsillar hypertrophy (grade III or IV), but an association with adenoids hypertrophy was detected in 66.66% of cases (p < 0.05). 77.28% of tonsils presented biofilms in their crypts, but hypertrophy and tonsillar follicle number were not related to the presence or absence of biofilms. Here, we demonstrated that symptoms like harsh raucous sound, tonsillar and adenoids hypertrophy, apnea, and cervical adenopathies are clearly related to the presence of biofilm in tonsils. Our results allow us to propose that biofilms are involved in the pathogenesis of tonsils and adenoids hypertrophy. The prevention of biofilms formation should be focused in the early stages, attempting to restrain bacterial attachment to the respiratory mucosa.

Identification of the fusion peptide of primate immunodeficiency viruses.

Membrane fusion induced by the envelope glycoproteins of human and simian immunodeficiency viruses (HIV and SIVmac) is a necessary step for the infection of CD4 cells and for the formation of syncytia after infection. Identification of the region in these molecules that mediates the fusion events is important for understanding and possibly interfering with HIV/SIVmac infection and pathogenesis. Amino acid substitutions were made in the 15 NH2-terminal residues of the SIVmac gp32 transmembrane glycoprotein, and the mutants were expressed in recombinant vaccinia viruses, which were then used to infect CD4-expressing T cell lines. Mutations that increased the overall hydrophobicity of the gp32 NH2-terminus increased the ability of the viral envelope to induce syncytia formation, whereas introduction of polar or charged amino acids in the same region abolished the fusogenic function of the viral envelope. Hydrophobicity in the NH2-terminal region of gp32 may therefore be an important correlate of viral virulence in vivo and could perhaps be exploited to generate a more effective animal model for the study of acquired immunodeficiency syndrome.