Pediatric tracheostomy: A large single-center experience.

OBJECTIVES: To describe the epidemiology, specifically the indications, complications, and outcomes, of pediatric tracheostomies performed in one tertiary referral unit. METHODS: Single-center retrospective cohort study of pediatric patients undergoing tracheostomy between May 2010 and May 2018 at the Newcastle upon Tyne Hospitals, United Kingdom. RESULTS: One hundred seventy-two pediatric tracheostomies were performed during the study period with a median age of 141 (interquartile range [IQR] 51-484) days. The most common primary indication was long-term ventilation (38.4%, 66 of 172), followed by weaning from ventilation in cardiac patients (22.1%, 38 of 172). Only 5.2% (9 of 172) of our cohort underwent tracheostomy for subglottic stenosis. The vast majority of tracheostomies were performed electively, with just 6.4% (11 of 172) performed as an emergency procedure. Early and late complication rates were 9.8% (15 of 153) and 40.0% (61 of 153), respectively. Tracheostomy decannulation was successful in 44.4% of children (68 of 153). The median duration the tracheostomy was in situ was 397 (IQR 106-708) days. All-cause mortality was 22.1% (38 of 172), with tracheostomy-related mortality at 1.2% (2 of 172). CONCLUSION: We report one of the largest contemporary case series of pediatric tracheostomies. Present-day pediatric tracheostomy is primarily performed as an elective procedure in ventilated children under the age of 1 year. Pediatric tracheostomy should be considered as a long-term intervention in many children. Nevertheless, a large proportion of children are ultimately decannulated. It is important to acknowledge the significant morbidity associated with this intervention and the small-but-present risk of tracheostomy-related mortality. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:E375-E380, 2020.

Pili mediate specific adhesion of Streptococcus pyogenes to human tonsil and skin.

Very little is known about the biological functions of pili that have recently been found to be expressed by important Gram-positive pathogens such as Corynebacterium diphtheriae, Streptococcus agalacticae, S. pneumoniae and S. pyogenes. Using various ex vivo tissue and cellular models, here we show that pili mediate adhesion of serotype M1 S. pyogenes strain SF370 to both human tonsil epithelium and primary human keratinocytes, which represent the two main sites of infection by this human-specific pathogen. Mutants lacking minor pilus subunits retained the ability to express cell-surface pili, but these were functionally defective. In contrast to above, pili were not required for S. pyogenes adhesion to either immortalized HEp-2 or A549 cells, highlighting an important limitation of these extensively used adhesion/invasion models. Adhering bacteria were internalized very effectively by both HEp-2 and A549 cells, but not by tonsil epithelium or primary keratinocytes. While pili acted as the primary adhesin, the surface M1 protein clearly enhanced adhesion to tonsil, but surprisingly, had the opposite effect on adhesion to keratinocytes. These studies provide clear evidence that S. pyogenes pili display an adhesive specificity for clinically relevant human tissues and are likely to play a critical role in the initial stages of infection.