Genomic analyses of Staphylococcus aureus clonal complex 45 isolates does not distinguish nasal carriage from bacteraemia.

Staphylococcus aureus is a colonizing opportunistic pathogen and a leading cause of bloodstream infection with high morbidity and mortality. S. aureus carriage frequency is reportedly between 20 and 40 % among healthy adults, with S. aureus colonization considered to be a risk factor for S. aureus bacteraemia. It is unknown whether a genetic component of the bacterium is associated with S. aureus bacteraemia in comparison to nasal carriage strains. Previous association studies primarily focusing on the clinical outcome of an S. aureus infection have produced conflicting results, often limited by study design challenged by sample collections and the clonal diversity of S. aureus. To date, no study has investigated whether genomic features separate nasal carriage isolates from S. aureus bacteraemia isolates within a single clonal lineage. Here we have investigated whether genomic features, including single-nucleotide polymorphisms (SNPs), genes, or kmers, distinguish S. aureus nasal carriage isolates from bacteraemia isolates that all belong to the same clonal lineage [clonal complex 45 (CC45)] using whole-genome sequencing (WGS) and a genome-wide association (GWA) approach. From CC45, 100 isolates (50 bacteraemia and 50 nasal carriage, geographically and temporally matched) from Denmark were whole-genome sequenced and subjected to GWA analyses involving gene copy number variation, SNPs, gene content, kmers and gene combinations, while correcting for lineage effects. No statistically significant association involving SNPs, specific genes, gene variants, gene copy number variation, or a combination of genes was identified that could distinguish bacteraemia isolates from nasal carriage isolates. The presented results suggest that all S. aureus nasal CC45 isolates carry the potential to cause invasive disease, as no core or accessory genome content or variations were statistically associated with invasiveness.

Bacterial cellulose as a new graft model for the Turkish delight technique in rhinoplasty: An experiment in 20 rats.

We conducted an experiment to investigate the effectiveness of bacterial cellulose, a new graft material, in correcting and preventing dorsal nasal disorder in rhinoplasty. The experiment was performed on 20 Wistar albino rats. The rats were evenly divided into two groups: a fascia group and a cellulose group. In the fascia group, grafts from the conchal cartilage were removed, shredded, and then wrapped in temporal muscle fascia. In the cellulose group, shredded cartilage was wrapped in the bacterial cellulose. These shredded gristle grafts, which were also placed in a subcutaneous area at the back of the rats, were excised after 60 days. We then performed histopathology to compare the health and integrity of the cartilage and the degree of vascularization, fibrosis, and chronic inflammation in the two groups. We found a significantly greater degree of vascularization (p = 0.004) and fibrosis (p = 0.005) in the fascia group and a significantly greater degree of chronic inflammation (p = 0.023) in the cellulose group. We found no statistically significant difference between the two groups in terms of cartilage health and integrity. Our results suggest that bacterial cellulose grafting may play a role as an alternative to fascia grafting for the wrapping of shredded cartilages in Turkish delight grafting, but further investigation is needed.

Cartilage on the floor: how effective is antibiotic sterilization?

OBJECTIVE: To determine the incidence of positive cultures from contaminated nasal cartilage and to demonstrate the effectiveness of antibiotic irrigation as a means of sterilization. DESIGN: A prospective study. SETTING: Tertiary referral centre. METHODS: Nasal septal cartilage was harvested during routine endoscopic septoplasties. The harvested cartilage was then dropped on the floor for 60 seconds. The cartilage was then divided into four equal portions, which were then divided into four experimental groups: (1) untreated, (2) normal saline soak for 60 seconds, (3) 40 mg/mL gentamicin solution soak for 60 seconds, and (4) 300 seconds. All specimens were sent for bacterial culture and sensitivity, along with nasal swabs and floor swabs. The incidence of bacterial contamination in the different groups was analyzed using the McNemar hypothesis. MAIN OUTCOME MEASURES: Correlation between bacterial culture results and treatments of contaminated nasal septal cartilages. RESULTS: Thirty-two patients were enrolled in this study. Thirty-one percent of the untreated specimens had bacterial contamination. Thirty-one percent of the saline-soaked specimens had significant bacterial growth. Bacterial growth was not observed in any of the specimens treated with gentamicin irrigation for 60 seconds (absolute reduction of 31%); one specimen (3%) in the 300 seconds gentamicin group had a positive culture. A correlation of 70% was observed in the bacterial growth observed in the swab of the operating room floor and the untreated cartilage. CONCLUSIONS: When no other options are available, this study demonstrates that cartilage dropped on the floor can be decontaminated by washing with gentamicin.

Necrosis of nasal cartilage due to mucormycosis in a patient with severe congenital neutropenia due to HAX1 deficiency.

Severe congenital neutropenia (SCN) is a primary immunodeficiency disease characterized by early onset of severe bacterial infection and persistent severe neutropenia. We describe an SCN patient with a history of recurrent infections. The clinical course was complicated by necrosis of the nasal cartilage due to mucormycosis. Molecular studies revealed a homozygous germline HAX1 mutation. Fungal infections may lead to serious complications in immunodeficient patients. Recurrent and severe infections should alert physicians to possible immunodeficiency disease. Early diagnosis and appropriate treatment are the most important keys to preventing irreversible organ damage.