Antibiofilm effects of amoxicillin-clavulanic acid and levofloxacin in patients with chronic rhinosinusitis with nasal polyposis.

PURPOSE: Microbial biofilms have been implicated in the pathogenesis of chronic rhinosinusitis with nasal polyposis (CRSwNP). The aim of our study was to evaluate in vitro effects of amoxicillin-clavulanic acid and levofloxacin on biofilm formation by bacterial species isolated from sinus tissue in patients with CRSwNP. METHODS: The sinus mucosal specimens were harvested from the upper parts and roof of ethmoid cavity of 48 patients with CRSwNP. Each sample was washed thoroughly in three separate beakers of sterile saline to remove any planktonic bacteria and further subjected to microbiology analysis. The biofilm-forming capacity of isolated strains was detected by microtiter-plate method and the effects of subinhibitory (1/2× to 1/16× MIC) and suprainhibitory concentrations (4, 8, 16, 32, and 64 µg/ml) of amoxicillin-clavulanic acid and levofloxacin on biofilm production were investigated. RESULTS: Bacterial strains were isolated in 42 (87.5%) patients: one microorganism in 80.9% and two microorganisms in 19.1% of patients. The most prevalent bacteria in CRSwNP biofilms were Staphylococcus epidermidis (34%) and S. aureus (28%) followed by S. haemolyticus (12%), Pseudomonas aeruginosa (8%), Moraxella catarrhalis (6%), Streptococcus pneumoniae (6%), and other staphylococci (6%). Subinhibitory concentrations of amoxicillin-clavulanic acid and levofloxacin significantly reduced biofilm formation (p < 0.01 and p < 0.05, respectively), with better efficacy of amoxicillin-clavulanic acid (1/2-1/8× MIC) on staphylococci and levofloxacin (1/2- 1/4× MIC) on M. catarrhalis and P. aeruginosa biofilm formation. Suprainhibitory concentrations of both tested antibiotics (4-64 µg/ml) significantly eradicated mature biofilms of staphylococci (p < 0.01). The effect of levofloxacin on eradication of staphylococcal biofilms was more noticeable, compared to the effect of amoxicillin-clavulanic acid (p < 0.01). Suprainhibitory concentrations of both tested antibiotics had no effect on eradication of previously formed M. catarrhalis and P. aeruginosa biofilms (p > 0.05). CONCLUSIONS: The amoxicillin-clavulanic acid and levofloxacin are shown to be potent antibiofilm agents in patients with CRSwNP. The effects of tested compounds depend on bacterial species and the volume of formed biofilm.

Laryngeal Granuloma - Benefit in Treatment with Zinc Supplementation?

Laryngeal granulomas present as contact and postintubation ulcers and granulomas. Essentially, a contact granuloma is a pseudotumor of the lateral wall of the posterior glottis. The most common etiological factor is voice abuse, with predisponing factors such as reflux disease. Postintubation ulcers and granulomas, although of different etiology, according to all the other traits belong to this clinical entity. The therapy of choice is conservative treatment. Surgical laser excision is indicated for resistant cases and those whose size is causing respiratory distress. Treatment of laryngeal granulomas with zinc supplementation is reported in the literature as one of the forms of conservative treatment, and we wanted to consider it in this review. Zinc is an essential mineral that plays a vital role in many biochemical reactions and is considered very important for wound healing.