# Acute Otitis Media in Children--Challenges of Antibiotic Resistance in the Post-Vaccination Era
## 1 Background  
Acute otitis media (AOM) represents a leading cause of antibiotic prescriptions in children worldwide [1] and a substantial economic burden on healthcare resources, even in the era of pneumococcal conjugate vaccines [2]. Approximately 80% of all children will experience at least one episode of AOM, with one third of cases with six or more episodes by the age of seven [3].  
The microbiological profile and the antibiotic resistance patterns are essential to guide the optimal treatment in AOM in children. While the etiology of AOM is clearly established, with the most prevalent microorganisms represented by _Streptococcus pneumoniae_, _Haemophilus influenzae_ and _Staphylococcus aureus_, the antimicrobial resistance data focuses mainly on _Streptococcus pneumoniae_, with limited data on other microorganisms [4]. Worldwide, there are large variations (0-65.8%) regarding the lack of susceptibility of _Streptococcus pneumoniae_ to penicillin, due to different pneumococcal conjugate vaccination rates, as well as due to the lack of uniformity in the availability and adherence to AOM guidelines [4]. In order to reduce antibiotic resistance, different guidelines on AOM management encourage a watchful waiting approach rather than immediate antibiotic treatment [5]. However, over-treatment with antibiotics and inaccurate dosing are still reported [6, 7]. In a recent study, [PERSON] et al. [8] found that most antibiotic prescriptions for AOM exceeded the duration recommended by the guidelines: 54% of children were treated for at least 10 days,probably due to extrapolations from the streptococcal tonsillitis treatment regimen. The authors underline that the medical decision regarding treatment duration is not always based on the severity of AOM or on the patient's age [8].  
Nowadays, the preferred therapeutic agents for AOM are represented by beta lactams, which act as inhibitors of the bacterial cell wall synthesis [9]. Amoxicillin, the first-line antibiotic for uncomplicated AOM, exerts its bactericidal action by binding to penicillin-binding proteins that inhibit transpeptididation (the cross-linking process in cell wall synthesis) [9]. In case of treatment failure, amoxicillin/clavulanic acid shows excellent response in beta-lactamase-producing _Haenophilus_ influenzae and penicillin-producing anaerbes [10]. This beta-lactamase inhibitor works by binding irreversibly to beta-lactamase, an enzyme which causes resistance to the original beta-lactam ring of amoxicillin [11]. Second-line options include several classes of antibiotics with different mechanisms of action, as follows: cephalosporporins (ceftriaxone, cefuroxime)--inhibits bacterial cell wall synthesis similar to amoxicillin; macrolides (azithromycin, clarithromycin, erythromycinomycin) and limcosamides (clindamycin)--inhibit bacterial protein synthesis; fluoroquinolones (levofloxacin)--inhibits deoxyribonucleic acid synthesis; trimethoprim/sulfamethoxazole--inhibits folic acid synthesis [5; 12].  
The aim of our study was to assess the bacterial spectrum of infection in children (0-18 years old) with AOM in a tertiary hospital in Romania and to investigate the antimicrobial resistance profile.