# Acute Otitis Media in Children--Challenges of Antibiotic Resistance in the Post-Vaccination Era
## 4 Discussions  
Antimicrobial resistance still represents a global threat as there are more than 670,000 infections every year due to antibiotic-resistant microorganisms [13]. The list of global priority pathogens \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**MIC * (\(\mathbf{\mu}\)g/mL)**} & \multicolumn{2}{c}{**Number of Strains**} \\ \cline{2-5}
**Antibiotic** & **S** & **R** & & \\  & **(Sensitive)** & **(Resistant)** & **S** & **R** \\ \hline Amoxicillin/clavulanic acid & \(\leq\)2/1 & \(>\)8/4 & 14 & 3 \\ Cefruoxime & \(<\)4 & - & 17 & - \\ Cefriaxone & \(\leq\)2 & - & 17 & - \\ Trimethoprim/sulfamethoxazole & \(\leq\)0.5/9.5 & \(\geq\)4/76 & 8 & 9 \\ \hline \hline \end{tabular}  
* MIC—minimum inhibitory concentration.  
\end{table} 
Table 4: Antibiotic resistance of _Haemophilus influenzae_ strains. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Bacteria**} & \multirow{2}{*}{**Strain Number**} & **Age Group (Average Age,** & **Antibiotic Resistant Classes** \\  & & **Median Age) * & TMP/SMX, macrolides, limcosamides (33 strains) \\ \hline \multirow{3}{*}{_Streptococcus pneumoniae_} & \multirow{3}{*}{41} & \multirow{3}{*}{6–48 (31, 16)} & \multirow{3}{*}{\begin{tabular}{c} TMP/SMX, macrolides, limcosamides, \\ penicillin, TMP/SMX, macrolides (4 strains) \\ \end{tabular} } \\  & & & TMP/SMX, macrolides, limcosamides, \\  & & & cephalosporors (4 strains) \\ \hline Culture negative & 27 & 5–84 (20, 15) & not applicable \\ \hline \multirow{2}{*}{_Haemophilus influenzae_} & \multirow{2}{*}{7} & \multirow{2}{*}{7–48 (20, 13)} & \multirow{2}{*}{\
\begin{tabular}{c} amoxicillin/clavulanic acid (3 strains) \\ TMP/SMX (4 strains) \\ \end{tabular} } \\  & & & TMP/SMX (4 strains) \\ \hline MRSA & 1 & 2 & methicillin-resistant strain \\ \hline \multirow{2}{*}{_Enterobacter aerogene_} & \multirow{2}{*}{1} & \multirow{2}{*}{6} & \multirow{2}{*}{
\begin{tabular}{c} MDR (cephalosporins, aminoglycos, \\ fluoroquinolones, ampicillin and \\ amoxicillin/clavulanic acid.) \\ \end{tabular} } \\  & & & amoxicillin \\ \hline _Monxella catarrathlis_ & 1 & 72 & beta-lactams (penicillins, cephalosporors) \\ \hline _Turicella oitiidis_ & 1 & 12 & not applicable ** \\ \hline \hline \end{tabular}  
* The age is reported as months old. **_Turicella oitiidis_ has not been tested with antibiotics.  
\end{table} 
Table 5: Microbiological profile in treatment failure cases. (GPP) published by the World Health Organization (WHO) includes, on the medium priority group, two of the major pathogens responsible for AOM in children: _Streptococcus pneumoniae_ and _Haemophilus influenzae_, due to penicillin non-susceptibility and ampicillin-resistant strains, respectively [14]. After the incorporation of pneumococcal conjugate vaccines into national immunization programs worldwide, a significant reduction in AOM episodes has been recorded. In the United States of America, after the introduction of pneumococcal conjugate vaccine 7 (PCV7), the frequency of otitis media has reduced by 28% and the antimicrobial prescriptions decreased by 42% [15]. Similarly, in the United Kingdom, [PERSON] et al. reported a 22% reduction in the incidence of otitis media in children younger than 10 years old following the introduction of PCV7, with an additional 19% reduction after PCV7 was replaced by PCV13 [16]. In Sweden, the incidence of severe otitis media in children aged less than 2 years old decreased by 32% after the introduction of PCV13 [17]. Besides these encouraging data in the frequency of otitis media strains, important decreases in antimicrobial-resistant vaccine-type pneumococcal infections have been reported: [PERSON] et al. investigated the impact of human vaccines on bacterial antimicrobial resistance, highlighting the importance of vaccines targeting _Streptococcus pneumoniae_ for reducing antibiotic consumption and antibiotic-resistant bacterial strains [18].