This document discusses the case of a 6-year-old girl diagnosed with right acute otitis media caused by Streptococcus pneumoniae. Her symptoms included fever for 4 days and right otalgia. Her exam found right ear pulling tenderness with pus. She was treated with ampicillin then amoxicillin. The document also discusses beta-lactam antibiotic resistance mechanisms in S. pneumoniae, which involve genetic mutations altering penicillin-binding proteins. The impact of PCV13 vaccination on resistant pneumococcal strains is also mentioned. Treatment of acute otitis media requires a pediatrician and ENT consultation.

1. 聖功醫院 兒科 洪毓棋醫師
Dose Pneumococcus matter at the post-PCV13 vaccination era?

2. Patient profile
• Age: 6 y/o
• Girl; 18kg; 120cm
• Development: seems mild Autism
• Visit date: 2023/5/10

3. Chief complaint
• Fever for 4 days with right otalgia yesterday

4. Present illness
• She had fever around 38.6’C for 4 days with 2 times LMD visit.
• She did not have obvious cough nor rhinorrhea recently.
• Today she complained of right otalgia.

6. Physical examination
• PR: 108 /min, RR: 24 /min, BT: 38.2 °C
• Consciousness: Alert
• Anterior fontanel: flat and soft
• Ear: right side pulling tenderness with pus coating
• Throat: not injected
• Chest: breath sound: clear, no retraction heart sound: regular, no murmur
• Abdomen: soft, flat
• Bowel sound: Normal active
• Skin : no rash

7. Past history
• Mild allergic rhinitis

8. Tentative diagnosis
• Right A.O.M with pus

9. Plans
• Check lab data for bacterial infection
• Ampicillin 200mg/kg/day Q6H
• Pursue pus culture result
• Consult ENT

10. Lab data 5/10
• 報告日期 檢驗項目 檢驗值 單位 標準值
• 2023/05/10 Blood Routine .
• 2023/05/10 W.B.C 17.43 1000/ul 3.25-9.16
• 2023/05/10 R.B.C 4.04 Mill/ul M4.5~5.9F4.0
• 2023/05/10 Hb 11.8 g/dl M13.5~17.5F1
• 2023/05/10 Hct 33.1 % M:41~53F:36~
• 2023/05/10 MCV 81.9 fl 82-98
• 2023/05/10 MCH 29.2 pg 27-32
• 2023/05/10 MCHC 35.6 g/dl 32-36
• 2023/05/10 Platelet 349 1000/ul 150-400
• 2023/05/10 RDW-SD 35.6 fL
• 2023/05/10 Neutro 86.8 % 40-75
• 2023/05/10 Lymph 7.1 % 20-50
• 2023/05/10 Monocyte 5.6 % 1-10
• 2023/05/10 Eosinophil 0.2 % 1-7
• 2023/05/10 Basophil 0.3 % 0-2
• 2023/05/10 CRP 15.09 mg/dl <0.50

12. Progression
• Right post-auricular tenderness in the first 2 days
during admission.
• ENT consultation:
• Augmenting is the first choice
• Ofloxacin ottic drop BID

14. • Infectious physician consultation:
• Ampicillin 900mg ivd q6h then switch to amoxicillin 1gm po q8h for total 7-10
days.

16. 過敏原
• IgE 免疫球蛋白E 252(H) 6-216 IU/ML
• Phad吸入性過敏原定性篩檢 Positive Negative :
• 細項
• d1屋塵璊 屋塵璊 59.9(H) <0.35 Ku/L
• i6德國蟑螂 德國蟑螂 0.04 <0.35 Ku/L
• d201熱帶五爪璊 熱帶五爪璊 0.09 <0.35 Ku/L
• ex2動物皮毛類檢查 0.02 <0.35 Ku/L
• mx2黴菌檢查 黴菌檢查 0.07 <0.35 Ku/L
• rx3花粉檢查 花粉檢查 0.02 <0.35 Ku/L

17. ENT
Augmenting 4ml BID for 10 days

18. Final diagnosis
• Right acute otitis media caused by Streptococcus Pneumoniae
• Amoxicillin 500mg q8h po
• Right conducting hearing loss, mild
• Allergic rhinitis

19. Antibiotics resistance
Beta-lactam

20. Beta-lactam antibiotics
• Penicillins
• Cephalosporins
• Cephamycins
• Carbapenems
• Monobactams
• Beta-lactamase inhibitors

21. • prompt diagnosis and administration of an antibiotic that
provides a level sufficient to inhibit or kill the infecting
organism,
• continuation of treatment at least until the host is able to
complete the curing and healing processes,
• drainage of infections of closed spaces if necessary,
• knowing what response to expect,
• being prepared to reevaluate if this response is not observed.
Principles of treating pneumococcal infection

22. ＡＯＭ的初始治療

25. Mechanism
• Decreased penetration to the target site
• Pseudomonas aeruginosa
• Alteration of the target site, penicillin-binding proteins (PBPs)
• penicillin resistance in pneumococci,
• methicillin (oxacillin) resistance in staphylococci,
• increasing intrinsic resistance to beta-lactams, such as gonococci,
enterococci, and Haemophilus influenzae.
• Inactivation by a bacterial enzyme, penicillinases, cephalosporinases, beta-
lactamases
• gram-negative bacilli
• Haemophilus influenzae

26. Clinical consideration
• treating the same pathogen will require different doses of a given β-lactam
depending on the site of infection.
• Because the mechanism of resistance of S. pneumoniae is a result of alterations
in PBPs and not a result of the production of b-lactamases, antimicrobial agents
containing b-lactamase inhibitors generally do not offer any additional activity.
• However, when empirically treating community-acquired infections, such as
pneumonia or acute otitis media, the use of amoxicillin/clavulanate may be
beneficial to cover b-lactamase–producing pathogens (e.g., Moraxella
catarrhalis, Haemophilus influenzae).

27. Impact of PCV13
感染控制雜誌, 中華民國 110 年 4 月第三十一卷二期

28. Impact of PCV
• Resistance strain: 15B, 23A, 23B, and 35B
• PCV15 (較 PCV13 增加血清型 22F 及 33F)
• PCV20 (較 PCV15 增加血清型 8、 10A、11A、12F 及 15B)

29. • AOM need pediatrics and ENT
• Further vaccination
The end?

31. S. pneumoniae is associated with greater clinical severity than other otopathogens, as
reflected by higher fever, more intense otalgia, and the potential for complications
such as bacteremia and mastoiditis
The mechanism of beta-lactam resistance of S. pneumoniae involves genetic
mutations which alter penicillin-binding protein structure, resulting in a decreased
affinity for all beta-lactam antibiotics.
Haemophilus influenzae
In other parts of the world, resistance to ampicillin and cephalosporins may be
associated with mutations in the penicillin binding proteins (beta-lactamase negative,
ampicillin-resistance)