Treatment and prevention of invasive pneumococcal disease

Genomic surveillance of invasive Streptococcus pneumoniae isolates in the period pre-PCV10 and post-PCV10 introduction in Brazil

In 2010, Brazil introduced the 10-valent pneumococcal conjugate vaccine (PCV10) into the national children’s immunization programme. This study describes the genetic characteristics of invasive Streptococcus pneumoniae isolates before and after PCV10 introduction. A subset of 466 [pre-PCV10 (2008–2009): n=232, post-PCV10 (2012–2013): n=234;<5 years old: n=310, ≥5 years old: n=156] pneumococcal isolates, collected through national laboratory surveillance, were whole-genome sequenced (WGS) to determine serotype, pilus locus, antimicrobial resistance and genetic lineages. Following PCV10 introduction, in the <5 years age group, non-vaccine serotypes (NVT) serotype 3 and serotype 19A were the most frequent, and serotypes 12F, 8 and 9 N in the ≥5 years old group. The study identified 65 Global Pneumococcal Sequence Clusters (GPSCs): 49 (88 %) were GPSCs previously described and 16 (12 %) were Brazilian clusters. In total, 36 GPSCs (55 %) were NVT lineages, 18 (28 %) vaccine serotypes (VT) and 11 (17 %) were both VT and NVT lineages. In both sampling periods, the most frequent lineage was GPSC6 (CC156, serotypes 14/9V). In the <5 years old group, a decrease in penicillin (P=0.0123) and cotrimoxazole (P<0.0001) resistance and an increase in tetracycline (P=0.019) were observed. Penicillin nonsusceptibility was predicted in 40 % of the isolates; 127 PBP combinations were identified (51 predicted MIC≥0.125 mg l⁻¹); cotrimoxazole (folA and/or folP alterations), macrolide (mef and/or ermB) and tetracycline (tetM, tetO or tetS/M) resistance were predicted in 63, 13 and 21.6 % of pneumococci studied, respectively. The main lineages associated with multidrug resistance in the post-PCV10 period were composed of NVT, GPSC1 (CC320, serotype 19A), and GPSC47 (ST386, serotype 6C). The study provides a baseline for future comparisons and identified important NVT lineages in the post-PCV10 period in Brazil.

Conquering the pneumococcal nemesis with oral antibiotics

Introduction: Streptococcus pneumoniae endocarditis (SPE) occurs in <3% of all EI cases due to the evolution of penicillin and vaccination. However, immunocompromised and unvaccinated patients are still at grave risk. Case: A 58-year-old African American male who used alcohol and intravenous (IV) drugs presented with confusion, fever, and hemoptysis. He had coarse rhonchi with a grade 2/5 holosystolic apical murmur. CT chest showed diffuse bilateral infiltrates. Blood cultures were positive for pansensitive Streptococcus pneumoniae. Echocardiogram demonstrated large vegetations on the anterior and posterior leaflets of the mitral valve with flail leaflet and severe eccentric mitral regurgitation. Patient was started on IV ceftriaxone, but after 3 weeks of therapy, he wished to leave against medical advice. He was discharged on combination oral therapy with successful resolution of SPE on follow-up. Discussion: Invasive pneumococcus is highly virulent causing irreversible valvular destruction or death. IV beta-lactams are first-line treatment, but there are currently no guideline-recommended alternatives for oral therapy. Recent data suggest partial oral therapy may be noninferior to IV only therapy. Conclusion: Switching to oral combination antibiotics after at least 2 weeks of IV therapy is an acceptable alternative to treat SPE.