a b s t r a c tObjectives: Parapneumonic pleural effusions/empyema (PPE/PE) are severe complications of communityacquired pneumonia. We investigated the bacterial aetiology and incidence of paediatric PPE/PE in Germany after the introduction of universal pneumococcal conjugate vaccine (PCV) immunization for infants. Methods: Children <18 years of age hospitalized with pneumonia-associated PPE/PE necessitating pleural drainage or persisting >7 days were reported to the German Surveillance Unit for Rare Diseases in Childhood between October 2010 and June 2017. All bacteria detected in blood or pleural fluid (by culture/PCR) were included, with serotyping for Streptococcus pneumoniae. Results: The median age of all 1447 PPE/PE patients was 5 years (interquartile range 3e10). In 488 of the 1447 children with PPE/PE (34%), 541 bacteria (>40 species) were detected. Aerobic gram-positive cocci accounted for 469 of 541 bacteria detected (87%); these were most frequently Streptococcus pneumoniae (41%), Streptococcus pyogenes (19%) and Staphylococcus aureus (6%). Serotype 3 accounted for 45% of 78 serotyped S. pneumoniae strains. Annual PPE/PE incidence varied between 14 (95%CI 12e16) and 18 (95%CI 16e21) PPE/PE per million children. Incidence of S. pneumoniae PPE/PE decreased from 3.5 (95%CI 2.5e4.6) per million children in 2010/11 to 1.5 (95%CI 0.9e2.4) in 2013/14 (p 0.002), followed by a reincrease to 2.2 (95%CI 1.5e3.2) by 2016/17 (p 0.205). Conclusions: In the era of widespread PCV immunization, cases of paediatric PPE/PE were still caused mainly by S. pneumoniae and, increasingly, by S. pyogenes. The re-increase in the incidence of PPE/PE overall and in S. pneumoniae-associated PPE/PE indicates ongoing changes in the bacterial aetiology and requires further surveillance.

Penicillin-resistant isolates of Streptococcus pneumoniae generally contain mosaic genes encoding the low-affinity penicillin-binding proteins (PBPs) PBP2x, PBP2b, and PBP1a. We now present evidence that PBP2a and PBP1b also appear to be low-affinity variants and are encoded by distinct alleles in β-lactam-resistant transformants of S. pneumoniae obtained with chromosomal donor DNA from aStreptococcus mitis isolate. Different lineages of β-lactam-resistant pneumococcal transformants were analyzed, and transformants with low-affinity variants of all high-molecular-mass PBPs, PBP2x, -2a, -2b, -1a, and -1b, were isolated. The MICs of benzylpenicillin, oxacillin, and cefotaxime for these transformants were up to 40, 100, and 50 μg/ml, respectively, close to the MICs for the S. mitis donor strain. Recruitment of low-affinity PBPs was accompanied by a decrease in cross-linked muropeptides as revealed by high-performance liquid chromatography of muramidase-digested cell walls, but no qualitative changes in muropeptide chemistry were detected. The growth rates of all transformants were identical to that of the parental S. pneumoniae strain. The results stress the potential for the acquisition by S. pneumoniae of high-level β-lactam resistance by interspecies gene transfer.

No abstract

In many European countries, the level of pneumococcal resistance to macrolides has now passed the level of resistance to penicillin G. A total of 82 erythromycin A-resistant isolates of Streptococcus pneumoniae were collected by 11 laboratories in seven European countries. All of the isolates were tested for antimicrobial susceptibility, analyzed for clonal relatedness by multilocus sequence typing, and characterized for macrolide resistance genotypes. The prevalence of the macrolide resistance genotypes varied substantially between countries. In France (87.5% of all strains), Spain (77.3%), Switzerland (80%), and Poland (100%), strains were predominantly erm(B) positive, whereas higher levels of mef(A)-positive strains were reported from Greece (100%) and Germany (33.3%). Macrolide resistance was caused by the oligoclonal spread of some multilocus sequence types, but significant differences in clonal distribution were noted between France and Spain, countries from which high levels of macrolide resistance have been reported. Overall, sequence type 81 (Spain23F-1 clone) was by far the most widespread. The mainly erm(B)-positive serotype 14 clone (sequence type 143), first reported in Poland in the mid-1990s, is now widespread in France.

Pneumococcal pneumonia was associated with a more severe clinical course demanding more medical resources as compared to non-pneumococcal pneumonia.

Different penicillin-binding proteins PBPs are affected in cefotaxime-resistant laboratory mutants compared to piperacillin-resistant mutants. PBP2x acts as the primary PBP target in cefotaxime-resistant mutants, whereas PBP2b is the primary target in piperacillin-resistant mutants. Depending on the mutations in PBP2x, it functions as a resistance determinant for cefotaxime only, or for penicillins as well. Mutations in PBP2x of laboratory mutants are found exclusively in the penicillin-binding domain that contains three homology boxes common to all penicillin-interacting enzymes. Most mutations relevant for resistance occur close to the SXN or the KT/SG box, or at the C-terminal end of the penicillin-binding domain, similar to mutations described in PBP2b of laboratory mutants. Amino acid alterations occur at similar sites also in PBP2x of beta-lactam-resistant clinical isolates and most of these proteins also contain changes in the SXXK box with the active site serine, suggesting that these alterations may be critical for resistance development in clinical isolates.

SummaryObjective: To evaluate the initial management of pediatric parapneumonic effusion or pleural empyema (PPE/PE) with regard to length of hospital stay (LOS). Methods: Collection of pediatric PPE/PE cases using a nationwide surveillance system (ESPED) from 10/2010 to 06/2013, in all German pediatric hospitals. Inclusion of PPE/PE patients <18 years of age requiring drainage or with a PPE/PE persistence >7 days. Staging of PPE/PE based on reported pleural sonographic imaging. Comparison of LOS after diagnosis between children treated with different forms of initial invasive procedures performed ≤3 days after PPE/PE diagnosis: pleural puncture, draining catheter, intrapleural fibrinolytic therapy, surgical procedures. Results: Inclusion of 645 children (median age 5 years); median total LOS 17 days. Initial therapy was non‐invasive in 282 (45%) cases and invasive in 347 (55%) cases (pleural puncture: 62 [10%], draining catheter: 153 [24%], intrapleural fibrinolytic therapy: 89 [14%], surgical procedures: 43 [7%]). LOS after diagnosis did not differ between children initially treated with different invasive procedures. Results remained unchanged when controlling for sonographic stage, preexisting diseases, and other potential confounders. Repeated use of invasive procedures was observed more often after initial non‐invasive treatment or pleural puncture alone than after initial pleural drainage, intrapleural fibrinolytic therapy or surgery. Conclusions: Initial treatment with intrapleural fibrinolytic therapy or surgical procedures did not result in shorter LOS than initial pleural puncture alone. Larger prospective studies are required to investigate which children benefit significantly from more intensive forms of initial invasive treatment. Pediatr Pulmonol. 2017;52:540–547. © 2016 The Authors. Pediatric Pulmonology Published by Wiley Periodicals, Inc.

Pneumococcal capsules are important in pneumococcal pathogenesis and vaccine development. Though conjugate vaccines have brought about a significant reduction in invasive pneumococcal disease (IPD) caused by vaccine serotypes, the relative serotype prevalence has shifted with dramatic emergence of serotype 24F in some countries. Herein, we describe fourteen isolates (thirteen IPD and one non-IPD) expressing a new capsule type, 24C, which resembles 24F but has a novel serological profile. We also describe the antigenic, biochemical, and genetic bases of 24F and 24C and the related serotypes 24A and 24B. Structural studies show that 24B, 24C, and 24F have identical polysaccharide backbones [β-Rib f- (1→4)-α-Rha p -(1→3)-β-Glc p NAc-(1→4)-β-Rha p -(1→4)-β-Glc p ] but with different side chains: 24F has arabinitol-phosphate, and 24B has ribitol-phosphate. 24C has a mixture of 24F and 24B repeating units, with ratio of ribitol to arabinitol being strain-dependent. In contrast, 24A capsule has a backbone without β-Rib f but with arabinitol-phosphate and phosphocholine side chains. These structures indicate that factor-sera 24d and 24e respectively recognize arabinitol and ribitol, which explains the serology of serogroup 24, including those of 24C. The structures can be genetically described by the bi-specificity of wcxG , capable of transferring arabinitol or ribitol when arabinitol is limiting. Arabinitol is likely not produced in 24B but is produced in reduced amounts in 24C due to various mutations in abpA or abpB genes. Our findings demonstrate how pneumococci modulate their capsule structure and immunologic properties with small genetic changes, thereby evading host immune responses. Our findings also suggest a potential for new capsule types within serogroup 24.