Microbiology of Bronchoalveolar Lavage Fluid in Children With Acute Nonresponding or Recurrent Community-Acquired Pneumonia: Identification of Nontypeable Haemophilus influenzae as a Major Pathogen

Schutter, Iris De; Wachter, Elke De; Crokaert, Françoise; Verhaegen, Jan; Soetens, Oriane; Piérard, Denis; Malfroot, Anne

doi:10.1093/cid/cir235

Cited by 77 publications

(84 citation statements)

References 39 publications

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“…Patients without definitive etiology appeared to harbor a particularly high abundance of H. influenzae complex. Nontypeable (NT) H. influenzae has increasingly been considered an important pathogen of pediatric pneumonia (19). Because it is a very frequent colonizer of the nasopharynx and it does not appear to be associated with elevated CRP concentrations, definitive attribution of etiology to this species may prove difficult.…”

Section: Discussionmentioning

confidence: 99%

Nasopharyngeal Microbiota in Healthy Children and Pneumonia Patients

et al. 2014

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bOur study is the first to compare the nasopharyngeal microbiota of pediatric pneumonia patients and control children by 454 pyrosequencing. A distinct microbiota was associated with different pneumonia etiologies. Viral pneumonia was associated with a high abundance of the operational taxonomic unit (OTU) corresponding to Moraxella lacunata. Patients with nonviral pneumonia showed high abundances of OTUs of three typical bacterial pathogens, Streptococcus pneumoniae complex, Haemophilus influenzae complex, and Moraxella catarrhalis. Patients classified as having no definitive etiology harbored microbiota particularly enriched in the H. influenzae complex. We did not observe a commensal taxon specifically associated with health. The microbiota of the healthy nasopharynx was more diverse and contained a wider range of less abundant taxa. P neumonia is the leading cause of childhood mortality worldwide, claiming 2 million lives yearly among young children (1). The etiology of pediatric pneumonia is complex and not routinely determined in clinical practice (2). Its definitive determination remains challenging (3). Clinical research shows that Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus are the leading pathogens of bacterial pneumonia (1, 4). Respiratory syncytial virus (RSV), parainfluenza, and influenza viruses are the main causes of pediatric viral pneumonia (e.g., see references 5 and 6). S. pneumoniae and H. influenzae frequently colonize the nasopharynx of young children, and the nasopharyngeal (NP) carriage of S. pneumoniae is considered key to pneumonia and other pneumococcal diseases (7). However, the mere nasopharyngeal presence of bacterial pathogens does not necessarily lead to invasive lung infection. Various mechanisms, such as competition with resident nonpathogenic microbiota, viral coinfection, or host immune factors are likely to affect the transition from nasopharyngeal colonization to pneumonia (8). The increasing accessibility of culture-independent sequencing methods has permitted microbiota description at various body sites (9), and the potential of commensal microbiota to modify the disease process is receiving increasing attention (10).Previous culture-independent studies of the nasopharyngeal microbiota of young children looked at healthy children (11) and compared the microbiota composition of healthy children and children with acute otitis media (12). In the present study, we analyzed the nasopharyngeal microbiota composition, including the presence of respiratory viruses, in pediatric pneumonia patients and matched healthy controls and looked for microbiota associations with the disease status. MATERIALS AND METHODS Patients and clinical samples.A prospective case-control study conducted in 2008 to 2009 in 3 major hospitals in Switzerland (Geneva, Lausanne, and Sion) to investigate pediatric community-acquired pneumonia etiology was described in detail elsewhere (13). Briefly, pneumonia cases were diagnosed according to the WHO criteria (14) in children 2 ...

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Section: Discussionmentioning

confidence: 99%

Nasopharyngeal Microbiota in Healthy Children and Pneumonia Patients

et al. 2014

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“…These are the main respiratory pathogens, together with M. catarrhalis, in children with non-CF bronchiectasis (Hare et al, 2010), PBB (Wurzel et al, 2014) and acute non-responsive or recurrent community-acquired pneumonia (De Schutter et al, 2011). PBB is considered a precursor to bronchiectasis in some settings (Chang et al, 2008), and pneumonia is also a major risk factor, particularly when it is severe or recurrent (Valery et al, 2004).…”

Section: Discussionmentioning

confidence: 99%

“…, as in our previous studies (Hare et al, 2010;Wurzel et al, 2014) and a study of lower-airway infections in children with communityacquired pneumonia (De Schutter et al, 2011). However, others have used different cut-offs, e.g.…”

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confidence: 90%

“…pneumococcal serotypes) may also be crucial for vaccine studies involving the lower airways (O'Grady et al, 2010). Our findings on lower-airway bacteriology in sequential lavages may be applicable to children with recurrent pneumonia (De Schutter et al, 2011). Implications for the management of acute pneumonia are limited, as, in the current era, BAL is rarely undertaken in children with acute pneumonia outside of the intensive care setting where children are mechanically ventilated.…”

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confidence: 94%

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Respiratory bacterial culture from two sequential bronchoalveolar lavages of the same lobe in children with chronic cough

Hare

Marsh

Smith‐Vaughan

et al. 2015

Journal of Medical Microbiology

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Identification of bacteria causing lower-airway infections is important to determine appropriate antimicrobial therapy. Flexible bronchoscopy with bronchoalveolar lavage (BAL) is used to obtain lower-airway specimens in young children. The first lavage (lavage-1) is typically used for bacterial culture. However, no studies in children have compared the detection of cultivable bacteria from sequential lavages of the same lobe. BAL fluid was collected from two sequential lavages of the same lobe in 79 children enrolled in our prospective studies of chronic cough. The respiratory bacteria Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus and Haemophilus parainfluenzae were isolated and identified using standard published methods. H. influenzae was differentiated from Haemophilus haemolyticus using PCR assays. Lower-airway infection was defined as $10 4 c.f.u. ml 21 BAL fluid. We compared cultivable bacteria from lavage-1 with those from the second lavage (lavage-2) using the k statistic. Lower-airway infections by any pathogen were detected in 46 % of first lavages and 39 % of second lavages. Detection was similar in both lavages for all pathogens; the k statistic was 0.7-0.8 for all bacteria except H. parainfluenzae. Of all infections detected in either lavage, 90 % were detected in lavage-1 and 78 % in lavage-2. However, culture of lavage-2 identified infections that would have been missed in 8 % of children, including infections by additional Streptococcus pneumoniae serotypes. Our findings support the continued use of lavage-1 for bacterial culture; however, culture of lavage-2 may yield additional identifications of bacterial pathogens in lower-airway infections.

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“…Pathogen interactions with ECM-proteins are particularly important after epithelial disruption (due to, e.g., chronic inflammation and viral infections), which leaves the basement membrane exposed [5]. This is supported by the fact that NTHi infections are commonly identified in COPD-patients or during co-infections with viral pathogens [3,38,39]. Other respiratory tract…”

Section: Discussionmentioning

confidence: 99%