Nasopharyngeal Biofilm‐Producing Otopathogens in Children with Nonsevere Recurrent Acute Otitis Media

Torretta, Sara; Marchisio, Paola; Drago, Lorenzo; Baggi, Elena; Vecchi, Elena De; Garavello, Werner; Nazzari, Erica; Pignataro, Lorenzo; Esposito, Susanna

doi:10.1177/0194599812438169

Cited by 44 publications

(39 citation statements)

References 25 publications

(74 reference statements)

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“…These results, to some extent, corroborate the results reported by Torretta and coworkers, who showed that biofilm-producing NTHi isolates were present in the nasopharynx of children with recurrent acute OM (22). More striking was the reduced level of biofilm formation by NTHi isolates collected from patients with CAP and COPD.…”

Section: Resultssupporting

confidence: 91%

“…The ability of NTHi to form biofilms in vitro is highly strain specific (21)(22)(23)(24), but the mechanism that determines whether a particular strain is able to form a biofilm is not known. Based on those previous studies, our work aimed to investigate whether the presence of PCho was associated with the level of biofilm formation by clinical NTHi strains isolated from the oropharynx of healthy children, middle ear fluid of children with OM, and sputum of adult patients with COPD and CAP.…”

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confidence: 99%

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Incorporation of Phosphorylcholine into the Lipooligosaccharide of Nontypeable Haemophilus influenzae Does Not Correlate with the Level of Biofilm Formation In Vitro

et al. 2014

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Nontypeable Haemophilus influenzae (NTHi) is an opportunistic pathogen that causes otitis media in children and communityacquired pneumonia or exacerbations of chronic obstructive pulmonary disease in adults. A large variety of studies suggest that biofilm formation by NTHi may be an important step in the pathogenesis of this bacterium. The objective of this report was to determine the relationship between the presence of phosphorylcholine in the lipooligosaccharide of NTHi and the level of biofilm formation. The study was performed on 111 NTHi clinical isolates collected from oropharyngeal samples of healthy children, middle ear fluid of children with otitis media, and sputum samples of patients with chronic obstructive pulmonary disease or community-acquired pneumonia. NTHi clinical isolates presented a large variation in the level of biofilm formation in a static assay and phosphorylcholine content. Isolates collected from the oropharynx and middle ear fluid of children tended to have more phosphorylcholine and made denser biofilms than isolates collected from sputum samples of patients with chronic obstructive pulmonary disease or community-acquired pneumonia. No correlation was observed between biofilm formation and the presence of phosphorylcholine in the lipooligosaccharide for either planktonic or biofilm growth. This lack of correlation was confirmed by abrogating phosphorylcholine incorporation into lipooligosaccharide through licA gene deletion, which had strain-specific effects on biofilm formation. Altogether, we present strong evidence to conclude that there is no correlation between biofilm formation in a static assay and the presence of phosphorylcholine in lipooligosaccharide in a large collection of clinical NTHi isolates collected from different groups of patients.

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Section: Resultssupporting

confidence: 91%

mentioning

confidence: 99%

Incorporation of Phosphorylcholine into the Lipooligosaccharide of Nontypeable Haemophilus influenzae Does Not Correlate with the Level of Biofilm Formation In Vitro

et al. 2014

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“…Recently, Torretta et al investigated nasopharyngeal biofilm-producing pathogens in children with a history of recurrent mild/moderate AOM. They found that biofilm-producing pathogens were more frequently isolated from the nasopharynx in the recurrent AOM group than in the control group, and H. influenzae was confirmed to be the main pathogen in the recurrent group (11). In addition, Bakaletz reported that biofilms contribute to both chronic otitis media and recurrent AOM (12).…”

Section: Discussionmentioning

confidence: 99%

“…Treatment failures and relapses of AOM in children are influenced not only by microbiological factors, such as antibiotic resistance (10), viral coinfection (16,17), biofilm formation (11,12), and invasion of epithelial cells (18), but also by host factors, including immaturity of the immune system (17), lack of breastfeeding (19), tubal dysfunction (20), recent antibiotic usage (21), and multiple episodes of AOM. In addition, environmental factors such as attending a day care center (2) and the presence of siblings (22) influence treatment failure and relapse of AOM.…”

Section: Discussionmentioning

confidence: 99%

Improvement Rate of Acute Otitis Media Caused by Haemophilus influenzae at 1 Week Is Significantly Associated with Time to Recovery

et al. 2013

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The susceptibilities of the isolates to ampicillin were determined, and microtiter biofilm assays and invasion assays using BEAS-2B cells were performed. The association between these bacterial characteristics and clinical relapses of AOM and treatment failures was evaluated. Seventy-four children (39 boys and 35 girls) with a median age of 1 year (interquartile range [IQR], 0.25 to 2 years) were enrolled. Among 74 H. influenzae isolates, 37 showed intermediate resistance or resistance to ampicillin (MIC, >2 g/ml). In the microtiter biofilm assay, the median optical density at 600 nm (OD 600 ) was 0.68 (IQR, 0.24 to 1.02), and 70 isolates formed biofilms. The median invasion rate was 15% (IQR, 0 to 10%), and 46 isolates invaded BEAS-2B cells. Relapses and treatment failures occurred in 19 and 6 children, respectively. There was no significant difference in the invasion rates between patients with and those without relapses or treatment failures. Also, there was no significant association between biofilm formation and relapse or treatment failure. The improvements in the severity scores after 1 week were significantly associated with the recovery time (P < 0.0001). We did not identify any significant association between relapse or treatment failure and bacterial factors. AOM has a multifactorial etiology, and this may explain why we could not find a significant association. An improvement in the severity score after 1 week of treatment may be a useful predictor of the outcome of AOM.A cute otitis media (AOM) is the most common disease of the upper respiratory tract in childhood, and treatment of AOM is the most frequent reason that children in the United States take antibiotics (1). In Japan, the incidence of AOM has increased recently, and many children now need hospitalization to receive intravenous antibiotics for the treatment of intractable AOM with persistent purulent otorrhea (2).We previously reported that Haemophilus influenzae can form a biofilm both in vitro (3) and in vivo (4). Bacterial biofilms are recognized as having an important role in various human infections, and the bacteria in a biofilm are more resistant to antibiotic therapy than are planktonic microorganisms, suggesting that biofilms might play an important role in the pathogenesis and chronicity of otitis media (3). In addition, an investigation of the mechanism of airway epithelium invasion by H. influenzae revealed that the bacteria are internalized by the adenoid cells of children (5). We also previously demonstrated that H. influenzae isolated from clinical samples can invade and destroy human bronchial epithelial cells (BEAS-2B cells) (6), suggesting that such activity might delay the resolution of AOM. However, the association between biofilm formation or invasion of bronchial epithelial cells and the clinical course and outcome of AOM due to H. influenzae has been unclear.Accordingly, we measured the biofilm formation and invasion of bronchial epithelial cells by H. influenzae isolated from children with AOM, and we evaluated the ...

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“…Biofilms can develop on artificial surfaces, like medical devices, but also on tissues or mucus, as observed, for example, with Streptococcus pneumoniae in nasopharynx colonization (9), otitis media (9-11), or chronic rhinosinusitis (12). Therefore, in vitro (13)(14)(15)(16)(17)(18) and in vivo (11,19,20) models of pneumococcal biofilms have been developed and used to study the pathophysiology of the infection as well as the activities of the antibiotics.…”

mentioning

confidence: 99%

Antibiotic Activity against Naive and Induced Streptococcus pneumoniae Biofilms in an In Vitro Pharmacodynamic Model

Vandevelde

Tulkens

2014

Antimicrob Agents Chemother

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Biofilms play a role in the pathogenicity of pneumococcal infections. A pharmacodynamic in vitro model of biofilm was developed that allows characterization of the activity of antibiotics against viability and biomass by using in parallel capsulated (ATCC 49619) and noncapsulated (R6) reference strains. Naive biofilms were obtained by incubating fresh planktonic cultures for 2 to 11 days in 96-well polystyrene plates. Induced biofilms were obtained using planktonic bacteria collected from the supernatant of 6-day-old naive biofilms. Biomass production was more rapid and intense in the induced model, but the levels were similar for both strains. Full concentration responses fitting sigmoidal regressions allowed calculation of maximal efficacies and relative potencies of drugs. All antibiotics tested (amoxicillin, clarithromycin, solithromycin, levofloxacin, and moxifloxacin) were more effective against young naive biofilms than against old or induced biofilms, except macrolides/ketolides, which were as effective at reducing viability in 2-day-old naive biofilms and in 11-day-old induced biofilms of R6. Macrolides/ketolides, however, were less potent than fluoroquinolones against R6 (approximately 5-to 20-fold-higher concentrations needed to reduction viability of 20%). However, at concentrations obtainable in epithelial lining fluid, the viabilities of mature or induced biofilms were reduced 15 to 45% (amoxicillin), 17 to 44% (macrolides/ketolides), and 12 to 64% (fluoroquinolones), and biomasses were reduced 5 to 45% (amoxicillin), 5 to 60% (macrolides/ketolides), and 10 to 76% (fluoroquinolones), with solithromycin and moxifloxacin being the most effective and the most potent agents (due to lower MICs) in their respective classes. This study allowed the ranking of antibiotics with respect to their potential effectiveness in biofilm-related infections, underlining the need to search for still more effective options.

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Nasopharyngeal Biofilm‐Producing Otopathogens in Children with Nonsevere Recurrent Acute Otitis Media

Abstract: The presence of nasopharyngeal BPOs is an important factor favoring RAOM; it is therefore useful investigating biofilms even in children with nonsevere recurrences of AOM without adenoid hypertrophy.

Cited by 44 publications

References 25 publications

Incorporation of Phosphorylcholine into the Lipooligosaccharide of Nontypeable Haemophilus influenzae Does Not Correlate with the Level of Biofilm Formation In Vitro

Incorporation of Phosphorylcholine into the Lipooligosaccharide of Nontypeable Haemophilus influenzae Does Not Correlate with the Level of Biofilm Formation In Vitro

Improvement Rate of Acute Otitis Media Caused by Haemophilus influenzae at 1 Week Is Significantly Associated with Time to Recovery

Antibiotic Activity against Naive and Induced Streptococcus pneumoniae Biofilms in an In Vitro Pharmacodynamic Model

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