Effect of p<scp>H</scp> and oxygen on biofilm formation in acute otitis media associated <scp>NTH</scp>i clinical isolates

Osgood, Robert; Salamone, Frank; Díaz, Alexis; Casey, Janet R.; Bajorski, Peter; Pichichero, Michael E.

doi:10.1002/lary.25102

Cited by 14 publications

(10 citation statements)

References 23 publications

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“…Although the two oxygen tension conditions tested provided a good development of biofilms, in quantitative tests, the condition of microaerophilia was superior to the condition of aerobiosis, particularly in biofilms formed using HAM-F12. A similar profile was observed by Osgood et al (2015) for the biofilms of Haemophilus influenzae formed in the condition of microaerophilia and with neutral pH. H. capsulatum , being a systemic pathogen, can develop in different regions of the body and with different oxygen tensions, therefore, verifying the influence of a lower or higher oxygen concentration in the development of biofilms is of paramount importance.…”

Section: Discussionsupporting

confidence: 74%

Biofilm Formation by Histoplasma capsulatum in Different Culture Media and Oxygen Atmospheres

et al. 2020

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Histoplasma capsulatum is a dimorphic fungus that causes an important systemic mycosis called histoplasmosis. It is an infectious disease with high prevalence and morbidity that affects the general population. Recently, the ability of these fungi to form biofilms, a phenotype that can induce resistance and enhance virulence, has been described. Despite some efforts, data regarding the impact of nutrients and culture media that affect the H. capsulatum biofilm development in vitro are not yet available. This work aimed to study H. capsulatum biofilms, by checking the influence of different culture media and oxygen atmospheres in the development of these communities. The biofilm formation by two strains (EH-315 and G186A) was characterized under different culture media: [Brain and Heart Infusion (BHI), Roswell Park Memorial Institute (RPMI) with 2% glucose, Dulbecco’s Modified Eagle’s Medium (DMEM) supplemented with 10% fetal bovine serum and nutrient medium HAM-F12 (HAM-F12) supplemented with glucose (18.2 g/L), glutamic acid (1 g/L), HEPES (6 g/L) and L-cysteine (8.4 mg/L)] and oxygen atmospheres (aerobiosis and microaerophilia), using the XTT reduction assay to quantify metabolic activities, crystal violet staining for biomass, safranin staining for the quantification of polysaccharide material and scanning electron microscopy (SEM) for the observation of topographies. Results indicated that although all culture mediums have stimulated the maturation of the communities, HAM-F12 provided the best development of biomass and polysaccharide material when compared to others. Regarding the oxygen atmospheres, both stimulated an excellent development of the communities, however in low oxygen conditions an exuberant amount of extracellular matrix was observed when compared to biofilms formed in aerobiosis, mainly in the HAM-F12 media. SEM images showed yeasts embedded by an extracellular matrix in several points, corroborating the colorimetric assays. However, biofilms formed in BHI, RPMI, and DMEM significantly induced yeast to hyphae reversal, requiring further investigation. The results obtained so far contribute to in vitro study of biofilms formed by these fungi and show that nutrition promoted by different media modifies the development of these communities. These data represent advances in the field of biofilms and contribute to future studies that can prove the role of these communities in the fungi-host interaction.

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Section: Discussionsupporting

confidence: 74%

Biofilm Formation by Histoplasma capsulatum in Different Culture Media and Oxygen Atmospheres

et al. 2020

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“…However, this theory is still debated, as a study by Mizrahi et al [41] failed to find any significant correlation between the presence of biofilm produced by non-typeable H. influenza and treatment failure or infectious recurrences in patients with AOM. These findings were supported by Osgood et al [42], who suggested that the aerobic conditions occurring during AOM episodes may limit biofilm formation.…”

Section: Nasopharyngeal Bacterial Biofilm: Is There a Correlation supporting

confidence: 74%

Role of Biofilms in Children with Chronic Adenoiditis and Middle Ear Disease

Torretta

Drago

Marchisio

et al. 2019

JCM

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Chronic adenoiditis occurs frequently in children, and it is complicated by the subsequent development of recurrent or chronic middle ear diseases, such as recurrent acute otitis media, persistent otitis media with effusion and chronic otitis media, which may predispose a child to long-term functional sequalae and auditory impairment. Children with chronic adenoidal disease who fail to respond to traditional antibiotic therapy are usually candidates for surgery under general anaesthesia. It has been suggested that the ineffectiveness of antibiotic therapy in children with chronic adenoiditis is partially related to nasopharyngeal bacterial biofilms, which play a role in the development of chronic nasopharyngeal inflammation due to chronic adenoiditis, which is possibly associated with chronic or recurrent middle ear disease. This paper reviews the current evidence concerning the involvement of bacterial biofilms in the development of chronic adenoiditis and related middle ear infections in children.

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“…Nasal biofilms are associated with increased nasal resistance, a measure of nasal obstruction [20]. The otopathogen non-typable Haemophilus influenza requires anaerobic conditions to form biofilms [21], and may therefore be aided by nasal congestion. Although direct evidence that nasal and nasopharyngeal biofilms connect nasal obstruction to COME is lacking, adenoid hypertrophy in particular is a risk factor for nasal obstruction, snoring, and COME, with the preferred explanation being that adenoids can act as a reservoir for otopathogens [22, 23].…”

Section: Discussionmentioning

confidence: 99%

Determinants of chronic otitis media with effusion in preschool children: a case–control study

et al. 2017

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BackgroundChronic otitis media with effusion (COME) is a prevalent upper airway infection resulting in hearing loss. The aim of this research was to determine risk factors for COME in preschool children.MethodsA case–control design was conducted in Auckland, New Zealand from May 2011 until November 2013. The cases were children aged 3 and 4 years referred for tympanostomy tube placement due to a diagnosis of COME (n = 178). The controls were a random sample of healthy children aged 3 and 4 years from primary care practices (n = 209). The children’s guardians completed an interviewer-administered questionnaire that covered topics including socio-demographic information, pregnancy and birth, infant feeding practices, home environment, and respiratory health. In addition, skin prick tests for atopy were performed. Odds ratios (OR) estimating the risk of COME independently associated with the exposures were calculated using a logistic regression model.ResultsChildren with COME frequently had nasal obstruction (OR: 4.38 [95% CI: 2.37–8.28]), always snored (OR: 3.64 [95% CI: 1.51–9.15]) or often snored (OR: 2.45 [95% CI: 1.04–5.96]), spent more hours per week in daycare (OR per hour/week: 1.03 [95% CI: 1.00–1.05]), had frequent colds (OR: 2.67 [95% CI: 1.59–4.53]), had siblings who had undergone tympanostomy tube placement (OR: 2.68 [95% CI: 1.22–6.02]), underwent long labour (OR: 2.59 [95% CI: 1.03–6.79]), and had early introduction of cow’s milk (OR: 1.76 [95% CI: 1.05–2.97]). Asian ethnicity (OR: 0.20 [95% CI: 0.07–0.53]) and having older siblings (OR: 0.54 [95% CI: 0.31–0.93]) were inversely associated with COME.ConclusionCOME in preschool children was associated with pathogen exposure, respiratory infection, and nasal obstruction. Strategies to prevent pathogen transmission warrant investigation. The novel findings of long labour and early cow’s milk introduction require replication in future studies.

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Effect of pH and oxygen on biofilm formation in acute otitis media associated NTHi clinical isolates

Abstract: NA.

Cited by 14 publications

References 23 publications

Biofilm Formation by Histoplasma capsulatum in Different Culture Media and Oxygen Atmospheres

Biofilm Formation by Histoplasma capsulatum in Different Culture Media and Oxygen Atmospheres

Role of Biofilms in Children with Chronic Adenoiditis and Middle Ear Disease

Determinants of chronic otitis media with effusion in preschool children: a case–control study

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