Identification of adenoid biofilms with middle ear pathogens in otitis-prone children utilizing SEM and FISH

Hoa, Michael; Tomovic, Senja; Nistico, Laura; Hall-Stoodley, Luanne; Stoodley, Paul; Sachdeva, Livjot; Berk, Richard S.; Coticchia, James M.

doi:10.1016/j.ijporl.2009.05.016

Cited by 100 publications

(91 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Fluorescence in situ hybridization (FISH) with probes specific for H. influenzae DNA has been used to identify the bacterium when Gram-negative bacilli are seen on microscopy of cerebrospinal fluid (188) and to detect H. influenzae DNA in adenoid biofilms of otitis-prone children (189) and in the mucosae of patients with chronic rhinosinusitis (190). Use of microarray hybridization for identification has been introduced for profiling the oral microbiotas of individuals (191,192) but has not yet evolved as a useful method for routine identification.…”

Section: Other Methodsmentioning

confidence: 99%

Classification, Identification, and Clinical Significance of Haemophilus and Aggregatibacter Species with Host Specificity for Humans

2014

View full text Add to dashboard Cite

SUMMARY The aim of this review is to provide a comprehensive update on the current classification and identification of Haemophilus and Aggregatibacter species with exclusive or predominant host specificity for humans. Haemophilus influenzae and some of the other Haemophilus species are commonly encountered in the clinical microbiology laboratory and demonstrate a wide range of pathogenicity, from life-threatening invasive disease to respiratory infections to a nonpathogenic, commensal lifestyle. New species of Haemophilus have been described ( Haemophilus pittmaniae and Haemophilus sputorum ), and the new genus Aggregatibacter was created to accommodate some former Haemophilus and Actinobacillus species ( Aggregatibacter aphrophilus , Aggregatibacter segnis , and Aggregatibacter actinomycetemcomitans ). Aggregatibacter species are now a dominant etiology of infective endocarditis caused by fastidious organisms (HACEK endocarditis), and A. aphrophilus has emerged as an important cause of brain abscesses. Correct identification of Haemophilus and Aggregatibacter species based on phenotypic characterization can be challenging. It has become clear that 15 to 20% of presumptive H. influenzae isolates from the respiratory tracts of healthy individuals do not belong to this species but represent nonhemolytic variants of Haemophilus haemolyticus . Due to the limited pathogenicity of H. haemolyticus , the proportion of misidentified strains may be lower in clinical samples, but even among invasive strains, a misidentification rate of 0.5 to 2% can be found. Several methods have been investigated for differentiation of H. influenzae from its less pathogenic relatives, but a simple method for reliable discrimination is not available. With the implementation of identification by matrix-assisted laser desorption ionization–time of flight mass spectrometry, the more rarely encountered species of Haemophilus and Aggregatibacter will increasingly be identified in clinical microbiology practice. However, identification of some strains will still be problematic, necessitating DNA sequencing of multiple housekeeping gene fragments or full-length 16S rRNA genes.

show abstract

Section: Other Methodsmentioning

confidence: 99%

Classification, Identification, and Clinical Significance of Haemophilus and Aggregatibacter Species with Host Specificity for Humans

2014

View full text Add to dashboard Cite

show abstract

“…Pneumococcal biofilms have been detected on nasal septum biopsy specimens from humans with sinusitis, on septal epithelia of experimentally challenged mice, and form in vitro on cultured respiratory epithelial cells and abiotic surfaces covered with bacterial media (13)(14)(15)(16)(17). Biofilm formation during colonization is thought to confer protection against host defenses and desiccation (18,19).…”

mentioning

confidence: 99%

Neuraminidase A-Exposed Galactose Promotes Streptococcus pneumoniae Biofilm Formation during Colonization

et al. 2016

View full text Add to dashboard Cite

f Streptococcus pneumoniae is an opportunistic pathogen that colonizes the nasopharynx. Herein we show that carbon availability is distinct between the nasopharynx and bloodstream of adult humans: glucose is absent from the nasopharynx, whereas galactose is abundant. We demonstrate that pneumococcal neuraminidase A (NanA), which cleaves terminal sialic acid residues from host glycoproteins, exposed galactose on the surface of septal epithelial cells, thereby increasing its availability during colonization. We observed that S. pneumoniae mutants deficient in NanA and ␤-galactosidase A (BgaA) failed to form biofilms in vivo despite normal biofilm-forming abilities in vitro. Subsequently, we observed that glucose, sucrose, and fructose were inhibitory for biofilm formation, whereas galactose, lactose, and low concentrations of sialic acid were permissive. Together these findings suggested that the genes involved in biofilm formation were under some form of carbon catabolite repression (CCR), a regulatory network in which genes involved in the uptake and metabolism of less-preferred sugars are silenced during growth with preferred sugars. Supporting this notion, we observed that a mutant deficient in pyruvate oxidase, which converts pyruvate to acetyl-phosphate under non-CCR-inducing growth conditions, was unable to form biofilms. Subsequent comparative transcriptome sequencing (RNA-seq) analyses of planktonic and biofilm-grown pneumococci showed that metabolic pathways involving the conversion of pyruvate to acetyl-phosphate and subsequently leading to fatty acid biosynthesis were consistently upregulated during diverse biofilm growth conditions. We conclude that carbon availability in the nasopharynx impacts pneumococcal biofilm formation in vivo. Additionally, biofilm formation involves metabolic pathways not previously appreciated to play an important role.

show abstract

“…pneumoniae forms multicellular biofilms within the upper respiratory tract in humans and in animal models (19)(20)(21)(22). Several studies have suggested that pneumococci in biofilms exhibit attenuated virulence in comparison to planktonic cells (23,24).…”

mentioning

confidence: 99%

Dynamic Changes in the Streptococcus pneumoniae Transcriptome during Transition from Biofilm Formation to Invasive Disease upon Influenza A Virus Infection

et al. 2014

View full text Add to dashboard Cite

f Streptococcus pneumoniae is a leading cause of infectious disease globally. Nasopharyngeal colonization occurs in biofilms and precedes infection. Prior studies have indicated that biofilm-derived pneumococci are avirulent. However, influenza A virus (IAV) infection releases virulent pneumococci from biofilms in vitro and in vivo. Triggers of dispersal include IAV-induced changes in the nasopharynx, such as increased temperature (fever) and extracellular ATP (tissue damage). We used whole-transcriptome shotgun sequencing (RNA-seq) to compare the S. pneumoniae transcriptome in biofilms, bacteria dispersed from biofilms after exposure to IAV, febrile-range temperature, or ATP, and planktonic cells grown at 37°C. Compared with biofilm bacteria, actively dispersed S. pneumoniae, which were more virulent in invasive disease, upregulated genes involved in carbohydrate metabolism. Enzymatic assays for ATP and lactate production confirmed that dispersed pneumococci exhibited increased metabolism compared to those in biofilms. Dispersed pneumococci also upregulated genes associated with production of bacteriocins and downregulated colonization-associated genes related to competence, fratricide, and the transparent colony phenotype. IAV had the largest impact on the pneumococcal transcriptome. Similar transcriptional differences were also observed when actively dispersed bacteria were compared with avirulent planktonic bacteria. Our data demonstrate complex changes in the pneumococcal transcriptome in response to IAV-induced changes in the environment. Our data suggest that disease is caused by pneumococci that are primed to move to tissue sites with altered nutrient availability and to protect themselves from the nasopharyngeal microflora and host immune response. These data help explain pneumococcal virulence after IAV infection and have important implications for studies of S. pneumoniae pathogenesis.

show abstract

Identification of adenoid biofilms with middle ear pathogens in otitis-prone children utilizing SEM and FISH

Cited by 100 publications

References 30 publications

Classification, Identification, and Clinical Significance of Haemophilus and Aggregatibacter Species with Host Specificity for Humans

Classification, Identification, and Clinical Significance of Haemophilus and Aggregatibacter Species with Host Specificity for Humans

Neuraminidase A-Exposed Galactose Promotes Streptococcus pneumoniae Biofilm Formation during Colonization

Dynamic Changes in the Streptococcus pneumoniae Transcriptome during Transition from Biofilm Formation to Invasive Disease upon Influenza A Virus Infection

Contact Info

Product

Resources

About