Simultaneous Identification of
            <i>Haemophilus Influenzae</i>
            and
            <i>Haemophilus Haemolyticus</i>
            using Real-Time PCR

Price, Erin P.; Harris, Tegan M.; Spargo, Jessie C; Nosworthy, Elizabeth; Beissbarth, Jemima; Chang, Anne B.; Smith‐Vaughan, Heidi; Sarovich, Derek S.

doi:10.2217/fmb-2016-0215

Cited by 32 publications

(19 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The presence of P. aeruginosa was also recorded. Throughout the study period, nontypeable H. influenzae (NTHi) and the commensal H. haemolyticus were differentiated from one another using either hpd#3, fucP, or hy4H, hypD, and siaT polymerase chain reaction (PCR) assays. Lower airway infection was defined as ≥ 10 4 colony‐forming units (CFU) per mL of BAL fluid in the first and/or second lavage aliquots …”

Section: Methodsmentioning

confidence: 99%

Do combined upper airway cultures identify lower airway infections in children with chronic cough?

Hare

Chang

Smith‐Vaughan

et al. 2019

Pediatric Pulmonology

Self Cite

View full text Add to dashboard Cite

Background Obtaining lower airway specimens is important for guiding therapy in chronic lung infection but is difficult in young children unable to expectorate. While culture‐based studies have assessed the diagnostic accuracy of nasopharyngeal or oropharyngeal specimens for identifying lower airway infection, none have used both together. We compared respiratory bacterial pathogens cultured from nasopharyngeal and oropharyngeal swabs with bronchoalveolar lavage (BAL) cultures as the “gold standard” to better inform the diagnosis of lower airway infection in children with chronic wet cough. Methods Nasopharyngeal and oropharyngeal swabs and BAL fluid specimens were collected concurrently from consecutive children undergoing flexible bronchoscopy for chronic cough and cultured for bacterial pathogens. Results In cultures from 309 children (median age, 2.3 years) with chronic endobronchial suppuration, all main pathogens detected (Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis) were more prevalent in nasopharyngeal than oropharyngeal swabs (37%, 34%, and 23% vs 21%, 6.2%, and 3.2%, respectively). Positive and negative predictive values for lower airway infection by any of these three pathogens were 63% (95% confidence interval [95% CI] 55, 70) and 85% (95% CI, 78, 91) for nasopharyngeal swabs, 65% (95% CI, 54, 75), and 66% (95% CI, 59, 72) for oropharyngeal swabs, and 61% (95% CI, 54,68), and 88% (95% CI, 81, 93) for both swabs, respectively. Conclusions Neither nasopharyngeal nor oropharyngeal swabs, alone or in combination, reliably predicted lower airway infection in children with chronic wet cough. Although upper airway specimens may be useful for bacterial carriage studies and monitoring antimicrobial resistance, their clinical utility in pediatric chronic lung disorders of endobronchial suppuration is limited.

show abstract

Section: Methodsmentioning

confidence: 99%

Do combined upper airway cultures identify lower airway infections in children with chronic cough?

Hare

Chang

Smith‐Vaughan

et al. 2019

Pediatric Pulmonology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Species-specific gene alignments were performed on samples positive for H. influenzae or S. pneumoniae by metagenomics (above our thresholds). Reads (after human DNA removal) were aligned to pathobiont-specific genes (siaT, ply -chosen from a literature search for species-specific genes in H. influenzae 56 and S. pneumoniae 15 , respectively) using minimap2 with default parameters for long-read data (-a -x map-ont) and the number of mapped reads visualised using qualimap. If a sample contained >1 copy of the specific gene it was considered positive for the species.…”

Section: Pathobiont-specific Gene Analysismentioning

confidence: 99%

Nanopore metagenomics enables rapid clinical diagnosis of bacterial lower respiratory infection

et al. 2019

View full text Add to dashboard Cite

show abstract

“…A real-time quantitative triplex PCR assay was designed to quantify NTHi, Hh and detect the HPL ORF. The targets used for discrimination of Hh (hypD) and NTHi (siaT) have previously been described and validated [41]. For detection of the HPL ORF, primers were designed based on the HPL ORF of Hh-BW1 (GenBank MN720274) [25].…”

Section: Triplex Real-time Pcr For the Quantification Of Nthi Hh Andmentioning

confidence: 99%

“…gDNA. Quantification of NTHi and Hh was expressed as genome equivalents (GE) calculated from the standard, as previously described [41]. Bacterial quantification from thermally extracted gDNA was validated against conventional bacterial quantification by optical density and colony counts.…”

Section: Triplex Real-time Pcr For the Quantification Of Nthi Hh Andmentioning

confidence: 99%

In Vitro Anti-NTHi Activity of Haemophilin-Producing Strains of Haemophilus haemolyticus

et al. 2020

View full text Add to dashboard Cite

Nontypeable Haemophilus influenzae (NTHi) is a leading causative organism of opportunistic respiratory tract infections. However, there are currently no effective vaccination strategies, and existing treatments are compromised by antibiotic resistance. We previously characterized Haemophilus haemolyticus (Hh) strains capable of producing haemophilin (HPL), a heme-binding protein that restricts NTHi growth by limiting its access to an essential growth factor, heme. Thus, these strains may have utility as a probiotic therapy against NTHi infection by limiting colonization, migration and subsequent infection in susceptible individuals. Here, we assess the preliminary feasibility of this approach by direct in vitro competition assays between NTHi and Hh strains with varying capacity to produce HPL. Subsequent changes in NTHi growth rate and fitness, in conjunction with HPL expression analysis, were employed to assess the NTHi-inhibitory capacity of Hh strains. HPL-producing strains of Hh not only outcompeted NTHi during short-term and extended co-culture, but also demonstrated a growth advantage compared with Hh strains unable to produce the protein. Additionally, HPL expression levels during competition correlated with the NTHi-inhibitory phenotype. HPL-producing strains of Hh demonstrate significant probiotic potential against NTHi colonization in the upper respiratory tract, however, further investigations are warranted to demonstrate a range of other characteristics that would support the eventual development of a probiotic.

show abstract

Simultaneous Identification of Haemophilus Influenzae and Haemophilus Haemolyticus using Real-Time PCR

Cited by 32 publications

References 43 publications

Do combined upper airway cultures identify lower airway infections in children with chronic cough?

Do combined upper airway cultures identify lower airway infections in children with chronic cough?

Nanopore metagenomics enables rapid clinical diagnosis of bacterial lower respiratory infection

In Vitro Anti-NTHi Activity of Haemophilin-Producing Strains of Haemophilus haemolyticus

Contact Info

Product

Resources

About