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Pizzutto SJ, Hare KM, Upham JW. Bronchiectasis in Children: Current Concepts in Immunology and Microbiology. Front Pediatr 2017; 5:123. [PMID: 28611970 PMCID: PMC5447051 DOI: 10.3389/fped.2017.00123] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 05/08/2017] [Indexed: 12/26/2022] Open
Abstract
Bronchiectasis is a complex chronic respiratory condition traditionally characterized by chronic infection, airway inflammation, and progressive decline in lung function. Early diagnosis and intensive treatment protocols can stabilize or even improve the clinical prognosis of children with bronchiectasis. However, understanding the host immunologic mechanisms that contribute to recurrent infection and prolonged inflammation has been identified as an important area of research that would contribute substantially to effective prevention strategies for children at risk of bronchiectasis. This review will focus on the current understanding of the role of the host immune response and important pathogens in the pathogenesis of bronchiectasis (not associated with cystic fibrosis) in children.
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Affiliation(s)
- Susan J Pizzutto
- Child Health Division, Menzies School of Health Research, Darwin, NT, Australia
| | - Kim M Hare
- Child Health Division, Menzies School of Health Research, Darwin, NT, Australia
| | - John W Upham
- Department of Respiratory Medicine, Princess Alexandra Hospital, Brisbane, QLD, Australia.,School of Medicine, The University of Queensland, Brisbane, QLD, Australia
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Smith-Vaughan HC, Beissbarth J, Bowman J, Hare KM, Price EP, Pickering J, Lehmann D, Chang AB, Morris PS, Marsh RL, Leach AJ. Geographic consistency in dominant, non-typeable Haemophilus influenzae genotypes colonising four distinct Australian paediatric groups: a cohort study. Pneumonia (Nathan) 2016; 8:13. [PMID: 28702292 PMCID: PMC5471799 DOI: 10.1186/s41479-016-0013-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 08/08/2016] [Indexed: 11/10/2022] Open
Abstract
Non-typeable Haemophilus influenzae (NTHi)-associated ear and respiratory diseases (including pneumonia) represent a major health burden in many parts of the world. NTHi strains retrieved from the upper airways commonly reflect those found in the lower airways. Despite growing genomic and genotyping data on NTHi, there remains a limited understanding of global and regional NTHi population structures. The aim of this study was to determine whether nasopharyngeal carriage in four Australian paediatric groups at varying risk of NTHi colonisation was dominated by the same NTHi genotypes. Genotyping data generated by PCR-ribotyping were evaluated for 3070 NTHi isolates colonising the nasopharynges of Aboriginal and non-Aboriginal children enrolled in four longitudinal studies in three separate urban and remote regions of Australia. Several NTHi PCR-ribotypes dominated in nasopharyngeal carriage, irrespective of study setting. Principal coordinates analysis confirmed a cluster of common PCR-ribotypes among all cohorts. In conclusion, we identified dominant PCR-ribotypes common to geographically disparate Australian paediatric populations. Future genomic analyses will shed further light on the precise factors underlying the dominance of certain NTHi strains in nasopharyngeal carriage.
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Affiliation(s)
- Heidi C. Smith-Vaughan
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory Australia
- School of Medicine, Griffith University, Gold Coast, Queensland Australia
| | - Jemima Beissbarth
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory Australia
| | - Jacinta Bowman
- Department of Microbiology and Infectious Diseases, PathWest Laboratory Medicine, Perth, Western Australia Australia
| | - Kim M. Hare
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory Australia
| | - Erin P. Price
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory Australia
| | - Janessa Pickering
- Telethon Kids Institute, The University of Western Australia, Perth, Western Australia Australia
- School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia Australia
| | - Deborah Lehmann
- Telethon Kids Institute, The University of Western Australia, Perth, Western Australia Australia
| | - Anne B. Chang
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory Australia
- Department of Respiratory and Sleep Medicine, Queensland Children’s Medical Research Institute, Children’s Health, Queensland University of Technology, Brisbane, Queensland Australia
| | - Peter S. Morris
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory Australia
- Royal Darwin Hospital, Darwin, Northern Territory Australia
| | - Robyn L. Marsh
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory Australia
| | - Amanda J. Leach
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory Australia
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Diversity of nontypeable Haemophilus influenzae strains colonizing Australian Aboriginal and non-Aboriginal children. J Clin Microbiol 2014; 52:1352-7. [PMID: 24501028 DOI: 10.1128/jcm.03448-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Nontypeable Haemophilus influenzae (NTHI) strains are responsible for respiratory-related infections which cause a significant burden of disease in Australian children. We previously identified a disparity in NTHI culture-defined carriage rates between Aboriginal and non-Aboriginal children (42% versus 11%). The aim of this study was to use molecular techniques to accurately determine the true NTHI carriage rates (excluding other culture-identical Haemophilus spp.) and assess whether the NTHI strain diversity correlates with the disparity in NTHI carriage rates. NTHI isolates were cultured from 595 nasopharyngeal aspirates collected longitudinally from asymptomatic Aboriginal (n=81) and non-Aboriginal (n=76) children aged 0 to 2 years living in the Kalgoorlie-Boulder region, Western Australia. NTHI-specific 16S rRNA gene PCR and PCR ribotyping were conducted on these isolates. Confirmation of NTHI by 16S rRNA gene PCR corrected the NTHI carriage rates from 42% to 36% in Aboriginal children and from 11% to 9% in non-Aboriginal children. A total of 75 different NTHI ribotypes were identified, with 51% unique to Aboriginal children and 13% unique to non-Aboriginal children (P<0.0001). The strain richness (proportion of different NTHI ribotypes) was similar for Aboriginal (19%, 65/346) and non-Aboriginal children (19%, 37/192) (P=0.909). Persistent carriage of the same ribotype was rare in the two groups, but colonization with multiple NTHI strains was more common in Aboriginal children than in non-Aboriginal children. True NTHI carriage was less than that estimated by culture. The Aboriginal children were more likely to carry unique and multiple NTHI strains, which may contribute to the chronicity of NTHI colonization and subsequent disease.
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Absence of an important vaccine and diagnostic target in carriage- and disease-related nontypeable Haemophilus influenzae. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 21:250-2. [PMID: 24285816 DOI: 10.1128/cvi.00632-13] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Nontypeable Haemophilus influenzae (NTHi)-associated disease is a major health problem globally. Whole-genome sequence analysis identified the absence of hpd genes encoding Haemophilus protein D in 3 of 16 phylogenetically distinct NTHi isolates. This novel finding is of potential clinical significance, as protein D and hpd represent important NTHi vaccine antigen and diagnostic targets, respectively.
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Murphy TF. Vaccine development for non-typeable Haemophilus influenzae and Moraxella catarrhalis: progress and challenges. Expert Rev Vaccines 2007; 4:843-53. [PMID: 16372880 DOI: 10.1586/14760584.4.6.843] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
An urgent need exists for vaccines to prevent infections caused by nontypeable Haemophilus influenzae and Moraxella catarrhalis. These bacteria cause otitis media in children, a clinical problem associated with enormous morbidity and cost. H. influenzae and M. catarrhalis also cause lower respiratory tract infections in adults with chronic lung disease. Infections in this clinical setting are associated with disability and death. Recent progress in identifying potential vaccine antigens in both bacteria raises great promise in developing effective vaccines. This paper reviews the key issues in vaccine development for H. influenzae and M. catarrhalis, including areas where progress has been stalled, and proposes areas that deserve investigation in the next 5 years.
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Affiliation(s)
- Timothy F Murphy
- University at Buffalo, State University of New York, Medical Research 151, Buffalo VAMC, 3495 Bailey Avenue, Buffalo, NY 14215, USA.
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Smith-Vaughan H, Byun R, Nadkarni M, Jacques NA, Hunter N, Halpin S, Morris PS, Leach AJ. Measuring nasal bacterial load and its association with otitis media. BMC EAR, NOSE, AND THROAT DISORDERS 2006; 6:10. [PMID: 16686940 PMCID: PMC1479363 DOI: 10.1186/1472-6815-6-10] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2005] [Accepted: 05/10/2006] [Indexed: 11/10/2022]
Abstract
Background Nasal colonisation with otitis media (OM) pathogens, particularly Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, is a precursor to the onset of OM. Many children experience asymptomatic nasal carriage of these pathogens whereas others will progress to otitis media with effusion (OME) or suppurative OM. We observed a disparity in the prevalence of suppurative OM between Aboriginal children living in remote communities and non-Aboriginal children attending child-care centres; up to 60% and <1%, respectively. This could not be explained by the less dramatic difference in rates of carriage of respiratory bacterial pathogens (80% vs 50%, respectively). In this study, we measured nasal bacterial load to help explain the different propensity for suppurative OM in these two populations. Methods Quantitative measures (colony counts and real-time quantitative PCR) of the respiratory pathogens S. pneumoniae, H. influenzae and M. catarrhalis, and total bacterial load were analysed in nasal swabs from Aboriginal children from remote communities, and non-Aboriginal children attending urban child-care centres. Results In both populations nearly all swabs were positive for at least one of these respiratory pathogens. Using either quantification method, positive correlations between bacterial load and ear state (no OM, OME, or suppurative OM) were observed. This relationship held for single and combined bacterial respiratory pathogens, total bacterial load, and the proportion of respiratory pathogens to total bacterial load. Comparison of Aboriginal and non-Aboriginal children, all with a diagnosis of OME, demonstrated significantly higher loads of S. pneumoniae and M. catarrhalis in the Aboriginal group. The increased bacterial load despite similar clinical condition may predict persistence of middle ear effusions and progression to suppurative OM in the Aboriginal population. Our data also demonstrated the presence of PCR-detectable non-cultivable respiratory pathogens in 36% of nasal swabs. This may have implications for the pathogenesis of OM including persistence of infection despite aggressive therapies. Conclusion Nasal bacterial load was significantly higher among Aboriginal children and may explain their increased risk of suppurative OM. It was also positively correlated with ear state. We believe that a reduction in bacterial load in high-risk populations may be required before dramatic reductions in OM can be achieved.
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Affiliation(s)
- Heidi Smith-Vaughan
- Menzies School of Health Research, Darwin, Australia
- Institute for Advanced Studies, Charles Darwin University, Darwin, Australia
| | - Roy Byun
- Institute of Dental Research, Westmead Millennium Institute and Westmead Centre for Oral Health, Sydney, Australia
| | - Mangala Nadkarni
- Institute of Dental Research, Westmead Millennium Institute and Westmead Centre for Oral Health, Sydney, Australia
| | - Nicholas A Jacques
- Institute of Dental Research, Westmead Millennium Institute and Westmead Centre for Oral Health, Sydney, Australia
| | - Neil Hunter
- Institute of Dental Research, Westmead Millennium Institute and Westmead Centre for Oral Health, Sydney, Australia
| | - Stephen Halpin
- Menzies School of Health Research, Darwin, Australia
- Institute for Advanced Studies, Charles Darwin University, Darwin, Australia
| | - Peter S Morris
- Menzies School of Health Research, Darwin, Australia
- Institute for Advanced Studies, Charles Darwin University, Darwin, Australia
- Northern Territory Clinical School, Flinders University, Adelaide, Australia
| | - Amanda J Leach
- Menzies School of Health Research, Darwin, Australia
- Institute for Advanced Studies, Charles Darwin University, Darwin, Australia
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Farjo RS, Foxman B, Patel MJ, Zhang L, Pettigrew MM, McCoy SI, Marrs CF, Gilsdorf JR. Diversity and sharing of Haemophilus influenzae strains colonizing healthy children attending day-care centers. Pediatr Infect Dis J 2004; 23:41-6. [PMID: 14743045 DOI: 10.1097/01.inf.0000106981.89572.d1] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Children attending day-care centers (DCCs) are at risk for Haemophilus influenzae nasopharyngeal colonization and acute otitis media. The degree to which a given strain circulates within a day-care center and the heterogeneity of strains among DCCs in a geographic area are not well-characterized. This study describes the prevalence rates of H. influenzae colonization in a large number of children attending day-care centers and examines the genetic diversity of colonizing strains and the degree of sharing among children. METHODS Throat cultures were collected from 198 healthy children <3 years old attending 16 day-care centers in Michigan. All H. influenzae isolates were genetically typed by enterobacterial repetitive intergenic consensus PCR as the initial screening technique to identify unique strains within each child. Pulsed field gel electrophoresis was used subsequently to examine the genetic diversity of strains between children. RESULTS There were 127 (64%) children colonized with H. influenzae. Wide variation in rates of colonization was identified among day-care centers (0 to 95%). A total of 179 genetically unique H. influenzae strains were isolated, and 47 children (37%) were colonized with 2 or more genetically distinct H. influenzae organisms. Evidence of sharing of the same strain in different children was found in 13 of 15 colonized DCCs and 23% of genotypically unique strains were shared. CONCLUSION The degree of sharing of H. influenzae among children in this study suggests transmission of these potentially pathogenic microorganisms in day-care centers.
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Affiliation(s)
- Rand S Farjo
- Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI 48109-0244, USA
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Abstract
PURPOSE OF REVIEW This review will consider recent developments in the clinical aspects of infections due to non-typeable Haemophilus influenzae. In addition, newer developments in the areas of mechanisms of pathogenesis, host pathogen interaction, immune responses and efforts toward vaccine development will be reviewed briefly. RECENT FINDINGS Non-typeable H. influenzae continues to be a common cause of otitis media in infants and children, sinusitis in children and adults, pneumonia in adults, and lower respiratory tract infection in adults with chronic obstructive pulmonary disease. While the rate of beta-lactamase production by isolates of H. influenzae varies geographically, most regions show a rate of 20-35% of isolates producing beta-lactamase. Recent studies have highlighted the possible role of bacterial biofilms formed by H. influenzae as a cause of otitis media. Several lines of evidence indicate that H. influenzae causes intracellular infection in the lower respiratory tract in chronic obstructive pulmonary disease and this observation has important implications in understanding the human immune response to the bacterium. Lipooligosaccharide is an important virulence factor for H. influenzae and research is generating new information on the complex role of this molecule in colonization and infection of the respiratory tract. Several surface molecules are under active evaluation as vaccine antigens. SUMMARY Non-typeable H. influenzae is an important cause of respiratory tract infections in children and adults. Most strains are susceptible to amoxicillin/clavulanate, fluoroquinolones and the newer macrolides. Research in the next decade promises substantial progress in the challenge of developing vaccines for nontypeable H. influenzae.
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Affiliation(s)
- Timothy F Murphy
- Department of Medicine, University at Buffalo, State University of New York, Buffalo, New York, USA.
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Coates HL, Morris PS, Leach AJ, Couzos S. Otitis media in Aboriginal children: tackling a major health problem. Med J Aust 2002; 177:177-8. [PMID: 12175319 DOI: 10.5694/j.1326-5377.2002.tb04727.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2002] [Accepted: 06/17/2002] [Indexed: 11/17/2022]
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