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Abstract
PURPOSE OF REVIEW Pneumonia is the main global cause of sepsis, and has been associated with high morbidity and high short and long-term mortality rates. As it may be caused by a wide spectrum of microorganisms, microbial diagnosis is challenging and the choice of adequate therapy remains an important problem. This review focuses on recently published studies of microbiological diagnostic tests and clinical assessments for pneumonia, including community-acquired pneumonia, hospital-acquired pneumonia, and ventilator-associated pneumonia. RECENT FINDINGS Over the past decade, the microbiological diagnosis of pneumonia has improved significantly - thanks to the development and implementation of molecular diagnostic tests for identifying the most frequent pathogens causing pneumonia and for determining their patterns of resistance. Molecular methods for the diagnosis of pneumonia focus on multiple target detection systems and pathogen detection arrays, and, more recently, have been used in combination with mass spectrometry. SUMMARY The implementation of rapid diagnostic techniques in routine clinical practice able to identify and determine the resistance patterns of the causative microbes may transform the management of pneumonia, improving the selection and administration of antimicrobial therapies especially in critically ill patients. The validation of new diagnostic technology platforms is crucial in order to assess their usefulness and to guide antimicrobial treatment in this population.
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Corrected and Republished from: A Nonfunctional Opsonic Antibody Response Frequently Occurs after Pneumococcal Pneumonia and Is Associated with Invasive Disease. mSphere 2020; 5:5/6/e01102-20. [PMID: 33328351 PMCID: PMC7758726 DOI: 10.1128/msphere.01102-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Numerous reports on the dynamics of antipneumococcal immunity in relation to immunization with pneumococcal vaccines and on the prevalence of naturally acquired immunity in various populations have been published. In contrast, studies on the dynamics of the humoral immune response triggered by pneumococcal infection are scarce. Naturally acquired opsonic antipneumococcal antibodies are commonly found in nonvaccinated adults and confer protection against infection and colonization. Despite this, only limited data exist regarding the adaptive immune response after pneumococcal exposure. To investigate the dynamics of naturally acquired antipneumococcal immunity in relation to an episode of infection, opsonic antibody activity was studied with paired acute-phase and convalescent-phase sera obtained from 54 patients with pneumococcal community-acquired pneumonia (CAP) using an opsonophagocytic assay (OPA). Results were compared with clinical characteristics and anticapsular immunoglobulin (Ig) concentrations. Interestingly, a nonfunctional opsonic antibody response (characterized by a decreased convalescent-phase serum OPA titer compared to that of the acute-phase serum or undetectable titers in both sera) was observed in 19 (35%) patients. The remaining individuals exhibited either an increased convalescent-phase OPA titer (n = 24 [44%]) or a detectable, but unchanged, titer at both time points (n = 11 [20%]). Invasive pneumococcal disease (i.e., bacteremia) was significantly more common among patients with a nonfunctional convalescent-phase response than in patients with other convalescent-phase responses. Anticapsular Ig concentrations were higher among patients with detectable convalescent-phase OPA titers (P = 0.003), and the greatest Ig concentration increase was observed among patients with an increased convalescent-phase response (P = 0.002). Our findings indicate that an episode of pneumococcal infection may act as an immunizing event. However, in some cases when patients with CAP also suffer from bacteremia, a nonfunctional opsonic antibody response may occur. Furthermore, the results suggest that factors other than anticapsular Ig concentrations determine opsonic antibody activity in serum. IMPORTANCE Numerous reports on the dynamics of antipneumococcal immunity in relation to immunization with pneumococcal vaccines and on the prevalence of naturally acquired immunity in various populations have been published. In contrast, studies on the dynamics of the humoral immune response triggered by pneumococcal infection are scarce. This study provides valuable information that will contribute to fill this knowledge gap. Our main results indicate that a functional immune response may fail after CAP, predominantly among patients with simultaneous bacteremia.
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3
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Manenzhe RI, Dube FS, Wright M, Lennard K, Mounaud S, Lo SW, Zar HJ, Nierman WC, Nicol MP, Moodley C. Characterization of Pneumococcal Colonization Dynamics and Antimicrobial Resistance Using Shotgun Metagenomic Sequencing in Intensively Sampled South African Infants. Front Public Health 2020; 8:543898. [PMID: 33072693 PMCID: PMC7536305 DOI: 10.3389/fpubh.2020.543898] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 08/17/2020] [Indexed: 11/13/2022] Open
Abstract
Background: There remains a significant proportion of deaths due to pneumococcal pneumonia in infants from low- and middle-income countries despite the marginal global declines recorded in the past decade. Monitoring changes in pneumococcal carriage is key to understanding vaccination-induced shifts in the ecology of carriage, patterns of antimicrobial resistance, and impact on health. We longitudinally investigated pneumococcal carriage dynamics in PCV-13 vaccinated infants by collecting nasopharyngeal (NP) samples at 2-weekly intervals from birth through the first year of life from 137 infants. As a proof of concept, 196 NP samples were retrieved from a subset of 23 infants to explore strain-level pneumococcal colonization patterns and associated antimicrobial-resistance determinants. These were selected on the basis of changes in serotype and antibiogram over time. NP samples underwent short-term enrichment for streptococci prior to total nucleic acid extraction and whole metagenome shotgun sequencing (WMGS). Reads were assembled and aligned to pneumococcal reference genomes for the extraction of pneumococcal and non-pneumococcal bacterial reads. Pneumococcal contigs were aligned to the Antibiotic Resistance Gene-ANNOTation database of acquired AMR genes. In silico pneumococcal capsular and multilocus sequence typing were performed. Results: Of the 196 samples sequenced, 174 had corresponding positive cultures for pneumococci, of which, 152 were assigned an in silico serotype. Metagenomic sequencing detected a single pneumococcal serotype in 85% (129/152), and co-colonization in 15% (23/152) of the samples. Twenty-two different pneumococcal serotypes were identified, with 15B/15C and 16F being the most common non-PCV13 serotypes, while 23F and 19A were the most common PCV13 serotypes. Twenty-six different sequence types (STs), including four novel STs were identified in silico. Mutations in the folA and folP genes, associated with cotrimoxazole resistance, were detected in 89% (87/98) of cotrimoxazole-non-susceptible pneumococci, as well as in the pbp1a and pbp2x genes, in penicillin non-susceptible ST705215B/15C isolates. Conclusions: Metagenomic sequencing of NP samples is a valuable culture-independent technique for a detailed evaluation of the pneumococcal component and resistome of the NP microbiome. This method allowed for the detection of novel STs, as well as co-colonization, with a predominance of non-PCV13 serotypes in this cohort. Forty-eight resistance genes, as well as mutations associated with resistance were detected, but the correlation with phenotypic non-susceptibility was lower than expected.
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Affiliation(s)
- Rendani I Manenzhe
- Division of Medical Microbiology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Felix S Dube
- Division of Medical Microbiology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Department of Molecular and Cell Biology, Faculty of Science, University of Cape Town, Cape Town, South Africa
| | | | - Katie Lennard
- Division of Computational Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | | | - Stephanie W Lo
- Parasites and Microbes Program, The Wellcome Sanger Institute, Cambridge, United Kingdom
| | - Heather J Zar
- Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital and South African - Medical Research Council Unit on Child & Adolescent Health, University of Cape Town, Cape Town, South Africa
| | | | - Mark P Nicol
- Division of Medical Microbiology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Division of Infection and Immunity, University of Western Australia, Perth, WA, Australia
| | - Clinton Moodley
- Division of Medical Microbiology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,National Health Laboratory Service, Groote Schuur Hospital, Cape Town, South Africa
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Pfefferle S, Christner M, Aepfelbacher M, Lütgehetmann M, Rohde H. Implementation of the FilmArray ME panel in laboratory routine using a simple sample selection strategy for diagnosis of meningitis and encephalitis. BMC Infect Dis 2020; 20:170. [PMID: 32087681 PMCID: PMC7036261 DOI: 10.1186/s12879-020-4904-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 02/18/2020] [Indexed: 12/13/2022] Open
Abstract
Background Infectious meningitis is a serious disease and patient outcome relies on fast and reliable diagnostics. A syndromic panel testing approach like the FilmArray ME can accelerate diagnosis and therefore decrease the time to pathogen specific therapy. Yet, its clinical utility is controversial, mainly because of a remaining uncertainty in correct interpretation of results, limited data on its performance on clinical specimens and its relatively high costs. The aim of this study was to analyze clinical performance of the assay in a real life setting at a tertiary university hospital using a pragmatic and simple sample selection strategy to reduce the overall cost burden. Methods Over a period of 18 months we received 4623 CSF samples (2338 hospitalizations, 1601 individuals). FilmArray ME analysis was restricted to CSF-samples with a high pretest probability of infectious meningitis, e.g. positive Gram-stain, samples in which leukocytes and/or bacteria were evident or urgent suspicion of infection was communicated by clinicians. N = 171 samples matched to our risk criteria and were subjected to FilmArray ME analysis. Those samples were also analyzed by reference methods: culture only (n = 45), PCR only (n = 20) or both methods (n = 106). Results 56/171 (32.75%) were FilmArray ME positive. Bacterial pathogens were detected in 30/56 (53.57%), viral pathogens were detected in 27/56 (48.21%) and yeast DNA was detected in 1/56 (1.79%) of positive samples. Double detection occurred in 2/56 samples. In 52/56 (92.86%) FilmArray ME positive samples, results could be confirmed by the reference assays (sensitivity = 96.30%, specificity =96.58%). Conclusion The FilmArray ME assay is a fast and reliable diagnostic tool for the management of infectious meningitis and can easily be implemented in routine diagnostic workflows. However, correlation of test results and underlying clinical symptoms requires experienced users and the awareness of potentially false negative or false positive results. Moreover, considering the need for antimicrobial susceptibility testing, the use of molecular tests as a stand-alone diagnostic cannot be recommended.
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Affiliation(s)
- Susanne Pfefferle
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
| | - Martin Christner
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Martin Aepfelbacher
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Marc Lütgehetmann
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Holger Rohde
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
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A Nonfunctional Opsonic Antibody Response Frequently Occurs after Pneumococcal Pneumonia and Is Associated with Invasive Disease. mSphere 2020; 5:5/1/e00925-19. [PMID: 32024704 PMCID: PMC7002313 DOI: 10.1128/msphere.00925-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Numerous reports on the dynamics of antipneumococcal immunity in relation to immunization with pneumococcal vaccines and on the prevalence of naturally acquired immunity in various populations have been published. In contrast, studies on the dynamics of the humoral immune response triggered by pneumococcal infection are scarce. This study provides valuable information that will contribute to fill this knowledge gap. Our main results indicate that a functional immune response frequently fails to occur after CAP, predominantly among patients with simultaneous bacteremia. Naturally acquired opsonic antipneumococcal antibodies are commonly found in nonvaccinated adults and confer protection against infection and colonization. Despite this, only limited data exist regarding the adaptive immune response after pneumococcal exposure. To investigate the dynamics of naturally acquired antipneumococcal immunity in relation to an episode of infection, opsonic antibody activity was studied with paired acute-phase and convalescent-phase sera obtained from 54 patients with pneumococcal community-acquired pneumonia (CAP) using an opsonophagocytic assay (OPA). Results were compared with clinical characteristics and anticapsular immunoglobulin (Ig) concentrations. Interestingly, a nonfunctional opsonic antibody response (characterized by a decreased convalescent-phase serum OPA titer compared to that of the acute-phase serum or undetectable titers in both sera) was observed in 19 (35%) patients. A nonfunctional convalescent-phase response was significantly more common among patients with invasive pneumococcal disease (i.e., bacteremia) than in patients without invasive disease (53%; P = 0.019). Remaining individuals exhibited either an increased convalescent-phase OPA titer (n = 24 [44%]) or a detectable, but unchanged, titer at both time points (n = 11 [20%]). No correlation was found between anticapsular Ig concentrations and OPA titers. Our findings indicate that an episode of pneumococcal infection may act as an immunizing event, leading to an improved antipneumococcal adaptive immune status. However, in some cases, when patients with CAP also suffer from bacteremia, a nonfunctional opsonic antibody response may occur. Furthermore, the results suggest that factors other than anticapsular Ig concentrations are important for opsonic antibody activity in serum. IMPORTANCE Numerous reports on the dynamics of antipneumococcal immunity in relation to immunization with pneumococcal vaccines and on the prevalence of naturally acquired immunity in various populations have been published. In contrast, studies on the dynamics of the humoral immune response triggered by pneumococcal infection are scarce. This study provides valuable information that will contribute to fill this knowledge gap. Our main results indicate that a functional immune response frequently fails to occur after CAP, predominantly among patients with simultaneous bacteremia.
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Jarovsky D, Grodzicki Ambrus T, Galvão Gurgel M, Jenné Mimica M, Volpe Arnoni M, Almeida FJ, Palazzi Sáfadi MA, Naaman Berezin E. Spontaneous pneumococcal peritonitis diagnosed by qPCR. IDCases 2019; 15:e00489. [PMID: 30656139 PMCID: PMC6327877 DOI: 10.1016/j.idcr.2019.e00489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 01/06/2019] [Accepted: 01/06/2019] [Indexed: 11/26/2022] Open
Abstract
Spontaneous bacterial peritonitis is an uncommon manifestation of invasive pneumococcal disease and frequently occurs when an underlying hepatic disease is present. Bacterial identification through culture can be particularly challenging in patients with prior or concurrent antimicrobial use. DNA amplification detects very few copies of target DNA under ideal conditions in CSF or pleural effusion and, therefore, can be useful in selected infections. A culture-negative spontaneous pneumococcal peritonitis without preexisting peritoneal disease diagnosed by qPCR is herein described.
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Affiliation(s)
- Daniel Jarovsky
- Pediatric Infectious Diseases Unit - Santa Casa de São Paulo, São Paulo, Brazil
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Isothermal and Sensitive Identification of Streptococcus pneumoniae Using Loop Mediated Isothermal Amplification Assay. ARCHIVES OF PEDIATRIC INFECTIOUS DISEASES 2017. [DOI: 10.5812/pedinfect.61604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Wright MS, McCorrison J, Gomez AM, Beck E, Harkins D, Shankar J, Mounaud S, Segubre-Mercado E, Mojica AMR, Bacay B, Nzenze SA, Kimaro SZM, Adrian P, Klugman KP, Lucero MG, Nelson KE, Madhi S, Sutton GG, Nierman WC, Losada L. Strain Level Streptococcus Colonization Patterns during the First Year of Life. Front Microbiol 2017; 8:1661. [PMID: 28932211 PMCID: PMC5592222 DOI: 10.3389/fmicb.2017.01661] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/16/2017] [Indexed: 01/20/2023] Open
Abstract
Pneumococcal pneumonia has decreased significantly since the implementation of the pneumococcal conjugate vaccine (PCV), nevertheless, in many developing countries pneumonia mortality in infants remains high. We have undertaken a study of the nasopharyngeal (NP) microbiome during the first year of life in infants from The Philippines and South Africa. The study entailed the determination of the Streptococcus sp. carriage using a lytA qPCR assay, whole metagenomic sequencing, and in silico serotyping of Streptococcus pneumoniae, as well as 16S rRNA amplicon based community profiling. The lytA carriage in both populations increased with infant age and lytA+ samples ranged from 24 to 85% of the samples at each sampling time point. We next developed informatic tools for determining Streptococcus community composition and pneumococcal serotype from metagenomic sequences derived from a subset of longitudinal lytA-positive Streptococcus enrichment cultures from The Philippines (n = 26 infants, 50% vaccinated) and South African (n = 7 infants, 100% vaccinated). NP samples from infants were passaged in enrichment media, and metagenomic DNA was purified and sequenced. In silico capsular serotyping of these 51 metagenomic assemblies assigned known serotypes in 28 samples, and the co-occurrence of serotypes in 5 samples. Eighteen samples were not typeable using known serotypes but did encode for capsule biosynthetic cluster genes similar to non-encapsulated reference sequences. In addition, we performed metagenomic assembly and 16S rRNA amplicon profiling to understand co-colonization dynamics of Streptococcus sp. and other NP genera, revealing the presence of multiple Streptococcus species as well as potential respiratory pathogens in healthy infants. A range of virulence and drug resistant elements were identified as circulating in the NP microbiomes of these infants. This study revealed the frequent co-occurrence of multiple S. pneumoniae strains along with Streptococcus sp. and other potential pathogens such as S. aureus in the NP microbiome of these infants. In addition, the in silico serotype analysis proved powerful in determining the serotypes in S. pneumoniae carriage, and may lead to developing better targeted vaccines to prevent invasive pneumococcal disease (IPD) in these countries. These findings suggest that NP colonization by S. pneumoniae during the first years of life is a dynamic process involving multiple serotypes and species.
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Affiliation(s)
| | | | | | - Erin Beck
- J. Craig Venter InstituteRockville, MD, United States
| | - Derek Harkins
- J. Craig Venter InstituteRockville, MD, United States
| | - Jyoti Shankar
- J. Craig Venter InstituteRockville, MD, United States
| | | | | | | | - Brian Bacay
- Research Institute of Tropical MedicineMuntinlupa City, Philippines
| | - Susan A Nzenze
- Respiratory and Meningeal Pathogens Research UnitSoweto, South Africa
| | - Sheila Z M Kimaro
- Respiratory and Meningeal Pathogens Research UnitSoweto, South Africa
| | - Peter Adrian
- Respiratory and Meningeal Pathogens Research UnitSoweto, South Africa
| | - Keith P Klugman
- Respiratory and Meningeal Pathogens Research UnitSoweto, South Africa
| | - Marilla G Lucero
- Research Institute of Tropical MedicineMuntinlupa City, Philippines
| | | | - Shabir Madhi
- Respiratory and Meningeal Pathogens Research UnitSoweto, South Africa
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Morpeth SC, Deloria Knoll M, Scott JAG, Park DE, Watson NL, Baggett HC, Brooks WA, Feikin DR, Hammitt LL, Howie SRC, Kotloff KL, Levine OS, Madhi SA, O'Brien KL, Thea DM, Adrian PV, Ahmed D, Antonio M, Bunthi C, DeLuca AN, Driscoll AJ, Githua LP, Higdon MM, Kahn G, Karani A, Karron RA, Kwenda G, Makprasert S, Mazumder R, Moore DP, Mwansa J, Nyongesa S, Prosperi C, Sow SO, Tamboura B, Whistler T, Zeger SL, Murdoch DR. Detection of Pneumococcal DNA in Blood by Polymerase Chain Reaction for Diagnosing Pneumococcal Pneumonia in Young Children From Low- and Middle-Income Countries. Clin Infect Dis 2017; 64:S347-S356. [PMID: 28575371 PMCID: PMC5447841 DOI: 10.1093/cid/cix145] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND. We investigated the performance of polymerase chain reaction (PCR) on blood in the diagnosis of pneumococcal pneumonia among children from 7 low- and middle-income countries. METHODS. We tested blood by PCR for the pneumococcal autolysin gene in children aged 1-59 months in the Pneumonia Etiology Research for Child Health (PERCH) study. Children had World Health Organization-defined severe or very severe pneumonia or were age-frequency-matched community controls. Additionally, we tested blood from general pediatric admissions in Kilifi, Kenya, a PERCH site. The proportion PCR-positive was compared among cases with microbiologically confirmed pneumococcal pneumonia (MCPP), cases without a confirmed bacterial infection (nonconfirmed), cases confirmed for nonpneumococcal bacteria, and controls. RESULTS. In PERCH, 7.3% (n = 291/3995) of cases and 5.5% (n = 273/4987) of controls were blood pneumococcal PCR-positive (P < .001), compared with 64.3% (n = 36/56) of MCPP cases and 6.3% (n = 243/3832) of nonconfirmed cases (P < .001). Blood pneumococcal PCR positivity was higher in children from the 5 African countries (5.5%-11.5% among cases and 5.3%-10.2% among controls) than from the 2 Asian countries (1.3% and 1.0% among cases and 0.8% and 0.8% among controls). Among Kilifi general pediatric admissions, 3.9% (n = 274/6968) were PCR-positive, including 61.7% (n = 37/60) of those with positive blood cultures for pneumococcus. DISCUSSION. The utility of pneumococcal PCR on blood for diagnosing childhood pneumococcal pneumonia in the 7 low- and middle-income countries studied is limited by poor specificity and by poor sensitivity among MCPP cases.
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Affiliation(s)
- Susan C Morpeth
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, United Kingdom
- Microbiology Laboratory, Middlemore Hospital, Counties Manukau District Health Board, Auckland, New Zealand
| | - Maria Deloria Knoll
- Department of International Health, International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - J Anthony G Scott
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, United Kingdom
| | - Daniel E Park
- Department of International Health, International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- Milken Institute School of Public Health, Department of Epidemiology and Biostatistics, George Washington University
| | | | - Henry C Baggett
- Global Disease Detection Center, Thailand Ministry of Public Health-US Centers for Disease Control and Prevention Collaboration, Nonthaburi
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - W Abdullah Brooks
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka and Matlab
| | - Daniel R Feikin
- Department of International Health, International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- Division of Viral Diseases, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Laura L Hammitt
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi
- Department of International Health, International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Stephen R C Howie
- Department of Paediatrics, University of Auckland
- Centre for International Health, University of Otago, Dunedin, New Zealand
- Medical Research Council Unit, Basse, The Gambia
| | - Karen L Kotloff
- Division of Infectious Disease and Tropical Pediatrics, Department of Pediatrics, Center for Vaccine Development, Institute of Global Health, University of Maryland School of Medicine, Baltimore
| | - Orin S Levine
- Department of International Health, International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- Bill & Melinda Gates Foundation, Seattle, Washington
| | - Shabir A Madhi
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit
- Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases Unit, University of the Witwatersrand, Johannesburg, South Africa
| | - Katherine L O'Brien
- Department of International Health, International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Donald M Thea
- Center for Global Health and Development, Boston University School of Public Health, Massachusetts
| | - Peter V Adrian
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit
- Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases Unit, University of the Witwatersrand, Johannesburg, South Africa
| | - Dilruba Ahmed
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka and Matlab
| | - Martin Antonio
- Medical Research Council Unit, Basse, The Gambia
- Department of Pathogen Molecular Biology, London School of Hygiene & Tropical Medicine
- Microbiology and Infection Unit, Warwick Medical School, University of Warwick, Coventry, United Kingdom ; Departments of
| | - Charatdao Bunthi
- Global Disease Detection Center, Thailand Ministry of Public Health-US Centers for Disease Control and Prevention Collaboration, Nonthaburi
| | - Andrea N DeLuca
- Department of International Health, International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- Epidemiology
| | - Amanda J Driscoll
- Department of International Health, International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | | | - Melissa M Higdon
- Department of International Health, International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Geoff Kahn
- Department of International Health, International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- Mental Health
| | - Angela Karani
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi
| | - Ruth A Karron
- International Health, Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Geoffrey Kwenda
- Department of Biomedical Sciences, School of Health Sciences, University of Zambia
- Zambia Center for Applied Health Research and Development, Lusaka
| | - Sirirat Makprasert
- Global Disease Detection Center, Thailand Ministry of Public Health-US Centers for Disease Control and Prevention Collaboration, Nonthaburi
| | - Razib Mazumder
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka and Matlab
| | - David P Moore
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit
- Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases Unit, University of the Witwatersrand, Johannesburg, South Africa
- Department of Paediatrics & Child Health, Chris Hani Baragwanath Academic Hospital and University of the Witwatersrand, Johannesburg, South Africa
| | - James Mwansa
- Zambia Center for Applied Health Research and Development, Lusaka
- Department of Pathology and Microbiology, University Teaching Hospital, Lusaka, Zambia
| | - Sammy Nyongesa
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi
| | - Christine Prosperi
- Department of International Health, International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Samba O Sow
- Centre pour le Développement des Vaccins, Bamako, Mali
| | | | - Toni Whistler
- Global Disease Detection Center, Thailand Ministry of Public Health-US Centers for Disease Control and Prevention Collaboration, Nonthaburi
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Scott L Zeger
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - David R Murdoch
- Department of Pathology, University of Otago, and
- Microbiology Unit, Canterbury Health Laboratories, Christchurch, New Zealand
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Bjarnason A, Lindh M, Westin J, Andersson LM, Baldursson O, Kristinsson KG, Gottfredsson M. Utility of oropharyngeal real-time PCR for S. pneumoniae and H. influenzae for diagnosis of pneumonia in adults. Eur J Clin Microbiol Infect Dis 2017; 36:529-536. [PMID: 27822652 PMCID: PMC5309271 DOI: 10.1007/s10096-016-2829-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 10/20/2016] [Indexed: 12/11/2022]
Abstract
A lack of sensitive tests and difficulties obtaining representative samples contribute to the challenge in identifying etiology in pneumonia. Upper respiratory tract swabs can be easily collected and analyzed with real-time PCR (rtPCR). Common pathogens such as S. pneumoniae and H. influenzae can both colonize and infect the respiratory tract, complicating the interpretation of positive results. Oropharyngeal swabs were collected (n = 239) prospectively from adults admitted to hospital with pneumonia. Analysis with rtPCR targeting S. pneumoniae and H. influenzae was performed and results compared with sputum cultures, blood cultures, and urine antigen testing for S. pneumoniae. Different Ct cutoff values were applied to positive tests to discern colonization from infection. Comparing rtPCR with conventional testing for S. pneumoniae in patients with all tests available (n = 57) resulted in: sensitivity 87 %, specificity 79 %, PPV 59 % and NPV 94 %, and for H. influenzae (n = 67): sensitivity 75 %, specificity 80 %, PPV 45 % and NPV 94 %. When patients with prior antimicrobial exposure were excluded sensitivity improved: 92 % for S. pneumoniae and 80 % for H. influenzae. Receiver operating characteristic curve analysis demonstrated for S. pneumoniae: AUC = 0.65 (95 % CI 0.51-0.80) and for H. influenzae: AUC = 0.86 (95 % CI 0.72-1.00). Analysis of oropharyngeal swabs using rtPCR proved both reasonably sensitive and specific for diagnosing pneumonia caused by S. pneumoniae and H. influenzae. This method may be a useful diagnostic adjunct to other methods and of special value in patients unable to provide representative lower airway samples.
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Affiliation(s)
- A Bjarnason
- Faculty of Medicine, University of Iceland, Reykjavik, Vatnsmyrarvegi 16, 101, Reykjavik, Iceland
- Departments of Medicine, Microbiology and Virology, Landspitali University Hospital, 101, Reykjavik, Iceland
| | - M Lindh
- Department of Infectious Diseases/Clinical Virology, University of Gothenburg, Medicinaregatan 3a-5b, 40530, Gothenburg, Sweden
| | - J Westin
- Department of Infectious Diseases/Clinical Virology, University of Gothenburg, Medicinaregatan 3a-5b, 40530, Gothenburg, Sweden
| | - L-M Andersson
- Department of Infectious Diseases/Clinical Virology, University of Gothenburg, Medicinaregatan 3a-5b, 40530, Gothenburg, Sweden
| | - O Baldursson
- Departments of Medicine, Microbiology and Virology, Landspitali University Hospital, 101, Reykjavik, Iceland
| | - K G Kristinsson
- Faculty of Medicine, University of Iceland, Reykjavik, Vatnsmyrarvegi 16, 101, Reykjavik, Iceland
- Departments of Medicine, Microbiology and Virology, Landspitali University Hospital, 101, Reykjavik, Iceland
| | - M Gottfredsson
- Faculty of Medicine, University of Iceland, Reykjavik, Vatnsmyrarvegi 16, 101, Reykjavik, Iceland.
- Departments of Medicine, Microbiology and Virology, Landspitali University Hospital, 101, Reykjavik, Iceland.
- Division of Infectious Diseases, Landspitali University Hospital, Fossvogur, 108, Reykjavik, Iceland.
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11
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Torres A, Lee N, Cilloniz C, Vila J, Van der Eerden M. Laboratory diagnosis of pneumonia in the molecular age. Eur Respir J 2016; 48:1764-1778. [PMID: 27811073 DOI: 10.1183/13993003.01144-2016] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 09/17/2016] [Indexed: 01/20/2023]
Abstract
Pneumonia remains a worldwide health problem with a high rate of morbidity and mortality. Identification of microbial pathogens which cause pneumonia is an important area for optimum clinical management of pneumonia patients and is a big challenge for conventional microbiological methods. The development and implementation of molecular diagnostic tests for pneumonia has been a major advance in the microbiological diagnosis of respiratory pathogens in recent years. However, with new knowledge regarding the microbiome, together with the recognition that the lungs are a dynamic microbiological ecosystem, our current concept of pneumonia is not totally realistic as this new concept of pneumonia involves a dysbiosis or alteration of the lung microbiome. A new challenge for microbiologists and clinicians has therefore arisen. There is much to learn regarding the information provided by this new diagnostic technology, which will lead to improvements in the time to antibiotic therapy, targeted antibiotic selection and more effective de-escalation and improved stewardship for pneumonia patients. This article provides an overview of current methods of laboratory diagnosis of pneumonia in the molecular age.
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Affiliation(s)
- Antoni Torres
- Dept of Pneumology, Institut Clinic del Tórax, Hospital Clinic of Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Ciber de Enfermedades Respiratorias (CIBERES), Barcelona, Spain
| | - Nelson Lee
- Division of Infectious Diseases, Dept of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Catia Cilloniz
- Dept of Pneumology, Institut Clinic del Tórax, Hospital Clinic of Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, Ciber de Enfermedades Respiratorias (CIBERES), Barcelona, Spain
| | - Jordi Vila
- Servei de Microbiologia, Hospital Clinic, ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), School of Medicine, Universitat de Barcelona, Barcelona, Spain
| | - Menno Van der Eerden
- Dept of Respiratory Medicine, Erasmus Medical Centre, Rotterdam, The Netherlands
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12
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Hatori K, Ohki S, Miki T, Hirai H, Yasuhara K, Obayashi T. Infected abdominal aortic aneurysm caused by Streptococcus pneumoniae diagnosed using polymerase chain reaction. Surg Case Rep 2016; 1:83. [PMID: 26943412 PMCID: PMC4572041 DOI: 10.1186/s40792-015-0085-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/08/2015] [Indexed: 11/28/2022] Open
Abstract
We report the case of a 55-year-old man who initially visited the emergency department of our hospital owing to fever, headache, and neck stiffness. He was diagnosed with meningitis because cerebrospinal fluid culture was positive for Streptococcus pneumoniae. After intravenous antibiotic treatment, the patient’s condition returned to normal. On hospital day 20, he complained of lumbar pain with abdominal distension. Because an abdominal computed tomography (CT) scan showed a small sacciform infrarenal abdominal aortic aneurysm, an infected aneurysm was suspected. However, cerebrospinal fluid and blood cultures were negative for S. pneumoniae. Seven days later, a second abdominal CT was performed that showed rapid expansion of the sacciform infrarenal abdominal aortic aneurysm. The patient was diagnosed with an infected abdominal aortic aneurysm and underwent surgery for resection of the aneurysm and in situ reconstruction with a rifampicin-soaked vascular prosthesis. Although blood and aneurysmal tissue cultures were negative for S. pneumoniae, the autolysin (lytA) gene, which is the target gene of S. pneumoniae, was detected in the abdominal aortic wall by using polymerase chain reaction (PCR). Therefore, appropriate molecular diagnostic techniques can be used for the rapid detection of pathogens. An accurate diagnosis can be used to direct postoperative antibiotic therapy.
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Affiliation(s)
- Kyohei Hatori
- Department of Cardiovascular Surgery, Isesaki Municipal Hospital, 12-1 Tsunatori-honmachi, Isesaki, Gunma, 372-0812, Japan.
| | - Satoshi Ohki
- Department of Cardiovascular Surgery, Isesaki Municipal Hospital, 12-1 Tsunatori-honmachi, Isesaki, Gunma, 372-0812, Japan
| | - Takao Miki
- Department of Cardiovascular Surgery, Isesaki Municipal Hospital, 12-1 Tsunatori-honmachi, Isesaki, Gunma, 372-0812, Japan
| | - Hanako Hirai
- Department of Cardiovascular Surgery, Isesaki Municipal Hospital, 12-1 Tsunatori-honmachi, Isesaki, Gunma, 372-0812, Japan
| | - Kiyomitsu Yasuhara
- Department of Cardiovascular Surgery, Isesaki Municipal Hospital, 12-1 Tsunatori-honmachi, Isesaki, Gunma, 372-0812, Japan
| | - Tamiyuki Obayashi
- Department of Cardiovascular Surgery, Isesaki Municipal Hospital, 12-1 Tsunatori-honmachi, Isesaki, Gunma, 372-0812, Japan
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13
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Using Nucleic Acid Amplification Techniques in a Syndrome-Oriented Approach: Detection of Respiratory Agents. Mol Microbiol 2016. [DOI: 10.1128/9781555819071.ch25] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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14
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Ganaie FA, Govindan V, Ravi Kumar KL. Standardisation and evaluation of a quantitative multiplex real-time PCR assay for the rapid identification of Streptococcus pneumoniae. Pneumonia (Nathan) 2015; 6:57-66. [PMID: 31641579 PMCID: PMC5922331 DOI: 10.15172/pneu.2015.6/559] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 06/19/2015] [Indexed: 12/14/2022] Open
Abstract
Rapid diagnosis of Streptococcus pneumoniae can play a significant role in decreasing morbidity and mortality of infection. The accurate diagnosis of pneumococcal disease is hampered by the difficulties in growing the isolates from clinical specimens and also by misidentification. Molecular methods have gained popularity as they offer improvement in the detection of causative pathogens with speed and ease. The present study aims at validating and standardising the use of 4 oligonucleotide primer-probe sets (pneumolysin [ply], autolysin [lytA], pneumococcal surface adhesion A [psaA] and Spn9802 [DNA fragment]) in a single-reaction mixture for the detection and discrimination of S. pneumoniae. Here, we validate a quantitative multiplex real-time PCR (qmPCR) assay with a panel consisting of 43 S. pneumoniae and 29 non-pneumococcal isolates, 20 culture positive, 26 culture negative and 30 spiked serum samples. A standard curve was obtained using S. pneumoniae ATCC 49619 strain and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) gene was used as an endogenous internal control. The experiment showed high sensitivity with lower limit of detection equivalent to 4 genome copies/µl. The efficiency of the reaction was 100% for ply, lytA, Spn9802 and 97% for psaA. The test showed sensitivity and specificity of 100% with culture isolates and serum specimens. This study demonstrates that qmPCR analysis of sera using 4 oligonucleotide primers appears to be an appropriate method for the genotypic identification of S. pneumoniae infection.
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Affiliation(s)
- Feroze A Ganaie
- Department of Microbiology, Kempegowda Institute of Medical Sciences, Hospital and Research Centre, K.R Road, V.V Puram, Bangalore, 560004 India
| | - Vandana Govindan
- Department of Microbiology, Kempegowda Institute of Medical Sciences, Hospital and Research Centre, K.R Road, V.V Puram, Bangalore, 560004 India
| | - K L Ravi Kumar
- Department of Microbiology, Kempegowda Institute of Medical Sciences, Hospital and Research Centre, K.R Road, V.V Puram, Bangalore, 560004 India
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15
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Kalia VC, Kumar R, Kumar P, Koul S. A Genome-Wide Profiling Strategy as an Aid for Searching Unique Identification Biomarkers for Streptococcus. Indian J Microbiol 2015; 56:46-58. [PMID: 26843696 DOI: 10.1007/s12088-015-0561-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 11/13/2015] [Indexed: 12/19/2022] Open
Abstract
The use of rrs (16S rRNA) gene is widely regarded as the "gold standard" for identifying bacteria and determining their phylogenetic relationships. Nevertheless, multiple copies of this gene in a genome is likely to give an overestimation of the bacterial diversity. In each of the 50 Streptococcus genomes (16 species, 50 strains), 4-7 copies of rrs are present. The nucleotide sequences of these rrs genes show high similarity within and among genomes, which did not allow unambiguous identification. A genome-wide search revealed the presence of 27 gene sequences common to all the Streptococcus species. Digestion of these 27 gene sequences with 10 type II restriction endonucleases (REs) showed that unique RE digestion in purH gene is sufficient for clear cut identification of 30 genomes belonging to 16 species. Additional gene-RE combinations allowed identification of another 15 strains belonging to S. pneumoniae, S. pyogenes, and S. suis. For the rest 5 strains, a combination of 2 genes was required for identifying them. The proposed strategy is likely to prove helpful in proper detection of pathogens like Streptococcus.
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Affiliation(s)
- Vipin Chandra Kalia
- Microbial Biotechnology and Genomics, CSIR - Institute of Genomics and Integrative Biology (IGIB), Delhi University Campus, Mall Road, Delhi, 110007 India ; Academy of Scientific and Innovative Research (AcSIR), 2, Rafi Marg, Anusandhan Bhawan, New Delhi, 110001 India
| | - Ravi Kumar
- Microbial Biotechnology and Genomics, CSIR - Institute of Genomics and Integrative Biology (IGIB), Delhi University Campus, Mall Road, Delhi, 110007 India
| | - Prasun Kumar
- Microbial Biotechnology and Genomics, CSIR - Institute of Genomics and Integrative Biology (IGIB), Delhi University Campus, Mall Road, Delhi, 110007 India
| | - Shikha Koul
- Microbial Biotechnology and Genomics, CSIR - Institute of Genomics and Integrative Biology (IGIB), Delhi University Campus, Mall Road, Delhi, 110007 India ; Academy of Scientific and Innovative Research (AcSIR), 2, Rafi Marg, Anusandhan Bhawan, New Delhi, 110001 India
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16
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McHugh MP, Gray SJ, Kaczmarski EB, Guiver M. Reduced turnaround time and improved diagnosis of invasive serogroup B Neisseria meningitidis and Streptococcus pneumoniae infections using a lyophilized quadruplex quantitative PCR. J Med Microbiol 2015; 64:1321-1328. [DOI: 10.1099/jmm.0.000154] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Martin P. McHugh
- Meningococcal Reference Unit, Public Health England, Manchester Laboratory, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, UK
| | - Steve J. Gray
- Meningococcal Reference Unit, Public Health England, Manchester Laboratory, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, UK
| | - Edward B. Kaczmarski
- Meningococcal Reference Unit, Public Health England, Manchester Laboratory, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, UK
| | - Malcolm Guiver
- Meningococcal Reference Unit, Public Health England, Manchester Laboratory, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, UK
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17
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Comparison of Binax NOW urine antigen test and pneumococcal DNA assay using qPCR before and after nasopharyngeal swabbing in healthy Malawian children. New Microbes New Infect 2015; 8:4-6. [PMID: 26543561 PMCID: PMC4589840 DOI: 10.1016/j.nmni.2015.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Revised: 07/10/2015] [Accepted: 08/07/2015] [Indexed: 11/29/2022] Open
Abstract
Diagnosis of invasive pneumococcal disease is challenging. We compared Binax NOW pneumococcal urinary antigen test with blood pneumococcal PCR in healthy Malawian children with and without pneumococcal carriage, and we found a high false-positive rate with Binax NOW. Blood pneumococcal PCR positivity was 66/88 (75%) compared to 5/27 (18%) when nasopharyngeal swabbing was performed first compared to after blood sampling for pneumococcal blood PCR. We speculate that nasopharyngeal swabbing may be causing a breach of mucosal integrity, leading to invasion into the bloodstream. These findings need to be confirmed with autolysin-based PCR assays.
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18
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Detection and prediction of Streptococcus pneumoniae serotypes directly from nasopharyngeal swabs using PCR. J Med Microbiol 2015; 64:836-844. [DOI: 10.1099/jmm.0.000097] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Hirvonen JJ, Seiskari T, Harju I, Rantakokko-Jalava K, Vuento R, Aittoniemi J. Use of an automated PCR assay, the GenomEra S. pneumoniae, for rapid detection of Streptococcus pneumoniae in blood cultures. Infect Dis (Lond) 2015; 47:796-800. [PMID: 26162002 DOI: 10.3109/23744235.2015.1063157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Streptococcus pneumoniae is recognized as a major cause of pneumonia, meningitis, and bacteremia. Since the mortality rate for pneumococcal bacteremia remains high, the reliable detection of the bacterium in blood samples is important. In this study, the performance of a new automated PCR assay, the GenomEra(™) S. pneumoniae, for direct detection of S. pneumoniae in blood cultures was investigated. METHODS In total, 200 samples were analyzed, including 90 previously identified culture collection isolates and 110 blood culture specimens. The species identification was confirmed with routine diagnostic methods including MALDI-TOF or 16S rDNA sequencing. RESULTS From culture collection, the GenomEra S. pneumoniae assay correctly identified all 37 S. pneumoniae isolates consisting of 18 different serotypes, while all 53 non-S. pneumoniae isolates yielded negative test results. Of 110 blood culture specimens, 46 grew S. pneumoniae and all were positive by the GenomEra assay direct from bottle. The detection sensitivity and specificity of the GenomEra assay for direct analysis of S. pneumoniae in signal positive blood culture bottles was 100%, respectively. With a straightforward sample preparation protocol of blood cultures the results were available within 55 min, thus being significantly quicker than by the routinely used identification methods (18-48 h). The two-step, time-resolved fluorometric measurement mode employed by the GenomEra CDX(™) instrument showed no interference from blood or charcoal. CONCLUSION The GenomEra S. pneumoniae assay is a tool that performs well for the rapid and reliable detection of S. pneumoniae in blood cultures.
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20
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Elberse K, van Mens S, Cremers AJ, Meijvis SCA, Vlaminckx B, de Jonge MI, Meis JF, Blauwendraat C, van de Pol I, Schouls LM. Detection and serotyping of pneumococci in community acquired pneumonia patients without culture using blood and urine samples. BMC Infect Dis 2015; 15:56. [PMID: 25885896 PMCID: PMC4330648 DOI: 10.1186/s12879-015-0788-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 01/29/2015] [Indexed: 11/23/2022] Open
Abstract
Background Treatment of community acquired pneumonia (CAP) patients with antibiotics before laboratory-confirmed diagnosis leads to loss of knowledge on the causative bacterial pathogen. Therefore, an increasing number of pneumococcal infections is identified using non-culture based techniques. However, methods for serotyping directly on the clinical specimen remain scarce. Here we present three approaches for detection and serotyping of pneumococci using samples from patients with CAP. Methods The first approach is quantitative PCR (qPCR) analysis on blood samples (n = 211) followed by capsular sequence typing (CST) to identify the serotype. The second approach, a urinary antigen assay (n = 223), designated as inhibition multiplex immunoassay (IMIA), is based on Luminex technology targeting 14 serotypes. The third approach is a multiplex immunoassay (MIA) (n = 171) also based on Luminex technology which detects serologic antibody responses against 14 serotypes. The three alternative assays were performed on samples obtained from 309 adult hospitalized CAP patients in 2007–2010 and the results were compared with those obtained from conventional laboratory methods to detect pneumococcal CAP, i.e. blood cultures, sputum cultures and BinaxNOW® urinary antigen tests. Results Using qPCR, MIA and IMIA, we were able to detect the pneumococcus in samples of 56% more patients compared to conventional methods. Furthermore, we were able to assign a serotype to the infecting pneumococcus from samples of 25% of all CAP patients, using any of the three serotyping methods (CST, IMIA and MIA). Conclusion This study indicates the usefulness of additional molecular methods to conventional laboratory methods for the detection of pneumococcal pneumonia. Direct detection and subsequent serotyping on clinical samples will improve the accuracy of pneumococcal surveillance to monitor vaccine effectiveness.
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Affiliation(s)
- Karin Elberse
- Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Laboratory for Infectious Diseases and Perinatal Screening, Antonie van Leeuwenhoeklaan 9, P.O.Box 1, 3720 BA, Bilthoven, The Netherlands.
| | - Suzan van Mens
- Departments of Medical Microbiology & Immunology, Sint Antonius Hospital Nieuwegein, P.O box 2500, 3430 EM, Nieuwegein, The Netherlands.
| | - Amelieke J Cremers
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525 GA, Nijmegen, The Netherlands. .,Laboratory of Medical Immunology, Department of Laboratory Medicine, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525 GA, Nijmegen, The Netherlands.
| | - Sabine C A Meijvis
- Department of Internal medicine, Sint Antonius Hospital Nieuwegein, P.O box 2500, 3430 EM, Nieuwegein, The Netherlands.
| | - Bart Vlaminckx
- Departments of Medical Microbiology & Immunology, Sint Antonius Hospital Nieuwegein, P.O box 2500, 3430 EM, Nieuwegein, The Netherlands.
| | - Marien I de Jonge
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525 GA, Nijmegen, The Netherlands. .,Laboratory of Medical Immunology, Department of Laboratory Medicine, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525 GA, Nijmegen, The Netherlands.
| | - Jacques F Meis
- Department of Medical Microbiology, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525 GA, Nijmegen, The Netherlands. .,Department of Medical Microbiology and Infectious Diseases, Canisius Wilhelmina Hospital, Weg door Jonkerbos 100, 6532 SZ, Nijmegen, The Netherlands.
| | - Cornelis Blauwendraat
- Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Laboratory for Infectious Diseases and Perinatal Screening, Antonie van Leeuwenhoeklaan 9, P.O.Box 1, 3720 BA, Bilthoven, The Netherlands.
| | - Ingrid van de Pol
- Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Laboratory for Infectious Diseases and Perinatal Screening, Antonie van Leeuwenhoeklaan 9, P.O.Box 1, 3720 BA, Bilthoven, The Netherlands.
| | - Leo M Schouls
- Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), Laboratory for Infectious Diseases and Perinatal Screening, Antonie van Leeuwenhoeklaan 9, P.O.Box 1, 3720 BA, Bilthoven, The Netherlands.
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Athlin S, Kaltoft M, Slotved HC, Herrmann B, Holmberg H, Konradsen HB, Strålin K. Association between serotype-specific antibody response and serotype characteristics in patients with pneumococcal pneumonia, with special reference to degree of encapsulation and invasive potential. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 21:1541-9. [PMID: 25230937 PMCID: PMC4248763 DOI: 10.1128/cvi.00259-14] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 08/30/2014] [Indexed: 11/20/2022]
Abstract
We studied the immunoglobulin (Ig) response to causative serotype-specific capsular polysaccharides in adult pneumococcal pneumonia patients. The serotypes were grouped according to their degree of encapsulation and invasive potential. Seventy patients with pneumococcal pneumonia, 20 of whom were bacteremic, were prospectively studied. All pneumococcal isolates from the patients were serotyped, and the Ig titers to the homologous serotype were determined in acute- and convalescent-phase sera using a serotype-specific enzyme-linked immunosorbent assay. The Ig titers were lower in bacteremic cases than in nonbacteremic cases (P < 0.042). The Ig titer ratio (convalescent/acute titer) was ≥2 in 33 patients, 1 to 1.99 in 20 patients, and <1 in 17 patients. Patients ≥65 years old had a lower median Ig titer ratio than did younger patients (P < 0.031). The patients with serotypes with a thin capsule (1, 4, 7F, 9N, 9V, and 14) and medium/high invasive potential (1, 4, 7F, 9N, 9V, 14, and 18C) had higher Ig titer ratios than did patients with serotypes with a thick capsule (3, 6B, 11A, 18C, 19A, 19F, and 23F) and low invasive potential (3, 6B, 19A, 19F, and 23F) (P < 0.05 for both comparisons after adjustment for age). Ig titer ratios of <1 were predominantly noted in patients with serotypes with a thick capsule. In 8 patients with pneumococcal DNA detected in plasma, the three patients with the highest DNA load had the lowest Ig titer ratios. In conclusion, a high antibody response was associated with serotypes with a thin capsule and medium/high invasive potential, although a low antibody response was associated with serotypes with a thick capsule and a high pneumococcal plasma load.
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Affiliation(s)
- Simon Athlin
- Department of Infectious Diseases, Örebro University Hospital, Örebro, Sweden
| | | | | | - Björn Herrmann
- Section of Clinical Microbiology, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Hans Holmberg
- Department of Infectious Diseases, Örebro University Hospital, Örebro, Sweden
| | | | - Kristoffer Strålin
- Department of Infectious Diseases, Örebro University Hospital, Örebro, Sweden Department of Medicine, Division of Infectious Diseases, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden
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Integration of clinical point-of-care requirements in a DNA microarray genotyping test. Biosens Bioelectron 2014; 61:605-11. [DOI: 10.1016/j.bios.2014.05.071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/07/2014] [Accepted: 05/22/2014] [Indexed: 11/20/2022]
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Abstract
Community-acquired pneumonia is one of the most common reasons for emergency department (ED) visits in children and adults. Despite its prevalence, there are many challenges to proper diagnosis and management of pneumonia. There is no accurate and timely etiologic gold standard to differentiate bacterial from viral disease, and there are limitations with precise risk stratification of patients to ensure appropriate site-of-care decisions. Clinical factors obtained by history and physical examination have limited the ability to diagnose pneumonia etiology and severity. Biomarkers offer information about the host response to infection and pathogen activity within the host that can serve to augment clinical features in decision-making. As science and technology progress, novel biomarkers offer great potential in aiding critical decisions for patients with pneumonia. This review summarizes existing knowledge about biomarkers of host response and pathogen activity, in addition to briefly reviewing emerging biomarkers using novel technologies.
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Dhoubhadel BG, Yasunami M, Yoshida LM, Thi HAN, Thi THV, Thi TAN, Watanabe K, Suzuki M, Morimoto K, Dang DA, Ariyoshi K. A novel high-throughput method for molecular serotyping and serotype-specific quantification of Streptococcus pneumoniae using a nanofluidic real-time PCR system. J Med Microbiol 2014; 63:528-539. [PMID: 24464695 DOI: 10.1099/jmm.0.071464-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Serotype-specific quantification data are essential for elucidating the complex epidemiology of Streptococcus pneumoniae and evaluating pneumococcal vaccine efficacy. Various PCR-based assays have been developed to circumvent the drawback of labour-intensive and time-consuming culture-based procedures for serotype determination and quantification of pneumococcus. Here, we applied a nanofluidic real-time PCR system to establish a novel assay. Twenty-nine primer pairs, 13 of which were newly designed, were selected for the assay to cover 50 serotypes including all currently available conjugate and polysaccharide vaccine serotypes. All primer pairs were evaluated for their sensitivity, specificity, efficiency, repeatability, accuracy and reproducibility on the Fluidigm Biomark HD System, a nanofluidic real-time PCR system, by drawing standard curves with a serial dilution of purified DNA. We applied the assay to 52 nasopharyngeal swab samples from patients with pneumonia confirmed by chest X-ray to validate its accuracy. Minimum detection levels of this novel assay using the nanofluidic real-time PCR system were comparable to the conventional PCR-based assays (between 30 and 300 copies per reaction). They were specific to their targets with good repeatability (sd of copy number of 0.1), accuracy (within ±0.1 fold difference in log10 copy number) and reproducibility (sd of copy number of 0.1). When artificially mixed DNA samples consisting of multiple serotypes in various ratios were tested, all the serotypes were detected proportionally, including a minor serotype of one in 1000 copies. In the nasopharyngeal samples, the PCR system detected all the culture-positive samples and 22 out of 23 serotypes identified by the conventional method were matched with PCR results. We conclude that this novel assay, which is able to differentially quantify 29 pneumococcus groups for 45 test samples in a single run, is applicable to the large-scale epidemiological study of pneumococcus. We believe that this assay will facilitate our understanding of the roles of serotype-specific bacterial loads and implications of multiple serotype detections in pneumococcal diseases.
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Affiliation(s)
- Bhim Gopal Dhoubhadel
- Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Japan
| | - Michio Yasunami
- Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Japan
| | - Lay-Myint Yoshida
- Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Japan
| | - Hien Anh Nguyen Thi
- Department of Bacteriology, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | - Thu Huong Vu Thi
- Department of Bacteriology, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | - Thuy Ai Nguyen Thi
- Department of Microbiology, Khanh Hoa General Hospital, NhaTrang, Vietnam
| | - Kiwao Watanabe
- Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Japan
| | - Motoi Suzuki
- Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Japan
| | - Konosuke Morimoto
- Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Japan
| | - Duc Anh Dang
- Department of Bacteriology, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | - Koya Ariyoshi
- Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Japan
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25
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Cremers AJH, Hagen F, Hermans PWM, Meis JF, Ferwerda G. Diagnostic value of serum pneumococcal DNA load during invasive pneumococcal infections. Eur J Clin Microbiol Infect Dis 2014; 33:1119-24. [PMID: 24449347 DOI: 10.1007/s10096-014-2050-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2013] [Accepted: 01/03/2014] [Indexed: 10/25/2022]
Abstract
Detection of pneumococcal DNA in blood could be a fast alternative for blood culture in invasive pneumococcal disease (IPD). In this study we compared the diagnostic value of the serum pneumococcal DNA load between different clinical syndromes in adults with bacteremic pneumococcal infections, also after initiation of antibiotic treatment. Adults hospitalized with a blood culture proven pneumococcal infection between December 2008 and June 2013 were retrospectively included. Pneumococcal DNA loads in corresponding serum samples were determined by qPCR. Data on clinical diagnosis, course of disease and antibiotic treatment were extracted from medical records. For 53 IPD cases eligible stored serum samples were retrieved. The proportion of samples positive in qPCR was lower in uncomplicated pneumonia compared with other clinical syndromes (59.5 % vs. 100 %, p = 0.005). The pneumococcal DNA load was higher in cases other than uncomplicated pneumonia (p = 0.043) as well as in more severe disease (p-values 0.018, 0.029 and 0.003 for PSI Risk Class IV/V, ICU admission and mortality, respectively). Both detection of pneumococcal DNA and distribution of load did not significantly change over the first days of hospitalization despite treatment with appropriate antibiotics. Detection of pneumococcal DNA in serum was more sensitive in clinical syndromes other than uncomplicated pneumonia. Furthermore, the pneumococcal DNA load was associated with the type of IPD and severity of disease. Since the serum pneumococcal DNA load seemed unaffected by antibiotic treatment during the first days of IPD, it may offer an alternative for culture methods after prior antibiotic use.
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Affiliation(s)
- A J H Cremers
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboudumc, PO box 9101, 6500 HB, Nijmegen, The Netherlands,
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26
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Song JY, Eun BW, Nahm MH. Diagnosis of pneumococcal pneumonia: current pitfalls and the way forward. Infect Chemother 2013; 45:351-66. [PMID: 24475349 PMCID: PMC3902818 DOI: 10.3947/ic.2013.45.4.351] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Indexed: 02/02/2023] Open
Abstract
Streptococcus pneumoniae is the most common cause of community-acquired pneumonia. However, it can also asymptomatically colonize the upper respiratory tract. Because of the need to distinguish between S. pneumoniae that is simply colonizing the upper respiratory tract and S. pneumoniae that is causing pneumonia, accurate diagnosis of pneumococcal pneumonia is a challenging issue that still needs to be solved. Sputum Gram stains and culture are the first diagnostic step for identifying pneumococcal pneumonia and provide information on antibiotic susceptibility. However, these conventional methods are relatively slow and insensitive and show limited specificity. In the past decade, new diagnostic tools have been developed, particularly antigen (teichoic acid and capsular polysaccharides) and nucleic acid (ply, lytA, and Spn9802) detection assays. Use of the pneumococcal antigen detection methods along with biomarkers (C-reactive protein and procalcitonin) may enhance the specificity of diagnosis for pneumococcal pneumonia. This article provides an overview of current methods of diagnosing pneumococcal pneumonia and discusses new and future test methods that may provide the way forward for improving its diagnosis.
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Affiliation(s)
- Joon Young Song
- Division of Infectious Diseases, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
| | - Byung Wook Eun
- Department of Pediatrics, Eulji General Hospital, Seoul, Korea
| | - Moon H Nahm
- Department of Pathology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA. ; Department of Microbiology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
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27
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Comparison of sputum and nasopharyngeal aspirate samples and of the PCR gene targets lytA and Spn9802 for quantitative PCR for rapid detection of pneumococcal pneumonia. J Clin Microbiol 2013; 52:83-9. [PMID: 24153121 DOI: 10.1128/jcm.01742-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We aimed to compare sputum and nasopharyngeal aspirate (NpA) samples and the PCR gene targets lytA and Spn9802 in quantitative PCR (qPCR) assays for rapid detection of pneumococcal etiology in community-acquired pneumonia (CAP). Seventy-eight adult patients hospitalized for radiologically confirmed CAP had both good-quality sputum and NpA specimens collected at admission. These samples were subjected to lytA qPCR and Spn9802 qPCR assays with analytical times of <3 h. Thirty-two patients had CAP with a pneumococcal etiology, according to conventional diagnostic criteria. The following qPCR positivity rates were noted in CAP cases with and without pneumococcal etiology: 96% and 15% (sputum lytA assay), 96% and 17% (sputum Spn9802 assay), 81% and 11% (NpA lytA assay), and 81% and 20% (NpA Spn9802 assay), respectively. The mean lytA and Spn9802 DNA levels were significantly higher in qPCR-positive sputum samples from cases with pneumococcal etiology than in qPCR-positive sputum samples from CAP cases without pneumococcal etiology or qPCR-positive NpA samples from cases with pneumococcal etiology (P < 0.02 for all comparisons). For detection of pneumococcal etiology, receiver operating characteristic curve analysis showed that sputum specimens were superior to NpA specimens as the sample type (P < 0.02 for both gene targets) and lytA tended to be superior to Spn9802 as the gene target. The best-performing test, the sputum lytA qPCR assay, showed high sensitivity (94%) and specificity (96%) with a cutoff value of 10(5) DNA copies/ml. In CAP patients with good sputum production, this test has great potential to be used for the rapid detection of pneumococcal etiology and to target penicillin therapy.
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28
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Cvitkovic Spik V, Beovic B, Pokorn M, Drole Torkar A, Vidmar D, Papst L, Seme K, Kogoj R, Müller Premru M. Improvement of pneumococcal pneumonia diagnostics by the use of rt-PCR on plasma and respiratory samples. ACTA ACUST UNITED AC 2013; 45:731-7. [PMID: 23826792 DOI: 10.3109/00365548.2013.804631] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND The aim of the study was to assess the performance of a real-time polymerase chain reaction (rt-PCR) assay on plasma and respiratory samples for the diagnosis of pneumococcal pneumonia. METHODS Three hundred and forty patients (160 children and 180 adults) with community-acquired pneumonia were included prospectively from January 2011 to May 2012. Blood samples were obtained simultaneously for culture and rt-PCR targeting the lytA gene. Respiratory samples were also obtained: nasopharyngeal swab in nearly all patients and sputum or tracheal aspirate when available. RESULTS Streptococcus pneumoniae was detected in 222 (65%) of 340 patients: 143 (89%) children and 79 (44%) adults. Pneumonia was assigned as definite pneumococcal in 96 (28.2%) of 340 patients, according to S. pneumoniae detected in blood: in 54 (33.8%) children - by rt-PCR in 51 (31.9%) and by culture in 5 (3.1%); and in 42 (23.3%) adults - by rt-PCR in 41 (22.8%) and by culture in 12 (6.7%). Pneumonia was considered as probably pneumococcal in 19 (10.6%) adults according to S. pneumoniae detected in sputum/tracheal aspirate, by rt-PCR in 19 and by culture in 5. In 18 adults and 89 children with S. pneumoniae detected only in the nasopharynx, pneumonia was considered as possibly pneumococcal; however it should be noted that nasopharyngeal colonization with S. pneumoniae is also common in children with other aetiologies of pneumonia. CONCLUSIONS rt-PCR on plasma and other samples performed significantly better than culture for the detection of pneumococcal pneumonia (p < 0.0005) in children and adults.
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Affiliation(s)
- Vesna Cvitkovic Spik
- From the Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana
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29
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Abstract
In recent years, quantitative real-time PCR tests have been extensively developed in clinical microbiology laboratories for routine diagnosis of infectious diseases, particularly bacterial diseases. This molecular tool is well-suited for the rapid detection of bacteria directly in clinical specimens, allowing early, sensitive and specific laboratory confirmation of related diseases. It is particularly suitable for the diagnosis of infections caused by fastidious growth species, and the number of these pathogens has increased recently. This method also allows a rapid assessment of the presence of antibiotic resistance genes or gene mutations. Although this genetic approach is not always predictive of phenotypic resistances, in specific situations it may help to optimize the therapeutic management of patients. Finally, an approach combining the detection of pathogens, their mechanisms of antibiotic resistance, their virulence factors and bacterial load in clinical samples could lead to profound changes in the care of these infected patients.
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Affiliation(s)
- Max Maurin
- Laboratoire de Bactériologie, Département des Agents Infectieux, Institut de Biologie et Pathologie, CHU de Grenoble, Université Joseph Fourier Grenoble 1, France.
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30
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Rolo D, S. Simões A, Domenech A, Fenoll A, Liñares J, de Lencastre H, Ardanuy C, Sá-Leão R. Disease isolates of Streptococcus pseudopneumoniae and non-typeable S. pneumoniae presumptively identified as atypical S. pneumoniae in Spain. PLoS One 2013; 8:e57047. [PMID: 23437306 PMCID: PMC3578818 DOI: 10.1371/journal.pone.0057047] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 01/16/2013] [Indexed: 11/27/2022] Open
Abstract
We aimed to obtain insights on the nature of a collection of isolates presumptively identified as atypical Streptococcus pneumoniae recovered from invasive and non-invasive infections in Spain. One-hundred and thirty-two isolates were characterized by: optochin susceptibility in ambient and CO2-enriched atmosphere; bile solubility; PCR-based assays targeting pneumococcal genes lytA, ply, pspA, cpsA, Spn9802, aliB-like ORF2, and a specific 16S rRNA region; multilocus sequence analysis; and antimicrobial susceptibility. By multilocus sequence analysis, 61 isolates were S. pseudopneumoniae, 34 were pneumococci, 13 were S. mitis, and 24 remained unclassified as non-pneumococci. Among S. pseudopneumoniae isolates, 51 (83.6%) were collected from respiratory tract samples; eight isolates were obtained from sterile sources. High frequency of non-susceptibility to penicillin (60.7%) and erythromycin (42.6%) was found. Only 50.8% of the S. pseudopneumoniae isolates displayed the typical optochin phenotype originally described for this species. None harbored the cpsA gene or the pneumococcal typical lytA restriction fragment length polymorphism. The Spn9802 and the specific 16S rRNA regions were detected among the majority of the S. pseudopneumoniae isolates (n = 59 and n = 49, respectively). The ply and pspA genes were rarely found. A high genetic diversity was found and 59 profiles were identified. Among the S. pneumoniae, 23 were capsulated and 11 were non-typeable. Three non-typeable isolates, associated to international non-capsulated lineages, were recovered from invasive disease sources. In conclusion, half of the atypical pneumococcal clinical isolates were, in fact, S. pseudopneumoniae and one-fourth were other streptococci. We identified S. pseudopneumoniae and non-typeable pneumococci as cause of disease in Spain including invasive disease.
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Affiliation(s)
- Dora Rolo
- Institut d'Investigació Biomèdica de Bellvitge, Hospital Universitari de Bellvitge, Microbiology Department, Universistat de Barcelona, Barcelona, Spain
- Centro de investigación en red de enfermedades respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Alexandra S. Simões
- Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Arnau Domenech
- Institut d'Investigació Biomèdica de Bellvitge, Hospital Universitari de Bellvitge, Microbiology Department, Universistat de Barcelona, Barcelona, Spain
- Centro de investigación en red de enfermedades respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Asunción Fenoll
- National Center for Microbiology, Instituto de Salud Carlos III, Madrid, Spain
| | - Josefina Liñares
- Institut d'Investigació Biomèdica de Bellvitge, Hospital Universitari de Bellvitge, Microbiology Department, Universistat de Barcelona, Barcelona, Spain
- Centro de investigación en red de enfermedades respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Hermínia de Lencastre
- Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- Laboratory of Microbiology, The Rockefeller University, New York, New York, United States of America
| | - Carmen Ardanuy
- Institut d'Investigació Biomèdica de Bellvitge, Hospital Universitari de Bellvitge, Microbiology Department, Universistat de Barcelona, Barcelona, Spain
- Centro de investigación en red de enfermedades respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Raquel Sá-Leão
- Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- * E-mail:
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31
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Williams DJ, Shah SS. Community-Acquired Pneumonia in the Conjugate Vaccine Era. J Pediatric Infect Dis Soc 2012; 1:314-28. [PMID: 26619424 PMCID: PMC7107441 DOI: 10.1093/jpids/pis101] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 10/05/2012] [Indexed: 12/27/2022]
Abstract
Community-acquired pneumonia (CAP) remains one of the most common serious infections encountered among children worldwide. In this review, we highlight important literature and recent scientific discoveries that have contributed to our current understanding of pediatric CAP. We review the current epidemiology of childhood CAP in the developed world, appraise the state of diagnostic testing for etiology and prognosis, and discuss disease management and areas for future research in the context of recent national guidelines.
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Affiliation(s)
- Derek J. Williams
- Division of Hospital Medicine, The Monroe Carell Jr Children's Hospital at Vanderbilt, and,Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee; Divisions of,Corresponding Author: Derek J. Williams, MD, MPH, 1161 21st Ave. South, CCC 5311 Medical Center North, Nashville, TN 37232. E-mail: derek.
| | - Samir S. Shah
- Infectious Diseases and,Hospital Medicine, Cincinnati Children's Hospital Medical Center,Department of Pediatrics, University of Cincinnati College of Medicine, Ohio
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32
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Abstract
Acute bacterial meningitis causes a substantial number of deaths in Cameroon. Among 170 children with acute meningitis, 112 were positive for a bacterial pathogen when tested using polymerase chain reaction amplification, and Streptococcus pneumoniae accounted for 57.1% of cases. Pneumococcal serotype coverage by 13-valent pneumococcal conjugate vaccine was 62.1%. This study shows that in Cameroon, 13-valent pneumococcal conjugate vaccine coverage is less than what is estimated for other African countries.
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33
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Dugard A, Chainier D, Barraud O, Garnier F, Ploy MC, Vignon P, François B. Early bacterial genome detection in body fluids from patients with severe sepsis: A pilot study. J Crit Care 2012; 27:416.e1-6. [DOI: 10.1016/j.jcrc.2011.11.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 11/03/2011] [Accepted: 11/07/2011] [Indexed: 10/14/2022]
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34
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Werno AM, Anderson TP, Murdoch DR. Association between pneumococcal load and disease severity in adults with pneumonia. J Med Microbiol 2012; 61:1129-1135. [DOI: 10.1099/jmm.0.044107-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Anja M. Werno
- Department of Pathology, University of Otago, Christchurch, New Zealand
- Microbiology Unit, Canterbury Health Laboratories, Christchurch, New Zealand
| | - Trevor P. Anderson
- Microbiology Unit, Canterbury Health Laboratories, Christchurch, New Zealand
| | - David R. Murdoch
- Department of Pathology, University of Otago, Christchurch, New Zealand
- Microbiology Unit, Canterbury Health Laboratories, Christchurch, New Zealand
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35
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Spindler C, Strålin K, Eriksson L, Hjerdt-Goscinski G, Holmberg H, Lidman C, Nilsson A, Ortqvist A, Hedlund J. Swedish guidelines on the management of community-acquired pneumonia in immunocompetent adults--Swedish Society of Infectious Diseases 2012. ACTA ACUST UNITED AC 2012; 44:885-902. [PMID: 22830356 DOI: 10.3109/00365548.2012.700120] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This document presents the 2012 evidence based guidelines of the Swedish Society of Infectious Diseases for the in- hospital management of adult immunocompetent patients with community-acquired pneumonia (CAP). The prognostic score 'CRB-65' is recommended for the initial assessment of all CAP patients, and should be regarded as an aid for decision-making concerning the level of care required, microbiological investigation, and antibiotic treatment. Due to the favourable antibiotic resistance situation in Sweden, an initial narrow-spectrum antibiotic treatment primarily directed at Streptococcus pneumoniae is recommended in most situations. The recommended treatment for patients with severe CAP (CRB-65 score 2) is penicillin G in most situations. In critically ill patients (CRB-65 score 3-4), combination therapy with cefotaxime/macrolide or penicillin G/fluoroquinolone is recommended. A thorough microbiological investigation should be undertaken in all patients, including blood cultures, respiratory tract sampling, and urine antigens, with the addition of extensive sampling for more uncommon respiratory pathogens in the case of severe disease. Recommended measures for the prevention of CAP include vaccination for influenza and pneumococci, as well as smoking cessation.
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Affiliation(s)
- Carl Spindler
- Department of Infectious Diseases, Karolinska University Hospital, Stockholm.
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36
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Evaluation of several biochemical and molecular techniques for identification of Streptococcus pneumoniae and Streptococcus pseudopneumoniae and their detection in respiratory samples. J Clin Microbiol 2012; 50:1171-7. [PMID: 22278834 DOI: 10.1128/jcm.06609-11] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The identification and detection of mitis group streptococci, which contain Streptococcus pneumoniae, have been hampered by the lack of sensitive and specific assays. In this study, we evaluated several biochemical and molecular assays for the identification of S. pneumoniae and Streptococcus pseudopneumoniae and their distinction from other mitis group streptococci using a collection of 54 isolates obtained by the routine culturing of 53 respiratory specimens from patients with community-acquired pneumonia. The combined results of the biochemical and molecular assays indicated the presence of 23 S. pneumoniae, 2 S. pseudopneumoniae, and 29 other mitis group streptococcal isolates. The tube bile solubility test that is considered gold standard for the identification of S. pneumoniae showed concordant results with optochin susceptibility testing (CO(2) atmosphere) and a real-time multiplex PCR assay targeting the Spn9802 fragment and the autolysin gene. Optochin susceptibility testing upon incubation in an O(2) atmosphere, bile solubility testing by oxgall disk, matrix-assisted laser desorption ionization-time of flight mass spectrometry, and sequence analysis of the tuf and rpoB genes resulted in several false-positive, false-negative, or inconclusive results. The S. pseudopneumoniae isolates could be identified only by molecular assays, and the multiplex real-time PCR assay was concluded to be most convenient for the identification of S. pneumoniae and S. pseudopneumoniae isolates. Using this method, S. pneumoniae and S. pseudopneumoniae DNA could be detected in the respiratory samples from which they were isolated and in an additional 11 samples from which only other streptococci were isolated.
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37
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Woodhead M, Blasi F, Ewig S, Garau J, Huchon G, Ieven M, Ortqvist A, Schaberg T, Torres A, van der Heijden G, Read R, Verheij TJM. Guidelines for the management of adult lower respiratory tract infections--summary. Clin Microbiol Infect 2012; 17 Suppl 6:1-24. [PMID: 21951384 DOI: 10.1111/j.1469-0691.2011.03602.x] [Citation(s) in RCA: 195] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.
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Affiliation(s)
- M Woodhead
- Department of Respiratory Medicine, Manchester Royal Infirmary, Oxford Road, Manchester, UK.
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38
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Woodhead M, Blasi F, Ewig S, Garau J, Huchon G, Ieven M, Ortqvist A, Schaberg T, Torres A, van der Heijden G, Read R, Verheij TJM. Guidelines for the management of adult lower respiratory tract infections--full version. Clin Microbiol Infect 2011; 17 Suppl 6:E1-59. [PMID: 21951385 PMCID: PMC7128977 DOI: 10.1111/j.1469-0691.2011.03672.x] [Citation(s) in RCA: 592] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. Background sections and graded evidence tables are also included. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.
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Affiliation(s)
- M Woodhead
- Department of Respiratory Medicine, Manchester Royal Infirmary, Oxford Road, Manchester, UK.
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39
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Harrison OB, Brueggemann AB, Caugant DA, van der Ende A, Frosch M, Gray S, Heuberger S, Krizova P, Olcen P, Slack M, Taha MK, Maiden MCJ. Molecular typing methods for outbreak detection and surveillance of invasive disease caused by Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae, a review. MICROBIOLOGY (READING, ENGLAND) 2011; 157:2181-2195. [PMID: 21622526 PMCID: PMC3980633 DOI: 10.1099/mic.0.050518-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Invasive disease caused by the encapsulated bacteria Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae remains an important cause of morbidity and mortality worldwide, despite the introduction of successful conjugate polysaccharide vaccines that target disease-associated strains. In addition, resistance, or more accurately reduced susceptibility, to therapeutic antibiotics is spreading in populations of these organisms. There is therefore a continuing requirement for the surveillance of vaccine and non-vaccine antigens and antibiotic susceptibilities among isolates from invasive disease, which is only partially met by conventional methods. This need can be met with molecular and especially nucleotide sequence-based typing methods, which are fully developed in the case of N. meningitidis and which could be more widely deployed in clinical laboratories for S. pneumoniae and H. influenzae.
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Affiliation(s)
- Odile B. Harrison
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
| | | | - Dominique A. Caugant
- Department of Bacteriology and Immunology, Norwegian Institute of Public Health, PO Box 4404 Nydalen, NO-0403 Oslo, Norway
| | - Arie van der Ende
- Academic Medical Center, Department of Medical Microbiology, Reference Laboratory for Bacterial Meningitis, PO Box 22660, 1100 DD Amsterdam, The Netherlands
| | - Matthias Frosch
- Institut für Hygiene und Mikrobiologie, Universität Würzburg, Josef-Schneider Strasse 2, 97080 Würzburg, Germany
| | - Stephen Gray
- Meningococcal Reference Unit, Health Protection Agency, PO Box 209, Clinical Sciences Building 2, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WZ, UK
| | - Sigrid Heuberger
- Österreichische Agentur für Gesundheit und Ernährungssicherheit GmbH, Bereich Humanmedizin, Institut für medizinische Mikrobiologie und Hygiene, Beethovenstraße 6, A-8010 Graz, Austria
| | - Paula Krizova
- National Reference Laboratory for Meningococcal Infections, National Institute of Public Health, Srobarova 48, Prague, Czech Republic
| | - Per Olcen
- Department of Laboratory Medicine, Clinical Microbiology and Immunology, Orebro University Hospital, SE-701 85 Orebro, Sweden
| | - Mary Slack
- Respiratory and Systemic Infection Laboratory, Health Protection Agency Centre for Infections, 61 Colindale Avenue, London NW9 5EQ, UK
| | | | - Martin C. J Maiden
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
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Sacchi CT, Fukasawa LO, Gonçalves MG, Salgado MM, Shutt KA, Carvalhanas TR, Ribeiro AF, Kemp B, Gorla MCO, Albernaz RK, Marques EGL, Cruciano A, Waldman EA, Brandileone MCC, Harrison LH. Incorporation of real-time PCR into routine public health surveillance of culture negative bacterial meningitis in São Paulo, Brazil. PLoS One 2011; 6:e20675. [PMID: 21731621 PMCID: PMC3120771 DOI: 10.1371/journal.pone.0020675] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 05/09/2011] [Indexed: 01/03/2023] Open
Abstract
Real-time (RT)-PCR increases diagnostic yield for bacterial meningitis and is ideal for incorporation into routine surveillance in a developing country. We validated a multiplex RT-PCR assay for Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae in Brazil. Risk factors for being culture-negative, RT-PCR positive were determined. The sensitivity of RT-PCR in cerebrospinal fluid (CSF) was 100% (95% confidence limits, 96.0%-100%) for N. meningitidis, 97.8% (85.5%-99.9%) for S. pneumoniae, and 66.7% (9.4%-99.2%) for H. influenzae. Specificity ranged from 98.9% to 100%. Addition of RT-PCR to routine microbiologic methods increased the yield for detection of S. pneumoniae, N. meningitidis, and H. influenzae cases by 52%, 85%, and 20%, respectively. The main risk factor for being culture negative and RT-PCR positive was presence of antibiotic in CSF (odds ratio 12.2, 95% CI 5.9-25.0). RT-PCR using CSF was highly sensitive and specific and substantially added to measures of meningitis disease burden when incorporated into routine public health surveillance in Brazil.
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Affiliation(s)
- Claudio T Sacchi
- Division of Medical Biology, Department of Immunology, Instituto Adolfo Lutz, São Paulo, Brazil.
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41
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van Mens SP, Meijvis SCA, Endeman H, van Velzen-Blad H, Biesma DH, Grutters JC, Vlaminckx BJM, Rijkers GT. Longitudinal analysis of pneumococcal antibodies during community-acquired pneumonia reveals a much higher involvement of Streptococcus pneumoniae than estimated by conventional methods alone. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2011; 18:796-801. [PMID: 21367978 PMCID: PMC3122512 DOI: 10.1128/cvi.00007-11] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Accepted: 02/23/2011] [Indexed: 11/20/2022]
Abstract
In up to half of all cases of community-acquired pneumonia (CAP), no pathogen can be identified with conventional diagnostic methods. The most common identified causative agent is Streptococcus pneumoniae. In this study, pneumococcal antibody responses during CAP were analyzed to estimate the contribution of the pneumococcus to all cases of CAP for epidemiological purposes. Pneumococcal antibodies against 14 different serotypes were measured in serum of hospitalized CAP patients. Patients participated in one of two consecutive clinical trials in a general 600-bed teaching hospital in the Netherlands (between October 2004 and June 2009). A significant pneumococcal immune response was defined as at least a 2-fold increase in antibody concentrations against a single serotype between an early (day 1) and a late (day 30) serum sample of each patient with an end concentration above 0.35 μg/ml. A total of 349 adult CAP patients participated in two consecutive clinical trials. For 200 patients, sufficient serum samples were available to determine antibody responses: 62 pneumococcal pneumonia patients, 57 nonpneumococcal pneumonia patients, and 81 patients with an unidentified causative agent. A significant immune response was detected in 45% (28/62 patients) of pneumococcal pneumonia patients, in 5% (3/57) of nonpneumococcal pneumonia patients, and in 28% (23/81) of patients with an unidentified causative agent. The estimated contribution of pneumococci in patients with an unidentified causative agent was calculated to be 57% (95% confidence interval, 36 to 86%). A substantial fraction of pneumococcal pneumonia patients do not elicit a serotype-specific immune response.
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Affiliation(s)
- Suzan P van Mens
- Department of Medical Microbiology & Immunology, Sint Antonius Hospital, P.O. Box 2500, 3430 EM Nieuwegein, The Netherlands.
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Josefson P, Strålin K, Ohlin A, Ennefors T, Dragsten B, Andersson L, Fredlund H, Mölling P, Olcén P. Evaluation of a commercial multiplex PCR test (SeptiFast) in the etiological diagnosis of community-onset bloodstream infections. Eur J Clin Microbiol Infect Dis 2011; 30:1127-34. [PMID: 21373774 DOI: 10.1007/s10096-011-1201-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Accepted: 02/10/2011] [Indexed: 01/06/2023]
Abstract
The commercial polymerase chain reaction (PCR) test, SeptiFast, is designed to identify the DNA of individual bacterial and fungal pathogens in whole blood. We aimed to evaluate the usefulness of the test for the detection of community-onset bloodstream infections. We prospectively included adult patients who were subjected to blood culture (BC) at an infectious diseases department. For the evaluation, one BC/PCR set (two BC bottles and one PCR tube) per patient was used. When several sets were obtained and analyzed, the first set with any positive result was evaluated. Among 1,093 consecutively included patients, BC was positive in 138 and PCR was positive in 107. Fifty positive PCR results were supported by BC in the same BC/PCR set, ten were supported by other cultures, and, additionally, ten were supported by the clinical presentation. Compared with BC, PCR showed specificities and negative predictive values of >97% for all detectable pathogens. The following sensitivities and positive predictive values (PPVs) were noted: Staphylococcus aureus, 67% and 43%; Streptococcus pneumoniae, 12% and 67%; other Streptococcus species, 43% and 77%; Escherichia coli, 53% and 56%; and Klebsiella species, 43% and 23%. If support from other cultures and the clinical presentation were included in the reference standard, the PPVs for the detection of these bacteria were 57%, 100%, 92%, 75%, and 69%, respectively. Although the specificities were high, the low sensitivities and suboptimal PPVs noted in the present study discourage routine use of the test in its present form for the detection of community-onset bloodstream infections.
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Affiliation(s)
- P Josefson
- Department of Infectious Diseases, Örebro University Hospital, 701 85 Örebro, Sweden.
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Azzari C, Cortimiglia M, Moriondo M, Canessa C, Lippi F, Ghiori F, Becciolini L, de Martino M, Resti M. Pneumococcal DNA is not detectable in the blood of healthy carrier children by real-time PCR targeting the lytA gene. J Med Microbiol 2011; 60:710-714. [PMID: 21349984 PMCID: PMC3167920 DOI: 10.1099/jmm.0.028357-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The diagnosis of invasive pneumococcal disease (IPD) is currently based on culture methods, which lack sensitivity, especially after antibiotic therapy. Molecular methods have improved sensitivity and do not require viable bacteria; however, their use is complicated by reports of low specificity with some assays. The present study investigated the specificity of a real-time PCR targeting lytA for the detection of IPD. A group of 147 healthy children, aged 6 months to 16 years (mean 6.4 years, median 4.9 years, interquartile range 6.4 years), who were in hospital for routine examinations, were tested for pneumococcal carrier status and for the presence of detectable pneumococcal DNA in their blood by real-time PCR targeting the pneumococcal lytA gene. In addition, 35 culture-positive biological samples were analysed. Urine was examined for the presence of pneumococcal DNA and C-polysaccharide antigen. Carriage was detected in 77 of the 147 subjects (52.4 %); however, regardless of carrier status, none of the subjects had a positive result from blood. Analysis of the culture-positive biological samples yielded positive results in 100 % (15/15) of cerebrospinal fluid samples and 95 % (19/20) of blood samples. All urine samples from healthy carriers were negative for DNA, whilst antigenuria was detected in 44/77 carriers (57.1 %). In conclusion, real-time PCR is both sensitive and specific and can be a useful tool in the routine diagnosis of IPD. Its sensitivity, which surpasses that of other methods for this purpose, does not come at the cost of reduced specificity.
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Affiliation(s)
- Chiara Azzari
- Department of Paediatrics, Anna Meyer Children's University Hospital, Florence, Italy
| | - Martina Cortimiglia
- Department of Paediatrics, Anna Meyer Children's University Hospital, Florence, Italy
| | - Maria Moriondo
- Department of Paediatrics, Anna Meyer Children's University Hospital, Florence, Italy
| | - Clementina Canessa
- Department of Paediatrics, Anna Meyer Children's University Hospital, Florence, Italy
| | - Francesca Lippi
- Department of Paediatrics, Anna Meyer Children's University Hospital, Florence, Italy
| | - Federica Ghiori
- Department of Paediatrics, Anna Meyer Children's University Hospital, Florence, Italy
| | - Laura Becciolini
- Department of Paediatrics, Anna Meyer Children's University Hospital, Florence, Italy
| | - Maurizio de Martino
- Department of Paediatrics, Anna Meyer Children's University Hospital, Florence, Italy
| | - Massimo Resti
- Department of Paediatrics, Anna Meyer Children's University Hospital, Florence, Italy
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DNA bacterial load in children and adolescents with pneumococcal pneumonia and empyema. Eur J Clin Microbiol Infect Dis 2010; 30:327-35. [DOI: 10.1007/s10096-010-1086-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 09/29/2010] [Indexed: 10/18/2022]
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PCR using blood for diagnosis of invasive pneumococcal disease: systematic review and meta-analysis. J Clin Microbiol 2009; 48:489-96. [PMID: 20007385 DOI: 10.1128/jcm.01636-09] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The use of molecular-based methods for the diagnosis of bacterial infections in blood is appealing, but they have not yet passed the threshold for clinical practice. A systematic review of prospective and case-control studies assessing the diagnostic utility of PCR directly with blood samples for the diagnosis of invasive pneumococcal disease (IPD) was performed. A broad search was conducted to identify published and unpublished studies. Two reviewers independently extracted the data. Summary estimates for sensitivity and specificity with 95% confidence intervals (CIs) were calculated by using the hierarchical summary receiver operating characteristic method. The effects of sample processing, PCR type, the gene-specific primer, study design, the participants' age, and the source of infection on the diagnostic odds ratios were assessed through meta-regression. Twenty-nine studies published between 1993 and 2009 were included. By using pneumococcal bacteremia for case definition and healthy people or patients with bacteremia caused by other bacteria as controls (22 studies), the summary estimates for sensitivity and specificity were 57.1% (95% CI, 45.7 to 67.8%) and 98.6% (95% CI, 96.4 to 99.5%), respectively. When the controls were patients suspected of having IPD without pneumococcal bacteremia (26 studies), the respective values were 66.4% (95% CI, 55.9 to 75.6%) and 87.8% (95% CI, 79.5 to 93.1%). With lower degrees of proof for IPD (any culture or serology result and the clinical impression), the sensitivity of PCR decreased and the specificity increased. All analyses were highly heterogeneous. The use of nested PCR and being a child were associated with low specificity, while the use of a cohort study design was associated with a low sensitivity. The lack of an appropriate reference standard might have caused underestimation of the performance of the PCR. Currently available methods for PCR with blood samples for the diagnosis of IPD lack the sensitivity and specificity necessary for clinical practice.
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