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Xing Y, Duan Z, Jiang Y, Li M, Lu W, Li J. Development and evaluation of a real-time multienzyme isothermal rapid amplification assay for rapid detection of Streptococcus pneumoniae. Sci Rep 2024; 14:17729. [PMID: 39085471 PMCID: PMC11291690 DOI: 10.1038/s41598-024-68524-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 07/24/2024] [Indexed: 08/02/2024] Open
Abstract
Streptococcus pneumoniae is a significant pathogen causing infectious diseases, including pneumonia, otitis media, septicemia, and meningitis. The introduction of multivalent vaccines has coincided with a remarkable decrease in the number of pneumococcal-related deaths. Despite this, pneumococcal infection remains a significant cause of death among children under 5 years old and adults aged 65 or older at a global level. Therefore, early detection of S. pneumoniae infection is crucial for prognosis of pneumococcal infection patients. In this study, we evaluated the utility of a real-time multienzyme isothermal rapid amplification (MIRA) assay for detecting S. pneumoniae and other non-S. pneumoniae bacterial species. A primer-probe set targeting the S. pneumoniae lytA gene was designed, followed by optimization of parameters for the MIRA assay. At the same time, we validated the real-time MIRA assay for detecting S. pneumoniae using 79 clinical isolates identified by VITEK MS. The results showed a detection sensitivity and specificity of 100%. These results demonstrate that the designed real-time MIRA assay is a promising, rapid, simple, and reliable method for detecting S. pneumoniae infection in resource-limited areas. It has great potential for application in detecting not only S. pneumoniae but also other non-S. pneumoniae bacterial species.
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Affiliation(s)
- Yun Xing
- Department of Laboratory Medicine, Daping Hospital, Army Medical University, Chongqing, China
| | - Zhixiong Duan
- Department of Laboratory Medicine, The Chen Jia Qiao Hospital of Sha Ping Ba District of Chongqing City, Chongqing, China
| | - Yuansu Jiang
- Department of Laboratory Medicine, Daping Hospital, Army Medical University, Chongqing, China
| | - Min Li
- Department of Laboratory Medicine, Daping Hospital, Army Medical University, Chongqing, China
| | - Weiping Lu
- Department of Laboratory Medicine, Daping Hospital, Army Medical University, Chongqing, China.
| | - Jin Li
- Department of Laboratory Medicine, Daping Hospital, Army Medical University, Chongqing, China.
- Department of Laboratory Medicine, Chongqing Medical University Affiliated Dazu Hospital, Chongqing, China.
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Wada FW, Desta AF, Gebre M, Mihret W, Seyoum T, Melaku K, Alemu A, Howe R, Mulu A, Mihret A. Pneumococcal colonization and coinfecting respiratory viruses in children under 5 years in Addis Ababa, Ethiopia: a prospective case-control study. Sci Rep 2024; 14:4174. [PMID: 38378681 PMCID: PMC10879120 DOI: 10.1038/s41598-024-54256-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 02/10/2024] [Indexed: 02/22/2024] Open
Abstract
A comprehensive understanding of the dynamics of Streptococcus pneumoniae colonization in conjunction with respiratory virus infections is essential for enhancing our knowledge of the pathogenesis and advancing the development of effective preventive strategies. Therefore, a case-control study was carried out in Addis Ababa, Ethiopia to investigate the colonization rate of S. pneumoniae and its coinfection dynamics with respiratory viruses among children under the age of 5 years. Samples from the nasopharyngeal and/or oropharyngeal, along with socio-demographic and clinical information, were collected from 420 children under 5 years old (210 cases with lower respiratory tract infections and 210 controls with conditions other than respiratory infections.). A one-step Multiplex real-time PCR using the Allplex Respiratory Panel Assays 1-4 was performed to identify respiratory viruses and bacteria. Data analysis was conducted using STATA software version 17. The overall colonization rate of S. pneumoniae in children aged less than 5 years was 51.2% (215/420). The colonization rates in cases and controls were 54.8% (115/210) and 47.6% (100/210), respectively (p = 0.14). Colonization rates were observed to commence at an early age in children, with a colonization rate of 48.9% and 52.7% among infants younger than 6 months controls and cases, respectively. The prevalence of AdV (OR, 3.11; 95% CI [1.31-8.19]), RSV B (OR, 2.53; 95% CI [1.01-6.78]) and HRV (OR, 1.7; 95% CI [1.04-2.78]) tends to be higher in children who tested positive for S. pneumoniae compared to those who tested negative for S. pneumoniae. Further longitudinal research is needed to understand and determine interaction mechanisms between pneumococci and viral pathogens and the clinical implications of this coinfection dynamics.
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Affiliation(s)
- Fiseha Wadilo Wada
- Armauer Hansen Research Institute, Ministry of Health, Addis Ababa, Ethiopia.
- Department of Biomedical Sciences, College of Natural and Computational Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
- Department of Medical Laboratory Sciences, College of Health Sciences and Medicine, Wolaita Sodo University, Wolaita Soddo, Ethiopia.
| | - Adey Feleke Desta
- Department of Biomedical Sciences, College of Natural and Computational Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Meseret Gebre
- Armauer Hansen Research Institute, Ministry of Health, Addis Ababa, Ethiopia
| | - Wude Mihret
- Armauer Hansen Research Institute, Ministry of Health, Addis Ababa, Ethiopia
| | - Tamrayehu Seyoum
- Armauer Hansen Research Institute, Ministry of Health, Addis Ababa, Ethiopia
| | - Kalkidan Melaku
- Armauer Hansen Research Institute, Ministry of Health, Addis Ababa, Ethiopia
| | - Ashenafi Alemu
- Armauer Hansen Research Institute, Ministry of Health, Addis Ababa, Ethiopia
| | - Rawleigh Howe
- Armauer Hansen Research Institute, Ministry of Health, Addis Ababa, Ethiopia
| | - Andargachew Mulu
- Armauer Hansen Research Institute, Ministry of Health, Addis Ababa, Ethiopia
| | - Adane Mihret
- Armauer Hansen Research Institute, Ministry of Health, Addis Ababa, Ethiopia
- Department of Microbiology, Immunology, and Parasitology, School of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
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Colomba C, Garbo V, Boncori G, Albano C, Bagarello S, Condemi A, Giordano S, Canduscio LA, Gallo C, Parrinello G, Cascio A. Streptococcus mitis as a New Emerging Pathogen in Pediatric Age: Case Report and Systematic Review. Antibiotics (Basel) 2023; 12:1222. [PMID: 37508318 PMCID: PMC10376791 DOI: 10.3390/antibiotics12071222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/20/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023] Open
Abstract
Streptococcus mitis, a normal inhabitant of the oral cavity, is a member of Viridans Group Streptococci (VGS). Generally recognized as a causative agent of invasive diseases in immunocompromised patients, S. mitis is considered to have low pathogenic potential in immunocompetent individuals. We present a rare case of sinusitis complicated by meningitis and cerebral sino-venous thrombosis (CSVT) caused by S. mitis in a previously healthy 12-year-old boy with poor oral health status. With the aim of understanding the real pathogenic role of this microorganism, an extensive review of the literature about invasive diseases due to S. mitis in pediatric patients was performed. Our data define the critical role of this microorganism in invasive infections, especially in immunocompetent children and in the presence of apparently harmful conditions such as sinusitis and caries. Attention should be paid to the choice of therapy because of VGS's emerging antimicrobial resistance patterns.
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Affiliation(s)
- Claudia Colomba
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
- Division of Pediatric Infectious Diseases, "G. Di Cristina" Hospital, ARNAS Civico Di Cristina Benfratelli, 90100 Palermo, Italy
| | - Valeria Garbo
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
| | - Giovanni Boncori
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
| | - Chiara Albano
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
| | - Sara Bagarello
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
| | - Anna Condemi
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
| | - Salvatore Giordano
- Division of Pediatric Infectious Diseases, "G. Di Cristina" Hospital, ARNAS Civico Di Cristina Benfratelli, 90100 Palermo, Italy
| | - Laura A Canduscio
- Division of Pediatric Infectious Diseases, "G. Di Cristina" Hospital, ARNAS Civico Di Cristina Benfratelli, 90100 Palermo, Italy
| | - Cristina Gallo
- Division of Radiology, "G. Di Cristina" Hospital, ARNAS Civico Di Cristina Benfratelli, 90100 Palermo, Italy
| | - Gaspare Parrinello
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
| | - Antonio Cascio
- Department of Health Promotion, Maternal and Infant Care, Internal Medicine and Medical Specialties, University of Palermo, 90100 Palermo, Italy
- Infectious and Tropical Diseases Unit, AOU Policlinico "P. Giaccone", 90100 Palermo, Italy
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Hislop MS, Allicock OM, Thammavongsa DA, Mbodj S, Nelson A, Shaw AC, Weinberger DM, Wyllie AL. High Levels of Detection of Nonpneumococcal Species of Streptococcus in Saliva from Adults in the United States. Microbiol Spectr 2023; 11:e0520722. [PMID: 37067447 PMCID: PMC10269540 DOI: 10.1128/spectrum.05207-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Accepted: 03/30/2023] [Indexed: 04/18/2023] Open
Abstract
While the sensitivity of detection of pneumococcal carriage can be improved by testing respiratory tract samples with quantitative PCR (qPCR), concerns have been raised regarding the specificity of this approach. We therefore investigated the reliability of the widely used lytA qPCR assay when applied to saliva samples from older adults in relation to a more specific qPCR assay (piaB). During the autumn/winter seasons of 2018/2019 and 2019/2020, saliva was collected at multiple time points from 103 healthy adults aged 21 to 39 (n = 34) and >64 (n = 69) years (n = 344 total samples). Following culture enrichment, extracted DNA was tested using qPCR for piaB and lytA. By sequencing the variable region of rpsB (S2 typing), we identified the species of bacteria isolated from samples testing lytA-positive only. While 30 of 344 (8.7%) saliva samples (16.5% individuals) tested qPCR-positive for both piaB and lytA, 52 (15.1%) samples tested lytA-positive only. No samples tested piaB-positive only. Through extensive reculture attempts of the lytA-positive samples collected in 2018/2019, we isolated 23 strains (in 8 samples from 5 individuals) that were also qPCR-positive for only lytA. Sequencing determined that Streptococcus mitis and Streptococcus infantis were predominantly responsible for this lytA-positive qPCR signal. We identified a comparatively large proportion of samples generating positive signals with the widely used lytA qPCR and identified nonpneumococcal Streptococcus species responsible for this signal. This highlights the importance of testing for the presence of multiple gene targets in tandem for reliable and specific detection of pneumococcus in polymicrobial respiratory tract samples. IMPORTANCE Testing saliva samples with quantitative PCR (qPCR) improves the sensitivity of detection of pneumococcal carriage. The qPCR assay targeting lytA, the gene encoding the major pneumococcal autolysin, has become widely accepted for the identification of pneumococcus and is even considered the "gold standard" by many. However, when applying this approach to investigate the prevalence of pneumococcal carriage in adults in New Haven, CT, USA, we identified nonpneumococcal Streptococcus spp. that generate positive signals in this widely used assay. By testing also for piaB (encoding the iron acquisition ABC transporter lipoprotein, PiaB), our findings demonstrate the importance of testing for the presence of multiple gene targets in tandem for reliable molecular detection of pneumococcus in respiratory tract samples; targeting only lytA may lead to an overestimation of true carriage rates.
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Affiliation(s)
- Maikel S. Hislop
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Orchid M. Allicock
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Darani A. Thammavongsa
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Sidiya Mbodj
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Allison Nelson
- Department of Internal Medicine, Section of Infectious Diseases, Yale School of Medicine, New Haven, Connecticut, USA
| | - Albert C. Shaw
- Department of Internal Medicine, Section of Infectious Diseases, Yale School of Medicine, New Haven, Connecticut, USA
| | - Daniel M. Weinberger
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Anne L. Wyllie
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
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Wyllie AL, Mbodj S, Thammavongsa DA, Hislop MS, Yolda-Carr D, Waghela P, Nakahata M, Stahlfeld AE, Vega NJ, York A, Allicock OM, Wilkins G, Ouyang A, Siqueiros L, Strong Y, Anastasio K, Alexander-Parrish R, Arguedas A, Gessner BD, Weinberger DM. Persistence of Pneumococcal Carriage among Older Adults in the Community despite COVID-19 Mitigation Measures. Microbiol Spectr 2023; 11:e0487922. [PMID: 37036377 PMCID: PMC10269788 DOI: 10.1128/spectrum.04879-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 03/20/2023] [Indexed: 04/11/2023] Open
Abstract
Reported rates of invasive pneumococcal disease were markedly lower than normal during the 2020/2021 winter in the Northern Hemisphere, the first year after the start of the COVID-19 pandemic. However, little is known about rates of carriage of pneumococcus among adults during this period. Between October 2020-August 2021, couples in the Greater New Haven Area, USA, were enrolled if both individuals were aged 60 years and above and did not have any individuals under the age of 60 years living in the household. Saliva samples and questionnaires regarding social activities and contacts and medical history were obtained every 2 weeks for a period of 10 weeks. Following culture-enrichment, extracted DNA was tested using qPCR for pneumococcus-specific sequences piaB and lytA. Individuals were considered positive for pneumococcal carriage when Ct values for piaB were ≤40. Results. We collected 567 saliva samples from 95 individuals (47 household pairs and 1 singleton). Of those, 7.1% of samples tested positive for pneumococcus, representing 22/95 (23.2%) individuals and 16/48 (33.3%) households. Study participants attended few social events during this period. However, many participants continued to have regular contact with children. Individuals who had regular contact with preschool and school-aged children (i.e., 2 to 9 year olds) had a higher prevalence of carriage (15.9% versus 5.4%). Despite COVID-19-related disruptions, a large proportion of older adults continued to carry pneumococcus. Prevalence was particularly high among those who had contact with school-aged children, but carriage was not limited to this group. IMPORTANCE Carriage of Streptococcus pneumoniae (pneumococcus) in the upper respiratory tract is considered a prerequisite to invasive pneumococcal disease. During the first year of the COVID-19 pandemic, markedly lower rates of invasive pneumococcal disease were reported worldwide. Despite this, by testing saliva samples with PCR, we found that older adults continued to carry pneumococcus at pre-pandemic levels. Importantly, this study was conducted during a period when transmission mitigation measures related to the COVID-19 pandemic were in place. However, our observations are in line with reports from Israel and Belgium where carriage was also found to persist in children. In line with this, we observed that carriage prevalence was particularly high among the older adults in our study who maintained contact with school-aged children.
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Affiliation(s)
- Anne L. Wyllie
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Sidiya Mbodj
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Darani A. Thammavongsa
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Maikel S. Hislop
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Devyn Yolda-Carr
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Pari Waghela
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Maura Nakahata
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Anne E. Stahlfeld
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Noel J. Vega
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Anna York
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Orchid M. Allicock
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Geisa Wilkins
- Yale Center for Clinical Investigation, New Haven, Connecticut, USA
| | - Andrea Ouyang
- Yale Center for Clinical Investigation, New Haven, Connecticut, USA
| | - Laura Siqueiros
- Yale Center for Clinical Investigation, New Haven, Connecticut, USA
| | - Yvette Strong
- Yale Center for Clinical Investigation, New Haven, Connecticut, USA
| | - Kelly Anastasio
- Yale Center for Clinical Investigation, New Haven, Connecticut, USA
| | | | - Adriano Arguedas
- Medical and Scientific Affairs, Pfizer Inc, Collegeville, Pennsylvania, USA
| | | | - Daniel M. Weinberger
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
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Miellet WR, Almeida ST, Trzciński K, Sá-Leão R. Streptococcus pneumoniae carriage studies in adults: Importance, challenges, and key issues to consider when using quantitative PCR-based approaches. Front Microbiol 2023; 14:1122276. [PMID: 36910231 PMCID: PMC9994646 DOI: 10.3389/fmicb.2023.1122276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 01/31/2023] [Indexed: 02/18/2023] Open
Abstract
Streptococcus pneumoniae causes significant morbidity and mortality among older adults. Detection of pneumococcal carriage is an accepted endpoint in pneumococcal conjugate vaccine studies. However, low sensitivity of culture-based approaches and nasopharyngeal samples have hampered adult S. pneumoniae carriage studies in the past. In contrast, detection of adult S. pneumoniae carriers with qPCR-based approaches can achieve high sensitivity and specificity and qPCR-based testing of oral samples improves accuracy of adult carriage detection. In this Viewpoint we outline a strategy for accurate qPCR-based testing. We recommend a dual-target approach for S. pneumoniae qPCR detection as no genetic target is universally present among or solely unique to it. Furthermore, we advise the evaluation of concordance among quantified qPCR targets to improve the accuracy of S. pneumoniae testing and qPCR-based serotyping. We do not recommend omission of qPCR-based oral sample testing as it will likely result in an underestimation of true adult carrier rates.
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Affiliation(s)
- Willem R Miellet
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, Netherlands.,Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - Sónia T Almeida
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Krzysztof Trzciński
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, Netherlands
| | - Raquel Sá-Leão
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
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Allicock OM, York A, Waghela P, Yolda-Carr D, Weinberger DM, Wyllie AL. Impact of Temporary Storage Conditions on the Viability of Streptococcus pneumoniae in Saliva. mSphere 2022; 7:e0033122. [PMID: 36409104 PMCID: PMC9769876 DOI: 10.1128/msphere.00331-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Nasopharyngeal swabs are considered the gold-standard sample type for the detection of Streptococcus pneumoniae carriage, but recent studies have demonstrated the utility of saliva in improving the detection of carriage in adults. Saliva is generally collected in its raw, unsupplemented state, unlike nasopharyngeal swabs, which are collected into stabilizing transport media. Few data exist regarding the stability of pneumococci in unsupplemented saliva during transport and laboratory storage. We therefore evaluated the effect of storage conditions on the detection of pneumococci in saliva samples using strains representing eight pneumococcal serotypes. The bacteria were spiked into raw saliva from asymptomatic individuals, and we assessed sample viability after storage at 4°C, room temperature, and 30°C for up to 72 h; at 40°C for 24 h; and following three freeze-thaw cycles. We observed little decrease in pneumococcal detection following culture enrichment and quantitative PCR (qPCR) detection of the piaB and lytA genes compared to testing fresh samples, indicating the prolonged viability of pneumococci in neat saliva samples. This sample stability makes saliva a viable sample type for pneumococcal carriage studies conducted in remote or low-resource settings and provides insight into the effect of the storage of saliva samples in the laboratory. IMPORTANCE For pneumococcal carriage studies, saliva is a sample type that can overcome some of the issues typically seen with nasopharyngeal and oropharyngeal swabs. Understanding the limitations of saliva as a sample type is important for maximizing its use. This study sought to better understand how different storage conditions and freeze-thaw cycles affect pneumococcal survival over time. These findings support the use of saliva as an alternative sample type for pneumococcal carriage studies, particularly in remote or low-resource settings with reduced access to health care facilities.
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Affiliation(s)
- Orchid M. Allicock
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Anna York
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Pari Waghela
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Devyn Yolda-Carr
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Daniel M. Weinberger
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
| | - Anne L. Wyllie
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, USA
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de Vasconcelos MGGC, Jarovsky D, Nunes GZ, Tridente DM, Grill JAT, Berezin EN. Molecular diagnostic of complicated pneumonia in the post-vaccine era. J Trop Pediatr 2022; 68:6760802. [PMID: 36228307 DOI: 10.1093/tropej/fmac086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
BACKGROUND The etiological diagnosis of community-acquired pneumonia (CAP) is still a challenge. We compared the conventional culture method and real-time polymerase chain reaction (RT-PCR) for the identification of Streptococcus pneumoniae in severe pediatric CAP. METHODS A retrospective hospital-based study was conducted. From 2012 to 2018, we have selected patients who had peripheral blood and/or pleural fluid collected for etiological investigation by RT-PCR. RESULTS We included 113 children (median age: 3 years; interquartile range 1-6 years). RT-PCR increased the detection rate of S. pneumoniae by 6.5 times using blood samples and eight times using pleural fluid samples. Patients subjected to RT-PCR showed more prolonged hospitalization (p = 0.006), fewer comorbidities (p = 0.03), presence of pleural effusion (p = 0.001), presence of young forms of leukocytes (p = 0.001) and radiograph with characteristics of pneumonia (p = 0.002). The presence of pleural effusion [odds ratio (OR) = 14.7, 95% confidence interval (CI) 1.6-133.9; p = 0.01] and young forms of leukocytes (OR = 8.9, 95% CI 0.9-84.4; p = 0.05) were risk factors for positive RT-PCR pneumococcal when multivariate analysis was performed. CONCLUSIONS RT-PCR is a reliable method for diagnosing severe CAP using sterile materials and a potentially applicable method in patients with clinical, radiological and non-specific laboratory characteristics of lower respiratory tract infection, especially in complicated cases with pleural effusion.
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Affiliation(s)
| | - Daniel Jarovsky
- Pediatric Infectious Disease Unit, Santa Casa de São Paulo, São Paulo 01221-010, Brazil
| | | | | | | | - Eitan Naaman Berezin
- Pediatric Infectious Disease Unit, Santa Casa de São Paulo, São Paulo 01221-010, Brazil
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Molecular surveillance of pneumococcal carriage following completion of immunization with the 13-valent pneumococcal conjugate vaccine administered in a 3 + 1 schedule. Sci Rep 2021; 11:24534. [PMID: 34969968 PMCID: PMC8718523 DOI: 10.1038/s41598-021-03720-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 12/08/2021] [Indexed: 11/08/2022] Open
Abstract
In a cross-sectional study, with the use of molecular methods, we aimed to gain insight into oropharyngeal pneumococcal colonization over time in 1212 Greek children recruited in general pediatric settings throughout the country; they were fully vaccinated with PCV13 (3 + 1 schedule). A single sample was obtained from each child at a time interval of 26 days to 70 months after administration of the 4th (booster) PCV13 dose; sampling time was divided into six time intervals. Carriage of Streptococcus pneumoniae was detected by real-time PCR targeting the lytA gene and isolates were serotyped by singleplex real-time PCR assays. Multiple control procedures to avoid false-positive results were applied. We showed an overall S. pneumoniae carriage rate of 48.6%. Serotyping identified typeable isolates in 82% of the total lytA-positive samples. Non-PCV13 serotypes represented 83.8% of total isolates when excluding serogroups with mixed PCV13 and non-PCV13 serotypes. In multivariate analysis daycare/school attendance emerged as the main contributing factor. Notably, serotypes 19A and 3 were the only two PCV13 serotypes the colonization rate of which increased over time (χ2 for trend P < 0.001 and P = 0.012, respectively). The application of the SP2020 gene on lytA-positive serotyped samples showed pneumococcal colonization in 97% of cases, and the overall colonization profile over time closely resembled that of the lytA gene. With the provisions of the methodological approach and age group of our study, the use of the oropharynx emerges as a reliable alternative to the nasopharynx in estimating pneumococcal carriage in epidemiological studies.
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Ganaie F, Branche AR, Peasley M, Rosch JW, Nahm MH. Oral streptococci expressing pneumococci-like cross-reactive capsule types can affect WHO recommended pneumococcal carriage procedure. Clin Infect Dis 2021; 75:647-656. [PMID: 34891152 DOI: 10.1093/cid/ciab1003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Carriage studies are fundamental to assess the effects of pneumococcal vaccines. Since a large proportion of oral streptococci carry homologs of pneumococcal genes, nonculture-based detection and serotyping of upper respiratory tract (URT) samples can be problematic. Herein, we investigated if culture-free molecular methods could differentiate pneumococci from oral streptococci carried by adults in URT. METHODS Paired nasopharyngeal (NP) and oropharyngeal (OP) samples were collected from 100 older adults twice a month for one year. Extracts from the combined NP+OP samples (n=2400) were subjected to lytA real-time PCR. Positive samples were subjected to pure culture isolation followed by species confirmation using multiple approaches. Multibead assay and whole-genome sequencing were used for serotyping. RESULTS lytA-PCR was positive in 301 combined NP+OP extracts, 20 of which grew probable pneumococcal-like colonies based on colony morphology and biochemical tests. Multiple approaches confirmed that four isolates were S. pneumoniae, three were S. psuedopneumoniae, and thirteen were S. mitis. Eight nonpneumococcal strains carried pneumococcus-like cps loci (size: ~18 to 25 kb) that showed >70% of nucleotide identity with their pneumococcal counterparts. While investigating the antigenic profile, we found some S. mitis strains (P066 and P107) reacted with both serotype-specific polyclonal (Type 39 and FS17b) and monoclonal (Hyp10AG1 and Hyp17FM1) antisera, whereas some strains (P063 and P074) reacted only with polyclonal antisera (Type 5 and FS35a). CONCLUSION The extensive capsular overlap suggests that pneumococcal vaccines could reduce carriage of oral streptococci expressing cross-reactive capsules. Further, direct use of culture-free PCR-based methods in URT samples has limited usefulness for carriage studies.
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Affiliation(s)
- Feroze Ganaie
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Angela R Branche
- Department of Medicine, University of Rochester, Rochester, NY, USA
| | - Michael Peasley
- Department of Medicine, University of Rochester, Rochester, NY, USA
| | - Jason W Rosch
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Moon H Nahm
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
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11
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Francois Watkins LK, Milucky JL, McGee L, Siné St-Surin F, Liu P, Tran T, Chochua S, Joseph G, Shang N, Juin S, Dely P, Patel R, Van Beneden CA. Nasopharyngeal Carriage of Streptococcus pneumoniae Among Young Children in Haiti Before Pneumococcal Conjugate Vaccine Introduction. J Infect Dis 2021; 224:S248-S257. [PMID: 34469560 DOI: 10.1093/infdis/jiab119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Streptococcus pneumoniae, or pneumococcus, is a leading cause of morbidity and mortality in children worldwide. Pneumococcal conjugate vaccines (PCV) reduce carriage in the nasopharynx, preventing disease. We conducted a pneumococcal carriage study to estimate the prevalence of pneumococcal colonization, identify risk factors for colonization, and describe antimicrobial susceptibility patterns among pneumococci colonizing young children in Port-au-Prince, Haiti, before introduction of 13-valent PCV (PCV13). METHODS We conducted a cross-sectional study of children aged 6-24 months at an immunization clinic in Port-au-Prince between September 2015 and January 2016. Consenting parents were interviewed about factors associated with pneumococcal carriage; nasopharyngeal swabs were collected from each child and cultured for pneumococcus after broth enrichment. Pneumococcal isolates were serotyped and underwent antimicrobial susceptibility testing. We compared frequency of demographic, clinical, and environmental factors among pneumococcus-colonized children (carriers) to those who were not colonized (noncarriers) using unadjusted bivariate analysis and multivariate logistic regression. RESULTS Pneumococcus was isolated from 308 of the 685 (45.0%) children enrolled. Overall, 157 isolates (50.8%) were PCV13 vaccine-type serotypes; most common were 6A (13.3%), 19F (12.6%), 6B (9.7%), and 23F (6.1%). Vaccine-type isolates were significantly more likely to be nonsusceptible to ≥1 antimicrobial (63.1% vs 45.4%, P = .002). On bivariate analysis, carriers were significantly more likely than noncarriers to live in a household without electricity or running water, to share a bedroom with ≥3 people, to have a mother or father who did not complete secondary education, and to have respiratory symptoms in the 24 hours before enrollment (P < .05 for all comparisons). On multivariable analysis, completion of the pentavalent vaccination series (targeting diphtheria, pertussis, tetanus, hepatitis B, and Haemophilus influenzae type b) remained significantly more common among noncarriers. CONCLUSIONS Nearly a quarter of healthy children surveyed in Haiti were colonized with vaccine-type pneumococcal serotypes. This baseline carriage study will enable estimation of vaccine impact following nationwide introduction of PCV13.
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Affiliation(s)
- Louise K Francois Watkins
- Respiratory Diseases Branch, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.,Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Jennifer L Milucky
- Respiratory Diseases Branch, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Lesley McGee
- Respiratory Diseases Branch, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | | | - Pengbo Liu
- Respiratory Diseases Branch, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.,Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
| | - Theresa Tran
- Respiratory Diseases Branch, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Sopio Chochua
- Respiratory Diseases Branch, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Gerard Joseph
- Laboratoire National de Santé Publique, Port-au-Prince, Haiti
| | - Nong Shang
- Respiratory Diseases Branch, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Stanley Juin
- Centers for Disease Control and Prevention, Port-au-Prince, Haiti
| | - Patrick Dely
- Ministère de la Santé Publique et de la Population, Directorate of Epidemiology, Laboratory and Research, Port-au-Prince, Haiti
| | - Roopal Patel
- Centers for Disease Control and Prevention, Port-au-Prince, Haiti.,Global Fund to Fight AIDS, Tuberculosis, and Malaria, Grand-Saconnex, Switzerland
| | - Chris A Van Beneden
- Respiratory Diseases Branch, Division of Bacterial Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.,Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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12
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Streptococcus pseudopneumoniae: Use of Whole-Genome Sequences To Validate Species Identification Methods. J Clin Microbiol 2021; 59:JCM.02503-20. [PMID: 33208473 DOI: 10.1128/jcm.02503-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 11/09/2020] [Indexed: 11/20/2022] Open
Abstract
A correct identification of Streptococcus pseudopneumoniae is a prerequisite for investigating the clinical impact of the bacterium. The identification has traditionally relied on phenotypic methods. However, these phenotypic traits have been shown to be unreliable, with some S. pseudopneumoniae strains giving conflicting results. Therefore, sequence-based identification methods have increasingly been used for identification of S. pseudopneumoniae In this study, we used 64 S. pseudopneumoniae strains, 59 S. pneumoniae strains, 22 S. mitis strains, 24 S. oralis strains, 6 S. infantis strains, and 1 S. peroris strain to test the capability of three single genes (rpoB, gyrB, and recA), two multilocus sequence analysis (MLSA) schemes, the single nucleotide polymorphism (SNP)-based phylogeny tool CSI phylogeny, a k-mer-based identification method (KmerFinder), average nucleotide identity (ANI) using fastANI, and core genome analysis to identify S. pseudopneumoniae Core genome analysis and CSI phylogeny were able to cluster all strains into distinct clusters related to their respective species. It was not possible to identify all S. pseudopneumoniae strains correctly using only one of the single genes. The MLSA schemes were unable to identify some of the S. pseudopneumoniae strains, which could be misidentified. KmerFinder identified all S. pseudopneumoniae strains but misidentified one S. mitis strain as S. pseudopneumoniae, and fastANI differentiated between S. pseudopneumoniae and S. pneumoniae using an ANI cutoff of 96%.
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13
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Sadowy E, Hryniewicz W. Identification of Streptococcus pneumoniae and other Mitis streptococci: importance of molecular methods. Eur J Clin Microbiol Infect Dis 2020; 39:2247-2256. [PMID: 32710352 PMCID: PMC7669753 DOI: 10.1007/s10096-020-03991-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/15/2020] [Indexed: 02/06/2023]
Abstract
The Mitis group of streptococci includes an important human pathogen, Streptococcus pneumoniae (pneumococcus) and about 20 other related species with much lower pathogenicity. In clinical practice, some representatives of these species, especially Streptococcus pseudopneumoniae and Streptococcus mitis, are sometimes mistaken for S. pneumoniae based on the results of classical microbiological methods, such as optochin susceptibility and bile solubility. Several various molecular approaches that address the issue of correct identification of pneumococci and other Mitis streptococci have been proposed and are discussed in this review, including PCR- and gene sequencing-based tests as well as new developments in the genomic field that represents an important advance in our understanding of relationships within the Mitis group.
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Affiliation(s)
- Ewa Sadowy
- Department of Molecular Microbiology, National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland.
| | - Waleria Hryniewicz
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland
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14
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Mosadegh M, Asadian R, Emamie AD, Rajabpour M, Najafinasab E, Azarsa M. Impact of Laboratory Methods and Gene Targets on Detection of Streptococcus pneumoniae in Isolates and Clinical Specimens. Rep Biochem Mol Biol 2020; 9:216-222. [PMID: 33178872 DOI: 10.29252/rbmb.9.2.216] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Background Timely identification of Streptococcus pneumoniae infections can lead to a decrease in mortality rates. Differentiation of S. pneumoniae from other similar species using traditional culture-based and molecular methods is problematic. In this study, we assessed the efficacy of identifying the blpA and lytA for the detection of S. pneumoniae from isolates and various clinical samples using molecular methods. Methods A total of 440 clinical samples were collected from patients with suspected invasive pneumococcal infections during February 2016 to October 2018. Biochemical tests were used to confirm the dubious colonies on 5% sheep blood agar. Fifty-seven confirmed isolates, 57 culture-positive samples, and 57 culture-negative samples were analyzed for the presence of blpA and lytA using both conventional and real-time PCR. Results All the isolates and culture-positive samples were positive for blpA and lytA by both PCR methods. Of the 57 culture-negative samples, conventional and real-time PCR amplified blpA from six and two samples, and lytA from seven and two samples, respectively. Conclusion The specificity of real-time PCR assay was significantly higher than that of conventional PCR for the identification of S. pneumoniae. In addition, it is suggested that respiratory secretions are not suitable specimen for direct diagnosis of pneumococcal infections.
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Affiliation(s)
- Mehrdad Mosadegh
- Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Rozita Asadian
- Department of Medical Laboratory Sciences, School of Paramedicine, Guilan University of Medical Sciences, Langeroud, Iran
| | - Amir Darb Emamie
- Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammadreza Rajabpour
- Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Elmira Najafinasab
- Department of Microbiology, Khoy University of Medical Sciences, Khoy, Iran
| | - Mohammad Azarsa
- Department of Microbiology, Khoy University of Medical Sciences, Khoy, Iran
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15
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Sadowy E, Bojarska A, Kuch A, Skoczyńska A, Jolley KA, Maiden MCJ, van Tonder AJ, Hammerschmidt S, Hryniewicz W. Relationships among streptococci from the mitis group, misidentified as Streptococcus pneumoniae. Eur J Clin Microbiol Infect Dis 2020; 39:1865-1878. [PMID: 32409955 PMCID: PMC7497345 DOI: 10.1007/s10096-020-03916-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Accepted: 04/24/2020] [Indexed: 01/18/2023]
Abstract
The aim of our study was to investigate phenotypic and genotypic features of streptococci misidentified (misID) as Streptococcus pneumoniae, obtained over 20 years from hospital patients in Poland. Sixty-three isolates demonstrating microbiological features typical for pneumococci (optochin susceptibility and/or bile solubility) were investigated by phenotypic tests, lytA and 16S rRNA gene polymorphism and whole-genome sequencing (WGS). All isolates had a 6-bp deletion in the lytA 3' terminus, characteristic for Mitis streptococc and all but two isolates lacked the pneumococcal signature cytosine at nucleotide position 203 in the 16S rRNA genes. The counterparts of psaA and ply were present in 100% and 81.0% of isolates, respectively; the spn9802 and spn9828 loci were characteristic for 49.2% and 38.1% of isolates, respectively. Phylogenetic trees and networks, based on the multilocus sequence analysis (MLSA) scheme, ribosomal multilocus sequence typing (rMLST) scheme and core-genome analysis, clearly separated investigated isolates from S. pneumoniae and demonstrated the polyclonal character of misID streptococci, associated with the Streptococcus pseudopneumoniae and Streptococcus mitis groups. While the S. pseudopneumoniae clade was relatively well defined in all three analyses, only the core-genome analysis revealed the presence of another cluster comprising a fraction of misID streptococci and a strain proposed elsewhere as a representative of a novel species in the Mitis group. Our findings point to complex phylogenetic and taxonomic relationships among S. mitis-like bacteria and support the notion that this group may in fact consist of several distinct species.
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Affiliation(s)
- Ewa Sadowy
- Department of Molecular Microbiology, National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland.
| | - Agnieszka Bojarska
- Department of Molecular Microbiology, National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland
| | - Alicja Kuch
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland
| | - Anna Skoczyńska
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland
| | | | | | | | - Sven Hammerschmidt
- Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Waleria Hryniewicz
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland
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16
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Farrar JL, Odiembo H, Odoyo A, Bigogo G, Kim L, Lessa FC, Feikin DR, Breiman RF, Whitney CG, Carvalho MG, Pimenta FC. Limited Added Value of Oropharyngeal Swabs for Detecting Pneumococcal Carriage in Adults. Open Forum Infect Dis 2020; 7:ofaa368. [PMID: 32995349 PMCID: PMC7505525 DOI: 10.1093/ofid/ofaa368] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/13/2020] [Indexed: 11/14/2022] Open
Abstract
We compared pneumococcal isolation rates and evaluated the benefit of using oropharyngeal (OP) specimens in addition to nasopharyngeal (NP) specimens collected from adults in rural Kenya. Of 846 adults, 52.1% were colonized; pneumococci were detected from both NP and OP specimens in 23.5%, NP only in 22.9%, and OP only in 5.7%. Ten-valent pneumococcal conjugate vaccine strains were detected from both NP and OP in 3.4%, NP only in 4.1%, and OP only in 0.7%. Inclusion of OP swabs increased carriage detection by 5.7%; however, the added cost of collecting and processing OP specimens may justify exclusion from future carriage studies among adults.
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Affiliation(s)
- Jennifer L Farrar
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Herine Odiembo
- Global Disease Detection Division (GDD) and International Emerging Infections Program (IEIP), Kenya Medical Research Institute (KEMRI)/CDC Public Health and Research Collaboration, Kisumu, Kenya
| | - Arthur Odoyo
- Global Disease Detection Division (GDD) and International Emerging Infections Program (IEIP), Kenya Medical Research Institute (KEMRI)/CDC Public Health and Research Collaboration, Kisumu, Kenya
| | - Godfrey Bigogo
- Global Disease Detection Division (GDD) and International Emerging Infections Program (IEIP), Kenya Medical Research Institute (KEMRI)/CDC Public Health and Research Collaboration, Kisumu, Kenya
| | - Lindsay Kim
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Fernanda C Lessa
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Daniel R Feikin
- Global Disease Detection Division (GDD) and International Emerging Infections Program (IEIP), Kenya Medical Research Institute (KEMRI)/CDC Public Health and Research Collaboration, Kisumu, Kenya
| | - Robert F Breiman
- Emory Global Health Institute, Emory University, Atlanta, Georgia, USA
| | - Cynthia G Whitney
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Maria G Carvalho
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Fabiana C Pimenta
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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17
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Abstract
Streptococcus pneumoniae (the pneumococcus) carriage is commonly used to measure effects of pneumococcal vaccines. Based on findings from culture-based studies, the World Health Organization recommends both nasopharyngeal (NP) and oropharyngeal (OP) sampling for detecting adult carriage. Given evidence of potential confounding by other streptococci, we evaluated molecular methods for pneumococcal identification and serotyping from 250 OP samples collected from adults in Fiji, using paired NP samples for comparison. Samples were screened using lytA quantitative PCR (qPCR), as well as pneumococcal identification and serotyping conducted by DNA microarray. A subset of OP samples were characterized by latex sweep agglutination and multiplex PCR. Alternate qPCR assays (piaB and bguR) for pneumococcal identification were evaluated. The lytA qPCR was less specific and had poor positive predictive value (PPV) in OP samples (88% and 26%, respectively) compared with NP samples (95% and 64%, respectively). Using additional targets piaB and/or bguR improved qPCR specificity in OP, although the PPV (42 to 53%) was still poor. Using microarray, we found that 102/107 (95%) of OP samples contained nonpneumococcal streptococci with partial or divergent complements of pneumococcal capsule genes. We explored 91 colonies isolated from 11 OP samples using various techniques, including multiplex PCR, latex agglutination, and microarray. We found that nonpneumococcal streptococci contribute to false positives in pneumococcal serotyping and may also contribute to spurious identification by qPCR. Our results highlight that molecular approaches should include multiple loci to minimize false-positive results when testing OP samples. Regardless of method, pneumococcal identification and serotyping results from OP samples should be interpreted with caution.IMPORTANCE Streptococcus pneumoniae (the pneumococcus) is a significant global pathogen. Accurate identification and serotyping are vital. In contrast with World Health Organization recommendations based on culture methods, we demonstrate that pneumococcal identification and serotyping with molecular methods are affected by sample type. Results from oropharyngeal samples from adults were often inaccurate. This is particularly important for assessment of vaccine impact using carriage studies, particularly in low- and middle-income countries where there are significant barriers for disease surveillance.
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18
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Arguedas A, Trzciński K, O'Brien KL, Ferreira DM, Wyllie AL, Weinberger D, Danon L, Pelton SI, Azzari C, Hammitt LL, Sá-Leão R, Brandileone MCC, Saha S, Suaya J, Isturiz R, Jodar L, Gessner BD. Upper respiratory tract colonization with Streptococcus pneumoniae in adults. Expert Rev Vaccines 2020; 19:353-366. [PMID: 32237926 DOI: 10.1080/14760584.2020.1750378] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Most of the current evidence regarding pneumococcal upper respiratory colonization in adults suggests that despite high disease burden, carriage prevalence is low. Contemporary studies on adult pneumococcal colonization have largely followed the pediatric approach by which samples are obtained mostly from the nasopharynx and bacterial detection is evaluated by routine culture alone. Recent evidence suggests that the 'pediatric approach' may be insufficient in adults and pneumococcal detection in this population may be improved by longitudinal studies that include samples from additional respiratory sites combined with more extensive laboratory testing. AREAS COVERED In this article, relevant literature published in peer review journals on adult pneumococcal colonization, epidemiology, detection methods, and recommendations were reviewed. EXPERT OPINION Respiratory carriage of Streptococcus pneumoniae has been underestimated in adults. Contemporary pneumococcal carriage studies in adults that collect samples from alternative respiratory sites such as the oropharynx, saliva, or nasal wash; are culture-enriched for pneumococcus; and use molecular diagnostic methods designed to target two pneumococcal DNA sequences should enhance pneumococcal detection in the adult respiratory tract. This finding may have implications for the interpretation of dynamics of pneumococcal transmission and vaccination.
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Affiliation(s)
- Adriano Arguedas
- Vaccines Medical Development & Scientific/Clinical Affairs, Pfizer Inc , Collegeville, PA, USA
| | - Krzysztof Trzciński
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina's Children Hospital, University Medical Centre Utrecht , Utrecht, The Netherlands
| | - Katherine L O'Brien
- Department of International Health, Johns Hopkins Bloomberg School of Public Health , Baltimore, MD, USA
| | | | - Anne L Wyllie
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health , New Haven, CT, USA
| | - Daniel Weinberger
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health , New Haven, CT, USA
| | | | - Stephen I Pelton
- Pediatric Infectious Diseases, Department of Pediatrics, Maxwell Finland Laboratory for Infectious Diseases, Boston Medical Center , Boston, MA, USA
| | - Chiara Azzari
- Meyer Children's Hospital and University of Florence , Florence, Italy
| | - Laura L Hammitt
- Department of International Health, Johns Hopkins Bloomberg School of Public Health , Baltimore, MD, USA
| | - Raquel Sá-Leão
- Instituto De Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa , Oeiras, Portugal
| | | | - Samir Saha
- Child Health Research Foundation , Matuail, Dhaka, Bangladesh
| | - Jose Suaya
- Vaccines Medical Development & Scientific/Clinical Affairs, Pfizer Inc , New York, NY, USA
| | - Raul Isturiz
- Vaccines Medical Development & Scientific/Clinical Affairs, Pfizer Inc , Collegeville, PA, USA
| | - Luis Jodar
- Vaccines Medical Development & Scientific/Clinical Affairs, Pfizer Inc , Collegeville, PA, USA
| | - Bradford D Gessner
- Vaccines Medical Development & Scientific/Clinical Affairs, Pfizer Inc , Collegeville, PA, USA
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19
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Pizzutti K, Perez VP, Barbiero C, d'Azevedo PA, Fischer GB, Dias C. Identifying pneumococci in parapneumonic pleural effusion: Is there a role for culture-independent methods? Pediatr Pulmonol 2020; 55:484-489. [PMID: 31738021 DOI: 10.1002/ppul.24568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 10/29/2019] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To evaluate culture-independent procedures (immunochromatography and quantitative polymerase chain reaction [qPCR]) in the detection and susceptibility of Streptococcus pneumoniae directly from culture-negative pleural fluid (PF) in children. METHOD Detection of S. pneumoniae in PF of children with parapneumonic effusion and/or empyema by using two culture-independent methods: an immunochromatographic membrane test (IMT) which identifies the pneumococcal C antigen, and a real-time PCR test to detect pneumococcal genes lytA and pbp2b, a marker of susceptibility of β-lactam agents, in PF samples. RESULTS We tested 36 PF specimens and recorded the previous use of antimicrobials. In the final analysis, 34 samples were included. IMT and qPCR presented positive results in 23 (67.6%) and 24 (70.6%) of the samples, respectively, showing a moderate agreement (k = 0.518) between the two methods. From the 36 children included, 34 (94.4%) had antibiotic data available by the time when PFs were collected. Thirty-four (100%) children had been given treatment before PF sampling, with 33 (97%) receiving β-lactam antibiotics administered empirically. Of the 24 lytA real-time positive samples, 21 (87.5%) were also positive for pbp2b, a marker of β-lactam susceptibility. CONCLUSION The reduced sensitivity of culture for pneumococcal detection can be improved through the addition of IMT and qPCR analysis. The utility of qPCR combining detection of lytA and a marker of β-lactam susceptibility should be explored further.
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Affiliation(s)
- Kauana Pizzutti
- Basic Health Sciences, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil
| | - Vinícius P Perez
- Basic Health Sciences, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil
| | - Caroline Barbiero
- Pediatric Pneumology, Hospital da Criança Santo Antônio da Santa Casa de Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil
| | - Pedro A d'Azevedo
- Basic Health Sciences, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil
| | - Gilberto B Fischer
- Pediatric Pneumology, Hospital da Criança Santo Antônio da Santa Casa de Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil
| | - Cícero Dias
- Basic Health Sciences, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil
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20
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Imai K, Nemoto R, Kodana M, Tarumoto N, Sakai J, Kawamura T, Ikebuchi K, Mitsutake K, Murakami T, Maesaki S, Fujiwara T, Hayakawa S, Hoshino T, Seki M, Maeda T. Rapid and Accurate Species Identification of Mitis Group Streptococci Using the MinION Nanopore Sequencer. Front Cell Infect Microbiol 2020; 10:11. [PMID: 32083020 PMCID: PMC7002467 DOI: 10.3389/fcimb.2020.00011] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 01/10/2020] [Indexed: 11/13/2022] Open
Abstract
Differentiation between mitis group streptococci (MGS) bacteria in routine laboratory tests has become important for obtaining accurate epidemiological information on the characteristics of MGS and understanding their clinical significance. The most reliable method of MGS species identification is multilocus sequence analysis (MLSA) with seven house-keeping genes; however, because this method is time-consuming, it is deemed unsuitable for use in most clinical laboratories. In this study, we established a scheme for identifying 12 species of MGS (S. pneumoniae, S. pseudopneumoniae, S. mitis, S. oralis, S. peroris, S. infantis, S. australis, S. parasanguinis, S. sinensis, S. sanguinis, S. gordonii, and S. cristatus) using the MinION nanopore sequencer (Oxford Nanopore Technologies, Oxford, UK) with the taxonomic aligner "What's in My Pot?" (WIMP; Oxford Nanopore's cloud-based analysis platform) and Kraken2 pipeline with the custom database adjusted for MGS species identification. The identities of the species in reference genomes (n = 514), clinical isolates (n = 31), and reference strains (n = 4) were confirmed via MLSA. The nanopore simulation reads were generated from reference genomes, and the optimal cut-off values for MGS species identification were determined. For 31 clinical isolates (S. pneumoniae = 8, S. mitis = 17 and S. oralis = 6) and 4 reference strains (S. pneumoniae = 1, S. mitis = 1, S. oralis = 1, and S. pseudopneumoniae = 1), a sequence library was constructed via a Rapid Barcoding Sequencing Kit for multiplex and real-time MinION sequencing. The optimal cut-off values for the identification of MGS species for analysis by WIMP and Kraken2 pipeline were determined. The workflow using Kraken2 pipeline with a custom database identified all 12 species of MGS, and WIMP identified 8 MGS bacteria except S. infantis, S. australis, S. peroris, and S. sinensis. The results obtained by MinION with WIMP and Kraken2 pipeline were consistent with the MGS species identified by MLSA analysis. The practical advantage of whole genome analysis using the MinION nanopore sequencer is that it can aid in MGS surveillance. We concluded that MinION sequencing with the taxonomic aligner enables accurate MGS species identification and could contribute to further epidemiological surveys.
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Affiliation(s)
- Kazuo Imai
- Department of Infectious Disease and Infection Control, Saitama Medical University, Saitama, Japan
- Center for Clinical Infectious Diseases and Research, Saitama Medical University, Saitama, Japan
| | - Rina Nemoto
- Department of Microbiology, Saitama Medical University, Saitama, Japan
| | - Masahiro Kodana
- Department of Laboratory Medicine, Saitama Medical University, Saitama, Japan
| | - Norihito Tarumoto
- Department of Infectious Disease and Infection Control, Saitama Medical University, Saitama, Japan
- Center for Clinical Infectious Diseases and Research, Saitama Medical University, Saitama, Japan
| | - Jun Sakai
- Department of Infectious Disease and Infection Control, Saitama Medical University, Saitama, Japan
- Center for Clinical Infectious Diseases and Research, Saitama Medical University, Saitama, Japan
| | - Toru Kawamura
- Department of Laboratory Medicine, Saitama Medical University, Saitama, Japan
| | - Kenji Ikebuchi
- Department of Laboratory Medicine, Saitama Medical University, Saitama, Japan
| | - Kotaro Mitsutake
- Department of Infectious Diseases and Infection Control, International Medical Center, Saitama Medical University, Saitama, Japan
| | - Takashi Murakami
- Center for Clinical Infectious Diseases and Research, Saitama Medical University, Saitama, Japan
- Department of Microbiology, Saitama Medical University, Saitama, Japan
| | - Shigefumi Maesaki
- Department of Infectious Disease and Infection Control, Saitama Medical University, Saitama, Japan
- Center for Clinical Infectious Diseases and Research, Saitama Medical University, Saitama, Japan
| | - Taku Fujiwara
- Department of Pediatric Dentistry, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Satoshi Hayakawa
- Division of Microbiology, Department of Pathology and Microbiology, Nihon University School of Medicine, Tokyo, Japan
| | - Tomonori Hoshino
- Division of Pediatric Dentistry, Meikai University School of Dentistry, Sakado, Japan
| | - Mitsuko Seki
- Division of Microbiology, Department of Pathology and Microbiology, Nihon University School of Medicine, Tokyo, Japan
- Division of Pediatric Dentistry, Meikai University School of Dentistry, Sakado, Japan
| | - Takuya Maeda
- Center for Clinical Infectious Diseases and Research, Saitama Medical University, Saitama, Japan
- Department of Laboratory Medicine, Saitama Medical University, Saitama, Japan
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21
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Ullberg M, Özenci V. Identification and antimicrobial susceptibility testing of Gram-positive and Gram-negative bacteria from positive blood cultures using the Accelerate Pheno™ system. Eur J Clin Microbiol Infect Dis 2019; 39:139-149. [PMID: 31641972 PMCID: PMC6962126 DOI: 10.1007/s10096-019-03703-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 09/04/2019] [Indexed: 12/03/2022]
Abstract
Rapid identification and antimicrobial susceptibility testing remain a crucial step for early efficient therapy of bloodstream infections. Traditional methods require turnaround times of at least 2 days, while rapid procedures are often associated with extended hands-on time. The Accelerate Pheno™ System provides microbial identification results within 90 min and susceptibility data in approximately 7 h directly from positive blood cultures with only few minutes of hands-on time. The aim of this study was, therefore, to evaluate the performance of the Accelerate Pheno™ System in identification and antimicrobial susceptibility testing of both Gram-positive and Gram-negative bacteria directly from clinical blood culture samples. We analyzed 108 and 67 blood culture bottles using the Accelerate PhenoTest™ BC kit with software version v1.0 and the FDA-cleared version v1.2, respectively. Reliable identification was achieved for Enterobacteriaceae, staphylococci, and enterococci, with 76/80 (95%), 42/46 (91%), and 10/11 (91%) correct identifications. Limitations were observed in the identification of streptococci, including Streptococcus pneumoniae and Streptococcus pyogenes, and coagulase-negative staphylococci. Antimicrobial susceptibility results for Enterobacteriaceae, for amikacin, ertapenem, ciprofloxacin, gentamicin, meropenem, and piperacillin-tazobactam ranged between 86 and 100% categorical agreement. Using v1.2, results for ceftazidime showed 100% concordance with the reference method. For staphylococci, the overall performance reached 92% using v1.2. Qualitative tests for detection of methicillin or macrolide-lincosamide-streptogramin B (MLSB) resistance caused major and very major errors for isolates. Overall, the present data show that the Accelerate Pheno™ system can, in combination with Gram stain, be used as a rapid complementation to standard microbial diagnosis of bloodstream infections.
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Affiliation(s)
- Måns Ullberg
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
- Department of Clinical Microbiology, Karolinska University Hospital, Huddinge, SE 141 86, Stockholm, Sweden
| | - Volkan Özenci
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden.
- Department of Clinical Microbiology, Karolinska University Hospital, Huddinge, SE 141 86, Stockholm, Sweden.
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22
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Peela SCM, Sistla S, Tamilarasu K, Krishnamurthy S, Adhishivam B. Validation of pneumococcal iron acquisition ( piaA) gene for accurate identification of Streptococcus pneumoniae. Indian J Med Microbiol 2019; 36:504-507. [PMID: 30880696 DOI: 10.4103/ijmm.ijmm_18_274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Purpose The pneumococcal iron acquisition (piaA) gene is found to be highly specific and hence proposed as a diagnostic marker for identification of pneumococci. The objective of the present study was to evaluate the piaA gene as a genetic marker for the identification of pneumococci. Methods Twenty isolates were initially sequenced for lytA gene using published primers. PiaA-PCR (piaA polymerase chain reaction) was performed using in-house primers and protocol. Based on the sensitivity and specificity results, a final sample of 30 pneumococcal isolates and 11 non-pneumococcal isolates confirmed with lytA- sequencing were selected. Statistical analyses were performed using OpenEpi v3.01 and GraphPad Quickcalc at P < 0.05 as the level of statistical significance. Results Of the initial 20 samples tested, piaA PCR was positive in only 71.43% (10/14) of the pneumococcal isolates but was 100% specific (0/6 non-pneumococcal isolates) P = 0.011. When the PCR was performed on 41 samples, the sensitivity increased to 73.33% (95% of confidence interval [CI] = 55.55-85.82) and specificity remained the same P < 0.001. The level of agreement between the PCR and lytA-sequencing was found to be moderate (κ = 0.694; 95% CI = 0.432-0.955). Conclusions PiaA-PCR can be used as a specific marker for the identification of pneumococcus, though it is less sensitive. As the level of agreement was moderate, further analyses on a large number of samples can give conclusive evidence for its use as a diagnostic marker for pneumococcus.
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Affiliation(s)
- Sreeram Chandra Murthy Peela
- Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
| | - Sujatha Sistla
- Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
| | - Kadhiravan Tamilarasu
- Department of Medicine, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
| | - Sriram Krishnamurthy
- Department of Pediatrics, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
| | - B Adhishivam
- Department of Neonatology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
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Abstract
S. pseudopneumoniae is an overlooked pathogen emerging as the causative agent of lower-respiratory-tract infections and associated with chronic obstructive pulmonary disease (COPD) and exacerbation of COPD. However, much remains unknown on its clinical importance and epidemiology, mainly due to the lack of specific markers to distinguish it from S. pneumoniae. Here, we provide a new molecular marker entirely specific for S. pseudopneumoniae and offer a comprehensive view of the virulence and colonization genes found in this species. Finally, our results pave the way for further studies aiming at understanding the pathogenesis and epidemiology of S. pseudopneumoniae. Streptococcus pseudopneumoniae is a close relative of the major human pathogen S. pneumoniae. It is increasingly associated with lower-respiratory-tract infections (LRTI) and a high prevalence of antimicrobial resistance (AMR). S. pseudopneumoniae is difficult to identify using traditional typing methods due to similarities with S. pneumoniae and other members of the mitis group (SMG). Using whole-genome sequencing of LRTI isolates and a comparative genomic approach, we found that a large number of pneumococcal virulence and colonization genes are present in the core S. pseudopneumoniae genome. We also reveal an impressive number of novel surface-exposed proteins encoded by the genome of this species. In addition, we propose a new and entirely specific molecular marker useful for the identification of S. pseudopneumoniae. Phylogenetic analyses of S. pseudopneumoniae show that specific clades are associated with allelic variants of core proteins. Resistance to tetracycline and macrolides, the two most common types of resistance, were found to be encoded by Tn916-like integrating conjugative elements and Mega-2. Overall, we found a tight association of genotypic determinants of AMR and phenotypic AMR with a specific lineage of S. pseudopneumoniae. Taken together, our results shed light on the distribution in S. pseudopneumoniae of genes known to be important during invasive disease and colonization and provide insight into features that could contribute to virulence, colonization, and adaptation.
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24
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Olwagen CP, Adrian PV, Madhi SA. Performance of the Biomark HD real-time qPCR System (Fluidigm) for the detection of nasopharyngeal bacterial pathogens and Streptococcus pneumoniae typing. Sci Rep 2019; 9:6494. [PMID: 31019272 PMCID: PMC6482308 DOI: 10.1038/s41598-019-42846-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 03/22/2019] [Indexed: 01/26/2023] Open
Abstract
Traditional qPCR assays for pneumococcal detection and serotype characterization require large sample volume, is expensive and labor intensive. We aimed to develop a quantitative nanofluidic Fluidigm assay to overcome some of these shortcomings. A quantitative Fluidigm assay was established to detect 11 bacterial pathogens, 55 pneumococcal serotypes and 6 serotypes of H. influenzae. The Fluidigm assay results were compared to conventional qPCR and culture. All reactions in the Fluidigm assay effectively amplified their respective targets with high sensitivity and specificity compared to qPCR. There was excellent concordance between qPCR and Fluidigm for detection of carriage prevalence (kappa > 0.75) and density (Rho > 0.95). Fluidigm identified an additional 7 (4.2%) serotypes over those detected by qPCR. There was a modest concordance between culture and Fluidigm for the majority of reactions detecting S. pneumoniae serotypes/serogroups (kappa > 0.6), with Fluidigm identifying an additional 113 (39.1%) serotypes. Discordant results between the three methods were associated with a low carriage density. The Fluidigm assay was able to detect common pneumococcal serotypes, H. influenzae serotypes, and other common nasopharyngeal bacterial organisms simultaneously. Deployment of this assay in epidemiological studies could provide better insight into the effect of PCV immunization on the nasopharyngeal microbiota in the community.
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Affiliation(s)
- Courtney P Olwagen
- Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Faculty Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - Peter V Adrian
- Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Faculty Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Shabir A Madhi
- Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Faculty Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, Faculty Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
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25
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Identification of Streptococcus pneumoniae by a real-time PCR assay targeting SP2020. Sci Rep 2019; 9:3285. [PMID: 30824850 PMCID: PMC6397248 DOI: 10.1038/s41598-019-39791-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 01/21/2019] [Indexed: 11/15/2022] Open
Abstract
Real-time PCR targeting lytA (the major autolysin gene) and piaB (permease gene of the pia ABC transporter) are currently used as the gold-standard culture-independent assays for Streptococcus pneumoniae identification. We evaluated the performance of a new real-time PCR assay – targeting SP2020 (putative transcriptional regulator gene) – and compared its performance with the assays previously described. A collection of 150 pneumococci, 433 non-pneumococci and 240 polymicrobial samples (obtained from nasopharynx, oropharynx, and saliva; 80 from each site) was tested. SP2020 and lytA-CDC assays had the best performance (sensitivity of 100% for each compared to 95.3% for piaB). The specificity for lytA and piaB was 99.5% and for SP2020 was 99.8%. Misidentifications occurred for the three genes: lytA, piaB and SP2020 were found in non-pneumococcal strains; piaB was absent in some pneumococci including a serotype 6B strain. Combining lytA and SP2020 assays resulted in no misidentifications. Most polymicrobial samples (88.8%) yielded concordant results for the three molecular targets. The remaining samples seemed to contain non-typeable pneumococci (0.8%), and non-pneumococci positive for lytA (1.7%) or SP2020 (8.7%). We propose that combined detection of both lytA-CDC and SP2020 is a powerful strategy for the identification of pneumococcus either in pure cultures or in polymicrobial samples.
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26
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Milucky J, Carvalho MDG, Rouphael N, Bennett NM, Talbot HK, Harrison LH, Farley MM, Walston J, Pimenta F, Lessa FC. Streptococcus pneumoniae colonization after introduction of 13-valent pneumococcal conjugate vaccine for US adults 65 years of age and older, 2015-2016. Vaccine 2019; 37:1094-1100. [PMID: 30685247 PMCID: PMC6371770 DOI: 10.1016/j.vaccine.2018.12.075] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 12/20/2018] [Accepted: 12/24/2018] [Indexed: 01/05/2023]
Abstract
BACKGROUND Vaccination of children with 13-valent pneumococcal conjugate vaccine (PCV13) led to declines in vaccine-type pneumococcal nasopharyngeal carriage among adults through indirect effects. In August 2014, PCV13 immunization of all U.S. adults ≥65 years of age was recommended. This study sought to define prevalence and serotype distribution of pneumococcal carriage among adults ≥65 years of age and to describe risk factors for colonization soon after introduction of PCV13 in adults. METHODS A cross-sectional survey of non-institutionalized U.S. adults ≥65 years of age was conducted in four states in 2015-2016. Demographic information, risk factors for disease, PCV13 vaccination history, and nasopharyngeal (NP) and oropharyngeal (OP) swabs were collected. NP and OP swabs were processed separately and pneumococcal isolates were serotyped by Quellung reaction. Antimicrobial susceptibility of pneumococcal isolates was performed. NP swabs also underwent real-time PCR for pneumococcal detection and serotyping. RESULTS Of 2989 participants, 45.3% (1354/2989) had been vaccinated with PCV13. Fifty-five (1.8%) carried pneumococcus (45 identified by culture and 10 by real-time PCR only) and PCV13 serotypes were found in eight (0.3%) participants. Almost half (22/45) of pneumococcal isolates were not susceptible to at least one of the antibiotics tested. Vaccine-type carriage among vaccinated and unvaccinated individuals was similar (0.2% vs. 0.1%, respectively). Respiratory symptoms were associated with higher odds of pneumococcal colonization (adjusted OR: 2.1; 95% CI = 1.1-3.8). CONCLUSIONS Pneumococcal carriage among non-institutionalized adults ≥65 years of age was very low. Less than 0.5% of both vaccinated and unvaccinated individuals in our study carried vaccine-type serotypes. Over a decade of PCV vaccination of children likely led to indirect effects in adults. However, given the low vaccine-type carriage rates we observed in an already high PCV13 adult coverage setting, it is difficult to attribute our findings to the direct versus indirect effects of PCV13 on adult carriage.
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Affiliation(s)
- Jennifer Milucky
- Centers for Disease Control and Prevention, National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, Atlanta, Georgia.
| | - Maria de Gloria Carvalho
- Centers for Disease Control and Prevention, National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, Atlanta, Georgia
| | - Nadine Rouphael
- Emory University School of Medicine, Department of Medicine, Atlanta, Georgia; Hope Clinic of the Emory Vaccine Center, Emory University, Decatur, Georgia
| | - Nancy M Bennett
- University of Rochester School of Medicine and Dentistry, Department of Medicine, Rochester, New York
| | - H Keipp Talbot
- Vanderbilt University Medical Center, Nashville, Tennessee
| | - Lee H Harrison
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Monica M Farley
- Emory University School of Medicine, Department of Medicine, Atlanta, Georgia; Atlanta Veterans Affairs Medical Center, Atlanta, Georgia
| | - Jeremy Walston
- Division of Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine
| | - Fabiana Pimenta
- Centers for Disease Control and Prevention, National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, Atlanta, Georgia
| | - Fernanda C Lessa
- Centers for Disease Control and Prevention, National Center for Immunization and Respiratory Diseases, Division of Bacterial Diseases, Atlanta, Georgia.
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27
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van Schaik ML, Duijkers R, Paternotte N, Jansen R, Rozemeijer W, van der Reijden WA, Boersma WG. Feasibility of a quantitative polymerase chain reaction assay for diagnosing pneumococcal pneumonia using oropharyngeal swabs. Mol Biol Rep 2019; 46:1013-1021. [PMID: 30569391 PMCID: PMC7089193 DOI: 10.1007/s11033-018-4558-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 12/06/2018] [Indexed: 11/30/2022]
Abstract
Streptococcus pneumoniae is the most important pathogen causing community-acquired pneumonia (CAP). The current diagnostic microbial standard detects S. pneumoniae in less than 30% of CAP cases. A quantitative polymerase chain reaction (PCR) targeting autolysin (lytA) is able to increase the rate of detection. The aim of this study is validation of this quantitative PCR in vitro using different available strains and in vivo using clinical samples (oropharyngeal swabs). The PCR autolysin (lytA) was validated by testing the intra- and inter-run variability. Also, the in vitro specificity and sensitivity, including the lower limit of detection was determined. In addition, a pilot-study was performed using samples from patients (n = 28) with pneumococcal pneumonia and patients (n = 28) with a pneumonia without detection of S. pneumoniae with the current diagnostic microbial standard, but with detection of either a viral and or another bacterial pathogen to validate this test further. The intra- and inter-run variability were relatively low (SD's ranging from 0.08 to 0.96 cycle thresholds). The lower limit of detection turned out to be 1-10 DNA copies/reaction. In-vitro sensitivity and specificity of the tested specimens (8 strains carrying lytA and 6 strains negative for lytA) were both 100%. In patients with pneumococcal and non-pneumococcal pneumonia a cut-off value of 6.000 copies/mL would lead to a sensitivity of 57.1% and a specificity of 85.7%. We were able to develop a quantitative PCR targeting lytA with good in-vitro test characteristics.
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Affiliation(s)
- M L van Schaik
- Department Pulmonology, Noordwest Ziekenhuisgroep, Alkmaar, The Netherlands
- Department Molecular Biology, Regional Laboratory for Medical Microbiology and Public Health, Haarlem, The Netherlands
- Department of Pulmonology, Isala clinics Zwolle, Dr. van Heesweg 2, 8025AB, Zwolle, The Netherlands
| | - R Duijkers
- Department Pulmonology, Noordwest Ziekenhuisgroep, Alkmaar, The Netherlands
| | - N Paternotte
- Department Pulmonology, Noordwest Ziekenhuisgroep, Alkmaar, The Netherlands
| | - R Jansen
- Department Molecular Biology, Regional Laboratory for Medical Microbiology and Public Health, Haarlem, The Netherlands
| | - W Rozemeijer
- Department Medical Microbiology, Noordwest Ziekenhuisgroep, Alkmaar, The Netherlands
| | - W A van der Reijden
- Department Molecular Biology, Regional Laboratory for Medical Microbiology and Public Health, Haarlem, The Netherlands
| | - W G Boersma
- Department Pulmonology, Noordwest Ziekenhuisgroep, Alkmaar, The Netherlands.
- Department of Pulmonary Diseases, Northwest Hospital Group, P.O. Box 501, 1800AM, Alkmaar, The Netherlands.
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28
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Camelo-Castillo A, Henares D, Brotons P, Galiana A, Rodríguez JC, Mira A, Muñoz-Almagro C. Nasopharyngeal Microbiota in Children With Invasive Pneumococcal Disease: Identification of Bacteria With Potential Disease-Promoting and Protective Effects. Front Microbiol 2019; 10:11. [PMID: 30745895 PMCID: PMC6360994 DOI: 10.3389/fmicb.2019.00011] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 01/07/2019] [Indexed: 01/26/2023] Open
Abstract
Background and Aims: The risk of suffering from some infectious diseases can be related to specific microbiota profiles. Specifically, the nasopharyngeal microbiota could play a role as a risk or protective factor in the development of invasive disease caused by S. pneumoniae. Methodology: We analyzed the nasopharyngeal microbiota of children with invasive pneumococcal disease (IPD) and that of healthy controls matched by age, sex, and seasonality from Catalonia, Spain. Epidemiological, microbiological and clinical variables were considered to compare microbiota profiles, analyzed by sequencing the V1-V4 region of the 16S rRNA gene. Results: Twenty-eight children with IPD (median age 43 months) and 28 controls (42.6 months) were included in the study. IPD children presented a significantly higher bacterial diversity and richness (p < 0.001). Principal coordinate analysis revealed three different microbiota profiles: microbiota A, dominated by the genus Dolosigranulum (44.3%); Microbiota B, mostly represented by Streptococcus (36.9%) and Staphylococcus (21.3%) and a high diversity of anaerobic genera including Veillonella, Prevotella and Porphyromonas; and Microbiota C, mainly containing Haemophilus (52.1%) and Moraxella (31.4%). The only explanatory factor for the three microbiotas was the classification of children into disease or healthy controls (p = 0.006). A significant negative correlation was found between Dolosigranulum vs. Streptococcus (p = 0.029), suggesting a potential antagonistic effect against pneumococcal pathogens. Conclusions: The higher bacterial diversity and richness in children with IPD could suggest an impaired immune response. This lack of immune competence could be aggravated by breastfeeding <6 months and by the presence of keystone pathogens such as Porphyromonas, a bacterium which has been shown to be able to manipulate the immune response, and that could favor the overgrowth of many proteolytic anaerobic organisms giving rise to a dramatic dysbiosis. From an applied viewpoint, we found suggestive microbiota profiles associated to IPD or asymptomatic colonization that could be used as disease biomarkers or to pave the way for characterizing health-associated inhabitants of the respiratory tract. The identification of beneficial bacteria could be useful to prevent pneumococcal infections by integrating those microorganisms in a probiotic formula. The present study suggests not only respiratory tract samples, but also breast milk, as a potential source of those beneficial bacteria.
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Affiliation(s)
- Anny Camelo-Castillo
- Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Desirée Henares
- Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, Barcelona, Spain.,Network of Epidemiology and Public Health, CIBERESP, Barcelona, Spain
| | - Pedro Brotons
- Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, Barcelona, Spain.,Network of Epidemiology and Public Health, CIBERESP, Barcelona, Spain
| | - Antonio Galiana
- Department of Microbiology, Hospital de Alicante, Alicante, Spain
| | | | - Alex Mira
- Network of Epidemiology and Public Health, CIBERESP, Barcelona, Spain.,Center for Advanced Research in Public Health, FISABIO Foundation, Valencia, Spain
| | - Carmen Muñoz-Almagro
- Institut de Recerca Sant Joan de Déu, Hospital Sant Joan de Déu, Barcelona, Spain.,Network of Epidemiology and Public Health, CIBERESP, Barcelona, Spain.,School of Medicine, Universitat Internacional de Catalunya, Barcelona, Spain
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Kovács E, Sahin-Tóth J, Tóthpál A, Kristóf K, van der Linden M, Tirczka T, Dobay O. Vaccine-driven serotype-rearrangement is seen with latency in clinical isolates: Comparison of carried and clinical pneumococcal isolates from the same time period in Hungary. Vaccine 2019; 37:99-108. [DOI: 10.1016/j.vaccine.2018.11.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 11/08/2018] [Accepted: 11/12/2018] [Indexed: 01/09/2023]
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30
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Streptococcus mitis Expressing Pneumococcal Serotype 1 Capsule. Sci Rep 2018; 8:17959. [PMID: 30568178 PMCID: PMC6299277 DOI: 10.1038/s41598-018-35921-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 11/08/2018] [Indexed: 01/22/2023] Open
Abstract
Streptococcus pneumoniae's polysaccharide capsule is an important virulence factor; vaccine-induced immunity to specific capsular polysaccharide effectively prevents disease. Serotype 1 S. pneumoniae is rarely found in healthy persons, but is highly invasive and a common cause of meningitis outbreaks and invasive disease outside of the United States. Here we show that genes for polysaccharide capsule similar to those expressed by pneumococci were commonly detected by polymerase chain reaction among upper respiratory tract samples from older US adults not carrying pneumococci. Serotype 1-specific genes were predominantly detected. In five oropharyngeal samples tested, serotype 1 gene belonging to S. mitis expressed capsules immunologically indistinct from pneumococcal capsules. Whole genome sequencing revealed three distinct S. mitis clones, each representing a cps1 operon highly similar to the pneumococcal cps1 reference operon. These findings raise important questions about the contribution of commensal streptococci to natural immunity against pneumococci, a leading cause of mortality worldwide.
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Sanz JC, Ríos E, Rodríguez-Avial I, Ramos B, Marín M, Cercenado E. Identification of Streptococcus pneumoniae lytA , plyA and psaA genes in pleural fluid by multiplex real-time PCR. Enferm Infecc Microbiol Clin 2018; 36:428-430. [DOI: 10.1016/j.eimc.2017.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/12/2017] [Accepted: 07/13/2017] [Indexed: 10/19/2022]
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Branche AR, Yang H, Java J, Holden-Wiltse J, Topham DJ, Peasley M, Frost MR, Nahm MH, Falsey AR. Effect of prior vaccination on carriage rates of Streptococcus pneumoniae in older adults: A longitudinal surveillance study. Vaccine 2018; 36:4304-4310. [PMID: 29871816 DOI: 10.1016/j.vaccine.2018.05.107] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 03/16/2018] [Accepted: 05/27/2018] [Indexed: 01/09/2023]
Abstract
INTRODUCTION Pneumococcus is a commensal of the upper respiratory tract and colonization is common in young children. Carriage studies have provided insights on vaccine effects in children and may also be useful for assessing vaccines in adults. However, culture based prevalence studies in older adults describe low colonization rates. Therefore, we assessed cumulative incidence of pneumococcal colonization in older adults using polymerase chain reaction (PCR) targeting the lytA gene and risk factors for carriage. METHODS 100 community-dwelling adults ≥65 years were enrolled the winter of 2015 and followed biweekly for 12 months. Medical, vaccination and illness history as well as nasopharyngeal (NP) and oropharyngeal (OP) samples were collected. Combined OP and NP were incubated in enrichment broth and screened using real-time lytA PCR. Samples from new colonization events (lytA PCR+) were cultured on gentamicin blood agar plates. Isolates identified by colony morphology as S. pneumoniae were serotyped using a multiplex combined immunoassay-PCR platform which classifies 96 serotypes. Cumulative incidence of pneumococcal carriage was calculated and risk factors for carriage assessed. RESULTS The cumulative incidence of colonization was 41% by PCR and 14% by culture. Monthly prevalence ranged from 0 to 17% by PCR and 1 to 4% by culture with peaks in the spring and fall. Demographics were similar between colonized and never colonized subjects although colonized were younger (72.4 vs. 75.0 years, P = 0.06). Vaccination with any pneumococcal vaccine before or during study period was associated with decreased risk of becoming colonized (p < 0.001) as was vaccination with either the 13-valent conjugated pneumococcal vaccine (PCV13) or 23-valent polysaccharide vaccine (PPSV23) (p < 0.001). CONCLUSION Pneumococcal colonization in older adults as detected by lytA PCR is frequent and pneumococcal vaccination appears to be associated with decreased risk of carriage. Further study is needed to understand the biological significance of molecular detection of pneumococcus in adults.
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Affiliation(s)
- Angela R Branche
- Department of Medicine, University of Rochester, Rochester, NY, USA.
| | - Hongmei Yang
- Department of Biostatistics and Computational Biology, University of Rochester, Rochester, NY, USA
| | - James Java
- Department of Biostatistics and Computational Biology, University of Rochester, Rochester, NY, USA
| | - Jeanne Holden-Wiltse
- Department of Biostatistics and Computational Biology, University of Rochester, Rochester, NY, USA
| | - David J Topham
- Department of Immunology and Microbiology, University of Rochester, Rochester, NY, USA
| | - Michael Peasley
- Department of Medicine, University of Rochester, Rochester, NY, USA
| | - Michael R Frost
- Department of Medicine, Division of Pulmonary, Allergy, & Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Moon H Nahm
- Department of Medicine, Division of Pulmonary, Allergy, & Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Ann R Falsey
- Department of Medicine, University of Rochester, Rochester, NY, USA
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Wyllie AL, Pannekoek Y, Bovenkerk S, van Engelsdorp Gastelaars J, Ferwerda B, van de Beek D, Sanders EAM, Trzciński K, van der Ende A. Sequencing of the variable region of rpsB to discriminate between Streptococcus pneumoniae and other streptococcal species. Open Biol 2018; 7:rsob.170074. [PMID: 28931649 PMCID: PMC5627049 DOI: 10.1098/rsob.170074] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 08/11/2017] [Indexed: 01/08/2023] Open
Abstract
The vast majority of streptococci colonizing the human upper respiratory tract are commensals, only sporadically implicated in disease. Of these, the most pathogenic is Mitis group member, Streptococcus pneumoniae Phenotypic and genetic similarities between streptococci can cause difficulties in species identification. Using ribosomal S2-gene sequences extracted from whole-genome sequences published from 501 streptococci, we developed a method to identify streptococcal species. We validated this method on non-pneumococcal isolates cultured from cases of severe streptococcal disease (n = 101) and from carriage (n = 103), and on non-typeable pneumococci from asymptomatic individuals (n = 17) and on whole-genome sequences of 1157 pneumococcal isolates from meningitis in the Netherlands. Following this, we tested 221 streptococcal isolates in molecular assays originally assumed specific for S. pneumoniae, targeting cpsA, lytA, piaB, ply, Spn9802, zmpC and capsule-type-specific genes. Cluster analysis of S2-sequences showed grouping according to species in line with published phylogenies of streptococcal core genomes. S2-typing convincingly distinguished pneumococci from non-pneumococcal species (99.2% sensitivity, 100% specificity). Molecular assays targeting regions of lytA and piaB were 100% specific for S. pneumoniae, whereas assays targeting cpsA, ply, Spn9802, zmpC and selected serotype-specific assays (but not capsular sequence typing) showed a lack of specificity. False positive results were over-represented in species associated with carriage, although no particular confounding signal was unique for carriage isolates.
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Affiliation(s)
- Anne L Wyllie
- Department of Paediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Yvonne Pannekoek
- Department of Medical Microbiology, Academic Medical Center, Amsterdam, the Netherlands
| | - Sandra Bovenkerk
- Department of Medical Microbiology, Academic Medical Center, Amsterdam, the Netherlands
| | - Jody van Engelsdorp Gastelaars
- Department of Paediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Bart Ferwerda
- Department of Neurology, Academic Medical Center, Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - Diederik van de Beek
- Department of Neurology, Academic Medical Center, Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - Elisabeth A M Sanders
- Department of Paediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, the Netherlands.,Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - Krzysztof Trzciński
- Department of Paediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Arie van der Ende
- Department of Medical Microbiology, Academic Medical Center, Amsterdam, the Netherlands.,The Netherlands Reference Laboratory for Bacterial Meningitis, Academic Medical Center, Amsterdam, the Netherlands
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Pathogen Identification by Multiplex LightMix Real-Time PCR Assay in Patients with Meningitis and Culture-Negative Cerebrospinal Fluid Specimens. J Clin Microbiol 2018; 56:JCM.01492-17. [PMID: 29237781 PMCID: PMC5786711 DOI: 10.1128/jcm.01492-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 11/30/2017] [Indexed: 11/20/2022] Open
Abstract
Acute bacterial meningitis is a medical emergency, and delays in initiating effective antimicrobial therapy result in increased morbidity and mortality. Culture-based methods, thus far considered the “gold standard” for identifying bacterial microorganisms, require 24 to 48 h to provide a diagnosis. In addition, antimicrobial therapy is often started prior to clinical sample collection, thereby decreasing the probability of confirming the bacterial pathogen by culture-based methods. To enable a fast and accurate detection of the most important bacterial pathogens causing meningitis, namely, Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Streptococcus agalactiae, and Listeria monocytogenes, we evaluated a commercially available multiplex LightMix real-time PCR (RT-PCR) in 220 cerebrospinal fluid (CSF) specimens. The majority of CSF samples were collected by lumbar puncture, but we also included some CSF samples from patients with symptoms of meningitis from the neurology department that were recovered from shunts. CSF samples were analyzed by multiplex RT-PCR enabling a first diagnosis within a few hours after sample arrival at our institute. In contrast, bacterial identification took between 24 and 48 h by culture. Overall, a high agreement of bacterial identification between culture and multiplex RT-PCR was observed (99%). Moreover, multiplex RT-PCR enabled the detection of pathogens, S. pneumoniae (n = 2), S. agalactiae (n = 1), and N. meningitidis (n = 1), in four culture-negative samples. As a complement to classical bacteriological CSF culture, the LightMix RT-PCR assay proved to be valuable by improving the rapidity and accuracy of the diagnosis of bacterial meningitis.
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lytA Quantitative PCR on Sputum and Nasopharyngeal Swab Samples for Detection of Pneumococcal Pneumonia among the Elderly. J Clin Microbiol 2017; 56:JCM.01231-17. [PMID: 29118170 PMCID: PMC5744198 DOI: 10.1128/jcm.01231-17] [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: 08/03/2017] [Accepted: 10/22/2017] [Indexed: 11/20/2022] Open
Abstract
Real-time quantitative PCR (qPCR) assay of sputum or nasopharyngeal specimens has shown promising results in the detection of pneumococcal community-acquired pneumonia (PncCAP). We applied qPCR for the autolysin gene (lytA) and compared sputum and nasopharyngeal swab (NPS) pneumococcal loads in elderly patients with community-acquired pneumonia (CAP), and specifically in patients with PncCAP, to those in patient groups with other respiratory diseases. We studied patients aged ≥65 years with radiologically confirmed CAP, clinical CAP not retrospectively radiologically confirmed, other acute respiratory infections, or stable chronic lung disease. Pneumococcal etiology of CAP was ascertained by using a combination of multiple diagnostic methods. We analyzed sputum and NPS specimens by lytA qPCR with 104 pneumococcal genome equivalents (GE)/ml as a cutoff for positivity. Among PncCAP patients, lytA qPCR detected pneumococci in 94% of the sputum samples and in large quantities (mean, 6.82 ± 1.02 log10 GE/ml) but less frequently in NPS (44%) and in smaller quantities (5.55 ± 0.92 log10 GE/ml). In all other patient groups, ≤10% of the sputum samples and <5% of the NPS samples were lytA qPCR positive; but when they were positive, the sputum pneumococcal loads were similar to those in the PncCAP patients, suggesting a pneumococcal etiology in these patients. This was supported by other pneumococcal assay results. Overall, sputum lytA qPCR positivity was more common in PncCAP patients than in the other patient groups, but the quantitative results were mainly similar. NPS lytA qPCR was less sensitive than sputum lytA qPCR in detecting PncCAP.
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Current challenges in the accurate identification of Streptococcus pneumoniae and its serogroups/serotypes in the vaccine era. J Microbiol Methods 2017; 141:48-54. [DOI: 10.1016/j.mimet.2017.07.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 07/30/2017] [Accepted: 07/31/2017] [Indexed: 11/21/2022]
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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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Slotved HC, Facklam RR, Fuursted K. Assessment of a novel bile solubility test and MALDI-TOF for the differentiation of Streptococcus pneumoniae from other mitis group streptococci. Sci Rep 2017; 7:7167. [PMID: 28769078 PMCID: PMC5540920 DOI: 10.1038/s41598-017-07772-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/03/2017] [Indexed: 01/25/2023] Open
Abstract
This study assesses a novel bile solubility test and MALDI-TOF for the differentiation of Streptococcus pneumoniae from other mitis group streptococci, including differentiation of S. pneumoniae from Streptococcus pseudopneumoniae. Eighty-four species verified mitis group isolates were subjected to our bile solubility test (which measures and calculates the differences of absorbance in the test tube containing 10% sodium deoxycholate versus a blank control tube, after incubation for 10 minutes at 36 °C using a spectrophotometer) and MALDI-TOF MS (both the standard result output and by visual spectra evaluation). Applying a calculated optimal cut-off absorbance-value of 2.1, differentiated S. pneumoniae from all but one other mitis group streptococci (one S. mitis isolate generated an OD-value above 2.1). MALDI-TOF score value identification identified correctly 46 S. pneumoniae and 4 S. pseudopneumoniae but misidentified 16 other mitis group strains. Visual spectra evaluation correctly identified all S. pneumoniae and S. pseudopneumoniae strains but misidentified 13 other mitis group strains. The bile solubility test based on spectrophotometric reading described in this study can differentiate S. pneumoniae from other Streptococcus species. Combining the bile solubility test and the MALDI-TOF spectra results provide a correct identification of all S. pneumoniae and S. pseudopneumoniae isolates.
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Affiliation(s)
- Hans-Christian Slotved
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark.
| | - Richard R Facklam
- Retired, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Kurt Fuursted
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
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El Moujaber G, Osman M, Rafei R, Dabboussi F, Hamze M. Molecular mechanisms and epidemiology of resistance in Streptococcus pneumoniae in the Middle East region. J Med Microbiol 2017. [DOI: 10.1099/jmm.0.000503] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Grace El Moujaber
- Laboratoire Microbiologie Santé et Environnement (LMSE), Ecole Doctorale des Sciences et de Technologie, Faculté de Santé Publique, Université Libanaise, Tripoli, Lebanon
| | - Marwan Osman
- Laboratoire Microbiologie Santé et Environnement (LMSE), Ecole Doctorale des Sciences et de Technologie, Faculté de Santé Publique, Université Libanaise, Tripoli, Lebanon
| | - Rayane Rafei
- Laboratoire Microbiologie Santé et Environnement (LMSE), Ecole Doctorale des Sciences et de Technologie, Faculté de Santé Publique, Université Libanaise, Tripoli, Lebanon
| | - Fouad Dabboussi
- Laboratoire Microbiologie Santé et Environnement (LMSE), Ecole Doctorale des Sciences et de Technologie, Faculté de Santé Publique, Université Libanaise, Tripoli, Lebanon
| | - Monzer Hamze
- Laboratoire Microbiologie Santé et Environnement (LMSE), Ecole Doctorale des Sciences et de Technologie, Faculté de Santé Publique, Université Libanaise, Tripoli, Lebanon
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Andrade DC, Borges IC, Bouzas ML, Oliveira JR, Fukutani KF, Queiroz AT, de Oliveira CI, Barral A, Van Weyenbergh J, Nascimento-Carvalho C. 10-valent pneumococcal conjugate vaccine (PCV10) decreases metabolic activity but not nasopharyngeal carriage of Streptococcus pneumoniae and Haemophilus influenzae. Vaccine 2017; 35:4105-4111. [DOI: 10.1016/j.vaccine.2017.06.048] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 06/09/2017] [Accepted: 06/19/2017] [Indexed: 01/30/2023]
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Evaluation of lytB Gene for Detection of Streptococcus pneumoniae in Isolates and Clinical Specimens by Real-Time PCR. Jundishapur J Microbiol 2017. [DOI: 10.5812/jjm.14378] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
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