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Yougbare I, McTague A, He L, Choy CH, Su J, Gajewska B, Azizi A. Anti-FIM and Anti-FHA Antibodies Inhibit Bordetella pertussis Growth and Reduce Epithelial Cell Inflammation Through Bacterial Aggregation. Front Immunol 2021; 11:605273. [PMID: 33384692 PMCID: PMC7770163 DOI: 10.3389/fimmu.2020.605273] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 11/11/2020] [Indexed: 11/19/2022] Open
Abstract
The pertussis vaccination is highly recommended for infants, children, and pregnant women. Despite a high coverage of vaccination, pertussis continues to be of public health concern as a re-emerging infectious disease. The mechanism by which vaccine-elicited anti-pertussis antibodies mediate direct bactericidal effects is poorly understood. In this study, we showed that the interaction of B. pertussis with A549 epithelial cells induce release of biological factors which enhance bacteria growth. Complement-depleted antisera from vaccine-immunized guinea pigs or monoclonal antibodies targeting FHA and FIM mediate bacteria aggregation and elicit bactericidal effects. Our in vitro results indicated that aggregation of bacteria through anti-FIM and anti-FHA specific antibodies is one of the major biological mechanisms to clear bacterial infections and restore epithelial cell survival in vitro. Our data also indicates that the anti-pertussis antibodies reduce secretion of proinflammatory chemokines and cytokines by preventing interaction of B. pertussis with host cells. The results of this study not only demonstrate mechanism of action of anti-FIM and anti-FHA antibodies, but also opens translational applications for potential therapeutic approaches or development of analytical assays such as in vitro potency assays.
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Affiliation(s)
- Issaka Yougbare
- Immunology platform, Analytical Sciences North America, Sanofi Pasteur, Toronto, ON, Canada
| | - Adam McTague
- Immunology platform, Analytical Sciences North America, Sanofi Pasteur, Toronto, ON, Canada
| | - Liwei He
- Immunology platform, Analytical Sciences North America, Sanofi Pasteur, Toronto, ON, Canada
| | - Christopher H Choy
- Immunology platform, Analytical Sciences North America, Sanofi Pasteur, Toronto, ON, Canada
| | - Jin Su
- Immunology platform, Analytical Sciences North America, Sanofi Pasteur, Toronto, ON, Canada
| | - Beata Gajewska
- Immunology platform, Analytical Sciences North America, Sanofi Pasteur, Toronto, ON, Canada
| | - Ali Azizi
- Immunology platform, Analytical Sciences North America, Sanofi Pasteur, Toronto, ON, Canada
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Tao Y, Tang M, Luo L, Xiang L, Xia Y, Li B, Cao Q, Mo X. Identification of etiologic agents and clinical characteristics for patients suspected of having pertussis in a large Children's Hospital in China. ANNALS OF TRANSLATIONAL MEDICINE 2019; 7:443. [PMID: 31700879 PMCID: PMC6803182 DOI: 10.21037/atm.2019.08.85] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 08/15/2019] [Indexed: 01/03/2023]
Abstract
BACKGROUND In China, pertussis is a major health problem with an increasing incidence despite immunization efforts. Timely and accurate diagnosis is essential for the optimal management of pertussis, especially in severe cases. METHODS Nasopharyngeal swabs or sputum specimens were obtained from patients suspected of having pertussis on the day of hospitalization at Shanghai Children's Medical Center from December 01, 2016, to November 30, 2017. The specimens were tested with the FilmArray Respiratory Panel, a multiplex polymerase chain reaction (PCR) assay that detects 16 viruses, Bordetella pertussis (B. pertussis), Mycoplasma pneumoniae (M. pneumoniae), and Chlamydophila pneumoniae (C. pneumoniae). RESULTS Among the 140 children studied, 50.0% (70/140) were detected with a single pathogen, 45.0% (63/140) were detected with multiple pathogens, and 5.0% (7/140) had no detected pathogens. Forty-nine (35%, 49/140) patients tested positive for B. pertussis. Respiratory syncytial virus (RSV), parainfluenza virus (Para) and rhinovirus/enterovirus (Rhino/Entero) were the most prevalent pathogens in patients with pertussis-like syndrome. No significant differences between the groups with pertussis and pertussis-like syndrome were observed regarding the clinical symptoms. Severe cases were more frequently observed in unvaccinated, premature and pertussis/RSV co-infection patients. CONCLUSIONS Our study highlights the importance of the timely and accurate diagnosis of pertussis based on both clinical symptoms and laboratory methods.
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Affiliation(s)
- Yue Tao
- Department of Infectious Diseases, Shanghai Children’s Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
- The Laboratory of Pediatric Infectious Diseases, Pediatric Translational Medicine Institute, Shanghai Children’s Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Mingyu Tang
- Department of Respiratory Medicine, Shanghai Children’s Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Lijuan Luo
- Department of Infectious Diseases, Shanghai Children’s Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Long Xiang
- Pediatric Intensive Care Unit, Shanghai Children’s Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Yijun Xia
- Medical Affairs Director, Great China | bioMérieux (Shanghai) Company, Limited, Shanghai 200127, China
| | - Biru Li
- Pediatric Intensive Care Unit, Shanghai Children’s Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Qing Cao
- Department of Infectious Diseases, Shanghai Children’s Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Xi Mo
- The Laboratory of Pediatric Infectious Diseases, Pediatric Translational Medicine Institute, Shanghai Children’s Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
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Solano R, Masa-Calles J, Garib Z, Grullón P, Santiago SL, Brache A, Domínguez Á, Caylà JA. Epidemiology of pertussis in two Ibero-American countries with different vaccination policies: lessons derived from different surveillance systems. BMC Public Health 2016; 16:1178. [PMID: 27876021 PMCID: PMC5118903 DOI: 10.1186/s12889-016-3844-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 11/15/2016] [Indexed: 12/18/2022] Open
Abstract
Background Pertussis is a re-emerging disease worldwide despite its high vaccination coverage. European and Latin-American countries have used different surveillance and vaccination policies against pertussis. We compared the epidemiology of this disease in two Ibero-American countries with different vaccination and surveillance policies. Methods We compared the epidemiology of pertussis in Spain and the Dominican Republic (DR). We present a 10-year observational study of reported pertussis based on suspected and/or probable cases of pertussis identified by the national mandatory reporting system in both countries between 2005 and 2014. Both countries have a similar case definition for pertussis surveillance, although Spain applies laboratory testing, and uses real time PCR and/or culture for case confirmation while in DR only probable and/or suspected cases are reported. We analyzed incidence, hospitalization, case-fatality rates, mortality and vaccination coverage. Results The average annual incidence in children aged <1 year was 3.40/100,000 population in Spain and 12.15/100,000 in DR (p = 0.01). While the incidence in DR was generally higher than in Spain, in 2011 it was six times higher in Spain than in DR. The highest infant mortality in Spain was 0.017/100,000 in 2011, and the highest in DR was 0.08/100,000 in 2014 (p = 0.01). The proportion of hospitalized cases per year among children <1 year varied between 22.0% and 93.7% in Spain, and between 1.1% and 29.4% in DR (p = 0.0002), while mortality varied from 0 to 0.017 and 0 to 0.08 per 100,000 population in Spain and DR, respectively (p = 0.001). Vaccination coverage was 96.5% in Spain and 82.2% in DR (p = 0.001). Conclusions Pertussis is a public health problem in both countries. Surveillance, prevention and control measures should be improved, especially in DR. Current vaccination programs are not sufficient for preventing continued pertussis transmission, even in Spain which has high vaccination coverage.
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Affiliation(s)
- Rubén Solano
- CIBER Epidemiology and Public Health (CIBERESP), Epidemiology Service-Barcelona Public Health Agency, Pl. Lesseps 1, 08023, Barcelona, Spain. .,Department of Public Health, University of Barcelona, Barcelona, Spain. .,Epidemiology Service, Barcelona Public Health Agency, Barcelona, Spain.
| | - Josefa Masa-Calles
- CIBER Epidemiology and Public Health (CIBERESP), Epidemiology Service-Barcelona Public Health Agency, Pl. Lesseps 1, 08023, Barcelona, Spain.,National Centre for Epidemiology, Carlos III Health Institute, Madrid, Spain
| | - Zacarías Garib
- Extended Immunizations Programme, Dominican Ministry of Health and Social Assistance, Santo Domingo, Dominican Republic
| | - Patricia Grullón
- Extended Immunizations Programme, Dominican Ministry of Health and Social Assistance, Santo Domingo, Dominican Republic
| | - Sandy L Santiago
- Extended Immunizations Programme, Dominican Ministry of Health and Social Assistance, Santo Domingo, Dominican Republic
| | - Altagracia Brache
- Extended Immunizations Programme, Dominican Ministry of Health and Social Assistance, Santo Domingo, Dominican Republic
| | - Ángela Domínguez
- CIBER Epidemiology and Public Health (CIBERESP), Epidemiology Service-Barcelona Public Health Agency, Pl. Lesseps 1, 08023, Barcelona, Spain.,Department of Public Health, University of Barcelona, Barcelona, Spain
| | - Joan A Caylà
- CIBER Epidemiology and Public Health (CIBERESP), Epidemiology Service-Barcelona Public Health Agency, Pl. Lesseps 1, 08023, Barcelona, Spain.,Epidemiology Service, Barcelona Public Health Agency, Barcelona, Spain
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Safarchi A, Octavia S, Luu LDW, Tay CY, Sintchenko V, Wood N, Marshall H, McIntyre P, Lan R. Pertactin negative Bordetella pertussis demonstrates higher fitness under vaccine selection pressure in a mixed infection model. Vaccine 2015; 33:6277-81. [PMID: 26432908 DOI: 10.1016/j.vaccine.2015.09.064] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 09/04/2015] [Accepted: 09/20/2015] [Indexed: 11/25/2022]
Abstract
Whooping cough or pertussis is a highly infectious respiratory disease in humans caused by Bordetella pertussis. The use of acellular vaccines (ACV) has been associated with the recent resurgence of pertussis in developed countries including Australia despite high vaccination coverage where B. pertussis strains that do not express pertactin (Prn), a key antigenic component of the ACV, have emerged and become prevalent. In this study, we used an in vivo competition assay in mice immunised with ACV and in naïve (control) mice to compare the proportion of colonisation with recent clinical Prn positive and Prn negative B. pertussis strains from Australia. The Prn negative strain colonised the respiratory tract more effectively than the Prn positive strain in immunised mice, out-competing the Prn positive strain by day 3 of infection. However, in control mice, the Prn positive strain out-competed the Prn negative strain. Our findings of greater ability of Prn negative strains to colonise ACV-immunised mice are consistent with reports of selective advantage for these strains in ACV-immunised humans.
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Affiliation(s)
- Azadeh Safarchi
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Sophie Octavia
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Laurence Don Wai Luu
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Chin Yen Tay
- Pathology and Laboratory Medicine, University of Western Australia, Perth, Western Australia, Australia
| | - Vitali Sintchenko
- Centre for Infectious Diseases and Microbiology-Public Health, Institute of Clinical Pathology and Medical Research-Pathology West, Westmead Hospital, New South Wales, Australia; Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, New South Wales, Australia
| | - Nicholas Wood
- National Centre for Immunisation Research and Surveillance, Children's Hospital at Westmead and University of Sydney, New South Wales, Australia
| | - Helen Marshall
- Vaccinology and Immunology Research Trials Unit, Women's and Children's Hospital and School of Paediatrics and Reproductive Health and Robinson Research Institute, University of Adelaide, South Australia, Australia
| | - Peter McIntyre
- National Centre for Immunisation Research and Surveillance, Children's Hospital at Westmead and University of Sydney, New South Wales, Australia
| | - Ruiting Lan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia.
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5
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Yang Y, Yao K, Ma X, Shi W, Yuan L, Yang Y. Variation in Bordetella pertussis Susceptibility to Erythromycin and Virulence-Related Genotype Changes in China (1970-2014). PLoS One 2015; 10:e0138941. [PMID: 26406905 PMCID: PMC4583996 DOI: 10.1371/journal.pone.0138941] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 09/06/2015] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES To investigate changes in virulence-related genotypes and in the antimicrobial susceptibility of Bordetella pertussis isolates collected from the 1970s to 2014 in the northern part of China. METHODS A total of 124 B. pertussis isolates from three periods, the 1970s, 2000-2008, and May 2013-Sept 2014, were typed by multilocus sequence typing (MLST) and tested for antimicrobial susceptibility and virulence-related genes. A fragment of the 23S rRNA gene from each of the 99 isolates from 2013-2014 was amplified and sequenced. RESULTS All isolates from 2000-2008 and 2013-2014 were identified as ST2, whereas isolates from the 1970s were ST1. PtxA2/ptxC1/ptxP1/prn1/fim2-1/fim3-1/tcfA2, which was the same as the vaccine strain, was the only type in the 1970s. During the 2000s and 2013-2014, the virulence type ptxA1/ptxC1/ptxP1/prn1/fim2-1/fim3-1/tcfA2 was dominant, with frequencies of 68.4% and 91.9%, respectively. Nine ptxP3 strains, which were more virulent, were detected after 2000. All 124 isolates were susceptible to levofloxacin, sulphamethoxazole/trimethoprim and tetracycline. The isolates from the 1970s and 2000-2008 were susceptible to all tested macrolides, whereas 91.9% of the 2013-2014 isolates were highly resistant (minimal inhibitory concentration, MIC >256 μg/ml). No ptxP3 strain was resistant to macrolides. All erythromycin-resistant strains except for one had the A2047G mutation in the 23S rRNA gene. CONCLUSIONS Macrolide resistance of the B. pertussis population has been a serious problem in the northern part of China. Because most of the epidemic clone of the pathogen expresses the same antigen profiles as the vaccine strain, except ptxA, improvements in immunization strategies may prevent the spread of infection and drug resistance.
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Affiliation(s)
- Ying Yang
- Key Laboratory of Major Diseases in Children and National Key Discipline of Pediatrics (Capital Medical University), Ministry of Education, National Clinical Research Center for Respiratory Diseases, Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Beijing Pediatric Research Institute, Beijing Children’s Hospital, Capital Medical University, Beijing, China
| | - Kaihu Yao
- Key Laboratory of Major Diseases in Children and National Key Discipline of Pediatrics (Capital Medical University), Ministry of Education, National Clinical Research Center for Respiratory Diseases, Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Beijing Pediatric Research Institute, Beijing Children’s Hospital, Capital Medical University, Beijing, China
| | - Xiang Ma
- Respiratory department, Qilu Children’s Hospital, Shandong University, Jinan, China
| | - Wei Shi
- Key Laboratory of Major Diseases in Children and National Key Discipline of Pediatrics (Capital Medical University), Ministry of Education, National Clinical Research Center for Respiratory Diseases, Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Beijing Pediatric Research Institute, Beijing Children’s Hospital, Capital Medical University, Beijing, China
| | - Lin Yuan
- Key Laboratory of Major Diseases in Children and National Key Discipline of Pediatrics (Capital Medical University), Ministry of Education, National Clinical Research Center for Respiratory Diseases, Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Beijing Pediatric Research Institute, Beijing Children’s Hospital, Capital Medical University, Beijing, China
| | - Yonghong Yang
- Key Laboratory of Major Diseases in Children and National Key Discipline of Pediatrics (Capital Medical University), Ministry of Education, National Clinical Research Center for Respiratory Diseases, Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Beijing Pediatric Research Institute, Beijing Children’s Hospital, Capital Medical University, Beijing, China
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Nicoli EJ, Ayabina D, Trotter CL, Turner KM, Colijn C. Competition, coinfection and strain replacement in models of Bordetella pertussis. Theor Popul Biol 2015; 103:84-92. [DOI: 10.1016/j.tpb.2015.05.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 05/18/2015] [Accepted: 05/20/2015] [Indexed: 11/15/2022]
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Poolman JT, Hallander H, Halperin SA. Pertussis vaccines: where to now? Expert Rev Vaccines 2014; 10:1497-500. [DOI: 10.1586/erv.11.147] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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8
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van der Ark AAJ, Hozbor DF, Boog CJP, Metz B, van den Dobbelsteen GPJM, van Els CACM. Resurgence of pertussis calls for re-evaluation of pertussis animal models. Expert Rev Vaccines 2014; 11:1121-37. [DOI: 10.1586/erv.12.83] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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9
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Kallonen T, He Q. Bordetella pertussisstrain variation and evolution postvaccination. Expert Rev Vaccines 2014; 8:863-75. [DOI: 10.1586/erv.09.46] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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10
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Poolman JT, Hallander HO. Acellular pertussis vaccines and the role of pertactin and fimbriae. Expert Rev Vaccines 2014; 6:47-56. [PMID: 17280478 DOI: 10.1586/14760584.6.1.47] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The introduction of acellular pertussis (Pa) vaccines in countries with a low uptake of whole-cell pertussis (Pw) vaccines has led to a dramatic reduction in pertussis disease. Diphtheria-tetanus-acellular pertussis (DTPa) vaccines have also ensured continued high level disease protection in these countries following the shift from Pw- to Pa-containing vaccines, and allowed pertussis booster programs to be implemented. Vaccines containing between one and five components have been licensed and implemented. Those with three or more components consisting of filamentous hemagglutinin (FHA), pertussis toxin (PT) and pertactin (PRN) are considered to be more effective than one/two-component Pa vaccines that contain only PT or both PT and FHA. Changes in circulating Bordetella pertussis strains may impact vaccine efficacy and, thus, incidence and transmission of pertussis and deserve to be followed carefully. To date, vaccine-induced shifts among fimbriae (FIM) are reported and this could impact the efficacy of FIM-containing vaccines. Currently, FIM3 appears to be dominant in most European countries, Canada and Australia. Data obtained from a DTPa5 vaccine containing FIM2 and FIM3 have indicated a shift towards an increase in FIM3-expressing B. pertussis clinical breakthrough cases when compared with control vaccine. By contrast, relatively minor PT and PRN sequence polymorphisms have been identified without demonstrable association with vaccination programs. Adsorption of PRN to aluminum salt appears critical for optimal protective capacity in murine pertussis lung challenge. In addition, clinical studies have shown anti-PRN antibody levels to be higher when PRN is adsorbed at a 8-microg dosage versus non-adsorbed PRN at a 3-microg dosage. The available data, therefore, demonstrate that appropriately formulated acellular vaccines containing PT and PRN are the preferred option for pertussis immunization.
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Affiliation(s)
- Jan T Poolman
- Head of Bacterial Vaccines, R&D Bacterial Vaccine Program, GlaxoSmithKline Biologicals, Rixensart, Belgium.
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Situación de la tos ferina en la Comunidad Valenciana: ¿asistimos a una reactivación epidémica? Enferm Infecc Microbiol Clin 2013; 31:590-4. [DOI: 10.1016/j.eimc.2012.11.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 11/17/2012] [Accepted: 11/19/2012] [Indexed: 01/15/2023]
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12
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Lam C, Octavia S, Bahrame Z, Sintchenko V, Gilbert GL, Lan R. Selection and emergence of pertussis toxin promoter ptxP3 allele in the evolution of Bordetella pertussis. INFECTION GENETICS AND EVOLUTION 2012; 12:492-5. [PMID: 22293463 DOI: 10.1016/j.meegid.2012.01.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 12/20/2011] [Accepted: 01/04/2012] [Indexed: 11/17/2022]
Abstract
Evolutionary studies using single nucleotide polymorphisms (SNPs) have separated Bordetella pertussis isolates into six major clusters, with recent isolates forming cluster I. The expansion of cluster I isolates was characterised by changes in genes encoding antigenic components in acellular vaccines, including pertactin (Prn). Here, we determined the initial emergence of the pertussis toxin promoter allele, ptxP3, from an evolutionary perspective. This allele was previously shown in a study from the Netherlands to be associated with increased pertussis toxin production as a result of a single base mutation in the ptxP. The ptxP region of 313 worldwide isolates was sequenced, including 208 isolates from Australia collected over a 40 year period. Eight alleles were identified, of which only two predominated: ptxP1 and ptxP3. One novel allele was also found. ptxP3 was only found in SNP cluster I of B. pertussis and its emergence is concurrent with the change to the non-vaccine prn2 allele. Our results suggest that the globally distributed cluster I of B. pertussis has the ability to evade vaccine induced selection pressure.
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Affiliation(s)
- Connie Lam
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
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13
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Boyer AE, Gallegos-Candela M, Lins RC, Kuklenyik Z, Woolfitt A, Moura H, Kalb S, Quinn CP, Barr JR. Quantitative mass spectrometry for bacterial protein toxins--a sensitive, specific, high-throughput tool for detection and diagnosis. Molecules 2011; 16:2391-413. [PMID: 21403598 PMCID: PMC6259840 DOI: 10.3390/molecules16032391] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 03/01/2011] [Accepted: 03/09/2011] [Indexed: 12/28/2022] Open
Abstract
Matrix-assisted laser-desorption time-of-flight (MALDI-TOF) mass spectrometry (MS) is a valuable high-throughput tool for peptide analysis. Liquid chromatography electrospray ionization (LC-ESI) tandem-MS provides sensitive and specific quantification of small molecules and peptides. The high analytic power of MS coupled with high-specificity substrates is ideally suited for detection and quantification of bacterial enzymatic activities. As specific examples of the MS applications in disease diagnosis and select agent detection, we describe recent advances in the analyses of two high profile protein toxin groups, the Bacillus anthracis toxins and the Clostridium botulinum neurotoxins. The two binary toxins produced by B. anthracis consist of protective antigen (PA) which combines with lethal factor (LF) and edema factor (EF), forming lethal toxin and edema toxin respectively. LF is a zinc-dependent endoprotease which hydrolyzes specific proteins involved in inflammation and immunity. EF is an adenylyl cyclase which converts ATP to cyclic-AMP. Toxin-specific enzyme activity for a strategically designed substrate, amplifies reaction products which are detected by MALDI-TOF-MS and LC-ESI-MS/MS. Pre-concentration/purification with toxin specific monoclonal antibodies provides additional specificity. These combined technologies have achieved high specificity, ultrasensitive detection and quantification of the anthrax toxins. We also describe potential applications to diseases of high public health impact, including Clostridium difficile glucosylating toxins and the Bordetella pertussis adenylyl cyclase.
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Affiliation(s)
- Anne E. Boyer
- Centers for Disease Control and Prevention, 4770 Buford Hwy, NE, Atlanta, GA 30341, USA; E-Mail: (A.E.B.)
| | - Maribel Gallegos-Candela
- Centers for Disease Control and Prevention, 4770 Buford Hwy, NE, Atlanta, GA 30341, USA; E-Mail: (A.E.B.)
| | - Renato C. Lins
- Battelle Analytical Services, Atlanta, at the Centers for Disease Control and Prevention, 4770 Buford Hwy, NE, Atlanta, GA 30341, USA
| | - Zsuzsanna Kuklenyik
- Centers for Disease Control and Prevention, 4770 Buford Hwy, NE, Atlanta, GA 30341, USA; E-Mail: (A.E.B.)
| | - Adrian Woolfitt
- Centers for Disease Control and Prevention, 4770 Buford Hwy, NE, Atlanta, GA 30341, USA; E-Mail: (A.E.B.)
| | - Hercules Moura
- Centers for Disease Control and Prevention, 4770 Buford Hwy, NE, Atlanta, GA 30341, USA; E-Mail: (A.E.B.)
| | - Suzanne Kalb
- Centers for Disease Control and Prevention, 4770 Buford Hwy, NE, Atlanta, GA 30341, USA; E-Mail: (A.E.B.)
| | - Conrad P. Quinn
- Centers for Disease Control and Prevention, 1600 Clifton Rd., Atlanta, GA 30333, USA
| | - John R. Barr
- Centers for Disease Control and Prevention, 4770 Buford Hwy, NE, Atlanta, GA 30341, USA; E-Mail: (A.E.B.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-770-488-7848; Fax: +1-770-488-0509
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Zhang L, Xu Y, Zhao J, Kallonen T, Cui S, Xu Y, Hou Q, Li F, Wang J, He Q, Zhang S. Effect of vaccination on Bordetella pertussis strains, China. Emerg Infect Dis 2011; 16:1695-701. [PMID: 21029526 PMCID: PMC3294513 DOI: 10.3201/eid1611.100401] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Strains in China may differ from those in countries that have long histories of high vaccination coverage. Whole-cell pertussis vaccine was introduced in China in the early 1960s. We used standard typing methods to compare 96 Bordetella pertussis isolates collected before and after introduction of vaccination, during 1953–2005. The following vaccine-type alleles of the pertussis toxin (ptx) gene were characteristic for all prevaccination strains: ptxA2, ptxA3, and ptxA4. The shift to ptxA1 occurred since 1963. All isolates collected since 1983 contained ptxA1. Pertactin (prn) allele 1, prn1, was predominant, although prn2 and prn3 have been detected since 2000. Serotypes fimbriae (Fim) 2 and Fim2,3 were found in all isolates collected before 1986. During 1997–2005, Fim3 became prevalent. Although changes in electrophoresis profiles over time were observed, the predominant profiles during 1997–2005 resembled those during the prevaccine era and those found in Europe before the 1990s. B. pertussis strains in China may differ from those in countries that have a long history of high vaccine coverage.
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Affiliation(s)
- Liu Zhang
- National Institute for the Control of Pharmaceutical and Biological Products, Beijing, People's Republic of China
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15
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Octavia S, Maharjan RP, Sintchenko V, Stevenson G, Reeves PR, Gilbert GL, Lan R. Insight into evolution of Bordetella pertussis from comparative genomic analysis: evidence of vaccine-driven selection. Mol Biol Evol 2010; 28:707-15. [PMID: 20833694 DOI: 10.1093/molbev/msq245] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Despite high vaccine coverage, pertussis incidence has increased substantially in recent years in many countries. A significant factor that may be contributing to this increase is adaptation to the vaccine by Bordetella pertussis, the causative agent of pertussis. In this study, we first assessed the genetic diversity of B. pertussis by microarray-based comparative genome sequencing of 10 isolates representing diverse genotypes and different years of isolation. We discovered 171 single nucleotide polymorphisms (SNPs) in a total of 1.4 Mb genome analyzed. The frequency of base changes was estimated as one per 32 kb per isolate, confirming that B. pertussis is one of the least variable bacterial pathogens. We then analyzed an international collection of 316 B. pertussis isolates using a subset of 65 of the SNPs and identified 42 distinct SNP profiles (SPs). Phylogenetic analysis grouped the SPs into six clusters. The majority of recent isolates belonged to clusters I-IV and were descendants of a single prevaccine lineage. Cluster I appeared to be a major clone with a worldwide distribution. Typing of genes encoding acellular vaccine (ACV) antigens, ptxA, prn, fhaB, fim2, and fim3 revealed the emergence and increasing incidence of non-ACV alleles occurring in clusters I and IV, which may have been driven by ACV immune selection. Our findings suggest that B. pertussis, despite its high population homogeneity, is evolving in response to vaccination pressure with recent expansion of clones carrying variants of genes encoding ACV antigens.
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Affiliation(s)
- Sophie Octavia
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
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Synergic effect of genotype changes in pertussis toxin and pertactin on adaptation to an acellular pertussis vaccine in the murine intranasal challenge model. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2010; 17:807-12. [PMID: 20357056 DOI: 10.1128/cvi.00449-09] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The Bordetella pertussis pertussis toxin and pertactin (Prn) are protective antigens and are contained in acellular pertussis vaccines. Polymorphisms in the A subunit of pertussis toxin (PtxA) and pertactin have been proposed to mediate vaccine resistance and contribute to pertussis reemergence. To test this hypothesis, previous studies compared clinical isolates expressing different alleles for the proteins. However, other virulence factors or virulence factor expression levels also may vary, confounding the analysis. To overcome these limitations, we constructed isogenic mutants of B. pertussis Tohama expressing the alleles ptxA1 or ptxA2 and prn1 or prn2 and compared the efficacies of an acellular pertussis vaccine against the mutants in a mouse model. While the vaccine was effective against all of the B. pertussis strains regardless of the allele expression pattern, the strain expressing ptxA1 and prn2 displayed a survival advantage over the other strains. These results suggest that an allele shift to the ptxA1 prn2 genotype may play a role in the emergence of pertussis in vaccinated populations.
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Immunodominance in mouse and human CD4+ T-cell responses specific for the Bordetella pertussis virulence factor P.69 pertactin. Infect Immun 2008; 77:896-903. [PMID: 19015250 DOI: 10.1128/iai.00769-08] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
P.69 pertactin (P.69 Prn), an adhesion molecule from the causative agent of pertussis, Bordetella pertussis, is present in cellular and most acellular vaccines that are currently used worldwide. Although both humoral immunity and cellular immunity directed against P.69 Prn have been implicated in protective immune mechanisms, the identities of CD4(+) T-cell epitopes on the P.69 Prn protein remain unknown. Here, a single I-A(d)-restricted B. pertussis conserved CD4(+) T-cell epitope at the N terminus of P.69 Prn was identified by using a BALB/c T-cell hybridoma. The epitope appeared immunodominant among four other minor strain-conserved P.69 Prn epitopes recognized after vaccination and B. pertussis infection, and it was capable of evoking a Th1/Th17-type cytokine response. B. pertussis P.69 Prn immune splenocytes did not cross-react with natural variants of the epitope as present in Bordetella parapertussis and Bordetella bronchiseptica. Finally, it was found that the immunodominant P.69 Prn epitope is broadly recognized in the human population by CD4(+) T cells in an HLA-DQ-restricted manner. During B. pertussis infection, the epitope was associated with a Th1-type CD4(+) T-cell response. Hence, this novel P.69 Prn epitope is involved in CD4(+) T-cell immunity after B. pertussis vaccination and infection in mice and, more importantly, in humans. Thus, it may provide a useful tool for the evaluation of the type, magnitude, and maintenance of B. pertussis-specific CD4(+) T-cell mechanisms in preclinical and clinical vaccine studies.
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Wood N, McIntyre P. Pertussis: review of epidemiology, diagnosis, management and prevention. Paediatr Respir Rev 2008; 9:201-11; quiz 211-2. [PMID: 18694712 DOI: 10.1016/j.prrv.2008.05.010] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Bordetella pertussis--the cause of pertussis or whooping cough--is an exclusively human pathogen. Disease elimination by vaccination should, therefore, be possible, but has proved elusive. Many industrialised countries with long established immunisation programs are currently seeing a resurgence of pertussis, despite universal vaccination with high uptake, with the highest burden in the least immunised age groups (infants under 6 months of age and persons over 10 years old). However, low recognition and reporting and insensitive diagnostic tests mean that the true burden of pertussis is still underestimated. Recently, efforts to improve diagnostic yield include the expanded use of polymerase chain reaction and serological tests but both have significant limitations. The range of antibiotics available for treatment and prophylaxis has expanded to include the newer macrolides, azithromycin and clarithromycin, and a range of universal and targeted vaccination strategies have been implemented or proposed. This paper reviews the current epidemiology of pertussis in developed countries, including modes of clinical presentation, diagnosis, management and potential vaccination strategies.
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Affiliation(s)
- Nicholas Wood
- National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases, The Children's Hospital at Westmead, University of Sydney, New South Wales, Australia.
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Maharjan RP, Gu C, Reeves PR, Sintchenko V, Gilbert GL, Lan R. Genome-wide analysis of single nucleotide polymorphisms in Bordetella pertussis using comparative genomic sequencing. Res Microbiol 2008; 159:602-8. [PMID: 18790049 DOI: 10.1016/j.resmic.2008.08.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2008] [Revised: 07/25/2008] [Accepted: 08/08/2008] [Indexed: 11/30/2022]
Abstract
Bordetella pertussis is known to be a genotypically homogeneous pathogen but the extent of homogeneity at the genomic level is unknown. A currently circulating B. pertussis isolate from Australia was compared with the genome-sequenced Tohama I strain isolated in Japan in the 1950s from a distantly related lineage. Microarray-based comparative genome sequencing (CGS) was used to detect single nucleotide polymorphisms (SNPs) in a total of 1.4 Mb of the 4.09 Mb genome, including 1012 coding-regions, 217 pseudogenes and 268 intergenic regions. The CGS analysis, followed by validation using real-time PCR and DNA sequencing, identified 70 SNPs and five 1-3 bp indels, giving an overall frequency of base changes of 1 per 20 kb. Thirty-two of the 56 SNPs in coding regions were non-synonymous, including five located in virulence-associated genes. The data also allowed us to compare genomic diversity with other "clonal" human pathogens such as Mycobacterium tuberculosis and Yersinia pestis, showing that B. pertussis may be one of the least variable pathogenic bacterial species.
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Affiliation(s)
- Ram P Maharjan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
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Abstract
Despite extensive immunization, the disease pertussis remains one of the world’s leading causes of vaccine-preventable deaths. An estimated 50 million cases and 300,000 deaths occur every year. A resurgence of pertussis is observed in highly immunized populations. Increasing numbers of pertussis are reported in adolescents and adults who transmit bacteria to newborns and infants to whom pertussis may be a life-threatening disease. Many studies have shown that the causes for the resurgence are multiple, such as increased awareness of disease, use of better diagnostic tools, improved surveillance methods and waning vaccine-induced immunity. Recently, antigenic divergence has been found between vaccine strains and clinical isolates in many countries with high vaccination coverage. Here, we summarize these findings and discuss the factors contributing to pertussis resurgence in immunized populations.
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Affiliation(s)
- Qiushui He
- Pertussis Reference Laboratory, National Public Health Institute, Kiinamyllynkatu 13, 20520 Turku, Finland
| | - Jussi Mertsola
- Department of Pediatrics, Turku University Hospital, Kiinamyllynkatu 4-8, 20520 Turku, Finland
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Is the Sequenced Bordetella pertussis strain Tohama I representative of the species? J Clin Microbiol 2008; 46:2125-8. [PMID: 18385436 DOI: 10.1128/jcm.02484-07] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Subtractive hybridization was carried out to identify differences between the sequenced genome of Bordetella pertussis Tohama I and those of two recently collected isolates. We identified genetic regions specific to recent isolates, old isolates, and isolates of B. parapertussis and B. bronchiseptica species. We conclude that Tohama I strain is not representative of the B. pertussis species.
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Phase variation and microevolution at homopolymeric tracts in Bordetella pertussis. BMC Genomics 2007; 8:122. [PMID: 17509142 PMCID: PMC1891110 DOI: 10.1186/1471-2164-8-122] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Accepted: 05/17/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Bordetella pertussis, the causative agent of whooping cough, is a highly clonal pathogen of the respiratory tract. Its lack of genetic diversity, relative to many bacterial pathogens, could limit its ability to adapt to a hostile and changing host environment. This limitation might be overcome by phase variation, as observed for other mucosal pathogens. One of the most common mechanisms of phase variation is reversible expansion or contraction of homopolymeric tracts (HPTs). RESULTS The genomes of B. pertussis and the two closely related species, B. bronchiseptica and B. parapertussis, were screened for homopolymeric tracts longer than expected on the basis of chance, given their nucleotide compositions. Sixty-nine such HPTs were found in total among the three genomes, 74% of which were polymorphic among the three species. Nine HPTs were genotyped in a collection of 90 geographically and temporally diverse B. pertussis strains using the polymerase chain reaction/ligase detection reaction (PCR/LDR) assay. Six HPTs were polymorphic in this collection of B. pertussis strains. Of note, one of these polymorphic HPTs was found in the fimX promoter, where a single base insertion variant was present in seven strains, all of which were isolated prior to introduction of the pertussis vaccine. Transcript abundance of fimX was found to be 3.8-fold lower in strains carrying the longer allele. HPTs in three other genes, tcfA, bapC, and BP3651, varied widely in composition across the strain collection and displayed allelic polymorphism within single cultures. CONCLUSION Allelic polymorphism at homopolymeric tracts is common within the B. pertussis genome. Phase variability may be an important mechanism in B. pertussis for evasion of the immune system and adaptation to different niches in the human host. High sensitivity and specificity make the PCR/LDR assay a powerful tool for investigating allelic variation at HPTs. Using this method, allelic diversity and phase variation were demonstrated at several B. pertussis loci.
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Caro V, Bouchez V, Guiso N, Gatti B, Agosti MR, Ayala SEG. Pertussis in Argentina and France. Vaccine 2007; 25:4335-9. [PMID: 17229502 DOI: 10.1016/j.vaccine.2006.08.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Revised: 08/11/2006] [Accepted: 08/16/2006] [Indexed: 10/24/2022]
Abstract
We have studied the epidemiology of pertussis in two countries, Argentina and France, which have similar histories of long-term mass vaccination with a whole-cell vaccine. Both countries display a comparable epidemiology, with an increase of the incidence of the disease in non-vaccinated newborns. We used pulsed-field gel electrophoresis (PFGE) analysis and genotyping to compare Bordetella pertussis clinical isolates recovered in Argentina and France in 2001-2004. The majority of the isolates harbors prn2 allele and belongs to PFGE IVbeta group. Isolates were found to be very similar genetically suggesting a common evolution of the disease in these two countries using the same vaccine.
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Caro V, Hot D, Guigon G, Hubans C, Arrivé M, Soubigou G, Renauld-Mongénie G, Antoine R, Locht C, Lemoine Y, Guiso N. Temporal analysis of French Bordetella pertussis isolates by comparative whole-genome hybridization. Microbes Infect 2006; 8:2228-35. [PMID: 16787756 DOI: 10.1016/j.micinf.2006.04.014] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Revised: 04/20/2006] [Accepted: 04/21/2006] [Indexed: 10/24/2022]
Abstract
Bordetella pertussis, a gram-negative beta-proteobacterium, is the agent of whooping cough in humans. Whooping cough remains a public health problem worldwide, despite well-implemented infant/child vaccination programs. It continues to be endemic and is observed cyclically in vaccinated populations. Classical molecular subtyping methods indicate that genome diversity among B. pertussis isolates is limited. Although the whole bacterial genome has been studied by pulsed-field gel electrophoresis, the genes implicated in the diversity have not been identified. We developed a B. pertussis whole-genome DNA microarray representing over 91% of the predicted coding sequences of the sequenced strain Tohama I. Genomic DNA from clinical isolates with various pulsed-field gel electrophoresis profile patterns was competitively hybridized with the DNA microarray and coding sequences were classified as present, absent or duplicated. Our data strongly suggest that the B. pertussis population is dynamic. In France, with highly vaccinated population, the genetic diversity is low and decreasing with time, and clonal expansion correlates with cycles of the disease. This decrease in diversity is essentially due to loss of genes and pseudogenes. The genes deleted are most of the time flanked by insertion sequences.
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Affiliation(s)
- Valérie Caro
- Molecular Prevention and Therapy of Human Diseases Unit, Institut Pasteur, FRE-CNRS 2849, National Center of Reference of Whooping Cough and other Bordetelloses, 25 rue du Dr Roux, 75724 Paris Cedex 15, France.
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Storsaeter J, Wolter J. Is there a need for a new generation of vaccines against pertussis? Expert Opin Emerg Drugs 2006; 11:195-205. [PMID: 16634696 DOI: 10.1517/14728214.11.2.195] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Current vaccines against pertussis have proved their safety and efficacy in large-scale clinical trials. Despite high vaccination coverage, pertussis is still prevalent and increasing, probably as a result of waning immunity. Addition of new antigens, such as adenylate cyclase, to current vaccines might improve some aspects of the immune response to vaccination, but are unlikely to significantly increase the duration of protection. Intranasal, oral and DNA pertussis vaccines are some way from clinical development, although one live attenuated, intranasal pertussis vaccine may soon enter Phase I trials. In the meantime, the potential of currently available safe and efficacious pertussis vaccines should be maximised. Rationalisation of pertussis boosters in childhood and introduction of widespread repeat booster vaccination in adolescents and adults would already lessen disease prevalence and morbidity among susceptible infants.
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Affiliation(s)
- Jann Storsaeter
- GlaxoSmithKline Biologicals, PO Box 516, SE-169 29 Solna, Sweden.
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Byrne S, Slack AT. Analysis of Bordetella pertussis pertactin and pertussis toxin types from Queensland, Australia, 1999-2003. BMC Infect Dis 2006; 6:53. [PMID: 16542440 PMCID: PMC1459169 DOI: 10.1186/1471-2334-6-53] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2005] [Accepted: 03/16/2006] [Indexed: 11/24/2022] Open
Abstract
Background In Australia two acellular Bordetella pertussis vaccines have replaced the use of a whole cell vaccine. Both of the licensed acellular vaccines contain the following three components; pertussis toxoid, pertussis filamentous haemagglutinin and the 69 kDa pertactin adhesin. One vaccine also contains pertussis fimbriae 2 and 3. Various researchers have postulated that herd immunity due to high levels of pertussis vaccination might be influencing the makeup of endemic B. pertussis populations by selective pressure for strains possessing variants of these genes, in particular the pertactin gene type. Some publications have suggested that B. pertussis variants may be contributing to a reduced efficacy of the existing vaccines and a concomitant re-emergence of pertussis within vaccinated populations. This study was conducted to survey the pertactin and pertussis toxin subunit 1 types from B. pertussis isolates in Queensland, Australia following the introduction of acellular vaccines. Methods Forty-six B. pertussis isolates recovered from Queensland patients between 1999 and 2003 were examined by both DNA sequencing and LightCycler™ real time PCR to determine their pertactin and pertussis toxin subunit 1 genotypes. Results Pertactin typing showed that 38 isolates possessed the prn1 allele, 3 possessed the prn2 allele and 5 possessed the prn3 allele. All forty-six isolates possessed the pertussis toxin ptxS1A genotype. Amongst the circulating B. pertussis population in Queensland, 82.5% of the recovered clinical isolates therefore possessed the prn1/ptxS1A genotype. Conclusion The results of this study compared to historical research on Queensland isolates suggest that B. pertussis pertactin and pertussis toxin variants are not becoming more prevalent in Queensland since the introduction of the acellular vaccines. Current prevalences of pertactin variants are significantly different to that described in a number of other countries with high vaccine coverage. Relative paucity of recovered isolates compared to notified infections, due primarily to non culture based pertussis diagnostics is however a confounding factor in the assessment of variant prevalence.
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Affiliation(s)
- Shane Byrne
- Public Health Microbiology, Queensland Health Scientific Services, Brisbane, Australia
| | - Andrew T Slack
- Public Health Microbiology, Queensland Health Scientific Services, Brisbane, Australia
- Molecular Pathology Department, Sullivan Nicolaides Pathology, Brisbane, Australia
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