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Bartonella henselae Recombinant Pap31 for the Diagnosis of Canine and Human Bartonelloses. Pathogens 2022; 11:pathogens11020182. [PMID: 35215127 PMCID: PMC8877253 DOI: 10.3390/pathogens11020182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/24/2022] [Accepted: 01/25/2022] [Indexed: 02/04/2023] Open
Abstract
Bartonella spp. comprise a genus of Gram-negative alphaproteobacteria that are slow growing, fastidious, and facultative intracellular pathogens with zoonotic potential. Immunofluorescent antibody assays (IFAs), Western blot (WB), and enzyme-linked immunosorbent assays (ELISAs), the frequently used modalities for the serological diagnosis of canine and human Bartonelloses, generate numerous false negative results. Therefore, the development of a reliable serodiagnostic assay for Bartonelloses is of clinical and epidemiological importance. Pap31, a heme binding surface protein of B. henselae, is associated with bacterial adhesion and related to bacterial colonization. To our knowledge, B. henselae Pap31 and its fragments (N-terminal (NTD), middle (MD), and C-terminal (CTD) domains) have not been investigated for the serodiagnosis of canine and human Bartonelloses. In this study, we evaluate the diagnostic utility of B. henselae recombinant whole Pap31 (rPap31) and Pap31 fragments by ELISA using sera from 70 dogs (36 Bartonella spp. IFA-positive (naturally infected), and 34 Bartonella spp. IFA- and PCR-negative (control dogs)) and 36 humans (18 Bartonella spp. IFA-positive (naturally infected) and 18 controls)). In the dogs, the area under the curve (AUC) score of recombinant whole Pap31 was 0.714 with a sensitivity of 42% and specificity of 94% at an OD cutoff value of 0.8955. Among the evaluated recombinant Pap31 proteins for the diagnosis of canine Bartonelloses, rPap31-NTD yielded the highest AUC score of 0.792 (95% CI 0.688–0.895) with a sensitivity of 44% and specificity of 100% at a cutoff value of 1.198. In concordance with this finding, rPap31-NTD also had the highest AUC score of 0.747 (95% CI 0.581–0.913) among the Pap31 recombinant proteins for the diagnosis of human Bartonelloses, with 39% sensitivity and 94% specificity at a cutoff value of 1.366. Recombinant whole Pap31 (rPap31) resulted in 72% sensitivity and 61% specificity at a cutoff value of 0.215 for human Bartonelloses. Due to either low sensitivity or questionable specificity, our findings indicate that recombinant Pap31 and the selected fragments may not be appropriate diagnostic targets in detecting anti-Bartonella antibodies in Bartonella-infected dogs and humans. The findings from this study can be used to further assess the antigenicity and immunogenicity of B. henselae Pap31 as a diagnostic target.
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Gonçalves JM, Cardoso TL, de Freitas SB, Woloski R, Neto ACPS, da Silva Pinto L, de Lemos ES, Hartwig DD. In silico analyses and design of chimeric proteins containing epitopes of Bartonella henselae antigens for the control of cat scratch disease. Appl Microbiol Biotechnol 2022; 106:8079-8091. [PMID: 36383248 PMCID: PMC9667432 DOI: 10.1007/s00253-022-12269-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/24/2022] [Accepted: 10/31/2022] [Indexed: 11/17/2022]
Abstract
Bartonella henselae is a Gram-negative bacterium that causes cat scratch disease (CSD), as well as bacteremia, endocarditis, and other clinical presentations. CSD remains one of the most common infections caused by bacteria in the genus Bartonella, and it is transmitted to humans through a scratch or cat bite. Vaccination and more efficient diagnostic methods would represent a promising and sustainable alternative measure for CSD control in humans and animals. Here, we described the in silico analyses and design of three recombinant chimeric proteins (rC1, rC2, and rC3), for use in the control of CSD. The chimeras were constructed with epitopes identified from the sequences of the GroEL, 17 kDa, P26, BadA, Pap31, OMP 89, and OMP 43, previously described as the most important B. henselae antigens. The rC1, rC2, and rC3 were expressed and purified using a heterologous system based on Escherichia coli and reacted with antibodies present in the sera of humans naturally infected. The chimeric proteins were used to immunize mice using Freund adjuvant, and the humoral immune response was evaluated. Animals immunized with rC1 and rC3 showed a significant IgG antibodies response from the 28th day (P < 0.05), and the animals immunized with the rC2 from the 35th day (P < 0.05) remained until the 56th day of experimentation, with a titer of 1:3200 (P < 0.05), 1:1600 (P < 0.05) and 1:1600 (P < 0.05) from rC1, rC2, and rC3, respectively. Significant production of IgA and IgG1 isotype was detected in animals immunized with rC1 and rC2 proteins. Additionally, analysis using 13 serum samples from naturally infected patients showed that the proteins are recognized by antibodies present in sera, reinforcing the possibility of using these chimeras for CSD control. KEY POINTS: • The recombinant chimeras were expressed in Escherichia coli with 37 kDa (rC1), 35 kDa (rC2), and 38 kDa (rC3). • Animals immunized with rC1, rC2, and rC3 showed significant antibody response. • The chimeras were recognized by the sera of naturally infected patients.
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Affiliation(s)
- Jênifer Malheiros Gonçalves
- Laboratório de Bacteriologia E Bioensaios (LaBBio), Departamento de Microbiologia E Parasitologia, Instituto de Biologia, Universidade Federal de Pelotas, Capão Do Leão, Rio Grande Do Sul Brazil ,Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico (CDTec), Universidade Federal Pelotas, Capão Do Leão, Rio Grande Do Sul Brazil
| | - Thayná Laner Cardoso
- Laboratório de Bacteriologia E Bioensaios (LaBBio), Departamento de Microbiologia E Parasitologia, Instituto de Biologia, Universidade Federal de Pelotas, Capão Do Leão, Rio Grande Do Sul Brazil
| | - Stella Buchhorn de Freitas
- Laboratório de Bacteriologia E Bioensaios (LaBBio), Departamento de Microbiologia E Parasitologia, Instituto de Biologia, Universidade Federal de Pelotas, Capão Do Leão, Rio Grande Do Sul Brazil ,Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico (CDTec), Universidade Federal Pelotas, Capão Do Leão, Rio Grande Do Sul Brazil
| | - Rafael Woloski
- Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico (CDTec), Universidade Federal Pelotas, Capão Do Leão, Rio Grande Do Sul Brazil
| | - Amilton Clair Pinto Seixas Neto
- Laboratório de Bacteriologia E Bioensaios (LaBBio), Departamento de Microbiologia E Parasitologia, Instituto de Biologia, Universidade Federal de Pelotas, Capão Do Leão, Rio Grande Do Sul Brazil
| | - Luciano da Silva Pinto
- Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico (CDTec), Universidade Federal Pelotas, Capão Do Leão, Rio Grande Do Sul Brazil
| | - Elba Sampaio de Lemos
- Laboratório de Hantaviroses E Rickettsioses (LHR), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ Brazil
| | - Daiane Drawanz Hartwig
- Laboratório de Bacteriologia E Bioensaios (LaBBio), Departamento de Microbiologia E Parasitologia, Instituto de Biologia, Universidade Federal de Pelotas, Capão Do Leão, Rio Grande Do Sul Brazil ,Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico (CDTec), Universidade Federal Pelotas, Capão Do Leão, Rio Grande Do Sul Brazil ,Biology Institute, Federal University of Pelotas, Pelotas, RS CEP 96010–900 Brazil
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Dichter AA, Schultze TG, Wenigmann A, Ballhorn W, Latz A, Schlüfter E, Ventosilla P, Guerra Allison H, Ugarte-Gil C, Tsukayama P, Kempf VAJ. Identification of immunodominant Bartonella bacilliformis proteins: a combined in-silico and serology approach. THE LANCET MICROBE 2021; 2:e685-e694. [DOI: 10.1016/s2666-5247(21)00184-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 06/30/2021] [Accepted: 07/09/2021] [Indexed: 11/15/2022] Open
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Immunogenic Peptides from Pap31 and SCS-α of Bartonella bacilliformis: One Step Closer to a Rapid Diagnostic Tool for Carrion's Disease. Pathogens 2021; 10:pathogens10080917. [PMID: 34451381 PMCID: PMC8400886 DOI: 10.3390/pathogens10080917] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 07/16/2021] [Accepted: 07/17/2021] [Indexed: 11/17/2022] Open
Abstract
Bartonella bacilliformis is the causal agent of Carrion’s disease, an overlooked illness endemic in the Andean Mountains with Peru being the most affected country. The diagnostic of this illness is a challenge due to the limited resources and the common symptomatology with other infectious diseases. The goal of this study was to identify immunogenic peptides from Pap31 and succinyl-CoA synthetase α (SCS-α) of B. bacilliformis that might be suitable for developing a serologic tool. The immunodominant character of Pap31 and SCS-α was determined by Western blotting and in-silico analysis. Subsequently, 35 peptides were selected for epitope mapping and their immunoreactivity was tested by enzyme-linked immunosorbent assay (ELISA). A total of 30 sera were tested including pre-exposed people with high IgM levels for Pap31/SCS-α (23 sera), patients (2 sera) as well as 5 sera with no reactivity to Pap31/SCS-α. The results indicate that Pap31-8 (187QAIGSAILKGTKDTGT202) and SCS-α-12 (59IFASVAEGKEKTGANA74) are the most immunogenic peptides, with Pap31-8 showing potential to discriminate between B. bacilliformis and the remaining Bartonella spp., and SCS-α-12 differentiating Bartonella spp. from other microorganisms.
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Lashnits E, Neupane P, Bradley JM, Richardson T, Maggi RG, Breitschwerdt EB. Comparison of Serological and Molecular Assays for Bartonella Species in Dogs with Hemangiosarcoma. Pathogens 2021; 10:pathogens10070794. [PMID: 34201572 PMCID: PMC8308881 DOI: 10.3390/pathogens10070794] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/18/2021] [Accepted: 06/18/2021] [Indexed: 11/23/2022] Open
Abstract
Currently, a gold standard diagnostic test for Bartonella infection in dogs is lacking. This represents a critical limitation for the development and evaluation of new diagnostic tests, as well as for the diagnosis of, and research on, bartonellosis in dogs. This retrospective observational study aims to compare the results of commonly performed and newly-reported Bartonella spp. diagnostic tests in banked clinical specimens from 90 dogs with hemangiosarcoma (HSA) using composite reference standard (CRS) and random effects latent class analysis (RE-LCA) techniques. Samples from each dog were tested using six serological or molecular diagnostic assays, including indirect fluorescent antibody (IFA) and Western blot (WB) for the detection of antibodies in serum, and qPCR and droplet digital PCR (ddPCR) in blood and fresh frozen tissue biopsy samples (mainly splenic HSA tumors and histopathologically normal spleen or skin/adipose tissue). Bartonella infection prevalence was estimated to be 78% based on the CRS (parallel testing with all six assays), and 64% based on the RE-LCA model. The assay with the highest diagnostic accuracy was qPCR performed on fresh frozen tissue biopsy samples (sensitivity: 94% by RE-LCA and 80% by CRS; specificity: 100%). When comparing newly-reported to traditional Bartonella diagnostic assays, ddPCR was more sensitive for the detection of Bartonella DNA than qPCR when testing blood samples (36% vs. 0%, p < 0.0001). Dogs that were positive on serological assays alone with negative molecular assays were highly unlikely (<3%) to be classified as infected by the RE-LCA model. These data indicate that Bartonella spp. DNA can be PCR amplified from fresh frozen tissues from a majority of dogs with HSA using both qPCR and ddPCR, supporting the use of these methods for future controlled studies comparing the prevalence of Bartonella spp. DNA in the tissue of dogs with HSA to that of unaffected controls.
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Affiliation(s)
- Erin Lashnits
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53713, USA;
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA; (P.N.); (J.M.B.); (T.R.); (R.G.M.)
| | - Pradeep Neupane
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA; (P.N.); (J.M.B.); (T.R.); (R.G.M.)
| | - Julie M. Bradley
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA; (P.N.); (J.M.B.); (T.R.); (R.G.M.)
| | - Toni Richardson
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA; (P.N.); (J.M.B.); (T.R.); (R.G.M.)
| | - Ricardo G. Maggi
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA; (P.N.); (J.M.B.); (T.R.); (R.G.M.)
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA
| | - Edward B. Breitschwerdt
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA; (P.N.); (J.M.B.); (T.R.); (R.G.M.)
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA
- Correspondence:
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Karuppusamy S, Mutharia L, Kelton D, Plattner B, Mallikarjunappa S, Karrow N, Kirby G. Detection of Mycobacterium avium Subspecies paratuberculosis (MAP) Microorganisms Using Antigenic MAP Cell Envelope Proteins. Front Vet Sci 2021; 8:615029. [PMID: 33614761 PMCID: PMC7887298 DOI: 10.3389/fvets.2021.615029] [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: 10/07/2020] [Accepted: 01/13/2021] [Indexed: 11/13/2022] Open
Abstract
Cell envelope proteins from Mycobacterium avium subspecies paratuberculosis (MAP) that are antigenically distinct from closely related mycobacterial species are potentially useful for Johne's Disease (JD) diagnosis. We evaluated the potential of ELISAs, based on six antigenically distinct recombinant MAP cell envelope proteins (SdhA, FadE25_2, FadE3_2, Mkl, DesA2, and hypothetical protein MAP1233) as well as an extract of MAP total cell envelope proteins, to detect antibodies against MAP in the sera of infected cattle. The sensitivity (Se) and specificity (Sp) of an ELISA based on MAP total cell envelope proteins, when analyzing 153 bovine serum samples, was 75 and 96%, respectively. Analysis of the same samples, using a commercial serum ELISA resulted in a Se of 56% and Sp of 99%. Results of ELISA analysis using plates coated with recombinant cell envelope proteins ranged from a highest Se of 94% and a lowest Sp of 79% for Sdh A to a lowest Se of 67% and a highest Sp of 95% for hypothetical protein MAP1233. Using polyclonal antibodies to MAP total cell envelope proteins, immunohistochemical analysis of intestinal and lymph node tissues from JD-positive cattle detected MAP organisms whereas antibodies to recombinant proteins did not. Finally, polyclonal antibodies to MAP total cell envelope protein and to recombinant SdhA, FadE25_2, and DesA2 proteins immunomagnetically separated MAP microorganisms spiked in PBS. These results suggest that antigenically distinct MAP cell envelope proteins and antibodies to these proteins may have potential to detect MAP infection in dairy cattle.
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Affiliation(s)
| | - Lucy Mutharia
- Department of Molecular and Cellular Biology, College of Biological Science, University of Guelph, Guelph, ON, Canada
| | - David Kelton
- Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - Brandon Plattner
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - Sanjay Mallikarjunappa
- Department of Animal Biosciences, Ontario Agricultural College, University of Guelph, Guelph, ON, Canada
| | - Niel Karrow
- Department of Animal Biosciences, Ontario Agricultural College, University of Guelph, Guelph, ON, Canada
| | - Gordon Kirby
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
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Ruiz J, Gomes C. In silico analysis of Pap31 from Bartonella bacilliformis and other Bartonella spp. INFECTION GENETICS AND EVOLUTION 2020; 84:104482. [PMID: 32738366 DOI: 10.1016/j.meegid.2020.104482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 07/18/2020] [Accepted: 07/23/2020] [Indexed: 01/01/2023]
Abstract
Pap31 is an outer membrane protein of Bartonella bacilliformis which is considered to be a potential antigenic candidate for the development of diagnostic tools. The present study aimed to compare Pap31 from B. bacilliformis with that of other Bartonella spp. The results showed the presence of at least 5 different B. bacilliformis Pap31 alleles, with the strain Ver097 being the most divergent (89.7% of identity with the reference strain KC583). The most significant finding was the presence of a variable number (1 to 3) of 6 amino acid tandem repeats (GTEGGG) in the different B. bacilliformis Pap31 alleles, with no similar structure in other established Bartonella spp., except for Bartonella ancashensis, another Bartonella spp. isolated from chronic cases of Carrion's disease. In both B. bacilliformis and B. ancashensis this repetitive region was coincident with the most predicted immunogenic region of the protein. In other microorganisms, the presence of amino acid tandem repeats has been related to the development of poorly functional antibodies. The findings of this study also suggest a utility of Pap31 amino acid tandem repeats as potential contributors to the immune evasion of Carrion's disease-related Bartonella spp. and the establishment of asymptomatic B. bacilliformis / B. ancashensis infections.
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Affiliation(s)
- Joaquim Ruiz
- Laboratorio de Microbiología Molecular y Genómica Bacteriana, Universidad Científica del Sur, Lima, Peru.
| | - Cláudia Gomes
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
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Lydy SL, Lascano MS, Garcia-Perez JE, Williams-Newkirk AJ, Grijalva MJ. Seroprevalence and risk factors for infection with Bartonella bacilliformis in Loja province, Ecuador. Emerg Microbes Infect 2018; 7:115. [PMID: 29941982 PMCID: PMC6018114 DOI: 10.1038/s41426-018-0110-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/23/2018] [Accepted: 04/25/2018] [Indexed: 11/28/2022]
Abstract
The seroprevalence and epidemiology of Bartonella bacilliformis infection in the Andean highlands of Ecuador is largely unknown. We conducted a sero-epidemiologic survey of 319 healthy children aged 1-15 years living in six rural, mountain communities in Loja Province, Ecuador. Blood was collected by finger stick onto filter paper and dried, and the eluted sera analyzed for antibodies to B. bacilliformis by rPap31 ELISA. Demographic, entomologic, and household variables were assessed to investigate associated risk factors for antibody seropositivity to B. bacilliformis. Seroprevalence of 28% was found among children in the study communities. Increased risk of seropositivity was associated with the presence of lumber piles near houses. Decreased risk of seropositivity was observed with the presence of animal waste and incremental 100 meter increases in elevation. Although investigation of clinical cases of Carrion's disease was not within the scope of this study, our serology data suggest that infection of children with B. bacilliformis is prevalent in this region of Ecuador and is largely unrecognized and undiagnosed. This study highlights the need to further investigate the prevalence, pathogenesis, epidemiology, and disease impact of this pathogen in Ecuador.
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Affiliation(s)
- Shari L Lydy
- Centers for Disease Control and Prevention, Division of Vector-Borne Diseases, Rickettsial Zoonoses Branch, Atlanta, GA, USA.
| | - Mauricio S Lascano
- Department of Biomedical Sciences, Ohio University, Heritage College of Osteopathic Medicine, Infectious and Tropical Disease Institute, Athens, OH, USA
- Pontificia Universidad Católica del Ecuador, Centro de Investigación para la Salud en América Latina, Escuela de Ciencias Biológicas, Quito, Ecuador
- Organization for Tropical Studies-North American Branch, Tropical Diseases, Environmental Change and Human Health Program, Durham, NC, USA
| | - Josselyn E Garcia-Perez
- Pontificia Universidad Católica del Ecuador, Centro de Investigación para la Salud en América Latina, Escuela de Ciencias Biológicas, Quito, Ecuador
- School of Medicine, Department of Microbiology and Immunology, University of Colorado, Denver, CO, USA
| | - Amanda J Williams-Newkirk
- Centers for Disease Control and Prevention, Division of Vector-Borne Diseases, Rickettsial Zoonoses Branch, Atlanta, GA, USA
- Centers for Disease Control and Prevention, Division of Foodborne, Waterborne, and Environmental Diseases, Enteric Disease Laboratory Branch, Atlanta, GA, USA
| | - Mario J Grijalva
- Department of Biomedical Sciences, Ohio University, Heritage College of Osteopathic Medicine, Infectious and Tropical Disease Institute, Athens, OH, USA
- Pontificia Universidad Católica del Ecuador, Centro de Investigación para la Salud en América Latina, Escuela de Ciencias Biológicas, Quito, Ecuador
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Identification and functional analysis of invasion associated locus B (IalB) in Bartonella species. Microb Pathog 2016; 98:171-7. [DOI: 10.1016/j.micpath.2016.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 03/30/2016] [Accepted: 05/10/2016] [Indexed: 11/19/2022]
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Qi Y, Gong W, Xiong X, Jiang J, Wang Y, Jiao J, Duan C, Wen B. Microarray of surface-exposed proteins of Rickettsia heilongjiangensis for serodiagnosis of Far-eastern spotted fever. BMC Infect Dis 2014; 14:332. [PMID: 24938647 PMCID: PMC4071148 DOI: 10.1186/1471-2334-14-332] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 06/13/2014] [Indexed: 11/17/2022] Open
Abstract
Background Far-eastern spotted fever (FESF) is an important emerging infectious disease in Northeast Asia. The laboratory diagnosis of FESF in hospitals is mainly based on serological methods. However, these methods need to cultivate rickettsial cells as diagnostic antigens, which is both burdensome and dangerous. Methods Eleven surface-exposed proteins (SEPs) were identified in our previous study and their recombinant proteins (rSEPs) fabricated on a microarray were serologically analyzed with seventeen paired sera from patients suffered from FESF in this study. Results All the rSEPs showed sensitivities of between 53% and 82% to acute-phase sera and of between 65% and 82% to convalescent-phase sera, and all the rSEPs except rRplA showed specificities of between 80% and 95%. The combination assay of two, three, or four of the four rSEPs (rOmpA-2, rOmpB-3, rRpsB, and rSdhB) showed better sensitivities of between 76% and 94% to the acute-phase sera or between 82% and 100% to the convalescent-phase sera and acceptable specificities of between 75% and 90%. Conclusions Our results suggest that the four rSEPs are more likely candidate antigens for serological diagnosis of FESF.
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Affiliation(s)
| | | | | | | | | | | | | | - Bohai Wen
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, 20 Dong-Dia-Jie Street, Fengtai, Beijing, China.
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