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Zahid A, Wilson JC, Grice ID, Peak IR. Otitis media: recent advances in otitis media vaccine development and model systems. Front Microbiol 2024; 15:1345027. [PMID: 38328427 PMCID: PMC10847372 DOI: 10.3389/fmicb.2024.1345027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 01/08/2024] [Indexed: 02/09/2024] Open
Abstract
Otitis media is an inflammatory disorder of the middle ear caused by airways-associated bacterial or viral infections. It is one of the most common childhood infections as globally more than 80% of children are diagnosed with acute otitis media by 3 years of age and it is a common reason for doctor's visits, antibiotics prescriptions, and surgery among children. Otitis media is a multifactorial disease with various genetic, immunologic, infectious, and environmental factors predisposing children to develop ear infections. Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis are the most common culprits responsible for acute otitis media. Despite the massive global disease burden, the pathogenesis of otitis media is still unclear and requires extensive future research. Antibiotics are the preferred treatment to cure middle ear infections, however, the antimicrobial resistance rate of common middle ear pathogens has increased considerably over the years. At present, pneumococcal and influenza vaccines are administered as a preventive measure against otitis media, nevertheless, these vaccines are only beneficial in preventing carriage and/or disease caused by vaccine serotypes. Otitis media caused by non-vaccine serotype pneumococci, non-typeable H. influenza, and M. catarrhalis remain an important healthcare burden. The development of multi-species vaccines is an arduous process but is required to reduce the global burden of this disease. Many novel vaccines against S. pneumoniae, non-typeable H. influenza, and M. catarrhalis are in preclinical trials. It is anticipated that these vaccines will lower the disease burden and provide better protection against otitis media. To study disease pathology the rat, mouse, and chinchilla are commonly used to induce experimental acute otitis media to test new therapeutics, including antibiotics and vaccines. Each of these models has its advantages and disadvantages, yet there is still a need to develop an improved animal model providing a better correlated mechanistic understanding of human middle ear infections, thereby underpinning the development of more effective otitis media therapeutics. This review provides an updated summary of current vaccines against otitis media, various animal models of otitis media, their limitations, and some future insights in this field providing a springboard in the development of new animal models and novel vaccines for otitis media.
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Affiliation(s)
- Ayesha Zahid
- Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia
| | - Jennifer C. Wilson
- School of Pharmacy and Medical Science, Griffith University, Gold Coast, QLD, Australia
| | - I. Darren Grice
- Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia
- School of Pharmacy and Medical Science, Griffith University, Gold Coast, QLD, Australia
| | - Ian R. Peak
- Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia
- School of Pharmacy and Medical Science, Griffith University, Gold Coast, QLD, Australia
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2
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Bair KL, Shafirstein G, Campagnari AA. In vitro Photodynamic Therapy of Polymicrobial Biofilms Commonly Associated With Otitis Media. Front Microbiol 2020; 11:558482. [PMID: 32983076 PMCID: PMC7487423 DOI: 10.3389/fmicb.2020.558482] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 08/12/2020] [Indexed: 11/15/2022] Open
Abstract
Otitis media (OM) is a prevalent pediatric infection characterized by painful inflammation of the middle ear. There are more than 700 million cases of OM diagnosed globally each year, with 50% of affected children under 5 years of age. Further, OM is the most common reason for children to receive antibiotic treatment in developed countries. The most recent work on this dynamic disease indicates that biofilms and polymicrobial infections play a role in recurrent OM and chronic OM, which are difficult to eradicate using standard antibiotic protocols. Antimicrobial photodynamic therapy (aPDT) is a promising new strategy for the treatment of resistant bacteria and persistent biofilms which lead to chronic infections. While PDT continues to be successfully used for oncological, dermatological, and dental applications, our work focuses on the efficacy of aPDT as it relates to otopathogens responsible for OM. Previous studies from our laboratory and others have shown that non-typeable Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis, the three most common otopathogens, are susceptible to different forms of aPDT. However, many cases of OM involve multiple bacteria and to date no one has investigated the efficacy of this technology on these complex polymicrobial biofilms. We treated polymicrobial biofilms of the three most common otopathogens with the photosensitizer Chlorin e6 (Ce6) and a continuous wave 405 ± 10 nm light emitted diode. Our data show significant bactericidal activity on polymicrobial biofilms associated with OM. These studies indicate that aPDT warrants further analysis as a possible treatment for OM and our results provide the foundation for future studies designed to identify the optimal aPDT parameters for polymicrobial biofilm-associated infections of the middle ear.
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Affiliation(s)
- Kirsten L Bair
- Department of Microbiology and Immunology, Jacobs School of Medicine, University at Buffalo, State University of New York, Buffalo, NY, United States
| | - Gal Shafirstein
- Department of Cell Stress Biology, Photodynamic Therapy Center, Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States
| | - Anthony A Campagnari
- Department of Microbiology and Immunology, Jacobs School of Medicine, University at Buffalo, State University of New York, Buffalo, NY, United States.,The Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, State University of New York, Buffalo, NY, United States
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Immunization with a Biofilm-Disrupting Nontypeable Haemophilus influenzae Vaccine Antigen Did Not Alter the Gut Microbiome in Chinchillas, Unlike Oral Delivery of a Broad-Spectrum Antibiotic Commonly Used for Otitis Media. mSphere 2020; 5:5/2/e00296-20. [PMID: 32295873 PMCID: PMC7160684 DOI: 10.1128/msphere.00296-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The prevalence of chronic and recurrent diseases, combined with the overuse/abuse of antibiotics that has led to the sobering emergence of bacteria resistant to multiple antibiotics, has mandated that we develop novel approaches to better manage these diseases or, ideally, prevent them. Biofilms play a key role in the pathogenesis of chronic and recurrent bacterial diseases but are difficult, if not impossible, to eradicate with antibiotics. We developed a vaccine antigen designed to mediate biofilm disruption; however, it is also important that delivery of this vaccine does not induce collateral damage to the microbiome. The studies described here validated a vaccine approach that targets biofilms without the consequences of an altered gut microbiome. While delivery of the antibiotic most commonly given to children with ear infections did indeed alter the gut microbiome, as expected, immunization via traditional injection or by noninvasive delivery to the skin did not result in changes to the chinchilla gut microbiome. The use of broad-spectrum antibiotics to treat diseases, such as the highly prevalent pediatric disease otitis media (OM), contributes significantly to the worldwide emergence of multiple-antibiotic-resistant microbes, and gut dysbiosis with diarrhea is a common adverse sequela. Moreover, for many diseases, like OM, biofilms contribute significantly to chronicity and recurrence, yet biofilm-resident bacteria are characteristically highly resistant to antibiotics. The most cost-effective way to both prevent and resolve diseases like OM, as well as begin to address the problem of growing antibiotic resistance, would be via the development of novel approaches to eradicate bacterial biofilms. Toward this goal, we designed a vaccine antigen that induces the formation of antibodies that prevent biofilm formation and, thereby, experimental OM in the middle ears of chinchillas by the predominant Gram-negative pathogen responsible for this disease, nontypeable Haemophilus influenzae. These antibodies also significantly disrupt preexisting biofilms formed by diverse pathogens. Whereas preclinical data strongly support the continued development of this vaccine antigen, which targets an essential structural element of bacterial biofilms, a concern has been whether active immunization would also lead to unintended collateral damage in the form of an altered gut microbiome. To address this concern, we assessed changes in the microbiome of the chinchilla gut over time after the delivery of either amoxicillin-clavulanate, the standard of care for OM, or after immunization with our biofilm-targeted vaccine antigen either via a traditional subcutaneous route or via a novel noninvasive transcutaneous route. We show that differences in the abundance of specific taxa were found only in the stools of antibiotic-treated animals. IMPORTANCE The prevalence of chronic and recurrent diseases, combined with the overuse/abuse of antibiotics that has led to the sobering emergence of bacteria resistant to multiple antibiotics, has mandated that we develop novel approaches to better manage these diseases or, ideally, prevent them. Biofilms play a key role in the pathogenesis of chronic and recurrent bacterial diseases but are difficult, if not impossible, to eradicate with antibiotics. We developed a vaccine antigen designed to mediate biofilm disruption; however, it is also important that delivery of this vaccine does not induce collateral damage to the microbiome. The studies described here validated a vaccine approach that targets biofilms without the consequences of an altered gut microbiome. While delivery of the antibiotic most commonly given to children with ear infections did indeed alter the gut microbiome, as expected, immunization via traditional injection or by noninvasive delivery to the skin did not result in changes to the chinchilla gut microbiome.
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Whitby PW, Morton DJ, Mussa HJ, Mirea L, Stull TL. A bacterial vaccine polypeptide protective against nontypable Haemophilus influenzae. Vaccine 2020; 38:2960-2970. [PMID: 32111525 DOI: 10.1016/j.vaccine.2020.02.054] [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] [Received: 10/22/2019] [Revised: 02/07/2020] [Accepted: 02/18/2020] [Indexed: 02/08/2023]
Abstract
Nontypeable strains of Haemophilus influenzae (NTHi) are one of the most common cause of otitis media and the most frequent infection associated with exacerbations of chronic obstructive pulmonary disease; there is currently no vaccine in the U.S. to prevent NTHi. Using bioinformatics and structural vaccinology, we previously identified several NTHi species-conserved and sequence-conserved peptides that mediate passive protection in the rat model of infection. Using these, and similar peptides, we designed Hi Poly 1, a Bacterial Vaccine Polypeptide, comprising 9 unique peptides from 6 different surface proteins. Recombinant Hi Poly 1 was purified by affinity chromatography. Forty chinchillas were immunized three times with 200 µg of Hi Poly 1 with alum adjuvant; similarly, 41 controls were immunized with adjuvant alone. The average Log2 IgG titer among immunized animals was 17.04, and IgG antibodies against each component peptide were detected. In the infant rat model, antisera from immunized chinchillas provided significant passive protection compared to PBS (p = 0.01) and pre-immune sera (p = 0.03). In the established chinchilla model of NTHi otitis media, the vaccinated group cleared infection faster than the control group as indicated by significantly decreased positive findings on video-otoscopy (p < 0.0001) and tympanometry (p = 0.0002) on day 7, and for middle ear fluid obtained by aspiration (p = 0.0001) on day 10 post-infection. Using 12 representative NTHi strains in a Live-Cell ELISA, greater antibody binding to each strain was detected with post Hi Poly 1 than the pre-immune chinchilla antisera. The data from this proof-of-principle study demonstrate the effectiveness of Hi Poly 1 against the NTHi in two relevant preclinical models of bacteremia and otitis media as well as surface antibody binding across the species. The Bacterial Vaccine Polypeptide approach to a vaccine against NTHi also serves as a paradigm for development of similar vaccines to protect against other bacteria.
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Affiliation(s)
- Paul W Whitby
- Department of Child Health, University of Arizona College of Medicine-Phoenix, United States; Phoenix Childrens Hospital, Phoenix, United States.
| | - Daniel J Morton
- Department of Child Health, University of Arizona College of Medicine-Phoenix, United States; Phoenix Childrens Hospital, Phoenix, United States
| | - Huda J Mussa
- Department of Child Health, University of Arizona College of Medicine-Phoenix, United States; Phoenix Childrens Hospital, Phoenix, United States
| | - Lucia Mirea
- Department of Child Health, University of Arizona College of Medicine-Phoenix, United States; Phoenix Childrens Hospital, Phoenix, United States
| | - Terrence L Stull
- Department of Child Health, University of Arizona College of Medicine-Phoenix, United States; Phoenix Childrens Hospital, Phoenix, United States
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Novotny LA, Bakaletz LO. Transcutaneous immunization with a nontypeable Haemophilus influenzae dual adhesin-directed immunogen induces durable and boostable immunity. Vaccine 2020; 38:2378-2386. [PMID: 32001071 DOI: 10.1016/j.vaccine.2020.01.052] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/16/2020] [Accepted: 01/18/2020] [Indexed: 12/21/2022]
Abstract
Otitis media (OM) is a very common pediatric disease and nontypeable Haemophilus influenzae (NTHI) is the predominant causative agent. We've developed a chimeric immunogen, chimV4, that simultaneously targets two NTHI adhesins, OMP P5 and the type IV pilus. Transcutaneous immunization (TCI) via bandaid with chimV4 plus the adjuvant dmLT provides significant protection against experimental NTHI-induced OM in chinchilla models. Herein, we now examined the durability and boostability of the induced immune response. Bandaid immunization with chimV4+dmLT followed by two sequential middle ear challenges with NTHI resulted in rapid bacterial clearance and significantly accelerated disease resolution. Moreover, TCI with chimV4+dmLT significantly increased mature B-cell phenotypes and antibody-secreting cells within nasal-associated lymphoid tissues, a response that was further augmented upon TCI two months later. Thus, bandaid immunization induced durable and boostable immunity. The simplicity and non-invasive nature of TCI with chimV4+dmLT supports its utility as a highly effective additional immunization strategy for NTHI-induced OM.
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Affiliation(s)
- Laura A Novotny
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Lauren O Bakaletz
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA; The Ohio State University College of Medicine, Columbus, OH 43210, USA.
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Bair KL, Campagnari AA. Moraxella catarrhalis Promotes Stable Polymicrobial Biofilms With the Major Otopathogens. Front Microbiol 2020; 10:3006. [PMID: 32010085 PMCID: PMC6974515 DOI: 10.3389/fmicb.2019.03006] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 12/13/2019] [Indexed: 12/18/2022] Open
Abstract
Otitis media (OM) is a prevalent pediatric infection characterized by painful inflammation of the middle ear. The Gram-negative diplococcus Moraxella catarrhalis is a commensal of the nasopharynx and one of three leading causative agents of OM. The most recent work on this multifaceted disease indicates that biofilms and polymicrobial infections play a pivotal role in recurrent and chronic OM, which are difficult to eradicate using standard antibiotic protocols. Although there have been significant advances in OM research, the actual bacterial and viral interactions leading to pathogenesis remain largely uncharacterized. However, colonization and persistence in the nasopharynx is clearly an essential first step. In this study, we assessed the role M. catarrhalis plays in the co-colonization and persistence of the other major otopathogens, Streptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi). We characterized both monomicrobial and polymicrobial biofilms using an in vitro nasopharyngeal colonization model. Biofilm assays were designed to mimic the nasopharynx and bacterial persistence was quantified over time. NTHi showed a steady and significant decline in viability over 20–48 h when this organism was in a dual species biofilm with S. pneumoniae. However, when M. catarrhalis was present in the polymicrobial biofilm NTHi survived for 48 h at 107 CFU per mL. In addition, an isogenic M. catarrhalis catalase-deficient mutant was also fully capable of protecting NTHi from the bactericidal activity of S. pneumoniae in a polymicrobial biofilm. Our results show that M. catarrhalis promotes a favorable environment for stable polymicrobial biofilms by enhancing the survival of NTHi in the presence of S. pneumoniae. These data suggest that colonization with M. catarrhalis promotes stable co-colonization with other otopathogens.
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Affiliation(s)
- Kirsten L Bair
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States
| | - Anthony A Campagnari
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States.,The Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, State University of New York, Buffalo, NY, United States
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7
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Transcutaneous Immunization with a Band-Aid Prevents Experimental Otitis Media in a Polymicrobial Model. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:CVI.00563-16. [PMID: 28381402 DOI: 10.1128/cvi.00563-16] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/27/2017] [Indexed: 11/20/2022]
Abstract
Otitis media (OM) is a common pediatric disease, and nontypeable Haemophilus influenzae (NTHI) is the predominant pathogen in chronic OM, recurrent OM, and OM associated with treatment failure. OM is also a polymicrobial disease, wherein an upper respiratory tract viral infection predisposes to ascension of NTHI from the nasopharynx, the site of colonization, to the normally sterile middle ear, resulting in disease. Using a clinically relevant viral-bacterial coinfection model of NTHI-induced OM, we performed transcutaneous immunization (TCI) via a band-aid delivery system to administer each of three promising NTHI vaccine candidates derived from bacterial adhesive proteins and biofilm mediators: recombinant soluble PilA (rsPilA), chimV4, and integration host factor. Each immunogen was admixed with the adjuvant LT(R192G/L211A), a double mutant of Escherichia coli heat-labile enterotoxin, and assessed for relative ability to prevent the onset of experimental OM. For each cohort, the presence of circulating immunogen-specific antibody-secreting cells and serum antibody was confirmed prior to intranasal NTHI challenge. After bacterial challenge, blinded video otoscopy and tympanometry revealed a significant reduction in the proportion of animals with signs of OM compared to levels in animals receiving adjuvant only, with an overall vaccine efficacy of 64 to 77%. These data are the first to demonstrate the efficacy afforded by TCI with a band-aid vaccine delivery system in a clinically relevant polymicrobial model of OM. The simplicity of TCI with a band-aid and the significant efficacy observed here hold great promise for reducing the global burden of OM in the pediatric population.
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8
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Ahearn CP, Gallo MC, Murphy TF. Insights on persistent airway infection by non-typeable Haemophilus influenzae in chronic obstructive pulmonary disease. Pathog Dis 2017; 75:3753446. [PMID: 28449098 PMCID: PMC5437125 DOI: 10.1093/femspd/ftx042] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/28/2017] [Indexed: 12/21/2022] Open
Abstract
Non-typeable Haemophilus influenzae (NTHi) is the most common bacterial cause of infection of the lower airways in adults with chronic obstructive pulmonary disease (COPD). Infection of the COPD airways causes acute exacerbations, resulting in substantial morbidity and mortality. NTHi has evolved multiple mechanisms to establish infection in the hostile environment of the COPD airways, allowing the pathogen to persist in the airways for months to years. Persistent infection of the COPD airways contributes to chronic airway inflammation that increases symptoms and accelerates the progressive loss of pulmonary function, which is a hallmark of the disease. Persistence mechanisms of NTHi include the expression of multiple redundant adhesins that mediate binding to host cellular and extracellular matrix components. NTHi evades host immune recognition and clearance by invading host epithelial cells, forming biofilms, altering gene expression and displaying surface antigenic variation. NTHi also binds host serum factors that confer serum resistance. Here we discuss the burden of COPD and the role of NTHi infections in the course of the disease. We provide an overview of NTHi mechanisms of persistence that allow the pathogen to establish a niche in the hostile COPD airways.
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Affiliation(s)
- Christian P. Ahearn
- Department of Microbiology and Immunology, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
- Clinical and Translational Research Center, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
| | - Mary C. Gallo
- Department of Microbiology and Immunology, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
- Clinical and Translational Research Center, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
| | - Timothy F. Murphy
- Department of Microbiology and Immunology, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
- Clinical and Translational Research Center, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
- Division of Infectious Disease, Department of Medicine, University at Buffalo, Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA
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Bluestone CD, Hebda PA, Alper CM, Sando I, Buchman CA, Stangerup SE, Felding JU, Swarts JD, Ghadiali SN, Takahashi H. 2. Eustachian Tube, Middle Ear, and Mastoid Anatomy; Physiology, Pathophysiology, and Pathogenesis. Ann Otol Rhinol Laryngol 2016; 194:16-30. [PMID: 15700932 DOI: 10.1177/00034894051140s105] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Charles D Bluestone
- Department of Otolaryngology, University of Pittsburgh School of Medicine, Children's Hospital of Pittsburgh, Pennsylvania, USA
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Giebink GS, Bakaletz LO, Barenkamp SJ, Eskola J, Green B, Gu XX, Harada T, Heikkinen T, Karma P, Klein JO, Kurono Y, Mogi G, Murphy TF, Ogra PL, Patel JA, Suzuki M, Yamanaka N. 7. Vaccine. Ann Otol Rhinol Laryngol 2016. [DOI: 10.1177/00034894021110s310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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11
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Giebink GS, Bakaletz LO, Barenkamp SJ, Green B, Gu XX, Heikkinen T, Hotomi M, Karma P, Kurono Y, Kyd JM, Murphy TF, Ogra PL, Patel JA, Pelton SI. 6. Vaccine. Ann Otol Rhinol Laryngol 2016. [DOI: 10.1177/00034894051140s110] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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12
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Khan MN, Ren D, Kaur R, Basha S, Zagursky R, Pichichero ME. Developing a vaccine to prevent otitis media caused by nontypeable Haemophilus influenzae. Expert Rev Vaccines 2016; 15:863-78. [PMID: 26894630 DOI: 10.1586/14760584.2016.1156539] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Nontypeable Haemophilus influenzae (NTHi) is a predominant organism of the upper respiratory nasopharyngeal microbiota. Its disease spectrum includes otitis media, sinusitis, non-bacteremic pneumonia and invasive infections. Protein-based vaccines to prevent NTHi infections are needed to alleviate these infections in children and vulnerable populations such as the elderly and those with chronic obstructive pulmonary disease (COPD). One NTHi protein is included in a pneumococcal conjugate vaccine and has been shown to provide efficacy. Our lab has been interested in understanding the immunogenicity of NTHi vaccine candidates P6, protein D and OMP26 for preventing acute otitis media in young children. We expect that continued investigation and progress in the development of an efficacious protein based vaccine against NTHi infections is achievable in the near future.
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Affiliation(s)
- M Nadeem Khan
- a Center for Infectious Disease and Immunology , Rochester General Hospital Research Institute , Rochester , NY , USA
| | - Dabin Ren
- a Center for Infectious Disease and Immunology , Rochester General Hospital Research Institute , Rochester , NY , USA
| | - Ravinder Kaur
- a Center for Infectious Disease and Immunology , Rochester General Hospital Research Institute , Rochester , NY , USA
| | - Saleem Basha
- a Center for Infectious Disease and Immunology , Rochester General Hospital Research Institute , Rochester , NY , USA
| | - Robert Zagursky
- a Center for Infectious Disease and Immunology , Rochester General Hospital Research Institute , Rochester , NY , USA
| | - Michael E Pichichero
- a Center for Infectious Disease and Immunology , Rochester General Hospital Research Institute , Rochester , NY , USA
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Therapeutic Transcutaneous Immunization with a Band-Aid Vaccine Resolves Experimental Otitis Media. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 22:867-74. [PMID: 26018536 DOI: 10.1128/cvi.00090-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 05/14/2015] [Indexed: 12/30/2022]
Abstract
Transcutaneous immunization (TCI) is a noninvasive strategy to induce protective immune responses. We describe TCI with a band-aid vaccine placed on the postauricular skin to exploit the unique organization of the stratum corneum and to promote the development of immune responses to resolve active experimental otitis media due to nontypeable Haemophilus influenzae (NTHI). This therapeutic immunization strategy induced significantly earlier resolution of middle ear fluid and rapid eradication of both planktonic and mucosal biofilm-resident NTHI within 7 days after receipt of the first immunizing band-aid vaccine. Efficacy was ascribed to the homing of immunogen-bearing cutaneous dendritic cells to the nasal-associated lymphoid tissue, induction of polyfunctional CD4(+) T cells, and the presence of immunogen-specific IgM and IgG within the middle ear. TCI using band-aid vaccines could expand the use of traditional parenteral preventative vaccines to include treatment of active otitis media, in addition to other diseases of the respiratory tract due to NTHI.
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Novotny LA, Jurcisek JA, Ward MO, Jordan ZB, Goodman SD, Bakaletz LO. Antibodies against the majority subunit of type IV Pili disperse nontypeable Haemophilus influenzae biofilms in a LuxS-dependent manner and confer therapeutic resolution of experimental otitis media. Mol Microbiol 2015; 96:276-92. [PMID: 25597921 DOI: 10.1111/mmi.12934] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2015] [Indexed: 12/12/2022]
Abstract
Despite resulting in a similar overall outcome, unlike antibodies directed against the DNABII protein, integration host factor (IHF), which induce catastrophic structural collapse of biofilms formed by nontypeable Haemophilus influenzae (NTHI), those directed against a recombinant soluble form of PilA [the majority subunit of Type IV pili (Tfp) produced by NTHI], mediated gradual 'top-down' dispersal of NTHI from biofilms. This dispersal occurred via a mechanism that was dependent upon expression of both PilA (and by inference, Tfp) and production of AI-2 quorum signaling molecules by LuxS. The addition of rsPilA to a biofilm-targeted therapeutic vaccine formulation comprised of IHF plus the powerful adjuvant dmLT and delivered via a noninvasive transcutaneous immunization route induced an immune response that targeted two important determinants essential for biofilm formation by NTHI. This resulted in significantly earlier eradication of NTHI from both planktonic and adherent populations in the middle ear, disruption of mucosal biofilms already resident within middle ears prior to immunization and rapid resolution of signs of disease in an animal model of experimental otitis media. These data support continued development of this novel combinatorial immunization approach for resolution and/or prevention of multiple diseases of the respiratory tract caused by NTHI.
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Affiliation(s)
- Laura A Novotny
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH, 43205, USA; The Ohio State University College of Medicine, Columbus, OH, 43210, USA
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15
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Whitby PW, VanWagoner TM, Seale TW, Morton DJ, Stull TL. Comparison of transcription of the Haemophilus influenzae iron/heme modulon genes in vitro and in vivo in the chinchilla middle ear. BMC Genomics 2013; 14:925. [PMID: 24373462 PMCID: PMC3879429 DOI: 10.1186/1471-2164-14-925] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 12/17/2013] [Indexed: 08/30/2023] Open
Abstract
Background Haemophilus influenzae is a significant cause of childhood otitis media, and also has an absolute growth requirement for heme. Recent microarray studies using three H. influenzae isolates were used to propose a putative core of genes responsive to iron and heme levels. Included in the core modulon were thirty seven genes that are preferentially expressed under iron/heme limitation, most of which are directly involved with iron and or heme acquisition. In this report, the core iron/heme modulon was further refined following microarray analysis of two additional nontypeable H. influenzae isolates from patients with otitis media. The transcriptional status of the genes comprising the refined iron/heme core modulon was then assessed in vivo, in a chinchilla model of otitis media. These in vivo experiments were performed to address the hypothesis that iron and heme regulated genes are both highly expressed in vivo and important, during clinical infection. Results Microarray analysis of two additional H. influenzae strains resulted in the definition of a core of iron/heme responsive genes. This core consisted of 35 genes maximally expressed under heme restriction and a further 20 genes maximally expressed in heme replete conditions. In vivo studies were performed with two nontypeable H. influenzae strains, 86-028NP and HI1722. The majority of operons identified as members of the core modulon by microarray were also actively upregulated in the chinchilla ear during otitis media. In 86-028NP, 70% of the operons were significantly upregulated while in HI1722 100% of the operons were upregulated in samples recovered from the chinchilla middle ear. Conclusion This study elucidates a conserved core of H. influenzae genes the transcription of which is altered by the availability of iron and heme in the growth environment, and further assesses transcription of these genes in vivo. Elucidation of this modulon allows for identification of genes with unrecognized roles in iron/heme acquisition or homeostasis and/or potential roles in virulence. Defining these core genes is also of potential importance in identifying targets for therapeutic and vaccine designs since products of these genes are likely to be preferentially expressed during growth in iron/heme restricted sites of the human body.
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Affiliation(s)
- Paul W Whitby
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City 73104, OK, USA.
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Shaffer TL, Balder R, Buskirk SW, Hogan RJ, Lafontaine ER. Use of the Chinchilla model to evaluate the vaccinogenic potential of the Moraxella catarrhalis filamentous hemagglutinin-like proteins MhaB1 and MhaB2. PLoS One 2013; 8:e67881. [PMID: 23844117 PMCID: PMC3699455 DOI: 10.1371/journal.pone.0067881] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 05/23/2013] [Indexed: 11/19/2022] Open
Abstract
Moraxella catarrhalis causes significant health problems, including 15–20% of otitis media cases in children and ∼10% of respiratory infections in adults with chronic obstructive pulmonary disease. The lack of an efficacious vaccine, the rapid emergence of antibiotic resistance in clinical isolates, and high carriage rates reported in children are cause for concern. In addition, the effectiveness of conjugate vaccines at reducing the incidence of otitis media caused by Streptococcus pneumoniae and nontypeable Haemophilus influenzae suggest that M. catarrhalis infections may become even more prevalent. Hence, M. catarrhalis is an important and emerging cause of infectious disease for which the development of a vaccine is highly desirable. Studying the pathogenesis of M. catarrhalis and the testing of vaccine candidates have both been hindered by the lack of an animal model that mimics human colonization and infection. To address this, we intranasally infected chinchilla with M. catarrhalis to investigate colonization and examine the efficacy of a protein-based vaccine. The data reveal that infected chinchillas produce antibodies against antigens known to be major targets of the immune response in humans, thus establishing immune parallels between chinchillas and humans during M. catarrhalis infection. Our data also demonstrate that a mutant lacking expression of the adherence proteins MhaB1 and MhaB2 is impaired in its ability to colonize the chinchilla nasopharynx, and that immunization with a polypeptide shared by MhaB1 and MhaB2 elicits antibodies interfering with colonization. These findings underscore the importance of adherence proteins in colonization and emphasize the relevance of the chinchilla model to study M. catarrhalis–host interactions.
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Affiliation(s)
- Teresa L. Shaffer
- Department of Microbiology, University of Georgia, Athens, Georgia, United States of America
| | - Rachel Balder
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Sean W. Buskirk
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Robert J. Hogan
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, United States of America
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia, Athens, Georgia, United States of America
| | - Eric R. Lafontaine
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, United States of America
- * E-mail:
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Confer AW, Ayalew S. The OmpA family of proteins: Roles in bacterial pathogenesis and immunity. Vet Microbiol 2013; 163:207-22. [DOI: 10.1016/j.vetmic.2012.08.019] [Citation(s) in RCA: 158] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 08/23/2012] [Indexed: 10/27/2022]
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Whitby PW, VanWagoner TM, Morton DJ, Seale TW, Springer JM, Hempel RJ, Stull TL. Signature-tagging of a bacterial isolate demonstrates phenotypic variability of the progeny in vivo in the absence of defined mutations. J Microbiol Methods 2012; 91:336-40. [PMID: 23085534 PMCID: PMC3506178 DOI: 10.1016/j.mimet.2012.10.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 10/03/2012] [Accepted: 10/09/2012] [Indexed: 11/22/2022]
Abstract
Awareness of the high degree of redundancy that occurs in several nutrient uptake pathways of Haemophilus influenzae led us to attempt to develop a quantitative STM method that could identify both null mutants and mutants with decreased fitness that remain viable in vivo. To accomplish this task we designed a modified STM approach that utilized a set of signature tagged wild-type (STWT) strains (in a single genetic background) as carriers for mutations in genes of interest located elsewhere in the genome. Each STWT strain differed from the others by insertion of a unique, Q-PCR-detectable, seven base pair tag into the same redundant gene locus. Initially ten STWTs were created and characterized in vitro and in vivo. As anticipated, the STWT strains were not significantly different in their in vitro growth. However, in the chinchilla model of otitis media, certain STWTs outgrew others by several orders of magnitude in mixed infections. Removal of the predominant STWT resulted in its replacement by a different predominant STWT on retesting. Unexpectedly we observed that the STWT exhibiting the greatest proliferation was animal dependent. These findings identify an inherent inability of the signature tag methodologies to accurately elucidate fitness in this animal model of infection and underscore the subtleties of H. influenzae gene regulation.
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Affiliation(s)
- Paul W Whitby
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
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19
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Novotny LA, Clements JD, Bakaletz LO. Kinetic analysis and evaluation of the mechanisms involved in the resolution of experimental nontypeable Haemophilus influenzae-induced otitis media after transcutaneous immunization. Vaccine 2012; 31:3417-26. [PMID: 23092856 DOI: 10.1016/j.vaccine.2012.10.033] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 08/31/2012] [Accepted: 10/09/2012] [Indexed: 01/09/2023]
Abstract
Transcutaneous immunization (TCI) is a simple and needle-free method with which to induce protective immune responses. Using a chinchilla model of nontypeable Haemophilus influenzae (NTHI)-induced otitis media (OM), we examined the efficacy afforded by TCI with a novel chimeric immunogen called 'chimV4' which targets two critical adhesins expressed by NTHI, outer membrane protein P5 and the majority subunit of NTHI Type IV pilus, PilA. Experimental OM was first established in cohorts of animals, and then TCI performed via a therapeutic immunization regime by rubbing vaccine formulations on hydrated pinnae. The kinetics of resolution of established experimental disease was evaluated by clinically-relevant assessments of OM, bacterial culture of planktonic and adherent NTHI within the middle ear and gross examination of the relative amount of NTHI mucosal biofilms within the middle ear space. Within seven days after primary TCI, a significant reduction in the signs of OM, significantly fewer NTHI adherent to the middle ear mucosa and significant resolution of mucosal biofilms was detected in animals that received chimV4+ the adjuvant LT(R192G-L211A), compared to animals administered LT(R192G-L211A) alone or saline by TCI (p<0.05) with eradication of NTHI within an additional seven days. The mechanism for rapid disease resolution involved efflux of activated dermal dendritic cells from the pinnae after TCI, secretion of factors chemotactic for CD4(+) T-cells, induction of polyfunctional IFNγ- and IL-17-producing CD4(+) T-cells and secretion of host defense peptide within the middle ear. These data support TCI as a therapeutic intervention against experimental NTHI-induced OM and begin to elucidate the host response to immunization by this noninvasive regimen.
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Affiliation(s)
- Laura A Novotny
- The Research Institute at Nationwide Children's Hospital, Center for Microbial Pathogenesis and The Ohio State University College of Medicine, 700 Children's Drive, Columbus, OH 43205, United States
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20
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Brockson ME, Novotny LA, Jurcisek JA, McGillivary G, Bowers MR, Bakaletz LO. Respiratory syncytial virus promotes Moraxella catarrhalis-induced ascending experimental otitis media. PLoS One 2012; 7:e40088. [PMID: 22768228 PMCID: PMC3387005 DOI: 10.1371/journal.pone.0040088] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 05/31/2012] [Indexed: 01/29/2023] Open
Abstract
Otitis media (OM) is a polymicrobial disease wherein prior or concurrent infection with an upper respiratory tract virus plays an essential role, predisposing the middle ear to bacterial invasion. In episodes of acute bacterial OM, respiratory syncytial virus (RSV) is the most commonly isolated virus and thus serves as an important co-pathogen. Of the predominant bacterial agents of OM, the pathogenesis of disease due to Moraxella catarrhalis is the least well understood. Rigorous study of M.catarrhalis in the context of OM has been significantly hindered by lack of an animal model. To bridge this gap, we assessed whether co-infection of chinchillas with M. catarrhalis and RSV would facilitate ascension of M. catarrhalis from the nasopharynx into the middle ear. Chinchillas were challenged intranasally with M. catarrhalis followed 48 hours later by intranasal challenge with RSV. Within 7 days, 100% of nasopharynges were colonized with M. catarrhalis and homogenates of middle ear mucosa were also culture-positive. Moreover, within the middle ear space, the mucosa exhibited hemorrhagic foci, and a small volume of serosanguinous effusion was present in one of six ears. To improve upon this model, and based on epidemiologic data, nontypeable Haemophilus influenzae (NTHI) was included as an additional bacterial co-pathogen via intranasal administration four days before M. catarrhalis challenge. With this latter protocol, M. catarrhalis was cultured from the nasopharynx and middle ear homogenates of a maximum of 88% and 79% animals, respectively, for up to 17 days after intranasal challenge with M. catarrhalis. Additionally, hemorrhagic foci were observed in 79% of middle ears upon sacrifice. Thus, these data demonstrated that co-infection with RSV and NTHI predisposed to M. catarrhalis-induced ascending experimental OM. This model can be used both in studies of pathogenesis as well as to investigate strategies to prevent or treat OM due to M. catarrhalis.
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Affiliation(s)
- M. Elizabeth Brockson
- The Research Institute at Nationwide Children’s Hospital, Center for Microbial Pathogenesis and The Ohio State University College of Medicine, Columbus, Ohio, United States of America
| | - Laura A. Novotny
- The Research Institute at Nationwide Children’s Hospital, Center for Microbial Pathogenesis and The Ohio State University College of Medicine, Columbus, Ohio, United States of America
| | - Joseph A. Jurcisek
- The Research Institute at Nationwide Children’s Hospital, Center for Microbial Pathogenesis and The Ohio State University College of Medicine, Columbus, Ohio, United States of America
| | - Glen McGillivary
- The Research Institute at Nationwide Children’s Hospital, Center for Microbial Pathogenesis and The Ohio State University College of Medicine, Columbus, Ohio, United States of America
| | - Martha R. Bowers
- The Research Institute at Nationwide Children’s Hospital, Center for Microbial Pathogenesis and The Ohio State University College of Medicine, Columbus, Ohio, United States of America
| | - Lauren O. Bakaletz
- The Research Institute at Nationwide Children’s Hospital, Center for Microbial Pathogenesis and The Ohio State University College of Medicine, Columbus, Ohio, United States of America
- * E-mail:
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21
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Morton DJ, Hempel RJ, Seale TW, Whitby PW, Stull TL. A functional tonB gene is required for both virulence and competitive fitness in a chinchilla model of Haemophilus influenzae otitis media. BMC Res Notes 2012; 5:327. [PMID: 22731867 PMCID: PMC3425130 DOI: 10.1186/1756-0500-5-327] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Accepted: 06/25/2012] [Indexed: 02/02/2023] Open
Abstract
Background Haemophilus influenzae requires heme for aerobic growth and possesses multiple mechanisms to obtain this essential nutrient. Methods An insertional mutation in tonB was constructed and the impact of the mutation on virulence and fitness in a chinchilla model of otitis media was determined. The tonB insertion mutant strain was significantly impacted in both virulence and fitness as compared to the wildtype strain in this model. Conclusions The tonB gene of H. influenzae is required for the establishment and maintenance of middle ear infection in this chinchilla model of bacterial disease.
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Affiliation(s)
- Daniel J Morton
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, 73104, USA.
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22
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Biological roles of nontypeable Haemophilus influenzae type IV pilus proteins encoded by the pil and com operons. J Bacteriol 2012; 194:1927-33. [PMID: 22328674 DOI: 10.1128/jb.06540-11] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We previously demonstrated that one or more products of the genes in the pil and com gene clusters of the opportunistic human respiratory pathogen nontypeable Haemophilus influenzae (NTHI) are required for type IV pilus (Tfp) biogenesis and function. Here, we have now demonstrated that the pilABCD and comABCDEF gene clusters are operons and that the product of each gene is essential for normal pilus function. Mutants with nonpolar deletions in each of the 10 pil and com genes had an adherence defect when primary human airway cells were used as the target. These mutants were also diminished in their ability to form a biofilm in vitro and, additionally, were deficient in natural transformation. Collectively, our data demonstrate that the product of each gene within these operons is required for the normal biogenesis and/or function of NTHI Tfp. Based on the similarity of PilA to other type IV pilins, we further predicted that the product of the pilA gene would be the major pilin subunit. Toward that end, we also demonstrated by immunogold labeling and mass spectrometry that PilA is indeed the majority type IV pilin protein expressed by NTHI. These new observations set the stage for experiments designed to dissect the function of each of the proteins encoded by genes within the pil and com gene clusters. The ability to characterize individual proteins with vital roles in NTHI colonization or pathogenesis has the potential to reduce the burden of NTHI-induced diseases through development of a Tfp-derived vaccine or a pilus-directed therapeutic.
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23
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Cope EK, Goldstein-Daruech N, Kofonow JM, Christensen L, McDermott B, Monroy F, Palmer JN, Chiu AG, Shirtliff ME, Cohen NA, Leid JG. Regulation of virulence gene expression resulting from Streptococcus pneumoniae and nontypeable Haemophilus influenzae interactions in chronic disease. PLoS One 2011; 6:e28523. [PMID: 22162775 PMCID: PMC3230614 DOI: 10.1371/journal.pone.0028523] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 11/09/2011] [Indexed: 01/25/2023] Open
Abstract
Chronic rhinosinusitis (CRS) is a common inflammatory disease of the sinonasal cavity mediated, in part, by polymicrobial communities of bacteria. Recent molecular studies have confirmed the importance of Streptococcus pneumoniae and nontypeable Haemophilus influenzae (NTHi) in CRS. Here, we hypothesize that interaction between S. pneumoniae and NTHi mixed-species communities cause a change in bacterial virulence gene expression. We examined CRS as a model human disease to validate these polymicrobial interactions. Clinical strains of S. pneumoniae and NTHi were grown in mono- and co-culture in a standard biofilm assay. Reverse transcriptase real-time PCR (RTqPCR) was used to measure gene expression of key virulence factors. To validate these results, we investigated the presence of the bacterial RNA transcripts in excised human tissue from patients with CRS. Consequences of physical or chemical interactions between microbes were also investigated. Transcription of NTHi type IV pili was only expressed in co-culture in vitro, and expression could be detected ex vivo in diseased tissue. S. pneumoniae pyruvate oxidase was up-regulated in co-culture, while pneumolysin and pneumococcal adherence factor A were down-regulated. These results were confirmed in excised human CRS tissue. Gene expression was differentially regulated by physical contact and secreted factors. Overall, these data suggest that interactions between H. influenzae and S. pneumoniae involve physical and chemical mechanisms that influence virulence gene expression of mixed-species biofilm communities present in chronically diseased human tissue. These results extend previous studies of population-level virulence and provide novel insight into the importance of S. pneumoniae and NTHi in CRS.
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Affiliation(s)
- Emily K Cope
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, United States of America.
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24
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Goodman SD, Obergfell KP, Jurcisek JA, Novotny LA, Downey JS, Ayala EA, Tjokro N, Li B, Justice SS, Bakaletz LO. Biofilms can be dispersed by focusing the immune system on a common family of bacterial nucleoid-associated proteins. Mucosal Immunol 2011; 4:625-37. [PMID: 21716265 DOI: 10.1038/mi.2011.27] [Citation(s) in RCA: 161] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Bacteria that cause chronic and/or recurrent diseases often rely on a biofilm lifestyle. The foundation of the biofilm structure is the extracellular polymeric substance (EPS) that acts as a barrier to both effectors of the immune system and antimicrobial agents. Recent work has highlighted extracellular DNA (eDNA) as a key component common to many pathogenic biofilms. Here, we show that the DNABII family of proteins, well known for their strong structural influences on intracellular DNA, was also critical for the integrity of the EPS matrix of biofilms that contain eDNA. In fact, antisera derived against a purified Escherichia coli DNABII family member rapidly disrupts the biofilm EPS formed by multiple human pathogens in vitro. In addition, when a member of this family of proteins was used as an immunogen in an animal model in which the bacteria had already formed a robust biofilm at the site of infection, the resultant targeted immune response strongly ameliorated this biofilm disease in vivo. Finally, this methodology to debulk the biofilm of EPS was shown to work synergistically with otherwise ineffective traditional anti-microbial approaches in vitro. We discuss the prospects for targeting DNABII family members as a potential universal strategy for treating biofilm diseases.
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Affiliation(s)
- S D Goodman
- Division of Biomedical Sciences, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, California, USA.
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25
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Novotny LA, Clements JD, Bakaletz LO. Transcutaneous immunization as preventative and therapeutic regimens to protect against experimental otitis media due to nontypeable Haemophilus influenzae. Mucosal Immunol 2011; 4:456-67. [PMID: 21326197 PMCID: PMC3118858 DOI: 10.1038/mi.2011.6] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Accepted: 01/18/2011] [Indexed: 02/04/2023]
Abstract
We have developed three nontypeable Haemophilus influenzae (NTHI) adhesin-derived immunogens that are significantly efficacious against experimental otitis media (OM) due to NTHI when delivered parenterally. We now expanded our preventative immunization strategies to include transcutaneous immunization (TCI) as a less invasive, but potentially equally efficacious, regimen to prevent OM due to NTHI. Additionally, we examined the potential of TCI as a therapeutic immunization regimen to resolve ongoing experimental OM. Preventative immunization with NTHI outer membrane protein (OMP) P5- and type IV pilus-targeted immunogens, delivered with the adjuvant LT(R192G-L211A), induced significantly earlier clearance of NTHI from the nasopharynges and middle ears of challenged chinchillas compared with receipt of immunogen or adjuvant alone. Moreover, therapeutic immunization resulted in significant resolution of established NTHI biofilms from the middle ear space of animals compared with controls. These data advocate TCI with the adhesin-directed immunogens as an efficacious regimen for prevention and resolution of experimental NTHI-induced OM.
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Affiliation(s)
- L A Novotny
- The Research Institute at Nationwide Children's Hospital, Department of Pediatrics, Center for Microbial Pathogenesis and The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - J D Clements
- Department of Microbiology and Immunology, Tulane University Health Sciences Center, New Orleans, Louisiana, USA
| | - L O Bakaletz
- The Research Institute at Nationwide Children's Hospital, Department of Pediatrics, Center for Microbial Pathogenesis and The Ohio State University College of Medicine, Columbus, Ohio, USA
- Nationwide Children's Hospital, Department of Otolaryngology and The Ohio State University College of Medicine, Columbus, Ohio, USA
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Abrogation of nontypeable Haemophilus influenzae protein D function reduces phosphorylcholine decoration, adherence to airway epithelial cells, and fitness in a chinchilla model of otitis media. Vaccine 2010; 29:1211-21. [PMID: 21167861 DOI: 10.1016/j.vaccine.2010.12.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Revised: 11/03/2010] [Accepted: 12/01/2010] [Indexed: 11/20/2022]
Abstract
The pneumococcal polysaccharide conjugate vaccine which includes a nonacylated protein D carrier from Haemophilus influenzae has been recently licensed for use in many countries. While this vaccine is protective against nontypeable Haemophilus influenzae (NTHI)-induced acute otitis media (OM), the mechanism underlying this protective efficacy is not yet fully understood. Protein D/glycerophosphodiester phosphodiesterase (PD/GlpQ) is an outer membrane lipoprotein expressed by NTHI that has been ascribed several functions, including host cell adherence and phosphorylcholine (PCho) acquisition. We found that a pd/glpQ NTHI mutant exhibited reduced adherence to airway epithelial cells, diminished phosphorylcholine (PCho) decoration of biofilms, and compromised fitness during experimental acute OM compared to the parent strain. We also found that exposure of NTHI to antibodies directed against the vaccine formulation recapitulated the PCho decoration and NTHI adherence phenotypes exhibited by PD/GlpQ-deficient NTHI, providing at least two likely mechanisms by which the pneumococcal polysaccharide-PD/GlpQ conjugate vaccine induces protection from NTHI-induced OM.
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Morton DJ, Seale TW, Bakaletz LO, Jurcisek JA, Smith A, VanWagoner TM, Whitby PW, Stull TL. The heme-binding protein (HbpA) of Haemophilus influenzae as a virulence determinant. Int J Med Microbiol 2009; 299:479-88. [PMID: 19451029 PMCID: PMC2749905 DOI: 10.1016/j.ijmm.2009.03.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Revised: 03/09/2009] [Accepted: 03/27/2009] [Indexed: 01/29/2023] Open
Abstract
Haemophilus influenzae has an absolute growth requirement for heme and the heme-binding lipoprotein (HbpA) and has been implicated in the utilization of this essential nutrient. We constructed an insertional mutation of hbpA in a type b and a nontypeable H. influenzae strain. In the type b strain, the hbpA mutant was impaired in utilization of heme complexed to either hemopexin or to albumin and in the utilization of low levels of heme but not in the utilization of heme at high levels or of hemoglobin or hemoglobin-haptoglobin complexes. In contrast, the hbpA mutant derivative of the nontypeable strain was impaired in utilization of all tested heme sources. We further examined the impact of the hbpA mutation in animal models of H. influenzae disease. The hbpA mutant of the nontypeable strain was indistinguishable from the wild-type strain in the chinchilla model of otitis media. The hbpA mutant derivative of the type b strain caused bacteremia as well as the wild-type strain in 5-day old infant rats. However, in 30-day old rats the hbpA caused significantly lower rates of bacteremia than the wild-type strain indicating a role for hbpA and heme acquisition in virulence in this model of H. influenzae disease. In conclusion, HbpA is important for heme utilization by multiple H. influenzae strains and is a virulence determinant in a model of H. influenzae invasive disease.
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Affiliation(s)
- Daniel J Morton
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
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Bakaletz LO. Chinchilla as a robust, reproducible and polymicrobial model of otitis media and its prevention. Expert Rev Vaccines 2009; 8:1063-82. [PMID: 19627188 DOI: 10.1586/erv.09.63] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
There is compelling evidence that many infectious diseases of humans are caused by more than one microorganism. Multiple diverse in vitro systems have been used to study these complex diseases, and although the data generated have contributed greatly to our understanding of diseases of mixed microbial etiology, having rigorous, reproducible and relevant animal models of human diseases are essential for the development of novel methods to treat or prevent them. All animal models have inherent limitations; however, they also have important advantages over in vitro methods, including the presence of organized organ systems and an intact immune system, which promote our ability to characterize the pathogenesis of, and the immune response to, sequential or coinfecting microorganisms. For the highly prevalent pediatric disease otitis media, or middle-ear infection, the chinchilla (Chinchilla lanigera) has served as a gold-standard rodent host system in which to study this multifactorial and polymicrobial disease.
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Affiliation(s)
- Lauren O Bakaletz
- The Research Institute at Nationwide Children's Hospital, Center for Microbial Pathogenesis, and Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH 43205, USA.
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Epitope mapping immunodominant regions of the PilA protein of nontypeable Haemophilus influenzae (NTHI) to facilitate the design of two novel chimeric vaccine candidates. Vaccine 2009; 28:279-89. [PMID: 19699813 DOI: 10.1016/j.vaccine.2009.08.017] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 07/30/2009] [Accepted: 08/06/2009] [Indexed: 02/02/2023]
Abstract
We designed and tested three PilA-derived vaccine candidates in a chinchilla model of ascending nontypeable Haemophilus influenzae (NTHI)-induced otitis media (OM). Delivery of antiserum directed against each immunogen conferred varying degrees of protection. Presentation of a B-cell epitope derived from the OMP P5 adhesin at the N-terminus of recombinant soluble PilA protein (as opposed to the C-terminus), resulted in a protective chimeric immunogen that combined epitopes from two distinct NTHI adhesins (type IV pili and OMP P5). Incorporating protective epitopes derived from two NTHI adhesins/virulence determinants into a single pediatric vaccine candidate to prevent OM has multiple potential inherent advantages.
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Maunsell FP, Donovan GA. Mycoplasma bovis Infections in young calves. Vet Clin North Am Food Anim Pract 2009; 25:139-77, vii. [PMID: 19174287 DOI: 10.1016/j.cvfa.2008.10.011] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Mycoplasma bovis has emerged as an important pathogen of young intensively reared calves in North America. A variety of clinical diseases are associated with M bovis infections of calves, including respiratory disease, otitis media, arthritis, and some less common presentations. Clinical disease associated with M bovis often is chronic, debilitating, and poorly responsive to antimicrobial therapy. Current control measures are centered on reducing exposure to M bovis through contaminated milk or other sources, and nonspecific control measures to maximize respiratory defenses of the calf. This article focuses on the clinical and epidemiologic aspects of M bovis infections in young calves.
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Affiliation(s)
- Fiona P Maunsell
- Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, P.O. Box 110880, Gainesville, FL 32611, USA.
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Pandey M, Batzloff MR, Good MF. Mechanism of protection induced by group A Streptococcus vaccine candidate J8-DT: contribution of B and T-cells towards protection. PLoS One 2009; 4:e5147. [PMID: 19340309 PMCID: PMC2660439 DOI: 10.1371/journal.pone.0005147] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Accepted: 03/13/2009] [Indexed: 11/28/2022] Open
Abstract
Vaccination with J8-DT, a leading GAS vaccine candidate, results in protective immunity in mice. Analysis of immunologic correlates of protection indicated a role of J8-specific antibodies that were induced post-immunization. In the present study, several independent experimental approaches were employed to investigate the protective immunological mechanisms involved in J8-DT-mediated immunity. These approaches included the passive transfer of mouse or rabbit immune serum/antibodies in addition to selective depletion of T-cell subsets prior to bacterial challenge. Passive transfer of J8-DT antiserum/antibodies from mice and rabbits conferred significant resistance against challenge to mice. To exclude the possibility of involvement of other host immune factors, the studies were repeated in SCID mice, which highlighted the need for an ongoing immune response for long-lived protection. Depletion of CD4+ and CD8+ T-cell subsets confirmed that an active de novo immune response, involving CD4+ T-helper cells, is required for continued synthesis of antibodies resulting in protection against GAS infection. Taken together these results indicate an involvement of CD4+ T-cells in J8-DT-mediated protection possibly via an ability to maintain antibody levels. These results have considerable relevance to the development of a broad spectrum passive immunotherapy for GAS disease.
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Affiliation(s)
- Manisha Pandey
- The Australian Centre for Vaccine Development, The Queensland Institute of Medical Research, PO Royal Brisbane Hospital, Brisbane, Australia
| | - Michael R. Batzloff
- The Australian Centre for Vaccine Development, The Queensland Institute of Medical Research, PO Royal Brisbane Hospital, Brisbane, Australia
| | - Michael F. Good
- The Australian Centre for Vaccine Development, The Queensland Institute of Medical Research, PO Royal Brisbane Hospital, Brisbane, Australia
- * E-mail:
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Pang B, Winn D, Johnson R, Hong W, West-Barnette S, Kock N, Swords WE. Lipooligosaccharides containing phosphorylcholine delay pulmonary clearance of nontypeable Haemophilus influenzae. Infect Immun 2008; 76:2037-43. [PMID: 18347044 PMCID: PMC2346676 DOI: 10.1128/iai.01716-07] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 01/25/2008] [Accepted: 03/06/2008] [Indexed: 11/20/2022] Open
Abstract
Nontypeable Haemophilus influenzae (NTHi) causes pulmonary infections in patients with chronic obstructive pulmonary disease and other mucociliary clearance defects. Like many bacteria inhabiting mucosal surfaces, NTHi produces lipooligosaccharide (LOS) endotoxins that lack the O side chain. Persistent NTHi populations express a discrete subset of LOS glycoforms, including those containing phosphorylcholine (PCho). In this study, we compared two NTHi strains with isogenic mutants lacking PCho for clearance from mice following pulmonary infection. Consistent with data from other model systems, populations of the strains NTHi 2019 and NTHi 86-028NP recovered from mouse lung contained an increased proportion of PCho+ variants compared to that in the inocula. PCho- mutants were more rapidly cleared. Serial passage of NTHi increased both PCho content and bacterial resistance to clearance, and no such increases were observed for PCho- mutants. Increased PCho content was also observed in NTHi populations within non-endotoxin-responsive C3H/HeJ and Toll-like receptor 4 null (TLR4-/-) mice, albeit at later times postinfection. Changes in bacterial subpopulations and clearance were unaffected in TLR2-/- mice compared to the subpopulations in and clearance from mice of the parental strain. The clearance of PCho- mutants occurred at earlier time points in both strain backgrounds and in all types of mice. Comparison of bacterial populations in lung tissue cryosections by immunofluorescent staining showed sparse bacteria within the air spaces of C57BL/6 mice and large bacterial aggregates within the lungs of MyD88-/- mice. These results indicate that PCho promotes bacterial resistance to pulmonary clearance early in infection in a manner that is at least partially independent of the TLR4 pathway.
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Affiliation(s)
- Bing Pang
- Department of Microbiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA
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Differential uptake and processing of a Haemophilus influenzae P5-derived immunogen by chinchilla dendritic cells. Infect Immun 2007; 76:967-77. [PMID: 18160476 DOI: 10.1128/iai.01395-07] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Dendritic cells (DCs) are potent antigen-presenting cells involved in the initiation and modulation of immune responses after immunization via their ability to process and present antigen to naive T cells. We wanted to examine the role of DCs in the development of protective immunity against nontypeable Haemophilus influenzae (NTHI)-induced experimental otitis media (OM) after intranasal immunization of chinchillas with an NTHI P5-derived synthetic peptide immunogen called LB1. As chinchilla DCs have not been described, we adapted well-established protocols to induce the differentiation of chinchilla bone marrow precursor cells into DCs, which resulted in cells that were morphologically and phenotypically similar to DCs of other species. In vitro, chinchilla DCs readily internalized LB1, upregulated expression of the maturation markers CD80 and major histocompatibility complex class II, and presented processed LB1 to primed CD3+ T cells, which resulted in antigen-specific T-cell proliferation. In vivo, LB1-activated DCs trafficked from the chinchilla nasal cavity primarily to the nasal-associated lymphoid tissues and were detected in close proximity to CD3+ T cells within this lymphoid aggregate. These data are the first to characterize chinchilla DCs and their functional properties. Furthermore, they suggest an important role for chinchilla DCs in the development of protective immunity against experimental NTHI-induced OM after intranasal immunization.
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A carcinoembryonic antigen-related cell adhesion molecule 1 homologue plays a pivotal role in nontypeable Haemophilus influenzae colonization of the chinchilla nasopharynx via the outer membrane protein P5-homologous adhesin. Infect Immun 2007; 76:48-55. [PMID: 17938212 DOI: 10.1128/iai.00980-07] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
In vitro studies suggest an important role for CEACAM1 (carcinoembryonic antigen-related cell adhesion molecule 1) in infection by multiple gram-negative bacteria. However, in vivo evidence supporting this role is lacking, largely because the bacterial adhesins involved in this host-microbe association do not bind to murine-derived CEACAM1. One of several adhesins expressed by nontypeable Haemophilus influenzae (NTHI), the outer membrane protein P5-homologous adhesin (or P5), is essential for colonization of the chinchilla nasopharynx and infection of the middle ear. Here we reveal that NTHI P5 binds to the chinchilla homologue of CEACAM1 and that rabbit anti-human carcinoembryonic antigen blocks NTHI colonization of the chinchilla nasopharynx, providing the first demonstration of a role for CEACAM receptor binding by any bacterial pathogen in vivo.
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Jurcisek JA, Bookwalter JE, Baker BD, Fernandez S, Novotny LA, Munson RS, Bakaletz LO. The PilA protein of non-typeable Haemophilus influenzae plays a role in biofilm formation, adherence to epithelial cells and colonization of the mammalian upper respiratory tract. Mol Microbiol 2007; 65:1288-99. [PMID: 17645732 DOI: 10.1111/j.1365-2958.2007.05864.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We recently described the expression of type IV pili (Tfp) by non-typeable Haemophilus influenzae (NTHI), a common respiratory tract pathogen. Prior to that report, Tfp were not thought to be produced by NTHI as they are not observed on NTHI when grown on chocolate agar or other commonly used growth media. To further characterize growth conditions permissive for the expression of NTHI Tfp, as well as determine their role in colonization and virulence, we transformed an NTHI otitis media isolate with a reporter plasmid containing the lux gene cluster driven by the pilA promoter. Transcription from the pilA promoter was demonstrated under a variety of in vitro growth conditions and, importantly, by ex vivo imaging of luciferase-producing NTHI in infected chinchillas. Luciferase-producing NTHI were also identified within a biofilm formed by NTHI in vivo. We further demonstrated a role for NTHI PilA in adherence to human respiratory epithelial cells, in colonization of the chinchilla respiratory tract as well as a requirement for PilA in biofilm development, both in vitro and in vivo. Collectively, our data demonstrate that NTHI express PilA in vivo, and that PilA plays an important role in the pathogenesis of an upper respiratory tract infection induced by NTHI.
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Affiliation(s)
- Joseph A Jurcisek
- Columbus Children's Research Institute, The Ohio State University College of Medicine, Department of Pediatrics, Center for Microbial Pathogenesis, Columbus, OH 43205, USA
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Hong W, Mason K, Jurcisek J, Novotny L, Bakaletz LO, Swords WE. Phosphorylcholine decreases early inflammation and promotes the establishment of stable biofilm communities of nontypeable Haemophilus influenzae strain 86-028NP in a chinchilla model of otitis media. Infect Immun 2006; 75:958-65. [PMID: 17130253 PMCID: PMC1828519 DOI: 10.1128/iai.01691-06] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Nontypeable Haemophilus influenzae (NTHi) is a leading causative agent of otitis media. Much of the inflammation occurring during NTHi disease is initiated by lipooligosaccharides (LOS) on the bacterial surface. Phosphorylcholine (PCho) is added to some LOS forms in a phase-variable manner, and these PCho(+) variants predominate in vivo. Thus, we asked whether this modification confers some advantage during infection. Virulence of an otitis media isolate (NTHi strain 86-028NP) was compared with that of an isogenic PCho transferase (licD) mutant using a chinchilla (Chinchilla lanigera) model of otitis media. Animals infected with NTHi 86-028NP licD demonstrated increased early inflammation and a delayed increase in bacterial counts compared to animals infected with NTHi 86-028NP. LOS purified from chinchilla-passed NTHi 86-028NP had increased PCho content compared to LOS purified from the inoculum. Both strains were recovered from middle ear fluids as long as 14 days postinfection. Biofilms were macroscopically visible in the middle ears of euthanized animals infected with NTHi 86-028NP 7 days and 14 days postchallenge. Conversely, less dense biofilms were observed in animals infected with NTHi 86-028NP licD 7 days postinfection, and none of the animals infected with NTHi 86-028NP licD had a visible biofilm by 14 days. Fluorescent antibody staining revealed PCho(+) variants within biofilms, similar to our prior results with tissue culture cells in vitro (S. L. West-Barnette, A. Rockel, and W. E. Swords, Infect. Immun. 74:1828-1836, 2006). Animals coinfected with equal proportions of both strains had equal persistence of each strain and somewhat greater severity of disease. We thus conclude that PCho promotes NTHi infection and persistence by reducing the host inflammatory response and by promoting formation of stable biofilm communities.
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Affiliation(s)
- Wenzhou Hong
- Department of Microbiology and Immunology, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA
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McGillivary G, Ray WC, Bevins CL, Munson RS, Bakaletz LO. A member of the cathelicidin family of antimicrobial peptides is produced in the upper airway of the chinchilla and its mRNA expression is altered by common viral and bacterial co-pathogens of otitis media. Mol Immunol 2006; 44:2446-58. [PMID: 17113647 PMCID: PMC1817667 DOI: 10.1016/j.molimm.2006.10.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Revised: 10/11/2006] [Accepted: 10/13/2006] [Indexed: 10/23/2022]
Abstract
Cationic antimicrobial peptides (AMPs), a component of the innate immune system, play a major role in defense of mucosal surfaces against a wide spectrum of microorganisms such as viral and bacterial co-pathogens of the polymicrobial disease otitis media (OM). To further understand the role of AMPs in OM, we cloned a cDNA encoding a cathelicidin homolog (cCRAMP) from upper respiratory tract (URT) mucosae of the chinchilla, the predominant host used to model experimental OM. Recombinant cCRAMP exhibited alpha-helical secondary structure and killed the three main bacterial pathogens of OM. In situ hybridization showed cCRAMP mRNA production in epithelium of the chinchilla Eustachian tube and RT-PCR was used to amplify cCRAMP mRNA from several other tissues of the chinchilla URT. Quantitative RT-PCR analysis of chinchilla middle ear epithelial cells (CMEEs) incubated with either viral (influenza A virus, adenovirus, or RSV) or bacterial (nontypeable H. influenzae, M. catarrhalis, or S. pneumoniae) pathogens associated with OM demonstrated distinct microbe-specific patterns of altered expression. Collectively, these data showed that viruses and bacteria modulate AMP messages in the URT, which likely contributes to the disease course of OM.
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Affiliation(s)
- Glen McGillivary
- Columbus Children’s Research Institute, Center for Microbial Pathogenesis and The Ohio State University College of Medicine & Public Health, 700 Children’s Drive, W591, Columbus, OH 43205, USA
| | - William C. Ray
- Columbus Children’s Research Institute, Center for Microbial Pathogenesis and The Ohio State University College of Medicine & Public Health, 700 Children’s Drive, W591, Columbus, OH 43205, USA
| | - Charles L. Bevins
- Department of Medical Microbiology and Immunology, University of California Davis School of Medicine, Tupper Hall Room 3146, Davis, CA 95616, USA
| | - Robert S. Munson
- Columbus Children’s Research Institute, Center for Microbial Pathogenesis and The Ohio State University College of Medicine & Public Health, 700 Children’s Drive, W591, Columbus, OH 43205, USA
| | - Lauren O. Bakaletz
- Columbus Children’s Research Institute, Center for Microbial Pathogenesis and The Ohio State University College of Medicine & Public Health, 700 Children’s Drive, W591, Columbus, OH 43205, USA
- *Corresponding author: Lauren O. Bakaletz, Ph.D., Center for Microbial Pathogenesis, The Ohio State University, College of Medicine & Public Health, Columbus Children’s Research Institute, Rm. W591, 700 Children’s Drive, Columbus, OH 43205-2696, Phone: (614) 722-2915, Fax: (614) 722-2818, E-mail:
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38
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Mason KM, Bruggeman ME, Munson RS, Bakaletz LO. The non-typeable Haemophilus influenzae Sap transporter provides a mechanism of antimicrobial peptide resistance and SapD-dependent potassium acquisition. Mol Microbiol 2006; 62:1357-72. [PMID: 17064364 DOI: 10.1111/j.1365-2958.2006.05460.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We have shown that non-typeable Haemophilus influenzae (NTHI) resists killing by antimicrobial peptides (APs). A mutant defective in expression of the sap (sensitivity to antimicrobial peptides) gene cluster product SapA is sensitive to killing by APs and is significantly attenuated in its ability to survive in a chinchilla model of otitis media compared with the parent strain. In NTHI, SapA is believed to function as the periplasmic solute binding protein of an ABC transporter. Here, we demonstrated that recombinant chinchilla beta defensin-1 specifically interacted with recombinant SapA and that AP exposure increased expression of the sap operon. We further demonstrated that the putative Sap transporter ATPase protein, SapD, was required for AP resistance as well as potassium uptake in NTHI strain 86-028NP. Loss of SapD additionally abrogated NTHI survival in vivo. Complementation of the sapD mutation restored the ability to grow in potassium-limited medium, resistance to AP-mediated killing and survival in vivo. Collectively, these data support a mechanism of Sap system-mediated resistance to APs that depends on Sap-dependent transport of APs and a Sap-dependent restoration of potassium homeostasis. Thus, NTHI required a functional Sap system to mediate bacterial survival and pathogenesis in vivo.
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Affiliation(s)
- Kevin M Mason
- Columbus Children's Research Institute and The Ohio State University College of Medicine and Public Health, Columbus, OH, USA
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Harrison A, Dyer DW, Gillaspy A, Ray WC, Mungur R, Carson MB, Zhong H, Gipson J, Gipson M, Johnson LS, Lewis L, Bakaletz LO, Munson RS. Genomic sequence of an otitis media isolate of nontypeable Haemophilus influenzae: comparative study with H. influenzae serotype d, strain KW20. J Bacteriol 2005; 187:4627-36. [PMID: 15968074 PMCID: PMC1151754 DOI: 10.1128/jb.187.13.4627-4636.2005] [Citation(s) in RCA: 169] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In 1995, the Institute for Genomic Research completed the genome sequence of a rough derivative of Haemophilus influenzae serotype d, strain KW20. Although extremely useful in understanding the basic biology of H. influenzae, these data have not provided significant insight into disease caused by nontypeable H. influenzae, as serotype d strains are not pathogens. In contrast, strains of nontypeable H. influenzae are the primary pathogens of chronic and recurrent otitis media in children. In addition, these organisms have an important role in acute otitis media in children as well as other respiratory diseases. Such strains must therefore contain a gene repertoire that differs from that of strain Rd. Elucidation of the differences between these genomes will thus provide insight into the pathogenic mechanisms of nontypeable H. influenzae. The genome of a representative nontypeable H. influenzae strain, 86-028NP, isolated from a patient with chronic otitis media was therefore sequenced and annotated. Despite large regions of synteny with the strain Rd genome, there are large rearrangements in strain 86-028NP's genome architecture relative to the strain Rd genome. A genomic island similar to an island originally identified in H. influenzae type b is present in the strain 86-028NP genome, while the mu-like phage present in the strain Rd genome is absent from the strain 86-028NP genome. Two hundred eighty open reading frames were identified in the strain 86-028NP genome that were absent from the strain Rd genome. These data provide new insight that complements and extends the ongoing analysis of nontypeable H. influenzae virulence determinants.
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Affiliation(s)
- Alistair Harrison
- Center for Microbial Pathogenesis, Columbus Children's Research Institute, Ohio State University College of Medicine and Public Health, Columbus, Ohio 43205, USA
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Gitiban N, Jurcisek JA, Harris RH, Mertz SE, Durbin RK, Bakaletz LO, Durbin JE. Chinchilla and murine models of upper respiratory tract infections with respiratory syncytial virus. J Virol 2005; 79:6035-42. [PMID: 15857989 PMCID: PMC1091680 DOI: 10.1128/jvi.79.10.6035-6042.2005] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2004] [Accepted: 01/09/2005] [Indexed: 01/01/2023] Open
Abstract
Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infections in infants and the elderly. While the primary infection is the most serious, reinfection of the upper airway throughout life is the rule. Although relatively little is known about either RSV infection of the upper respiratory tract or host mucosal immunity to RSV, recent literature suggests that RSV is the predominant viral pathogen predisposing to bacterial otitis media (OM). Herein, we describe mouse and chinchilla models of RSV infection of the nasopharynx and Eustachian tube. Both rodent hosts were susceptible to RSV infection of the upper airway following intranasal challenge; however, the chinchilla proved to be more permissive than the mouse. The chinchilla model will likely be extremely useful to test the role of RSV in bacterial OM and the efficacy of RSV vaccine candidates designed to provide mucosal and cytotoxic T-lymphocyte immunity. Ultimately, we hope to investigate the relative ability of these candidates to potentially protect against viral predisposal to bacterial OM.
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Affiliation(s)
- Negin Gitiban
- Columbus Children's Research Institute, Rm. W591, The Ohio State University College of Medicine & Public Health, Department of Pediatrics, 700 Children's Drive, Columbus, OH 43205-2696, USA
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Bakaletz LO, Baker BD, Jurcisek JA, Harrison A, Novotny LA, Bookwalter JE, Mungur R, Munson RS. Demonstration of Type IV pilus expression and a twitching phenotype by Haemophilus influenzae. Infect Immun 2005; 73:1635-43. [PMID: 15731063 PMCID: PMC1064948 DOI: 10.1128/iai.73.3.1635-1643.2005] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Haemophilus influenzae is considered a nonmotile organism that expresses neither flagella nor type IV pili, although H. influenzae strain Rd possesses a cryptic pilus locus. We demonstrate here that the homologous gene cluster pilABCD in an otitis media isolate of nontypeable H. influenzae strain 86-028NP encodes a surface appendage that is highly similar, structurally and functionally, to the well-characterized subgroup of bacterial pili known as type IV pili. This gene cluster includes a gene (pilA) that likely encodes the major subunit of the heretofore uncharacterized H. influenzae-expressed type IV pilus, a gene with homology to a type IV prepilin peptidase (pilD) as well as two additional uncharacterized genes (pilB and pilC). A second gene cluster (comABCDEF) was also identified by homology to other pil or type II secretion system genes. When grown in chemically defined medium at an alkaline pH, strain 86-028NP produces approximately 7-nm-diameter structures that are near polar in location. Importantly, these organisms exhibit twitching motility. A mutation in the pilA gene abolishes both expression of the pilus structure and the twitching phenotype, whereas a mutant lacking ComE, a Pseudomonas PilQ homologue, produced large appendages that appeared to be membrane bound and terminated in a slightly bulbous tip. These latter structures often showed a regular pattern of areas of constriction and expansion. The recognition that H. influenzae possesses a mechanism for twitching motility will likely profoundly influence our understanding of H. influenzae-induced diseases of the respiratory tract and their sequelae.
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Affiliation(s)
- Lauren O Bakaletz
- Department of Pediatrics, Columbus Children's Research Institute, Center for Microbial Pathogenesis, The Ohio State University College of Medicine and Public Health, 700 Children's Dr., Columbus, OH 43205-2696, USA.
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Mason KM, Munson RS, Bakaletz LO. A mutation in the sap operon attenuates survival of nontypeable Haemophilus influenzae in a chinchilla model of otitis media. Infect Immun 2005; 73:599-608. [PMID: 15618200 PMCID: PMC538956 DOI: 10.1128/iai.73.1.599-608.2005] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacteria have evolved strategies to resist killing by antimicrobial peptides (APs), important effectors of innate immunity. The sap (sensitivity to antimicrobial peptides) operon confers resistance to AP-mediated killing of Salmonella. We have recently shown that sapA gene expression is upregulated in the middle ear in a chinchilla model of nontypeable Haemophilus influenzae (NTHI)-induced otitis media. Based on these findings, we constructed an NTHI strain containing a Lux reporter plasmid driven by the sapA promoter and demonstrated early yet transient expression of the sap operon within sites of the chinchilla upper airway upon infection. We hypothesized that the sap operon products mediate NTHI resistance to APs. In order to test this hypothesis, we constructed a nonpolar mutation in the sapA gene of NTHI strain 86-028NP, a low-passage-number clinical isolate. The sapA mutant was approximately eightfold more sensitive than the parent strain to killing by recombinant chinchilla beta-defensin 1. We then assessed the ability of this mutant to both colonize and cause otitis media in chinchillas. The sapA mutant was significantly attenuated compared to the parent strain in its ability to survive in both the nasopharynx and the middle ear of the chinchilla. In addition, the mutant was impaired in its ability to compete with the parent strain in a dual-strain challenge model of infection. Our results indicate that the products of the sap operon are important for resisting the activity of APs and may regulate, in part, the balance between normal carriage and disease caused by NTHI.
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Affiliation(s)
- Kevin M Mason
- Department of Pediatrics, Center for Microbial Pathogenesis, Columbus Children's Research Institute, The Ohio State University College of Medicine and Public Health, Columbus, OH 43205-2696, USA
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Novotny LA, Mason KM, Bakaletz LO. Development of a chinchilla model to allow direct, continuous, biophotonic imaging of bioluminescent nontypeable Haemophilus influenzae during experimental otitis media. Infect Immun 2005; 73:609-11. [PMID: 15618201 PMCID: PMC538955 DOI: 10.1128/iai.73.1.609-611.2005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We transformed a nontypeable Haemophilus influenzae clinical isolate with a plasmid containing the luxCDABE operon driven by the H. influenzae outer membrane protein P2 promoter. Herein, we demonstrate the ability to detect bioluminescence and to monitor infection within the nasopharynges, eustachian tubes, and middle ears of chinchillas after intranasal and transbullar challenges.
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Affiliation(s)
- Laura A Novotny
- Center for Microbial Pathogenesis, Columbus Children's Research Institute, The Ohio State University College of Medicine and Public Health, Rm. W591, 700 Children's Dr., Columbus, OH 43205-2696, USA
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44
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Lim DJ, Hermansson A, HellstrÖ SO, Hussl B, Alper CM, Uno Y, Andalibi A, Jung TTK, Bakaletz LO, Kawauchi H, Buchman CA, Kerschner J, Cayé-Thomasen P, Lin J, Chole RA, Merchant SN, Herman P, Lee HY, Kang SH, Paparella MM. 3. Animal Models; Anatomy and Pathology; Pathogenesis; Cell Biology and Genetics. Ann Otol Rhinol Laryngol 2005. [DOI: 10.1177/000348940511401s01] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Abstract
Although polymicrobial diseases are not a new concept for microbiologists, they are experiencing a resurgence of interest owing to the development of suitable animal models and new molecular techniques that allow these diseases to be studied effectively. This broad review provides an excellent introduction to this fascinating topic. Examples are included of each type of polymicrobial disease and the animal models that are used to study these diseases are discussed. In many instances, schematics for the animal model are presented. Viral co-infections including bovine viral diarrhoeal viruses, porcine reproductive and respiratory syndrome, mixed hepatitis virus infections and HIV co-infection with hepatitis virus are discussed, together with attempts to model these diseases in animals. Viral and bacterial co-infections are reviewed with a special focus on otitis media and the rodent models that have been used to probe this important childhood illness. Of the polybacterial diseases, periodontitis is one of the best understood and a clinically relevant rodent model is now available. This model, and the role of biofilm formation in periodontitis are examined. Fungal infections of humans are often referred to as 'opportunistic' but in fact these infections are often fungal co-infections with viruses such as HIV and fungal mixed co-infections. The roles of these infections in disease and the rodent models used to study them are discussed. Parasite co-infections are thought to have a role in the severity of malaria and the severity of Lyme arthritis. These diseases and attempts to model them are evaluated. Finally, co-infections that are associated with virus-induced immunosuppression are discussed, together with their animal models.
Polymicrobial diseases involve two or more microorganisms that act synergistically, or in succession, to mediate complex disease processes. Although polymicrobial diseases in animals and humans can be caused by similar organisms, these diseases are often also caused by organisms from different kingdoms, genera, species, strains, substrains and even by phenotypic variants of a single species. Animal models are often required to understand the mechanisms of pathogenesis, and to develop therapies and prevention regimes. However, reproducing polymicrobial diseases of humans in animal hosts presents significant challenges.
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Affiliation(s)
- Lauren O Bakaletz
- Center for Microbial Pathogenesis, Columbus Children's Research Institute, Department of Pediatrics, The Ohio State University College of Medicine & Public Health, 700 Children's Drive, Columbus, Ohio 43205-2696, USA.
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Jurcisek JA, Durbin JE, Kusewitt DF, Bakaletz LO. Anatomy of the nasal cavity in the chinchilla. Cells Tissues Organs 2004; 174:136-52. [PMID: 12835577 DOI: 10.1159/000071154] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2003] [Indexed: 11/19/2022] Open
Abstract
There is currently great interest worldwide in developing noninvasive methods for the delivery of vaccines for upper respiratory tract diseases, including middle ear infection (otitis media, OM). One such noninvasive approach believed to have great potential for the prevention of diseases of the airway is to deliver vaccines by the intranasal (i.n.) route. Induction of a local, mucosal immune response in the upper respiratory tract, and particularly in the nasopharynx, would be a highly efficacious approach to prevention of OM. The chinchilla is the preferred rodent host for studying OM. However, although the anatomy of the chinchilla vomeronasal organ, inner ear, middle ear and Eustachian tube have been well-studied, to date there have been no reports in the literature of a similar complete analysis of the nasopharynx and nasal cavities of the chinchilla. In order to develop a relevant animal model of i.n. delivery as a potential immunization approach for the prevention of OM and to use these models for preclinical assessments of various vaccine candidates, it was important that we better understand the anatomy of the chinchilla nasal cavities and nasopharynx. Our anatomical studies revealed that the naso- and maxilloturbinates of the chinchilla nasal cavity more closely resemble the simple turbinates found in other rodents rather than the branched or complex turbinates seen in dogs, cats, and rabbits thus facilitating the i.n. delivery of vaccine candidates. The chinchilla nasal mucosa also contains numerous lymphoid aggregates like that of other rodents. Our findings thus suggest that we will be able to deliver i.n. vaccines effectively to chinchillas and that these vaccines will likely be able to induce specific immune responses.
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Affiliation(s)
- Joseph A Jurcisek
- Department of Pediatrics, Ohio State University College of Medicine and Public Health, Columbus, Ohio 43205-2696, USA
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Swords WE, Moore ML, Godzicki L, Bukofzer G, Mitten MJ, VonCannon J. Sialylation of lipooligosaccharides promotes biofilm formation by nontypeable Haemophilus influenzae. Infect Immun 2004; 72:106-13. [PMID: 14688087 PMCID: PMC343998 DOI: 10.1128/iai.72.1.106-113.2004] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nontypeable Haemophilus influenzae (NTHi) is a major cause of opportunistic respiratory tract infections, including otitis media and bronchitis. The persistence of NTHi in vivo is thought to involve bacterial persistence in a biofilm community. Therefore, there is a need for further definition of bacterial factors contributing to biofilm formation by NTHi. Like other bacteria inhabiting host mucosal surfaces, NTHi has on its surface a diverse array of lipooligosaccharides (LOS) that influence host-bacterial interactions. In this study, we show that LOS containing sialic (N-acetyl-neuraminic) acid promotes biofilm formation by NTHi in vitro and bacterial persistence within the middle ear or lung in vivo. LOS from NTHi in biofilms was sialylated, as determined by comparison of electrophoretic mobilities and immunochemical reactivities before and after neuraminidase treatment. Biofilm formation was significantly reduced in media lacking sialic acid, and a siaB (CMP-sialic acid synthetase) mutant was deficient in biofilm formation in three different in vitro model systems. The persistence of an asialylated siaB mutant was attenuated in a gerbil middle ear infection model system, as well as in a rat pulmonary challenge model system. These data show that sialylated LOS glycoforms promote biofilm formation by NTHi and persistence in vivo.
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Affiliation(s)
- W Edward Swords
- Department of Microbiology and Immunology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA.
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Morton DJ, Bakaletz LO, Jurcisek JA, VanWagoner TM, Seale TW, Whitby PW, Stull TL. Reduced severity of middle ear infection caused by nontypeable Haemophilus influenzae lacking the hemoglobin/hemoglobin–haptoglobin binding proteins (Hgp) in a chinchilla model of otitis media. Microb Pathog 2004; 36:25-33. [PMID: 14643637 DOI: 10.1016/j.micpath.2003.08.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Since Haemophilus influenzae lacks enzymes necessary for synthesis of the porphyrin ring, it has an absolute growth requirement for a porphyrin source. This requirement can be satisfied in vitro by hemoglobin and hemoglobin complexed to haptoglobin. The products of the hgp genes mediate the utilization of heme from hemoglobin-haptoglobin. These genes are also involved in the use of heme from hemoglobin, although additional gene products independently mediate the acquisition of heme from this substrate. Different strains of H. influenzae possess one to four hgp genes. A nontypeable H. influenzae mutant lacking all the hgp genes was constructed and compared to the wild-type strain in a chinchilla (Chinchilla lanigera) model of otitis media. Compared to the wild-type strain, the hgp-deficient mutant exhibited a significantly delayed onset of detectable middle ear infection and significantly reduced duration of infection as assessed by both video otoscopy and tympanometry and as evidenced by viable bacterial counts in middle ear effusions. In addition, the maximum bacterial load in the middle ears of chinchillas infected with the mutant strain was significantly reduced when compared to the parent. These data indicate that the hemoglobin/hemoglobin-haptoglobin binding proteins are required for bacterial proliferation during H. influenzae-induced otitis media in chinchillas.
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Affiliation(s)
- Daniel J Morton
- Department of Pediatrics, University of Oklahoma Health Sciences Center, CHO 2308, 940 NE 13th Street, Oklahoma City, OK 73104, USA
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Novotny LA, Bakaletz LO. The fourth surface-exposed region of the outer membrane protein P5-homologous adhesin of nontypable Haemophilus influenzae is an immunodominant but nonprotective decoying epitope. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 171:1978-83. [PMID: 12902501 DOI: 10.4049/jimmunol.171.4.1978] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Nontypable Haemophilus influenzae is a major cause of otitis media and other mucosal infections. After natural disease in children and experimental disease in chinchillas, we found a hierarchical pattern of immunodominance among the four surface-exposed regions of the P5-homologous adhesin, with the greatest response directed to region 4. However, Ab to region 4 is not protective. When this natural but biased response was refocused to region 3 by immunization, augmented bacterial clearance and protection from ascending otitis media was observed. Collectively, the data indicate that region 4 contains a highly immunodominant but nonprotective decoying epitope, the presence of which dampens the immune response to a subdominant but protective epitope in region 3.
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Affiliation(s)
- Laura A Novotny
- Division of Molecular Medicine, Department of Pediatrics, Columbus Children's Research Institute, Ohio State University College of Medicine and Public Health, Columbus, OH 43205, USA
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Kyd JM, Cripps AW, Novotny LA, Bakaletz LO. Efficacy of the 26-kilodalton outer membrane protein and two P5 fimbrin-derived immunogens to induce clearance of nontypeable Haemophilus influenzae from the rat middle ear and lungs as well as from the chinchilla middle ear and nasopharynx. Infect Immun 2003; 71:4691-9. [PMID: 12874350 PMCID: PMC165997 DOI: 10.1128/iai.71.8.4691-4699.2003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The rat middle ear and lung clearance model has been used to show that the nontypeable Haemophilus influenzae 26-kDa outer membrane protein OMP26 is highly efficacious as a mucosal immunogen, inducing significantly enhanced clearance in immunized rats upon direct challenge of these two anatomic sites. Similarly, the chinchilla model of middle ear and nasopharyngeal clearance has been used to show that two P5 fimbrin adhesin-derived immunogens, LB1 and lipoprotein D (LPD)-LB1(f)(2,1,3), are highly efficacious as parenteral immunogens. Both induced significantly augmented clearance of nontypeable H. influenzae upon challenge of these sites. Here, these three nontypeable H. influenzae immunogens in addition to six bovine serum albumin and keyhole limpet hemocyanin conjugates of the synthetic peptide LB1(f) were assayed for relative efficacy in the reciprocal rodent model system. OMP26 was assayed in the chinchilla host by a parenteral immunization route, with clearance of the middle ear and nasopharynx used as outcome measures. Both LB1 and LPD-LB1(f)(2,1,3) were assayed in the rat host with a mucosal immunization route and clearance of nontypeable H. influenzae from the lungs and middle ears as outcome measures. Both of the immunogens were found to induce a high-titered and specific immune responses in the heterologous host system. Moreover, each was found to be highly efficacious in the reciprocal host system, providing strong support for the continued development and inclusion of both OMP26 and P5 fimbrin-derived peptides as candidate vaccine antigens directed at otitis media caused by nontypeable H. influenzae.
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Affiliation(s)
- Jennelle M Kyd
- Division of Science and Design, Gadi Research Centre, University of Canberra, Canberra, Australia.
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