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Characterization of the Phase-Variable Autotransporter Lav Reveals a Role in Host Cell Adherence and Biofilm Formation in Nontypeable Haemophilus influenzae. Infect Immun 2022; 90:e0056521. [PMID: 35258316 PMCID: PMC9022572 DOI: 10.1128/iai.00565-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Lav is an autotransporter protein found in pathogenic Haemophilus and Neisseria species. Lav in nontypeable Haemophilus influenzae (NTHi) is phase-variable: the gene reversibly switches ON-OFF via changes in length of a locus-located GCAA(n) simple DNA sequence repeat tract. The expression status of lav was examined in carriage and invasive collections of NTHi, where it was predominantly not expressed (OFF). Phenotypic study showed lav expression (ON) results in increased adherence to human lung cells and denser biofilm formation. A survey of Haemophilus species genome sequences showed lav is present in ∼60% of NTHi strains, but lav is not present in most typeable H. influenzae strains. Sequence analysis revealed a total of five distinct variants of the Lav passenger domain present in Haemophilus spp., with these five variants showing a distinct lineage distribution. Determining the role of Lav in NTHi will help understand the role of this protein during distinct pathologies.
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Pereira RFC, Guarnieri JPDO, da Silva CFM, Bernardes BG, Lancellotti M. Whole-genome analysis of haemophilus influenzae invasive strains isolated from campinas state University hospital. An epidemiological approach 2012 - 2019 and ancestor strains. Braz J Infect Dis 2021; 26:101667. [PMID: 34958740 PMCID: PMC9387462 DOI: 10.1016/j.bjid.2021.101667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 11/16/2022] Open
Abstract
Thirteen Haemophylus influenzae invasive strains isolated from patients at Clinical Hospital of State University of Campinas, from May 2013 through August 2019, was submitted to Illumina genome sequencing HiSeq platform. Further in silico analysis of serogroup and Multi Locus Sequence Typing (MLST) from whole DNA sequencing had demonstrated the actual clonal distribution in the Campinas Metropolitan region. Thus, results showed the existence of a new ST Haemophilus influenzae found in the Brazilian territory and an increase of strains belonging to serogroup a (three strains also belonging to ST23). In conclusion, we observed an increase of non-typable H. influenzae (NTHi) and a strain involved in invasive diseases in the Campinas – São Paulo region after frequent detection of those serotypes and genotypes in other Brazilian regions.
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Affiliation(s)
- Rafaella Fabiana Carneiro Pereira
- Biotechnology Laboratory, LABIOTEC, Faculty of Pharmaceutical Sciences (FCF), Campinas State University UNICAM, São Paulo, SP, Brazil
| | - João Paulo de Oliveira Guarnieri
- Biotechnology Laboratory, LABIOTEC, Faculty of Pharmaceutical Sciences (FCF), Campinas State University UNICAM, São Paulo, SP, Brazil
| | - Carlos Fernando Macedo da Silva
- Biotechnology Laboratory, LABIOTEC, Faculty of Pharmaceutical Sciences (FCF), Campinas State University UNICAM, São Paulo, SP, Brazil
| | - Bruno Gaia Bernardes
- Biotechnology Laboratory, LABIOTEC, Faculty of Pharmaceutical Sciences (FCF), Campinas State University UNICAM, São Paulo, SP, Brazil
| | - Marcelo Lancellotti
- Biotechnology Laboratory, LABIOTEC, Faculty of Pharmaceutical Sciences (FCF), Campinas State University UNICAM, São Paulo, SP, Brazil.
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Pereira RFC, Theizen TH, Machado D, Guarnieri JPDO, Gomide GP, Hollanda LMD, Lancellotti M. Analysis of potential virulence genes and competence to transformation in Haemophilus influenzae biotype aegyptius associated with Brazilian Purpuric Fever. Genet Mol Biol 2021; 44:e20200029. [PMID: 33395458 PMCID: PMC7816109 DOI: 10.1590/1678-4685-gmb-2020-0029] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 11/18/2020] [Indexed: 11/21/2022] Open
Abstract
Brazilian Purpuric Fever (BPF) is a hemorrhagic pediatric illness caused by Haemophilus influenzae biogroup aegyptius (Hae), a bacterium that was formerly associated with self-limited purulent conjunctivitis. BPF is assumed to be eradicated. However, the virulence mechanisms inherent to Hae strains associated with BPF is still a mystery and deficient in studies. Here, we aim to analyze the role of the autotransporter genes related to adherence and colonization las, tabA1, and hadA genes through RT-qPCR expression profiling and knockout mutants. Relative quantification by real-time PCR after infection in human cells and infant rat model suggests that las was initially downregulated probably duo to immune evasion, tabA1, and hadA were overexpressed in general, suggesting an active role of TabA1 and HadA1 adhesins in Hae in vitro and in vivo. Transformation attempts were unsuccessful despite the use of multiple technical approaches and in silico analysis revealed that Hae lacks genes related to competence in Haemophilus, which could be part of the elucidation of the difficulty of genetically manipulating Hae strains.
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Affiliation(s)
| | - Thais Holtz Theizen
- Universidade Estadual de Campinas, Departamento de Bioquímica e Biologia Tecidual, Instituto de Biologia, Campinas, SP, Brazil
| | - Daisy Machado
- Universidade Estadual de Campinas, Departamento de Bioquímica e Biologia Tecidual, Instituto de Biologia, Campinas, SP, Brazil
| | | | - Gabriel Piccirillo Gomide
- Universidade Estadual de Campinas - UNICAMP, Faculdade de Ciências Farmacêuticas - FCF, Campinas, SP, Brazil
| | - Luciana Maria de Hollanda
- Universidade Estadual de Campinas, Departamento de Bioquímica e Biologia Tecidual, Instituto de Biologia, Campinas, SP, Brazil
| | - Marcelo Lancellotti
- Universidade Estadual de Campinas, Departamento de Bioquímica e Biologia Tecidual, Instituto de Biologia, Campinas, SP, Brazil.,Universidade Estadual de Campinas - UNICAMP, Faculdade de Ciências Farmacêuticas - FCF, Campinas, SP, Brazil
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Closed Complete Annotated Genome Sequences of Five Haemophilus influenzae Biogroup
aegyptius
Strains. Microbiol Resour Announc 2019; 8:8/45/e01198-19. [PMID: 31699771 PMCID: PMC6838629 DOI: 10.1128/mra.01198-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Haemophilus influenzae biogroup aegyptius is a cause of conjunctivitis in children. Biogroup aegyptius strains also caused fatal outbreaks of invasive disease, known as Brazilian purpuric fever (BPF), in the 1980s. BPF is fatal if untreated. Here, we report the complete genome sequences of five strains of Haemophilus influenzae biogroup aegyptius. Haemophilus influenzae biogroup aegyptius is a cause of conjunctivitis in children. Biogroup aegyptius strains also caused fatal outbreaks of invasive disease, known as Brazilian purpuric fever (BPF), in the 1980s. BPF is fatal if untreated. Here, we report the complete genome sequences of five strains of Haemophilus influenzae biogroup aegyptius.
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