Bordetella parapertussis
Classification
Domain: Bacteria
Phylum: Proteobacteria
Class: Betaproteobacteria
Order: Burkholderiales
Family: Alcaligenaceae
Genus and Species: Bordetella parapertussis [1]
Species
Bordetella parapertussis
Description and Significance
Describe the appearance, habitat, etc. of the organism, and why you think it is important.
‘’Bordetella parapertussis’’ is a Gram-negative β-proteobacteria coccobacillus, Additionally, It is an obligate aerobe, thriving in environments rich in oxygen. [6] This bacterium primarily inhabits the human respiratory mucosa, where it establishes infection and spreads through person-to-person transmission. It can also infect sheep, causing respiratory illness in these animals. B. parapertussis strains isolated from humans, ‘’B. parapertussis (hu)’’, and those from sheep, ‘’B. parapertussis (ov)’’, are genetically distinct, suggesting independent evolution from a common ancestor, B. bronchiseptica. [6]
B. parapertussis is a significant pathogen, causing upper respiratory tract infections characterized by pertussis, or whooping cough. Although typically producing a milder form of whooping cough compared to Bordetella pertussis, it can still lead to severe symptoms, especially in infants under six months of age. The bacterium contributes to outbreaks of whooping cough, accounting for 5-30% of cases, particularly in regions with acellular pertussis immunization programs. [12] Notably, the increase in ‘’B. parapertussis’’ cases may be attributed to its fitness under the pressure of acellular pertussis vaccines, as it does not express pertussis toxin (Ptx), a major virulence factor targeted by these vaccines. [9] Understanding ‘’B. parapertussis’’ is crucial for disease management and vaccination strategies, given its role in respiratory infections and its potential to evade existing vaccines, highlighting the importance of ongoing research and surveillance efforts.
Genome Structure
Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence?
Bordetella parapertussis typically possesses a single circular chromosome, with a genome size of approximately 4.7 million base pairs (Mbp) and a G+C content of 65%. Comparative genomic analysis has identified 81 single nucleotide polymorphisms and 13 short insertions and deletions compared to the reference genome Bordetella parapertussis 12822, indicating ongoing evolutionary changes.
This bacterium has diverged into two distinct lineages: one causing whooping cough in infants and the other infecting sheep. It shares a common ancestor with B. pertussis, both having evolved independently from B. bronchiseptica ancestors.
Unlike B. pertussis, B. parapertussis is oxidase-negative, suggesting differences in respiratory mechanisms. It can utilize other oxidases in electron transport due to the absence of cytochrome c oxidase.
A specific genome sequence, IRBP134, isolated from a fully vaccinated infant in Iran, was sequenced using Nextseq technology. The assembly generated 72 scaffolds with a genome size of 4,720,964 base pairs, including 4,620 potential coding sequences and 55 RNA sequences. The presence of 63 tRNAs and one large and one small subunit of ribosomal RNA was also identified in the genome annotation. [9]
Cell Structure, Metabolism and Life Cycle
Interesting features of cell structure; how it gains energy; what important molecules it produces.
Ecology and Pathogenesis
Habitat; symbiosis; biogeochemical significance; contributions to environment.
If relevant, how does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
References
[1] [Schoch CL, et al. NCBI Taxonomy: a comprehensive update on curation, resources and tools. Database (Oxford). 2020: baaa062. PubMed: 32761142 PMC: PMC7408187]
[6] Parkhill, J., Sebaihia, M., Preston, A. et al. Comparative analysis of the genome sequences of Bordetella pertussis, Bordetella parapertussis and Bordetella bronchiseptica. Nat Genet 35, 32–40 (2003). https://doi-org.proxyiub.uits.iu.edu/10.1038/ng1227
[9] Safarchi, A., Saedi, S., Tay, C. Y., Lamichhane, B., Nakhost Lotfi, M., & Shahcheraghi, F. (2022). Genome Characteristic of Bordetella parapertussis Isolated from Iran. Current microbiology, 79(10), 314. https://doi.org/10.1007/s00284-022-03009-x
[12] Brinig, M. M., Register, K. B., Ackermann, M. R., & Relman, D. A. (2006). Genomic features of Bordetella parapertussis clades with distinct host species specificity. Genome biology, 7(9), R81. https://doi.org/10.1186/gb-2006-7-9-r81
Author
Page authored by Sachin Gupta and Erin Goertzen, students of Prof. Jay Lennon at Indiana University.
