The key difference between Pasteurella and Haemophilus is that Paeteurella is a genus of gram-negative facultative anaerobic bacteria that are zoonotic pathogens while Haemophilus is a genus of gram-negative, pleomorphic, coccobacilli bacteria which need blood for the growth.
Pasteurellaceae is a large family of gram-negative facultative anaerobic bacteria. Moreover, they are rod-shaped obligatory parasitic bacteria. They don’t have flagella. Hence, they are nonmotile. Furthermore, they are commensal organisms of the respiratory tract of birds and mammals. However, a majority of bacteria become opportunistic pathogens. There are 13 genera in this bacterial family. Among them, Pasteurella and Haemophilus are two best-known genera, which consist of several important veterinary species. They possess an outer membrane consisting mainly of lipopolysaccharides. Their pathogenicity is mainly related to lipopolysaccharide (LPS) or lipooligosaccharide (LOS), adhesins, capsules, iron acquisition systems, and toxins.
CONTENTS
1. Overview and Key Difference
2. What is Pasteurella
3. What is Haemophilus
4. Similarities Between Pasteurella and Haemophilus
5. Side by Side Comparison – Pasteurella vs Haemophilus in Tabular Form
6. Summary
What is Pasteurella?
Pasteurella is a genus comprised of gram-negative, facultative anaerobic bacteria. They belong to bacterial order of Pasteurellales and family of Pasteurellaceae. Pasteurella species are non-motile, non-spore forming and pleomorphic. They exhibit bipolar staining features or safety pin appearance. Moreover, many species of this genus are catalase and oxidase positive.
Figure 01: Pasteurella
Pasteurella species are zoonotic pathogens. Humans get the infections of Pasteurella species mainly via bites, scratches, or licks of domestic animals. They live as a part of the normal flora of the nose and mouth of many livestock, poultry, and domestic pet species, especially in dogs and cats. P. multocida is the species that causes infections in humans commonly. Since Pasteurella species are antibiotic sensitive, they can be controlled by antibiotics such as chloramphenicol, penicillin, tetracycline, enrofloxacin, oxytetracycline, ampicillin and macrolides.
What is Haemophilus?
Haemophilus is another genus belonging to family Pasteurellaceae. Haemophilus species are gram-negative facultative anaerobic bacteria which are pleomorphic and non-motile. They are coccobacilli resembling the pathogenic bacilli. Moreover, they are non-sporing bacteria. These bacteria need hemin and or nicotinamide adenine dinucleotide (NAD+) (factor V) for growth. Due to the requirement of blood during the growth, they have given the name Haemophilus.
Figure 02: Haemophilus spp.
Haemophilus species are human pathogens that cause bacteremia, pneumonia, meningitis and chancroid. However, their pathogenicity is not related to the production of toxin or other extracellular products.
What are the Similarities Between Pasteurella and Haemophilus?
- Pasteurella and Haemophilus are two genera of gram-negative facultative anaerobic bacteria.
- They belong to order: Pasteurellales and family: Pasteurellaceae.
- Both genera show a polyphyletic organization.
- They are rod-shaped bacteria.
- Also, they are pleomorphic, nonmotile and non-spore forming bacteria.
What is the Difference Between Pasteurella and Haemophilus?
Pasteurella is a genus of gram-negative facultative anaerobic pleomorphic bacteria that are zoonotic pathogens while Haemophilus is a genus of gram-negative, pleomorphic, coccobacilli bacteria which need blood for the growth. So, this is the key difference between Pasteurella and Haemophilus. Moreover, Pasteurella species cause upper respiratory tract infections mainly in humans while Haemophilus species cause bacteremia, pneumonia, meningitis and chancroid.
Summary – Pasteurella vs Haemophilus
Pasteurella and Haemophilus are two genera of family Pasteurellaceae. Members of these two genera are gram-negative, rod-shaped, facultative anaerobic bacteria which are pleomorphic and non-motile. Haemophilus species need blood for growth. Both types of bacterial species are human pathogens. Pasteurella species cause upper respiratory tract infections while Haemophilus species cause bacteremia, pneumonia, meningitis and chancroid. Thus, this summarizes the difference between Pasteurella and Haemophilus.
Reference:
1. Musher, Daniel. “Haemophilus Species”. Ncbi.Nlm.Nih.Gov, 2020, Available here.
2. “Pasteurella”. En.Wikipedia.Org, 2020, Available here.
Image Courtesy:
1. “PHIL 3621” By Centers for Disease Control and Prevention, Office of the Associate Director for Communications, Division of Public Affairs Dr. R. Weaver – (Public Domain) via Commons Wikimedia
2. “Haemophilus influenzae sputum 1000x edited” By Microman12345 – Own work (CC BY-SA 4.0) via Commons Wikimedia