Haemophilus influenzae

General Information

Haemophilus influenzae is a fascinating microorganism with a rich history and significant impact on human health. This bacterium is particularly notable for its role in causing a variety of serious infections, especially in children. One of the most critical aspects of H. influenzae is its ability to cause invasive diseases such as meningitis, septicemia, and pneumonia. The type b strain, often referred to as Hib, was historically a leading cause of bacterial meningitis in young children before the introduction of the Hib vaccine. H. influenzae is also unique due to its requirement for specific growth factors, namely hemin (X factor) and nicotinamide adenine dinucleotide (V factor), which are typically found in blood. This requirement makes it a fastidious organism, often necessitating enriched media for laboratory cultivation. From a research perspective, H. influenzae is valuable due to its well-characterized genome. It was the first free-living organism to have its entire genome sequenced, a milestone achieved in 1995. This accomplishment has provided profound insights into bacterial genetics and pathogenesis, making H. influenzae a model organism for studying bacterial evolution and gene function. Additionally, H. influenzae exhibits a remarkable ability to undergo genetic transformation, allowing it to acquire new genetic material from its environment. This capability contributes to its adaptability and potential for developing antibiotic resistance, which is a significant concern in clinical settings. In summary, Haemophilus influenzae is a microorganism of great interest due to its historical impact on public health, its specific growth requirements, its role in advancing genomic research, and its genetic adaptability. These characteristics make it a critical subject of study in microbiology and infectious disease research.

Haemophilus influenzae is a small, pleomorphic bacterium that is notable for its role in human disease, particularly as a pathogen responsible for respiratory tract infections, meningitis, and other serious conditions, especially in children. This organism is encapsulated, with the type b strain (H. influenzae type b, or Hib) being the most virulent and historically significant due to its association with invasive diseases. The development of the Hib vaccine has dramatically reduced the incidence of infections caused by this strain, showcasing the organism's impact on public health and vaccination strategies. One of the unique aspects of H. influenzae is its requirement for specific growth factors, namely hemin (factor X) and nicotinamide adenine dinucleotide (NAD, factor V), which makes it an interesting subject for studies on bacterial nutrition and metabolism. This dependency on growth factors is a defining characteristic that differentiates it from many other bacteria, leading to its classification as a fastidious organism. In addition to its pathogenic potential, H. influenzae has been a valuable model organism in microbiological research. Its relatively simple growth requirements and genetic tractability have made it a useful tool for studying bacterial genetics, pathogenesis, and the mechanisms of antibiotic resistance. Researchers have utilized H. influenzae to explore the interactions between bacteria and the host immune system, providing insights that are applicable to a broader range of bacterial pathogens. Furthermore, the organism's ability to undergo horizontal gene transfer contributes to its genetic diversity and adaptability, making it a subject of interest in studies of microbial evolution and epidemiology. The ongoing research into H. influenzae continues to reveal important information about bacterial behavior, virulence factors, and the development of effective treatments and vaccines.

Taxonomy

Superkingdom: Bacteria

Phylum: Pseudomonadota

Class: Gammaproteobacteria

Order: Pasteurellales

Family: Pasteurellaceae

Genus: Haemophilus

Species: Haemophilus influenzae

NCBI ID

727

Genome Info

FTP Path:
ftp.ncbi.nlm.nih.gov/genomes/all/GCA/000/931/575/GCA_000931575.1_ASM93157v1

File for sequence-based predictions:
GCA_000931575.1_ASM93157v1_genomic.fasta

Descriptions

Clinical Implications and Relevance

Source: gpt-4o-mini-2024-07-18

The bacterium Haemophilus influenzae is a significant pathogen associated with various infections in humans, particularly in children and immunocompromised individuals. It is best known for causing bacterial meningitis, pneumonia, and otitis media. The encapsulated type b (Hib) strain is particularly virulent and has been linked to severe disease outcomes, including sepsis and epiglottitis. The introduction of the Hib vaccine has dramatically reduced the incidence of these diseases, highlighting the importance of vaccination in preventing infections caused by this organism. In terms of pathogenicity, H. influenzae employs several strategies to evade the host's immune response, including the production of a polysaccharide capsule that inhibits phagocytosis. This ability to evade immune detection contributes to its virulence and the severity of the diseases it causes. Moreover, H. influenzae has been noted for its potential antimicrobial resistance, particularly to beta-lactam antibiotics, which complicates treatment options. Resistance mechanisms include the production of beta-lactamases and alterations in penicillin-binding proteins, making it crucial for clinicians to consider susceptibility testing when treating infections. In addition to its role as a pathogen, certain non-typeable strains of H. influenzae are being studied for their potential as probiotics, as they may play a role in maintaining respiratory tract health and modulating the immune response in the upper respiratory tract. However, more research is needed to fully understand these applications. Overall, H. influenzae remains a clinically relevant organism due to its association with serious diseases, its mechanisms of immune evasion, and its emerging antimicrobial resistance patterns.

Habitat and Ecological Niches

Source: gpt-4o-mini-2024-07-18

Haemophilus influenzae is primarily associated with the human respiratory tract, where it is commonly found as a part of the normal flora. This microorganism thrives in the nasopharyngeal region, particularly in environments that are warm and moist, which are conducive to its growth and survival. Notably, it plays a significant role in the human microbiome, contributing to the balance of microbial communities and potentially influencing host immune responses. In addition to its presence in the respiratory tract, H. influenzae can also be found in other environments, such as oral cavities and throat regions, where it may engage in symbiotic relationships with other microorganisms. These interactions can help maintain a healthy microbial balance, although under certain conditions, H. influenzae can become pathogenic, leading to infections such as pneumonia, meningitis, and otitis media. The adaptability of H. influenzae to various nutrient-rich environments allows it to thrive in diverse conditions, but it is particularly well-suited to the mucosal surfaces of the human body. Its ability to form biofilms on these surfaces can enhance its survival and persistence, further emphasizing its role in both health and disease. Overall, H. influenzae exemplifies the complex interactions within the human microbiome and its impact on human health.

Industrial Application

Source: gpt-4o-mini-2024-07-18

The microorganism Haemophilus influenzae has several notable industrial applications, particularly in the fields of biotechnology and pharmaceutical development. This bacterium is primarily known for its role in human health, but its applications extend into various industrial sectors. In pharmaceutical development, Haemophilus influenzae is significant due to its association with respiratory infections and its use in vaccine production. The bacterium has been instrumental in the development of conjugate vaccines, which are designed to protect against diseases caused by encapsulated bacteria. For instance, the Hib vaccine, which targets Haemophilus influenzae type b, has been crucial in reducing the incidence of bacterial meningitis in children. This application highlights the importance of the organism in vaccine production and public health initiatives. In the realm of biotechnology, Haemophilus influenzae has been utilized in genetic studies and molecular biology. Its relatively simple genome has made it a model organism for understanding bacterial genetics and gene expression. This research can lead to advancements in genetic engineering and synthetic biology, where the insights gained from studying Haemophilus influenzae can be applied to develop new biotechnological tools and methods. While Haemophilus influenzae is not directly linked to biofuel production or waste management, its role in understanding microbial interactions and pathogenicity can indirectly influence these fields by informing the development of microbial consortia that may be used in biodegradation processes or in the production of biofuels through engineered pathways. Overall, Haemophilus influenzae serves as a critical organism in biotechnology and pharmaceutical development, with its contributions to vaccine production and genetic research being particularly noteworthy.

Phenotypes and Predictions

The table shows the phenotypes and predictions. Cell colors indicate the class of the value. When literature-based data is available, a checkmark (✓) indicates a correct prediction, while an ✗ indicates an incorrect prediction.

Literature-based phenotypes: 9

LLM predicted phenotypes: 4

Phenotype	High-quality annotation	anthropic/claude-3.5-sonnet	anthropic/claude-3.5-sonnet	meta-llama/llama-3-8b-instruct:nitro	google/palm-2-chat-bison-32k	google/gemma-7b-it	google/gemini-flash-1.5	meta-llama/llama-3-70b-instruct:nitro	anthropic/claude-3-haiku:beta	perplexity/llama-3-sonar-small-32k-chat	mistralai/mistral-7b-instruct	google/gemini-pro	openai/gpt-3.5-turbo-0125	openai/gpt-3.5-turbo-0125	openai/gpt-4o	openai/gpt-4o	openai/gpt-4	openai/gpt-4	mistralai/mixtral-8x7b-instruct:nitro	mistralai/mixtral-8x7b-instruct:nitro	google/gemini-pro-1.5	google/gemini-pro-1.5	openchat/openchat-7b	openchat/openchat-7b	microsoft/phi-3-mini-128k-instruct	microsoft/phi-3-mini-128k-instruct	microsoft/wizardlm-2-8x22b	microsoft/wizardlm-2-8x22b
Motility	N/A	false	false	true	false	true	false	false	false	true	true	false	false	false	false	false	false	false	false	false	false	false	true	true	false	false	false	false
Gram staining	gram stain negative	N/A	gram stain negative ✓	gram stain negative ✓	gram stain negative ✓	gram stain negative ✓	gram stain negative ✓	gram stain negative ✓	gram stain negative ✓	gram stain negative ✓	gram stain negative ✓	gram stain negative ✓	N/A	gram stain negative ✓	N/A	gram stain negative ✓	N/A	gram stain negative ✓	N/A	gram stain negative ✓	N/A	gram stain negative ✓	N/A	gram stain negative ✓	N/A	gram stain negative ✓	N/A	gram stain negative ✓
Aerophilicity	aerobic	facultatively anaerobic ✗	facultatively anaerobic ✗	N/A	facultatively anaerobic ✗	N/A	N/A	N/A	N/A	N/A	N/A	N/A	facultatively anaerobic ✗	facultatively anaerobic ✗	facultatively anaerobic ✗	facultatively anaerobic ✗	facultatively anaerobic ✗	facultatively anaerobic ✗	facultatively anaerobic ✗	facultatively anaerobic ✗	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Extreme environment tolerance	FALSE	false ✓	false ✓	false ✓	false ✓	true ✗	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓
Biofilm formation	N/A	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	false	false	true	true
Animal pathogenicity	TRUE	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓
Biosafety level	biosafety level 2	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 2 ✓	biosafety level 1 ✗	biosafety level 1 ✗	biosafety level 2 ✓	biosafety level 2 ✓
Health association	N/A	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true
Host association	TRUE	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓	true ✓
Plant pathogenicity	FALSE	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓	false ✓
Spore formation	N/A	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false
Hemolysis	gamma	beta ✗	beta ✗	beta ✗	N/A	alpha ✗	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Cell shape	bacillus	coccus ✗	coccus ✗	coccus ✗	bacillus ✓	bacillus ✓	bacillus ✓	bacillus ✓	coccus ✗	bacillus ✓	coccus ✗	bacillus ✓	bacillus ✓	bacillus ✓	bacillus ✓	bacillus ✓	bacillus ✓	bacillus ✓	coccus ✗	coccus ✗	coccus ✗	coccus ✗	coccus ✗	coccus ✗	coccus ✗	coccus ✗	coccus ✗	coccus ✗

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