The main difference between cellular and non-cellular pathogens is that cellular pathogens are treated with antibiotics, whereas non-cellular pathogens are not treated with antibiotics.
Cellular and non-cellular pathogens are two types of pathogens that can cause diseases. They are microorganisms that can be like bacteria and protozoa.
Key Areas Covered
1. What are Cellular Pathogens
– Definition, Facts, Features
2. What are Non-cellular Pathogens
– Definition, Facts, Features
3. Similarities Between Cellular and Non-cellular Pathogens
– Outline of Common Features
4. Difference Between Cellular and Non-cellular Pathogens
– Comparison of Key Differences
5. FAQ – Cellular and Non-cellular Pathogens
– Answers to frequently asked questions
Key Terms
Cellular Pathogens, Non-cellular Pathogens
What are Cellular Pathogens
Cellular pathogens are microorganisms composed of bacteria, fungi, helminths, and protozoa.
Bacteria
Bacteria are unicellular prokaryotes that are freely living biological cells of fewer micrometers long cells. Since bacteria are prokaryotes, they lack membrane-bound organelles such as nuclei, mitochondria, and chloroplasts. Generally, one of the main characteristic features of bacteria is the presence of a cell wall made up of peptidoglycans. Some bacteria contain an envelope surrounding the cell wall. Their genetic material occurs in the cytoplasm as a single circular DNA molecule. Another characteristic feature of bacteria is the presence of extrachromosomal DNA elements known as plasmids, which are essential in recombinant DNA technology.
Figure 1: Bacteria
Fungi
Fungi refer to unicellular or multicellular, spore-producing organisms feeding on organic matter. Multicellular fungi produce fungal hyphae, which are tiny, thread-like structures. A mass of hyphae is called the mycelium. The cell wall of fungi is made up of chitin. Since they are saprotrophs, fungi absorb nutrients through the cell wall. Both sexual and asexual reproduction of fungi occurs through the production of spores.
Helminths
Helminths are multicellular parasitic worms. They are also known as metazoan. Generally, helminths show bilateral symmetry. The outer covering of their body is the cuticle or integument. Also, they reproduce inside the host’s body. In addition, most helminths require multiple intermediate hosts to complete their life cycle. Usually, a heavy worm load can follow various infections. Moreover, the two main types of helminths are Platyhelminthes and Nemathelminthes.
Protozoa
Protozoa is a group of unicellular eukaryotes belonging to the kingdom Protista. Generally, they are single-celled organisms. As they are eukaryotes, they have a nucleus in their cytoplasm. However, some protozoans have multiple nuclei in their cytoplasm. Also, their cytoplasm consists of two regions known as ectoplasm and endoplasm. Furthermore, some protozoans are free-living in the environment, while others are endoparasitic, which means they live inside organisms. Parasitic protozoans can live either inside body tissues or in the blood.
What are Non-cellular Pathogens
Non-cellular pathogens are microorganisms composed of viruses and virions.
Virus
A virus is a non-living, small, infectious agent which can only replicate inside a host cell. Generally, viruses are not equipped with the cellular mechanisms required by the replication, including DNA replication and protein synthesis. Therefore, they must depend on a host cell to replicate their nucleic acids and synthesize their protein coat. Hence, viruses are obligate intracellular parasites that invade cells, causing diseases.
Figure 2: Virus
Virion
A virion is a complete infectious virus particle with a genome containing a few DNA or RNA. Also, it has a protein coat and a capsid. The capsid that encloses the nucleic acid forms the nucleocapsid. It provides specificity to the virus. A fatty membrane occurs in certain virions, encompassing the capsid. Apart from that, most virions infect plants.
Furthermore, deletions of the alpha genes result in alpha thalassemia.
Similarities Between Cellular and Non-cellular Pathogens
- Cellular and non-cellular pathogens are two pathogen types that can cause human diseases.
- They can be microorganisms like bacteria and protozoa.
- They reproduce and grow independently inside the host.
Difference Between Cellular and Non-cellular Pathogens
Definition
Cellular pathogens refer to microorganisms composed of cells, such as bacteria and protozoa. Noncellular pathogens refer to microorganisms not composed of cells, such as viruses and prions.
Type of Microorganisms
Cellular pathogens include bacteria, fungi, helminths, and protozoa, while noncellular pathogens include viruses and prions.
Also Known as
Cellular pathogens are also known as pathogenic organisms, while noncellular pathogens are also known as pathogenic agents.
Growth and Reproduction
Cellular pathogens grow and reproduce independently inside the host, while non-cellular pathogens require a host to grow and multiply.
Antibiotics
Antibiotics kill cellular pathogens, while antibiotics do not kill non-cellular pathogens.
FAQ: Cellular and Non-cellular Pathogens
What are the differences between cellular and acellular pathogens?
Cellular microbes are bacteria, fungi, protists, and archaea. They are either unicellular or multicellular. Acellular pathogens include other pathogenic agents like viruses, prions, and viroids.
What are examples of cellular pathogens?
Bacterial pathogens include Mycobacterium tuberculosis, Salmonella enterica, Legionella pneumophila, and Chlamydia trachomatis.
What is an example of a nonpathogenic bacteria?
Lactobacillus acidophilus is an example of nonpathogenic bacterium. It is a part of normal intestinal flora. Staphylococcus epidermidis is another example of nonpathogenic bacteria, which is also a part of the normal skin flora.
Conclusion
In brief, cellular and non-cellular pathogens are two pathogens that can cause diseases in humans. Cellular pathogens include bacteria, fungi, helminths, and protozoa. They are pathogenic organisms that reproduce and grow independently inside the host. Significantly, they can be killed by antibiotics. In comparison, non-cellular pathogens include viruses and virions. They are pathogenic agents. Also, they require a host to grow and reproduce. Importantly, they are not killed by antibiotics. Therefore, the main difference between cellular and non-cellular pathogens is their ability to react with antibiotics.
References:
1. Burrell CJ, Howard CR, Murphy FA. Virion Structure and Composition. Fenner and White’s Medical Virology. 2017:27–37. doi: 10.1016/B978-0-12-375156-0.00003-5. Epub 2016 Nov 11. PMCID: PMC7173522.
Image Courtesy:
- “Bacteria, why do they make me sick 10” By Emw – Own Work (CC BY SA 4.0) via Commons Wikimedia
- “Coronavirus. SARS-CoV-2” By Emw (CC BY SA 4.0) via Commons Wikimedia
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