9 Dangerous Bacteria that Are Harmful to Humans

04 January, 2021
Even though not all bacteria are deadly, some dangerous bacteria can harm your body. They can also provoke different illnesses if not detected and treated in time. 

At the beginning of the year, the World Health Organization (WHO) published the list of the most harmful bacteria for humans. Among those published, you can find the ones that took the most human lives.

Knowing which these are, their symptoms, and associated illnesses is important to maintain your personal and family health.

The majority cause common diseases that put lives at risk if we don’t treat them.

In addition, this list also indicates the need for medical laboratories to find new antibiotics to combat each threat in an effective way.

1. Acineobacter baumannii, one of the most dangerous bacteria

Acinetobacter baumannii.

This is perhaps the most resistant bacteria at this time. Thousands die each year due to this bacteria. After all, it creates antibodies that are resistant to drugs.

  • It starts with aggressive pneumonia accompanied by a strong urinary tract infection.
  • As a result, finding better drugs to fight this bacteria is a high priority in laboratories.

2. Pseudomonas aeruginosa

The attacks from this pathogen are various. Because of this, they’re sometimes difficult to identify.

  • This dangerous bacteria is related to patients with AIDS and cystic fibrosis.
  • In addition, it also can begin with a simple dermatitis or by ingesting contaminated water.

Its grave danger is in its capacity to reproduce in people who have AIDS. At the same time, this tends to cause pulmonary complications and strong infections for persons who are compromised with another virus.

Discover: The Symptoms of Human Immunodeficiency Virus (HIV)

3. Enterobacteriaceae

This bacteria is in a family of microorganisms whose diseases basically affect the digestive and excretory system (in other words, the colon, the stomach, and the intestines).

  • In fact, this group of dangerous bacteria is responsible for infantile gastroenteritis, salmonella, typhoid fever, and dysentery.
  • In the past, these diseases took a high number of lives during the time of the plague.
  • Besides, many of these dangerous bacteria have a great resistance to penicillin.

4. Enterococus faecium

This bacteria coexists in the human intestines, but also can turn into a damaging agent.

Enterococcus faecium is responsible for neonatal meningitis. This is an infection that causes headaches, a stiff neck, fever, and photophobia.

  • Currently, it has a high priority. However, it isn’t at the top of the list.
  • The problem with it is that it’s resistant to antibiotics.

5. Staphylococcus aureus

There are bacteria that can link to a group of infections and diseases in various organs of the human body. This is the case with Staphylococcus aureus. As a result, it’s capable of causing problems in the skin and the respiratory and digestive systems. 

Consequently, this microorganism can cause these conditions, among others:

  • Conjunctivitis.
  • Cellulitis.
  • Sepsis.
  • Meningitis.
  • Pneumonia.

In addition, the great majority of these infections occur in hospitals.

6. Helicobacter pylori

Helicobacter pylori.

This is a bacteria that attacks the stomach exclusively. In general, it infects the gastric mucous and generates bloating. It can also cause the following diseases:

  • Gastritis.
  • Septic ulcer.
  • Irritated colon.
  • Lymphoma.

In some cases, people contract this bacteria and have no symptoms throughout their life. Saliva, feces, and dental plaque transmit this bacteria.

This article may interest you: Herbal Remedies to Fight a Helicobacter Pylori Infection

7.  Campylobacter

In this case, we’re talking about the major carrier of food poisoning in the world. These are its common symptoms:

  • Vomiting.
  • Fever.
  • Diarrhea.
  • Abdominal pain.

Additionally, it can cause arthritis and Guillain-Barré disease. This is an bacterial agent this can be perfectly eliminated with conventional antibiotics. However, it’s also true that it’s one of the most common and most dangerous bacteria.

Especially important is that ingesting food or water that’s contaminated, a virus, or contact with an infected animal can transmit Campylobacter.

8. Salmonella, another of the dangerous bacteria

Salmonella is a form of Enterobacteriaceae that causes salmonella.

  • The incubation period is from one week to almost one month.
  • Symptoms go from a fever to vomiting, diarrhea, and upset stomach.

After incubation, the symptoms could last up to two months in the worst cases. Salmonella can survive for long periods of time in dairy products such as butter, milk, and chocolate.

Discover: Which Are Better: Full-Fat or Low-Fat Dairy Products?

9. Neisseria gonorrhaeae

Neisseria gonorrhoeae.
Bacteria Neisseria gonorrhoeae inside phagocytes, gonoccoccus, diplococci which cause sexually transmitted infection gonorrhoea. 3D illustration. Incomplete phagocytosis.

Some dangerous infections are contagious by means of sexual contact. That’s the case with this bacteria.

  • As its name indicates, this microbe can cause gonorrhea.
  • Simple antibiotics such as ampicillin or penicillin can stop this disease if detected in time.

Get regular check-ups

Experts recommend getting at least annual check-ups to check the state of your health and if there’s anything you need to improve on.

Always follow good lifestyle habits and, in case of persistent symptoms and discomfort, consult your doctor as soon as you can. Early detection and treatment of any disease (including those caused by the most harmful and dangerous bacteria that we discussed here) is vital.

Finally, remember that you should avoid self medicating, since it could cause complications. If you want to take any medication, it’s best to consult your family doctor.

  • Weinstock, G. M. (2012). Genomic approaches to studying the human microbiota. Nature. https://doi.org/10.1038/nature11553
  • Faust, K., Sathirapongsasuti, J. F., Izard, J., Segata, N., Gevers, D., Raes, J., & Huttenhower, C. (2012). Microbial co-occurrence relationships in the Human Microbiome. PLoS Computational Biology. https://doi.org/10.1371/journal.pcbi.1002606
  • Hyde, E. R., Haarmann, D. P., Lynne, A. M., Bucheli, S. R., & Petrosino, J. F. (2013). The living dead: bacterial community structure of a cadaver at the onset and end of the bloat stage of decomposition. PloS One. https://doi.org/10.1371/journal.pone.0077733