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The influence that Bacteria have on symptoms/diseases in the human body


Clostridium Botulinum

The Clostridium Botulinum bacteria produces a neurotoxin that leads to a disease known as botulism. Based on the transmission botulism is classified as foodborne (ingestion of botulinum toxin) [1]; infantile (baby infest spores of botulinum toxin producing bacteria); wound botulism and iatrogenic is botulinum toxin overdosing in cosmetic or during its medical applications.

There are several manifestations of Clostridium Botulinum infection like blurred vision, slurred speech, dry mouth and muscle weakness among adults, nausea, vomiting diarrhea linked to foodborne toxins. The infants usually manifest the disease as constipation, reduced feeding and respiratory distress. If the infection is confirmed, then botulinum antitoxin is a treatment of choice [2]. 

Clostridium difficile

This bacteria produces two exotoxins A and B associated with bacterial toxicity[3]. These toxins are linked with several symptoms including diarrhea, loss of appetite and abdominal pain. Transmission of bacteria is through the fecal-oral route. Disinfection and routine cleaning are recommended to avoid contamination with this bacterial species.

This bacteria is also linked to inflammatory responses in the colon and mostly elderly adults are subject to infection associated with the bacterium. Although diarrheal symptoms related with Clostridium difficile are globally present, however, in the United States of American almost half a million people get sick due to this bacterial infection and the overall infection trend is on the rise [4, 5].

Clostridium tetani

The Clostridium tetani is a bacteria responsible for causing tetanus [6]. The pathological aspects associated with tetanus is the secretion of a biological toxin tetanospasmin that lead to symptoms like pain and spasm in the human body besides respiratory distress [7]. The tetanospasmin secreted by Clostridium tetani is a potent neurotoxin having some similarities with the botulinum toxin.

The bacterial toxin exerts its effect through disrupting the functioning of neurotransmitters. The transmission of this bacteria into the human is linked with the entry of bacterial spores through open wounds. These spores are mainly in the feces of several mammals including horses, cow, sheep, and dogs.

Neisseria gonorrhea

A sexually transmitted disease gonorrhea is caused by a pathogenic Neisseria gonorrhoeae [8]. The bacteria mainly grows in the anaerobic environments as such urethra, cervix; rectum is the primary sites of infection where bacteria can multiply. It has been reported that urethra in males and endocervix and urethra in females are the regions where this bacteria mainly replicate for subsequent infection in surroundings.

As such, the sexual contacts mainly contribute towards this bacteria transmission. A child on birth can also acquire this bacteria from the mother if she is infected with this bacteria. The bacterial infection is associated with inflammatory responses leading to the destruction of the epithelial cells mainly in the female urogenital system [9].

Pseudomonas aeruginosa

This bacteria is mainly an opportunistic pathogen and only causes infections among immunocompromised individuals [10]. Mainly the bacteria are present in soils and water and get access into the human body either through contact or drinking bacterially contaminated items. Several infections like respiratory ailments, dermatitis, and gastrointestinal infections are due to this bacteria in the people having weakened immune system.

This bacteria is also considered as a nosocomial pathogen by the Center for Disease Control (CDC) of the USA. In US hospitals, this bacteria is considered as the fourth most common nosocomial pathogen [11, 12]. Several people in the hospitals having debilitating diseases are prone to this bacterial infections.

Salmonella typhi

Infection with Salmonella typhi leads to enteric fever also known as typhoid fever [13]. It has been estimated that almost 17 million individuals get this bacterial infection. Bacterial transmission among humans is through the fecal-oral route and linked with poor hygienic conditions. Water contaminated with bacteria and contaminated eggs are considered as the primary source of bacterial infection transfer to humans.

There are high mortality and morbidity associated with this infection leading to the death of almost 0.6 million individuals. These bacteria cause disease by secreting an endotoxin and several other virulence factors. This bacteria has the capability to deceive the innate immune system and can survive during phagocytic activity of the immune cells [14].

Staphylococcus aureus

This bacteria is responsible for causing a variety of superficial skin infections like blisters, abscesses, including redness and swelling. Besides this life threatening disease like endocarditis, osteomyelitis and lung infections (pneumonia) is also due to this bacterial infections. Although infections caused by Staphylococcus aureus are mainly superficial in nature, however, the bacterial transmission can also take place through the bloodstream as it traverses into the human circulatory system.

Besides this direct contact with an infected person and using contaminated objects is also a factor in transmitter Staphylococcus aureus infection from one person to another [15]. A major issue with Staphylococcus aureus infection is the emergence of antibiotic resistance strains threatening the overall health care system [16, 17].

Streptococcus pneumonia

The Streptococcus pneumonia causes a variety of pneumococcal diseases including lungs, ear and sinus infections and bacteremia [18]. The bacteria is mainly transmitted from person-to-person through close contact, coughing and sneezing. This bacterial disease is prevalent all over the world, and sometimes travelers are a major conduit for carrying pneumococcal infection from one place to the other.

The bacterial infections increase in winter and spring although it stays around all the years. Outbreaks of Streptococcus pneumonia have also been reported in certain parts of the world. The pneumococcal vaccine is highly effective in protecting from this bacterial infection, and a variety of vaccines are used to protect people from this bacterial infection [19].

Treponema pallidum

This unique spirochete bacterium species is responsible for causing syphilis, a sexually transmitted disease [20]. The bacterial infection has several stages including primary, secondary, latent and tertiary. For example, primary syphilis is characterized sores around the genitals due to bacterial infection, whereas the secondary stage of syphilis has a skin rash, fever, and swollen lymph nodes.

The tertiary syphilis is more severe in nature and needs medical attention. If the sex partner is diagnosed with syphilis care should be taken to avoid its transmission besides proper treatment measures. Expecting mothers can transfer syphilis causing bacteria to their newborn thus putting them at the risk of several bacterial infections [21, 22].

Vibrio cholera

Intestinal infection with Vibrio cholera is the cause of diarrhea among humans [23]. Approximately 3-5 million people are a victim of this bacterial infection every year and among this 0.1 million die. Besides diarrhea, the bacteria infection is associated with vomiting and leg cramps. The water loss in Vibrio cholera infection should be adequately replenished other death may occur.

The Vibrio cholera is mainly found in water and foods, and their contamination with fecal material of a person with cholera is associated with its further transmission. Water or food contaminated with this bacteria results in disease that should be appropriately treated for better outcomes [23].

Professor Dr. Muhammad Mukhtar


1. Rafie, S., et al., Botulism Outbreak in a Family after Ingestion of Locally Produced Cheese. Iran J Med Sci, 2017. 42(2): p. 201-204.

2. May, M.L., M.A. Corkeron, and M. Stretton, Infant botulism in Australia: availability of human botulinum antitoxin for treatment. Med J Aust, 2010. 193(10): p. 614-5.

3. Aktories, K., C. Schwan, and T. Jank, Clostridium difficile Toxin Biology. Annu Rev Microbiol, 2017.

4. Dumyati, G., et al., Community-associated Clostridium difficile infections, Monroe County, New York, USA. Emerg Infect Dis, 2012. 18(3): p. 392-400.

5. Michael, K., et al., Clostridium difficile Environmental Contamination within a Clinical Laundry Facility in the USA. FEMS Microbiol Lett, 2016.

6. Gomes, A.P., et al., Clostridium tetani infections in newborn infants: a tetanus neonatorum review. Rev Bras Ter Intensiva, 2011. 23(4): p. 484-91.

7. Volgin Iu, B., I.B. Pavlova, and K.L. Shakhanina, [Extraction of a specific ferroglobulin for tetanospasmin and an electron microscopic study of the process of toxinogenesis in Cl. tetani]. Zh Mikrobiol Epidemiol Immunobiol, 1974(2): p. 79-83.

8. Suay-Garcia, B. and M.T. Perez-Gracia, Drug-resistant Neisseria gonorrhoeae: latest developments. Eur J Clin Microbiol Infect Dis, 2017. 36(7): p. 1065-1071.

9. Low, N. and M. Unemo, Molecular tests for the detection of antimicrobial resistant Neisseria gonorrhoeae: when, where, and how to use? Curr Opin Infect Dis, 2016. 29(1): p. 45-51.

10. Kalai, S., et al., [Pseudomonas aeruginosa isolated in immunocompromised patients: antimicrobial resistance, serotyping, and molecular typing]. Med Mal Infect, 2005. 35(11): p. 530-5.

11. Lolans, K., et al., First nosocomial outbreak of Pseudomonas aeruginosa producing an integron-borne metallo-beta-lactamase (VIM-2) in the United States. Antimicrob Agents Chemother, 2005. 49(8): p. 3538-40.

12. Micek, S.T., et al., Pseudomonas aeruginosa nosocomial pneumonia: impact of pneumonia classification. Infect Control Hosp Epidemiol, 2015. 36(10): p. 1190-7.

13. Fresnay, S., et al., Importance of Salmonella Typhi-Responsive CD8+ T Cell Immunity in a Human Typhoid Fever Challenge Model. Front Immunol, 2017. 8: p. 208.

14. Crawford, R.W., et al., Loss of very-long O-antigen chains optimizes capsule-mediated immune evasion by Salmonella enterica serovar Typhi. MBio, 2013. 4(4).

15. Denis, O., Route of transmission of Staphylococcus aureus. Lancet Infect Dis, 2017. 17(2): p. 124-125.

16. Haaber, J., J.R. Penades, and H. Ingmer, Transfer of Antibiotic Resistance in Staphylococcus aureus. Trends Microbiol, 2017.

17. Saba, C.K.S., J.K. Amenyona, and S.W. Kpordze, Prevalence and pattern of antibiotic resistance of Staphylococcus aureus isolated from door handles and other points of contact in public hospitals in Ghana. Antimicrob Resist Infect Control, 2017. 6: p. 44.

18. File, T.M., Jr., Streptococcus pneumoniae and community-acquired pneumonia: a cause for concern. Am J Med, 2004. 117 Suppl 3A: p. 39S-50S.

19. Andrade, D.C., et al., Effect of Pneumococcal Conjugate Vaccine on the Natural Antibodies and Antibody Responses Against Protein Antigens From Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis in Children With Community-acquired Pneumonia. Pediatr Infect Dis J, 2016. 35(6): p. 683-9.

20. Salado-Rasmussen, K., et al., Molecular Typing of Treponema pallidum in Denmark: A Nationwide Study of Syphilis. Acta Derm Venereol, 2016. 96(2): p. 202-6.

21. Freyne, B., et al., Universal perinatal screening for Treponema pallidum: the role of a dedicated infectious diseases team for prevention of mother-to-child transmission. Sex Transm Infect, 2013. 89(7): p. 582.

22. Freyne, B., et al., Perinatal Treponema pallidum: evidence based guidelines to reduce mother to child transmission. Ir Med J, 2014. 107(1): p. 14-6.

23. Virology: What makes bird flu jump species? Nature, 2017. 543(7647): p. 593.

Topics: Bacteria

Professor Dr. Muhammad Mukhtar

Written by Professor Dr. Muhammad Mukhtar

Professor Dr. Muhammad Mukhtar has over 25 years teaching experience in biomedical sciences. Besides teaching, he has a very strong portfolio of academic administration and he is an accomplished researcher in the area of infectious diseases. Dr. Mukhtar received his Ph.D. in Biosciences from the Drexel University of Philadelphia, USA, and also completed a Graduate Certificate in Research Management from Thomas Jefferson University of Philadelphia, USA. He served in various academic/administrative positions in the USA on an outstanding scientist (O-1) visa.