What do bacteria used as "biological weapons" look like? Multiple images revealing the secrets of pathogens

2021-04-02 | Mr. Warmhearted |

Editor's note

Bacteria, parasites, and viruses are everywhere, but they are so small that they cannot be recognized by our naked eyes. However, with the continuous advancement of microscopy technology, we can now see the true appearance of these microorganisms. Recently, IBM specializes50 scanning electron microscopy images from the National Institute of Allergy and Infectious Diseases of the United States are displayed to show the splendor of the microscopic world. The pictures include bacteria, viruses, spirochetes and immune cells.

Previously, we specially presented 20+ microscopic images about viruses and parasites. Today, we specially selected the images about bacteria and gave a brief introduction to related knowledge.

Biological weapons: Francis Tularensis

Francis tularensis can cause Tularemia tularemia. The infected person will have symptoms such as high fever, pain in the body, enlarged glands and difficulty in swallowing and eating. Because of the low minimum infectious dose of the bacteria, strong toxicity and easy passageAerosol spread, so it is regarded as a first-level terrorist biological agent.

In the early 20th century, several vaccines were developed against this bacterium. Among them, the most widely studied vaccine strain is the live attenuated vaccine strain LVS, which is derived from the virulent strain of Tulariaceae subspecies Arctic. Although, LVS vaccineIt still has a certain degree of toxicity in humans and animals, but its effectiveness has been preliminarily proven in humans[1]. At present, the vaccine is only used to vaccinate high-risk persons and has not been applied to the general public.

The picture above is a scanning electron microscopy image of mouse macrophages infected by Francis Tularensis LVS strain. After the critical point is dry during the film production process, cellophane tape is used to contact the cell surface, causing the macrophages to dry and crack, exposing the inside of the cell.Bacteria. Bacteria blue are located in the cytoplasm or vesicles.

The killer of gonorrhea: Neisseria gonorrhoeae

Gonorrhoea is one of the most common sexually transmitted bacterial diseases in the world. It is caused by Neisseria gonorrhoeae infection. Common symptoms include urethral secretion and urethral pain. If treatment is not timely, possible complications include pelvic cavityInflammation and infertility.

According to WHO's data, the number of gonorrhea patients is as high as 78 million people every year [2]. It is a common sexually transmitted disease in my country, and it is also a category B that needs to be focused on prevention and treatment as stipulated in the "Law of the People's Republic of China on the Prevention and Control of Infectious Diseases" infectious disease.

The picture above is a scanning electron microscope image of Neisseria gonorrhoeae that causes gonorrhea.

The murderer of tuberculosis: Mycobacterium tuberculosis

TB is a chronic infectious disease caused by Mycobacterium tuberculosis infection, which can spread from person to person through the air. Due to the increasing number of drug-resistant cases, it has become a global public health problem.

Mycobacterium tuberculosis can invade all organs of the human body, but it mainly invades the lungs. It is called tuberculosis, which is mainly manifested as cough and sputum. Common symptoms of renal tuberculosis are dysuria, urgency, etc. In addition, tuberculosis patients generally stillThere will be weakness, low fever, night sweats, etc. [3].

The picture above is a scanning electron microscope image of Mycobacterium tuberculosis that causes tuberculosis.

Syphilis killer: Treponema pallidum

Syphilis is caused by Treponema pallidum infection, which can cause vascular collapse, local blood supply obstruction, vascular inflammation, tissue necrosis, etc. Syphilis is widely spread around the world, and millions of people get sick each year, but in low- and middle-incomeIn the country, the morbidity and mortality rates are rising [4].

The picture above is a scanning electron microscope image of Treponema pallidum that causes syphilis.

Recurrent tick-borne fever: Treponema burgdorferi

Treponema spirochetes can cause tick-borne recurrent fever. This disease is very popular in the high-altitude areas and coniferous forests of the western United States and southern British Columbia, Canada.

Patients with this disease usually start from 4 to 18 days after being bitten by a tick infected with Borrelia Helmoniae. It is characterized by recurrent fever accompanied by various other manifestations, including headaches and muscles.Pain, joint pain, chills, vomiting, abdominal pain, etc.

If the patient's blood microscopy is positive for Borrelia worms, it can be confirmed as tick-borne recurrent fever [5].

The picture above is a scanning electron microscope image of Borrelia Hermosa.

Multiple drug resistance: methicillin-resistant Staphylococcus aureus

Staphylococcus aureus is one of the common pathogens, which can cause food poisoning, skin and tissue infections, even bacteremia and endocarditis. Invasive materials such as catheters and stents are considered to be Staphylococcus aureusOne of the main factors of infection.

In the pre-antibiotic era, the mortality rate caused by invasive Staphylococcus aureus infection has been very high. It was not until the advent of penicillin that this situation changed. But the good times did not last long. Due to the widespread use of penicillin, Staphylococcus aureusPenicillin resistance has developed.

In response to penicillin-resistant Staphylococcus aureus, methicillin, a semi-synthetic penicillin, came out in 1959. However, methicillin-resistant Staphylococcus aureus MRSA appeared rapidly in a short period of time, andIt is resistant to almost all penicillin antibiotics and has become the main pathogenic bacteria of current hospital infections [6].

The picture above shows the MRSA surrounded by cell debris taken under a scanning electron microscope.

The picture above shows the interaction between the MRSA252 strain and human white blood cells. The MRSA252 strain is one of the main causes of hospital infections in the United States and the United Kingdom.

The picture above is a scanning electron microscope image of neutrophils ingesting MRSA.

The picture above shows the entanglement between MRSA and dead neutrophils.

Hospital-acquired infection: Carbapenem-resistant Klebsiella pneumoniae

Klebsiella pneumoniae belongs to the Enterobacteriaceae family and is a normal microorganism in the human oral cavity and intestines. However, some Klebsiella pneumoniae are pathogenic and are common microorganisms that cause hospital-acquired infections. 20~80% of pneumoniaKlebsiella is resistant to at least one antibiotic, including cephalosporins, fluoroquinolones, aminoglycosides and carbapenems.

In 2002, Klebsiella pneumoniae that produces VIM carbapenemase appeared in a hospital in Greece, and then the bacterium spread widely all over the world. Carbapenem-resistant Klebsiella pneumoniae is a kind of multipleDrug-resistant bacteria can cause serious hospital infections, with high treatment failure rates and mortality rates, and have posed a serious threat to global human health [7].

The above two pictures show the interaction between carbapenem-resistant Klebsiella pneumoniae and human neutrophils.

Streptococcus: Type A and Type B are different

Streptococcus belongs to the order Firmicutes Lactobacillus, and Gram stain is positive. Streptococcus cell division occurs on the same axis, so when they grow, they often form pairs or chains, which may be bent orFracture. Most streptococci are facultative anaerobes. Common streptococci include type A streptococcus and type B streptococcus.

Type A streptococcus can cause invasive and non-invasive infections, among which common non-invasive infections include streptococcal pharyngitis, impetigo and scarlet fever. Invasive infections caused by type A streptococcus,Often more serious, such as streptococcal toxic shock syndrome, necrotizing fasciitis, pneumonia, and bacteremia.

It is estimated that more than 500,000 people die from type A Streptococcus infections worldwide each year, making it one of the world’s main pathogens [8].

The picture above is a scanning electron microscope image of type A streptococcus yellow infected human neutrophils.

Type B streptococcus can cause pneumonia and meningitis in newborns and the elderly. It is the most common cause of meningitis in infants aged 1 to 3 months. They can also be colonized in the intestine and female reproductive tract, increasing pregnancy fetusesThe risk of premature rupture of the membrane and infection of the infant [9].

The picture above is a scanning electron microscope image of group B streptococci.

Good and bad: Escherichia coli

E. coli naturally exists in the normal animal intestinal microbiome, but some of them can cause diseases under certain conditions, mainly caused by infections such as specific fimbriae antigens and pathogenic toxins. TriggeredDiseases include gastrointestinal infections, urinary tract infections, arthritis, meningitis, and sepsis [10].

The picture above is a scanning electron microscope image of Escherichia coli growing on a culture medium.


1.Jia Qingmei,Horwitz Marcus A,F. tularensisLive Attenuated Tularemia Vaccines for Protection Against Respiratory Challenge With Virulent subsp. .[J] .Front Cell Infect Microbiol, 2018, 8: 154.

2.M?ynarczyk-Bonikowska Beata,Majewska Anna,Malejczyk Magdalena et al. Multiresistant Neisseria gonorrhoeae: a new threat in second decade of the XXI century.[J] .Med Microbiol Immunol, 2020, 209: 95-108.

3.Acharya Bodhraj,Acharya Ashma,Gautam Sanjay et al. Advances in diagnosis of Tuberculosis: an update into molecular diagnosis of Mycobacterium tuberculosis.[J] .Mol Biol Rep, 2020, 47: 4065-4075.

4.Gogarten JF,Düx A,Schuenemann VJ et al. Tools for opening new chapters in the book of Treponema pallidum evolutionary history.[J] .Clin Microbiol Infect, 2016, 22: 916-921.

5.Schwan, Tom G.; Policastro, Paul F.; Miller, Zachary; Thompson, Robert L.; Damrow, Todd; Keirans, James E. September 2003. Tick-borne Relapsing Fever Caused by Borrelia hermsii,Montana.[J]. Emerging Infectious Diseases. 9 9: 1151–1154.

6.Jian M, Chen L, Wang J, et al. Current methodologies on genotyping for nosocomial pathogen methicillin-resistant Staphylococcus aureus MRSA[J]. Microbial Pathogenesis, 2017, 107:17-28.

7.Karampatakis Theodoros,Antachopoulos Charalampos,Iosifidis Elias et al. Molecular epidemiology of carbapenem-resistant Klebsiella pneumoniae in Greece.[J] .Future Microbiol, 2016, 11: 809-23.

8.Cohen-Poradosu R, Kasper DL 2007. Group A streptococcus epidemiology and vaccine implications. [J] Clin. Infect. Dis. 45 7: 863–5. doi:10.1086/521263.

9.Schrag S, Gorwitz R, Fultz-Butts K, Schuchat A 2002. Prevention of perinatal group B streptococcal disease. Revised guidelines from CDC [J]. MMWR Recomm Rep. 51 RR-11: 1–twenty two.



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Mr. Warmhearted
Founder of the Enthusiastic Biotechnology Research Institute, editor-in-chief of the Enthusiastic Daily, and executive chairman of the China Intestinal Conference

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