College Bio Final - 12 Bacterial Pathogens

Corynebacterium Diphtheriae 

• Causes diphtheria

• Gram-positive bacilli (rods)

• Affects the membrane of the throat and nose

• Discovered by German bacteriologist Edwin Klebs and Friedrich Löffler in 1884

• transmitted by touching an infected wound, handling an infected person’s things, or airborne droplets

• There’s skin diphtheria where ulcers, pain, redness, and swelling occur on the skin

• most common in children until vaccine was created in 1923

• without vaccine diphtheria can lead to breathing problems, heart, and nerve damage

• Big outbreak in the 1990s in the Soviet Union 

• Cases of deported worldwide in 2017 (8,819) was the most since 2004

Treponema Pallidum

• Causes syphilis

• Gram negative spirilli (spirochete)

• Affects the genitals

• Identified as a disease in 1838 by Philippe Ricord

• Bacteria that causes treponema pallidum was discovered in 1905 by Franz Eihard Schulz & Eric Hoffman

• Spread by sexual contact, blood, transfusion, or pregnancy

• When France invaded Italy in 1494 syphilis pandemic broke out in Europe

• Consists of sores, rashes, lesions, and potential damage to the organs

• Can be treated with the antibiotic penicillin

• Belongs to domain bacteria

Vibrio Cholerae:

• Causes cholera (severe diarrhea)

• Gram negative bacilli (rods)

• Was discovered twice:

  • 1st by Italian physician Filippo Pacini in 1854

  • Then by German microbiologist Robert Koch in 1883

• Spread by consuming liquids and food contaminated with the bacteria (like raw/undercooked shellfish)/the feces of a infected person

• Treatment includes fluid replacement, antibiotics (doxycycline), and a few vaccines

• Several outbreaks throughout history

  • 1852–1859 in Asia, Europe, North America and Africa

  • 1992–1993 in Bangladesh in India

Klebsiella Pneumonia:

• Causes pneumonia

• Gram negative bacilli (rods)

• Affects the lungs

• Described by German microbiologist and pathologist Carl Friedländer in 1882

• However, named after German microbiologist Edwin Klebs in 1886

• Spread by person- to- person contact (someone who is infected), wounds, contaminated medical objects, and water/soil

• Treated with antibiotics were hard to do as some strange have developed resistance

• Outbreaks:

  • Virginia Mason Medical Center in October 2022– 31 infected & 7 died

  • ICU of St. Elizabeth Hospital, Tilberg, Netherlands in 2000 – outbreak caused by contaminated, breastmilk, sink, bath soap, etc.

Bacillus Anthracis

• Causes anthrax

• Gram positive bacilli (rods) with spores

• Affects the lungs, skin, stomach, and intestines

• Discovered in 1850 by Pierre Rayer & Casimir-Joseph Davaine 

• Robert Koch linked bacillus anthracis to anthrax in 1876

• Anthrax is a spore that infects hosts (normal animals) 

• Spread through breathing in anthrax spores, eating or drinking things contaminated with spores, getting spores in wounds, or being exposed to infected animals, their meat or hides

• Treated with antibiotics and there is a vaccine but only for those 18–65 years old, who are at risk of exposure to anthrax or for unvaccinated people exposed

• Outbreaks:

  • Texas 2019 (increased animal cases and a human)

  • 2001 bioterrorism anthrax attack in the US (22 people were infected with anthrax after being exposed to spores sent through the mail – 5 died)

  • 2009–2013 46 heroin users died in Europe after contracting anthrax through injecting illegal drugs

Legionella Pneumophila

• Causes legionnaires disease

• Gram negative bacilli (rods)

• Affects the respiratory system

• In 1976 in Pennsylvania there was an outbreak of a mystery illness where 221 people were infected and 34 died

  • A CDC microbiologist, Dr. Joseph McDade isolated that new bacteria and named it after the Legionnaires convention

• The bacteria can grow and spread in human-made building water systems and affect people breathing in mist or swallowing water

• Causes severe pneumonia, lung failure, and death

• Treated with antibiotics

Clostridium Tetani

• Causes tetanus

• Gram positive bacilli (rods)

• Affects the muscles

• Very common in newborns

• There’s record dating back to the 5th century BC that contains descriptions of tetanus

• In 1889 Kitasato Shibasaburo isolated the organism from a human

• Sports of the bacteria are common in the environment (soil, dust) & are spread through broken skin

• Once in the body tetanus releases toxins that eventually blocked the messengers that control voluntary muscle movement

• There are vaccines that help prevent people from getting tetanus and also prevent neonatal tetanus

• Common in countries with adequate immunization

  • Outbreaks include Yogyakarta, Indonesia in 2010 (139 cases after the earthquake) & Uganda in 2014 there were 3,350 non-neonatal cases

Mycobacterium Leprae

• Causes leprosy

• Gram positive bacilli (rods)

• Affects the skin, nerves, eyes, and nose

• Earliest evidence of leprosy was a skeleton in India dating back 4,000 years ago in medieval Europe

• In 1873 Gerhard Armauer Hansen, an Norwegian physician, discovered mycobacterium

• Leprosy spreads through droplets from the nose and mouth from close contact with an untreated, infected person over a period of time

• Causes skin lesions, thicken, skin, enlarged nerves, loss of sensation, facial changes

• There is a vaccine & is also treatable with multi-drug therapy 

• In 2020 there were 159 cases of leprosy in US with 81% of the cases being in Florida

Salmonella Typhi

• Causes typhoid fever

• Gram negative bacilli (rods)

• Affects the intestines

• In 1880 Karl Joseph Eberth described salmonella typhi 

• In 1884 pathologist George Gaffky confirmed that

• Typhoid fever is caused by contaminated food or water

• Once salmonella is ingested it multiplies and spreads into the bloodstream

• There is a vaccine for typhoid fever, and it can be treated by antibiotics

• Outbreaks: 

  • Typhoid fever thought to have been responsible for a widespread plague in Athens in 430 BC

  • Caused Jamestown (English colony) to die out according to historians

  • Beijing apartment building in 2022 linked to contaminated water in the building

Yersinia Enterocolitica (pestis)

• Causes the bubonic plague

• Gram negative bacilli (rids)

• Affects the lymph nodes

• In 1894 Alexandre Yersin isolated, and identified the bacteria in Hong Kong

• Bubonic plague is caused by a bite from an infected flea, and exposure to infected animals

• The bacteria will travel to the lymph nodes and replicate in it

• The flea bites can turn into painful skin lesions

• There is a vaccine only available to those who are at high risk of exposure (ex. healthcare workers)

• Bubonic plague is known as the black death: a devastated population throughout Europe, the Middle East, and northern Africa in the 14th century

Neisseria Gonorrhoeae

• Causes gonorrhea

• Gram negative cocci (sphere)

• Affects the genitals

• In 1879 German physician Albert Ludwig Sovesmund Neisser discovered the bacteria 

• Gonorrhea, also known as the clap, is an STD spread through sexual contact (fluid)

• Treatment includes antibiotics & shots

• To prevent these condoms, get tested, and don’t have sex with someone who’s infected

• Gonorrhea includes painful urination & greenish discharge of puss

• Men who have sex with men are at higher risk

• In the US after Covid regulations were lifted there was a big increase of cases

• Belongs to domain bacteria

Shigella Dysenteriae

• Causes (bacillary) dysentery

• Gram negative bacilli (rods)

• Affects the digestive system

• Kiyoshi Shiga identified the bacteria in 1898 in Japan

• Caused by a bacterial infection (diarrhea) that causes inflammation of the intestines

  • Most common type of dysentery

• Spread their flies (from feces to food), consuming food or water contaminated by an infected person, and physical contact (including sex) with an infected person

• Dysentery is usually the result of poor hygiene

• Dysentery usually resolves on its own

• South Africa in 2021– 48 cases and 16 hospitalized