Academic Master


Natural Sciences: Bacterial Pathogens



Genus Species

Gram Reaction Morphology Diseases Caused Symptoms of Disaese
Bacillus B. cereus Gram- Positive rod-shaped bacilli with square ends

Flagella driven motility

Foodborne illnesses such as the emetic (vomiting) syndrome and the diarrhoeal syndrome.
  • severe nausea vomiting, and diarrhea due to indigestion of the infeceted food
Bacillus B. Anthracis  Gram-Positive 
  • Rod-shaped bacterium
  • endospore-forming
  • Anthrax:  Pulmonary Anthrax, Gastrointestinal Anthrax

Usually caused to livestock and human beings

  • Fever and chills run through body
  • Discomfort in Chest
  • Shortness of breath
  • Confusion or dizziness
  • Cough
  • Nausea, vomiting, or stomach pains
  • Headache
  • Sweats (often drenching)
Bartonella henselae B. henselae Gram- Negative
  • Rod shaped bacteria
  • No flagella
  • Twitching motility
cat-scratch disease (bartonellosis)
  • papule at the site the microbe entered
  • aches, nausea, and abdominal pain,
  • malaise
Bordetella B. pertussis Gram-Negative
  • rod-shaped, coccoid
  • Motile
 Respiratory infection such as pertussis or whooping cough
  • Rapid coughs followed by a high-pitched “whoop” sound.
  • Vomiting during or after coughing fits.
  • Exhaustion after coughing fits
Borrelia B. burgdorferi Gram-Negative
  • Rod shaped bacteria with helical flagella
  • spirochete bacterium
Lyme disease caused by Blacklegged ticks
  • fever, headache, fatigue
  • Causes skin rash called erythema migrans.
Campylobacter C. Jejuni Gram- Negative slender rods

have one or more helical turns


common spirillum bacterium

Campylobacter or human gastroenteritis (Foodborne disease)
  • inflammatory, sometimes bloody diarrhea
  • mostly including stomach cramps, fever and pain
Chlamydia C. trachomatis Gram- Negative
  • coccoid or rod-shaped and require growing cells to remain sustainable
  • Pelvic inflammatory disease


  • Infection near the testicles (epididymitis).
  • Prostate gland infection
  • Ectopic pregnancy
  • Infertility
  • Reactive arthritis
  • Painful urination
  • Vaginal discharge in women
  • Discharge from the penis in men
  • Painful sexual intercourse in women
  • Bleeding between periods and after sex in women
  • Testicular pain in men
Clostridium C.Botulinum Gram-Positive
  • Cells of most strains occur as straight or slightly curved rods
  • Motile with the help of peritrichous flagella
  • Paralysis
  • Poisoning
  • Difficulty swallowing
  • Muscle weakness
  • Double vision
  • Drooping eyelids
  • Blurry vision
  • Slurred speech
  • Difficulty breathing
  • Difficulty moving the eyes
Clostridium C. difficile Gram- Positive
  • Rod shaped
  • motile by peritrichous flagella and spore forming in nature
  • Clostridioides
  • Severe diarrhea and colitis (an inflammation of the colon)
  • Watery diarrhea ( in worst cases10 to 15 times a day)
  • Abdominal cramping and pain, which may be severe
  • Rapid heart rate
  • Dehydration
  • Fever
  • Nausea
  • Increased white blood cell count
  • Kidney failure
  • Loss of appetite
  • Swollen abdomen
  • Weight loss
  • Blood or pus in the stool
Clostridium C. perfringens Gram- Positive
  • Rod shaped
  • Spore forming
Food poisoning


diarrhea and stomach cramps

profuse vomiting (instant vomiting after intake of food)

indigestion of food


Clostridium C. tetani Gram-Positive
  • Enlarged and tennis racket- or drumstick-shaped when forming spores
  • Usually rod shaped
  • Motile with the help of flagella
  • Jaw cramping.
  • Sudden involuntary muscle tightening (muscle spasms) – often in the stomach
  • Painful muscle stiffness all over the body
  • Trouble swallowing
  • Jerking or staring (seizures)
  • Headache
  • Fever and sweating
  • Changes in blood pressure and fast heart rate
Corynebacterium C. diphtheria Gram-Positive
  • non-motile, non-encapsulated, non-sporulating
  • rod-shaped
  • Difficulty breathing
  • Heart failure
  • Paralysis, and even death
Gardnerella G. vaginalis Gram-Variable
  • Non-motile
  • Slow growing bacillus
  • Non-spore-forming
Bacterial Vaginosis (BV)
  • Thin, gray, white or green vaginal discharge.
  • Foul-smelling “fishy” vaginal odor.
  • Vaginal itching.
  • Burning during urination.


H. influenzae Gram-Negative
  • bacilli or coccobacilli with random arrangements
  • rod shaped
  • Pneumonia
  • Bloodstream infection.
  • Meningitis.
  • Epiglotittis
  • Cellulitis
  • Infectious arthritis
  • swelling in the throat
  • inflammation of the joint
  • Fever and chills.
  • Excessive tiredness.
  • Pain in the belly.
  • Nausea with or without vomiting.
  • Diarrhea.
  • Anxiety.
  • Shortness of breath or difficulty breathing.
  • Altered mental status (confusion)
  • Fever
Helicobacter pylori H. pylori Gram-Negative
  • Spiral shaped or Helix shaped
  • Curved or straight rods
  • Motile with the help of its flagella
  • Peptic ulcer
  • Chronic gastritis
  • Risk factor for gastric carcinoma and Gastric B-cell lymphoma
  • Burning pain in your stomach after eating anything
  • Unplanned weight loss.
  • Bloating
  • Nausea and vomiting (bloody vomit)
  • Indigestion (dyspepsia)
  • Burping
  • Loss of appetite
  • Dark stools
Klebsiella K. pneumoniae Gram-Negative
  • Non- Motile
  • rod-shaped bacterium
  • Urinary tract infection (UTI),
  • Pneumonia
  • Intra-abdominal infection,
  • Bloodstream infection (BSI),
  • Meningitis
  • Pyogenic liver abscess
  • Fever
  • Chills
  • Coughing
  • Yellow or bloody mucus
  • Shortness of breath
  • Chest pain
  • Burning while urination
Legionella L. pneumophila Gram- Negative
  • Thin pleomorphic
  • Flagellated
  • Non-spore forming
Legionnaires’ disease
  • Cough
  • shortness of breath
  • high fever
  • muscle pains, and headaches
  • Nausea, vomiting, and diarrhea may also occur.
Listeria L. monocytogenes Gram- Positive
  • Non-spore-forming
  • Motile
  • Rod-shaped bacterium.
  • Listerosis
  • Sepsis
  • Meningitis
  • Encephalitis
  • Intrauterine infections
  • Spontaneous abortions in pregnant women
  • Headache.
  • Stiff neck.
  • Confusion or changes in alertness.
  • Loss of balance.
  • Convulsions
Mycobacterium M. leprae Gram-Positive
  • Rod-shaped bacterium
  • Parallel sides and rounded ends
  • Hansen’s disease (Leprosy)
  • Discolored patches of skin, usually flat, that may be numb and look faded (lighter than the skin around)
  • Growths (nodules) on the skin.
  • Thick, stiff or dry skin
  • Painless ulcers on the soles of feet
  • Painless swelling or lumps on the face or earlobes.
  • Loss of eyebrows or eyelashes
Mycobacterium M. tuberculosis Gram- Positive
  • Non-motile
  • Large rod-shaped bacterium
  • Phelgm producing cough
  • Weight loss.
  • Night sweats.
  • High temperature.
  • Tiredness and fatigue.
  • Loss of appetite.
  • Swelling around the neck
Mycoplasma M. Pneumoniae Gram-Negative Elongated Shape or

  • spindle shaped pleomorphic bacterium
  • Mycoplasma pneumonia
  • Primary atypical pneumonia,
  • Tracheobronchitis and upper respiratory tract disease
  • sore throat and hoarseness,
  • fever
  • produce non-bloody sputum
  • in worst case causes ulceration and
Neisseria N. gonorrhoeae Gram- Negative
  • coccus which is present in pairs (diplococci) kidney/coffee bean shape
  • discharge from the vagina (watery, creamy, or slightly green)
  • Pain or burning sensation while urinating.
  • Heavier periods or spotting
  • Sore throat
  • pain during sexual intercourse
  • sharp pain in the lower abdomen
  • Fever
Neisseria N. meningitidis Gram-negative
  • Coffee-bean shaped diplococci
  • Meningitis
  • Meningococcemia
  • Fever and chills.
  • Fatigue (feeling tired)
  • Vomiting.
  • Cold hands and feet.
  • Severe aches or pain in the muscles, joints, chest, or abdomen (belly)
  • Rapid breathing.
  • Diarrhea.
Providencia P. Stuartii Gram- Negative
  • Straight rod
  • Flagellate bacterium
Urinary tract infections
  • Fever, dry mucous membranes, suprapubic tenderness, and flank pain in pyelonephritis
Pseudomonas P. aeruginosa Gram- Negative
  • Rod-shaped bacterium
  • Malignant external otitis
  • Endophthalmitis
  • Endocarditis
  • Meningitis
  • Pneumonia
  • Septicemia
  • Ears: pain and discharge.
  • Skin: rash, which can include pimples filled with pus.
  • Eyes:pain, redness, swelling.
  • Bones or joints: joint pain and swelling; neck or back pain that lasts weeks.
  • Wounds: green pus or discharge that may have a fruity smell.
  • Digestive tract: headache, diarrhea.


R. rickettsia Gram- Negative
  • Rod-shaped or variably spherical, non-filterable bacteria
  • Non-motile
  • Tibola
  • Lymphangitis-associated rickettsiosis
  • Epidemic typhus
  • Sylvatic typhus
  • Murine typhus
  • Sudden fever, chills, and headache
  • Malaise and myalgia
  • Nausea, vomiting
Salmonella Serotype Enteritidis S. Enteritidis Gram- Negative
  • Rod-shaped
  • non-motile bacteria
  • non- spore formation
  • Diarrhea, fever
  • Abdominal cramps
Salmonella enterica serotype typhi S. Typhi Gram- Negative
  • Enteric rod
  • Motile
Typhoid fever
  • Sustained fever
  • Weakness,
  • stomach pains
  • Headache, loss of appetite
Staphylococcus S. aureus Gram- Positive
  • Round-shaped bacterium
  • Impetigo
  • Boils
  • Cellulitis
  • Folliculitis
  • Carbuncles
  • Scalded skin syndrome
  • Abscesses
  • Pneumonia
  • Septic arthritis
  • Toxic shock syndrome
  • blisters, abscesses, and redness and swelling
  • fever, rash, dangerously low blood pressure
Streptococcus S. mutans Gram- Postive
  • Round bacterium
  • Appear in chains
  • Dental Carries
  • Bacteremia
  • Infective endocarditis
  • Fever, chills, sweats
  • Anorexia
  • weight loss,
  • Malaise
Streptococcus  S. Pneumoniae Gram-Positive
  • lancet-shaped
  • Non-Motile
  • 100 known serotypes
  • Pneumonia


  • Fever, Cough, shortness of breath, chest pain, stiff neck,
  • Confusion increased sensitivity to light, joint pain, chills, ear pain
  • Irritating behavior
  • In severe cases, hearing loss,
  • Brain damage, and death


S.pyogenes Gram- Positive
  • Round shaped (Cocci)
  • Extracellular
  • non-motile
  • non-sporing
  • Pharyngitis
  • tonsillitis
  • Scarlet fever
  • Cellulitis, erysipelas
  • Rheumatic fever,
  • Post-streptococcal glomerulonephritis
  • Necrotizing fasciitis
  • Myonecrosis
  • Lymphangitis.
  • Cough.
  • Rhinorrhea.
  • Hoarseness.
  • Oral ulcers.
  • Conjunctivitis
  • Body ache
  • Blur vision
  • High fever
  • Unable to gulp food
Treponema T. pallidum Gram- Negative
  • spirochete bacterium
  • helically coiled
  • Syphilis
  • Bejel
  • Yaws
  • Fever
  • Swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches, and fatigue
Vibrio V. Cholerae Gram-Negative
  • Highly Motile
  • Comma shaped
  • Profuse watery diarrhea,
  • Vomiting
  • Thirsty feeling
  • Leg Cramps
  • Restlessness or irritability
Yersinia Y. pestis Gram- Negative
  • Non-Motile
  • Coccobacillus bacterium
  • Without spores
  • Plague
  • Bubonic Plague
  • Pneumonic Plague
  • Fever, chills, head and body aches, and weakness, vomiting and nausea.

(“Table”) (“What Are the Five Pathogens?”)

(Diseases and Conditions – Mayo Clinic)

Works Cited

Ryan, Kenneth J., et al. “Pathogenesis of bacterial infections.” Sherris Medical Microbiology (6th ed.). New York: McGraw Hill Education (2014): 391.

Diseases and Conditions – Mayo Clinic. Accessed 2 Nov. 2021.

“Table: Classification of Common Pathogenic Bacteria.” MSD Manual Professional Edition, Accessed 25 Oct. 2021.

“What Are the Five Pathogens?” MedicineNet, Accessed 25 Oct. 2021.



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