| Organism Genus Species | Gram Reaction | Morphology | Diseases Caused | Symptoms of Disease |
| 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 diarrhoea due to indigestion of the infected 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 the 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 where the microbe entered
- aches, nausea, and abdominal pain,
- malaise
|
| Bordetella | B. pertussis | Gram-Negative | - rod-shaped, coccoid
- Motile
| Respiratory infections 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 black-legged ticks | - fever, headache, fatigue
- It causes a skin rash called erythema migrans.
|
| Campylobacter | C. Jejuni | Gram- Negative | slender rods have one or more helical turns Motile common spirillum bacterium | Campylobacter or human gastroenteritis (Foodborne disease) | - inflammatory, sometimes bloody diarrhoea
- 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
Chlamydia - 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
| Botulism | - 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 diarrhoea and colitis (inflammation of the colon)
| - Watery diarrhoea ( 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 | | Food poisoning Diarrhea | diarrhoea and stomach cramps profuse vomiting (instant vomiting after intake of food) indigestion of food nausea |
| Clostridium | C. tetani | Gram-Positive | - Enlarged and tennis racket- or drumstick-shaped when forming spores
- Usually rod-shaped
- Motile with the help of flagella
| Tetanus | - 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
| Diphtheria | - 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, grey, white or green vaginal discharge.
- Foul-smelling “fishy” vaginal odour.
- Vaginal itching.
- Burning during urination.
|
| Haemophilus | H. influenzae | Gram-Negative | - bacilli or coccobacilli with random arrangements
- rod-shaped
| - Pneumonia
- Bloodstream infection.
- Meningitis.
- Epiglottitis
- 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 factors 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 diarrhoea may also occur.
|
| Listeria | L. monocytogenes | Gram- Positive | - Non-spore-forming
- Motile
- Rod-shaped bacterium.
| - Listeriosis
- 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)
| - Discoloured 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
| Tuberculosis | - Phlegm 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 the worst case, it causes ulceration and
|
| Neisseria | N. gonorrhoeae | Gram- Negative | - coccus, which is present in pairs (diplococci) kidney/coffee bean shape
| Gonorrhea | - 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 | | - 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, diarrhoea.
|
| Rickettsia | 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
| Gastroenteritis | - Diarrhea, fever
- Abdominal cramps
|
| Salmonella enterica serotype Typhi | S. Typhi | Gram- Negative | | Typhoid fever | - Sustained fever
- Weakness,
- stomach pains
- Headache, loss of appetite
|
| Staphylococcus | S. aureus | Gram- Positive | | - 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- Positive | - 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
| Meningitis | - Fever, Cough, shortness of breath, chest pain, stiff neck,
- Confusion increased sensitivity to light, joint pain, chills, ear pain
- Irritating behaviour
- In severe cases, hearing loss,
- Brain damage and death
|
| Streptococcus | 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
| | - 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
| Cholera | - Profuse watery diarrhoea,
- 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, weakness, vomiting and nausea.
|
