Bacterial Infections

Explanation: Klebsiella is responsible for developing penumonia in a chronic alcholic person

Endospore formation is seen in Clostridium difficile

Explanation -
Reactive arthritis occurs after following infection -
Genitourinary tract ( Chlamydia) 
Gastrointestinal tract ( Shigella,Salmonella,Yersinia,Camphylobacter) 

Explanation: Secondary pulmonary tuberculosis classically involves the apex of the upper lobes of one or both lungs

Explanation :
Bacterial spores are small oval or spherical structures that are very resistant to high temperatures, radiation, desiccation, and chemical agents.
When they are formed intracellularly, they are called endospore.
The bacterial cell producing spore is called vegetative cell.

Common organism of meningitis in neonate is E. coli

Explanation: proteus produces swarming growth. & produces alkaline urine that leads to stone formation.

All other are lesion in neurosyphilis

Explanation -
Chlamydia trachomatis causes -
Uretheritis,
Pneumonia
Conjunctivitis
Lymphogranuloma venereum
Trachoma.

Chlamydia is intracellular so can't be seen under microscope. & has flexible thin wall.

The source of transmission is humans with active tuberculosis who release mycobacteria present in sputum.

Most common location of secondary tuberculosis of lung is Apex

VDRL is Non-Specific antibody tests for syphilis

• Pseudomonas aeruginosa most commonly causes hospital-acquired infections

Most common types of tertiary disease are gumma (benign granulomatous lesion), cardiovascular syphilis (ascending aorta aneurysm) & symptomatic neurosyphilis (tabes dorsalis and paresis).

Explanation -
Transplacental transmission  :
Treponema pallidum
Listeria monocytogens
Cytomegalovirus 
Parbovirus B19
Rubella virus
Measles virus
HIV
Toxoplasma gondii 

Through birth canal :
Streptococcus agalactiae

Explanation :
Live bacterial vaccine -
BCG,Live cholera vaccine,Typhoid vaccine
Live viral vaccine -
MMR,Varicella,Influenza,Rota virus,OPV,Small pox, Adeno virus,Yellow fever vaccine.

Shallow and punched out ulcer is found in chancre

The most common cause of “traveler’s diarrhea” is Escherichia coli

Scenario reveals primary syphilis chancre which is painless.

E coli causes meningitis in neonate

Explanation: Gram-negative bacilli (Escherichia coli, Proteus) and Group B streptococci causes meningitis in neonate

Explanation: E.coli is the most common cause of UTI

• Infection by M. tuberculosis proceeds in steps, from initial infection of macrophages to a subsequent TH1 response that both contains the bacteria and causes tissue damage

Causes of acute pneumonias in the community include H. influenzae and M. catarrhalis (both associated with acute exacerbations of COPD), S. aureus (usually secondary to viral respiratory infections), K. pneumoniae (observed in patients who are chronic alcoholics), P. aeruginosa (seen in persons with cystic fibrosis, in burn victims, and in patients with neutropenia), and L. pneumophila, seen particularly in organ transplant recipients.

Explanation: WBC & nitrite in urine is suggestive of UTI

• S. pneumoniae (the pneumococcus) is the most common cause of community-acquired acute pneumonia; the distribution of inflammation is usually lobar.

Explanation: Tularaemia and spores of bacillus used as bioterrorism

Explanation :
Mycobacterium -
Rigid cell wall contain mycolic acid
M.fortuitum is rapid growing
Causes growth primarily in lungs

Explanation: Syphilis is caused by T.pallidum

Cellulitis is spreading infection & caused by S. Pyogens. Hyaluronidase is the spreading factor.

Explanation : Listeria causes more significant invasive infection , especially in pregnant women, older adults ( over 55 years ) and the immunocompromised.

Explanation: Streptococcus pneumoniae or pneumococcus is the most common cause of acute community-acquired pneumonia.

• When the vertebrae are affected, the disease is referred to as Pott disease.

• Secondary pulmonary tuberculosis classically involves the apex of the upper lobes of one or both lungs.

Pseudomembranous enterocolitis is caused by Cl. Difficile

IFN-γ is the critical mediator that enables macrophages to contain the M. tuberculosis infection.

Botulinum toxin block the release of acetylcholine & produces descending weakness & paralysis.

Explanation : M. Leprae has tropism for Schwann cells & skin macrophages.

Explanation :
Superantigen -
Enterotoxin of staphylococcus
Toxic shock syndrome toxin of s.aureus
All toxin of steptococcus
Enterotoxin of bacillus
Enterotoxin of clostridium.

Listeria monocytogenes most frequently causes Meningitis

Explanation :
Organism causes UTI :
E.coli (most common) 
Proteus
Staphylococcus saphrophyticus ( Young women)
Staph.epidermidis
Enterococcus
Klebsiella
Pseudomonas

• The term atypical organisms is used for Mycoplasma pneumoniae, Chlamydophila pneumoniae, Coxiella burnetii, and viruses (influenza viruses types A and B, human metapneumovirus)

Explanation: Campylobacter species have been linked to GBS & post infectious reactive arthritis.

Explanation: Streptococcus has several enzymes that helps for rapid spreading (hyaluronidase).

Explanation -
Streptococcus agalactiae or group B streptococcus (GBS), E.coli is 
well-known and common pathogenic agent of neonatal sepsis and meningitis caused by the colonization of the maternal birth canal.

The obligate intracellular bacteria Rickettsia prowazekii

Staphylococcus aureus causes Scalded skin syndrome

Explanation :
Most common cause of community acquired pneumonia -
Streptococcus pneumoniae
Nosochomial / hospital acquired pneumonia -
E.coli

Transplacental transmission occurs in Syphilis

The obligate intracellular bacteria Rickettsia prowazekii

Diseases caused by viridans streptococcus - Endocarditis

Explanation: H. pylori is Gram-negative and spiral, and has multiple flagella at one end, which make it motile, allowing it to burrow and live beneath the mucus layer adherent to the epithelial surface.

• The presence of numerous neutrophils containing the typical gram-positive, lancet-shaped diplococci supports the diagnosis of pneumococcal pneumonia

Explanation: Leptospirainterrogans persist indefinitely in the convoluted tubules of the kidney.

Explanation -
Bilateral planter extension found in- structural lesions such as hemorrhage, brain and spinal cord tumors, and multiple sclerosis, and in abnormal metabolic states such as hypoglycemia, hypoxia, and anesthesia,infection - meningitis,encephalitis.

Explanation -
Causes of acute monoarthritis :
Septic arthritis 
Gout
Pseudogout
Haemathroses
Trauma
Monoarticular presentation of polyarthritis

Explanation: Nearly all peptic ulcers are associated with H. pylori infection, NSAIDs or cigarette smoking. Among them H. pylori infection is most common

Explanation :
Toxin production by S.aureus -
Enterotoxin
Toxic shock syndrome toxin
Exfoliatin
Leukocidins

Bacterial zoonotic diseases Plague

• Lymphadenitis is the most frequent presentation of extrapulmonary tuberculosis, usually occurring in the cervical region (“scrofula”).