Helicobacter pylori

Helicobacter pylori is a spiral-shaped bacterium causing peptic and gastric ulcers, linked to stomach cancer. It survives stomach acidity by producing urease, creating an alkaline environment. Spread via fecal-oral route, it induces inflammation in the gastric mucosa. Diagnosis involves invasive and non-invasive tests, treatment includes antibiotics and protein-pump inhibitors. Prevention focuses on hygiene.

SALMONELLA (S. TYPHI)

Salmonella Typhi, a Gram-negative rod, causes typhoid fever in humans, transmitted through contaminated food and water. Non-typhoid strains, like S. Typhimurium, cause gastrointestinal infections. Infections primarily spread via the fecal-oral route, and effective prevention includes good hygiene, proper food handling, and clean water. Treatment involves antibiotics and hydration.

RICKETTSIA PROWAZEKII

Rickettsia prowazekii is an obligate intracellular parasite causing epidemic typhus, primarily transmitted via lice bites. Symptoms include vasculitis, thrombosis, and systemic infections. Diagnosis involves serological tests and cell culture. Treatment includes chloramphenicol and tetracyclines; prevention focuses on vector control and hygiene. RMSF and Q fever are related rickettsial diseases.

STREPTOCOCCUS PYOGENES

Streptococcus pyogenes, a Group A Streptococcus, is a Gram-positive bacterium causing pharyngitis and various streptococcal diseases like scarlet fever, cellulitis, and necrotizing fasciitis. It produces numerous virulence factors including streptolysins and exotoxins. Diagnosis involves cultural, microscopic, and serological tests. Treatment includes antibiotics like penicillin, and no vaccines exist currently.

STAPHYLOCOCCUS AUREUS

Staphylococcus aureus, a Gram-positive bacterium, is often found in the nose and skin of humans. It causes various infections including pneumonia, gastroenteritis, and toxic shock syndrome, aided by its production of toxins and enzymes. Resistant strains like MRSA are prevalent. Prevention relies on hygiene practices, as vaccines are unavailable.