Definition: Known as enterics, this family contains some of the most pathogenic organisms involved in intestinal infections.
Characteristics:
Gram-negative straight rods, non-spore forming.
Ubiquitous in soil, water, and food sources (fruits, vegetables).
All members of the family ferment glucose, are catalase positive but oxidase negative.
They are often motile with flagella and not nutritionally fastidious.
They reduce nitrate to nitrite.
Pathogens categorized into two groups:
Frank Pathogens: Cause disease in healthy individuals. Major contributors to diarrhea and intestinal diseases globally.
Opportunistic Pathogens: Normally part of flora but can cause infections when the host is compromised.
Major Pathogenic Genera: Includes Salmonella, Shigella, Yersinia, and some Escherichia species.
Diarrhea: Liquid or soft stool characterizing frequent excretion.
Dysentery: Characterized by bloody, mucus-filled stools post frequent watery stools, often accompanied by abdominal pain and fever.
Enteritis: Inflammation of the intestine, linked with gastrointestinal symptoms.
Gastroenteritis: Involves both intestinal and stomach inflammation leading to symptoms like vomiting and diarrhea.
Enteric Fever: Acute illness presenting with fever, headache, and abdominal pain, sometimes involving bacteremia.
Causes dysentery-like symptoms without causing bloody diarrhea but may result in pus-filled stools.
Invasive, can penetrate intestinal cells leading to severe inflammation and discomfort.
Commonly found in childhood diarrhea outbreaks, especially in day care settings. Adheres to intestinal cells and destroys microvilli without invading.
Known as traveler's diarrhea; caused by contaminated food or water, leading to severe, watery diarrhea without blood.
High infectious dose required for symptoms to manifest, lasting typically 1-5 days.
An infectious strain defined by its strain type, notably E. coli O157:H7.
Associated with severe illness and can cause hemolytic uremic syndrome, potentially leading to kidney failure and death.
Transmission: Often linked to processed meats, unpasteurized dairy, or contaminated water sources.
Strains can be opportunistic or frank pathogens, depending on the context of infection and host condition.
Focus on safety measures in food preparation to prevent outbreaks of severe strains in casual dining settings.
Understanding the pathogenic characteristics of Enterobacteriaceae is key for diagnosis, treatment, and preventive measures in public health, especially concerning diarrheal diseases in children and individuals with compromised immune systems.