Salmonella

Classification

General Characteristics

Salmonella spp.

• Features:
  • Gram stain Gram stain Klebsiella and structure: gram-negative bacilli Bacilli Shigella
  • Motility Motility The motor activity of the gastrointestinal tract. Gastrointestinal Motility: motile and flagellated
  • Non-lactose-fermenting microbes; ferment glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance and mannose
  • Oxidase-negative bacilli Bacilli Shigella
  • Inactivated by acids Acids Chemical compounds which yield hydrogen ions or protons when dissolved in water, whose hydrogen can be replaced by metals or basic radicals, or which react with bases to form salts and water (neutralization). An extension of the term includes substances dissolved in media other than water. Acid-Base Balance
  • Ability to produce hydrogen sulfide (H₂S)
  • Growth medium:
    • Eosin methylene blue (EMB), MacConkey, or deoxycholate medium used to detect non-lactose-fermenting microbes
    • Selective for Salmonella-Shigella ( SS SS Scleroderma (systemic sclerosis) is an autoimmune condition characterized by diffuse collagen deposition and fibrosis. The clinical presentation varies from limited skin involvement to diffuse involvement of internal organs. Scleroderma): Hektoen enteric (HE) agar, SS SS Scleroderma (systemic sclerosis) is an autoimmune condition characterized by diffuse collagen deposition and fibrosis. The clinical presentation varies from limited skin involvement to diffuse involvement of internal organs. Scleroderma agar
• Associated diseases: typhoid Typhoid Typhoid (or enteric) fever is a severe, systemic bacterial infection classically caused by the facultative intracellular and Gram-negative bacilli Salmonella enterica serotype Typhi (S. Typhimurium, formerly S. typhi). S. paratyphi serotypes A, B, or C can cause a similar syndrome. Enteric Fever (Typhoid Fever) fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, gastroenteritis Gastroenteritis Gastroenteritis is inflammation of the stomach and intestines, commonly caused by infections from bacteria, viruses, or parasites. Transmission may be foodborne, fecal-oral, or through animal contact. Common clinical features include abdominal pain, diarrhea, vomiting, fever, and dehydration. Gastroenteritis/ enterocolitis Enterocolitis Inflammation of the mucosa of both the small intestine and the large intestine. Etiology includes ischemia, infections, allergic, and immune responses. Yersinia spp./Yersiniosis, bacteremia Bacteremia The presence of viable bacteria circulating in the blood. Fever, chills, tachycardia, and tachypnea are common acute manifestations of bacteremia. The majority of cases are seen in already hospitalized patients, most of whom have underlying diseases or procedures which render their bloodstreams susceptible to invasion. Glycopeptides

Clinically relevant species

Salmonella enterica is the primary species and has the following serotypes:

• Typhoidal (serotypes that cause typhoid Typhoid Typhoid (or enteric) fever is a severe, systemic bacterial infection classically caused by the facultative intracellular and Gram-negative bacilli Salmonella enterica serotype Typhi (S. Typhimurium, formerly S. typhi). S. paratyphi serotypes A, B, or C can cause a similar syndrome. Enteric Fever (Typhoid Fever) or enteric fever Enteric Fever Typhoid (or enteric) fever is a severe, systemic bacterial infection classically caused by the facultative intracellular and Gram-negative bacilli Salmonella enterica serotype Typhi (S. Typhimurium, formerly S. typhi). S. paratyphi serotypes A, B, or C can cause a similar syndrome. Enteric Fever (Typhoid Fever)):
  • S. enterica serotype typhi (formerly S. typhi)
  • S. paratyphi
• Nontyphoidal (all other serotypes associated with foodborne gastroenteritis Gastroenteritis Gastroenteritis is inflammation of the stomach and intestines, commonly caused by infections from bacteria, viruses, or parasites. Transmission may be foodborne, fecal-oral, or through animal contact. Common clinical features include abdominal pain, diarrhea, vomiting, fever, and dehydration. Gastroenteritis, most common in the United States):
  • S. enteritidis
  • S. typhimurium

Pathogenesis

Transmission and virulence Virulence The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its virulence factors. Proteus

• Reservoirs:
  • Typhoidal: human GI tract
  • Nontyphoidal:
    • Farm animals Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, animalia was one of the kingdoms. Under the modern three domain model, animalia represents one of the many groups in the domain eukaryota. Cell Types: Eukaryotic versus Prokaryotic: poultry, cattle, and pigs
    • Pets: turtles, parrots, rodents, cats, and dogs
• Transmission:
  • Fecal-oral route Fecal-oral route Echovirus
  • Ingestion of food products (commonly contaminated or undercooked foods, including poultry and eggs)
  • Infecting dose of S. enterica infection:
    • Varies with serotype
    • Considerably higher than Shigella Shigella Shigella is a genus of gram-negative, non-lactose-fermenting facultative intracellular bacilli. Infection spreads most commonly via person-to-person contact or through contaminated food and water. Humans are the only known reservoir. Shigella (human-to-human transmission by direct contact unlikely)
  • S. enterica is inactivated by acids Acids Chemical compounds which yield hydrogen ions or protons when dissolved in water, whose hydrogen can be replaced by metals or basic radicals, or which react with bases to form salts and water (neutralization). An extension of the term includes substances dissolved in media other than water. Acid-Base Balance. Smaller inocula can infect individuals on antacids or patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with achlorhydria Achlorhydria A lack of hydrochloric acid in gastric juice despite stimulation of gastric secretion. Gastritis.
• Virulence Virulence The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its virulence factors. Proteus:
  • Vi capsular polysaccharide antigen Antigen Substances that are recognized by the immune system and induce an immune reaction. Vaccination:
    • Surface polysaccharide in Salmonella typhi 
    • Interferes with phagocytosis Phagocytosis The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (phagocytes). Innate Immunity: Phagocytes and Antigen Presentation
  • H (flagellar) antigen Antigen Substances that are recognized by the immune system and induce an immune reaction. Vaccination: required for motility Motility The motor activity of the gastrointestinal tract. Gastrointestinal Motility
  • O ( lipopolysaccharide Lipopolysaccharide Lipid-containing polysaccharides which are endotoxins and important group-specific antigens. They are often derived from the cell wall of gram-negative bacteria and induce immunoglobulin secretion. The lipopolysaccharide molecule consists of three parts: lipid a, core polysaccharide, and o-specific chains (o antigens). When derived from Escherichia coli, lipopolysaccharides serve as polyclonal b-cell mitogens commonly used in laboratory immunology. Klebsiella) antigen Antigen Substances that are recognized by the immune system and induce an immune reaction. Vaccination: produces smooth colonies on agar
  • Pili:
    • Bind BIND Hyperbilirubinemia of the Newborn to D-mannose receptors Receptors Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors on eukaryotic Eukaryotic Eukaryotes can be single-celled or multicellular organisms and include plants, animals, fungi, and protozoa. Eukaryotic cells contain a well-organized nucleus contained by a membrane, along with other membrane-bound organelles. Cell Types: Eukaryotic versus Prokaryotic cell types
    • Similar to Escherichia coli Escherichia coli The gram-negative bacterium Escherichia coli is a key component of the human gut microbiota. Most strains of E. coli are avirulent, but occasionally they escape the GI tract, infecting the urinary tract and other sites. Less common strains of E. coli are able to cause disease within the GI tract, most commonly presenting as abdominal pain and diarrhea. Escherichia coli type 1 Type 1 Spinal Muscular Atrophy pili in function and morphology

Disease process

• Entry in humans via ingestion:
  • Some organisms survive gastric-acid exposure → small bowel Small bowel The small intestine is the longest part of the GI tract, extending from the pyloric orifice of the stomach to the ileocecal junction. The small intestine is the major organ responsible for chemical digestion and absorption of nutrients. It is divided into 3 segments: the duodenum, the jejunum, and the ileum. Small Intestine: Anatomy
  • From the lumen, Salmonella spp., mediated by their pili, can:
    • Penetrate M (microfold) cells of Peyer patches Patches Vitiligo (gut-associated lymphoid system)
    • Penetrate epithelial cells of the bowel
• In the bowel:
  • Organisms proliferate → Peyer patch Patch Nonpalpable lesion > 1 cm in diameter Generalized and Localized Rashes hyperplasia Hyperplasia An increase in the number of cells in a tissue or organ without tumor formation. It differs from hypertrophy, which is an increase in bulk without an increase in the number of cells. Cellular Adaptation and inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation ( fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, abdominal symptoms)
  • Salmonella spp. go further into the lamina propria Lamina propria Whipple’s Disease.
  • Proliferation leads to:
    • Further invasion and recruitment Recruitment Skeletal Muscle Contraction of mononuclear cells and lymphocytes Lymphocytes Lymphocytes are heterogeneous WBCs involved in immune response. Lymphocytes develop from the bone marrow, starting from hematopoietic stem cells (HSCs) and progressing to common lymphoid progenitors (CLPs). B and T lymphocytes and natural killer (NK) cells arise from the lineage. Lymphocytes: Histology → may cause ulcerations
    • Disruption of sodium Sodium A member of the alkali group of metals. It has the atomic symbol na, atomic number 11, and atomic weight 23. Hyponatremia and chloride Chloride Inorganic compounds derived from hydrochloric acid that contain the Cl- ion. Electrolytes transport between cells and intestinal lumen → diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea
• In severe cases:
  • Replication persists in the reticuloendothelial system → hepatosplenomegaly Hepatosplenomegaly Cytomegalovirus
  • Invading pathogens enter bloodstream → sepsis Sepsis Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock. Sepsis and Septic Shock

Diseases Caused by Salmonella

Typhoidal species (Salmonella typhi and paratyphi)

Typhoid Typhoid Typhoid (or enteric) fever is a severe, systemic bacterial infection classically caused by the facultative intracellular and Gram-negative bacilli Salmonella enterica serotype Typhi (S. Typhimurium, formerly S. typhi). S. paratyphi serotypes A, B, or C can cause a similar syndrome. Enteric Fever (Typhoid Fever) fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever or enteric fever Enteric Fever Typhoid (or enteric) fever is a severe, systemic bacterial infection classically caused by the facultative intracellular and Gram-negative bacilli Salmonella enterica serotype Typhi (S. Typhimurium, formerly S. typhi). S. paratyphi serotypes A, B, or C can cause a similar syndrome. Enteric Fever (Typhoid Fever):

• Description:
  • Severe systemic illness in which bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology enter the bloodstream and disseminate in organs and lymphoid tissue
  • More common in:
    • Children, young adults
    • Impoverished regions
    • Travelers (to endemic areas)
• Course of disease:
  • 1st week:
    • Gradually rising fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
    • Relative bradycardia Bradycardia Bradyarrhythmia is a rhythm in which the heart rate is less than 60/min. Bradyarrhythmia can be physiologic, without symptoms or hemodynamic change. Pathologic bradyarrhythmia results in reduced cardiac output and hemodynamic instability causing syncope, dizziness, or dyspnea. Bradyarrhythmias
    • Pulse-temperature dissociation Dissociation Defense Mechanisms
    • Constipation Constipation Constipation is common and may be due to a variety of causes. Constipation is generally defined as bowel movement frequency < 3 times per week. Patients who are constipated often strain to pass hard stools. The condition is classified as primary (also known as idiopathic or functional constipation) or secondary, and as acute or chronic. Constipation
  • 2nd week:
    • Persistent fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
    • Abdominal pain Abdominal Pain Acute Abdomen ( diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea or constipation Constipation Constipation is common and may be due to a variety of causes. Constipation is generally defined as bowel movement frequency < 3 times per week. Patients who are constipated often strain to pass hard stools. The condition is classified as primary (also known as idiopathic or functional constipation) or secondary, and as acute or chronic. Constipation)
    • Rose spots Rose spots Small, speckled, rose-colored exanthem most commonly on the lower chest/abdomen Enteric Fever (Typhoid Fever): salmon-colored macules (trunk)
  • 3rd week:
    • Ileocecal lymphatic hyperplasia Hyperplasia An increase in the number of cells in a tissue or organ without tumor formation. It differs from hypertrophy, which is an increase in bulk without an increase in the number of cells. Cellular Adaptation of Peyer patch Patch Nonpalpable lesion > 1 cm in diameter Generalized and Localized Rashes (can lead to perforation Perforation A pathological hole in an organ, blood vessel or other soft part of the body, occurring in the absence of external force. Esophagitis)
    • Peritonitis Peritonitis Inflammation of the peritoneum lining the abdominal cavity as the result of infectious, autoimmune, or chemical processes. Primary peritonitis is due to infection of the peritoneal cavity via hematogenous or lymphatic spread and without intra-abdominal source. Secondary peritonitis arises from the abdominal cavity itself through rupture or abscess of intra-abdominal organs. Penetrating Abdominal Injury
    • Bacteremia Bacteremia The presence of viable bacteria circulating in the blood. Fever, chills, tachycardia, and tachypnea are common acute manifestations of bacteremia. The majority of cases are seen in already hospitalized patients, most of whom have underlying diseases or procedures which render their bloodstreams susceptible to invasion. Glycopeptides
    • Intestinal bleeding
    • Hepatosplenomegaly Hepatosplenomegaly Cytomegalovirus
    • Altered mental status Altered Mental Status Sepsis in Children (toxic encephalopathy Encephalopathy Hyper-IgM Syndrome)
  • If no complications, symptoms resolve over weeks
• Treatment:
  • Fluoroquinolones Fluoroquinolones Fluoroquinolones are a group of broad-spectrum, bactericidal antibiotics inhibiting bacterial DNA replication. Fluoroquinolones cover gram-negative, anaerobic, and atypical organisms, as well as some gram-positive and multidrug-resistant (MDR) organisms. Fluoroquinolones (check susceptibility as resistance Resistance Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow. Ventilation: Mechanics of Breathing is a possibility)
  • Other options: azithromycin Azithromycin A semi-synthetic macrolide antibiotic structurally related to erythromycin. It has been used in the treatment of Mycobacterium avium intracellulare infections, toxoplasmosis, and cryptosporidiosis. Macrolides and Ketolides or 3rd-generation cephalosporins Cephalosporins Cephalosporins are a group of bactericidal beta-lactam antibiotics (similar to penicillins) that exert their effects by preventing bacteria from producing their cell walls, ultimately leading to cell death. Cephalosporins are categorized by generation and all drug names begin with “cef-” or “ceph-.” Cephalosporins
  • In severe systemic illness (e.g., delirium Delirium Delirium is a medical condition characterized by acute disturbances in attention and awareness. Symptoms may fluctuate during the course of a day and involve memory deficits and disorientation. Delirium, stupor): addition of dexamethasone Dexamethasone An anti-inflammatory 9-fluoro-glucocorticoid. Antiemetics

Chronic carrier Carrier Vaccination state:

• Description:
  • Excretion of Salmonella in stool or urine > 12 months post infection
  • More frequent in:
    • Women
    • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with cholelithiasis Cholelithiasis Cholelithiasis (gallstones) is the presence of stones in the gallbladder. Most gallstones are cholesterol stones, while the rest are composed of bilirubin (pigment stones) and other mixed components. Patients are commonly asymptomatic but may present with biliary colic (intermittent pain in the right upper quadrant). Cholelithiasis/biliary-tract disease (can ↑ risk of gallbladder cancer Gallbladder Cancer Cholecystectomy)
    • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with urinary tract Urinary tract The urinary tract is located in the abdomen and pelvis and consists of the kidneys, ureters, urinary bladder, and urethra. The structures permit the excretion of urine from the body. Urine flows from the kidneys through the ureters to the urinary bladder and out through the urethra. Urinary Tract: Anatomy abnormalities or Schistosoma Schistosoma Schistosomiasis is an infection caused by Schistosoma, a trematode. Schistosomiasis occurs in developing countries with poor sanitation. Freshwater snails are the intermediate host and are transmitted to humans through skin contact with contaminated fresh water. The clinical presentation occurs as a result of the host’s immune response to antigens from the eggs. Schistosoma/Schistosomiasis bladder Bladder A musculomembranous sac along the urinary tract. Urine flows from the kidneys into the bladder via the ureters, and is held there until urination. Pyelonephritis and Perinephric Abscess infection (rare)
• Course of disease:
  • Asymptomatic carriers Carriers The Cell: Cell Membrane
  • Carriers Carriers The Cell: Cell Membrane can transmit bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology in cases of improper handwashing.
  • High risk of transmission via foods (e.g., Mary Mallon, or “ Typhoid Typhoid Typhoid (or enteric) fever is a severe, systemic bacterial infection classically caused by the facultative intracellular and Gram-negative bacilli Salmonella enterica serotype Typhi (S. Typhimurium, formerly S. typhi). S. paratyphi serotypes A, B, or C can cause a similar syndrome. Enteric Fever (Typhoid Fever) Mary”)
• Treatment: 
  • Fluoroquinolone for 4 weeks (if susceptible)
  • Limited evidence with amoxicillin Amoxicillin A broad-spectrum semisynthetic antibiotic similar to ampicillin except that its resistance to gastric acid permits higher serum levels with oral administration. Penicillins and trimethoprim-sulfamethoxazole (TMP-SMX)
  • Cholecystectomy Cholecystectomy Cholecystectomy is a surgical procedure performed with the goal of resecting and extracting the gallbladder. It is one of the most common abdominal surgeries performed in the Western world. Cholecystectomy is performed for symptomatic cholelithiasis, cholecystitis, gallbladder polyps > 0.5 cm, porcelain gallbladder, choledocholithiasis and gallstone pancreatitis, and rarely, for gallbladder cancer. Cholecystectomy in some cases

Nontyphoidal species (Salmonella enteritidis and typhimurium)

Enterocolitis Enterocolitis Inflammation of the mucosa of both the small intestine and the large intestine. Etiology includes ischemia, infections, allergic, and immune responses. Yersinia spp./Yersiniosis/ gastroenteritis Gastroenteritis Gastroenteritis is inflammation of the stomach and intestines, commonly caused by infections from bacteria, viruses, or parasites. Transmission may be foodborne, fecal-oral, or through animal contact. Common clinical features include abdominal pain, diarrhea, vomiting, fever, and dehydration. Gastroenteritis:

• Description:
  • Most common presentation of Salmonella infection
  • Most common occurrence:
    • Consumption of poultry, eggs, and egg products (Salmonellae passed from chicken to eggs transovarially)
    • Consumption of contaminated water, meat, and other food products
    • Contact with animal reservoirs (especially pets) also increases the risk.
• Course of disease:
  • From 8–72 hours after exposure:
    • Nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics, vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia, fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
    • Abdominal pain Abdominal Pain Acute Abdomen and diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea
    • ↑ Ingested dose of bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology: ↑ severity and duration of illness
  • Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever resolves by the 3rd day.
  • Diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea can take up to 10 days to resolve.
  • Chronic carrier Carrier Vaccination state is rare (but may occur in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with gallstones Gallstones Cholelithiasis (gallstones) is the presence of stones in the gallbladder. Most gallstones are cholesterol stones, while the rest are composed of bilirubin (pigment stones) and other mixed components. Patients are commonly asymptomatic but may present with biliary colic (intermittent pain in the right upper quadrant). Cholelithiasis).
• Treatment:
  • Hydration and electrolyte replacement
  • For mild symptoms and immunocompetent patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship: antibiotics not used, disease is self-limiting Self-Limiting Meningitis in Children
  • For severe illness (e.g., diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea 9–10 times/day) and/or immunocompromised immunocompromised A human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation. Gastroenteritis individuals:
    • Fluoroquinolones Fluoroquinolones Fluoroquinolones are a group of broad-spectrum, bactericidal antibiotics inhibiting bacterial DNA replication. Fluoroquinolones cover gram-negative, anaerobic, and atypical organisms, as well as some gram-positive and multidrug-resistant (MDR) organisms. Fluoroquinolones (caution in children, may result in cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage: Histology abnormalities)
    • Other options: TMP-SMX, azithromycin Azithromycin A semi-synthetic macrolide antibiotic structurally related to erythromycin. It has been used in the treatment of Mycobacterium avium intracellulare infections, toxoplasmosis, and cryptosporidiosis. Macrolides and Ketolides, 3rd-generation cephalosporins Cephalosporins Cephalosporins are a group of bactericidal beta-lactam antibiotics (similar to penicillins) that exert their effects by preventing bacteria from producing their cell walls, ultimately leading to cell death. Cephalosporins are categorized by generation and all drug names begin with “cef-” or “ceph-.” Cephalosporins
  • For chronic carriers Carriers The Cell: Cell Membrane:
    • 4–6 weeks of antibiotics
    • Cholecystectomy Cholecystectomy Cholecystectomy is a surgical procedure performed with the goal of resecting and extracting the gallbladder. It is one of the most common abdominal surgeries performed in the Western world. Cholecystectomy is performed for symptomatic cholelithiasis, cholecystitis, gallbladder polyps > 0.5 cm, porcelain gallbladder, choledocholithiasis and gallstone pancreatitis, and rarely, for gallbladder cancer. Cholecystectomy in some cases

Bacteremia Bacteremia The presence of viable bacteria circulating in the blood. Fever, chills, tachycardia, and tachypnea are common acute manifestations of bacteremia. The majority of cases are seen in already hospitalized patients, most of whom have underlying diseases or procedures which render their bloodstreams susceptible to invasion. Glycopeptides:

• Description:
  • < 1% of Salmonella gastroenteritis Gastroenteritis Gastroenteritis is inflammation of the stomach and intestines, commonly caused by infections from bacteria, viruses, or parasites. Transmission may be foodborne, fecal-oral, or through animal contact. Common clinical features include abdominal pain, diarrhea, vomiting, fever, and dehydration. Gastroenteritis, with majority of bacteremia Bacteremia The presence of viable bacteria circulating in the blood. Fever, chills, tachycardia, and tachypnea are common acute manifestations of bacteremia. The majority of cases are seen in already hospitalized patients, most of whom have underlying diseases or procedures which render their bloodstreams susceptible to invasion. Glycopeptides cases in individuals < 5 years of age
  • Involves more invasive species (such as serotypes choleraesuis, heidelberg)
  • More common in:
    • Immunocompromised immunocompromised A human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation. Gastroenteritis patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship
    • Infants and the elderly
    • Hemoglobinopathies Hemoglobinopathies A group of inherited disorders characterized by structural alterations within the hemoglobin molecule. Anemia: Overview and Types
    • Schistosomiasis Schistosomiasis Infection with flukes (trematodes) of the genus schistosoma. Three species produce the most frequent clinical diseases: Schistosoma haematobium (endemic in Africa and the Middle East), Schistosoma Mansoni (in Egypt, northern and southern Africa, some West Indies islands, northern 2/3 of South america), and Schistosoma japonicum (in Japan, China, the Philippines, Celebes, Thailand, Laos). S. mansoni is often seen in Puerto Ricans living in the United States. Schistosoma/Schistosomiasis, malaria Malaria Malaria is an infectious parasitic disease affecting humans and other animals. Most commonly transmitted via the bite of a female Anopheles mosquito infected with microorganisms of the Plasmodium genus. Patients present with fever, chills, myalgia, headache, and diaphoresis. Plasmodium/Malaria
    • Chronic granulomatous disease Granulomatous disease A defect of leukocyte function in which phagocytic cells ingest but fail to digest bacteria, resulting in recurring bacterial infections with granuloma formation. When chronic granulomatous disease is caused by mutations in the cybb gene, the condition is inherited in an X-linked recessive pattern. When chronic granulomatous disease is caused by cyba, ncf1, ncf2, or ncf4 gene mutations, the condition is inherited in an autosomal recessive pattern. Common Variable Immunodeficiency (CVID)
• Course of disease: 
  • Can include septic arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis, endocarditis Endocarditis Endocarditis is an inflammatory disease involving the inner lining (endometrium) of the heart, most commonly affecting the cardiac valves. Both infectious and noninfectious etiologies lead to vegetations on the valve leaflets. Patients may present with nonspecific symptoms such as fever and fatigue. Endocarditis, osteomyelitis Osteomyelitis Osteomyelitis is an infection of the bone that results from the spread of microorganisms from the blood (hematogenous), nearby infected tissue, or open wounds (non-hematogenous). Infections are most commonly caused by Staphylococcus aureus. Osteomyelitis, and meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis
  • Endovascular infection (most common in abdominal aorta Abdominal Aorta The aorta from the diaphragm to the bifurcation into the right and left common iliac arteries. Posterior Abdominal Wall: Anatomy):
    • Rare but serious complication
    • Causes aneurysms and atherosclerotic plaques
• Treatment (longer course):
  • Fluoroquinolones Fluoroquinolones Fluoroquinolones are a group of broad-spectrum, bactericidal antibiotics inhibiting bacterial DNA replication. Fluoroquinolones cover gram-negative, anaerobic, and atypical organisms, as well as some gram-positive and multidrug-resistant (MDR) organisms. Fluoroquinolones
  • Alternatives: 3rd-generation cephalosporins Cephalosporins Cephalosporins are a group of bactericidal beta-lactam antibiotics (similar to penicillins) that exert their effects by preventing bacteria from producing their cell walls, ultimately leading to cell death. Cephalosporins are categorized by generation and all drug names begin with “cef-” or “ceph-.” Cephalosporins, TMP-SMX, ampicillin Ampicillin Semi-synthetic derivative of penicillin that functions as an orally active broad-spectrum antibiotic. Penicillins

Comparison with Shigella

Both Salmonella and Shigella Shigella Shigella is a genus of gram-negative, non-lactose-fermenting facultative intracellular bacilli. Infection spreads most commonly via person-to-person contact or through contaminated food and water. Humans are the only known reservoir. Shigella can invade the GI tract and cause diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea.