Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
The pistachio nut recall in March 2009 is only one example of numerous product recalls in recent years due to fears of contracting Salmonella food poisoning. Similarly, this year products processed by the Peanut Corporation of America (PCA) were found to be the source of a Salmonella outbreak. In 2008, an outbreak arose from the consumption of certain jalapeño and serrano peppers from Mexico. As these and numerous other outbreaks illustrate, virtually any food can become contaminated with one of the many species of Salmonella.
Salmonella is a bacterial infection that is passed to humans from animals, including poultry, cattle, pigs, and domestic animals. Eating undercooked poultry and drinking unpasteurized milk are among the ways humans can acquire the infection. But increasing media coverage has focused on vegetable products as the source of many Salmonella outbreaks. When vegetables or fruits are the source of an outbreak, it means that these products have been handled unsafely, such as processing or preparation on surfaces that have become contaminated with animal feces or raw poultry. Another way for vegetables to become contaminated is by an infected food handler.
Salmonella (S.) is the genus name for a large number (over 2,500) of types of
bacteria. Each type is distinctly identifiable by its specific protein
coating. The types are otherwise closely related. Salmonella bacteria are rod-shaped,
flagellated, Gram stain-negative, and are known to cause disease in humans,
animals, and birds (especially poultry) worldwide. The two major diseases caused by
Salmonella spp. are gastroenteritis and typhoid fever (typhoid and paratyphoid fevers) in humans.
The terminology that identifies the particular protein coats, or serovars, is not well settled, and what previously were thought to be various species of the genus
Salmonella are now thought to be serovars of only two species, S. enterica and
S. bongori, by many researchers. However, these designations are not always accepted in the scientific literature. and so common serovars that have been named in the past are still used (for example,
S. typhi, S. typhimurium, S. paratyphi, S. enteritidis, S. cholerasuis, S. saintpaul). Minor variations in some serovars are termed subspecies and assigned a number. The serovars are identified by the Kauffman-White classification that uses two major types of antigens (somatic O, along with envelope antigens that may mask O antigens, and flagellar or H antigens) to distinguish the over 2,500 types of
Salmonella bacteria. Sometimes laboratories or other reporting agencies identify isolates simply as
Salmonella spp. (species) and do not identify the serovars. Nomenclature of these closely related bacteria is likely to remain in flux, even in the current literature.
The bacteria were first
isolated by Theobald Smith in 1885 from pigs. The genus name Salmonella was
derived from the last name of D.E. Salmon, who was Smith's director. In 1896, diagnosis of
Salmonella spp. infection in humans was accomplished.
What are Salmonella poisoning symptoms?
Salmonellosis (gastroenteritis characterized by nausea, vomiting, and
diarrhea) is the most common disease caused by the organisms. Abdominal cramping also may occur. Salmonellosis thus produces the symptoms that are commonly referred to as food poisoning. Although food poisoning is usually a mild disease,
the nausea, vomiting, and diarrhea can lead to dehydration and even death (about 500 per year in the U.S.). It is important to note that many other organisms (for example, viruses,
E. coli, Shigella) and toxins (for example, botulism, mushroom toxin,
or pesticides) can produce food poisoning symptoms. However, over 1.4 million cases of salmonellosis occur per year
in the U.S., and the rest of industrialized countries have similar high rates. Countries with poor sanitation have a much higher incidence of
salmonellosis. Unfortunately, the above symptoms can occur with many types of infectious organisms such as
Shigella, Staphylococcus, Campylobacter, some additional bacteria, viruses, and protozoa.
Typhoid fever occurs when some of the Salmonella organisms (often identified as
Salmonella typhi or S. typhi) are not killed by the normal human immune defenses (macrophage cells) after they enter the gastrointestinal tract. Salmonella then survive and grow in the human spleen, liver, and other organs
and may reach the blood (bacteremia). Salmonella can be shed from the
liver to the gallbladder, where they can continue to survive and be
secreted into the patient's feces for up to a year. Symptoms of typhoid include
high fevers up to 104 F, sweating, inflammation of the stomach and
intestines, and diarrhea. Symptoms usually resolve, but many patients
become Salmonella carriers. Approximately half of patients develop
slow heartbeat (bradycardia), and about 30% of patients get flat,
slightly raised red or rose-colored spots on the chest and abdomen.
Typhoid fever is also referred to as enteric fever.
Paratyphoid fever, like typhoid fever, is also termed enteric fever. Paratyphoid fever has symptoms like typhoid, but it's usually not as severe. Subtypes are A, B, and C and vary by having small changes in symptoms, such as more rose spots (A), gastroenteritis in conjunction with herpes labialis and gastroenteritis (B), rarely, with septicemia and abscesses (C). S. paratyphi is the organism that causes this disease.
Gastroenteritis (viral gastroenteritis, stomach flu) is an infection caused by a variety of viruses that results in vomiting and/or diarrhea. Even though it is often called the "stomach flu," it is not caused by the influenza viruses. Viruses that can cause gastroenteritis (stomach flu) include: rotaviruses, adenoviruses, caliciviruses, astroviruses, Norwalk virus, and a group of Noroviruses. Gastroenteritis is not caused by bacteria. The main symptoms of gastroenteritis include vomiting and watery diarrhea, however, headache, fever, and abdominal cramps (stomach ache) may also be present.
Diarrhea is a change is the frequency and looseness of bowel movements. Cramping, abdominal pain, and the sensation of rectal urgency are all symptoms of diarrhea. Absorbents and anti-motility medications are used to treat diarrhea.
There are many symptoms involved in the 1st, 2nd and 3rd trimesters of pregnancy. The first early pregnancy symptom is typically a missed period, but others include breast swelling and tenderness, nausea and sometimes vomiting, fatigue and bloating. Second trimester symptoms include backache, weight gain, itching, and possible stretch marks. Third trimester symptoms are additional weight gain, heartburn, hemorrhoids, swelling of the ankles, fingers, and face, breast tenderness, and trouble sleeping. Read more to learn about recommended procedures and tests for each stage of a healthy pregnancy.
Dehydration is the excessive loss of body water. There are a number of causes of dehydration including heat exposure, prolonged vigorous exercise, and some diseases of the gastrointestinal tract. The best way to treat dehydration is to prevent it from occurring.
Nausea is an uneasiness of the stomach that often precedes vomiting. Nausea and vomiting are not diseases, but they are symptoms of many conditions. The causes of vomiting differ according to age, and treatment depends upon the cause of nausea and vomiting.
Although a fever technically is any body temperature above the normal of 98.6 degrees F. (37 degrees C.), in practice a person is usually not considered to have a significant fever until the temperature is above 100.4 degrees F (38 degrees C.). Fever is part of the body's own disease-fighting arsenal: rising body temperatures apparently are capable of killing off many disease- producing organisms.
Sepsis (blood poisoning) is a potentially deadly infection with signs and symptoms that include elevated heart rate, low or high temperature, rapid breathing and/or a white blood cell count that is too high or too low and has more than 10% band cells. Most cases of sepsis are caused by bacterial infections, and some cases are caused by fungal infections. Treatment requires hospitalization, IV antibiotics, and therapy to treat any organ dysfunction.
Typhoid fever is an illness caused by the Salmonella typhi bacteria. The illness is contracted by ingesting the bacteria in contaminated water or food. Symptoms include headaches, fever, diarrhea, lethargy, aches and pains, and poor appetite. Treatment focuses on killing the Salmonella bacteria with antibiotics.
Food poisoning is common, but can also be life threatening. The most common form of food poisoning is caused by bacteria and include symptoms such as fever, abdominal pain, diarrhea, nausea and vomiting.
Inflammation of the inner lining of the colon is referred to as colitis. Symptoms of the inflammation of the colon lining include diarrhea, pain, and blood in the stool. There are several causes of colitis including infection, ischemia of the colon, inflammatory bowel disease (Crohn's disease, Ulcerative colitis, or microscopic colitis). Treatment depends on the cause of the colitis.
Septic arthritis, or infectious arthritis, is infection of one or more joints by bacteria, viruses, or fungi. Symptoms and signs of septic arthritis include fever, joint pain, chills, swelling, redness, warmth, and stiffness. Treatment involves antibiotics and the drainage of the infected joint.
Shigellosis is a disease caused by the Shigella bacteria. Bloody diarrhea, stomach cramps and fever are common symptoms. Mild infections usually resolve on their own. Antibiotics are used to treat more severe cases.
Drug resistance (antimicrobial resistance) is the ability of bacteria, fungi, parasites, and viruses to grow, even in the presence of a drug that would normally kill it (or limit it's growth). Drug resistance is a growing problem, particularly for infections such as MRSA, VRE (vancomycin-resistant enterococci), tuberculosis, HIV, STDs, gonorrhea, flu, pneumonia, malaria, E. coli, salmonella, Campylobacter, which causes diarrhea and gastroenteritis. Learn how to protect yourself from resistance to drugs.
Bioterrorism is a form of terrorism where there is the intentional release of biological agents such as viruses, germs, or bacteria. Diseases caused by bioterrorism agents include anthrax, botulism, plague, smallpox, tularemia, brucellosis, food poisoning, Q fever, ricin toxin poisoning, cholera, epidemic typhus, viral encephalitis, XDR TB, and MDR TB.
Enterovirulent Escherichia coli (E. coli) are strains of related bacteria that have a strong propensity to cause gastrointestinal tract infections. Examples of strains include: EHEC (enterohemorrhagic E. coli), ETEC (enterotoxigenic E. coli), EPEC (enteropathogenic E. coli), EIEC (enteroinvasive E. coli), EAEC (enteroadherent E. coli), and EAggEC (enteroaggregative E. coli). Symptoms may vary depending on the strain the individual contracts. Infection is spread generally through contaminated food or drink.
Colitis is inflammation of the inner lining of the colon and is associated with
diarrhea,
pain, and
blood in the stool. There are
numerous reasons for the colon to become inflamed including:
infection,
loss of blood
supply to the colon,
inflammatory bowel disease, and
invasion of the colon wall
with collagen or
lymphocytic white blood cells.
Anatomy of the colon
The colon is
a hollow, muscular tube that receives products of digestion from the small intestine and
ultimately eliminates them from the body through the anus. The colon is
located in the abdomen and has numerous sections that are named based on their location.
Colitis can affect different sections of the colon.
The colon begins in the
right lower abdomen with the cecum
(located just above the appendix) into which the
products of digestion empty from the small intestin...
The pistachio nut recall in March 2009 is only one example of numerous 
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