Stool Culture

Gastroenteritis and bacterial diarrhea are the most common forms of infections that occur both in children and adults. These infections are predominant in tropical regions. The most common etiology for diarrhea is either through parasitic infections or bacterial infections. Both these forms have distinctive clinical characteristics. The identification of the type of disease caused can provide a comprehensive route to differentiate and treat the disease through appropriate anti-parasitic or anti-microbial drugs.

Clinical symptoms

Gastroenteritis or enteric fever identification is characterized by abdominal discomfort, diarrhea and extreme dehydration. In most cases, these kinds of infections occur because of food or water borne contamination. The differential diagnosis of this condition in order to identify the disease is done through additional clinical symptoms, physiological changes and bio-chemical metabolic pathways. One of the most important factors in the identification of bacterial enteric fever is the presence of associated sepsis and spiking fever. In addition to this, in epidemic and highly infectious diseases like Cholera, caused by Vibrio cholera, the cyclic AMP(adenosine mono phosphate) levels are elevated leading to intense dehydration which can be fatal if left unattended.

Diagnosis

In case of bacterial enteric fever or associated diarrheas, stool specimens help understand and identify the type of organism causing the disease. Stool specimens are collected by patients in sterile container and the areas of stool in which blood and mucous are present are used for processing as they are useful portions of the specimen. The obtained media is usually transported by incorporating a transport media to avoid bacterial count decline because of varied PH of the external environment.

Microbiological media such as Selenite feces broth, Mackonkey agar, Salmonella Shigella agar, TCBS medium and Nagglers medium are used in the culture laboratory to identify disease causing organisms such as Salmonella(Typhoid, enteric fever) Shigella( Diarrhea) E.coli 0167or entero - hemorrhagic (Traveler's Diarrhea), Clostridium Botulinum(Food poisoning), Vibrio cholera( Cholera) and Campylobacter.

Apart from these bacteria, stool cultures are also done to identify the presence of enteric viruses such as Rota virus which causes viral gastroenteritis. All organisms isolated are subjected to respective antimicrobial assay to determine the suitable drugs for the respective organism. Careful precautions are taken and clinical details of the patient are recorded by the microbiologist to administer specific drugs for specific organisms. This helps to prescribe medications to specific persons too, such as pregnant and lactating women and children.

Diarrhea

Diarrhea is a common illness caused worldwide. It is caused due to various reasons; infectious organisms such as bacteria, viruses and parasites of intestinal origin. The predominant clinical factor with respect to diarrhea is the onset of vomiting and fever causing extreme dehydration which is fatal and sometimes life threatening.

Bacterial diarrhea: In this case, bacteria such as Salmonella and Shigella and enterogenic E.coli cause damage to the intestinal wall causing more bowel movements and enteric fever. The diagnosis of bacterial diarrhea is done by stool culture and by serological analysis in case of Salmonella induced fever.

Viral Diarrhea: Viral diarrhea is most commonly noticed in children and it is usually self limiting after a period of four to five days. Symptoms include weakness, fever, irritability and sometimes vomiting.

Parasites: Intestinal parasites especially protozoan such as Giardia, Entamoeba and cryptosporidium cause diarrhea. Some are zoonotic on origin and mostly caused by feco-oral route.

Drug Induced: Diarrhea can also be caused because of the administration of certain type drugs such as antibiotics, anticancer and magnesium containing antacids.

Food allergies: Food induced diarrhea is common with those who eat at various places often. Some people are lactose intolerant and consumption of any diary product may induce diarrhea.

Treatment of Diarrhea

Diarrhea can be fatal if untreated. The most common form of treatment is through fluid replacement, rest and consumption of probiotics during the administration of antibiotics. Anti-parasitic drugs and antibiotics are most often prescribed. The WHO recommends ORS solutions in case children and adults as the preliminary step towards treatment and prevention of dehydration.

E Coli

E Coli is a bacterium that lives in the digestive tract of humans and animals. It is generally present in the gut of warm blooded animals. Excluding the strain E coli 0157:H7, the rest of the strains are understood to be harmless. The aforementioned strain causes severe diarrhea. There are a few strains that can cause urinary tract infections or other kinds of infections. Though not diagnosed and reported as often, E coli can occur in adults as well as in children of any age group. The infection can be very severe in old people and young children. E coli infection settles down on its own within 10 days from the onset of the condition; however in a few cases it may get life threatening.

• E-coli infection is contracted when a person comes in contact with the stool or feces of a human who is the carrier of the infectious strain.
  
  
• E coli can also spread from person to person. When an infected person does not wash his/her hands properly and thoroughly after bowel movement, and touches another person's hand or objects there are chances of infection spread.
  
  
• Raw meat, fruits, vegetables and milk can be contaminated by E coli. They can be the carriers of the bacteria.
  
  
• Water is another major source of E coli bacteria. When feces of the infected person get into water bodies, the water gets contaminated and if it consumed without proper purification it can spread the bacteria.

E coli symptoms

Symptoms show up in 3-4 days after coming in contact with the infection source. Common symptoms reported include blood in the stool, bloody diarrhea, nausea, vomiting and stomach cramps. But the symptoms mentioned here are broad and they do not necessarily indicate the specific symptoms of E coli. In severe cases, symptoms may include fever, bruising, minimal urine output and pale skin.

E coli can be diagnosed through stool culture. In general the condition settles down on its own. Sipping water frequently helps the body to recover from dehydration. Do not indulge in self treatment as anti diarrhea pills at this stage may slow down the recovery. In severe cases of infection, blood transfusion and dialysis is suggested.

E coli prevention

• Drink only treated, purified and chlorinated water.
  
• Avoid eating raw fruits and vegetables while traveling out.
  
• Avoid drinking water from outside taps.
  
• Avoid consuming pink hamburger.
  
• Avoid using ice cubes from unclean sources.
  
• Defrost meat in oven or in the refrigerator, do not allow it to defrost on its own over the counter.
  
• Cook all types of beef at 160 degrees F.
  
• Do not taste raw ground beef while cooking.
  
• Do not transfer cooked beef to a plate that had raw beef before.
  
• Wash your hands thoroughly with soap and water after using the bathroom.
  
• In the kitchen wash your hands thoroughly with warm water and soap particularly after handling meat products.
  
• Always store raw meat, poultry and other food items separately.
  
• Use pasteurized milk and dairy products.
  
• Do not drink water without boiling it.
  
• Refrigerate left over food immediately if you plan to consume it again.