RECTAL SWAB CULTURE

LAB3629

Collect in culturette.

The specimen should be submitted to the lab as soon as possibile after collection, preferably in less than 1 hour

sterile swab bactiswab

Set Up:Daily Report Available:3 days

Stool cultures and rectal swabs are done to discover an etiologic agent in patients with diarrhea and/or to define a bacterial carrier state. Enteric pathogens routinely screened in a culture include: Salmonella, Shigella, Campylobacter, Vibrio, and E coli 0157:H7. Also reported, if present, are a predominance of Staphylococcus aureus, yeast or beta streptococcus. Salmonella is a common agent of human diarrhea. Infections are usually acquired from lower animal sources (contaminated meat, milk, turtle feces, etc.). A relatively large inoculum (10(6) -10(9) organism) is needed to establish infection in healthy adults, but infants and other persons with poor host defenses can become infected with smaller inocula. The usual clinical presentation is one of a gastroenteritis, with or without bacteremia and fever. Shigella is commonly the cause of bacillary dysentery, a condition characterized by frequent passage of stools containing blood and mucus and accompanied by painful defecation. Extraintestinal infection is rare. The organism is highly communicable (less than 200 organisms can cause infection) and is usually spread person to person or by ingestion of contaminated food or water. Campylobacter jujuni is thought to be the single most common bacterial cause of human diarrhea. Most infections are a result of contact with contaminated animal feces, meat or milk, or from contact with infected human cases. The agent is easily transmitted and has a short incubation period (about 2 days). Infection typically presents as a diarrhea with abdominal cramping and occasionally, bloody stools. An inflammatory bowel disease (Crohns disease) presentation is also possible. Infection during pregnancy may result in septic abortion, stillbirth, or premature labor. Staphylococcus aureus can produce two diverse types of gastrointestinal problems. The organism can multiply in food, usually that which is prepared a long time in advance of being eaten and produce an enteric toxin. Ingestion of the contaminated food results in destruction of the Staphylococci in the stomach; but the enterotoxin produces a severe, but self-limiting diarrhea. This organism, rarely, can also produce a post-antibiotic infective colitis in patients whose normal fecal flora has been altered or destroyed by antibiotics not active against Staphylococci. Yersinia enterocolitica is an uncommonly encountered gastrointestinal pathogen which can cause a febrile diarrhea with intense pain that may be mistaken for peritonitis or appendicitis. Yersinia pseudotuberculosis infection is most likely to present as a mesenteric lymphadenitis. Vibrio cholerae is an easily transmissible enteric pathogen capable of producing illness and death due to dehydration and vomiting. Vibrio parahaemolyticus, which is usually acquired from eating contaminated seafood, induces an explosive watery diarrhea with cramping abdominal pain. Although fluid support is the most important aspect of therapy, use of tetracyclines may shorten the course of the disease. E coli 0157:H7 is an important enteric pathogen that causes a disease termed hemorrhagic colitis, characterized by severe abdominal pain with cramps, watery diarrhea followed by grossly bloody diarrhea and evidence of colonic inflammation but little or no fever. Rarely, use of broad spectrum antibiotic therapy can result in diarrhea due to overgrowth by yeast. Cancer patients and newborns are especially susceptible. Ulceration and pseudomembrane formation in the bowel are common findings in severe gastrointestinal Candidiasis.