Overview
Escherichia coli enteritis is a common intestinal bacterial infectious disease in China, also known as pathogenic Escherichia coli infection. Escherichia coli enteritis is the second most common disease that causes diarrhea in patients, and the clinical manifestations vary depending on the type of infection, the site of invasion, and the body’s resistance, etc. In general, patients with mild forms of the disease mainly suffer from loss of appetite and diarrhea. In general, the clinical manifestations of light-type patients are mainly loss of appetite and diarrhea. In addition to the manifestations of light-type patients, medium-type patients are often accompanied by nausea, vomiting, mild dehydration and acidosis. Severe patients in addition to intestinal symptoms, often accompanied by moderate and severe dehydration and acidosis symptoms, and even acute renal failure. The treatment of Escherichia coli enteritis is mainly fluid therapy, anti-infection therapy and microecological therapy.
Causes
The cause of Escherichia coli enteritis is intestinal infection with pathogenic Escherichia coli. As a resident bacterium in the intestinal tract of both humans and animals, Escherichia coli is not normally pathogenic, but can cause intestinal infections under certain conditions, leading to Escherichia coli enteritis. Six pathogenic Escherichia coli types have been confirmed, including pathogenic Escherichia coli (EPEC), enterotoxigenic Escherichia coli (ETEC), hemorrhagic Escherichia coli (EHEC), invasive Escherichia coli (EIEC), E. coli agglomerans (EAggEC), and diffuse adherent Escherichia coli (EAEC). The causative bacterial type varies in different regions, and in China it is mainly enterotoxigenic Escherichia coli and pathogenic Escherichia coli. Escherichia coli enteritis is contagious, the source of infection is mainly patients with Escherichia coli enteritis and carriers of the pathogen, and the way of contagion is through direct contact with infected or ingested contaminated food or water, the disease can develop in all age groups.
Symptoms
The clinical manifestations of Escherichia coli enteritis vary according to the type of infection, the site of invasion and the resistance of the body.
(I) Enterotoxigenic Escherichia coli enteritis (ETEC)
Mostly occurs in summer. The incubation period is 1 to 2 days, and the onset of disease is rapid. Light-type patients have mild symptoms, which can be cured after several times of evacuation of loose stools. In more severe cases, fever, vomiting, frequent diarrhea and other symptoms, diarrhea in large quantities, stools are watery or egg-shaped, and some patients may suffer from dehydration, electrolyte disorders and acidosis. Severe patients with persistent high fever, diarrhea more than 10 times a day, often yellow-green watery stools, mostly accompanied by nausea, vomiting, vomiting, large amount of patients can appear obvious dehydration and acidosis symptoms, and even acute renal failure.
(B) Pathogenic Escherichia coli enteritis (EPEC)
The main clinical manifestations are similar to those of enterotoxigenic Escherichia coli enteritis, including abdominal pain, diarrhea, fever, nausea, vomiting, etc., and dehydration and acidosis may occur in severe cases.
(C) Invasive Escherichia coli enteritis (EIEC)
Invasive Escherichia coli enteritis has a more acute onset, and its performance is very similar to that of bacillary dysentery, which is mainly characterized by high fever, frequent diarrhea, and mucous stools with pus and blood and a fishy odor. Mostly accompanied by nausea, vomiting, acute and severe symptoms. Severe patients may have systemic toxic symptoms, and even shock.
(D) Hemorrhagic Escherichia coli enteritis (EHEC)
Hemorrhagic Escherichia coli enteritis has a long incubation period, and the clinical manifestations vary in severity, with mild diarrhea and abdominal pain in mild patients. Severe patients show severe abdominal pain, frequent diarrhea, yellow watery stools or blood-water stools, with a special odor. A small portion of infants and young children and elderly patients can be accompanied by hemolytic uremic syndrome and thrombocytopenic purpura.
(E) Adherent Escherichia coli enteritis (EAEC)
Adherent Escherichia coli enteritis acute performance and enterotoxigenic Escherichia coli enteritis similar, manifested as abdominal pain, diarrhea, fever, nausea, vomiting. Adherent Escherichia coli enteritis can cause prolonged diarrhea, diarrhea lasts more than 14 days, dehydration and acidosis symptoms can occur, and the later stage can cause intestinal malabsorption and malnutrition.
Examination
(I) Stool culture
Collect fresh feces with pus, blood or mucus for examination. Generally, BAP, SS, MAC/EMB medium can be used for culture. Escherichia coli are red colonies on MAC medium and purple-black colonies on EMB medium. If in line with the biochemical characteristics of Escherichia coli, it can be judged as Escherichia coli intestinal infection.
(B) Identification of bacterial type
The identification of enterotoxigenic Escherichia coli is mainly detected by ST and LT enterotoxins, and the commonly used methods include immunological methods such as Biken test, ELISA, staphylococcal paracoagulant test, DNA probes, PCR amplification and other genetic tests, as well as serum O:H typing.
Pathogenic Escherichia coli was identified mainly by serum O:H typing, DNA probes and PCR amplification. Pathogenic Escherichia coli were characterized by a positive eae gene test, a positive EAF plasmid test, and a negative enterotoxin test.
Invasive Escherichia coli was identified by serum O:H typing, virulence tests such as guinea pig cornea test and HEP-2 monolayer cell invasion test, and detection of invasive macroplasmids by DNA probe and PCR amplification. Invasive Escherichia coli enteritis is very similar to bacillary dysentery, but can be differentiated by sodium acetate, ammonium gluconate, and mucinate tests, which are all positive for invasive Escherichia coli and negative for Shigella.
The identification of hemorrhagic Escherichia coli is mainly through serum O157:H7 typing, as well as DNA probe and PCR amplification detection of stx gene, eae gene and pO157 plasmid.
The identification of aggregating Escherichia coli is mainly through HEP-2 cell adhesion test and EAggEC large plasmid detection.
Diagnosis
A history of direct contact with patients with Escherichia coli enteritis or carriers of the pathogen, as well as ingestion of contaminated water or food, with symptoms such as abdominal pain, diarrhea, nausea, vomiting, fever, dehydration and acidosis. Fecal isolation and culture of pathogenic Escherichia coli. The diagnosis is clear when the bacterial type is identified as a pathogenic Escherichia coli.
Treatment
The treatment principle of Escherichia coli enteritis is to prevent and correct dehydration, rationalize medication, strengthen nursing care, and prevent complications. The main treatment methods include fluid therapy, anti-infection therapy, microecological therapy and dietary therapy.
(I) Fluid therapy
Severe vomiting or diarrhea, due to more dehydration, should be rehydrated, through oral medication and intravenous rehydration methods, to correct water and electrolyte disorders, to prevent severe dehydration and acidosis.
(ii) Anti-infection treatment
According to the results of fecal bacterial culture and drug sensitivity test, sensitive antimicrobial drugs should be used for anti-infection treatment, commonly used drugs include doxycycline, compound sulfamethoxazole, norfloxacin, amikacin, polymyxin E, ampicillin, neomycin and so on.
(iii) Micro-ecological therapy
Microecological therapy is also a commonly used method nowadays. Oral probiotics can help restore the ecological balance of normal intestinal flora, inhibit the colonization and invasion of pathogenic bacteria and control diarrhea. Commonly used drugs include Bifidobacterium bifidum, Lactobacillus acidophilus, Streptococcus faecalis, and Bacillus aerobicus preparations.
(iv) Diet therapy
When diarrhea, feeding and absorption are reduced, while the recovery of intestinal mucosal injury, vigorous metabolism in fever, and loss of protein in invasive enteritis make the nutritional requirement increase. If the dietary restrictions are too strict or fasting for too long often results in malnutrition, complicating acidosis, which can lead to prolonged illness. Therefore, it should be emphasized to continue the diet to supplement the consumption of the disease, in order to shorten the recovery time after diarrhea. Food should be reasonably adjusted according to the disease condition, individual digestion and absorption function and eating habit. Those with severe vomiting can temporarily fast for 4-6 h (without water), and resume breast milk and the original already familiar diet as soon as possible. After the diarrhea stops, gradually resume a nutritious diet, and add meals once a day for 2 weeks.
Hazards
Escherichia coli enteritis may cause frequent diarrhea and vomiting, and in severe cases, dehydration and acidosis may occur, seriously affecting the patient’s daily life and work. If treatment is not timely, serious complications often occur, such as acidosis, hypokalemia, hemolytic uremic syndrome, etc. In severe cases, respiratory muscle paralysis, intestinal paralysis, cardiac arrhythmia, or even cardiac arrest, which is life-threatening. Severe infections can lead to death in infants and young children.