Proteus food poisoning

　　1. Etiology

　　Deformans are Gram-negative bacilli of the Enterobacteriaceae family, presenting polymorphic shapes, with flagella all over the body, no spores, no capsules, and active motility. They are facultative anaerobes with low nutritional requirements, and can grow on both nutrient agar and blood agar. The optimal growth temperature is 10-43°C. Their colonies often have a crawling characteristic, do not form single colonies, and can form single colonies when the agar content is increased to 5%. There is hemolysis on blood agar plates. Biochemical characteristics include positive hydrogen sulfide, positive phenylalanine deaminase, and strong positive urease. Antigenic structures include somatic (O) and flagellar (H) antigens. Deformans are classified into: Proteus vulgaris, Proteus mirabilis, Proteus myxofaciens, and Proteus penneri, based on differences in antigens and biochemical properties. The first three are mainly responsible for food poisoning.

　　2、Pathogenesis

　　The onset and severity of the disease are related to the number of bacteria ingested (it is generally considered to be above 10^5 per gram), the toxins produced, and the body's defense function, among other factors. The pathogenicity of Proteus is mainly due to the enterotoxin produced by the bacteria. Proteus can produce a cell-bound hemolytic factor with good adhesion and strong invasive force on human migrating cells. Some strains can produce alpha hemolysin with cytotoxic effects. Proteus can also produce histidine decarboxylase, which can convert histidine in meat into histamine, and the intake of histamine exceeding 100mg can cause allergic symptoms similar to histamine poisoning.

　　Severe dehydration and acidosis, even shock and heart failure, may occur as serious complications. Light or moderate dehydration and metabolic poisoning are often accompanied. In some cases, there may be symptoms of upper respiratory tract infection before gastrointestinal symptoms appear. This disease is self-limiting, with a course of about one week. However, a few children may still have poor absorption of disaccharides, especially lactose, in a short period of time, and diarrhea may last for several weeks, with some cases lasting up to several months.

　　A preliminary diagnosis can be made based on the consumption of suspected food, collective onset among co-eaters, and clinical manifestations. Food poisoning caused by Proteus may be due to the different types, quantities, and metabolic products of the bacteria in the food, resulting in different symptoms. Common types include gastroenteritis and allergic types, or both may be present in the same patient.

　　The incubation period of the gastroenteritis type is 3 to 20 hours, with an abrupt onset, nausea, vomiting, abdominal pain, diarrhea, watery diarrhea with mucus, foul smell, no pus or blood, occurring several to more than ten times a day. One-third to one-half of the patients have gastrointestinal symptoms followed by fever and chills, which lasts for several hours and then decreases. Severe cases may have dehydration or shock.

　　The incubation period of the allergic type is 1/2 to 2 hours, characterized by general congestion, flushed face, drunken appearance, pruritus all over the body, mild gastrointestinal symptoms, and a few patients may develop urticaria.

　　Since Proteus can parasitize in the normal human intestinal tract and food can also be contaminated by Proteus, when suspected of Proteus food poisoning, the suspected food, vomit, and feces should be cultured for bacteria, which can isolate the same type of Proteus. The isolated Proteus must be tested for hemagglutination to confirm. The agglutination titer of ordinary Proteus to OX19 and Proteus mirabilis to OXK should increase by more than 4 times to make a definite diagnosis. If an indirect hemagglutination test is performed, the sensitivity can be increased by 2 to 16 times. In recent years, a rapid synchronous qualitative and quantitative detection method - UPS method has been established for the biochemical characteristics of Proteus on urea (urea), phenylalanine (phenylalanine), and hydrogen sulfide (hydrogensulfide). The correct identification rate is 100%, the sensitivity is 100 times higher than that of the spreading growth observation method in the past, the reporting time has been reduced from 4 to 15 days to 4 to 24 hours, and it has high precision and strong specificity, not affected by the type of sample and other factors.

　　How to prevent Proteus food poisoning

　　What laboratory tests are needed for Proteus food poisoning

　　1. Take the patient's serum during the acute and convalescent stages (12-15 days after poisoning) and use the isolated strain to measure the serum agglutination titer. If the titer during the convalescent stage is four times higher than that during the acute stage, it has diagnostic significance. At the same time, healthy people should be used as controls, which should be negative. 2. Collect suspicious food, vomit, and feces for bacterial culture, and the same type of Proteus can be isolated. The isolated Proteus must be tested for hemagglutination to confirm. The agglutination titer of common Proteus to OX19 and atypical Proteus to OXK should increase by more than 4 times to make a definite diagnosis. If indirect hemagglutination tests are performed, the sensitivity can be increased by 2-16 times. In recent years, a rapid synchronous qualitative and quantitative detection method - UPS method has been established based on the biochemical characteristics of Proteus to urea (urea), phenylalanine (phenylalanine), and hydrogen sulfide (hydrogensulfide), with a correct identification rate of 100%.

　　Buy pasteurized milk instead of raw milk, and fruits and vegetables must be washed clean; food must be thoroughly heated, and the temperature of all parts of the food must reach above 70℃; the storage time of cooked food should not be too long, and it is best to eat it as soon as it is taken off the stove; store cooked food properly, and store it at a temperature above 60℃ or below 10℃; reheat the stored cooked food thoroughly before eating, ensuring that all parts reach above 70℃; avoid contact between cooked and raw food; separate the knives, cutting boards, and other utensils used for raw and cooked food to prevent cross-contamination; wash hands, and wash hands again before and after processing food; keep kitchen utensils and the kitchen clean, and the surfaces of all utensils used to prepare food must be kept absolutely clean; change the towels every day and boil them for disinfection before reuse; avoid contact between insects, rodents, and other animals with food; drink safe and hygienic water and do not drink raw water.

　　1. Drug treatment

　　1. Gastroenteritis type

　　(1) Symptomatic treatment: The disease is mostly self-limiting and can recover spontaneously within one or two days without treatment. If vomiting and diarrhea are severe, rehydration and antispasmodic agents may be administered.

　　(2) Antibacterial drug treatment: For severe cases, norfloxacin 0.2g/time, 4 times/day, or chloramphenicol 0.25-0.5g/time, 4 times/day, taken orally, may be selected.

　　(3) Allergic type is mainly treated with antihistamines, such as chlorpheniramine 4mg/time, 3 times/day, taken orally. For severe cases, hydrocortisone or dexamethasone intravenous infusion may be used.

　　(4) In cases of severe abdominal pain, antispasmodic analgesics such as atropine and belladonna can be used for treatment.

　　(5) In cases of severe vomiting, antivomiting drugs such as chlorpromazine, atropine, metoclopramide, and胃复安 can be used for treatment.

　　(6) In cases of severe diarrhea, antidiarrheal drugs such as bismuth subcarbonate, activated carbon, tannic acid protein, and Compound Camphor Liniment can be used for treatment.

　　(7) In cases of high fever, physical cooling or antipyretic analgesics such as aspirin and paracetamol can be taken for treatment.

　　(8) In cases of dehydration and acidosis, timely intravenous fluid administration should be performed to correct the imbalance of water and electrolytes and acid-base balance.

　　(9) Pay attention to prevent serious complications such as shock and heart failure.

　　Second, traditional Chinese medicine treatment methods for food poisoning caused by Proteus mirabilis

　　1. Damp-heat in the gastrointestinal tract

      Nausea and vomiting, stuffy epigastric pain and abdominal pain, urgent diarrhea, or not feeling comfortable after defecation, yellow-brown feces with foul smell, burning sensation around the anus, restless and thirsty, short and yellow urine, red tongue with yellow greasy coating, slippery and rapid or slippery and rapid pulse. Clear heat and remove dampness. Add ingredients such as the Decoction for Burning Light or the Decoction of Silkworm faeces.

　　2. Cold and dampness in the intestines

      Diarrhea with clear fluid, even like water, abdominal pain and intestinal rumbling, stuffy feeling in the chest and reduced appetite, or accompanied by chills and fever, white greasy coating on the tongue, soft and slow pulse. Disperse cold and remove dampness. Add ingredients such as Herba Agastaches to the Powder for Harmonizing the Middle Jiao and Promoting Vitality, or add Herba Agastaches and Radix Aucklandiae to the Decoction of Gastrodia and Poria.

　　3. Food retention in the gastrointestinal tract

      Vomiting sour and putrid substances, loss of appetite, abdominal pain and diarrhea, flatus with foul smell, intestinal rumbling, pain reduced after defecation, feces smelling like rotten eggs, nausea and vomiting, abdominal distension, greasy or thick coating on the tongue, slippery pulse, reduce food retention and promote digestion. Combine the Pill for Harmonizing the Middle Jiao with the Pill for Promoting Bowel Movement and Reducing Retention of Food.

　　4. Deficiency of Yin and Qi

      Vomiting and diarrhea, thirst and desire for drinks, fatigue and shortness of breath, dry and sunken skin, sunken eyes, red tongue with dry coating, fine and rapid pulse without root. Tonify Qi and generate fluid. Add ingredients such as yam, Dendrobium, Prunus mume, and white peony to the Powder for Generating Qi and Nourishing Fluid.

　　5. Yang deficiency syndrome

      Loose stools, slippery and uncontrollable, nausea and vomiting, pale complexion, cold extremities, drenched with cold sweat, confused spirit, pale tongue with slippery coating, faint or floating rapid pulse. Revitalize Yang and secure the essence. Adjustments to the recipe of the Decoction for Revitalizing Yang and Stabilizing the Essence.

　　6. Single prescription

     (1) 30g of Portulaca oleracea, 15g of Sophora flavescens, decocted in water for oral administration. (1) 120g of hawthorn, 10g of Magnolia officinalis, decocted in water for oral administration. (3) 15g of Scutellaria baicalensis, 15g of Houttuynia cordata, 6g of Phellodendron amurense, decocted in water for oral administration. (4) Appropriate amount of fresh garlic, taken with food. (5) 30-60 grams of Pteris nervosa, decocted in water.