Symptoms of gastrointestinal anaerobes infection?

summary

Anaerobic bacteria is the main component of normal flora, which can cause infection in any tissues and organs of human body. In recent years, with the continuous improvement of culture technology, anaerobes can be isolated and identified in time? Let's talk about it.

Symptoms of gastrointestinal anaerobes infection?

1. Central nervous system infection focal suppurative infection, such as brain abscess and subdural empyema, is often associated with anaerobic bacteria infection. In contrast, extradural empyema and meningitis caused by anaerobes are rare. (1) brain abscess: anaerobes are the main pathogenic bacteria of brain abscess. The invasion routes and primary lesions are as follows: ① otitis media (often chronic) and mastoiditis are the most common, which directly spread to the brain. Brain abscesses are often located in the temporal lobe or cerebellum. ② Hematogenous dissemination of brain abscess, often multiple personality, common in the gray matter and white matter junction, mostly in the frontal lobe, parietal lobe and occipital lobe, rarely in the temporal lobe or cerebellum. The infection may originate from lung or thoracic infection, including subacute or chronic lung abscess, bronchiectasis, empyema, necrotizing pneumonia, etc. ③ Sinusitis, pathogenic bacteria often directly spread and cause brain abscess, mainly in the frontal lobe and temporal lobe, pathogenic bacteria to Bacteroides is the most common. ④ Others include trauma, congenital heart disease (right to left shunt), oral or dental infection, inflammation of tonsil or pharynx, infective endocarditis, urinary tract infection, abdominal abscess, etc. The most common pathogenic bacteria are Bacteroides, Prevotella, Fusobacterium and Streptococcus digestive, especially Bacteroides fragilis. Clostridium and actinomycetes are occasionally seen. The main clinical manifestations are space occupying lesions, such as headache, mental disorder, drowsiness or dullness, cerebral nerve palsy, optic disc edema, etc. there may also be hemiplegia, aphasia, seizures, etc. The symptoms of toxemia may not be obvious and fever may not be present. EEG, brain ultrasound, radionuclide scan, brain CT, MRI, cerebral angiography are helpful for diagnosis and localization. Cerebrospinal fluid examination showed that protein increased, sugar normal, white blood cells can be slightly increased. If the abscess breaks into the ventricle, the symptoms of purulent meningitis and increased intracranial pressure can appear quickly. (2) meningitis: anaerobes rarely cause meningitis. Anaerobes only account for 1% of bacterial meningitis, but there are individual reports of 9%. Chronic otitis media and / or mastoiditis were the most common primary lesions, followed by surgery (or laminectomy). Clostridium, Bacteroides fragilis, anaerococcus and Clostridium perfringens were common pathogenic bacteria. Clostridium perfringens is the most common pathogen in Anaerobe meningitis and trauma caused by secondary infection of head and neck cancer, but Bacteroides is rare. Anaerobe septicemia can be complicated with meningitis, but the incidence is not high. The incidence of neonatal anaerobe septicemia and meningitis is high. The pathogenic bacteria often come from the mother's birth canal, or the mother has a history of amnionitis at birth. In addition to meningitis, acute necrotizing vasculitis is more common with thrombosis. The clinical manifestation is similar to that of purulent meningitis. The meningitis caused by Corynebacterium brevis vaccine may be stroke like or chronic meningitis type. The increase of cerebrospinal fluid cells is mainly monocytes. (3) others: anaerobic bacteria can also cause subdural empyema, epidural empyema, spinal subdural abscess, ependymal inflammation, central nervous system thrombophlebitis, cerebrospinal fluid shunt postoperative infection (a few can be caused by the hair follicle or sebaceous gland more acne short rod vaccine), etc.

2. Sepsis and endocarditis (1) sepsis: Previous studies have shown that the incidence of sepsis caused by anaerobic bacteria can be as high as 10% - 15%. The incidence rate of neonatal anaerobic bacteria sepsis is high. However, the incidence rate of anaerobic septicemia has dropped to 5% or less in recent years, which may be related to the use of anti anaerobe drugs widely used in the prevention or early treatment of anaerobic infections or mixed infections. Arteriosclerosis, alcoholism, liver cirrhosis, diabetes, malignant tumor, bedsore ulcer and the end stage of nephropathy (peritoneal dialysis, nephrectomy, kidney transplantation) are prone to anaerobic septicemia. Two thirds to three fourths of anaerobic septicemia were caused by Gram negative anaerobic bacteria, especially Bacteroides fragilis; The second was peptic Streptococcus (about 10%) and Clostridium (5% - 10%); With the development of technology, lepothrix, Selenomonas and anaerobiospirillum have been found in blood culture. Anaerobic septicemia is often secondary to focal infection. Bacteroides fragilis septicemia, most of which are invaded by intestinal tract, and some of which come from female reproductive tract. The blood culture of gastrointestinal invaders was positive for many times and often infected by many kinds of bacteria. However, multiple positive blood cultures of female genital tract invaders are rare, but multiple bacterial infections are common. The clinical manifestations were the same as those of aerobic septicemia, such as fever, increased white blood cell count, septic shock (30%) and disseminated intravascular coagulation. The incidence of jaundice is 10% - 40%. Migrating purulent lesions (10% - 28%) and septic thrombophlebitis (5% - 12%). Septicemia can be fulminant with high mortality, such as Clostridium perfringens septicemia, which often has hemolysis, jaundice, shock and renal failure. In recent years, it has also been found that some cases of sepsis are mild, without serious manifestations of toxemia, but with a benign course. The course of disease is self limited and can be recovered without antibacterial treatment. Some female patients and newborn blood culture confirmed Clostridium perfringens, but also showed mild symptoms. (2) endocarditis: the incidence of endocarditis caused by anaerobes varies from 1.5% to 10% of endocarditis, and is increasing day by day. The common pathogenic bacteria were Bacteroides, Clostridium, Clostridium anaerobes, Corynebacterium keratinii vaccine, microaerobes and Streptococcus anaerobes. Most of the primary lesions were in oropharynx. The clinical manifestation is different from the general subacute bacterial endocarditis, which is more common in patients without primary heart disease. Anaerobes invade normal valves and often cause embolism and valve destruction. The more serious complications were myocardial abscess or destruction or perforation of valves and other supporting structures. It often causes heart failure. If it is caused by anaerobic or microaerobic Streptococcus, it is similar to Streptococcus viridis, and can also invade the original diseased valve.

3. Respiratory system infection (1) upper respiratory tract infection: the upper part of the respiratory tract is connected with the oropharynx, and the types of bacteria are basically similar; It is found that anaerobic bacteria are more than aerobic bacteria, the common ones are Clostridium and Streptococcus, followed by Bacteroides. Prevotella melanogenes is an important pathogen in tooth and gingival infections, but it is difficult to detect because of its complex culture conditions. At present, the most common infections are chronic sinusitis, peritonsillar abscess, periodontal infection, chronic otitis media, mastoiditis and so on. (2) intrathoracic infection: lower respiratory tract anaerobic bacteria infection is mainly manifested in four clinical symptoms, namely aspiration pneumonia, lung abscess, necrotizing pneumonia and empyema. The above-mentioned infections are often caused by inhalation of oropharyngeal contents, which are often caused by changes in consciousness and weakening of local defense function, such as bronchial obstructive lesions (foreign bodies, lung cancer, etc.), hypoxia, smoking, alcoholism, esophageal obstruction, suppurative lesions of upper respiratory tract, etc., and the secretion or pus is easily inhaled. In addition to inhalation (the most common), pulmonary infection can also be blood borne, spread from distant infection focus (pelvic or abdominal cavity is more common) or sepsis thrombus. Most of the anaerobic thoracic infections are mixed. There are two to nine kinds of bacteria, including aerobic bacteria and facultative bacteria. Most of the anaerobic bacteria were bacilli (especially Bacteroides fragilis), Prevotella, Fusobacterium (especially Clostridium nucleatum) and peptic Streptococcus, while gram positive non bacillus and Clostridium were relatively rare.

matters needing attention

1. Try to prevent the reduction of tissue redox potential. 2. Prevent the normal anaerobic bacteria in the body: or the introduction of anaerobic bacteria in vitro into the wound, close the cavity, etc. For traumatic wounds, debridement should be done as soon as possible, foreign bodies and invalid cavities should be removed, and good blood supply should be reconstructed; There are indications for prophylactic use of antibiotics in abdominal penetrating trauma, especially when colon is involved. Chronic lesions such as chronic otitis media, sinusitis and mastoiditis should be treated actively to prevent intracranial anaerobic infection. In case of weakness, unconsciousness or dysphagia, attention should be paid to prevent inhalation when eating. Patients with valvular heart disease should be treated with prophylactic antimicrobial therapy during dental and oral surgery. In order to prevent postpartum sepsis, attention should be paid to the management of premature rupture of membranes, prolonged labor and postpartum hemorrhage. 3. Timely treatment of infection can prevent serious anaerobic infection by limiting it to a specific site before spread. Careful cleaning of the wound, removal of foreign bodies and early initiation of antibiotic treatment are effective preventive measures. Intravenous antibiotics are used to prevent infection before, after and during abdominal surgery.