Healthy anaerobes and can infect people with impaired resistance or with tissue damage. Mixed anaerobic infections may include both individual anaerobic species or more anaerobic species with any number of non-anaerobic isolates. The symptoms depend on the site of infection. The diagnosis is usually clinically in combination with a Gram stain and Anaerobierkulturen. Treatment is with antibiotics and surgical drainage and debridement.
Hundreds of types of non-spore forming anaerobes are part of the physiological flora of the skin, oral cavity, gastrointestinal tract and vagina. If these commensal relationships are disturbed (eg. As by surgery, trauma, poor blood supply or tissue necrosis), a few of these pathogens can together lead to infectious diseases with high morbidity and mortality. After establishment of infection in the affected region of the body, the infection can spread locally or blood stream to distant sites.
Healthy anaerobes and can infect people with impaired resistance or with tissue damage. Mixed anaerobic infections may include both individual anaerobic species or more anaerobic species with any number of non-anaerobic isolates. The symptoms depend on the site of infection. The diagnosis is usually clinically in combination with a Gram stain and Anaerobierkulturen. Treatment is with antibiotics and surgical drainage and debridement. Hundreds of types of non-spore forming anaerobes are part of the physiological flora of the skin, oral cavity, gastrointestinal tract and vagina. If these commensal relationships are disturbed (eg. As by surgery, trauma, poor blood supply or tissue necrosis), a few of these pathogens can together lead to infectious diseases with high morbidity and mortality. After establishment of infection in the affected region of the body, the infection can spread locally or blood stream to distant sites. Often, aerobic and anaerobic bacteria coexist in the infected region, therefore, appropriate procedures are required for the isolation and culture, not to overlook the anaerobes. Anaerobes may be the main cause of the infection in the following: The Pleuraräume and lung In intra-abdominal, gynecological, central nervous system, upper respiratory and cutaneous infections bacteremia etiology The principal anaerobic gram-positive cocci, which are involved in mixed anaerobic infections is Peptococci Peptostreptococci These anaerobes are part of the normal flora of the mouth, upper respiratory tract and the colon. To the essentially anaerobic gram-negative bacteria, which are involved in various mixed anaerobic infections, include Bacteroides fragilis, Prevotella melaninogenica, Fusobacterium sp B. fragilis group is part of the normal intestinal flora and includes the anaerobic pathogens most frequently isolated from intra-abdominal and pelvic infection. Pathogens within the Prevotella group and Fusobacterium sp are part of the normal oral and large intestinal flora. Pathophysiology Mixed Anaerobic infections can usually be characterized as follows: They tend to occur with a local collection of pus or abscesses. The reduced in avascular and necrotic tissue O2 tension and a low redox potential are important prerequisites for the survival of the pathogen. When it comes to bacteremia, this usually does not result in disseminated intravascular coagulation (DIC) and purpura. Clostridial infections can lead to septic shock, but most other anaerobic infections do not. Some anaerobic bacteria have unique virulence factors. The virulence of B. fragilis are probably responsible for its frequent isolation from clinical specimens despite its relative rarity in the physiological flora compared to other Bacteroides sp. This pathogen has a polysaccharide capsule that apparently stimulated the formation of abscesses. By means of an experimental model for intra-abdominal sepsis has been shown that B. fragilis alone is able to cause abscesses, while other Bacteroides sp. need to download a synergistic effect of other pathogens. Another virulence factor, a potent endotoxin is involved in septic shock, which with severe pharyngitis by Fusobacterium sp. is associated. The morbidity and mortality of anaerobic and mixed bacterial sepsis is as high as that of a triggered by aerobic pathogens sepsis. Anaerobic infections are often complicated by a deep-seated tissue necrosis. The Gesamtletalitätsrate in severe intra-abdominal sepsis and mixed anaerobic pneumonias tends to be high. A B. fragilis bacteremia has a high mortality rate, especially in the elderly and patients with a tumor disease. Symptoms and signs Patients usually have fever, rigor and a critical medical condition, a shock usually kist not exist. In a Fusobacterium septicemia can cause a DIC. For specific infections (and symptoms) that are caused by various anaerobic pathogens see elsewhere in MSDManual disorders that are often caused by different * anaerobic organisms. Anaerobes rarely come in urinary tract infections, in septic arthritis and infective endocarditis. Disorders that are often caused by different * anaerobic organisms Anaerobic cellulitis aspiration pneumonia Bartholinisches glandular fever brain abscess Chronic otitis media Chronic sinusitis decubitus or ischemic Ulkusinfektionen Dental abscesses endometritis epidural and Subduralempyem Human bite infections Intra-abdominal abscesses abscess Ludwig’s angina Lung Unterkieferosteomyelitis Necrotizing gingivitis necrotizing colitis mucositis (cancrum oris) Nichtgonorrhöischer Parametrialer tubo-ovarian abscess abscess Pelvic peritonitis periodontitis peritonitis septic thrombophlebitis Skenedr seninfektion Vincent Angina * With aerobic or anaerobic other. Diagnosis Clinical suspicion Gram stain and culture Clinical clues to the presence of anaerobic pathogens conclude with an infection in near mucous membranes, anaerobic flora wear ischemia, tumor, penetrating trauma, foreign objects or perforated bowel Spreading gangrene, skin, subcutaneous tissue, fascia and muscles affect Fecal odor in purulent or infected tissue abscess formation of gas in the tissue septic thrombophlebitis missing response to antibiotics without significant anaerobic activity a Anaerobierinfektion should be suspected in any foul-smelling wound or in a Gram preparation of pus microscopically detectable pleomorphic mixed flora. There should be only samples normally sterile compartments taken as kommensalische contaminants could otherwise be easily interpreted as pathogens. For all materials Gram staining and aerobic cultures should be performed. A Gram stain, particularly in a Bacteroides infection, and cultures at anaerobes may be falsely negative. The antibiotic susceptibility testing of anaerobes is difficult, and the results can be possibly only ? 1 week after the initial culture. However, if the species is known, the resistance behavior can usually be predicted. Therefore, many laboratories do not perform routine sensitivity tests for anaerobes. Therapy drainage and debridement antibiotics choice varies depending on the site of infection in an established infection, the pus is drained and devitalized tissue, foreign bodies and necrotic tissue to be removed. Organperforationen must be treated by occlusion or drainage. Whenever possible, the blood supply should be restored. Septic thrombophlebitis may require a venous ligation and antibiotics. Since the results of Anaerobierkultur might not be available until after 3-5 days, starting with antibiotic therapy prior to detection of pathogens sensitivity. Antibiotics work sometimes even if some of the bacterial species in a mixed infection against the used antibiotic resistant, especially if an adequate surgical debridement and there sufficient drainage be performed. Antibiotics are chosen based on the site of infection and the resulting probable pathogens. Oropharyngeal anaerobic infections and lung abscesses oropharyngeal infections may not be able to respond to therapy and therefore require a drug that is effective against penicillin-resistant anaerobes (see below). Oropharyngeal infections and lung abscesses should be treated with clindamycin or a ?-lactam / ?-lactamase inhibitor combination such as amoxicillin / clavulanic acid. For patients allergic to penicillin, clindamycin or metronidazole (excl. One effective against aerobic pathogens and microaerophils drug) hilfreich.GI or anaerobic infections of the female pelvis Gastrointestinal or pelvic (in women) Anaerobierinfektionen likely to contain obligate anaerobic gram-negative bacteria such as B. fragilis and facultative gram-negative bacteria such as Escherichia coli; antibiotic applications must be effective against both. Resistance of B. fragilis and other obligate anaerobic gram-negative bacteria to penicillins and cephalosporins of 3rd and 4th generation occur. However, the following drugs have an excellent in vitro activity against B. fragilis and are effective: (. E.g., imipenem / cilastatin, meropenem, ertapenem) metronidazole carbapenems ?-lactam / ?-lactamase combinations (such as piperacillin. / tazobactam, ampicillin / sulbactam, amoxicillin / clavulanic acid, ticarcillin / clavulanate) Tigezyklin moxifloxacin No monotherapy appears to be superior. Among the drugs that are less predictable in vitro activity against B. fragilis, include clindamycin, cefoxitin and cefotetan. All but clindamycin and metronidazole may be used as monotherapy, as these substances also have good activity against facultative anaerobic gram-negative pathogens. Metronidazole is against clindamycinresistente B. fragilis, effective, has a unique bactericidal activity against anaerobes, and usually does not lead to pseudomembranous colitis, which occurs occasionally in clindamycin. Concerns about a potential mutagenicity of metronidazole were previously not clinically confirmed. Because many therapies that Anaerobierinfektionen are effective currently used to treat gastrointestinal or pelvic (in women) against facultative gram-negative bacteria, the use of a potential nephrotoxic aminoglycoside is (to enteric facultative gram-negative bacteria cover) plus. An antibiotic against B. not fragilis longer justified. Prevention before elective colorectal surgery should patients have preoperative gut renovation, consisting of laxatives enemas antibiotics Most surgeons give both oral and parenteral antibiotics. In a colorectal emergency surgery only parenteral antibiotics are used. Examples of oral therapies are neomycin (or kanamycin) plus erythromycin or metronidazole. these drugs are not earlier than 18-24 hours given before the procedure. Examples of parenteral preoperative therapies are cefotetan, cefoxitin or cefazolin plus metronidazole and ertapenem. these drugs are given within 1 h before the procedure. Preoperative administration of parenteral antibiotics reduces the likelihood of bacteremia, reduced secondary or metastatic suppurative complications and prevents the local spread of infection in the area of ??the surgical site. During lengthy interventions intraoperative antibiotics may be given every 1 to 2 half-life of the antibiotic. Typically, the post-operative antibiotics be continued for more than 24 hours after surgery. one of the following therapies for patients with confirmed allergy or adverse reaction to ?-lactams Recommended clindamycin and gentamicin, aztreonam, or ciprofloxacin, metronidazole and gentamicin or ciprofloxacin Conclusion Mixed anaerobic infections occur when the normal commensal relationship between the normal flora of the mucous membranes (z. B. skin, mouth, GI tract, vagina) is faulty (for. example, by surgery, injury, ischemia or necrosis). The infections tend to occur with a local collection of pus or abscesses. The clinical suspicion in the clinical setting due to the presence of gangrene, pus, abscess, gas in the tissue and / or fecal odor. Drainage and debridement of the infected area and antibiotics selected according to the site of infection (and thus likely pathogens).