Necrotizing infections

In fasciitis or necrotizing infections caused by beta-hemolytic streptococci of group A, parenteral high-dose penicillin combined with clindamycin is the treatment of choice. For the treatment of abscesses, antibiotics which are able to kill large quantities of resting bacteria, such as clindamycin and the quinolones, are preferred. 

Initial reaction. In all known cases of effective biotic sensitization of plants reported to date, a critical factor appears to be the necrosis of host cells in the zone of initial infection. However, while non-necrotic infections are ineffective inducers, necrosis per se is not effective in inducing resistance. Injury by abiotic agents such as heat, chemicals, dry ice, or various extracts from plants and microbes does not protect cucumbers against lagenarium (8-10). Infection of tobacco by a wide variety of Peronosporales fungi other than P. tabacina frequently causes severe necrosis, but does not induce systemic resistance against blue mold (Tiizun and Kuc, unpublished). 

Clostridial myonecrosis is a necrotizing infection that involves the skeletal muscle. Gas production and muscle necrosis are prominent features of this infection, which readily explains why this infection is commonly referred to as gas gangrene. ° The infection advances rapidly, often over a matter of a few hours." Most infections occur after surgery or trauma, with Clostridium perfringens identified as the most common etiologic agent. 

Because marked systemic symptoms are seen commonly in necrotizing infections, blood samples should be collected for complete blood count and chemistry profile, as well as for bacterial culture. 

Bronchiectasis is defined pathologically as an abnormal permanent dilation of bronchi and bronchioles due to chronic necrotizing infection of these airways (Robbins et al. 1999). Based on gross morphologic appearance, Reid (1950) classified bronchiectasis into cyhn-drical, varicose, or cystic type. With the exception of infectious diseases, cystic fibrosis is probably the most common cause of cHnically important bronchiectasis in the Caucasian population (Cartier et al. 1999). Bron-... 

In the very early phases of the acute inflammatory response most of the cells invading the damaged area are polymorphonuclear neutrophils, also denoted as PMNs, which serve as initial line of defense and source of proinflammatory cytokines. These cells, which usually live for 4-5 days, circulate in the blood until they are attracted by chemokines into injured tissues. Whereas physical injury does not recruit many neutrophils, infections with bacteria or fungi elicit a striking neutrophil response. The characteristic pus of a bacterial abscess is composed mainly of apoptotic (apoptosis) and necrotic PMNs. Emigration of neutrophils from the blood starts with a process denoted as margination where neutrophils come to lie at the periphery of flowing blood cells and adhere to endothelial cells (Fig. 1). L-Selectin is expressed... 

CMV polyradiculopathy AIDS Acute Lumbosacral pain saddle anesthesia rapidly progressive flaccid paraparesis CMV infection necrotizing neuropathy... 

Chamouard JM, Smadja D et al (1993) [Neuropathy caused by necrotizing vasculitis in HIV-1 infection]. Rev Neurol (Paris) 149(5) 358-361... 

Galassi G, Gentilini M et al (1998) Motor neuron disease and HIV-1 infection in a 30-year-old HIV-positive heroin abuser a causal relationship Clin Neuropathol 17(3) 131-135 Gherardi R, Lebargy F et al (1989) Necrotizing vasculitis and HIV replication in peripheral nerves. N Engl J Med 321(10) 685-686... 

Inflammatory materials are released fiom necrotic cells and directly fixm the infective agent. It is not always clear to what extent these can be related to actions by the host or by the pathogen. Inflammation causes swelling, pain and reddening of the tissues, and sometimes loss of function of the organs affected. These reactions may sometimes be the major sign and symptom of the disease. 

Pancreatic necrosis is a diffuse inflammation of the pancreas with infectious etiology. Pancreatic necrosis occurs within the first 2 weeks of acute pancreatitis and develops in 10% to 30% of patients with acute pancreatitis. The necrotic pancreas can become secondarily infected with enteric gramnegative bacteria (such as E. coli), and disseminated infection may result from pancreatic necrosis.7,8... 

Finally, CA-MRSA produces the virulent Panton-Valentine leukcocidin toxin. It destroys leukocytes, causes severe tissue damage and necrosis, and has been associated with both necrotizing skin infections and pneumonia.14... 

Necrotizing fasciitis (NF) is an uncommon, rapidly progressive, life-threatening infection of the subcutaneous tissue and fascia. Its associated mortality rate is approximately 25% and is nearly 70% in patients who present with septic shock.3,19... 

Another important necrotizing skin and soft tissue infection is clostridial myonecrosis (gas gangrene). Clostridial myonecrosis can develop spontaneously but most often occurs after trauma. Clostridium perfringens is the most common causative pathogen. 

Historically, osteomyelitis has been classified as acute or chronic based on duration of disease (Fig. 78-2).2,4 However, there are no established definitions for acute and chronic infections.2-4 Acute infection has been defined as first episode or recent onset of symptoms (less than 1 week).2,3 Chronic osteomyelitis is generally defined as relapse of the disease or symptoms persisting beyond 4 weeks.2,3 Others describe chronic osteomyelitis as the presence of necrotic bone.3 ... 

Dirty Obvious preexisting infection present (abscess, pus, or necrotic tissue present) Not indicated antibiotics used for treatment... 

Necrotizing fasciitis A severe soft-tissue infection involving the... 

Source control Removal of the primary cause of an infection such as contaminated prosthetic materials (e.g., catheters), necrotic tissue, or drainage of an abscess. Antimicrobials are unlikely to be effective if the process or source that led to the infection is not controlled. 

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