Streptococci, group hemolytic

Tracer species a-Hemolytic streptococci E. coli Bacteroides fragilis group... 

Erysipelas (Saint Anthony s fire) is an infection of the superficial layers of the skin and cutaneous lymphatics. The infection is almost always caused by /3-hemolytic streptococci, with S. pyogenes (Group A streptococci) responsible for most infections. 

When treatment is initiated before definitive culture and sensitivity results are known, consider that these agents are only effective in the treatment of infections caused by pneumococci, group A beta-hemolytic streptococci, and penicillin G-resistant and penicillin G-sensitive staphylococci. 

Continue therapy at least 24 to 48 hours after symptoms and fever subside. Treat all infections caused by group A -hemolytic streptococci for at least 10 days. 

Treat Group A beta-hemolytic streptococci infections for at least 10 days. 

Mupirocin is not related to any of the sys-temically used antibiotics. It is an inhibitor of bacterial protein synthesis and is especially active against gram-positive aerobic bacteria, e.g. methicillin-resistant S. aureus and group A beta-hemolytic streptococci. Absorption through the skin is minimal. Intranasal application may be associated with irritation of mucous membranes. 

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. 

Post-streptococcal glomerulonephritis is the result of infection with the nephritogenic strain of group A hemolytic streptococci. The streptococci are usually isolated from patients with a sore throat and, in developing countries, skin infection like impetigo or infected scabies is an important cause. There is no specific treatment except for antihypertensives, salt restriction and diuretics. Corticosteroids are of no value. The disease is self-limiting but, in some adults, it may progress to chronic renal failure. 

The clinical uses of penicillin G include endocarditis caused by S. viridans (or Streptococcus hovix), pharyngitis (group A (3-hemolytic streptococci), cat bite cellulitis Pasteurella multocida), and syphilis (Treponema pallidum). 

The selection of a particular antibiotic depends upon the diagnosis and, when appropriate, in vitro culture and sensitivity studies of clinical samples. The pathogens isolated from most infected dermatoses are group A B-hemolytic streptococci, Staphylococcus aureus, or both. The pathogens present in surgical wounds will be those resident in the environment. 

Mupirocin (pseudomonic acid A) is structurally unrelated to other currently available topical antibacterial agents. Most gram-positive aerobic bacteria, including methicillin-resistant S aureus (MRSA), are sensitive to mupirocin (see Chapter 50). It is effective in the treatment of impetigo caused by S aureus and group A -hemolytic streptococci. 

Retapamulin is a semisynthetic pleromutilin derivative effective in the treatment of uncomplicated superficial skin infection caused by group hemolytic streptococci and S aureus, excluding MRSA. Topical retapamulin 1% ointment is indicated for use in adult and pediatric patients, 9 months or older, for the treatment of impetigo. Recommended treatment regimen is twice-daily application for 5 days. Retapamulin is well tolerated with only occasional local irritation of the treatment site. 

Streptokinase [strep toe KYE nase] is an extracellular protein purified from culture broths of Group C p-hemolytic streptococci. 

With hyaluronic acid, much of the informative work on its biosynthesis has accrued from studies with bacteria. Group A hemolytic streptococci have long been known (K6) to produce hyaluronic acid identical with that present in mammalian connective tissues. The participation of uridine nucleotides in the biosynthesis of hyaluronic acid is now well... 

A 54-year-old man with rheumatoid arthritis for 12 years was given infliximab, with remission. He then developed a painful, confluent, erythematous, pustular rash over his trunk and limbs. Skin biopsy showed an acute pustular dermatitis. Five hours later he collapsed with a tachycardia (140/minute) and a blood pressure of 120/70 mmHg. He was apyrexial. His left leg was very tense, painful, and swollen, and he had a disseminated intravascular coagulopathy. There was marked necrosis of his adductor compartment and fascia of his left thigh and necrotic muscles were debrided. Blood cultures and skin swabs grew group A hemolytic streptococci. He then became unstable and died, despite efforts at resuscitation. 

Cellulitis results when the integrity of the skin is broken due to an abrasion, ulceration, skin puncture, or surgical wound. Moderate to severe infections can progress to more serious infections such as osteomyelitis if not adequately treated. Cellulitis is most commonly caused by group A beta-hemolytic streptococci (Streptococcus pyogenes) and Staphylococcus aureus. Wound cultures have a very low yield and rarely identify the causative pathogen. Thus, cultures are rarely done and therapy is usually presumptive. 

Using this procedure, Consden and Stanier were able to show that a hydrolyzate of Group A hemolytic streptococci contained hexosamine, rhamnose, ribose, and glucose and, also, that a hydrolyzate of purified, human fibrin contained uronic acid, hexosamine, mannose, and galactose. A similar combination of techniques has been employed by Woodin in a study of the composition of a comeal mucopolysaccharide. It is of interest that the conditions of acidic hydrolysis necessary for releasing the n-glucos-amine moiety from heparin also result in destruction of the concomitantly released n-glucuronic acid. Traces of the intact uronic acid may be revealed by zone electrophoresis of the hydrolyzates. ... 

Hyalm onate is produced both by animals and bacteria. It was first obtained by Meyer and Palmer from the vitreous humor of cattle eyes. Since then, it has been isolated from many sources, such as Wharton s jellyconnective tissue, skin, cock s comb, synovial fluid, Rous sarcoma, myxoedemal fluids, and encapsulated strains of hemolytic streptococci. Aerobacter aerogenes may also produce hyaluronate. Group A streptococci have been principally used for the investigation of the biosynthesis of hyaluronic acid. 

When D-glucose-l-C is incubated with hemolytic streptococci, equal specific activities are found in derived acetate from the medium and derived acetate from hyaluronate. This indicates a ready exchange between free acetate and hyaluronate acetyl groups. 

Nafcillin. sodium may be used in infections cau.sed solely by penicillin G-resislant staphylococci or when streptococci are present also. Although it is recommended that it be used exclu.sively for such resi.stant infections, nafcillin is also effective against pneumococci and group A hemolytic streptococci. Because, like other penicillins, it may cau.se allergic side cffcct.s. it should be administered with care. 

Streptokinase. Streptokinase (Kabikinasc. Streptase) is a catabolic 47.000-Da protein secreted by group C fi-hemolytic streptococci. It is a protein with no intrinsic enzymatic activity. Streptokinase activates plasminogen to plasmin. a proteolytic enzyme that hydrolyzes fibrin and... 

Infection has been identified retrospectively as a common precipitating factor in psoriasis. About 25% of patients have initial onset of the disease after clinically documented infections, and more than one half have exacerbations within 3 weeks after an upper respiratory infection. A variant known as guttate (small drop-like plaques) psoriasis is often associated with infections of group A /3-hemolytic streptococci. ... 

Rasmussen JE. The relationship between infection with group A beta hemolytic streptococci and the development of psoriasis. Pediatr Infect DisJ 2000 19 153-154. 

Kaplan EL, Johnson DR, del Rosario MC, et al. Susceptibility of group A beta-hemolytic streptococci to thirteen antibiotics Examination of 301 strains isolated in the United States between 1994 and 1997. Pediatr Infect Dis J 1999 18 1069-1072. 

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