Streptococcal cultures

The manufacturers of sodium hyaluronate stress the importance of substance purity. Many manufacturers have their own methods to achieve this high quality. Numerous sources are known to harbor sodium hyaluronate rooster combs, umbilical cord or streptococcal cultures (Fig. 28). 

Mirsky (89) has demonstrated that fibrinoliriic activity of streptococcal cultures may be inhibited by the crystalline pancreatic trypsin inhibitor of Kunitz and Northrop (72) and by the soybean trypsin... 

Streptokinase and streptodornase are isolated following growth of non-pathogenic streptococcal producer strains in media containing excess glucose. They are obtained as a crude mixture from the culture filtrate and can be prepared relatively free of each other. They are commercially available as either streptokinase injection or as a combination of streptokinase and streptodornase. 

As streptococcal cellulitis is indistinguishable clinically from staphylococcal cellulitis, administration of a semisynthetic penicillin (nafrillin or oxacillin) or first-generation cephalosporin (cefazolin) is recommended until a definitive diagnosis, by skin or blood cultures, can be made (Table 47-4). If documented to be a mild cellulitis secondary to streptococci, oral penicillin VK, or intramuscular procaine penicillin may be administered. More severe streptococcal infections should be treated with IV antibiotics (such as ceftriaxone 50 to 100 mg/kg as a single dose). 

A negative rapid streptococcal antigen test can be used to rule out streptococcal angina in patients with nonspecific symptoms and thus the need for antibiotics. When traditional throat cultures are used, complications of poststreptococcal infection can still be avoided when treatment is initiated upon a positive culture result. 

Even in the setting of a classic infectious disease for which isolation techniques have been established for decades (eg, pneumococcal pneumonia, pulmonary tuberculosis, streptococcal pharyngitis), the sensitivity of the culture technique may be inadequate to identify all cases of the disease. 

Agglutination reactions have many applications in clinical medicine that can be used to type blood cells for transfusion, to identify bacterial cultures, and to detect the presence and relative amount of specific antibody in a patient s serum. For example agglutination of antibody-coated latex beads has become a popular commercial method for the rapid diagnosis of various conditions such as pregnancy and streptococcal infections. 

During cheese ripening, proteases associated with starter culture organisms are released into cheese after cell lysis (Law et al. 1974). The proteolytic activity associated with lysed lactic streptococci is necessary for proper flavor development in Cheddar and other cheese varieties. The role of streptococcal proteases and peptidases appears to be production of flavor compound precursors such as methionine and other amino acids, rather than direct production of flavor compounds (Law et al. 1976A). Additional discussion of cheese ripening is presented in Chapter 12. 

Relationship between Starter Cultures and Streptococcal Antibiotics. When antibiotic-producing and non-antibiotic-producing strains of S. lactis and S. cremoris from commercial starter cultures were mixed in equal proportions, the antibiotic-producing strains soon predominated (Hoyle and Nichols 1948). Domination occurred after 24 to 48 hr. (Collins 1961). Emergence of a predominant strain may be accompanied by a loss of starter activity and renders the starter more susceptible to complete inactivation by bacteriophage. 

Bacteria (see Note 1) different strains of S. pyogenes have been used in mouse models of streptococcal skin infection including the commercially available S. pyogenes strains DSM 2071, which can be obtained from the German Culture Collection or from The American Type Culture Collection (ATCC2105). 

Bacterial endocarditis. An aminoglycoside, usually gentamicin, should comprise part of the antimicrobial combination for enterococcal, streptococcal or staphylococcal infection of the heart valves, and for the therapy of clinical endocarditis which fails to yield a positive blood culture. 

Fries SM. Diagnosis of group A streptococcal pharyngitis in a private clinic comparative evaluation of an optical immunoassay method and culture. J Pediatr 1995 126 933-6. 

After culture and sensitivity results are obtained, antibiotic therapy should be adjusted appropriately (Fig. 45-5). If the patient does not show signs of clinical improvement within 72 hours after antibiotic treatment is initiated, the culture should be repeated and the patient re-evaluated. For streptococcal or enterococcal peritonitis, IP ampicillin (125 mg/L in each exchange) is the preferred treatment. For Enterococcus, the addition of an aminoglycoside, depending on sensitivities, may be warranted for synergy. In addition, if the Enterococcus is resistant to both ampicillin and vancomycin, linezolid or quinupristin/dalfopristin are recommended. However, quinupristin/ dalfopristin is not effective against E.faecalis. 

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