Date of Award

1-1-1987

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Microbiology & Immunology

Abstract

Staphylococcus aureus is a gram-positive, catalase-positive, coagulase positive, non-motile, facultatively anaerobic coccus usually arranged in irregular clusters that commonly causes pustules, carbuncles, impetigo, cellulitis, and post-surgical wound infections. S. aureus also causes septicemia, endocarditis, pneumonia, meningitis, osteomyelitis, exfoliative skin disease, scalded skin syndrome, toxic shock syndrome, and food poisoning. The method currently used for distinguishing among strains of Staphylococcus aureus is bacteriophage typing.The goal of this research was to develop a biotyping system for differentiating among strains of S. aureus. The parameters selected for the biotyping system included: DNase, phosphatase, gelatinase, urease, arginine decarboxylase, fermentation of mannitol, galactose, lactose, maltose, mannose, turanose, saccharose, and trehalose, nitrate reduction, acetylmethylcarbinol production and hemolysis. The biochemical tests were assigned an arbitrary numerical value based on the principles of the octal code which resulted in a biotype number.The biotyping system was applied to S. aureus isolates, 86 obtained from hospital patients and 55 obtained from healthy carriers. The result of the biotyping system indicated that the 141 isolates represented 36 biotypes. The biotypes ranged from 067710 to 777771. The biotypes varied from a single character difference to biotypes having seven character differences. The most frequently isolated biotype was 767771. The following eight biotypes were common to both healthy and sick individuals: 667771, 707771, 767670, 767671, 767770, 767771, 777770, and 777771.The results of this research indicate that the species designation S. aureus is biochemically heterogeneous and the differences observed could be used as an epidemiologic tool in investigations of nosocomial infections, community outbreaks, and recurrent infections caused by S. aureus.The biotyping system is not time-consuming, difficult to perform, or expensive, and does not depend on highly specialized equipment.

Download

Share

COinS