The relationship of pathogenic coagulase-negative staphylococci to Staphylococcus aureus

Abstract

Coagulase-negative pathogenic staphylococci were studied physiologically and serologically to determine their relationship to Staphylococcus aureus. When 46 characters were studied and tallied, the 21 coagulase-negative pathogenic strains made up a heterogeneous intermediate group sharing not all the characters of S. aureus but appreciably more than S. epidermidis. Some characters among the coagulase-negative pathogens indicating a relationship to S. aureus were serotyping, lysostaphin sensitivity, growth rates, and endogenous respiration. Seventy-one percent of the coagulase-negative pathogenic strains were resistant to penicillin; of these, 80% were multiple antibiotic resistant.From these results it would appear that the genus Staphylococcus cannot be divided satisfactorily into demarcated species but that strains within this genus form a continuous spectrum between the two presently recognizable extremes with new subtypes evolving as characters are lost. If a species must be designated under the existing system of classification, a strain producing coagulase can be called S. aureus. However, coagulase-negative pathogenic strains cannot be classified with accuracy as S. epidermidis on the basis of the absence of this single character, coagulase.

Antimicrobial Susceptibility and Selection of Resistance Among Staphylococcus epidermidis Isolates Recovered from Patients with Infections of Indwelling Foreign Devices

“…No resistant subpopulations were found, and the three resistant isolates were easily identified by routine susceptibility testing. This resistance may be plasmid-mediated, as has been described for S. aureus (16). …”

Epidemiology of Antibiotic and Heavy Metal Resistance in Bacteria: Resistance Patterns in Staphylococci Isolated from Populations Not Known to be Exposed to Heavy Metals

“…With the exception of one major (28 strains resistant to penicillin, erythromycin, tetracycline, and all three metals) and several minor classes, most of the multiple antibiotic-resistant strains are coagulase negative ( epidermidis (29). On the other hand, there is some evidence that little genetic homology exists between coagulase-positive and coagulase-negative strains of staphylococci (N. H. Nielsen, Bacteriol.…”

<i>In vitro</i> Activity of Chloramphenicol Combined with Cephalothin against DNase-Positive, Multiple-Antibiotic Resistant Strains of <i>Staphylococcus epidermidi</i><i>s</i>

“…Lately, an increasing number of laboratories have reported the isola tion of DNase-positive strains of Staph, epidermidis, which were consid ered to be of 'intermediate' pathogenicity [14,15]. A significant number of our isolates proved resistant to a variety of the commonly used anti biotics.…”