Lysogeny In Coagulase-Negative Staphylococci

Abstract

C o A GU LA s E -NE G A T I v E staphylococci (Staphylococcus epidermidis) are generally considered non-pathogenic. Recently, however, they have been associated with an increasing number of infections complicating cardiac surgery and ventriculo-atrial shunt operations for the treatment of hydrocephalus (Quinn, Cox and Fisher, 1965;Holt, 1969). In most of these cases the route of infection has not been established, nor is it clear whether the hospital is the source of the causative organisms.To obtain a better understanding of the host-parasite relation and the epidemiology in the hospital environment of coagulase-negative staphylococci, a typing system to characterise individual strains seems highly desirable. Classification by means of biochemical tests according to the system proposed by Baird-Parker (1 963) has recently given encouraging results in distinguishing between strains of Staph. epidermidis (Bentley et al., 1968;Holt).Phage-typing proved to be of considerable value in the study of Staph. aureus infections. The typing phages were isolated from lysogenic Staph. aureus strains and in general do not lyse coagulase-negative staphylococci. Phages active on coagulase-negative staphylococci have been described (Rountree, 1947;Rippon, 1956 ;Comtois, 1962), but lysogeny in coagulasenegative staphylococci has been demonstrated only rarely (Karska et al., 1960;Comtois). The occurrence of lysogenic Staph. epiderrnidis strains was studied systematically to evaluate the possibility of obtaining phages suitable for typing purposes. MATERIALS AND METHODSStrains Coagulase-negative staphylococci were collected from staff, patients and air in the Department of Thoracic Surgery, University Hospital, Utrecht, from medical students that had not yet been in contact with the hospital environment, and from a sample of the population of the village of Vleuten, near Utrecht.~~ ~~

Phage typing of coagulase-negative staphylococci and micrococci

“…The preliminary studies reported here, in confirmation of the work reported by Verhoef et al (1971aVerhoef et al ( , b, 1972 …”

A serological method for distinguishing coagulase-negative staphylococci from micrococci

“…Agglutination would be a useful quick screening test for sorting out staphylococci from micrococci, a procedure highly desirable before phage typing as it is known that the phages concerned act mainly on staphylococci (Verhoef et al, 1971a andb, 1972;Dean et al, 1973). Using agglutination as a screening test would not result in missing strains for typing as it was found that the percentage of typable staphylococci after biochemical did not differ statistically from that after serological screening.…”

Transduction of Tetracycline Resistance in Staphylococcus epidermidis

“…Transduction was observed in S. epidermidis of biotype 1 only, but few strains of other biotypes were included in the study. Biotype 1 is the most frequent group of S. epidermidis isolated from patients, and these organisms are occasionally implicated in infection (8,15 (14,15), who found that two groups of phages could be induced from lysogenic S. epidermidis strains: phages which were active on other S. epidermidis and phages active against S. aureus. Transduction between staphylococcal species may require particular S. epidermidis phages.…”