Intergeneric and Intrageneric Inhibition Between Strains of Propionibacterium Acnes and Micrococcaceae, Particularly Staphylococcus Epidermidis, Isolated from Normal Skin and Acne Lesions

Abstract

P. acnes; (2) to determine whether strains of P . acnes produce inhibitors of S. epidermidis and of P. acnes; and (3) to determine the frequency of occurrence of inhibitory strains on normal and acne skin.MATERIALS AND METHODS Media. Nutrient Broth Number 2, Blood Agar Base, and Reinforced Clostridial Medium were obtained from Oxoid Limited, Southwark Bridge Road, London, SE1 9HF. Brain Heart Infusion Agar was purchased from Difco Laboratories, PO Box 14B, Central Avenue, West Molesey, Surrey.Source of bacteria. All strains of bacteria were isolated from the faces or backs of 44 subjects attending the acne clinic at the Leeds General Infirmary or from employees of the Department of Microbiology, University of Leeds (table I). All subjects were in the age range 15-30 years, with the exception of one patient aged 39 who had severe acne. There were 29 females and 15 males. Patients were graded according to a modification of the scheme of Burton et al. (1971), increasing the number of grades within the ' low acne ' group.Only subjects without evidence of acne on face, back and chest were regarded as controls.Samples were obtained from the skin surface with swabs soaked in nutrient broth. Organisms were released from the swab by agitation in 10 ml of nutrient broth on a rotamixer for 5 s; 0.1-ml volumes of the undiluted and tenfold diluted samples were plated out on heated blood agar (7 % v/v horse blood, Oxoid) for isolation of Micrococcaceae and on Brain Heart Infusion Agar with 0.3 % glucose added for isolation of P. acnes. Plates were incubated at 37"C, for 2 days aerobically for Micrococcaceae and 7 days anaerobically for P. acnes in an atmosphere of H2 plus 10 % C02 in Baird and Tatlock cold-catalyst anaerobic jars.Strains for use in inhibition tests were selected on the basis of predominant colonial types of either P. acnes or Micrococcaceae, verified by Gram staining and coded as follows: M = Micrococcaceae; P = Propionibacterium; F = isolated from face; B = isolated from back; hence MF1 , MB2, PF1 , PB2, etc.

Antagonism within populations of micro-organisms from normal human skin

“…Six months after isolation, only six strains from subjects 1 to 10 still produced inhibitors. Similar instability has been reported by Taylor and Mayr-Harting (1 970), Lachowicz andSienienska (1976) andHolland et al (1979).…”

“…They recognised that only 10% of patients carry inhibitory strains. Holland, Cunliffe and Eady (1979) discerned no difference between the prevalence of inhibitory strains on normal skin and skin bearing acne lesions, and they established that inhibitory strains o f Prupiunibacterium acnes outnumbered inhibitory Micrococcaceae by four to one on the face and the back.…”

“…Thus, the methods of demonstrating antagonism v a r i d from simultaneous antagonism (Selwyn and Ellis, 1972) to deferred antagonism (Holland et al, 1979). For indicator organisms, Pillsbury and Rebel1 ( I 952) used strains not originating from the skin.…”

Carriage of inhibitor-producing organisms on human skin

“…They are careful to emphasise that not all "inhibition" or "antagonism" observed on agar medium is the result of antibiotic production. The low rates of producer strains in the present series and in those of Wiseman (1967) andHolland et al (1979) when compared with the findings of Selwyn (1975) thus seem referable to the more stringent test t ,.xlditions when media containing only small amounts of glucose are used. Antibiotics produced by Micrococcaceae are polypeptides (Halbert, Swick and Sonn, 1953;Hsu and Wiseman, 1972).…”

Studies on antagonism between porcine skin bacteria

“…Certain strains of bacteria are capable of inhibiting the growth of other organisms by the production of diffusible inhibitor substances (Barrow 1963). Such production of inhibitors by members of the human skin flora has been investigated both in uitro (Marsh & Selwyn 1977;Holland et al 1979) and in uiuo (Noble & Willie 1980a;Selwyn et al 1975) as a possible defence against infection by pathogenic organisms. Attention has also been paid to the interactions of bacteria on the skin of animals and the potential of using an animal disease as a model for studying bacterial interactions in other species (Lloyd & Noble 1982).…”