Morphology, Haemolysis and Environmental sources of catalase-positive Campylobacters

Abstract

Literature relating to the isolation, identification and importance of catalase-positive campylobacters is reviewed and the need for further work emphasized. Campylobacters have been isolated directly, or after enrichment, from faeces of diarrhoeic patients, from piglets and from sewage and the efficiency of various procedures compared. Attempts to devise a selective medium using dyes were unsuccessful. Campylobacters occur commonly in Reading sewage, the sewage treatment works removes 99.9%, but about 1010 campylobacters/ day are released into the nearby river from the works. Biotyping and serotyping showed that the types in sewage were similar to those isolated from human faeces ana in beef, lamb and chicken meats on sale in Reading. Differentiation betwn campylobacters was studied in two regards. After developing a method involving treatment with Mitomycin to facilitate production of long helical organisms, measurements were made of wavelength and amplitude. It was confirmed that, in general, the thermophilic campylobacters have smaller wavelength and amplitude than the C.fetus subspecies but there was an important exception in that the long organisms of the type strain of f.laridis (NCTC 11352) had wavelength indistinguishable from f.fetus. Separation of the two subspecies of C.fetus could not be achieved using this characteristic. Four strains representing difrerent campylobactersall showed chdlldccl handed helix when examined by scanning electron mocroscopy Haemolysis hitherto generally regarded as not a property of catalase-positive campylobacters, has been demonstrated by most c.jejuni and a few c.coli strains when cultured on heart infusion agar (Difco) at 42°C for 4 days. None of the campylobacters gave a positive CAMP reaction with either Staphylococcus aureus or Streptococcus agalactiae.