Characterization of envelope proteins from Pasteurella haemolytica and Pasteurella multocida

A method was devised for the reproducible isolation of envelopes from Pasteurella haemolytica serotype A2. It was also possible to prepare envelopes from other serotypes of P. haemolytica and Pasteurella multocida using this methodology. Examination of these preparations by SDS-PAGE showed major differences between strains of P. haemolytica and strains of P. multocida which allowed the clear distinction of isolates of these species. Amongst the P. haemolytica serotypes it was possible to distinguish envelope preparations made from A biotype and T biotype organisms easily, but it was not possible to identify individual serotypes from each other. Envelope profiles were sufficiently different between the individual P. multocida serotypes examined to allow each to be identified by its polypeptide profile. Experiments using radiolabelling, antibody absorption, and susceptibility to protease digestion, together with heat modifiability and detergent solubility characteristics indicated that 13 of the envelope proteins were probably surface-located. A high molecular mass immunogenic envelope protein was shown, by immunoblotting, to be present in all strains of P. haemolytica and P. multocida examined.     

Transformation of Pasteurella novicida

Deoxyribonucleic acid from a streptomycin-resistant mutant of Pasteurella novicida transformed portions of P. novicida streptomycin-sensitive populations to streptomycin-resistant. Similarly, mutants auxotrophic for tryptophan or purine biosynthesis were also transformed to nutritional independence.     

Morphology of Pasteurella multocida bacteriophages

Twenty-one tailed phages with icosahedral heads belong to the Myoviridae, Siphoviridae, and Podoviridae families and to four morphological types. Type AU, with 10 phages, has a contractile tail and is morphologically identical with coliphage P2. Lysates contain contracted tail sheaths assembled end-to-end and abnormal structures with long tails and multiple tail sheaths. Types C-2 and 32, with one and three phages, respectively, have long, noncontractile tails. Type 22 includes seven phages, has a short tail, and resembles coliphage T7. Our results agree with previous biological data and suggest that types AU, C-2, 32, and 22 correspond to four different phage species.     

Selective media for Pasteurella pneumotropica

Bacteria from the subcutaneous abscesses which appeared in a laboratory colony of DS mouse since October of 1977 were identified as Pasteurella pneumotropica by various biological examinations. The abscess formation was limited to multiparous female mice over 100 day-age, but virgin females were free from the disease. The MIC of various antibacterial substances showed that potassium tellurite, kanamycin and bacitracin were effective to isolate the organism selectively from various infection sites harboring many other species of bacteria. A novel NKBT medium was prepared by adding these antibacterial substances to the heart infusion agar (HIA) supplemented by 10% Fildes digested blood. A fluid culture medium, TGN broth was prepared for multiplication of the organism by adding 10% Fildes digested blood and potassium tellurite to GN broth. To isolate the organism from the pharyngo-larynx a direct application of mucus wiped off the infection site onto the culture medium was sufficient, but pre-multiplication in the TGN broth was required for isolation of the organism from gut contents before inoculation onto the NKBT medium. The pre-cultivation in the TGN broth vastly improved the recovery of the organism especially from feces. Thereby we could easily detect the latent infection of this bacterium without sacrificing animals.     

Pasteurella Septica Infections in Humans

Five instances of infection by Pasteurella septica, an organism which closely resembles H. influenzae on methods of presumptive bacteriology, are reported from an acute treatment general hospital practice over a period of three months. This infection decidedly outnumbers those caused by other Pasteurella species in North America. The organism is apt to be identified as H. influenzae, Friedlander''s bacillus or Mima polymorpha. Unlike these, it shows extreme sensitivity to penicillin, sometimes combined with resistance to antibiotics that inhibit or kill these other organisms.While in the past Pasteurella septica infection was considered to be characterized by persistent local infection following domestic animal scratches or bites, it is clear that it is more often found in cases of respiratory tract infection and peripheral septic disease. In three of the five cases reported, exposure to animals was the source of infection.Because mixed infection with confusingly similar organisms may occur, lack of awareness of extreme penicillin sensitivity of Pasteurella septica may account for persistent failure of antibiotic therapy.