IV. INVESTIGATION OF C. DIPHTHERIAE
169
(c) Reference strains have to be stored either by monthly transfers on
sealed Loeffler slants and kept at room temperature in the dark, or lyophilised.
7. Biological materials for phage typing
I t is advisable to perform phage typing only in specialised reference
laboratories. Recommended are the sets of 22 original and 33 additional
phages, preferably supplied by the Cantacuzino Institute, Bucharest,
Romania, stocked or produced in each reference laboratory (from stocked
phage strains available from the Cantacuzino Institute).
8. Biological materials for lysogenicity
A large set of indicator sensitive strains from every biotype is recommended. These sensitive strains may either be provided by the Cantacuzino
Institute or be selected in each country from local strains.
9. Biological materials for bacteriocin typing
A set of 20 bacteriocinogenic corynebacteria are today available in the
Cantacuzino Institute. I n England, Dr Zamiri (Sheffield) and in Canada,
Sheila Toshach (Edmonton Alberta IJniversity) may provide reference
strains.
However, it is advisable in the present state of bacteriocin typing to also
select additional local bacteriocinogenic strains.
XV. GENERAL CONCLUSIONS
The effectiveness of the national epidemiological programme of surveillance and control of diphtheria in Romania has led to a spectacular drop
in diphtheria morbidity during the last 20 years (from 6 per 100 000 in
1955 to zero case in 1976, 1977).
The level of antidiphtheria1 immunity has increased from 60% in 1955,
to 96% Schick negative reactors in 1977, and concomitantly there has been
a decrease in toxigenicity among circulating strains of C. d$htheriae (from
86% in 1955-1966 to 5% in 1977).
REFERENCES
Anderson, J. S., Happold, F. C., McLeod, J . W. and Thompson, J. G. (1931).
Anderson, J. S., Cooper, K. E., Happold, F. C. and McLeod, J. W. (1933). J .
Babes, V. (1886). Bull. SOC. Anat. (Paris), 61, 72.
Banach, T. M. and Hawirko, R. Z. (1966).J. Bnct., 92,1304-1310.
Barber, C., Calalb, G., Meitert, E., Saragea A., Stgnicg, E. and Stoian, C. (1963)
J . Path. Bact., 34, 667-681.
Path. Bact., 36, 169-182.
Arch. roum. Path. exp., 22, 357-367.
169
(c) Reference strains have to be stored either by monthly transfers on
sealed Loeffler slants and kept at room temperature in the dark, or lyophilised.
7. Biological materials for phage typing
I t is advisable to perform phage typing only in specialised reference
laboratories. Recommended are the sets of 22 original and 33 additional
phages, preferably supplied by the Cantacuzino Institute, Bucharest,
Romania, stocked or produced in each reference laboratory (from stocked
phage strains available from the Cantacuzino Institute).
8. Biological materials for lysogenicity
A large set of indicator sensitive strains from every biotype is recommended. These sensitive strains may either be provided by the Cantacuzino
Institute or be selected in each country from local strains.
9. Biological materials for bacteriocin typing
A set of 20 bacteriocinogenic corynebacteria are today available in the
Cantacuzino Institute. I n England, Dr Zamiri (Sheffield) and in Canada,
Sheila Toshach (Edmonton Alberta IJniversity) may provide reference
strains.
However, it is advisable in the present state of bacteriocin typing to also
select additional local bacteriocinogenic strains.
XV. GENERAL CONCLUSIONS
The effectiveness of the national epidemiological programme of surveillance and control of diphtheria in Romania has led to a spectacular drop
in diphtheria morbidity during the last 20 years (from 6 per 100 000 in
1955 to zero case in 1976, 1977).
The level of antidiphtheria1 immunity has increased from 60% in 1955,
to 96% Schick negative reactors in 1977, and concomitantly there has been
a decrease in toxigenicity among circulating strains of C. d$htheriae (from
86% in 1955-1966 to 5% in 1977).
REFERENCES
Anderson, J. S., Happold, F. C., McLeod, J . W. and Thompson, J. G. (1931).
Anderson, J. S., Cooper, K. E., Happold, F. C. and McLeod, J. W. (1933). J .
Babes, V. (1886). Bull. SOC. Anat. (Paris), 61, 72.
Banach, T. M. and Hawirko, R. Z. (1966).J. Bnct., 92,1304-1310.
Barber, C., Calalb, G., Meitert, E., Saragea A., Stgnicg, E. and Stoian, C. (1963)
J . Path. Bact., 34, 667-681.
Path. Bact., 36, 169-182.
Arch. roum. Path. exp., 22, 357-367.