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Pyocin types of Pseudomonas aeruginosa isolated from infections in Laǵos University Teaching Hospital
Journal
of Hospital
Infection
(1982) 3, 87-89
SHORT REPORT
Pyocin types of Pseudomonas aeruginosa isolated from infections in Lagos University Teaching Hospital A. 0. Coker, C. E. Anyiwo, S. F. Lawal, 0. Ogunbi, Q. Lasi, S. 0. Daniel and M. Dawodu
Departments of Microbiology and Parasitology and Community Health, Lagos University Teachiqg Hospital, Surulere, Lagos Introduction
Since Pseudomonas aeruginosa has been recognized as the cause of serious morbidity and high mortality in hospital patients (Feingold, 1970; Ogunbi and Anyiwo, 1977; Daniel, 1977) it has become necessary to pyocin-type isolates from the Lagos University Teaching Hospital in order to assess the distribution and frequency of particular types for epidemiological purposes. Materials and methods
Source of strains The pseudomonas strains investigated were obtained from a stock collection of 172 local isolates from patients with burns, surgical wounds and skin infections. They were collected over a period of 12 months (January-December 1979) having been primarily identified and confirmed as Ps. aeruginosa in our routine laboratory. Pyocin typing The method used was that described by Gillies and Govan (1966) and Heckmann (1972). Identification of pyocin types was based on the pattern of inhibition of the indicator strains according to the latest complete table which lists 105 types (Govan, 1978; Heckmann, 1972). Results
Out of the 172 strains of Ps. aeruginosa investigated, 170 (98.8 per cent) were typable. Two strains were unclassified (Table I). Out of the eight different types identified: types 24 (44.8 per cent); V.A. 52 (37.8 per cent); 50 (5.8 per cent) and 17 (4.1 per cent) were the commonest. Others were 28 (2.9 per cent), V.A. 40 (2.3 per cent), 19 (1.2 per cent) and 31 (1.2 per cent). c195-67434010087
+ 03$32.00/0
0 WKz The Hospital
87
Infection
Society
A. 0. Coker et d.
88 Table
I. Distribution
of pyocin types from
Pyocin type
Unclassifiable
wow&,
burns and skin infections
No. of strains
Per cent of total strains
172
100-o
31 strains Total
Discussion
Typability of the isolates, as expected, was high thus comparing favourably with a similar study carried out by Baltch and Griflin (1972). From our results we have established that the prevalent types of Ps. aeruginosa involved in hospital-acquired infections at the Lagos University Teaching Hospital are 24 and V.A. 52. These were similar to those found in an earlier study in a different region of Nigeria (Alausa et al., 1968). It is noteworthy that types 1, 3, 5 and 10 reported as prevalent elsewhere (Heckmann, 1972; Bergan, 1973 ; Govan, 1978) were not seen in our study, probably due to the small number of isolates examined. Efforts will be intensified in future to look for these types in a larger stock of isolates. The two isolates termed ‘unclassifiable’ were not pyocin typable and therefore may be new. Both were tested in parallel with the 170 typable isolates. The two strains showed inhibitory reactions not comparable with the inhibitory reactions of any of the pyocin-typable strains described by Heckmann (1972) and Govan (1978). We envisage that the data provided in this report will provide a useful epidemiological tool for tracing the source of pseudomonas infections in future. We thank Professor Gillies of the University of Edinburgh for supplying a set of indicator strains used, and the staff of our routine bacteriology laboratory for providing the stock of isolates investigated.
References Alausa, K. O., Fayinka, 0. A., Montefiore, D. & Okubadejo, 0. A. (1968). Pyocine typing of hospital strains of Pseudomonas pyocyanae. Journal of Nigeria Medical Association 5, 27. Baltch, A. L. & Griffin, P. E. (1972). Pseudomonas aeruginosa: pyocine types and clinical experience with infections in a general hospital. American Journal of .Medical Sciences 264, 233. Bergan, T. (1973). Epidemiological markers for Pseudomonas aeruginosa: serogrouping, pyocine typing and their interrelations. Acta Pathologica Microbiologica Scandinavica
81, 70. Daniel, S. 0. (1977). An epidemiological study of nosocomial University Teaching Hospital. Community Health 8, 139.
infections
at the Lagos
Pyocin types of Pseudomonas aerughosa
89
Feingold, D. S. (1970). Hospital-acquired infections. New EnglandJournal of Medicine 283, 1384. Gillies, R. R. & Govan, J. R. W. (1966). Tying of Pseudomonas pyocyanea by pyocine production. Journal of Pathology and Bacteria 91, 339. Govan, J. R. W. (1978). Pyocin typing of Pseudomonas aeruginosa. In Methods in Microbiology, Vol. 10. (Bergan, T. & Norris, J. R., Eds), pp. 61-91. Academic Press, London. Heckmann, M. G. (1972). Pyocine typing of Pseudomonas aeruginosa. Clinical and epidemiological aspects. American Journal of Clinical Pathology 57, 35. Ogunbi, 0. & Anyiwo? C. E. (1977). A review of two year activities 1974-1975, Lagos University Teaching Hospital infection control programme. Proceedings of First National Symposium on Nosocomial Infections, ch. 12, pp. 57-62. Litramed, Lagos, Nigeria.
of Hospital
Infection
(1982) 3, 87-89
SHORT REPORT
Pyocin types of Pseudomonas aeruginosa isolated from infections in Lagos University Teaching Hospital A. 0. Coker, C. E. Anyiwo, S. F. Lawal, 0. Ogunbi, Q. Lasi, S. 0. Daniel and M. Dawodu
Departments of Microbiology and Parasitology and Community Health, Lagos University Teachiqg Hospital, Surulere, Lagos Introduction
Since Pseudomonas aeruginosa has been recognized as the cause of serious morbidity and high mortality in hospital patients (Feingold, 1970; Ogunbi and Anyiwo, 1977; Daniel, 1977) it has become necessary to pyocin-type isolates from the Lagos University Teaching Hospital in order to assess the distribution and frequency of particular types for epidemiological purposes. Materials and methods
Source of strains The pseudomonas strains investigated were obtained from a stock collection of 172 local isolates from patients with burns, surgical wounds and skin infections. They were collected over a period of 12 months (January-December 1979) having been primarily identified and confirmed as Ps. aeruginosa in our routine laboratory. Pyocin typing The method used was that described by Gillies and Govan (1966) and Heckmann (1972). Identification of pyocin types was based on the pattern of inhibition of the indicator strains according to the latest complete table which lists 105 types (Govan, 1978; Heckmann, 1972). Results
Out of the 172 strains of Ps. aeruginosa investigated, 170 (98.8 per cent) were typable. Two strains were unclassified (Table I). Out of the eight different types identified: types 24 (44.8 per cent); V.A. 52 (37.8 per cent); 50 (5.8 per cent) and 17 (4.1 per cent) were the commonest. Others were 28 (2.9 per cent), V.A. 40 (2.3 per cent), 19 (1.2 per cent) and 31 (1.2 per cent). c195-67434010087
+ 03$32.00/0
0 WKz The Hospital
87
Infection
Society
A. 0. Coker et d.
88 Table
I. Distribution
of pyocin types from
Pyocin type
Unclassifiable
wow&,
burns and skin infections
No. of strains
Per cent of total strains
172
100-o
31 strains Total
Discussion
Typability of the isolates, as expected, was high thus comparing favourably with a similar study carried out by Baltch and Griflin (1972). From our results we have established that the prevalent types of Ps. aeruginosa involved in hospital-acquired infections at the Lagos University Teaching Hospital are 24 and V.A. 52. These were similar to those found in an earlier study in a different region of Nigeria (Alausa et al., 1968). It is noteworthy that types 1, 3, 5 and 10 reported as prevalent elsewhere (Heckmann, 1972; Bergan, 1973 ; Govan, 1978) were not seen in our study, probably due to the small number of isolates examined. Efforts will be intensified in future to look for these types in a larger stock of isolates. The two isolates termed ‘unclassifiable’ were not pyocin typable and therefore may be new. Both were tested in parallel with the 170 typable isolates. The two strains showed inhibitory reactions not comparable with the inhibitory reactions of any of the pyocin-typable strains described by Heckmann (1972) and Govan (1978). We envisage that the data provided in this report will provide a useful epidemiological tool for tracing the source of pseudomonas infections in future. We thank Professor Gillies of the University of Edinburgh for supplying a set of indicator strains used, and the staff of our routine bacteriology laboratory for providing the stock of isolates investigated.
References Alausa, K. O., Fayinka, 0. A., Montefiore, D. & Okubadejo, 0. A. (1968). Pyocine typing of hospital strains of Pseudomonas pyocyanae. Journal of Nigeria Medical Association 5, 27. Baltch, A. L. & Griffin, P. E. (1972). Pseudomonas aeruginosa: pyocine types and clinical experience with infections in a general hospital. American Journal of .Medical Sciences 264, 233. Bergan, T. (1973). Epidemiological markers for Pseudomonas aeruginosa: serogrouping, pyocine typing and their interrelations. Acta Pathologica Microbiologica Scandinavica
81, 70. Daniel, S. 0. (1977). An epidemiological study of nosocomial University Teaching Hospital. Community Health 8, 139.
infections
at the Lagos
Pyocin types of Pseudomonas aerughosa
89
Feingold, D. S. (1970). Hospital-acquired infections. New EnglandJournal of Medicine 283, 1384. Gillies, R. R. & Govan, J. R. W. (1966). Tying of Pseudomonas pyocyanea by pyocine production. Journal of Pathology and Bacteria 91, 339. Govan, J. R. W. (1978). Pyocin typing of Pseudomonas aeruginosa. In Methods in Microbiology, Vol. 10. (Bergan, T. & Norris, J. R., Eds), pp. 61-91. Academic Press, London. Heckmann, M. G. (1972). Pyocine typing of Pseudomonas aeruginosa. Clinical and epidemiological aspects. American Journal of Clinical Pathology 57, 35. Ogunbi, 0. & Anyiwo? C. E. (1977). A review of two year activities 1974-1975, Lagos University Teaching Hospital infection control programme. Proceedings of First National Symposium on Nosocomial Infections, ch. 12, pp. 57-62. Litramed, Lagos, Nigeria.