Laboratory Animals (1976) 10, 365-373.
365
THE MICROBIOLOGICAL
AND PARASITOLOGICAL
STATUS OF LABORATORY ANIMALS FROM ACCREDITED
BREEDERS
IN THE UNITED
KINGDOM
b)i
STEPHEN
SPARROW
Medical Research Council Laboratory Animals Centre, Woodmansterne Road, Carshalfol/, SM5 4EF SUMMARY
The incidence of significant organisms isolated from mice, hamsters, rats, guinea-pigs and rabbits from Accredited Breeders in the United Kingdom (1970-1974) is recorded. An improvement in quality in the case of mice, rats and guinea-pigs as a result of hysterectomy derivation is demonstrated, and the importance of the various organisms is discussed. There has been, over the years, a steady move towards the defined laboratory animal. In the field of microbiology this has given rise to terms such as specified-pathogen-free (SPF), minimal disease (M D), germfree, gnotobiotic, axenic, and others in less common use. A corol]ary to better definition has been improved quality, although these concepts should be regarded an separate entities. In ]950 the Laboratory Anima]s Centre introduced an Accrediation Scheme for commercial breeders of laboratory animals with the aim of improving the quality of animals available to the research worker. In] 969 the Scheme was extended in order to monitor the quality and thus define the animal microbiologically in a rational way (Townsend, 1969). Since the terms specified-pathogen-free, germfree, axenic and so on were open to wide interpretation a system of star grading was introduced based on the absence of certain organisms from the colony as determined by routine patho]ogical screening of the colony by the Centre. The results from this screening procedure has given an opportunity to examine the pattern of disease in commercial colonies over an extended period. There have been a number of surveys of laboratory animal disease but mostly they have examined a narrow spectrum uf organisms and have rarely been concerned with commercia] sources. Seamer & Chesterman (1967) published the results of a questionnaire sent to 46 research establishments. Flynn, Brennan & Fritz (1965) carried out an examination of mice from I I com-
366
S. SPARROW
mercial colonies in the USA for bacterial pathogens and parasites. Also in America, Poiley (1970) surveyed murine viruses from 22 colonies over a 22 month period and tried to relate his findings to levels of management. In Japan, Tan,aka, Ohshima & Fujinami (1974) carried out a comprehensive survey of parasites of mice, rats, guinea-pigs and rabbits involving 5213 animals from 35 colonies. There have, of course, been many investigations of individual organisms from the different laboratory species and many commercial breeders publish the results of screening their own animals for pathogens, but the general health status of laboratory animals from commercial sources is unknown in most countries. MATERIALS
AND
METHODS
Animals from a total of 15 mouse, 7 hamster, 9 rat, 27 guinea-pig and 26 rabbit colonies were examined over a 4 year period from 1970 to March 1974. Some colonies were not examined over the entire period as a number of breeders resigned from the Scheme during the 4 years. This was particularly the case for guinea-pig and rabbit breeders. 6 adult and 2 weaner animals were selected from each colony every 6 months for those graded Category 3 or above, and every 12 months for Category ] and 2. They were transported to the pathology laboratory in sterile filter containers; 2 adults and 2 weaners were examined for parasites and 4 adults bacteriologically, except in the case of rabbits where the numbers were I adult, 1 weaner and 2 adults respectively. The procedures adopted for examination and the cultural methods for the various organisms are described by the Accreditation Microbiological Advisory Committee (1972). To be graded in the various categories (LAC, ] 969) colonies had to be free of specified organisms. Category *: Shigella spp., Salmonella spp., Mycobacterium tuberculosis, Yersinia pseudotuberculosis, pathogenic dermatrophic fungi, and Sarcoptes scabei. Category **: lntermediate stages of cestodes, obligate parasitic ectromelia (mice), and myxomatosis (rabbits).
arthropods,
Category ***: Mycoplasma spp. (rats and mice), Pasteurella spp., Bordetella bronchiseptica, Streptobacillus moniliformis (rats and mice), Coccidia spp., pathogenic helminths, Corynebacterium murium (mice), Treponema cuniculi (rabbits). Category ****: Pneumococcus spp., Klebsiella pneumoniae, cytogenes, all pathogenic protozoa, all helminths, Mycoplasma and guinea-pigs), Piriformis necrophorus (rabbits).
Listeria monospp. (hamsters
LABORATORY
ANIMAL
PATHOGEN
STATUS
367
RESULTS
The results for mice, hamsters and rats, guinea-pigs and rabbits cover a period from 1970 until March 1974. In Tables 1, 2, 3,4 apd 5 the 1st column gives the number of groups (as a percentage) from which the various organisms were isolated and the 2nd column gives the percentage number of animals from which the organisms were isolated in infected colonies. Fig 1 shows the average number of organisms isolated per group of animals for each year since 1970. Fig. 2 shows the percentage number of groups of mice, rats, Table 1. The isolation of organisms from 96 groups of mice.
% incidence/ group Pasteurella pneumotropica Hexamita muris Entamoeba muris Myobia musculi Trichomonas spp. Syphacia obvelata Mycoplasma pulmonis Aspiculuris tetraptera Giardia muris Cysticercus fasciolaris Eimeria spp. Hymenolepis nana
f. ml/llOcida, Salmonella montevideo, Klebsiella
% incidence in infected colonies
65,6 29·2 27·1 26·0 24·0 21·9 16·7 13,5 8,3
83 71 59 95
4·2
31 100
87 67 93
67 75
3·1 2-l
63
spp., Mycoptes muscufillus and an unidentified
Pasteurella spp. were isolated from 1 group each.
Table 2. The isolation of organisms from 32 groups of hamsters.
% incidence/ group Giardia spp. Trichomonas spp. Pasteurella pneumotropia Syphacia obvelata Hexamita spp. Entamoeba muris Pasteurella multocida Hymenolepis nana Pasteurella haemolytica Pasteurella (unidentified) Trichuris muris Demodex aurati and D. criceti
% incidence/ animal
84,4
90
81·3 81·3 56,3
99
70
50·0 37'5 21·9 ]2,5 6,3
61 94 81 43 44 37
3·1
25
3·1
25
3·1
100
S. SPARROW
368
Table 3. The isolation of organisms
from 67 groups of rats.
% Pasteurella pneumotropica Syphacia obvelata Hexamita muris Entamoeba muris Trichomonas spp. Mycoplasma pulmonis Giardia muris Myobia
incidence! group 58·2
musculi
Polyp/ax spp. Bordetella bronchiseptica
% incidence! animal
82
38,8
72
28·4 28·4
93
26-9 23-9
82
70 84
10·4 7·5
89
4·5
100
4,5
42
89
Streptobacillus moniliformis, Klebsiella spp., Mycoptes musculinus and an unidentified Pasteurella spp. were isolated from I group each.
Table 4. The isolation of organisms from 64 groups of guinea-pigs.
% Gliricola porcelli Pasteurella pneumotropica Gyropus ovalis Chirodiscoides caviae Bordetella bronchiseptica Pasteurella multocida Pasteurella haemolytica Pasteurella spp. Paraspidodera uncinata Salmonella typhimurium
Table 5. The isolation of organisms
incidence/ group
65·1 36,5 34,9 J 1·8 14·3
6,4 4,8 3·2 3·2 1·6
animal
98 49
79 100
50 25 25 63 75
25
from 62 groups of rabbits.
% incidence! Cheyletiella parasitivorax Bordetella bronchiseptica Listophorus gibbus Pasteurella multocida Passalurus ambiguus Pasteurella pneumotropica Psoroptes cuniculi Pasteurella spp.
% incidence!
% incidence/
group
animal
82·8 43'] 22·4
85
86 92
5·2
54 50 65 83
3,4
100
16·0 8,6
5·2
LABORATORY
ANIMAL
PATHOGEN
STATUS
369
and guinea-pigs that were graded at Category *** (3) or **** (4) for each year since 1970. No group of hamsters has been graded higher than Category ** (2) and only 1 group of rabbits.
/.,
5
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A
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.'/
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...P'" /.,
4
o- ..- .. -
, a ....,
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",' .. -(j' .'
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~ 3
-'.
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; .••.•ry mice. Laboratory Animal Care 15, 440-447. LAC (1969, J974). The Accreditation and Recognition Schemes for Suppliers of Laboratory Animals. Manual Series No. I. Jst and 2nd editions. Nikkels, R. J. & Mullink, J. W. M. A. (1971). Bordetella bronchiseptica pneumonia in guineapigs. Description of the disease and elimination by vaccination. Zeitschrift fiir Versuchstiertkunde 13, 105-111. Owen, D. (1972). Common parasites of laboratory rodents and lagomorphs. Laboratory Animals Centre Handbook 1. London: Her Majesties Stationery Office. Owen, D. (1973). The occurrence of Demodex aurati and Demodex criceti in the Syrian hamster (Mesocricetus auratus) in the United Kingdom. Veterinary Record 92, 282-284. Poi ley, S. M. (1970). A survey of indigenous murine viruses in a variety of production and research animal facilities. Laboratory Animal Care 20, 643-650. Seamer, J. & Chestermann, F. C. (1967). A survey of disease in laboratory animals. taboratory Animals 1, 117-139. Sebesteny, A. (1969). Pathogenicity of intestinal flagellates in mice. Laboratory Animals 3, 71-77. Scbesteny, A. (1974). The transmission of intestinal flagellates between mice and rats. Laboratory Animals 8, 79-81. Tanaka, H., Ohshima, S. & Fujinami, F. (1974). A survey of parasites in commercially available small laboratory mammals. Experimental Animals 23, 15-30. Townsend, G. (1969). The grading of commercially bred laboratory animals. Veterinary Record 83, 225-226. van der Schaaf, A., Mullink, J. W. M. A., Nikkels, R. J. & Goudswaard, J. (1970). Pasteurella pneumotropica as a casual microorganism of multiple subcutaneous abscesses in a colony Wistar rats. Zeitschrift fiir Versuchstierkunde 12, 356-362. Watson, W. T., Goldsboro, J. A., Williams, F. P. & Sueur, R. (1975). Experimental respiratory infection with Pasteurella multocida and Bordetella bronchiseptica in rabbits. Laboratory Animal Science 25, 459-464.
365
THE MICROBIOLOGICAL
AND PARASITOLOGICAL
STATUS OF LABORATORY ANIMALS FROM ACCREDITED
BREEDERS
IN THE UNITED
KINGDOM
b)i
STEPHEN
SPARROW
Medical Research Council Laboratory Animals Centre, Woodmansterne Road, Carshalfol/, SM5 4EF SUMMARY
The incidence of significant organisms isolated from mice, hamsters, rats, guinea-pigs and rabbits from Accredited Breeders in the United Kingdom (1970-1974) is recorded. An improvement in quality in the case of mice, rats and guinea-pigs as a result of hysterectomy derivation is demonstrated, and the importance of the various organisms is discussed. There has been, over the years, a steady move towards the defined laboratory animal. In the field of microbiology this has given rise to terms such as specified-pathogen-free (SPF), minimal disease (M D), germfree, gnotobiotic, axenic, and others in less common use. A corol]ary to better definition has been improved quality, although these concepts should be regarded an separate entities. In ]950 the Laboratory Anima]s Centre introduced an Accrediation Scheme for commercial breeders of laboratory animals with the aim of improving the quality of animals available to the research worker. In] 969 the Scheme was extended in order to monitor the quality and thus define the animal microbiologically in a rational way (Townsend, 1969). Since the terms specified-pathogen-free, germfree, axenic and so on were open to wide interpretation a system of star grading was introduced based on the absence of certain organisms from the colony as determined by routine patho]ogical screening of the colony by the Centre. The results from this screening procedure has given an opportunity to examine the pattern of disease in commercial colonies over an extended period. There have been a number of surveys of laboratory animal disease but mostly they have examined a narrow spectrum uf organisms and have rarely been concerned with commercia] sources. Seamer & Chesterman (1967) published the results of a questionnaire sent to 46 research establishments. Flynn, Brennan & Fritz (1965) carried out an examination of mice from I I com-
366
S. SPARROW
mercial colonies in the USA for bacterial pathogens and parasites. Also in America, Poiley (1970) surveyed murine viruses from 22 colonies over a 22 month period and tried to relate his findings to levels of management. In Japan, Tan,aka, Ohshima & Fujinami (1974) carried out a comprehensive survey of parasites of mice, rats, guinea-pigs and rabbits involving 5213 animals from 35 colonies. There have, of course, been many investigations of individual organisms from the different laboratory species and many commercial breeders publish the results of screening their own animals for pathogens, but the general health status of laboratory animals from commercial sources is unknown in most countries. MATERIALS
AND
METHODS
Animals from a total of 15 mouse, 7 hamster, 9 rat, 27 guinea-pig and 26 rabbit colonies were examined over a 4 year period from 1970 to March 1974. Some colonies were not examined over the entire period as a number of breeders resigned from the Scheme during the 4 years. This was particularly the case for guinea-pig and rabbit breeders. 6 adult and 2 weaner animals were selected from each colony every 6 months for those graded Category 3 or above, and every 12 months for Category ] and 2. They were transported to the pathology laboratory in sterile filter containers; 2 adults and 2 weaners were examined for parasites and 4 adults bacteriologically, except in the case of rabbits where the numbers were I adult, 1 weaner and 2 adults respectively. The procedures adopted for examination and the cultural methods for the various organisms are described by the Accreditation Microbiological Advisory Committee (1972). To be graded in the various categories (LAC, ] 969) colonies had to be free of specified organisms. Category *: Shigella spp., Salmonella spp., Mycobacterium tuberculosis, Yersinia pseudotuberculosis, pathogenic dermatrophic fungi, and Sarcoptes scabei. Category **: lntermediate stages of cestodes, obligate parasitic ectromelia (mice), and myxomatosis (rabbits).
arthropods,
Category ***: Mycoplasma spp. (rats and mice), Pasteurella spp., Bordetella bronchiseptica, Streptobacillus moniliformis (rats and mice), Coccidia spp., pathogenic helminths, Corynebacterium murium (mice), Treponema cuniculi (rabbits). Category ****: Pneumococcus spp., Klebsiella pneumoniae, cytogenes, all pathogenic protozoa, all helminths, Mycoplasma and guinea-pigs), Piriformis necrophorus (rabbits).
Listeria monospp. (hamsters
LABORATORY
ANIMAL
PATHOGEN
STATUS
367
RESULTS
The results for mice, hamsters and rats, guinea-pigs and rabbits cover a period from 1970 until March 1974. In Tables 1, 2, 3,4 apd 5 the 1st column gives the number of groups (as a percentage) from which the various organisms were isolated and the 2nd column gives the percentage number of animals from which the organisms were isolated in infected colonies. Fig 1 shows the average number of organisms isolated per group of animals for each year since 1970. Fig. 2 shows the percentage number of groups of mice, rats, Table 1. The isolation of organisms from 96 groups of mice.
% incidence/ group Pasteurella pneumotropica Hexamita muris Entamoeba muris Myobia musculi Trichomonas spp. Syphacia obvelata Mycoplasma pulmonis Aspiculuris tetraptera Giardia muris Cysticercus fasciolaris Eimeria spp. Hymenolepis nana
f. ml/llOcida, Salmonella montevideo, Klebsiella
% incidence in infected colonies
65,6 29·2 27·1 26·0 24·0 21·9 16·7 13,5 8,3
83 71 59 95
4·2
31 100
87 67 93
67 75
3·1 2-l
63
spp., Mycoptes muscufillus and an unidentified
Pasteurella spp. were isolated from 1 group each.
Table 2. The isolation of organisms from 32 groups of hamsters.
% incidence/ group Giardia spp. Trichomonas spp. Pasteurella pneumotropia Syphacia obvelata Hexamita spp. Entamoeba muris Pasteurella multocida Hymenolepis nana Pasteurella haemolytica Pasteurella (unidentified) Trichuris muris Demodex aurati and D. criceti
% incidence/ animal
84,4
90
81·3 81·3 56,3
99
70
50·0 37'5 21·9 ]2,5 6,3
61 94 81 43 44 37
3·1
25
3·1
25
3·1
100
S. SPARROW
368
Table 3. The isolation of organisms
from 67 groups of rats.
% Pasteurella pneumotropica Syphacia obvelata Hexamita muris Entamoeba muris Trichomonas spp. Mycoplasma pulmonis Giardia muris Myobia
incidence! group 58·2
musculi
Polyp/ax spp. Bordetella bronchiseptica
% incidence! animal
82
38,8
72
28·4 28·4
93
26-9 23-9
82
70 84
10·4 7·5
89
4·5
100
4,5
42
89
Streptobacillus moniliformis, Klebsiella spp., Mycoptes musculinus and an unidentified Pasteurella spp. were isolated from I group each.
Table 4. The isolation of organisms from 64 groups of guinea-pigs.
% Gliricola porcelli Pasteurella pneumotropica Gyropus ovalis Chirodiscoides caviae Bordetella bronchiseptica Pasteurella multocida Pasteurella haemolytica Pasteurella spp. Paraspidodera uncinata Salmonella typhimurium
Table 5. The isolation of organisms
incidence/ group
65·1 36,5 34,9 J 1·8 14·3
6,4 4,8 3·2 3·2 1·6
animal
98 49
79 100
50 25 25 63 75
25
from 62 groups of rabbits.
% incidence! Cheyletiella parasitivorax Bordetella bronchiseptica Listophorus gibbus Pasteurella multocida Passalurus ambiguus Pasteurella pneumotropica Psoroptes cuniculi Pasteurella spp.
% incidence!
% incidence/
group
animal
82·8 43'] 22·4
85
86 92
5·2
54 50 65 83
3,4
100
16·0 8,6
5·2
LABORATORY
ANIMAL
PATHOGEN
STATUS
369
and guinea-pigs that were graded at Category *** (3) or **** (4) for each year since 1970. No group of hamsters has been graded higher than Category ** (2) and only 1 group of rabbits.
/.,
5
./
A
\ \
.'/
/'
...P'" /.,
4
o- ..- .. -
, a ....,
.\ \
'"
\
",' .. -(j' .'
\ \ \
~ 3
-'.
0...
,","'0.-...
.~
; .••.•ry mice. Laboratory Animal Care 15, 440-447. LAC (1969, J974). The Accreditation and Recognition Schemes for Suppliers of Laboratory Animals. Manual Series No. I. Jst and 2nd editions. Nikkels, R. J. & Mullink, J. W. M. A. (1971). Bordetella bronchiseptica pneumonia in guineapigs. Description of the disease and elimination by vaccination. Zeitschrift fiir Versuchstiertkunde 13, 105-111. Owen, D. (1972). Common parasites of laboratory rodents and lagomorphs. Laboratory Animals Centre Handbook 1. London: Her Majesties Stationery Office. Owen, D. (1973). The occurrence of Demodex aurati and Demodex criceti in the Syrian hamster (Mesocricetus auratus) in the United Kingdom. Veterinary Record 92, 282-284. Poi ley, S. M. (1970). A survey of indigenous murine viruses in a variety of production and research animal facilities. Laboratory Animal Care 20, 643-650. Seamer, J. & Chestermann, F. C. (1967). A survey of disease in laboratory animals. taboratory Animals 1, 117-139. Sebesteny, A. (1969). Pathogenicity of intestinal flagellates in mice. Laboratory Animals 3, 71-77. Scbesteny, A. (1974). The transmission of intestinal flagellates between mice and rats. Laboratory Animals 8, 79-81. Tanaka, H., Ohshima, S. & Fujinami, F. (1974). A survey of parasites in commercially available small laboratory mammals. Experimental Animals 23, 15-30. Townsend, G. (1969). The grading of commercially bred laboratory animals. Veterinary Record 83, 225-226. van der Schaaf, A., Mullink, J. W. M. A., Nikkels, R. J. & Goudswaard, J. (1970). Pasteurella pneumotropica as a casual microorganism of multiple subcutaneous abscesses in a colony Wistar rats. Zeitschrift fiir Versuchstierkunde 12, 356-362. Watson, W. T., Goldsboro, J. A., Williams, F. P. & Sueur, R. (1975). Experimental respiratory infection with Pasteurella multocida and Bordetella bronchiseptica in rabbits. Laboratory Animal Science 25, 459-464.
