Biomedical subjects
Publications and source records attributed to M Bisgaard.
Comparison of phenotypical characters obtained from the type strain of Pasteurella caballi and a previously unclassified P.sp., isolated from an infected wound on a veterinary surgeon, allowed classification of the P.sp. with P. caballi. The P.sp. was isolated in a mixed culture with Escherichia coli and probably represents the first human isolate of P. caballi.
We performed hybridizations between labeled rRNAs from seven representative members of the family Pasteurellaceae and from three other taxa on the one hand and DNAs from 53 strains known or presumed to belong to the Pasteurellaceae on the other hand. The members of the Pasteurellaceae are most closely related to members of the Enterobacteriaceae, the Vibrionaceae, the Aeromonadaceae, and the genus Alteromonas. The family Pasteurellaceae is very heterogeneous. There are at least seven rRNA branches. Several organisms with the same genus name are dispersed over the entire dendrogram. The "Histophilus ovis," [Haemophilus] ducreyi, [Actinobacillus] actinomycetemcomitans, and [Haemophilus] aphrophilus rRNA branches are separate and quite remote from the three authentic genera in this family; this might justify eventual later separate generic status. DNA-rRNA hybridization with suitable, labeled rRNA probes is an excellent method to establish whether an organism belongs in the Pasteurellaceae; e.g., some strains of Bisgaard's taxa 7, 13, and 16 and of the gas-producing "SP" group certainly belong in this family, whereas three bovine lymphangitis organisms (strains NCTC 10547, NCTC 10549, and NCTC 10553), [Haemophilus] piscium ATCC 10801T (T = type strain), and [Pasteurella] piscicida ATCC 17911 belong in the Enterobacteriaceae, the Aeromonadaceae, and the Vibrionaceae, respectively.
Body temperature, P-cortisol, P-glucose, P-transferrin, haematocrit and total and differential leucocyte counts were investigated in 24 men undergoing inguinal herniotomy, but otherwise healthy. The patients were randomized to general anaesthesia (GA, n = 8), epidural analgesia (E, n = 8) or epidural analgesia + indomethacin (E + I, n = 8). The rectal temperature rose significantly after surgery, except in the E + I group, and increase in blood granulocytes was significantly less in these patients than in the GA group. Group E showed intermediate changes. P-transferrin changes were similar in all three groups. Glucose and cortisol showed only slight increase in the GA group and constant values in groups E and E + I. It is concluded that prostaglandins may play a role in mediating the surgical stress response, but that factors other than neural stimuli and prostaglandins are important in releasing postoperative granulocytosis.
Several unclassified strains were obtained during investigations of the aerobic pharyngeal flora of healthy white laboratory mice originating from four different colonies. Nineteen strains formed a group tentatively designated taxon 12. Comparative investigations including taxon 12, P. ureae sensu stricto. "P. urea" strain Ackerman 80-443D, P. pneumotropica sensu stricto, P. pneumotropica type Heyl, P. pneumotropica type Henriksen and "H. influenzae-murium" showed that taxon 12 was identical with "P. ureae" strain Ackerman 80-443D but different from P. ureae sensu stricto and other species belonging to the family Pasteurellaceae Pohl 1981. The G + C content of DNA from the suggested reference strain for taxon 12 was within the limits for Pasteurellaceae. DNA:DNA hybridizations linked taxon 12 to the genus Actinobacillus via the avian hemolytic Actinobacillus-like complex (27). The name Actinobacillus muris is proposed for taxon 12.
Reinvestigations of 121 strains previously described as Actinobacillus lignieresii showed that only fifteen strains (12%) had phenotypic characters compatible with A. lignieresii sensu stricto. Four strains were diagnosed as Pasteurella multocida and nine strains as P. haemolytica biogroup 1. The remaining organisms had phenotypic characters compatible with Pasteurellaceae, but could not be classified with accepted species. Fifty-one of the strains investigated had phenotypic characters allowing classification with P. haemolytica biogroups 6 through 9. In addition 19 strains made up at least two new biogroups within the bovine and ovine P. haemolytica complex. Twenty-seven unclassified ovine isolates formed a heterogeneous group provisionally designated taxon 18. At least four biovars were demonstrated within taxon 18. The taxonomic significance of characters separating the P. haemolytica complex and taxon 18 as well as characters separating biogroups within these groups remains to be investigated genetically. The necessity of extended phenotypic characterization within the family Pasteurellaceae Pohl 1981 is underlined by the present findings.
The taxonomic relationship of 23 unclassified canine and feline strains of Pasteurellaceae and five strains received as Pasteurella spp. or Haemophilus influenzae-murium was investigated by phenotypic and genetic characterization. Eleven strains were classified with four recently described species of genus Pasteurella sensu stricto. Fourteen canine and feline strains formed a homogeneous group, tentatively designated taxon 16. Both phenotypic characters and mol% G + C in DNA and genome size indicate classification of taxon 16 with genus Pasteurella. DNA/DNA hybridizations, however, failed to locate taxon 16 on genus level with accepted or proposed species of the family Pasteurellaceae Pohl 1981. Two additional species obtained from rats and mice remained unclassified, in addition to a human isolate obtained from a dog-bite. The necessity of detailed phenotypic characterization within the family Pasteurellaceae Pohl 1981 needs to be stressed.
The taxonomic relationship of 116 isolates of Pasteurella haemolytica was re-investigated by conventional phenotypic characterization. Seventy-nine characters were examined. Ninety strains were classified with previously described biovars of P. haemolytica. The remaining strains made up at least six new biogroups within the P. haemolytica-complex. "Key-characters" separating these groups included ornithine, L(+)arabinose, D(-)sorbitol, cellobiose, beta-glucosidase, glycosides and alpha-fucosidase. The taxonomic significance of these characters is uncertain. Determinations of genome size, mol% G + C in DNA and DNA:DNA hybridizations are in progress to obtain further information on the taxonomic significance of the present findings.
Genetic investigations of selected bovine and ovine strains of Pasteurella haemolytica sensu stricto (biogroup 1), P. haemolytica biogroups 2, 3, 5 and 9, P. testudinis and porcine isolates of so-called P. haemolytica, tentatively designated taxon 15, confirmed the existence of these phenotypically delineated taxa. Evidence was further obtained to indicate that P. haemolytica biogroups 1, 2, 3, 5 and 9 and P. testudinis constitute a new genus within the family Pasteurellaceae Pohl 1981, and that P. testudinis represents a "missing link" between so-called P. haemolytica biovars A and T. The proposed genus seems to contain several new species. Additional investigations are, however, indicated before final conclusions can be drawn. The authors desist from proposing genus and species names for the same reasons. Porcine strains provisionally named taxon 15 seem to constitute a separate group within the family Pasteurellaceae Pohl 1981, underlining the distinct degree of specificity members of this family show for host species.
169 strains of P. multocida ssp. multocida, 24 strains of P. multocida ssp. septica, 22 strains of P. multocida ssp. gallicida, and 8 strains of P. avium and P. canis, respectively, were tested for toxin production in EBL-cell culture assay. Toxin production was only demonstrated in strains belonging to P. multocida ssp. multocida. Toxigenic strains were derived from pigs, calves, cats, dogs, rabbits and turkeys.
Incorrect diagnosis of species belonging to the family Pasteurellaceae Pohl 1981 is often due to inadequate laboratory identification techniques. Reinvestigations of 56 human isolates of Pasteurellaceae and comparison of the results obtained with those obtained from nine reference strains in 65 different tests allowed classification of 26 strains as P. multocida ssp. multocida, 11 strains as P. multocida ssp. septica, 12 strains as P. canis, 4 strains as P. dagmatis and 1 strain as P. stomatitis. Two strains were tentatively classified with P. haemolytica biogroup 2(T) and the SP-group, respectively. The present investigation also showed that the type strains of P. gallinarum and Haemophilus aphrophilus were phenotypically related. Members of the family Pasteurellacea Pohl 1981 should be considered as potential etiologic agents of any local infection following animal bites or scratches.
During routine bacteriological examination of pneumonic calf lungs it was experienced that many Pasteurella multocida-like isolates had a fermentation pattern different from what is generally accepted for P. multocida sensu stricto. Forty-one out of 50 strains selected for further investigation were phenotypically related and formed a group of indole-, mannitol-and sorbitol-negative P. multocida-like strains, which was tentatively designated taxon 13. Deoxyribonucleic acid/deoxyribonucleic acid hybridizations including both ornithine positive and ornithine negative strains of taxon 13 allowed the classification of the former as P. multocida biovar 6 and the latter as V factor independent strains of Haemophilus avium.
During the present investigation evidence was obtained to indicate that porcine Pasteurella haemolytica-like strains were sufficiently different from P. haemolytica sensu stricto to constitute a new taxon within the family Pasteurellaceae Pohl 1981. Thirteen strains formed a homogenous group tentatively designated taxon 15. The final taxonomical position of taxon 15, however, has to await further taxonomical investigations, including determinations of mol% G+C in DNA and DNA: DNA hybridizations. A species name has not been suggested, for the same reasons.
Evidence was obtained to indicate that equine strains of organisms previously described as Actinobacillus suis or hemolytic variants of Actinobacillus equuli might constitute a separate group of organisms provisionally designated taxon 11. Four biovars were noticed within taxon 11. Selected DNA:DNA hybridizations support the classification of the mannitol positive biovar 2 of taxon 11 distinct from porcine A. suis. The final taxonomical position of taxon 11, however, has to await more detailed genetic studies including all biovars of taxon 11. A species name has not been suggested for the same reasons. The present observations also indicate that strains identified as taxon 11 apparently constitute a part of the normal bacterial flora in the oral cavity of horses.
An age related and breeder flock associated hemorrhagic disorder has recently been demonstrated in Danish broilers. The present paper deals with the etiology of the disorder in addition to clinical signs and pathological lesions associated with the syndrome. Additionally some epidemiological observations are presented.
Cultural, morphologic, and biochemical characteristics of previously unreported taxa isolated from poultry and tentatively assigned to genus Actinobacillus Brumpt 1910 were compared to those of Actinobacillus lignieresii, A equuli, A. seminis, A. suis, avian haemolytic Actinobacillus sp., A.salpingitidis, avian Pasteurella haemolytica-like strains, P haemolytica biovar T, P, ureae. P. multocida, P. pneumotropica, P. gallinarum and P. anatipestifer. Evidence as obtained to indicate that taxon 1--3 was closely related to genus Actinobacillus Brumpt 1910, but sufficiently different from established species within that genus to constitute new distinct species. Taxon 4 had the cultural and biochemical characters of strains previously described by Clark and Godfrey. Strains designated P haemolytica-like could not be separated from A. salpingitidis on the basis of phenotypical characters. The final taxonomical position of taxon 1-4 in addition to strains designated avian haemolytic Actinobacillus sp. and P. haemolytica-like, however, has to await further taxonomical investigations including determination of mol % G + C in DNA and DNA hybridization, for which reason species names have been omitted.
Among 116,886 egg-laying chickens slaughtered 438 (0.37%) were condemned because of salpingitis (Table I). Profuse growth of a single bacterial species was demonstrated in 96 out of 150 randomly selected cases of salpingitis (Table II). E. coli was isolated from 64 cases (43%). P. haemolytica, Pr. mirabilis and P. gallinarum occurred next most frequently, and made up 26 cases. Staph. aureus, Str. faecalis and Moraxella sp. finally accounted for six cases. A mixed flora was demonstrated in 16 cases (11%) while unspecific growth or no growth was recorded in 38 cases (25%). The bacteriological findings in cases of salpingitis in egg-laying chickens routinely received for post mortem examination were in accordance with the findings above in carcasses condemned because of salpingitis, except in a single case in which Bact. fragilis was obtained in pure culture. Salmonella spp. could not be demonstrated. No correlation could be demonstrated between the nature of the pathological changes and the bacteriological findings. Nineteen different O-groups of E. coli were found, O2 being the one occurring most frequently (Table III). Changing the environment from a floor type with bedding to cages or sloping wire floor without bedding does not seem to have resulted in a change of bacterial species associated with salpingitis in egg-laying chickens. The food-hygienic implications of salpingitis seem to be the same for laying hens as for broilers.
The prevalence of salpingitis in broilers at slaughter seems to be rather constant, constituting 0.02--0.03% of the broilers slaughtered (Table I & Figure 1). Profuse growth of Escherichia coli in pure culture was obtained from the salpinx of all 123 investigated carcasses with chronic salpingitis. Primary blood agar plates examined showed a pure culture as to O-group as well. Of 22 different O-groups demonstrated, 01, 02, 07 and 053 were most prevalent, constituting 47% of the strains (Table III). Salmonella spp. were not demonstrated. Etiology, pathogenesis and possible food hygienic consequences are discussed in the light of the present findings.
Investigations among ducks on ten different farms showed a high prevalence of Vibrio cholerae in cavum nasi and Pharynx after the ducks were admitted to the open field. In no case was Vibrio cholerae isolated from ducks which had never been outside the houses. At least six serovars were isolated, 0:54 being the most prevalent. All the strains isolated produced a distinctive cytotoxic effect in YI adrenal cells and caused fluid accumulation in rabbit gut loops. Migratory birds were incriminated as the source of initial contamination.