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Henrik Christensen - One of the best experts on this subject based on the ideXlab platform.
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Immunological and molecular techniques used for determination of serotypes in Pasteurellaceae
Methods in Microbiology, 2020Co-Authors: Henrik Christensen, Janine T. Bossé, Niels Nørskov-lauritsen, Øystein Angen, Magne BisgaardAbstract:Abstract Serotyping has been used to categorize most pathogenic members of Pasteurellaceae of human or animal importance. In particular, serotyping of isolates from vaccine breaks is of primary importance to ensure that vaccines used are covering outbreak isolates in the region. Traditional serotyping methods are available for Pasteurella multocida, Actinobacillus pleuropneumoniae, Glaesserella parasuis (older name Haemophilus parasuis), Mannheimia haemolytica, Avibacterium paragallinarum, Haemophilus influenzae, and Aggregatibacter actinomycetemcomitans. PCR-based methods to predict the serotypes have been developed for all agents with the exception of Avibacterium paragallinarum. For several of the species, work is in progress to predict serotypes from whole genomic sequences. The combination of population structures determined by whole genomic sequencing and the prediction of serotypes provides a strong synergy in epidemiological investigations of the species of Pasteurellaceae involved in disease in humans and animals.
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Revised taxonomy and nomenclature of rodent Pasteurellaceae: Implications for monitoring.
Laboratory animals, 2018Co-Authors: R Boot, Werner Nicklas, Henrik ChristensenAbstract:Pasteurellosis is a well-recognized disease with similar pathology in all laboratory rodent species. Pasteurella pneumotropica is the most frequently mentioned member of the Pasteurellaceae isolated from mice and rats. Numerous other Pasteurellaceae taxa have been obtained from mice, rats, and other rodent species. Recently, rodent Pasteurellaceae have been submitted to comprehensive genetic and phenotypic (polyphasic) taxonomic studies. As a result they are now classed within six validly published new genera, namely Cricetibacter, Mesocricetibacter, Mannheimia, Muribacter, Necropsobacter, and Rodentibacter. All previously used names such as P. pneumotropica have become obsolete. The new classification forms a firm basis for the correct phenotypic identification of Pasteurellaceae from laboratory animals and for the selection of strains for pathogenicity studies. Consequences of taxonomic changes notably involve molecular methods used for the detection of Pasteurellaceae infection in laboratory animal colonies. Testing may be done using primer sets that detect all Pasteurellaceae taxa or sets developed to detect host-specific members of the family.
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Prevalence of Taxa of Pasteurellaceae Among Populations of Healthy Captive Psittacine Birds.
Avian diseases, 2017Co-Authors: Magne Bisgaard, Mads F Bertelsen, Anders Miki Bojesen, Di Xin, Henrik ChristensenAbstract:SUMMARY Sixty-two strains of Pasteurellaceae-like bacteria were isolated from the tracheas of 87 clinically healthy psittacine birds in two Danish zoos. The isolates were identified by a combination of rpoB and 16S rRNA gene sequencing and by matrix-assisted laser desorption–ionization time of flight. Twenty-eight strains belonged to the genus Volucribacter or were related to this genus and to the unnamed taxon 34 of Bisgaard, and 28 strains were related to the unnamed taxon 44 of Bisgaard. Four strains were identified as Pasteurella multocida, two isolates were classified with the related taxon 45 of Bisgaard, and a single isolate was classified as Pasteurella sp. The investigation documented an unrecognized reservoir of rarely reported and unclassified or unnamed species of Pasteurellaceae-like bacteria in psittacine birds. The results were in accordance with a recent report on isolation of Pasteurellaceae from diseased psittacine birds, and the investigation documented that the same taxa of Pasteurella...
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Testudinibacter aquarius gen. nov., sp. nov., a member of the family Pasteurellaceae isolated from the oral cavity of freshwater turtles.
International journal of systematic and evolutionary microbiology, 2015Co-Authors: Mie Johanne Hansen, Henrik Christensen, Anders Miki Bojesen, Elin Anna Erica Pennanen, Mads F BertelsenAbstract:A total of 13 Pasteurellaceae isolates from healthy freshwater turtles were characterized by genotypic and phenotypic tests. Phylogenetic analysis of partial 16S rRNA and rpoB gene sequences showed that the isolates investigated formed a monophyletic group. The closest related species based on 16S rRNA gene sequencing was Chelonobacter oris CCUG 55632T with 94.4 % similarity and the closest related species based on rpoB gene sequence comparison was [Pasteurella] testudinis CCUG 19802T with 91.5 % similarity. All the investigated isolates exhibited phenotypic characteristics of the family Pasteurellaceae. However, they could be separated from existing genera of the Pasteurellaceae by the following test results: indole, ornithine decarboxylase and Voges–Proskauer positive; and methyl red, urease and PNPG (α-glucosidase) negative. No X- or V-factor requirement was observed. A zone of β-haemolysis surrounded the colonies after 24 h of incubation on bovine blood agar at 37 °C. Acid was produced from l-arabinose, dulcitol, d-mannitol, sucrose and trehalose. Representative strain ELNT2xT had a fatty acid profile that was characteristic for members of the Pasteurellaceae. ELNT2xT expressed only one respiratory quinone, ubiquinone-8 (100 %). The DNA G+C content of strain ELNT2xT was 42.8 mol%. On the basis of both phylogenetic and phenotypic evidence, it is proposed that the strains should be classified as representatives of a novel species of a new genus, Testudinibacter aquarius gen. nov., sp. nov. The type strain of Testudinibacter aquarius is ELNT2xT ( = CCUG 65146T = DSM 28140T), which was isolated from the oral cavity of a captive eastern long-necked turtle (Chelodina longicollis) in Denmark in 2012.
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ursidibacter maritimus gen nov sp nov and ursidibacter arcticus sp nov two new members of the family Pasteurellaceae isolated from the oral cavity of bears
International Journal of Systematic and Evolutionary Microbiology, 2015Co-Authors: Henrik Christensen, Mie Johanne Hansen, Mads F Bertelsen, Anders Miki Bojesen, Mira Strom Braaten, Christian Sonne, Rune DietzAbstract:Thirty-three suspected strains of the family Pasteurellaceae isolated from the oral cavity of polar and brown bears were characterized by genotypic and phenotypic tests. Phylogenetic analysis of partial 16S rRNA gene and rpoB sequences showed that the investigated isolates formed two closely related monophyletic groups, representing two novel species of a new genus. Based on 16S rRNA gene sequence comparison Bibersteinia trehalosi was the closest related species with a validly published name, with 95.4 % similarity to the polar bear group and 94.4 % similarity to the brown bear group. Otariodibacter oris was the closest related species based on rpoB sequence comparison with a similarity of 89.8 % with the polar bear group and 90 % with the brown bear group. The new genus could be separated from existing genera of the family Pasteurellaceae by three to ten phenotypic characters, and the two novel species could be separated from each other by two phenotypic characters. It is proposed that the strains should be classified as representatives of a new genus, Ursidibacter gen. nov., with two novel species: the type species Ursidibacter maritimus sp. nov., isolated from polar bears (type strain Pb43106T = CCUG 65144T = DSM 28137T, DNA G+C content 39.3 mol%), and Ursidibacter arcticus sp. nov., isolated from brown bears (type strain Bamse61T = CCUG 65145T = DSM 28138T).
Peter Kuhnert - One of the best experts on this subject based on the ideXlab platform.
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Identification of animal Pasteurellaceae by MALDI-TOF mass spectrometry.
Methods in molecular biology (Clifton N.J.), 2014Co-Authors: Joachim Frey, Peter KuhnertAbstract:Species of the family Pasteurellaceae play an important role as primary or opportunistic, predominantly respiratory, pathogens in domestic and wild animals. Some of them cause severe disease with high economic losses in commercial animal husbandry. Hence, rapid and accurate differentiation of Pasteurellaceae is important and signifies a particular challenge to diagnostic laboratories. Identification and differentiation of Pasteurellaceae is mostly done using phenotypic tests or genetic identification based on sequence similarity of housekeeping genes, such as the rrs gene encoding the 16S ribosomal RNA (16S rRNA). Both approaches are time consuming, laborious, and costly, therefore often delaying the final diagnosis of disease or epidemics. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry represents an alternative rapid and reliable method for the differentiation of most members of the family Pasteurellaceae. It is able to differentiate within a few minutes the currently known 18 genera and most of the over 60 species and subspecies of Pasteurellaceae including many members encountered in veterinary diagnostic laboratories. A few closely related species and subspecies that cannot be discriminated by MALDI-TOF are easily identified further by complementary simple tests, such as hemolysis done simultaneously or routinely during pathogen isolation.
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The Family Pasteurellaceae
The Prokaryotes, 2014Co-Authors: Henrik Christensen, Peter Kuhnert, Niels Nørskov-lauritsen, Paul J. Planet, Magne BisgaardAbstract:This chapter describes the systematics and evolution of Pasteurellaceae with emphasis on new information generated since the 3rd edition of The Prokaryotes which only included chapters dealing with Haemophilus, Actinobacillus, and Pasteurella. A major source of new information for the current chapter has been provided by whole genome sequences now available for many taxa of the family. Some 100 species and species-like taxa have been documented and 18 genera of Pasteurellaceae reported so far. Members of the family include specialized commensals, potential pathogens, or pathogens of vertebrates and mainly survive poorly in other habitats including the external environment. The pathogenic members are of major importance to animal production and human health. Members of Pasteurellaceae have relatively small genomes, probably as a result of adaption to a special habitat. The most important species in veterinary microbiology include Pasteurella multocida, Actinobacillus pleuropneumoniae, [Haemophilus] parasuis, Mannheimia haemolytica, Bibersteinia trehalosi, and Avibacterium paragallinarum, while Haemophilus influenzae and Aggregatibacter actinomycetemcomitans represent the most important species as to human disease. Traditional isolation techniques are still used in both human and veterinary clinical diagnostic laboratories although genetically based diagnostic methods have replaced traditional biochemical/physiological methods for characterization and identification. For all species, MALDI-TOF can now be used as a diagnostic tool. As control and if MALDI-TOF equipment is not at hand, PCR-based specific detection is possible for Pasteurella multocida, Actinobacillus pleuropneumoniae, [Haemophilus] parasuis, Mannheimia haemolytica, Avibacterium paragallinarum, Gallibacterium anatis, Haemophilus influenzae, and Aggregatibacter actinomycetemcomitans. A lot of work has been directed towards identification of virulence factors and understanding host microbe interactions involved in disease.
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identification of animal Pasteurellaceae by maldi tof mass spectrometry
Journal of Microbiological Methods, 2012Co-Authors: Peter Kuhnert, Bożena M. Korczak, Magne Bisgaard, Sybille Schwendener, Henrik Christensen, Joachim FreyAbstract:Species of the family Pasteurellaceae play an important role as primary or opportunistic animal pathogens. In veterinary diagnostic laboratories identification of this group of bacteria is mainly done by phenotypic assays while genetic identification based on housekeeping genes is mostly used for research and particularly important diagnostic samples. MALDI-TOF MS seems to represent a promising alternative to the currently practiced cumbersome, phenotypic diagnostics carried out in many veterinary diagnostic laboratories. We therefore assessed its application for animal associated members of the family Pasteurellaceae. The Bruker Biotyper 3.0 database was complemented with reference spectra of clinically relevant as well as commensal animal Pasteurellaceae species using generally five strains per species or subspecies and tested for its diagnostic potential with additional, well characterized field isolates. About 250 strains comprising 15 genera and more than 40 species and subspecies were included in the study, covering most representatives of the family. A high discrimination at the genus and species level was observed. Problematic discrimination was only observed with some closely related species and subspecies. MALDI-TOF MS was shown to represent a highly potent method for the diagnosis of this group of animal pathogens, combining speed, precision and low running costs.
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Proposal of Bisgaardia hudsonensis gen. nov., sp. nov. and an additional genomospecies, isolated from seals, as new members of the family Pasteurellaceae.
International Journal of Systematic and Evolutionary Microbiology, 2011Co-Authors: G. Foster, Bożena M. Korczak, Robert Higgins, D. Leclair, I. Mikaelian, I.a. Patterson, Peter KuhnertAbstract:Phenotypic and phylogenetic studies were performed on eight Gram-negative-staining, rod-shaped bacteria isolated from seals. Biochemical and physiological studies showed identical profiles for all of the isolates and indicated that they were related to the family Pasteurellaceae. 16S rRNA gene sequencing demonstrated that the organism represented a distinct cluster with two sublines within the family Pasteurellaceae with
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proposal of bisgaardia hudsonensis gen nov sp nov and an additional genomospecies isolated from seals as new members of the family Pasteurellaceae
International Journal of Systematic and Evolutionary Microbiology, 2011Co-Authors: G. Foster, Bożena M. Korczak, Robert Higgins, D. Leclair, I. Mikaelian, I.a. Patterson, Peter KuhnertAbstract:Phenotypic and phylogenetic studies were performed on eight Gram-negative-staining, rod-shaped bacteria isolated from seals. Biochemical and physiological studies showed identical profiles for all of the isolates and indicated that they were related to the family Pasteurellaceae. 16S rRNA gene sequencing demonstrated that the organism represented a distinct cluster with two sublines within the family Pasteurellaceae with <96% sequence similarity to any recognized species. Multilocus sequence analysis (MLSA) including rpoB, infB and recN genes further confirmed these findings with the eight isolates forming a genus-like cluster with two branches. Genome relatedness as deduced from recN gene sequences suggested that the isolates represented a new genus with two species. On the basis of the results of the phylogenetic analysis and phenotypic criteria, it is proposed that these bacteria from seals are classified as Bisgaardia hudsonensis gen. nov., sp. nov. (the type species) and Bisgaardia genomospecies 1. The G+C content of the DNA was 39.5 mol%. The type strain of Bisgaardia hudsonensis gen. nov., sp. nov. is M327/99/2(T) (=CCUG 43067(T)=NCTC 13475(T)=98-D-690B(T)) and the reference strain of Bisgaardia genomospecies 1 is M1765/96/5 (=CCUG 59551=NCTC 13474).
Magne Bisgaard - One of the best experts on this subject based on the ideXlab platform.
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Immunological and molecular techniques used for determination of serotypes in Pasteurellaceae
Methods in Microbiology, 2020Co-Authors: Henrik Christensen, Janine T. Bossé, Niels Nørskov-lauritsen, Øystein Angen, Magne BisgaardAbstract:Abstract Serotyping has been used to categorize most pathogenic members of Pasteurellaceae of human or animal importance. In particular, serotyping of isolates from vaccine breaks is of primary importance to ensure that vaccines used are covering outbreak isolates in the region. Traditional serotyping methods are available for Pasteurella multocida, Actinobacillus pleuropneumoniae, Glaesserella parasuis (older name Haemophilus parasuis), Mannheimia haemolytica, Avibacterium paragallinarum, Haemophilus influenzae, and Aggregatibacter actinomycetemcomitans. PCR-based methods to predict the serotypes have been developed for all agents with the exception of Avibacterium paragallinarum. For several of the species, work is in progress to predict serotypes from whole genomic sequences. The combination of population structures determined by whole genomic sequencing and the prediction of serotypes provides a strong synergy in epidemiological investigations of the species of Pasteurellaceae involved in disease in humans and animals.
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Prevalence of Taxa of Pasteurellaceae Among Populations of Healthy Captive Psittacine Birds.
Avian diseases, 2017Co-Authors: Magne Bisgaard, Mads F Bertelsen, Anders Miki Bojesen, Di Xin, Henrik ChristensenAbstract:SUMMARY Sixty-two strains of Pasteurellaceae-like bacteria were isolated from the tracheas of 87 clinically healthy psittacine birds in two Danish zoos. The isolates were identified by a combination of rpoB and 16S rRNA gene sequencing and by matrix-assisted laser desorption–ionization time of flight. Twenty-eight strains belonged to the genus Volucribacter or were related to this genus and to the unnamed taxon 34 of Bisgaard, and 28 strains were related to the unnamed taxon 44 of Bisgaard. Four strains were identified as Pasteurella multocida, two isolates were classified with the related taxon 45 of Bisgaard, and a single isolate was classified as Pasteurella sp. The investigation documented an unrecognized reservoir of rarely reported and unclassified or unnamed species of Pasteurellaceae-like bacteria in psittacine birds. The results were in accordance with a recent report on isolation of Pasteurellaceae from diseased psittacine birds, and the investigation documented that the same taxa of Pasteurella...
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The Family Pasteurellaceae
The Prokaryotes, 2014Co-Authors: Henrik Christensen, Peter Kuhnert, Niels Nørskov-lauritsen, Paul J. Planet, Magne BisgaardAbstract:This chapter describes the systematics and evolution of Pasteurellaceae with emphasis on new information generated since the 3rd edition of The Prokaryotes which only included chapters dealing with Haemophilus, Actinobacillus, and Pasteurella. A major source of new information for the current chapter has been provided by whole genome sequences now available for many taxa of the family. Some 100 species and species-like taxa have been documented and 18 genera of Pasteurellaceae reported so far. Members of the family include specialized commensals, potential pathogens, or pathogens of vertebrates and mainly survive poorly in other habitats including the external environment. The pathogenic members are of major importance to animal production and human health. Members of Pasteurellaceae have relatively small genomes, probably as a result of adaption to a special habitat. The most important species in veterinary microbiology include Pasteurella multocida, Actinobacillus pleuropneumoniae, [Haemophilus] parasuis, Mannheimia haemolytica, Bibersteinia trehalosi, and Avibacterium paragallinarum, while Haemophilus influenzae and Aggregatibacter actinomycetemcomitans represent the most important species as to human disease. Traditional isolation techniques are still used in both human and veterinary clinical diagnostic laboratories although genetically based diagnostic methods have replaced traditional biochemical/physiological methods for characterization and identification. For all species, MALDI-TOF can now be used as a diagnostic tool. As control and if MALDI-TOF equipment is not at hand, PCR-based specific detection is possible for Pasteurella multocida, Actinobacillus pleuropneumoniae, [Haemophilus] parasuis, Mannheimia haemolytica, Avibacterium paragallinarum, Gallibacterium anatis, Haemophilus influenzae, and Aggregatibacter actinomycetemcomitans. A lot of work has been directed towards identification of virulence factors and understanding host microbe interactions involved in disease.
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Occurrence of Pasteurellaceae bacteria in the oral cavity of selected marine mammal species.
Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians, 2012Co-Authors: Mie Johanne Hansen, Magne Bisgaard, Henrik Christensen, Mads F Bertelsen, Anders Miki BojesenAbstract:The occurrence of bacteria belonging to Pasteurellaceae in the oral cavity of captive marine mammals was investigated using culture and subsequent geno- and phenotypic characterization and phylogenetic analyses. A total of 89 bacterial isolates from pinnipeds tentatively classified with the family Pasteurellaceae were further characterized by phylogenetic analysis of rpoB gene sequences, which showed that the isolates investigated formed five distinct groups. Four strains from California sea lions (Zalophus californianus) made up group I, which was classified with Pasteurella canis. Group II comprised four strains from harbor seals (Phoca vitulina) and grey seals (Halichoerus grypus) classified with Pasteurella stomatis. Group III consisted of 28 strains, isolated from harbor and gray seals and represented Bisgaardia genomospecies 1. Two strains from a harbor and a grey seal, group IV, were classified with Bisgaardia hudsonensis. Fifty-two strains from northern fur seals (Callorhinus ursinus), walruses (Odobenus rosmarus), and California and Steller sea lions (Eumetopias jubatus) formed group V and represented Otariodibacter oris. No Pasteurellaceae isolates were obtained from cetaceans, but Pasteurellaceae were isolated from all sampled pinnipeds. On the basis of these results, it is very likely that Pasteurellaceae bacteria represent a part of the normal oral flora in pinnipeds.
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Otariodibacter oris gen. nov., sp. nov., a member of the family Pasteurellaceae isolated from the oral cavity of pinnipeds
International Journal of Systematic and Evolutionary Microbiology, 2012Co-Authors: Mie Johanne Hansen, Henrik Christensen, Anders Miki Bojesen, Mads Frost Bertelsen, Magne BisgaardAbstract:A total of 27 bacterial isolates from California sea lions and a walrus tentatively classified within the family Pasteurellaceae was further characterized by genotypic and phenotypic tests. Phylogenetic analysis of partial 16S rRNA and rpoB gene sequences showed that the isolates investigated formed a monophyletic group, tentatively designated Bisgaard taxon 57. According to 16S rRNA gene sequences, the most closely related species with a validly published name was Bisgaardia hudsonensis and the most closely related species based on rpoB sequence comparison was Pasteurella multocida subsp. multocida; highest similarities between the isolates and the type strains of B. hudsonensis and P. multocida subsp. multocida were 95.0 and 88.2%. respectively. All isolates of Bisgaard taxon 57 exhibit the phenotypic characters of the family Pasteurellaceae . Members of Bisgaard taxon 57 can be separated from existing genera of the Pasteurellaceae by the following tests: positive reactions for catalase, oxidase, Voges–Proskauer and indole; no X- or V-factor dependency; and acid production from l-arabinose (slow), l-fucose, maltose and trehalose, but not from dulcitol, d-mannitol, d-mannose or sucrose. The main fatty acids of Bisgaard taxon 57 (CCUG 59994T) are C14 : 0, C16 : 0, C16 : 1ω7c and the summed feature C14 : 0 3-OH/iso-C16 : 1 I. This fatty acid profile is characteristic of members of the Pasteurellaceae . The quinone profile of Bisgaard taxon 57 (DSM 23800T) was similar to that of other genera in the Pasteurellaceae . The DNA G+C content of strain Baika1T is 36.2 mol%, which is at the lower end of the range for members of the family Pasteurellaceae . On the basis of both phylogenetic and phenotypic evidence, it is proposed that members of Bisgaard taxon 57 should be classified as representatives of a novel species in a new genus, Otariodibacter oris gen. nov., sp. nov. The type strain of Otariodibacter oris is Baika1T ( = CCUG 59994T = DSM 23800T), which was isolated from the oral cavity of a healthy California sea lion in Copenhagen Zoo, Denmark, in 2007.
Joachim Frey - One of the best experts on this subject based on the ideXlab platform.
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Identification of animal Pasteurellaceae by MALDI-TOF mass spectrometry.
Methods in molecular biology (Clifton N.J.), 2014Co-Authors: Joachim Frey, Peter KuhnertAbstract:Species of the family Pasteurellaceae play an important role as primary or opportunistic, predominantly respiratory, pathogens in domestic and wild animals. Some of them cause severe disease with high economic losses in commercial animal husbandry. Hence, rapid and accurate differentiation of Pasteurellaceae is important and signifies a particular challenge to diagnostic laboratories. Identification and differentiation of Pasteurellaceae is mostly done using phenotypic tests or genetic identification based on sequence similarity of housekeeping genes, such as the rrs gene encoding the 16S ribosomal RNA (16S rRNA). Both approaches are time consuming, laborious, and costly, therefore often delaying the final diagnosis of disease or epidemics. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry represents an alternative rapid and reliable method for the differentiation of most members of the family Pasteurellaceae. It is able to differentiate within a few minutes the currently known 18 genera and most of the over 60 species and subspecies of Pasteurellaceae including many members encountered in veterinary diagnostic laboratories. A few closely related species and subspecies that cannot be discriminated by MALDI-TOF are easily identified further by complementary simple tests, such as hemolysis done simultaneously or routinely during pathogen isolation.
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identification of animal Pasteurellaceae by maldi tof mass spectrometry
Journal of Microbiological Methods, 2012Co-Authors: Peter Kuhnert, Bożena M. Korczak, Magne Bisgaard, Sybille Schwendener, Henrik Christensen, Joachim FreyAbstract:Species of the family Pasteurellaceae play an important role as primary or opportunistic animal pathogens. In veterinary diagnostic laboratories identification of this group of bacteria is mainly done by phenotypic assays while genetic identification based on housekeeping genes is mostly used for research and particularly important diagnostic samples. MALDI-TOF MS seems to represent a promising alternative to the currently practiced cumbersome, phenotypic diagnostics carried out in many veterinary diagnostic laboratories. We therefore assessed its application for animal associated members of the family Pasteurellaceae. The Bruker Biotyper 3.0 database was complemented with reference spectra of clinically relevant as well as commensal animal Pasteurellaceae species using generally five strains per species or subspecies and tested for its diagnostic potential with additional, well characterized field isolates. About 250 strains comprising 15 genera and more than 40 species and subspecies were included in the study, covering most representatives of the family. A high discrimination at the genus and species level was observed. Problematic discrimination was only observed with some closely related species and subspecies. MALDI-TOF MS was shown to represent a highly potent method for the diagnosis of this group of animal pathogens, combining speed, precision and low running costs.
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The role of RTX toxins in host specificity of animal pathogenic Pasteurellaceae.
Veterinary microbiology, 2011Co-Authors: Joachim FreyAbstract:RTX toxins are bacterial pore-forming toxins that are particularly abundant among pathogenic species of Pasteurellaceae, in which they play a major role in virulence. RTX toxins of several primary pathogens of the family of Pasteurellaceae are directly involved in causing necrotic lesions in the target organs. Many RTX toxins are known as haemolysins because they lyse erythrocytes in vitro, an effect that is non-specific, but which serves as a useful marker in bacteriological identification and as an easily measurable signal in vitro in experimental studies. More recent studies have shown that the specific targets of most RTX toxins are leukocytes, with RTX toxins binding to the corresponding β-subunit (CD18) of β2 integrins and then exerting cytotoxic activity. After uptake by the target cell, at sub-lytic concentrations, some RTX toxins are transported to mitochondria and induce apoptosis. For several RTX toxins the binding to CD18 has been shown to be host specific and this seems to be the basis for the host range specificity of these RTX toxins. Observations on two very closely related species of the Pasteurellaceae family, Actinobacillus suis, a porcine pathogen particularly affecting suckling pigs, and Actinobacillus equuli subsp. haemolytica, which causes pyosepticaemia in new-born foals (sleepy foal disease), have revealed that they express different RTX toxins, named ApxI/II and Aqx, respectively. These RTX toxins are specifically cytotoxic for porcine and equine leukocytes, respectively. Furthermore, the ApxI and Aqx toxins of these species, when expressed in an isogenetic background in Escherichia coli, are specifically cytotoxic for leukocytes of their respective hosts. These data indicate the determinative role of RTX toxins in host specificity of pathogenic species of Pasteurellaceae.
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Routine phenotypic identification of bacterial species of the family Pasteurellaceae isolated from animals
Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians Inc, 2008Co-Authors: Florence Dousse, Peter Kuhnert, Bożena M. Korczak, Andreas Thomann, Isabelle Brodard, Yvonne Schlatter, R. Miserez, Joachim FreyAbstract:Pasteurellaceae are bacteria with an important role as primary or opportunistic, mainly respiratory, pathogens in domestic and wild animals. Some species of Pasteurellaceae cause severe diseases with high economic losses in commercial animal husbandry and are of great diagnostic concern. Because of new data on the phylogeny of Pasteurellaceae, their taxonomy has recently been revised profoundly, thus requiring an improved phenotypic differentiation procedure to identify the individual species of this family. A new and simplified procedure to identify species of Actinobacillus, Avibacterium, Gallibacterium, Haemophilus, Mannheimia, Nicoletella, and Pasteurella, which are most commonly isolated from clinical samples of diseased animals in veterinary diagnostic laboratories, is presented in the current study. The identification procedure was evaluated with 40 type and reference strains and with 267 strains from routine diagnostic analysis of various animal species, including 28 different bacterial species. Type, reference, and field strains were analyzed by 16S ribosomal RNA (rrs) and rpoB gene sequencing for unambiguous species determination as a basis to evaluate the phenotypic differentiation schema. Primary phenotypic differentiation is based on b-nicotinamide adenine dinucleotide (b-NAD) dependence and hemolysis, which are readily determined on the isolation medium. The procedure divides the 28 species into 4 groups for which particular biochemical reactions were chosen to identify the bacterial species. The phenotypic identification procedure allowed researchers to determine the species of 240 out of 267 field strains. The procedure is an easy and cost-effective system for the rapid identification of species of the Pasteurellaceae family isolated from clinical specimens of animals.
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Nicoletella semolina gen. nov., sp. nov., a New Member of Pasteurellaceae Isolated from Horses with Airway Disease
Journal of clinical microbiology, 2004Co-Authors: Peter Kuhnert, Joachim Frey, Bożena M. Korczak, Enevold Falsen, Reto Straub, Anneliese Hoops, Patrick Boerlin, Reinier MuttersAbstract:Gram-negative, nonmotile bacteria that are catalase, oxidase, and urease positive are regularly isolated from the airways of horses with clinical signs of respiratory disease. On the basis of the findings by a polyphasic approach, we propose that these strains be classified as Nicoletella semolina gen. nov, sp. nov., a new member of the family Pasteurellaceae. N. semolina reduces nitrate to nitrite but is otherwise biochemically inert; this includes the lack of an ability to ferment glucose and other sugars. Growth is fastidious, and the isolates have a distinctive colony morphology, with the colonies being dry and waxy and looking like a semolina particle that can be moved around on an agar plate without losing their shape. DNA-DNA hybridization data and multilocus phylogenetic analysis, including 16S rRNA gene (rDNA), rpoB, and infB sequencing, clearly placed N. semolina as a new genus in the family Pasteurellaceae. In all the phylogenetic trees constructed, N. semolina is on a distinct branch displaying approximately 5% 16S rDNA, approximately 16% rpoB, and approximately 20% infB sequence divergence from its nearest relative within the family Pasteurellaceae. High degrees of conservation of the 16S rDNA (99.8%), rpoB (99.6%), and infB (99.7%) sequences exist within the species, indicating that N. semolina isolates not only are phenotypically homogeneous but also are genetically homogeneous. The type strain of N. semolina is CCUG43639(T) (DSM16380(T)).
Anders Miki Bojesen - One of the best experts on this subject based on the ideXlab platform.
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Prevalence of Taxa of Pasteurellaceae Among Populations of Healthy Captive Psittacine Birds.
Avian diseases, 2017Co-Authors: Magne Bisgaard, Mads F Bertelsen, Anders Miki Bojesen, Di Xin, Henrik ChristensenAbstract:SUMMARY Sixty-two strains of Pasteurellaceae-like bacteria were isolated from the tracheas of 87 clinically healthy psittacine birds in two Danish zoos. The isolates were identified by a combination of rpoB and 16S rRNA gene sequencing and by matrix-assisted laser desorption–ionization time of flight. Twenty-eight strains belonged to the genus Volucribacter or were related to this genus and to the unnamed taxon 34 of Bisgaard, and 28 strains were related to the unnamed taxon 44 of Bisgaard. Four strains were identified as Pasteurella multocida, two isolates were classified with the related taxon 45 of Bisgaard, and a single isolate was classified as Pasteurella sp. The investigation documented an unrecognized reservoir of rarely reported and unclassified or unnamed species of Pasteurellaceae-like bacteria in psittacine birds. The results were in accordance with a recent report on isolation of Pasteurellaceae from diseased psittacine birds, and the investigation documented that the same taxa of Pasteurella...
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Pasteurellaceae bacteria from the oral cavity of Tasmanian devils (Sarcophilus Harrisii) show high minimum inhibitory concentration values towards aminoglycosides and clindamycin.
Letters in applied microbiology, 2016Co-Authors: Nicole Gutman, Mie Johanne Hansen, Mads F Bertelsen, Anders Miki BojesenAbstract:Threatened by Devil Facial Tumor Disease, the Tasmanian devil populations are vulnerable and decreasing. Additionally, the devils’ biting behaviour elevates their risk of acquiring bite wound infections caused by members of the bacterial Pasteurellaceae family that are natural inhabitants of the oral microbiota. In medical management of such bite wounds, antimicrobial susceptibility profiles are crucial. Prior to this investigation, no available data on minimal inhibitory concentration (MIC) values existed. A total of 26 isolates obtained from the oral cavity of 26 healthy Tasmanian devils were tested for their antimicrobial susceptibility by broth micro dilution. Most prominently, high MIC values for clindamycin (≥ 4 μ g ml −1 ), gentamicin (≥ 8 μ g ml −1 ) and amikacin (≥ 32 μ g ml −1 ), were observed for 92, 77 and 73% of the strains tested respectively. This study may be used as a guideline for antimicrobial therapy against bite wound infections caused by Pasteurellaceae originating from the oral cavity of Tasmanian devils.
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Testudinibacter aquarius gen. nov., sp. nov., a member of the family Pasteurellaceae isolated from the oral cavity of freshwater turtles.
International journal of systematic and evolutionary microbiology, 2015Co-Authors: Mie Johanne Hansen, Henrik Christensen, Anders Miki Bojesen, Elin Anna Erica Pennanen, Mads F BertelsenAbstract:A total of 13 Pasteurellaceae isolates from healthy freshwater turtles were characterized by genotypic and phenotypic tests. Phylogenetic analysis of partial 16S rRNA and rpoB gene sequences showed that the isolates investigated formed a monophyletic group. The closest related species based on 16S rRNA gene sequencing was Chelonobacter oris CCUG 55632T with 94.4 % similarity and the closest related species based on rpoB gene sequence comparison was [Pasteurella] testudinis CCUG 19802T with 91.5 % similarity. All the investigated isolates exhibited phenotypic characteristics of the family Pasteurellaceae. However, they could be separated from existing genera of the Pasteurellaceae by the following test results: indole, ornithine decarboxylase and Voges–Proskauer positive; and methyl red, urease and PNPG (α-glucosidase) negative. No X- or V-factor requirement was observed. A zone of β-haemolysis surrounded the colonies after 24 h of incubation on bovine blood agar at 37 °C. Acid was produced from l-arabinose, dulcitol, d-mannitol, sucrose and trehalose. Representative strain ELNT2xT had a fatty acid profile that was characteristic for members of the Pasteurellaceae. ELNT2xT expressed only one respiratory quinone, ubiquinone-8 (100 %). The DNA G+C content of strain ELNT2xT was 42.8 mol%. On the basis of both phylogenetic and phenotypic evidence, it is proposed that the strains should be classified as representatives of a novel species of a new genus, Testudinibacter aquarius gen. nov., sp. nov. The type strain of Testudinibacter aquarius is ELNT2xT ( = CCUG 65146T = DSM 28140T), which was isolated from the oral cavity of a captive eastern long-necked turtle (Chelodina longicollis) in Denmark in 2012.
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ursidibacter maritimus gen nov sp nov and ursidibacter arcticus sp nov two new members of the family Pasteurellaceae isolated from the oral cavity of bears
International Journal of Systematic and Evolutionary Microbiology, 2015Co-Authors: Henrik Christensen, Mie Johanne Hansen, Mads F Bertelsen, Anders Miki Bojesen, Mira Strom Braaten, Christian Sonne, Rune DietzAbstract:Thirty-three suspected strains of the family Pasteurellaceae isolated from the oral cavity of polar and brown bears were characterized by genotypic and phenotypic tests. Phylogenetic analysis of partial 16S rRNA gene and rpoB sequences showed that the investigated isolates formed two closely related monophyletic groups, representing two novel species of a new genus. Based on 16S rRNA gene sequence comparison Bibersteinia trehalosi was the closest related species with a validly published name, with 95.4 % similarity to the polar bear group and 94.4 % similarity to the brown bear group. Otariodibacter oris was the closest related species based on rpoB sequence comparison with a similarity of 89.8 % with the polar bear group and 90 % with the brown bear group. The new genus could be separated from existing genera of the family Pasteurellaceae by three to ten phenotypic characters, and the two novel species could be separated from each other by two phenotypic characters. It is proposed that the strains should be classified as representatives of a new genus, Ursidibacter gen. nov., with two novel species: the type species Ursidibacter maritimus sp. nov., isolated from polar bears (type strain Pb43106T = CCUG 65144T = DSM 28137T, DNA G+C content 39.3 mol%), and Ursidibacter arcticus sp. nov., isolated from brown bears (type strain Bamse61T = CCUG 65145T = DSM 28138T).
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OCCURRENCE OF Pasteurellaceae BACTERIA IN THE ORAL CAVITY OF THE TASMANIAN DEVIL (SARCOPHILUS HARRISII)
Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians, 2015Co-Authors: Lena Brix, Mie Johanne Hansen, Mads F Bertelsen, Androo Kelly, Anders Miki BojesenAbstract:Abstract: The occurrence of bacteria belonging to the family Pasteurellaceae in the oral cavity of captive Tasmanian devils (Sarcophilus harrisii) was investigated using phenotypic and subsequent genotypic characterization and phylogenetic analyses. A total of 62 bacterial isolates obtained from Tasmanian devils, tentatively classified with the family Pasteurellaceae, were further characterized by phylogenetic analysis of rpoB gene sequence similarity, which showed that the isolates investigated formed five distinct groups. A total of 15 strains formed a novel genus-like group within Pasteurellaceae. Thirty-six strains grouped with the type strain of Frederiksenia canicola. Five strains clustered with the type strain of Pasteurella multocida. Interestingly, four of the P. multocida–like strains were β-hemolytic when incubated on blood agar, which is atypical for this genus. Five strains grouped with a 100% rpoB similarity with Pasteurella dagmatis. Finally, a single strain showed 97.1% resemblance to Hae...