Pasteurella

Int J Syst Evol Microbiol, 2005 Jan, 55(Pt 1), 209 - 23
Emended description of porcine {Pasteurella} aerogenes, {Pasteurella} mairii and {Actinobacillus} rossii; Christensen H et al.; The aim of this study was to improve the definition and identification of a group of veterinarily important bacteria referred to as the {Pasteurella} aerogenes-{Pasteurella} mairii-{Actinobacillus} rossii complex . These organisms have mainly been isolated from the reproductive and intestinal tracts of pigs and in most cases have been considered as opportunistic pathogens . A collection of 87 strains were characterized by phenotypic analysis from which 41 strains were selected for 16S rRNA gene sequence comparison, out of which 23 have been sequenced in the present study . One group of 21 strains phenotyped as biovars 1, 3-5, 9-11, 19 and 25-27, including the type strain of {P.} aerogenes, showed 16S rRNA gene sequence similarities of 99.6 % or higher; another group of 18 strains including biovars 2, 6-8, 12-15, 21, 23, 24 and 26A and the type strain of {A.} rossii showed 97.8 % or higher 16S rRNA gene sequence similarity . Between the two groups, 93.8-95.7 % 16S rRNA gene sequence similarity was observed . Strains of {P.} mairii showed 99.5 % similarity, with 95.5-97.2 and 93.8-95.5 % similarity to strains of {P.} aerogenes and {A.} rossii, respectively . Four strains could not be classified with any of these groups and belonged to other members of Pasteurellaceae . Comparisons were also made to DNA-DNA hybridization data . Biovars 1, 9, 10, 11 and 19, including the type strain of {P.} aerogenes, linked at 70 % DNA reassociation, whereas strains identified as biovars 2, 6, 7, 8, 12, 15 and 21 of {P.} aerogenes linked at 81 % . The latter group most likely represents {A.} rossii based on the 16S rRNA gene sequence comparisons . DNA reassociation between the {P.} aerogenes and {A.} rossii groups was at most 37 %, whereas 47 % was the highest DNA reassociation found between {P.} aerogenes and {P.} mairii . The study showed that {P.} aerogenes, {P.} mairii and {A.} rossii can not be easily separated and may consequently be misidentified based on current knowledge of their phenotypic characteristics . In addition, these taxa are difficult to separate from other taxa of the Pasteurellaceae . A revised scheme for separation based upon phenotypic characters is suggested for the three species {P.} aerogenes emend., {P.} mairii emend . and {A.} rossii emend., with the respective type strains ATCC 27883(T), NCTC 10699(T) and ATCC 27072(T).

J Vet Med Sci, 2004 Dec, 66(12), 1603 - 4
Protectivity of an Immunoaffinity-Purified 39 kDa Capsular Protein of Avian Pasteurella multocida in Mice; Ali HA et al.; A 39 kDa protein of avian Pasteurella multocida strain P-1059 (serovar A:3) was purified from a crude capsular extract by immunoaffinity chromatography by using a ligand of purified mouse monoclonal antibody to the 39 kDa capsular protein of the strain . Protective activity of the purified 39 kDa protein antigen was determined by inoculation of ddY mice twice with 25 or 125 mug of the protein and challenge-exposure with 10 or 50 LD(50) of strains P-1059 or X-73 (serovar A:1) . The results showed that the antigen gave high protection (60 to 100%) . These results indicated that the 39 kDa protein of avian P . multocida is a cross-protective antigen over serovars A:1 and A:3.

Trop Anim Health Prod, 2004 Nov, 36(8), 743 - 50
Antibiotic sensitivity patterns among Indian strains of avian Pasteurella multocida; Shivachandra SB et al.; An investigation was carried out to study the antibiotic sensitivity of avian strains of Pasteurella multocida and to select an effective antimicrobial agent for control of avian pasteurellosis in India . A total of 123 strains of P . multocida recently isolated from different avian species (chicken, duck, turkey, quail, and goose), from different regions of India were subjected to antibiotic sensitivity tests using 20 different antibiotics . Absolute resistance was observed against sulfadiazine . The studies indicated that the strains were most sensitive to chloramphenicol (73.98%), followed by enrofloxacin (71.54%), lincomycin (64.23%), norfloxacin (61.79%) and doxycycline-HCl (56.91%) . The majority of the strains were found to exhibit intermediate sensitivity . Chloramphenicol was selected and suggested for treatment . Antibiogram studies also revealed the emergence of multidrug-resistant strains of P . multocida among Indian poultry.

J Clin Microbiol, 2005 Jan, 43(1), 259 - 70
Characterization of sucrose-negative Pasteurella multocida variants, including isolates from large-cat bite wounds; Christensen H et al.; To validate the identification of Pasteurella multocida-like bacteria negative for acid formation from sucrose, including isolates from bite wounds caused by large cats, 17 strains were phenotypically and genotypically characterized . Phylogenetic analysis of partially sequenced rpoB and infB genes showed the monophyly of the strains characterized and the reference strains of P . multocida . The sucrose-negative strains formed two groups, one related to reference strains of P . multocida and the other related to a separate species-like group (taxon 45 of Bisgaard) . DNA-DNA hybridization further documented the species-like nature of this group . Ribotyping showed the heterogeneity of all strains except four strains that shared the same ribotype and that were isolated from bovine lungs . Phylogenetic analysis by 16S rRNA sequence comparison showed the monophyly of the strains characterized and the reference strains of P . multocida . Two strains isolated from leopard bite wounds were related to the type strain of P . dagmatis; however, they represented a new taxon (taxon 46 of Bisgaard), in accordance with their distinct phenotypic and genotypic identifications . The present study documents that sucrose-negative strains of P . multocida-like bacteria belong to two genotypically distinct groups . The study further confirms the phenotypic heterogeneity of P . multocida strains and documents two new species-like taxa of Pasteurella related to P . multocida . Until diagnostic tools have been further elaborated, special care should be taken in the identification of Pasteurella-like bacteria isolated from bite wounds caused by large cats . The evidence of phenotypic and genotypic divergence calls for the further development of PCR tests and DNA sequencing to document doubtful isolates.

Vet Immunol Immunopathol, 2005 Feb 10, 103(3-4), 187 - 93
Incubation of bovine PMNs with conditioned medium from BHV-1 infected peripheral blood mononuclear cells increases their susceptibility to Mannheimia haemolytica leukotoxin; Leite F et al.; Active infection with bovine herpesvirus-1 (BHV-1) increases the susceptibility of cattle to secondary bacterial pneumonia with Mannheimia (Pasteurella) haemolytica A1 . In the present study we found that bovine PMNs incubated with conditioned media from BHV-1 infected peripheral blood mononuclear cells (PBMCs) exhibited increased LFA-1 expression, enhanced LKT binding and increased LKT cytotoxicity . These effects were abrogated when the conditioned medium was pre-incubated with an anti-IL-1beta Mab before being added to the PMNs . These findings suggest that BHV-1 infection, and the resulting release of IL-1beta and perhaps other inflammatory cytokines, can stimulate activation of LFA-1 in bystander bovine PMNs, thus enhancing the binding and biological effects of LKT.

Carbohydr Res, 2005 Jan 17, 340(1), 59 - 68
Structural analysis of the lipopolysaccharide of Pasteurella multocida strain VP161: identification of both Kdo-P and Kdo-Kdo species in the lipopolysaccharide; St Michael F et al.; The structure of the lipopolysaccharide from the Pasteurella multocida strain VP161 was elucidated . The lipopolysaccharide was subjected to a variety of degradative procedures . The structures of the purified products were established by monosaccharide and methylation analyses, NMR spectroscopy and mass spectrometry . The following structures for the lipopolysaccharides were determined on the basis of the combined data from these experiments . Based on the NMR data, all sugars were found in pyranose ring forms, and Kdo is 2-keto-3-deoxy-octulosonic acid, l-alpha-d-Hep is l-glycero-d-manno-heptose, PPEtn is pyrophosphoethanolamine and PCho is phosphocholine . Intriguingly, when the O- and fully deacylated LPS was examined, it was evident that there was variability in the arrangement of the Kdo region of the molecule . Glycoforms were found with a Kdo-P moiety, as well as glycoforms elaborating a Kdo-Kdo group . Furthermore the Glc II residue was not attached to Hep I when two Kdo residues were present, but it was attached when the Kdo-P arrangement was elaborated, suggesting a biosynthetic incompatibility due to either steric hindrance or an inappropriate acceptor conformation . This variation in the Kdo region of the LPS was also observed in several other Pasteurella multocida strains investigated including the genome strain Pm70.

Infect Immun, 2005 Jan, 73(1), 413 - 21
Pasteurella multocida toxin activates human monocyte-derived and murine bone marrow-derived dendritic cells in vitro but suppresses antibody production in vivo; Bagley KC et al.; Pasteurella multocida toxin (PMT) is a potent mitogen for fibroblasts and osteoblastic cells . PMT activates phospholipase C-beta through G(q)alpha, and the activation of this pathway is responsible for its mitogenic activity . Here, we investigated the effects of PMT on human monocyte-derived dendritic cells (MDDC) in vitro and show a novel activity for PMT . In this regard, PMT activates MDDC to mature in a dose-dependent manner through the activation of phospholipase C and subsequent mobilization of calcium . This activation was accompanied by enhanced stimulation of naive alloreactive T cells and dominant inhibition of interleukin-12 production in the presence of saturating concentrations of lipopolysaccharide . Surprisingly, although PMT mimics the activating effects of cholera toxin on human MDDC and mouse bone marrow-derived dendritic cells, we found that PMT is not a mucosal adjuvant and that it suppresses the adjuvant effects of cholera toxin in mice . Together, these results indicate discordant effects for PMT in vitro compared to those in vivo.

Antimicrob Agents Chemother, 2005 Jan, 49(1), 414 - 7
dfrA20, A novel trimethoprim resistance gene from Pasteurella multocida; Kehrenberg C et al.; A novel trimethoprim resistance gene, designated dfrA20, was detected on the 11-kb plasmid pCCK154 from Pasteurella multocida . The dfrA20 gene codes for a dihydrofolate reductase of 169 amino acids . Sequence comparisons revealed that the DfrA20 protein differed distinctly from all dihydrofolate reductases known so far.

Vet Res Commun, 2004 Nov, 28(8), 657 - 67
Prevalent serotypes of Pasteurella multocida isolated from different animal and avian species in India; Kumar AA et al.; Identification and estimation of the prevalence of Pasteurella multocida organisms in different animal and avian species in India during November 2000 to July 2003 was carried out . Out of 418 samples collected from different outbreaks suspected to be caused by P . multocida, a total of 206 bacterial cultures were identified as P . multocida on the basis of cultural, morphological and biochemical characteristics . All the 206 cultures were isolated from different domestic animal species (cattle, buffalo, sheep, goat, pig and rabbit), avian species (chicken, duck, quail, turkey, goose) and wild animals such as leopard and deer . Serotyping of P . multocida cultures revealed the presence of various serotypes (A:1, A:3, A:1,3, A:4, B:2, D:1 and -:1) among the livestock population . P . multocida polymerase chain reaction (PCR) assay applied on different forms of bacterial cultures (bacterial culture lysate, direct bacterial colony and mixed bacterial culture lysate) yielded an amplified product of approximately 460 bp specific for P . multocida . The results of PCR assay correlated well with conventional methods of identification . The present investigation revealed the presence of varied serotypes among livestock and PCR assay was found to be useful for rapid, sensitive and specific diagnosis of pasteurellosis in animals and avian species.

Tidsskr Nor Laegeforen, 2004 Dec 16, 124(24), 3194 - 6
{Bite wound infections}; Yaqub S et al.; BACKGROUND: The lifetime risk of experiencing a bite wound, human or animal, is approximately 50%, and bite wounds account for approximately 1% of all visits to emergency departments . The majority of bite wounds are inflicted by dogs and cats . MATERIAL AND METHODS: A review of the literature on the diagnosis and treatment of bite wound infections is presented . RESULTS: The most common pathogens associated with bite wounds are Streptococcus species, Staphylococcus species, Pasteurella multocida, Capnocytophaga canimorsus and anaerobic bacteria . Sporadically other pathogens are isolated from bite wounds . Human bites differ from animal bites by higher prevalence of Staphylococcus aureus and Eikenella corrodens . INTERPRETATION: It is important to be aware of the possibility of complicating infections following bite wounds, particularly after cat bites . Phenoxymethyl penicillin should be the drug of choice in treatment of infections associated with cat and dog bites . However, in case of slow recovery or no improvement, simultaneous lymphadenopathy or pneumonia, S . aureus or Francisella tularensis should be suspected; ciprofloxacin is recommended . For human bite infections the recommend treatment is phenoxymethyl penicillin in combination with penicillinase-stable penicillin.

J Vet Med B Infect Dis Vet Public Health, 2004 Dec, 51(10), 467 - 9
Identification of Pasteurella multocida Serogroup F Isolates in Rabbits; Jaglic Z et al.; Summary A total of 24 Pasteurella multocida rabbit isolates obtained from 24 rabbit flocks in the Czech Republic during the period of between 2001 and 2004 were analysed by capsular PCR typing . Apart from isolates identified as serogroups A (n = 14, 58.4%) and D (n = 2, 8.3%), eight isolates (33.3%) were identified as members of serogroup F . This serogroup had been predominantly associated with poultry infections so far . The rabbit serogroup F isolates were characterized in detail by ribotyping with restriction to endonuclease MspI revealing two distinct ribotypes . Seven serogroup F isolates were assigned to ribotype 1 and one isolate was assigned to ribotype 2.

South Med J, 2004 Nov, 97(11), 1113 - 5
Spontaneous bacterial peritonitis with Pasteurella multocida in cirrhosis: case report and review of literature; Tamaskar I et al.; Most Pasteurella multocida human infections involve skin and soft tissues and invariably develop after a bite or a scratch from a dog or a cat . However, other infections with this organism occur infrequently . Enteric microorganisms are the common cause of spontaneous bacterial peritonitis (SBP) . We report a case of SBP in a cirrhotic patient from P . multocida . English literature (Pubmed) review revealed 12 adult cases of SBP in cirrhotic patients with P multocida . Nine patients were exposed to animals, though a break in the skin or a bite was not reported in each case . The SBP was fatal in four of these patients.

Berl Munch Tierarztl Wochenschr, 2004 Nov-Dec, 117(11-12), 480 - 92
{Data on the prevalence of antimicrobial susceptibility of veterinary pathogens from cattle and pigs: national antibiotic resistance monitoring 2002/2003 of the BVL}; Wallmann J et al.; The national antimicrobial resistance monitoring determines the current quantitative resistance level of life-stock pathogens, in order to permit the evaluation and surveillance of the distribution of resistances on a valid basis . During the examination period from June 2002 to July 2003, a total of 1849 pathogens was collected, following a representative German-wide pattern in collaboration with 29 laboratories . The selection of examined bacterial strains included different specimen causing respiratory diseases in fattening pigs (Pasteurella multocida, Bordetella bronchiseptica) and cattle (Pasteurella multocida, Mannheimia haemolytica), respectively, as well as strains causing mastitis in dairy cows (Staphylococcus spp., Streptococcus spp., E . coli) . Determination of the in-vitro susceptibility (minimal inhibitory concentration) to at least 17 antimicrobial agents was performed centrally by the BVL using the microdilution broth method . The findings approximately match results of an analogous study conducted in 2001, and correspondingly revealed significantly lower resistance-values in comparison to data published for Germany so far . No correlation could be established between the incidence of resistance and differing stock densities . By means of the resistance monitoring data gathered by the BVL, the risk potential of antimicrobials applied in Germany can be reliably defined . This valuable information about the epidemiological situation of resistance in Germany can be helpful to veterinarians as a decision guidance when choosing appropriate means of therapy . Accordingly, the results stated by the BVL are apt to provide an important contribution to improving the safety of food-animal products . The experiences obtained from the monitoring also show that valid data about the antimicrobial susceptibility can only be raised on an interdisciplinary approach (federal agencies, county diagnostic laboratories, universities, industry) . Currently, the BVL put into practice a study with an extended spectrum of bacterial species and indications.

J Clin Microbiol, 2004 Dec, 42(12), 5542 - 8
Nicoletella semolina gen . nov., sp . nov., a new member of Pasteurellaceae isolated from horses with airway disease; Kuhnert P et al.; 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)).

Microbiology, 2004 Dec, 150(Pt 12), 4199 - 210
Genetic diversity among Pasteurella multocida strains of avian, bovine, ovine and porcine origin from England and Wales by comparative sequence analysis of the 16S rRNA gene; Davies RL; Genetic diversity among 86 Pasteurella multocida isolates was investigated by comparative sequence analysis of a 1468 bp fragment of the 16S rRNA gene . The strains included 79 field isolates recovered from birds (poultry) (22), cattle (21), pigs (26) and sheep (10) within England and Wales, four Asian isolates associated with bovine haemorrhagic septicaemia, and the type strains of the three subspecies of P . multocida . Dulcitol and sorbitol fermentation patterns were also determined to establish correlations between subspecies status and phylogenetic relatedness . Nineteen 16S rRNA types were identified, but these were clustered into two distinct phylogenetic lineages, A and B . Sequences within lineages A and B had a mean number of nucleotide differences of 21.12+/-3.90 . Isolates within lineage A were associated with birds, cattle, pigs and sheep, whereas those belonging to lineage B were recovered from birds and a cat . Eighty-seven per cent of the isolates were classified as P . multocida subsp . multocida by dulcitol and sorbitol fermentation patterns, but these have diverse 16S rRNA gene sequences that were represented in both lineages A and B . Avian P . multocida subsp . septica isolates were associated exclusively with lineage B, but bovine P . multocida subsp . septica isolates were present in lineage A . P . multocida subsp . gallicida isolates of avian, bovine and porcine origin represent a homogeneous group within lineage A, but they have the same 16S rRNA type as certain P . multocida subsp . multocida isolates . These findings provide strong support for the view that dulcitol and sorbitol fermentation patterns are inaccurate indicators of genetic relatedness among P . multocida strains . Avian capsular type B isolates and capsular type B and E isolates associated with haemorrhagic septicaemia of cattle and water buffaloes are closely related and form a distinct cluster within lineage A . The current subspecies nomenclature of P . multocida neither accurately reflects the 16S rRNA-based phylogenetic relationships among isolates nor does it adequately encompass the full range of diversity within the species . The study provides a 16S rRNA-based evolutionary framework that will form the basis of further studies into the genetic diversity of P . multocida and will also help in the reclassification of the species.

J Bacteriol, 2004 Dec, 186(24), 8529 - 32
Identification of a distinct, cryptic heparosan synthase from Pasteurella multocida types A, D, and F; Deangelis PL et al.; The extracellular polysaccharide capsules of Pasteurella multocida types A, D, and F are composed of hyaluronan, N-acetylheparosan (heparosan or unsulfated, unepimerized heparin), and unsulfated chondroitin, respectively . Previously, a type D heparosan synthase, a glycosyltransferase that forms the repeating disaccharide heparosan backbone, was identified . Here, a approximately 73% identical gene product that is encoded outside of the capsule biosynthesis locus was also shown to be a functional heparosan synthase . Unlike PmHS1, the PmHS2 enzyme was not stimulated greatly by the addition of an exogenous polymer acceptor and yielded smaller- molecular-weight-product size distributions . Virtually identical hssB genes are found in most type A, D, and F isolates . The occurrence of multiple polysaccharide synthases in a single strain invokes the potential for capsular variation.

Respir Care, 2004 Dec, 49(12), 1528 - 9
Community-acquired pneumonia due to Pasteurella multocida; Marinella MA; Most cases of community-acquired pneumonia result from infection with predictable common pathogens . However, rare patients develop pneumonia from unusual bacterial species such as Pasteurella multocida, a Gram-negative oral commensal of most dogs and cats . The majority of P . multocida infections involve skin and soft tissue and complicate a bite or scratch . I report the case of an elderly man who owned 16 cats and developed bacteremic pneumonia with P . multocida . .

Int J Antimicrob Agents, 2004 Dec, 24(6), 592 - 8
A seven-year survey of susceptibility to marbofloxacin of pathogenic strains isolated from pets; Meunier D et al.; This study, Vetoquinol S.A . epidemiosurveillance, was conducted from 1994 to 2001 in order to determine the susceptibility (by MIC determination) to marbofloxacin (a third generation fluoroquinolone used only in individual administration for animals) . Strains from infected pets originated from six European countries . Isolates were collected from urinary infections (Escherichia coli), respiratory infections (Pasteurella multocida), dermatological infections (Staphylococcus intermedius, Pseudomonas aeruginosa) and otitis (S . intermedius, P . aeruginosa) . The MIC distribution for each species was the same both before and after the launch of marbofloxacin in 1995 . In E . coli, a resistant population was present before the use of marbofloxacin; this resistance was induced by co- or cross-resistance to other antibiotics used previously . Over this period, there was no significant evolution of MIC(90) for any bacterial species studied and no development of resistance was observed . Marbofloxacin was the most active antibiotic against P . multocida isolates and had the lowest MIC . No difference in MIC distribution was seen between the S . intermedius (unimodal distribution) isolated from dermatological infections and those from otitis . This was also true for P . aeruginosa . The use of marbofloxacin was not found to have induced a significant increase or spread of resistant bacteria.

Pediatr Infect Dis J, 2004 Nov, 23(11), 1063 - 5
Pasteurella multocida meningitis and cervical spine osteomyelitis in a neonate; Hirsh D et al.; A 20-day-old male infant presented with fever, decreased alertness and quadriparesis as a result of Pasteurella multocida meningitis and C1-2 vertebral osteomyelitis . Although his household contained 2 pet cats, there was no history of bites, scratches or licks . We speculate that colonization of the nasopharynx was followed by contiguous spread to the retropharyngeal soft tissue, cervical vertebrae and meninges.

Chest, 2004 Nov, 126(5), 1636 - 44
Intrapleural injection of transforming growth factor-beta antibody inhibits pleural fibrosis in empyema; Kunz CR et al.; STUDY OBJECTIVES: Transforming growth factor (TGF)-beta is a cytokine that has been demonstrated to be an important modulator of inflammation and angiogenesis, as well as a potent stimulator of pleural fluid production and fibrosis . We previously demonstrated that rising levels of pleural fluid TGF-beta(1) correlate with pleural fibrosis in experimental empyema in rabbits . In this study, our hypothesis is that neutralization of TGF-beta with an intrapleural injection of a monoclonal antibody to TGF-beta will decrease pleural fibrosis in empyema . DESIGN: Prospective, randomized, blinded study . SETTING: Animal research laboratory . SUBJECTS: Nineteen rabbits . INTERVENTIONS: An empyema was induced in 19 rabbits by intrapleural injection of Pasteurella multocida . A panspecific monoclonal antibody to TGF-beta was injected into the pleural space on 2 subsequent concurrent days in nine rabbits . Ten rabbits received intrapleural injections of bacteria alone and served as controls . All animals were then killed on day 6 . Immunohistochemistry, using the antibody to TGF-beta, was performed on pleural tissue specimens from the control rabbits . MEASUREMENTS AND RESULTS: Immunohistochemistry revealed localization of TGF-beta to macrophages in the exudative material and the visceral pleura . After injection of the antibody to TGF-beta, the amount of purulent, exudative material in the pleural space of the nine experimental animals was markedly decreased at autopsy on day 6, relative to control animals . All markers of empyema and pleural fibrosis were also significantly decreased in the rabbits receiving intrapleural anti-TGF-beta . CONCLUSIONS: TGF-beta localizes to macrophages in experimental empyema . Early intrapleural injection of an antibody to TGF-beta inhibits empyema formation and significantly decreases pleural fibrosis in experimental empyema.

Glycobiology . 2004 Nov 10; {Epub ahead of print}
Structural analysis of the lipopolysaccharide from Pasteurella multocida genome strain Pm70 and identification of the putative lipopolysaccharide glycosyltransferases; St Michael F et al.; Pasteurella multocida is an important multi-species veterinary pathogen . The cell surface lipopolysaccharide (LPS) is an important virulence factor and forms the basis of the serotyping scheme, although little structural information about the LPS is known . The structure of the LPS from the Pasteurella multocida genome strain Pm70 was elucidated in this study . The LPS was subjected to a variety of degradative procedures . The structures of the purified products were established by monosaccharide and methylation analyses, NMR spectroscopy and mass spectrometry . The following structure for the core oligosaccharide was determined on the basis of the combined data from these experiments, where based on the NMR data all sugars were found in pyranose ring forms . Glucose, galactose and N-acetyl-galactosamine residues were all present as D-isomers . Kdo is 2-keto-3-deoxy-octulosonic acid, L-alpha-D-Hep is L-glycero-D-manno-heptose, and PEtn is phosphoethanolamine . Identification of the core oligosaccharide structure enabled a search for glycosyltransferase homologues in the Pm70 genome, and revealed a clustering of the genes putatively responsible for outer core oligosaccharide biosynthesis.

Vet Microbiol, 2004 Nov 30, 104(1-2), 55 - 62
Invasion of chicken embryo fibroblast cells by avian Pasteurella multocida; Al-haj Ali H et al.; Invasion of chicken embryo fibroblast (CEF) cells by the virulent encapsulated Pasteurella multocida strains P-1059 (serovar A:3) and X-73 (serovar A:1) and an avirulent noncapsulated derivative P-1059B (serovar -:3) was investigated . The number of intracellular bacteria increased for all the strains after 2, 4 and 6 h post-inoculation to CEF cells . By 6 h post-inoculation, the number of invaded bacteria of encapsulated strains was significantly higher than noncapsulated strain and reached 150- and 112-fold for strains P-1059 and X-73, respectively, while it was 9-fold for strain P-1059B as compared to the number of invaded bacteria recovered after 2 h post-inoculation . Electron microscopy of invasion by encapsulated strains showed that the bacteria were adhering to CEF cells membrane after 1 h of inoculation . By 4-h, one or two bacteria were detected within membrane-bound vacuoles of the intracellular space . The number of intracellular bacteria markedly increased at 14 h post-inoculation . Invasion of all strains was inhibited significantly when the monolayers were treated with periodic acid (P<0.001) or trypsin (P<0.05) . The treatment of bacteria with hyaluronidase did not affect invasion . The present results indicate that avian P . multocida capsular type A strains are invasive and that the receptor on CEF cell surface might be glycoprotein.

Avian Dis, 2004 Sep, 48(3), 463 - 70
Pasteurella multocida infection in heterophil-depleted chickens; Bojesen AM et al.; The present study was aimed at elucidating the role of heterophil granulocytes during the initial infection with Pasteurella multocida subsp . multocida in chickens . Chickens (17 and 19 wk old) were depleted of their heterophil granulocytes by 5-fluorouracil treatment . When the heterophil blood counts were significantly reduced, the birds were inoculated intratracheally with 1.8-4.3 x 10(4) colony-forming units of P . multocida . Twelve, 24, or 48 hr postinoculation, the birds were euthanatized and examined for macroscopic and histologic lesions in the lungs . Bacterial invasion was determined by culture of P . multocida from the spleen . Recruitment of heterophils into the respiratory tract during infection was found to contribute considerably to the lung lesions in chickens and was found to mediate tissue damage, possibly allowing a more rapid systemic spread of P . multocida . However, during progression of the infection, the heterophil-mediated necrosis in chickens seemed to stimulate giant cell demarcation of infected lung tissue, which coincided with the clearance of P . multocida from the spleen, thus hampering further invasion . Consequently, heterophil activation plays a dual role for the outcome of a P . multocida infection in chickens, where it initially seems to promote invasion and systemic spread but subsequently helps limit the infection by giant cell formation and bacterial clearance.

Vet Microbiol, 2004 Nov 15, 103(3-4), 201 - 7
An experimental mouse model of progressive atrophic rhinitis of swine; Jordan RW et al.; Pasteurella multocida is responsible for a variety of diseases of veterinary importance, including the pig disease progressive atrophic rhinitis (PAR) . The feasibility of using the mouse as an experimental model of PAR was evaluated . We experimentally infected the upper respiratory tract of immature mice with a pig isolate of P . multocida that produces the toxin responsible for causing the nasal lesions characteristic of PAR . We tracked the health status and weight gain of these mice for one month following infection, after which the mice were killed and the integrity of the nasal turbinates was examined . Mice infected with P . multocida appeared healthy throughout the study, although the growth rate of these mice was reduced significantly compared with non-infected control animals . Infected animals also demonstrated marked nasal atrophy analogous to that seen in naturally occurring PAR of swine, with shortening and thinning of the turbinate scrolls and inflammatory cell involvement . The mouse therefore provides a convenient model for the further investigation of PAR of swine.

Berl Munch Tierarztl Wochenschr, 2004 Sep-Oct, 117(9-10), 367 - 86
{Pasteurella: insights into the virulence determinants of a heterogenous bacterium}; Ewers C et al.; Pasteurella (P.) multocida is the causative agent of numerous economically relevant diseases worldwide . These are enzootic bronchopneumonia in cattle and sheep and hemorraghic septicemia in cattle and buffaloes, Rhinitis atrophicans in swine, snuffles in rabbit, and fowl cholera . All disease complexes are associated with certain capsular and somatic antigens . Even as human pathogen P . multocida is of increasing importance, causing wound infections, and even septicemia, meningitis, and endocarditis . Despite extensive research activities including the genome analysis of one fowl cholera isolate in the year 2001 there are a lot of open questions concerning the molecular pathogenic mechanisms . Problems encountered are the high antigenic variability and the wide host spectrum of P . multocida as well as different courses of infection . In consequence there are enormous difficulties in producing vaccines . Transcriptomics and proteomics hopefully will give new insight into the pathogenesis of P . multocida infections in different hosts . A frequent problem particular in classical diagnostic laboratories is the diagnosis of P . multocida and its differentiation from other P . species and Mannheimia (M.) haemolytica . The biochemical identification of P . multocida is not reliable due to variable phenotypical characteristics often caused by different culture conditions, and it is time consuming and cost-intensive . Extensive molecular biologic studies concerning the prevalence and distribution of virulence associated genes known so far in P . species, which will be described in detail in this paper, could contribute to the establishment of a diagnostic tool, such as a multiplex polymerase chain reaction, that would provide a cheap and time-saving identification and characterization of wildtype strains.

Schweiz Arch Tierheilkd, 2004 Sep, 146(9), 417 - 22
{Comparison of antimicrobial resistance pattern of selected respiratory tract pathogens isolated from different animal species}; Wettstein K et al.; The antibiotic resistance pattern of respiratory tract pathogens isolated of different animal species suffering from respiratory tract diseases has been investigated by antibiograms performed by agar diffusion test . The results show that the resistance situation in Switzerland is favourable compared with studies from other countries . However, high resistance rates were found in certain species: 61% of Streptococcus spp . were resistant to erythromycin and 44% to tetracycline, 59% of Bordetella bronchiseptica were resistant to ampicillin and 50% of Mannheimia (Pasteurella) haemolytica were multiresistant to tetracycline, ampicillin and streptomycine . The gram negative isolates were widely resistant to streptomycine.

J Wildl Dis, 2004 Jul, 40(3), 377 - 82
Are wetlands the reservoir for avian cholera?
Samuel MD, Shadduck DJ, Goldberg DR.
Wetlands have long been suspected to be an important reservoir for Pasteurella multocida and therefore the likely source of avian cholera outbreaks . During the fall of 1995-98 we collected sediment and water samples from 44 wetlands where avian cholera epizootics occurred the previous winter or spring . We attempted to isolate P . multocida in sediment and surface water samples from 10 locations distributed throughout each wetland . We were not able to isolate P . multocida from any of the 440 water and 440 sediment samples collected from these wetlands . In contrast, during other investigations of avian cholera we isolated P . multocida from 20 of 44 wetlands, including 7% of the water and 4.5% of the sediment samples collected during or shortly following epizootic events . Our results indicate that wetlands are an unlikely reservoir for the bacteria that causes avian cholera.

J Vet Diagn Invest, 2004 Sep, 16(5), 458 - 60
Molecular epidemiology of two fowl cholera outbreaks on a free-range chicken layer farm; Zhang P et al.; Two outbreaks of fowl cholera on a multiage free-range egg farm were investigated . The outbreaks occurred in 1994 and 2002 . A total of 22 strains of Pasteurella multocida were available for study, 11 from the 1994 outbreak and 11 from the 2002 outbreak . Lesions typical of acute fowl cholera were seen in the 1994 outbreak, whereas both acute and chronic fowl cholera occurred in the 2002 outbreak . The isolates were examined in an extended phenotypic typing methodology, by a P . multocida-specific polymerase chain reaction (PCR), by the Heddleston somatic serotyping scheme, and by restriction endonuclease analysis (REA) typing using the enzyme HpaII . All 22 strains had the same phenotypic properties, all were confirmed as P . multocida by PCR, all were Heddleston serovar 4, and all had the same REA pattern . The results indicate that these 2 outbreaks were caused by the same clone of P . multocida--despite the 8-year time period between the outbreaks.

J Vet Diagn Invest, 2004 Sep, 16(5), 426 - 31
Isolation and antimicrobial susceptibilities of bacterial pathogens from bovine pneumonia: 1994--2002; Welsh RD et al.; Between 1994 and 2002, a total of 390 (46.3%) Mannheimia haemolytica, 292 (34.7%) Pasteurella multocida, and 160 (19.0%) Histophilus somni were isolated at the Oklahoma Animal Disease Diagnostic Laboratory from lungs from 6-18-month-old beef cattle with pneumonia . The ratio of M . haemolytica isolations to P . multocida isolations decreased from 3.1 in 1994 to 0.8 in 2000 while increasing to 1.5 in 2002 . Mannheimia haemolytica isolations significantly (P < 0.05) decreased from 62.5% in 1994 to between 30.6% and 50.4% in 1998--2002 . Pasteurella multocida isolations significantly (P < 0.05) increased from 20.0% in 1994 to between 28.6% and 47.4% in 1998--2002 . Histophilus somni isolations were <19% except in 1998 (40.8%) and 1999 (23%) . Antimicrobial susceptibilities for M . haemolytica significantly declined for erythromycin (P = 0.0001), florfenicol (P = 0.0004), spectinomycin (P = 0.0001), and tilmicosin (P = 0.03) . For P . multocida, antimicrobial susceptibilities significantly declined for erythromycin (P = 0.0001), florfenicol (P = 0.004), spectinomycin (P = 0.03), sulfachloropyridizine (P = 0.028), tetracycline (P = 0.017), tilmicosin (P = 0.0001), and trimethoprim/sulfamethoxazole (P = 0.0003) . Antimicrobial susceptibilities for H . somni were variable for spectinomycin and sulfachloropyridizine, whereas susceptibilities to other antibiotics remained consistently high.

Mol Microbiol, 2004 Oct, 54(1), 239 - 50
Identification and characterization of the Pasteurella multocida toxin translocation domain; Baldwin MR et al.; The Pasteurella multocida toxin (PMT) is a potent mitogen which enters the cytosol of eukaryotic cells via a low pH membrane translocation event . In common with the Escherichia coli cytotoxic necrotizing factor 1 (CNF1), the core of the PMT translocation domain is composed of two predicted hydrophobic helices (H1 - residues 402-423, H2 - 437-457) linked by a hydrophilic loop (PMT-TL - 424-436) . The peptide loop contains three acidic residues (D425, D431 and E434), which may play a role equivalent to D373, D379 and E382/383 in CNF1 . To test this hypothesis, a series of point mutants was generated in which acidic residues were mutated into the permanently charged positive residue lysine . Individual mutation of D425, D431 and E434 each caused a four- to sixfold reduction in toxin activity . Interestingly, mutation of D401 located immediately outside the predicted helix-loop-helix motif completely abolished toxin activity . Individual mutations did not affect cell binding nor greatly altered toxin structure, but did prevent translocation of the surface-bound proteins into the cytosol after a low pH pulse . Moreover, we demonstrate using an in vitro assay that PMT undergoes a pH-dependent membrane insertion.

Rev Physiol Biochem Pharmacol, 2004, 152, 93 - 109 Epub 2004.
Pasteurella multocida toxin as a tool for studying Gq signal transduction; Wilson BA et al.; Pasteurella multocida toxin (PMT) stimulates and subsequently uncouples phospholipase C (PLC) signal transduction through its selective action on the Galphaq subunit . This review summarizes what is currently known about the molecular action of PMT on Gq and the resulting cellular effects . Examples are presented illustrating the use of PMT as a powerful tool for dissecting the molecular mechanisms involving pertussis toxin (PT)-insensitive heterotrimeric G proteins.

FEMS Microbiol Lett, 2004 Oct 1, 239(1), 125 - 30
Isolation and characterization of a cytotoxin produced by Plesiomonas shigelloides P-1 strain; Okawa Y et al.; In order to clarify the enteropathogenicity of Plesiomonas shigelloides, we investigated a cytotoxin produced by the P-1 strain isolated from patients suffering from diarrhea . The cytotoxicity of the culture filtrate of the strain reached a maximum in culture at 37 degrees C after 12 h shaken in BHI medium . The cytotoxin in the cultures was purified by (NH4)2SO4 precipitation, and Sephacryl S-100, Mono Q HR, and Superdex 200 HR column chromatographies . An approximate 340-fold purification was achieved, with a recovery of about 1.4%, from the culture supernatant . The cytotoxin is heat-stable, and is a complex of three major proteins (LPS-binding proteins with molecular weights of 32, 40, and 48 kDa), with lipopolysaccharide (LPS) giving a total a molecular weight of more than 600 kDa . The ratio of protein to LPS in the cytotoxin was 6-5 . The cytotoxic activity was reduced by about 80% by proteinase K treatment or when incubated with anti-cholera toxin antibody (Anti-CT) . Western blotting of the cytotoxin with Anti-CT demonstrated the presence of two anti-cholera toxin-reactive protein (ACRP) bands with molecular weights of 40 kDa (a major single protein band) and 48 kDa . The N-terminal amino acid sequence (20 residues) of the 40 kDa protein was 75% identical to Pasteurella multocida cell membrane proteins . The cytotoxin gave a positive reaction in the suckling mouse assay whereas LPS alone hardly exhibited any cytotoxic or enterotoxigenic activity . In conclusion, P . shigelloides produces a cytotoxin that consists of a complex of protein and LPS with the former component exhibiting both cytotoxicity and enteropathogenicity . This cytotoxin has the potential to have an important role in the enteropathogenicity of P . shigelloides.

J Infect Chemother, 2004 Aug, 10(4), 250 - 2
Pasteurella multocida septicemia caused by close contact with a domestic cat: case report and literature review; Kimura R et al.; We report here a case of Pasteurella multocida infection caused by cat exposure presenting with septic shock, sinusitis, and pneumonia . The patient was a febrile 20-year-old woman who had been experiencing disturbed consciousness progressively . She had close contact with a domestic cat and had received some scratches on both arms . A magnetic resonance imaging (MRI) scan of the head showed a high intensity in the paranasal cavity, and a computed tomographic (CT) scan of the chest showed bilateral lung consolidations . The pathogen was identified as P . multocida by the cultures from blood and nasal discharge . She was given intensive antibiotic therapy with ceftriaxone and piperacillin, continuous hemodiafiltration (CHDF) therapy, and anticoagulation therapy . Owing to these therapeutic regimens, the septic shock was successfully treated without complications . We also review the literature on P . multocida septicemia.

Clin Diagn Lab Immunol, 2004 Sep, 11(5), 825 - 34
Serological response to Pasteurella multocida NanH sialidase in persistently colonized rabbits; Sanchez S et al.; Pasteurella multocida is a mucosal pathogen that colonizes the upper respiratory system of rabbits . Respiratory infections can result, but the bacteria can also invade the circulatory system, producing abscesses or septicemia . P . multocida produces extracellular sialidase activity, which is believed to augment colonization of the respiratory tract and the production of lesions in an active infection . Previously, it was demonstrated that some isolates of P . multocida contain two unique sialidase genes, nanH and nanB, that encode enzymes with different substrate specificities (S . Mizan, A . D . Henk, A . Stallings, M . Meier, J . J . Maurer, and M . D . Lee, J . Bacteriol . 182:6874-6883, 2000) . We developed a recombinant antigen enzyme-linked immunosorbent assay (ELISA) based on the NanH sialidase of P . multocida and demonstrated that rabbits that were experimentally colonized with P . multocida produce detectable anti-NanH immunoglobulin M (IgM) and IgG in serum, although they demonstrated no clinical signs of pasteurellosis . In addition, clinically ill pet rabbits infected with P . multocida possessed IgM and/or IgG antibody against NanH . The NanH ELISA may be useful for the diagnosis of P . multocida infections in sick rabbits as well as for screening for carriers in research rabbit colonies.

Can J Vet Res, 2004 Jul, 68(3), 188 - 92
Bacteriology and somatic cell counts in milk samples from ewes on a Scottish farm; Hariharan H et al.; Milk samples from 50 sheep on a single Scottish research farm were collected weekly for 10 wk postpartum . Samples were analyzed for somatic cell counts (SCC) each week and bacteriologic culture was done for 7 of the 10 wk . A total of 492 udder half samples were cultured, of which 467 had corresponding cell count data . Statistical analysis on complete SCC and culture data showed no association between SCC and bacterial isolation, even when more than 10 colonies of a single bacterial species were present . Only 3.6% of the samples were simultaneously positive for high count (> 10 colonies from 0.01 mL of milk) of any one bacterial species and high SCC (> 1 x 10(6)/mL) . The bacteria recovered were: Staphylococcus equorum (19 times), S . xylosus (7 times), S . simulans (6 times), Streptococcus uberis (3 times) and other streptococci (4 times), Mannheimia (Pasteurella) haemolytica (2 times), Staphylococcus aureus (1 time), S . capitis (1 time), and Enterococcus faecium (1 time) . There was an association between the test day and SCC, with higher SCC values in the first 2 wk . In addition, significantly higher SCC values were found in the oldest animals compared to the other age groups.

J Bacteriol, 2004 Sep, 186(17), 5741 - 52
Sequence diversity and molecular evolution of the heat-modifiable outer membrane protein gene (ompA) of Mannheimia(Pasteurella) haemolytica, Mannheimia glucosida, and Pasteurella trehalosi; Davies RL et al.; The OmpA (or heat-modifiable) protein is a major structural component of the outer membranes of gram-negative bacteria . The protein contains eight membrane-traversing beta-strands and four surface-exposed loops . The genetic diversity and molecular evolution of OmpA were investigated in 31 Mannheimia (Pasteurella) haemolytica, 6 Mannheimia glucosida, and 4 Pasteurella trehalosi strains by comparative nucleotide sequence analysis . The OmpA proteins of M . haemolytica and M . glucosida contain four hypervariable domains located at the distal ends of the surface-exposed loops . The hypervariable domains of OmpA proteins from bovine and ovine M . haemolytica isolates are very different but are highly conserved among strains from each of these two host species . Fourteen different alleles representing four distinct phylogenetic classes, classes I to IV, were identified in M . haemolytica and M . glucosida . Class I, II, and IV alleles were associated with bovine M . haemolytica, ovine M . haemolytica, and M . glucosida strains, respectively, whereas class III alleles were present in certain M . haemolytica and M . glucosida isolates . Class I and II alleles were associated with divergent lineages of bovine and ovine M . haemolytica strains, respectively, indicating a history of horizontal DNA transfer and assortative (entire gene) recombination . Class III alleles have mosaic structures and were derived by horizontal DNA transfer and intragenic recombination . Our findings suggest that OmpA is under strong selective pressure from the host species and that it plays an important role in host adaptation . It is proposed that the OmpA protein of M . haemolytica acts as a ligand and is involved in binding to specific host cell receptor molecules in cattle and sheep . P . trehalosi expresses two OmpA homologs that are encoded by different tandemly arranged ompA genes . The P . trehalosi ompA genes are highly diverged from those of M . haemolytica and M . glucosida, and evidence is presented to suggest that at least one of these genes was acquired by horizontal DNA transfer.

J Biol Chem, 2004 Oct 1, 279(40), 42345 - 9 Epub 2004 Aug 05.
Synchronized chemoenzymatic synthesis of monodisperse hyaluronan polymers; Jing W et al.; The length of the hyaluronan (HA) polysaccharide chain dictates its biological effects in many cellular and tissue systems . Long and short HA polymers often appear to have antagonistic or inverse effects . However, no source of very defined, uniform HA polymers with sizes greater than 10 kDa is currently available . We present a method to produce synthetic HA with very narrow size distributions in the range of approximately 16 kDa to approximately 2 MDa . The Pasteurella HA synthase enzyme, pmHAS, catalyzes the synthesis of HA polymer utilizing monosaccharides from UDP-sugar precursors . Recombinant pmHAS will also elongate exogenously supplied HA oligosaccharide acceptors in vitro in a nonprocessive fashion . As a result of bypassing the slow initiation step in vitro, the elongation process is synchronized in the presence of acceptor; thus all of polymer products are very similar in length . In contrast, without the use of an acceptor, the final polymer size range is difficult to predict and the products are more polydisperse . HA polymers of a desired size are constructed by controlling the reaction stoichiometry (i.e . molar ratio of precursors and acceptor molecules) . The use of modified acceptors allows the synthesis of HA polymers containing tags (e.g . fluorescent, radioactive) . In this scheme, each molecule has a single foreign moiety at the reducing terminus . Alternatively, the use of radioactive UDP-sugar precursors allows the synthesis of uniformly labeled native HA polymers . Overall, synthetic HA reagents with monodisperse size distributions and defined structures should assist in the elucidation of the numerous roles of HA in health and disease.

J Rheumatol, 2004 Aug, 31(8), 1663 - 5
Septic arthritis caused by Actinobacillus ureae in a patient with rheumatoid arthritis receiving anti-tumor necrosis factor-alpha therapy; Kaur PP et al.; Actinobacillus ureae, formerly known as Pasteurella ureae, is a rare human pathogen . We describe a case of septic arthritis and abscess formation caused by this unusual organism in a patient with rheumatoid arthritis, who was being treated with tumor necrosis factor-alpha inhibitors.

Vet Microbiol, 2004 Aug 19, 102(1-2), 117 - 22
Differentiation of Pasteurella multocida isolates from cases of atrophic rhinitis in pigs from Zimbabwe by RAPD and ribotyping; Dziva F et al.; Atrophic rhinitis in pigs is rarely reported in Southern Africa . To determine the relationship between Pasteurella multocida clones from clinical cases of atrophic rhinitis, twenty-one strains were characterised by selected phenotypic and genotypic methods . Biochemical analysis classified 18 strains as P . multocida subspecies multocida, whilst the remainder were grouped into separate unassigned biotypes . Capsular groups A (16/21) and D (l/21) were found among the isolates by PCR . Four ribotype patterns were obtained following HpaII ribotyping, whilst random amplification of polymorphic DNA (RAPD) revealed three main clusters . However, subclusters were also noted for each RAPD cluster . Our results indicate that RAPD offers a better discrimination of strains than ribotyping and that none of the phenotypic characters were directly related to the genotypic clusters.

Int J Syst Evol Microbiol, 2004 Jul, 54(Pt 4), 1393 - 9
Phylogeny of the family Pasteurellaceae based on rpoB sequences; Korczak B et al.; Sequences of the gene encoding the beta-subunit of the RNA polymerase (rpoB) were used to delineate the phylogeny of the family Pasteurellaceae . A total of 72 strains, including the type strains of the major described species as well as selected field isolates, were included in the study . Selection of universal rpoB-derived primers for the family allowed straightforward amplification and sequencing of a 560 bp fragment of the rpoB gene . In parallel, 16S rDNA was sequenced from all strains . The phylogenetic tree obtained with the rpoB sequences reflected the major branches of the tree obtained with the 16S rDNA, especially at the genus level . Only a few discrepancies between the trees were observed . In certain cases the rpoB phylogeny was in better agreement with DNA-DNA hybridization studies than the phylogeny derived from 16S rDNA . The rpoB gene is strongly conserved within the various species of the family of Pasteurellaceae . Hence, rpoB gene sequence analysis in conjunction with 16S rDNA sequencing is a valuable tool for phylogenetic studies of the Pasteurellaceae and may also prove useful for reorganizing the current taxonomy of this bacterial family.

Colloids Surf B Biointerfaces, 2004 Aug 1, 36(3-4), 127 - 37
Lipid composition-dependent incorporation of multiple membrane proteins into liposomes; Daghastanli KR et al.; Membrane proteins from bacteria Pasteurella multocida were used as a model for studying its incorporation into liposomes . An important step to achieve efficient high yield protein incorporation in proteoliposomes is the study of the more suitable lipid composition . To this end, we compared the amount of total protein, reconstituted by co-solubilization methods, into liposomes of phospholipids with different polar head groups and acyl chain lengths . The liposomes and proteoliposomes were characterised by isopycnic centrifugation in sucrose gradient and by dynamic light scattering . Experimental and theoretical results were compared considering the effects exerted through the hydrocarbon chain length, volume, and optimal cross-sectional area of the phospholipid (combined in the geometrical critical packing parameter, lipid-protein matching), critical spontaneous radius of curvature of the bilayer vesicle, phase transition temperature of the lipid and ratio of lipid-protein molecules present in the vesicles . The highest incorporation of multiple proteins was found with dipalmitoylphosphatidylcholine (DPPC), reaching a yield of 93% compared to the lower relative amounts incorporated in proteoliposomes of the other lipids . The incorporation of multiple proteins induces a proportional enhancement of vesicular dimension, since DPPC-proteoliposomes have an average diameter of 1850A, compared to the 1430A for pure DPPC vesicles.

Glycobiology, 2004 Dec, 14(12), 1217 - 28 Epub 2004 Jul 14.
Production of N-sulfated polysaccharides using yeast-expressed N-deacetylase/N-sulfotransferase-1 (NDST-1); Saribas AS et al.; Heparan sulfate/heparin N-deacetylase/N-sulfotransferase-1 (NDST-1) is a critical enzyme involved in heparan sulfate/heparin biosynthesis . This dual-function enzyme modifies the GlcNAc-GlcA disaccharide repeating sugar backbone to make N-sulfated heparosan . N-sulfation is an absolute requirement for the subsequent epimerization and O-sulfation steps in heparan sulfate/heparin biosynthesis . We have expressed rat liver (r) NDST-1 in Saccharomyces cerevisiae as a soluble protein . The yeast-expressed enzyme has both N-deacetylase and N-sulfotransferase activities . N-acetyl heparosan, isolated from Escherichia coli K5 polysaccharide, de-N-sulfated heparin (DNSH) and completely desulfated N-acetylated heparan sulfate (CDSNAcHS) are all good substrates for the rNDST-1 . However, N-desulfated, N-acetylated heparin (NDSNAcH) is a poor substrate . The rNDST-1 was partially purified on heparin Sepharose CL-6B . Purified rNDST-1 requires Mn(2+) for its enzymatic activity, can utilize PAPS regenerated in vitro by the PAPS cycle (PAP plus para-nitrophenylsulfate in the presence of arylsulfotransferase IV), and with the addition of exogenous PAPS is capable of producing 60-65% N-sulfated heparosan from E . coli K5 polysaccharide or Pasteurella multocida polysaccharide.

J Microbiol Methods, 2004 Aug, 58(2), 263 - 7
Specific PCR identification of Pasteurella multocida based on putative transcriptional regulator genes; Liu D et al.; Pasteurella multocida is an important animal pathogen that may also infect humans through animal bites and scratches . After comparison of transcriptional regulator gene sequences from the P . multocida genome with other DNA sequences at GenBank, we identified two genes (i.e., Pm0762 and Pm1231) uniquely present in P . multocida . By using oligonucleotide primers (Pm0762F/R and Pm1231F/R) designed from these genes in PCR, it was found that specific DNA products of expected sizes were obtained with genomic DNA from P . multocida only, but not from other bacteria . These results indicated that the putative transcriptional regulator genes Pm0762 and Pm1231 are species-specific, and that the PCR methods targeting these genes provide a useful means of rapidly and precisely identifying P . multocida from other bacteria . Further elucidation of the roles and functions of these putative transcriptional regulator genes (Pm0762 and Pm1231) and their protein products may help provide valuable insight into the molecular mechanism of P . multocida virulence and pathogenicity.

Vet Res, 2004 May-Jun, 35(3), 309 - 24
Pathophysiological changes occurring during Escherichia coli endotoxin and Pasteurella multocida challenge in piglets: relationship with cough and temperature and predicitive value for intensity of lesions; Halloy DJ et al.; The aims of this study were (1) to correlate cough and body temperature (BT) with the severity of bronchopneumonia in pigs, (2) to determine whether these clinical signs can be used to early diagnose bronchopneumonia and (3) to assess the predictive values of cough and BT regarding lung lesions . Bronchopneumonia was induced by administering E . coli endotoxin (LPS) combined with Pasteurella multocida type A (PmA) in the trachea of 13 piglets . Saline-instilled negative controls (n = 8), PmA inoculated (n = 6) and LPS instilled (n = 5) groups were also constituted . Cough and BT were recorded daily while the bronchopneumonia severity was assessed using bronchoalveolar lavage fluid (BALF) cytology, cytokines and measurement of lung lesion volume . Changes in expiratory breathing pattern were also measured (Penh) . The combination of LPS and PmA induced a subacute bronchopneumonia characterised by macrophage, neutrophil, and lymphocyte infiltration, changes in Penh and an increase in the mRNA level of IFN-gamma while IL8, IL-18 and TNF-alpha mRNA levels remained unchanged . The daily body weight gain of infected animals was significantly reduced . Cough and BT changes were proportional to the intensity of the lung inflammatory process, functional respiratory changes and to the extent of macroscopic lesions . When comparing the individual values of cough and BT to thresholds defined for both parameters, an early diagnosis of pneumonia was possible . Considering the pooled data of each group, it was possible to define thresholds allowing an early segregation between the groups of diseased and healthy piglets . The daily values of cough and BT were predictive for the volume of lung lesions recorded at the end of the trial . In conclusion, cough and BT appear as potential indicators for the intensity and the evolution of the respiratory disease . They also seem to be good predictors for the magnitude of lung lesions and weight gain recorded at the study endpoint .

Vet Immunol Immunopathol, 2004 Aug, 100(3-4), 197 - 207
Pathophysiological and immune cell responses in calves prior to and following lung challenge with formalin-killed Pasteurella multocida biotype A:3 and protection studies involving subsequent homologous live challenge; Dowling A et al.; Pneumonic pasteurellosis is a common respiratory infection in cattle that has major economic and welfare implications world-wide and the incidence in the UK due to Pasteurella multocida, currently the same as that associated with Mannheimia haemolytica, is increasing . Whereas much is known regarding the pathogenesis of M . haemolytica infections little information is available on the pathogenic process of pasteurellosis initiated by P . multocida . In the present work calf systemic and innate immune responses to intratracheal challenge with formalin-killed P . multocida biotype A:3 and to subsequent experimental lung infection with live P . multocida were investigated . Eight-week-old calves were challenged intratracheally on day 0 with either 10(9) colony forming units (cfu) of formalin-killed P . multocida biotype A:3 in 300 ml saline (n = 10) or 300 ml saline alone (n = 10), followed, at day 21, by challenge with 10(9) cfu live P . multocida . Pathophysiological and lung phagocyte responses were assessed by clinical monitoring, sequential lung lavage and blood sampling . Results for samples obtained before, during and after challenge showed clinical and acute phase protein responses to both bacterial culture and saline control treatments, although higher responses were associated with bacterial challenge . Phagocytosis of P . multocida during 1h incubation periods with lavaged cells in vitro was unaffected by exposure in vivo to killed P . multocida and there was evidence that P . multocida was able to survive intracellularly during this assay . There was no indication that lung exposure to formalin-killed P . multocida conferred protection against subsequent homologous live challenge.

J Zoo Wildl Med, 2004 Mar, 35(1), 88 - 93
A Pasteurella-like bacterium associated with pneumonia in captive megachiropterans; Helmick KE et al.; A novel Pasteurella-like organism was recovered postmortem from lung tissue of two captive Wahlberg's epauleted fruit bats (Epomophorus wahlbergi), with severe, unilateral pneumonia . The bats had been recently shipped and died shortly after release from a 30-day quarantine . One presented with clinical signs of anorexia and lethargy before death; the other died without prior clinical symptoms . The same Pasteurella-like organism was recovered antemortem from subcutaneous abscesses in two captive little golden mantled flying foxes (Pteropus pumilus) housed with additional E . wahlbergi . The organism was also cultured on tracheal wash from one Malaysian flying fox (Pteropus vampyrus) and another E . wahlbergi, both demonstrating clinical signs of pneumonia . All recovered isolates appeared morphologically and biochemically similar to the initial isolates and were further characterized as either a Pasteurella or Actinobacillus organism on the basis of biochemical and cellular fatty acid profiles . Screening of the current collection using pharyngeal swabs isolated this organism from 12 of 15 E . wahlbergi, two of three P . vampyrus, one of 26 island flying foxes (Pteropus hypomelanus), and one of nine Rodrigues fruit bats (Pteropus rodricensis) . The organism was not identified in pharyngeal culture from eight Indian flying foxes (Pteropus giganteus), nine Egyptian fruit bats (Rousettus aegypticus), or an additional 16 P . pumilus.

J Biol Chem, 2004 Aug 13, 279(33), 34150 - 5 Epub 2004 Jun 10.
Action of Pasteurella multocida toxin depends on the helical domain of Galphaq; Orth JH et al.; Pasteurella multocida produces a 146-kDa protein toxin (PMT), which activates multiple cellular signal transduction pathways, resulting in the activation of phospholipase Cbeta, RhoA, Jun kinase, and extracellular signal-regulated kinase . Using Galpha(q)/Galpha(11) -deficient cells, it was shown that the PMT-induced pleiotropic effects are mediated by Galpha(q) but not by the highly related Galpha(11) protein (Zywietz, A., Gohla, A., Schmelz, M., Schultz, G., and Offermanns, S . (2001) J . Biol . Chem . 276, 3840-3845) . Here we studied the molecular basis of the unique specificity of PMT to distinguish between Galpha(q) and/or Galpha(11) . Infection of Galpha(q) -deficient cells with retrovirus-encoding Galpha(q) caused reconstitution of PMT-induced activation of phospholipase Cbeta, whereas Galpha(11) -encoding virus did not reconstitute PMT activity . Chimeras between Galpha(q) and/or Galpha(11) revealed that a peptide region of Galpha(q), covering amino acid residues 105-113, is essential for the action of PMT to activate phospholipase Cbeta . Exchange of glutamine 105 or asparagine 109 of Galpha(11), which are located in the all-helical domain of the Galpha subunit, with the equally positioned histidines of Galpha(q), renders Galpha(11) capable of transmission PMT-induced phospholipase Cbeta activation . The data indicate that the all-helical domain of Galpha(q) is essential for the action of PMT and suggest an essential functional role of this domain in signal transduction via G(q) proteins.

Can J Vet Res, 2004 Apr, 68(2), 118 - 27
Experimental infectious respiratory disease in groups of calves: lobar distribution, variance, and sample-size requirements for vaccine evaluation; Jericho KW et al.; The distribution and variance of respiratory disease produced with aerosols of bovine herpesvirus 1 (BHV-1) and Mannheimia haemolytica in control (183 calves in 44 experiments) and vaccinated calves were studied in experiments conducted at the Animal Diseases Research Institute, Lethbridge, Alberta, from 1975 to 1989 . All calves had been born and raised at this institute and exposed similarly for 5 min by means of a face mask to viral and bacterial aerosols produced by a Collison atomizer (particles < 3 microm in diameter) . We summarized the macroscopic pathological responses of pneumonia (main end point), tonsillitis, tracheitis, and other microbiologic and experimental variables . We also summarized the lobar distribution of pneumonia in 202 control and 192 vaccinated calves with this disease model and in calves similarly exposed to parainfluenza 3 virus/M . haemolytica or BHV-1/Pasteurella multocida . Pneumonia in control calves began in ventral tissues of all lobes, with lobar preferences, and progressed dorsally, the dorsal parts of both large caudal lobes being least affected . A high variance of pneumonia was evident within and among experiments . From the magnitude of variance observed in the control groups, the number of calves per group required in vaccine-challenge studies using this BHV-1/M . haemolytica disease model was estimated . Such estimates are required for any disease model used in vaccine-challenge studies.

Microbiology, 2004 Jun, 150(Pt 6), 1757 - 67
Revised description and classification of atypical isolates of Pasteurella multocida from bovine lungs based on genotypic characterization to include variants previously classified as biovar 2 of Pasteurella canis and Pasteurella avium; Christensen H et al.; Strains deviating in key phenotypic characters, mainly isolated from cases of bovine pneumonia in five European countries, were genotyped in order to examine their genotypic relationship with Pasteurella multocida . Twenty-two strains of Pasteurella avium biovar 2, including variants in indole, xylose and mannitol, 18 strains of Pasteurella canis biovar 2 and variants of this taxon, five strains of P . multocida subsp . septica showing variations in indole and ornithine decarboxylase, nine strains of P . multocida subsp . multocida showing variation in ornithine decarboxylase and mannitol, and type strains of the subspecies of P . multocida were included . Ribotyping was used to examine the relationship of the strains, and 13 types, each containing between one and 20 isolates, were observed . Identical ribotypes were observed in some cases for P . avium biovar 2 and either P . canis biovar 2 or P . multocida subsp . septica . ITS (16S-23S rRNA internal transcribed spacer) fragment-length profiling showed identity of the majority of strains (47 of 52), representing all four taxa, with only five divergent strains . A 16S rRNA sequence comparison of 11 strains representing the main ribotype clusters showed 99.9 % similarity to the type strain of P . multocida subsp . multocida, but only 97.4 % similarity was obtained to P . canis (biovar 1) and 93.7 % to P . avium (biovar 1) . A species-specific PCR test for P . multocida gave a positive result with biovar 2 variants of P . avium and P . canis . DNA-DNA hybridizations between strains of P . multocida, biovar 2 variants of P . avium and P . canis, and P . multocida subsp . septica confirmed similarity at the species level . It is proposed, on the basis of genotypic similarity, that P . multocida be reclassified to include the biovar 2 variants of P . avium and P . canis and that the existence of the biovar 2 variants of P . avium and P . canis is highly questionable . It is concluded that the redefined P . multocida is genotypically homogeneous, although phenotypically diverse lineages exist with respect to ornithine decarboxylase, indole and mannitol, characters that have been regarded as essential for identification to the species level . A formal reclassification of the species is not possible, however, since too few strains have been found to vary in these key characters . Considering the phenotypic diversity of P . multocida, identification will have to depend partly on genotypic methods and the source host also seems important for safe diagnosis.

Microbiology, 2004 Jun, 150(Pt 6), 1723 - 34
Molecular cloning of haemoglobin-binding protein HgbA in the outer membrane of Actinobacillus pleuropneumoniae; Srikumar R et al.; From the porcine pathogen Actinobacillus pleuropneumoniae cultivated in iron-deficient or haem-deficient media, haemoglobin (Hb)-agarose affinity purification was exploited to isolate an outer-membrane protein of approximately 105 kDa, designated HgbA . Internal peptide sequences of purified HgbA were used to design oligonucleotide primers for PCR amplification, yielding amplicons that showed partial sequences with homology to hgbA of Pasteurella multocida . Upon screening two genomic libraries of A . pleuropneumoniae serotype 1 strain 4074, positive clones were assembled into an ORF of 2838 bp . HgbA (946 aa) includes a signal peptide of 23 aa and the deduced HgbA sequence (104 890 Da) also demonstrated a possible Ton box . The promoter region of hgbA from A . pleuropneumoniae serotype 1 showed consensus for -35 and -10 sequences and a putative Fur-binding site . RT-PCR confirmed that hgbA of A . pleuropneumoniae is upregulated in response to diminished levels of iron in the culture medium . While an internally deleted hgbA mutant was unable to use pig Hb as sole source of iron for growth, flow cytometry confirmed its Hb binding; the internally deleted sequences may not be required for Hb binding, but appear necessary for the iron supply from Hb . HgbA is required for growth of A . pleuropneumoniae in the presence of Hb as sole iron source.

Infect Immun, 2004 Jun, 72(6), 3436 - 43
A heptosyltransferase mutant of Pasteurella multocida produces a truncated lipopolysaccharide structure and is attenuated in virulence; Harper M et al.; Pasteurella multocida is the causative agent of fowl cholera in birds . In a previous study using signature-tagged mutagenesis, we identified a mutant, AL251, which was attenuated for virulence in mice and in the natural chicken host . Sequence analysis indicated that AL251 had an insertional inactivation of the gene waaQ(PM), encoding a putative heptosyl transferase, required for the addition of heptose to lipopolysaccharide (LPS) (M . Harper, J . D . Boyce, I . W . Wilkie, and B . Adler, Infect . Immun . 71:5440-5446, 2003) . In the present study, using mass spectrometry and nuclear magnetic resonance, we have confirmed the identity of the enzyme encoded by waaQ(PM) as a heptosyl transferase III and demonstrated that the predominant LPS glycoforms isolated from this mutant are severely truncated . Complementation experiments demonstrated that providing a functional waaQ(PM) gene in trans can restore both the LPS to its full length and growth in mice to wild-type levels . Furthermore, we have shown that mutant AL251 is unable to cause fowl cholera in chickens and that the attenuation observed is not due to increased serum sensitivity.

Int J Med Microbiol, 2004 Apr, 293(7-8), 505 - 12
The pasteurella multocida toxin interacts with signalling pathways to perturb cell growth and differentiation; Lax AJ et al.; Some years ago we showed that the Pasteurella multocida toxin (PMT) is a potent mitogen for cells in culture . It is an intracellularly acting toxin that stimulates several signal transduction pathways . The heterotrimeric G-protein, Gq, is stimulated, which in turn causes activation of protein kinase C and an increase in inositol trisphosphates . The Rho GTPase is also activated, leading via the Rho kinase, to activation of the focal adhesion kinase and to cytoskeletal rearrangements . Analysis of the PMT sequence suggested the presence of three domains that encode receptor binding, translocation and catalytic domains . The location of all three domains has been confirmed directly . Competitive binding assays confirmed that the N-terminus of PMT encoded the receptor-binding domain, while cytoplasmic microinjection of expressed PMT fragments identified the location of the C-terminal catalytic domain . Recently, we have demonstrated the presence of key amino acids that affect membrane insertion within the putative transmembrane domain . Several lines of evidence suggest that PMT activates Galphaq, and that this is one potential molecular target for the toxin . Galphaq is known to be tyrosine phosphorylated when activated normally via a G-protein-coupled receptor (GPCR), and it has been suggested that this is an essential part of the activation process . We have shown that PMT induces Galphaq tyrosine phosphorylation, but that this is not essential for activation of the G-protein . Furthermore, a totally inactive mutant of PMT stimulates Galpha phosphorylation without leading to its activation . Phosphorylation of Galphaq triggered by the inactive mutant potentiates activation of Gq via a GPCR, demonstrating that phosphorylation of Gq cannot lead to receptor uncoupling . Natural or experimental infection of animals with toxigenic P . multocida, or injection with purified recombinant PMT causes loss of nasal turbinate bone . The effects on bone have been analysed in vitro using cultures of osteoblasts--cells that lay down bone . PMT blocks the formation of mature calcified bone nodules and the expression of differentiation markers such as CBFA-1, alkaline phosphatase and osteocalcin . These effects can be partially prevented by inhibitors of Rho or Rho kinase function, implicating this pathway in osteoblast differentiation . Indeed, inhibitors of Rho stimulate the formation of bone nodules in vitro . In summary, PMT is a novel toxin that acts via signalling pathways to promote proliferation in many cells, while specifically inhibiting differentiation in osteoblast cells.

Harefuah, 2004 Feb, 143(2), 92 - 6, 168
{Pasteurella multocida infections--10 years' experience}; Paz A et al.; Dog and cat bites are commonly seen at emergency rooms, but have been inadequately characterized . This study attempted to characterize the clinical features of 10 patients from whom P . multocida was cultured . During the past 10 years, 108 patients have been hospitalized for pet bites, at a rate of 3.4/10,000 hospitalizations . Five patients had a documented exposure to cats, 3 to dogs, and two had an unknown exposure . The mean age was 50.8 years (+/- 20.5) and 80% were men . An average delay of 5.7 days was noted from exposure to hospitalization, and additional 4.4 days until P . multocida was characterized . P . multocida was cultured from wounds in six patients, and three patients had bacteremia; another patient had septic arthritis . Six patients needed debridement and the average hospital stay was 11.7 days (3 times our hospital's average) . Animal bites may take a complicated course . Our findings call for reassessment of the need for prophylaxis in animal bites.

Int J Syst Evol Microbiol, 2004 May, 54(Pt 3), 813 - 8
Reclassification of Bisgaard taxon 33, with proposal of Volucribacter psittacicida gen . nov., sp . nov . and Volucribacter amazonae sp . nov . as new members of the Pasteurellaceae; Christensen H et al.; A total of 25 strains isolated from parrots, budgerigars, parakeets (Psittaciformes) and a chicken, mostly associated with respiratory disease or septicaemia, were classified as a new genus, Volucribacter gen . nov., within the family Pasteurellaceae, on the basis on unique phenotypic characteristics and clear monophyly as determined by 16S rRNA gene sequence comparison . Comparison of 16S rRNA gene sequences from six strains showed at least 98.8 % similarity and the closest similarity outside the genus was found to Bisgaard taxon 34 and to Pasteurella avium, at 94.6 and 94.5 %, respectively . Phenotypes that separate the new genus from other genera of the Pasteurellaceae included at least two characters . The genus includes two species, Volucribacter psittacicida sp . nov . and Volucribacter amazonae sp . nov., corresponding to the two biovars previously outlined, underlining that most isolates have been obtained from psittacine birds . The two species can be separated by fermentation of meso-inositol, (-)-L-fucose, maltose and dextrin and a positive ONPG test . The type strains for Volucribacter psittacicida and Volucribacter amazonae are respectively Gerl . 236/81(T) (=CCUG 47536(T)=DSM 15534(T)) and 146/S8/89(T) (=CCUG 47537(T)=DSM 15535(T)).

Vet Immunol Immunopathol, 2004 Jun, 99(3-4), 193 - 202
BHV-1 infection and inflammatory cytokines amplify the interaction of Mannheimia haemolytica leukotoxin with bovine peripheral blood mononuclear cells in vitro; Leite F et al.; Bovine herpesvirus-1 (BHV-1) has been reported to increase the susceptibility of cattle to respiratory disease caused by Mannheimia (Pasteurella) haemolytica A1 . The principal virulence factor of M . haemolytica is a leukotoxin (LKT) that can specifically kill ruminant leukocytes following its binding to the beta2-integrin CD11a/CD18 (lymphocyte function-associated antigen 1 (LFA-1)) . In this study, we investigated the effects of experimental infection of bovine peripheral blood mononuclear cells (MNCs) with BHV-1 in vitro, on the subsequent interaction of these cells with the M . haemolytica LKT . We found that BHV-1 infection increased LFA-1 expression (as assessed by flow cytometry), and subsequently enhanced LKT binding and cytotoxicity to bovine MNCs . We also found that BHV-1 infection increased CD18, IL-1beta, and IFN-gamma mRNA expression by MNCs . As previously reported for bovine polymorphonuclear neutrophils (PMNs), MNCs increased their expression of LFA-1, and their LKT binding and cytotoxicity, following exposure to IL-1beta, TNF-alpha, and IFN-gamma . These findings suggest that BHV-1 infection, and the resulting release of inflammatory cytokines, can stimulate expression of LFA-1 in bovine MNCs, thus enhancing the binding and biological effects of LKT . If such a mechanism occurs in vivo it might explain, in part, the increased susceptibility of BHV-1 infected cattle to bovine pasteurellosis .

Vet Microbiol, 2004 May 20, 100(1-2), 43 - 53
Characterization of a 39kDa capsular protein of avian Pasteurella multocida using monoclonal antibodies; Ali HA et al.; The role of a 39kDa protein of avian Pasteurella multocida in pathogenesis of fowl cholera was investigated using monoclonal antibodies (Mabs) . Mabs were prepared by immunization of BALB/c mice with a crude capsular extract (CCE) of P . multocida strain P-1059 (serovar A:3) . Totally eight hybridomas producing Mab were obtained . Immunoblot analysis of the hybridomas revealed that all the Mabs recognized a 39kDa protein of CCE . Treatment of CCE antigen with proteinase K or periodic acid indicated that the epitope recognized was proteinaceous . The Mabs reacted with a major 39kDa protein of CCE from encapsulated strains but not with any protein of non-capsulated strains indicating that a direct correlation between encapsulation and the 39kDa protein . Immunoelectron microscopy on strain P-1059 and the non-capsulated derivative P-1059B (serovar -:3) reacting with the Mabs and gold-labeled anti-mouse IgG indicated that the protein is associated with the capsule . The Mabs significantly inhibited the adherence of encapsulated P . multocida strains to chicken embryo fibroblast cells, but only slightly that of non-capsulated strains . Mice passively immunized with the Mabs were protected from lethal challenge with virulent strains P-1059 and X-73 (serovar A:1) . Thus the capsular 39kDa protein was determined to be an adherence factor and a cross-protective antigen of avian P . multocida type A strains.

Int J Infect Dis, 2004 May, 8(3), 171 - 4
A case of Pasteurella multocida peritoneal dialysis-associated peritonitis and review of the literature; Cooke FJ et al.; OBJECTIVES: Two episodes of peritoneal dialysis-associated peritonitis, which occurred four months apart and were both due to Pasteurella multocida, were noted in a 73 year old woman . This report aims to describe the clinical history of these episodes and the microbiological investigations that were undertaken . The relevant literature will also be discussed . METHODS AND RESULTS: Basic microbiological tests identified the organism as Pasteurella multocida, and further work at a specialist laboratory classified it as Pasteurella multocida subsp . multocida . Pulsed field gel electrophoresis confirmed that the strains isolated from the two clinical episodes originated from the same clone . A literature search was performed, looking particularly for patients who experienced more than one episode of peritonitis caused by Pasteurella spp, whether due to recurrence or re-infection . CONCLUSIONS: It is likely that the infection resulted from a domestic cat, as there was evidence of a cat bite to the dialysis tubing in the period between the two episodes . Re-infection with two identical strains of pasteurella is more probable than relapse, for reasons discussed . Strict hygiene and avoiding contact between dialysis tubing and domestic animals must be emphasised to try to prevent pasteurella and other animal-associated infections in this already vulnerable population.

Pediatr Infect Dis J, 2004 Apr, 23(4), 368 - 70
Pasteurella aerogenes hamster bite peritonitis; Freeman AF et al.; Pasteurella multocida has been reported to cause peritoneal dialysis-associated peritonitis after a cat bite or scratch to the catheter . We report a teenager with hamster bite peritonitis caused by P . aerogenes, an organism predominantly isolated from swine.

Curr Microbiol, 2004 Mar, 48(3), 189 - 95
Evaluation of PCR based on gene apxIVA associated with 16S rDNA sequencing for the identification of Actinobacillus pleuropneumoniae and related species; da Costa MM et al.; The pleuropneumonia caused by Actinobacillus pleuropneumoniae (App) is one the most important swine respiratory diseases . Biochemical and serological tests are widely applied for App diagnosis and characterization . However, in some isolates, conflicting results are found . The present work focus on the characterization of 29 isolates biochemically classified as A . pleuropneumoniae, collected from swine in herds with or without a clinical history of pleuropneumonia . Sixteen isolates were from healthy swine, initially classified as nonserotypable A . pleuropneumoniae; they displayed differences in the molecular characterization patterns of App (genes cpx and apxI, II, and III) . Those bacteria that could not be serotyped were submitted to rDNA 16S sequencing . All 29 isolates were analyzed by PCR for the presence of the apxIVA gene . Thirteen isolates (45%) were confirmed to be A . pleuropneumoniae by PCR, nine being from diseased animals (31%) and four from healthy animals (14%) with conclusive serotyping . The rDNA 16S sequencing was used to classify the other 16 isolates in related species other than A . pleuropneumoniae, resulting in eleven A . minor, three A . porcinus, and two Pasteurella sp . Because of conflicting results between biochemical tests and rDNA 16S sequencing, the biochemical characterization was repeated, and the new results were in agreement with the rDNA 16S sequencing data . Biochemical characterization proved to be efficient for the majority of the A . pleuropneumoniae isolates . Nevertheless, conventional tests can render conflicting results, and other methodologies, such as amplification of A . pleuropneumoniae specific apxIVA gene and rDNA 16S sequencing, are very useful for improved classification . We also observed a great variety in rDNA 16S sequences from different A . minor isolates.

J Vet Diagn Invest, 2004 Mar, 16(2), 121 - 5
Evaluation of Pasteurella multocida isolated from rabbits by capsular typing, somatic serotyping, and restriction endonuclease analysis; El Tayeb AB et al.; The goal of this study was to characterize Pasteurella multocida isolated from rabbits . Five hundred and fifty-three apparently healthy rabbits were sampled for this study . Nasal swabs were collected from each rabbit for P . multocida isolation and identification . Isolates were further characterized by capsular and somatic antigens and genomic DNA fingerprinting . Thirty-nine P . multocida isolates were recovered from 553 rabbits (7%) . Capsular typing was done by depolymerization of P . multocida capsule by Staphylococcus aureus hyaluronidase and by disc diffusion with mucopolysaccharidase enzymes (heparinase III, chondroitinase AC, and hyaluronidase) . Thirty-one (79%) of the isolates were capsular type A, and 8 isolates (21%) had untypable (UT) capsules . The gel-diffusion precipitin test was used to determine the somatic type of P . multocida isolates . Nineteen isolates were somatic serotype 3 (49%), 12 were serotype 1 (31%), 1 was serotype 2, 2 were serotype 5, 2 were serotype 12 with a weak reaction to antiserum raised against serotype 7 (5%), and 1 was serotype 4 . Two of the isolates (5%) were UT . Restriction endonuclease analysis of the DNA of the isolates revealed 7 distinct profiles by digestion with HindIII, and 12 profiles were obtained with HpaII, whereas digestion with EcoRI did not differentiate between any of the P . multocida DNA isolates studied . The DNA restriction endonuclease enzyme HpaII was found more useful for differentiating between DNA fingerprints of P . multocida rabbit isolates . However, no correlation between capsular type, somatic serotypes, and DNA fingerprints was seen in this study.

Res Vet Sci, 2004 Jun, 76(3), 179 - 85
Specific identification of Pasteurella multocida serogroup-A isolates by PCR assay; Gautam R et al.; A polymerase chain reaction (PCR) assay targeting the hyaC-hyaD gene was developed and used to identify strains of Pasteurella multocida belonging to serogroup-A . A set of serogroup-specific-PCR primers amplified a 564 bp product from genomic DNA prepared from bacterial cells or directly from bacterial colonies . This method detected as low as 10 ng of bacterial DNA and had a specificity of 100% for P . multocida serogroup-A . A nested PCR method yielded a single 374 bp product . All fifty isolates were also shown to be identical by restriction fragment length polymorphism (RFLP) analysis of the PCR products after digestion with BglII.

Berl Munch Tierarztl Wochenschr, 2004 Mar-Apr, 117(3-4), 97 - 115
{Mannheimia haemolytica and the pathogenesis of enzootic bronchopneumonia}; Ewers C et al.; Mannheimia (M.) haemolytica (formerly Pasteurella {P.} haemolytica) is the primary aetiological agent of pneumonic pasteurellosis--one of the most important respiratory diseases in cattle and sheep . While bovine pneumonic pasteurellosis is regarded to be mainly caused by M . haemolytica serotype A1, and in Germany during the last years also by serotype A6, sheep can be infected by all serotypes although there is an increased prevalence of serotypes A2 and A5-7 . The obligate pathogenicity of M . haemolytica is proven by isolation of pure cultures from pneumonic lungs as well as by infection studies . Knowledge about the virulence mechanisms of M . haemolytica and their molecular basis are fragmentary, most probably due to the complex gene regulation of virulence associated factors in lung tissues . This review summarizes the current literature covering virulence factors to substantiate a model of pathogenesis . After serotype A1 strains have colonized the bovine upper respiratory tract they replace other serotypes by mechanisms unknown to date . After fulminant proliferation in the upper respiratory tract the microorganisms colonize the lower respiratory tract, finally entering alveolar spaces . An inflammatory cascade is initiated by M . haemolytica LPS and Leukotoxin, causing activation of the complement system and release of cytokines . Pathognomonic for bovine pneumonic pasteurellosis is the strong influx of neutrophiles accompanied by accumulation of fibrin, finally causing necrosis of alveolar spaces . Depending on lesion size this fibronecrotizing pneumonia can result in death of the animals . In addition, possible protective antigens are discussed . There is still a great effort in the development of efficacious vaccines against pneumonic pasteurellosis in cattle and sheep caused by various M . haemolytica serotypes worldwide . The scarce knowledge concerning presence and distribution of virulence associated factors in M . haemolytica strains and their role in pathogenesis made it difficult to determine a suitable vaccine candidate in the past . In addition, there is lack of knowledge concerning the variability of virulence factors in individual isolates . Genome sequence analysis of M . haemolytica, enabling proteomics and transciptomics, hopefully will give new insight into the pathogenesis of pneumonic pasteurellosis.

J S Afr Vet Assoc, 2003 Dec, 74(4), 135 - 6
Pasteurella testudinis associated with respiratory disease and septicaemia in leopard (Geochelone pardalis) and other tortoises in South Africa; Henton MM; The first recorded isolates of Pasteurella testudinis from South African tortoises kept in captivity is presented . P . testudinis was found in association with respiratory disease in affected animals.

Vet Microbiol, 2004 Mar 5, 98(3-4), 251 - 60
tRNA-intergenic spacer PCR for the identification of Pasteurella and Mannheimia spp; Catry B et al.; tRNA-intergenic spacer PCR (tDNA-PCR) was evaluated for its effectiveness in differentiating Pasteurella and Mannheimia (sub)species predominantly of ruminant origin . For this purpose, 38 reference strains and 13 field isolates belonging to both genera were investigated . tDNA-PCR enabled discrimination of all Pasteurella species tested (Pasteurella (P.) aerogenes, P . avium, P . canis, P . lymphangitidis, P . multocida, P . trehalosi) . For the differentiation of the subspecies of P . multocida, an additional dulcitol reaction was required . Two of the five so far-defined Mannheimia species, M . granulomatis and M . varigena, had a distinct fingerprinting profile . The remaining three phylogenetically highly related species (M . haemolytica, M . glucosida, and M . ruminalis) clustered together . Nevertheless, M . ruminalis is non-haemolytic, and M . haemolytica and M . glucosida can be differentiated on the basis of two additional phenotypic characteristics (beta-glucosidase and aesculin hydrolysis) . In conclusion, tDNA-PCR is a useful tool in differentiating organisms belonging to the genera Pasteurella and Mannheimia.

Microbes Infect, 2004 Mar, 6(3), 290 - 8
Genomic-scale analysis of Pasteurella multocida gene expression during growth within liver tissue of chickens with fowl cholera; Boyce JD et al.; We have recently reported the gene expression profile of Pasteurella multocida during growth in the blood of chickens with fowl cholera . Here we report the gene expression profile of P . multocida during growth in the livers of similarly infected chickens . We compared expression profiles of bacteria harvested from the livers of infected chickens with late-stage fowl cholera with those of bacteria grown in rich medium . Independent analysis of bacterial expression profiles from three individual chickens indicated that 93 P . multocida genes were always differentially expressed during growth in liver tissue . Of these 93 genes, 49 were upregulated and 44 downregulated in the host . Many of the upregulated genes were involved in energy production and conversion (9/49) and carbohydrate transport and metabolism (8/49), and a number of these have been shown to be induced under anaerobic conditions in other species . The downregulated genes were generally of unknown or poorly characterised functions (14/44) . Comparison of the differentially regulated gene sets identified for growth in liver with those identified previously for growth in blood allowed the identification of a core set of 13 upregulated and 16 downregulated genes that were differentially regulated in at least five of the six infections studied.

Vet Microbiol, 2004 Apr 5, 99(2), 145 - 58
Characterisation of bovine strains of Pasteurella multocida and comparison with isolates of avian, ovine and porcine origin; Davies RL et al.; One hundred and fifty-three bovine Pasteurella multocida strains recovered primarily from cases of pneumonia and mastitis in England and Wales over an 11-year period were characterised by capsular PCR typing, comparison of outer membrane protein (OMP) profiles, and multilocus sequence analysis . All of the strains were of capsular type A with the exception of a single capsular type F isolate . Thirteen distinct OMP profiles (OMP-types) were identified based mainly on molecular mass heterogeneity of the heat-modifiable (OmpA) and porin (OmpH) proteins . However, 85% of the isolates were represented by just five OMP-types and 39% of the strains were of a single OMP-type . Multilocus sequence analysis revealed a limited degree of genetic diversity among bovine P . multocida isolates; strains of the same OMP-type have identical genetic backgrounds and represent distinct clones . Analysis of OMP variation was more discriminating than multilocus sequence analysis because strains of different OMP-types had the same, or similar, genetic backgrounds . The association of a small number of clones with the majority of cases of bovine pneumonia suggests that these clones have an increased capacity to cause disease compared to less frequently recovered clones . Molecular mass heterogeneity of OmpA and OmpH, in strains of the same or similar genetic background, suggests that these proteins are subject to diversifying selection within the host and might play important roles in host-pathogen interactions . Comparison of the OMP profiles of bovine isolates with those of avian, ovine and porcine strains showed that a high proportion of the respiratory tract infections in each of these species are caused by different strains of P . multocida . However, the presence of small numbers of closely related strains in more than one host species suggests that transmission of bacteria between different host species is also a factor in the population biology of P . multocida.

Vet Microbiol, 2004 Apr 5, 99(2), 103 - 12
Pasteurella multocida contains multiple immunogenic haemin- and haemoglobin-binding proteins; Bosch M et al.; Iron-dependent outer membrane proteins (IROMPs) play an important role in bacterial pathogenesis and present several attributes of potential vaccine candidates . TBLASTN analysis of the Pasteurella multocida Pm70 genome using the same molecules of other bacterial pathogens as a query identified eight putative haemin and haemoglobin receptors for this organism . Quantitative binding assays have demonstrated that the proteins PM0040, PM0236, PM0741, PM1081, PM1428, PM0592 and HgbA bind both haemin and haemoglobin, whereas PM0576 and PM1282 ORFs only bind either haemoglobin or haemin, respectively . Furthermore, Western blot analysis showed that P . multocida-infected mice generate specific antibodies against PM0040, PM0236, PM0741, PM1081, PM1428, PM0592 and HgbA proteins . Nevertheless, inoculation of mice with any single one of these receptors alone did not protect against P . multocida infection.

Arthroscopy, 2004 Mar, 20(3), 311 - 3
Arthroscopic treatment of septic arthritis in a patient with posterior stabilized total knee arthroplasty; Polzhofer GK et al.; We report on a case of arthroscopic treatment of septic arthritis of the knee in a 73-year-old woman with a posterior stabilized knee endoprosthesis . Six months after arthroplasty of the right knee joint because of osteoarthritis, the patient experienced an erysipelas of the right lower leg after a cat bite . Although given intravenous antibiotic therapy, the patient developed septic arthritis of the right knee . Pasteurella multocida could be identified as the causative organism . The joint infection was classified as stage I according to Gachter . Via arthroscopic joint debridement, partial synovialectomy, the use of continuous irrigation-suction drains, and intravenous antibiotic therapy, the empyema could be cured without removal of the total endoprosthesis of the right knee.

J Bone Miner Res, 2004 Apr, 19(4), 661 - 70 Epub 2004 Jan 05.
Regulation of osteoblast differentiation by Pasteurella multocida toxin (PMT): a role for Rho GTPase in bone formation; Harmey D et al.; The role of the Rho-Rho kinase signaling pathway on osteoblast differentiation was investigated using primary mouse calvarial cells . The bacterial toxin PMT inhibited, whereas Rho-ROK inhibitors stimulated, osteoblast differentiation and bone nodule formation . These effects correlated with altered BMP-2 and -4 expression . These data show the importance of Rho-ROK signaling in osteoblast differentiation and bone formation . INTRODUCTION: The signal transduction pathways controlling osteoblast differentiation are not well understood . In this study, we used Pasteurella multocida toxin (PMT), a unique bacterial toxin that activates the small GTPase Rho, and specific Rho inhibitors to investigate the role of Rho in osteoblast differentiation and bone formation in vitro . MATERIALS AND METHODS: Primary mouse calvarial osteoblast cultures were used to investigate the effects of recombinant PMT and Rho-Rho kinase (ROK) inhibitors on osteoblast differentiation and bone nodule formation . Osteoblast gene expression was analyzed using Northern blot and RT-PCR, and actin rearrangements were visualized after phalloidin staining and confocal microscopy . RESULTS: PMT stimulated the proliferation of primary mouse calvarial cells and markedly inhibited the differentiation of osteoblast precursors to bone nodules with a concomitant inhibition of osteoblastic marker gene expression . There was no apparent causal relationship between the stimulation of proliferation and inhibition of differentiation . PMT caused cytoskeletal rearrangements because of activation of Rho, and the inhibition of bone nodules was completely reversed by the Rho inhibitor C3 transferase and partly reversed by inhibitors of the Rho effector, ROK . Interestingly, Rho and ROK inhibitors alone potently stimulated osteoblast differentiation, gene expression, and bone nodule formation . Finally, PMT inhibited, whereas ROK inhibitors stimulated, bone morphogenetic protein (BMP)-2 and -4 mRNA expression, providing a possible mechanism for their effects on bone nodule formation . CONCLUSIONS: These results show that PMT inhibits osteoblast differentiation through a mechanism involving the Rho-ROK pathway and that this pathway is an important negative regulator of osteoblast differentiation . Conversely, ROK inhibitors stimulate osteoblast differentiation and may be potentially useful as anabolic agents for bone.

J Comp Pathol, 2004 Feb-Apr, 130(2-3), 137 - 42
Characterization of Pasteurella spp . strains isolated from human infections; Donnio PY et al.; This report describes the distribution of species and capsular groups in a collection of 143 strains of Pasteurella recovered from human patients . The organism isolated most frequently was Pasteurella multocida subsp . multocida . As in animals, most of the group A strains were recovered from the respiratory tract . The distribution of species in relation to the animal source suggests that P . multocida subsp . multocida is more infective than other Pasteurella species or subspecies for man.

Vet Res Commun, 2004 Jan, 28(1), 17 - 25
Cloning and sequencing of a 16 kDa outer membrane protein gene of Pasteurella multocida P52; Goswami PP et al.; The outer membrane proteins (OMPs) of Pasteurella multocida are potential immunogens . The 16 kDa OMP of P . multocida P52, serotype B:2, was identified as one of the major immunodominant antigens . The gene omp16, encoding a 16 kDa outer membrane protein, was amplified, cloned into a pBluescript SK(-) vector and sequenced . Complete sequence homology was observed between the 16 kDa OMP gene of P . multocida P52 (serotypes B:2) and P . multocida T16 (somatic serotype 3,4) . This gene was distributed among different serotypes of P . multocida and found to localize in a 6.0 kb HindII fragment of the P . multocida genome.

Can J Vet Res, 2004 Jan, 68(1), 66 - 70
Antibody response in sows and piglets following vaccination against Mycoplasma hyopneumoniae, toxigenic Pasteurella multocida, and Actinobacillus pleuropneumoniae; Kristensen CS et al.; The aim of the experimental study was to compare the humoral immune response and occurrence of adverse effects following single or multiple simultaneous vaccination of sows against Mycoplasma hyopneumonia, toxigenic Pasteurella multocida, and Actinobacillus pleuropneumoniae . In addition, passively transferred antibodies to piglets were studied until weaning at 3 weeks of age . Fever was seen in a few sows within the first 12 hours after the 1st and 2nd vaccination . No difference in the occurrence of other adverse effects was observed between groups . Antibody levels were significantly higher in vaccinated sows and their offspring compared with the control group . This was found to be independent of single or simultaneous vaccinations with the 3 vaccines . In conclusion, applying multiple vaccines simultaneously to sows appeared not to influence the occurrence of adverse effects or the sow's serum levels of antibodies at the time of farrowing, nor the offspring's serum levels up to 3 weeks of age.

J Arthroplasty, 2004 Feb, 19(2), 244 - 7
Acute pasteurella multocida in total knee arthroplasty; Stiehl JB et al.; Pasturella multocida is a rare cause of joint sepsis in total joint arthroplasty, and all case reports have identified a distant source of infection from an animal bite that has caused potential hematogenous seeding of the prosthesis . We report a case in which no potential distal wound source was found and the only likely etiology was local wound seeding from an old injury . In that injury, a saddle stirrup had caused a severe traumatic soft tissue injury as a horse had rolled over the patient . We draw attention to the fact that this particular bacteria is virulent in producing septic contamination of a total joint prosthesis, and aggressive treatment is indicated when such infection is identified.

JAAPA, 2003 Apr, 16(4), 28 - 32, 34, 37
Managing dog, cat, and human bite wounds; Correira K; All bite wounds require the same general approach regarding history and physical exam, selective ancillary testing, wound cleaning, and immobilization . Primary closure should be considered only for bites in which the concerns about cosmetic outcome outweigh the risk of infection . Antibiotic prophylaxis should be initiated for patients with high-risk bite wounds and for those who are at risk for serious wound infection complications . The chosen antibiotic should cover beta-lactamase-producing aerobic and anaerobic organisms, including Pasteurella species in animal bites and E corrodens in human bites.

J Clin Pathol, 2004 Feb, 57(2), 210 - 2
Fatal Pasteurella dagmatis peritonitis and septicaemia in a patient with cirrhosis: a case report and review of the literature; Ashley BD et al.; Pasteurella species cause zoonotic infections in humans . Human pasteurella infections usually manifest as local skin or soft tissue infection following an animal bite or scratch . Systemic infections are less common and are limited to patients at the extremes of age or those who have serious underlying disorders, including cirrhosis . Most human pasteurella infections are caused by the multocida species . We report a case of Pasteurella dagmatis peritonitis and septicaemia in a patient with cirrhosis . The infection followed a scratch inflicted by a pet dog . Despite appropriate antibiotic treatment the infection proved fatal . Spontaneous bacterial peritonitis caused by P dagmatis has not been reported previously . Pasteurella dagmatis is a relatively recently described species, which is rarely reported as a human pathogen . This species may be misidentified unless commercial identification systems are supplemented by additional biochemical tests.

Infect Immun, 2004 Feb, 72(2), 1195 - 8
Identification of five outer membrane-associated proteins among cross-protective factor proteins of Pasteurella multocida; Tabatabai LB et al.; Fowl cholera is caused by Pasteurella multocida serovars A:1, A:3, and A:4 . The 39-kDa cross-protective factor protein and four other membrane proteins of the membrane proteome of P . multocida were identified . We determined that the 39-kDa cross-protective protein was Pasteurella lipoprotein B, or PlpB.

Infect Immun, 2004 Feb, 72(2), 701 - 8
Two TonB systems in Actinobacillus pleuropneumoniae: their roles in iron acquisition and virulence; Beddek AJ et al.; Iron acquisition in vivo by Actinobacillus pleuropneumoniae depends upon a functional TonB system . Tonpitak et al . (W . Tonpitak, S . Thiede, W . Oswald, N . Baltes, and G.-F . Gerlach, Infect . Immun . 68:1164-1170, 2000) have described one such system, associated with tbpBA encoding the transferrin receptor, and here we report a second, termed tonB2 . This gene cluster (exbB2-exbD2-tonB2) is highly homologous to those in other Pasteurellaceae, unlike the earlier system described (now termed tonB1), suggesting that it is the indigenous system for this organism . Both tonB2 and tonB1 are upregulated upon iron restriction . TonB2, but not TonB1, was found to be essential for growth in vitro when the sole source of iron was hemin, porcine hemoglobin, or ferrichrome . In the case of iron provided as iron-loaded porcine transferrin, neither tonB mutant was viable . The tonB1 phenotype could be explained by a polar effect of the mutation on transcription of downstream tbp genes . We propose that TonB2 is crucial for the acquisition of iron provided in this form, interacting with accessory proteins of the TonB1 system that have been demonstrated to be necessary by Tonpitak et al . TonB2 appears to play a much more important role in A . pleuropneumoniae virulence than TonB1 . In an acute porcine infection model, the tonB2 mutant was found to be highly attenuated, while the tonB1 mutant was not . We hypothesize that acquisition of the tonB1-tbp gene cluster confers a biological advantage through its capacity to utilize transferrin-iron but that TonB1 itself plays little or no part in this process.

Vaccine, 2004 Jan 26, 22(5-6), 643 - 9
Maternally derived humoral immunity to bovine viral diarrhea virus (BVDV) 1a, BVDV1b, BVDV2, bovine herpesvirus-1, parainfluenza-3 virus bovine respiratory syncytial virus, Mannheimia haemolytica and Pasteurella multocida in beef calves, antibody decline by half-life studies and effect on response to vaccination; Fulton RW et al.; The passive immunity transferred to calves from their dams was investigated in a beef herd to determine half-life of antibody, estimated time to seronegative status and effect on immunization . One hundred two beef calves in a commercial ranch under standard management conditions were utilized . Samples were collected at branding (day 0) . This was the first possible date to collect samples postcalving . This was approximately 2 months postcalving, and days 95 and 116 . The calves were divided into two groups: vaccinates (51) and nonvaccinates (51) . The calves were vaccinated with a commercial inactivated viral vaccine containing bovine viral diarrhea virus (BVDV)1a, BVDV2, bovine herpesvirus-1 (BHV-1), parainfluenza-3 virus (PI-3V), and bovine respiratory syncytial virus (BRSV) on days 0 and 95 . Half of the vaccinated and unvaccinated calves also received one dose of an experimental Mannheimia haemolytica and Pasteurella multocida vaccine at day 95 . Serums were tested for neutralizing antibody titers to BVDV1a, BVDV1b, BVDV2, BHV-1, PI-3V, and BRSV . Antibodies were detected by ELISA to M . haemolytica whole cell, M . haemolytica leukotoxin, and P . multocida outer membrane protein (OMP) . The mean half-life of viral antibodies in nonvaccinated calves to each virus was: BVDV1a, 23.1 days (d); BVDV1b, 22.8 d; BVDV2, 22.9 d; BHV-1, 21.2 d; PI-3V, 30.3 d; and BRSV, 35.9 d . The mean half-life of viral antibodies was greater for vaccinates than for nonvaccinates for all viruses except BRSV . The calculated mean time to seronegative status for nonvaccinates based on titers at day 0 was: BVDV1a, 192.2 d; BVDV1b, 179.1 d; BVDV2, 157.8 d; BHV-1, 122.9 d; PI-3V, 190.6 d; and BRSV, 186.7 d . There was an active immune response after vaccination with two doses to all the viruses, except BRSV . Mean antibody titers of vaccinates at day 116 were statistically higher than nonvaccinates for all viruses except BRSV . However on an individual calf basis there were few seroconversions (four-fold rise or greater to BVDV1a, BVDV1b, BVDV2, PI-3V, or BRSV; or two-fold rise for BHV-1) in the presence of viral antibodies . The predicted time of seronegative status for a group of calves for vaccination programs may not be appropriate as there may be a range of titers for all calves at day 0 . In this study the range for BVDV1a was 16-16,384; BVDV1b, 8-8192; BVDV2, 0-8192; BHV-1, 0-935; PI-3V, 8-2048; and BRSV, 8-4096 . Using the half-life of 23 d for BVDV1a, the time thereafter for seronegative status would be 46 and 299 d compared to the calculated date of 192.2 d using the mean of estimated time to seronegative status for all the calves . There was an active humoral response in the vaccinated calves to M . haemolytica and P . multocida . Cowherd humoral immunity based on serum antibodies should be monitored as it may relate to transfer of maternal antibodies to calves . Exceptionally high levels of viral antibodies transferred to calves could interfere with the antibody response to vaccination.

J Am Anim Hosp Assoc, 2003 Nov-Dec, 39(6), 563 - 6
Hematogenous septic arthritis in the dog: results of five patients treated nonsurgically with antibiotics; Fitch RB et al.; This retrospective study evaluates the effectiveness of nonsurgical treatment using antibiotics to treat hematogenous septic arthritis in five dogs . Giant-breed dogs were over-represented, with all dogs <1 year of age . Synovial fluid cultures were positive in all cases, with common bacterial species isolated that included Streptococcus B-haemolytic spp., Pasteurella multocida, and Staphylococcus intermedius . Dogs treated with appropriate duration and selection of antibiotics had clinical resolution with no residual deficits . This report and a previous clinical report demonstrate that hematogenous septic arthritis can be successfully treated nonsurgically with antibiotic therapy.

J Wildl Dis, 2003 Oct, 39(4), 897 - 903
Sharing of Pasteurella spp . between free-ranging bighorn sheep and feral goats; Rudolph KM et al.; Pasteurella spp . were isolated from feral goats and free-ranging bighorn sheep (Ovis canadensis canadensis) in the Hells Canyon National Recreation Area bordering Idaho, Oregon, and Washington (USA) . Biovariant 1 Pasteurella haemolytica organisms were isolated from one goat and one of two bighorn sheep found in close association . Both isolates produced leukotoxin and had identical electrophoretic patterns of DNA fragments following cutting with restriction endonuclease HaeIII . Similarly Pasteurella multocida multocida a isolates cultured from the goat and one of the bighorn sheep had D type capsules, serotype 4 somatic antigens, produced dermonecrotoxin and had identical HaeIII electrophoretic profiles . A biovariant U(beta) P.haemolytica strain isolated from two other feral goats, not known to have been closely associated with bighorn sheep, did not produce leukotoxin but had biochemical utilization and HaeIII electrophoretic profiles identical to those of isolates from bighorn sheep . It was concluded that identical Pasteurella strains were shared by the goats and bighorn sheep . Although the direction of transmission could not be established, evidence suggests transmission of strains from goats to bighorn sheep . Goats may serve as a reservoir of Pasteurella strains that may be virulent in bighorn sheep; therefore, goats in bighorn sheep habitat should be managed to prevent contact with bighorn sheep . Bighorn sheep which have nose-to-nose contact with goats should be removed from the habitat.

J Wildl Dis, 2003 Oct, 39(4), 808 - 16
Pasteurella multocida from outbreaks of avian cholera in wild and captive birds in Denmark; Pedersen K et al.; An outbreak of avian cholera was observed among wild birds in a few localities in Denmark in 2001 . The highest mortalities were among breeding eiders (Somateria mollissima) and gulls (Larus spp.) . Pulsed-field gel electrophoresis (PFGE) was conducted using ApaI and SmaI as restriction enzymes and restriction enzyme analysis (REA) using HpaII . The Pasteurella multocida subsp . multocida strain isolated from birds in this outbreak was indistinguishable from a strain that caused outbreaks in 1996 and 2003 . Most isolates from domestic poultry had other PFGE patterns but some were indistinguishable from the outbreak strain . Among 68 isolates from wild birds, only one PFGE and one REA pattern were demonstrated, whereas among 23 isolates from domestic poultry, 14 different SmaI, 12 different ApaI, and 10 different HpaII patterns were found . The results suggest that a P . multocida strain has survived during several years among wild birds in Denmark.

J Wildl Dis, 2003 Oct, 39(4), 798 - 807
Characterization of Pasteurella multocida isolates from wetland ecosystems during 1996 to 1999; Samuel MD et al.; We cultured 126 Pasteurella multocida isolates, 92 from water and 34 from sediment samples collected from wetlands in the Pacific and Central flyways of the United States between 1996 and 1999 . Most (121) of the isolates were P . multocida serotype 1, but serotypes 3, 3/4, 10, and 11 were also found . Many (82) of the isolates were further characterized by DNA fingerprinting procedures and tested in Pekin ducks for virulence . Almost all the serotype 1 isolates we tested caused mortality in Pekin ducks . Serotype 1 isolates varied in virulence, but the most consistent pattern was higher mortality in male ducks than in females . We found no evidence that isolates found in sediment vs . water, between Pacific and Central flyways, or during El Nino years had consistently different virulence . We also found a number of non-serotype 1 isolates that were avirulent in Pekin ducks . Isolates had DNA fingerprint profiles similar to those found in birds that died during avian cholera outbreaks.

J Antimicrob Chemother, 2004 Feb, 53(2), 379 - 82 Epub 2004 Jan 16.
In vitro activities of spectinomycin and comparator agents against Pasteurella multocida and Mannheimia haemolytica from respiratory tract infections of cattle; Schwarz S et al.; OBJECTIVES: Prior to the renewal of spectinomycin licensing for veterinary uses in Germany, 154 Pasteurella multocida and 148 Mannheimia haemolytica strains from respiratory tract infections in cattle were investigated for their MICs of spectinomycin and other antimicrobial agents . The data obtained should serve as a baseline from which to judge the future development of resistance . Moreover, the in vitro activity of spectinomycin in comparison with other antimicrobials should be assessed . METHODS: MIC determination for all 302 strains was performed by the broth dilution method and evaluated according to NCCLS standards . MIC(50) and MIC(90) values were calculated . Strains resistant to spectinomycin were subjected to PCR assays for genes known to mediate spectinomycin resistance in Gram-negative and Gram-positive bacteria . RESULTS: With the exception of resistance to sulfamethoxazole in P . multocida and M . haemolytica, and resistance to ampicillin in M . haemolytica, an overall low level of resistance was detected . A total of 93.5% of the P . multocida and 98.6% of the M . haemolytica strains were susceptible to spectinomycin, with MIC(90)s of 32 mg/L . PCR analysis showed that none of the spectinomycin-resistant strains carried any of the aadA gene subtypes, nor the genes spc or aad(9) . CONCLUSIONS: Prior to the renewal of spectinomycin, only a small number of spectinomycin-resistant strains was detected among bovine P . multocida and M . haemolytica . The genes responsible for spectinomycin resistance in these strains seemed to be different from those so far known to occur in other Gram-negative and Gram-positive bacteria.

Microb Pathog, 2004 Mar, 36(3), 159 - 69
Pharmacological inhibition of Mannheimia haemolytica lipopolysaccharide and leukotoxin-induced cytokine expression in bovine alveolar macrophages; Malazdrewich C et al.; The inflammatory cytokines tumor necrosis factor-alpha (TNFalpha), interleukin-1 beta (IL-1beta), and interleukin-8 (IL-8) are believed to contribute to the pathogenesis of lung injury in bovine pneumonic mannheimiosis (BPM) caused by Mannheimia (Pasteurella) haemolytica . Inflammatory cytokines may, therefore, represent therapeutic targets to be modulated for the purpose of treating or preventing this important disease of cattle . The purpose of this study was to evaluate the ability of six pharmacological agents to suppress the expression of TNFalpha, IL-1beta, and IL-8 genes and proteins in bovine alveolar macrophages (AM) exposed to M . haemolytica lipopolysaccharide (LPS) and leukotoxin (LktA) in vitro . The compounds tested included dexamethasone (DEX), tetrahydropapaveroline (THP), pentoxifylline (PTX), rolipram (ROL), SB203580 (SB), and thalidomide (THL) . Cytokine expression was induced by the addition of purified M . haemolytica LPS and LktA to AM cell cultures following pretreatment with inhibitor compounds . Secretion of TNFalpha, IL-1beta, and IL-8 proteins into the cell culture supernatant was measured using enzyme-linked immunosorbent assays, and steady-state accumulation of cytokine-specific mRNA was measured by northern blot analysis . Dose-dependent inhibition of cytokine secretion occurred in response to pretreatment of AM with DEX (TNFalpha, IL-1beta, IL-8), THP (TNFalpha, IL-1beta, IL-8), PTX (TNFalpha, IL-1beta, IL-8), ROL (TNFalpha, IL-1beta), and SB (TNFalpha, IL-8) . Significant dose-dependent inhibition of cytokine mRNA expression occurred in response to pretreatment with DEX (TNFalpha, IL-1beta, IL-8), THP (TNFalpha, IL-1beta, IL-8), and PTX (TNFalpha) . DEX was the most effective inhibitor by far; pretreatment with this compound yielded greater than 95% inhibition of cytokine gene and protein expression over a broad range of concentrations . These findings demonstrate that DEX, THP, PTX, ROL, and SB are capable of suppressing inflammatory cytokine secretion by bovine AM in vitro . If pulmonary cytokine secretion may be similarly inhibited in vivo, anti-cytokine therapy may represent a novel strategy for the management of BPM.

Avian Dis, 2003 Oct-Dec, 47(4), 1491 - 5
Outbreak of Fowl cholera in Baikal teals in Korea; Kwon YK et al.; Fowl cholera (FC) caused by Pasteurella multocida was diagnosed in waterfowl, Baikal teals (Anas formosa), submitted to the National Veterinary Research and Quarantine in Korea . The total number of mortalities was 13,228 out of approximately 100,000 birds that wintered in Cheonsoo Bay, the most important habitat area of Baikal teals in the world . Clinical signs were detected in only a few birds because of sudden death . Grossly, the dead Baikal teals had lesions consistent with FC, including multifocal necrotic foci in the liver with enlargement, petechial or ecchymotic hemorrhages on the heart, and mucoid exudates in the duodenal mucosa . Microscopically, there were hepatocytic necrosis with bacterial colonization, hemorrhage and necrosis in the myocardium, and hemorrhagic enteritis . Pasteurella multocida was isolated from the liver and the heart of all birds examined, and the isolate (P-627) was the serotype 1 X 12 X 13 by the agar gel immunodiffusion test . In order to estimate the virulence of P-627, 5-wk-old commercial ducks were exposed intramuscularly or intratracheally to the bacterium . On the basis of mortality rate, the isolate, P-627, was found to be highly virulent . This is the first report of an outbreak of FC in Baikal teals in Korea.

Avian Dis, 2003 Oct-Dec, 47(4), 1384 - 92
Molecular characterization of plasmids with antimicrobial resistant genes in avian isolates of Pasteurella multocida; Wu JR et al.; The complete nucleotide sequences of two plasmids from avian isolates of Pasteurella multocida that caused outbreaks of fowl cholera in Taiwan were determined . The entire sequences of the two plasmids, designated as pJR1 and pJR2, were 6792 bp and 5252 bp . Sequence analysis showed that the plasmid pJR1 contained six major genes: the first gene (sulII) encoded a type II sulfonamide resistant dihydropteroate synthase, the second gene (tetG) encoded a tetracycline resistance protein, the third gene (catB2) encoded a chloramphenicol acetyltransferase, the fourth gene (rep) encoded a replication protein, and the fifth and sixth genes (mbeCy and deltambeAy) encoded proteins involved in the mobilization of plasmid . The plasmid pJR2 contained five major genes: the first gene (deltaintI1) encoded a truncated form of a type I integrase, the second gene (aadA1) encoded an aminoglycoside adenylyltransferase that confers resistance to streptomycin and spectinomycin, the third gene (blaP1) encoded a beta-lactamase that confers resistance to ampicillin and carbenicillin, and the fourth and fifth genes might encode proteins involved in the plasmid replication or segregation . Sequence comparisons showed that the antibiotic resistance genes found in pJR1 and pJR2 exhibited a high degree of sequence homology to the corresponding genes found in a great variety of gram-negative bacteria, including Escherichia coli, Salmonella enterica Typhimurium DT104, Psedomonas spp., P . multocida, Mannheimia spp., and Actinobacills pleuropneumoniae, which suggests that these resistance genes were disseminated in these bacteria . Although sulII and tetG genes were found previously in P . multocida or Mannheimia spp., this is the first report on the presence of catB2, aadA1, and blaP1 genes in bacteria of the family Pasturellaceae . Moreover, the aadA1 and blaP1 genes found in pJR2 were organized into an integron structure, which is a site-specific recombination system capable of capturing and mobilizing antibiotic resistance genes . This is also the first report on the presence of an integron in bacteria of the family Pasteurellaceae . The presence of a P . multocida integron might facilitate the spreading of antibiotic resistance genes between P . multocida and other gram-negative bacteria.

Vet Microbiol, 2003 Dec 30, 97(3-4), 229 - 43
A 39 kDa protein mediates adhesion of avian Pasteurella multocida to chicken embryo fibroblast cells; Borrathybay E et al.; To clarify the role of avian Pasteurella multocida capsule in pathogenesis, adhesion of capsulated strains P-1059, X-73 and Pm-18, and noncapsulated strains P-1059B, Pm-1 and Pm-3 to chicken embryo fibroblast (CEF) cells was compared . Number of adherent organisms of the capsulated strains to CEF cells were approximately three times as much as noncapsulated strains indicating that adhesive properties were enhanced by the presence of bacterial capsule . Pretreatments of the bacterial cells with heat, trypsin, or with antiserum caused a marked decrease in adhesion of capsulated strain P-1059 and its noncapsulated variant P-1059B . However, depolymerization of capsular hyaluronic acid with high dose of hyaluronidase enhanced adhesion of these strains . Combined treatments of the bacterial cells with both hyaluronidase and trypsin significantly (P < 0.05) inhibited the adherence of strain P-1059 as compared to the treatment only with trypsin, but strain P-1059B was not affected . SDS-PAGE profiles of crude capsular extract (CCE) prepared from capsulated strain P-1059 and its noncapsulated variant P-1059B grown on dextrose starch agar (DSA) plates by heating at 56 degrees C in a 2.5% NaCl solution demonstrated eight protein bands of 28, 34, 36, 39, 52, 56, 63 and 93 kDa . The 28, 34 and 36 kDa proteins were commonly major for both strains, and the 39 kDa protein was major only for strain P-1059 but poor in strain P-1059B . Outer membrane protein (OMP) profiles were identical with a major protein at 34 kDa and four minor proteins between the two strains . The adhesion of strain P-1059 and strain P-1059B to CEF cells was inhibited significantly (P < 0.01) by treatment with rabbit antisera against P-1059, P-1059B, CCE or 39 kDa protein of strain P-1059 as compared to the treatment with either PBS or with normal rabbit serum . These results indicated that an antigenic 39 kDa protein in the capsule may be responsible for adhesion of avian P . multocida type A strains to CEF cells as a virulence factor.

Vet Microbiol, 2003 Dec 30, 97(3-4), 215 - 27
Capsule thickness and amounts of a 39 kDa capsular protein of avian Pasteurella multocida type A strains correlate with their pathogenicity for chickens; Borrathybay E et al.; Capsule thickness of avian Pasteurella multocida type A strains was determined by transmission electron microscopy after labeling with polycationic ferritin and compared with their pathogenicity for chickens . The capsule thickness of P . multocida strains Pm-18 and X-73 was 81.4 and 50.1 nm on average, respectively . These strains were highly virulent for chicken, whereas the less virulent strains Pm-1 and Pm-3 had a thin and irregular capsule, 21.0 and 29.8 nm on average, respectively . However, the thickest capsule was observed in strain P-1059, 101.2 nm on average, and the strain revealed moderate virulence . The noncapsulated variant P-1059B, which was derived from strain P-1059, revealed low virulence . The six P . multocida strains were examined with regard to protein content on the capsule of organisms . Amounts of total proteins of crude capsular extract (CCE) from capsulated strains were approximately twice those of the noncapsulated strains . The amount of an antigenic 39 kDa protein in the CCE were found to correlate with the capsule thickness, since heavily capsulated strains exhibited the greatest amount, whereas noncapsulated strains including noncapsulated and low virulent variant P-1059B possessed little 39 kDa protein . The results demonstrated that the capsule thickness and the quantity of a 39 kDa capsular protein of avian P . multocida type A strains correlated with their pathogenicity for chickens.

Mol Microbiol, 2004 Jan, 51(1), 255 - 69
The Pasteurella multocida toxin is encoded within a lysogenic bacteriophage; Pullinger GD et al.; Toxigenic strains of Pasteurella multocida produce a 146 kDa toxin (PMT) that acts as a potent mitogen . Sequence analysis of the structural gene for PMT, toxA, previously suggested it was horizontally acquired, because it had a low G + C content relative to the P . multocida genome . To address this, the sequence of DNA flanking toxA was determined . The sequence analysis showed the presence of homologues to bacteriophage tail protein genes and a bacteriophage antirepressor, suggesting that the toxin gene resides within a prophage . In addition to phage genes, the toxA flanking DNA contained a homologue of a restriction/modification system that was shown to be functional . The presence of a bacteriophage was demonstrated in spent medium from toxigenic P . multocida isolates . Its production was increased by mitomycin C addition, a treatment that is known to induce the lytic cycle of many temperate bacteriophages . The genomes of bacteriophages from three different toxigenic P . multocida strains had similar but not identical restriction profiles, and were approximately 45-50 kb in length . The prophages from two of these had integrated at the same site in the chromosome, in a tRNA gene . Southern blot analysis confirmed that these bacteriophages contained the toxA gene.

J Pediatr (Rio J), 2001 Nov-Dec, 77(6), 469 - 74
{Experimental empyema in rats through intrapleural injection of bacteria}; Fraga JC et al.; OBJECTIVE: To evaluate empyema formation in rats through the injection of two bacteria (Pasteurella multocida and Staphylococcus aureus), using a simple, easy-to-use surgical technique . METHODS: Twenty four anesthetized Wistar white rats, 250-300g in weight, submitted to right anterior thoracotomy, muscular retraction and injection of a 0.2ml solution into pleural space according the following scheme: Group I (n=12): injection of 10(10) Pasteurella multocida cultured in brain heart infusion broth . Group II (n=8): injection of 10(10) Staphylococcus aureus cultured in brain heart infusion broth . Group III (n=4): injection of bacterium-free brain heart infusion (control) . The rats were sacrificed after seven days, and pleural reaction was assessed by macroscopy . Mortality, and intrathoracic liquid volume were evaluated, and bacteriological tests were also performed . RESULTS: Seven rats died within the first 48 hours in Group I (Pasteurella multocida); five completed the experiment, but none of them presented empyema . Only one animal died within the first 24 hours in Group II (Staphylococcus aureus); seven (88%) presented empyema at the time of sacrifice . All animals survived in Group III (control), without empyema or thoracic abnormalities . Pleural inoculation of Staphylococcus aureus (Group II) was significantly associated with empyema formation (P<0.001) . In this group, the amount of pleural liquid ranged from 0.9 to 3.9ml . CONCLUSION: It is possible to induce empyema in rats through Staphylococcus aureus pleural injection by a simple surgical technique . Differently from other experiments, the pleural injection of Pasteurella multocida did not provoke empyema in rats.

Vet Parasitol, 2003 Nov 14, 117(3), 213 - 20
Neospora caninum in sheep: a herd case report; Hassig M et al.; Neospora caninum was detected by means of PCR in the brain of 4 out of 20 aborted fetuses in a flock of 117 sheep exhibiting a persistent abortion problem, and N . caninum tissue cysts were furthermore found in encephalitic lesions in one of the PCR-positive fetuses . Toxoplasma gondii was detected as aborting agent in another 3 out of 20 fetuses . Antibodies to N . caninum (by indirect fluorescence antibody test (IFAT)) were found in 10.3% of 117 ewes and antibodies for T . gondii were found in 97.4% of 117 ewes . Other organisms associated with abortion were Chlamydia psittaci in three fetuses and Pasteurella multocida in one fetus . This is the first report of N . caninum associated abortion in naturally infected sheep.

J Vet Sci, 2000 Dec, 1(2), 87 - 95
Immunologic reactivity of a lipopolysaccharide-protein complex of type A Pasteurella multocida in mice; Ryu HI et al.; The immunologic reactivity of a lipopolysaccharide (LPS)-protein complex isolated from a potassium thiocyanate extract of a Pasteurella multocida (capsular type A and somatic type 3) strain was evaluated in mice . The LPS-protein complex provided 100% protection in mice against a challenge with the homologous strain . However, when the complex was fractionated into LPS and protein moieties by phenol-water treatment, both components lacked immunogenicity . The complex and extracted components were mitogenic for mouse B lymphocytes with the protein moiety the most active . Although immune serum against the LPS-protein complex protected mice against challenge thereby indicating a role for humoral immunity, the LPS-protein complex of P . multocida was also found to induce cell-mediated immunity . This cell-mediated immunity was demonstrated in mice immunized with the complex by: (1) . mitogenic responses of T lymphocytes, (2) . induction of delayed type hypersensitivity reaction in the hind footpads, and (3) . enhanced resistance to challenge infection with Salmonella enteritidis.

J Vet Sci, 2002 Mar, 3(1), 47 - 57
Effective methods for the production of immunoglobulin Y using immunogens of Bordetella bronchiseptica, Pasteurella multocida and Actinobacillus pleuropneumoniae; Shin NR et al.; Swine respiratory diseases induce severe economic losses in the swine industry worldwide . Several methods have been developed and applied to control these diseases . However, there are still problems of disease control in the swine industry . Recently, egg yolk antibodies have been found to offer several advantages for disease control in animals and humans . In a previous study (24), antibodies to several causative pathogens of swine respiratory diseases were developed . However, several problems remained, especially in terms of reduced laying rates . Therefore, experimental vaccines were reformulated with various bacterial antigens of the swine respiratory diseases . After immunizing hens with the antigens, antibody profiles and other effects including laying rates were investigated and compared to those of the previous study . Profiles of antibody titers were very similar with those of the previous study . However, side effects, such as depression, weakness, reduction of laying rates and mortality, were dramatically lowered and laying rates were increased in hens injected with certain experimental vaccines . In particular, laying rates of hens injected with vaccines against atrophic rhinitis were increased up to 84% by injecting a vaccine composed of only the DNTs of B . bronchiseptica and P . multocida D:4 . Efficacies of the vaccines against swine pneumonic pasteurellosis and pleuropneumonia were very similar with those of the previous study . These results suggest that new vaccines could be effective in the production of egg yolk antibodies against the causative agents of swine respiratory diseases.

Scand J Infect Dis, 2003, 35(10), 764 - 5
A case of Pasteurella haemolytica sepsis in a patient with mitral valve disease who developed a splenic abscess; Takeda S et al.; We report a patient with sepsis caused by Pasteurella haemolytica, an extremely rare etiologic agent of human infection, who had mitral valve disease and developed a splenic abscess.

Epidemiol Infect, 2003 Oct, 131(2), 939 - 46
Molecular typing of Mannheimia (Pasteurella) haemolytica serotype A1 isolates from cattle in Japan; Katsuda K et al.; Pulsed field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD) methods were applied for molecular typing of 130 Mannheimia (Pasteurella) haemolytica serotype A1 isolates obtained from 13 prefectures in Japan . These isolates were divided into 15 ApaI PFGE profiles that formed six distinct clusters (clusters A-F) . Fifty-three (40.7%) isolates were classified in cluster B, and 20.0, 13.8, 12.3, 6.9 and 6.1% of isolates were in clusters E, A, F, D and C, respectively . The isolates of cluster B were differentiated into seven subtypes (B1-B7) and subtype B5 contained 63% (34/53) of isolates . RAPD revealed four banding patterns (types I-IV), and among 130 isolates 60.7% (79/130) of isolates were RAPD type I . All of the RAPD type I isolates were grouped into clusters A-C by PFGE . There was no relationship between molecular typing and geographic origin of these isolates . These results indicate that isolates of M . haemolytica A1 strain with various molecular profiles have already spread in Japan and may have caused sporadic infections.

Vet Res Commun, 2003 Sep, 27(6), 433 - 44
The efficacy of a bivalent vaccine against pasteurellosis and rabbit haemorrhagic disease virus; Peshev R et al.; Rabbit haemorrhagic disease virus (RHDV) and Pasteurella multocida bacteria cause severe losses among rabbit populations . The efficacy of a recently developed bivalent vaccine against pasteurellosis and RHDV was investigated . Doses exceeding 2 haemagglutinating units (HU) of viral antigen were sufficient to protect rabbits against infection with RHDV . The bivalent vaccine appeared to be safe for use in all age groups of rabbits, including pregnant females, even after treatment with 20 times the normal vaccine dose . Rabbits injected with 8 or 4 HU of bivalent vaccine showed high antibody titres against both organisms for 9 months after inoculation . The antibody levels against RHDV in young rabbits at 30 days of age were elevated when they originated from mothers with high antibody titres . The most suitable period for vaccination of offspring appeared to be around 50 days of age . The bivalent vaccine against pasteurellosis and RHDV combined speed and longevity of the immune response . Immune protection against pasteurellosis and RHDV can thus be achieved with only one manipulation.

J Wildl Dis, 2003 Jul, 39(3), 732 - 5
Avian cholera in a southern giant petrel (Macronectes giganteus) from Antarctica; Leotta GA et al.; A southern giant petrel (Macronectes giganteus) was found dead at Potter Peninsula, King George Island, South Shetland, Antarctica . The adult male was discovered approximately 48 hr after death . Macroscopic and microscopic lesions were compatible with avian cholera and the bacterium Pasteurella multocida subsp . gallicida, serotype A1 was isolated from lung, heart, liver, pericardial sac, and air sacs . In addition, Escherichia coli was isolated from pericardial sac and air sacs . This is the first known report of avian cholera in a southern giant petrel in Antarctica.

J Wildl Dis, 2003 Jul, 39(3), 536 - 44
Characterization of Pasteurella multocida associated with pneumonia in bighorn sheep; Weiser GC et al.; Pasteurella multocida is a highly diverse group of bacteria recognized as important pathogens . Although P . multocida is not ordinarily associated with disease in Rocky Mountain bighorn sheep (Ovis canadensis canadensis), numerous isolates were cultured in high numbers from free-ranging bighorn sheep in the Hells Canyon area of Idaho, Washington, and Oregon (USA) during the winter of 1995-96 . Animals captured in Hells Canyon and held in captivity, and their offspring, also harbored P . multocida . Biochemical utilization tests on 90 isolates identified three subspecies: P . multocida multocida a (n = 54); P . multocida multocida b (n = 13); and P . multocida gallicida (n = 15); and a non-speciated biotype, U6 (n = 8) . Genomic DNA digestion with restriction endonuclease Hha I separated the isolates into 62 unique restriction fragment length polymorphism profiles . Capsular type A was predominant (72% of isolates) . Only one isolate type, which may have been transmitted from a feral goat, was capsular type D, possessed the structural gene, toxA, for dermonecrotoxin detected by polymerase chain reaction, and produced toxin as determined by monoclonal antibody immunoblot . In conclusion, bighorn sheep in this study carried diverse types of generally non-toxigenic P . multocida associated with epizootic pneumonia.

Avian Dis, 2003 Jul-Sep, 47(3), 649 - 55
Pasteurella multocida-associated sinusitis in khaki Campbell ducks (Anas platyrhynchos); Songserm T et al.; Pasteurella multocida group B, serotype 3, was isolated from sinusitis-affected khaki Campbell ducks . To study the role of P . multocida in sinusitis, commercial khaki Campbell ducks were experimentally infected with P . multocida alone or combined with Escherichia coli . In Expt . 1, experimental ducks were infected with P . multocida intranasally or ocularly . A comparison was done by intranasal inoculation with pooled nasal discharge from the affected ducks or phosphate-buffered saline . The ducks intranasally inoculated with the nasal discharge or P . multocida showed sinusitis . In Expt . 2, E . coli alone or a combination of P . multocida and E . coli was intranasally inoculated into experimental ducks . The ducks intranasally inoculated with the combination of P . multocida and E . coli had sinusitis, the same as found in the field but less severe than that of the field cases . Pasteurella multocida was already present in litter/floor of duck farms . We concluded that P . multocida played a role in induction of sinusitis . However, the sinusitis in ducks may be initiated by poor management, especially in the brooding period of ducks.

FEMS Immunol Med Microbiol, 2003 Oct 24, 39(1), 51 - 9
Modulation of the humoral immune response of swine and mice mediated by toxigenic Pasteurella multocida; Jordan RW et al.; Progressive atrophic rhinitis is an upper respiratory tract disease of pigs caused by toxigenic strains of the bacterium Pasteurella multocida . In this study the effect of P . multocida on the humoral immune response of pigs and mice was investigated . Pigs were given live intranasal challenge with either a toxigenic strain or a non-toxigenic strain of P . multocida, or were given daily intranasal instillation of a cell-free lysate of the toxigenic strain . Mice were given a live intranasal challenge of either a toxigenic or a non-toxigenic strain of P . multocida . All of the animals were immunised with ovalbumin and serum concentrations of anti-ovalbumin antibodies were quantified and compared between different treatment groups and control animals . Intranasal challenge with toxigenic P . multocida caused a significant reduction in the levels of anti-ovalbumin IgG in both species . A similar effect was seen in pigs given a cell-free extract of toxigenic P . multocida . Whilst the mechanism of this suppression is unclear, we surmise that immunomodulation of the host is an important virulence factor for toxigenic P . multocida, and could be an important function of the toxin . This immunomodulatory effect may enhance colonisation of P . multocida aiding horizontal transmission and may predispose to concurrent infection with other potential pathogens.

J Comp Pathol, 2003 Nov, 129(4), 251 - 8
Septicaemia and arthritis in pigs experimentally infected with Pasteurella multocida capsular serotype A; Ono M et al.; Twenty-five caesarean-derived, colostrum-deprived (CDCD) pigs and 18 specific pathogen-free pigs, aged 8 to 14 weeks, were inoculated intranasally or intratracheally with Pasteurella multocida capsular serotype A, isolated from a severe pneumonic lesion in a growing pig . The pigs were killed for necropsy on day 6 or 14 post-inoculation (PI) or, in the case of the only fatally infected animal, examined at the time of death . One CDCD pig, inoculated intratracheally with 5 ml of a bacterial suspension containing 1.7x10(9) colony-forming-units/ml, died of septicaemia on day 1 PI . Histological lesions such as severe pleuropneumonia, thrombi in glomerular capillaries, haemorrhage of the spleen, and abscesses in the tonsillar crypts were observed . The organism was recovered from a number of sites and its antigens were detected immunohistochemically in the pneumonic lesions, blood vessels of the tissues, and tonsillar crypts in the dead pig . Pneumonia, pleural adhesions and suppurative arthritis in the extremital joints were observed grossly in 3/29, 8/29 and 7/29 intratracheally inoculated pigs, respectively . In intranasally inoculated pigs, no macroscopical abnormalities were seen; histologically, however, exudative bronchopneumonia and fibrinous pleurisy were observed in 9/14 and 4/14 pigs, respectively . No significant changes were seen in the tissues of uninfected control pigs . The organism was recovered from the lesions and P . multocida type A antigen was demonstrated immunohistochemically . The organism was rarely recovered from the liver, spleen or lymph nodes (bronchopulmonary or mesenteric) . The results suggest that P . multocida capsular serotype A alone can cause not only pneumonia in pigs but also septicaemia or arthritis.

Vet J, 2003 Nov, 166(3), 251 - 6
Association of porcine circovirus 2 with porcine respiratory disease complex; Kim J et al.; A retrospective study was performed on natural cases of porcine respiratory disease complex (PRDC) to determine the association and prevalence of PRDC with porcine circovirus 2 (PCV2) and other co-existing pathogens in Korea . Histologically, alveolar septa were markedly thickened by infiltrates of mononuclear cells . Moderate to marked multifocal peribronchial and peribronchiolar fibrosis were present and often extended into the airway lamina propria . Among the 105 pigs with PRDC, 85 were positive for PCV2, 66 were positive for porcine reproductive and respiratory syndrome virus (PRRSV), 60 were positive for porcine parvovirus (PPV), and 14 were positive for swine influenza virus (SIV) . There were 80 co-infections and 25 single infections . A co-infection of PCV2 with another additional bacterial pathogen is frequently diagnosed in PRDC . The combination of PCV2 and Pasteurella multocida (38 cases) was most prevalent followed by PCV2 and Mycoplasma hyopneumoniae (33 cases) . The consistent presence of PCV2, but lower prevalence of other viral and bacterial pathogens in all pigs examined with PRDC, has led us to speculate that PCV2 plays an important role in PRDC.

J Vet Med B Infect Dis Vet Public Health, 2003 Sep, 50(7), 347 - 51
Isolation of Mycoplasmas from nasal swabs of calves affected with respiratory diseases and antimicrobial susceptibility of their isolates; Hirose K et al.; Nasal swabs of 293 calves were examined for Mycoplasma . The samples were collected from calves affected with respiratory diseases on 71 farms in various parts of Japan between 1996 and 1997 . Mycoplasma bovirhinis was isolated from 47 of 293 calves (16.0%) . Mycoplasma alkalescens, M . bovis, M . arginini, M . bovigenitalium and Acholeplasma spp . were isolated from 19 (6.5%), seven (2.4%), four (1.4%), four (1.4%) and 18 (6.1%) calves, respectively . Pasteurella multocida and P . haemolytica were isolated from 60% of Mycoplasma-positive calves . However, other bacteria were not isolated from calves . To evaluate the antimicrobial susceptibility of their isolates, 68 M . bovirhinis, 21 M . alkalescens and 10 M . bovis strains were examined for 12 antimicrobial agents . All isolates showed higher susceptibility to tiamulin than to the other drugs used in the study . However, erythromycin had no effect on any of the Mycoplasma strains studied . The field isolates were less susceptible than the type strains to some drugs, such as spiramycin, oxytetracycline and tylosin.

Annu Rev Microbiol, 2003, 57, 29 - 55
Molecular pathogenicity of the oral opportunistic pathogen Actinobacillus actinomycetemcomitans; Henderson B et al.; Periodontitis is mankind's most common chronic inflammatory disease . One severe form of periodontitis is localized aggressive periodontitis (LAP), a condition to which individuals of African origin demonstrate an increased susceptibility . The main causative organism of this disease is Actinobacillus actinomycetemcomitans . A member of the Pasteurellaceae, A . actinomycetemcomitans produces a number of interesting putative virulence factors including (a) an RTX leukotoxin that targets only neutrophils and monocytes and whose action is influenced by a novel type IV secretion system involved in bacterial adhesion; (b) the newly discovered toxin, cytolethal distending toxin (CDT); and (c) a secreted chaperonin 60 with potent leukocyte-activating and bone resorbing activities . This organism also produces a plethora of proteins able to inhibit eukaryotic cell cycle progression and proteins and peptides that can induce distinct forms of proinflammatory cytokine networks . A range of other proteins interacting with the host is currently being uncovered . In addition to these secreted factors, A . actinomycetemcomitans is invasive with an unusual mechanism for entering, and traveling within, eukaryotic cells . This review focuses on recent advances in our understanding of the molecular and cellular pathogenicity of this fascinating oral bacterium.

Berl Munch Tierarztl Wochenschr, 2003 Sep-Oct, 116(9-10), 401 - 16
{Phenotypic and genotypic methods for epidemiological typing of veterinary important bacterial pathogens of the genera Staphylococcus, Salmonella, and Pasteurella}; Schwarz S et al.; Molecular typing methods are capable of providing detailed strain characteristics which are commonly far beyond the capacities of phenotypic typing methods . Such molecular-based characteristics have proved to be very helpful in epidemiological studies of bacterial pathogens . The primary criteria that all typing methods should fulfill include (1) the typeability of the strains in question, (2) the reproducibility of the results, and (3) a high discriminatory power . In general, molecular typing methods can be differentiated with regard to their use in methods that can be applied to virtually all bacteria (e.g . plasmid profiling, ribotyping, macrorestriction analysis) and methods which can only be used for typing of certain bacterial genera or species (e.g . IS200 typing of certain Salmonella enterica subsp . enterica serovars, or coa-PCR of coagulase-positive staphylococci) . In the present review, various phenotypic and molecular methods for the epidemiological typing of bacteria of the genera Staphylococcus, Salmonella, and Pasteurella are described and their advantages/disadvantages--also with regard to the fulfillment of the above-mentioned primary criteria--are critically assessed.

Enferm Infecc Microbiol Clin, 2003 Aug-Sep, 21(7), 334 - 9
{Bacteremia due to Pasteurella spp.: a rare process in our hospital over the last 8 years}; Felix M et al.; OBJECTIVES: To review and update the epidemic and clinical knowledge concerning disseminated blood disease caused by Pasteurella species in our area . METHODS: Retrospective study of Pasteurella species bacteremia (PSB) episodes occurring in patients attended from January 1994 to December 2001 in a single tertiary hospital . RESULTS: Among the 31 clinical samples remitted to the Microbiology Laboratory in which a species of Pasteurella was identified, 5 (16%) corresponded to positive blood cultures in 5 patients . Pasteurella multocida was the predominant species, identified in 70% of all isolations and all but one positive blood culture . All the patients were adults over 50 years old and all had underlying illnesses causing comorbidity or some degree of immunocompromise, with cardiovascular and hypertensive conditions being the most frequent; only one patient had liver cirrhosis . In all cases, except one, contact or coexistence with dogs or cats was documented . The clinical presentation of PSB was non-specific and only two episodes were related with a possible focal, soft-tissue origin . There were no serious complications, such as septic shock, organ failure or invasive disease (meningitis or endocarditis) . All patients cured with antimicrobial treatment, although surgical debridement of infected bite wounds was required in two cases . The betalactams and other families of antibiotics showed excellent in vitro activity against the five strains of Pasteurella isolated . CONCLUSIONS: PSB occurred in adult patients having a wide range of underlying illnesses and comorbidity factors . Most of them had contact with pets, though traumatic lesions were not present in all cases . Clinical presentation did not differ from other types of severe sepsis . Susceptibility and outcome of primary treatment with penicillins and other betalactams shows that they are still appropriate therapy . More emphasis should be placed on preventive measures related to care and hygiene among individuals with pets.

Scand J Infect Dis, 2003, 35(8), 512 - 4
Pasteurella haemolytica in human urine; Lejbkowicz F et al.; Pasteurella haemolytica was isolated from a human urine specimen . This unusual human pathogen showed a mucoid colony with a modest haemolysis and typical biochemical characteristics . API 20E and API 20NE identified the bacterium as Pasteurella spp . and P . haemolytica, respectively . To the authors' knowledge, this is the first reported case of P . haemolytica in human urine.

J Clin Microbiol, 2003 Sep, 41(9), 4095 - 100
Evaluation of a multiplex PCR test for simultaneous identification and serotyping of Actinobacillus pleuropneumoniae serotypes 2, 5, and 6; Jessing SG et al.; Serotype-specific DNA regions involved in the biosynthesis of capsular polysaccharides (cps region) were used to develop a multiplex PCR test for the simultaneous species identification and serotyping of Actinobacillus pleuropneumoniae serotypes 2, 5, and 6 . Primers specific for serotypes 2, 5, and 6 were combined with the already existing species-specific primers used in a PCR test based on the omlA gene . The PCR test was evaluated with serotype reference strains of A . pleuropneumoniae as well as 182 Danish field isolates previously serotyped by latex agglutination or immunodiffusion . For all serologically typeable strains, a complete correspondence was found between the results obtained by the multiplex PCR test and the results obtained by the traditional serotyping methods . Six of eight serologically nontypeable strains could be allocated to a serotype on the basis of the multiplex PCR results . The species specificity of the assay was evaluated with a collection of 93 strains representing 29 different species within the family Pasteurellaceae, as well as species normally found in the respiratory tracts of swine . All of these strains were negative by the multiplex PCR test, including 50 field isolates of the phylogenetically closely related species Actinobacillus lignieresii . When the multiplex PCR test was used to test Danish field strains, it was able to identify the serotypes of approximately 94% of all strains isolated from swine with clinical disease . More than 90% of the isolates that cross-reacted by the latex agglutination test were of serotype 2, 5, or 6 . Determination of the serotype by PCR represents a convenient and specific method for the serotyping of A . pleuropneumoniae in diagnostic laboratories.

Microb Pathog, 2003 Oct, 35(4), 147 - 57
Molecular and immunological characterization of Pasteurella multocida serotype A:3 OmpA: evidence of its role in P . multocida interaction with extracellular matrix molecules; Dabo SM et al.; Pasteurella multocida OmpA-like gene (PmOmpA) was cloned and characterized . The mature protein had a molecular mass of 35,075 Da and significant similarity with Escherichia coli (E . coli) OmpA proteins . Membrane topology analyses predict that like E . coli OmpA, the N-terminal half of PmOmpA exists as an eight-stranded transmembrane antiparallel beta-barrel that displays four variable hydrophilic and surface-exposed regions with predicted antigenic peaks that may be involved in serum resistance or adherence . In addition, the Ala-Pro repeat region between the N-terminal beta-barrel and C-terminal periplasmic domains is completely missing in PmOmpA . PmOmpA was expressed in E . coli and immunoblots analysis revealed that the recombinant PmOmpA was immunogenic, and expressed in vivo.The binding of PmOmpA to biotinylated Madin Darby bovine kidney (MDBK) cells surface proteins, fibronectin and heparin was demonstrated . Furthermore, PmOmpA binds MDBK monolayers and pre-treatment of P . multocida whole cells with anti-PmOmpA significantly reduced adherence to fibronectin . Ligand blot analysis revealed that fibronectin binds to the native and heat modified forms of PmOmpA when heated at 37 and 100 degrees C, respectively . Collectively these data indicate that PmOmpA may be involved in P . multocida 232 adherence to host cells via heparin and/or fibronectin bridging.

Antimicrob Agents Chemother, 2003 Sep, 47(9), 2978 - 80
New plasmid-borne antibiotic resistance gene cluster in Pasteurella multocida; Kehrenberg C et al.; A new antibiotic resistance gene cluster comprising genes for sulfonamide (sul2), streptomycin (strA-strB), and tetracycline {tetR-tet(H)} resistance was detected on plasmid pVM111 from Pasteurella multocida . The tetR-tet(H) gene region was inserted between sul2 and strA, possibly by illegitimate recombination . Two potential recombination sites of 18 and 25 bp were identified.

Infect Immun, 2003 Sep, 71(9), 5440 - 6
Signature-tagged mutagenesis of Pasteurella multocida identifies mutants displaying differential virulence characteristics in mice and chickens; Harper M et al.; Pasteurella multocida is the causative agent of fowl cholera in birds . Signature-tagged mutagenesis (STM) was used to identify potential virulence factors in a mouse septicemia disease model and a chicken fowl cholera model . A library of P . multocida mutants was constructed with a modified Tn916 and screened for attenuation in both animal models . Mutants identified by the STM screening were confirmed as attenuated by competitive growth assays in both chickens and mice . Of the 15 mutants identified in the chicken model, only 5 were also attenuated in mice, showing for the first time the presence of host-specific virulence factors and indicating the importance of screening for attenuation in the natural host.

Vaccine, 2003 Sep 8, 21(25-26), 3988 - 97
Pasteurella multocida- and Pasteurella haemolytica-ghosts: new vaccine candidates; Marchart J et al.; Pasteurella multocida is an important animal pathogen . Bacterial ghosts produced by the expression of phage PhiX174 lysis gene E are empty cells devoid of cytoplasmic and genomic material . Lysis of P . multocida 7A and P . haemolytica A1 carrying Pasteurella-specific lysis vectors (pSR2 and pSON2) occurred 140 min after induction of gene E expression induced by temperature upshift . The E-mediated cell lysis and killing activity was the same in both Pasteurella species and no viable cells could be detected after lysis of P . multocida and P . haemolytica.Pasteurella ghosts were used for immunization of rabbits and mice . Rabbits immunized subcutaneously with either P . multocida- or P . haemolytica-ghosts developed antibodies reacting with the immunizating strain, as well as with other Pasteurella strains . The number of proteins in whole cell protein extracts recognized by the sera constantly increased during the observation period of 51 days . In addition, dose-dependent protection against homologous challenge was observed in mice immunized with P . multocida-ghosts . Animals which received 1.15 x 10(8) ghosts and a challenge dose of up to 60 cfu (LD90), showed 100% protection . According to these results, we suggest ghosts of P . multocida and P . haemolytica as new vaccine candidates.

Microbiology, 2003 Aug, 149(Pt 8), 2283 - 90
Alteration of DNA adenine methylase (Dam) activity in Pasteurella multocida causes increased spontaneous mutation frequency and attenuation in mice; Chen L et al.; Pasteurella multocida is one of the primary bacterial pathogens associated with bovine respiratory disease (BRD) complex . Relatively few virulence factors of P . multocida have been characterized, and there is a need for improved vaccines for prevention of BRD . In other Gram-negative species, DNA adenine methylase (Dam) regulates the expression of virulence genes, and appropriate expression of Dam is required for virulence . In this study, the authors cloned and sequenced the P . multocida A1 dam gene and demonstrated that it is able to restore Dam function in an Escherichia coli dam mutant . When P . multocida dam was placed under the control of a constitutively expressed promoter on a plasmid, it caused an increased spontaneous mutation rate in P . multocida . In addition, the plasmid-mediated alteration of Dam production in P . multocida caused it to be highly attenuated in mice . These findings indicate that appropriate expression of Dam is required for virulence of P . multocida, which is believed to be the first report that Dam is required for virulence of a species in the Pasteurellaceae . Therefore, Dam may function as a virulence gene regulator in the Pasteurellaceae, similar to previously reported findings from other Gram-negative species.

Microbiology, 2003 Aug, 149(Pt 8), 2273 - 81
fur-independent regulation of the Pasteurella multocida hbpA gene encoding a haemin-binding protein; Garrido ME et al.; Treatment of bacterial cultures with chelating agents such as 2,2'-dipyridyl (DPD) induces expression of iron-regulated genes . It is known that in the gamma-Proteobacteria, the Fur protein is the major regulator of genes encoding haem- or haemoglobin-binding proteins . Electrophoretic analysis of outer-membrane proteins of the gamma-proteobacterium Pasteurella multocida has revealed the induction of two proteins of 60 and 40 kDa in DPD-treated cultures in both wild-type and fur-defective strains . These two proteins have the same N-terminal amino acid sequence, which identifies this protein as the product of the PM0592 ORF . Analysis of the sequence of this ORF, which encodes a protein of 60 kDa, revealed the presence of a hexanucleotide (AAAAAA) at which a programmed translational frameshift can occur giving rise to a 40 kDa protein . Analyses conducted in Escherichia coli, using the complete PM0592 ORF and a derivative truncated at the hexanucleotide position, have shown that both polypeptides bind haemin . For this reason, the PM0592 ORF product has been designated HbpA (for haemin-binding protein) . Expression studies using both RT-PCR and lacZ fusions, as well as electrophoretic profiles of outer-membrane protein composition, have demonstrated that the hbpA gene is negatively regulated by iron, manganese and haemin through a fur-independent pathway . Despite the fact that serum of mice infected with P . multocida contained antibodies that reacted with both the 60 and 40 kDa products of the hbpA gene, these proteins did not offer protection when used in immunization assays against this micro-organism.

FEMS Microbiol Lett, 2003 Aug 8, 225(1), 9 - 14
Regulation of capsule biosynthesis in serotype A strains of Pasteurella multocida; Watt JM et al.; The capsule of Pasteurella multocida serotype A strain ATCC 11039 is composed of hyaluronic acid and is an important virulence factor . Repeated subculturing of certain capsular serotype A strains results in dissociation from a capsulated to a noncapsulated phenotype with a concomitant loss of virulence . Although noncapsulated variants have been thought to arise as a result of mutation, the molecular mechanisms underlying this event are unknown . In this study, we demonstrate that restoration of the capsulated phenotype occurs in vivo subsequent to intraperitoneal inoculation of BALB/c mice with a noncapsulated variant . Moreover, reverse transcription polymerase chain reaction analysis revealed the capsule locus to be under transcriptional control . Cloning and sequencing of a 290-bp fragment within the promoter containing intergenic region of the capsule locus of 11039/iso revealed no significant alterations occurred subsequent to subculturing . These results demonstrate that serotype A P . multocida strain ATCC 11039 regulates capsule expression in response to an unidentified environmental factor(s), thereby providing insights into the molecular mechanisms underlying colonial dissociation.

J Biol Chem, 2003 Oct 17, 278(42), 41093 - 8 Epub 2003 Jul 25.
Crystal structure of Pasteurella haemolytica ferric ion-binding protein A reveals a novel class of bacterial iron-binding proteins; Shouldice SR et al.; Pasteurellosis caused by the Gram-negative pathogen Pasteurella haemolytica is a serious disease leading to death in cattle . To scavenge growth-limiting iron from the host, the pathogen utilizes the periplasmic ferric ion-binding protein A (PhFbpA) as a component of an ATP-binding cassette transport pathway . We report the 1.2-A structure of the iron-free (apo) form of PhFbpA, which is a member of the transferrin structural superfamily . The protein structure adopts a closed conformation, allowing us to reliably assign putative iron-coordinating residues . Based on our analysis, PhFbpA utilizes a unique constellation of binding site residues and anions to octahedrally coordinate an iron atom . A surprising finding in the structure is the presence of two formate anions on opposite sides of the iron-binding pocket . The formate ions tether the N- and C-terminal domains of the protein and stabilize the closed structure, also providing clues as to probable candidates for synergistic anions in the iron-loaded state . PhFbpA represents a new class of bacterial iron-binding proteins.

Antimicrob Agents Chemother, 2003 Aug, 47(8), 2703 - 5
In vitro activities of florfenicol against bovine and porcine respiratory tract pathogens; Priebe S et al.; Florfenicol in vitro activities for a total of 756 bacterial isolates from respiratory tract infections of cattle and swine were comparatively investigated by the agar diffusion method and the microdilution broth method . Florfenicol showed high in vitro activity against Pasteurella multocida, Mannheimia haemolytica, Actinobacillus pleuropneumoniae, and Streptococcus suis, with all of the isolates inhibited by </=2 micro g of florfenicol per ml.

Arch Pediatr, 2003 May, 10(5), 439 - 41
{Meningitis and osteitis caused by Pasteurella multocida in a three-month-old infant}; Perrin I et al.; Pasteurella multocida is usually responsible for local infections occurring after animal bites . It can also be responsible for meningitis in infants . A three-month old infant was admitted to hospital with a diagnosis of bacterial meningitis and hip osteitis . Cultures of cerebrospinal fluid, blood and joint liquid were positive to Pasteurella multocida . Licking from the family dog was the transmission mode in this case . Despite initial neurological complications, clinical evolution was favourable after three weeks of intravenous antibiotic therapy followed by an oral administration for three months . Pasteurella multocida meningitis is rare in infants . It can be associated with arthritis, osteitis and septicaemia . Besides animal bites, licking is also a mode of contamination.

J Vet Med Sci, 2003 Jun, 65(6), 737 - 40
Protective effect of Pasteurella multocida cell-free antigen and toxoid against challenge with toxigenic strains of pasteurella multocida in mice; Uchida C et al.; The cell-free antigen (CFA) obtained from the culture supernatant of Pasteurella multocida (P . multocida) and the toxin (PMT) purified from CFA were inactivated and mixed with oil adjuvant to prepare a trial vaccine . Both of the mice immunized with CFA and PMT toxoid vaccine were noticeably protected against intratracheal challenge with toxigenic strains of P . multocida . Nevertheless, the protective indices of the mice immunized with CFA vaccine indicate that it is more protective and clears away the bacteria more promptly than in the mice immunized with PMT vaccine . The results suggested that CFA would possibly be good as an effective antigen to toxigenic strains of P . multocida infection.

J Appl Microbiol, 2003, 95(2), 354 - 63
Phylogenetic analysis by 16S rDNA gene sequence comparison of avian taxa of Bisgaard and characterization and description of two new taxa of Pasteurellaceae; Christensen H et al.; AIMS: Characterization and classification of members of Pasteurellaceae isolated from birds by extended phenotypic characterization and 16S rDNA gene sequence comparison . METHODS AND RESULTS: A total of 95 avian isolates were subjected to extended phenotypic characterization . Thirteen bacterial strains selected from main phenotypic clusters and isolated from parrot, parakeet, budgerigar, partridge, pheasant, chicken, duck, hawk and gull were subsequently characterized by 16S rDNA gene sequencing . Eight of the sequenced strains were classified with six taxa of Bisgaard of which two (34 and 40) have not been published before, and the properties of four others (14, 22, 26 and 32) changed upon the characterization of these new isolates . Of the remaining strains, one was identified as a phenotypic variant in maltose and dextrin of Pasteurella gallinarum another as a trehalose positive variant of taxon 3 of Bisgaard . The remaining three strains sequenced were not closely related to existing taxa of Pasteurellaceae . However, they were found to belong to the Avian cluster with 92-97% 16S rDNA gene sequence similarity . CONCLUSION: The study allowed the classification of bacteria isolated from birds by the integrated use of extended phenotypic characterization and 16S rDNA gene sequence analysis . Only the application of 16S rDNA gene sequencing allows a correct identification of variant strains . SIGNIFICANCE AND IMPACT OF THE STUDY: The description of new taxa within the bacterial family Pasteurellaceae will subsequently allow additional isolates of these taxa to be identified and improve the diagnosis and epidemiological understanding of bacteria causing disease in birds.

J Biol Chem, 2003 Sep 12, 278(37), 35199 - 203 Epub 2003 Jul 02.
Rapid chemoenzymatic synthesis of monodisperse hyaluronan oligosaccharides with immobilized enzyme reactors; DeAngelis PL et al.; We describe the chemoenzymatic synthesis of a variety of monodisperse hyaluronan (beta 4-glucuronic acid-beta 3-N-acetylglucosamine (HA)) oligosaccharides . Potential medical applications for HA oligosaccharides (approximately 10-20 sugars in length) include killing cancerous tumors and enhancing wound vascularization . Previously, the lack of defined oligosaccharides has limited the exploration of these sugars as components of new therapeutics . The Pasteurella multocida HA synthase, pmHAS, a polymerizing enzyme that normally elongates HA chains rapidly (approximately 1-100 sugars/s), was converted by mutagenesis into two single-action glycosyltransferases (glucuronic acid transferase and N-acetylglucosamine transferase) . The two resulting enzymes were purified and immobilized individually onto solid supports . The two types of enzyme reactors were used in an alternating fashion to produce extremely pure sugar polymers of a single length (up to HA20) in a controlled, stepwise fashion without purification of the intermediates . These molecules are the longest, non-block, monodisperse synthetic oligosaccharides hitherto reported . This technology platform is also amenable to the synthesis of medicant-tagged or radioactive oligosaccharides for biomedical testing . Furthermore, these experiments with immobilized mutant enzymes prove both that pmHAS-catalyzed polymerization is non-processive and that a monomer of enzyme is the functional catalytic unit.

Vet Microbiol, 2003 Jul 30, 94(4), 313 - 23
Expression of a truncated Pasteurella multocida toxin antigen in Bordetella bronchiseptica; Rajeev S et al.; Mild or subclinical respiratory infections caused by Bordetella bronchiseptica are widespread in pigs despite multiple control efforts . Infection with virulent B . bronchiseptica strains is a common risk factor in the establishment of toxin-producing strains of Pasteurella multocida in the nasal cavity of pigs leading to the disease, atrophic rhinitis (AR) . This study was designed to explore the possibility of expressing a protective epitope of P . multocida toxin (PMT) in B . bronchiseptica to create single-component mucosal vaccine to control atrophic rhinitis in pigs . To achieve this, a P . multocida toxin fragment (PMTCE), that was non-toxic and protective against lethal challenge in mice, was cloned into a broad-host-range plasmid, PBBR1MCS2, and introduced into B . bronchiseptica by electroporation . The Pasteurella gene construct was placed under the regulatory control of a promoter region that was separately isolated from B . bronchiseptica and appears to be part of the heat shock protein gene family . B . bronchiseptica harboring the plasmid under antibiotic selection expressed the 80kDa PMTCE as determined by PAGE and Western blot with a PMT-specific monoclonal antibody . When introduced into the respiratory tracts of mice, B . bronchiseptica harboring the plasmid construct was reisolated in declining numbers for 72h post-inoculation . Antibody responses (IgM, IgA and IgG) to B . bronchiseptica were detected in serum and respiratory lavage, but PMTCE-specific antibodies were not detected . While further refinements of PMT expression in B . bronchiseptica are necessary, this study provides a basis for the development of a single-component, live-attenuated vaccine against atrophic rhinitis.

Chemosphere, 2003 Aug, 52(7), 1125 - 33
Toxicity of fluoranthene and its biodegradation metabolites to aquatic organisms; Sepic E et al.; The toxicity of nine stable products of the biodegradation of fluoranthene with the pure bacterial strain Pasteurella sp . IFA was studied . For their quantification, an improved analytical procedure with two-step liquid-liquid extraction, derivatisation and gas chromatographic-mass spectrometric detection was used . Growth inhibition and immobility tests for fluoranthene and its metabolites were carried out using algae (Scenedesmus subspicatus), bacteria (Pseudomonas putida) and crustaceans (Daphnia magna and Thamnocephalus platyurus) . Tests using the alga S . subspicatus revealed that with the exception of 9-hydroxyfluorene, which was only four times less toxic than fluoranthene, all the other metabolites were 37 to approximately 3000 times less toxic than the parent material . P . putida cells were resistant to fluoranthene and its primary metabolites, but were inhibited by low molecular weight intermediates, especially benzoic acid . Fluoranthene was not toxic to T . Platyurus, but was toxic to D . magna . Its primary metabolites (including 9-fluorenone and 9-hydroxyfluorene) were toxic to D . magna, and a low molecular weight metabolite (2-carboxybenzaldehyde) was highly toxic to T . platyurus.

Exp Anim, 2003 Apr, 52(2), 145 - 51
Evaluation of a forced-air-ventilated micro-isolation system for protection of mice against Pasteurella pneumotropica; Hasegawa M et al.; Studies to date have established that the physical environment inside cages can be controlled adequately by setting the intra-cage ventilation at 60 air changes per hour in a forced-air-ventilated micro-isolation system (FVMIS) . In this study, the capability of FVMIS to prevent inter-cage transmission of microorganisms was evaluated using Pasteurella pneumotropica as a reference microorganism . One FVMIS rack and a conventional rack were used, and cages with mice positive for P . pneumotropica and those with P . pneumotropica-free mice were housed on both racks . The mice were examined for P . pneumotropica contamination every 4 weeks after initiating the experiment for 12 weeks using a polymerase chain reaction method . Some P . pneumotropica-free mice housed in open air cages in the conventional rack became positive for P . pneumotropica (four of 28 animals after 4 weeks; eight of 28 animals after 12 weeks), but all P . pneumotropica-free mice housed in the FVMIS cages remained negative for the bacterium throughout the experiment . The results demonstrate that FVMIS can prevent inter-cage transmission of P . pneumotropica when proper cage handling practice is under taken.

J Biol Chem, 2003 Aug 29, 278(35), 32719 - 25 Epub 2003 Jun 10.
Pasteurella multocida toxin facilitates inositol phosphate formation by bombesin through tyrosine phosphorylation of G alpha q; Baldwin MR et al.; The intracellularly acting Pasteurella multocida toxin (PMT) is a potent mitogen that stimulates Gq-dependent formation of inositol trisphosphate . We show that PMT, a nontoxic mutant of PMT (PMTC1165S), and bombesin each stimulate time-dependent phosphorylation of G alpha q at tyrosine 349 . Although PMT and PMTC1165S each cause phosphorylation of G alpha q, only the wild-type toxin activates Gq . Pretreatment of cells with wild-type or mutant PMT potentiated the formation of inositol phosphates stimulated by bombesin equally . These data show that PMT potentiates bombesin receptor signaling through tyrosine phosphorylation of Gq and distinguishes between the two proposed models of Gq activation, showing that tyrosine phosphorylation is not linked to receptor uncoupling.

Glycobiology, 2003 Oct, 13(10), 661 - 71 Epub 2003 Jun 10.
Analysis of the two active sites of the hyaluronan synthase and the chondroitin synthase of Pasteurella multocida; Jing W et al.; Type A Pasteurella multocida produces a hyaluronan (HA) capsule to enhance infection . The 972-residue HA synthase, pmHAS, polymerizes the linear HA polysaccharide composed of alternating beta3N-acetylglucosamine (GlcNAc)-beta4glucuronic acid (GlcUA) . We demonstrated previously that pmHAS possesses two independent glycosyltransferase sites . Here we further define the sites and putative motifs . Deletion of residues 1-117 does not affect HA polymerizing activity . The carboxyl-terminal boundary of the GlcUA-transferase resides within residues 686-703 . Both transferase sites contain a DXD motif essential for HA synthase activity . D247N or D249N mutants possessed only GlcUA-transferase activity, whereas D527N or D529N mutants possessed only GlcNAc-transferase activity, further confirming our assignment of the two active sites within the synthase polypeptide . A potential role of the DXD motif in substrate binding was supported by experiments utilizing high UDP-sugar concentrations that partially rescued the activity of certain mutants . The WGGED sequence motif is involved in GlcNAc-transferase activity because mutants with substitutions at E369 or D370 possessed only GlcUA-transferase activity . Type F P . multocida synthesizes an unsulfated chondroitin (beta3GalNAc-beta4GlcUA) capsule . A chimeric enzyme consisting of residues 1-427 of pmHAS and residues 421-704 of pmCS, the homologous chondroitin synthase, was an active HA synthase . The converse chimeric enzyme consisting of residues 1-420 of pmCS and residues 428-703 of pmHAS was a functional chondroitin synthase . Analyses of a panel of pmHAS/pmCS chimeric enzymes identified a 44-residue region, corresponding to pmHAS residues 225-265, involved in UDP-hexosamine selectivity . Overall, these findings further support the model of two independent transferase sites within a single polypeptide.

Vaccine, 2003 Jun 20, 21(21-22), 2980 - 5
Response of calves persistently infected with noncytopathic bovine viral diarrhea virus (BVDV) subtype 1b after vaccination with heterologous BVDV strains in modified live virus vaccines and Mannheimia haemolytica bacterin-toxoid; Fulton RW et al.; Seronegative persistently infected (PI) calves with bovine viral diarrhea virus (BVDV) subtype 1b were vaccinated with each of four modified live virus (MLV) BVDV vaccines and a Mannheimia haemolytica bacterin-toxoid . Nasal swabs and peripheral blood leukocytes (PBL) were collected for virus isolation and serums were collected after vaccination and tested for BVDV1a, BVDV1b, BVDV2, bovine herpesvirus-1 (BHV-1), bovine parainfluenza-3 virus (PI-3V), and bovine respiratory syncytial virus (BRSV) antibodies . M . haemolytica and Pasteurella multocida antibodies were detected using ELISA procedures . None of the PI calves developed mucosal disease (MD) after MLV vaccination . None of the BVDV PI calves seroconverted to BVDV1b after MLV vaccination . Calves receiving MLV vaccines seroconverted to the respective type/subtype in the vaccine . Calves receiving a MLV vaccine with noncytopathic (NCP) BVDV1 (subtype not designated) did not seroconvert to BVDV1a, BVDV1b, or BVDV2 . The PI calves were positive for BVDV subtype 1b, in the PBL and nasal swabs throughout the study . Calves receiving each of three vaccines with known BVDV1a strains had BVDV1a positive samples after vaccination, in some but not all calves, up to Day 28 . The PI BVDV1b calves did not respond with increased M . haemolytica antibodies after vaccination compared to BVDV negative calves receiving the same M . haemolytica vaccine.

Eur J Emerg Med, 2003 Jun, 10(2), 130 - 2
Cat bite in an old patient: is it a simple injury?
Luchansky M, Bergman M, Djaldetti R, Salman H.
An 84-year-old woman bitten by her domestic cat developed a severe wound infection caused by Pasteurella multocida . Although she was treated with antibiotics according to the bacterial sensitivity, the infection progressed to sepsis and became complicated by transient renal failure caused by interstitial nephritis . The need in the emergency department for a thorough examination of patients with domestic animal-inflicted injuries, the indication for surgical debridement, and the isolation of the offender by early obtained cultures are considered . The administration of the properly chosen antibiotics and prophylactic vaccination against rabies and tetanus are discussed.

Microb Pathog, 2003 Jun, 34(6), 267 - 75
Prior exposure to Mannheimia haemolytica leukotoxin or LPS enhances beta(2)-integrin expression by bovine neutrophils and augments LKT cytotoxicity; Leite F et al.; Mannheimia (Pasteurella) haemolytica serotype1 produces a variety of virulence factors that play an important role during the pathogenesis of bovine pneumonic pasteurellosis . Among these, a leukotoxin (LKT) and lipopolysaccharide (LPS) are thought to be the primary virulence factors that contribute to the characteristic pathology of pasteurellosis . Recent evidence suggests that M . haemolytica LKT binding to bovine leukocytes is mediated by the beta(2)-integrin CD11a/CD18 (LFA-1), which subsequently induces activation and death of these cells . Exposure of bovine peripheral blood neutrophils (PMNs) to LKT or LPS induces expression of inflammatory cytokines, which in turn can increase LFA-1 expression and conformational activation . In this study we demonstrated, by flow cytometry and Western blot, that bovine PMNs increased their LFA-1 expression following in vitro exposure to M . haemolytica LKT and LPS . Increased LFA-1 expression by PMNs exposed to LKT and LPS was associated with increased LKT binding and cell death . The results of this study suggest that M . haemolytica LKT and LPS might cooperatively increase LFA-1 expression, and by so doing amplify the lung inflammation that characterizes bovine pasteurellosis.

Can J Neurol Sci, 2003 May, 30(2), 155 - 8
Acute disseminated encephalomyelitis associated with Pasteurella multocida meningitis; Proulx NL et al.; OBJECTIVE: To describe a case of Pasteurella multocida meningitis associated with acute disseminated encephalomyelitis (ADEM) . CASE REPORT: A 33-year-old woman employed in a dog pound presented herself to hospital with fever and meningismus and was found to have culture positive Pasteurella multocida meningitis . Despite appropriate antibiotic treatment her clinical course was characterized by a persistent fever and worsening encephalopathy, which prompted further neurological investigation . Spinal fluid exam and serial MRI scans as well as her one-year clinical course were found to be compatible with ADEM . CONCLUSION: Persistent fever and worsening encephalopathy in meningitis may indicate a para-infectious immune process such as ADEM, and may serve as indications for further neurological investigation.

J Vet Pharmacol Ther, 2003 Jun, 26(3), 173 - 9
The effects of danofloxacin and tilmicosin on neutrophil function and lung consolidation in beef heifer calves with induced Pasteurella (Mannheimia) haemolytica pneumonia; Fajt VR et al.; Pneumonia caused by Pasteurella (Mannheimia) haemolytica was induced in weaned beef heifer calves, approximately 6 months of age . Calves were treated at 20 h after challenge with therapeutic doses of danofloxacin or tilmicosin . Peripheral blood neutrophils were collected at 3, 24 and 48 h after treatment . The ex vivo effects on neutrophil function, neutrophil apoptosis, and hematological parameters were examined, as was the effect on percentage lung consolidation . Neutrophil function assays included random migration under agarose, cytochrome C reduction, iodination, Staphylococcus aureus ingestion, chemotaxis, and antibody-dependent and antibody-independent cell-mediated cytotoxicity . Apoptosis was determined using a cell death detection kit . Killing was performed at 72 h after treatment . Statistical comparisons were made among the three groups of challenged-treated animals: saline, danofloxacin, and tilmicosin . Comparisons were also made between nonchallenged nontreated animals (NCH) and challenged saline-treated animals . There were no significant differences for any of the neutrophil function assays or neutrophil apoptosis among the challenged-treated groups . This suggests that danofloxacin and tilmicosin have no clinically significant effects on neutrophil function or apoptosis . There were also no significant differences in percentage lung consolidation among the challenged-treated groups . Significant differences were found between the NCH calves and the challenged saline-treated calves in several neutrophil assays, which were attributed to effects of P . haemolytica infection.

Arch Bronconeumol, 2003 May, 39(5), 236 - 8
{Pasteurella multocida infection of cavitated lung squamous carcinoma}; Haya Fernandez C et al.; Pasteurella multocida has rarely been reported to cause lung disease in humans . Infection usually arises from bites or scratches from animal carriers of the pathogen . Cases of pneumonia, lung abscess, airway infection or infection of pre-existing bronchiectasis have been described, usually in individuals who are in direct contact with carrier animals and who have a chronic debilitating disease . It is unusual for P . multocida to be ingested and appear among oropharyngeal flora in humans.We report the first case published (Medline search 1966-2002) of a cavitated lung with squamous carcinoma that became infected by P . multocida in an elderly patient who denied contact with potential carrier animals . We believe that the P . multocida infection in humans is underdiagnosed because clinical suspicion is low and the bacterium is highly susceptible to common antibiotics.

Vet Microbiol, 2003 Jun 24, 94(1), 79 - 92
Iron acquisition by Actinobacillus suis: identification and characterization of transferrin receptor proteins and encoding genes; Bahrami F et al.; Actinobacillus suis is an important pathogen of swine, especially in high-health-status herds . A published report mentioning the binding of porcine transferrin (Tf) by at least one strain of A . suis suggested that A . suis, like other members of the Pasteurellaceae, can acquire Tf-bound iron by means of a siderophore-independent, receptor-mediated mechanism . The objective of the present study was to characterize the components involved in this process, if present . Growth assays, with seven strains, confirmed that A . suis can use porcine (but not human or bovine) Tf as an iron source for growth . In solid phase binding assays, total membranes derived from all strains exhibited strong binding of porcine Tf, but only if the membranes were from organisms grown under iron-restricted conditions . An affinity-isolation procedure allowed the isolation of putative Tf-binding polypeptides ( approximately 100 and approximately 63 kDa) from comparable membranes from all strains . PCR approaches allowed the amplification, cloning and sequencing of A . suis tonB, exbB, exbD, tbpB and tbpA homologues . Reverse transcription (RT)-PCR, using RNA from organisms grown under iron-replete and iron-restricted conditions, revealed that tonB, exbB, exbD, tbpB and tbpA are transcribed as a single unit with expression being up-regulated in response to iron restriction . The calculated molecular masses of the predicted, mature TbpA (104.3 kDa) and TbpB (63.4 kDa) proteins suggest strongly that the affinity-isolated, approximately 100 and approximately 63 kDa Tf-binding polypeptides represent TbpA and TbpB, respectively . It is concluded that the acquisition of Tf-bound iron by A . suis involves mechanisms analogous to those found in other members of the Pasteurellaceae.

Microb Pathog, 2003 May, 34(5), 217 - 26
Biological effects of two genetically defined leukotoxin mutants of Mannheimia haemolytica; Thumbikat P et al.; Mannheimia(Pasteurella)haemolytica serotype 1 is the primary causative agent responsible for bovine pneumonic mannheimiosis, also known as shipping fever in cattle . The bacterium produces a variety of virulence factors, foremost of which is the exotoxic leukotoxin . The leukotoxin is a calcium-dependent cytolysin that is a member of the RTX (repeats in toxin) family and exhibits a narrow cell-type and species specificity and has biological effects only on ruminant leukocytes and platelets . The genetic organization of the leukotoxin is comprised of four genes: lktC, lktA, lktB and lktD . The lktA structural gene encodes the protoxin (pro-LktA) and lktC encodes a transacylase that post-translationally modifies the inactive pro-LktA to a biologically active wild-type leukotoxin (LktA) . The LktA has been implicated as the key factor that contributes to the pathogenesis of lung injury associated with the disease and considerable efforts have been employed in abrogating toxin function while retaining immunogenicity, with an eye towards design of attenuated vaccines . We hypothesized that the pro-LktA retains the ability to cause biological effects on target cells as has been reported in the case of the closely related RTX toxin alpha-hemolysin (HlyA) . We also examined the biological effects of an amino-terminal truncation mutant leukotoxin DeltaLktA on target cells . Thus the objectives of our study were to investigate whether two different mutant leukotoxins, one a nonacylated pro-LktA, and the other lacking 344 amino acids at the N-terminal end of the LktA protein; DeltaLktA, are capable of (i) . binding to the beta2-integrin leukotoxin receptor, (ii) . inducing the elevation of second messenger intracellular calcium ({Ca(2+)}(i)), and (iii) . inducing inflammatory gene expression, reactive oxygen metabolites (ROMs) and cytolysis in target cells . Our results demonstrate that neither acylation nor the amino terminal 344 amino acids are required for LktA binding but are essential for LktA-induced {Ca(2+)}(i) elevation, generation of ROM, generation of the inflammatory cytokine IL-8 and cytolysis in target cells.

J Antimicrob Chemother, 2003 May, 51 Suppl 2, ii9 - 16
Linezolid in vitro: mechanism and antibacterial spectrum; Livermore DM; Oxazolidinones are prominent among the new Gram-positive antimicrobial agents now becoming available . They were discovered by DuPont Pharmaceuticals in the late 1980s but linezolid, the first analogue suitable for development, was found only when the family was re-examined by Pharmacia in the 1990s . Oxazolidinones bind to the 50S subunit of the prokaryotic ribosome, preventing formation of the initiation complex for protein synthesis . This is a novel mode of action; other protein synthesis inhibitors either block polypeptide extension or cause misreading of mRNA . Linezolid MICs vary slightly with the test method, laboratory, and significance attributed to thin hazes of bacterial survival, but all workers find that the susceptibility distributions are narrow and unimodal, with MIC values between 0.5 and 4 mg/L for streptococci, enterococci and staphylococci . Full activity is retained against Gram-positive cocci resistant to other antibiotics, including methicillin-resistant staphylococci and vancomycin-resistant enterococci . MICs are 4-8 mg/L for Moraxella, Pasteurella and Bacteroides spp . but other Gram-negative bacteria are resistant as a result of endogenous efflux activity . Resistance is difficult to select in vitro but has been reported during therapy in a few enterococcal infections and in two MRSA cases to date; the mechanism entails mutation of the 23S rRNA that forms the binding site for linezolid . Risk factors for selection of resistance include indwelling devices, undrained foci, protracted therapy and underdosage.

Biochemistry, 2003 May 6, 42(17), 4971 - 7
His1205 and His1223 are essential for the activity of the mitogenic Pasteurella multocida toxin; Orth JH et al.; Pasteurella multocida produces a 146-kDa protein toxin (PMT), which activates multiple cellular signal-transduction pathways, resulting in the activation of PLCbeta, Rho, JNK, and ERK . In addition to an essential cysteine residue at position 1165, PMT contains several histidine residues in the catalytically important C-terminal part of the protein . To elucidate the role of the histidine residues, we treated PMT with the histidine-modifying substance diethyl pyrocarbonate (DEPC) . DEPC inhibited PMT in a time- and concentration-dependent manner, suggesting that one or several histidine residues are essential for the biological activity of PMT . In experiments in which PMT was directly delivered into the cytosol of EBL cells by electroporation, we show that DEPC treatment inhibits the catalytically important histidine residues . Leucine substitutions of eight individual histidine residues in the C-terminal catalytic domain of PMT were constructed, and the effect on the biological activity of PMT was analyzed by determining PLCbeta, Rho, and ERK activation . Substitution of two histidine residues, H1205 and H1223, led to inactivation of the resulting PMT proteins, indicating that H1205 and H1223 play an important role in biological activity of the toxin . In addition, we show that the mutant toxins appear to be correctly folded, as judged by protease digestion . The precise function of H1205 and H1223 is not yet known . However, treatment of PMT with the cation chelating substance 1,10-phenantroline led to inactivation of the toxin, indicating that the essential histidine residues and cysteine 1165 might be involved in metal ion binding.

Avian Dis, 2003 Jan-Mar, 47(1), 218 - 22
Detection of pigeon circovirus by polymerase chain reaction; Roy P et al.; Pigeon circovirus was identified by polymerase chain reaction (PCR) in young pigeons belonging to 12 different lofts . Viral DNA was extracted from formalin-fed, paraffin-imbedded tissues containing primarily bursa and occasionally liver and spleen with a commercial kit . PCR primers were selected from a published sequence for columbid circovirus and evaluated in a PCR assay . The histopathologic examination of various tissues revealed basophilic globular intracytoplasmic inclusions in the mononuclear cells of the bursa of Fabricius and occasionally in the spleen characteristic for a circovirus . Transmission electron microscopy of a few bursas of Fabricius revealed virus particles measuring 18-21 nm . All the samples were negative by PCR for psittacine beak and feather disease (PBFD) virus and chicken infectious anemia virus . The primers for both pigeon circovirus and PBFD virus did not react in PCR with the chicken anemia virus DNA . Most of the circovirus-infected pigeons had concurrent infections of Escherichia coli, Salmonella, Pasteurella, Aspergillus, candidiasis, nematodiasis, or capillariasis.

Avian Dis, 2003 Jan-Mar, 47(1), 211 - 4
Cellulitis in Japanese quail (Coturnix coturnix japonica); Burns KE et al.; A case of cellulitis was observed in Japanese quail (Coturnix coturnix japonica) reared for commercial meat production . This condition in Japanese quail has not been reported in the literature . This incident was the first, and to date only, occurrence of cellulitis in this processing plant . The cellulitis lesions were localized to the subcutis overlying the breast and inner thigh . Carcasses of processed birds and live birds from the affected farm were presented to the Poultry Diagnostic and Research Center, University of Georgia . Escherichia coli was cultured from the lesion . The affected live birds displayed lameness and had osteomyelitis . Pasteurella multocida serotype 3,4 was cultured from the liver and bone marrow of affected birds . Approximately 4.61% of the processed carcasses from the flock were condemned because of cellulitis . This represented a 10fold increase from the typical condemnation rate . Further investigation revealed birds were placed in higher than normal density; therefore, we theorize that the concurrent pasteurellosis and increased placement density resulted in the cellulitis condition.

Avian Dis, 2003 Jan-Mar, 47(1), 54 - 8
Evaluation of the effect of heating an oil-emulsion Pasteurella multocida bacterin on tissue reaction and immunity; Burns KE et al.; Killed vaccines in oil emulsions are critical components of breeder and layer vaccination programs . Current vaccination sites are limited, and each has inherent problems . Oil emulsion vaccines are associated with increased condemnations of spent fowl when vaccines are injected intramuscularly into the breast . In an attempt to reduce tissue reaction when injected into the breast muscle, a commercially available Pasteurella multocida bacterin was heated to 41 C (100 F) for 5 hr prior to administration . A second treatment group was injected with the same bacterin at room temperature, 25 C . The vaccine was injected into the breast muscle at 10 and 18 wk of age into white Leghorn hens . Seroconversion was evaluated using P . multocida enzyme-linked immunosorbent assay (ELISA) at 10, 18, and 24 wk . Treatment and control groups were euthanized and lesions scored at 24 wk of age . One replicate was challenged with type 1 P . multocida at 24 wk of age . Lesion scores for the heated vaccine group were significantly lower than the room temperature vaccine . ELISA titers were not significantly different at 24 wk between the two treatment group; however, a significant rise in antibody titer was observed at 18 wk in the group that was injected with the heated vaccine . Survivability to challenge was improved in birds injected with the heated vaccine . Results suggest that heating of a P . multocida bacterin reduces local tissue reaction without having a deleterious effect on immunity as measured by ELISA and challenge.

Am J Obstet Gynecol, 2003 Apr, 188(4), 1115 - 6
Postoperative wound infection with Pasteurella multocida from a pet cat; Chun ML et al.; We summarize an unusual postoperative wound infection that was caused by Pasteurella multocida from a house cat licking the incision in an obese gynecologic oncology patient . A 48-year-old morbidly obese woman had a wound abscess 6 weeks after hysterectomy and panniculectomy for a International Federation of Gynecology and Obstetrics stage IA grade 1 endometrial cancer . P multocida was cultured from the abscess and the patient was treated with drainage and intravenous antibiotics . Further history revealed that her house cat had licked the wound . P multocida wound infection is a potential complication for people with dog or cat contact postoperatively . Penicillin G is the antibiotic of choice for treatment.

Antimicrob Agents Chemother, 2003 May, 47(5), 1742 - 5
In vitro susceptibilities of Rhodococcus equi and other common equine pathogens to azithromycin, clarithromycin, and 20 other antimicrobials; Jacks SS et al.; The objective of this study was to determine in vitro activities of azithromycin (AZM), clarithromycin (CLR), and 20 other antimicrobial agents against Rhodococcus equi and other common equine bacterial pathogens . A total of 201 bacterial isolates from various equine clinical samples were examined . CLR was more active than AZM against R . equi, with MICs at which 90% of the isolates were inhibited of 0.12 and 1.0 micro g/ml, respectively . Other antimicrobial agents highly active against at least 90% of R . equi isolates in vitro included rifampin, gentamicin, and imipenem . Both AZM and CLR showed good activity against beta-hemolytic streptococci and Staphylococcus spp . AZM was more active than other macrolides against Pasteurella spp . and Salmonella enterica.

Vaccine, 2003 May 16, 21(17-18), 1901 - 6
Efficacy of recombinant sialoglycoprotease in protection of cattle against pneumonic challenge with Mannheimia (Pasteurella) haemolytica A1; Shewen PE et al.; Secreted recombinant sialoglycoprotease fusion protein (Gcp-F) of Mannheimia (Pasteurella) haemolytica A1 was examined for its ability to protect cattle from experimental challenge with M . haemolytica A1 . Five M . haemolytica vaccines were compared including Gcp-F, logarithmic phase culture supernate (Presponse) and Presponse enriched with Gcp-F, recombinant leukotoxin (rLkt) or both . All calves receiving Gcp-F had significant serum antibody responses to this antigen, measured by ELISA, prior to challenge . Those vaccinated with Gcp-F alone had significantly lower percent pneumonic tissue than unvaccinated controls and a trend (P=0.085, one-tailed test) to lower clinical scores . Calves receiving Presponse with Gcp-F and rLkt had lower percent pneumonic tissue than those receiving Presponse alone, and calves receiving Presponse enriched with Gcp-F and/or rLkt had lower mean clinical scores, but the differences were not significant . This trial demonstrates the protective capacity of sialoglycoprotease . While, remarkably, recombinant Gcp-F provided some protection alone the results support its practical potential as a component of a multiple antigen vaccine.

J Heart Valve Dis, 2003 Mar, 12(2), 261 - 3
Pasteurella multocida aortic valve endocarditis: case report and literature review; Fayad G et al.; Pasteurella multocida is a rare cause of infective endocarditis that occurs mostly in immunocompromised patients and is therefore associated with a high mortality rate . The case is reported of a 48-year-old male patient with liver cirrhosis, who developed aortic valve endocarditis caused by P . multocida . The infection was detected by blood cultures . The patient presented with generalized symptoms and initial neurologic symptoms suggestive of meningitis . Transthoracic echocardiography conducted after the discovery of a diastolic murmur revealed a large vegetation on the aortic valve, and notable insufficiency . These findings were confirmed at surgery, where-upon the patient underwent aortic valve replacement using a bioprosthetic valve . Subsequently he developed a recurrent episode of endocarditis that was successfully treated with antibiotic therapy . Other similar cases reported in the literature are reviewed.

FEMS Microbiol Lett, 2003 Apr 11, 221(1), 31 - 7
The high-affinity zinc-uptake system znuACB is under control of the iron-uptake regulator (fur) gene in the animal pathogen Pasteurella multocida; Garrido ME et al.; The Pasteurella multocida znuACB genes encoding a high-affinity zinc-uptake system have been identified and cloned . In contrast to what happens in Escherichia coli, znuA is not physically linked to znuCB . Through lacZ transcriptional fusions it has been demonstrated that zinc negatively regulates both znuA and znuCB operons . Nevertheless, and contrary to that determined so far for all other znuACB bacterial systems known, P . multocida znuACB genes are not under control of the zur gene, which is absent in this bacterial species, but rather are under its iron-uptake regulator (fur) gene . Furthermore, construction of defective mutants has demonstrated that P . multocida znuA and znuCB transcriptional units are required for virulence of this organism in a mouse model.

Scand J Infect Dis, 2003, 35(2), 132 - 3
Spontaneous empyema and overwhelming septic shock due to Pasteurella multocida; Laupland KB et al.; Invasive Pasteurella multocida infection, although uncommon, has been recognized to occur more frequently among patients with hepatic cirrhosis . This study reports a fatal case of bacteremic P . multocida empyema without pneumonia associated with refractory septic shock in a patient with both cirrhosis and asplenia.

J Endotoxin Res, 2003, 9(1), 25 - 32
Association of LPS chemotype of Mannheimia (Pasteurella) haemolytica A1 with disease virulence in a model of ovine pneumonic pasteurellosis; Hodgson JC et al.; Host responses during pneumonic pasteurellosis were compared in sheep infected with strains of Mannheimia (Pasteurella) haemolytica A1 differing in their O-antigen type . Nine-week-old, specific pathogen-free lambs were infected intratracheally with parainfluenza type 3 virus (10(8) TCID(50)) followed 7 days later by 5-6 x 10(7) CFU of M . haemolytica A1 possessing rough (group R, 6 lambs) or smooth (group S, 6 lambs) lipopolysaccharide, or saline (group C, 4 lambs) . Group C lambs remained afebrile with no evidence of endotoxaemia or bacteraemia and biochemical parameters were normal . Group R and group S lambs became febrile within 2-3 h postinfection and the response was higher and more prolonged in group R lambs . Four group R and 2 group S lambs developed clinical pneumonic pasteurellosis within 24-48 h and the severity of disease correlated with episodes of endotoxaemia, bacteraemia and elevated eicosanoid concentrations . At post-mortem, M . haemolytica (10(7)-10(9) CFU/g) was isolated from the lungs of all 6 group R lambs but from only 1 group S lamb . The results indicate an association between the incidence and severity of ovine pneumonic pasteurellosis and LPS chemotype and suggest an important role for LPS chemotype in determining host-species susceptibility to lung infection.

J Clin Microbiol, 2003 Apr, 41(4), 1743 - 6
Use of single-enzyme amplified fragment length polymorphism for typing Pasteurella multocida subsp . multocida isolates from pigs; Moreno AM et al.; Single-enzyme amplified fragment length polymorphism (SE-AFLP) analyses were used to differentiate 97 isolates of porcine Pasteurella multocida subsp . multocida . The strains, isolated from animals with pneumonia, rhinitis, and septicemia, were classified as capsular types A, D, and F . SE-AFLP showed a discriminatory index of 0.87 and identified 18 different profiles.

FEBS Lett, 2003 Apr 10, 540(1-3), 106 - 10
Stimulation of the alpha1A adrenergic receptor inhibits PDGF-induced PDGF beta receptor Tyr751 phosphorylation and PI 3-kinase activation; Lin HY et al.; Several reports indicate that some G(alphaq)-coupled receptors antagonize the activation of phosphatidylinositol (PI) 3-kinase by receptor tyrosine kinases . We used Rat-1 fibroblasts expressing the alpha(1A) adrenergic receptor to study how this G(alphaq)-coupled receptor inhibits platelet-derived growth factor (PDGF) activation of PI 3-kinase . Phenylephrine (PE) stimulation of the alpha(1A) adrenergic receptor inhibited PDGF-induced binding of PI 3-kinase to the PDGF receptor (PDGFR) and phosphorylation of the PDGFR at Tyr751, which forms a docking site for PI 3-kinase . By contrast, activation of phospholipase C gamma by PDGF and phosphorylation of the PDGFR at Tyr716 and Tyr771 were not inhibited by PE . The protein tyrosine phosphatase SHP-2, which dephosphorylates Tyr751 on the PDGFR, was more active in cells treated with PDGF plus PE than in cells treated with either agent alone . PDGF-induced PI 3-kinase signaling was also inhibited by treatment of cells with Pasteurella multocida toxin to activate G(alphaq) . These results suggest that the alpha(1A) adrenergic receptor, and perhaps other G(alphaq)-coupled receptors, uses tyrosine dephosphorylation to block PI 3-kinase activation by PDGF .

J Wildl Dis, 2003 Jan, 39(1), 125 - 35
Comparison of methods to detect Pasteurella multocida in carrier waterfowl; Samuel MD et al.; We conducted laboratory challenge trials using mallard ducks (Anas platyrhynchos) to compare methods for detecting carriers of Pasteurella multocida, the bacterium that causes avian cholera, in wild birds . Birds that survived the initial infection were euthanized at 2-4 wk intervals up to 14 wk post challenge . Isolates of P . multocida were obtained at necropsy from 23% of the birds that survived initial infection . We found that swab samples (oral, cloacal, nasal, eye, and leg joint) were most effective for detecting carrier birds up to 14 wk post infection . No detectable differences in isolation were observed for samples stored in either 10% dimethysulfoxide or brain heart infusion broth . The frequency of detecting carriers in our challenge trials appeared to be related to mortality rates observed during the trial, but was not related to a number of other factors including time after challenge, time delays in collecting tissues postmortem, and route of infection . In our trials, there was little association between antibody levels and carrier status . We concluded that swabs samples collected from recently dead birds, stored in liquid nitrogen, and processed using selective broth provide a feasible field method for detecting P . multocida carriers in wild waterfowl.

Vet Clin Pathol, 1997, 26(4), 198 - 202
Expression of tissue factor in experimental bovine pneumonic pasteurellosis and endotoxemia; Rashid J et al.; Tissue factor (TF), a cell surface-associated cofactor and activator of coagulation factor VII, has been implicated in the local and systemic activation of coagulation associated with sepsis . This study describes the pattern of TF expression in experimental bovine pneumonic pasteurellosis and endotoxemia . Immunohistochemical techniques were used to localize TF antigen in tissue sections . Tissue factor expression was not observed in tissues from control animals . In response to Pasteurella haemolytica challenge, TF was expressed within alveolar walls, by mononuclear inflammatory cells within alveoli, and in walls of arteries, arterioles, bronchi, and bronchioles . Tissue factor was not detected in unaffected lung, liver, spleen, lymph node or kidney tissue . Administration of Escherichia coli endotoxin intravenously resulted in tissue factor expression in lung, spleen, and lymph node tissue . Results of this study indicate that TF is expressed locally at sites of inflammation and systemically in endotoxemia . Therefore, TF may be involved in coagulation events associated with pneumonic pasteurellosis.

Bioorg Med Chem Lett, 2003 Apr 7, 13(7), 1373 - 5
Azalide 3,6-ketals: antibacterial activity and structure-activity relationships of aryl and hetero aryl substituted analogues; Sakya SM et al.; Aryl and hetero aryl substituted 3,6-ketals of 15-membered azalide analogues were synthesized and were found to have potent in vitro antibacterial activity against veterinary pathogens, including Staphylococcus aureus and Pasteurella multocida.

Int J Syst Evol Microbiol, 2003 Jan, 53(Pt 1), 275 - 87
Genetic relationships among avian isolates classified as Pasteurella haemolytica, 'Actinobacillus salpingitidis' or Pasteurella anatis with proposal of Gallibacterium anatis gen . nov., comb . nov . and description of additional genomospecies within Gallibacterium gen . nov; Christensen H et al.; Bacteria of the avian {Pasteurella haemolytica}-'Actinobacillus salpingitidis' complex have been associated with different pathological conditions in birds, among which salpingitis and peritonitis in chickens of layer type seem to dominate . The aim of this study was to classify these bacteria by comparison of 37 strains tentatively classified as biovars of the avian {P . haemolytica}-'A . salpingitidis' complex or as Pasteurella anatis . PFGE, AFLP and plasmid profiling showed that strains representing different biovars were genotypically different . Phylogenetic analysis of 22 strains characterized by 16S rRNA gene sequence comparison showed that strains classified as biovars 5, 8 and 9 were closely related to the suggested type strain of 'A . salpingitidis' (98.4-99.9% similarity), whereas the remaining strains classified in 12 biovars or as P . anatis were closely related to the type strain of P . anatis (98.1-100% similarity) . The two groups were related at 95.7-97.1% similarity . The closest similarity outside this group was 94.6%, between biovar 15 and Bisgaard taxon 3 . DNA-DNA hybridization was performed with 34 strains and showed binding above 85% for strains of biovars 5 and 8, including the suggested type strain of 'A . salpingitidis' . Two strains of P . anatis (F 149T and F 279) were closely related at 79% DNA binding to 27 strains of biovars 1,3, 4, 11, 12, 17-20, 22 and 24 . A new genus, Gallibacterium gen . nov., is proposed to include the avian {P . haemolytica}-'A . salpingitidis'-P . anatis complex, since these taxa form a monophyletic unit with similarities above 95% on the basis of 16S rRNA sequence comparison and they are unrelated to other genera of the family Pasteurellaceae Pohl 1981 . The new genus consists of Gram-negative, non-motile, rod-shaped or pleomorphic bacteria . The bacteria are catalase-, oxidase- and phosphatase-positive . Nitrate is reduced and acid is produced without gas formation from glycerol, (-)D-ribose, (+)D-xylose, (-)D-mannitol, (-)D-fructose, (+)D-galactose, (+)D-glucose, (+)D-mannose, sucrose and raffinose . The genus Gallibacterium can be separated from other genera of Pasteurellaceae by differences in catalass, symbiotic growth, haemolysis, urease, indole, acid production from (+)D-xylose, (-)D-mannitol, (-)D-sorbitol, (+)D-mannose, maltose, raffinose and dextrin and ONPG and PNPG tests . Pasteurella anatis Mutters et al . 1985 is transferred to the new genus as Gallibacterium anatis gen . nov., comb . nov . Genomospecies 1 of Gallibacterium is proposed to include the former biovars 5 and 8 of the avian {P . haemolytica}-'A . salpingitidis' complex . The type strain of Gallibacterium anatis is F 149T (=ATCC 43329T = NCTC 11413T) and the reference strain of Gallibacterium genomospecies 1 is CCM 5974.

Ann Pharmacother, 2003 Mar, 37(3), 392 - 4
Aztreonam treatment of Pasteurella multocida cellulitis and bacteremia; Winner JS et al.; OBJECTIVE: To report a case of Pasteurella multocida cellulitis and bacteremia treated successfully with aztreonam . CASE SUMMARY: An 81-year-old white man with multiple antibiotic allergies was admitted with severe cellulitis of the left arm and bacteremia due to P . multocida . The patient was treated for 14 days with aztreonam and had complete resolution of the infection . DISCUSSION: To our knowledge, this is the first published case describing successful treatment of P . multocida cellulitis and bacteremia with aztreonam . Antimicrobials recommended for use in P . multocida infections include penicillin, ampicillin, amoxicillin, second- and third-generation cephalosporins, tetracyclines, fluoroquinolones, and trimethoprim/sulfamethoxazole . There is very little information in the current literature regarding the activity of aztreonam toward P . multocida . CONCLUSIONS: This case demonstrates the potential use of aztreonam for P . multocida cellulitis and bacteremia in those instances where antibiotics of choice cannot be given.

Exp Anim, 2003 Jan, 52(1), 67 - 70
Experimental evaluation of cross-contamination between cryotubes containing mouse 2-cell embryos and murine pathogens in liquid nitrogen tanks; Kyuwa S et al.; It has been suspected that embryos stored in liquid nitrogen tanks may become contaminated with murine pathogens, if some pathogens had been introduced to the tanks accidentally . To examine this, we stored tubes containing embryos with tubes containing mouse hepatitis virus (MHV) or Pasteurella pneumotropica in liquid nitrogen tanks and examined whether progeny mice derived from the embryos were contaminated with the pathogens or not . After storing for 6 months or 1 year the frozen embryos were thawed and implanted into the oviducts of pseudopregnant female mice, and the mice were bred in vinyl isolators . We could not detect serum antibodies to MHV and isolate Pasteurella pneumotropica in the progeny mice, suggesting that cross-contamination between tubes in a liquid nitrogen tank scarcely occurs.

Vet Microbiol, 2003 May 19, 93(2), 145 - 52
Novel protease produced by a Pasteurella trehalosi serotype 10 isolate from a pneumonic bighorn sheep: characteristics and potential relevance to protection; McNeil HJ et al.; A strain of Pasteurella trehalosi serotype 10, E(CO)-100, isolated from a bighorn sheep that had succumbed to pneumonic pasteurellosis during an epizootic, was compared to well-characterized strains of P . trehalosi serotype 10 and Mannheimia haemolytica serotype 1 . The gene for leukotoxin A (lktA) from E(CO)-100 was sequenced and found to be identical on an amino acid basis to a published sequence for lktA from P . trehalosi serotype 10 . However, the toxic activity in culture supernatant measured over time for E(CO)-100 was quite different from reference strains . Typically, the ability of the supernatant to lyse target cells increases over time corresponding to the logarithmic growth of the organism, peaks at mid to late phase, then declines gradually . Supernatant from E(CO)-100 exhibited a sharp decline in toxicity after mid-logarithmic growth to undetectable levels . Investigation of this anomaly using a commercial kit with a porcine gelatin/bovine albumin substrate matrix revealed high protease activity in the supernatant of this strain compared to another P . trehalosi serotype 10 and to a M . haemolytica serotype 1 . Protease activity was also visualized using gelatin based zymogram gels . This protease was not substrate specific as it was shown to degrade leukotoxin . Activity was neutralized by bighorn sera in a titratable manner . There was an association between the ability to neutralize protease and low pneumonic lung scores in bighorn sheep experimentally challenged with E(CO)-100 (r=0.5, P=0.1) . This previously unidentified protease may be an important protective antigen in vaccines designed to prevent pneumonic pasteurellosis resulting from P . trehalosi in bighorn sheep.

Vet Res Commun, 2003 Jan, 27(1), 3 - 14
Diversity of Mannheimia haemolytica and pasteurella trehalosi serotypes from apparently healthy sheep and abattoir specimens in the highlands of Wollo, North East Ethiopia; Sisay T et al.; The prevalence and serotypic diversity of Mannheimia {Pasteurella} haemolytica and Pasteurella trehalosi from nasal swabs, sera and abattoir specimens from sheep in the highlands of Wollo, North East Ethiopia was investigated . Prevalence rates of 83% and 75% of these microorganisms were found in the serum samples and nasal swabs, respectively, from apparently healthy sheep . In a local abattoir, 205 lungs were investigated, 34% of which showed pneumonia, from which samples were collected from 51 lungs and the same number of corresponding tonsils . Mannheimia and Pasteurella species were isolated from 59% of these pneumonic lungs and 69% of the respective tonsils . M . haemolytica serotypes accounted for 41 (59%) and P . trehalosi for 11 (32%) of the isolates from the abattoir specimens . The majority (67%) of isolates from nasal swabs were P . trehalosi, M . haemolytica being isolated f rom 4 (13%) of the swabs . M . glucosida was isolated only from the tonsils . The predominant serotypes of the isolates from both the nasal swabs and the abattoir specimens were M . haemolytica A1 (17%) and P . trehalosi T4 (16%) and T3 (13%) . P . trehalosi T15 was less commonly encountered, while M . haemolytica A9 and A13 were not isolated . Studies on sera from 100 sheep indicated that antibodies against M . haemolytica serotype A1 (14%) were most common, followed by A5 and A8 (each 10%) and A9 and P . trehalosi T3 (each 9%) and T4 (8%) . Antibodies against M . glucosida or serotype All occurred in 2% of the sera . Multiple serotypes were common in all types of samples . The importance of including in vaccines the most prevalent serotypes involved in the pneumonia of sheep in the area is discussed.

J Antimicrob Chemother, 2003 Mar, 51(3), 665 - 9
Experimental pneumococcal pleural empyema model: the effect of moxifloxacin; Strahilevitz J et al.; OBJECTIVES: Pleural empyema is a serious complication of pneumonia, the optimal therapy of which is still unknown . The objective of this study was to evaluate the use of moxifloxacin in this condition . METHODS: Pleural empyema was induced in rabbits by intrapleural administration of Pasteurella multocida (10(5-6) cfu) or turpentine (0.3 mL) followed 3 h later by instillation of Streptococcus pneumoniae (ATCC 49619) (10(6) cfu) into the pleural cavity . The MICs of moxifloxacin for S . pneumoniae and P . multocida were 0.4 and 0.05 mg/L, respectively . Starting 30 h following S . pneumoniae challenge intramuscular moxifloxacin 12.5 and 25 mg/kg was administered x 4 (every 12 h) . Pleural empyema fluid samples were obtained for bacterial count at 12 h intervals following the first three moxifloxacin administrations . Moxifloxacin levels in pleural empyema and serum samples were obtained at 0, 30, 60, 120, 240, 360 and 480 min and 12 h after the 4th dose and determined by bioassay . RESULTS: In control animals, S . pneumoniae (and P . multocida) persisted in the pleural empyema . S . pneumoniae also persisted in the pleural empyema fluid when moxifloxacin was administered at 12.5 mg/kg (x4 administrations) . Mean serum and pleural empyema peak moxifloxacin levels (following the 25 mg/kg dose) were 7.6 (+/-3.2) and 4.8 (+/-2.5) mg/L, respectively . Pleural empyema peak moxifloxacin concentration lagged 1 h after serum moxifloxacin . Serum and pleural empyema half-lives were approximately 1.5 and approximately 6 h, respectively . Serum AUC(1-12) was 29.4 (+/-6.8) mg.h/L and serum area under the inhibitory concentration curve (AUIC) was 73.5 mg.h/L . Pleural empyema AUC(1-12) was 34.3 (+/-11.7) mg/L and pleural empyema AUIC was 85.8 mg.h/L . S . pneumoniae was eradicated from pleural empyema following a single dose of moxifloxacin 25 mg/kg in 52% of the animals and in 96% following four doses . Moxifloxacin was also effective in eradication of P . multocida . The rate of pleural empyema sterilization was related to moxifloxacin serum AUIC (r = 0.82) as well as serum peak moxifloxacin level (r = 0.84), but not to pleural empyema AUIC (r = 0.19) or pleural empyema peak levels . The results were similar for both methods of induction of pleural empyema . CONCLUSIONS: Moxifloxacin appears to penetrate well into experimental pleural empyema and effectively sterilize it from S . pneumoniae . Sterilization of S . pneumoniae is related to serum AUIC rather than to moxifloxacin pharmacokinetics in pleural empyema.

Vaccine, 2003 Mar 28, 21(13-14), 1415 - 22
Protective immunity against pasteurellosis in cattle, induced by Pasteurella haemolytica ghosts; Marchart J et al.; Pasteurella haemolytica is a cattle pathogen of significant economic impact . An effective vaccine against bovine pneumonic pasteurellosis is therefore of high importance . Apart from economic concerns, pasteurellosis caused by P . haemolytica is a serious disease leading to death in cattle if it remains untreated . In this study P . haemolytica-ghosts are presented as a promising vaccine candidate in cattle . To obtain sufficient vaccination material a fermentation protocol for P . haemolytica-ghost production was established . With the obtained experimental P . haemolytica-ghost vaccine, cattle immunization studies were performed based on a Pasteurella cattle challenge model developed specifically for vaccine validation . It was shown that protective immunization of cattle against homologous challenge was induced by adjuvanted P . haemolytica-ghosts . The level of protection was similar to a commercially available vaccine.

Ann Biol Clin (Paris), 2003 Jan-Feb, 61(1), 15 - 21
{Human pasteurellosis: diagnosis, treatment and precautions}; Gautier-Lerestif AL et al.; The circumstances of diagnosis of human pasteurellosis are reviewed . The diagnosis is usually suspected for animal bite or scratch wounds . Conversely, in other infections the diagnosis is only based on bacteriological data . Phenotypic misidentification of Pasteurellaceae from clinical material is common . The phenotypic criteria of identification of the six species of human pathogen Pasteurella are presented . We emphasise that bite wound specimens have to be cultured for aerobic and anaerobic bacteria and yield an average of 5 bacterial isolates per culture . Antibiotic therapy relies upon amino-penicillins or cephalosporins, although b-lactamase producing strains are scarce . Fluoroquinolones can be an alternative for systemic infections . Molecular typing unequivocally points out the risk of transmission from pets to humans . Immunocompromised persons have to be made aware of precautions.

J Clin Ultrasound, 2003 Mar-Apr, 31(3), 159 - 62
Pasteurella multocida tenosynovitis of the hand: sonographic findings; Garcia Triana M et al.; Pasteurella multocida is a common cause of infection in humans subsequent to bites or scratches by dogs and, particularly, cats . This infection usually results in superficial skin and soft tissue infections . Sonography can be used for diagnosing inflammatory conditions affecting tendons, including acute and chronic tenosynovitis . P . multocida tenosynovitis is rare, and the diagnosis can be missed if adequate tests are not performed . We report 2 cases of P . multocida tenosynovitis of the hand and wrist in which sonography played a valuable role in assessing the affected tissues and guiding fine-needle aspiration of fluid accumulations in the involved tendon sheaths . The diagnosis was confirmed microbiologically in each case .

Avian Pathol, 2002 Dec, 31(6), 603 - 10
Genotypic heterogeneity of Pasteurella gallinarum as shown by ribotyping and 16S rRNA sequencing; Christensen H et al.; Forty-five strains mainly isolated from chickens in Zimbabwe and Denmark, two pig and three rat isolates all identified as Pasteurella gallinarum by conventional phenotypic tests were characterized by ribotyping, and selected strains were subsequently analysed by 16S rRNA gene sequencing . High genotypic diversity was observed, the number of ribotypes totalling 24 . A major group of 47 isolates including the type strain of P . gallinarum clustered at 56% similarity and included 21 ribotypes . Ribotyping showed that some genotypes of P . gallinarum seem to be globally distributed . The three isolates from rodents did not share even a single common ribotype fragment with strains from birds and the pig isolates . Two avian isolates from Denmark and Zimbabwe and the pig strain showed from 97.6 to 99.8% 16S rRNA sequence similarity with the type strain of P . gallinarum and with type strains of Pasteurella volantium and Pasteurella avium . Two rat strains showed 98.6% 16S rRNA gene sequence similarity with each other, but were only related with P . gallinarum at 93% similarity . These isolates showed the highest similarity with {Actinobacillus} muris at 96.4 to 95.0% similarity . We suggest that conventional identification of P . gallinarum consequently should consider the source of isolation to obtain a correct diagnosis, and that isolation from animals other than fowl should be confirmed by genotypic analysis such as 16S rRNA gene sequence comparison.

Plasmid, 2003 Jan, 49(1), 18 - 29
Construction and evaluation of a plasmid vector for the expression of recombinant lipoproteins in Escherichia coli; Cullen PA et al.; Outer membrane lipoproteins are emerging as key targets for protective immunity to many bacterial pathogens . Heterologous expression of lipoproteins in Escherichia coli does not always result in high level expression of acylated recombinant protein . Thus, these proteins do not take up their correct membrane topology and are lacking the immunostimulatory properties endowed by the lipid . To this end, we have designed a lipoprotein expression vector (pDUMP) that results in the production of fusion proteins containing the E . coli major outer membrane lipoprotein (Lpp) signal sequence, lipoprotein signal peptidase recognition site, and the +2 outer membrane sorting signal at their N termini . To test the ability of pDUMP to express lipoproteins from heterologous hosts, the surface lipoprotein PsaA from the Gram-positive organism Streptococcus pneumoniae and the outer membrane lipoproteins MlpA from the Gram-negative Pasteurella multocida and BlpA from the spirochete Brachyspira hyodysenteriae were cloned into both hexahistidine fusion vectors and pDUMP . High level expression of antigenically active protein from both the hexahistidine fusion vectors and pDUMP resulted in abundant bands of the predicted molecular masses when analyzed by SDS-PAGE . When grown in the presence of 3{H}palmitic acid, proteins encoded by pDUMP were observed to incorporate palmitic acid whilst the hexahistidine fusion proteins did not . Using mass spectrometry and image analysis we determined the efficiency of lipidation between the three clones to vary from 31.7 to 100% . In addition, lipidated, but not hexahistidine, forms of the proteins were presented on the E . coli surface .

Clin Infect Dis, 2003 Feb 15, 36(4), E58 - 60 Epub 2003 Jan 31.
Pasteurella multocida urinary tract infection with molecular evidence of zoonotic transmission; Liu W et al.; We describe a patient with a urinary tract infection (UTI) caused by Pasteurella multocida . Pulsed-field gel electrophoresis revealed that the clinical isolate recovered from the patient was identical (100% band match) to P . multocida isolates recovered from the patient's cat, but the isolate differed from an isolate recovered from a visiting cat and from a laboratory control strain . The patient also had abnormal urologic anatomy secondary to surgery; this has also been associated with P . multocida UTI.

Curr Microbiol, 2003 Mar, 46(3), 174 - 9
Effects of aerosolized dust in goats on lung clearance of Pasteurella and Mannheimia species; Purdy CW et al.; The objective was to determine whether the inhalation of large quantities of feedyard dust predisposed the animals to pulmonary bacterial proliferation . Two control groups, C1 and C2, did not receive dust treatments, and two principal groups (P1 and P2) received a total of 14 dust treatments each . The C1 and P1 groups of goats each received a transthoracic challenge of live Mannheimia haemolytica (4 x 10(6) colony forming units, CFU) The C2 and P2 groups of goats each received a transthoracic challenge of live Pasteurella multocida (1.0 x 10(6) CFU/goat) . The results showed that dusted animals had fever when compared with non-dusted controls . In addition, dusted animals demonstrated a leukocytosis with neutrophilia after the first dust treatment that was not sustainable . Finally, dusted animals demonstrated pulmonary clearance of two potential bacterial pathogens that was not significantly different from that shown by control (not dusted) animals.

Indian J Exp Biol, 2002 Jan, 40(1), 106 - 8
Heat modifiability of outer membrane protein of Pasteurella multocida serotype B:2; Pal A et al.; Outer membrane proteins (OMP) are generally porins, functioning as molecular sieves assisting in the transmembrane transportation . Heat modifiable characteristics of OMP from P . multocida B: 2 have been explored to know their basic characteristics on event of temperature rise . A major band of 32 kDa and two minor bands of approximately 39 and approximately 28 kDa were found to be heat modifiable . It is suggested that boiling at 100 degrees C in presence of beta mercaptoethanol for 5 min is sufficient for characterisation of OMP by Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis.

Vet Rec, 2003 Jan 4, 152(1), 7 - 10
Comparative analyses of Pasteurella multocida strains associated with the ovine respiratory and vaginal tracts; Davies RL et al.; Thirty-five isolates of Pasteurella multocida from the vagina and respiratory tract of sheep were compared by analysing their capsular polysaccharide types and outer membrane protein profiles . The phylogenetic relationships of selected isolates with respect to reference strains of P . multocida were also determined by comparative 16S rRNA sequence analysis . Three capsular types, A, D and F, and three major outer membrane protein types were identified, and there were four different combinations of these characteristics which probably marked four individual clones of P . multocida . Strains representing three of these clones were recovered from cases of ovine pneumonia, whereas isolates of the fourth clone were associated exclusively with the vagina of healthy ewes and the liver of a dead septicaemic lamb on the same farm . Analysis of the 16S rRNA sequences showed that there was 100 per cent identity between representative pneumonic isolates and reference strains of P . multocida subspecies galliseptica and P . multocida subspecies multocida . The 16S rRNA genes of representative vaginal and liver isolates from the same farm were identical but differed from the other strains at one nucleotide position, providing strong evidence that the vaginal and liver isolates represent a distinct subpopulation of P . multocida.

Infect Immun, 2003 Feb, 71(2), 663 - 70
Toll-like receptor 4-positive macrophages protect mice from Pasteurella pneumotropica-induced pneumonia; Hart ML et al.; This study investigates Toll-like receptor 4 (TLR4)-positive macrophages in early recognition and clearance of pulmonary bacteria . TLR4 is a trans-membrane receptor that is the primary recognition molecule for lipopolysaccharide of gram-negative bacteria . The TLR4(Lps-del) mouse strains C57BL10/ScN (B10) and STOCK Abb(tm1) TLR4(Lps-del) Slc11a1(s)(B10 x C2D) are susceptible to pulmonary infections and develop pneumonia when naturally or experimentally infected by the opportunistic bacterium Pasteurella pneumotropica . Since these mice have the TLR4(Lps-del) genotype, we hypothesized that reconstitution of mice with TLR4-positive macrophages would provide resistance to this bacterium . A cultured macrophage cell line (C2D macrophages) and bone marrow cells from C2D mice were adoptively transferred to B10 and B10 x C2D mice by intraperitoneal injection . C2D macrophages increased B10 and B10 x C2D mouse resistance to P . pneumotropica . In C2D-recipient mice there was earlier transcription of tumor necrosis factor alpha and chemokines JE and macrophage inflammatory protein 2 (MIP-2) in the lungs of B10 and B10 x C2D mice, and there was earlier transcription of KC and MIP-1alpha in B10 x C2D mice . In addition, the course of inflammation following experimental Pasteurella challenge was altered in C2D recipients . C2D macrophages also protected B10 x C2D mice, which lack CD4(+) T cells . These data indicate that macrophages are critical for pulmonary immunity and can provide host resistance to P . pneumotropica . This study indicates that TLR4-positive macrophages are important for early recognition and clearance of pulmonary bacterial infections.

Acta Clin Belg, 2002 Sep-Oct, 57(5), 254 - 6
Pasteurella multocida in peritoneal dialysis: a rare cause of peritonitis associated with exposure to domestic cats; Kanaan N et al.; Pasteurella multocida is a rare cause of peritonitis in peritoneal dialysis patients with only 10 cases reported in the literature so far . All cases were observed in patients with close contact with cats, usually with a direct puncture of the dialysis tubing . We report a case of Pasteurella multocida peritonitis in a patient maintained under continuous cycling peritoneal dialysis (CCPD), who had frequent and close contact with cats . Patients should be made aware of this potential complication and advised to keep domestic animals away from the location of their peritoneal exchanges.

Clin Oncol (R Coll Radiol), 2002 Dec, 14(6), 497 - 8
Pasteurella multocida infection in a post-chemotherapy neutropenic host following cat exposure; Gowda RV et al.; We report a case of Pasteurella multocida infection in a neutropenic patient . History of contact with animals is important, particularly in patients who present with localized cellulitis and neutropenic fever . Clinical features and treatment of the disease are discussed.

IUBMB Life, 2002 Oct, 54(4), 201 - 11
Functional characteristics and catalytic mechanisms of the bacterial hyaluronan synthases; Weigel PH; The first gene for a glycosaminoglycan synthase to be cloned was the hyaluronan (HA) synthase from S . pyogenes, which we reported in 1993 . Since then, at least 20 bacterial, viral, or eukaryotic HA synthase gene or cDNA sequences and two bacterial chondroitin synthase genes have been reported . During the last decade a great deal has been elucidated about the structure, function, and mechanisms of action of the bacterial HA synthases, which are the focus of this review . Very rapid progress has been made in elucidating the mechanism of HA synthesis by the HA synthase from Pasteurella multocida . Although little of this information is applicable to understanding the mechanism of action of streptococcal HA synthases, good progress has also been made in understanding how these latter enzymes work.

Pol J Vet Sci, 2002, 5(4), 251 - 5
Transfer of maternal passive immunity to kids in goat herd; Pisarska A et al.; The efficiency of tranfer of maternal immunity and its infuence on the kids' health was observed in a herd in which kids (n=20) had whole contact with the dam (n=13) . The factors associated with dam, kid and human, which influence the efficiency of passive transfer were observed . It was estimated that the single-born kids reached higher serum gamma-globulin level (mean 23.14 g/dm3) than twin kids (mean 18.2 g/dm3) (p < 0.05) . The gamma-globulin level was the highest in single-born kids at 48 h, and in twin kids in 24 h of life . The IgG class antibodies to herd-homologous strains of Pasteurella multocida and Escherichia coli were estimated using ELISA in sera, colostrum and milk whey samples of dams and sera of kids . It was found that maternal antibodies specific to these two facultative pathogens decreased in kids sera rapidly and the self humoral immune response occurred within the period of observation . Two kids delivered by goats with lowest hierarchic position in the herd showed failure of passive transfer, and died at the 10th and 12th weeks of life due to chronic infections induced by both above mentioned bacterial strains.

J Gen Appl Microbiol, 1999 Dec, 45(6), 269 - 275
Molecular characterization of Pasteurella multocida isolates from rabbits; Al-Haddawi MH et al.; Forty isolates of Pasteurella multocida from healthy (17 isolates) and diseased (23 isolates) rabbits were assayed for the presence of plasmids in seeking to determine whether any correlation exists between the presence of plasmids and health status, sensitivity to antimicrobial agents, capsular and somatic type, and the anatomic site of isolation . Six isolates were found harboring plasmids . A similar ladder pattern ranging from 18 to 3 megadalton (Mda) were found in three isolates recovered from diseased rabbits . One band of molecular weight 6.6 Mda was shared by four of five (4/5) isolates from the diseased rabbits . No correlation was found between the presence of the common plasmids and serotype, resistance to antimicrobial agents, and anatomic sites from which the bacteria were cultured . Random amplification polymorphic DNA was applied to subtype all the isolates of P . multocida . Two single primers were tested for their abilities to generate individual fingerprints by using PCR . Primer 1 grouped the isolates into 7 profiles, and primer 2 grouped them into 15 . Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) results show the presence of a wide heterogeneity within P . multocida isolates . Therefore RAPD-PCR is an efficient technique to detect the DNA polymorphism and could be used to discriminate P . multocida of rabbit isolates together with serologic typing.

J Med Microbiol, 2003 Jan, 52(Pt 1), 59 - 67
Characterization and comparison of Pasteurella multocida strains associated with porcine pneumonia and atrophic rhinitis; Davies RL et al.; One hundred and fifty-eight porcine strains of Pasteurella multocida, recovered primarily from cases of pneumonic pasteurellosis or progressive atrophic rhinitis (PAR) in England and Wales, were characterized by determination of their capsular types, presence or absence of the toxA gene and molecular mass heterogeneity of the heat-modifiable (OmpA) and porin (OmpH) proteins . Eighteen groups (clones) of strains were identified on the basis of specific combinations of capsular type, toxA status and outer-membrane protein (OMP)-type . The data provided evidence that different subpopulations of P . multocida are responsible for pneumonia and PAR in pigs . The majority (88 %) of cases of pneumonia were associated exclusively with non-toxigenic capsular type A strains of OMP-types 1.1, 2.1, 3.1 and 5.1 and capsular type D isolates of OMP-type 6.1 . These strains were recovered from widespread geographical locations within England and Wales over a 12-year period and represented mostly single sporadic cases . The association of a small number of P . multocida variants with the majority of cases of porcine pneumonia suggests that these strains are not opportunistic pathogens of low virulence but represent primary pathogens with a relatively high degree of virulence . In contrast, the majority (76 %) of cases of PAR were associated with toxA-containing capsular type D strains of OMP-type 4.1 and capsular type A and D strains of OMP-type 6.1 . Toxigenic capsular type A strains associated with PAR and non-toxigenic capsular type A strains associated with pneumonia represent distinct subpopulations of P . multocida that can be differentiated by their OMP-types . The association of capsular types A and D with strains of the same OMP-types, and the absence and presence of the toxA gene in strains of the same OMP-types, suggest that horizontal transfer of capsular biosynthesis and toxA genes has occurred between strains representing certain subpopulations of P . multocida.

Vet Microbiol, 2003 Mar 20, 92(1-2), 103 - 9
Survey of restriction-modification systems and transformation in Mannheimia haemolytica and Pasteurella trehalosi; Hill AE et al.; A significant obstacle to molecular studies of Mannheimia (Pasteurella) haemolytica, has been its resistance to genetic transformation . The lack of competence of many M . haemolytica strains has been attributed to the presence of restriction modification systems . In this study, representative strains of 12 M . haemolytica serotypes and four Pasteurella trehalosi serotypes were successfully transformed by electroporation using a recombinant vector derived from the native M . haemolytica A1 serotype plasmid pNSF2176 . Transformation was achieved despite PCR-based evidence for the presence of genes encoding a type I restriction enzyme, phaI, and a type II restriction enzyme hsdM, in each of the M . haemolytica strains.

J Control Release, 2002 Dec 13, 85(1-3), 227 - 35
Immunization of rabbits against a bacterial pathogen with an alginate microparticle vaccine; Suckow MA et al.; Pasteurella multocida is an important bacterial pathogen of domestic rabbits . To evaluate the ability of a thiocyanate extract (PTE) of P . multocida to stimulate an immune response and protect against infection with P . multocida, rabbits were immunized subcutaneously or intranasally on Days 7, 21 and 35 . Cholera toxin, a potent mucosal adjuvant, was included in one treatment group . Rabbits immunized subcutaneously (SC) or intranasally (IN) had significant increases in serum anti-PTE IgG but not IgA . In contrast, only rabbits immunized IN with PTE developed significant titers of nasal lavage anti-PTE IgA and cholera toxin significantly enhanced this response . In a second study rabbits were immunized via the drinking water with PTE incorporated into alginate microparticles on Days 7, 14 and 21 . Mild increases in serum IgG were noted in rabbits immunized with PTE in microparticles, with or without cholera toxin, and this increase was significant (P<or=0.05) on Day 21 for rabbits receiving PTE and cholera toxin . Nasal lavage anti-PTE IgA was significantly (P<or=0.05) increased in rabbits immunized orally with PTE, with or without cholera toxin, in microparticles . This effect was not enhanced by cholera toxin . Rabbits orally immunized with PTE in microparticles had significantly fewer colony forming units of homologous P . multocida recovered from the lungs and nasopharynx following an intranasal challenge . These results demonstrate that PTE incorporated into alginate microparticles and administered orally is immunogenic and confers protective immunity.

Aust Vet J, 2002 Nov, 80(11), 681 - 3
Arthroscopic management of septic polyarthritis in a dog; Fearnside SM et al.; A 4 1/2-month-old male Neapolitan Mastiff was presented with a history of severe non weight-bearing lameness, depression and anorexia, following 6 weeks of intermittent thoracic limb lameness that had deteriorated in the previous 72 hours . Haematogenous septic polyarthritis involving the right elbow joint and left glenohumeral joint was diagnosed, with blood and joint cultures revealing a Pasteurella species . Arthroscopy was utilised to facilitate joint evaluation and effect drainage of both joints . Clinical remission was achieved within 48 hours . Arthroscopy provided a minimally invasive yet thorough joint examination, lavage, and drainage of fibrinopurulent debris, thereby allowing early postoperative mobility and minimal morbidity.

Vet Microbiol, 2003 Feb 2, 91(2-3), 169 - 82
Diversity of avian Pasteurella multocida strains based on capsular PCR typing and variation of the OmpA and OmpH outer membrane proteins; Davies RL et al.; One hundred avian Pasteurella multocida isolates recovered from cases of fowl cholera and related infections in England and Wales over a 13-year period were characterised by capsular PCR typing and analysis of outer membrane protein (OMP) profiles . Sixty-eight percent of the strains were of capsular type A, 14% were type F, 5% were type D, 4% were type B and 9% were untypable . Nineteen distinct OMP profiles (OMP-types) were identified based mainly on molecular mass heterogeneity of the heat-modifiable (OmpA) and porin (OmpH) proteins . Fifty-six percent of the isolates were represented by 15 OMP-types, whereas 44% of the isolates were associated with four OMP-types . The extensive molecular mass heterogeneity of the OmpA and OmpH proteins supports previous findings that avian P . multocida strains are very diverse . Furthermore, the isolates studied were associated with different clinical symptoms and were recovered from a wide range of lesions and tissues . The high degree of strain diversity together with the wide variety of clinical symptoms suggest that certain avian strains of P . multocida are opportunistic pathogens of relatively low virulence . Strains of capsular types B, D and F, as well as the untypable isolates, were associated exclusively with specific OMP-types and represent distinct and widely disseminated clonal groups . These observations support the view that avian strains of P . multocida have a clonal population structure . Based on previous studies, the molecular mass heterogeneity of the OmpA and OmpH proteins might provide a selective advantage to P . multocida by generating antigenic variation.

Vet Pathol, 2002 Nov, 39(6), 706 - 11
Cellular distribution of anionic antimicrobial peptide in normal lung and during acute pulmonary inflammation; Fales-Williams AJ et al.; Anionic peptides (APs) are small antimicrobial peptides present in human and ovine lung . In this study APs were also detected in bovine lung, and production of APs in lungs with acute inflammation induced by various stimuli was determined . The distribution and intensity of APs were determined by immunohistochemistry in lungs of 1) neonatal calves (1-3 days of age) inoculated with Mannheimia (Pasteurella) haemolytica, a known inducer of the bovine beta-defensin lingual antimicrobial peptide (LAP) or pyrogen-free saline (PFS), and 2) growing calves (3 months of age) similarly inoculated with M . haemolytica, a lipopolysaccharide (LPS) from M . haemolytica, an LPS-associated protein from M . haemolytica, or PFS . APs were also detected by western blots with the same antibody in lungs of the calves above, as well as in calves inoculated with Pseudomonas aeruginosa, and an adult cow . Anionic peptide (AP) immunoreactivity was detected in bands (approximate weights) in the western blots of lung at 28-30 (strongest signal), 31, 45, and 52-60 kd regardless of inoculum . The adult cow lacked bands at 45 kd, but it had additional bands at 64 (inconsistently) and 35-38 kd . All these band sizes are consistent with those of the western blots of human and ovine lung . The cellular distribution of APs in lung of neonatal and growing cattle was similar to that in lung of human and sheep . In lungs with acute inflammation induced by live bacteria, LPS, or protein, AP distribution and intensity were similar to those in control (PFS-inoculated) lungs and slightly decreased in bronchioles . This work demonstrates that AP is present in lung of cattle and is thereby conserved among two ruminant species and man . Distribution and intensity of AP production are not enhanced by infection or acute inflammation and are decreased in bronchioles, which suggests that AP is not induced like beta-defensins such as LAP, but, instead, is produced constitutively.

Vet Pathol, 2002 Nov, 39(6), 697 - 705
A selectin inhibitor decreases neutrophil infiltration during acute Mannheimia haemolytica pneumonia; Radi ZA et al.; The degree to which the selectin inhibitor TBC1269 reduces neutrophil infiltration in specific microscopic locations of the lung during acute pneumonia of neonates was determined . Neonatal calves were inoculated intrabronchially with Mannheimia (Pasteurella) haemolytica or saline, and lung tissue was collected at 2 and 6 hours postinoculation (PI) . One 6-hour group inoculated with M . haemolytica received TBC1269 intravenously before and after inoculation with M . haemolytica . Infiltrates of neutrophils were significantly higher in the alveolar lumen and septae but lower in the bronchial lumen and epithelium at 6 hours PI than at 2 hours PI . Significantly fewer neutrophils (P < 0.05) were present in the alveolar lumen and septae, and the bronchiolar lumen and lamina propria in the lungs of TBC1269-treated calves compared with untreated calves at 6 hours PI . TBC1269 did not alter the infiltration into bronchi and blood vessels or the expression of the selectin-independent adhesion molecule, ICAM-1 . This work suggests that during acute pneumonia of neonates 1) neutrophil infiltrates progressively increase in the alveolar lumens and septae but decrease in the bronchial lumen and epithelium with time, 2) TBC1269 reduces neutrophil infiltration into specific regions of alveoli and bronchioles rather than uniformly throughout the lung, and 3) selectin inhibition does not affect the location and intensity of ICAM-1 expression.

Infect Immun, 2002 Dec, 70(12), 6871 - 9
Genomic scale analysis of Pasteurella multocida gene expression during growth within the natural chicken host; Boyce JD et al.; Little is known about the genomic-scale transcriptional responses of bacteria during natural infections . We used whole-genome microarray analysis to assess the transcriptional state of the gram-negative pathogen Pasteurella multocida, the causative agent of fowl cholera, during infection in the natural chicken host . We compared the expression profiles of bacteria harvested from the blood of septicemic chickens experiencing late-stage fowl cholera with those from bacteria grown in rich medium . Independent analysis of bacterial expression profiles from the infection of three individual chickens indicated that 40 genes were differentially expressed in all three individuals, 126 were differentially expressed in two of the three individuals, and another 372 were differentially expressed in one individual . Real-time reverse transcription-PCR assays were used to confirm the expression ratios for a number of genes . Of the 40 genes differentially expressed in all three individuals, 17 were up-regulated and 23 were down-regulated in the host compared with those grown in rich medium . The majority (10 of 17) of the up-regulated genes were involved in amino acid transport and metabolism and energy production and conversion, clearly indicating how P . multocida alters its biosynthetic and energy production pathways to cope with the host environment . In contrast, the majority (15 of 23) of down-regulated genes were of unknown or poorly characterized functions . There were clear differences in gene expression between the bacteria isolated from each of the three chickens, a finding consistent with individual host variation being an important factor in determining pathogen gene expression . Interestingly, bacteria from only two of the three infected animals had a gene expression profile highly similar to that observed during growth under iron-limiting conditions, suggesting that severe iron starvation may not always occur during P . multocida infection.

New Microbiol, 2002 Oct, 25(4), 427 - 36
Coinfection with BHV-1 modulates cell adhesion and invasion by P . multocida and Mannheimia (Pasteurella) haemolytica; Galdiero M et al.; Viruses are thought to facilitate bacterial infections of the respiratory tract . The present study shows the effect of BHV-1 on Pasteurella multocida and Mannheimia haemolytica adherence and invasion of MDBK cells . The virus-infected MDBK cells become more susceptible to the adherence of both species of Pasteurella . The observed adherence increase depends on the length of virus pre-incubation time and on virus concentration . When MDBK cells are not infected with virus, they are only invaded by P . multocida, while M . haemolytica is not able to penetrate . The viral infection favours also the invasion by M . haemolytica.

J Bacteriol, 2002 Dec, 184(23), 6714 - 20
Transcriptional response of Pasteurella multocida to defined iron sources; Paustian ML et al.; Pasteurella multocida was grown in iron-free chemically defined medium supplemented with hemoglobin, transferrin, ferritin, and ferric citrate as iron sources . Whole-genome DNA microarrays were used to monitor global gene expression over seven time points after the addition of the defined iron source to the medium . This resulted in a set of data containing over 338,000 gene expression observations . On average, 12% of P . multocida genes were differentially expressed under any single condition . A majority of these genes encoded P . multocida proteins that were involved in either transport and binding or were annotated as hypothetical proteins . Several trends are evident when the data from different iron sources are compared . In general, only two genes (ptsN and sapD) were expressed at elevated levels under all of the conditions tested . The results also show that genes with increased expression in the presence of hemoglobin did not respond to transferrin or ferritin as an iron source . Correspondingly, genes with increased expression in the transferrin and ferritin experiments were expressed at reduced levels when hemoglobin was supplied as the sole iron source . Finally, the data show that genes that were most responsive to the presence of ferric citrate did not follow a trend similar to that of the other iron sources, suggesting that different pathways respond to inorganic or organic sources of iron in P . multocida . Taken together, our results demonstrate that unique subsets of P . multocida genes are expressed in response to different iron sources and that many of these genes have yet to be functionally characterized.

J Vet Diagn Invest, 2002 Nov, 14(6), 515 - 9
Porcine circovirus type 2 (PCV-2) coinfections in US field cases of postweaning multisystemic wasting syndrome (PMWS); Pallares FJ et al.; The prevalence of different pathogens detected in combination with porcine circovirus type 2 (PCV-2) was studied retrospectively in field cases of postweaning multisystemic wasting syndrome (PMWS) diagnosed at the Iowa State University Veterinary Diagnostic Laboratory, Ames, Iowa, between January 2000, and September 2001 . The presence of PCV-2 antigen in lymphoid tissues and/or lung, demonstrated by immunohistochemistry, together with moderate to severe lymphoid depletion and/or granulomatous lymphadenitis, was used as the criteria for the diagnosis of PMWS . A total of 484 cases fulfilled these criteria . Most of the cases (294/369) of PMWS occurred in pigs between the ages of 8 and 18 weeks, with a peak at 10 weeks of age . Porcine reproductive and respiratory syndrome virus was detected in 51.9% of the cases, Mycoplasma hyopneumoniae in 35.5%, bacterial septicemia in 14.0%, bacterial pneumonia in 7.6%, swine influenza virus in 5.4%, and PCV-2 alone in 1.9% . In cases with bacterial septicemia the most frequently isolated pathogen was Streptococcus suis . In cases with bacterial pneumonia, Pasteurella multocida was the most prevalent.

Vet Rec, 2002 Oct 19, 151(16), 472 - 6
Isolation of mycoplasma species from the lower respiratory tract of healthy cattle and cattle with respiratory disease in Belgium; Thomas A et al.; Between 1997 and 2000, a total of 150 healthy cattle and 238 animals with respiratory disease were examined for six Mycoplasma species . Attempts were made to detect Mycoplasma canis, Mycoplasma dispar and Ureaplasma diversum in calves with recurrent disease, and all three of these species were identified in calves with recurrent disease and in healthy lungs . In healthy calves, 84 per cent of bronchoalveolar lavage fluids were mycoplasma free; when cultures were positive, Mycoplasma bovirhinis was the only species isolated . Mycoplasmas were isolated from 78 per cent of animals suffering recurrent respiratory disease and from 65 per cent of acute respiratory cases . Mycoplasma bovis was isolated from bronchoalveolar lavages from 35 per cent of calves suffering recurrent respiratory disease, and from 50 per cent of acute cases, and from 20 per cent of pneumonic cases examined postmortem . M bovis was associated with other Mycoplasma species in 44 per cent of cases . M dispar was also isolated from 45.5 per cent of calves suffering recurrent respiratory disease, often in association with M bovis . M canis was identified for the first time in diseased Belgian cattle . Other mycoplasmas, including Mycoplasma arginini, Mycoplasma alkalescens and U diversum, were isolated less frequently . Associations between mycoplasmas and other pathogens were often observed . Among lungs infected with Pasteurella and/or Mannheimia species, more than 50 per cent were mixed infections with M bovis.

Vet Res Commun, 2002 Oct, 26(7), 513 - 22
Comparative analysis of the outer membrane protein profiles of isolates of the Pasteurella multocida (B:2) associated with haemorrhagic septicaemia; Tomer P et al.; Outer membrane proteins (OMP) of P . multocida (serotype B:2) field isolates (n = 6) and a vaccine strain (P-52) were extracted by a sarkosyl method and characterized using SDS-PAGE and immunoblotting . About 20 polypeptide bands were observed in the profile of the vaccine strain with MW ranging from 16 to 90 kDa and, based on band thickness and intensity of staining, three polypeptides of MW 31, 33 and 37 kDa were considered to be the major OMPs . The profiles of the field isolates showed minor differences when compared with that of the vaccine strain . The OMP of 33 kDa was only expressed by the vaccine strain . Four field isolates expressed an OMP of 39 kDa, which did not appear in the profiles of the remaining two field isolates and the P-52 strain . Similarly, an OMP of 25 kDa was exclusively seen in the profile of a single isolate . By immunoblotting studies, using anti-P . multocida (P-52) whole-cell hyperimmune serum raised in rabbits as well as buffalo immune sera, it became evident that the polypeptide of 37 kDa was the most antigenic OMP in the profiles of all the isolates, including the P-52 strain . Other polypeptides were either weakly antigenic or visible in the profile of only a few of the isolates . The study thus identified the major OMP of P . multocida (B:2) and suggested that this highly antigenic 37 kDa OMP has potential for further protective and immunodiagnostic studies.

Vet Immunol Immunopathol, 2002 Nov, 90(1-2), 107 - 10
Mannheimia haemolytica serotype 1 and Pasteurella trehalosi serotype 10 culture supernatants contain fibrinogen-binding proteins; McNeil HJ et al.; Fibrinogen-binding proteins were found in the culture supernatants of Mannheimia haemolytica serotype 1 (ATCC 43270) and Pasteurella trehalosi serotype 10 (ECO-100) . Sheep fibrinogen was biotinylated and shown to bind to proteins in the culture supernatants by modified western blot . Fibrinogen-binding proteins in the culture supernatant may be important virulence factors leading to the characteristic fibrinous pneumonia caused by these organisms and may be critical antigenic targets for immune prophylaxis.

Equine Vet J Suppl, 2002 Sep, (34), 417 - 24
Evidence of an association between inflammatory airway disease and EIPH in young Thoroughbreds during training; Newton JR et al.; In an epidemiological study of risk factors for exercise-induced pulmonary haemorrhage (EIPH) in young Thoroughbreds in the UK, in which 148 horses contributed 1614 horse-months of data, there were 64 (4%) episodes of endoscopically visible tracheal bleeding and 824 (51%) episodes of increased quantities of haemosiderophages in tracheal washes . There were increases in prevalence and risk of EIPH by both definitions with age from < or = 2- > or = 4 years, season of sampling from winter (Nov-Jan) to autumn (Aug-Oct) and several different measures of airway inflammation, including tracheal mucus, neutrophil proportion, inflammation score and fungal material in tracheal washes . There was considerable variability in the prevalence of EIPH between trainers . EIPH in the preceding month significantly increased the risk of the condition the following month . There was no evidence that EIPH was associated with infection of the airways with even large numbers of Streptococcus zooepidemicus or Pasteurella-like spp., which are significantly associated with airway inflammation in younger racehorses . Multiple logistic regression modelling that took account of random variability between horses and the effects of each trainer and an episode the preceding month, confirmed that after controlling for the other risk factors, EIPH was still significantly associated with increasing age, different seasons, airway inflammation and evidence of airway fungal material.

Int J Med Microbiol, 2002 Sep, 292(3-4), 149 - 58
RTX toxins in Pasteurellaceae; Frey J et al.; RTX toxins (repeats in the structural toxin) are pore-forming protein toxins produced by a broad range of pathogenic Gram-negative bacteria . In vitro, RTX toxins mostly exhibit a cytotoxic and often also a hemolytic activity . They are particularly widespread in species of the family Pasteurellaceae which cause infectious diseases, most frequently in animals but also in humans . Most RTX toxins are proteins with a molecular mass of 100-200 kDa and are post-translationally activated by acylation via a specific activator protein . The repeated structure of RTX toxins, which gave them their name, is composed of iterative glycine-rich nonapeptides binding Ca2+ on the C-terminal half of the protein . Genetic analysis of RTX toxins of various species of Pasteurellaceae and of a few other Gram-negative bacteria gave evidence of horizontal transfer of genes encoding RTX toxins and led to speculations that RTX toxins might have originated from Pasteurellaceae . The toxic activities of RTX toxins in host cells may lead to necrosis and apoptosis and the underlying detailed mechanisms are currently under investigation . The impact of RTX toxins in pathogenicity and the immune responses of the host were described for several species of Pasteurellaceae . Neutralizing antibodies were shown to significantly reduce the cytotoxic activity of RTX toxins . They constitute a valuable strategy in the development of immuno-prophylactics against several animal diseases caused by pathogenic species of Pasteurellaceae . Although many RTX toxins possess cytotoxic and hemolytic activities toward a broad range of cells and erythrocytes, respectively, a few RTX toxins were shown to have cytotoxic activity only against cells of specific hosts and/or show cell-type specificity . Further evidence exists that RTX toxins play a potential role in host specificity of certain pathogens.

Avian Pathol, 2002 Apr, 31(2), 183 - 91
Serum resistance of Pasteurella multocida in avian and porcine sera, and comparative virulence investigations of selected serum-sensitive and resistant strains in chickens; Muhairwa AP et al.; Growth in serum of Pasteurella multocida and related species in chicken, turkey, duck and pig sera were compared, and selected serum-resistant and serum-sensitive strains were inoculated into 18-week-old layers . Eighty-seven field strains of Pasteurella spp . and nine reference strains representing different clones defined by restriction endonuclease analysis (REA) profiles were used in the study . Serum activity was measured by changes in the optical density (OD) of the serum after inoculation and incubation at 41 degrees C for chicken, turkey and duck serum and 39 degrees C for pig serum . Serum activity was measured by comparison with previously determined serum-resistant (P-1059) and serum-sensitive (CU vaccine) strains, and classified into highly serum-resistant, moderately serum-resistant and serum-sensitive . Strains of the same REA type were found to have identical growth curves and the same maximum OD values when tested in serum from the same host species . Turkey serum was shown to be less inhibitory to a wide range of P . multocida strains than chicken, duck and pig sera . Serum-resistant strains were demonstrated among avian as well as mammalian strains . Among the avian strains, the proportion of serum-resistant strains was higher in outbreak strains than in strains from apparently healthy carriers . Removal of the capsule from selected strains by hyaluronidase treatment failed to change the serum activity . The most severe lesions in experimentally infected chickens were produced by a serum-resistant strain; however, lesions were also found in chickens infected by serum-sensitive strains, indicating the involvement of multiple factors in the virulence of P . multocida . Further investigations on serum resistance are indicated in order to relate other host and bacterial factors responsible for the development of fowl cholera.

Avian Pathol, 2002 Aug, 31(4), 399 - 406
Pathology of an atypical strain of Pasteurella gallinarum infection in chickens; Shivaprasad HL et al.; Gross and microscopic pathology caused by an atypical strain of Pasteurella gallinarum (Fresno strain) was compared in chickens with that caused by the American Type Culture Collection type strain . Ten 21-day-old broiler chickens were inoculated intranasally with 10(7) colony forming units or intramuscularly with 10(5) colony forming units of either strain . The birds were killed 7 days later, and gross and microscopic lesions were studied . Grossly, there was extensive white discoloration of pectoral muscles with mild fibrinous exudate in birds inoculated intramuscularly with the Fresno strain of P . gallinarum . Most of these birds also had severe fibrinous exudation over the heart, the capsule of the liver, the air sac, and in the hock joints . Microscopically, there was severe chronic pyogranulomatous airsacculitis, pericarditis, perihepatitis, myositis, synovitis, and granulomatous pneumonia . One bird had severe acute multifocal hepatitis . From this study, it is evident that the Fresno strain of P . gallinarum was more pathogenic than the American Type Culture Collection type strain when given intramuscularly.

Prev Vet Med, 2002 Nov 15, 55(4), 217 - 40
Use of Akaike information criteria for model selection and inference . An application to assess prevention of gastrointestinal parasitism and respiratory mortality of Guinean goats in Kolda, Senegal; Lancelot R et al.; A field experiment was carried out in Kolda (southern Senegal) from July 1986 to July 1988 . Its goals were to: (1) describe the patterns of mortality of female Guinean goats by age, season and year; (2) assess preventive measures against respiratory diseases and gastrointestinal parasitism in reducing mortality; and (3) estimate the overall impact of these measures on survival to 1 year of age . Preventive measures for respiratory disease included vaccination against peste des petits ruminants (PPR) and pneumonic pasteurellosis (Pasteurella multocida types A and D) . Control of gastrointestinal parasites was by deworming does with morantel (7.5mg kg(-1), three times during the rainy season) . The effects of vaccines and deworming were tested in a randomised factorial field experiment with villages being the experimental units . A total of 19 villages, 113 goat herds and 1,458 goats were included in the study . Generalised linear models of survival for five cohorts of goats (defined by five different birth seasons) used a binomial assumption for the response distribution and a complementary log-log link . Explanatory variables included age, season, year, vaccination, deworming and their interactions . A complex a priori model was built on the basis of previous epidemiological knowledge; a purposely selected set of simpler models was compared to this full model by the Akaike information criterion (AIC) and derived statistics . Inference on 1-year survival and treatment effects accounted for model-selection uncertainty . It was carried out with a bootstrap procedure and used information from the whole set of selected models.Large variations in mortality by year and season were observed but no regular seasonal pattern was apparent . Mortality probabilities of kids in dewormed groups decreased quickly after birth, but remained elevated up to 9 months of age in the non-dewormed groups . Deworming lowered the risk of mortality . Vaccination alone was not protective (except during an observed outbreak of PPR).

Ann N Y Acad Sci, 2002 Oct, 969, 224 - 8
Avian cholera on north coast California: distinctive epizootiological features; Botzler RG; Between 1945 and 2001, avian cholera (Pasteurella multocida infection) was confirmed at 27 epizootics in 18 different years on northcoastal California . Estimated mortality ranged from 1 to 6750 birds per site, with a median total mortality of about 1000 birds per year . Eight epizootics involved < 150 birds; thus, minor epizootics were common . Annual total wildfowl mortality ranged from 0.4% to 7.0% of estimated live populations; median annual mortality for American coots (Fulica americana) (11.5%) surpassed that of tundra swans (Cygnus columbianus) (0.2%) and ducks (0.2%) . Coots comprised > 50% of total wildfowl mortality in 16 of 17 epizootics . Overall, coots comprised 82% of known avian cholera mortality, but only 34% of the live wildfowl present; ducks and swans died much less frequently . Wildfowl at one site consistently died in a sequential pattern; there was no sequential mortality at other sites.

Infect Immun, 2002 Nov, 70(11), 6460 - 3
Association of Pasteurella multocida toxin with vimentin; Shime H et al.; To help understand the molecular mechanisms of Pasteurella multocida toxin (PMT) action, we searched for a cellular protein interacting with PMT . The ligand overlay assay revealed a 60-kDa cellular protein that binds to a region from the 840th to 985th amino acids of the toxin . This protein was identified as vimentin by peptide mass fingerprinting . The N-terminal head domain of vimentin was further found to be responsible for the binding to the toxin.

Infect Immun, 2002 Nov, 70(11), 5955 - 64
Characterization of the Pasteurella multocida hgbA gene encoding a hemoglobin-binding protein; Bosch M et al.; Reverse transcriptase PCR analyses have demonstrated that open reading frames (ORFs) PM0298, PM0299, and PM0300 of the animal pathogen Pasteurella multocida constitute a single transcriptional unit . By cloning and overexpression studies in Escherichia coli cells, the product of ORF PM0300 was shown to bind hemoglobin in vitro; this ORF was therefore designated hgbA . In vitro and in vivo quantitative assays demonstrated that the P . multocida hgbA mutant bound hemoglobin to the same extent as the wild-type strain, although the adsorption kinetics was slightly slower for the hgbA cells . In agreement with this, the virulence of P . multocida hgbA cells was not affected, suggesting that other functional hemoglobin receptor proteins must be present in this organism . On the other hand, P . multocida mutants defective in PM0298 and PM0299 could be isolated only when a plasmid containing an intact copy of the gene was present in the cells, suggesting that these genes are essential for the viability of this bacterial pathogen . By adapting the recombinase-based expression technology in vivo to P . multocida, we also demonstrated that the transcriptional PM0298-PM0299-hgbA unit is iron regulated and that its expression is triggered in the first 2 h following infection in a mouse model . Furthermore, hybridization experiments showed that the hgbA gene is widespread in P . multocida strains regardless of their serotype or the animal from which they were isolated.

Carbohydr Res, 2002 Sep 27, 337(17), 1547 - 52
Identification of the capsular polysaccharides of Type D and F Pasteurella multocida as unmodified heparin and chondroitin, respectively; DeAngelis PL et al.; Pasteurella multocida is a pathogenic Gram-negative bacterial species that infects a wide variety of animals and humans . A notable morphological feature of many isolates is the extracellular capsule . The ability to remove the capsule by treatment with certain glycosidases has been utilized to discern various capsular types called A, D and F . Based on this preliminary evidence, these microbes have capsules made of glycosaminoglycans, linear polysaccharides composed of repeating disaccharide units containing an amino sugar . Glycosaminoglycans are also abundant components of the vertebrate extracellular matrix . It has been shown previously that the major Type A capsular material was hyaluronan (hyaluronic acid) . We report that the Type D polymer is an unmodified heparin (N-acetylheparosan) with a -->4)-beta-D-Glcp-UA-(1-->4)-alpha-D-Glcp-NAc-(1--> repeating unit and the Type F polymer is an unmodified chondroitin with a -->4)-beta-D-Glcp-UA-(1-->3)-beta-D-Galp-NAc-(1--> repeating unit . The monosaccharide compositions, disaccharide profiles, and 1H NMR analyses are consistent with these identifications . The molecular size of the Pasteurella polymers is approximately 100-300 kDa as determined by gel electrophoresis and multi-angle laser light scattering; this size is much greater than the 10-30 kDa size of the analogous polymers isolated from animal tissues . The glycosaminoglycan capsular polymers are relatively non-immunogenic virulence factors that enhance microbial pathogenicity.

J Vet Diagn Invest, 2002 Sep, 14(5), 389 - 95
Minimum inhibitory concentration breakpoints and disk diffusion inhibitory zone interpretive criteria for tilmicosin susceptibility testing against Pasteurella multocida and Actinobacillus pleuropneumoniae associated with porcine respiratory disease; Shryock TR et al.; Tilmicosin is a novel macrolide antibiotic developed for exclusive use in veterinary medicine . Tilmicosin has been approved as a feed premix to control porcine respiratory disease associated with Pasteurella multocida and Actinobacillus pleuropneumoniae . The development of antimicrobial susceptibility testing guidelines for tilmicosin was predicated on the relationship of clinical efficacy studies that demonstrated a favorable therapeutic outcome, on pharmacokinetic data, and on in vitro test data, as recommended by the National Committee for Clinical Laboratory Standards (NCCLS) . The approved breakpoints for the minimum inhibitory concentration dilution testing for both species are resistant, > or = 32 microg/ml, and susceptible, < or = 16 microg/ml . The zone of inhibition interpretive criteria for disk diffusion testing with a 15-microg tilmicosin disk are resistant, < or = 10 mm, and susceptible, > or = 11 mm.

J Wildl Dis, 2002 Jul, 38(3), 545 - 51
Aerobic salivary bacteria in wild and captive Komodo dragons; Montgomery JM et al.; During the months of November 1996, August 1997, and March 1998, saliva and plasma samples were collected for isolation of aerobic bacteria from 26 wild and 13 captive Komodo dragons (Varanus komodoensis) . Twenty-eight Gram-negative and 29 Gram-positive species of bacteria were isolated from the saliva of the 39 Komodo dragons . A greater number of wild than captive dragons were positive for both Gram-negative and Gram-positive bacteria . The average number of bacterial species within the saliva of wild dragons was 46% greater than for captive dragons . While Escherichia coli was the most common bacterium isolated from the saliva of wild dragons, this species was not present in captive dragons . The most common bacteria isolated from the saliva of captive dragons were Staphylococcus capitis and Staphylococcus capitis and Staphylococcus caseolyticus, neither of which were found in wild dragons . High mortality was seen among mice injected with saliva from wild dragons and the only bacterium isolated from the blood of dying mice was Pasteurella multocida . A competitive inhibition enzyme-linked immunosorbent assay revealed the presence of anti-Pasteurella antibody in the plasma of Komodo dragons . Four species of bacteria isolated from dragon saliva showed resistance to one or more of 16 antimicrobics tested . The wide variety of bacteria demonstrated in the saliva of the Komodo dragon in this study, at least one species of which was highly lethal in mice and 54 species of which are known pathogens, support the observation that wounds inflicted by this animal are often associated with sepsis and subsequent bacteremia in prey animals.

Exp Anim, 2002 Jul, 51(4), 401 - 5
Elimination of Pasteurella pneumotropica from a contaminated mouse colony by oral administration of Enrofloxacin; Ueno Y et al.; Enrofloxacin, a fluoroquinolone bactericidal antibiotic, was administered in an attempt to eradicate Pasteurella pneumotropica (P . pneumotropica) from a contaminated mouse colony . Contaminated mice, maintained within 4 animal rooms, were administered Enrofloxacin in drinking water at a daily dosage of 25.5 mg/kg for 2 weeks . Following one week of Enrofloxacin treatment, mice were selected randomly from each room and examined for P . pneumotropica . This procedure was repeated two or three times until all mice examined tested negative for the Pasteurella strain . With the exception of one room, treated mice consistently tested negative for P . pneumotropica for up to 45 weeks following completion of Enrofloxacin treatment . Thus, oral administration of Enrofloxacin significantly eliminated P . pneumotropica from a contaminated mouse colony.

Bioorg Med Chem Lett, 2002 Oct 7, 12(19), 2771 - 4
Synthesis and activity of a novel class of tribasic macrocyclic antibiotics: the triamilides; Letavic MA et al.; The stereoselective synthesis of two novel series of tribasic macrocyclic antibiotics with potent in vitro activity against Pasteurella multocida and Escherichia coli strains of bacteria is described . The in vitro activity can be significantly influenced by the nature of the substituents on the C-4" aminoalcohol, with the stereochemistry of the C-4" alcohol playing a less critical role . The effect of substitution and stereochemistry on the in vivo activity in a murine model of respiratory infection is also described.

Res Vet Sci, 2002 Aug, 73(1), 37 - 44
Experimental induction of pneumonic pasteurellosis in calves by intratracheal infection with Pasteurella multocida biotype A:3; Dowling A et al.; The study aimed to establish an experimental model to investigate the pathogenesis of lung infection by Pasteurella multocida, an important cause of bovine respiratory disease . An experimental model is required to assist the development of an effective vaccine . Sixteen 8-week-old calves were challenged intratracheally with 10(9) or 10(10) colony forming units of P . multocida in either 60 or 300 ml saline in a 2 x 2 factorial experiment . All animals became dull within 2-6h post-infection (p.i.) and two calves were killed humanely because of suspected endotoxic shock . Remaining animals showed increased respiratory rates by 15-20 h p.i . and, at 23 h p.i., calves given the high dose, high volume challenge showed higher (P < 0.05) rectal temperatures . From 24 to 36 h p.i., clinical signs decreased in a majority of animals . Plasma haptoglobin concentrations increased (P < 0.05) in calves given the high volume challenge irrespective of the number of bacteria . At post-mortem examination (4d p.i.), lung lesions, mainly in the apical lobes, were found in all calves . Histopathological examination showed areas of purulent pneumonia with a tendency to abscessation and inflamed interlobular septa characterised by accumulation of neutrophils and oedema . The clinical and pathological responses described were typical of bovine pneumonic pasteurellosis.

J Clin Microbiol, 2002 Sep, 40(9), 3438 - 41
Taxonomic subgroups of Pasteurella multocida correlate with clinical presentation; Chen HI et al.; Pasteurella multocida is a small nonmotile gram-negative coccobacillus that is found in the nasopharynx and gastrointestinal tract of many wild and domesticated animals . In humans it most commonly causes cellulitis and localized superficial skin abscesses following an animal bite or scratch . The respiratory tract is the second most common site of infection for PASTEURELLA: Of the more than 17 species of Pasteurella known, Pasteurella multocida subsp . multocida and Pasteurella multocida subsp . septica are among the most common pathogens in humans . With the use of molecular techniques, distinction between different subspecies of P . multocida can be made more easily and accurately . We used the sequence of the 16S ribosomal DNA (rDNA) and repetitive extragenic palindromic sequence-PCR (REP-PCR) to characterize 20 strains (14 of P . multocida subsp . multocida and 6 of P . multocida subsp . septica; the 16S rDNA is identical for P . multocida subsp . multocida and Pasteurella multocida subsp . gallicida but differs from that of P . multocida subsp . septica) isolated from various anatomic sites . We found excellent correlation between the 16S rDNA sequence (a marker for a small conserved region of the genome), REP-PCR (a marker for a large portion of the genome), and biochemical tests (trehalose and sorbitol) . We also found a correlation between the clinical presentation and the taxonomic group, with P . multocida subsp . septica more often associated with wounds than with respiratory infections (67 versus 17%, respectively) (P < 0.05, Z test) and P . multocida subsp . multocida more often associated with respiratory infections than with wounds (71 versus 14%, respectively) (P < 0.05, Z test).

Genetics, 2002 Aug, 161(4), 1385 - 94
Genomic changes in nucleotide and dinucleotide frequencies in Pasteurella multocida cultured under high temperature; Xia X et al.; We used 94 RAPD primers of different nucleotide composition to probe the genomic differences between a highly virulent P . multocida strain and an attenuated vaccine strain derived from the virulent strain after culturing the latter under increasing temperature for approximately 14,400 generations . The GC content of the vaccine strain is significantly (P < 0.05) lower than that of the virulent strain, contrary to the popular hypothesis of covariation between the GC content and temperature . The frequencies of AA, TA, and TT dinucleotides were higher, and those of AT, GC, and CG dinucleotides were lower, in the vaccine strain than in the virulent strain . A statistic called genomic RAPD entropy is formulated to measure the randomness of the genome, and the genome of the vaccine strain is more random than that of the virulent strain . These differences between the virulent and vaccine strains are interpreted in terms of mutation and selection under increased culturing temperature . A method for estimating substitution rates is developed in the appendix.

Scand J Infect Dis, 2002, 34(7), 536 - 8
Malakoplakia of the lung caused by Pasteurella multocida in a patient with AIDS; Bastas A et al.; We present a case of malakoplakia of the lung caused by Pasteurella multocida in a patient with AIDS . This is the first report to implicate P . multocida in the pathogenesis of malakoplakia.

Infect Immun, 2002 Sep, 70(9), 5058 - 64
Bovine CD18 is necessary and sufficient to mediate Mannheimia (Pasteurella) haemolytica leukotoxin-induced cytolysis; Deshpande MS et al.; Leukotoxin (Lkt) secreted by Mannheimia (Pasteurella) haemolytica is an RTX toxin which is specific for ruminant leukocytes . Lkt binds to beta(2) integrins on the surface of bovine leukocytes . beta(2) integrins have a common beta subunit, CD18, that associates with three distinct alpha chains, CD11a, CD11b, and CD11c, to give rise to three different beta(2) integrins, CD11a/CD18 (LFA-1), CD11b/CD18 (Mac-1), and CD11c/CD18 (CR4), respectively . Our earlier studies revealed that Lkt binds to all three beta(2) integrins, suggesting that the common beta subunit, CD18, may be the receptor for Lkt . In order to unequivocally elucidate the role of bovine CD18 as a receptor for Lkt, a murine cell line nonsusceptible to Lkt (P815) was transfected with cDNA for bovine CD18 . One of the transfectants, 2B2, stably expressed bovine CD18 on the cell surface . The 2B2 transfectant was effectively lysed by Lkt in a concentration-dependent manner, whereas the P815 parent cells were not . Immunoprecipitation of cell surface proteins of 2B2 with monoclonal antibodies specific for bovine CD18 or murine CD11a suggested that bovine CD18 was expressed on the cell surface of 2B2 as a heterodimer with murine CD11a . Expression of bovine CD18 and the Lkt-induced cytotoxicity of 2B2 cells were compared with those of bovine polymorphonuclear neutrophils and lymphocytes . There was a strong correlation between cell surface expression of bovine CD18 and percent cytotoxicity induced by Lkt . These results indicate that bovine CD18 is necessary and sufficient to mediate Lkt-induced cytolysis of target cells.

Antimicrob Agents Chemother, 2002 Sep, 46(9), 3068 - 70
In vitro activities of garenoxacin (BMS-284756) against 170 clinical isolates of nine Pasteurella species; Goldstein EJ et al.; The in vitro susceptibilities of 170 clinical isolates plus 12 American Type Culture Collection strains of Pasteurella species comprising nine species and three Pasteurella multocida subspecies were studied by an agar dilution method . Garenoxacin (BMS-284756), a new des-fluoro(6) quinolone, was active at <or=0.06 micro g/ml against all isolates, including four beta-lactamase-producing strains, with >90% of the strains susceptible to <or=0.008 micro g/ml . Garenoxacin was generally 1 to 2 dilutions more active than levofloxacin and moxifloxacin and was the most active agent tested . Cefoxitin required 1 micro g/ml for inhibition of 51 of 182 (29%) of strains, and 3 strains (also beta-lactamase producers) were resistant to doxycycline.

Antimicrob Agents Chemother, 2002 Sep, 46(9), 3013 - 9
Pharmacokinetic and pharmacodynamic profiles of danofloxacin administered by two dosing regimens in calves infected with Mannheimia (Pasteurella) haemolytica; Sarasola P et al.; The pharmacokinetics and pharmacodynamics of danofloxacin in calves with induced Mannheimia (Pasteurella) haemolytica pneumonia were evaluated . Calves received either saline as an intravenous (IV) bolus or danofloxacin (0.738 mg/kg of body weight) administered as either a single IV bolus or a 36-h continuous IV infusion . Blood samples and bronchial secretions were collected before and at predetermined times over 48 h following the start of treatment . Calves were assessed clinically throughout, and lung consolidation was assessed at necropsy . Bronchial secretions and lung tissue were cultured for M . haemolytica . Bolus administration of danofloxacin produced a high maximum drug concentration-to-MIC ratio (C(max):MIC) of 14.5 and a time period of 9.1 h when plasma danofloxacin concentrations exceeded the MIC (T>MIC) . Following danofloxacin infusion, the C(max):MIC was low (2.3), with a long T>MIC (33.3 h) . The area under the curve-to-MIC ratios were 43.3 and 49.1 for the bolus and infusion administrations, respectively . The single bolus of danofloxacin was more effective than the same dose administered by continuous infusion, as indicated by a significantly lower (P < 0.05) number of animals with M . haemolytica in bronchial secretions after treatment and lower rectal temperatures in the 24 h after the start of treatment . Thus, danofloxacin exhibited concentration-dependent antimicrobial activity in cattle with respiratory disease caused by M . haemolytica.

Aust Vet J, 2002 Jan-Feb, 80(1-2), 87 - 91
Phenotypic characterisation of Australian sheep and cattle isolates of Mannheimia haemolytica, Mannheimia granulomatis and Mannheimia varigena; Blackall PJ et al.; OBJECTIVE: To perform a comprehensive phenotypic characterisation of 35 isolates of bacteria previously identified as haemolytic Pasteurella-Actinobacillus and obtained from cattle and sheep . DESIGN: The 35 isolates that had been obtained from Australian animals, 30 from cattle and five from sheep, were compared with reference strains of the five recognised species of the genus Mannheimia--M . haemolytica, M . glucosida, M . granulomatis, M . ruminalis and M . varigena . RESULTS: Thirty-four of the isolates could be confidently assigned to three species of the genus Mannheimia . Twenty-nine were M . haemolytica, with 25 being isolated from cattle and four from sheep . All but three of the bovine M . haemolytica were isolated from pneumonic lungs . Of the three remaining bovine M . haemolytica isolates, one was obtained in pure culture from a bovine milk sample and the other two as part of a mixed flora associated with a middle ear infection of a calf suffering mucosal disease . Of the four ovine M . haemolytica isolates, two were isolated in pure culture from milk and two, also in pure culture, from pneumonic lungs . Three bovine isolates were identified as M . granulomatis--one from a tongue abscess, one from a jaw abscess and one from a lung showing suppurative bronchopneumonia . Two bovine isolates were identified as M . varigena--one coming from an udder and the other from a spleen . The available diagnostic records provided no information on whether these isolates were associated with a disease process . The remaining isolate was obtained from an ovine tongue abscess and could not be assigned to a recognised species within the genus Mannheimia . CONCLUSION: The study represents the first time that M . haemolytica, M . granulomatis and M . varigena have been recognised as being present in cattle and sheep in Australia . Veterinary laboratories that encounter Pasteurella-Actinobacillus-like organisms from cattle and sheep should attempt as complete a characterisation as possible to help improve our knowledge of the disease potential of these organsims.

Haematologica, 2002 Aug, 87(8), 795 - 803
Clinical value of the quantitative expression of the three epitopes of CD34 in 300 cases of acute myeloid leukemia; Maynadie M et al.; BACKGROUND AND OBJECTIVES: The various epitopes of the CD34 molecule have been classified according to their different sensitivities to enzymatic cleavage by neuraminidase, chymopapain and a glycoprotease from Pasteurella haemolytica . Although monoclonal antibodies have been developed that specifically identify these epitopes, few studies have evaluated the distribution and quantitative expression of such epitopes on leukemic blasts . DESIGN AND METHODS: We report here a prospective multicenter study in which we examined and quantified the expression of the 3 classes of CD34 on fresh leukemic blast cells from 300 cases of acute myeloid leukemia (AML) . The binding of monoclonal antibodies was studied by flow cytometry, allowing evaluation of blast cell positivity as well as their mean fluorescence intensity . These quantitative data were made comparable between centers by means of a calibration curve established with the same reagents in all laboratories . RESULTS: Quantitative expression of class I epitope was significantly higher than that of class II and class III epitopes (p<0.0001) . The three classes were more frequently expressed in M0 and M1 and less in M3 and M5 . The highest levels of CD34 expression were observed in M2, M0 and M1 and the lowest in M3, M5 and BAL for class II and III . CD34 expression was lower for all classes in cases with a normal karyotype, compared to in cases with structural or numerical abnormalities . INTERPRETATION AND CONCLUSIONS: In cases with a t(9;22) the expression of class I was significantly higher than that of class II and III and the opposite was observed in AML with t(15;17) . Moreover, as a whole, a high intensity of class III CD34 appeared to be a marker of good prognosis.

Scand J Infect Dis . 2002;34(6):473.
Pasteurella multocida and intrauterine device: a woman and her pets; Loiez C et al.; Human infections with Pasteurella multocida are frequently attributed to transmission from animals . Although some cases of prosthetic implant infections have been described few gynecological cases have been reported . We describe a case of intrauterine device endometritis due to P . multocida.

Biochem Biophys Res Commun, 2002 Jul 12, 295(2), 561 - 9
G(q/11) is involved in insulin-stimulated inositol phosphoglycan putative mediator generation in rat liver membranes: co-localization of G(q/11) with the insulin receptor in membrane vesicles; Sleight S et al.; Insulin signaling to generate inositol phosphoglycans (IPGs) was demonstrated to occur via the participation of the heterotrimeric G-proteins G(q/11) . IPGs were measured as two specific inositol markers, myo-inositol and chiro-inositol after strong acid hydrolysis . Insulin and Pasteurella multocida toxin (PMT) generated both myo-inositol and chiro-inositol IPGs in a dose-dependent manner . PMT has been shown to activate G(q) specifically . Insulin action was abrogated by pre-treatment with anti G(q/11) antibody . Western blotting demonstrated the enrichment of both insulin receptor beta subunit and G(q/11) in the liver membrane vesicles . Vesicles also contained clathrin, caveolin PLC beta 1 and PLC Delta . Immunogold staining revealed the co-localization of both insulin receptor beta subunit and G(q/11) in an approximate stochiometric ratio of 1:3 . No vesicles were detected with either component alone . The present and considerable published data provide strong evidence for insulin signaling both via a tyrosine kinase cascade mechanism and via heterotrimeric G-protein interactions.

J Clin Microbiol, 2002 Aug, 40(8), 3025 - 31
DNA fingerprinting of Pasteurella multocida recovered from avian sources; Amonsin A et al.; Repetitive sequence-based PCR (rep-PCR) and amplified fragment length polymorphism (AFLP) were used to characterize a sample of 43 field isolates and 4 attenuated vaccine strains of Pasteurella multocida recovered from multiple avian species . Both rep-PCR and AFLP assays were rapid and reproducible, with high indices of discrimination . Concordance analyses of rep-PCR and AFLP with somatic serotyping indicate that, in general, somatic serotyping is a poor indicator of genetic relatedness among isolates of P . multocida . In addition, the data provide evidence of host specificity of P . multocida clones . Overall, the results of our study indicate that the rep-PCR and AFLP techniques enable rapid fingerprinting of P . multocida isolates from multiple avian species and enhance the investigation of fowl cholera outbreaks.

Can J Vet Res, 2002 Jul, 66(3), 181 - 90
Bovine viral diarrhea virus (BVDV) 1b: predominant BVDV subtype in calves with respiratory disease; Fulton RW et al.; The prevalence of bovine viral diarrhea virus (BVDV) infections was determined in 2 groups of stocker calves with acute respiratory disease . Both studies used calves assembled after purchase from auction markets by an order buyer and transported to feedyards, where they were held for approximately 30 d . In 1 study, the calves were mixed with fresh ranch calves from a single ranch . During the studies, at day 0 and at weekly intervals, blood was collected for viral antibody testing and virus isolation from peripheral blood leukocytes (PBLs), and nasal swabs were taken for virus isolation . Samples from sick calves were also collected . Serum was tested for antibodies to bovine herpesvirus-1 (BHV-1), BVDV1a, 1b, and 2, parainfluenza 3 virus (PI3V), and bovine respiratory syncytial virus (BRSV) . The lungs from the calves that died during the studies were examined histopathologically, and viral and bacterial isolation was performed on lung homogenates . BVDV was isolated from calves in both studies; the predominant biotype was noncytopathic (NCP) . Differential polymerase chain reaction (PCR) and nucleic acid sequencing showed the predominant subtype to be BVDV1b in both studies . In 1999, NCP BVDV1b was detected in numerous samples over time from 1 persistently infected calf; the calf did not seroconvert to BVDV1a or BVDV2 . In both studies, BVDV was isolated from the serum, PBLs, and nasal swabs of the calves, and in the 1999 study, it was isolated from lung tissue at necropsy . BVDV was demonstrated serologically and by virus isolation to be a contributing factor in respiratory disease . It was isolated more frequently from sick calves than healthy calves, by both pen and total number of calves . BVDV1a and BVDV2 seroconversions were related to sickness in selected pens and total number of calves . In the 1999 study, BVDV-infected calves were treated longer than noninfected calves (5.643 vs 4.639 d; P = 0.0902) . There was a limited number of BVDV1a isolates and, with BVDV1b used in the virus neutralization test for antibodies in seroconverting calves' serum, BVDV1b titers were higher than BVDV1a titers . This study indicates that BVDV1 strains are involved in acute respiratory disease of calves with pneumonic Mannheimia haemolytica and Pasteurella multocida disease . The BVDV2 antibodies may be due to cross-reactions, as typing of the BVDV strains revealed BVDV1b or la but not BVDV2 . The BVDV1b subtype has considerable implications, as, with 1 exception, all vaccines licensed in the United States contain BVDV1a, a strain with different antigenic properties . BVDV1b potentially could infect BVDV1a-vaccinated calves.

Can J Vet Res, 2002 Jul, 66(3), 173 - 80
Evaluation of health status of calves and the impact on feedlot performance: assessment of a retained ownership program for postweaning calves; Fulton RW et al.; The objective of this study was to evaluate animal health status at entry to a feedlot against feedlot performance and carcass value . There were 24 herds represented by 417 calves in a retained ownership program . The health status at entry was represented by the levels of serum antibody to infectious bovine rhinotracheitis virus (IBRV), bovine viral diarrhea viruses 1 and 2 (BVDV1a, BVDV2), parainfluenza 3 virus (PI3V), bovine respiratory syncytial virus (BRSV), Mannheimia haemolytica, and Pasteurella multocida, as well as by the presence of virus in nasal swabs and blood leukocytes and the presence of bacteria in nasal swabs . The presence or absence of viruses or bacteria at entry did not predict subsequent illness . However, there were predictors of illness severity (number of treatments) and performance parameters of feedlot performance . Herds with a low morbidity rate had higher levels of BVDV1a antibodies than herds with a high morbidity rate . On both an individual-animal and a herd-average basis, calves with low levels of antibody to BVDV1a and BVDV2 had increased total treatment costs . Also, for individual animals and the herd as a whole, low levels of antibody to P . multocida, BVDV1a, and BVDV2 were related to decreased net value to owner (carcass value minus total feedlot cost) . Calves treated twice or more had lower levels of antibody to BVDV1a than those treated once or not at all . Differences in herd morbidity rate and treatment costs were more related to appropriate timing of vaccine (last dose at or near delivery of calf) or lack of a 2nd dose of killed vaccine . This was best illustrated by the levels of antibody to BVDV1a . The results of this study were used to formulate recommendations for the subsequent year.

Int J Antimicrob Agents, 2002 Jul, 20(1), 69 - 72
Antimicrobial anionic peptide binds in vivo to Mannheimia (Pasteurella) haemolytica attached to ovine alveolar epithelium; Heidari M et al.; Endogenous antimicrobial peptide activity in vivo has rarely been demonstrated . To assess this, Mannheimia haemolytica (log(10) 10.20 cfu) was deposited into the lungs of adult sheep, which were killed at 0, 5, 10 and 20 min for necropsy . At 0 min, M . haemolytica appeared normal and monoclonal antibody to antimicrobial anionic peptide (AP) and Protein A-colloidal gold identified AP already bound to the bacterial surface . At 5-20 min, many organisms were distorted with flocculated intracellular constituents characteristic of AP cellular damage indicating that AP can bind to and presumably help inactivate organisms in vivo.

Infect Immun, 2002 Aug, 70(8), 4336 - 43
Inflammatory cytokines enhance the interaction of Mannheimia haemolytica leukotoxin with bovine peripheral blood neutrophils in vitro; Leite F et al.; Mannheimia (Pasteurella) haemolytica A1 produces several virulence factors that play an important role in the pathogenesis of bovine pneumonic pasteurellosis . Foremost among these is a leukotoxin (LKT) that specifically kills ruminant leukocytes . Recent evidence suggests that M . haemolytica LKT binding to bovine leukocytes is mediated by the beta(2)-integrin CD11a/CD18 (lymphocyte function-associated antigen 1 {LFA-1}), which subsequently induces activation and cytolysis of these cells . Inflammatory cytokines, which are released during viral and bacterial infection, are reported to increase LFA-1 expression and conformational activation . We investigated the effects of the inflammatory cytokines interleukin-1beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha), and gamma interferon (IFN-gamma) on the interaction of M . haemolytica LKT with bovine peripheral blood neutrophils (PMNs) . In this study we demonstrated, by flow cytometry, that bovine PMNs increased their binding to an anti-bovine LFA-1 monoclonal antibody (BAT75A) following in vitro incubation with IL-1beta, TNF-alpha, or IFN-gamma . Incubation with cytokines also increased CD18 expression, as assessed by real-time PCR and by Western blotting . Increased LFA-1 expression by PMNs exposed to cytokines was associated with increased LKT binding and cytotoxicity . The latter represented, at least in part, enhanced PMN apoptosis, as assessed by propidium iodine staining and caspase-3 activation . The results of this study suggest that inflammatory cytokines may play an important role in enhancing the biological response of bovine PMNs to M . haemolytica LKT.

Surg Today, 2002, 32(6), 513 - 5
Pasteurella multocida endocarditis: report of a case; Fukumoto Y et al.; The present case involves a 48-year-old male patient who presented with Pasteurella multocida endocarditis associated with preexisting mitral valve stenosis . A mitral valve replacement was successfully performed after 3 weeks of intravenous infusion with antibiotics . Pasteurella multocida is a normal inhabitant of the oral cavity of dogs and cats . Therefore, people who have frequent contact with these animals should be examined periodically for signs of infection.

J Cataract Refract Surg, 2002 Jul, 28(7), 1251 - 5
Effect of haptic angulation on posterior capsule opacification in modern foldable lenses with a square, truncated optic edge; Schmidbauer JM et al.; PURPOSE: To analyze the effect of different haptic angulations on posterior capsule opacification (PCO) in a modern foldable intraocular lens (IOL) with a square-edged optic designed to reduce the incidence of PCO . SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA . METHODS: Ten Dutch Belted, serum Pasteurella-free pigmented rabbits of the same age and sex had bilateral phacoemulsification with endocapsular IOL implantation . The eyes were implanted with Centerflex IOLs (Rayner) with haptic angulations of 0 degree (n = 8), 5 degrees (n = 4), 10 degrees (n = 4), or 15 degrees (n = 4).RESULTS: There was no statistical difference in central PCO, peripheral PCO, and measured IOL decentration among the angulation groups . CONCLUSION: With the Centerflex IOL, haptic angulation did not seem to be a significant factor influencing PCO . It appears that the barrier effect of the IOL's truncated, square-edged optic overrides the angulation factor in preventing PCO.

Vet Res Commun, 2002 Apr, 26(3), 179 - 88
Antigenic relationships within the genus Salmonella as revealed by anti-Salmonella enteritidis monoclonal antibodies; Malik M et al.; A panel of 38 monoclonal antibodies (MAbs) that react with outer membrane proteins (OMPs) of Salmonella enteritidis was produced . On the basis of their binding pattern in ELISA, the MAbs were divided into three groups . The first group, consisting of 15 MAbs, was found to be Salmonella-specific as they did not cross-react with Escherichia coli or Pasteurella multocida . The second group of 15 MAbs cross-reacted with E . coli but not with P . multocida, reflecting the closer antigenic relationship of E . coli with Salmonella . The third group of 8 MAbs cross-reacted with both E . coli and P . multocida, indicating that the antigenic determinants identified by these MAbs are conserved in all the three genera . The antigenic relationship of the Salmonella serovars (S . enteritidis, S . gallinarum, S . typhimurium, S . dublin, S . agona, S . indiana and S . choleraesuis) was studied using OMPs prepared from them and the anti-S . enteritidis MAbs . Three MAbs appeared to be specific for S . enteritidis as they did not cross-react with any of the other Salmonella serovars . Twelve of the 38 MAbs cross-reacted with all the serovars tested . Six of these were specific to the Salmonella genus as they did not cross-react with any of the other Gram-negative bacteria tested . The reactivity pattern of the other MAbs indicated that S . gallinarum was antigenically close to S . enteritidis, followed in order by S . dublin, S . agona, S . typhimurium and S . indiana, whereas S . choleraesuis seemed to be antigenically quite distant from S . enteritidis.

J Vet Pharmacol Ther, 2002 Jun, 25(3), 175 - 80
Dose determination and confirmation of a long-acting formulation of ceftiofur (ceftiofur crystalline free acid) administered subcutaneously for the treatment of bovine respiratory disease; Hibbard B et al.; The objective of this work was to determine and confirm an effective dose of ceftiofur crystalline free acid sterile oil suspension (CCFA-SS, 100 mg ceftiofur equivalents (CE)/mL}, a long-acting single-administration ceftiofur formulation, for the treatment of the bacterial component of bovine respiratory disease (BRD) . Study 1 was a dose determination study that used an intratracheal Mannheimia haemolytica (Pasteurella haemolytica) challenge model to evaluate single-administration doses of CCFA-SS at 0.0, 1.1, 2.2, 3.3, 4.4 or 5.5 mg CE/kg body weight (BW) for the treatment of BRD . Data from this study were used to select doses for field testing in three multi-location clinical studies . In Study 2, the efficacy of a single administration dose of CCFA-SS at 4.4 mg CE/kg BW was compared with a negative control for the treatment of naturally occurring BRD in feedlot cattle . Treatments were administered when uniform clinical signs of BRD were present . Study 3 used a design similar to Study 2, and compared single-administration doses of CCFA-SS at 3.0 or 4.4 mg CE/kg BW with the positive-control tilmicosin (Micotil(R) 300 Injection, Elanco Animal Health) at 10 mg/kg BW . Study 4 compared the efficacy of single doses of CCFA-SS of 1.1-8.8 mg CE/kg BW with tilmicosin at 10 mg/kg BW . A total of 1176 cattle were included in these clinical studies . In Study 1, a dose of 4.55 mg CE/kg BW was determined to be effective . This was rounded to 4.4 mg CE/kg for field testing . In Study 2, a single dose of CCFA-SS at 4.4 mg CE/kg BW had a higher treatment success rate on day 14 (61%) than negative controls (26%, P < 0.01) . However, in Study 3 this dose was judged to be at the beginning of an efficacious dose range for the treatment of BRD when compared with tilmicosin . In Study 4, day 28 treatment success rates were higher for CCFA-SS at 4.4-8.8 CE/kg BW than for tilmicosin (P=0.002) or the noneffective CCFA-SS dose of 1.1 mg CE/kg BW (P < 0.001) . Based on decision criteria for Study 4, the effective dose was determined to be 4.4-5.5 mg CE/kg BW . These clinical studies demonstrated that a single dose of CCFA-SS (100 mg CE/mL) administered subcutaneously (s.c.) in the neck at 4.4-5.5 mg CE/kg BW is an effective treatment for BRD in feedlot cattle . However, this route of administration is no longer being considered for this formulation because of the ceftiofur residues that are present at the injection site for extended periods of time.

Med Pregl, 2001, 54 Suppl 1, 39 - 42
{Treatment of bite wounds and cat-scratch disease}; Jovanovic J et al.; Although rabies is the most serious consequence of animal bite injuries, in urban rabies-free countries the risk of rabies is far lower than the risk of bacterial infections of the wound . The most frequent etiologic cause of the wound infections after dog bites is Pasteurella multocida, as well as in the case of bites by cats, after which cat-scratch disease may also develop, its main cause being Bartonella henselae . All bite injuries must be carefully cleaned and disinfected; it is necessary to estimate the need of antirabies and antitetanus protection, and to introduce antibiotic treatment for prevention, particularly in the case of deep sting wounds caused mostly by cats.

Res Vet Sci, 2002 Jun, 72(3), 194 - 200
Development of a clinical syndrome resembling haemorrhagic septicaemia in the buffalo following intravenous inoculation of Pasteurella multocida serotype B:2 endotoxin and the role of tumour necrosis factor-alpha; Horadagoda NU et al.; Clinical changes and acute phase responses, including tumour necrosis factor-alpha (tnfalpha), in six buffalo calves were examined following intravenous inoculation of a bolus of endotoxin (1 microg kg(-1) bodyweight in 10 ml of phosphate-buffered saline { pbs }) extracted from Pasteurella multocida serotype B:2, the bacterium responsible for haemorrhagic septicaemia (hs) in Asia . Endotoxin injection caused a rapid onset of clinical signs characterised by dullness, sternal recumbency, elevated rectal temperatures, excessive salivation and dyspnoea that lasted for up to 12 hours post-inoculation (p.i.) . Serum concentrations of tnfalpha rose within 1 hour p.i . to reach peak values ranging between 8 and 140 ng ml(-1) at 1-2 hours p.i . and then declined rapidly to baseline levels 3-5 hours p.i . Endotoxin injection induced other acute phase changes, including a rapid leucopenia and reductions in the serum concentrations of iron and zinc and a delayed but prolonged increase in haptoglobin from 12 hours p.i . that reached a plateau from about 60 hours p.i . Three control calves injected with 10 ml pbs showed no clinical or blood compositional changes . By reproducing key signs of hs the work confirms a pivotal role of endotoxin in the pathogenesis of hs and emphasises the exquisite sensitivity of the buffalo to P multocida endotoxin .

J Neurochem, 2002 Jun, 81(5), 1116 - 29
Phospholipase C-mediated signalling is not required for histamine-induced catecholamine secretion from bovine chromaffin cells; Donald AN et al.; A possible role for signalling through phospholipase C in histamine-induced catecholamine secretion from bovine adrenal chromaffin cells has been investigated . Secretion evoked by histamine over 10 min was not prevented by inhibiting inositol-1,4,5-trisphosphate receptors with 2-APB, by blocking ryanodine receptors with a combination of ryanodine and caffeine, or by depleting intracellular Ca(2+) stores by pretreatment with thapsigargin . Inhibition of protein kinase C with Ro31-8220 also failed to reduce secretion . Inhibition of phospholipase C with ET-18-OCH(3) reduced both histamine- and K(+) -induced inositol phosphate responses by 70-80% without reducing their secretory responses . Stimulating phospholipase C with Pasteurella multocida toxin did not evoke secretion or enhance the secretory response to histamine . The secretory response to histamine was little affected by tetrodotoxin or by substituting extracellular Na(+) with N -methyl-d-glucamine(+) or choline(+), or by substituting external Cl(-) with nitrate(-) . Blocking various K(+) channels with apamin, charybdotoxin, Ba(2+), tetraethylammonium, 4-aminopyridine, tertiapin or glibenclamide failed to reduce the ability of histamine to evoke secretion . These results indicate that histamine evokes secretion by a mechanism that does not require inositol-1,4,5-trisphosphate-mediated mobilization of stored Ca(2+), diacylglycerol-mediated activation of protein kinase C, or activation of phospholipase C . The results are consistent with histamine acting by depolarizing chromaffin cells through a phospholipase C-independent mechanism.

Infect Immun, 2002 Jul, 70(7), 3355 - 62
Protective immunity conferred by attenuated aroA derivatives of Pasteurella multocida B:2 strains in a mouse model of hemorrhagic septicemia; Tabatabaei M et al.; Hemorrhagic septicemia (HS) is a fatal systemic disease of cattle and buffaloes . In South Asia HS is caused by infection with Pasteurella multocida serotype B:2 . Some control is achieved with alum-precipitated or oil-adjuvanted killed whole-cell vaccines injected subcutaneously, but these vaccines provide only short-term immunity and require annual administration for effective use . Live attenuated vaccines have the advantage of a natural route of entry into the host, but for live strains to be used as vaccines, the mode of attenuation should be well defined . We constructed aroA attenuated derivatives of two P . multocida serotype B:2 strains by allelic exchange of the native aroA sequence with aroA sequences disrupted with a kanamycin resistance cassette or with marker-free aroA sequences containing an internal deletion . These strains were confirmed to be aroA mutants by PCR and Southern blot analysis, enzyme assay, and lack of growth on minimal medium . The aroA derivatives were highly attenuated for virulence in a mouse model of HS . Mouse challenge experiments showed that intraperitoneal or intranasal vaccination of an aroA strain completely protected mice against challenge with a high dose (>1,000 50% lethal doses) of either the parent strain or the other wild-type B:2 strain . The spread of the parent and the aroA derivatives to different organs was compared when the organisms were inoculated by different routes.

Avian Dis, 2002 Apr-Jun, 46(2), 505 - 8
Increased mortality in turkeys selected for increased body weight following vaccination with a live Newcastle disease virus vaccine; Saif YM et al.; Candidate male and female breeders from nine genetic lines of turkeys that were reared intermingled, with the sexes housed in different buildings on the same farm, were vaccinated with a live Newcastle disease virus vaccine (B1 type, LaSota) just prior to the commencement of egg production . In 1999, an average mortality for all lines of 5.8% occurred during the 10 days immediately following vaccination and the level of mortality varied among lines . Mortality was, in general, greater in large-bodied lines than in small-bodied lines . Affected birds exhibited gross multiple areas of focal necrosis in the liver and spleen and congestion of the heart and lungs . The percentage mortality occurring following similar vaccination in 2000 averaged 2.6 for the 10 days following vaccination and mortality was greater (P < or = 0.05) in one line (F line) than the other genetic groups and higher in females than in males . Mortality in the F line, selected for increased body weight and known to be susceptible to various diseases, averaged 15.1% for both years . Attempts failed in both years to isolate Pasteurella multocida or other bacteria . There was a positive correlation between increased body weight and increased mortality following vaccination with the live LaSota vaccine.

Avian Dis, 2002 Apr-Jun, 46(2), 370 - 7
A serotype-specific polymerase chain reaction for identification of Pasteurella multocida serotype 1; Rocke TE et al.; A serotype-specific polymerase chain reaction (PCR) assay was developed for detection and identification of Pasteurella multocida serotype 1, the causative agent of avian cholera in wild waterfowl . Arbitrarily primed PCR was used to detect DNA fragments that distinguish serotype 1 from the other 15 serotypes of P . multocida (with the exception of serotype 14) . Oligonucleotide primers were constructed from these sequences, and a PCR assay was optimized and evaluated . PCR reactions consistently resulted in amplification products with reference strains 1 and 14 and all other serotype 1 strains tested, with cell numbers as low as 2.3 cells/ml . No amplification products were produced with other P . multocida serotypes or any other bacterial species tested . To compare the sensitivity and further test the specificity of this PCR assay with traditional culturing and serotyping techniques, tissue samples from 84 Pekin ducks inoculated with field strains of P . multocida and 54 wild lesser snow geese collected during an avian cholera outbreak were provided by other investigators working on avian cholera . PCR was as sensitive (58/64) as routine isolation (52/64) in detecting and identifying P . multocida serotype 1 from the livers of inoculated Pekins that became sick or died from avian cholera . No product was amplified from tissues of 20 other Pekin ducks that received serotypes other than type 1 (serotype 3, 12 x 3, or 10) or 12 control birds . Of the 54 snow geese necropsied and tested for P . multocida, our PCR detected and identified the bacteria from 44 compared with 45 by direct isolation . The serotype-specific PCR we developed was much faster and less labor intensive than traditional culturing and serotyping procedures and could result in diagnosis of serotype 1 pasteurellosis within 24 hr of specimen submission.

J Bacteriol, 2002 Jul, 184(13), 3734 - 9
Transcriptional response of Pasteurella multocida to nutrient limitation; Paustian ML et al.; Bacteria often encounter environments where nutrient availability is limited, and they must adapt accordingly . To identify Pasteurella multocida genes that are differentially expressed during nutrient limitation, we utilized whole-genome microarrays to compare levels of gene expression during growth in rich and minimal media . Our analysis showed that the levels of expression of a total of 669 genes, representing approximately one-third of the genome, were detectably altered over the course of the experiment . A large number (n = 439) of genes, including those involved in energy metabolism, transport, protein synthesis, and binding, were expressed at higher levels in rich medium, suggesting that, upon exposure to a rich environment, P . multocida immediately begins to turn on many energy-intensive biosynthetic pathways or, conversely, turns these genes off when it is exposed to a nutrient-deficient environment . Genes with increased expression in minimal medium (n = 230) included those encoding amino acid biosynthesis and transport systems, outer membrane proteins, and heat shock proteins . Importantly, our analysis also identified a large number (n = 164) of genes with unknown functions whose expression was altered during nutrient limitation . Overall, the results of our study show that a wide repertoire of genes, many of which have yet to be functionally classified, undergo transcriptional regulation in P . multocida in response to growth in minimal medium and provide a strong foundation to investigate the transcriptional response of this multispecies pathogen to growth in a nutrient-limited environment.

Int J Syst Evol Microbiol, 2002 May, 52(Pt 3), 699 - 704
Pasteurella skyensis sp . nov., isolated from Atlantic salmon (Salmo salar L.); Birkbeck TH et al.; From four separate incidents of disease in farmed Atlantic salmon over a four-year period, gram-negative rod-shaped bacteria were consistently isolated by culture on sea-water blood agar . Biochemical and physiological tests indicated that the organism was related to the family Pasteurellaceae, and this was confirmed from the 16S rRNA gene sequence . Comparison of the 16S rRNA gene sequence with those of 45 members of the Pasteurellaceae showed that the closest phylogenetic relationship was with an organism termed 'Pasteurella phocoenarum', isolated from a porpoise, for which the 16S rRNA gene sequence has been recorded but for which the properties have yet to be published . It is proposed that this bacterium isolated from salmon should be classified as a new species, namely Pasteurella skyensis sp . nov . The type strain of Pasteurella skyensis sp . nov . is strain 95A1T (= NCTC 13204T = NCIMB 13593T).

Vet Rec, 2002 May 25, 150(21), 658 - 64
Infectious agents associated with respiratory disease in pheasants; Welchman Dde B et al.; In a case-control study of the infectious agents associated with natural outbreaks of respiratory disease in pheasants, 28 batches of birds from sites affected by disease and eight batches of birds from unaffected sites were examined by six veterinary laboratories in England, Wales and Scotland, and tested for mycoplasmas, other bacteria and viruses . Sinusitis was the commonest sign of disease and was associated with Mycoplasma gallisepticum as detected by PCR in the trachea (P < 0.05) and conjunctiva (P < 0.01) . Sinusitis was also associated with pasteurella cultured from the sinus (P < 0.05), antibody to avian pneumovirus (APV) (P < 0.01) and avian coronaviruses as detected by reverse-transcriptase PCR (P < 0.05); there was no association between disease and APV as detected by PCR . Avian coronaviruses were the most common infectious agents detected . They were genetically close to infectious bronchitis virus (IBV) but differed in their gene sequence from all the serotypes of IBV previously identified in domestic fowl, and serological tests with six known IBV types showed little cross reactivity . Mycoplasma species other than M gallisepticum were cultured in 18 batches of pheasants but, with the exception of Mycoplasma gallinaceum, were not associated with disease.

Vet Microbiol, 2002 Jul 9, 87(3), 221 - 35
Characterization of, and immune responses of mice to, the purified OmpA-equivalent outer membrane protein of Pasteurella multocida serotype A:3 (Omp28); Gatto NT et al.; Pasteurella multocida A:3 is a major cause of bovine pneumonia . A major antigenic heat-modifiable 28kDa outer membrane protein (Omp28) was previously identified . The purpose of this study was to purify and characterize Omp28 immunologically and structurally . Omp28 was extracted from N-lauroylsarcosine-insoluble protein preparations by a combination of detergent fractionation with Zwittergent 3-14 and chromatography . Partial N-terminal amino acid sequence confirmed Omp28 as a member of the OmpA-porin family . However, porin activity could not be demonstrated in a lipid-bilayer assay . Heat modifiability of purified Omp28 was demonstrated, and Omp28 was found in outer membrane fraction of P . multocida . Surface exposure of Omp28 was demonstrated by partial protease digestion of intact bacteria, by binding of anti-Omp28 polyclonal ascites fluid to the bacterial surface, and by partial inhibition of anti-outer membrane antiserum binding by previous incubation of the bacteria with anti-Omp28 serum . CD-1 mice vaccinated with purified Omp28 developed a significant antibody titer (P<0.05) compared to the control treatment group but were not protected from a homologous intraperitoneal bacterial challenge . By contrast, treatment groups vaccinated with P . multocida outer membrane, formalin-killed P . multocida or a commercial vaccine were significantly protected from challenge . In vitro complement-mediated killing of P . multocida was observed in post-vaccination sera of outer membrane, formalin-killed P . multocida, and commercial vaccine-treatment groups, but not with sera from the Omp28-treatment group . In conclusion, although Omp28 is surface exposed and antigenic, it may not be a desirable immunogen for stimulating immunity to P . multocida.

Vet Ther, 2002 Spring, 3(1), 22 - 30
Dose determination and confirmation for ceftiofur crystalline-free acid administered in the posterior aspect of the ear for control and treatment of bovine respiratory disease; Hibbard B et al.; Three studies were conducted to determine and confirm the effective dosage rate of ceftiofur crystalline-free acid sterile suspension (CCFA-SS, 200 mg ceftiofur equivalents {CE}/ml), a long-acting ceftiofur formulation, for control and treatment of bovine respiratory disease (BRD) . In each study, CCFA-SS was administered once by subcutaneous (SC) injection in the middle third of the posterior aspect of the ear . Study 1 was conducted using an intratracheal challenge with Mannheimia (formerly Pasteurella) haemolytica and dosages ranging from 0 to 8.8 mg CE/kg to select a dosage for further field testing . In Study 2, a single dose of CCFA-SS at 0.0, 4.4, or 6.6 mg CE/kg was administered when uniform clinical signs of BRD were present in feedlot cattle . Study 3 was conducted in several feedlots to evaluate the efficacy, practicality, and safety of CCFA-SS at 4.4 or 6.6 mg CE/kg compared with a placebo control or tilmicosin for preemptive control of BRD . In Study 1, the effective dose was determined to be 5.35 mg CE/kg; therefore, 4.4 and 6.6 mg CE/kg were selected as the dosages for further field testing . Administration of CCFA-SS at 4.4 or 6.6 mg CE/kg improved treatment success compared with negative controls (P < or =.05 for both doses) in Study 2 . In Study 3, a single administration of 4.4 or 6.6 mg CE/kg was comparable to tilmicosin (P <.001) and was significantly better than placebo (P <.001) for the control of BRD . Using the ear as an administration site was acceptable under field conditions and was well tolerated by all animals . These studies demonstrated that a single administration of CCFA-SS by SC injection in the middle third of the posterior aspect of the ear at 4.4 or 6.6 mg CE/kg is effective, safe, and practical for preemptive control and treatment of the bacterial component of BRD in feedlot cattle . Administration in an inedible tissue results in a short withdrawal time and no injection-site trimming at slaughter.

FEMS Microbiol Lett, 2002 May 7, 210(2), 201 - 8
Pasteurella multocida exbB, exbD and tonB genes are physically linked but independently transcribed; Bosch M et al.; The exbB, exbD and tonB genes of the Pasteurella multocida animal pathogen have been cloned by complementation of an Escherichia coli tonB mutant . Despite these three genes being physically linked, RT-PCR analysis, lacZ transcriptional fusions and construction of insertional mutants have demonstrated that they do not constitute an operon, but rather are transcribed independently from each other . Furthermore, expression of these three genes is under iron control as revealed by lacZ fusions and Fur titration assay analysis . Moreover, each of these three genes is necessary for the virulence of P . multocida cells and all of them contribute equally to the infectious process of this microorganism.

Gene, 2002 Feb 20, 285(1-2), 101 - 8
Sequencing analysis of a putative human O-sialoglycoprotein endopeptidase gene (OSGEP) and analysis of a bidirectional promoter between the OSGEP and APEX genes; Seki Y et al.; We performed cDNA and genomic cloning, sequencing and promoter analysis of the putative human O-sialoglycoprotein endopeptidase gene OSGEP (a homologue of gcp, a Pasteurella haemolytica A1 glycoprotease) . The cloned OSGEP cDNA is 1311 nucleotides long, and encodes a protein consisting of 335 amino acids with predicted molecular mass of 36.4 kDa . The amino acid sequence of OSGEP showed 29.7% identity with that of P . haemolytica glycoprotease . The OSGEP gene is 7.75 kb long, consists of 11 exons and 10 introns, and lies immediately adjacent to the APEX gene (which encodes APEX nuclease, a multifunctional DNA repair enzyme) in 5'-to-5' orientation . The promoter region of the OSGEP gene lacks the typical TATA box, but has putative regulatory elements in the CpG island . Northern blot analysis showed ubiquitous expression of the OSGEP gene in several tissues, and we observed similarities in expression patterns between OSGEP and APEX . In order to study the regulation of OSGEP gene expression, we analyzed the OSGEP promoter region by luciferase assay using HeLa cells . A functional region required for full transcription activity was narrowed down to a 23 bp region containing a CCAAT box . It has been reported that this CCAAT box promotes basal transcription in the APEX direction . We thus conclude that a bidirectional promoter containing a CCAAT box regulates transcription of both the OSGEP and APEX genes.

J Clin Microbiol, 2002 Jun, 40(6), 2163 - 8
Random amplified polymorphic DNA and amplified fragment length polymorphism analyses of Pasteurella multocida isolates from fatal fowl cholera infections; Huber BS et al.; Fowl cholera, a disease caused by Pasteurella multocida, continues to be a major problem for the poultry industry . The sources of pathogenic organisms responsible for most sporadic epidemics remain unconfirmed, although attenuated vaccines that retain a low level of virulence have occasionally been implicated in outbreaks of the disease . One of the vaccines most commonly used to prevent fowl cholera is the M-9 strain . In the present study, 61 clinical isolates from turkeys that died of fowl cholera from 1997 to 1999 on 36 Utah farms were analyzed and compared to the M-9 vaccine strain . Genetic analyses of the isolates were done by random amplified polymorphic DNA (RAPD) analysis and amplified fragment length polymorphism (AFLP) fingerprinting . The results of these genetic analyses were correlated with the vaccination status of the flock, isolate serotype, and geographic location . Although both genetic techniques effectively identified similar subtle genomic differences, RAPD analysis provided only 77% of the detail provided by AFLP analysis . While a relationship between genetic profile and serotype was evident, no significant relationship indicating geographic influence was found (P = 0.351) . Interestingly, organisms isolated from vaccinated flocks were significantly closer genetically to the M-9 vaccine strain than isolates from unvaccinated birds were (P = 0.020) . Statistical analyses revealed that this relationship could not have been determined by serotyping alone (P = 0.320), demonstrating the value of AFLP and RAPD analyses in the characterization of disease-causing strains.

Vet Microbiol, 2002 Jun 20, 87(2), 159 - 74
Characterization of Aqx and its operon: the hemolytic RTX determinant of Actinobacillus equuli; Berthoud H et al.; Actinobacillus equuli, a member of the family Pasteurellaceae is the etiologic agent of a frequently lethal septicemia in neonatal foals as well as other more chronic diseases like arthritis, pleuritis, pneumonia or peritonitis . It may also be isolated from the oral cavity of healthy horses . Hemolytic isolates of A . equuli are known but so far no virulence determinants have been described for this bacterial species . By screening hemolytic A . equuli strains with specific gene probes, a hemolysin, designated Aqx (A . equuli RTX (repeats in the structural toxin)) was identified . This hemolysin was shown to be an RTX type of toxin by characterization of the aqxCABD operon . All hemolytic A . equuli isolates contained a functional aqxCABD operon and expressed the Aqx hemolysin as shown by genetic and phenotypic assays . The structural toxin AqxA is the hemolysin of A . equuli as shown by expression of recombinant aqx constructs in E . coli . Its hemolytic activity can be inhibited by specific antibodies raised against AqxA . Sequence analysis of the 16S rRNA gene (rrs) of the taxonomically diffuse group of A . equuli and related strains defined two phylogenetically distinct groups . The presence of the Aqx operon is not correlated with this phylogenetic grouping . The operon is found in both groups of A . equuli strains where it specifies the hemolytic activity and is supposedly to be a determinative virulence factor . The aqx operon was not found in closely related members of the Pasteurellaceae family . The description of the Aqx hemolysin will open new ways for studying the pathogenesis of A . equuli.

Scand J Infect Dis, 2002, 34(3), 213 - 7
Pasteurella multocida meningitis: case report and review of the last 11 y; Green BT et al.; Pasteurella multocida meningitis is a rare clinical occurrence . We report a new case and review the 28 other cases described in the English literature . A history of recent animal contact remains strongly associated with P . multocida meningitis (noted in 89% of all cases), with licking of mucus surfaces or injured skin being most common . Bacteremia was present in 63% of all patients . Spread from an adjacent site of infection continues to be an important factor, with otitis media being documented or strongly suspected in 24% of all cases . The presenting signs and symptoms were characteristic of bacterial meningitis, with fever, headache, nucal rigidity and an altered level of consciousness being present in most patients . Cerebrospinal fluid analysis was typical for bacterial meningitis . Penicillin G or ampicillin was the most common definitive treatment; however, third-generation cephalosporins have been successful . The mean duration of treatment was 14 d . Neurologic complications were present in 17% of patients overall and mortality remains substantial at 25% . Although not statistically significant, there is a trend toward decreased neurologic complications and mortality during the last 11 y.

J Vet Med B Infect Dis Vet Public Health, 2002 Apr, 49(3), 130 - 4
Treatment of experimentally induced Pasteurella multocida infections in broilers and turkeys: comparative studies of different oral treatment regimens; Sarkozy G et al.; Experimental fowl cholera was induced in 60 healthy 10-week-old broiler chickens and 8-week-old turkeys by intramuscular inoculation with approximately 80 colony-forming units (cfu) of Pasteurella multocida X-73 strain and with approximately 70 cfu of P . multocida P-1059 strain, respectively . This method of infection proved to be useful for evaluating the efficacy of anti-microbial medication, by measuring mortality, weight gain, pathological responses and frequency of re-isolation of P . multocida . The efficacies of two different dosing methods, continuous and pulse dosing, were compared . Using the continuous-dosing method, norfloxacin was administered to drinking water at 100 mg/l for 5 days in chickens . Efficacies were slightly improved compared with pulse dosing at 15 mg/kg bodyweight for the same length of time . The opposite was observed in turkeys, to the degree of control of mortality and maintenance of weight gain.

New Microbiol, 2002 Apr, 25(2), 195 - 204
p53 and c-myc activation by Pasteurella haemolytica leukotoxin is correlated with bovine mononuclear cells apoptosis; Marcatili A et al.; To analyse the role of Pasteurella haemolytica Leukotoxin (LKT) in the mechanism of apoptotic cell death of bovine lymphocytes, we evaluated DNA fragmentation and p53 and c-myc expression . P . haemolytica strain ATCC 14003 was cultivated for LKT production . DNA fragmentation was analysed by electrophoresis on Agarose gel . DNA strand breaks in individual apoptotic cells were also detected by an in situ Terminal deoxy nucleotidyl Transferase (TdT) . The Polymerase Chain Reaction (PCR) procedure was used for verified p53 and c-myc activation by P . haemolytica LKT . LKT was able to induce DNA fragmentation in a dose and time-dependent fashion . The greatest apoptotic effect was obtained using LKT at a concentration of 0.25 U . The results show that p53 and c-myc activation by LKT is correlated with apoptosis of bovine lymphocytes and monocytes . Our data suggest that LKT may have an important role in the bacterial virulence of Pasteurella haemolytica.

Vet Rec, 2002 May 4, 150(18), 569 - 71
Protection of piglets against atrophic rhinitis by vaccinating the sow with a vaccine against Pasteurella multocida and Bordetella bronchiseptica; Riising HJ et al.; The efficacy of a new vaccine against atrophic rhinitis in pigs was tested in the Netherlands and Denmark . The vaccine contained protein dO (a truncated Pasteurella multocida toxin which is immunogenic and non-toxic), inactivated Bordetella bronchiseptica whole cells, and an adjuvant . The sows were either vaccinated intramuscularly with 2 ml of the vaccine at six to eight and two to four weeks before expected farrowing or left unvaccinated as controls . All the piglets were challenged intranasally with B bronchiseptica when three to seven days old and with P multocida three to four days later . Pigs born to the vaccinated sows performed significantly better than pigs born to the control sows when judged on growth, average daily weight gain and snout scores . The challenge organisms were reisolated more frequently from the control pigs than from the pigs in the vaccinated group . The vaccinated sows and their progeny developed high titres of antibodies against B bronchiseptica and P multocida toxin.

J Am Acad Dermatol, 2002 May, 46(5 Suppl), S151 - 2
Pasteurella canis osteomyelitis and cutaneous abscess after a domestic dog bite; Hara H et al.; The genus Pasteurella is part of the normal oral flora of many animals, including domestic cats and dogs . In humans, Pasteurella may cause complications ranging from cellulitis to septicemia but rarely causes osteomyelitis or septic arthritis after bites and/or scratches by cats and dogs . Although Pasteurella multocida is a common cause of infection, other Pasteurella species have also been cultured from wounds in humans . We describe here, a case of a cutaneous abscess and acute osteomyelitis associated with P canis after a domestic dog bite . To our knowledge, no previous case of P canis has been reported as the cause of acute osteomyelitis in humans.

Dtsch Tierarztl Wochenschr, 2002 Apr, 109(4), 205 - 9
Cytokine mRNA expression in experimental porcine pneumonia; Berndt A et al.; A porcine Pasteurella multocida (P . m.) infection model was established to study the spatial distribution of cytokine mRNA-expressing cells in lung tissue during acute pneumonia . The mRNA detection was performed by non-radioactive, formamide-free in situ hybridization (ISH) using oligonucleotides against the porcine interleukins (IL): IL-1 beta, IL-2, IL-4, IL-6, IL-8, TNF alpha and TGF beta . Cytokine mRNA-expressing macrophages were demonstrated by a double staining procedure combining immunohistochemistry (IH) using the primary antibody 2G6 with IL-1 beta, IL-6 and TGF beta ISH . With the exception of some stained TNF alpha-expressing cells, no IL mRNA was detectable in the lung of unaffected animals . The experimental P . m . pneumonia was characterized by a predominant, exudative and an additional proliferative interstitial component as well as abscess formation in the lung . Many cells of the region between the abscess membrane and the affected lung area showed high IL-6, IL-1 beta, IL-4 as well as TGF beta and few cells low IL-8 mRNA expression with characteristic distribution patterns . The ISH/IH double staining procedure revealed that at least some of the IL-6 or TGF beta-producing cells belonged to the 2G6-positive macrophages.

Dtsch Tierarztl Wochenschr, 2002 Apr, 109(4), 193 - 200
{Consequences of short term fluctuations of the environmental temperatures in calves--Part 2: Effects on the health status of animals within three weeks after exposure}; Reinhold P et al.; The aim of the present study was to examine consequences of sudden changes in ambient temperature over a 4-hour period (see part 1 {ELMER & REINHOLD, 2002}) on respiratory health in clinically healthy calves . Therefore, the relationship between short-term changes in ambient temperature and the occurrence of clinical respiratory disease was checked over a period of 3 weeks after exposure in 10 calves exposed to 5 degrees C, in 9 calves exposed to 35 degrees C and in 8 control calves (kept at 18-20 degrees C) . Within the period beginning 3 days before exposure and lasting until up to 21 days after exposure, each calf was examined clinically . Rectal temperature and respiratory rate were measured daily . All calves were euthanised on day 21 after exposure . Macroscopically visible pneumonic lesions were evaluated using a semiquantitative system . Tissue samples from tonsils, bronchi, trachea, lung and mediastinal lymph nodes were examined bacteriologically . In contrast to non-exposed control calves, severe respiratory illness was observed in individual calves of both exposed groups (5 degrees C, 35 degrees C) . Significant increases in body temperature, respiratory rate and animal losses (2 calves died in the group exposed to 5 degrees C, one calf died in the group exposed to 35 degrees C) were the main clinical findings . At necropsy (3 weeks after exposure), no pneumonic lesions were observed in control calves--despite the fact that this group had the highest microbiological colonisation rates in tonsils and in large airways, i.e . trachea and bronchi, within all groups . However, variable pneumonic lung lesions were seen in remaining calves exposed to cold or warm air (5 degrees C, 35 degrees C) . The microbiological examination confirmed that mainly Mycoplasma spp . were identified in the lung tissue of calves exposed to 5 degrees C while Pasteurella multocida and/or Mannheimia haemolytica were the only germs found in the lung tissue of calves exposed to 35 degrees C . The results of parts 1 and 2 of the present study related to health issues of calves should be taken into account for future legislation on animal welfare.

Circ Res, 2002 May 3, 90(8), 850 - 7
Dual actions of the Galpha(q) agonist Pasteurella multocida toxin to promote cardiomyocyte hypertrophy and enhance apoptosis susceptibility; Sabri A et al.; Previous attempts to delineate the consequences of Galpha (q) activation in cardiomyocytes relied largely on molecular strategies in cultures or transgenic mice . Modest levels of wild-type Galpha(q) overexpression induce stable cardiac hypertrophy, whereas intense Galpha(q) stimulation induces cardiomyocyte apoptosis . The precise mechanism(s) whereby traditional targets of Galpha (q) subunits that induce hypertrophy also trigger cardiomyocyte apoptosis is not obvious and is explored with recombinant Pasteurella multocida toxin (rPMT, a Galpha(q) agonist) . Cells cultured with rPMT display cardiomyocyte enlargement, sarcomeric organization, and increased atrial natriuretic factor expression in association with activation of phospholipase C, novel protein kinase C (PKC) isoforms, extracellular signal-regulated protein kinase (ERK), and (to a lesser extent) JNK/p38-MAPK . rPMT stimulates the ERK cascade via epidermal growth factor (EGF) receptor transactivation in cardiac fibroblasts, but EGF receptor transactivation plays no role in ERK activation in cardiomyocytes . Surprisingly, rPMT (or novel PKC isoform activation by PMA) decreases basal Akt phosphorylation; rPMT prevents Akt phosphorylation by EGF or IGF-1 and functionally augments cardiomyocyte apoptosis in response to H2O2 . These results identify a Galpha(q)-PKC pathway that represses basal Akt phosphorylation and impairs Akt stimulation by survival factors . Because inhibition of Akt enhances cardiomyocyte susceptibility to apoptosis, this pathway is predicted to contribute to the transition from hypertrophy to cardiac decompensation and could be targeted for therapy in heart failure.

Vet Microbiol, 2002 May 24, 86(4), 313 - 24
The effect of concurrent infections with Pasteurella multocida and Ascaridia galli on free range chickens; Dahl C et al.; Pasteurella multocida and Ascaridia galli are observed with high prevalences in free range chickens in Denmark, but the impact is unknown . A study was carried out to examine the interaction between A . galli and P . multocida in chickens and the impact on production.Five groups, each with 20 18-week-old Lohmann Brown chickens were infected . Group 1 was orally infected with 1000+/-50 embryonated A . galli eggs . Group 2 received 10(4) cfu P . multocida intratracheally . Group 3 was infected with A . galli and subsequently with P . multocida . Group 4 was infected with P . multocida followed by A . galli . Group 5 was the control . The study ran for 11 weeks where clinical manifestations, weight gain and egg production were recorded . Excretion of P . multocida was determined on individual basis and blood smears were made for differential counts . At the end of the study pathological lesions and the number of adult worms, larvae and eggs in the faeces were recorded.The birds were more severely affected when infected with both pathogens compared to single infections with A . galli or P . multocida, respectively . A lower weight gain and egg production was observed with dual infections . A . galli infection followed by a secondary P . multocida infection resulted in more birds with pathological lesions and continued P . multocida excretion.In conclusion a negative interaction between A . galli and P . multocida was observed and it is postulated that free range chickens are at higher risk of being subjected to outbreaks of fowl cholera when they are infected with A . galli.

J Bacteriol, 2002 May, 184(9), 2539 - 42
Identification of fur and fldA homologs and a Pasteurella multocida tbpA homolog in Histophilus ovis and effects of iron availability on their transcription; Ekins A et al.; tbpA, fur, and fldA homologs from two strains (9L and 3384Y) of the sheep pathogen Histophilus ovis were sequenced . The predicted TbpA proteins of these strains are homologs of the Pasteurella multocida TbpA protein and collectively represent the second example of a new subfamily of TonB-dependent receptors . tbpA transcripts were readily detected by reverse transcription (RT)-PCR with RNA isolated from strain 9L grown under iron-restricted conditions in the presence or absence of bovine transferrin (Tf) . However, with strain 3384Y and depending on the primer pair, tbpA transcripts were detected by RT-PCR predominantly when the RNA was from cells grown under iron-restricted conditions in the presence of bovine Tf . In both strains, the fldA homolog was found to be immediately upstream of fur and, based on RT-PCR, these genes are transcribed as a single unit; the availability of iron and the presence or absence of bovine Tf in the growth medium had no apparent effect on the relative amounts of the fldA-fur transcripts.

J Biol Chem, 2002 Jun 14, 277(24), 21567 - 75 Epub 2002 Apr 09.
Molecular cloning and characterization of chondroitin polymerase from Escherichia coli strain K4; Ninomiya T et al.; Escherichia coli strain K4 produces the K4 antigen, a capsule polysaccharide consisting of a chondroitin backbone (GlcUA beta(1-3)-GalNAc beta(1-4))(n) to which beta-fructose is linked at position C-3 of the GlcUA residue . We molecularly cloned region 2 of the K4 capsular gene cluster essential for biosynthesis of the polysaccharide, and we further identified a gene encoding a bifunctional glycosyltransferase that polymerizes the chondroitin backbone . The enzyme, containing two conserved glycosyltransferase sites, showed 59 and 61% identity at the amino acid level to class 2 hyaluronan synthase and chondroitin synthase from Pasteurella multocida, respectively . The soluble enzyme expressed in a bacterial expression system transferred GalNAc and GlcUA residues alternately, and polymerized the chondroitin chain up to a molecular mass of 20 kDa when chondroitin sulfate hexasaccharide was used as an acceptor . The enzyme exhibited apparent K(m) values for UDP-GlcUA and UDP-GalNAc of 3.44 and 31.6 microm, respectively, and absolutely required acceptors of chondroitin sulfate polymers and oligosaccharides at least longer than a tetrasaccharide . In addition, chondroitin polymers and oligosaccharides and hyaluronan polymers and oligosaccharides served as acceptors for chondroitin polymerization, but dermatan sulfate and heparin did not . These results may lead to elucidation of the mechanism for chondroitin chain synthesis in both microorganisms and mammals.

Vet Immunol Immunopathol, 2002 Mar, 85(3-4), 179 - 88
Pathological and immunological changes after challenge infection with Pasteurella multocida in naive and immunized calves; Mathy NL et al.; Challenge infections of calves with Pasteurella multocida were established to characterize the local inflammatory response and determine the effect of previous exposure to live bacteria on the post-challenge immune response . Experimental infections were established by intratracheal inoculation of P . multocida in both naive calves and calves that had been previously vaccinated with two subcutaneous (s.c.) injections of live bacteria . Histological, immunohistological and cytokine expression studies were performed on bronchoalveolar lavage (BAL) samples, lung parenchymal tissues and lung lymph nodes (LN) . In comparison to uninfected control animals in which no lung lesions were observed, a patchy to confluent bronchopneumonia was observed following infection of naive calves, characterized by abscess formation, haemorrhage, oedema and suppurative consolidation . Cellular analysis following infection of naive animals was characterized by an influx of neutrophils in the BAL, with macrophages and dendritic cells observed in the lesion perimeter . A significant increase in the number of CD8(+) blasts expressing MHC (major histocompatibility) II was also observed in the BAL of infected calves . Decreased expression of interleukin (IL)-1 beta and increased expression of IL-8 compared to naive unchallenged controls was apparent in lung LN . In comparison, a more limited pathology was observed in vaccinated animals post-challenge, indicating partial protection conferred by the s.c . immunization with live bacteria . Studies of vaccinated animals showed the presence of bronchial-associated lymphoid tissue (BALT) in the lung tissue and an increase in the number of B-cells and CD4(+) T-cells expressing MHCII in the lung LN after challenge . In contrast to primary infection, there was no significant influx of neutrophils in the BAL . Instead, a population of newly recruited monocytes/macrophages was observed . Increased IL-2 expression and decreased IL-8 expression was observed in the LN, while IL-1 beta expression was not detected . The reduced neutrophil and increase monocyte response in the vaccinated calves may be associated with significant changes in the gamma delta T lymphocyte population in the BAL.

Scand J Infect Dis, 2002, 34(2), 138 - 9
Pasteurella multocida septicaemia in 2 Swedish patients; Berge A et al.; The clinical manifestation of human infections with Pasteurella multocida is most often cellulitis and this pathogen rarely causes septicaemia . We describe 2 Swedish patients with P . multocida septicaemia who were admitted to the same ward within the space of 7 months.

Vet Q, 2002 Feb, 24(1), 40 - 6
The Dutch Brucella abortus monitoring programme for cattle: the impact of false-positive serological reactions and comparison of serological tests; Emmerzaal A et al.; The Dutch national Brucella abortus eradication programme for cattle started in 1959 . Sporadic cases occurred yearly until 1995; the last infected herd was culled in 1996 . In August 1999 the Netherlands was declared officially free of bovine brucellosis by the European Union . Before 1999, the programme to monitor the official Brucella-free status of bovine herds was primarily based on periodical testing of dairy herds with the milk ring test (MRT) and serological testing of all animals older than 1 year of age from non-dairy herds, using the micro-agglutination test (MAT) as screening test . In addition, serum samples of cattle that aborted were tested with the MAT . The high number of false positive reactions in both tests and the serum agglutination test (SAT) and complement fixation test (CFT) used for confirmation seemed to result in unnecessary blockade of herds, subsequent testing and slaughter of animals . For this reason, a validation study was performed in which three indirect enzyme-linked immunosorbent assays (ELISAs), the CFT and the SAT were compared using a panel of sera from brucellosis-free cattle, sera from experimentally infected cattle, and sera from cattle experimentally infected with bacteria which are known to induce cross-reactive antibodies (Pasteurella, Salmonella, Yersinia, and Escherichia) . Moreover, four ELISAs and the MRT were compared using a panel of 1000 bulk milk samples from Brucella-free herds and 12 milk samples from Brucella abortus- infected cattle . It is concluded that the ELISA obtained from ID-Lelystad is the most suitable test to monitor the brucelosis free status of herds because it gives rise to fewer false-positive reactions than the SAT.

Vet Q, 2002 Feb, 24(1), 35 - 9
Clinical efficacy of florfenicol in the treatment of calf respiratory tract infections; Aslan V et al.; This paper reports on a study of the aetiology of calf pneumonia and the clinical efficacy of florfenicol, a new antibiotic in Turkey . Twenty-seven weaned and unweaned calves (13 males and 14 females) between 1 and 16 months of age brought to the clinics of Selcuk University, Faculty of Veterinary Science . Broncho-alveolar lavage (BAL) fluid samples were taken from the animals diagnosed to have upper respiratory tract infection associated with bronchitis (N=2), bronchitis (N=5), bronchopneumonia (N=4), pneumonia (N=3), pleuropneumonia (N=11), bronchopneumonia plus pulmonary oedema (N=2) based on the results of the clinical and laboratory examinations . Then microbiological isolation and antibiotic culturing were performed . The animals were treated with 1 ml/15 kg (20 mg/kg) florfenicol (Nuflor, DIF) twice within 48 hours via intramuscular injection . At the end of the treatment, 23 of the weaned and unweaned calves were completely healed, 1 calf had died and 3 calves showed no healing . The results of BAL samples and microbiological examinations of the 3 calves that did not respond to the treatment indicated that these cases were affected by mixed infections of yeasts, fungi, and bacteria . Widespread pleuropneumonia was observed . According to the results of the microbiological examination of the BAL samples, Mannheimia (Pasteurella) haemolytica had the highest isolation rate (25%) compared with the other isolated bacteria, namely, Klebsiella pneumonia (20%), Actinomyces pyogenes (15%), beta-hemolytic streptococci . (10%), Staphylococcus spp . (5%), and E . coli (5%) . The study also revealed fungi {Penicillum spp . (5%) and Aspergillus spp . (5%)} and two calves (10%) had a yeast infection. . We conclude that florfenicol has a high bacteriological and clinical efficacy (100% and 96% respectively) in the treatment of calf respiratory tract diseases.

Vaccine, 2002 Mar 15, 20(13-14), 1797 - 802
Evaluation of vaccines for atrophic rhinitis--a comparison of three challenge models; Magyar T et al.; We compared three challenge models for the assessment of atrophic rhinitis (AR) vaccines: combined infection with Bordetella bronchiseptica (Bb) and Pasteurella multocida (Pm); application of acetic acid (AA) to the nasal mucosa followed by Pm infection; and Bb infection alone . Two vaccines were tested using standardized criteria, notably nasal lesion scores . The vaccines provided different levels of protection in the Bb and the AA/Pm challenges, but were similar in the combined (Bb/Pm) challenge . It is clear that the AA/Pm model shows the protective value of only the Pm component, whereas the single Bb challenge reflects the protective value merely of the Bb component of a combined vaccine . These results suggest that the best assessment of protection is provided if the two specific challenges are performed separately.

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