Pasteurella multocida infection from a cougar bite. A review of cougar attacks.

A serious shortage of nurses has developed since 1984 despite a growing number of employed nurses and a substantial decline in the number of hospital inpatient days. The evidence suggests that the shortage is the result of an increased demand for nurses, not a decline in supply. The increased demand in large part has resulted from the substitution of registered nurses for licensed practical nurses, aides, and other patient services personnel. The substitution was feasible because nurses'' wages have been depressed compared with those of other hospital employees. The shortage is likely to abate if nurses'' wages increase, making substitution more costly. Even in the absence of continuing wage increases, hospitals could ease the shortage by restructuring patient services and enabling nurses to spend a greater portion of their time in direct patient care.     

Naturally acquired Pasteurella multocida subsp. multocida infection in a closed colony of rabbits: characteristics of isolates

Twelve litters, comprising 41 rabbits aged 35 to 60 days old, in a closed university colony, were monitored for acquisition of nasal Pasteurella multocida subsp. multocida infection. Isolates from 11 infected rabbits were characterized by colonial morphology, capsular type, biotype and antibiotic resistance. Selected isolates were further characterized by somatic antigen typing. Two major strains of P. multocida subsp. multocida were detected in the colony. One strain had mucoid colonies, fermented few carbohydrates and was serotype A:5, whereas, the other strain had smooth iridescent colonies, non-typeable capsular antigen, type 3 somatic antigen and fermented more than twice as many carbohydrates.     

Naturally acquired Pasteurella multocida infection in rabbits: immunological aspects

Natural infection with P. multocida in New Zealand White rabbits was followed in 2 to 3 weeks by development of immunoglobulin (Ig)M and IgG serum antibodies. The IgM response peaked and returned to lower levels within several weeks after infection, whereas the IgG response progressively increased and remained elevated.     

Bacteriological and serological studies on Pasteurella multocida infection in rabbits

Bacteriological and serological examinations were made on Pasteurella multocida infection in two rabbit-breeding colonies. The organism was localized in the paranasal sinuses of 53 of 54 infected rabbits, excreting to the external nares of 49 rabbits. It was also isolated from the trachea and middle and inner ear of half of the infected animals and occasionally from the conjunctiva, lung and heart. The infection rate of the organism was very low (4.3%) in sucklings younger than a month old, but increased with advancing age, reaching nearly 100% in adults more than five months of age. A rapid increase of the infection rate was observed at two to three months of age. Serum antibody against somatic antigen of P. multocida was demonstrated in infected rabbits by use of the tube agglutination test, showing a close correlation with isolation of the organism in adults. Sucklings younger than one month of age from infected dams were significantly resistant to experimental nasal infection of P. multocida.     

A dot-immunobinding assay for the serodiagnosis of Pasteurella multocida infection in laboratory rabbits

A dot-immunobinding assay was developed to detect serum IgG specific for lipopolysaccharide of rabbit isolates of P. multocida. The assay detected serum IgG as early as 1 week after experimental subclinical nasal infection, whereas 8 weeks were required to detect antibody by a gel diffusion precipitin test. The assay was more reliable than nasal cultures, in that up to 46% of 16 weekly nasal washings of some infected rabbits failed to yield P. multocida. The bacterial antigen (proteinase k digested cell lysate) used in the assay reacted with IgG that did not cross-react with lipopolysaccharide antigens of B. bronchiseptica, P. pneumotropica or P. hemolytica. The assay is sensitive and specific, easily performed, cost effective, requires no special laboratory instruments and provides a permanent easily stored record.     

R-Plasmids in Pasteurella multocida.

Multiple drug-resistant strains of Pasteurella multocida were associated with a high incidence of fatal pneumonia in feedlot cattle. A representative strain, CAH160, resistant to tetracycline (Tc), streptomycin (Sm), and sulfonamide (Su) was studied. The minimal inhibitory concentration (MIC) of Tc was 32 μg/ml while Sm had an MIC of 256 μg/ml. Plasmid DNA was isolated from CAH160 by cesium chloride-ethidium bromide centrifugation. Agarose gel electrophoresis showed that at least three distinct species of plasmid DNA were present. DNA isolated from CAH160 was used to transform Escherichia coli K12 strain C600 r_k^?m_k^?. Transformants resistant to Tc; to Sm, Su; and to Tc, Sm, Su were obtained. Contour length measurements of plasmid DNA isolated from transformant cells showed that Tc resistance was associated with a 3-Mdal plasmid (pSR10), while Sm, Su resistance resided on a 2.7-Mdal molecule (pSR11). More than 20% of the transformants were resistant to Tc, Sm, Su and contained both plasmid species. In E. coli the MIC of Tc was 256 μg/ml and that of Sm was 64 μg/ml. The buoyant density of pSR10 was 1.699 g/cm³, while the density of pSR11 was 1.709 g/cm³.     

Transmission of Pasteurella multocida in rabbits

Contact and airborne transmission of P. multocida in rabbits was evaluated in an artificially controlled environment. Transmission by contact occurred more readily from rabbits with acute infections than from rabbits with chronic infections. However, airborne transmission to rabbits in adjacent cages did not occur.     

Morphology of Pasteurella multocida bacteriophages

Twenty-one tailed phages with icosahedral heads belong to the Myoviridae, Siphoviridae, and Podoviridae families and to four morphological types. Type AU, with 10 phages, has a contractile tail and is morphologically identical with coliphage P2. Lysates contain contracted tail sheaths assembled end-to-end and abnormal structures with long tails and multiple tail sheaths. Types C-2 and 32, with one and three phages, respectively, have long, noncontractile tails. Type 22 includes seven phages, has a short tail, and resembles coliphage T7. Our results agree with previous biological data and suggest that types AU, C-2, 32, and 22 correspond to four different phage species.     

Experimental respiratory infection with Pasteurella multocida and Bordetella bronchiseptica in rabbits.

Eight-to-10-wk-old offspring of a colony of specific pathogen free [Eda:(NZW x FG)F1BR] rabbits were exposed to cultures of Pasteurella multocida and Bordetella bronchiseptica. Two groups of 9 animals each were exposed to cultures of either species of bacteria intranasally and killed 2, 7, 14, and 21 da postinoculation. Five of 9 rabbits in each group developed a mucopurulent nasal discharge 4-7 da postinoculation. The remaining 4 rabbits in each group failed to develop clinical signs. The gross and microscopic lesions did not differ in character or distribution among the inoculated rabbits. The infection was characterized by an acute upper respiratory syndrome accompanied by a mild bronchopneumonia.     

Acute meningoencephalomyelitis in a rabbit infected with Pasteurella multocida

Pasteurella multocida was isolated in pure culture from the optic chiasm of a rabbit that was euthanatized subsequent to acute development of neurological signs. Histopathologically, there was meningoencephalomyelitis, bilateral otitis interna, retrobulbar cellulitis, optic neuritis and iritis. The ocular involvement, severity of the spinal lesions and the lack of otitis media was unusual.     

Ultrastructural localization of the Pasteurella multocida toxin in a toxin-producing strain

Toxigenic strains of Pasteurella multocida produce the 147 kDa protein Pasteurella multocida toxin (PMT) which is responsible for the osteoclastic bone resorption in progressive atrophic rhinitis in pigs and induces such resorption in all experimental animals tested so far. In the present study we have carried out immunocytochemistry on formaldehyde- and glutaraldehyde-fixed ultracryocut P. multocida using a pool of monoclonal antibodies against different epitopes on PMT as the first layer and affinity purified rabbit anti-mouse IgG as the second layer. Goat anti-rabbit IgG conjugated with 5 nm gold particles was used as marker. The gold particles were silver-enhanced prior to examination in the transmission electron microscope. Whole bacteria were also immunostained after fixation and critical point drying and examined by scanning transmission electron microscopy. The results showed that PMT was located in the cytoplasm of P. multocida. PMT could not be detected on intact, undamaged P. multocida by scanning electron microscopy. Neither pili nor flagella could be detected on the surface of the negatively stained P. multocida strains investigated. PMT has a series of characteristics encompassed in the definition of an exotoxin. However, that PMT was not secreted by living intact P. multocida is unexpected for an exotoxin.     

Untersuchungen zur Oberfläuchenstruktur von Pasteurella multocida

Detailed studies of the surface structures are an important requirement for the development of efficient vaccines against enzootic pneumonia in calves and piglets caused by Pasteurella multocida. Electron microscopical examination after Alcian Blue staining shows capsular material extending far into the surrounding medium. The extent of the capsules depicted by light microscopy did not correlate with virulence and immunogenicity. However, the extent of the capsules was effected by different culture conditions. The immunization with extract material resulted in a good protection against homologous infection. It has been shown that different cultivation conditions can result in heterogeneity of LPS and in altered OMP-profiles.