Equine abortion associated with placentitis caused by Pasteurella pneumotropica / Aborto equino associado a placentite por Pasteurella pneumotropica

Pasteurella pneumotropica is a bacterium that has so far not been described as a cause of placentitis in animals. Two cases of aborted equine fetuses were sent to the Department of Veterinary Pathology of the "Universidade Federal do Rio Grande do Sul" (SPV-UFRGS) for anatomopathological examination. Both cases presented suppurative placentitis associated with multiple basophilic bacterial cells. After bacterial isolation and biochemical analysis, P. pneumotropica was identified.(AU)

Pasteurella pneumotropica é uma bactéria que até o momento não foi descrita como causa de placentite em animais. Dois casos de fetos equinos abortados foram enviados ao Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul (SPV-UFRGS) para exame anatomopatológico. Em ambos os casos se observou placentite supurativa associada a múltiplas colônias bacterianas basofílicas. Após o isolamento bacteriano e análise bioquímica, indentificou-se P. pneumotropica.(AU)

Equine abortion associated with placentitis caused by Pasteurella pneumotropica / Aborto equino associado a placentite por Pasteurella pneumotropica

Pasteurella pneumotropica is a bacterium that has so far not been described as a cause of placentitis in animals. Two cases of aborted equine fetuses were sent to the Department of Veterinary Pathology of the "Universidade Federal do Rio Grande do Sul" (SPV-UFRGS) for anatomopathological examination. Both cases presented suppurative placentitis associated with multiple basophilic bacterial cells. After bacterial isolation and biochemical analysis, P. pneumotropica was identified.

Pasteurella pneumotropica é uma bactéria que até o momento não foi descrita como causa de placentite em animais. Dois casos de fetos equinos abortados foram enviados ao Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul (SPV-UFRGS) para exame anatomopatológico. Em ambos os casos se observou placentite supurativa associada a múltiplas colônias bacterianas basofílicas. Após o isolamento bacteriano e análise bioquímica, indentificou-se P. pneumotropica.

Identification of a large repetitive RTX immunogen in a highly virulent Rodentibacter heylii strain.

Rodentibacter (R.) heylii is frequently detected in laboratory rodents. Repeats in toxin (RTX) toxins are considered important virulence factors of this major murine pathogen. We evaluated the virulence of a R.heylii strain negative for all known RTX toxin genes and Muribacter (M.) muris, a commensal in mice, in experimental infections of C57BL/6 and BALB/c mice. Experimental intranasal infection with 108 CFU of the pnxI-, pnxII- and pnxIII- R. heylii strain resulted in 75% and 100% mortality in C57BL/6 and BALB/c mice, respectively. In early losses, multiple internal organs were infected and purulent bronchopneumonia was the main pathology. Intranasal application of M. muris did not result in mortality or severe weight loss. Immunoproteomics led to the identification of a surface-associated and specific immunogen, which was designated as R. heylii immunogen A (RhiA) and which was exclusively recognised by sera obtained from mice infected with this R. heylii pathotype. RhiA is a 262.6 kDa large protein containing long imperfect tandem repeats and C-terminal RTX consensus sequences. Immunohistochemical analysis confirmed that this R.heylii pathotype expresses RhiA in the lower respiratory tract. In summary, this study describes a specific immunogen in a virulent R. heylii, strain which is an excellent antigen for pathotype-specific serological screenings and which might carry out RTX-related functions.

Septic arthritis of the ankle: Do not forget Pasteurella pneumotropica.

Pasteurella pneumotropica is an important bacterial pathogen in both animals and humans. Most reported Pasteurella infections in humans involve skin and soft tissues, often after an animal bite, scratch, or lick to an open wound. We report a case of septic arthritis with Pasteurella pneumotropica in a diabetic and cardiopathic patient who was the victim of a rat bite in the street, with a good evolution after medical and surgical treatment.

Differentiation of Rodentibacter pneumotropicus, Rodentibacter heylii and Muribacter muris by MALDI-TOF MS.

The pathogens Rodentibacter (R.) pneumotropicus and R. heylii as well as the commensal Muribacter (M.) muris are frequently isolated in mice. In this study, a MALDI-TOF MS database was extended with spectra of well characterized strains of these species. Compared to a multiplex PCR, all examined out-of-sample isolates were correctly identified.

Sensitive and immunogen-specific serological detection of Rodentibacter pneumotropicus infections in mice.

BACKGROUND: Rodentibacter (R.) pneumotropicus colonizes the respiratory and urogenital tracts of laboratory mice with a reported moderate serological prevalence from 4 to 13%. Thus, regular tests to identify this pathogen in mice are recommended for animal facilities. However, a recent study indicated that current serological assays are partly insensitive, as C57BL/6 and BALB/c mice infected with R. pneumotropicus were incorrectly screened as seronegative. RESULTS: Here, we report a systematic analysis of protein and lipopolysaccharides antigens by immunoblot and ELISA that allowed establishing a sensitive test system able to differentiate between R. pneumotropicus and the closely related species R. heylii. Furthermore, the main immunogen, designated as 'characteristic antigen for Rodentibacter of laboratory origin 1' (CARLO-1), was identified by two-dimensional gel electrophoresis followed by immunoblot and tandem mass spectrometry in a preparation of outer membrane proteins. An indirect ELISA relying on the recombinantly expressed protein provided high sensitivity, specificity, and selectivity. The corresponding carlo1 gene was highly conserved (> 97%) among 21 isolates of R. pneumotropicus and R. heylii. CONCLUSION: The newly identified protein CARLO-1 is well suited for the sensitive and specific serological detection of Rodentibacter infections in mice. Indirect differentiation of R. pneumotropicus and R. heylii infections may be possible using an ELISA based on a whole-cell antigen preparation. All four established ELISA systems using a whole-cell preparation, lipopolysaccharides, outer-membrane proteins and protein CARLO-1 as antigen, respectively, outperformed a commercial ELISA in terms of sensitivity.

From the [Pasteurella] pneumotropica complex to Rodentibacter spp.: an update on [Pasteurella] pneumotropica.

The species [Pasteurella] pneumotropica has been reclassified into the new genus Rodentibacter, within the family Pasteurellaceae. Along with the type species (Rodentibacter pneumotropicus) of the new genus, seven new species have been named. These organisms were formerly mainly known as the [P.] pneumotropica complex and [P.] pneumotropica was considered as the most important Pasteurellaceae species colonizing laboratory rodents. The aim of this review is to update the veterinary relevant aspects of clinical manifestations, pathogenesis, virulence and diagnostics of members of Rodentibacter with a focus on the most important species from a veterinary perspective. The organisms are obligate commensals of the mucous membranes and members of Rodentibacter are not able to persist for long in the environment. Members of Rodentibacter spp. are responsible for the most prevalent bacterial infections in laboratory mice and rats, but are also common in rodents outside laboratory settings. Some Rodentibacter spp. produce mainly localised disease in connection with favouring factors and seldomly act as primary pathogens in healthy immunocompetent animals. The subclinical infection with Rodentibacter spp. can affect the results of certain types of research using contaminated animals thus placing them on a list of microbes which are often not tolerated in experimental rodent facilities. The presences of RTX toxins, YadA-like proteins and a capsule with possible role in the pathogenesis have been described. Some species of Rodentibacter are able to form robust biofilms which might be involved in colonisation and persistence within the host. Current possibilities for diagnostics and differentiation among Rodentibacter spp. are outlined and options for treatment and control are provided.

Clonal outbreaks of [ Pasteurella] pneumotropica biovar Heyl in two mouse colonies.

The aim of this study was to document the pathogenic role of biovar Heyl of [ Pasteurella] pneumotropica in mouse colonies. Fifty-three isolates associated with mastitis and orbital, cutaneous and vaginal abscesses as well as isolates from the nose and vagina of healthy mice were investigated. According to phenotypic characteristics and rpoB sequencing, the isolates were identified as [ P.] pneumotropica biovar Heyl. Pulsed-field gel electrophoresis (PFGE) revealed five closely related profiles separated by only one to four fragments. The outbreak strains diverged from epidemiologically unrelated strains with the same rpoB sequence type, as shown by the PFGE profiles. The investigation documented that members of biovar Heyl of [ P.] pneumotropica caused disease outbreaks in mouse colonies since the clonality indicated a primary role of [ P.] pneumotropica biovar Heyl in the infections observed.

Identification of a virulence determinant that is conserved in the Jawetz and Heyl biotypes of [Pasteurella] pneumotropica.

[Pasteurella] pneumotropica is a ubiquitous bacterium frequently isolated from laboratory rodents. Although this bacterium causes various diseases in immunosuppressed animals, little is known about major virulence factors and their roles in pathogenicity. To identify virulence factors, we sequenced the genome of [P.] pneumotropica biotype Heyl strain ATCC 12555, and compared the resulting non-contiguous draft genome sequence with the genome of biotype Jawetz strain ATCC 35149. Among a large number of genes encoding virulence-associated factors in both strains, four genes encoding for YadA-like proteins, which are known virulence factors that function in host cell adherence and invasion in many pathogens. In this study, we assessed YadA distribution and biological activity as an example of one of virulence-associated factor shared, with biotype Jawetz and Heyl. More than half of mouse isolates were found to have at least one of these genes; whereas, the majority of rat isolates did not. Autoagglutination activity, and ability to bind to mouse collagen type IV and mouse fibroblast cells, was significantly higher in YadA-positive than YadA-negative strains. To conclude, we identified a large number of candidate genes predicted to influence [P.] pneumotropica pathogenesis.

Research progress on Pasteurella pneumotropica / 中国实验动物学报

Pasteurella pneumotropica is an opportunistic and zoonotic pathogen .It mainly infects rodents , especial-ly immunodeficient or immunosuppressied animals , and causes inflammation and abscesses .It is one of the highest positive rate infection pathogens in laboratory animals .The contamination and asymptomatic infections of Infection of P.pneumo-tropica could significantly interfere in vary experiments .This review will deal with P.pneumotropica epidemiology, detection and identification methods , molecular typing and control and so on .

Phenotypic analysis of Pasteurella pneumotropica in laboratory animals in Beijing area / 中国比较医学杂志

Objective To improve the accuracy of detection through analyzing the phenotypes of P.pneumotropica isolates in laboratory animals in Beijing area .Methods 306 suspicious P.pneumotropica strains were identified by biochemical identification and 16S rDNA sequencing.Then, to obtain the phylogenetic relationships combined with colony characteristics on blood agar plates and biochemical characteristics of 53 biotypes .Results BD Phoenix 100 automated bacterial identification system and 16S rDNA sequencing identified P.pneumotropica positive rate of 306 isolates were 164/306 and 227/306, respectively.There were 140 phenotypes in 227 true-positive strains, of which 106 were biotype Heyl and 23 were biotype Jawetz .Conclusions In the samples of laboratory animals in Beijing area , P.pneumotropica infection mainly are of biotype Heyl , and less is of biotype Jawetz .The phenotypes are diverse and widely distributed .

Intranasal immunization with a non-adjuvanted adhesive protein descended from Pasteurella pneumotropica and its preventive efficacy against opportunistic infection in mice.

Intranasal vaccination is one of the most effective means of protecting against invading and colonizing pathogens because the vaccine elicits a mucosal immune response. The exploitation of vaccine adjuvants and delivery systems for intranasal vaccines is an important way to evoke antigen immunogenicity and elicit a better immune response at the mucosal sites. In the present study, we assessed the potential of intranasal immunization using a non-adjuvanted bacterial adhesive protein toward the host organs. We evaluated intranasal immunization with modified recombinant PnxIIIA (MP3) from Pasteurella pneumotropica and its preventive efficacy against opportunistic infection caused by P. pneumotropica, without using any adjuvants or delivery systems. The 100-kDa MP3 was confirmed to retain its immunogenicity and binding activity to collagen type I similar to the parent PnxIIIA. When MP3 was fused to green-fluorescent protein and inoculated into C57BL/6J mice intranasally, fluorescence intensity in the intranasal airway could be observed until 3 h after inoculation. Mice were intranasally immunized with MP3 at a maximum of 4 doses, with 7-day intervals. The antibody titer of serum IgG and IgA specific for MP3, as well as that of bronchoalveolar lavage fluid IgA, showed more than 9 (log2) after 3 or 4 rounds of immunization. Experimentally infecting immunized mice with P. pneumotropica resulted in the inability to isolate the bacterium from the nasal cavity, trachea, conjunctiva, or cecum with more than 3 doses in the immunized mice. Although the detection in each organ seldom changed with less than 2 rounds of immunization, unlike that observed in the non-immunized mice, the detection remarkably decreased with 3 or more rounds of immunization. These results suggest that intranasal immunization with a non-adjuvanted adhesive protein could have preventive effects against opportunistic infection by P. pneumotropica.