scholarly journals Effect of Aerial Ammonia on Porcine Infection of the Respiratory Tract with Toxigenic Pasteurella multocida

1999 ◽  
Vol 40 (3) ◽  
pp. 197-203
Author(s):  
M. Andreasen ◽  
P. Bœkbo ◽  
J. P. Nielsen
1992 ◽  
Vol 4 (4) ◽  
pp. 419-422 ◽  
Author(s):  
Terry L. Bowersock ◽  
Tom Hooper ◽  
Ronald Pottenger

The use of an enzyme-linked immunosorbent assay (ELISA) as a means of detecting dermone-crotoxin-producing strains of Pasteurella multocida was investigated. The assay was evaluated as a means to identify toxigenic P. multocida isolates recovered from nasal secretions of swine with atrophic rhinitis. The sensitivity and specificity of the ELISA for detecting dermonecrotoxin-producing P. multocida strains were compared to those of mouse-inoculation and cytotoxicity assays. The ELISA was highly sensitive and more specific than animal inoculation or tissue culture assay and is thus a more effective method for screening swine herds for the presence of toxigenic strains of P. multocida. The ELISA is a rapid, effective, economical way to identify toxigenic P. multocida isolates.


2009 ◽  
Vol 139 (1-2) ◽  
pp. 97-105 ◽  
Author(s):  
Astrid Bethe ◽  
Lothar H. Wieler ◽  
Hans-J. Selbitz ◽  
Christa Ewers

1999 ◽  
Vol 6 (2) ◽  
pp. 199-203 ◽  
Author(s):  
T. D. C. Hamilton ◽  
J. M. Roe ◽  
C. M. Hayes ◽  
P. Jones ◽  
G. R. Pearson ◽  
...  

ABSTRACT Pigs reared commercially indoors are exposed to air heavily contaminated with particulate and gaseous pollutants. Epidemiological surveys have shown an association between the levels of these pollutants and the severity of lesions associated with the upper respiratory tract disease of swine atrophic rhinitis. This study investigated the role of aerial pollutants in the etiology of atrophic rhinitis induced by Pasteurella multocida. Forty, 1-week-old Large White piglets were weaned and divided into eight groups designated A to H. The groups were housed in Rochester exposure chambers and continuously exposed to the following pollutants: ovalbumin (groups A and B), ammonia (groups C and D), ovalbumin plus ammonia (groups E and F), and unpolluted air (groups G and H). The concentrations of pollutants used were 20 mg m−3 total mass and 5 mg m−3 respirable mass for ovalbumin dust and 50 ppm for ammonia. One week after exposure commenced, the pigs in groups A, C, E, and G were infected with P. multocida type D by intranasal inoculation. After 4 weeks of exposure to pollutants, the pigs were killed and the extent of turbinate atrophy was assessed with a morphometric index (MI). Control pigs kept in clean air and not inoculated with P. multocida (group H) had normal turbinate morphology with a mean MI of 41.12% (standard deviation [SD], ± 1.59%). In contrast, exposure to pollutants in the absence of P. multocida (groups B, D, and F) induced mild turbinate atrophy with mean MIs of 49.65% (SD, ±1.96%), 51.04% (SD, ±2.06%), and 49.88% (SD, ±3.51%), respectively. A similar level of atrophy was also evoked by inoculation with P. multocida in the absence of pollutants (group G), giving a mean MI of 50.77% (SD, ±2.07%). However, when P. multocida inoculation was combined with pollutant exposure (groups A, C, and E) moderate to severe turbinate atrophy occurred with mean MIs of 64.93% (SD, ±4.64%), 59.18% (SD, ±2.79%), and 73.30% (SD, ±3.19%), respectively. The severity of atrophy was greatest in pigs exposed simultaneously to dust and ammonia. At the end of the exposure period, higher numbers of P. multocida bacteria were isolated from the tonsils than from the nasal membrane, per gram of tissue. The severity of turbinate atrophy in inoculated pigs was proportional to the number of P. multocida bacteria isolated from tonsils (r 2 = 0.909, P < 0.05) and nasal membrane (r 2 = 0.628, P< 0.05). These findings indicate that aerial pollutants contribute to the severity of lesions associated with atrophic rhinitis by facilitating colonization of the pig’s upper respiratory tract byP. multocida and also by directly evoking mild atrophy.


1998 ◽  
Vol 36 (5) ◽  
pp. 1260-1265 ◽  
Author(s):  
T. D. C. Hamilton ◽  
J. M. Roe ◽  
C. M. Hayes ◽  
A. J. F. Webster

Pigs reared in intensive production systems are continuously exposed to ammonia released by the microbial degradation of their excrement. Exposure to this gas has been shown to increase the severity of the disease progressive atrophic rhinitis by facilitating colonization of the pig’s upper respiratory tract by Pasteurella multocida. The etiological mechanism responsible for this synergy was investigated by studying the colonization kinetics of P. multocida enhanced by ammonia and comparing them with those evoked by an established disease model. Three-week-old Large White piglets were weaned and allocated to five experimental groups (groups A to E). Pigs in groups A and B were exposed continuously to ammonia at 20 ppm for the first 2 weeks of the study. Pigs in group C were pretreated with 0.5 ml of 1% acetic acid per nostril on days −2 and −1 of the study. On day 0 all the pigs in groups A, C, and D were inoculated with 1.4 × 108 toxigenic P. multocida organisms given by the intranasal route. The kinetics of P. multocida colonization were established by testing samples obtained at weekly intervals throughout the study. The study was terminated on day 37, and the extent of turbinate atrophy was determined by using a morphometric index. The results of the study showed that exposure to aerial ammonia for a limited period had a marked effect on the colonization of toxigenic P. multocidain the nasal cavities of pigs, which resulted in the almost total exclusion of commensal flora. In contrast, ammonia had only a limited effect on P. multocida colonization at the tonsil. The exacerbation of P. multocida colonization by ammonia was restricted to the period of ammonia exposure, and the number ofP. multocida organisms colonizing the upper respiratory tract declined rapidly upon the cessation of exposure to ammonia. During the exposure period, the ammonia levels in mucus recovered from the nasal cavity and tonsil were found to be 7- and 3.5-fold higher, respectively, than the levels in samples taken from unexposed controls. Acetic acid pretreatment also induced marked colonization of the nasal cavity which, in contrast to that induced by ammonia, persisted throughout the time course of the study. Furthermore, acetic acid pretreatment induced marked but transient colonization of the tonsil. These findings suggest that the synergistic effect of ammonia acts through an etiological mechanism different from that evoked by acetic acid pretreatment. A strong correlation was found between the numbers of P. multocida organisms isolated from the nasal cavity and the severity of clinical lesions, as determined by using a morphometric index. The data presented in the paper highlight the potential importance of ammonia as an exacerbating factor in respiratory disease of intensively reared livestock.


2020 ◽  
Author(s):  
Nonzee Hanchanachai ◽  
Pramote Chumnanpuen ◽  
Teerasak E-KOBON

Abstract Background: The porcine respiratory tract harbours multiple microorganisms, and the interactions between these organisms could be associated with animal health status. Pasteurella multocida is a culturable facultative anaerobic bacterium isolated from healthy and diseased porcine respiratory tracts. The interaction between P. multocida and other aerobic commensal bacteria in the porcine respiratory tract is not well understood. This study aimed to determine the interactions between porcine P. multocida capsular serotype A and D strains and other culturable aerobic bacteria isolated from porcine respiratory tracts using a coculture assay in conditioned media followed by calculation of the growth rates and interaction parameters.Results: One hundred and sixteen bacterial samples were isolated from five porcine respiratory tracts, and 93 isolates were identified and phylogenetically classified into fourteen genera based on 16S rRNA sequences. Thirteen isolates from Gram-negative bacterial genera and two isolates from the Gram-positive bacterial genus were selected for coculture with P. multocida. From 17x17 (289) interaction pairs, the majority of 220 pairs had negative interactions indicating competition for nutrients and space, while 17 pairs were identified as mild cooperative or positive interactions indicating their coexistence. All conditioned media, except those of Acinetobacter, could inhibit P. multocida growth. Conversely, the conditioned media of P. multocida also inhibited the growth of nine isolates plus themselves.Conclusion: Negative interaction was the major interactions among the coculture of these 15 representative isolates and the coculture with P. multocida. The conditioned media in this study might be further analysed to identify critical molecules and examined by the in vivo experiments. The study proposed the possibility of using these molecules in conditioned media to control P. multocida growth.


2020 ◽  
Author(s):  
Nonzee Hanchanachai ◽  
Pramote Chumnanpuen ◽  
Teerasak E-KOBON

Abstract Background: The porcine respiratory tract harbours various microorganisms, and the interactions between these organisms could be associated with animal health status. Pasteurella multocida is a culturable facultative anaerobic bacterium isolated from healthy and diseased porcine respiratory tracts. The interaction between P. multocida and other aerobic commensal bacteria in the porcine respiratory tract is not well understood. This study aimed to determine the interactions between porcine P. multocida capsular serotype A and D strains and other culturable aerobic bacteria isolated from porcine respiratory tracts using a coculture assay in conditioned media followed by calculation of the growth rates and interaction parameters.Results: One hundred and sixteen bacterial isolates from five porcine respiratory tracts and 93 isolates were phylogenetically classified into fourteen genera based on 16S rRNA sequences. Fifteen representative isolates were selected for coculture with P. multocida. From 17x17 interaction pairs, the majority of 220 pairs had negative interactions indicating competition for nutrients and space, while 17 pairs were identified as mild cooperative or positive interactions indicating their coexistence. All conditioned media, except those of Acinetobacter, could inhibit P. multocida growth. Conversely, the conditioned media of P. multocida also inhibited the growth of nine isolates plus themselves. Conclusion: Healthy porcine provides conditions to maintain the balance of these aerobic commensal communities and has an inhibitory effect on pathogens. Therefore, the conditioned media in this study might be further analysed to identify critical molecules. The study proposed the possibility of using these molecules in conditioned media to control P. multocida diseases and enhance porcine health.


1983 ◽  
Vol 113 (13) ◽  
pp. 304-304 ◽  
Author(s):  
J. Rutter ◽  
P. Luther

Sign in / Sign up

Export Citation Format

Share Document