Use of recombinant ApxIV in serodiagnosis of Actinobacillus pleuropneumoniae infections, development and prevalidation of the ApxIV ELISA

Dreyfus, Anou; Schaller, Alain; Nivollet, S.; Segers, R. P. A. M.; Kobisch, Marylène; Mieli, L.; Soerensen, V.; Hüssy, Daniela; Miserez, R.; Zimmermann, Werner; Inderbitzin, F.; Frey, Joachim

doi:10.1016/j.vetmic.2004.01.004

Cited by 55 publications

(55 citation statements)

References 31 publications

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“…The toxin genes apxIIA (log 2 = 12.94; SD = 0.85) and apxIVA (log 2 = 11.14; SD = 0.30) were, however, both actively transcribed during the study period. The RTX toxin, ApxIV, is not expressed in vitro but activates high levels of serum antibodies during infection [63], [64]. The apxIVA gene and has previously been demonstrated to be specifically induced during infection [11].…”

Section: Resultsmentioning

confidence: 99%

Transcriptional Portrait of Actinobacillus pleuropneumoniae during Acute Disease - Potential Strategies for Survival and Persistence in the Host

et al. 2012

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BackgroundGene expression profiles of bacteria in their natural hosts can provide novel insight into the host-pathogen interactions and molecular determinants of bacterial infections. In the present study, the transcriptional profile of the porcine lung pathogen Actinobacillus pleuropneumoniae was monitored during the acute phase of infection in its natural host.Methodology/Principal FindingsBacterial expression profiles of A. pleuropneumoniae isolated from lung lesions of 25 infected pigs were compared in samples taken 6, 12, 24 and 48 hours post experimental challenge. Within 6 hours, focal, fibrino hemorrhagic lesions could be observed in the pig lungs, indicating that A. pleuropneumoniae had managed to establish itself successfully in the host. We identified 237 differentially regulated genes likely to encode functions required by the bacteria for colonization and survival in the host. This group was dominated by genes involved in various aspects of energy metabolism, especially anaerobic respiration and carbohydrate metabolism. Remodeling of the bacterial envelope and modifications of posttranslational processing of proteins also appeared to be of importance during early infection. The results suggested that A. pleuropneumoniae is using various strategies to increase its fitness, such as applying Na+ pumps as an alternative way of gaining energy. Furthermore, the transcriptional data provided potential clues as to how A. pleuropneumoniae is able to circumvent host immune factors and survive within the hostile environment of host macrophages. This persistence within macrophages may be related to urease activity, mobilization of various stress responses and active evasion of the host defenses by cell surface sialylation.Conclusions/SignificanceThe data presented here highlight the importance of metabolic adjustments to host conditions as virulence factors of infecting microorganisms and help to provide insight into the mechanisms behind the efficient colonization and persistence of A. pleuropneumoniae during acute disease.

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Section: Resultsmentioning

confidence: 99%

Transcriptional Portrait of Actinobacillus pleuropneumoniae during Acute Disease - Potential Strategies for Survival and Persistence in the Host

et al. 2012

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“…different from A. pleuropneumoniae organisms. That issue has been overcome in this novel FMIA approach with the inclusion of the ApxIV toxin, which is produced by all 15 serovars of A. pleuropneumoniae and is specific for infections with that species (20).…”

Section: Discussionmentioning

confidence: 99%

“…The CFT (19), currently required for importation of live animals into the People's Republic of China, is laborious, timeconsuming, and expensive to use. Among the different ELISAs, those targeting ApxIV toxin to quantify circulating levels of the antibody to A. pleuropneumoniae (20), those targeting ApxI, ApxII, or ApxIII for the detection of specific antibodies to Apx exotoxins (21), those targeting capsular polysaccharides of A. pleuropneumoniae to identify antibodies against groups of its serovars (22), and serovar-specific ELISAs based on long-chain lipopolysaccharides (23) have been widely used and offer better sensitivities and specificities than the CFT. It has also been demonstrated that ELISAs utilizing different antigens or that are performed under different assay conditions may have conflicting results and cross-reactions between A. pleuropneumoniae serovars and other bacterial species, and this may be problematic (2,3).…”

mentioning

confidence: 99%

Simultaneous Detection of Antibodies against Apx Toxins ApxI, ApxII, ApxIII, and ApxIV in Pigs with Known and Unknown Actinobacillus pleuropneumoniae Exposure Using a Multiplexing Liquid Array Platform

Giménez-Lirola¹,

Jiang²,

Sun³

et al. 2013

Clin. Vaccine Immunol.

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c Surveillance for the presence of Actinobacillus pleuropneumoniae infection in a population plays a central role in controlling the disease. In this study, a 4-plex fluorescent microbead-based immunoassay (FMIA), developed for the simultaneous detection of IgG antibodies to repeat-in-toxin (RTX) toxins (ApxI, ApxII, ApxIII, and ApxIV) of A. pleuropneumoniae, was evaluated using (i) blood serum samples from pigs experimentally infected with each of the 15 known A. pleuropneumoniae serovars or with Actinobacillus suis, (ii) blood serum samples from pigs vaccinated with a bacterin containing A. pleuropneumoniae serovar 1, 3, 5, or 7, and (iii) blood serum samples from pigs with an unknown A. pleuropneumoniae exposure status. The results were compared to those obtained in a previous study where a dual-plate complement fixation test (CFT) and three commercially available enzyme-linked immunosorbent assays (ELISAs) were conducted on the same sample set. On samples from experimentally infected pigs, the 4-plex Apx FMIA detected specific seroconversion to Apx toxins as early as 7 days postinfection in a total of 29 pigs inoculated with 14 of the 15 A. pleuropneumoniae serovars. Seroconversion to ApxII and ApxIII was detected by FMIA in pigs inoculated with A. suis. The vaccinated pigs showed poor humoral responses against ApxI, ApxII, ApxIII, and ApxIV. In the field samples, the humoral response to ApxIV and the A. pleuropneumoniae seroprevalence increased with age. This novel FMIA (with a sensitivity of 82.7% and a specificity of 100% for the anti-ApxIV antibody) was found to be more sensitive and accurate than current tests (sensitivities, 9.5 to 56%; specificity, 100%) and is potentially an improved tool for the surveillance of disease and for monitoring vaccination compliance.

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“…However, detection of antibodies against ApxIA, ApxIIA, ApxIIIA is not completely specific for A pleuropneumoniae , since cross-reactions with antibodies against other Actinobacillus species ( A suis, A rossii, A lignieresii, A porcitonsillarum ) are possible (Dreyfus and others 2004, Gottschalk 2012). A fourth RTX toxin, ApxIVA, is only secreted during infection by all 15 serotypes, and it is specific for A pleuropneumoniae infection (Dreyfus and others 2004). Therefore, the ApxIV ELISA can be used as a reliable tool to assess infection.…”

Section: Discussionmentioning

confidence: 99%

Efficacy of vaccination againstActinobacillus pleuropneumoniaein two Belgian farrow‐to‐finish pig herds with a history of chronic pleurisy

Sacristán

Michiels

Martens³

et al. 2014

Veterinary Record

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The efficacy of an Actinobacillus pleuropneumoniae subunit vaccine based on ApxIA, ApxIIA, ApxIIIA and OMP-2 (Porcilis App, MSD) was investigated in two farrow-to-finish pig herds (A and B) affected by chronic pleurisy. In total, 1161 pigs were included. At three weeks of age, the pigs were randomly allocated to non-vaccinated control (NV; n=580) and vaccinated (V; n=581) groups. At 6 and 10 weeks of age, pigs were injected with Porcilis-APP (V group) or adjuvant (NV group). At slaughter (26 weeks), pleurisy and pneumonia lesions were assessed. All pigs were weighed individually at 6 and 26 weeks of age, and average daily weight gain (ADG; g/pig/day) was calculated. Mortality and days of additional treatment (DAT) were registered during the whole experiment. Data were analysed using binary logistic regression or analysis of variance for proportions or continuous variables, respectively. The prevalence of pleurisy and pneumonia was (NV-A=19.3, V-A=7.9, (P=0.000); NV-B=17.9, V-B=0.7, (P=0.000)) and (NV-A=42.4, V-A=21.2, (P=0.000); NV-B=46.7, V-B=19.0, (P=0.000)), respectively. The ADG was NV-A=632±157, V-A=647±91, (P=0.162); NV-B=660±115, V-B=670±82, (P=0.232). The mortality during the experiment was NV-A=5.7, V-A=1.8, (P=0.015); NV-B=2.3, V-B=1.0, (P=0.170) per cent. The DAT was: NV-A=15.04±1.41, V-A=14.95±0.67, (P=0.010); NV-B=21.68±2.43, V-B=16.99±0.62, (P=0.000). The present study showed a significant reduction of the prevalence of pleurisy and pneumonia, and antimicrobial use in V pigs from both herds, and in mortality in V pigs from one herd.

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Use of recombinant ApxIV in serodiagnosis of Actinobacillus pleuropneumoniae infections, development and prevalidation of the ApxIV ELISA

Cited by 55 publications

References 31 publications

Transcriptional Portrait of Actinobacillus pleuropneumoniae during Acute Disease - Potential Strategies for Survival and Persistence in the Host

Transcriptional Portrait of Actinobacillus pleuropneumoniae during Acute Disease - Potential Strategies for Survival and Persistence in the Host

Simultaneous Detection of Antibodies against Apx Toxins ApxI, ApxII, ApxIII, and ApxIV in Pigs with Known and Unknown Actinobacillus pleuropneumoniae Exposure Using a Multiplexing Liquid Array Platform

Efficacy of vaccination againstActinobacillus pleuropneumoniaein two Belgian farrow‐to‐finish pig herds with a history of chronic pleurisy

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