Update on Mycoplasma hyopneumoniae infections in pigs : knowledge gaps for improved disease control

Mycoplasma hyopneumoniae (M. hyopneumoniae) is the primary pathogen of enzootic pneumonia, a chronic respiratory disease in pigs. Infections occur worldwide and cause major economic losses to the pig industry. The present paper reviews the current knowledge on M. hyopneumoniae infections, with emphasis on identification and analysis of knowledge gaps for optimizing control of the disease. Close contact between infected and susceptible pigs is the main route of M. hyopneumoniae transmission. Management and housing conditions predisposing for infection or disease are known, but further research is needed to better understand M. hyopneumoniae transmission patterns in modern pig production systems, and to assess the importance of the breeding population for downstream disease control. The organism is primarily found on the mucosal surface of the trachea, bronchi and bronchioles. Different adhesins and lipoproteins are involved in the adherence process. However, a clear picture of the virulence and pathogenicity of M. hyopneumoniae is still missing. The role of glycerol metabolism, myoinositol metabolism and the Mycoplasma Ig binding protein-Mycoplasma Ig protease system should be further investigated for their contribution to virulence. The destruction of the mucociliary apparatus, together with modulating the immune response, enhances the susceptibility of infected pigs to secondary pathogens. Clinical signs and severity of lesions depend on different factors, such as management, environmental conditions and likely also M. hyopneumoniae strain. The potential impact of strain variability on disease severity is not well defined. Diagnostics could be improved by developing tests that may detect virulent strains, by improving sampling in live animals and by designing ELI-SAs allowing discrimination between infected and vaccinated pigs. The currently available vaccines are often cost-efficient, but the ongoing research on developing new vaccines that confer protective immunity and reduce transmission should be continued, as well as optimization of protocols to eliminate M. hyopneumoniae from pig herds

Porcine circovirus 3 is highly prevalent in serum and tissues and may persistently infect wild boar (Sus scrofa scrofa)

Porcine circovirus 3 (PCV‐3) prevalence has been minimally investigated in wild boar; dynamics of infection and viral tissue distribution are currently unknown. In this study, serum samples from 518 wild boar (from years 2004 to 2018) were used to study frequency of infection. Also, serum samples from 19 boar captured and recaptured at least two times for a period of time from 1 month to 1 year were collected to determine PCV‐3 infection dynamics. Finally, to elucidate PCV‐3 DNA organic distribution, sera, different tissues and faeces were obtained from 35 additional wild boar. PCV‐3 DNA was extracted and amplified with a conventional PCR. For the PCV‐3 PCR‐positive sera from the longitudinally sampled and different tissue types, a quantitative PCR was performed. Genome sequence was obtained from a number of PCV‐3 PCR‐positive samples from different years, different time‐points of infection and tissues. Obtained results confirmed the susceptibility of wild boar to the virus, showing high frequency of PCV‐3 detection (221 out of 518, 42.66%) and demonstrating circulation at least since 2004. Compiled data indicate the possibility of long‐term infections, since 5 out of 10 PCV‐3 PCR‐positive boars longitudinally sampled showed positivity in samplings separated for more than 5 months. All tested tissue types' harboured PCV‐3 genome, with the highest percentage of PCR positivity in submandibular lymph node, tonsil, lung, liver, spleen and kidney. The amount of DNA in all tested PCV‐3 PCR‐positive samples was moderate to low. All partial and complete PCV‐3 sequences obtained from wild boar displayed high nucleotide identity, higher than 98%. In conclusion, this study further confirms that wild boar is susceptible to PCV‐3 infection, showing high frequency of detection in this animal species. Furthermore, PCV‐3 can be found in different tissues of wild boar and is apparently able to cause persistent infection.Instituto Nacional de Investigación y Tecnologia Agraria y Alimentaria. Grant Number: E‐RTA2017‐00007‐00‐0

Mycoplasma hyopneumoniae variability : current trends and proposed terminology for genomic classification

Mycoplasma hyopneumoniae (M. hyopneumoniae) is the aetiologic agent of enzootic pneumonia in swine, a prevalent chronic respiratory disease worldwide. Mycoplasma hyopneumoniae is a small, self-replicating microorganism that possesses several characteristics allowing for limited biosynthetic abilities, resulting in the fastidious, host-specific growth and unique pathogenic properties of this microorganism. Variation across several isolates of M. hyopneumoniae has been described at antigenic, proteomic, transcriptomic, pathogenic and genomic levels. The microorganism possesses a minimal number of genes that regulate the transcription process. Post-translational modifications (PTM) occur frequently in a wide range of functional proteins. The PTM by which M. hyopneumoniae regulates its surface topography could play key roles in cell adhesion, evasion and/or modulation of the host immune system. The clinical outcome of M. hyopneumoniae infections is determined by different factors, such as housing conditions, management practices, co-infections and also by virulence differences among M. hyopneumoniae isolates. Factors contributing to adherence and colonization as well as the capacity to modulate inflammatory and immune responses might be crucial. Different components of the cell membrane (i.e. proteins, glycoproteins and lipoproteins) may serve as adhesins and/or be toxic for the respiratory tract cells. Mechanisms leading to virulence are complex and more research is needed to identify markers for virulence. The utilization of typing methods and complete or partial-gene sequencing for M. hyopneumoniae characterization has increased in diagnostic laboratories as control and elimination strategies for this microorganism are attempted worldwide. A commonly employed molecular typing method for M. hyopneumoniae is Multiple-Locus Variable number tandem repeat Analysis (MLVA). The agreement of a shared terminology and classification for the various techniques, specifically MLVA, has not been described, which makes inferences across the literature unsuitable. Therefore, molecular trends for M. hyopneumoniae have been outlined and a common terminology and classification based on Variable Number Tandem Repeats (VNTR) types has been proposed

Retrospective detection of Porcine circovirus 3 (PCV-3) in pig serum samples from Spain

Porcine circovirus 3 (PCV‐3) is an emerging circovirus species that has recently been reported in different countries around the world, suggesting a widespread circulation. In this study, sera samples originating from 654 pigs of different production phases and clinical/pathological conditions, submitted for diagnostic purposes between 1996 and 2017, were randomly selected. Detection of PCV‐3 genome in such samples was attempted with a previously described PCR method, and the partial genome sequence was obtained from selected PCV‐3‐positive samples from different years. Compiled data confirmed that PCV‐3 has been circulating in the Spanish pig population since 1996. The overall frequency of PCV‐3 PCR‐positive samples in the study period was 11.47% (75 of 654). Phylogenetic analysis of twelve PCV‐3 partial sequences obtained showed a high nucleotide identity with the already known PCV‐3 sequences, with minor variations among years. No significant correlation was found between the detection of PCV‐3 and any production phase nor clinical/pathological condition. These results confirm PCV‐3 circulation at least since 1996 in the Spanish pig population with a low/moderate frequency. Although the information obtained was limited, PCV‐3 did not appear to be linked to any specific pathological condition or age group.info:eu-repo/semantics/publishedVersio

Mycoplasma hyopneumoniae variability: Current trends and proposed terminology for genomic classification

Mycoplasma hyopneumoniae (M. hyopneumoniae) is the aetiologic agent of enzootic pneumonia in swine, a prevalent chronic respiratory disease worldwide. Mycoplasma hyopneumoniae is a small, self‐replicating microorganism that possesses several characteristics allowing for limited biosynthetic abilities, resulting in the fastidious, host‐specific growth and unique pathogenic properties of this microorganism. Variation across several isolates of M. hyopneumoniae has been described at antigenic, proteomic, transcriptomic, pathogenic and genomic levels. The microorganism possesses a minimal number of genes that regulate the transcription process. Post‐translational modifications (PTM) occur frequently in a wide range of functional proteins. The PTM by which M. hyopneumoniae regulates its surface topography could play key roles in cell adhesion, evasion and/or modulation of the host immune system. The clinical outcome of M. hyopneumoniae infections is determined by different factors, such as housing conditions, management practices, co‐infections and also by virulence differences among M. hyopneumoniae isolates. Factors contributing to adherence and colonization as well as the capacity to modulate inflammatory and immune responses might be crucial. Different components of the cell membrane (i.e. proteins, glycoproteins and lipoproteins) may serve as adhesins and/or be toxic for the respiratory tract cells. Mechanisms leading to virulence are complex and more research is needed to identify markers for virulence. The utilization of typing methods and complete or partial‐gene sequencing for M. hyopneumoniae characterization has increased in diagnostic laboratories as control and elimination strategies for this microorganism are attempted worldwide. A commonly employed molecular typing method for M. hyopneumoniae is Multiple‐Locus Variable number tandem repeat Analysis (MLVA). The agreement of a shared terminology and classification for the various techniques, specifically MLVA, has not been described, which makes inferences across the literature unsuitable. Therefore, molecular trends for M. hyopneumoniae have been outlined and a common terminology and classification based on Variable Number Tandem Repeats (VNTR) types has been proposed.info:eu-repo/semantics/acceptedVersio

Update on Mycoplasma hyopneumoniaeinfections in pigs: Knowledge gaps for improved disease control

Mycoplasma hyopneumoniae(M. hyopneumoniae) is the primary pathogen of enzooticpneumonia, a chronic respiratory disease in pigs. Infections occur worldwide andcause major economic losses to the pig industry. The present paper reviews the cur-rent knowledge onM. hyopneumoniaeinfections, with emphasis on identificationand analysis of knowledge gaps for optimizing control of the disease. Close contactbetween infected and susceptible pigs is the main route ofM. hyopneumoniaetrans-mission. Management and housing conditions predisposing for infection or diseaseare known, but further research is needed to better understandM. hyopneumoniaetransmission patterns in modern pig production systems, and to assess the impor-tance of the breeding population for downstream disease control. The organism isprimarily found on the mucosal surface of the trachea, bronchi and bronchioles. Dif-ferent adhesins and lipoproteins are involved in the adherence process. However, aclear picture of the virulence and pathogenicity ofM. hyopneumoniaeis still missing.The role of glycerol metabolism, myoinositol metabolism and theMycoplasmaIgbinding protein—MycoplasmaIg protease system should be further investigated fortheir contribution to virulence. The destruction of the mucociliary apparatus,together with modulating the immune response, enhances the susceptibility ofinfected pigs to secondary pathogens. Clinical signs and severity of lesions dependon different factors, such as management, environmental conditions and likely alsoM. hyopneumoniaestrain. The potential impact of strain variability on disease sever-ity is not well defined. Diagnostics could be improved by developing tests that maydetect virulent strains, by improving sampling in live animals and by designing ELI-SAs allowing discrimination between infected and vaccinated pigs. The currentlyavailable vaccines are often cost-efficient, but the ongoing research on developingnew vaccines that confer protective immunity and reduce transmission should becontinued, as well as optimization of protocols to eliminateM. hyopneumoniaefrompig herds.info:eu-repo/semantics/acceptedVersio

26 Efekty uboczne kompleksowej raodioterapii u chorych na nowotwory narządów płciowych

Radioterapia jest jedną z podstawowych metod leczenia onkologicznego w raku szyjki i błony śluzowej macicy. Ze względu na różną radiowrażliwość narządów miednicy mniejszej autorzy pracy zwrócili szczególną uwagę na ewentualną obecność objawów uszkodzenia przewodu pokarmowego, układu moczowego i szpiku kostnego.W okresie 1998–2000 w Klinice Ginekologii Operacyjnej poddano obserwacji 40 chorych poddanych kompleksowej radioterapii. Wszystkie pacjentki w trakcie teleterapii otrzymały całkowitą dawkę 28 Gy na guz w okresie 4 tygodni oraz poddane zostały brachyterapii. W zależności od stopnia zaawansowania klinicznego nowotworu zastosowano:-u 25 chorych ze stopniem klinicznym nowotworu I i II – brachyterapię dopochwową w dawce 24 Gy (w 3 cotygodniowych frakcjach);-u 15 chorych ze stopniem zaawansowania II, III i IV – brachyterapię domaciczną w dawce 40 Gy (w 5 cotygodniowych frakcjach).Brachyterapię stosowano za pomocą microSelectronu HDR firmy Nucletron z użyciem żródła irydowego Ir192 z nominalną aktywnością 10 Ci (370GBq).Zaobserwowano:[[tgroup cols="3"]][[colspec colname="col1"/]][[colspec colname="col2"/]][[colspec colname="col3"/]][[tbody]][[row]][[entry align="left"]]1. Objawy uszkodzenia przewodu pokarmowego:[[/entry]][[entry align="left"]]nudności i wymioty[[/entry]][[entry align="left"]]− 4(10%)[[/entry]][[/row]][[row]][[entry/]][[entry align="left"]]biegunka[[/entry]][[entry align="left"]]− 6(15%)[[/entry]][[/row]][[row]][[entry align="left"]]2. Objawy podrażnienia układu moczowego (objawy dyzuryczne + zmiany w badaniu ogó1nym moczu):[[/entry]][[entry/]][[entry align="left"]]− 22 (55%)[[/entry]][[/row]][[row]][[entry align="left"]]3. Objawy uszkodzenia szpiku kostnego:[[/entry]][[entry align="left"]]niedokrwistość :[[/entry]][[entry align="left"]]− 3 (7,5%)[[/entry]][[/row]][[row]][[entry/]][[entry align="left"]]leukopenia:[[/entry]][[entry align="left"]]− 9 (22,5%)[[/entry]][[/row]][[/tbody]][[/tgroup]]Uzyskane wyniki potwierdzają względnie niski odsetek notowanych powikłań. Jest to dowodem na to, że tylko właściwa ocena kliniczna i prawidłowo prowadzona dozymetria przy kompleksowej radioterapii umożliwiają minimalizację objawów ubocznych

UV-C irradiation is able to inactivate pathogens found in commercially collected porcine plasma as demonstrated by swine bioassay

Liquid porcine plasma is an animal origin raw material for the manufacturing process of spray-dried porcine plasma that is used in pig nutrition worldwide. In previous studies we found that the application of ultraviolet light C (UV-C) in liquid plasma that was inoculated with a variety of bacteria or viruses of importance in the swine industry can be considered as redundant safety steps because in general achieve around 4 logs reduction for most of these pathogens. However, the final validation of the UV-C light as safety feature should be conducted with commercial liquid plasma and using the pig bioassay model. As a first objective, the potential infectivity of a raw liquid plasma product collected from an abattoir was tested by means of a swine bioassay. We used Porcine circovirus 2 (PCV-2), a ubiquitous virus that has been systematically detected by PCR in porcine plasma at abattoirs as selection criteria for commercial liquid plasma lot. As a second aim of the study, the effects of different doses of UV-C irradiation on the selected raw liquid plasma were assayed in the animal bioassay. Moreover, other swine infecting agents, including Porcine reproductive and respiratory syndrome virus (PRRSV), were also determined in the original plasma and monitored in the inoculated animals. Pigs negative for PCV-2 and PRRSV genome and antibodies were allotted to one of five groups (6 to 8 pigs/ group) and injected intra-peritoneally with 10 mL of their assigned inoculum at 50 d of age. Negative control pigs (group 1) were injected with PBS. Positive control pigs (group 5) were injected with a PCV-2 inoculum. Groups 2, 3 and 4 were injected with liquid porcine plasma that had been subjected to 0 (raw plasma), 3000 or 9000 J/L UV-C irradiation, respectively. Group 2 pigs (0 J/L UV-C) got infection by PRRSV but no PCV-2 infection or seroconversion. However, one pig from group 2 seroconverted to Rotavirus A (RVA) and Hepatitis E virus (HEV) and three group 2 pigs seroconverted to Porcine parvovirus (PPV). Groups 1, 3 and 4 pigs showed no evidence of infection or seroconversion associated with the tested viruses or any other pathogens found in the liquid plasma before UV-C irradiation. Group 5 pigs developed PCV-2 infectivity as expected. UV-C irradiation of liquid plasma at 3000 and 9000 J/L was effective in preventing PRRSV and other pathogens transmission. Moreover, raw liquid plasma was non-infectious for PCV-2 in naïve pigs.info:eu-repo/semantics/publishedVersio

Oral application of freeze-dried yeast particles expressing the PCV2b Cap protein on their surface induce protection to subsequent PCV2b challenge in vivo

Porcine circovirus type 2 (PCV2) is now endemic in every major pig producing country, causing PCV-associated disease (PCVAD), linked with large scale economic losses. Current vaccination strategies are based on the capsid protein of the virus and are reasonably successful in preventing PCVAD but fail to induce sterile immunity. Additionally, vaccinating whole herds is expensive and time consuming. In the present study a “proof of concept” vaccine trial was employed to test the effectiveness of powdered freeze-dried recombinant Saccharomyces cerevisiae yeast stably expressing the capsid protein of PCV2b on its surface as an orally applied vaccine. PCV2-free pigs were given 3 doses of vaccine or left un-vaccinated before challenge with a defined PCV2b strain. Rectal temperatures were measured and serum and faeces samples were collected weekly. At the end of the study, pigs were euthanized, tissue samples taken and tested for PCV2b load by qPCR and immunohistochemistry. The peak of viraemia in sera and faeces of unvaccinated pigs was higher than that of vaccinated pigs. Additionally more sIgA was found in faeces of vaccinated pigs than unvaccinated. Vaccination was associated with lower serum concentrations of TNFα and IL-1β but higher concentrations of IFNα and IFNγ in comparison to the unvaccinated animals. At the end of the trial, a higher viral load was found in several lymphatic tissues and the ileum of unvaccinated pigs in comparison to vaccinated pigs. The difference between groups was especially apparent in the ileum. The results presented here demonstrate a possible use for recombinant S. cerevisiae expressing viral proteins as an oral vaccine against PCV2. A powdered freeze-dried recombinant S. cerevisiae used as an oral vaccine could be mixed with feed and may offer a cheap and less labour intensive alternative to inoculation with the additional advantage that no cooling chain would be required for vaccine transport and storage

Descriptive analyses of maternally-derived antibody levels against porcine circovirus 2 (PCV-2) in 3- and 21-day-old piglets from farms of four European countries using different vaccination protocols in sows

Background Up to now, information on the levels of maternally-derived antibodies (MDA) against PCV-2 in suckling piglets born to sows vaccinated with different strategies is scarce in the literature. In the present observational study, the PCV-2-specific MDA titres from piglets from 109 farms (thirty 3-day-old and thirty 21-day-old piglets per farm) across four different European countries (France n = 30, Germany n = 27, Italy n = 22 and Spain n = 30) using different sow vaccination strategies (during gestation, as a gilt, as a piglet or never) were assessed. Results In all four countries, mean log PCV-2 MDA titres were higher in 3-day-old piglets than in the 3-week-old ones, being significant in most of all the comparisons performed. Within each country, the highest PCV-2-specific MDA titres were observed in the 3-day-old piglets born to sows vaccinated during gestation. Indeed, in the four countries, more than 60% of this subpopulation (3-day-old piglets from sows vaccinated during pregnancy) had the highest log PCV-2 titres detectable with the ELISA technique used in this study. The lowest MDA titres were more variable. Whereas in France and Germany the lowest titres corresponded to 21-day-old piglets born from sows vaccinated as a piglet, in Italy, they corresponded to 21-day-old piglets derived from sows vaccinated as a gilt and in Spain to 21-day-old piglets born from non-vaccinated sows. In this study, PCV-2-specific MDA titres at 3 and 21 days of age were not affected by sow parity. Conclusions Data obtained could be considered as a European global overview of PCV-2-specific MDA titres present in the pre-vaccinated piglet populations in different European countries, with titres tending to be higher in younger piglets, but with values variable among countries and sow vaccination strategies