Seroprevalence of Mycoplasma synoviae in Dutch commercial poultry farms

Quantification of the effect of vaccination on the control of horizontal transmission of Mycoplasma synoviae under field conditions

Beside biosecurity, vaccination is important for Mycoplasma synoviae (MS) control as it has been shown to contribute to the reduction of economic impact and, experimentally, also lessens horizontal transmission. In this study, the effect of MS live vaccination on horizontal transmission was quantified under field conditions by analysing 4-year MS monitoring data from non-MS-vaccinated broiler and layer breeders and MS-vaccinated broiler breeders with good biosecurity in single-age housing systems. Flocks were monitored at 20 and 30 weeks of age and every 12 weeks thereafter. At every sampling, 60 blood samples or 24 tracheal swabs were tested using rapid plate agglutination test and ELISA serially or MS DIVA PCR, respectively. The MS incidence rate was calculated and the association with vaccination was analysed by logistic regression. The average MS incidence rate per 1000 weeks was 11.6 cases for non-MS-vaccinated broiler breeders and decreased from 29.6 to 5.6 cases with successive vaccinated production cycles. In non-MS-vaccinated layer breeders it was 3.6. A significant negative association with MS incidence was found after vaccinating four to six successive production cycles compared to non-MS-vaccinated or only one production cycle vaccinated breeders (odds ratio (OR) = 0.23, P = 0.05 & OR = 0.12, P = 0.01, respectively). A significant negative association with MS in non-MS-vaccinated layer breeders (OR = 0.29, P = 0.00) was observed compared to non-MS-vaccinated broiler breeders, possibly due to more controlled contact structures within the layer breeder industry. The results suggest that vaccination and control of contacts contribute to the reduction of between-farm MS transmission.

Mycoplasma gallisepticum and Mycoplasma synoviae in Turkeys in Poland

The pathogenic mycoplasmas are among the bacteria causing significant losses in the poultry industry worldwide. Mycoplasma gallisepticum (MG) and M. synoviae (MS) are economically important pathogens causing chronic respiratory disease, decreased growth, egg production and hatchability rates, and significant downgrading of carcasses. Effective diagnosis of infection with these species in poultry is highly requisite considering their two routes of spreading-horizontal and vertical. Their prevalence and molecular epidemiology were investigated in 184 turkey flocks in Poland. Tracheal samples were selected from 144 broiler flocks and 40 turkey breeder flocks collected in 2015-2023. The prevalence of MG was determined by real-time PCR targeting the 16S rRNA gene and PCR targeting the mgc2 gene, and MS was determined by a 16-23S rRNA real-time PCR and a vlhA gene PCR. Further identification and molecular characterization were carried out using PCR and sequencing. M. gallisepticum and M. synoviae were found in 8.33% and 9.72% of turkey broiler flocks respectively. The phylogenetic analysis of MG isolates in most cases showed high similarity to the ts-11-like strains. MS isolates showed high similarity to strains isolated from flocks of laying hens causing EAA. Additional tests detected Ornithobacterium rhinotracheale, Gallibacterium anatis, Enterococcus faecalis and Enterococcus faecium, Staphylococcus aureus and Riemerella anatipestifer. These secondary pathogens could have significantly heightened the pathogenicity of the mycoplasma infections studied.

Colloidal gold based immunochromatographic detection of Mycoplasmopsis synoviae infection and its prevalence in avian species of Karachi, Pakistan

Avian mycoplasmosis is an infection that commonly prevails in birds, particularly in poultry chickens. Among mycoplasmosis causing organisms, Mycoplasmopsis synoviae is a predominant and lethal pathogen to the aves. Considering the increased incidence of infections by M. synoviae, the prevalence of M. synoviae was deduced in poultry chickens and fancy birds of Karachi region. The lungs and tracheal samples from chicken and dead fancy birds and swab samples from live fancy birds were collected and investigated by amplifying 16 s rRNA gene of M. synoviae. Biochemical characteristics of M. synoviae was also evaluated. Furthermore, surface-associated membrane proteins, that represent key antigens for diagnosis of M. synoviae infection was extracted by Triton X- 114 method. Results showed that M. synoviae was detected more frequently in lungs than in trachea, that could be due to its invasion capacity and tissue affinity. SDS PAGE analysis of extracted membrane proteins showed two prominent hydrophobic proteins of different molecular mass including proteins of 150 and 50 kDa. Protein of 150 kDa was purified by size exclusion chromatography and it exhibited agglutinogen activity. Purified protein was used in the development of one-step immunochromatographic (ICT) assay for the detection of antibodies against M. synoviae using gold nanoparticles coated with polyclonal antibodies. Low levels of antibodies were detected by the developed ICT kit, which has 88% sensitivity with 92% specificity.

NADH oxidase of Mycoplasma synoviae is a potential diagnostic antigen, plasminogen/fibronectin binding protein and a putative adhesin

BACKGROUND

Mycoplasma synoviae (MS) is an important pathogen causing respiratory diseases and arthritis in chickens and turkeys, thus, resulting in serious economic losses to the poultry industry. Membrane-associated proteins are thought to play important roles in cytoadherence and pathogenesis. NADH oxidase (NOX) is an oxidoreductase involved in glycolysis, which is thought to be a multifunctional protein and potential virulence factor in some pathogens. However, little is known regarding the NOX of MS (MSNOX). We previously demonstrated that MSNOX was a metabolic enzyme distributed in not only the cytoplasm but also the MS membrane. This study was aimed at exploring NOX's potential as a diagnostic antigen and its role in MS cytoadherence.

RESULTS

Western blots and ELISAs indicated that recombinant MSNOX (rMSNOX) protein reacted with sera positive for various MS isolates, but not MG isolates or other avian pathogens, thus, suggesting that rMSNOX is a potential diagnostic antigen. In addition, rabbit anti-rMSNOX serum showed substantial complement-dependent mycoplasmacidal activity toward various MS isolates and MG R_low. MSNOX protein was found not only in the cytoplasm but also on the membrane of MS through suspension immunofluorescence and immunogold electron microscopy assays. Indirect immunofluorescence assays indicated that rMSNOX adhered to DF-1 cells, and this adherence was inhibited by rabbit anti-rMSNOX, but not anti-MG serum. Furthermore, indirect immunofluorescence and colony counting assays confirmed that the rabbit anti-rMSNOX serum inhibited the adherence of various MS isolates but not MG R_low to DF-1 cells. Moreover, plasminogen (Plg)- and fibronectin (Fn)-binding assays demonstrated that rMSNOX bound Plg and Fn in a dose-dependent manner, thereby further confirming that MSNOX may be a putative adhesin.

CONCLUSION

MSNOX was identified to be a surface immunogenic protein that has good immunoreactivity and specificity in Western blot and ELISA, and therefore, may be used as a potential diagnostic antigen in the future. In addition, rMSNOX adhered to DF-1 cells, an effect inhibited by rabbit anti-rMSNOX, but not anti-MG serum, and anti-rMSNOX serum inhibited the adherence of various MS isolates, but not MG R_low, to DF-1 cells, thus indicating that the inhibition of adherence by anti-MSNOX serum was MS specific. Moreover, rMSNOX adhered to extracellular matrix proteins including Plg and Fn, thus suggesting that NOX may play important roles in MS cytoadherence and pathogenesis. Besides, rabbit anti-rMSNOX serum presented complement-dependent mycoplasmacidal activity toward both MS and MG, indicating the MSNOX may be further studied as a potential protective vaccine candidate.

Multispectral Portable Fibre-Optic Reflectometer for the Classification of the Origin of Chicken Eggshells in the Case of Mycoplasma synoviae Infections

The proper classification of the origins of food products is a crucial issue all over the world nowadays. In this paper, the authors present a device-a multispectral portable fibre-optic reflectometer and signal processing patch-together with a machine-learning algorithm for the classification of the origins of chicken eggshells in the case of Mycoplasma synoviae infection. The sensor device was developed based on previous studies with a continuous spectrum in transmittance and selected spectral lines in reflectance. In the described case, the sensor is based on the integration of reflected spectral data from short spectral bands from the VIS and NIR region, which are produced by single-colour LEDs and introduced to the sample via a fibre bundle. The measurement is carried out in a sequence, and the reflected signal is pre-processed to be put in the machine learning algorithm. The support vector machine algorithm is used together with three different types of data normalization. The obtained results of the F-score factor for classification of the origins of samples show that the percentages of eggs coming from Mycoplasma synoviae infected hens are up to 87% for white and 96% for brown eggshells.

First Molecular Survey to Detect Mycoplasma gallisepticum and Mycoplasma synoviae in Poultry Farms in a Strategic Production District of Sicily (South-Italy)

Simple Summary

Avian mycoplasmosis is caused by several pathogenic mycoplasmas of which Mycoplasma gallisepticum (MG) and M. synoviae (MS) are the most important. These bacteria may cause both respiratory disease and synovial infections in poultry, resulting in severe economic losses. The aim of this work was to determine the occurrence of MG and MS among commercial and rural laying hens located in Ragusa province (South Italy), using a duplex real time PCR. Four hundred tracheal swabs were collected from seven commercial and 25 rural farms without any clinical disease history. The prevalence in the studied flocks was 28.6% (commercial) and 40% (rural) for MG, and 42.8% (commercial) and 44% (rural) for MS. The overall prevalence at animal level was 12.5% for MG and 23.25% for MS. Data obtained show a lower prevalence of MG than MS in the studied farms. Moreover, both pathogens were spread in rural and commercial farms underlining the importance of surveillance and control of these infections.

Abstract

Mycoplasmas are recognized as avian pathogens, which may cause both respiratory disease and synovial infections in poultry, resulting in severe economic losses. Our study aims to determine the occurrence of Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) among commercial and rural laying hens located in Ragusa province (South Italy), using a duplex real time PCR. Four hundred tracheal swabs were collected from seven commercial (200 swabs) and 25 rural (200 swabs) farms without any clinical disease history. Out of 400 swabs collected, 50 (12.5%) and 93 (23.25%) were positive for MG and MS, respectively. In particular, 9 (18%) and 22 (23.65%) positive swabs for MG and MS, respectively, originated from commercial farms, compared to 41 (82%) and 71 (76.34%) obtained from rural farms. Data obtained show a lower prevalence of MG than MS in the studied farms. Moreover, both pathogens were spread in rural and commercial farms. PCR could be concluded as a rapid and sensitive method for the identification of MG and MS in areas where commercial farms that are declared Mycoplasma-free and rural flocks coexist. These data highlight the importance of surveillance also in rural poultry to monitoring the occurrence of mycoplasmas strains in strategic productive districts.

Investigation of Serotype Prevalence of Escherichia coli Strains Isolated from Layer Poultry in Greece and Interactions with Other Infectious Agents

Colibacillosis is the most common bacterial disease in poultry and it is caused by avian pathogenic Escherichia coli (APEC), which is assigned to various O-serogroups. Previous studies have shown that APEC strains are more often related to certain O-serogroups such asO78, O2 and O1. E. coli has been reported to act either as a primary or secondary agent in complicating other infections. The aim of this study was to investigate the occurrence of and characterize the O-serogroups of E. coli strains isolated from commercial layer and layer breeder flocks showing macroscopic lesions of colibacillosis and increased or normal mortality in Greece. Furthermore, we attempted to assess the interaction between infectious agents such as Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS), infectious bronchitis (IBV) and infectious laryngotracheitis (ILT) with E. coli infections in layer flocks with increased mortality. Our study revealed that in addition to the common serogroups (O78, O2), many other, and less common serogroups were identified, including O111. The O78, O111 and O2 serogroups were frequently detected in flocks with lesions of colibacillosis and increased mortality whereas O2, O88 and O8 were reported more commonly in birds with colibacillosis lesions but normal mortality rates. These data provide important information for colibacillosis monitoring and define preventative measures, especially by using effective vaccination programs because E. coli vaccines are reported to mainly offer homologous protection. Finally, concerning the association of the four tested infectious agents with E. coli mortality, our study did not reveal a statistically significant effect of the above infectious agents tested with E. coli infection mortality.

Antibiotic resistance of Mycoplasma Synoviae strains isolated in China from 2016 to 2019

Background

In the past decade, Mycoplasma synoviae (M. synoviae) infection has become widely prevalent in China, has caused serious economic losses and has become one of the most important diseases in the chicken industry. Medication is a general approach for the control of M. synoviae infection, but antibiotics are sometimes ineffective in clinical practice. To investigate the sensitivity of M. synoviae to antimicrobials commonly used in the treatment of M. synoviae infection, the antibiotic susceptibility of 32 M. synoviae strains isolated from China from 2016 to 2019 were determined using the minimum inhibitory concentration (MIC) method.

Results

All isolates had low MIC values for the combination of lincomycin and spectinomycin, pleuromutilin, and macrolides. However, the M. synoviae isolates displayed variance in MICs for doxycycline hydrochloride with a range of 0.25 to 8 μg/mL, and oxytetracycline hydrochloride with a range of 0.5 to 8 μg/mL. Three and one M. synoviae isolates showed intermediate MIC values to doxycycline hydrochloride and oxytetracycline hydrochloride, respectively. High MIC values for enrofloxacin were detected in all isolates with MICs ranging from 4 to 32 μg/mL. Furthermore, comparison of the parC QRDR identified a mutation at nucleotide position 254 (C254T) resulting in a Thr 85 Ile amino acid change in all M. synoviae isolates and the reference strain ATCC 25204 being resistant to enrofloxacin. Moreover, mutations at Glu 804 Gly and Thr 686 Ala of gyrA QRDR were identified in all M. synoviae isolates and ATCC 25204. The mutation in the QRDR of the parE gene resulted in amino acid changes at positions 197 (Pro to Ser) in 27/32 M. synoviae isolates.

Conclusion

Three nonsynonymous mutations in gyrA and parE were first identified to be related to enrofloxacin resistance. Our results showed that M. synoviae resistance to enrofloxacin is widespread.

Epidemiological investigations and locally determined genotype diversity of Mycoplasma synoviae in Central China from 2017 to 2019

Mycoplasma synoviae (M. synoviae) has been identified worldwide to cause respiratory diseases, infectious synovitis, airsacculitis, and eggshell apex abnormalities (EAA) in commercial chickens, which results in substantial economic losses to the poultry industry. Therefore, in this study, 258 flocks were investigated between 2017 and 2019 for M. synoviae by screening samples from Central China. Subsequently, 129 M. synoviae strains were isolated, with a positive rate of 50%. Moreover, a higher incidence of M. Synoviae infections was in layers (74.1%) than in broilers (20%) in this study. The 5′-end conserved segment of the variable lipoprotein hemagglutinin A (vlhA) gene of these isolates was then cloned and sequenced because it is a common genomic target identified so far for M. synoviae genotyping. Genotyping of all isolates was based on the phylogenetic analysis and length analysis of the proline-rich-repeat (PRR) regions, respectively. Phylogenetic analysis based on 5′-end conserved segment of the vlhA gene (76–421 nt) assigned the majority of the occurring strains as being from group 6, and others from groups 2 and 3. Results identified that these isolates were of 6 types: A (38aa), D (23aa), E (19aa), I (28aa), J (20aa), and L (35aa), based on the size of the PRR region analysis. Furthermore, most of the isolates (81.4% were identified as type L. Additionally, the epidemic types included only I and L in 2017; however, the types rose to 5 (A, D, E, I, L) in 2018 and rose to 6 (A, D, E, I, J, L) in 2019. These data showed the genotype diversity of M. synoviae in Central China. The high rate of positive flocks suggests the urgent need to take real-time supervisory controls of this Mycoplasma species in avian flocks.

Pooled molecular occurrence of Mycoplasma gallisepticum and Mycoplasma synoviae in poultry: A systematic review and meta-analysis

Worldwide, Mycoplasma gallisepticum (MG) and M. synoviae (MS) are the main agents responsible for chronic respiratory disease in poultry. Therefore, we conducted a systematic review and meta-analysis to estimate their occurrence. We searched electronic databases to find peer-reviewed publications reporting the molecular detection of MG and MS in poultry and used meta-analysis to estimate their pooled global occurrence (combined flock and individual), aggregating results at the regional and national levels. We performed a subgroup meta-analysis for subpopulations (broilers, layers, breeders and diverse poultry including turkeys, ducks and ostriches) and used meta-regression with categorical modifiers. We retrieved 2294 publications from six electronic databases and included 85 publications from 33 countries that reported 62 studies with 22,162 samples for MG and 48 studies with 26,413 samples for MS. The pooled global occurrence was 38.4% (95% CI: 23.5-54.5) for MS and 27.0% (20.4-34.2) for MG. Among regions, Europe and Central Asia had the lowest occurrence for both pathogens, while MG and MS were highly prevalent in South Asia and sub-Saharan Africa, respectively. At the national level, MG occurrence was higher in Algeria, Saudi Arabia and Sudan, whereas China, Egypt and Ethiopia reported higher values of MS. Among the poultry subpopulations, MS and MG were more prevalent in the breeders and layers (62.6% and 31.2%, respectively) than in diverse poultry. The year of publication, the sample size and the level of ambient air pollution (measured indirectly by PM2.5) were associated with the occurrence of both mycoplasmas. Our study revealed high and heterogeneous occurrence values of MG and MS and justifies the need for early detection and improved control measures to reduce the spread of these pathogens.

Clinical expression, epidemiology and monitoring of Mycoplasma gallisepticum and Mycoplasma synoviae: an update

Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) are of clinical and economic importance for the global poultry industry. Many countries and integrations are involved in monitoring programs to control both mycoplasma species. This review provides an extensive historic overview of the last seven decades on the development of the knowledge regarding the factors that influence the clinical expression of the disease, the epidemiology and monitoring of both MG and MS. This includes the detection of new virulent strains, studies unravelling the transmission routes, survival characteristics and the role of other avian hosts. Also the role of molecular typing tests in unravelling epidemiology, and factors that complicate the interpretation of test results such as heterologous mycoplasma infections, use of heterologous oil-emulsion vaccines, use of antibiotic treatments, occurrence of MG and MS strains with low virulence, and last but not least the use of live and/or inactivated MG and MS vaccines are discussed.

Seroprevalence and prevalence of Mycoplasma synoviae in laying hens and broiler breeders in Spain

Mycoplasma species are worldwide recognized poultry pathogens, with Mycoplasma synoviae being the second most important species from the clinical point of view that causes considerable economic losses in the poultry industry. The aim of this study was to assess the seroprevalence, prevalence, and phylogenetic variants of M. synoviae present in layers and broiler breeders' farms of Gallus gallus species located in eastern Spain. Thus, 19 and 23 flocks of layers and broiler breeders, respectively, were analyzed at 3 different ages. To assess seroprevalence, sera samples were analyzed by ELISA. Tracheal swabs were tested by PCR to assess the prevalence. A M. synoviae seroprevalence of 95 and 74% was detected in layers and broiler breeders, respectively. Regarding age-wise analysis, the positive rates obtained seemed to be higher as the age of sampling increased. As per PCR results, a prevalence of 95% in layers and 35% in broiler breeders was obtained. The genetic analysis showed that the strains present in broilers breeders were vaccine strains (MS H strain). In contrast, 6 different field strains were detected in layer hens. In conclusion, this study carried out in eastern Spain showed a higher seroprevalence and prevalence of M. synoviae field strains in layer flocks regarding broiler breeders, highlighting the usefulness of monitoring flocks to control this poultry pathogen. Moreover, our findings suggest M. synoviae vaccination in broiler breeders could be an effective prevention strategy.

Investigation on eggshell apex abnormality (EAA) syndrome in France: isolation of Mycoplasma synoviae is frequently associated with Mycoplasma pullorum

BACKGROUND

Mycoplasma synoviae (MS) is known to cause Eggshell Apex Abnormality (EAA) syndrome characterized by an altered shell surface with increased translucency on the apex. However, no large-scale studies have been conducted to obtain prevalence data of EAA and MS isolates associated to this syndrome. This manuscript reports the results of two field studies performed in the French poultry industry (2015-2017): focusing mainly on investigation of presence and prevalence of EAA in different types of laying hen flocks (phase 1), and isolation of MS strains from EAA-infected flocks (phase 2).

RESULTS

The first survey included 77 farms of commercial layers in three French egg-production regions, hosting 40 flocks in alternative systems (ALT) and 56 in furnished cages (FC). Seven flocks (4 FC and 3 ALT) presented EAA clinical signs, giving a prevalence of 7.3% in this studied sample. A second independent field study was conducted to identify MS by in vitro cultivation and PCR in samples from 28 flocks with clinical signs of EAA. Different types of biological specimens were collected in EAA-affected flocks and submitted to the laboratory. M. synoviae was detected in 25/28 flocks, from both production systems (5/5 ALT and 20/23 FC). Detection of MS was significantly higher in tracheal swabs (59%) than in cloacal (10.5%), albumen (3.6%) and egg yolk (1.1%) swabs. It is worth to mention that attempts to clone MS from positive samples were often hampered by the presence of another Mycoplasma species, which showed fast growing behaviour in the selective media used in this study (Frey Medium 4 and Frey Medium 4 supplemented with erythromycin). The use of MALDI-TOF mass spectrometry in combination with next-generation sequencing (NGS) results allowed the identification of this fast growing mycoplasma as Mycoplasma pullorum, which was detected in 14 of the 25 (56%) MS-positive flocks.

CONCLUSIONS

These results confirmed the presence of the EAA syndrome in MS-positive flocks of layers in France, reared in different regions and in different production systems (ALT and FC). Studies need to be conducted to test whether M. pullorum may influence the expression of clinical signs of EAA in MS-infected layer farms.

Molecular detection of Mycoplasma synoviae and avian reovirus infection in arthritis and tenosynovitis lesions of broiler and breeder chickens in Santa Catarina State, Brazil

Infectious arthritis or tenosynovitis in broiler and breeder chickens results in major loss of productivity because of reduced growth and downgrading at processing plants. The most common causative agents of avian infectious arthritis are the bacterium Mycoplasma synoviae and avian reoviruses (ARVs) (family Reoviridae, genus Orthoreovirus). In this study, we evaluated the occurrence of these two pathogens in arthritis or tenosynovitis lesions of broilers and breeder flocks in southern Brazil using molecular detection. Tissue sections from tibiotarsal joints with visible lesions from 719 broilers and 505 breeders were analysed using pathogen-specific polymerase chain reaction (PCR) assays. In breeders, 41.2% (n = 296) of lesions were positive for M. synoviae, 26.4% (n = 190) were positive for ARV, while co-infection was present in 12.2% (n = 88) of the samples. In broilers, 20.8% (n = 105) of lesions were positive for M. synoviae, 11.9% (n = 60) for ARV and 7.7% (n = 39) of these cases were positive for both pathogens. Post-mortem examination revealed lesions with varying degrees of gross pathological severity. Histopathological examination showed intense, diffuse lymphohistiocytic inflammatory infiltrates with heterophil accumulation, primarily in the synovial capsule and digital flexor tendon, in all samples. Improved strategies for early detection and control of these major avian pathogens are highly desirable for preventing the spread of infection and reducing economic losses in the poultry industry.

Relative contribution of vertical, within-farm and between-farm transmission of Mycoplasma synoviae in layer pullet flocks

In this study, the relative contribution of vertical transmission, within-farm transmission and between-farm transmission of Mycoplasma synoviae in layer pullet flocks was quantified using logistic regression analysis. Data from 311 Dutch pullet flocks, of which 172 (55%) were positive for M. synoviae, were included in the study. Also the M. synoviae status of the parent stock of these flocks was included. The M. synoviae status was determined with the M. synoviae rapid plate agglutination test. Data analysis showed that vertical transmission was the most important transmission route for M. synoviae in layers as is demonstrated by an odds ratio of 5.8 (P = 0.000). A positive association with M. synoviae infections was found for layer pullet flocks on a multi-house farm where at least one other flock was M. synoviae-positive compared to single-house farms (odds ratio 3.1, P = 0.022), while a negative association was found when no other M. synoviae-positive flocks were present (odds ratio = 0.2, P = 0.003). No association was found between M. synoviae status of pullet flocks and poultry farm density. Odds ratios were 0.54 (P = 0.288) and 0.34 (P = 0.073), respectively, for medium and highest poultry farm density compared to lowest poultry farm density. This is the first time that the relative contribution of horizontal and vertical transmission of M. synoviae has been quantified. These results can be extrapolated to M. synoviae control in general, and emphasize the importance of M. synoviae control in parent stock and practical channelling.

Prevalence and Phylogenetic Analysis of Mycoplasma Synoviae Strains Isolated from Polish Chicken Layer Flocks

Introduction

Mycoplasma synoviae (MS) is a chicken pathogen of major economic importance.

Material and Methods

Between 2010 and 2016, 906 commercial layer chicken flocks in Poland were examined for MS, and the phylogenetic relationship among the strains was established. Regionally dispersed samples were collected and tested with the use of real-time PCR to detect the 16S-23S intergenic spacer region. Positive samples were also tested with LAMP and conventional PCR to detect the vlhA gene.

Results

MS genetic material was detected in 265 (29%) of the tested flocks by real-time PCR, in 227 by the LAMP method and in 202 (22%) by conventional PCR. The by-year percentage of positive samples began at 34% in 2010, rose to 44% in 2012, and declined to 29% in 2016. A phylogenetic analysis of Polish M. synoviae strains using a partial sequence of the vlhA gene showed nine genotypes (A-I), the most frequently occurring being F and C. Pathogenic Polish MS field isolates (n = 27) collected from chickens with clinical signs of infection were grouped for their characteristic symptoms: respiratory for genotypes C, E, F, and I (n = 13), EAA and a drop in laying for genotypes F, E, and C (n = 12), and synovitis for genotype A (n = 2).

Conclusion

These data showed the country's isolate diversity. The high prevalence suggests the need to introduce appropriate control programmes. This is the first report of molecular epidemiological data on M. synoviae infection in layer chickens in Poland.

Real-time Loop-mediated Isothermal Amplification (LAMP) of mgc2 Gene of Mycoplasma Gallisepticum

Introduction

Mycoplasma gallisepticum is considered the most pathogenic and economically significant avian Mycoplasma spp. for the worldwide poultry industry. The aim of this study was to develop a novel and sensitive real-time loop-mediated isothermal amplification (LAMP) assay based on the amplification of its mgc2 gene sequence for its rapid molecular detection in poultry.

Material and Methods

Blood samples from 300 broiler and layer chickens were screened using a rapid serum agglutination (RSA) test. A real-time LAMP reaction was conducted with seropositive swab samples at 60ºC for 90 min in an ESEQuant tube scanner using 6-carboxyfluorescein as the reporting dye.

Results

The sensitivity of the developed assay was 10 fg/µL of DNA. The assay was found 100% specific, showing no cross-reactivity with other avian Mycoplasma species. The proportion found of the positive samples by the real-time LAMP was 58%. In comparison, the RSA was found to detect 52% of positive cases.

Conclusion

The mgc2 real-time LAMP emerged as a more sensitive and accurate method for molecular detection of M. gallisepticum than RSA. Robustness and precision give it applicability as a potential field diagnostic tool for M. gallisepticum control. The study will be beneficial in reducing economic losses that M. gallisepticum inflicts on the poultry industry. This is the first reported development of a real-time LAMP assay based on the amplification of the mgc2 gene sequence using an ESEQuant tube scanner for galline M. gallisepticum detection.

Epidemiological investigation of Mycoplasma Synoviae in native chicken breeds in China

Backgroud

Mycoplasma synoviae (M. synoviae) is widely distributed around the world, and leads to serious economic losses in the world every year. Nevertheless, the incidence and epidemiology of M. synoviae infection in China have remained unclear.

Results

In this study we demonstrate that over 9773 broiler chicken flocks in 16 Chinese provinces were affected by M. synoviae between 2010 and 2015. Our epidemiological study revealed that M. synoviae was widely prevalent in multi-aged Chinese native breeder chickens, and the prevalence of M. synoviae in embryos of breeders reached up to 16.29%. In addition, our data showed that chickens aged 14 days or younger carried simultaneously high levels of maternal antibody against M. synoviae and high M. synoviae infection (10%), and low M. synoviae antibody levels in breeders and high proportion of M. synoviae infection in embryos could increase the chances of incidence in the offspring. Finally, our results also indicated that 3- to 7-week-old chickens might be most the susceptible to M. synoviae and, therefore, might play a key role in the horizontal transmission of M. synoviae.

Conclusion

Our findings suggest that M. synoviae is widely circulating in Chinese native chickens, accordingly, effective control measures are urgently needed to control the spread.

Quantification of the horizontal transmission of Mycoplasma synoviae in non-vaccinated and MS-H-vaccinated layers

The number of newly infected birds attributable to one infectious bird per day (= transmission rate β) was assessed in non-vaccinated and MS-H-vaccinated experimental specified pathogen-free White Leghorns after Mycoplasma synoviae challenge. Furthermore, the effect of vaccination on the shedding of the challenge strain was determined. The following groups were made: a negative control group (n = 5), a vaccinated (MS-H vaccine by eye drop (>10^5.7 colour changing units/bird)) non-challenged group (n = 5), two non-vaccinated challenged groups (n = 18 each) and two vaccinated challenged groups (n = 18 each). In the challenged groups, six seeder birds were intratracheally inoculated with 10^5.4 colony forming units (CFUs)/bird. Trachea swabs were taken at day (D)2, D3, D4, D5, D7, D9, D11, D14, D17, D21, D25, D28, D32, D35, D42 and D46 after contact with seeders and analyzed with a quantitative PCR able to detect the vaccine and field strain separately. The transmission rate and shedding were estimated using the susceptible exposed infectious transmission model and a linear mixed model, respectively. The mean shedding of the challenge strain was 10^6.4 CFU equivalents M. synoviae/g trachea mucus in vaccinates shedding MS-H, while in the birds not shedding the vaccine (non-vaccinates and vaccinates not shedding MS-H) it was 10^6.9 CFU equivalents M. synoviae/g trachea mucus. In vaccinates shedding MS-H, β was 0.0012 (95% C.I.: 0.00048 - 0.0024), while in birds not shedding vaccine (non-vaccinates and vaccinates not shedding MS-H) a significantly higher β of 0.022 (95% C.I.: 0.015 - 0.031) was found.

Molecular identification of Mycoplasma synoviae from seroprevalent commercial breeder farms at Chittagong district, Bangladesh

Aim:

Worldwide, Mycoplasma synoviae (MS) is an important pathogen of poultry, especially for chicken and turkey. It causes respiratory tract infection and infectious sinusitis. The study was conducted to determine the seroprevalence of MS infection with associated risk factors and identification of MS organism in unvaccinated flocks of commercial breeder farms of the Chittagong district, Bangladesh.

Materials and Methods:

A total of 365 serum samples were collected and tested for MS using serum plate agglutination (SPA) test for determination of MS seroprevalence. On the other hand, tracheal swabs were collected from each seropositive flocks for polymerase chain reaction (PCR) to determine the presence of MS organism.

Results:

Among the farms, the highest prevalence was found to be 69% and the lowest prevalence was 28% with the average 60%. The seroprevalence of MS infection in breeder farms was highest 70% with the flock size >10,000 birds, whereas it was lowest 57% in the flocks ranging from 4000 to 7000. According to age group, the prevalence was found highest 70% in >60 weeks age group of birds and lowest 42% in 10-19 weeks group. The seroprevalence of MS in winter season was found as highest as 64%, whereas it was found lowest 60% in the summer season. There was a statistically significant difference (p<0.01) among the seroprevalence of MS in different breeder farms, flock size, and age groups, but there was no significant (p>0.05) difference in the winter, summer, and rainy season. To confirm the presence of MS in the samples, PCR test was applied using specific primers to amplify a 214 bp region of the 16S rRNA gene of the organism. In PCR, all seropositive flocks showed a positive result for MS.

Conclusion:

As the plate agglutination test result showed 100% similar with PCR result, it can be suggested that agglutination test is better than molecular and culture techniques for MS detection and it is also cheaper and less time-consuming method.

High seroprevalence of respiratory pathogens in hobby poultry

Seroprevalence studies on respiratory pathogens have been done extensively in commercial laying hens, broilers, and, to a lesser extent, backyard poultry. In Europe, seroprevalence studies in backyard and fancy breed poultry flocks are scarce and limited to a few pathogens, such as Mycoplasma gallisepticum (MG); others, such as Ornithobacterium rhinotracheale (ORT), are missing. A commercial ELISA for detection of antibodies against six selected pathogens was performed on 460 serum samples from chickens across Flanders. Anti-ORT antibodies were, by far, the most prevalent, with a prevalence of 95.4%. Infectious bronchitis virus, Mycoplasma synoviae, and avian metapneumovirus antibodies were found in 75.6%, 76.3%, and 63.5% of the animals, respectively. Antibodies against MG and infectious laryngotracheitis virus were found in 36.7% and 30% of the animals, respectively. These data demonstrate the high seroprevalence of respiratory pathogens among hobby poultry; therefore, it is possible that this group could act as a reservoir for commercially kept poultry.

Rapid detection of Mycoplasma synoviae by loop-mediated isothermal amplification

Mycoplasma synoviae (MS) remains a serious concern in production of poultry and affects world production of chickens and turkeys. Loop-mediated isothermal amplification (LAMP) of DNA has been recently used for the identification of different economically important avian pathogens. The aim of this study was to develop LAMP for simple and inexpensive detection of MS strains in poultry using specifically designed primers targeting hemagglutin A (vlh) gene. The assay was conducted in a water bath for 1 h at 63 °C. The results were visualized after addition of SYBR Green(®) fluorescent dye. LAMP was specific exclusively for MS without cross-reactivity with other Mycoplasma species. The sensitivity of LAMP was determined as 10(-1) CFU/ml and was 1,000 times higher than MS-specific polymerase chain reaction. LAMP assay was conducted on 18 MS field strains to ensure its reliability and usefulness. This is the first report on LAMP development and application for the rapid detection of MS isolated from chickens. This simple method may be applied by diagnostic laboratories without access to expensive equipment.

Avian diseases which affect egg production and quality

This chapter addresses diseases and syndromes which have been shown, or are reported, to have adverse effects on egg production and quality. However, any disease of poultry can adversely affect egg production and quality indirectly, by affecting the health of the bird. The main topics are the effect on egg production and quality of bacteria (Salmonella, Mycoplasma, Escherichia coli, infectious coryza, Ornithobacterium, Gallibacterium, spirochaetosis), viruses (infectious bronchitis virus, egg drop syndrome, swollen head syndrome, avian encephalomyelitis, influenza, Newcastle disease, laryngotracheitis), syndromes (fatty liver haemorrhagic syndrome, cage layer osteoporosis) and toxic agents. A short section on clinical perspectives reports on information obtained from practising poultry veterinarians as such observations can provide valuable starting points for future research.