Enhancer of Zeste homolog 2-mediated histone H3 lysine 27 trimethylation silences LIM domain-containing protein 1 and activates hippo signaling in Mycoplasma pathogenesis.

Day-old vaccination with the Vaxsafe MG304 live-attenuated vaccine protects chickens from tracheal transcriptional changes induced by chronic infection with Mycoplasma gallisepticum.

The article presents the results of a clinical trial of an oral combination antimicrobial drug based on doxycycline and tylosin in the treatment of farm animals (broiler chickens, weaned piglets, calves up to 8 weeks of age) with bacterial respiratory diseases. Respiratory mycoplasmosis of broilers, pneumonia of calves and piglets were detected. The sensitivity of microorganisms, pathogens of respiratory infections, to doxycycline and tylosin was studied by the diffusion agar method using standard antibiotic discs. The sensitivity of most pathogens to the active ingredients of the drug was established. Thus, all isolates of Mycoplasma gallisepticum, the pathogen of respiratory mycoplasmosis of broilers, were sensitive (70%), or moderately sensitive (30%) to tylosin; 4 strains (40%) were sensitive to doxycycline, moderately sensitive and resistant – 3 strains (30%). In most cases, pathogens of pneumonia of calves and piglets were sensitive to at least one of the active ingredients of the drug. Oral administration of the studied combined antimicrobial drug with drinking water (broiler chickens, piglets) and feed (calves) at the recommended dosage lead to clinical recovery of the vast majority of animals (92% of broiler chickens; 86.7% of calves, 86.7% of piglets). Therefore, the use of a combination of doxycycline and tylosin for the treatment of bacterial respiratory infections at the recommended dose (10 mg of doxycycline and 10 mg of tylosin per kg of animal body weight for 5 days) is effective provided susceptibility of the pathogens to these antibiotics.

Oral immunization with recombinant Saccharomyces cerevisiae expressing TM1 of Mycoplasma gallisepticum induces unique specific antibodies and protective immunity.

Development of Tb-Anthracene-9-Carboxaldehyde complex as a novel optical biosensor for rapid mycoplasma detection in serum samples of infected chickens.

Vaccination is a key control measure for most avian diseases, including the endemic Newcastle disease (ND), Mycoplasmosis, and Colibacillosis in Egypt. This study evaluated three inactivated monovalent commercial vaccines, one for each infection, and an inactivated trivalent locally prepared vaccine for the same diseases. The evaluation included challenge tests for the three diseases and monitoring of antibody levels using the hemagglutination inhibition test for ND and Enzyme-Linked Immunosorbent Assay (ELISA) for Mycoplasmosis. The trivalent vaccine showed protective percentages of 100%, 80%, and 80% against the three diseases, respectively. The monovalent commercial vaccines provided protections of 100%, 70%, and 70%, respectively. Hemagglutinating antibody titers for the trivalent vaccine were 6.9 and 6.5 log 2 at the second-week post-vaccination for LaSota and GVII antigens, respectively. In comparison, the monovalent commercial vaccine showed 4 log 2 at the first-week post-vaccination for LaSota antigen and 6.7 log 2 at the second-week post-vaccination for GVII antigen. The ELISA antibody titers for Mycoplasmosis in both trivalent and monovalent vaccines increased gradually from the first-week post-vaccination (1043 and 987) to peak at the seventh-week post-vaccination (2266 and 2226), respectively. In conclusion, the inactivated trivalent vaccine against ND, Mycoplasmosis, and Colibacillosis demonstrated high potency, efficacy, and safety. Cite this article as: Omar, D. M., Gadallah, F. M., Abdrabo, M. A., Gamal, F. E., Monir, N. M., Gamil, M. A. , Abdel Rahman, M. A. A., Marden, N. A., Abu Zaid, R. A., Abd El-Aziz, H. M. G., Khedr, A. A., & Omar, L. M. (2025). Immunological study on chickens vaccinated with a trivalent combined inactivated Mycoplasma gallisepticum, Escherichia coli, and newcastle disease virus (ND) vaccine. Acta Veterinaria Eurasia, 2025, 51, 0014, doi: 10.5152/actavet.2025.25014.

This study aimed to investigate the effect of Mycoplasma gallisepticum infection on Immune organs and Immune response of ND vaccine in broiler chickens .210 day- old Broiler chicks were randomly assigned to seven equal groups as following G1: control was not received any treatment, G2: only M. gallisepticum infection, G3: only ND vaccine, G4 ND vaccine and M. gallisepticum infection , G5: ND vaccine and M. gallisepticum infection and treated with probiotic G6: ND vaccine and M. gallisepticum infection and treated with Glycyrrhizic Acid by drinking water, G7 : ND vaccine and M. gallisepticum infection and treated with tylosin by drinking water. Blood samples were collected at 1st, 5th, 10th, 16th, 25th, 27th and 35th day for immunological tests and histopathological examination of spleen and bursa of fabricious at the result revealed the highest level of the ND antibody titers in G5, G6, G7,G1 and G3 respectively. Histopathological analysis of the spleen organ revealed necrosis in G4, white pulp hyperplasia in G6 and G7 while the lesions of bursa indicate that severe hyperplasia in M. gallisepticum infection group. The study concluded that probiotic and glycyrrhizic acid reduce effect of M. gallisepticum infection on immune response and immune organs.

Infectious diseases caused by pathogenic microorganisms have caused serious economic losses to animal husbandry, and the use of appropriate disinfectants is crucial for eliminating these pathogens. Plant essential oils (PEOs), as natural bioproducts, have the characteristics of safety, non-toxicity, and broad spectrum. In this study, the inhibition efficacies against bacteria, viruses, and mycoplasmas of a compound PEO disinfectant (designated as Lei-Huo-Fu) were evaluated through determination of minimum inhibitory concentration (MIC) and bactericidal rate against Escherichia coli, Staphylococcus aureus, and Salmonella spp.; inactivation rate of avian infectious bronchitis virus (IBV); as well as determination of MIC of Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS). The results showed that the MIC values of the PEO disinfectant against Escherichia coli, Staphylococcus, and Salmonella spp. were as low as 0.00375 µg/mL to 0.03 µg/mL. The bactericidal rates against Escherichia coli, Staphylococcus aureus, and Salmonella spp. reached over 95% within 30 min at a concentration of 0.03 µg/mL. For three dominant prevalent genotype strains of LX4-type, Mass-type, and Taiwan-type of IBV, the inactivation rates achieved by the PEO disinfectant at a concentration of 0.015 µg/mL and a disinfection time of 30 min were all above 99.9%. The MIC of the PEO disinfectant against MG and MS was 0.001875 µg/mL and 0.00375 µg/mL, respectively. In conclusion, the compound PEO disinfectant (Lei-Huo-Fu) has significant inhibitory effects on bacteria, viruses, and mycoplasmas, and possesses broad-spectrum antimicrobial activity. However, it is important to note that these findings are based on laboratory assays, and the efficacy in practical settings, along with the exact mechanisms of action, require further investigation. In this study, the compound PEO disinfectant demonstrates promising in vitro efficacy, suggesting its potential as a candidate for development into a safe, efficient, and natural disinfectant, pending further validation.

Isolation and Molecular Characterization of Mycoplasma gallisepticum from Domestic Poultry in Sanliurfa, Turkey

Prevalence and antimicrobial susceptibility of Mycoplasma gallisepticum and Mycoplasma synoviae isolated from the central peninsular Malaysia.

Development of droplet digital PCR (ddPCR) for the detection and quantification of Mycoplasma gallisepticum in duck flocks.

Protective role of UDP-glucosyltransferases against deoxynivalenol-induced proventriculitis in chicks.

Few studies exist in which host-pathogen systems have been studied within months of their emergence and followed for many years, making it possible to test the virulence-transmission hypothesis and to determine if a pathogen becomes more or less virulent over time. Around 1994 the bacterium Mycoplasma gallisepticum jumped from poultry to House Finches (Haemorhous mexicanus) and other wild birds in the US. Bacterial virulence increased as it rapidly spread across eastern North America, causing House Finch abundance to decline by half. The new M. gallisepticum variants that eventually colonized the western US had lost a substantial part of their genome and had a reduced virulence. In our study, initial survival of M. gallisepticum was lower in eastern US than in western US isolates, and birds with a higher bacterial load showed higher transmission rates, but this relationship differed between birds inoculated with eastern versus western isolates. Western isolates were less pathogenic (similar pathogen loads caused less-severe disease) than eastern isolates and had lower transmission rates for a given bacterial load. Our study provides insights into how pathogens spreading after a host shift and across a continent may respond to novel evolutionary pressures in diverse ways.

The pathogenic avian mycoplasmas, such as Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) are responsible for causing significant economic losses to the poultry industry. The present study was aimed at serodiagnosis of MG and MS infection in broiler chicken flocks using serum plate agglutination test (SPAT), indirectenzyme linked immunosorbent assay (i-ELISA) and Dot-ELISA, followed by measuring the relative diagnostic efficacy of SPAT and Dot-ELISA in reference to i-ELISA. The blood samples (n68) collected from the broiler chicken aging 46 weeks affected with respiratory tract infection from poultry farms located in Mathura district of Uttar Pradesh, India were used in the study. Initially, SPAT was used to detect MG and MS antibodies in collected sera. In SPAT, 36.76 and 72.06 sera were found positive for MG and MS antibodies, respectively. Later, the samples were screened using laboratory standardized i-ELISA and Dot-ELISA. The culture of MG (NCBI accession no. KX759104.1) and MS (NCBI accession no. KY486506.1) isolates were used to prepare antigens to standardize i-ELISA and Dot-ELISA. Using i-ELISA, the seropositivity of MG and MS antibodies in collected sera was found to be 85.29 and 80.88, respectively. However, seropositivity of MG and MS antibodies using Dot-ELISA was found to be 66.18 and 77.94, respectively. The i-ELISA was used as gold standard test to compare the diagnostic efficacy of SPAT and Dot-ELISA. The relative diagnostic sensitivity, specificity and kappa values for the detection of MG and MS using SPAT was found to be 43.10, 100, 0.1822 and 86.09, 100, 0.7574, respectively. However, the relative diagnostic sensitivity, specificity and kappa values for the detection of MG and MS using Dot-ELISA was found to be 77.59, 100, 0.2524 and 96.36, 100, 0.9102, respectively. The present study reports that i-ELISA and Dot-ELISA should be used along with SPAT for accurate detection of avian mycoplasmas infection in poultry flocks affected with respiratory tract infection.

Six 11-wk-old, commercial, Broad-Breasted White, meat turkeys were submitted to the Turlock branch of the California Animal Health & Food Safety (CAHFS) laboratory for autopsy and diagnostic work-up. Clinical signs in the turkeys of the affected flock included depression, ruffled feathers, swollen periorbital areas, rales, and sneezing. A mortality of 50% (5,000 of 10,000) was reported at the time of case submission. Flock morbidity was 100% by 12 wk of age, and mortality eventually exceeded 90%. Fibrinous pleuropneumonia, airsacculitis, increased luminal mucoid exudate in the nasal cavities and tracheas, mottled and enlarged spleens, and hepatomegaly were the most remarkable gross findings. Microscopically, fibrinoheterophilic pneumonia and epicarditis with intralesional bacterial colonies, and necrotizing hepatitis and splenitis, were noted. Mycoplasmoides (Mycoplasma) gallisepticum (MG) was detected in tracheal and sinus pools by quantitative real-time PCR. Multilocus sequence analysis of the mgc2 gene and IGSR segment of MG differentiated our strain from MG vaccine strains, but were similar to MG isolates detected previously in other commercial turkey operations in California. Pasteurella multocida was isolated from air sacs, lungs, tracheas, hearts, and livers, and classified as profile HhaI 0001, strain X-73, by restriction enzyme analysis DNA fingerprinting. Coinfection with P. multocida and MG in a susceptible flock resulted in rapid elevation of mortality and significant economic losses in this commercial meat turkey operation.

This study is aimed at evaluating the efficacy of essential oil-based microemulsions in combination with antimicrobials against Mycoplasma gallisepticum (MG), a major respiratory pathogen in poultry. MG was isolated from 1.1% of broiler and 0.5% of breeder flocks, with the highest incidence recorded during winter and autumn, particularly in farms located in Giza and Sharkia governorates. Among 37 confirmed isolates, eight were positive for the mgc2 gene, while six carried gapA and crmA. Cumin, camphor, and olive microemulsions exhibited favorable physicochemical characteristics. GC-MS analysis identified α-citral, ( +)-2-bornanone, and cis-vaccenic acid as the major components of cumin, camphor, and olive oils, respectively. Notably, olive/camphor and cumin microemulsions were rich in cis-vaccenic acid and linoleoyl chloride, respectively. Antibiotic susceptibility testing revealed that all isolates were resistant to lincomycin, erythromycin, spectinomycin, and tiamulin, with 50% exhibiting complete resistance to all antibiotics. Tylosin showed partial activity, inhibiting 37.5% of isolates (MIC 0.25-4 µg/mL). Camphor microemulsion demonstrated the highest antimicrobial effect (MIC 0.08-5 µg/mL). The most significant synergistic interaction was observed between cumin oil and either oxytetracycline or spiramycin, as well as between camphor microemulsion and doxycycline against MG isolates. Furthermore, combination treatments significantly downregulated the expression of mgc2, crmA, and gapA genes. These findings highlight the promising role of essential oil-based microemulsions as effective adjuncts in MG control strategies.

Exploiting an evolutionary constraint: Targeting TatD nuclease with chrysosplenol D disrupts Mycoplasma gallisepticum infection.

Newcastle disease (ND) is a highly contagious and economically significant viral infection that affects poultry globally, with recurrent outbreaks occurring even among vaccinated flocks in Egypt. Caused by the Newcastle disease virus (NDV), the disease results in substantial losses due to high mortality rates, decreased productivity, and the imposition of trade restrictions. This study aimed to develop a rapid, sensitive, and field-deployable diagnostic assay based on real-time reverse transcription recombinase-aided amplification (RT-RAA) for the detection of all NDV genotypes in clinical avian specimens. Primers and an exo-probe were designed based on the most conserved region of the NDV matrix gene. After testing ten primer combinations, the pair NDV RAA-F1 and RAA-R5 demonstrated the highest sensitivity, detecting as low as 6.89 EID50/mL (95% CI). The RT-RAA assay showed excellent clinical sensitivity and specificity, with no cross-reactivity to other common respiratory pathogens such as avian influenza virus, infectious bronchitis virus, Mycoplasma gallisepticum or infectious laryngotracheitis virus. All 25 field samples that were tested positive by real-time RT-PCR, including those with high CT values (~35), were detected by RT-RAA in 2–11 min, indicating superior sensitivity and speed. The assay requires only basic equipment and can be performed under isothermal conditions, making it highly suitable for on-site detection in resource-limited or rural settings. The successful implementation of RT-RAA can improve NDV outbreak response, support timely vaccination strategies, and enhance disease control efforts. Overall, the assay presents a promising alternative to conventional diagnostic methods, contributing to the sustainability and productivity of the poultry sector in endemic regions.

Isolation, molecular characterization and phylogenetic analysis of Mycoplasma gallisepticum and Mycoplasma synoviae strains recovered from commercial broiler chicken flocks affected with respiratory tract infections

Variability in acquired protection, whether from prior pathogen exposure or vaccination, is increasingly recognized as a key determinant of host population-level variation in disease traits. It remains unclear whether this extends to the within-host physiological environment and what the consequences are for reinfecting pathogens. Here, we asked whether prior pathogen exposure of hosts induces gene expression heterogeneity in the host and/or pathogen during infection. We quantified gene expression in vivo following high-dose pathogen challenge of house finches (Haemorhous mexicanus) previously given controlled, varied exposure histories to a bacterial pathogen (Mycoplasma gallisepticum; MG). To measure gene expression heterogeneity, we collected transcriptomic data from two host tissues (conjunctiva and spleen), and, simultaneously, from pathogen infecting the primary site of infection (conjunctiva). In the conjunctiva, but not the spleen, prior pathogen exposure induced significant heterogeneity in host gene expression relative to pathogen-naïve hosts. Further, hosts that received a lower prior exposure dose rather than a higher primary dose showed the greatest within-group heterogeneity in expression during re-challenge. Functional enrichment analyses for significantly variable host genes indicated an over-representation of terms involved in the immune system’s response to pathogens, namely a diversified inflammatory response, in birds with prior pathogen exposure. The infecting pathogen from the conjunctiva followed similar patterns of heterogeneity in host gene expression, where pathogen infecting hosts with prior exposure had more heterogeneous expression than those infecting pathogen-naïve hosts. While the exact mechanisms that underlie greater variation in gene expression cannot be resolved by this study, our results are consistent with the hypothesis that prior host exposure induces a within-host environment that promotes heterogeneous gene expression across both hosts and pathogens. This suggests that to understand the coevolutionary dynamics of infectious diseases we must consider not only the genetic sequence variation, but also gene expression variation in host and pathogen.