Hyorhinis Infection Research Articles

Mycoplasma hyorhinis infection promotes TNF-α signaling and SMAC mimetic-mediated apoptosis in human prostate cancer

Growing evidence suggests an association between Mycoplasma infections and the development and progression of prostate cancer (PCa). In this study, we report that chronic and persistent M. hyorhinis infection induced robust TNF-α secretion from PCa cells. TNF-α secreted from M. hyorhinis-infected PCa cells subsequently led to activation of the NF-κB pathway. Chronic M. hyorhinis infection induced gene expression of pro-inflammatory cytokines and chemokines in a NF-κB-dependent manner and promoted cell proliferation, migration, and invasion in PCa cells. The elimination of M. hyorhinis in PCa cells significantly blocked TNF-α secretion, gene expression of cytokines and chemokines, migration, and invasion in PCa cells, suggesting M. hyorhinis-induced TNF-α plays an important role to promote malignant transformation of PCa. Furthermore, second mitochondria-derived activator of caspases (SMAC) mimetics potentiated caspase activation and cell death in M. hyorhinis-infected PCa by antagonizing inhibitor of apoptosis proteins (IAPs) activity. Tissue microarray analysis indicated that TNF-α is co-expressed in M. hyorhinis-infected human patient tissues. Findings from this study advance our understanding of the mycoplasma-oncogenesis process and suggest the potential for new approaches for preventions, diagnosis, and therapeutic approaches against prostate cancers.

Establishment of a Mycoplasma hyorhinis challenge model in 5-week-old piglets.

Mycoplasma hyorhinis is an emerging swine pathogen with high prevalence worldwide. The main lesions caused are arthritis and polyserositis, and the clinical manifestation of the disease may result in significant economic losses due to decreased weight gain and enhanced medical costs. We aimed to compare two challenge routes to induce M. hyorhinis infection using the same clinical isolate. Five-week-old, Choice hybrid pigs were inoculated on 2 consecutive days by intravenous route (Group IV-IV) or by intravenous and intraperitoneal routes (Group IV-IP). Mock-infected animals were used as control (control group). After the challenge, the clinical signs were recorded for 28 days, after which the animals were euthanized. Gross pathological and histopathological examinations, PCR detection, isolation, and genotyping of the re-isolated Mycoplasma sp. and culture of bacteria other than Mycoplasma sp. were carried out. The ELISA test was used to detect anti-M. hyorhinis immunoglobulins in the sera of all animals. Pericarditis and polyarthritis were observed in both challenge groups; however, the serositis was more severe in Group IV-IV. Statistically significant differences were detected between the challenged groups and the control group regarding the average daily weight gain, pathological scores, and ELISA titers. Additionally, histopathological scores in Group IV-IV differed significantly from the scores in the control group. All re-isolated strains were the same or a close genetic variant of the original challenge strain. Our results indicate that both challenge routes are suitable for modeling the disease. However, due to the evoked more severe pathological lesions and the application being similar to the hypothesized natural route of infection in Group IV-IV, the two-dose intravenous challenge is recommended by the authors to induce serositis and arthritis associated with M. hyorhinis infection.

Perturbations of gut microbiome and metabolome of pigs infected with Mycoplasma hyorhinis.

Mycoplasma hyorhinis is a prevalent respiratory pathogen in swine, causing significant economic loss to pig producers. There is growing evidence that respiratory pathogen infections have a great impact on intestinal microecology. To study the effect of M. hyorhinis infection on gut microbial composition and metabolome profile, we infected pigs with M. hyorhinis and performed metagenomic sequencing analysis of fecal sample and liquid chromatography/tandem mass spectrometry (LC-MS/MS) analysis of gut digesta. RESULTS: It is discovered that pigs infected with M. hyorhinis can enrich Sutterella and Mailhella, and deplete Dechloromonas, Succinatimonas, Campylobacter, Blastocystis, Treponema and Megasphaera. Moreover, the M. hyorhinis infected pigs had higher abundances of bacterium_0_1xD8_71, Ruminococcus_sp__CAG_353, Firmicutes_bacterium_CAG_194, Firmicutes_bacterium_CAG_534, bacterium_1xD42_87, etc., and lower abundances of Chlamydia_suis, Megasphaera_elsdenii, Treponema_porcinum, Bacteroides_sp__CAG_1060, Faecalibacterium_prausnitzii, etc. Metabolomics analysis revealed that some lipids and lipid-like molecules were increased in small intestine, while most of lipids and lipid-like molecules metabolites were decreased in large intestine. These altered metabolites induce changes in intestinal sphingolipid metabolism, amino acid metabolism and thiamine metabolism. These findings demonstrate that the pigs infection with M. hyorhinis can alter the gut microbial composition and metabolites structure, which may further affect amino acid metabolism and lipid metabolism in intestine. This article is protected by copyright. All rights reserved.

Antimicrobial susceptibility profiles of Mycoplasma hyorhinis strains isolated from five European countries between 2019 and 2021.

Mycoplasma hyorhinis is an emerging swine pathogen bacterium causing polyserositis and polyarthritis in weaners and finishers. The pathogen is distributed world-wide, generating significant economic losses. No commercially available vaccine is available in Europe. Therefore, besides improving the housing conditions for prevention, antimicrobial therapy of the diseased animals is the only option to control the infection. Our aim was to determine the minimal inhibitory concentrations (MIC) of ten antimicrobials potentially used against M. hyorhinis infection. The antibiotic susceptibility of 76 M. hyorhinis isolates from Belgium, Germany, Hungary, Italy and Poland collected between 2019 and 2021 was determined by broth micro-dilution method and mismatch amplification mutation assay (MAMA). Low concentrations of tiamulin (MIC90 0.312 μg/ml), doxycycline (MIC90 0.078 μg/ml), oxytetracycline (MIC90 0.25 μg/ml), florfenicol (MIC90 2 μg/ml) and moderate concentrations of enrofloxacin (MIC90 1.25 μg/ml) inhibited the growth of the isolates. For the tested macrolides and lincomycin, a bimodal MIC pattern was observed (MIC90 >64 μg/ml for lincomycin, tulathromycin, tylosin and tilmicosin and 5 μg/ml for tylvalosin). The results of the MAMA assay were in line with the conventional method with three exceptions. Based on our statistical analyses, significant differences in MIC values of tiamulin and doxycycline were observed between certain countries. Our results show various levels of antimicrobial susceptibility among M. hyorhinis isolates to the tested antibiotics. The data underline the importance of susceptibility monitoring on pan-European level and provides essential information for proper antibiotic choice in therapy.

Dysbiosis of Gut Microbiota and Intestinal Barrier Dysfunction in Pigs with Pulmonary Inflammation Induced by Mycoplasma hyorhinis Infection.

ABSTRACTLung inflammation induced by Mycoplasma hyorhinis infection accounts for significant economic losses in the swine industry. Increasing evidence suggests that there is cross talk between the lungs and the gut, but little is known about the effect of the lung inflammation caused by M. hyorhinis infection on gut microbiota and intestinal barrier function. Here, we investigated changes in the fecal microbiotas of pigs with M. hyorhinis infection and the microbial regulatory role of such infection in intestinal barrier function. We infected pigs with M. hyorhinis and performed 16S rRNA gene sequencing analyses of fecal samples, data-independent acquisition (DIA) quantitative proteomic analyses of intestinal mucosa, and analyses of barrier dysfunction indicators in serum. We found that pigs with M. hyorhinis infection exhibit lung and systemic inflammation, as reflected by the histopathological changes and activation of the TLR4/MyD88/NF-κB p65 signaling pathway in lung tissue, as well as the increased concentrations of serum inflammatory cytokines. Gut microbiotas tended to become disturbed, as evidenced by the enrichment of opportunistic pathogens. The increased diamine oxidase activities and d-lactate concentrations in serum and the decreased relative mRNA expression of Occludin, ZO-1, and Mucin2 indicated the impairment of intestinal barrier function. Quantitative proteomic analyses showed a variety of altered proteins involved in immunomodulatory and inflammatory functions. There was a positive correlation between the abundance of opportunistic pathogens and inflammatory-cytokine concentrations, as well as intestinal immunomodulatory proteins. Our results suggest that lung inflammation induced by M. hyorhinis infection can contribute to the dysbiosis of gut microbiota and intestinal barrier dysfunction, and dysbiosis of gut microbiota was associated with systemic inflammation and intestinal immune status.IMPORTANCE Cumulative evidence suggests that bacterial pneumonia may contribute to the dysbiosis of the gut microbiota and other gastrointestinal symptoms. Our experiment has demonstrated that lung inflammation induced by M. hyorhinis infection was associated with gut microbiota dysbiosis and intestinal barrier dysfunction, which may provide a theoretical basis for exploring the gut-lung axis based on M. hyorhinis infection.

Nucleic acid aptamer controls mycoplasma infection for inhibiting the malignancy of esophageal squamous cell carcinoma

Esophageal cancer is one of the most frequent malignant tumors of the digestive tract, among which esophageal squamous cell carcinoma (ESCC) is the main pathological type worldwide. Previous studies have shown microbial infections in the upper digestive tract to be a potential risk factor in ESCC etiology. In this study, we identified that Mycoplasma hyorhinis infection promoted the malignancy of ESCC. In response, we generated a single-stranded DNA aptamer, ZY3A, against M.hyorhinis using the cell-SELEX strategy. The underlying recognition mechanism of ZY3A on M.hyorhinis involves its binding to M.hyorhinis-specific p37 protein. This tool allowed us to provide the first proof-of-concept evidence using a nucleic acid aptamer to control mycoplasma infection. More specifically, we found that ZY3A could neutralize M.hyorhinis infection on ESCC cells by blocking the interaction between p37 protein and its receptor TLR4 on the ESCC cell membrane. As a result, ZY3A inhibited the migration and invasion of M.hyorhinis-infected ESCC cells invitro and metastasis invivo. Taken together, these findings indicate that aptamer ZY3A is a potential candidate for development into a novel molecular tool for treatment of M.hyorhinis infection and a safe first-in-class M.hyorhinis-targeting antitumor agent.

A core genome multilocus sequence typing scheme for Mycoplasma hyorhinis

Mycoplasma (M.) hyorhinis is a commensal and pathobiont residing in the upper respiratory tract in swine and with the ability to spread systemically, mainly causing polyserositis and polyarthritis in nursery pigs. Since little is known on the epidemiology of M. hyorhinis infection, whole genome sequences of 73 strains isolated from pigs in Austria (n = 71) and Germany (n = 2), that have been isolated from clinically affected pigs during routine diagnostics, and publicly available genomes of eight M. hyorhinis strains were analyzed in the presented study. For this purpose, a core genome multi locus sequence typing (cgMLST) scheme encompassing 453 target genes was developed using the Ridom© SeqSphere + software. Results were compared to two previously described conventional MLST schemes and to a core genome single nucleotide polymorphism (cgSNP) analysis approach. Core genome MLST showed high diversity among the M. hyorhinis strains studied and while certain isolates from one farm or a single animal formed cgMLST clusters (≤ 8 allele differences), no isolates with identical allele profiles were identified. In addition, cgMLST had superior discriminatory power (Simpson’s ID = 0.995) over conventional MLST (Simpson’s ID = 0.952 and 0.985), while demonstrating a lack of congruence between conventional MLST and genome-wide relationship. Core genome SNP results were highly congruent with cgMLST results but lacked in resolution when comparing closely related isolates. Thus, cgMLST is the most suitable method for epidemiological investigations such as outbreak analysis, and to gain insights into M. hyorhinis population structure.

Development of a molecular biological assay for the detection of markers related to decreased susceptibility to macrolides and lincomycin in Mycoplasma hyorhinis.

The control of Mycoplasma hyorhinis infection relies mainly on antimicrobial therapy. However, the antibiotic susceptibility testing of the bacteria is usually not performed before applying the treatment, and thus therapeutic failures are not uncommon. In the case of M. hyorhinis, several antibiotic-resistance-related single nucleotide polymorphisms (SNPs) are known but assays for their detection have not been described yet. The aims of the present study were to investigate macrolide- and lincomycin-resistance-related SNPs in Hungarian M. hyorhinis isolates and to develop mismatch amplification mutation assays (MAMA) to detect the identified resistance markers. Minimal inhibitory concentrations (MIC) of different drugs and whole genome sequences of 37 M. hyorhinis isolates were used to find the resistance-related mutations. One MAMA assay was designed to detect the mutation of the 23S rRNA gene at nucleotide position 2058 (Escherichia coli numbering). For further evaluation, the assay was challenged with 17 additional isolates with available MIC data and 15 DNA samples from clinical specimens. The genotypes of the samples were in line with the MIC test results. The developed assay supports the practice of targeted antibiotic usage; hence it may indirectly reduce some bacterial resistance-related public health concerns.

Mycoplasma hyorhinis infection promotes tyrosine kinase inhibitor (TKI) resistance in lung adenocarcinoma patients.

To explore the relationship between Mycoplasma hyorhinis infection and tyrosine kinase inhibitor (TKI) resistance in lung adenocarcinoma patients. Mycoplasma hyorhinis infection can be verified with the monoclonal antibody PD4, which specifically recognizes a distinct protein of M. hyorhinis. Immunohistochemistry (IHC), using PD4 to detect M. hyorhinis, was performed on paraffin-embedded lung adenocarcinoma tissues of patients who had epidermal growth factor (EGFR) mutations and had received oral TKI. The number of patients enrolled in our study was 101. Assessments following TKI treatment were performed until objective disease progression or stable disease at the cutoff date was reached. In all of the patients, the primary endpoint was investigator-assessed progression-free survival (PFS). Immunohistochemistry revealed that 61 of 101 cases (60.4%) of lung adenocarcinoma were positive for M. hyorhinis, which comprised of 31 low-positive cases and 30 high-positive cases; the remaining 40 cases (39.6%) were negative. The median PFS was significantly longer in the negative group [18months (95% CI 14.15-21.85)] than in the low-positive group [10months (95% CI 7.70-12.30); hazard ratio (HR) 4.095, 95% CI 2.254-7.438; p < 0.001] and in the high-positive group [4months (95% CI 2.85-5.15); HR 31.703, 95% CI 14.425-69.678; p < 0.001]. The results of the subgroup analysis were satisfactory. The PFS benefit with negative M. hyorhinis infection was consistent across subgroups. In this retrospective, exploratory analysis, M. hyorhinis infection significantly reduced PFS. With increased levels of M. hyorhinis infection, the progression of the disease was more advanced, likely due to the hydrolysis of TKI by M. hyorhinis. A strong correlation was found between M. hyorhinis infection and TKI resistance in lung adenocarcinoma. This study provides potent evidence that M. hyorhinis hydrolyses TKI and will assist in the research of related mechanisms in the future. It provides an option to improve the efficacy of TKI, including strategies to decrease M. hyorhinis infection, thereby reducing long-term distress in TKI resistance patients with EGFR mutations.

Early detection and differential serodiagnosis of Mycoplasma hyorhinis and Mycoplasma hyosynoviae infections under experimental conditions.

Mycoplasma hyorhinis (MHR) and Mycoplasma hyosynoviae (MHS) are common opportunistic pathogens in the upper respiratory tract and tonsils of swine. The identification of the specific species involved in clinical cases using conventional diagnostic methods is challenging. Therefore, a recombinant chimeric polypeptide based on the seven known variable lipoproteins (A-G) specific of MHR and a cocktail of surface proteins detergent-extracted from MHS cultures were generated and their suitability as antemortem biomarkers for serodiagnosis of MHR- and MHS-infection were evaluated by ELISA. M. hyorhinis and MHS ELISA performance, evaluated using serum samples collected over a 56-day observation period from pigs inoculated with MHR, MHS, M. hyopneumoniae, M. flocculare, or Friis medium, varied by assay, targeted antibody isotype, and cutoffs. The progressions of MHR and MHS clinical diseases were evaluated in relation to the kinetics of the isotype-specific antibody response in serum and bacterial shedding in oral fluids during the observation period. In pigs inoculated with MHR, bacterial DNA was detected in one or more of the 5 pens at all sampling points throughout the study, IgA was first detected at DPI 7, one week before the first clinical signs, with both IgA and IgG detected in all samples collected after DPI 14. The peak of MHS shedding (DPI 8) coincided with the onset of the clinical signs, with both IgA and IgG detected in all serum samples collected ≥ DPI 14. This study demonstrated, under experimental conditions, that both ELISAs were suitable for early detection of specific antibodies against MHR or MHS. The diagnostic performance of the MHR and MHS ELISAs varied depending on the selected cutoff and the antibody isotype evaluated. The high diagnostic and analytical specificity of the ELISAs was particularly remarkable. This study also provides insights into the infection dynamics of MHR-associated disease and MHS-associated arthritis not previously described.

Mycoplasma exploits mammalian tunneling nanotubes for cell-to-cell dissemination

Using tunneling nanotubes (TNTs), various pathological molecules and viruses disseminate to adjacent cells intercellularly. Here, we show that the intracellular invasion of Mycoplasma hyorhinis induces the formation of actin- and tubulin-based TNTs in various mammalian cell lines. M. hyorhinis was found in TNTs generated by M. hyorhinis infection in NIH3T3 cells. Because mycoplasma-free recipient cells received mycoplasmas from M. hyorhinis-infected donor cells in a mixed co-culture system and not a spatially separated co-culture system, direct cell-to-cell contact via TNTs was necessary for the intracellular dissemination of M. hyorhinis. The activity of Rac1, which is a small GTP binding protein, was increased by the intracellular invasion of M. hyorhinis, and its pharmacological and genetic inhibition prevented M. hyorhinis infection-induced TNT generation in NIH3T3 cells. The pharmacological and genetic inhibition of Rac1 also reduced the cell-to-cell dissemination of M. hyorhinis. Based on these data, we conclude that intracellular invasion of M. hyorhinis induces the formation of TNTs, which are used for the cell-to-cell dissemination of M. hyorhinis.

Mycoplasma hyorhinis infection promotes gastric cancer cell motility via β-catenin signaling.

BackgroundWe previously identified that Mycoplasma hyorhinis infection promotes gastric cancer cell motility. The β‐catenin signaling pathway is critical to determining malignant cancer cell phenotypes; however, the association between M hyorhinis and the β‐catenin signaling pathway is unclear.MethodsWe performed subcellular fractionation and immunofluorescence staining to observe β‐catenin accumulation in the nucleus. The expression of downstream β‐catenin genes was detected by quantitative RT‐PCR. Gastric cancer cell motility was examined by transwell chamber migration and wound healing assays, and a co‐immunoprecipitation assay was used to detect the proteins associated with the membrane protein p37 of M hyorhinis.ResultsWe found that M hyorhinis infection promoted nuclear β‐catenin accumulation and enhanced the expression of downstream β‐catenin genes. M hyorhinis‐promoted gastric cancer cell motility was counteracted by treatment with the β‐catenin inhibitor XAV939 or β‐catenin knockdown. We further detected a protein complex containing LRP6, GSK3β, and p37 in M hyorhinis‐infected cells. M hyorhinis also induced LRP6 phosphorylation in a GSK3β‐dependent fashion. Knockdown of LRP6 or GSK3β abolished M hyorhinis‐induced cell motility.ConclusionOur results reveal that the β‐catenin signaling pathway could be activated by M hyorhinis infection, thereby contributing to M hyorhinis‐induced gastric cancer cell motility.

Antibiotic susceptibility profiles of Mycoplasma hyorhinis strains isolated from swine in Hungary

Mycoplasma hyorhinis is a common pathogen of swine causing mainly polyserositis and arthritis, but it has also been implicated as a cause of pneumonia. The economic losses due to M. hyorhinis infection could be reduced by antibiotic treatment. The aim of this study was to determine minimal inhibitory concentrations (MIC) of antibiotics potentially used to combat M. hyorhinis in swine production.Thirty-eight Hungarian M. hyorhinis strains isolated between 2014 and 2017 were examined by microbroth dilution tests for fifteen antimicrobial agents. Low MIC values of tetracyclines (MIC50 0.078 μg/ml for doxycycline, ≤0.25 μg/ml for oxytetracycline) and pleuromutilins (MIC50 0.156 μg/ml for tiamulin, ≤0.039 μg/ml for valnemulin) were detected against all strains. Fluoroquinolones (MIC50 0.625 μg/ml), gentamicin (MIC50 1 μg/ml) and florfenicol (MIC50 2 μg/ml) inhibited the growth of Hungarian isolates at moderate MIC values. Most of the strains were inhibited by spectinomycin with low or moderate MIC values (MIC50 4 μg/ml) except one strain (>64 μg/ml). Numerous isolates showed decreased susceptibility to macrolides and lincomycin (MIC90 >64 for tylosin, tilmicosin, tulathromycin, gamithromycin, lincomycin, 8 μg/ml for tylvalosin).This study serves as evidence for the increasing resistance to macrolides and lincomycin in mycoplasmas, and also reports the occurrence of strains with extremely high MIC values to spectinomycin thus emphasizes the importance of the prudent use of antibiotics. Based on our results, tetracyclines and pleuromutilins are the most active compounds in vitro against the Hungarian M. hyorhinis strains.

Mycoplasma hyorhinis reduces sensitivity of human lung carcinoma cells to Nutlin-3 and promotes their malignant phenotype.

MDM2 inhibitors are promising anticancer agents that induce cell cycle arrest and tumor cells death via p53 reactivation. We examined the influence of Mycoplasma hyorhinis infection on sensitivity of human lung carcinoma cells NCI-H292 to MDM2 inhibitor Nutlin-3. In order to unveil possible mechanisms underlying the revealed effect, we investigated gene expression changes and signal transduction networks activated in NCI-H292 cells in response to mycoplasma infection. Sensitivity of NCI-Н292 cells to Nutlin-3 was estimated by resazurin-based cell viability assay. Genome-wide transcriptional profiles of NCI-H292 and NCI-Н292Myc.h cell lines were determined using Illumina Human HT-12 v3 Expression BeadChip. Search for key transcription factors and key node molecules was performed using the geneXplain platform. Ability for anchorage-independent growth was tested by soft agar colony formation assay. NCI-Н292Myc.h cells were shown to be 1.5- and 5.2-fold more resistant to killing by Nutlin-3at concentrations of 15 and 30µM than uninfected NCI-Н292 cells (P < 0.05 and P < 0.001, respectively). Transcriptome analysis revealed differential expression of multiple genes involved in cancer progression and metastasis as well as epithelial-mesenchymal transition (EMT). Moreover, we have shown experimentally that NCI-Н292Myc.h cells were more capable of growing and dividing without binding to a substrate. The most likely mechanism explaining the observed changes was found to be TLR4- and IL-1b-mediated activation of NF-κB pathway. Our results provide evidence that mycoplasma infection is an important factor modulating the effect of MDM2 inhibitors on cancer cells and is able to induce EMT-related changes.

Mycoplasma hyorhinis infection in early cases of mycoplasmal pneumonia in swine and evaluation of diagnostic assays

ABSTRACT: Mycoplasmal pneumonia is an important disease in the pig industry. Due to the controversial role of Mycoplasma hyorhinis in this disease, confirmation of the presence of this bacterium and the identification of its roles in respiratory disease remain major challenges. The objectives of this study were to evaluate the presence of M. hyorhinis in early cases of mycoplasmal pneumonia and to determine the usefulness of fluorescent in situ hybridization (FISH) for the diagnosis of respiratory mycoplasmosis in naturally infected pigs. Ninety M. hyopneumoniae and/or M. hyorhinis-infected lung tissue samples based on diagnostic mosaic (DM) were used. The average age of the animals was 116 and 57 days (P&lt;0.01) for groups 1 (positive-M. hyopneumoniae only) and 2 (positive-M. hyorhinis only), respectively. These findings suggest that development of lesions caused by M. hyorhinis occurs earlier than for M. hyopneumoniae. Using the DM as the gold standard, the sensitivity and specificity of FISH for M. hyopneumoniae were 75 and 100%, respectively, and were 40 and 73.3% for the immunohistochemistry (IHC). The sensitivity and specificity of FISH for M. hyorhinis were 76.7 and 100%, respectively. These findings demonstrate that FISH can be a useful tool for diagnosing mycoplasmosis. Viral antigens (PCV2 or influenza A) were detected in 53.3% (16/30) of the samples in group 2 (M. hyorhinis-PCR positive) and 13.3% (4/30) of the samples in group 1 (M. hyopneumoniae-PCR positive). This finding indicates that the association of M. hyorhinis and viral infection in nursery pigs likely starts due to a viral immunosuppressive condition.

Occurrence of Mycoplasma hyorhinis infections in fattening pigs and association with clinical signs and pathological lesions of Enzootic Pneumonia

Respiratory disorders in fattening pigs are of major concern worldwide. Particularly Enzootic Pneumonia remains a problem for the pig industry. This chronic respiratory disease is primarily caused by Mycoplasma hyopneumoniae (M. hyopneumoniae). However, more recently it was hypothesised that M. hyorhinis can also cause similar lung lesions.To investigate the relevance of M. hyorhinis as a cause of pneumonia in fattening pigs 10 farms in Switzerland (considered free of Enzootic Pneumonia) and 20 farms in Germany (regarded as endemic for Enzootic Pneumonia) with a history of chronic and/or recurrent respiratory diseases were included in the study. During a one-time farm visit the coughing index was determined in the batch of oldest fattening pigs in each farm before submission to slaughter. In total, 1375 lungs from these pigs were collected at the abattoir and individually scored for lesions. Furthermore, 600 lungs with, if present, indicative lesions for Enzootic Pneumonia (purple to grey areas of tissue consolidation in the cranio-ventral lung lobes) were tested for mycoplasma species by culture and by real-time PCR for the presence of M. hyorhinis and M. hyopneumoniae.In total, 15.7% of the selected lungs were tested positive for M. hyorhinis by real-time PCR. The prevalence of M. hyorhinis was 10% in Switzerland and 18.5% in Germany and differed significantly between these two countries (p=0.007). M. hyorhinis was detected significantly more often in pneumonic lungs (p=0.004) but no significant association was found between M. hyorhinis and the coughing index or the M. hyopneumoniae status of the pig. M. hyopneumoniae was detected in 0% and 78.5% of the selected lungs in Switzerland and Germany, respectively.We found no evidence that M. hyorhinis alone can lead to similar lung lesions as seen by an infection with M. hyopneumoniae in fattening pigs. In addition, a simultaneous infection with both M. hyorhinis and M. hyopneumoniae did not aggravate the observed lung lesions. Moreover, the presence of M. hyorhinis showed no clinical effect in terms of coughing at least at the end of the fattening phase. However, different levels of virulence of M. hyorhinis isolates as well as interactions with viral pathogens like porcine reproductive and respiratory syndrome virus (PRRSV) or porcine circovirus type 2 (PCV2) were reported in the literature and need to be further investigated.

Cross reactivity among the swine mycoplasmas as identified by protein microarray

Mycoplasmas are cell wall-less bacteria that infect a variety of animals in a species-specific manner. In swine, Mycoplasma hyopneumoniae is the most virulent and presents the most disease and economic problems to the swine industry. Serological assays are commonly used to assess colonization and disease, but antigenic cross-reactivity between M. hyopneumoniae and other mycoplasma species, most notably Mycoplasma hyorhinis, Mycoplasma hyosynoviae and Mycoplasma flocculare, is a concern. The extent of cross-reactivity has not been thoroughly investigated. These studies were designed to identify M. hyopneumoniae proteins that are recognized by rabbit hyperimmune sera raised against the other swine mycoplasmas. Our results indicate extensive cross-reactivity between M. flocculare and M. hyopneumoniae, which explains previous reports seen with ELISA assays. Only three of the thirty-nine M. hyopneumoniae proteins tested showed no cross reactivity with the other three swine mycoplasmas, mhp182 (42kDa C-terminal fragment), mhp638 and mhp684 (C-terminal fragment). Two proteins, mhp384 and mhp511, were cross-reactive with hyperimmune sera generated against three of the four species. None of the anti-M. hyorhinis hyperimmune sera reacted to any of the M. hyopneumoniae proteins. These results suggest that inapparent M. flocculare infections could produce positive responses in M. hyopneumoniae serological assays due to cross-reactivity, and that M. hyosynoviae infections are less likely to do so and M. hyorhinis infections unlikely to affect assay results.

N-Terminal Polypeptide of Annexin A2 Decreases Infection of Mycoplasma hyorhinis to Gastric Cancer Cells.

Mycoplasma infection in human and its contamination in cell cultures are worldwide problems. The drugs currently available for preventing or treating mycoplasma infection suffer from low sensitivity, strong resistance and high toxicity. Our previous work showed that Mycoplasma hyorhinis (M. hyorhinis) infection was mediated by the interaction between p37 of M. hyorhinis and Annexin A2 (ANXA2) of host cells, however the translational value of this mechanism was unknown. Herein, we synthesized the N-terminal of ANXA2 polypeptide (A2PP) and found that A2PP could decrease the infection of M. hyorhinis to gastric cancer cells and block M. hyorhinis infection-induced cell migration. Furthermore, we found that A2PP could reduce M. hyorhinis contamination of passage cells. Moreover, compared with the commercial antibiotics commonly used in cell culture to prevent M. hyorhinis infection, A2PP demonstrated a more effectiveness but a low toxicity on cell growth. Thus, our study for the first time revealed A2PP’s potential for the treatment and prevention of M. hyorhinis infection.

Diagnosis of Mycoplasma hyorhinis infection in pigs by PCR amplification of 16S-23S rRNA internal transcribed spacer region

Diagnosis of Mycoplasma hyorhinis infection in pigs by PCR amplification of 16S-23S rRNA internal transcribed spacer region

Mycoplasma hyorhinis: a potential risk factor in gastric cancer progression

Persistent infection of Mycoplasma hyorhinis (M. hyorhinis) is associated with various types of cancer. However, to date, there is few study identifying host factors mediating its infection and its effect on cancer patients’ prognosis also remains unknown. Recently, we reported for the first time that M. hyorhinis infects mammalian cells and promotes gastric cancer cell invasiveness via its membrane protein p37, and host Annexin A2 (ANXA2) is the cell receptor mediating M. hyorhinis infection. Downstream of ANXA2, NF-kB pathway is activated and mediates M. hyorhinis -driven cell migration. Furthermore, we demonstrated that M. hyorhinis p37 protein expression in gastric cancer tissues positively correlates with tumor metastasis and predicts poor survival. In conclusion, our study uncovers the mechanism by which M. hyorhinis infects mammalian cells and promotes cancer cell migration and unveils the effect of M. hyorhinis infection on gastric cancer survival.