Mycoplasma leachii sp. nov. as a new species designation for Mycoplasma sp. bovine group 7 of Leach, and reclassification of Mycoplasma mycoides subsp. mycoides LC as a serovar of Mycoplasma mycoides subsp. capri

Mycoplasma mycoides subspecies capri, an uncommon mastitis and respiratory pathogen isolated in a German flock of goats

Mycoplasma mycoides ssp. capri (Mmc) is one of the etiological microorganisms of contagious agalactia, which is among the diseases causing the highest economical losses in small ruminants. We report a disease outbreak in a German flock that led to significant suffering of goats characterized by mastitis, arthritis, pleuropneumonia and sudden deaths. Mmc was persistently isolated from many animals both from milk, and from a number of different swab and tissue samples. A number of closely related Mycoplasma spp. have to be taken into consideration to rule out important animal epizootics listed by European Animal Health Law and the World Organisation for Animal Health (WOAH). Some goats developed cross-reacting antibodies against Mycoplasma mycoides ssp. mycoides. Although Mmc is believed to be an uncommon microorganism in Germany, this study highlights that veterinarians should consider this pathogen in their work during herd health monitoring in Central Europe. Although eradication was not fully achieved, autogenous vaccination significantly seemed to improve animal health and welfare.

Comparative genomics of Mycoplasma feriruminatoris, a fast-growing pathogen of wild Caprinae

Mycoplasma feriruminatoris is a fast-growing Mycoplasma species isolated from wild Caprinae and first described in 2013. M. feriruminatoris isolates have been associated with arthritis, kerato conjunctivitis, pneumonia and septicemia, but were also recovered from apparently healthy animals. To better understand what defines this species, we performed a genomic survey on 14 strains collected from free-ranging or zoo-housed animals between 1987 and 2017, mostly in Europe. The average chromosome size of the M. feriruminatoris strains was 1,040±0,024 kbp, with 24 % G+C and 852±31 CDS. The core genome and pan-genome of the M. feriruminatoris species contained 628 and 1312 protein families, respectively. The M. feriruminatoris strains displayed a relatively closed pan-genome, with many features and putative virulence factors shared with species from the M. mycoides cluster, including the MIB-MIP Ig cleavage system, a repertoire of DUF285 surface proteins and a complete biosynthetic pathway for galactan. M. feriruminatoris genomes were found to be mostly syntenic, although repertoires of mobile genetic elements, including Mycoplasma Integrative and Conjugative Elements, insertion sequences, and a single plasmid varied. Phylogenetic- and gene content analyses confirmed that M. feriruminatoris was closer to the M. mycoides cluster than to the ruminant species M. yeatsii and M. putrefaciens. Ancestral genome reconstruction showed that the emergence of the M. feriruminatoris species was associated with the gain of 17 gene families, some of which encode defence enzymes and surface proteins, and the loss of 25 others, some of which are involved in sugar transport and metabolism. This comparative study suggests that the M. mycoides cluster could be extended to include M. feriruminatoris. We also find evidence that the specific organization and structure of the DnaA boxes around the oriC of M. feriruminatoris may contribute to drive the remarkable fast growth of this minimal bacterium.

Characterization of atypical Mycoplasma anserisalpingitidis strains

Mycoplasma anserisalpingitidis is a waterfowl colonizing mycoplasma, mainly found in geese. In this study, we compared the whole genomes of five atypical M. anserisalpingitidis strains originating from China, Vietnam and Hungary, with the rest of the collection. Common methods used in the description of species are genomic analyses like the analysis of 16 S - intergenic transcribed spacer (ITS) - 23 S rRNA, of housekeeping genes, of the average nucleotide identity (ANI) and average amino acid identity (AAI) and phenotypic analyses like testing the growth inhibition and the growth parameters of the strains. The atypical strains showed notable genomic differences in all of the genetic analyses: on average ANI and AAI 95% (M. anserisalpingitidis ANI Minimum: 92.45, Maximum: 95.10; AAI Minimum: 93.34, Maximum: 96.37). The atypical strains formed a separate branch among the M. anserisalpingitidis strains in all phylogenetic studies. The small genome size and possibly higher mutation rate of the M. anserisalpingitidis species likely contributed to the observed genetic difference. Based on genetic analyses, the studied strains clearly represent a new genotype of M. anserisalpingitidis. The atypical strains showed slower growth in the medium containing fructose and three of the atypical strains showed diminished growth in the inhibition test. However, no definitive geno-phenotype associations were found regarding the fructose metabolism pathway in the atypical strains. The atypical strains are potentially at an early stage of speciation.

Clinicopathological and Sero-Molecular Detection of Mycoplasma capricolum subsp. capripneumoniae in Goats in Southern Areas of Pakistan

Contagious caprine pleuropneumonia (CCPP) is a highly fatal infectious disease of goats, caused by Mycoplasma capricolum subsp. capripneumoniae (Mccp). This disease is causing huge economic losses to the goat industry in Pakistan. However, little is known about the epidemiology of CCPP, especially in the hard areas of Khyber Pakhtunkhwa (KP), Pakistan, despite having a huge population of goats. Therefore, this study aimed to elucidate sero-molecular epidemiology and pathology associated with Mccp infection in goats in southern areas of KP including Dera Ismail Khan (DI Khan), Bannu, Karak, and Kohat. A total of 200 (50 from each area) serum samples were collected from clinically infected goats, whereas 600 various samples (nasal swab n = 50, pleural fluid n = 50, lungs n = 50 at each selected area of study) were collected from live goats showing respiratory clinical signs and dead/slaughter goats having lesions in the lungs/pleura. A commercial competitive ELISA kit confirmed anti-Mccp antibodies in altogether 17% of serum samples, while area-wise seroprevalence was recorded as follows: Kohat, 28%, Bannu, 18%, DI Khan, 14%, and Karak, 8%. Moreover, a total of 5.5% of samples collected from clinically positive live and dead goats for Mccp were found by species-specific PCR, whereas area-wise molecular prevalence of Mccp was found in 3% samples from Kohat, 7.33%, Bannu, 6%, Khan, 5.33%, and Karak, 3.33%. Of 400 clinically examined goats, 242 (60%) had nasal discharge, 207 (51%) had pyrexia, 50.75% (203) had coughing, 48.25% (193) had pneumonia, 23% (92) had lacrimation, 7.75% (31) had pneumonia with lacrimation, and 10 (2.5%) showed all signs. Of the total 200 dead/slaughtered goats, pleural fluid was found in 36 goats and consolidation and red hepatization were observed in 40 and 42 goats, respectively. The present study found the presence of prevailing Mccp strain in the goat population of the study area. The highest prevalence of Mccp was found in collected samples from Kohat by PCR. The highest seroprevalence of Mccp was found in serum samples collected from Kohat by ELISA.

Development and Evaluation of a Combined Contagious Bovine Pleuropneumonia (CBPP) and Lumpy Skin Disease (LSD) Live Vaccine

Mycoplasma mycoides subsp. mycoides (Mmm) is the causative agent of contagious bovine pleuropneumonia (CBPP). Lumpy skin disease (LSD) is a viral disease of cattle caused by lumpy skin disease virus (LSDV). LSD and CBPP are both transboundary diseases spreading in the same areas of Africa and Asia. A combination vaccine to control CBPP and LSD offers significant value to small-scale livestock keepers as a single administration. Access to a bivalent vaccine may improve vaccination rates for both pathogens. In the present study, we evaluated the LSDV/CBPP live combined vaccine by testing the generation of virus neutralizing antibodies, immunogenicity, and safety on target species. In-vitro assessment of the Mycoplasma effect on LSDV growth in cell culture was evaluated by infectious virus titration and qPCR during 3 serial passages, whereas in-vivo interference was assessed through the antibody response to vaccination. This combined Mmm/LSDV vaccine could be used to protect cattle against both diseases with a single vaccination in the endemic countries. There were no adverse reactions detected in this study and inoculated cattle produced high levels of specific antibodies starting from day 7 post-vaccination, suggesting that this combination vaccine is both safe and effective.

Addressing the Antimicrobial Resistance of Ruminant Mycoplasmas Using a Clinical Surveillance Network

Antimicrobial resistance (AMR) surveillance of mycoplasmas of veterinary importance has been held back for years due to lack of harmonized methods for antimicrobial susceptibility testing (AST) and interpretative criteria, resulting in a crucial shortage of data. To address AMR in ruminant mycoplasmas, we mobilized a long-established clinical surveillance network called "Vigimyc." Here we describe our surveillance strategy and detail the results obtained during a 2-year monitoring period. We also assess how far our system complies with current guidelines on AMR surveillance and how it could serve to build epidemiological cut-off values (ECOFFs), as a first attainable criterion to help harmonize monitoring efforts and move forward to clinical breakpoints. Clinical surveillance through Vigimyc enables continuous collection, identification and preservation of Mycoplasma spp. isolates along with metadata. The most frequent pathogens, i.e., M. bovis and species belonging to M. mycoides group, show stable clinicoepidemiological trends and were included for annual AST. In the absence of interpretative criteria for ruminant mycoplasmas, we compared yearly minimum inhibitory concentration (MIC) results against reference datasets. We also ran a SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis on the overall service provided by our AMR surveillance strategy. Results of the 2018-2019 surveillance campaign were consistent with the reference datasets, with M. bovis isolates showing high MIC values for all antimicrobial classes except fluoroquinolones, and species of the Mycoides group showing predominantly low MIC values. A few new AMR patterns were detected, such as M. bovis with lower spectinomycin MICs. Our reference dataset partially complied with European Committee on Antimicrobial Susceptibility Testing (EUCAST) requirements, and we were able to propose tentative epidemiological cut-off values (TECOFFs) for M. bovis with tilmicosin and spectinomycin and for M. mycoides group with tilmicosin and lincomycin. These TECOFFs were consistent with other published data and the clinical breakpoints of Pasteurellaceae, which are often used as surrogates for mycoplasmas. SWOT analysis highlighted the benefit of pairing clinical and antimicrobial resistance surveillance despite the AST method-related gaps that remain. The international community should now direct efforts toward AST method harmonization and clinical interpretation.

A novel MLSA allelic profile 'A15' of Mycoplasma mycoides subsp mycoides in Niger

Mycoplasma mycoides subsp. mycoides (Mmm) is the aetiological agent of contagious bovine pleuropneumonia (CBPP). The aim of the present study was to identify the profiles of the Mmm strains isolated in Niger using the ‘Multilocus Sequence Analysis’ (MLSA) typing technique based on polymorphism analysis of housekeeping and non‐coding genes. The investigation was conducted on samples (n=22) comprising of lung tissues, lymph node and pleural fluids. Following classical PCR, Mmm positive amplicons (n=6) were identified. These positive amplicons were then amplified using eight loci of the PG1 reference strain (LocPG1‐0001, Loc‐PG1‐0103, Loc‐PG1‐0287, Loc‐PG1‐0431, Loc‐PG1‐0489, Loc‐PG1‐0523, Loc‐PG1‐0710 and Loc‐PG1‐0827). Sequencing followed by the determination of the profile of each strain by the combination of the allele numbers revealed three different MLSA profiles namely; A11, E01 and A15. The profiles A11 and E01 were previously identified. The novel profile identified in this study was named profile A15. The difference was detected while comparing sequences of non‐coding loci. This novel profile was named ‘A15’ according to the similarities with African reference strain profile ‘A00’ at the seven loci level (loc‐0103, loc‐0287, loc‐0431, loc‐0489, loc‐0523, loc‐0710 and loc‐0827). For CBPP control measures, identification and molecular characterization of Mmm strains is very important. Thus, the use of MLSA technique is relevant to identify profiles of Mmm circulating in Niger. Other countries where CBPP is still endemic are encouraged to use a MLSA scheme to address this issue and, most importantly, to rapidly trace back the origin of outbreaks, which will help reduce the transmission and spread of the disease. In addition, mapping the profiles of strains circulating in each of the countries of the sub‐region is necessary for effective control of CBPP.

Contagious Bovine Pleuropneumonia: Challenges and Prospects Regarding Diagnosis and Control Strategies in Africa

Contagious bovine pleuropneumonia (CBPP) is an infectious and contagious respiratory disease of cattle, caused by Mycoplasma mycoides subsp. mycoides (Mmm). In this review, basic epidemiological features of CBPP, complicated by existing different strains of Mycoplasmas with similar biochemical characteristics, with preference to Sub-Saharan Africa are discussed. Many sub-Saharan African countries are challenged by variable gaps that include diagnostic tools and control strategies. Science-based issues on diagnostic procedures, vaccination, treatment, and other control strategies are discussed. Participatory epidemiology (PE), a diagnostic technique used in the identification and solving of animal health problems in rural communities, was also discussed. PE application, in conjunction with conventional diagnostic tools, will improve CBPP identification in pastoral rural communities and promote control of the disease in Africa. Furthermore, adequate CBPP control can be achieved through stronger political commitments from governments by prioritizing the disease among major diseases of high economic importance to the livestock industry for surveillance and control. Investment in CBPP control in endemic African countries will assure food security, livelihoods and the general well-being of people, and international trade.

Baseline analysis of Mycoplasma mycoides subsp. mycoides antigens as targets for a DIVA assay for use with a subunit vaccine for contagious bovine pleuropneumonia

BACKGROUND

Mycoplasma mycoides subsp. mycoides (Mmm) is the causative agent of contagious bovine pleuropneumonia in cattle. A prototype subunit vaccine is being developed, however, there is currently no diagnostic test that can differentiate between infected cattle and those vaccinated with the prototype subunit vaccine. This study characterized Mmm proteins to identify potential antigens for use in differentiating infected from vaccinated animals.

RESULTS

Ten Mmm antigens expressed as recombinant proteins were tested in an indirect ELISA using experimental sera from control groups, infected, and vaccinated animals. Data were imported into R software for analysis and drawing of the box and scatter plots while Cohen's Kappa assessed the level of agreement between the Mmm antigens. Two vaccine antigens (MSC_0499 and MSC_0776) were superior in detecting antibodies in sera of animals vaccinated with the subunit vaccines while two non-vaccine antigens (MSC_0636 and LppB) detected antibodies in sera of infected animals showing all clinical stages of the disease. Sensitivity and specificity of above 87.5% were achieved when the MSC_0499 and MSC_0636 antigens were tested on sera from vaccinated and infected animals.

CONCLUSIONS

The MSC_0499 and MSC_0776 antigens were the most promising for detecting vaccinated animals, while MSC_0636 and LppB were the best targets to identify infected animals. Further testing of sera from vaccinated and infected animals collected at different time intervals in the field should help establish how useful a diagnostic test based on a cocktail of these proteins would be.

Contagious Bovine Pleuropneumonia: A Comprehensive Overview

Contagious bovine pleuropneumonia (CBPP) is a respiratory disease of cattle that is listed as notifiable by the World Organization for Animal Health. It is endemic in sub-Saharan Africa and causes important productivity losses due to the high mortality and morbidity rates. CBPP is caused by Mycoplasma mycoides subsp. mycoides (Mmm) and is characterized by severe fibrinous bronchopneumonia and pleural effusion during the acute to subacute stages and by pulmonary sequestra in chronic cases. Additional lesions can be detected in the kidneys and in the carpal and tarsal joints of calves. Mmm infection occurs through the inhalation of infected aerosol droplets. After the colonization of bronchioles and alveoli, Mmm invades blood and lymphatic vessels and causes vasculitis. Moreover, Mmm can be occasionally demonstrated in blood and in a variety of other tissues. In the lung, Mmm antigen is commonly detected on bronchiolar and alveolar epithelial cells, in lung phagocytic cells, within the wall of blood and lymphatic vessels, inside necrotic areas, and within tertiary lymphoid follicles. Mmm antigen can also be present in the cytoplasm of macrophages within lymph node sinuses, in the germinal center of lymphoid follicles, in glomerular endothelial cells, and in renal tubules. A complete pathological examination is of great value for a rapid presumptive diagnosis, but laboratory investigations are mandatory for definitive diagnosis. The purpose of this review is to describe the main features of CBPP including the causative agent, history, geographic distribution, epidemiology, clinical course, diagnosis, and control. A special focus is placed on gross and microscopic lesions in order to familiarize veterinarians with the pathology and pathogenesis of CBPP.

Contagious Agalactia In Sheep And Goats: Current Perspectives

Contagious agalactia (CA) is a disease caused equally by four Mycoplasma species, in single or mixed infections. Clinical signs are multiple, including mastitis, arthritis, keratoconjunctivitis, pneumonia, and septicemia, non-specific, and expressed differently depending whether sheep or goats are affected, on causative mycoplasmas as well as type of husbandry. CA has been reported worldwide and its geographic distribution maps to that of small ruminant breeding areas. However, as current diagnostic tests are expensive and difficult to implement, it is certainly underdiagnosed and prevalence data are only available for a few countries. CA control relies on vaccines, chemotherapy and good herd management practices. It requires long-term commitment but is often unsuccessful, with frequent clinical relapses. The persistence of the etiological agents, despite their overall susceptibility to antimicrobials, comes from their genetic plasticity and capacity to escape the host immune response. The existence of asymptomatic carriers and the numerous sources of infections contribute to rapid spread of the disease and complicate the control and prevention efforts. Here we review all these aspects in order to highlight recent progress made and identify gaps in knowledge or tools needed for better disease management. Discussion also underlines the detrimental effect of contagious agalactia on small ruminant welfare.

Host-Pathogen Interactions of Mycoplasma mycoides in Caprine and Bovine Precision-Cut Lung Slices (PCLS) Models

Respiratory infections caused by mycoplasma species in ruminants lead to considerable economic losses. Two important ruminant pathogens are Mycoplasma mycoides subsp. Mycoides (Mmm), the aetiological agent of contagious bovine pleuropneumonia and Mycoplasma mycoides subsp. capri (Mmc), which causes pneumonia, mastitis, arthritis, keratitis, and septicemia in goats. We established precision cut lung slices (PCLS) infection model for Mmm and Mmc to study host-pathogen interactions. We monitored infection over time using immunohistological analysis and electron microscopy. Moreover, infection burden was monitored by plating and quantitative real-time PCR. Results were compared with lungs from experimentally infected goats and cattle. Lungs from healthy goats and cattle were also included as controls. PCLS remained viable for up to two weeks. Both subspecies adhered to ciliated cells. However, the titer of Mmm in caprine PCLS decreased over time, indicating species specificity of Mmm. Mmc showed higher tropism to sub-bronchiolar tissue in caprine PCLS, which increased in a time-dependent manner. Moreover, Mmc was abundantly observed on pulmonary endothelial cells, indicating partially, how it causes systemic disease. Tissue destruction upon prolonged infection of slices was comparable to the in vivo samples. Therefore, PCLS represents a novel ex vivo model to study host-pathogen interaction in livestock mycoplasma.

Comparative genomics analysis of Mycoplasma capricolum subsp. capripneumoniae 87001

Mycoplasma capricolum subsp. capripneumoniae (Mccp), belongs to Mycoplasma mycoides cluster and is a causal pathogen of contagious caprine pleuropneumonia (CCPP). This paper presents the complete annotated genome sequence of Mccp Strain 87001-a strain that was isolated from pneumonia affected goats on a farm in China, and comparative genomics analysis of five Mccp genomes in addition to comparative genomics within Mycoplasma mycoides cluster. The Mccp strain 87001 genome consists of a single circular chromosome 1017333 bp in length and encodes 898 open reading frames (orfs) averaging 944 bp in length. Fifty eight potential virulence genes were identified, including variable surface lipoproteins, hemolysin A, and P60 surface lipoprotein. Comparative genomic analysis revealed eight virulence genes and four extracellular genes which remained unchanged in five Mccp genomes for forty years, which can be used as potential target for drug development and vaccine design. We revealed 183 Mccp unique genes as markers to distinguish Mccp with other mycoplasma strains from goats, and different virulence factors contributing to host specificity and different syndrome of bovine pathogens and caprine pathogens.

Contagious caprine pleuropneumonia - a comprehensive review

Contagious caprine pleuropneumonia (CCPP) is a serious disease of goats, occasionally sheep and wild ruminants, caused by Mycoplasma capricolum subspecies capripneumoniae (Mccp). The disease is characterized by severe serofibrinous pleuropneumonia, very high morbidity (∼100%), and mortality (80–100%). CCPP affects goats in more than 40 countries of the world thereby posing a serious threat to goat farming around the globe. The characteristic clinical signs of CCPP are severe respiratory distress associated with sero-mucoid nasal discharge, coughing, dyspnea, pyrexia, pleurodynia, and general malaise. In later stages, severe lobar fibrinous pleuropneumonia, profuse fluid accumulation in pleural cavity, severe congestion of lungs and adhesion formation is observed. Mycoplasmal antigen interactions with host immune system and its role in CCPP pathogenesis are not clearly understood. CCPP is not a zoonotic disease. Diagnosis has overcome cumbersome and lengthy conventional tests involving culture, isolation, and identification by advanced serological (LAT, cELISA) or gene-based amplification of DNA (PCR, RFLP, and hybridization) and sequencing. The latex agglutination test (LAT) is rapid, simple, and better test for field and real-time diagnosis applicable to whole blood or serum and is more sensitive than the CFT and easier than the cELISA. Moreover, the studies on antibiotic sensitivity and exploration of novel antibiotics (fluoroquinolones, macrolides) can help in better therapeutic management besides preventing menace of antibiotic resistance. Re-visiting conventional prophylactic measures focussing on developing novel strain-based or recombinant vaccines using specific antigens (capsular or cellular) should be the most important strategy for controlling the disease worldwide.

Essential metabolism for a minimal cell

JCVI-syn3A, a robust minimal cell with a 543 kbp genome and 493 genes, provides a versatile platform to study the basics of life. Using the vast amount of experimental information available on its precursor, Mycoplasma mycoides capri, we assembled a near-complete metabolic network with 98% of enzymatic reactions supported by annotation or experiment. The model agrees well with genome-scale in vivo transposon mutagenesis experiments, showing a Matthews correlation coefficient of 0.59. The genes in the reconstruction have a high in vivo essentiality or quasi-essentiality of 92% (68% essential), compared to 79% in silico essentiality. This coherent model of the minimal metabolism in JCVI-syn3A at the same time also points toward specific open questions regarding the minimal genome of JCVI-syn3A, which still contains many genes of generic or completely unclear function. In particular, the model, its comparison to in vivo essentiality and proteomics data yield specific hypotheses on gene functions and metabolic capabilities; and provide suggestions for several further gene removals. In this way, the model and its accompanying data guide future investigations of the minimal cell. Finally, the identification of 30 essential genes with unclear function will motivate the search for new biological mechanisms beyond metabolism.

One way that researchers can test whether they understand a biological system is to see if they can accurately recreate it as a computer model. The more they learn about living things, the more the researchers can improve their models and the closer the models become to simulating the original. In this approach, it is best to start by trying to model a simple system.

Biologists have previously succeeded in creating ‘minimal bacterial cells’. These synthetic cells contain fewer genes than almost all other living things and they are believed to be among the simplest possible forms of life that can grow on their own. The minimal cells can produce all the chemicals that they need to survive – in other words, they have a metabolism. Accurately recreating one of these cells in a computer is a key first step towards simulating a complete living system.

Breuer et al. have developed a computer model to simulate the network of the biochemical reactions going on inside a minimal cell with just 493 genes. By altering the parameters of their model and comparing the results to experimental data, Breuer et al. explored the accuracy of their model. Overall, the model reproduces experimental results, but it is not yet perfect. The differences between the model and the experiments suggest new questions and tests that could advance our understanding of biology. In particular, Breuer et al. identified 30 genes that are essential for life in these cells but that currently have no known purpose.

Continuing to develop and expand models like these to reproduce more complex living systems provides a tool to test current knowledge of biology. These models may become so advanced that they could predict how living things will respond to changing situations. This would allow scientists to test ideas sooner and make much faster progress in understanding life on Earth. Ultimately, these models could one day help to accelerate medical and industrial processes to save lives and enhance productivity.

First report of Mycoplasma leachii isolation associated with disease in dairy calves in Argentina

There are few reports about the isolation of Mycoplasma species associated with cattle disease in Argentina. In this work we describe the detection of Mycoplasma leachii associated with disease in dairy calves in Santa Fe Province, Argentina. Samples obtained from a 4 day-old dairy calf suffering from polyarthritis and from two other calves, one with arthritis and the other one with a mandibular abscess, were subjected to microbiological culture. Classical culture and generic PCR confirmed the presence of Mycoplasma spp. The spacer region between the 16S and 23S ribosomal RNA gene from the first isolate was amplified and sequenced. The sequence obtained showed 99% identity with M. leachii. A PCR was developed to amplify a specific fragment of the 16S-23S ITS region corresponding to M. leachii, which allowed to identify the isolates associated with disease in calves.

Phylogenetic framework for the phylum Tenericutes based on genome sequence data: proposal for the creation of a new order Mycoplasmoidales ord. nov., containing two new families Mycoplasmoidaceae fam. nov. and Metamycoplasmataceae fam. nov. harbouring Eperythrozoon, Ureaplasma and five novel genera

The genus Mycoplasma, including species earlier classified in the genera Eperythrozoon and Haemobartonella, contains ~ 120 species and constitutes an extensively polyphyletic assemblage of bacteria within the phylum Tenericutes. Due to their small genome sizes and lack of unique characteristics, the relationships among the mycoplasmas/Tenericutes are not reliably discerned. Using genome sequences for 140 Tenericutes, their evolutionary relationships were examined using multiple independent approaches. Phylogenomic trees were constructed for 63 conserved proteins, 45 ribosomal proteins, three main subunits of RNA polymerase and 16S rRNA gene sequences. In all of these trees, Tenericutes species reliably grouped into four main clades designated as the "Acholeplasma", "Spiroplasma", "Pneumoniae" and "Hominis" clusters. These clades are also distinguished based on a similarity matrix constructed based on 16S rRNA gene sequences. Mycoplasma species were dispersed across 3 of these 4 clades highlighting their extensive polyphyly. In parallel, our comparative genomic analyses have identified > 100 conserved signature indels (CSIs) and 14 conserved signature proteins (CSPs), which are uniquely shared by the members of four identified clades, strongly supporting their monophyly and identifying them in molecular terms. Mycoplasma mycoides, the type species of the genus Mycoplasma, and a small number of other Mycoplasma species, formed a strongly supported clade within the "Spiroplasma" cluster. Nine CSIs and 14 CSPs reliably distinguish this clade from all other Mycoplasmatales species. The remainder of the Mycoplasmatales species are part of the "Pneumoniae" and "Hominis" clusters, which group together in phylogenetic trees. Here we are proposing that the order Mycoplasmatales should be emended to encompass only the Mycoplasma species within the "Spiroplasma" cluster and that a new order, Mycoplasmoidales ord. nov., should be created to encompass the other Mycoplasma species. The "Pneumoniae" and the "Hominis" clusters are proposed as two new families, Mycoplasmoidaceae fam. nov., which includes the genera Eperythrozoon, Ureaplasma, and the newly proposed genera Malacoplasma and Mycoplasmoides, and Metamycoplasmataceae fam. nov. to contain the newly proposed genera Metamycoplasma, Mycoplasmopsis, and Mesomycoplasma. The results presented here allow reliable discernment, both in phylogenetic and molecular terms, of the members of the two proposed families as well as different described genera within these families including members of the genus Eperythrozoon, which is comprised of uncultivable organisms. The taxonomic reclassifications proposed here, which more accurately portray the genetic diversity among the Tenericutes/Mycoplasma species, provide a new framework for understanding the biological and clinical aspects of these important microbes.

Cloning and expression of P67 protein of Mycoplasma leachii

AIM

The present study was undertaken to clone, express and study the immunogenicity of P67 protein of Mycoplasma leachii.

MATERIALS AND METHODS

P67 gene was amplified from genomic DNA of M. leachii. The polymerase chain reaction (PCR) product was inserted in pRham N-His SUMO Kan vector and was used to transform competent Escherichia cloni 10G cells. Recombinant protein expression was done by inducing cells with 0.2% Rhamnose. Purification was done using nickel nitrilotriacetic acid affinity chromatography. Western blot and dot blot analysis were performed to assess the immunoreactivity of P67 protein.

RESULTS

PCR amplicon size of P67 gene was found to be 1500 base pair. The size of the fusion protein with SUMO tag was 79 kDa in sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis. The recombinant P67 fusion protein expressed in pRham N-His SUMO Kan vector was found to be immunogenic in both western blot and dot blot analysis.

CONCLUSION

Western blot and dot blot analysis of P67 protein of M. leachii revealed that the protein is immunogenic. Further work is needed to evaluate the role of P67 antigen of M. leachii as an immunodiagnostic agent.

Mmm-derived lipid-associated membrane proteins activate IL-1β production through the NF-κB pathway via TLR2, MyD88, and IRAK4

Mycoplasma mycoides subsp.mycoides (Mmm) is a pathogen that causes pneumonia, otitis media, and arthritis in young calves. Its pathogenesis is attributed in part to excessive immune responses. Mmm-derived lipid-associated membrane proteins (LAMPs) are potent inducers of the host innate immune system; however, interactions between Mmm-derived LAMPs as pathogenic agents, toll-like receptors (TLRs), and the signaling pathways responsible for activating inflammation and nuclear factor (NF)-κB have not been fully elucidated. Here, we analyzed the expression kinetics of interleukin (IL)-1β in Mmm-derived LAMP-stimulated embryonic bovine lung (EBL) cells and found that Mmm-derived LAMPs induced IL-1β expression. Subcellular localization analysis revealed the nuclear translocation of the NF-κB p65 subunit after EBL cells were stimulated with Mmm-derived LAMPs. Furthermore, a specific inhibitor assay demonstrated that NF-κB is required for Mmm-derived LAMP-induced IL-1β expression. Additionally, overexpression of TLR2, myeloid differentiation primary response gene 88 (MyD88), and IL-1 receptor-associated kinase 4 (IRAK4) increased IL-1β expression during LAMP stimulation, and TLR2-neutralizing antibodies reduced IL-1β expression in EBL cells during LAMP stimulation. Furthermore, LAMPs inhibited IL-1β expression following transfection with dominant-negative MyD88 and IRAK4 variants. These results suggested that Mmm-derived LAMPs activate IL-1β production through the NF-κB pathway via TLR2, MyD88, and IRAK4.

Identification and Characterization of Mycoplasma feriruminatoris sp. nov. Strains Isolated from Alpine Ibex: A 4th Species in the Mycoplasma mycoides Cluster Hosted by Non-domesticated Ruminants?

The genus Mycoplasma, a group of free-living, wall-less prokaryotes includes more than 100 species of which dozens are primary pathogens of humans and domesticated animals. Mycoplasma species isolated from wildlife are rarely investigated but could provide a fuller picture of the evolutionary history and diversity of this genus. In 2013 several isolates from wild Caprinae were tentatively assigned to a new species, Mycoplasma (M.) feriruminatoris sp. nov., characterized by an unusually rapid growth in vitro and close genetic proximity to ruminant pathogenic species. We suspected that atypical isolates recently collected from Alpine ibex in France belonged to this new species. The present study was undertaken to verify this hypothesis and to further characterize the French ibex isolates. Phylogenetic analyses were performed to identify the isolates and position them in trees containing several other mycoplasma species pathogenic to domesticated ruminants. Population diversity was characterized by genomic macrorestriction and by examining the capacity of different strains to produce capsular polysaccharides, a feature now known to vary amongst mycoplasma species pathogenic to ruminants. This is the first report of M. feriruminatoris isolation from Alpine ibex in France. Phylogenetic analyses further suggested that M. feriruminatoris might constitute a 4th species in a genetic cluster that so far contains only important ruminant pathogens, the so-called Mycoplasma mycoides cluster. A PCR assay for specific identification is proposed. These French isolates were not clonal, despite being collected in a restricted region of the Alps, which signifies a considerable diversity of the new species. Strains were able to concomitantly produce two types of capsular polysaccharides, β-(1→6)-galactan and β-(1→6)-glucan, with variation in their respective ratio, a feature never before described in mycoplasmas.

Impact of donor-recipient phylogenetic distance on bacterial genome transplantation

Genome transplantation (GT) allows the installation of purified chromosomes into recipient cells, causing the resulting organisms to adopt the genotype and the phenotype conferred by the donor cells. This key process remains a bottleneck in synthetic biology, especially for genome engineering strategies of intractable and economically important microbial species. So far, this process has only been reported using two closely related bacteria, Mycoplasma mycoides subsp. capri (Mmc) and Mycoplasma capricolum subsp. capricolum (Mcap), and the main factors driving the compatibility between a donor genome and a recipient cell are poorly understood. Here, we investigated the impact of the evolutionary distance between donor and recipient species on the efficiency of GT. Using Mcap as the recipient cell, we successfully transplanted the genome of six bacteria belonging to the Spiroplasma phylogenetic group but including species of two distinct genera. Our results demonstrate that GT efficiency is inversely correlated with the phylogenetic distance between donor and recipient bacteria but also suggest that other species-specific barriers to GT exist. This work constitutes an important step toward understanding the cellular factors governing the GT process in order to better define and eventually extend the existing genome compatibility limit.

Qualitative and quantitative impacts assessment of contagious bovine pleuropneumonia in Fulani pastoral herds of North-central Nigeria: The associated socio-cultural factors

Contagious bovine pleuropneumonia is one of the most important trans-boundary disease affecting Fulani cattle herds of Nigeria and whose control is urgently needed. A Participatory Epidemiology approach and cross-sectional study were concurrently conducted to investigate qualitative and quantitative impacts of CBPP, respectively and associated socio-cultural factors that influenced exposure of Fulani nomadic pastoral communities to its risk in Niger State, North-central Nigeria between January and December 2013. A total of nine pastoral communities were purposively selected for qualitative impact assessment using Participatory Rural Appraisal tools, while 765 cattle randomly sampled from 125 purposively selected nomadic herds were analyzed using c-ELISA. Data on socio-cultural characteristics were collected using structured questionnaires administered on nomadic herd owners of the 125 selected herds. Kendall's Coefficient of Concordance W statistics and OpenEpi 2.3 were used for statistical analyses. Pastoralists' dependent factors associated with their socio-cultural activities were tested using Chisquare tests and likelihood backward logistic regressions. The mean proportional piles (relative qualitative impact) of CBPP was 12.6%, and nomads agreement on this impact was strong (W=0.6855) and statistically significant (P<0.001). This was validated by 16.2% (95% CI: 13.7, 19.0) sero-positive (quantitative impact). Highest sero-prevalence of 25.3% was observed in Northern agro-ecological zone, while lowest of 6.2% was in Eastern zone. Pastoralists in the age groups 51-60 and 61-70 years were more likely (OR 13.07; 95% CI: 3.21, 53.12 and OR 7.10; 95% CI: 1.77, 28.33, respectively) to have satisfactory information/awareness on CBPP and lowland transhumance pastoralists were more likely (OR 5.21; 95% CI: 2.01, 13.54) to have satisfactory information. Socio-cultural activities of extensive husbandry system was six times more likely (OR 5.79; 95% CI: 2.55, 13.13) to be satisfactory practice that influenced CBPP occurrence in herds, while culture of borrowing and loaning of cattle was twenty times more likely (OR 19.94; 95% CI: 6.36, 62.48) to be satisfactory practice that influenced CBPP occurrence in herds. Also, sharing a water source that caused concentration of stocks in one point was fifty three times more likely (OR 53.08; 95% CI: 14.91, 189.00) to be satisfactory practice that influenced occurrence of the disease in herds. This study highlighted the critical gap that exists in terms of significant influence of socio-cultural factors on CBPP occurrence in pastoral herds in Nigeria. Thus, CBPP surveillance, control and prevention programs that take these factors into consideration will be beneficial to the livestock industry in Nigeria, and indeed Africa.

Development of a Novel Cocktail Enzyme-Linked Immunosorbent Assay and a Field-Applicable Lateral-Flow Rapid Test for Diagnosis of Contagious Bovine Pleuropneumonia

Contagious bovine pleuropneumonia (CBPP) is a severe respiratory disease that is widespread in sub-Saharan Africa. It is caused by Mycoplasma mycoides subsp. mycoides, a bacterium belonging to the Mycoplasma mycoides cluster. In the absence of an efficient CBPP vaccine, improved and easy-to-use diagnostic assays for recurrent testing combined with isolation and treatment of positive animals represent an option for CBPP control in Africa. Here we describe the comprehensive screening of 17 immunogenic Mycoplasma mycoides subsp. mycoides proteins using well-characterized bovine sera for the development of a novel cocktail enzyme-linked immunosorbent assay (ELISA) for laboratory use. Two recombinant Mycoplasma immunogens, MSC_0136 and MSC_0636, were used to set up a standardized cocktail ELISA protocol. According to the results from more than 100 serum samples tested, the sensitivity and specificity of the novel cocktail ELISA were 85.6% and 96.4%, respectively, with an overall diagnostic accuracy comparable to that of the Office International des Epizooties (OIE)-prescribed serological assays. In addition, we provide a proof of principle for a field-applicable, easy-to-use commercially produced prototype lateral-flow test for rapid (<30-min) diagnosis of CBPP.

Changes in pathogenicity and immunogenicity of Mycoplasma mycoides subsp. mycoides strains revealed by comparative genomics analysis

Mycoplasma mycoides subsp. mycoides is the causative agent of contagious bovine pleuropneumonia. A pathogenic strain BEN-1 was isolated from bovine lung and underwent continuous passages in rabbits for 468 generations. During this process, the strain's strong virulence became weak and, gradually, it lost the ability to confer protective immunity in cattle but developed virulence in rabbits. In order to gain insight into the mechanisms behind the reduction in virulence and the loss of immunogenicity, we sequenced five representative strains of the BEN series, including the original strain (BEN-1), the strain generation that first acquired virulence in rabbits (BEN-50), the two vaccine strain generations (BEN-181 and BEN-326), and the strain generation showing the greatest loss of immunogenicity (BEN-468). The gene mutation rate in the four different propagation stages varied greatly, and over half of variations observed in each generation were removed during the propagation process. However, the variation maintained in the BEN-468 generation might contribute to its changes in virulence and immunogenicity. We thus identified 18 genes associated with host adaptation, six genes contributing to virulence in cattle, and 35 genes participating in conferring immunity in cattle. These findings might help us optimize the vaccine to obtain more effective immunization results.

Sero-positivity and associated risk factors for contagious bovine pleuropneumonia under two cattle production systems in North Central Nigeria

A cross-sectional survey of 765 cattle in 125 nomadic and 375 cattle in 125 sedentary herds was conducted to investigate prevalence and risk factors for contagious bovine pleuropneumonia (CBPP) in the two production systems of Niger State in North Central Nigeria, between January and August 2013. Data on herd characteristics were collected using structured questionnaires administered on herd owners. Serological analysis was conducted using competitive enzyme linked immunosorbent assay (c-ELISA) test. Descriptive, univariate, and multivariate statistical analyses were conducted with OpenEpi version 2.3.1 software. Statistical significance was held at P < 0.05. CBPP sero-prevalence in nomadic cattle was 16.2 % (confidence interval (CI) 13.7-19.0) and 9.6 % (CI 6.9-12.9) in sedentary cattle. The overall cattle-level sero-prevalence for two the cattle production systems was 14.0 % (CI 12.1-16.1). Age and agro-ecological zones were significantly (P < 0.001 and P < 0.001, respectively) associated with sero-positivity to Mmm in nomadic production. Agro-ecological zone C had the highest sero-prevalence (25.3 %, CI 20.2-31.0). No significant cattle factors were detected in sedentary production. Factors significantly associated with CBPP occurrence at herd-level were contacts with other herds during grazing (P < 0.001) and at watering points (P < 0.001). Others were introduction of new cattle into herd (P < 0.001), outbreaks of CBPP in an area (P < 0.001), socio-cultural factors of cattle gifts and dowry payment (P < 0.001), herd composition of keeping cattle and small ruminants together (P < 0.001), and long trekking during migrations (P = 0.0009). This study had shown the burden of CBPP in the two production systems. Sero-diagnosis and risk factor identification should be institutionalized as elements of epidemio-surveillance and control strategies for CBPP, especially in resource-poor pastoralists' settlements in Nigeria.

High quality draft genomes of the Mycoplasma mycoides subsp. mycoides challenge strains Afadé and B237

Members of the Mycoplasma mycoides cluster' represent important livestock pathogens worldwide. Mycoplasma mycoides subsp. mycoides is the etiologic agent of contagious bovine pleuropneumonia (CBPP), which is still endemic in many parts of Africa. We report the genome sequences and annotation of two frequently used challenge strains of Mycoplasma mycoides subsp. mycoides, Afadé and B237. The information provided will enable downstream 'omics' applications such as proteomics, transcriptomics and reverse vaccinology approaches. Despite the absence of Mycoplasma pneumoniae like cyto-adhesion encoding genes, the two strains showed the presence of protrusions. This phenotype is likely encoded by another set of genes.

Galactofuranose in Mycoplasma mycoides is important for membrane integrity and conceals adhesins but does not contribute to serum resistance

Mycoplasma mycoides subsp. capri (Mmc) and subsp. mycoides (Mmm) are important ruminant pathogens worldwide causing diseases such as pleuropneumonia, mastitis and septicaemia. They express galactofuranose residues on their surface, but their role in pathogenesis has not yet been determined. The M. mycoides genomes contain up to several copies of the glf gene, which encodes an enzyme catalysing the last step in the synthesis of galactofuranose. We generated a deletion of the glf gene in a strain of Mmc using genome transplantation and tandem repeat endonuclease coupled cleavage (TREC) with yeast as an intermediary host for the genome editing. As expected, the resulting YCp1.1-Δglf strain did not produce the galactofuranose-containing glycans as shown by immunoblots and immuno-electronmicroscopy employing a galactofuranose specific monoclonal antibody. The mutant lacking galactofuranose exhibited a decreased growth rate and a significantly enhanced adhesion to small ruminant cells. The mutant was also 'leaking' as revealed by a β-galactosidase-based assay employing a membrane impermeable substrate. These findings indicate that galactofuranose-containing polysaccharides conceal adhesins and are important for membrane integrity. Unexpectedly, the mutant strain showed increased serum resistance.

Whole Blood Transcriptome Analysis of Mycoplasma mycoides Subsp. mycoides-Infected Cattle Confirms Immunosuppression but Does Not Reflect Local Inflammation

Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides (Mmm), is a severe respiratory disease of cattle responsible for major economic losses in sub-Saharan Africa. Disease control relies mainly on the use of empirically attenuated vaccines that provide limited protection. Thus, understanding the virulence mechanisms used by Mmm as well as the role of the host immune system in disease development, persistence, and control is a prerequisite for the development of new, rationally designed control strategies. The aim of this study was to assess the use of whole blood transcriptome analysis to study cattle-Mmm interactions, starting by the characterization of the bovine response to Mmm infection during the acute form of the disease. For that purpose, we compared the transcriptome profile of whole blood from six cattle, before challenge by contact with Mmm-infected animals and at the appearance of first clinical signs, using a bovine microarray. Functional analysis revealed that 680 annotated genes were differentially expressed, with an overwhelming majority of down-regulated genes characterizing an immunosuppression. The main bio-functions affected were "organismal survival", "cellular development, morphology and functions" and "cell-to cell signaling and interactions". These affected functions were consistent with the results of previous in vitro immunological studies. However, microarray and qPCR validation results did not highlight pro-inflammatory molecules (such as TNFα, TLR2, IL-12B and IL-6), whereas inflammation is one of the most characteristic traits of acute CBPP. This global gene expression pattern may be considered as the result, in blood, of the local pulmonary response and the systemic events occurring during acute CBPP. Nevertheless, to understand the immune events occurring during disease, detailed analyses on the different immune cell subpopulations, either in vivo, at the local site, or in vitro, will be required. Whole blood transcriptome analysis remains an interesting approach for the identification of bio-signatures correlating to recovery and protection, which should facilitate the evaluation and validation of novel vaccine formulations.

Quantitative risk assessment of entry of contagious bovine pleuropneumonia through live cattle imported from northwestern Ethiopia

Contagious bovine pleuropneumonia (CBPP) is a highly contagious bacterial disease of cattle caused by Mycoplasma mycoides subspecies mycoides small colony (SC) bovine biotype (MmmSC). It has been eradicated from many countries; however, the disease persists in many parts of Africa and Asia. CBPP is one of the major trade-restricting diseases of cattle in Ethiopia. In this quantitative risk assessment the OIE concept of zoning was adopted to assess the entry of CBPP into an importing country when up to 280,000 live cattle are exported every year from the northwestern proposed disease free zone (DFZ) of Ethiopia. To estimate the level of risk, a six-tiered risk pathway (scenario tree) was developed, evidences collected and equations generated. The probability of occurrence of the hazard at each node was modelled as a probability distribution using Monte Carlo simulation (@RISK software) at 10,000 iterations to account for uncertainty and variability. The uncertainty and variability of data points surrounding the risk estimate were further quantified by sensitivity analysis. In this study a single animal destined for export from the northwestern DFZ of Ethiopia has a CBPP infection probability of 4.76×10(-6) (95% CI=7.25×10(-8) 1.92×10(-5)). The probability that at least one infected animal enters an importing country in one year is 0.53 (90% CI=0.042-0.97). The expected number of CBPP infected animals exported any given year is 1.28 (95% CI=0.021-5.42). According to the risk estimate, an average of 2.73×10(6) animals (90% CI=10,674-5.9×10(6)) must be exported to get the first infected case. By this account it would, on average, take 10.15 years (90% CI=0.24-23.18) for the first infected animal to be included in the consignment. Sensitivity analysis revealed that prevalence and vaccination had the highest impact on the uncertainty and variability of the overall risk.

Analysis of immune responses to recombinant proteins from strains of Mycoplasma mycoides subsp. mycoides, the causative agent of contagious bovine pleuropneumonia

Current contagious bovine pleuropneumonia (CBPP) vaccines are based on live-attenuated strains of Mycoplasma mycoides subsp. mycoides (Mmm). These vaccines have shortcomings in terms of efficacy, duration of immunity and in some cases show severe side effects at the inoculation site; hence the need to develop new vaccines to combat the disease. Reverse vaccinology approaches were used and identified 66 candidate Mycoplasma proteins using available Mmm genome data. These proteins were ranked by their ability to be recognized by serum from CBPP-positive cattle and thereafter used to inoculate naïve cattle. We report here the inoculation of cattle with recombinant proteins and the subsequent humoral and T-cell-mediated immune responses to these proteins and conclude that a subset of these proteins are candidate molecules for recombinant protein-based subunit vaccines for CBPP control.

A large-scale genomic approach affords unprecedented resolution for the molecular epidemiology and evolutionary history of contagious caprine pleuropneumonia

Contagious caprine pleuropneumonia (CCPP), caused by Mycoplasma capricolum subsp. capripneumoniae (Mccp), is a devastating disease of domestic goats and of some wild ungulate species. The disease is currently spreading in Africa and Asia and poses a serious threat to disease-free areas. A comprehensive view of the evolutionary history and dynamics of Mccp is essential to understand the epidemiology of CCPP. Yet, analysing the diversity of genetically monomorphic pathogens, such as Mccp, is complicated due to their low variability. In this study, the molecular epidemiology and evolution of CCPP was investigated using a large-scale genomic approach based on next-generation sequencing technologies, applied to a sample of strains representing the global distribution of this disease. A highly discriminatory multigene typing system was developed, allowing the differentiation of 24 haplotypes among 25 Mccp strains distributed in six genotyping groups, which showed some correlation with geographic origin. A Bayesian approach was used to infer the first robust phylogeny of the species and to date the principal events of its evolutionary history. The emergence of Mccp was estimated only at about 270 years ago, which explains the low genetic diversity of this species despite its high mutation rate, evaluated at 1.3 × 10⁻⁶ substitutions per site per year. Finally, plausible scenarios were proposed to elucidate the evolution and dynamics of CCPP in Asia and Africa, though limited by the paucity of Mccp strains, particularly in Asia. This study shows how combining large-scale genomic data with spatial and temporal data makes it possible to obtain a comprehensive view of the epidemiology of CCPP, a precondition for the development of improved disease surveillance and control measures.

Field-Applicable Recombinase Polymerase Amplification Assay for Rapid Detection of Mycoplasma capricolum subsp. capripneumoniae

Contagious caprine pleuropneumonia (CCPP) is a highly contagious disease caused by Mycoplasma capricolum subsp. capripneumoniae that affects goats in Africa and Asia. Current available methods for the diagnosis of Mycoplasma infection, including cultivation, serological assays, and PCR, are time-consuming and require fully equipped stationary laboratories, which make them incompatible with testing in the resource-poor settings that are most relevant to this disease. We report a rapid, specific, and sensitive assay employing isothermal DNA amplification using recombinase polymerase amplification (RPA) for the detection of M. capricolum subsp. capripneumoniae. We developed the assay using a specific target sequence in M. capricolum subsp. capripneumoniae, as found in the genome sequence of the field strain ILRI181 and the type strain F38 and that was further evidenced in 10 field strains from different geographical regions. Detection limits corresponding to 5 × 10³ and 5 × 10⁴ cells/ml were obtained using genomic DNA and bacterial culture from M. capricolum subsp. capripneumoniae strain ILRI181, while no amplification was obtained from 71 related Mycoplasma isolates or from the Acholeplasma or the Pasteurella isolates, demonstrating a high degree of specificity. The assay produces a fluorescent signal within 15 to 20 min and worked well using pleural fluid obtained directly from CCPP-positive animals without prior DNA extraction. We demonstrate that the diagnosis of CCPP can be achieved, with a short sample preparation time and a simple read-out device that can be powered by a car battery, in <45 min in a simulated field setting.

Exploitation of plasmin(ogen) by bacterial pathogens of veterinary significance

The plasminogen (Plg) system plays an important homeostatic role in the degradation of fibrin clots, extracellular matrices and tissue barriers important for cellular migration, as well as the promotion of neurotransmitter release. Plg circulates in plasma at physiologically high concentrations (150-200μg ml(-1)) as an inactive proenzyme. Proteins enriched in lysine and other positively charged residues (histidine and arginine) as well as glycosaminoglycans and gangliosides bind Plg. The binding interaction initiates a structural adjustment to the bound Plg that facilitates cleavage by proteases (plasminogen activators tPA and uPA) that activate Plg to the active serine protease plasmin. Both pathogenic and commensal bacteria capture Plg onto their cell surface and promote its conversion to plasmin. Many microbial Plg-binding proteins have been described underpinning the importance this process plays in how bacteria interact with their hosts. Bacteria exploit the proteolytic capabilities of plasmin by (i) targeting the mammalian fibrinolytic system and degrading fibrin clots, (ii) remodeling the extracellular matrix and generating bioactive cleavage fragments of the ECM that influence signaling pathways, (iii) activating matrix metalloproteinases that assist in the destruction of tissue barriers and promote microbial metastasis and (iv) destroying immune effector molecules. There has been little focus on the exploitation of the fibrinolytic system by veterinary pathogens. Here we describe several pathogens of veterinary significance that possess adhesins that bind plasmin(ogen) onto their cell surface and promote its activation to plasmin. Cumulative data suggests that these attributes provide pathogenic and commensal bacteria with a means to colonize and persist within the host environment.

Cyto-adherence of Mycoplasma mycoides subsp. mycoides to bovine lung epithelial cells

Background

Mycoplasma mycoides subsp. mycoides (Mmm) is the causative agent of contagious bovine pleuropneumonia (CBPP), a respiratory disease of cattle, whereas the closely related Mycoplasma mycoides subsp. capri (Mmc) is a goat pathogen. Cyto-adherence is a crucial step in host colonization by mycoplasmas and subsequent pathogenesis. The aim of this study was to investigate the interactions between Mmm and mammalian host cells by establishing a cyto-adherence flow cytometric assay and comparing tissue and species specificity of Mmm and Mmc strains.

Results

There were little significant differences in the adherence patterns of eight different Mmm strains to adult bovine lung epithelial cells. However, there was statistically significant variation in binding to different host cells types. Highest binding was observed with lung epithelial cells, intermediate binding with endothelial cells and very low binding with fibroblasts, suggesting the presence of effective adherence of Mmm on cells lining the airways of the lung, which is the target organ for this pathogen, possibly by high expression of a specific receptor. However, binding to bovine fetal lung epithelial cells was comparably low; suggesting that the lack of severe pulmonary disease seen in many infected young calves can be explained by reduced expression of a specific receptor.

Conclusions

Mmm bound with high efficiency to adult bovine lung cells and less efficiently to calves or goat lung cells. The data show that cyto-adherence of Mmm is species- and tissue- specific confirming its role in colonization of the target host and subsequent infection and development of CBPP.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-015-0347-3) contains supplementary material, which is available to authorized users.

Highly dynamic genomic loci drive the synthesis of two types of capsular or secreted polysaccharides within the Mycoplasma mycoides cluster

Mycoplasmas of the Mycoplasma mycoides cluster are all ruminant pathogens. Mycoplasma mycoides subsp. mycoides is responsible for contagious bovine pleuropneumonia and is known to produce capsular polysaccharide (CPS) and exopolysaccharide (EPS). Previous studies have strongly suggested a role for Mycoplasma mycoides subsp. mycoides polysaccharides in pathogenicity. Mycoplasma mycoides subsp. mycoides-secreted EPS was recently characterized as a β(1→6)-galactofuranose homopolymer (galactan) identical to the capsular product. Here, we extended the characterization of secreted polysaccharides to all other members of the M. mycoides cluster: M. capricolum subsp. capripneumoniae, M. capricolum subsp. capricolum, M. leachii, and M. mycoides subsp. capri (including the LC and Capri serovars). Extracted EPS was characterized by nuclear magnetic resonance, resulting in the identification of a homopolymer of β(1→2)-glucopyranose (glucan) in M. capricolum subsp. capripneumoniae and M. leachii. Monoclonal antibodies specific for this glucan and for the Mycoplasma mycoides subsp. mycoides-secreted galactan were used to detect the two polysaccharides. While M. mycoides subsp. capri strains of serovar LC produced only capsular galactan, no polysaccharide could be detected in strains of serovar Capri. All strains of M. capricolum subsp. capripneumoniae and M. leachii produced glucan CPS and EPS, whereas glucan production and localization varied among M. capricolum subsp. capricolum strains. Genes associated with polysaccharide synthesis and forming a biosynthetic pathway were predicted in all cluster members. These genes were organized in clusters within two loci representing genetic variability hot spots. Phylogenetic analysis showed that some of these genes, notably galE and glf, were acquired via horizontal gene transfer. These findings call for a reassessment of the specificity of the serological tests based on mycoplasma polysaccharides.

Complete Genome Sequence of Mycoplasma capricolum subsp. capripneumoniae Strain 9231-Abomsa

Mycoplasma capricolum subsp. capripneumoniae is the etiological agent of contagious caprine pleuropneumonia. We report here the complete and annotated genome sequence of M. capricolum subsp. capripneumoniae strain 9231-Abomsa.

Studies into the prevalence of Mycoplasma species in small ruminants in Benue State, North-central Nigeria

The indicative prevalence of respiratory Mycoplasma species in small ruminants (SR) was determined in North-central Nigeria. Nasal swabs from 172 sheep and 336 goats from the Northeast, Northwest and South Senatorial Districts of Benue State were examined. Initial Mycoplasma isolation used Mycoplasma culture techniques followed by digitonin sensitivity testing. Species identification was done using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE). Overall, Mycoplasma organisms were isolated from 131 (25.8 %) of the 508 SR examined. Prevalence rates of 18.1 and 29.8 % were recorded for sheep and goats, respectively. A total of 135 isolates of Mycoplasma belonging to three different species were identified: Mycoplasma ovipneumoniae (127), Mycoplasma arginini (7) and Mycoplasma mycoides subspecies capri (1). More than one Mycoplasma species were detected in four (3.1 %) of the 131 confirmed Mycoplasma positive cultures. Mycoplasma was isolated from 16.2 and 29.1 % of animals with and without respiratory signs, respectively. The high isolation rate of mycoplasmas in apparently healthy and clinically sick sheep and goats in this study indicates a carrier status in these SR which may constitute a serious problem in disease control.

Detection of Ureaplasma spp. in semen samples from sheep in Brazil

A study was conducted to verify the presence of mycoplasmas and ureaplasmas DNA in sheep semen samples from the State of Pernambuco. The PCR assay was conducted of according with standard protocols with generic primers. Mollicutes DNA was detected in 26.0% and Ureaplasma spp. in 12.0% of semen samples.

Complete genomes of two dipteran-associated spiroplasmas provided insights into the origin, dynamics, and impacts of viral invasion in spiroplasma

Spiroplasma is a genus of wall-less, low-GC, Gram-positive bacteria with helical morphology. As commensals or pathogens of plants, insects, ticks, or crustaceans, they are closely related with mycoplasmas and form a monophyletic group (Spiroplasma–Entomoplasmataceae–Mycoides) with Mycoplasma mycoides and its relatives. In this study, we report the complete genome sequences of Spiroplasma chrysopicola and S. syrphidicola from the Chrysopicola clade. These species form the sister group to the Citri clade, which includes several well-known pathogenic spiroplasmas. Surprisingly, these two newly available genomes from the Chrysopicola clade contain no plectroviral genes, which were found to be highly repetitive in the previously sequenced genomes from the Citri clade. Based on the genome alignment and patterns of GC-skew, these two Chrysopicola genomes appear to be relatively stable, rather than being highly rearranged as those from the Citri clade. Phylogenetic analyses suggest that the susceptibility to plectroviral invasion probably originated in the common ancestor of the Citri clade or one of its subclades. This susceptibility may be attributed to the absence of antiviral systems found in the Chrysopicola clade. Using the virus-free genomes of the Chrysopicola clade as references, we inferred the putative viral integration sites in the Citri genomes. Comparisons of syntenic regions suggest that the extensive viral invasion in the Citri clade promoted genome rearrangements and expansions. More importantly, the viral invasion may have facilitated horizontal gene transfers that contributed to adaptation in the Citri clade.

Cattle immunized against the pathogenic L-α-glycerol-3-phosphate oxidase of Mycoplasma mycoides subs. mycoides fail to generate neutralizing antibodies and succumb to disease on challenge

The membrane-associated enzyme L-α-glycerol-3-phosphate oxidase (GlpO) of Mycoplasma mycoides subs. mycoides (Mmm), the causal agent of contagious bovine pleuropneumonia (CBPP) has been identified as a virulence factor responsible for the release of toxic by-products such as H2O2 that mediate host cell injury. Since CBPP pathogenesis is based on host inflammatory reactions, we have determined the capacity of recombinant GlpO to generate in vivo protective responses against challenge in immunized cattle. We also investigated whether sera raised against recombinant GlpO in cattle and mice inhibit production of H2O2 by Mmm. Immunization of cattle with recombinant GlpO did not protect against challenge with a virulent strain of Mmm. Further, although both murine and bovine antisera raised against recombinant GlpO detected recombinant and native forms of GlpO in immunoblot assays with similar titres, only murine antibodies could neutralize GlpO enzymatic function. The data raise the possibility that Mmm has adapted to evade potential detrimental antibody responses in its definitive host.

Proteomic approach for identification of immunogenic proteins of Mycoplasma mycoides subsp. capri

In this study, an immunoproteomic approach was used to identify immunodominant proteins from Mycoplasma mycoides subsp. capri isolates. Membrane proteins, extracted through TX-114 phase partitioning, were separated using mono- and two-dimensional electrophoresis and detected by Western blotting with pooled sera from naturally infected goats. A total of 27 immunoreactive spots, corresponding to 13 different proteins, were identified using nanoLC-ESI-MSMS. Function annotation revealed that most of these proteins were metabolic enzymes involved in carbohydrate and energy metabolism. The immunogenic proteins identified in this study: pyruvate dehydrogenase, dihydrolipoamide acetyltransferase, dihydrolipoyl dehydrogenase, phosphate acetyltransferase, phosphopyruvate hydratase, adenine phopshoribosyltransferase, transketolase, translation elongation factor G, translation elongation factor Ts, FMN-dependent NADH-azoreductase, peptide methionine sulfoxide reductase, inorganic diphosphatase and trigger factor may be used as biomarkers for the serological diagnosis of contagious agalactia caused by M. mycoides subsp. capri.

A Type III restriction-modification system in Mycoplasma mycoides subsp. capri

The sequenced genome of Mycoplasma mycoides subsp. capri revealed the presence of a Type III restriction–modification system (MmyCI). The methyltransferase (modification) subunit of MmyCI (M.MmyCI) was shown to recognize the sequence 5′-TGAG-3′ and methylate the adenine. The coding region of the methyltransferase gene contains 12 consecutive AG dinucleotide repeats that result in a translational termination at a TAA codon immediately beyond the repeat region. This strain does not have MmyCI activity. A clone was found with 10 AG repeats such that the gene is in frame, and this strain has MmyCI activity, suggesting that the expression of the MmyCI methyltransferase may be phase variable.

Complete Genome Sequence of Mycoplasma putrefaciens Strain 9231, One of the Agents of Contagious Agalactia in Goats

Mycoplasma putrefaciens is one of the etiologic agents of contagious agalactia in goats. We report herein the complete genome sequence of Mycoplasma putrefaciens strain 9231.

Contagious agalactia due to Mycoplasma spp. in small dairy ruminants: epidemiology and prospects for diagnosis and control

Contagious agalactia (CA) is a serious disease of small dairy ruminants that has a substantial economic impact on the goat and sheep milk industries. The main aetiological agent of the disease is Mycoplasma agalactiae, although other species, such as Mycoplasma mycoides subsp. capri, Mycoplasma capricolum subsp. capricolum and Mycoplasma putrefaciens, are pathogenic in goats. There are two clinical-epidemiological states of CA in sheep and goats; herds and flocks may exhibit outbreaks of CA or may be chronically infected, the latter with a high incidence of subclinical mastitis and only occasional clinical cases. The complex epidemiology of CA is related to the genetic characteristics and mechanisms of molecular variation of the Mycoplasma spp. involved, along with presence of CA-mycoplasmas in wild ruminant species. In goats, the situation is particularly complex and asymptomatic carriers have been detected in chronically infected herds. The coexistence of other non-pathogenic mycoplasmas in the herd further complicates the diagnosis of CA and the design of efficient strategies to control the disease. Routes of infection, such as the venereal route, may be involved in the establishment of chronic infection in herds. Current challenges include the need for improved diagnostic methods for detection of chronic and subclinical infections and for the design of more efficient vaccines.

Isothermal loop-mediated amplification (LAMP) for diagnosis of contagious bovine pleuro-pneumonia

Background

Contagious Bovine Pleuropneumonia (CBPP) is the most important chronic pulmonary disease of cattle on the African continent causing severe economic losses. The disease, caused by infection with Mycoplasma mycoides subsp. mycoides is transmitted by animal contact and develops slowly into a chronic form preventing an early clinical diagnosis. Because available vaccines confer a low protection rate and short-lived immunity, the rapid diagnosis of infected animals combined with traditional curbing measures is seen as the best way to control the disease. While traditional labour-intensive bacteriological methods for the detection of M. mycoides subsp. mycoides have been replaced by molecular genetic techniques in the last two decades, these latter approaches require well-equipped laboratories and specialized personnel for the diagnosis. This is a handicap in areas where CBPP is endemic and early diagnosis is essential.

Results

We present a rapid, sensitive and specific diagnostic tool for M. mycoides subsp. mycoides detection based on isothermal loop-mediated amplification (LAMP) that is applicable to field conditions. The primer set developed is highly specific and sensitive enough to diagnose clinical cases without prior cultivation of the organism. The LAMP assay detects M. mycoides subsp. mycoides DNA directly from crude samples of pulmonary/pleural fluids and serum/plasma within an hour using a simple dilution protocol. A photometric detection of LAMP products allows the real-time visualisation of the amplification curve and the application of a melting curve/re-association analysis presents a means of quality assurance based on the predetermined strand-inherent temperature profile supporting the diagnosis.

Conclusion

The CBPP LAMP developed in a robust kit format can be run on a battery-driven mobile device to rapidly detect M. mycoides subsp. mycoides infections from clinical or post mortem samples. The stringent innate quality control allows a conclusive on-site diagnosis of CBPP such as during farm or slaughter house inspections.