Mannheimia indoligenes sp. nov., proposed for clade V organisms of Mannheimia.

A set of 25 strains belonging to clade V of Mannheimia mainly isolated from cattle was investigated and is proposed to represent Mannheimia indoligenes sp. nov. The species can be separated from the other validly published species of the genus by pheno- and genotype. Only indole separates M. indoligenes and Mannheimia varigena while two to seven characters separate M. indoligenes from other species of Mannheimia. Thirteen strains belonging to biogroups 6, 7, 8C, 9, 10, 12 and UG5 formed a monophyletic group based on 16S rRNA gene sequence comparisons with 98-100 % similarity. Eight of these strains were further included in the whole genome comparison. Digital DNA-DNA hybridization showed that the similarities between the suggested type strain M14.4T and the other strains of M. indoligenes were 62.9 % or higher. The average nucleotide identity was 95.5 % or higher between M14.4T and the other strains of the species. The rpoB gene sequence similarity was 95-100 % within M. indoligenes. MALDI-TOF allowed a clear separation from other Mannheimia species further supporting classification as a novel species and making it the diagnostic identification tool of choice for M. indoligenes. The type strain is M14.4T (=CCUG 77347T=DSM 116804T) isolated from a cattle tongue in Scotland.

Serological and molecular detection as well as typing of Leptospira spp. in foxes, raccoons, and other wild carnivores in North-Eastern Germany, 2021-2022.

Leptospirosis is a worldwide zoonosis caused by pathogenic Leptospira spp. While the latter are reported from various mammal hosts such as humans, dogs, or rodents, less is known about their presence in wild carnivores. We therefore investigated the presence of Leptospira spp. in foxes, raccoons, badgers, raccoon dogs, and martens in North-Eastern Germany. Kidney, urine, and blood specimens obtained from legally hunted or road-killed animals were tested by real-time PCR and by serogroup specific antibody detection for the presence of Leptospira spp. Additionally, kidney and urine specimens were tested by real-time PCR for the presence of Brucella spp. and Francisella tularensis, with all being negative for these two zoonotic pathogens. Leptospira spp. were detected by PCR in 12.6 % (n = 21/166) and serologically in 26.2 % (n = 53/202) of tissue and serum samples, respectively. Antibodies to 15 different serogroups were identified with Javanica (n = 25) and Bataviae (n = 12) being predominant. A high sero-prevalence of 34.0 % and 18.6 % in foxes and raccoons, respectively, and the presence of ST17 associated with human and animal leptospirosis indicates a reservoir and the zoonotic potential of these wild animals.

Canine Staphylococcaceae circulating in a Kenyan animal shelter.

Animal shelters, especially in resource-poor countries, bring together pets from different regions and with different backgrounds. The crowding of such animals often results in infectious diseases, such as respiratory infections. This study characterized Staphylococcaceae from diseased and apparently healthy dogs housed in an animal shelter in Kenya, to determine their antibiotic resistance profiles, their genetic relatedness, and the presence of dominant clones. Therefore, bacteria were collected from all 167 dogs present in the shelter in June 2015 and screened for Staphylococcaceae using standard cultivation techniques. In all, 92 strains were isolated from 85 dogs and subsequently sequenced by PacBio long-read sequencing. Strains encompassed nine validated species, while S. aureus (n = 47), S. pseudintermedius (n = 21), and Mammaliicoccus (M.) sciuri (n = 16) were the three most dominant species. Two S. aureus clones of ST15 (CC15) and ST1292 (CC1) were isolated from 7 and 37 dogs, respectively. All 92 strains isolated were tested for their antimicrobial susceptibility by determining the minimum inhibitory concentrations. In all, 86 strains had resistance-associated minimal inhibitory concentrations to at least one of the following antimicrobials: tetracycline, benzylpenicillin, oxacillin, erythromycin, clindamycin, trimethoprim, kanamycin/gentamicin, or streptomycin. Many virulence-encoding genes were detected in the S. aureus strains, other Staphylococcaceae contained a different set of homologs of such genes. The presence of mobile genetic elements, such as plasmids and prophages, known to facilitate the dissemination of virulence- and resistance-encoding genes, was also assessed. The unsuspected high presence of two S. aureus clones in about 50% of dogs suggests dissemination within the shelter and a human source.IMPORTANCEMicrobiological data from sub-Saharan Africa are scarce compared to data from North America, Europe, or Asia, and data derived from dogs, the man's best friend, kept in sub-Saharan Africa are largely missing. This work presents data on Staphylococcaceae mainly isolated from the nasal cavity of dogs stationed at a Kenyan shelter in 2015. We characterized 92 strains isolated from 85 dogs, diseased and apparently healthy ones. The strains isolated covered nine validated species and we determined their phenotypic resistance and characterized their complete genomes. Interestingly, Staphylococcus aureus of two predominant genetic lineages, likely to be acquired from humans, colonized many dogs. We also detected 15 novel sequence types of Mammaliicoccus sciuri and S. pseudintermedius indicating sub-Saharan-specific phylogenetic lineages. The data presented are baseline data that guide antimicrobial treatment for dogs in the region.

Field validation of an antibiotic-free hoof spray to effectively treat ovine footrot by eliminating virulent Dichelobacter nodosus.

Ovine footrot caused by Dichelobacter nodosus is a highly contagious hoof disease negatively impacting animal welfare and causing major economic losses to the sheep industry. Bactericidal footbaths have shown to be an efficient treatment option and will be used in the national footrot control program in Switzerland. However, the application of footbaths is laborious and economically not sound for small flock holders. We therefore tested in a field study the Intra Repiderma spray for its applicability and efficacy to treat ovine footrot. Ten independent flocks fulfilling defined parameters (e.g. clinical signs, positive for D. nodosus, flock size) could be identified and were included in the study. Farms were visited weekly to fortnightly and clinical scores and swabs for D. nodosus real-time (rt)PCR were taken. Treatment with the Intra Repiderma spray was started after initial claw trimming at the very first visit and was carried out three times within a week. Clearly visible clinical improvement was evident after one week of treatment. Virulent D. nodosus amounts on feet declined constantly during treatment which was continued until all sheep of a flock tested rtPCR-negative (1-10 weeks). Results indicate that a highly effective improvement of clinical signs and complete elimination of virulent D. nodosus can be achieved with the spray treatment. Therefore, it is a valuable alternative to cumbersome footbaths especially for small flocks. A sustainable control of footrot and its pathogen in a successfully treated flock can be maintained by strict biosecurity measures and continued treatment as far as necessary.

Development of a new multiplex quantitative PCR for the detection of Glaesserella parasuis, Mycoplasma hyorhinis, and Mycoplasma hyosynoviae.

Glaesserella parasuis, Mycoplasma hyorhinis, and Mycoplasma hyosynoviae are important porcine pathogens responsible for polyserositis, polyarthritis, meningitis, pneumonia, and septicemia causing significant economic losses in the swine industry. A new multiplex quantitative polymerase chain reaction (qPCR) was designed on one hand for the detection of G. parasuis and the virulence marker vtaA to distinguish between highly virulent and non-virulent strains. On the other hand, fluorescent probes were established for the detection and identification of both M. hyorhinis and M. hyosynoviae targeting 16S ribosomal RNA genes. The development of the qPCR was based on reference strains of 15 known serovars of G. parasuis, as well as on the type strains M. hyorhinis ATCC 17981T and M. hyosynoviae NCTC 10167T . The new qPCR was further evaluated using 21 G. parasuis, 26 M. hyorhinis, and 3 M. hyosynoviae field isolates. Moreover, a pilot study including different clinical specimens of 42 diseased pigs was performed. The specificity of the assay was 100% without cross-reactivity or detection of other bacterial swine pathogens. The sensitivity of the new qPCR was demonstrated to be between 11-180 genome equivalents (GE) of DNA for M. hyosynoviae and M. hyorhinis, and 140-1200 GE for G. parasuis and vtaA. The cut-off threshold cycle was found to be at 35. The developed sensitive and specific qPCR assay has the potential to become a useful molecular tool, which could be implemented in veterinary diagnostic laboratories for the detection and identification of G. parasuis, its virulence marker vtaA, M. hyorhinis, and M. hyosynoviae.

Genomic Characterization and Antimicrobial Susceptibility of Dromedary-Associated Staphylococcaceae from the Horn of Africa.

Members of the Staphylococcaceae family, particularly those of the genus Staphylococcus, encompass important human and animal pathogens. We collected and characterized Staphylococcaceae strains from apparently healthy and diseased camels (n = 84) and cattle (n = 7) in Somalia and Kenya. We phenotypically characterized the strains, including their antimicrobial inhibitory concentrations. Then, we sequenced their genomes using long-read sequencing, closed their genomes, and subsequently compared and mapped their virulence- and resistance-associated gene pools. Genome-based phylogenetics revealed 13 known Staphylococcaceae and at least two novel species. East African strains of different species encompassed novel sequence types and phylogenetically distant clades. About one-third of the strains had non-wild-type MICs. They were resistant to at least one of the following antimicrobials: tetracycline, benzylpenicillin, oxacillin, erythromycin, clindamycin, trimethoprim, gentamicin, or streptomycin, encoded by tet(K), blaZ/blaARL, mecA/mecA1, msrA/mphC, salA, dfrG, aacA-aphD, and str, respectively. We identified the first methicillin- and multidrug-resistant camel S. epidermidis strain of sequence type (ST) 1136 in East Africa. The pool of virulence-encoding genes was largest in the S. aureus strains, as expected, although other rather commensal strains contained distinct virulence-encoding genes. We identified toxin-antitoxin (TA) systems such as the hicA/hicB and abiEii/abiEi families, reported here for the first time for certain species of Staphylococcaceae. All strains contained at least one intact prophage sequence, mainly belonging to the Siphoviridae family. We pinpointed potential horizontal gene transfers between camel and cattle strains and also across distinct Staphylococcaceae clades and species. IMPORTANCE Camels are a high value and crucial livestock species in arid and semiarid regions of Africa and gain importance giving the impact of climate change on traditional livestock species. Our current knowledge with respect to Staphylococcaceae infecting camels is very limited compared to that for other livestock species. Better knowledge will foster the development of specific diagnostic assays, guide promising antimicrobial treatment options, and inform about potential zoonotic risks. We characterized 84 Staphylococcaceae strains isolated from camels with respect to their antimicrobial resistance and virulence traits. We detected potentially novel Staphylococcus species, resistances to different classes of antimicrobials, and the first camel multidrug-resistant S. epidermidis strain of sequence type 1136.

Risk factors associated with the infection of sheep with Dichelobacter nodosus.

Ovine footrot is a highly contagious foot disease caused by the gram-negative bacterium Dichelobacter nodosus (D. nodosus). In a recent report, we showed a prevalence of 42.9% D. nodosus positive swabs across Germany. In this follow-up study, we used real-time PCR results for D. nodosus and footrot scores of 9297 sheep from 208 flocks and collated these data with survey data on herd and animal characteristics and herd management. The aims of the present study were to investigate herd and animal factors associated with D. nodosus infection and footrot scores in individual sheep. Multivariable analyses with generalized mixed models showed that month of recording, breed, herdbook membership, use of antibiotics, and footbaths in the past 3-10 years, signs of footrot in the past 12 months and flock environment of the sheep, modelled as a random farm effect within region, were significant risk factors. Among the 21 different breeds, Romney had the lowest risk of D. nodosus infection, while Swifter had the highest risk and German Merino and German White Heath were the next breeds at highest risk of D. nodosus infection. The variance between farms in the prevalence of D. nodosus was large and accounted for 84% of the total variance in the mixed model analysis. We conclude that specific and as yet unknown effects influencing D. nodosus infections in flocks, as well as breed and weather, are the most important effects on D. nodosus infection in sheep, pointing towards the need to establish adequate infection control at farm level.

Wielerella bovis gen. nov., sp. nov. a member of the family Neisseriaceae associated with bovine endocarditis.

Seven bacterial strains isolated from bovine endocarditis in six animals from different geographic regions were investigated in a polyphasic taxonomic approach. Phylogenetic analysis based on 16S rRNA gene sequences placed all seven isolates on a distinct, monophyletic cluster in the family Neisseriaceae with closest similarity to type strains of Alysiella filiformis (97.06 %) and Kingella kingae (96.34 %). Whole genome sequence analysis of isolates confirmed their species status, with an average nucleotide identity >96 % between isolates and <80 % to other type species of genera of Neisseriaceae while digital DNA-DNA hybridization values were >80 % and<18 %, respectively. The DNA G+C content was 42.5-43.0 mol%. Whole genome sequence based phylogeny showed the isolates being monophyletic and separated from established genera, thereby forming a new genus within the family Neisseriaceae. Similarly, analysis of MALDI-TOF MS reference spectra clustered the isolates close together and clearly separated from other genera, making this the method of choice for identification. Biochemical markers based on classical as well as commercial identification schemes allowed separation from closely related Neisseriaceae genera, even though the new taxon is biochemically not very active. Major fatty acids are C12 : 0, C14 : 0 and C16 : 0. The major quinone is ubiquinone Q-8. In the polar lipid profile, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phospholipid were predominant. We propose the novel genus Wielerella with the type species Wielerella bovis gen. nov., sp. nov. The type strain is CCUG 44465T (=DSM 113289T=JF 2483T) isolated post mortem from a cow with endocarditis in Switzerland.

Seroprevalence of Mycoplasma hyopneumoniae in sows fifteen years after implementation of a control programme for enzootic pneumonia in Switzerland.

Mycoplasma hyopneumoniae is the etiological agent of enzootic pneumonia (EP), an economically important chronic respiratory disease in pigs. M. hyopneumoniae impacts the mucociliary clearance system by disrupting the cilia and modulates the immune response, resulting in intermittent dry non-productive cough. For progressive control of EP in Switzerland, a corresponding programme was fully implemented in 2004. It is based on total depopulation strategies of affected fattening farms as well as partial depopulation in breeding farms. Surveillance of EP status in Switzerland is mainly based on real-time PCR of nasal swabs from coughing animals or suspicious lungs and thereby sporadic cases are still observed every year. In order to obtain information on the seroprevalence, serum samples of 5021 sows from 968 farms collected in 2018 at eight different slaughterhouses were analyzed for the presence of M. hyopneumoniae-specific antibodies using a commercial ELISA kit. The overall seroprevalence was low with 0.98% of sows testing positive and these seropositive animals could be allocated to 3.92% of farms tested. Most seropositive farms presented weakly positive singleton reactors and only one farm showed several strongly seropositive animals. In conclusion, the serological status mirrors the successful progressive control of M. hyopneumoniae in the Swiss domestic pig population over the years. The current study underlines the added value of serological testing in the surveillance of EP in a country with low prevalence and confirms the sustained benefit of strategic control programmes.

Serological Diversity of Dichelobacter nodosus in German Sheep Flocks.

Footrot is one of the major causes of lameness in sheep and leads to decreased animal welfare and high economic losses. The causative agent is the Gram-negative anaerobic bacterium Dichelobacter nodosus. The prevalence of D. nodosus in 207 sheep flocks across Germany was 42.9%. Based on the sequence variation in the type IV fimbrial gene fimA, D. nodosus can be subdivided into ten serogroups (A-I and M). There are commercially available vaccines covering nine serogroups, but the efficacy is low compared to bivalent vaccines. The aim of this study was to investigate the diversity of serogroups in Germany at the flock and animal levels. In total, we detected at least one serogroup in 819 samples out of 969 D. nodosus-positive samples from 83 flocks using serogroup-specific singleplex PCR for the serogroups A-I. Serogroup A was most prevalent at the animal level, followed by serogroups B, H and C. At the flock level, serogroups A and B had the highest prevalence, each with 64%, but only 40% of flocks had both. The average number of serogroups per animal was 1.42 (range one to five) and, per flock, 3.10 (range one to six). The serogrouping showed within-flock specific clusters but were widely distributed, with 50 different combinations across the flocks. The factors associated with the number of serogroups per animal and single serogroups were the load of D. nodosus, footrot score, sheep breed and flock. Our results indicate that efficient vaccination programs would benefit from tailor-made flock-specific vaccines and regular monitoring of circulating serotypes in the flock to be able to adjust vaccine formulations for nationwide progressive control of footrot in Germany.

Complete genome for Actinobacillus pleuropneumoniae serovar 8 reference strain 405: comparative analysis with draft genomes for different laboratory stock cultures indicates little genetic variation.

We report here the complete genome sequence of the widely studied Actinobacillus pleuropneumoniae serovar 8 reference strain 405, generated using the Pacific Biosciences (PacBio) RS II platform. Furthermore, we compared draft sequences generated by Illumina sequencing of six stocks of this strain, including the same original stock used to generate the PacBio sequence, held in different countries and found little genetic variation, with only three SNPs identified, all within the degS gene. However, sequences of two small plasmids, pARD3079 and p405tetH, detected by Illumina sequencing of the draft genomes were not identified in the PacBio sequence of the reference strain.

Minimalistic mycoplasmas harbor different functional toxin-antitoxin systems.

Mycoplasmas are minute bacteria controlled by very small genomes ranging from 0.6 to 1.4 Mbp. They encompass several important medical and veterinary pathogens that are often associated with a wide range of chronic diseases. The long persistence of mycoplasma cells in their hosts can exacerbate the spread of antimicrobial resistance observed for many species. However, the nature of the virulence factors driving this phenomenon in mycoplasmas is still unclear. Toxin-antitoxin systems (TA systems) are genetic elements widespread in many bacteria that were historically associated with bacterial persistence. Their presence on mycoplasma genomes has never been carefully assessed, especially for pathogenic species. Here we investigated three candidate TA systems in M. mycoides subsp. capri encoding a (i) novel AAA-ATPase/subtilisin-like serine protease module, (ii) a putative AbiEii/AbiEi pair and (iii) a putative Fic/RelB pair. We sequence analyzed fourteen genomes of M. mycoides subsp. capri and confirmed the presence of at least one TA module in each of them. Interestingly, horizontal gene transfer signatures were also found in several genomic loci containing TA systems for several mycoplasma species. Transcriptomic and proteomic data confirmed differential expression profiles of these TA systems during mycoplasma growth in vitro. While the use of heterologous expression systems based on E. coli and B. subtilis showed clear limitations, the functionality and neutralization capacities of all three candidate TA systems were successfully confirmed using M. capricolum subsp. capricolum as a host. Additionally, M. capricolum subsp. capricolum was used to confirm the presence of functional TA system homologs in mycoplasmas of the Hominis and Pneumoniae phylogenetic groups. Finally, we showed that several of these M. mycoides subsp. capri toxins tested in this study, and particularly the subtilisin-like serine protease, could be used to establish a kill switch in mycoplasmas for industrial applications.

Detection of treponemes in digital dermatitis lesions of captive European bison (Bison bonasus).

A newly-discovered foot disease of unknown origin in captive European Bison (Bison bonasus) was recently detected at Berne Animal Park. Dermatitis of the interdigital cleft of varying degrees of severity was diagnosed in all animals (n = 10). The aim of this study was to describe the gross and histological lesions of the interdigital cleft found in 10 captive European bison and to identify involved potential pathogens in affected feet using molecular-based methods for Treponema spp., Dichelobacter nodosus and Fusobacterium necrophorum. Lesions were scored according to the degree of gross pathology at limb level. In a single animal, the gross lesions were restricted to focal lesions on the dorsal aspect of the digital skin of each foot (score 1), whereas all other animals showed at least one foot with extended lesions including the interdigital cleft (score 2). The presence of viable spirochaetes was observed in all animals using dark field microscopy. Applying fluorescence in situ hybridisation (FISH) on biopsies, Treponema spp. were identified, infiltrating the skin lesions in varying numbers in nine animals. Nested PCRs for Treponema medium, Treponema phagedenis and Treponema pedis of swab samples showed three positive animals out of ten for the latter two, whereas pooled biopsy samples were positive in all ten animals for at least T. phagedenis (9/10) and/or T. pedis (7/10), while all samples were negative for T. medium. However, none of these Treponema species could be isolated and sequence analysis of the amplified products showed 100% match of 365 base pairs (bp) to Treponema phylotype PT3 and almost full match (530 of 532 bp, 99.6%) to Treponema phylotype PT13. The presence of T. phagedenis, PT3 and PT13 phylotypes was confirmed by FISH analyses. The phylotypes of T. phagedenis were present in all hybridized positive biopsies of Treponema spp., and PT13 and PT3 were less abundant. Neither D. nodosus nor F. necrophorum were detected. The histological Treponema score was mostly mild. Digital dermatitis in captive European Bison is contagious and differs from bovine digital dermatitis, concerning associated pathogens as well as gross appearance.

Complete Genome Sequences of the Methicillin-Resistant Strain Staphylococcus aureus 17Gst354 and Its Prophage Staphylococcus Phage vB_StaphS-IVBph354.

We report the complete 2,783,931-bp circular genome sequence of the human methicillin-resistant strain Staphylococcus aureus 17Gst354, isolated from a nasal swab. The strain possessed an additional 4,397-bp plasmid. Moreover, we induced and sequenced its temperate phage Staphylococcus phage vB_StaphS-IVBph354, which has a circular genome of 41,970 bp.

Reclassification of [Haemophilus] haemoglobinophilus as Canicola haemoglobinophilus gen. nov., comb. nov. including Bisgaard taxon 35.

[Haemophilus] haemoglobinophilus and the unpublished Bisgaard taxon 35 are associated with respiratory and urogenital tract infections in dogs. A total of 21 strains including the type strain of [Haemophilus] haemoglobinophilus were included in the investigation. Strains of [Haemophilus] haemoglobinophilus and taxon 35 formed a monophyletic group demonstrating at least 97.8 and 96.5% similarities within the group based upon 16S rRNA and rpoB gene sequence comparisons, respectively. Glaesserella australis was the most closely related species to [Haemophilus] haemoglobinophilus and taxon 35 with 96.1 % 16S rRNA gene sequence similarity which is slightly higher than the 95 % separating most genera of the family Pasteurellaceae. However, the conserved protein sequence phylogeny documented a unique position of [Haemophilus] haemoglobinophilus with only 81 % identity to the most closely related species, genomospecies 1 of the genus Rodentibacter which is lower than the 85 % separating most genera of the family Pasteurellaceae. The conserved protein sequence identity to Haemophilus influenzae, the type species of the genus, was 77%, demonstrating that [Haemophilus] haemoglobinophilus is not properly classified as a member of the genus Haemophilus. On the basis of the phylogenetic comparisons, the taxa [Haemophilus] haemoglobinophilus and taxon 35 are proposed to be included with a novel genus Canicola with one species, Canicola haemoglobinophilus which is reclassified from [Haemophilus] haemoglobinophilus. Phenotypic characters obtained with isolates genetically approved to represent Canicola haemoglobinophilus were in accordance with those of the members of the family Pasteurellaceae, and the novel genus can be separated from most of the existing genera by a positive catalase reaction, lack of V-factor requirement for growth, lack of haemolysis of blood agar and negative Voges-Proskauer and urease tests. The novel genus cannot be separated by biochemical and physiological characteristics alone from the genera Aggregatibacter, Avibacterium, Frederiksenia and Spirabiliibacterium. However, MALDI-TOF mass spectroscopy and also RpoB amino acid signatures allowed a clear separation from these taxa, supporting the existence of a novel genus. The DNA G+C content is 37.0-37.8 mol% for the genus, based on the whole genomic sequences. The type strain of Canicola haemoglobinophilus is CCUG 3714T (=ATCC 19416T=NCTC 1659T) isolated in 1901 from the prepuce of a dog in Germany.

Perspectives for improvement of Mycoplasma hyopneumoniae vaccines in pigs.

Mycoplasma hyopneumoniae (M. hyopneumoniae) is one of the primary agents involved in the porcine respiratory disease complex, economically one of the most important diseases in pigs worldwide. The pathogen adheres to the ciliated epithelium of the trachea, bronchi, and bronchioles, causes damage to the mucosal clearance system, modulates the immune system and renders the animal more susceptible to other respiratory infections. The pathogenesis is very complex and not yet fully understood. Cell-mediated and likely also mucosal humoral responses are considered important for protection, although infected animals are not able to rapidly clear the pathogen from the respiratory tract. Vaccination is frequently practiced worldwide to control M. hyopneumoniae infections and the associated performance losses, animal welfare issues, and treatment costs. Commercial vaccines are mostly bacterins that are administered intramuscularly. However, the commercial vaccines provide only partial protection, they do not prevent infection and have a limited effect on transmission. Therefore, there is a need for novel vaccines that confer a better protection. The present paper gives a short overview of the pathogenesis and immune responses following M. hyopneumoniae infection, outlines the major limitations of the commercial vaccines and reviews the different experimental M. hyopneumoniae vaccines that have been developed and tested in mice and pigs. Most experimental subunit, DNA and vector vaccines are based on the P97 adhesin or other factors that are important for pathogen survival and pathogenesis. Other studies focused on bacterins combined with novel adjuvants. Very few efforts have been directed towards the development of attenuated vaccines, although such vaccines may have great potential. As cell-mediated and likely also humoral mucosal responses are important for protection, new vaccines should aim to target these arms of the immune response. The selection of proper antigens, administration route and type of adjuvant and carrier molecule is essential for success. Also practical aspects, such as cost of the vaccine, ease of production, transport and administration, and possible combination with vaccines against other porcine pathogens, are important. Possible avenues for further research to develop better vaccines and to achieve a more sustainable control of M. hyopneumoniae infections are discussed.

Ovine footrot: A review of current knowledge.

Footrot is a contagious foot disease mainly affecting sheep. It is caused by the Gram-negative anaerobic bacterium Dichelobacter nodosus. Warm, wet environmental conditions favour development of footrot, and under perfect conditions, it takes just 2-3 weeks from infection to manifestation of clinical signs. Affected sheep show lameness of various degrees and often graze while resting on their carpi. Local clinical signs vary in severity and extent from interdigital inflammation (benign footrot) to underrunning of the complete horn shoe in advanced stages of virulent footrot. Laboratory diagnosis ideally involves collection of four-foot interdigital swab samples followed by competitive real time PCR, allowing for detection of the presence of D. nodosus and differentiation between benign and virulent strains. Laboratory-based diagnostics at the flock level based on risk-based sampling and pooling of interdigital swab samples are recommended. The list of treatment options of individual sheep includes careful removal of the loose undermined horn, local or systemic administration of antimicrobials, systemic administration of non-steroidal anti-inflammatories (NSAIDs) and disinfectant footbathing. Strategies for control at the flock level are manifold and depend on the environmental conditions and the procedures traditionally implemented by the respective country. Generally, measures consist of treatment/culling of infected sheep, vaccination and prevention of reinfection of disease-free flocks. Gaining deeper insight into the beneficial effects of NSAIDs, screening for eco-friendly footbath solutions, developing better vaccines, including the development of a robust, reproducible infection model and elucidation of protective immune responses, as well as the elaboration of effective awareness training programs for sheep farmers, are relevant research gaps.

Prevalence of Dichelobacter nodosus and Ovine Footrot in German Sheep Flocks.

The bacterium Dichelobacter nodosus (D. nodosus) is the causative agent of ovine footrot. The aim of this field study was to determine the prevalence of D. nodosus in German sheep flocks. The sheep owners participated voluntarily in the study. More than 9000 sheep from 207 flocks were screened for footrot scores using a Footrot Scoring System from 0 to 5 and sampling each sheep using one interdigital swab for all four feet of the sheep. The detection and discrimination between benign and virulent strains was done employing a real-time PCR. Our results showed a mean prevalence of 42.93% of D. nodosus in German sheep on an animal level. Underrunning of hoof horn on at least one foot (Scores 3-5) was detected in 567 sheep (6.13%). Sheep with four clinically healthy feet were found through visual inspection in 47.85% of all animals included in this study. In total, 1117 swabs from sheep with four clinically healthy feet tested positive for D. nodosus. In 90.35% of the positive swabs, virulent D. nodosus were detected. Benign D. nodosus were detected in 4.74% of the D. nodosus-positive swabs while 4.91% tested positive for both, benign and virulent D. nodosus. In 59 flocks D. nodosus were not detected and in 115 flocks only virulent D. nodosus were found while seven flocks tested positive for benign strains.

A filter-assisted culture method for isolation of Treponema spp. from bovine digital dermatitis and their identification by MALDI-TOF MS.

Digital dermatitis (DD) is a major infectious foot disease of cattle worldwide. Some DD stages are associated with lameness, and the disease has significant economic and animal welfare consequences. The pathogenesis of the disease is not yet fully understood, but Treponema spp. have been associated consistently with clinical cases. Isolation of these fastidious bacteria is difficult and cumbersome. We describe an improved method enabling the culturing of the 3 Treponema spp. (T. pedis, T. phagedenis, and T. medium) from bovine foot specimens derived from DD lesions, using a combination of membrane filtering and subsequent growth on selective agar media. The entire procedure from sampling to verification of individual Treponema spp. takes up to 24 d. In addition, we established a MALDI-TOF MS-based identification method to be applied for confirmation of the different Treponema spp. This scheme provides an unambiguous, simple, and straightforward identification procedure for DD-associated Treponema spp.

Mannheimia pernigra sp. nov., isolated from bovine respiratory tract.

Over a period of 1 year, 270 isolates identified as Taxon 39 of Bisgaard were obtained from the nasopharynx of veal calves at 11 epidemiologically independent Swiss fattening farms. Two isolates from each farm and the Australian Taxon 39 reference strain BNO311 were further characterized by genetic and phenotypic methods. Phylogenetic analysis of 16S rRNA and recN gene sequences placed the isolates in a single, distinct cluster within the genus Mannheimia. As to the rpoB gene, most isolates clustered together, but four strains formed a separate cluster close to Mannheimia varigena. Genome sequence analysis of isolates from both rpoB clusters confirmed their species status, with an average nucleotide identity (ANI) >98.9 % between isolates and <84 % to the closest species, M. varigena. Based upon whole genome sequences, the G+C content was determined as 39.1 mol%. Similarly, analysis of MALDI-TOF MS reference spectra clustered the isolates clearly separated from the other Mannheimia species, making this the method of choice for identification. In addition, numerous biochemical markers based on classical as well as commercial identification schemes were determined, allowing separation from other Mannheimia species and identification of the new taxon. Major fatty acids for strain 17CN0883T are C14 : 0, C16 : 0, C16 : 1 ω7c and C18 : 1 ω7c. Major respiratory quinones are ubiquinone-7 and ubiquinone-8. We propose the name Mannheimia pernigra sp. nov. for former Taxon 39 of Bisgaard. The type strain is 17CN0883T (=CCUG 74657T=DSM 111153T) isolated from a veal calf in Switzerland.