Arcanobacterium buesumense sp. nov., isolated from an anal swab of a male harbour seal (Phoca vitulina).

A polyphasic taxonomic study was performed on an unidentified previously described Arcanobacterium-like Gram-positive strain 2701T isolated from an anal swab of a dead male harbour seal. Comparative 16S rRNA sequencing showed that the bacterium belonged to the genus Arcanobacterium in the family Arcanobacteriaceae. The genome sequence of the strain was obtained by Borowiak et al. [1]. The genome had a G+C content of 49 mol% and a total length of 1.94 Mb. The presence of the major menaquinone MK-9(H4) supported the affiliation of the isolate with the genus Arcanobacterium. The polar lipid profile consisted of diphosphatidylglycerol and an unidentified phospholipid as major components and two unidentified lipids, a further unidentified phospholipid, two unidentified phosphoglycolipids as well as phosphatidylglycerol. The major fatty acids were C16 : 0, C18 : 1 and C18 : 0. Biochemical and phylogenetic analyses clearly distinguished the isolate from other members of the genus Arcanobacterium and closely related other species. Based on these results, it is proposed that the unknown Arcanobacterium sp. strain 2701T should be classified as representing a novel species with the name Arcanobacterium buesumense sp. nov. The type strain is 2701T (=DSM 112952T=LMG 32446T).

Development of a loop-mediated isothermal amplification (LAMP) assay for molecular identification of Trueperella abortisuis isolated from pigs.

The first description of Trueperella (T.) abortisuis was presented in Japan in 2009 by Azuma and colleagues. In the current study, eight T. abortisuis strains were identified by a newly developed loop-mediated isothermal amplification (LAMP) assay based on the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) encoding gene gap. Two T. abortisuis strains were obtained from prepuce of a seven-month-old boar and pooled foetal stomach contents in the United Kingdom, while the other six T. abortisuis strains were recovered from aborted foetal material of six pigs from a single farm in Germany. The developed LAMP assay showed an analytical sensitivity of 22 pg µL-1T. abortisuis DNA. T. abortisuis DSM 19515T and field strain T. abortisuis P504054/19/1 were directly detectable in artificially contaminated vaginal swabs up to concentrations of 980 CFU and 770 CFU per swab, respectively. There was no cross reactivity with control strains representing six species of genus Trueperella and six species of the closely related genus Arcanobacterium and Schaalia (Actinomyces) hyovaginalis. Further field research is required to determine the usefulness of the designed LAMP assay for identifying T. abortisuis isolated from pigs of various origins and from test samples directly obtained at farm level.

Arcanobacterium bovis sp. nov., isolated from the milk of a cow with mastitis.

A polyphasic taxonomic study was performed on an unidentified Arcanobacterium-like Gram-stain-positive bacterium designated strain C605018/01/1T isolated from a milk sample collected from the udder of a cow at post mortem. Comparative 16S rRNA gene sequencing showed that the bacterium belonged to the genus Arcanobacterium and was most closely related to the type strain of Arcanobacterium pluranimalium (99.76 %); sequence similarities to all other Arcanobacterium species were below 97 %. The wet-lab DNA-DNA hybridization values among strain C605018/01/1T and A. pluranimalium DSM 13483ᵀ were low, 16.9 % (reciprocal, 49.8 %). Pertaining to the whole genome sequence with a total length of 2.02 Mb and 1654 protein counts, the novel strain C605018/01/01T displayed a G+C content of 51.6 % mol%. The presence of the major menaquinone MK-9(H4) supported the affiliation of this strain to the genus Arcanobacterium. The polar lipid profile consisted of the major components diphosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, phosphatidylinositol-mannoside and unidentified glycolipid and aminophospholipids. Based on these results it is proposed that strain C605018/01/1T should be classified as representing a novel species, Arcanbacterium bovis sp. nov. The type strain C605018/01/1T (CCUG 45425T=DSM 107286T=BCCM/LMG 30783T).

Studies on Trueperella pyogenes isolated from an okapi (Okapia johnstoni) and a royal python (Python regius).

BACKGROUND: The present study was designed to characterize phenotypically and genotypically two Trueperella pyogenes strains isolated from an okapi (Okapia johnstoni) and a royal python (Python regius). CASE PRESENTATION: The species identity could be confirmed by phenotypic properties, by MALDI-TOF MS analysis and by detection of T. pyogenes chaperonin-encoding gene cpn60 with a previously developed loop-mediated isothermal amplification (LAMP) assay. Furthermore, sequencing of the 16S ribosomal RNA (rRNA) gene, the 16S-23S rDNA intergenic spacer region (ISR), the target genes rpoB encoding the ß-subunit of bacterial RNA polymerase, tuf encoding elongation factor tu and plo encoding the putative virulence factor pyolysin allowed the identification of both T. pyogenes isolates at species level. CONCLUSIONS: Both strains could be clearly identified as T. pyogenes. The T. pyogenes strain isolated in high number from the vaginal discharge of an okapi seems to be of importance for the infectious process; the T. pyogenes strain from the royal python could be isolated from an apparently non-infectious process. However, both strains represent the first isolation of T. pyogenes from these animal species.

Arcanobacterium wilhelmae sp. nov., isolated from the genital tract of a rhinoceros (Rhinoceros unicornis).

A taxonomic study using a polyphasic approach was performed on an unidentified Arcanobacterium-like Gram-stain-positive bacterium isolated from the genital tract of a rhinoceros. Comparative 16S rRNA gene sequencing showed that the bacterium belonged to the genus Arcanobacterium and was most closely related to the type strains of Arcanobacterium canis (98.8 % 16S rRNA gene sequence similarity), Arcanobacterium phocisimile (97.8 %), Arcanobacterium phocae (97.7 %), Arcanobacterium haemolyticum (97.4 %), Arcanobacterium hippocoleae (96.6 %), Arcanobacterium pinnipediorum (96.4 %) and Arcarnobacterium pluranimalium (95.4 %). DNA-DNA hybridization values between strain 647T and Arcanobacterium canisDSM 25104T were very low, 13.4 % (reciprocal 15.9 %). The genomic DNA G+C content of strain 647T was 58.7 mol%. The presence of the major menaquinone MK-9(H4) supported the affiliation of this strain to the genus Arcanobacterium. The polar lipid profile consisted of the major components diphosphatidylglycerol, phosphatidylcholine and an unidentified phosphoglycolipid. The results of physiological and biochemical testing clearly distinguished the unknown bacterium from other species of the genus Arcanobacterium. Based on these tests, it is proposed that the unknown bacterium should be classified as a representative of a novel species of the genus Arcanobacterium named Arcanobacterium wilhelmaesp. nov. The type strain is 647T (=DSM 102162T=LMG 29418T).

Fatal infection in three Grey Slender Lorises (Loris lydekkerianus nordicus) caused by clonally related Trueperella pyogenes.

BACKGROUND: Trueperella pyogenes is a worldwide known bacterium causing mastitis, abortion and various other pyogenic infections in domestic animals like ruminants and pigs. In this study we represent the first case report of three unusual fatal infections of Grey Slender Lorises caused by Trueperella pyogenes. Meanwhile, this study represents the first in-depth description of the multilocus sequence analysis (MLSA) on T. pyogenes species. CASE PRESENTATION: Three Trueperella pyogenes were isolated from three different Grey Slender Lorises, which died within a period of two years at Frankfurt Zoo (Frankfurt am Main - Germany). The three Grey Slender Loris cases were suffering from severe sepsis and died from its complication. During the bacteriological investigation of the three cases, the T. pyogenes were isolated from different organisms in each case. The epidemiological relationship between the three isolates could be shown by four genomic DNA fingerprint methods (ERIC-PCR, BOX-PCR, (GTG)5-PCR, and RAPD-PCR) and by multilocus sequence analysis (MLSA) investigating four different housekeeping genes (fusA-tuf-metG-gyrA). CONCLUSION: In this study, we clearly showed by means of using three different rep-PCRs, by RAPD-PCR and by MLSA that the genomic fingerprinting of the investigated three T. pyogenes have the same clonal origin and are genetically identical. These results suggest that the same isolate contaminated the animal's facility and subsequently caused cross infection between the three different Grey Slender Lorises. To the best of our knowledge, this is the first epidemiological approach concentrating on T. pyogenes using MLSA.

Arcanobacterium pinnipediorum sp. nov., isolated from a harbour seal.

A polyphasic taxonomic study was performed on an unidentified Arcanobacterium-like, Gram-stain-positive bacterium, strain 2710T, isolated from a harbour seal. Comparative 16S rRNA gene sequence analysis showed that this bacterial strain belonged to the genus Arcanobacterium and was related most closely to the type strains of Arcanobacterium phocae (98.4 % similarity) and Arcanobacterium phocisimile (97.5 %). 16S rRNA gene sequence similarities to the type strains of other Arcanobacterium species were between 95.3 and 96.9 %. DNA-DNA hybridization values between strain 2710T and A. phocae DSM 10002T and A. phocisimile LMG 27073T were 4.7 % (reciprocal 56 %) and 23 % (reciprocal 7.7 %), respectively. The presence of the major menaquinone MK-9(H4) and a polar lipid profile with the major compounds diphosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside supported the affiliation of strain 2710T to the genus Arcanobacterium. The major fatty acids were C16:0, C18:1ω9c, C18:0 and C18:2ω6,9c/anteiso-C18:0. The peptidoglycan structure was of cross-linkage type A5α (l-Lys-l-Lys-d-Glu). Physiological and biochemical tests clearly distinguished the isolate from other members of the genus Arcanobacterium. Based on these tests, it is proposed that this unknown bacterium should be classified as a novel species of the genus Arcanobacterium, with the name Arcanobacterium pinnipediorum sp. nov. The type strain is 2710T ( = DSM 28752T = LMG 28298T).

Arcanobacterium canis strain DSM 25104 isolated from an English bulldog suffering from otitis externa: complete genome sequence.

Many species of the genus Arcanobacterium are known as opportunistic pathogens and have been isolated in association with infectious diseases in humans and animals. Here, we present the complete genome sequence of another opportunistic pathogenic representative, namely Arcanobacterium canis, isolated from the otitis externa of an English bulldog.

Arcanobacterium phocisimile sp. nov., isolated from harbour seals.

A polyphasic taxonomic study was performed on two previously unidentified Arcanobacterium-like Gram-positive strains isolated from harbour seals. Comparative 16S rRNA gene sequencing showed that both bacteria belonged to the genus Arcanobacterium and were most closely related to Arcanobacterium haemolyticum CIP 103370(T) (98.4% 16S rRNA gene sequence similarity), A. canis P6775(T) (97.4%), A. phocae DSM 10002(T) (97.4%), A. pluranimalium M430/94/2(T) (95.7%) and A. hippocoleae CCUG 44697(T) (95.5%). The presence of the major menaquinone MK-9(H4) supported the affiliation of the isolates with the genus Arcanobacterium. The polar lipid profile consisted of major amounts of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, an unidentified phospholipid and two unidentified glycolipids. The major fatty acids were C16:0, C18:0, C18:1ω9c and summed feature 5 (comprising C18:2ω6,9c and/or anteiso-C18:0). Physiological and biochemical tests clearly distinguished the isolates from other members of the genus Arcanobacterium. Based on the common origin and various physiological properties comparable to those of A. phocae, it is proposed that the isolates are classified as members of a novel species with the name Arcanobacterium phocisimile sp. nov. The type strain is 2698(T) (=LMG 27073(T) =CCM 8430(T)).

Identification of the novel potential pathogen Trueperella pecoris with interspecies significance by LAMP diagnostics.

Trueperella pecoris was described as a new species of the genus Trueperella in 2021 and might be pathogenic to various animal species. However, the lack of a suitable diagnostic test system stands in the way of epidemiological surveys to clarify possible causalities. In this study, a Loop-mediated Isothermal Amplification (LAMP) assay was developed and validated that was highly specific for T. pecoris. The assay provided an analytical sensitivity of 0.5 pg/25 µL and showed 100% inclusivity and exclusivity for 11 target and 33 non-target strains, respectively. Three different DNA extraction methods were evaluated to select the most LAMP-compatible method for cell disruption in pure and complex samples. Using an on-site applicable single-buffer DNA extraction with additional heating, the cell-based detection limit was 2.3 CFU/reaction. Finally, the LAMP assay was validated by means of artificially contaminated porcine lung tissue samples in which minimal microbial loads between 6.54 and 8.37 × 103 CFU per swab sample were detectable. The LAMP assay established in this study represents a suitable diagnostic procedure for identifying T. pecoris in clinical specimens and will help to collect epidemiological data on the pathogenicity of this species.

Arcanobacterium pinnipediorum Strain DSM 28752 Isolated from a Harbour Seal: Complete Genome Sequence.

The genus Arcanobacterium is constantly growing as novel species are identified. In particular, harbor seals have proven to be a common reservoir for bacteria of this genus. Here, we announce the complete genome sequence of another Arcanobacterium species-namely, Arcanobacterium pinnipediorum strain DSM 28752, isolated from a harbor seal.

Arcanobacterium canis sp. nov., isolated from otitis externa of a dog, and emended description of the genus Arcanobacterium Collins et al. 1983 emend. Yassin et al. 2011.

A polyphasic taxonomic study was performed on an unidentified Arcanobacterium-like Gram-stain-positive bacterium isolated from otitis externa of a dog. Comparative 16S rRNA gene sequencing showed that the bacterium belonged to the genus Arcanobacterium and was most closely related to the type strains of Arcanobacterium haemolyticum (97.2 %), Arcanobacterium hippocoleae (96.5 %) and Arcanobacterium phocae (96.4 %). The presence of the major menaquinone MK-9(H(4)) supported the affiliation of this strain to the genus Arcanobacterium. The polar lipid profile contained the major lipids phosphatidylcholine, diphosphatidylglycerol, phosphatidylinositol mannoside and an unidentified phospholipid (PL2). Major fatty acids were C(14 : 0), C(16 : 0), C(18 : 0), C(18 : 1)ω9c and C(18 : 2)ω6,9c/anteiso-C(18 : 0) (detected as a summed feature). C(10 : 0) and C(12 : 0) were present in minor amounts. The results of physiological and biochemical testing clearly distinguished the unknown bacterium from other species of the genus Arcanobacterium. Based on these tests, it is proposed that the unknown bacterium should be classified in the novel species Arcanobacterium canis sp. nov. The type strain of Arcanobacterium canis is P6775(T) (= CCM 7958(T) = CCUG 61573(T) = CIP 110339(T)). An emended description of the genus Arcanobacterium is also provided.

Actinomyces weissii sp. nov., isolated from dogs.

Two Gram-positive, rod-shaped, non-spore-forming bacteria were isolated from the oral cavities of two dogs. On the basis of 16S rRNA gene sequence similarities both strains were shown to belong to the genus Actinomyces and were most closely related to Actinomyces bovis (97.3% and 97.5%, respectively). The polyamine profile of the two isolates and Actinomyces bovis DSM 43014(T) was composed of spermidine and spermine as the major components. Menaquinone MK-9 was the major compound in the quinone system of the two strains and Actinomyces bovis. The polar lipid profiles of strains 2298(T) and 4321 were almost identical, containing diphosphatidylglycerol as the major compound, and moderate to trace amounts of phosphatidylcholine, phosphatidylinositol, phosphatidylinositol-mannoside, phosphatidylglycerol and several unidentified lipids. A highly similar polar lipid profile was detected in Actinomyces bovis DSM 43014(T) supporting the affiliation of strains 2298(T) and 4321 to the genus Actinomyces. The typical major fatty acids were C(16:0), C(18:0) and C(18:1)ω9c. Fatty acids C(14:0) and C(18:2)ω6,9c were found in minor amounts. The results of physiological and biochemical analyses revealed clear differences between both strains and the most closely related species of the genus Actinomyces. Thus, strains 2298(T) and 4321 represent a novel species, for which the name Actinomyces weissii sp. nov., is proposed, with strain 2298(T) ( = CIP 110333(T) = LMG 26472(T) = CCM 7951(T) = CCUG 61299(T)) as the type strain.

Identification of Trueperella bernardiae isolated from peking ducks (Anas platyrhynchos domesticus) by phenotypical and genotypical investigations and by a newly developed loop-mediated isothermal amplification (LAMP) assay.

Trueperella (T.) bernardiae is a well-known bacterial pathogen in infections of humans, rarely in animals. In the present study, five T. bernardiae isolates, isolated from five Peking ducks of four different farms, were identified by phenotypic properties, by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, and genotypically by sequencing the 16S ribosomal RNA (rRNA) gene, the superoxide dismutase A encoding gene sodA, and the glyceraldehyde-3-phosphate dehydrogenase encoding gene gap. In addition, the T. bernardiae isolates could be identified with a newly developed loop-mediated isothermal amplification (LAMP) assay based on the gyrase encoding housekeeping gene gyrA. All these tests clearly identified the T. bernardiae isolates to the species level. However, the detection of the specific gene gyrA with the newly designed LAMP assay appeared with a high sensitivity and specificity, and could help to identify this bacterial species in human and animal infections in future. The importance of the T. bernardiae isolates for the clinical condition of the ducks and for the problems at farm level remains unclear.

First isolation of Arcanobacterium pinnipediorum from a grey seal pup (Halichoerus grypus) in the UK.

In the present study, a single Arcanobacterium (A.) pinnipediorum strain isolated from discharge of a jaw swelling of a grey seal pup (Halichoerus grypus) in England, UK, was identified. This strain was further characterized by phenotypical investigations, by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), by Fourier transform infrared spectroscopy (FT-IR), and genotypically by sequencing the 16S rRNA gene and the genes gap encoding glyceraldehyde 3-phosphate dehydrogenase, tuf encoding elongation factor tu, and rpoB encoding the ß subunit of bacterial RNA polymerase. The present study gives a first detailed characterization of the species A. pinnipediorum from a grey seal in the UK. However, the route of infection of the grey seal with the bacterial pathogen remains unclear.

Complete Genome Sequence of Arcanobacterium phocisimile Strain DSM 26142, Isolated from a Harbor Seal.

Bacteria of the genus Arcanobacterium can be found in a variety of hosts. The species Arcanobacterium phocisimile was originally identified in a free-living harbor seal in the German North Sea in 2004. Here, we announce the complete genome sequence of Arcanobacterium phocisimile strain DSM 26142.

Complete Genome Sequence of Arcanobacterium sp. Strain 2701, Isolated from a Harbor Seal.

Arcanobacterium spp. are Gram-positive bacteria which can be found in a wide range of hosts and can be associated with disease in humans and animals. Here, we announce the complete genome sequence of Arcanobacterium sp. strain 2701, isolated from a harbor seal from the North Sea.

Epidemiological analysis of Arcanobacterium phocae isolated from cases of mink dermatitis of a single farm.

The present study was designed to identify nine Arcanobacterium phocae strains isolated from cases of mink dermatitis of a single farm in Finland and characterize the strains for epidemiological relationships. All nine strains and previously described A. phocae used for comparative purposes were identified and further characterized phenotypically, by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), by Fourier Transform Infrared Spectroscopy (FT-IR) and genotypically by detection of phocaelysin encoding gene phl with a previously developed loop-mediated isothermal amplification (LAMP) assay and by sequencing 16S rRNA gene and gene phl, the elongation factor tu encoding gene tuf and the ß subunit of bacterial RNA polymerase encoding gene rpoB. Genetic relatedness among isolates was determined using whole-genome single nucleotide polymorphism (wgSNP) analysis. The wgSNP results, partly the MALDI-TOF MS and FT-IR analyses and sequencing of the genes, revealed that the nine A. phocae strains recovered from a single farm showed close sequence similarities among each other and differed from previously investigated A. phocae strains isolated from other farms and animals in Finland and from the A. phocae type strain. This indicated a close epidemiological relationship of the A. phocae strains isolated from a single farm and that the nine A. phocae strains of the present study might have developed from a common ancestor.

Epidemiological analysis of Trueperella abortisuis isolated from cases of pig abortion of a single farm.

The present study was designed to characterize six Trueperella (T.) abortisuis strains, cultured over a period of 5 months from fetus and abortion material of six pigs of a single farm in Mecklenburg-West Pomerania federal state, Germany. It was of interest to investigate the epidemiological relationships of the six strains among each other and whether a single bacterial clone was responsible for the abortion situation of the single farm. All six strains were identified phenotypically, by MALDI-TOF MS analysis and by phylogenetic analysis based on 16S rRNA gene and gap (encoding the glyceraldehyde 3-phosphate dehydrogenase) and tuf (encoding elongation factor tu) gene sequencing. Further genotypic comparison was performed using different genomic DNA fingerprint methods including BOX-PCR, (GTG)5-PCR, and three RAPD-PCRs. The sequence analysis of the genes gap and tuf and the genomic DNA fingerprinting results revealed, as noval findings, that the six T. abortisuis strains cultured from a single farm represent six different bacterial clones showing a genetic variability of this bacterial species in the pig population. All six T. abortisuis strains were isolated in mixed culture with several other bacterial species. However, the T. abortisuis strain, generally found in high numbers, seemed to be responsible for the abortion situation in the farm.

Phenotypic and genotypic characterization of Arcanobacterium haemolyticum isolates from infections of horses.

The present study was designed to characterize phenotypically and genotypically seven Arcanobacterium haemolyticum strains obtained from infections of six horses. All seven strains showed the cultural and biochemical properties typical of A. haemolyticum and were susceptible to most of the antibiotics tested. The species identification could be confirmed by amplification and sequencing of the 16S rRNA gene and the 16S-23S rRNA intergenic spacer region and by PCR amplification of species-specific parts of the gene encoding phospholipase D in A. haemolyticum. Use of the latter could possibly improve future identification of this generally human pathogenic bacterial species which, according to the present results, seems to occur also in infections of horses.