Rhodococcus indonesiensis sp. nov. a new member of the Rhodococcus ruber lineage isolated from sediment of a neutral hot spring and reclassification of Rhodococcus electrodiphilus (Ramaprasad et al. 2018) as a later heterotypic synonym of Rhodococcus ruber (Kruse 1896) Goodfellow and Alderson 1977 (Approved Lists 1980).

A polyphasic study was designed to determine the taxonomic status of isolate CSLK01-03T, which was recovered from an Indonesian neutral hot spring and provisionally assigned to the genus Rhodococcus. The isolate was found to have chemotaxonomic, cultural and morphological properties typical of rhodococci. It has a rod-coccus lifecycle and grows from 10 to 39 °C, from pH 6.5 to 8.0 and in the presence of 0-10 % (w/v) sodium chloride. Whole-organism hydrolysates contain meso-diaminopimelic acid, arabinose and galactose, the predominant menaquinone is MK-8 (H2), the polar lipid pattern consists of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol mannosides, phosphatidylmethylethanolamine and two unidentified components, it produces mycolic acids, and C16:0 is the major fatty acid. Whole-genome analyses show that the isolate and Rhodococcus electrodiphilus LMG 29881T (GenBank accession: JAULCK000000000) have genome sizes of 5.5 and 5.1 Mbp, respectively. These strains and Rhodococcus aetherivorans DSM 44752T and Rhodococcus ruber DSM 43338T form well-supported lineages in 16S rRNA and whole-genome trees that are close to sister lineages composed of the type strains of Rhodococcus rhodochrous and related Rhodococcus species. The isolate can be distinguished from its closest evolutionary neighbours using combinations of cultural and phenotypic features, and by low DNA-DNA hybridization values. Based on these data it is proposed that isolate CSLK01-03T (=CCMM B1310T=ICEBB-06T=NCIMB 15214T) be classified in the genus Rhodococcus as Rhodococcus indonesiensis sp. nov. The genomes of the isolate and its closest phylogenomic relatives are rich in biosynthetic gene clusters with the potential to synthesize new natural products, notably antibiotics. In addition, whole-genome-based taxonomy revealed that Rhodococcus electrodiphilus LMG 29881T and Rhodococcus ruber DSM 43338T belong to a single species. It is, therefore, proposed that R. electrodiphilus be recognized as a heterotypic synonym of R. ruber.

Is the bacterial genus name Rhodococcus Zopf 1891 illegitimate? Request for an Opinion.

In 2014, it was reported that the bacterial genus name Rhodococcus Zopf 1891 was illegitimate due to the priority of the cyanobacterial genus name Rhodococcus Hansgirg 1884. Since that time, the consequences of this conclusion have been largely ignored, whilst changes have been made to relevant Rules of the International Code of Nomenclature of Prokaryotes, including significant changes to the way in which the Code treats the names of members of Cyanobacteriota. Given the complexity of the nomenclatural issues, we request the opinion of the Judicial Commission of the International Committee on Systematics of Prokaryotes as to whether the genus name Rhodococcus Zopf 1891 (Approved Lists 1980) is illegitimate.

Novel method to plan and design services. Using software to optimise the head and neck cancer patient's commute to hospital.

Travelling for hospital appointments represents a significant burden to patients. We have developed a computer programme that accurately evaluates patient commutes between their home and treatment hospital in public and private transport. This has been applied to a cohort of Head and Neck Cancer (HNC) patients to plan the locations of satellite hospitals and assess their impact on patients' commutes. Patients diagnosed with HNC were identified from our hospital's database between December 2019 and January 2022. Using Python, commuting distances from patients' postcodes to our tertiary referral hospital were calculated. These commutes incorporated routes along defined roads, traffic data, and were calculated using public and private transport. Patient commutes from their postcodes to four satellite hospitals were also calculated. We identified their closest hospital and compared that journey to the patients' journey to our tertiary centre. We included 709 patients in our analysis. Patients would have a significantly shorter journey distance and time in both public and private transport if satellite hospitals were used for appointments alongside our tertiary centre. Average travel times would reduce by 10 minutes in private and 25 minutes in public transport. Furthermore, 70% of patients required ≥2 forms of public transport to get to our hospital. This would drop to 44.1% of patients if satellite hospitals were included in our service. Our programme would allow the most accessible sites to be identified for establishing outreach clinics at appropriate satellite hospitals, therefore improving patient access to healthcare.

Micromonospora parastrephiae sp. nov. and Micromonospora tarensis sp. nov., isolated from the rhizosphere of a Parastrephia quadrangularis plant growing in the Salar de Tara region of the Central Andes in Chile.

Two novel Micromonospora strains, STR1-7T and STR1S-6T, were isolated from the rhizosphere of a Parastrephia quadrangularis plant growing in the Salar de Tara region of the Atacama Desert, Chile. Chemotaxonomic, cultural and phenotypic features confirmed that the isolates belonged to the genus Micromonospora. They grew from 20 to 37 °C, from pH7 to 8 and in the presence of up to 3 %, w/v NaCl. The isolates formed distinct branches in Micromonospora gene trees based on 16S rRNA gene sequences and on a multi-locus sequence analysis of conserved house-keeping genes. A phylogenomic tree generated from the draft genomes of the isolates and their closest phylogenetic neighbours showed that isolate STR1-7T is most closely related to Micromonospora orduensis S2509T, and isolate STR1S-6 T forms a distinct branch that is most closely related to 12 validly named Micromonospora species, including Micromonospora saelicesensis the earliest proposed member of the group. The isolates were separated from one another and from their closest phylogenomic neighbours using a combination of chemotaxonomic, genomic and phenotypic features, and by low average nucleotide index and digital DNA-DNA hybridization values. Consequently, it is proposed that isolates STR1-7T and STR1S-6T be recognized as representing new species in the genus Micromonospora, namely as Micromonospora parastrephiae sp. nov. and Micromonospora tarensis sp. nov.; the type strains are STR1-7T (=CECT 9665T=LMG 30768T) and STR1S-6T (=CECT 9666T=LMG 30770T), respectively. Genome mining showed that the isolates have the capacity to produce novel specialized metabolites, notably antibiotics and compounds that promote plant growth, as well as a broad-range of stress-related genes that provide an insight into how they cope with harsh abiotic conditions that prevail in high-altitude Atacama Desert soils.

Streptantibioticus silvisoli sp. nov., acidotolerant actinomycetes from pine litter, reclassification of Streptomyces cocklensis, Streptomyces ferralitis, Streptomyces parmotrematis and Streptomyces rubrisoli as Actinacidiphila cocklensis comb. nov., Streptantibioticus ferralitis comb. nov., Streptantibioticus parmotrematis comb. nov. and Streptantibioticus rubrisoli comb. nov., and emended descriptions of the genus Streptantibioticus, the family Streptomycetaceae and Streptomyces iconiensis.

Filamentous actinomycetes, designated SL13 and SL54T, were isolated from pine litter and their taxonomic status resolved using a polyphasic approach. The isolates exhibit chemotaxonomic and morphological properties consistent with their classification in the family Streptomycetaceae. They form extensively branched substrate mycelia bearing aerial hyphae that differentiate into straight chains of cylindrical spores. The whole-organism hydrolysates contain ll-diaminopimelic acid, glucose, mannose and ribose, the predominant isoprenologue is MK-9(H8), the polar lipids are diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylglycerol and glycophospholipids, and the major fatty acids are anteiso-C15 : 0, iso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0. Phylogenetic trees based on 16S rRNA gene sequences and multilocus gene sequences of conserved housekeeping genes show that the isolates form a well-supported lineage that is most closely related to Streptomyces parmotrematis NBRC 115203T. All of these strains form a well-defined clade in the multilocus sequence analysis tree together with Streptantibioticus cattleyicolor DSM 46488T, Streptomyces ferralitis DSM 41836T and Streptomyces rubrisoli DSM 42083T. Draft genomes assemblies of the isolates are rich in biosynthetic gene clusters predicted to produce novel specialized metabolites and stress-related genes which provide an insight into how they have adapted to the harsh conditions that prevail in pine litter. Phylogenomically, both isolates belong to the same lineage as the type strains of S. cattleyicolor, S. ferralitis, S. parmotrematis and S. rubrisoli; these relationships are underpinned by high average amino acid identity, average nucleotide identity and genomic DNA-DNA hybridization values. These metrics confirm that isolates SL13 and SL54T belong to a novel species that is most closely related to S. parmotrematis NBRC 115203T and that these strains together with S. ferralitis DSM 41836T, S. rubrisoli DSM 42083T belong to the genus Streptantibioticus. Consequently, it is proposed that the isolates be recognized as a new Streptantibioticus species, Streptantibioticus silvisoli comb. nov., with isolate SL54T (=DSM 111111T=PCM3044T) as the type strain, and that S. ferralitis, S. parmotrematis and S. rubrisoli be transferred to the genus Streptantibioticus as Streptantibioticus ferralitis comb. nov., Streptantibioticus parmotrematis comb. nov. and Streptantibioticus rubrisoli comb. nov. Emended descriptions are given for the genus Streptantibioticus, the family Streptomycetaceae and for Streptomyces iconiensis which was found to be a close relative of the isolates in the 16S rRNA gene sequence analyses. It is also proposed that Streptomyces cocklensis be transferred to the genus Actinacidiphila as Actinacidiphila cocklensis comb. nov based on its position in the MLSA and phylogenomic trees and associated genomic data.

Early versus late removal of urinary catheter after kidney transplantation.

BACKGROUND: The optimal treatment for end-stage kidney disease is kidney transplantation. During the operation, a catheter is introduced into the bladder and remains in place postoperatively to allow the bladder to drain. This decreases tension from the cysto-ureteric anastomosis and promotes healing. Unfortunately, urinary catheters can pose an infection risk to patients as they allow bacteria into the bladder, potentially resulting in a urinary tract infection (UTI). The longer the catheter remains in place, the greater the risk of developing a UTI. There is no consensus approach to the time a catheter should remain in place post-transplant. Furthermore, the different timings of catheter removal are thought to be associated with different incidences of UTI and postoperative complications, such as anastomotic breakdown. OBJECTIVES: This review aimed to compare patients who had their catheter removed < 5 days post-transplant surgery to those patients who had their catheter removed ≥ 5 days following their kidney transplant. Primary outcome measures between the two groups included: the incidence of symptomatic UTIs, the incidence of asymptomatic bacteriuria and the incidence of major urological complications requiring intervention and treatment. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies up to 13 April 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov. SELECTION CRITERIA: All randomised controlled trials (RCTs) and quasi-RCTs comparing timing of catheter removal post-transplantation were eligible for inclusion. All donor types were included, and all recipients were included regardless of age, demographics or type of urinary catheter used. DATA COLLECTION AND ANALYSIS: Results from the literature search were screened by two authors to identify if they met our inclusion criteria. We designated removal of a urinary catheter before five days (120 hours) as an 'early removal' and anything later than this as a 'late removal.' The studies were assessed for quality using the risk of bias tool. The primary outcome of interest was the incidence of asymptomatic bacteriuria. Statistical analyses were performed using the random effects model, and results were expressed as relative risk (RR) with 95% confidence intervals (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. MAIN RESULTS: Two studies (197 patients) were included in our analysis. One study comprised a full-text article, and the other was a conference abstract with very limited information. The risk of bias in the included studies was generally either high or unclear. It is uncertain whether early versus late removal of the urinary catheter made any difference to the incidence of asymptomatic bacteriuria (RR 0.89, 95% Cl 0.17 to 4.57; participants = 197; I2 = 88%; very low certainty evidence). Data on other outcomes, such as the incidence of UTI and the incidence of major urological complications, were lacking. Furthermore, the follow-up of patients across the studies was short, with no patients being followed beyond one month. AUTHORS' CONCLUSIONS: A high-quality, well-designed RCT is required to compare the effectiveness of early catheter removal versus late catheter removal in patients following a kidney transplant. At the present time, there is insufficient evidence to suggest any difference between early and late catheter removal post-transplant, and the studies investigating this were generally of poor quality.

Donor Liver Blood Tests and Liver Transplant Outcomes: UK Registry Cohort Study.

BACKGROUND: Safely increasing organ utilization is a global priority. Donor serum transaminase levels are often used to decline livers, despite minimal evidence to support such decisions. This study aimed to investigate the impact of donor "liver blood tests" on transplant outcomes. METHODS: This retrospective cohort study used the National Health Service registry on adult liver transplantation (2016-2019); adjusted regressions models were used to assess the effect of donor "liver blood tests" on outcomes. RESULTS: A total of 3299 adult liver transplant recipients were included (2530 following brain stem death, 769 following circulatory death). Peak alanine transaminase (ALT) ranged from 6 to 5927 U/L (median = 45). Donor cause of death significantly predicted donor ALT; 4.2-fold increase in peak ALT with hypoxic brain injury versus intracranial hemorrhage (adjusted P < 0.001). On multivariable analysis, adjusting for a wide range of factors, transaminase level (ALT or aspartate aminotransferase) failed to predict graft survival, primary nonfunction, 90-d graft loss, or mortality. This held true in all examined subgroups, that is, steatotic grafts, donation following circulatory death, hypoxic brain injury donors, and donors, in which ALT was still rising at the time of retrieval. Even grafts from donors with extremely deranged ALT (>1000 U/L) displayed excellent posttransplant outcomes. In contrast, donor peak alkaline phosphatase was a significant predictor of graft loss (adjusted hazard ratio = 1.808; 1.016-3.216; P = 0.044). CONCLUSIONS: Donor transaminases do not predict posttransplant outcomes. When other factors are favorable, livers from donors with raised transaminases can be accepted and transplanted with confidence. Such knowledge should improve organ utilization decision-making and prevent future unnecessary organ discard. This provides a safe, simple, and immediate option to expand the donor pool.

Novel species of Frankia, Frankia gtarii sp. nov. and Frankia tisai sp. nov., isolated from a root nodule of Alnus glutinosa.

The status of four Frankia strains isolated from a root nodule of Alnus glutinosa was established in a polyphasic study. Taxogenomics and phenotypic features show that the isolates belong to the genus Frankia. All four strains form extensively branched substrate mycelia, multilocular sporangia, vesicles, lack aerial hyphae, but contain meso-diaminopimelic acid as the diamino acid of the peptidoglycan, galactose, glucose, mannose, ribose, xylose and traces of rhamnose as cell wall sugars, iso-C16:0 as the predominant fatty acid, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol as the major polar lipids, have comparable genome sizes to other cluster 1, Alnus-infective strains with structural and accessory genes associated with nitrogen fixation. The genome sizes of the isolates range from 7.0 to 7.7 Mbp and the digital DNA G + C contents from 71.3 to 71.5 %. The four sequenced genomes are rich in biosynthetic gene clusters predicted to express for novel specialized metabolites, notably antibiotics. 16S rRNA gene and whole genome sequence analyses show that the isolates fall into two lineages that are closely related to the type strains of Frankia alni and Frankia torreyi. All of these taxa are separated by combinations of phenotypic properties and by digital DNA:DNA hybridization scores which indicate that they belong to different genomic species. Based on these results, it is proposed that isolates Agncl-4T and Agncl-10, and Agncl-8T and Agncl-18, be recognised as Frankia gtarii sp. nov. and Frankia tisai sp. nov. respectively, with isolates Agncl-4T (=DSM 107976T = CECT 9711T) and Agncl-8T (=DSM 107980T = CECT 9715T) as the respective type strains.

Gordonia pseudamarae sp. nov., a home for novel actinobacteria isolated from stable foams on activated sludge wastewater treatment plants.

The taxonomic status of two Gordonia strains, designated BEN371 and CON9T, isolated from stable foams on activated sludge plants was the subject of a polyphasic study which also included the type strains of Gordonia species and three authenticated Gordonia amarae strains recovered from such foams. Phylogenetic analyses of 16S rRNA gene sequences showed that these isolates formed a compact cluster suggesting a well-supported lineage together with a second branch containing the G. amarae strains. A phylogenomic tree based on sequences of 92 core genes extracted from whole genome sequences of the isolates, the G. amarae strains and Gordonia type strains confirmed the assignment of the isolates and the G. amarae strains to separate but closely associated lineages. Average nucleotide index (ANI) and digital DNA-DNA hybridisation (dDDH) similarities showed that BEN371 and CON9T belonged to the same species and had chemotaxonomic and morphological features consistent with their assignment to the genus Gordonia. The isolates and the G. amarae strains were distinguished using a range of phenotypic features and by low ANI and dDDH values of 84.2 and 27.0 %, respectively. These data supplemented with associated genome characteristics show that BEN371 and CON9T represent a novel species of the genus Gordonia. The name proposed for members of this taxon is Gordonia pseudamarae sp. nov. with isolate CON9T (=DSM 43602T=JCM 35249T) as the type strain.

The diagnostic yield of head and neck imaging in symptomatic patients with a normal clinical examination.

AIM: Nationally, concern has been raised about the overuse of diagnostic testing. In patients with unilateral otalgia and no history of Head and Neck Cancer (HNC), 1% had a malignancy detected on imaging that was not detected on clinical examination. METHODS: We performed a retrospective review of "MRI soft tissue neck" scans performed at our hospital from May 2020 to May 2021. Patients were excluded if their scan was not ordered for HNC symptoms. Previous HNC patients undergoing follow-up imaging were also included. RESULTS: In total, 326 scan requests were analyzed. Of the 132 patients without clinical features of overt disease, only one received a new diagnosis of HNC. This patient had previously had a HNC and was undergoing routine follow-up imaging. CONCLUSION: Our data demonstrate that performing MRI scans in symptomatic patients with a normal examination, FNE, and no history of HNC does not benefit the diagnosis or management of these patients.

A stable home for an equine pathogen: valid publication of the binomial Prescottella equi gen. nov., comb. nov., and reclassification of four rhodococcal species into the genus Prescottella.

Opinion 106 of the Judicial Commission has clarified the nomenclature of the taxon variously named Rhodococcus equi, 'Prescottella equi' and Rhodococcus hoagii. As a consequence, we present here the genus name Prescottella and that of its nomenclatural type species, Prescottella equi comb. nov., for valid publication and propose the reclassification of four rhodococcal species as novel combinations in the genus, namely Prescottella agglutinans Guo et al. 2015 comb. nov., Prescottella defluvii Kämpfer et al. 2014 comb. nov., Prescottella soli Li et al. 2015 comb. nov. and Prescottella subtropica Lee et al. 2019 comb. nov. In addition, we note that a clinical isolate, strain 86-07 (=W8901), likely represents an additional species within the genus Prescottella. Nearly a century after the original description of the type strain of the type species as Corynebacterium equi, we provide a stable home for Prescottella equi and its relatives.

Discovery, isolation, heterologous expression and mode-of-action studies of the antibiotic polyketide tatiomicin from Amycolatopsis sp. DEM30355.

A genomic and bioactivity informed analysis of the metabolome of the extremophile Amycolatopsis sp. DEM30355 has allowed for the discovery and isolation of the polyketide antibiotic tatiomicin. Identification of the biosynthetic gene cluster was confirmed by heterologous expression in Streptomyces coelicolor M1152. Structural elucidation, including absolute stereochemical assignment, was performed using complementary crystallographic, spectroscopic and computational methods. Tatiomicin shows antibiotic activity against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). Cytological profiling experiments suggest a putative antibiotic mode-of-action, involving membrane depolarisation and chromosomal decondensation of the target bacteria.

Systematic whole-genome sequencing reveals an unexpected diversity among actinomycetoma pathogens and provides insights into their antibacterial susceptibilities.

Mycetoma is a neglected tropical chronic granulomatous inflammatory disease of the skin and subcutaneous tissues. More than 70 species with a broad taxonomic diversity have been implicated as agents of mycetoma. Understanding the full range of causative organisms and their antibiotic sensitivity profiles are essential for the appropriate treatment of infections. The present study focuses on the analysis of full genome sequences and antibiotic inhibitory concentration profiles of actinomycetoma strains from patients seen at the Mycetoma Research Centre in Sudan with a view to developing rapid diagnostic tests. Seventeen pathogenic isolates obtained by surgical biopsies were sequenced using MinION and Illumina methods, and their antibiotic inhibitory concentration profiles determined. The results highlight an unexpected diversity of actinomycetoma causing pathogens, including three Streptomyces isolates assigned to species not previously associated with human actinomycetoma and one new Streptomyces species. Thus, current approaches for clinical and histopathological classification of mycetoma may need to be updated. The standard treatment for actinomycetoma is a combination of sulfamethoxazole/trimethoprim and amoxicillin/clavulanic acid. Most tested isolates had a high IC (inhibitory concentration) to sulfamethoxazole/trimethoprim or to amoxicillin alone. However, the addition of the ß-lactamase inhibitor clavulanic acid to amoxicillin increased susceptibility, particularly for Streptomyces somaliensis and Streptomyces sudanensis. Actinomadura madurae isolates appear to have a particularly high IC under laboratory conditions, suggesting that alternative agents, such as amikacin, could be considered for more effective treatment. The results obtained will inform future diagnostic methods for the identification of actinomycetoma and treatment.

Actinospica acidithermotolerans sp. nov., a novel actinomycete isolated from sediment from an Indonesian hot spring.

A polyphasic study was designed to resolve the taxonomic position of isolate MGRD01-02T which was recovered from an acidic hot spring in Indonesia and assigned to the genus Actinospica. Phylogenetic analyses based on 16S rRNA gene sequences show that the isolate is most closely related to the type strains of Actinospica acidiphila (98.5%), Actinospica robiniae (97.8%) and Actinospica durhamensis (96.8%). Morphological and chemotaxonomic data underpin the assignment of the isolate to the genus Actinospica as it forms an extensively branched substrate mycelium which carries tufts of white aerial hyphae that differentiate into straight to flexuous chains of cylindrical spores with faint rugose surfaces, contains 2,6-diamino-3-hydroxydiaminopimelic acid in the peptidoglycan, mixtures of hydrogenated menaquinones with nine isoprene units, iso-C 15:O and iso-C 16:O as major fatty acids and phosphatidylethanolamine as the diagnostic phospholipid. Whole-genome sequence analyses show that the isolate, A. durhamensis CSCA 57T and Actinocrinis puniceicyclus DSM 45168T have genome sizes of 7.9, 9.6 and 6.7 Mbp, respectively. A phylogenomic tree shows that they form distinct branches in a well-supported clade, a result supported by associated phenotypic data. Average nucleotide identity and digital DNA:DNA hybridization similarities are below the recommended thresholds for assigning strains to the same species; they also indicate that isolate MGRD01-02T is most closely related to the A. durhamensis and A. robiniae strains. Corresponding amino acid identity and conserved protein data not only support these relationships but also confirm the taxonomic integrity of the genus Actinocrinis. Based on these results, it is proposed that isolate MGRD01-02T (= CCMM B1308T = ICEBB-09T = NCIMB 15218T) be classified in the genus Actinospica as Actinospica acidithermotolerans sp. nov. The draft genome of the isolate and its closest phylogenomic neighbours contain biosynthetic gene clusters with the potential to produce new natural products, notably antibiotics.

Genome-based classification of Streptomyces pinistramenti sp. nov., a novel actinomycete isolated from a pine forest soil in Poland with a focus on its biotechnological and ecological properties.

A genomic-based polyphasic study was undertaken to establish the taxonomic status and biotechnological and ecological potential of a Streptomyces strain, isolate SF28T, that was recovered from the litter layer in a Polish Pinus sylvestris forest. The isolate had morphological characteristics and chemotaxonomic properties consistent with its classification in the genus Streptomyces. It formed long straight chains of spores with smooth surfaces, contained LL-diaminopimelic acid, glucose and ribose in whole-organism hydrolysates, produced major proportions of straight, iso- and anteiso- fatty acids, hexa- and octa-hydrogenated menaquinones with nine isoprene units and had a polar lipid pattern composed of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, glycophospholipids and three uncharacterized components. Phylogenetic trees prepared using 16S rRNA gene and multilocus gene sequences of conserved housekeeping genes showed that the isolate formed a branch that was loosely associated with the type strains of several validly published Streptomyces species. A draft genome generated for the isolate was rich in natural product-biosynthetic gene clusters with the potential to produce new specialised metabolites, notably antibiotics, and stress related genes which provide an insight into how it may have become adapted to the harsh conditions that prevail in acidic forest soils. A phylogenomic tree based on the genomes of the isolate and its phylogenetic neighbours confirmed that it formed a distinct lineage well separated from its closest evolutionary relatives. The isolate shared low average nucleotide identity and digital DNA:DNA hybridization values with its phylogenomic neighbours and was also distinguished from them using a combination of cultural and micromorphological properties. Given this wealth of taxonomic data it is proposed that isolate SF28T (= DSM 113360 T = PCM 3163 T) be classified in the genus Streptomyces as Streptomyces pinistramenti sp. nov. The isolate showed pronounced antimicrobial activity, especially against fungal plant pathogens.

Nocardia noduli sp. nov., a novel actinobacterium with biotechnological potential.

A genome-based polyphasic study was undertaken to establish the taxonomic status of an actinobacterium strain isolated from an actinorhizal root nodule. Strain ncl1T was found to have chemotaxonomic, cultural and morphological properties characteristic of members of the genus Nocardia. The strain was closely related to Nocardia aurea in the phylogenetic trees based on 16S rRNA gene and genome sequences. The draft genome of the strain is 8.9 Mbp in size, has a genomic DNA G + C content of 67.0% and was predicted to contain at least 19 biosynthetic gene clusters encoding for specialized metabolites. Strain ncl1T was distinguished from its closest neighbour, N. aurea DSM 103986T, by a broad range of phenotypic properties and by low average nucleotide identity and digital DNA-DNA hybridization scores. Consequently, the strain represents a novel Nocardia species for which the name Nocardia noduli sp. nov. is proposed. The type strain is ncl1T (CECT 30123T = DSM 110878T). The present study provides further evidence that actinorhizal nodules are a source of novel species of Nocardia.

Genome insights into the pharmaceutical and plant growth promoting features of the novel species Nocardia alni sp. nov.

BACKGROUND: Recent studies highlighted the biosynthetic potential of nocardiae to produce diverse novel natural products comparable to that of Streptomyces, thereby making them an attractive source of new drug leads. Many of the 119 Nocardia validly named species were isolated from natural habitats but little is known about the diversity and the potential of the endophytic nocardiae of root nodule of actinorhizal plants. RESULTS: The taxonomic status of an actinobacterium strain, designated ncl2T, was established in a genome-based polyphasic study. The strain was Gram-stain-positive, produced substrate and aerial hyphae that fragmented into coccoid and rod-like elements and showed chemotaxonomic properties that were also typical of the genus Nocardia. It formed a distinct branch in the Nocardia 16S rRNA gene tree and was most closely related to the type strains of Nocardia nova (98.6%), Nocardia jiangxiensis (98.4%), Nocardia miyuensis (97.8%) and Nocardia vaccinii (97.7%). A comparison of the draft genome sequence generated for the isolate with the whole genome sequences of its closest phylogenetic neighbours showed that it was most closely related to the N. jiangxiensis, N. miyuensis and N. vaccinii strains, a result underpinned by average nucleotide identity and digital DNA-DNA hybridization data. Corresponding taxogenomic data, including those from a pan-genome sequence analysis showed that strain ncl2T was most closely related to N. vaccinii DSM 43285T. A combination of genomic, genotypic and phenotypic data distinguished these strains from one another. Consequently, it is proposed that strain ncl2T (= DSM 110931T = CECT 30122T) represents a new species within the genus Nocardia, namely Nocardia alni sp. nov. The genomes of the N. alni and N. vaccinii strains contained 36 and 29 natural product-biosynthetic gene clusters, respectively, many of which were predicted to encode for a broad range of novel specialised products, notably antibiotics. Genome mining of the N. alni strain and the type strains of its closest phylogenetic neighbours revealed the presence of genes associated with direct and indirect mechanisms that promote plant growth. The core genomes of these strains mainly consisted of genes involved in amino acid transport and metabolism, energy production and conversion and transcription. CONCLUSIONS: Our genome-based taxonomic study showed that isolate ncl2T formed a new centre of evolutionary variation within the genus Nocardia. This novel endophytic strain contained natural product biosynthetic gene clusters predicted to synthesize novel specialised products, notably antibiotics and genes associated with the expression of plant growth promoting compounds.

Generation of a high quality library of bioactive filamentous actinomycetes from extreme biomes using a culture-based bioprospecting strategy.

Introduction: Filamentous actinomycetes, notably members of the genus Streptomyces, remain a rich source of new specialized metabolites, especially antibiotics. In addition, they are also a valuable source of anticancer and biocontrol agents, biofertilizers, enzymes, immunosuppressive drugs and other biologically active compounds. The new natural products needed for such purposes are now being sought from extreme habitats where harsh environmental conditions select for novel strains with distinctive features, notably an ability to produce specialized metabolites of biotechnological value. Methods: A culture-based bioprospecting strategy was used to isolate and screen filamentous actinomycetes from three poorly studied extreme biomes. Actinomycetes representing different colony types growing on selective media inoculated with environmental suspensions prepared from high-altitude, hyper-arid Atacama Desert soils, a saline soil from India and from a Polish pine forest soil were assigned to taxonomically predictive groups based on characteristic pigments formed on oatmeal agar. One hundred and fifteen representatives of the colour-groups were identified based on 16S rRNA gene sequences to determine whether they belonged to validly named or to putatively novel species. The antimicrobial activity of these isolates was determined using a standard plate assay. They were also tested for their capacity to produce hydrolytic enzymes and compounds known to promote plant growth while representative strains from the pine forest sites were examined to determine their ability to inhibit the growth of fungal and oomycete plant pathogens. Results: Comparative 16S rRNA gene sequencing analyses on isolates representing the colour-groups and their immediate phylogenetic neighbours showed that most belonged to either rare or novel species that belong to twelve genera. Representative isolates from the three extreme biomes showed different patterns of taxonomic diversity and characteristic bioactivity profiles. Many of the isolates produced bioactive compounds that inhibited the growth of one or more strains from a panel of nine wild strains in standard antimicrobial assays and are known to promote plant growth. Actinomycetes from the litter and mineral horizons of the pine forest, including acidotolerant and acidophilic strains belonging to the genera Actinacidiphila, Streptacidiphilus and Streptomyces, showed a remarkable ability to inhibit the growth of diverse fungal and oomycete plant pathogens. Discussion: It can be concluded that selective isolation and characterization of dereplicated filamentous actinomyctes from several extreme biomes is a practical way of generating high quality actinomycete strain libraries for agricultural, industrial and medical biotechnology.

Catenulispora pinistramenti sp. nov., novel actinobacteria isolated from pine forest soil in Poland.

The taxonomic status of two filamentous actinobacteria, isolates NF23 and NL8T, recovered from the litter layer of a pine forest soil in Poland was established in a genome-based polyphasic study. The isolates showed a combination of chemotaxonomic, morphological and physiological properties associated with their classification in the genus Catenulispora. They formed a well supported lineage within the Catenulispora 16S rRNA gene tree and were most closely related to the type strains of Catenulispora acidiphila (99.1%), Catenulispora pinisilvae (99.9 %) and Catenulispora rubra (99.1 %), and like them, were found to have large genomes (10.8 and 11.5 Mbp, respectively). A phylogenomic tree based on the draft genomes of isolates NF23 and NL8T and their phylogenetic neighbours showed that they formed a distinct branch in the Catenulispora clade that was most closely related to C. pinisilvae DSM 111109T. The isolates shared a combination of genomic, genotypic and phenotypic features, and had high average nucleotide index (ANI) and digital DNA:DNA hybridization (dDDH) similarities consistent with their assignment to the same species. The isolates were distinguished from the C. acidiphila, C. pinisilvae and C. rubra strains by a wealth of taxonomic data and by low ANI (84.9-93.9 %) and dDDH (29.6-54.7 %) values. It is proposed that the isolates be classified in the genus Catenulispora as C. pinistramenti sp. nov. with isolate NL8T (=DSM 111110T=PCM 3045T) as the type strain. The genomes of strains NF23 and NL8T are rich in natural product-biosynthetic gene clusters hence these strains have the potential to synthesize new specialised metabolites.

Genome-based classification of the Streptomyces violaceusniger clade and description of Streptomyces sabulosicollis sp. nov. from an Indonesian sand dune.

A polyphasic study was designed to determine the taxonomic provenance of a strain, isolate PRKS01-29T, recovered from an Indonesian sand dune and provisionally assigned to the Streptomyces violaceusniger clade. Genomic, genotypic and phenotypic data confirmed this classification. The isolate formed an extensively branched substrate mycelium which carried aerial hyphae that differentiated into spiral chains of rugose ornamented spores, contained LL-as the wall diaminopimelic acid, MK-9 (H6, H8) as predominant isoprenologues, phosphatidylethanolamine as the diagnostic phospholipid and major proportions of saturated, iso- and anteiso- fatty acids. Whole-genome sequences generated for the isolate and Streptomyces albiflaviniger DSM 41598T and Streptomyces javensis DSM 41764T were compared with phylogenetically closely related strains, the isolate formed a branch within the S. violaceusniger clade in the resultant phylogenomic tree. Whole-genome sequences data showed that isolate PRKS01-29T was most closely related to the S. albiflaviniger strain but was distinguished from the latter and from other members of the clade using combinations of phenotypic properties and average nucleotide identity and digital DNA:DNA hybridization scores. Consequently, it is proposed that isolate PRKS01-29T (= CCMM B1303T = ICEBB-02T = NCIMB 15210T) should be classified in the genus Streptomyces as Streptomyces sabulosicollis sp. nov. It is also clear that streptomycetes which produce spiral chains of rugose ornamented spores form a well-defined monophyletic clade in the Streptomyces phylogenomic tree., the taxonomic status of which requires further study. The genome of the type strain of S. sabulosicollis contains biosynthetic gene clusters predicted to produce new natural products.