Gordonia otitidis sp. nov., isolated from a patient with external otitis

Gordonia prachuapensis sp. nov. and Gordonia sesuvii sp. nov., two novel actinobacteria isolated from mangrove sediments and leaves of halophyte Sesuvium portulacastrum in Thailand

A polyphasic approach was used to characterize two novel actinobacterial strains, designated PKS22-38T and LSe1-13T, which were isolated from mangrove soils and leaves of halophyte Sesuvium portulacastrum (L.), respectively. Phylogenetic analyses based on 16S rRNA gene sequences showed that they belonged to the genus Gordonia and were most closely related to three validly published species with similarities ranging from 98.6 to 98.1 %. The genomic DNA G+C contents of strains PKS22-38T and LSe1-13T were 67.3 and 67.2 mol%, respectively. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the two strains were 93.3 and 54.9 %, respectively, revealing that they are independent species. Meanwhile, the ANI and dDDH values between the two novel strains and closely related type strains were below 80.5 and 24.0 %, respectively. Strains PKS22-38T and LSe1-13T contained C16 : 0, C18 : 1  ω9c and C18 : 0 10-methyl (TBSA) as the major fatty acids and diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol as the main phospholipids. The predominant menaquinone was MK-9(H2). Based on phenotypic, chemotaxonomic, phylogenetic and genomic data, strains PKS22-38T and LSe1-13T are considered to represent two novel species within the genus Gordonia, for which the names Gordonia prachuapensis sp. nov. and Gordonia sesuvii sp. nov. are proposed, with strain PKS22-38T (=TBRC 17540T=NBRC 116256T) and strain LSe1-13T (=TBRC 17706T=NBRC 116396T) as the type strains, respectively.

Focusing on Gordonia Infections: Distribution, Antimicrobial Susceptibilities and Phylogeny

The immunosuppression conditions and the presence of medical devices in patients favor the Gordonia infections. However, the features of this aerobic actinomycete have been little explored. Strains (n = 164) were characterized with 16S rDNA and secA1 genes to define their phylogenetic relationships, and subjected to broth microdilution to profile the antimicrobial susceptibilities of Gordonia species that caused infections in Spain during the 2005-2021 period. Four out of the eleven identified species were responsible for 86.0% of the infections: Gordonia sputi (53.0%), Gordonia bronchialis (18.3%), Gordonia terrae (8.5%) and Gordonia otitidis (6.1%). Respiratory tract infections (61.6%) and bacteremia (21.9%) were the most common infections. The secA1 gene resolved the inconclusive identification, and two major clonal lineages were observed for G. sputi and G. bronchialis. Species showed a wide antimicrobial susceptibility profile. Cefoxitin resistance varies depending on the species, reaching 94.2% for G. sputi and 36.0% for G. terrae. What is noteworthy is the minocycline resistance in G. sputi (11.5%), the clarithromycin resistance in G. bronchialis secA1 lineage II (30.0%) and the amoxicillin-clavulanate and cefepime resistance in G. terrae (21.4% and 42.8%, respectively). G. sputi and G. bronchialis stand out as the prevalent species causing infections in Spain. Resistance against cefoxitin and other antimicrobials should be considered.

Gordonia sputi-associated bloodstream infection in a renal transplant patient with chronic indwelling central venous catheter: a case report and literature review

Introduction

Although rare, human infections caused by Gordonia spp. have been reported, especially within the immunocompromised population and those with long-term indwelling devices. We report a case of Gordonia spp. bacteraemia in a renal transplant patient and present a literature review on microbiological identification methods of this organism.

Case Presentation

A 62-year-old female renal transplant recipient admitted to hospital with a 2-month history of dry cough and fevers occurring weekly when receiving electrolyte replacement infusions via a Groshong line. Over 2 weeks, blood cultures repeatedly isolated a Gram-positive bacillus solely in aerobic bottles, and this was initially reported as Rhodococcus spp. by the local microbiology laboratory. Chest computed tomography (CT) showed multiple ground-glass lung opacities suggestive of septic pulmonary emboli. As central line-associated bloodstream infection was suspected, empirical antibiotics were initiated and the Groshong line was removed. The Gram-positive bacillus was later confirmed by the reference laboratory as Gordonia sputi via 16S rRNA sequencing. Vancomycin and ciprofloxacin for a duration of 6 weeks were completed as targeted antimicrobial therapy. After treatment, the patient remained symptom-free with marked improvement on repeat CT chest imaging.

Conclusion

This case illustrates the challenges surrounding identification of Gordonia spp. and other aerobic actinomycetes. 16S rRNA gene sequencing may be a preferred identification method, especially when initial workup of a weakly acid-fast organism fails to make an identification or shows discrepant results using traditional diagnostic modalities.

Efficient AntiMycolata Agents by Increasing the Lipophilicity of Known Antibiotics through Multicomponent Reactions

New antibiotic agents were prepared using Povarov and Ugi multicomponent reactions upon the known drugs sulfadoxine and dapsone. The prepared derivatives, with increased lipophilicity, showed improved efficiency against Mycolata bacteria. Microbiological guidance for medicinal chemistry is a powerful tool to design new and effective antimicrobials. In this case, the readily synthesized compounds open new possibilities in the search for antimicrobials active on mycolic acid-containing bacteria.

Methods of Identifying Gordonia Strains in Clinical Samples

Gordonia spp. are members of the family Gordoniacea in the suborder Corynebacteriales; their habitat, in most cases, is soil. Many representatives of this genus are human or veterinary pathogens. The main cause of the lack of a standardized approach to dealing with infections caused by Gordonia is their erroneous identification and little information regarding their susceptibility to antimicrobial drugs. This review presents the most common methods for identifying Gordonia strains, including modern approaches for identifying a species. The main prospects and future directions of this field of knowledge are briefly presented.

Gordonia zhenghanii sp. nov. and Gordonia liuliyuniae sp. nov., isolated from bat faeces

Four mesophilic actinobacteria (HY002T, HY442, HY366T and HY285) isolated from the faeces of bats collected in southern China were found to be strictly aerobic, non-motile, rod-shaped, oxidase-negative, Gram-stain-positive and catalase-positive. Strains HY002T and HY366T contained meso-diaminopimelic acid as the diagnostic diamino acid and MK-9(H2) the sole respiratory quinone. Arabinose, galactose and ribose were detected in the whole-cell hydrolysates of both type strains. The main cellular fatty acids (> 10.0%) of all strains were C16 : 0, C18 : 1  ω9c, 10-methyl-C18 : 0 and summed feature 3. Strains HY002T and HY366T contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidyl inositol mannosides as the major polar lipids. The phylogenetic/phylogenomic analyses based on 16S rRNA gene and genomic sequence comparison revealed that the four strains belong to the genus Gordonia , most closely related to G. neofelifaecis NRRL B-59395T(98.2–98.3% sequence similarity) on the EzBioCloud database. The G+C contents of strains HY002T and HY366T based on genomic DNA were 66.5 and 66.9%, respectively. The DNA–DNA relatedness values between the two types strains and members of the genus Gordonia were far below 70 % (18.6–23.1 %). All genotypic and phenotypic data indicated that the four strains are representatives of two novel separate species, for which the names Gordonia zhenghanii sp. nov. and Gordonia liuliyuniae sp. nov. are proposed, with HY002T (=CGMCC 4 7757T=JCM 34 878T) and HY366T (=CGMCC 1 19146T=JCM 34 879T) as the respective type strains.

A pediatric case of Gordonia otitidis bacteremia detected by long-term blood culture

For immunocompromised patients receiving chemotherapy or bone mallow transplantation, slow-growing bacteria should also be considered one of the pathogenic microorganisms. However, there is no evidence pertaining to the microbiological tests associated with a patient with febrile neutropenia before peripheral blood stem cell harvest (PBSCH). We report a case of a 4-year-old cancer-bearing female presenting with a catheter-related bloodstream infection due to Gordonia otitidis. We detected G. otitidis from long-term blood cultures for approximately 6 days and prevented iatrogenic bacteremia by identifying the same organism from the culture of the PBSC sample and postponing the scheduled PBSCH. If febrile neutropenia occurs before PBSCH, we should collect multiple sets of blood cultures and culture them for a longer period.

Gordonia jinghuaiqii sp. nov. and Gordonia zhaorongruii sp. nov., isolated from Tibetan Plateau wildlife

Four mesophilic and Gram-stain-positive strains (zg-686^T/zg-691 and HY186^T/HY189) isolated from Tibetan Plateau wildlife (PR China) belong to the genus Gordonia according to 16S rRNA gene and genomic sequence-based phylogenetic/genomic results. They have a DNA G+C content range of 67.4-68.3 mol% and low DNA relatedness (19.2-27.6 %) with all available genomes in the genus Gordonia. Strains zg-686^T/zg-691 and HY186^T/HY189 had C_18 : 1ω9c, C_18 : 0 10-methyl, C_16 : 1 ω7c/C_16 : 1ω6c and C_16 : 0 as major cellular fatty acids. The polar lipids detected in strains zg-686^T and HY186^T included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidyl inositol mannoside and phosphatidylinositol. The respiratory quinones comprised MK8(H₂) (10.8 %) and MK9(H₂) (89.2 %) for strain zg-686^T, and MK6 (7.7 %), MK8(H₂) (8.4 %), MK8(H₄) (3.1 %) and MK9(H₂) (80.8 %) for strain HY186^T. Optimal growth conditions were pH 7.0, 35-37 °C and 0.5-1.5 % NaCl (w/v) for strains pair zg-686^T/zg-691, and pH 7.0, 28 °C and 1.5 % (w/v) NaCl for strains pair HY186^T/HY189. Based on these genotypic and phenotypic results, these four strains could be classified as two different novel species in the genus Gordonia, for which the names Gordonia jinghuaiqii sp. nov. and Gordonia zhaorongruii sp. nov. are proposed. The type strains are zg-686^T (=GDMCC 1.1715^T =JCM 33890^T) and HY186^T (=CGMCC 4.7607^T =JCM 33466^T), respectively.

Gordonia crocea sp. nov. and Gordonia spumicola sp. nov. isolated from sludge of a wastewater treatment plant

Two novel actinobacteria, designated NBRC 107696^T and NBRC 107697^T, were isolated from sludge samples from a wastewater treatment plant and their taxonomic positions were investigated by a polyphasic approach. The cells of the strains were aerobic, rod-shaped, non-motile and non-endospore-forming. The strains contained glutamic acid, alanine and meso-diaminopimelic acid in the peptidoglycan. Galactose and arabinose were detected as cell-wall sugars. The predominant menaquinone was identified as MK-9(H₂) and the major fatty acids were C_{16  :  0}, C_18 : 1ω9c and C_16 : 1ω7c. The DNA G+C contents of NBRC 107696^T and NBRC 107697^T were 68.07 and 68.99 mol%, respectively. Phylogenetic analyses based on 16S rRNA gene sequence comparisons revealed that NBRC 107696^T and NBRC 107697^T were a clade with members of the genus Gordonia. The highest 16S rRNA gene sequence similarity values were obtained with Gordonia araii IFM 10211^T (98.9 %) for NBRC 107697^T, and Gordonia malaquae IMMIB WWCC-22^T, Gordonia neofelifaecis AD-6^T and Gordonia humi CC-12301^T (98.1 %) for NBRC 107696^T, respectively. The digital DNA-DNA relatedness data coupled with the combination of genotypic and phenotypic data indicated that the two strains are representatives of two novel separate species. The names proposed to accommodate these two strains are Gordonia spumicola sp. nov. and Gordonia crocea sp. nov., and the type strains are NBRC 107696^T (=IFM 10067^T=TBRC 11239^T) and NBRC 107697^T (=IFM 10881^T=TBRC 11240^T), respectively.

Sternal osteomyelitis by Gordonia Bronchialis in an immunocompetent patient after open heart surgery

Gordonia is a catalase-positive, aerobic, nocardioform, Gram-positive staining actinomycete that also shows weak acid-fast staining. Several Gordonia species are commonly found in the soil. The bacterium has been isolated from the saliva of domesticated/wild dogs as well. In hospitalized patients, most commonly it is found in the setting of intravascular catheter-related infections. However, recent reports show that it is being increasingly isolated from sternal wounds, skin/neoplastic specimens and from pleural effusions. Gordonia shares many common characteristics with Rhodococcus and Nocardia. Ergo, it is commonly misrecognized as Nocardia or Rhodococcus. Since this pathogen requires comprehensive morphological and biochemical testing, it is often difficult and cumbersome to isolate the species. Broad-range Polymerase Chain Reaction (PCR) and sequencing with genes like 16S rRNA or hsp65 are used to correctly identify the species. Identification is essential for choosing and narrowing the right antimicrobial agent. Herein, we report our experience with a patient who presented with sternal osteomyelitis after infection with this elusive bug.

Studies of antimicrobial resistance in rare mycobacteria from a nosocomial environment

BACKGROUND

Nontuberculous mycobacteria (NTM) are ubiquitous in nature and recognized agents of opportunistic infection, which is often aggravated by their intrinsic resistance to antimicrobials, poorly defined therapeutic strategies and by the lack of new drugs. However, evaluation of their prevalence in anthropogenic environments and the associated antimicrobial resistance profiles have been neglected. In this work, we sought to determine minimal inhibitory concentrations of 25 antimicrobials against 5 NTM isolates recovered from a tertiary-care hospital surfaces. Antimicrobial susceptibilities of 5 other Corynebacterineae isolated from the same hospital were also determined for their potential clinical relevance.

RESULTS

Our phylogenetic study with each of the NTM isolates confirm they belong to Mycobacterium obuense, Mycobacterium mucogenicum and Mycobacterium paragordonae species, the latter initially misidentified as strains of M. gordonae, a species frequently isolated from patients with NTM disease in Portugal. In contrast to other strains, the M. obuense and M. mucogenicum examined here were resistant to several of the CLSI-recommended drugs, suggestive of multidrug-resistant profiles. Surprisingly, M. obuense was susceptible to vancomycin. Their genomes were sequenced allowing detection of gene erm (erythromycin resistance methylase) in M. obuense, explaining its resistance to clarithromycin. Remarkably, and unlike other strains of the genus, the Corynebacterium isolates were highly resistant to penicillin, ciprofloxacin and linezolid.

CONCLUSIONS

This study highlights the importance of implementing effective measures to screen, accurately identify and control viable NTM and closely related bacteria in hospital settings. Our report on the occurrence of rare NTM species with antibiotic susceptibility profiles that are distinct from those of the corresponding Type strains, along with unexpected resistance mechanisms detected seem to suggest that resistance may be more common than previously thought and also a potential threat to frail and otherwise vulnerable inpatients.

Evaluation of Well Designs to Improve Access to Safe and Clean Water in Rural Tanzania

The objective of this study was to examine three well designs: drilled wells (20–30 m deep), closed dug wells (>5 m deep), and hand-dug open wells (<5 m deep), to determine the water quality for improving access to safe and clean water in rural communities. Heterotrophic plate count (HPC), total coliforms (TC), Escherichia coli (E. coli) and turbidity, were used to assess the water quality of 97 wells. Additionally, the study looked at the microflora diversity of the water, focusing on potential pathogens using outgrowth, PCR, and genome sequencing for 10 wells. Concentrations of TC for the open dug wells (4 × 10⁴ CFU/100 mL) were higher than the drilled (2 × 10³ CFU/100 mL) and closed dug wells (3 × 10³ CFU/100 mL). E. coli concentration for drilled and closed dug wells was <22 MPN (most probable number)/100 mL, but higher for open wells (>154 MPN/100 mL). The drilled well turbidity (11 NTU) was within the standard deviation of the closed well (28 NTU) compared to open dug wells (49 NTU). Drilled and closed wells had similar microbial diversity. There were no significant differences between drilled and closed dug wells. The covering and lining of hand-dug wells should be considered as an alternative to improve access to safe and clean water in rural communities.

An insight into the ecology, diversity and adaptations of Gordonia species

The bacterial genus Gordonia encompasses a variety of versatile species that have been isolated from a multitude of environments. Gordonia was described as a genus about 20 years ago, and to date, 39 different species have been identified. Gordonia is recognized for symbiotic associations with multiple hosts, including aquatic (marine and fresh water) biological forms and terrestrial invertebrates. Some Gordonia species isolated from clinical specimens are known to be opportunistic human pathogens causing secondary infections in immunocompromised and immunosuppressive individuals. They are also predominant in mangrove ecosystems and terrestrial sites. Members of the genus Gordonia are ecologically adaptable and show marked variations in their properties and products. They generate diverse bioactive compounds and produce a variety of extracellular enzymes. In addition, production of surface active compounds and carotenoid pigments allows this group of microorganisms to grow under different conditions. Several isolates from water and soil have been implicated in bioremediation of different environments and plant associated species have been explored for agricultural applications. This review highlights the prevalence of the members of this versatile genus in diverse environments, details its associations with living forms, summarizes the biotechnologically relevant products that can be obtained and discusses the salient genomic features that allow this Actinomycete to survive in different ecological niches.

Gordonia hongkongensis sp. nov., isolated from blood culture and peritoneal dialysis effluent of patients in Hong Kong

Two bacterial strains, HKU50T and HKU46, were isolated in Hong Kong from the blood culture and the peritoneal dialysis effluent of two patients. The strains are Gram-stain-positive, acid-fast, non-motile, non-sporulating bacilli. They grow on Columbia agar with 5 % defibrinated sheep blood and brain-heart infusion agar under aerobic conditions with 5 % CO2 at 37 °C as pink-to-orange, non-haemolytic colonies. The strains are catalase-positive and oxidase-negative, and have a unique biochemical profile distinguishable from other closely related species. DNA sequencing revealed that both isolates possessed multiple intra-genomic 16S rRNA gene copies (99.8-100 % sequence identities to Gordonia lacunae NRRL B-24551T and Gordonia terrae NRRL B-16283T). Phylogenetic analysis of the 16S rRNA gene, secA1 and gyrB showed that the two isolates formed a distinct branch within the genus Gordonia and were most closely related to G. lacunae and G. terrae. DNA-DNA hybridization demonstrated ≤53.7 % and ≤49.4 % DNA relatedness between the two isolates and G. lacunae, and between the two isolates and G. terrae, respectively. Hierarchical cluster analysis of MALDI-TOF MS main spectrum profiles showed that strains HKU50T and HKU46 were closely related to each other, but were distinct from G. lacunae, G. terrae, or any other species of the genus Gordonia in the Bruker database. The chemotaxonomic traits of the two strains were highly similar, and the major fatty acids were summed feature 4 (iso-C15 : 0 2-OH/C16 : 1trans-9), C16 : 0, C18 : 1cis-9, and tuberculostearic acid. A novel species named Gordonia hongkongensis sp. nov. is proposed to accommodate strains HKU50T and HKU46, with strain HKU50T (=CCOS 955T=CIP 111027T=NBRC 111234T=NCCP 16210T) as the type strain.

Gordonia iterans sp. nov., isolated from a patient with pneumonia

A second novel clinical actinobacterial strain, designated IFM 10348T, was isolated from the sputum of the same Japanese patient with bacterial pneumonia from whom the type strain of Gordonia araii had been isolated. The strains differed in phylogenetic position and drug-resistance profiles. The taxonomic position of strain IFM 10348T was clarified by phenotypic, chemotaxonomic and phylogenetic studies. Phylogenetic analyses based on 16S rRNA gene sequences clearly demonstrated that strain IFM 10348T occupied a distinct clade within the genus Gordonia and was related closely to Gordonia malaquae DSM 45064T and Gordonia hirsuta DSM 44140T (97.3 and 97.1 % similarities, respectively). Strain IFM 10348T was also clearly differentiated from G. malaquae DSM 45064T and G. hirsuta DSM 44140T based on gyrB and secA1 gene sequence similarity values. Strain IFM 10348T had MK-9(H2) as the predominant menaquonine, contained meso-diaminopimelic acid, arabinose, galactose and glucosamine as cell-wall components, and contained C18 : 1ω9c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0 as the major cellular fatty acids. Mycolic acids were present. The DNA G+C content of strain IFM 10348T was 68.0 mol%. DNA–DNA relatedness data coupled with the combination of genotypic and phenotypic data indicated that strain IFM 10348T represents a novel species of the genus Gordonia , for which the name Gordonia iterans sp. nov. is proposed. The type strain is IFM 10348T ( = CCTCC M2011245T = NCCB 100436T).

Gordonia bacteremia

Gordonia species are ubiquitous aerobic actinomycetes that rarely cause infection in humans. We report the second known case of Gordonia otitidis catheter-related bacteremia in an immunocompromised patient and review four additional cases of Gordonia bacteremia seen at our institution over the past 14 years. In addition, the existing literature on Gordonia infections is reviewed.

Gordonia phosphorivorans sp. nov., isolated from a wastewater bioreactor with phosphorus removal

Two Gram-stain-positive, non-endospore-forming actinobacteria (Ca8Tand Ca14) were isolated from a bioreactor with extensive phosphorus removal. Based on 16S rRNA gene sequence similarity comparisons, strains Ca8T and Ca14 were shown to belong to the genus Gordonia and were most closely related to Gordonia hirsuta DSM 44140T (98.0 % sequence similarity) and Gordonia hydrophobica DSM 44015T (97.2 %). In comparison with the sequences of the type strains of all other species of the genus Gordonia tested, similarities were below 97 %. The quinone systems of the strains were determined to consist predominantly of MK-9H2. The polar lipid profile for both organisms consisted of diphosphatidylglycerol, phosphatidylglycerol, phospatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. Whole-organism hydrolysates contained meso-diaminopimelic acid as the diamino acid of the peptidoglycan; mycolic acids were detected as well. These chemotaxonomic traits and the major fatty acids, which were C16 : 1 cis-9, C16 : 0 and C18 : 1 and tuberculostearic acid strongly supported the grouping of strains Ca8T and Ca14 into the genus Gordonia . The two strains showed a DNA–DNA similarity of 96 %. DNA–DNA hybridizations of strain Ca8T with G. hirsuta DSM 44140T and G. hydrophobica DSM 44015T resulted in values of 26.3 and 25.0 %, respectively. These results and those of the physiological and biochemical tests allowed a clear phenotypic differentiation of strains Ca8T and Ca14 from the most closely related species of the genus Gordonia . It is concluded that strains Ca8T and Ca14 represent a novel species, for which the name Gordonia phosphorivorans sp. nov. is proposed, with the type strain Ca8T ( = DSM 45630T = CCUG 61533T = CCM 7957T = LMG 26648T).

Tibial osteomyelitis caused by Gordonia bronchialis in an immunocompetent patient

Gordonia species are aerobic Gram-positive bacilli that rarely cause human infections, often in the setting of indwelling intravascular catheters. We report the first case of osteomyelitis caused by Gordonia bronchialis in a healthy immunocompetent host in the absence of an intravascular catheter.

The strengths and weaknesses of Gordonia: a review of an emerging genus with increasing biotechnological potential

This review about the genus Gordonia provides a current overview of recent research on a young genus that was introduced in the year 1997 ( Stackebrandt et al., 1997 ). This emerging genus has attracted increasing environmental, industrial, biotechnological and medical interest during the last few years, in particular due to the capabilities of its members to degrade, transform, and synthesize organic compounds as well as to the pathogenic effects that have been described in many case studies. The number of publications about Gordonia has increased significantly after the year 2004 (the year of the first Gordonia review published by Arenskötter et al.) describing 13 new validly published species (type strains), many newly described physiological and metabolic capabilities, new patent applications and many new case reports of bacterial infections. Members of the genus Gordonia are widely distributed in nature and it is therefore important to unravel the species richness and metabolic potential of gordoniae in future studies to demonstrate their environmental impact especially on the degradation of persistent organic compounds and their ecological participation in the carbon cycle of organic material in soil and water. This review summarizes mainly the current state of importance and potential of the members of this genus for the environmental and biotechnological industry ("the strengthsâ) and briefly its pathogenic impact to humans ("the weaknessesâ).

Involvement of two latex-clearing proteins during rubber degradation and insights into the subsequent degradation pathway revealed by the genome sequence of Gordonia polyisoprenivorans strain VH2

The increasing production of synthetic and natural poly(cis-1,4-isoprene) rubber leads to huge challenges in waste management. Only a few bacteria are known to degrade rubber, and little is known about the mechanism of microbial rubber degradation. The genome of Gordonia polyisoprenivorans strain VH2, which is one of the most effective rubber-degrading bacteria, was sequenced and annotated to elucidate the degradation pathway and other features of this actinomycete. The genome consists of a circular chromosome of 5,669,805 bp and a circular plasmid of 174,494 bp with average GC contents of 67.0% and 65.7%, respectively. It contains 5,110 putative protein-coding sequences, including many candidate genes responsible for rubber degradation and other biotechnically relevant pathways. Furthermore, we detected two homologues of a latex-clearing protein, which is supposed to be a key enzyme in rubber degradation. The deletion of these two genes for the first time revealed clear evidence that latex-clearing protein is essential for the microbial utilization of rubber. Based on the genome sequence, we predict a pathway for the microbial degradation of rubber which is supported by previous and current data on transposon mutagenesis, deletion mutants, applied comparative genomics, and literature search.

Gordonia bronchialis bacteremia and pleural infection: case report and review of the literature

Gordonia species are aerobic actinomycetes recently recognized as causing human disease, often in the setting of intravascular catheter-related infections. We describe a case of Gordonia bronchialis bacteremia and pleural space infection in the absence of an indwelling intravascular catheter and review the breadth of reported infections with this emerging pathogen.

Gordonia humi sp. nov., isolated from soil

A Gram-stain-positive, non-endospore-forming actinobacterium (CC-12301T) was isolated from soil attached to a spawn used in the laboratory to grow the edible mushroom Agaricus brasiliensis. Based on 16S rRNA gene sequence similarities, strain CC-12301T was shown to belong to the genus Gordonia and was most closely related to the type strains of Gordonia hydrophobica (97.6 % similarity), Gordonia terrae (97.5 %), Gordonia amarae (97.5 %) and Gordonia malaquae (97.4 %). The quinone system was determined to consist predominantly of menaquinone MK-9(H2), minor amounts of MK-8(H2) and MK-7(H2). The polar lipid profile consisted of the major compounds diphosphatidylglycerol and phosphatidylethanolamine, moderate amounts of two phosphatidylinositol mannosides and phosphatidylinositol and minor amounts of phosphatidylglycerol, three unidentified glycolipids, two phosphoglycolipids and a phospholipid. Mycolic acids were present. These chemotaxonomic traits and the major fatty acids, which were C16 : 1 cis9, C16 : 0, C18 : 1 and tuberculostearic acid (10-methyl C18 : 0), supported the affiliation of strain CC-12301T to the genus Gordonia. The results of physiological and biochemical tests allowed clear phenotypic differentiation of strain CC-12301T from the most closely related Gordonia species. Strain CC-12301T therefore represents a novel species, for which the name Gordonia humi sp. nov. is proposed, with the type strain CC-12301T (=DSM 45298T =CCM 7727T).

Phylogenetic studies of Gordonia species based on gyrB and secA1 gene analyses

Phylogenetic relations within the genus Gordonia were analyzed using partial gyrB and secA1 gene sequences of 23 type species in comparison with those of 16S rRNA gene. The gyrB and secA1 phylogenies showed agreement with that constructed using 16S rRNA gene sequences. The degrees of divergence of the gyrB and secA1 genes were approximately 3.4 and 1.7 times greater, respectively, than that of 16S rRNA gene. The gyrB gene showed more discriminatory power than either the secA1 or 16S rRNA gene, facilitating clear differentiation of any two Gordonia species using gyrB gene analysis. Our data indicate that gyrB and secA1 gene sequences are useful as markers for phylogenetic study and identification at the species level of the genus Gordonia.

Gordonia species: emerging pathogens in pediatric patients that are identified by 16S ribosomal RNA gene sequencing

Gordonia species are emerging pathogens that are often misidentified as Rhodococcus or Nocardia species but are reliably distinguished by 16S ribosomal RNA gene sequencing. We present a case series of 6 episodes of catheter-associated infection caused by Gordonia species in 5 patients seen at a tertiary care pediatric hospital and describe the management and outcomes of this infection in adults and children.

Gordonia shandongensis sp. nov., isolated from soil in China

The taxonomic position of strain SD29T, isolated from soil, was clarified using a polyphasic taxonomic approach. The organism produced an elementary branching mycelium which fragmented into rod/coccus-shaped elements and it possessed meso-diaminopimelic acid, arabinose, galactose as diagnostic diamino acid and sugars, MK-9(H2) as predominant menaquinone, phospholipids of type PII and mycolic acid. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SD29T was most closely related to Gordonia hydrophobica DSM 44015T and Gordonia sihwensis DSM 44576T, forming a distinct but loosely related branch in the phylogenetic tree. A number of physiological properties readily separated the isolate from its nearest neighbours. It is evident from genotypic and phenotypic data that strain SD29T represents a novel species of the genus Gordonia, for which the name Gordonia shandongensis sp. nov. is proposed. The type strain is SD29T (=CGMCC 4.3492T=JCM 13907T).

Gordonia soli sp. nov., a novel actinomycete isolated from soil

A soil isolate, strain CC-AB07T, was characterized using a polyphasic approach. This organism had chemotaxonomic and morphological properties consistent with its classification in the genusGordonia. 16S rRNA gene sequence analysis showed that the novel strain formed a monophyletic branch at the periphery of the evolutionary radiation occupied by the genusGordonia, its closest neighbours being the type strains ofGordonia alkanivorans,Gordonia amicalis,Gordonia bronchialis,Gordonia desulfuricans,Gordonia polyisoprenivoransandGordonia rhizosphera. The novel isolate was distinguished from all of these type strains using a range of phenotypic properties and bygyrBgene sequence analysis. It was evident from the genotypic and phenotypic data that strain CC-AB07Tshould be classified as representing a novel species in the genusGordonia, for which the nameGordonia solisp. nov. is proposed. The type strain is CC-AB07T(=BCRC 16810T=DSM 44995T).

Gordonia araii sp. nov. and Gordonia effusa sp. nov., isolated from patients in Japan

Two bacterial strains, IFM 10211T and IFM 10200T, were isolated from the sputum of two Japanese patients, and were subjected to a polyphasic taxonomic study. The two strains were found to have morphological, physiological and chemotaxonomic properties that were consistent with their assignment to the genus Gordonia, except for a few chemotaxonomic characteristics. Almost complete 16S rRNA gene sequences of the two strains were determined; the data showed that they are related distantly to Gordonia amarae, Gordonia hirsuta, Gordonia hydrophobica and Gordonia sihwensis, showing 16S rRNA gene sequence similarities to the type strains of these species of 96.2–97.9 %. DNA–DNA relatedness data coupled with the combination of genotypic and phenotypic data indicated that the two strains are representatives of two novel, separate species. The names proposed to accommodate these two strains are Gordonia araii sp. nov. (type strain IFM 10211T=DSM 44811T=NBRC 100433T=JCM 12131T) and Gordonia effusa sp. nov. (type strain IFM 10200T=DSM 44810T=NBRC 100432T=JCM 12130T).