Phylogenetic analysis of some Aerococcus-like organisms from clinical sources: description of Helcococcus kunzii gen. nov., sp. nov

Helcococcus kunzii, a skin-colonising microorganism with pathogenic capacity: a case of polymicrobial intracranial empyema

Helcococcus kunzii is a Gram-positive anaerobic facultative coccus that colonises the skin. Human infection is rare, with very few cases being described in the literature. The authors present the case of a 17-year-old man, with a history of cholesteatoma, diagnosed with mastoiditis complicated by intracranial empyema. After urgent surgical drainage, Gram staining revealed a Gram-negative bacillus and a Gram-positive coccus. The latter exhibited fastidious growth, presented as small grey colonies in blood agar, and was afterwards identified as H. kunzii The patient was started on intravenous antibiotics, switched to oral route after 8 weeks and fully recovered. To the best of our knowledge, this is the third case of an intracranial infection in which H. kunzii is involved, two of them occurring in patients with cholesteatoma.

First Chinese case report of Helcococcus kunzii in a patient with diabetic foot

BACKGROUND

Infection of Helcococcus kunzii(H. kunzii) from diabetic foot wound is rarely reported. This case report describes the infection of H.kunzii and highlights the therapeutic effect on H.kunzii from a diabetic foot wound.

CASE PRESENTATION

In this study, one H. kunzii strain was isolated from a patient with diabetic foot, which was confirmed by 16S rRNA gene analysis and MALDI-TOF-MS. It is the first Chinese case of H. kunzii in a patient with diabetic foot. As a result of the lack of antibiotic sensitivity data and multiple comorbidities, antibiotics were used cautiously, and those administered during the first 3 months were ineffective. Then, vacuum sealing drainage (VSD) was applied during hospitalization; no antibiotics were used and the wound healed well.

CONCLUSIONS

VSD alone may be more effective in treating diabetic feet infected with H. kunzii, which may provide reference for clinical treatment of H. kunzii infection from diabetic foot.

Lagierella massiliensis gen. nov., sp. nov., Isolated from a Stool Sample

Strain Marseille-P2012^T was described to represent a new bacterial genus belonging to the phylum Firmicutes using the taxonogenomics concept. It was isolated from stool samples of a healthy 2-year-old Senegalese boy in a study of the human gut microbiota. This strain is a Gram-positive, anaerobic, non-motile and coccus-shaped bacterium. The 16S rRNA gene sequence of strain Marseille-P2012 exhibited 90.5% similarity with Finegoldia magna strain ATCC 29,328, the phylogenetically closest species with standing in nomenclature. The genome of strain Marseille-P2012^T is 1,832,315 bp-long with 32.46 mol% of G + C content. With regard to its phenotypic, biochemical and genomic characteristics, this bacterium was classified as a new bacterial genus and species, Lagierella massiliensis gen. nov., sp. nov., with strain Marseille-P2012^T (= CSUR P2012 = DSM100854) as type strain.

Vegetative Valvular Endocarditis and Hepatitis Associated with Helcococcus ovis in a 7-year-old White Leghorn Rooster

Helcococcus ovis is a slow-growing, pyridoxal-dependent, Gram-positive coccus belonging to the Peptostreptococcaceae family. Bacteria belonging to the genus Helcococcus are considered normal inhabitants of keratinized epithelium in humans; however, several reports support their role as pathogens in humans and several animal species. This case report describes the identification of H. ovis in a white leghorn rooster with valvular vegetative endocarditis and hepatitis. In February 2017 one dead, 7-yr-old, white leghorn rooster was submitted to the California Animal Health and Food Safety Turlock laboratory for diagnostic testing. Postmortem and microscopic examination revealed vegetative endocarditis and aortic thrombosis associated with large numbers of Gram-positive cocci. Myocarditis and extensive necrotic hepatitis were also noticed. Helcococcus ovis was isolated in large numbers from the aortic endothelium and confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Bacterial colonies become evident 48 hr postincubation and exhibited a satellite growth around Escherichia coli on blood agar plates. A similar relationship has been described between Helcococcus spp. and Staphylococcus aureus. The primary site of infection in this chicken was not determined. To our understanding this is the first report of H. ovis infection in an avian species. The fastidious nature and nutritional requirements of Helcococcus spp. must be considered in order to allow proper identification and avoid misdiagnosis. Further studies are needed to define pathogenesis, virulence factors, and predisposing conditions associated with this microorganism.

Citroniella saccharovorans gen. nov. sp. nov., a member of the family Peptoniphilaceae isolated from a human fecal sample from a coastal traditional community member

A novel Gram-stain-positive, non-motile, non-spore-forming coccus-shaped obligately anaerobic bacterium was recovered from a fecal sample obtained from an individual from a traditional community located on the southern coast of Peru. The results of analysis based on 16S rRNA gene sequencing indicated the novel bacterium to be phylogenetically distinct from other genera of members of the Peptoniphilaceae family, sharing a loose affinity with the genera Ezakiella, Finegoldia, Gallicola and Parvimonas. The major cellular fatty acids of the novel isolate were determined to be C16:0, C17:1ω8c, and C18:1ω9c. The DNA G+C content was 29.9 mol%. End products of metabolism from peptone yeast glucose broth (PYG) were determined to be acetate and methyl succinate. The diagnostic diamino acid present in the cell wall was lysine. On the basis of the phenotypic, chemotaxonomic and phylogenetic results the organism is a member of a novel genus belonging to the family Peptoniphilaceae for which the name Citroniella saccharovorans gen nov. sp. nov., is proposed. The type strain is M6.X9^T (DSM 29873^T=CCUG 66799^T).

Helcococcus ovis in a patient with an artificial eye: a case report and literature review

BACKGROUND

Helcococcus ovis, belonging to the genus of Helcococcu in Peptostreptococcaceae, is one kind of facultative anaerobic and gram-positive cocci, which was first isolated from a mixed infection in sheep in 1999. To our knowledge, it's known as an invasive pathogen in animals, and never been reported as a human pathogen in published literature. The aims of this work are to describe the first report of H. ovis which was recovered from the artificial eye of human case and perform a literature review.

CASE PRESENTATION

A 26 year-old man reporting pyogenic infection with an artificial eye attended ophthalmic ward in Tongji hospital. After physical examination, clinical and laboratory investigations, the diagnosis of eye infection caused by Helcococcus ovis and Staphylococcus aureus was established. Receiving a medico-surgical approach, the patient was successfully treated. The treatment consisted in intravenous cefotaxime and ornidazole, levofloxacin eye drops during two weeks and removing of right artificial eye with debridement.

CONCLUSIONS

We describe here the first known case of H. ovis which was recovered from human artificial eye. This report different from previous data found in the literature emphasizes the invasive potential of this bacterial species as a pathogen in human. Prospectively, the application of next generation sequencing tools would contribute to a more accurate classification of clinical strains.

Helcococcus kunzii prosthetic valve endocarditis secondary to lower extremity cellulitis

An 88-year-old man with history of bioprosthetic aortic valve replacement was hospitalised with fever, chills, malaise and right lower extremity cellulitis. Laboratory investigations revealed leucocytosis and blood cultures grew Helcococcus kunzii Although transoesophageal echocardiography was negative for endocarditis, the patient was treated with 4 week of intravenous ceftriaxone. However, he was readmitted 6 weeks later with symptoms of fever, chills and hypoxia in setting of recurrent H. kunzii bacteraemia. A repeat transoesophageal echocardiogram revealed a mobile mass on bioprosthetic aortic valve, severe perivalvular insufficiency with pseudoaneurysm formation, and severe native mitral and tricuspid valve regurgitation. Cardiothoracic surgery was consulted and the patient underwent replacement of aortic valve and aortic root, and tricuspid and mitral valve repairs. Histological examination of excised bioprosthetic aortic valve revealed active endocarditis with cocci identified on silver stain. Patient was successfully treated with 4-week course of intravenous ceftriaxone and was doing well at 2-year follow-up.

Microbial diversity of extreme habitats in human homes

High-throughput sequencing techniques have opened up the world of microbial diversity to scientists, and a flurry of studies in the most remote and extreme habitats on earth have begun to elucidate the key roles of microbes in ecosystems with extreme conditions. These same environmental extremes can also be found closer to humans, even in our homes. Here, we used high-throughput sequencing techniques to assess bacterial and archaeal diversity in the extreme environments inside human homes (e.g., dishwashers, hot water heaters, washing machine bleach reservoirs, etc.). We focused on habitats in the home with extreme temperature, pH, and chemical environmental conditions. We found a lower diversity of microbes in these extreme home environments compared to less extreme habitats in the home. However, we were nonetheless able to detect sequences from a relatively diverse array of bacteria and archaea. Habitats with extreme temperatures alone appeared to be able to support a greater diversity of microbes than habitats with extreme pH or extreme chemical environments alone. Microbial diversity was lowest when habitats had both extreme temperature and one of these other extremes. In habitats with both extreme temperatures and extreme pH, taxa with known associations with extreme conditions dominated. Our findings highlight the importance of examining interactive effects of multiple environmental extremes on microbial communities. Inasmuch as taxa from extreme environments can be both beneficial and harmful to humans, our findings also suggest future work to understand both the threats and opportunities posed by the life in these habitats.

Novel chromosome-encoded erm(47) determinant responsible for constitutive MLSB resistance in Helcococcus kunzii

OBJECTIVES

The aim of the study was to identify the determinant responsible for erythromycin resistance in Helcococcus kunzii clinical isolate UCN99 and to characterize the genetic support and environment of this novel gene.

METHODS

MICs were determined using the broth microdilution method according to EUCAST guidelines. The entire genome sequence of H. kunzii UCN99 was determined using a 454/Roche GS Junior sequencer. The fragment encompassing the new resistance gene and its own promoter was cloned into the pAT29 shuttle vector and the recombinant plasmid pAT29Ωerm(47) was expressed in both Staphylococcus aureus and Streptococcus agalactiae. The transcription start site (TSS) was experimentally determined by 5' RACE-PCR.

RESULTS

UCN99 exhibited a constitutive macrolide/lincosamide/streptogramin B (MLS_B) resistance phenotype, suggesting the presence of an Erm protein. WGS allowed the identification of a novel gene, named erm(47), encoding a protein sharing 44%-48% amino acid identity with known Erm methylases. In both S. aureus and S. agalactiae, the introduction of pAT29Ωerm(47) conferred a significant increase (≥16-fold) in MICs of all macrolides and lincosamides tested, as well as a 4-fold increase in MICs of quinupristin (streptogramin B), confirming the MLS_B resistance. The TSS identification revealed the presence of a short leader peptide, potentially implicated in a translational attenuation mechanism. It was also demonstrated that erm(47) was harboured by a 81 kb genomic island integrated into a chromosomal gene.

CONCLUSIONS

This is the first description of a novel MLS_B resistance determinant, named erm(47). The prevalence of this gene among Gram-positive cocci must be further investigated to determine its clinical significance.

In vitro antimicrobial susceptibility of Helcococcus kunzii and molecular analysis of macrolide and tetracycline resistance

Thanks to the recent advent of matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) technology, Helcococcus kunzii is now easily identifiable and considered as an opportunistic pathogen. However, data about antimicrobial susceptibilities remain very limited. The aim of the study was, then, to assess its in vitro susceptibility to 18 antimicrobial agents and to investigate the genetic basis of macrolide and tetracycline resistance. Thirty-nine human clinical isolates of H. kunzii collected from 2008 to 2013 were studied, as well as the type strain ATCC 51366(T). Minimum inhibitory concentrations (MICs) of penicillin G, amoxicillin, cefotaxime, imipenem, gentamicin, erythromycin, clindamycin, quinupristin-dalfopristin, ciprofloxacin, levofloxacin, tetracycline, tigecycline, vancomycin, teicoplanin, linezolid, daptomycin, cotrimoxazole and rifampin were determined by the microdilution method. Screening for macrolide [erm(A) including erm(TR), erm(B), erm(C), erm(F), erm(T), erm(X), msr(A) and mef(A)] and tetracycline [tet(L), tet(M) and tet(O)] resistance genes was performed, as well as the detection of mutations in 23S rRNA. Except for one strain resistant to cefotaxime, all strains were categorised as susceptible to β-lactams, glycopeptides, linezolid, daptomycin and tigecycline. Whereas ciprofloxacin and gentamicin exhibited limited activity, 95% of strains were categorised as susceptible to levofloxacin. Concerning erythromycin, a bimodal distribution was observed, with 29 'wild-type' strains (MICs from 0.25 to 2 mg/L) and 11 'resistant' strains (MICs ≥ 256 mg/L), including ten harbouring erm(TR). Two isolates exhibited acquired tetracycline resistance (MICs of 16 mg/L) by the production of tet(M). This large study on the in vitro antimicrobial susceptibility of H. kunzii suggests that β-lactams (especially penicillins) should be preferred for the treatment.

Infectious endocarditis caused by Helcococcus kunzii in a vascular patient: a case report and literature review

Background

Helcococcus kunzii is a facultative anaerobic bacterium that was first described by Collins et al. in 1993, and was initially considered as a commensal of the human skin, in particular of lower extremities. Human infections caused by H. kunzii remain rare with only a few cases published in the pubmed database. Nevertheless recent reports indicate that this microorganism has to be considered as an opportunistic pathogen that can be involved in severe infections in human. To the best of our knowledge, we describe here the first known case of infectious endocarditis caused by H. kunzii.

Case presentation

A 79 year-old man reporting severe polyvascular medical history attended the emergency ward for rapid deterioration of his general state of health. After physical examination and paraclinical investigations, the diagnosis of infectious endocarditis on native mitral valve caused by Helcococcus kunzii was established based on Dukes criteria. MALDI-TOF mass spectrometry and 16S rDNA sequencing allowed an accurate identification to the species level of Helcococcus kunzii. The patient was successfully treated by a medico-surgical approach. The treatment consisted in intravenous amoxicillin during four weeks and mitral valve replacement with a bioprosthestic valve. After an in depth review of patient’s medical file, the origin of infection remained unknown. However, a cutaneous portal of entry cannot be excluded as the patient and his General Practitioner reported chronic ulcerations of both feet.

Conclusions

We describe here the first case of endocarditis caused by H. kunzii in an elderly patient with polyvascular disease. This report along with previous data found in the literature emphasizes the invasive potential of this bacterial species as an opportunistic pathogen, in particular for patient with polyvascular diseases. MALDI-TOF mass spectrometry and 16S rDNA sequencing are reliable tools for H. kunzii identification. We also sequenced in this work H.kunzii type strain 103932T CIP and deposited in the Genbank under accession number KM403387. We noticed a 14 base difference between our sequence and the original sequence deposited by Collins et al. under Genbank accession number X69837. Hopefully, the spread of next generation sequencing tools would lead to a more accurate classification of clinical strains.

Identification and Clinical Significance of Helcococcus kunzii in Human Samples

From 2008 to 2013, 39 Helcococcus kunzii strains were collected from human clinical specimens (79% from foot ulcers), and 85% of the 39 patients were infected. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and molecular methods accurately identified all isolates. This large study of clinical observations confirms the potential pathogenic role of H. kunzii.

Multi-drug resistant helcococcus-like organism isolated from a chest abscess

We report a case of multi-drug resistant Helcococcus-like organism isolated in pure culture from a chest abscess in a 31-year-old pregnant woman.

Ezakiella peruensis gen. nov., sp. nov. isolated from human fecal sample from a coastal traditional community in Peru

A novel Gram-stain positive, non-motile, non-sporeforming coccus-shaped, obligately anaerobic bacterium was isolated from a fecal sample of an individual residing in a traditional Peruvian community. The organism was characterized using biochemical, chemotaxonomic and phylogenetic methods. Comparative 16S rRNA gene sequence analyses and phenotypic characteristics demonstrated that the organism was biochemically and phenotypically related, but distinct, from a group of organisms referred to as the Gram-stain positive anaerobic cocci (GPAC). The major cellular fatty acids of the novel isolate were determined to be C16:0 (18.3%), C18:1ω9c (39.8%), C18:2ω6,9c/C18:0 ANTE (13.2%). Fermentation end products from PYG are acetate and formate. Cell-wall peptidoglycan was found to be A4α (L-Lys-L-Ala-L-Glu) and the G + C content was determined to be 38.4 mol%. Based on the phenotypic, chemotaxonomic, and phylogenetic results, Ezakiella peruensis gen. nov., sp. nov., is now proposed. The type strain is M6.X2(T) (DSM 27367(T) = NBRC 109957 (T) = CCUG 64571(T)).

Predominance of cluster I Clostridium in hydrogen fermentation of galactose seeded with various heat-treated anaerobic sludges

To identify the key bacterial populations in hydrogen fermentation of galactose, a fermentor seeded with a heat-treated sludge was operated. After 27h of fermentation, the proportion of butyric acid increased to 69.4wt.% and the gas production yield reached 1.0molH2/molgalactose. In the pyrosequencing of 16S rDNA, an increase of the proportion of the phylum Firmicutes from 4.2% to 92% (mostly cluster I Clostridium) was observed. To verify the predominance and the ubiquity of the cluster, five fermentors seeded with different heat-treated anaerobic sludges having different feedstock compositions and digestion temperatures were investigated using qPCR analyses. The abundance of the cluster increased >100-fold during the fermentation, regardless of the inocula. Moreover, the abundance was negatively correlated with the lag time of hydrogen production and positively correlated with the hydrogen production rate, demonstrating the relevance of the cluster to hydrogen production. Taken together, the results clearly revealed the importance of cluster I Clostridium in the hydrogen fermentation of galactose.

Identification and clinical significance of Helcococcus species, with description of Helcococcus seattlensis sp. nov. from a patient with urosepsis

Helcococcus spp. are Gram-positive, catalase-negative, facultatively anaerobic cocci that are associated with wound and prosthetic joint infections as well bacteremia and empyema. Five Helcococcus spp. strains were isolated from our patient population, including 2 strains of Helcococcus kunzii from trauma-associated wounds, 2 Helcococcus sueciensis strains from blood and abscess, and a novel Helcococcus spp. strain from blood associated with urosepsis. Based on the phenotypic and phylogenetic evidence, we propose that the unknown bacterium be classified as Helcococcus seattlensis sp. nov. We found that all 5 tested Helcococcus strains grew as satellite colonies around Staphylococcus aureus and, interestingly, both H. kunzii strains were isolated together with S. aureus. In addition to 16S rRNA gene sequencing, conventional methods for leucine aminopeptidase (LAP) and pyrrolidonyl arylamidase (PYR) testing can be cost-effective and efficient for differentiation of Helcococcus spp. from Abiotrophia and Granulicatella species. Using nonstandard methods, we found that all tested Helcococcus spp. had high MICs of >4/76 μg/ml for trimethoprim-sulfamethoxazole, an antibiotic commonly used to treat urinary tract infections. High MICs for erythromycin, azithromycin, and clindamycin, and intermediate to high MICs for moxifloxacin, levofloxacin, and gentamicin were also observed among the Helcococcus strains.

First report of brain abscess caused by a satelliting phenotypic variant of Helcococcus kunzii

Helcococcus kunzii was isolated from a brain abscess in a diabetic patient with cholesteatoma and demonstrated satellitism around Staphylococcus aureus in culture. This is the first reported case of severe central nervous system infection due to H. kunzii and the first description of a satelliting phenotypic variant of this organism.

Non-contiguous finished genome sequence and description of Kallipyga massiliensis gen. nov., sp. nov., a new member of the family Clostridiales Incertae Sedis XI

Kallipyga massiliensis strain ph2(T) is the type strain of Kallipyga massiliensis gen. nov., sp. nov., the type species of the new genus Kallipyga within the family Clostridiales Incertae Sedis XI. This strain, whose genome is described here, was isolated from the fecal flora of a 26-year-old woman suffering from morbid obesity. K. massiliensis is an obligate anaerobic coccus. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 1,770,679 bp long genome (1 chromosome but no plasmid) contains 1,575 protein-coding and 50 RNA genes, including 4 rRNA genes.

Management of chronic osteomyelitis of the tibia with life-threatening complications under negative pressure wound therapy and isolation of Helcococcus kunzii

We report the case of an 86-year-old man with severe wound infection originating from a chronic crural ulcer of the lower limb, which under negative pressure wound therapy led to excessive tissue necrosis and perforation of the anterior tibial artery. A swab taken 10 and 7 days preoperatively was positive for Helcococcus kunzii. H. kunzii has been described as a potentially pathogenic organism. The questions whether the negative pressure wound therapy itself caused the bleeding or the negative pressure wound therapy, which generates an anaerobic atmosphere, has triggered the growth and invasion of the facultative anaerobic bacterium H. kunzii and owing to the infection the artery perforated or whether the bacteria has no influence at all remain currently unanswered. After surgical debridement the signs of infection were completely eliminated, and a free musculocutaneous flap led to rapid healing of the wound. Following which H. kunzii was no longer detectable.

Male circumcision significantly reduces prevalence and load of genital anaerobic bacteria

Male circumcision reduces female-to-male HIV transmission. Hypothesized mechanisms for this protective effect include decreased HIV target cell recruitment and activation due to changes in the penis microbiome. We compared the coronal sulcus microbiota of men from a group of uncircumcised controls (n = 77) and from a circumcised intervention group (n = 79) at enrollment and year 1 follow-up in a randomized circumcision trial in Rakai, Uganda. We characterized microbiota using16S rRNA gene-based quantitative PCR (qPCR) and pyrosequencing, log response ratio (LRR), Bayesian classification, nonmetric multidimensional scaling (nMDS), and permutational multivariate analysis of variance (PerMANOVA). At baseline, men in both study arms had comparable coronal sulcus microbiota; however, by year 1, circumcision decreased the total bacterial load and reduced microbiota biodiversity. Specifically, the prevalence and absolute abundance of 12 anaerobic bacterial taxa decreased significantly in the circumcised men. While aerobic bacterial taxa also increased postcircumcision, these gains were minor. The reduction in anaerobes may partly account for the effects of circumcision on reduced HIV acquisition.

The bacterial changes identified in this study may play an important role in the HIV risk reduction conferred by male circumcision. Decreasing the load of specific anaerobes could reduce HIV target cell recruitment to the foreskin. Understanding the mechanisms that underlie the benefits of male circumcision could help to identify new intervention strategies for decreasing HIV transmission, applicable to populations with high HIV prevalence where male circumcision is culturally less acceptable.

Prosthetic joint infection caused by Helcococcus kunzii

Helcococcus kunzii was isolated by sonication and conventional cultures obtained from a case of infection following total knee prosthesis in an immunocompetent patient. The patient recovered uneventfully. This is the first known case of an H. kunzii prosthetic joint infection.

Helcococcus kunzii isolated from a sow with purulent urocystitis

Helcococcus kunzii has never been reported in veterinary medicine. The isolation of H. kunzii from a sow with purulent urocystitis is described, suggesting this organism's potential pathogenic role in swine.

Murdochiella asaccharolytica gen. nov., sp. nov., a Gram-stain-positive, anaerobic coccus isolated from human wound specimens

Two strains of previously unknown Gram-stain-positive, anaerobic, coccus-shaped bacteria from human wound specimens were characterized using phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies and distinguishable biochemical characteristics demonstrated that these two unknown strains, WAL 1855C(T) and WAL 2038E, are genotypically homogeneous and constitute a novel lineage within Clostridium cluster XIII. There was 13-14 % 16S rRNA gene sequence divergence between the novel strains and the most closely related species, Parvimonas micra, Finegoldia magna and species of Helcococcus. Based on the phenotypic and phylogenetic findings, a novel genus and species, Murdochiella asaccharolytica gen. nov., sp. nov., are proposed. Strain WAL 1855C(T) (=ATCC BAA-1631(T) =CCUG 55976(T)) is the type strain of Murdochiella asaccharolytica.

Isolation of Helcococcus ovis from sheep with pleuritis and bronchopneumonia

Helcococcus ovis is a newly established species in the genus Helcococcus. The clinical significance of this organism in sheep has not been reported. In the current report, isolation of H. ovis from a 6-month-old mixed-breed ewe lamb that died of respiratory disease is described. Pathologic examination revealed severe, focally extensive, chronic necrotizing pleuritis with intralesional coccobacilli and mild, multifocal, subacute mucopurulent bronchopneumonia, indicating a bacterial etiology. A Gram-positive bacterium was isolated in heavy growth from the lung tissue. DNA sequence analysis on the 16S rDNA gene demonstrated that the isolate was H. ovis. To the authors' knowledge, this is the first report of isolation of H. ovis associated with infection in sheep with pleuritis and bronchopneumonia.

Helcococcus ovis, an emerging pathogen in bovine valvular endocarditis

The initial isolation of Helcococcus ovis from a valvular thrombus prompted us to investigate the prevalence of this bacterium in bovine valvular endocarditis. Specimens from 55 affected hearts were examined by culture using Columbia blood agar and cross streaking the inoculated plate with a Staphylococcus aureus strain. As confirmed by 16S rRNA gene sequencing, H. ovis was isolated with an unexpectedly high frequency of 33%, predominantly as heavy growth and pure culture. The majority of H. ovis isolates showed distinct satellitism around S. aureus and pyridoxal dependency, resembling "nutritionally variant streptococci" (now assigned to the genera Abiotrophia and Granulicatella). Using the API rapid ID 32 Strep, API ZYM, and Rosco Diatabs systems, incongruent results were obtained for alkaline phosphatase, beta-galactosidase, beta-glucuronidase, and leucine aminopeptidase activities. Based on the satellitism/pyridoxal dependency; hemolysis on blood agar; the API rapid ID 32 Strep results for arginine dihydrolase, alpha-galactosidase, beta-galactosidase, beta-glucuronidase, and pyroglutamic acid arylamidase activities; hippurate hydrolysis; and acidification of sucrose, a scheme for the identification of H. ovis and its differentiation from other members of the Helcococcus genus and the pyridoxal-dependent species Abiotrophia defectiva, Granulicatella adiacens, and Granulicatella elegans is proposed. By establishing specific fluorescence in situ hybridization, large H. ovis aggregates were specifically detected within the fibrinous exudate of the valvular thrombi. Our results demonstrate for the first time that H. ovis represents an emerging pathogen in bovine valvular endocarditis that is frequently isolated if appropriate culture conditions are used.

Isolation of Helcococcus kunzii from plantar phlegmon in a vascular patient

Helcococcus kunzii has previously been considered to belong to the normal skin flora of podiatry patients. Here, H. kunzii was isolated in abundance from a pus specimen collected by incision and drainage of plantar phlegmon. This fastidious Gram-positive species was unambiguously identified with the colorimetric VITEK 2 GP card identification system. This suggests that this phenotypic identification system is able to identify promptly H. kunzii, which should be considered a potential pathogen.

Life-threatening invasive Helcococcus kunzii infections in intravenous-drug users and ermA-mediated erythromycin resistance

We report the first two cases of life-threatening invasive Helcococcus kunzii infection, with primary bacteremia and empyema thoracis, respectively. Gram smears of both H. kunzii isolates showed a mixture of gram-positive and gram-negative cocci. The isolate from the first patient, resistant to erythromycin and clindamycin, possessed an ermA gene.

Bacteremia in a patient with colonic carcinoma caused by a novel Sedimentibacter species: Sedimentibacter hongkongensis sp. nov

A bacterium was isolated from the blood culture of a 91-year-old patient with colonic carcinoma. The cells were strict anaerobic, motile, Gram-negative, sporulating, straight, or slightly curved rods. The bacterium grew on agar using the BACTEC anaerobic blood culture broth or buffered charcoal yeast extract agar as pinpoint colonies after 72 h of incubation at 37 degrees C in anaerobic conditions. It did not grow on blood agar, chocolate agar, MacConkey agar, nutrient agar or broth, brain heart infusion agar or broth, Brucella agar, or cooked meat medium. It produces catalase but not cytochrome oxidase. 16S rRNA gene sequencing and phylogenetic analysis showed that it is closely related to Sedimentibacter hydroxybenzoicus and Sedimentibacter saalensis, with 10.5% and 11.9% differences between the 16S rRNA gene sequence of the bacterium and those of S. hydroxybenzoicus and S. saalensis respectively. A new species, Sedimentibacter hongkongenesis sp. nov., is proposed, for which HKU2(T) is the type strain.

Helcococcus ovis isolated from a pulmonary abscess in a horse

Helcococcus ovis, a recently described organism cultured from sheep, was isolated in pure culture from a pulmonary abscess in a horse. This is the first report of this organism in horses and the first report in veterinary medicine to clearly demonstrate a pathogenic role for this organism.

Helcococcus sueciensis sp. nov., isolated from a human wound

A previously undescribed, Gram-positive, catalase-negative, coccus-shaped organism that originated from a human wound was subjected to taxonomic study. On the basis of its cellular morphology and the results of biochemical testing, the unknown organism was identified tentatively as a member of the genus Helcococcus, but it did not correspond to either of the two recognized species of this genus. Comparative 16S rRNA gene sequencing studies confirmed that the bacterium was associated phylogenetically with the genus Helcococcus, with the unidentified organism forming a hitherto unknown subline within the genus. On the basis of biochemical, molecular chemical and molecular phylogenetic evidence, it is proposed that the unknown organism that was recovered from a human wound should be classified as a novel species of the genus Helcococcus, namely Helcococcus sueciensis sp. nov. The type strain is CCUG 47334T (=CIP 108183T).

Prosthetic joint infection due to "Helcococcus pyogenes" [corrected]

Helcococci have previously been associated with the colonization of ulcers and infections of the skin and soft tissues. We describe a case of prosthetic joint infection due to a previously undescribed organism that is genetically most closely related to Helcococcus.

Valvular endocarditis associated with Helcococcus ovis infection in a bovine

A 12-month-old Angus bull calf with a history of fever and lethargy of several weeks' duration was necropsied. Macroscopic findings included general dehydration, congestion, and edema within the craniodorsal lobes of the lung, multifocal ecchymotic hemorrhages on the dorsal epaxial and gluteal muscles, bloody ingesta within the gastrointestinal tract, and a 4- x 4- x 5-cm irregular plaque located on the right atrioventricular heart valve. Microscopically, there were focally extensive pulmonary alveolar infiltrates of histiocytes and neutrophils, large numbers of necrotic hypereosinophilic hepatocytes located within the centrilobular and midzonal regions of the liver, and, within the plaque from the right atrioventricular valve, a large mass formed by abundant laminated fibrin that contained numerous small multifocal aggregates of gram-positive cocci. This report describes the first apparent isolation of Helcococcus ovis from cattle.

Isolation of Helcococcus kunzii from a post-surgical foot abscess

We report here a case in which a strain of Helcococcus kunzii was isolated from a foot abscess, in an immunocompetent patient, after surgery for metatarsal fracture. Correct species identification of the strain was readily obtained on the basis of morphological and biochemical features, together with 16S rRNA analysis. This case demonstrates that this species should be considered a potential pathogen in patients with no underlying disease.

Meningoencephalitis associated with Globicatella sanguinis infection in lambs

Thirty lambs displayed symptoms of meningoencephalitis. An unusual gram-positive coccus was isolated in pure culture from the blood and brain samples from one of the affected animals, and phenotypic and phylogenetic characterization showed this to be Globicatella sanguinis. This is the first report of the isolation of G. sanguinis in pure culture from an animal infection.

Comparison of three commercial rapid identification systems for the unusual gram-positive cocci Dolosigranulum pigrum, Ignavigranum ruoffiae, and Facklamia species

We evaluated three rapid identification systems-The Biomerieux rapid ID 32 STREP (ID32), the BBL Crystal rapid gram-positive identification (Crystal), and the Remel IDS RapID STR (IDS) systems-for their ability to identify 7 strains of Alloiococcus otitidis, 27 strains of Dolosigranulum pigrum, 3 strains of Ignavigranum ruoffiae, and 18 strains of 4 different Facklamia species. Since none of these six species of gram-positive cocci are included in the identification databases for these systems, the correct identification for the strains tested should be "unacceptable ID" for the ID32 and Crystal systems or "no choice" for the IDS system. The ID32 system identified all 27 strains of D. pigrum, 6 of 18 Facklamia species, and 2 of 3 cultures of I. ruoffiae as "unacceptable ID." The Crystal system identified 10 of 27 D. pigrum, 2 of 18 Facklamia species, and 2 of 3 I. ruoffiae strains as "unacceptable ID." The IDS system identified only 1 culture of D. pigrum as "no choice," but it also identified 2 cultures of D. pigrum as a "questionable microcode" and 19 cultures of D. pigrum as an "inadequate ID, E. faecalis 90%, S. intermedius 9%." A total of 2 of the 18 cultures of Facklamia and all 3 of the I. ruoffiae cultures were correctly identified as "no choice." The most common misidentifications of Facklamia species by the ID32 and IDS systems were as various Streptococcus species and as Gemella species. In the Crystal system, the most common erroneous identification was Micrococcus luteus. These data indicate the need for the commercial manufacturers of these products to update their databases to include newly described species of gram-positive cocci.

Facklamia languida sp. nov., isolated from human clinical specimens

Three strains of a gram-positive catalase-negative, facultatively anaerobic coccus-shaped organism originating from human clinical samples were characterized by phenotypic and molecular taxonomic methods. Sequencing of genes encoding 16S rRNA showed that the strains are phylogenetically closely related (99.9 to 100% sequence similarity) and represent a new subline within the genus Facklamia. The unknown bacterium was readily distinguished from all currently described species of the genus Facklamia (viz., Facklamia hominis, Facklamia ignava, and Facklamia sourekii) by biochemical tests and electrophoretic analysis of whole-cell proteins. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Facklamia languida sp. nov. The type strain of F. languida is CCUG 37842.

Breast abscess associated with Helcococcus kunzii

Helcococcus kunzii, a nonvirulent member of the human skin flora, has recently been implicated in causing infections in immunosuppressed patients. We report a case of breast abscess associated with H. kunzii in an immunocompetant patient and discuss the criteria used in its identification and our observations of susceptibility testing for this species.

Facklamia ignava sp. nov., isolated from human clinical specimens

Two strains of a hitherto-undescribed gram-positive, catalase-negative coccus isolated from human sources were characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strains are genealogically identical and constitute a new line close to, but distinct from, Facklamia hominis. The unknown bacterium was readily distinguished from F. hominis by biochemical tests and electrophoretic analysis of whole-cell proteins. On the basis of phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Facklamia ignava sp. nov. The type strain of Facklamia ignava is CCUG 37419.

Use of enzyme tests in characterization and identification of aerobic and facultatively anaerobic gram-positive cocci

The contribution of enzyme tests to the accurate and rapid routine identification of gram-positive cocci is introduced. The current taxonomy of the genera of aerobic and facultatively anaerobic cocci based on genotypic and phenotypic characterization is reviewed. The clinical and economic importance of members of these taxa is briefly summarized. Tables summarizing test schemes and kits available for the identification of staphylococci, enterococci, and streptococci on the basis of general requirements, number of tests, number of taxa, test classes, and completion times are discussed. Enzyme tests included in each scheme are compared on the basis of their synthetic moiety. The current understanding of the activity of enzymes important for classification and identification of the major groups, methods of testing, and relevance to the ease and speed of identification are reviewed. Publications describing the use of different identification kits are listed, and overall identification successes and problems are discussed. The relationships between the results of conventional biochemical and rapid enzyme tests are described and considered. The use of synthetic substrates for the detection of glycosidases and peptidases is reviewed, and the advantages of fluorogenic synthetic moieties are discussed. The relevance of enzyme tests to accurate and meaningful rapid routine identification is discussed.

Colonization of skin by Helcococcus kunzii

In order to investigate the role of Helcococcus kunzii as a colonizer of skin and as a possible participant in diabetic foot ulcers, we used a selective medium to culture both lower- and upper-extremity skin from a study group of podiatry patients (60 diabetics and 60 nondiabetics) and a control group of 50 healthy volunteers. Although differences in colonization were not statistically significant, a trend toward higher colonization rates in the group of podiatry patients was noted. H. kunzii appears to preferentially colonize the skin of the feet, and while its pathogenic role in diabetic foot ulcers is difficult to establish, it may be a previously unrecognized component of the polymicrobial flora characteristically isolated from patients with these infections.

Lactic acid bacteria of foods and their current taxonomy

Application of molecular genetic techniques to determine the relatedness of food-associated lactic acid bacteria has resulted in significant changes in their taxonomic classification. During the 1980s the genus Streptococcus was separated into the three genera Enterococcus, Lactococcus and Streptococcus. The lactic acid bacteria associated with foods now include species of the genera Carnobacterium, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus, Tetragenococcus, Vagococcus and Weissella. The genus Lactobacillus remains heterogeneous with over 60 species (ymol% G+C content ranging from 33 to 55), of which about one-third are strictly heterofermentative. However, many changes have been made and reorganization of the genus along lines that do not follow previous morphological or phenotypic differentiation from Leuconostoc and Pediococcus is being studied. Phylogenetically belonging to the Actinomyces branch of the bacteria, Lactobacillus bifidus has been moved to the genus Bifidobacterium also on account of its greater than 50 mol% G+C content. It is therefore no longer considered one of the lactic acid bacteria senso strictu, which form part of the Clostridium branch of the bacteria. The new genus Weissella has been established to include one member of the genus Leuconostoc (Leuc, paramesenteroides) and heterofermentative lactobacilli with unusual interpeptide bridges in the peptidoglycan. Contrary to the clear-cut division of the streptococci, morphological and physiological features of Weissella do not directly support this grouping which now incorporates species that produce D(-)- as well as DL-lactate. The new genus Carnobacterium is morphologically similar to the lactobacilli, but it shares some physiological similarities (e.g. growth at pH 9.5) and a common phylogenetic branch with the genus Enterococcus. The review includes information on the taxonomic changes and the relationship of the bacteria of food fermentation and spoilage.

Helcococcus kunzii as sole isolate from an infected sebaceous cyst

Helcococcus kunzii was isolated in pure culture from pus drained from an infected sebaceous cyst associated with marked cellulitis. The cyst was excised one month later after the inflammation had subsided with flucloxacillin treatment. This is the first report of the isolation of H. kunzii as the sole pathogen from an infected site.

Identification, classification, and clinical relevance of catalase-negative, gram-positive cocci, excluding the streptococci and enterococci

Several new genera and species of gram-positive, catalase-negative cocci that can cause infections in humans have been described. Although these bacteria were isolated in the clinical laboratory, they were considered nonpathogenic culture contaminants and were not thought to be the cause of any diseases. Isolation of pure cultures of these bacteria from normally sterile sites has led to the conclusion that these bacteria can be an infrequent cause of infection. This review describes the new bacteria and the procedures useful for clinical laboratories to aid in their identification. The clinical relevance and our experience with the various genera and species are reviewed and discussed.