Lung abscess secondary to lung cancer with a coinfection of Granulicatellaadiacens and other bacteria: a case report.

BACKGROUND: Granulicatella adiacens is facultative anaerobic Gram-positive bacteria, which mainly involve bacterial endocarditis and bacteremia, but there are few reports of local suppurative infection. A case of lung abscess with a coinfection of Granulicatella adiacens and other bacteria in a lung cancer patient will be reported in this paper. To our knowledge, this is the first case report describing lung abscess due to G.adiacens. CASE PRESENTATION: A 52-year-old Chinese woman was admitted to the hospital, She complained of coughing and expectoration for 1 month, shortness of breath for half a month, and dyspnea for 1 day. After a series of examinations, she was diagnosed with lung abscess, pleural effusion, and bronchogenic carcinoma. Draining pus culture demonstrated Granulicatella adiacens. After more than 5 weeks of antibiotic therapies in total, she gradually recovered to fight against lung cancer. CONCLUSION: This is the first reported lung abscess caused by G.adiacens. In immunosuppressed hosts, G.adiacens is a virulent pathogen associated with a spectrum of intrathoracic suppurative. Earlier diagnosis and proper drainage surgery with effective antibiotics treatment are very important, and antimicrobial treatment should be more than 5 weeks. When complex pulmonary infection interferes with the CT diagnosis, clinical suspicion of lung cancer should be increased if G.adiacens or Eikenella corrodens is detected from a pulmonary infection.

Aortic Endograft Infection with Mycobacterium chimaera and Granulicatella adiacens, Switzerland, 2014.

We describe an aortic endograft infection caused by Mycobacterium chimaera and Granulicatella adiacens, successfully treated with prolonged antimicrobial drug therapy after complete explantation of the infected endoprosthesis and extra-anatomical reconstruction. Whole-genome sequencing analysis did not indicate a close relationship to bacterial strains known to cause infections after cardiac surgery.

Relative presence of Streptococcus mutans, Veillonella atypica, and Granulicatella adiacens in biofilm of complete dentures.

AIMS AND OBJECTIVE: Oral biofilms in denture wearers are populated with a large number of bacteria, a few of which have been associated with medical conditions such as sepsis and infective endocarditis (IE). The present study was designed to investigate the relative presence of pathogenic bacteria in biofilms of denture wearers specifically those that are associated with IE. METHODS: Biofilm samples from 88 denture wearers were collected and processed to extract total genomic DNA. Eight of these samples were subjected to 16S rRNA gene sequencing analysis to first identify the general bacterial occurrence pattern. This was followed by species-specific quantitative polymerase chain reaction (qPCR) on entire batch of 88 samples to quantify the relative copy numbers of IE-associated pathogens. RESULTS: 16S rRNA gene analysis of eight biofilm samples identified bacteria from Firmicutes, Actinobacteria, Proteobacteria, Bacteroidetes, and Fusobacteria species. Interestingly, Streptococcus mutans, Veillonella atypica, and Granulicatella adiacens from Firmicutes, all known to be associated with early-onset sepsis and IE was present in five of eight biofilm samples. The other three samples carried bacteria from genus Proteobacteria with Neisseria flava and Neisseria mucosa, which are known to be commensals, as dominant species. Species-specific qPCR of S. mutans V. atypica, and G. adiacens on 88 biofilm DNA samples identified the presence of S. mutans in 83%, V. atypica in 79%, and G. adiacens in 76% of samples. CONCLUSION: The findings from the present study demonstrate co-occurrence of S. mutans, V. atypica, and G. adiacens in a majority of denture wearers, which is clinically significant as elderly patients with compromised immune system are more prone to develop IE. To the best of our knowledge, the co-occurrence of S. mutans, V. atypica, and G. adiacens is being reported for the first time in biofilms of denture wearers.

Prosthetic joint infection caused by Granulicatella adiacens: a case series and review of literature.

BACKGROUND: Bone and joint infection involving Granulicatella adiacens is rare, and mainly involved in cases of bacteremia and infectious endocarditis. Here we report three cases of prosthetic joint infection involving G. adiacens that were successfully treated with surgery and prolonged antimicrobial treatment. We also review the two cases of prosthetic joint infection involving G. adiacens that are reported in the literature. CASE PRESENTATION: Not all five cases of prosthetic joint infection caused by G. adiacens were associated with bacteremia or infectious endocarditis. Dental care before the onset of infection was observed in two cases. The median time delay between arthroplasty implantation and the onset of infection was of 4 years (ranging between 2 and 10 years). One of our cases was identified with 16srRNA gene sequencing, one case with MALDI-TOF mass spectrometry, and one case with both techniques. Two literature cases were diagnosed by 16srRNA gene sequencing. All five cases were cured after surgery including a two-stage prosthesis exchange in three cases, a one-stage prosthesis exchange in one case, and debridement, antibiotics, irrigation, and retention of the prosthesis in one case, and prolonged antimicrobial treatment. CONCLUSION: Prosthetic joint infection involving G. adiacens is probably often dismissed due to difficult culture or misdiagnosis, in particular in the cases of polymicrobial infection. Debridement, antibiotics, irrigation, and retention of the prosthesis associated with prolonged antimicrobial treatment (≥ 8 weeks) should be considered as a treatment strategy for prosthetic joint infection involving G. adiacens.

Granulicatella adiacens Bacterial Infection After Pancreatectomy Whipple's Procedure.

Background: Granulicatella adiacens inhabits the oral cavity, urogenital, and gastrointestinal tracts and is a typical commensal of human mucosal surfaces. It rarely causes disease. Identification of these gram-positive cocci can be challenging. Case Report: In a 58-year-old male in an oncology center, we report the first occurrence of bacterial infection caused by G. adiacens. After a precise diagnosis of the infection, the patient received effective treatment. Conclusion: Owing to a lack of sufficient diagnostic tools, G. adiacens may be a more notable pathogen than has been previously identified. Sensitivity testing standards are desperately needed.

Arteriovenous Graft Infection Due to Granulicatella adiacens.

Granulicatella adiacens is a gram-positive coccus that is normally found in the human oral cavity and gastrointestinal and urogenital tracts but can rarely cause infection. When it does cause infection, Granulicatella adiacens has been most associated with bacteremia and endovascular infection, but to our knowledge, there are no previously documented cases of arteriovenous graft (AVG) infection. We present a case of Granulicatella adiacens bacteremia with associated AVG infection.

Infective endocarditis caused by Granulicatella adiacens.

Granulicatella adiacens, a recently nomenclatured bacterium, was considered as one of the nutritionally variant streptococci (NVS) and is a mouth commensal. It is redesignated as a streptococcus like bacterium since it differs from streptococci. We report a case of infective endocarditis (IE) caused by this fastidious and unusual bacteria in a 63-year-old man with rheumatic valvular heart disease. G. adiacens was isolated from four of his blood culture samples, which was sensitive to beta lactams, moderately sensitive to gentamicin and resistant to erythromycin and co-trimoxazole. Patient recovered completely on treatment with high dose of ampicillin and gentamicin for 28 days.

Granulicatella adiacens Causing a Parapharyngeal Abscess in a 10-Month-Old Infant: A Rare-Case Report and Literature Review of Deep Neck Infections (DNIs) in Children.

Granulicatella adiacens is a rare variant of the Streptococcus bacteria. When isolated, G. adiacens has been described in cases of endocarditis and bacteremia, but less commonly seen in isolated pyogenic infections. We report a case of a parapharyngeal abscess caused by G. adiacens in an otherwise healthy 10-month-old infant, which was successfully treated with antibiotics and surgical drainage. To the best of our knowledge, this is the first described case of a pediatric deep soft tissue neck infection caused by G. adiacens with one other report in an adult. Additionally, of all localized infections from this bacteria, this is only the second reported case in the pediatric population. We also include an evidence-based literature review of the clinical presentation, microbiology, imaging modalities, and management approach to deep neck infections (DNIs).

A Case Series and Literature Review of Subacute Infective Endocarditis: A Clinical Challenge.

Endocarditis is a life-threatening, relatively rare disease caused by an infection of the endocardial epithelium of the heart. Its clinical presentation is highly variable, depending on whether it presents acutely, subacutely, or chronically. Also, the wide array of causal etiologies and pathogens makes its diagnosis and treatment complex and challenging. The main etiological agents are Staphylococci and Streptococci, while fastidious microorganisms are infrequent agents of this pathology. Advancements in the identification of microorganisms with novel molecular techniques have revealed new previously unidentified pathogens. Despite their low frequency, these fastidious pathogens are highly relevant, as they have been associated with a higher rate of complications and mortality. Therefore, it is necessary to be aware of the wide array of clinical presentations and important considerations for the management of patients with subacute endocarditis with atypical microorganisms. In this article, we present a case series involving three different clinical presentations of subacute endocarditis with fastidious microorganisms, which required extensive medical management and surgical valve repair with favorable and unfavorable outcomes. We also engage in a review of the literature on their microbiology, diagnosis, and treatment.

Granulicatella adiacens Endocarditis of a Bioprosthetic Aortic Valve.

Infective endocarditis (IE) is relatively uncommon; however, when it is diagnosed, it is usually among those with known cardiac valvular abnormalities. The most common pathogens that cause endocarditis are streptococci (mainly viridans), enterococci, and other streptococci species. An extremely rare pathogen that could cause IE is Granulicatella. This gram-positive coccus classically inhabits human mucosal surfaces and only rarely causes disease. We present an incredibly rare case of a 74-year-old female with a bioprosthetic aortic valve replacement, who presented with headache and weakness and was subsequently found to have recurrent Granulicatella adiacens infective endocarditis.

Granulicatella Adiacens as an Unusual Cause of Microbial Keratitis: A Metagenomic Approach.

Metagenomics Next-Generation Sequencing can provide taxonomic and functional profiles of microbial keratitis communities without the need to culture infected corneal samples. We share our experience on a case with negative culture but positive metagenomic results.

Granulicatella Adiacens as an Unusual Cause of Microbial Keratitis and Endophthalmitis: A Case Series and Literature Review.

PURPOSE: To report two cases of microbial keratitis and/or endophthalmitis involving Granulicatella adiacens. METHODS: Case series. RESULTS: 24-year-old female with a history of Herpes simplex virus 1 (HSV-1) and Candida parapsilosis keratitis presented with a geographic epithelial defect and infiltrate in the left eye. Cultures were positive for HSV-1 and G. adiacens. Keratitis resolved with topical vancomycin and oral valacyclovir. A 65-year-old female with a history of type II diabetes and failed therapeutic penetrating keratoplasty presented with inferior corneal graft haze and vitreous inflammation of the right eye. Therapeutic penetrating keratoplasty and pars plana vitrectomy were performed, and the corneal button returned positive for G. adiacens. The patient was treated with topical and intravitreal vancomycin as well as topical and systemic steroids. CONCLUSIONS: These cases expand the literature on G. adiacens keratitis and endophthalmitis and corroborate the role of steroid use and prior surgery as paramount risk factors.

Granulicatella adiacens as an Unusual Cause of Empyema: A Case Report and Review of Literature.

Granulicatella adiacens , a nutritionally variant Streptococcus (NVS), is part of the normal commensal flora of human mouth, genital, and intestinal tracts and rarely causes disease. It has been mostly reported from bacteremia and endocarditis cases, but rarely can cause vertebral osteomyelitis, pancreatic abscess, otitis media, and endovascular, central nervous system, ocular, oral, bone and joint, and genitourinary infections. Due to requirement of fastidious culture conditions and non-specific colony morphology, serious diagnostic difficulties may arise in cases of NVS infections. Here, we are reporting a rare fatal infection of G. adiacens presented with empyema complicated to sepsis and necrotizing fasciitis. Clinicians should be aware of the pathogenic potential of Granulicatella adiacens (a normal commensal flora of human mouth, genital and intestinal tracts). Appropriate supplemented media and a reliable detection system should be used to identify these fastidious organisms. We present this rare case to bring awareness among clinicians regarding such a rare but potentially fatal infection.

Successful identification of Granulicatella adiacens in postoperative acute infectious endophthalmitis using a bacterial 16S ribosomal RNA gene-sequencing platform with MinION™: A case report.

Purpose: To evaluate the efficacy of identifying the bacteria by aqueous sampling and vitreous sampling in postoperative infectious endophthalmitis using 16S ribosomal RNA (rRNA) gene analysis with a nanopore sequencer (MinION™). Observation: A 55-year-old woman who underwent cataract surgery at an ophthalmology clinic 18 days ago was referred to our hospital for suspected endophthalmitis. She had light perception visual acuity in her right eye; however, the eye was severely inflamed, with a hypopyon and a fibrinous membrane in the anterior chamber. The fundus was not visible because of vitreous opacity on a B-scan image. Based on the diagnosis of postoperative acute infectious endophthalmitis, we performed a vitrectomy, intraocular lens extraction, and silicone oil tamponade. On postoperative day 14, the inflammation resolved. An aqueous sample was collected before surgical treatment, and the vitreous sample was collected during the operation. Both samples underwent 16S rRNA gene analysis with a nanopore sequencer MinION™ to identify the causative organism. Conclusions and Importance: In the aqueous humor, Granulicatella adiacens and Cutibacterium acnes were identified before the operation, while only Granulicatella adiacens was detected in the vitreous sample after the operation. Although the aqueous humor sample might contain commensal bacteria, it could provide a predictable result before the operation. It can also provide a substitute for a vitreous sample to allow earlier identification of the causative organism.

Novel double beta-lactam therapy for Granulicatella adiacens infective endocarditis.

Granulicatella adiacens, a nutritionally variant streptococci (NVS) is a well described organism associated with endocarditis. Previously communicated cases have documented the use of double beta-lactam therapy with ampicillin and ceftriaxone to treat patients with infective endocarditis due to Enterococcus faecalis and Streptocossus pneumoniae. We describe the first case of Granulicatella adiacens infective endocarditis in a patient successfully treated with the combination of intravenous ampicillin and ceftriaxone and document their synergistic activity.

Granulicatella adiacens: An uncommon diagnosis of prosthetic hip joint infection. A case report with review of the literature.

We report a case of prosthetic hip infection in a 79 year old man caused by Granulicatella adiacens. The diagnosis was achieved using broad range 16S PCR gene analysis at an early stage, after joint aspiration and culture failed to yield a pathogen. Staged revision surgery together with administration of appropriate antibiotics resulted in cure. Granulicatella adiacens is a nutritionally variant streptococcus (NVS). It has been increasingly reported to cause significant morbidities involving various systems. Its insidious growth due to complex growth requirements, has made its diagnosis challenging, and often delays appropriate antibiotic administration.

Nutritionally variant streptococci causing endophthalmitis associated with intravitreal anti-vascular endothelial growth factor injection.

PURPOSE: To describe the clinical course and microbial properties of the first two reported cases of nutritionally variant Streptococci (Granulicatella adiacens and Abiotrophia defectiva) endophthalmitis following intravitreal anti-vascular endothelial growth factor injection (IVI). OBSERVATIONS: A 74 year-old female developed Granulicatella adiacens endophthalmitis following IVI. The patient underwent a pars plana vitrectomy and visual acuity recovered to 20/30 in six weeks. Similarly, an 88 year-old male developed Abiotrophia defectiva endophthalmitis after IVI. After a pars plana vitrectomy, the visual acuity recovered to 20/60 at five weeks. CONCLUSIONS AND IMPORTANCE: Endophthalmitis due to Streptococcus species has traditionally resulted in uniformly poor visual outcomes. However, nutritionally variant Streptococci, now reclassified as Granulicatella and Abiotrophia species, appear to have a less aggressive clinical course and better visual acuity outcomes. To the authors' knowledge, these are the first reports of nutritionally variant Streptococci following IVI related endophthalmitis.

Contribution of different adherent properties of Granulicatella adiacens and Abiotrophia defectiva to their associations with oral colonization and the risk of infective endocarditis.

Granulicatella adiacens (G. adiacens) and Abiotrophia defectiva (A. defectiva) colonize the oral cavity and form part of the normal flora in the intestinal and genitourinary tracts. As reported previously, the frequency of isolation of G. adiacens from the oral cavity was much higher than that of A. defectiva. However, it has been reported that compared with G. adiacens, A. defectiva was isolated at considerably higher frequencies from the blood of patients with infective endocarditis (IE). Hence, in this study, the in vitro interaction of G. adiacens and A. defectiva strains with host surfaces and biofilm formation was examined to assess whether their different adhesive properties contribute to their associations with oral colonization and IE, respectively. G. adiacens exhibited an increased binding ability to saliva-coated hydroxyapatite beads than A. defectiva following the addition of CaCl2. Furthermore, biofilm formation was observed only for G. adiacens with the use of a polystyrene tube and scanning electron microscopy analysis. Conversely, A. defectiva displayed significantly greater adherence to human umbilical vein endothelial cells and immobilized fibronectin than G. adiacens. These findings suggest that differences in binding properties to host components imply specific binding mechanisms in G. adiacens and A. defectiva, which might mediate selective colonization in the oral cavity or are associated with the pathogenicity of endocarditis.

Subspecies Niche Specialization in the Oral Microbiome Is Associated with Nasopharyngeal Carcinoma Risk.

Oral health and changes in the oral microbiome have been associated with both local and systemic cancer. Poor oral hygiene is a known risk factor for nasopharyngeal carcinoma (NPC), a virally associated head and neck cancer endemic to southern China. We explored the relationship between NPC and the oral microbiome using 16S rRNA sequencing in a study of 499 NPC patients and 495 population-based age and sex frequency-matched controls from an area of endemicity of Southern China. We found a significant reduction in community richness in cases compared to that in controls. Differences in the overall microbial community structure between cases and controls could not be explained by other potential confounders; disease status explained 5 times more variation in the unweighted UniFrac distance than the next most explanatory variable. In feature-based analyses, we identified a pair of coexcluding Granulicatella adiacens amplicon sequence variants (ASVs) which were strongly associated with NPC status and differed by a single nucleotide. The G. adiacens variant an individual carried was also associated with the overall microbial community based on beta diversity. Co-occurrence analysis suggested the two G. adiacens ASVs sit at the center of two coexcluding clusters of closely related organisms. Our results suggest there are differences in the oral microbiomes between NPC patients and healthy controls, and these may be associated with both a loss of microbial diversity and niche specialization among closely related commensals.IMPORTANCE The relationship between oral health and the risk of nasopharyngeal carcinoma (NPC) was previously established. However, the role of oral microbiome has not been evaluated in the disease in a large epidemiological study. This paper clearly establishes a difference in the oral microbiomes between NPC patients and healthy controls which cannot be explained by other confounding factors. It furthermore identifies a pair of closely related coexcluding organisms associated with the disease, highlighting the importance of modern methods for single-nucleotide resolution in 16S rRNA sequence characterization. To the best of our knowledge, this is one of the first examples of cancer-associated niche specialization of the oral microbiome.