Granulicatella infection: diagnosis and management

Distribution of streptococcal groups causing infective endocarditis: a descriptive study

The purpose of this study was to describe the distribution of streptococci causing infective endocarditis (IE). A total of 296 patients with definite IE admitted from July 2007 to December 2014 were identified, with microbial identification done by a combination of blood culture, valve culture, and valve polymerase chain reaction (PCR). The overall distribution of streptococci was 76% viridans (n = 224), 17% pyogenic (50), 6% nutritionally variant (17), and 2% anaerobic (5). Sixty-three (21%) viridans group streptococci were not identified further. The distribution of the remaining 161 viridans group streptococci was Streptococcus mitis group 61%, S. bovis group 15%, S. mutans group 13%, S. anginosus group 9%, and S. salivarius group 1%. Of the 50 pyogenic streptococci, 78% were S. agalactiae and 16% were S. dysgalactiae. PCR was significantly more sensitive than culture in identifying streptococci in excised heart valves.

Septic arthritis caused by Granulicatella adiacens after anterior cruciate ligament reconstruction

Septic arthritis after knee arthroscopy is an extremely rare condition. A rate of 0.15-0.84% cases of postoperative infection is estimated in several series. The arthroscopy procedure most frequently related with an infectious complication is anterior cruciate ligament (ACL) reconstruction, with a prevalence of 0.3-1.7% cases. Staphylococcus sp. is the pathogen most commonly cultured. We describe a case of septic arthritis after ACL reconstruction. We found no published case of septic arthritis caused by this microorganism after knee arthroscopy. It is probably the first case published in the literature.

Successful treatment of an acute infective endocarditis secondary to fish bone penetrating into left atrium caused by Granulicatella adiacens and Candida albicans: A case report

RATIONAL

Infective endocarditis caused by a foreign body of the upper digestive tract is rare. We report a rare case of Granulicatella adiacens and Candida albicans coinfection acute endocarditis combined with systematic embolization caused by a fish bone from the esophagus penetrating into the left atrium.

PATIENT CONCERN

A 42-year-old woman was admitted to our hospital because of fever, abdominal pain, headache, and right limb weakness.

DIAGNOSES

Clinical examination indicated endocarditis and systemic embolisms secondary to a fish bone from the esophagus penetrating into the left atrium. The emergency surgery confirmed the diagnosis. Cultures of blood and vegetation show G adiacens and C albicans.

INTERVENTIONS

Antimicrobial therapy lasted 6 weeks after surgery.

OUTCOMES

The patient was discharged with excellent condition7 weeks after hospitalization and was well when followed 6 months later.

LESSONS

The successful treatment of this patient combines quick diagnosis, timely surgery, and effective antimicrobial regimen. This rare possibility should be kept up in mind in acute infective endocarditis cases.

Changes in the lung bacteriome in relation to antipseudomonal therapy in children with cystic fibrosis

The lung in cystic fibrosis (CF) is home to numerous pathogens that shorten the lives of patients. The aim of the present study was to assess changes in the lung bacteriome following antibiotic therapy targeting Pseudomonas aeruginosa in children with CF. The study included nine children (9-18 years) with CF who were treated for their chronic or intermittent positivity for Pseudomonas aeruginosa. The bacteriomes were determined in 16 pairs of sputa collected at the beginning and at the end of a course of intravenous antibiotic therapy via deep sequencing of the variable region 4 of the 16S rRNA gene, and the total bacterial load and selected specific pathogens were assessed using quantitative real-time PCR. The effect of antipseudomonal antibiotics was observable as a profound decrease in the total 16S rDNA load (p = 0.001) as well as in a broad range of individual taxa including Staphylococcus aureus (p = 0.03) and several members of the Streptococcus mitis group (S. oralis, S. mitis, and S. infantis) (p = 0.003). Improvements in forced expiratory volume (FEV₁) were associated with an increase in Granulicatella sp. (p = 0.004), whereas a negative association was noted between the total bacterial load and white blood cell count (p = 0.007). In conclusion, the data show how microbial communities differ in reaction to antipseudomonal treatment, suggesting that certain rare species may be associated with clinical parameters. Our work also demonstrates the utility of absolute quantification of bacterial load in addition to the 16S rDNA profiling.

Isotretinoin and lymecycline treatments modify the skin microbiota in acne

Oral retinoids and tetracyclines have a major role in acne treatment. Here, we report for the first time the effect of isotretinoin and lymecycline therapy on the skin microbiota in cheek, back and armpit swab samples of acne vulgaris patients using 16S ribosomal RNA (16S rRNA) gene amplicon sequencing. Propionibacterium acnes was the most common in sebaceous areas of healthy and untreated acne skin and more abundant in back than cheek samples. Five taxa, including a Streptococcus taxon, differed significantly between the cheek samples of healthy controls and acne patients, and acne severity was positively correlated with the abundance of Propionibacterium. Both treatments reduced clinical acne grades and the abundance of Propionibacterium, while the abundance of several other taxa was significantly higher in treated cheek samples compared with untreated ones. Less variation was observed in back samples and none in armpit samples. There were no differences in alpha diversity between control and acne patients in any of the sampled skin areas, but the diversity of the microbiota on the cheek and the back was significantly increased after acne treatments. This study provides insight into the skin microbiota in acne and how it is modulated by systemic acne treatment.

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.

Infections related to Granulicatella adiacens: Report of two cases and review of literature

Infections due to nutritionally variant streptococci are diagnosed rarely due to difficulties encountered during identification and isolation. Mortality rate in these infections is high therefore appropriate supplemented media and reliable detection systems should be implemented to isolate these fastidious organisms. Here, we describe two cases of Granulicatella adiacens infections. All microbiologic identifications were made with MALDI-TOF Vitek MS (BioMerieux, France), and the results confirmed by 16S ribotyping.

In vivo model for microbial invasion of tooth root dentinal tubules

Objective

Bacterial penetration of dentinal tubules via exposed dentine can lead to root caries and promote infections of the pulp and root canal system. The aim of this work was to develop a new experimental model for studying bacterial invasion of dentinal tubules within the human oral cavity.

Material and Methods

Sections of human root dentine were mounted into lower oral appliances that were worn by four human subjects for 15 d. Roots were then fixed, sectioned, stained and examined microscopically for evidence of bacterial invasion. Levels of invasion were expressed as Tubule Invasion Factor (TIF). DNA was extracted from root samples, subjected to polymerase chain reaction amplification of 16S rRNA genes, and invading bacteria were identified by comparison of sequences with GenBank database.

Results

All root dentine samples with patent tubules showed evidence of bacterial cell invasion (TIF value range from 5.7 to 9.0) to depths of 200 mm or more. A spectrum of Gram-positive and Gram-negative cell morphotypes were visualized, and molecular typing identified species of Granulicatella, Streptococcus, Klebsiella, Enterobacter, Acinetobacter, and Pseudomonas as dentinal tubule residents.

Conclusion

A novel in vivo model is described, which provides for human root dentine to be efficiently infected by oral microorganisms. A range of bacteria were able to initially invade dentinal tubules within exposed dentine. The model will be useful for testing the effectiveness of antiseptics, irrigants, and potential tubule occluding agents in preventing bacterial invasion of dentine.

Bacterial Communities Associated with Atherosclerotic Plaques from Russian Individuals with Atherosclerosis

Atherosclerosis is considered a chronic disease of the arterial wall and is the major cause of severe disease and death among individuals all over the world. Some recent studies have established the presence of bacteria in atherosclerotic plaque samples and suggested their possible contribution to the development of cardiovascular disease. The main objective of this preliminary pilot study was to better understand the bacterial diversity and abundance in human atherosclerotic plaques derived from common carotid arteries of individuals with atherosclerosis (Russian nationwide group) and contribute towards the further identification of a main group of atherosclerotic plaque bacteria by 454 pyrosequencing their 16S ribosomal RNA (16S rRNA) genes. The applied approach enabled the detection of bacterial DNA in all atherosclerotic plaques. We found that distinct members of the order Burkholderiales were present at high levels in all atherosclerotic plaques obtained from patients with atherosclerosis with the genus Curvibacter being predominant in all plaque samples. Moreover, unclassified Burkholderiales as well as members of the genera Propionibacterium and Ralstonia were typically the most significant taxa for all atherosclerotic plaques. Other genera such as Burkholderia, Corynebacterium and Sediminibacterium as well as unclassified Comamonadaceae, Oxalobacteraceae, Rhodospirillaceae, Bradyrhizobiaceae and Burkholderiaceae were always found but at low relative abundances of the total 16S rRNA gene population derived from all samples. Also, we found that some bacteria found in plaque samples correlated with some clinical parameters, including total cholesterol, alanine aminotransferase and fibrinogen levels. Finally, our study indicates that some bacterial agents at least partially may be involved in affecting the development of cardiovascular disease through different mechanisms.

An unusual case of thoracic empyema caused by Granulicatella elegans (nutritionally variant streptococci) in a patient with pulmonary tuberculosis and human immunodeficiency virus infection

INTRODUCTION

Nutritionally variant streptococci (NVS) are an infrequent cause of human infection with Granulicatella elegans being the least encountered species in clinical specimens. The most common infection caused by NVS is infective endocarditis.

CASE PRESENTATION

We report an unusual case of thoracic empyema due to G. elegans in a patient with pulmonary tuberculosis (TB) and human immunodeficiency virus infection. The patient responded favourably to drainage and penicillin.

CONCLUSION

This case illustrates that even though TB is responsible for the majority of pleural effusions in this setting, other rare opportunistic bacteria may cause infection in susceptible patients. Therefore, microbiological investigations should be performed in all patients presenting with pleural effusion.

Granulicatella adiacens prosthetic hip joint infection after dental treatment

INTRODUCTION

Granulicatella adiacens is a Gram-positive bacteria and a normal component of oral flora. It is also found in dental plaques, endodontic abscesses and can rarely cause more serious infections.

CASE PRESENTATION

We describe a prosthetic hip joint infection in an 81-year-old fit and healthy man due to Granulicatella adiacens who underwent a prolonged dental intervention two days earlier without antibiotic prophylaxis. The infection was successfully treated with surgical intervention and a combination of antibiotics. The patient eventually succumbed to severe community-acquired pneumonia two months later.

CONCLUSION

Current guidelines recommend avoidance of antibiotic prophylaxis prior to dental treatment in patients who have no co-morbidities and no prior operation on the index prosthetic joint. This case report indicates that infections of prosthetic joints may be associated with dental procedures even in fit and healthy patients without the recognized risk factors.

Successful treatment of periprosthetic joint infection caused by Granulicatella para-adiacens with prosthesis retention: a case report

BACKGROUND

Granulicatella and Abiotrophia spp. are difficult to detect due to their complex nutritional requirements. Infections with these organisms are associated with high treatment failure rates. We report the first implant-associated infection caused by Granulicatella para-adiacens, which was cured with anti-microbial treatment consisting of anti-biofilm-active rifampin and debridement, exchange of mobile parts and retention of the prosthesis.

CASE PRESENTATION

Patient with a history of left hip arthroplasty presented with acute onset of fever, pain and limited range of motion of the left hip. Arthrocentesis of the affected joint yielded purulent fluid and exchange of mobile parts of the prosthesis, but retention of fixed components was performed. Granulicatella para-adiacens grew from preoperative and intraoperative cultures, including sonication fluid of the removed implant. The transesophageal echocardiography showed a vegetation on the mitral valve; the orthopantogram demonstrated a periapical dental abscess. The patient was treated with intravenous penicillin G and gentamicin for 4 weeks, followed by levofloxacin and rifampin for additional 2 months. At discharge and at follow-up 1, 2 and 5 years later, the patient was noted to have a functional, pain-free, and radiologically stable hip prosthesis and the serum C-reactive protein was normal.

CONCLUSIONS

Although considered a difficult-to-treat organism, we report a successful treatment of the Granulicatella hip prosthesis infection with prosthesis retention and a prolonged antibiofilm therapy including rifampin. The periapical dental abscess is considered the primary focus of hematogenously infected hip prosthesis, underlining the importance treatment of periodontitis prior to arthroplasty and of proper oral hygiene for prevention of hematogenous infection after arthroplasty.

Infective endocarditis due to Abiotrophia defectiva and Granulicatella spp. complicated by infectious intracranial cerebral aneurysms: a report of three cases and review of the literature

Nutritionally variant streptococci, now classified as Abiotrophia defectivaor Granulicatella spp., are thought to account for 2 % of all infective endocarditis cases but estimates of their frequency are complicated by changes in nomenclature and difficulties in obtaining positive microbiology cultures. Their growth characteristics and difficulty undertaking antibiotic susceptibility testing may impede optimal antibiotic treatment decisions. We describe three patients with definite infective endocarditis due to these organisms seen at our hospital between 2005 and 2010, all of whom presented with neurological symptoms due to infectious intracranial cerebral aneurysms. We recommend that, for patients with left-sided infective endocarditis due to A. defictiva and Granulicatella spp., clinicians should consider imaging the central nervous system.

Case Report of Granulicatella adiacens as a Cause of Bacterascites

Granulicatella adiacens is a Gram-positive coccus, formerly grouped with nutritionally variant Streptococcus, often found as commensal bacteria of the human oral cavity, urogenital tract, and gastrointestinal tract. Prior case reports have demonstrated Granulicatella spp. as a pathogen that can cause bacteremia and infective endocarditis particularly of prosthetic valves and pacemaker leads. Here, we report on a unique case of Granulicatella adiacens bacterascites in a 50-year-old male.

Nutritionally variant streptococci bacteremia in cancer patients: a retrospective study, 1999-2014

BACKGROUND

Nutritionally variant Streptococci (NVS), Abiotrophia and Granulicatella are implicated in causing endocarditis and blood stream infections more frequently than other sites of infection. Neutropenia and mucositis are the most common predisposing factors for infection with other pathogens in cancer patients. In this study, we investigated the clinical characteristics of NVS bacteremia in cancer patients and identified risk factors and outcomes associated with these infections.

MATERIALS AND METHODS

We retrospectively reviewed all cases of NVS bacteremia occurring from June 1999 to April 2014 at H. Lee Moffitt Cancer Center and Research Institute. The computerized epidemiology report provided by the microbiology laboratory identified thirteen cancer patients with NVS bacteremia. We collected data regarding baseline demographics and clinical characteristics such as age, sex, underlying malignancy, neutropenic status, duration of neutropenia, treatment, and outcome.

RESULTS

Thirteen patients were identified with positive NVS blood stream infection. Ten patients (77%) had hematologic malignancies, including chronic lymphocytic leukemia (CLL)(1), multiple myeloma (MM)(1), acute myelogenous leukemia (AML)(4), and non-Hodgkin's lymphoma (NHL)(4). The non-hematologic malignancies included esophageal cancer(2) and bladder cancer (1).

CONCLUSION

NVS should be considered as a possible agent of bacteremia in cancer patients with neutropenia and a breach in oral, gastrointestinal and genitourinary mucosa (gingivitis/mucositis).

Viable bacteria associated with red blood cells and plasma in freshly drawn blood donations

Objectives

Infection remains a leading cause of post-transfusion mortality and morbidity. Bacterial contamination is, however, detected in less than 0.1% of blood units tested. The aim of the study was to identify viable bacteria in standard blood-pack units, with particular focus on bacteria from the oral cavity, and to determine the distribution of bacteria revealed in plasma and in the red blood cell (RBC)-fraction.

Design

Cross-sectional study. Blood were separated into plasma and RBC-suspensions, which were incubated anaerobically or aerobically for 7 days on trypticase soy blood agar (TSA) or blue lactose plates. For identification colony PCR was performed using primers targeting 16S rDNA.

Setting

Blood donors attending Capital Region Blood Bank, Copenhagen University Hospital, Rigshospitalet, Hvidovre, Denmark, October 29^th to December 10^th 2013.

Participants

60 donors (≥50 years old), self-reported medically healthy.

Results

Bacterial growth was observed on plates inoculated with plasma or RBCs from 62% of the blood donations. Growth was evident in 21 (35%) of 60 RBC-fractions and in 32 (53%) of 60 plasma-fractions versus 8 of 60 negative controls (p = 0.005 and p = 2.6x10^-6, respectively). Propionibacterium acnes was found in 23% of the donations, and Staphylococcus epidermidis in 38%. The majority of bacteria identified in the present study were either facultative anaerobic (59.5%) or anaerobic (27.8%) species, which are not likely to be detected during current routine screening.

Conclusions

Viable bacteria are present in blood from donors self-reported as medically healthy, indicating that conventional test systems employed by blood banks insufficiently detect bacteria in plasma. Further investigation is needed to determine whether routine testing for anaerobic bacteria and testing of RBC-fractions for adherent bacteria should be recommended.

Granulicatella adiacens subacute bacterial endocarditis as the underlying cause of type II mixed cryoglobulinaemia

A 57-year-old man with type II mixed cryoglobulinaemia presented to the emergency department with a history of worsening lethargy, malaise and non-drenching night sweats in a relapsing-remitting pattern. He was diagnosed with type II mixed cryoglobulinaemia 7 months ago following episodes of fever, night sweats, lethargy and malaise associated with a non-blanching, purpuric, raised erythematous rash that responded partially to immunosuppressive therapy and short courses of oral antibiotics. A single blood culture then yielded Granulicatella adiacens which was reported as a possible contaminant and therefore, not pursued. Despite numerous other investigations, the underlying cause of his type II cryoglobulinaemia remained undetermined. On his current presentation, the physical examination revealed signs of infective endocarditis. Two further blood cultures grew G. adiacens. The diagnosis of infective endocarditis was established on a transoesophageal echocardiography, and the subsequent antibiotic and surgical therapy resulted in complete remission of his type II mixed cryoglobulinaemia.

Detection of Identical Isolates of Enterococcus faecalis from the Blood and Oral Mucosa in a Patient with Infective Endocarditis

The detection of infective endocarditis (IE) of oral origin has been previously discussed. However, there are few reports confirming this infection using molecular biological techniques. We herein describe the case of a 67-year-old man who developed IE. Blood culture samples and strains obtained from the gingival and buccal mucosa showed 100% identity to Enterococcus faecalis JCM 5803 on sequencing of 16S rRNA gene fragments. A random amplification of polymorphic DNA (RAPD) analysis showed the same pattern for these samples, thus confirming the identity of E. faecalis isolates in the blood and oral mucosa. Our observations provide novel information regarding the level of identity between IE pathogens and oral bacteria.

Case series of infective endocarditis caused by Granulicatella species

BACKGROUND

Nutritionally variant streptococci (NVS) are Gram-positive cocci characterized by their dependence on pyridoxal or cysteine supplementation for growth in standard blood culture media. They are responsible for severe infections in immunocompetent and immunosuppressed hosts, including infective endocarditis (IE). NVS have been divided into two different genera, Granulicatella and Abiotrophia.

METHODS

We report four cases of IE caused by Granulicatella species, including clinical presentation, echocardiographic characteristics, treatments received, and outcomes. We also performed a literature search for previously reported cases of IE caused by Granulicatella species to better characterize this condition.

RESULTS

A total of 29 cases of Granulicatella endocarditis were analyzed, including the four newly reported cases. The aortic (44%) and mitral (38%) valves were those most commonly affected. Multivalvular involvement was observed in 13% of cases. The mean vegetation length was 16mm. Complications were frequent, including heart failure (30%), embolism (30%), and perivalvular abscess (11%). The most frequent antibiotic regimen (85%) was penicillin or one of its derivatives plus gentamicin. The mortality rate was 17%.

CONCLUSIONS

Endocarditis due to Granulicatella species is a rare and severe condition. Complications are frequent despite the use of appropriate antibiotic regimens.

Oral microbiota distinguishes acute lymphoblastic leukemia pediatric hosts from healthy populations

In leukemia, oral manifestations indicate aberrations in oral microbiota. Microbiota structure is determined by both host and environmental factors. In human hosts, how health status shapes the composition of oral microbiota is largely unknown. Taking advantage of advances in high-throughput sequencing, we compared the composition of supragingival plaque microbiota of acute lymphoblastic leukemia (ALL) pediatric patients with healthy controls. The oral microbiota of leukemia patients had lower richness and less diversity compared to healthy controls. Microbial samples clustered into two major groups, one of ALL patients and another of healthy children, with different structure and composition. Abundance changes of certain taxa including the Phylum Firmicutes, the Class Bacilli, the Order Lactobacillales, the Family Aerococcaceae and Carnobacteriaceae, as well as the Genus Abiotrophia and Granulicatella were associated with leukemia status. ALL patients demonstrated a structural imbalance of the oral microbiota, characterized by reduced diversity and abundance alterations, possibly involved in systemic infections, indicating the importance of immune status in shaping the structure of oral microbiota.

Comparison of MALDI-TOF MS and VITEK 2 system for laboratory diagnosis of Granulicatella and Abiotrophia species causing invasive infections

Granulicatella and Abiotrophia spp. were known as nutritionally variant streptococci (NVS). Such strains have caused major diagnostic difficulties due to fastidious culturing and unspecific colony morphology. The present study is aimed at comparing the performance of laboratory available diagnostic methods for NVS isolates and determining the antimicrobial susceptibility of these isolates. Fourteen clinical invasive isolates, consisting of 10 Granulicatella adiacens, 1 Granulicatella elegans, and 3 Abiotrophia defectiva were in parallel analyzed by 2 matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) systems, i.e., Bruker MS and Vitek MS, as well as Vitek 2 for the species determination. 16S rRNA gene sequencing was applied as a reference method. The Vitek MS gave correct identification for all 14 isolates. The Bruker MS could correctly identify 8/10 G. adiacens, 0/1 G. elegans, and 3/3 A. defectiva isolates at the first analysis occasion, and all 14 isolates became identifiable after repeated tests. The Vitek 2 system could identify 6/10 G. adiacens, 1/1 G. elegans, and 2/3 A. defectiva isolates at the species level. Antimicrobial susceptibilities of 11 antibiotics were determined by Etest. Resistance against ciprofloxacin, ceftriaxone, rifampicin, and tetracycline were observed in 4, 10, 4, and 1 isolates, respectively. In conclusion, MALDI-TOF MS is a useful tool for the rapid diagnosis of NVS. Phenotypic testing by Vitek 2 is only partially effective for the accurate identification of such strains. The emergence of resistant NVS isolates indicates the necessity of monitoring antimicrobial susceptibilities of such uncommon pathogens.

Granulicatella bacteraemia in children: two cases and review of the literature

Background

Granulicatella spp. is a fastidious bacteria responsible for bacteremia and endocarditis which are fatal in about 20% of the cases. These severe infections are uncommon in children under 17 years of age and have proven extremely difficult to treat.

Cases presentation

We report a brief review of the literature and two cases of NVS bacteremia by Granulicatella complicated by infective endocarditis (IE). The first one is that of a 7-year-old Caucasian female with Shone syndrome and IE involving the pulmonary valve homograft, confirmed by echocardiography. The second case is that of a 5-year-old Caucasian male. In this patient echocardiogram was negative for signs of IE; however, a “possible” IE was suspected on the basis of a cardiac catheterization 3 weeks before the onset of fever. Since in both our patients clinical failure of first line antibiotic treatment was observed, we used a combination of meropenem with another anti-streptococcal drug with excellent results.

Conclusion

In Granulicatella bacteremia in the pediatric population, combination antimicrobial therapy including meropenem should be considered as a second line treatment in non-responding patients.