Granulicatella Species Research Articles

A shared group of bacterial taxa in the duodenal microbiota of undernourished Pakistani children with environmental enteric dysfunction.

Environmental enteric dysfunction (EED) is a subclinical syndrome of altered small intestinal function postulated to be an important contributor to childhood undernutrition. The role of small intestinal bacterial communities in the pathophysiology of EED is poorly defined due to a paucity of studies where there has been a direct collection of small intestinal samples from undernourished children. Sixty-three members of a Pakistani cohort identified as being acutely malnourished between 3 and 6 months of age and whose wasting (weight-for-length Z-score [WLZ]) failed to improve after a 2-month nutritional intervention underwent esophagogastroduodenoscopy (EGD). Paired duodenal luminal aspirates and duodenal mucosal biopsies were obtained from 43 children. Duodenal microbiota composition was characterized by sequencing bacterial 16S rRNA gene amplicons. Levels of bacterial taxa (amplicon sequence variants [ASVs]) were referenced to anthropometric indices, histopathologic severity in biopsies, expression of selected genes in the duodenal mucosa, and fecal levels of an immunoinflammatory biomarker (lipocalin-2). A "core" group of eight bacterial ASVs was present in the duodenal samples of 69% of participants. Streptococcus anginosus was the most prevalent, followed by Streptococcus sp., Gemella haemolysans, Streptococcus australis, Granulicatella elegans, Granulicatella adiacens, and Abiotrophia defectiva. At the time of EGD, none of the core taxa were significantly correlated with WLZ. Statistically significant correlations were documented between the abundances of Granulicatella elegans and Granulicatella adiacens and the expression of duodenal mucosal genes involved in immune responses (dual oxidase maturation factor 2, serum amyloid A, and granzyme H). These results suggest that a potential role for members of the oral microbiota in pathogenesis, notably Streptococcus, Gemella, and Granulicatella species, warrants further investigation.IMPORTANCEUndernutrition among women and children is a pressing global health problem. Environmental enteric dysfunction (EED) is a disease of the small intestine (SI) associated with impaired gut mucosal barrier function and reduced capacity for nutrient absorption. The cause of EED is ill-defined. One emerging hypothesis is that alterations in the SI microbiota contribute to EED. We performed a culture-independent analysis of the SI microbiota of a cohort of Pakistani children with undernutrition who had failed a standard nutritional intervention, underwent upper gastrointestinal tract endoscopy, and had histologic evidence of EED in their duodenal mucosal biopsies. The results revealed a shared group of bacterial taxa in their duodenums whose absolute abundances were correlated with levels of the expression of genes in the duodenal mucosa that are involved in inflammatory responses. A number of these bacterial taxa are more typically found in the oral microbiota, a finding that has potential physiologic and therapeutic implications.

Case Series of Granulicatella Bacteremia: A Single-centered, Five-year Retrospective Study.

Granulicatella species are rare, nutritionally variant streptococci that cause infective endocarditis. Their clinical and microbiological characteristics remain unknown. We reviewed five years of Granulicatella cases in our hospital database (Jan 2017-Jun 2022), finding 6 Granulicatella adiacens cases and 1 Granulicatella elegans case. Clinical backgrounds and bacteremia sources were diverse; 3 cases developed polymicrobial bacteremia. Antimicrobial testing showed non-susceptibility to penicillin G in 4 of 7 cases (57.1%), and high susceptibility to carbapenems and vancomycin in all cases. Determining optimal antibiotic therapy for Granulicatella infections is vital in this era of antimicrobial resistance.

Granulicatella adiacens infective endocarditis

Infective endocarditis is an unconventional infectious disease nonetheless life-threatening. A roundabout of 3% to 5% cases of Streptococcal infective endocarditis is caused by nutritionally variant Streptococci (NVS). Granulicatella species is one of the atypical causes of infective endocarditis. In this context, the authors are disclosing a case of infective endocarditis in an underlying rheumatic heart disease patient, caused by Granulicatella adiacens. The patient had breathlessness for the past four months, on and off fever for two months anew and mid-diastolic murmur with vegetation in aortic valve as appeared by echocardiogram. The blood cultures were tested positive for Granulicatella adiacens. The patient was successfully treated with intravenous vancomycin for a period of six weeks.

Clinical characteristics and outcome of infective endocarditis due to Abiotrophia and Granulicatella compared to Viridans group streptococci

To describe the clinical characteristics and outcome of Abiotrophia and Granulicatella infective endocarditis and compare them with Viridans group streptococci infective endocarditis. All patients in the International Collaboration on Endocarditis (ICE) - prospective cohort study (PCS) and the ICE-PLUS cohort were included (n = 8112). Data from patients with definitive or possible IE due to Abiotrophia species, Granulicatella species and Viridans group streptococci was analyzed. A propensity score (PS) analysis comparing the ABI/GRA-IE and VGS-IE groups according to a 1:2 ratio was performed. Forty-eight (0.64%) cases of ABI/GRA-IE and 1,292 (17.2%) VGS-IE were included in the analysis. The median age of patients with ABI/GRA-IE was lower than VGS-IE (48.1 years vs. 57.9 years; p = 0.001). Clinical features and the rate of in-hospital surgery was similar between ABI/GRA-IE and VGS-IE (52.1% vs. 45.4%; p = 0.366). Unadjusted in-hospital death was lower in ABI/GRA-IE than VGS-IE (2.1% vs. 8.8%; p = 0.003), and cumulative six-month mortality was lower in ABI/GRA-IE than VGS-IE (2.1% vs. 11.9%; p<0.001). After PS analysis, in-hospital mortality was similar in both groups, but six-month mortality was lower in the ABI/GRA IE group (2.1% vs. 10.4%; p = 0.029). Patients with ABI/GRA-IE were younger, had similar clinical features and rates of surgery and better prognosis than VGS-IE.

Abiotrophia and Granulicatella Infections in Cancer Patients: A Single-Center Chart Review Study

Objectives: Nutritionally Variant Streptococci (NVS) comprise two primary genera that have been identified from human specimens, particularly the Abiotrophia and Granulicatella species. These infections are often complicated to manage due to the difficulty identifying these organisms, indolent course of disease, and variable resistance to common antimicrobial agents. The wide breadth of disease presentations involving these organisms has not been fully elucidated, particularly in the immunosuppressed cancer patient population. Method: We performed a retrospective chart review on 28 patients from an academic cancer center with positive NVS cultures, from January 2012 to July 2018. We reviewed patient characteristics, culture data, immunodeficiency status, response to antibiotic therapy, and outcomes of infection. Results: Of twenty-eight patients, fifteen patients developed bacteremia from either Abiotrophia or Granulicatella species, while thirteen patients had positive wound or body fluid cultures. Most patients with bacteremia had underlying hematologic malignancies and neutropenia. Patients with positive wound or body fluid cultures had an invasive procedure at the related site. Intravenous (IV) vancomycin was the most common agent used, and all but two patients were treated with multiple antibiotic regimens. Conclusions: Infections with NVS have been reported with a variety of clinically infectious presentations and should be considered in cancer patients with neutropenia or in patients who have undergone invasive procedures. Bacteremia was the most common complication, especially in the setting of hematologic malignancy and neutropenia. Focal body site infection was also a common complication related to invasive procedures in immunocompetent patients. Overall mortality was low and related to complications of septic shock. J Microbiol Infect Dis 2020; 10(2):89-97.

RARE BACTERIAL INFECTIVE ENDOCARDITIS UNMASKING SIGMOID NEOPLASIA

Granulicatella species is a nutritionally variant streptococci (NVS) which is a normal flora of the oral cavity, intestinal tract and genitourinary tract. It accounts for about 5% of all streptococcal endocarditis. However since it is a fastidious organism, these cases are likely misdiagnosed as

1074. Management and Outcomes of Infective Endocarditis Due to Nutritionally Variant Streptococci

BackgroundNutritionally variant streptococci (NVS) are an infrequent cause of infective endocarditis (IE) and management recommendations are based on weak levels of evidence largely derived from case reports, small case series, and animal models of experimental endocarditis. Moreover, taxonomic changes have led to some confusion in designation of these organisms.MethodsWe retrospectively collected and analyzed data from 33 patients with NVS IE from 1970 to 2017. Only patients who met modified Duke Criteria for IE were included.ResultsMean patient age was 55 years and 61% were males. The most common comorbidities included diabetes mellitus (12%), malignancy (3%), heart failure (16%), coronary artery disease (25%), and chronic liver disease (9%). Predisposing valve abnormalities included rheumatic heart disease (11%), bicuspid aortic valve (22%), transplant valvulopathy (3%), mitral valve prolapse (3%), and congenital heart disease (11%). Cultures were reported as NVS (70%), Granulicatella species (18%) and Abiotrophia species (12%). Echocardiogram findings included vegetations (67%), new regurgitation (55%), perivalvular abscess (3%), mitral valve prolapse (3%), and ruptured mitral valve chordae (3%). Both prosthetic (26%) and native valve IE (74%) was seen, and the valves involved were aortic (37%), mitral (50%) and both aortic and mitral (13%). Complications were seen in 27% of patients, including heart failure (17%), splenic infarct (11%), stroke (8%), mycotic aneurysm (3%), and glomerulonephritis (2%). In vitro susceptibility to penicillin, ceftriaxone, and vancomycin was 88%, 80%, and 100%, respectively. The majority (77%) of patients were treated with a combination of β-lactam and aminoglycoside. Median duration of treatment was 33 days. Surgery was performed in 50% of patients with no significant difference in survival between those who were treated with combined medical/surgical treatment and those treated with medical therapy alone. Overall survival at 1, 4, and 10 years was 93%, 83%, and 66%, respectively.ConclusionIE due to NVS is a rare entity and is associated with a high rate of serious complications and may involve multiple valves. Long-term, two-thirds of the patients survived more than 10 years.Disclosures All authors: No reported disclosures.

Epidemiology, Clinical Features, and Outcome of Infective Endocarditis due to Abiotrophia Species and Granulicatella Species: Report of 76 Cases, 2000-2015.

Infective endocarditis (IE) caused by Abiotrophia (ABI) and Granulicatella (GRA) species is poorly studied. This work aims to describe and compare the main features of ABI and GRA IE. We performed a retrospective study of 12 IE institutional cases of GRA or ABI and of 64 cases published in the literature (overall, 38 ABI and 38 GRA IE cases). ABI/GRA IE represented 1.51% of IE cases in our institution between 2000 and 2015, compared to 0.88% of HACEK (Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, Kingella)-related IE and 16.62% of Viridans group streptococci (VGS) IE. Institutional ABI/GRA IE case characteristics were comparable to that of VGS, but periannular complications were more frequent (P = .008). Congenital heart disease was reported in 4 (10.5%) ABI and in 11 (28.9%) GRA cases (P = .04). Mitral valve was more frequently involved in ABI than in GRA (P < .001). Patient sex, prosthetic IE, aortic involvement, penicillin susceptibility, and surgical treatment were comparable between the genera. New-onset heart failure was the most frequent complication without genera differences (P = .21). Five (13.2%) ABI patients and 2 (5.3%) GRA patients died (P = .23). Factors associated with higher mortality were age (P = .02) and new-onset heart failure (P = .02). The genus (GRA vs ABI) was not associated with higher mortality (P = .23). GRA/ABI IE was more prevalent than HACEK IE and approximately one-tenth as prevalent as VGS; periannular complications were more frequent. GRA and ABI genera IE presented similar clinical features and outcomes. Overall mortality was low, and related to age and development of heart failure.

Coaggregation and biofilm growth of Granulicatella spp. with Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans.

BackgroundMembers of fastidious Granulicatella and Aggregatibacter genera belong to normal oral flora bacteria that can cause serious infections, such as infective endocarditis. Aggregatibacter actinomycetemcomitans has long been implicated in aggressive periodontitis, whereas DNA-based methods only recently showed an association between Granulicatella spp. and dental diseases. As bacterial coaggregation is a key phenomenon in the development of oral and nonoral multispecies bacterial communities it would be of interest knowing coaggregation pattern of Granulicatella species with A. actinomycetemcomitans in comparison with the multipotent coaggregator Fusobacterium nucleatum.The aim was to investigate coaggregation and biofilm formation of Granulicatella elegans and Granulicatella adiacens with A. actinomycetemcomitans and F. nucleatum strains.ResultsF. nucleatum exhibited significantly (p < 0.05) higher autoaggregation than all other test species, followed by A. actinomycetemcomitans SA269 and G. elegans. A. actinomycetemcomitans CU1060 and G. adiacens did not autoaggregate. G. elegans with F. nucleatum exhibited significantly (p < 0.05) higher coaggregation than most others, but failed to grow as biofilm together or separately. With F. nucleatum as partner, A. actinomycetemcomitans strains SA269, a rough-colony wild-type strain, and CU1060, a spontaneous smooth-colony laboratory variant, and G. adiacens were the next in coaggregation efficiency. These dual species combinations also were able to grow as biofilms. While both G. elegans and G. adiacens coaggregated with A. actinomycetemcomitans strain SA269, but not with CU1060, they grew as biofilms with both A. actinomycetemcomitans strains.ConclusionsG. elegans failed to form biofilm with F. nucleatum despite the strongest coaggregation with it. The ability of Granulicatella spp. to coaggregate and/or form biofilms with F. nucleatum and A. actinomycetemcomitans strains suggests that Granulicatella spp. have the potential to integrate into dental plaque biofilms.

Discrepant Satellitism for Identification ofGranulicatellaadiacens Isolates

Discrepant Satellitism for Identification of<i>Granulicatella</i>adiacens Isolates

Diarrhea in young children from low-income countries leads to large-scale alterations in intestinal microbiota composition.

BackgroundDiarrheal diseases continue to contribute significantly to morbidity and mortality in infants and young children in developing countries. There is an urgent need to better understand the contributions of novel, potentially uncultured, diarrheal pathogens to severe diarrheal disease, as well as distortions in normal gut microbiota composition that might facilitate severe disease.ResultsWe use high throughput 16S rRNA gene sequencing to compare fecal microbiota composition in children under five years of age who have been diagnosed with moderate to severe diarrhea (MSD) with the microbiota from diarrhea-free controls. Our study includes 992 children from four low-income countries in West and East Africa, and Southeast Asia. Known pathogens, as well as bacteria currently not considered as important diarrhea-causing pathogens, are positively associated with MSD, and these include Escherichia/Shigella, and Granulicatella species, and Streptococcus mitis/pneumoniae groups. In both cases and controls, there tend to be distinct negative correlations between facultative anaerobic lineages and obligate anaerobic lineages. Overall genus-level microbiota composition exhibit a shift in controls from low to high levels of Prevotella and in MSD cases from high to low levels of Escherichia/Shigella in younger versus older children; however, there was significant variation among many genera by both site and age.ConclusionsOur findings expand the current understanding of microbiota-associated diarrhea pathogenicity in young children from developing countries. Our findings are necessarily based on correlative analyses and must be further validated through epidemiological and molecular techniques.

Granulicatella infection: diagnosis and management

Granulicatella species, along with the genus Abiotrophia, were originally known as 'nutritionally variant streptococci'. They are a normal component of the oral flora, but have been associated with a variety of invasive infections in man and are most noted as a cause of bacterial endocarditis. It is often advised that Granulicatella endocarditis should be treated in the same way as enterococcal endocarditis. We review here the published data concerning diagnosis and treatment of Granulicatella infection, and include some observations from local cases, including four cases of endocarditis.

WS20.1 Target minority bacterial population in cystic fibrosis lung microbiota

Staphylococcus aureus is one of the most frequently encountered species in Cystic Fibrosis (CF) lung microbiota. However its frequent presence on agar plates from sputum samples of CF patients likely impaired the culture of other minority bacterial species that may be responsible for lung exacerbations. In order to discover this minority bacterial population, we examined the sputum sample of a CF patient using conventional culture dependent with or without inhibition of S. aureus growth with vancomycin and compare our results to culture independent molecular techniques. Using standard cultures as well as selective media at different physico-chemical conditions, we isolate Staphylococcus aureus in the majority of our culture conditions and media. Interestingly, after pre-incubation of the sample with Vancomycin to inhibit Staphylococcus aureus growth, we isolate new bacterial species (Granulicatella, Streptococcus, Rothia, Lactobacillus and Propionibacterium species), especially Actinomyces radicidentis, a rare bacterial species associated with endodontic infections never described in the context of CF. Using 16S rDNA PCR amplification and sequencing of subsequent clones, we identified Streptococcus, Granulicatella, Rothia, Abiotropha, Peptostreptococcus, Lachnospiraceae and Actinomyces along with S. aureus confirming the culture dependent findings. In conclusion, the use of various bacterial inhibitors to inhibit the growth of the dominant bacteria may help to discover the minority bacterial population that could be new or emerging species in the context of CF.

New Consensus Guidelines from the Clinical and Laboratory Standards Institute for Antimicrobial Susceptibility Testing of Infrequently Isolated or Fastidious Bacteria

The Clinical and Laboratory Standards Institute (CLSI) recently published a new laboratory guideline for antimicrobial susceptibility testing of infrequently encountered or fastidious bacteria not covered in previous CLSI publications. The organisms include Aeromonas species, Bacillus species, and Vibrio species that may cause infections following environmental exposure. Fastidious organisms that may cause endocarditis or medical device infections include Abiotrophia and Granulicatella species; coryneform bacteria; Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella group gram-negative rods; and the instrinsically vancomycin-resistant gram-positive organisms Erysipelothrix, Lactobacillus, Leuconostoc, and Pediococcus species. Organisms not previously covered in depth in CLSI guidelines include Branhamella catarrhalis, Campylobacter jejuni, Campylobacter coli, Listeria species, and Pasteurella species. Clinically important drug resistance has been reported for each of these organisms. The guidelines provide recommendations for when it may be important to test these organisms, how standard methods may be easily adapted for testing, and appropriate interpretive criteria for results. Communication with infectious diseases clinicians prior to performing such testing is emphasized.

Bloodstream and endovascular infections due to Abiotrophia defectiva and Granulicatella species.

BackgroundAbiotrophia and Granulicatella species, previously referred to as nutritionally variant streptococci (NVS), are significant causative agents of endocarditis and bacteraemia. In this study, we reviewed the clinical manifestations of infections due to A. defectiva and Granulicatella species that occurred at our institution between 1998 and 2004.MethodsThe analysis included all strains of NVS that were isolated from blood cultures or vascular graft specimens. All strains were identified by 16S rRNA sequence analysis. Patients' medical charts were reviewed for each case of infection.ResultsEleven strains of NVS were isolated during the 6-year period. Identification of the strains by 16S rRNA showed 2 genogroups: Abiotrophia defectiva (3) and Granulicatella adiacens (6) or "para-adiacens" (2). The three A. defectiva strains were isolated from immunocompetent patients with endovascular infections, whereas 7 of 8 Granulicatella spp. strains were isolated from immunosuppressed patients, mainly febrile neutropenic patients. We report the first case of "G. para-adiacens" bacteraemia in the setting of febrile neutropenia.ConclusionWe propose that Granulicatella spp. be considered as a possible agent of bacteraemia in neutropenic patients.

Central nervous system infections due to Abiotrophia and Granulicatella species: an emerging challenge?

Although Abiotrophia and Granulicatella species, previously referred to as nutritionally variant streptococci, were initially identified over 40 years ago, isolation of these pathogens from the central nervous system (CNS) was first noted only recently. Recognition of CNS involvement with these organisms is of great concern given the association of Abiotrophia/Granulicatella infections with increased morbidity and mortality as well as greater bacteriologic failure and relapse rates. We describe A. defectiva and G. adiacens CNS infections in two patients and review the existing literature of CNS involvement with these bacteria. The clinical presentation and initial cerebrospinal fluid analysis has varied substantially across reported patients. While most infections have been characterized primarily by a localized infection (e.g., abscess), evidence of meningitis has usually also been present. Furthermore, nearly all cases have followed neurosurgical procedures suggesting possible introduction of the organism into the CNS at the time of surgery. Given the significant negative clinical impact of Abiotrophia/Granulicatella infections, elucidation of the emerging epidemiology of CNS infections with these bacteria is warranted.

Granulicatella and Abiotrophia species: cause or consequence?

Granulicatella and Abiotrophia species: cause or consequence?

Bacteriologic findings associated with chronic bacterial maxillary sinusitis in adults.

An open-label, multicenter study was performed to assess bacteriologic findings associated with chronic bacterial maxillary sinusitis in adults. Seventy aerobic (52.2%) and 64 anaerobic (47.8%) pathogens were recovered from clinically evaluable patients at baseline (before therapy). The most commonly isolated anaerobes were Prevotella species (31.1%), anaerobic streptococci (21.9%), and Fusobacterium species (15.6%). The aerobes most frequently recovered included Streptococcus species (21.4%), Haemophilus influenzae (15.7%), Pseudomonas aeruginosa (15.7%), and Staphylococcus aureus and Moraxella catarrhalis (10.0% each). Recurrences of signs or symptoms of bacterial maxillary sinusitis associated with anaerobes were twice as frequent as were those associated with aerobes when counts of anaerobes were > or =10(3) cfu/mL. A pathogenic role for Granulicatella species in cases of chronic sinusitis was documented for the first time.