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Antimicrobial Agents and Chemotherapy Dec 2015Nutritionally variant streptococci (NVS) are fastidious Gram-positive cocci comprised of the species Abiotrophia defectiva, Granulicatella adiacens, and Granulicatella...
Nutritionally variant streptococci (NVS) are fastidious Gram-positive cocci comprised of the species Abiotrophia defectiva, Granulicatella adiacens, and Granulicatella elegans. NVS are an important cause of bacteremia and infective endocarditis (IE) associated with significant morbidity and mortality. Antimicrobial susceptibility testing (AST) was performed for 14 antimicrobials using the broth microdilution MIC method described in the Clinical and Laboratory Standards Institute (CLSI) M45 guideline. A total of 132 clinical NVS blood isolates collected from 2008 to 2014 were tested. Species level identification of NVS isolates was achieved by 16S rRNA gene sequencing and/or matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Ninety isolates were identified as G. adiacens, 37 as A. defectiva, and 5 as G. elegans. All isolates were susceptible to vancomycin (MIC90 = 1 μg/ml), and none displayed high-level resistance to aminoglycosides. G. adiacens was considerably more susceptible to penicillin than A. defectiva (38.9% versus 10.8% of isolates susceptible) but was less susceptible to cephalosporins than was A. defectiva (43.3% versus 100% of isolates susceptible to ceftriaxone). Several isolates were resistant to levofloxacin (6%), erythromycin (51%), and clindamycin (10%). The MIC90 for daptomycin was ≥ 4 μg/ml for G. adiacens and A. defectiva. G. elegans isolates were 100% susceptible to all antimicrobials tested, with the exception of erythromycin, to which only 20% were susceptible. This study provides antimicrobial susceptibility data for a recent collection of NVS and demonstrates important NVS species-related differences with respect to susceptibility to penicillin, cephalosporins, carbapenems, and daptomycin. Species-level identification of NVS organisms when susceptibility testing is not readily available may aid in treatment decisions.
Topics: Abiotrophia; Anti-Bacterial Agents; Carnobacteriaceae; Gram-Positive Bacterial Infections; Humans; Los Angeles; Microbial Sensitivity Tests; Molecular Typing; RNA, Ribosomal, 16S; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; beta-Lactams
PubMed: 26666926
DOI: 10.1128/AAC.02645-15 -
Antimicrobial Agents and Chemotherapy Aug 2016MICs of 25 Abiotrophia defectiva and 109 Granulicatella adiacens isolates were determined by broth microdilution. Using CLSI breakpoints, the susceptibilities of A....
MICs of 25 Abiotrophia defectiva and 109 Granulicatella adiacens isolates were determined by broth microdilution. Using CLSI breakpoints, the susceptibilities of A. defectiva and G. adiacens isolates were, respectively, 24% and 34% to penicillin, 92% and 22% to ceftriaxone, 48% and 3% to cefepime, 72% and 87% to meropenem, 92% and 10% to cefotaxime, 100% and 97% to levofloxacin, 92% and 80% to clindamycin, and 24% and 50% to erythromycin. All isolates were susceptible to vancomycin. In the penicillin-susceptible subgroup, all A. defectiva isolates were susceptible to ceftriaxone; however, 62% of G. adiacens isolates were ceftriaxone nonsusceptible.
Topics: Abiotrophia; Anti-Infective Agents; Carnobacteriaceae; Cefepime; Cefotaxime; Cephalosporins; Clindamycin; Erythromycin; Levofloxacin; Microbial Sensitivity Tests; Penicillins; Vancomycin
PubMed: 27216060
DOI: 10.1128/AAC.00485-16 -
Frontiers in Cellular and Infection... 2019Despite reports on the occurrence of in infective endocarditis, few mechanistic studies on its virulence characteristics or pathogenicity are available. Proteins...
Despite reports on the occurrence of in infective endocarditis, few mechanistic studies on its virulence characteristics or pathogenicity are available. Proteins secreted by this species may act as determinants of host-microbe interaction and play a role in virulence. Our aim in this study was to investigate and functionally characterize the secretome of . Proteins in the secretome preparation were digested by trypsin and applied to nanoLC-ESI-MS/MS. By using a combined mass spectrometry and bioinformatics approach, we identified 101 proteins. Bioinformatics tools predicting subcellular localization revealed that 18 of the secreted proteins possessed signal sequence. More than 20% of the secretome proteins were putative virulence proteins including serine protease, superoxide dismutase, aminopeptidase, molecular chaperone DnaK, and thioredoxin. Ribosomal proteins, molecular chaperones, and glycolytic enzymes, together known as "moonlighting proteins," comprised fifth of the secretome proteins. By Gene Ontology analysis, more than 60 proteins of the secretome were grouped in biological processes or molecular functions. KEGG pathway analysis disclosed that the secretome consisted of enzymes involved in biosynthesis of antibiotics. Cytokine profiling revealed that secreted proteins stimulated key cytokines, such as IL-1β, MCP-1, TNF-α, and RANTES from human PBMCs. In summary, the results from the current investigation of the secretome provide a basis for understanding possible pathogenic mechanisms of .
Topics: Bacterial Proteins; Carnobacteriaceae; Computational Biology; Endocarditis; Humans; Proteomics; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Virulence Factors
PubMed: 31069174
DOI: 10.3389/fcimb.2019.00104 -
Journal of Clinical Orthopaedics and... 2020is a nutritional variant of streptococcus (NVS), which has been rarely reported as an etiologic agent in spondylodiscitis (SD). (Review)
Review
BACKGROUND
is a nutritional variant of streptococcus (NVS), which has been rarely reported as an etiologic agent in spondylodiscitis (SD).
MATERIAL AND METHODS
We report a case of a 51-year-old male with from chronic low-back pain associated with right sciatica and ipsilateral monoparesis. Spinal MRI showed radiological signs on L1-L2 and L5-S1 discs consistent with SD. We also performed a systematic review of the pertinent literature in order to retrieve all the key information regarding microbiological and clinical features.
RESULTS
Including our patients, seven cases with a mean age 56 ± 10.2 years were reported in English literature. Six patients were conservatively managed with antibiotic therapy (66%), whereas three with surgery in combination with antibiotics (33%). An endocarditis was associated in three cases, and a pacemaker infection in one. All patients received targeted antibiotic therapy resulting in a quick improvement of clinical symptoms with favorable outcome. Our case is the only with a skip spontaneous SD, which needed a surgical decompression due to the associated neurological symptoms.
CONCLUSIONS
This incidence of SD sustained by could be underestimated due to their particular microbiological conditions requested for their cultures. However, this infection should be suspected in cases of culture-negative SD, especially when associated with endocarditis.
PubMed: 32879584
DOI: 10.1016/j.jcot.2019.07.002 -
Journal of Laboratory Physicians Sep 2022, a nutritionally variant (NVS), is part of the normal commensal flora of human mouth, genital, and intestinal tracts and rarely causes disease. It has been mostly...
, a nutritionally variant (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 presented with empyema complicated to sepsis and necrotizing fasciitis. Clinicians should be aware of the pathogenic potential of (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.
PubMed: 36119420
DOI: 10.1055/s-0042-1744236 -
Scientific Reports Jan 2022Descriptions of the small intestinal microbiota are deficient and conflicting. We aimed to get a reliable description of the jejunal bacterial microbiota by...
Descriptions of the small intestinal microbiota are deficient and conflicting. We aimed to get a reliable description of the jejunal bacterial microbiota by investigating samples from two separate jejunal segments collected from the luminal mucosa during surgery. Sixty patients with morbid obesity selected for elective gastric bypass surgery were included in this survey. Samples collected by rubbing a swab against the mucosa of proximal and mid jejunal segments were characterized both quantitatively and qualitatively using a combination of microbial culture, a universal quantitative PCR and 16S deep sequencing. Within the inherent limitations of partial 16S sequencing, bacteria were assigned to the species level. By microbial culture, 53 patients (88.3%) had an estimated bacterial density of < 1600 cfu/ml in both segments whereof 31 (51.7%) were culture negative in both segments corresponding to a bacterial density below 160 cfu/ml. By quantitative PCR, 46 patients (76.7%) had less than 10 bacterial genomes/ml in both segments. The most abundant and frequently identified species by 16S deep sequencing were associated with the oral cavity, most often from the Streptococcus mitis group, the Streptococcus sanguinis group, Granulicatella adiacens/para-adiacens, the Schaalia odontolytica complex and Gemella haemolysans/taiwanensis. In general, few bacterial species were identified per sample and there was a low consistency both between the two investigated segments in each patient and between patients. The jejunal mucosa of fasting obese patients contains relatively few microorganisms and a core microbiota could not be established. The identified microbes are likely representatives of a transient microbiota and there is a high degree of overlap between the most frequently identified species in the jejunum and the recently described ileum core microbiota.
Topics: Adult; Aged; Bacteria; DNA, Bacterial; Female; Gastric Bypass; Gastrointestinal Microbiome; High-Throughput Nucleotide Sequencing; Humans; Intestinal Mucosa; Jejunum; Male; Middle Aged; Obesity, Morbid; Real-Time Polymerase Chain Reaction; Ribotyping; Young Adult
PubMed: 35102222
DOI: 10.1038/s41598-022-05723-9 -
Journal of Oral Science Jan 2020Granulicatella adiacens (G. adiacens) and Abiotrophia defectiva (A. defectiva) colonize the oral cavity and form part of the normal flora in the intestinal and...
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 CaCl. 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.
Topics: Abiotrophia; Endocarditis, Bacterial; Endothelial Cells; Humans; Streptococcus
PubMed: 31708553
DOI: 10.2334/josnusd.19-0021 -
BMC Musculoskeletal Disorders Jun 2017Bone and joint infection involving Granulicatella adiacens is rare, and mainly involved in cases of bacteremia and infectious endocarditis. Here we report three cases of... (Review)
Review
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.
Topics: Adult; Aged; Carnobacteriaceae; Female; Hip Prosthesis; Humans; Knee Prosthesis; Male; Middle Aged; Prosthesis-Related Infections
PubMed: 28645272
DOI: 10.1186/s12891-017-1630-1 -
BMC Microbiology May 2015Members of fastidious Granulicatella and Aggregatibacter genera belong to normal oral flora bacteria that can cause serious infections, such as infective endocarditis....
BACKGROUND
Members 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.
RESULTS
F. 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.
CONCLUSIONS
G. 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.
Topics: Aggregatibacter actinomycetemcomitans; Bacterial Adhesion; Biofilms; Carnobacteriaceae; Dental Plaque; Fusobacterium nucleatum; Humans; Species Specificity
PubMed: 26025449
DOI: 10.1186/s12866-015-0439-z -
Scientific Reports Jun 2022Host determinants for formation/composition of human oral microbiota remain to be clarified, although microorganisms entering the mouth cannot necessarily colonize the...
Host determinants for formation/composition of human oral microbiota remain to be clarified, although microorganisms entering the mouth cannot necessarily colonize the oral environment. Here we show that human oral-abundant bacteria degraded host glycosaminoglycans (GAGs) in saliva and gingiva, and certain bacteria significantly grew on hyaluronan (HA), a kind of GAGs. Microbial communities from teeth or gingiva of healthy donors assimilated HA. Metagenomic analysis of human oral microbiota under different carbon sources revealed HA-driven Granulicatella growth. HA-degrading bacterial strains independently isolated from teeth and gingiva were identified as Granulicatella adiacens producing extracellular 130 kDa polysaccharide lyase as a HA-degrading enzyme encoded in a peculiar GAG genetic cluster containing genes for isomerase KduI and dehydrogenase DhuD. These findings demonstrated that GAGs are one of the host determinants for formation/composition of oral microbiota not only for colonization but also for the adaptation to the host niche. Especially, HA enhanced the G. adiacens propagation.
Topics: Bacteria; Carnobacteriaceae; Glycosaminoglycans; Humans; Hyaluronic Acid; Microbiota; Streptococcus
PubMed: 35768476
DOI: 10.1038/s41598-022-14857-9