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Diagnostic Microbiology and Infectious... Nov 2023To develop an in-house matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) library for improved identification of species and...
OBJECTIVES
To develop an in-house matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) library for improved identification of species and subspecies of the Streptococcus bovis/Streptococcus equinus-complex (SBSEC).
METHODS
A total of 236 SBSEC isolates from blood stream infections and culture collections, determined by whole genome sequencing to subspecies level, were grown in brain heart infusion broth. Mass spectra were collected using the Bruker MALDI Biotyper system after ethanol-formic acid extraction. Main spectral profiles from 117 isolates were used to create the "SBSEC-CMRS library." The remaining 119 spectra were used for evaluation of Bruker MALDI Biotyper (MBT) Compass Library Revision K (2022) and the SBSEC-CMRS library.
RESULTS
The Bruker library correctly identified species and subspecies in 72 of 119 (61 %) isolates, while the SBSEC-CMRS library identified 116 of 119 (97 %), using a cutoff score of ≥2.0.
CONCLUSIONS
The SBSEC-CMRS library showed sufficient diagnostic accuracy, and can be implemented in clinical practice for SBSEC species and subspecies identification.
Topics: Humans; Streptococcus bovis; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Streptococcus
PubMed: 37598592
DOI: 10.1016/j.diagmicrobio.2023.116045 -
American Journal of Translational... 2023Preterm premature rupture of membranes (PPROM) is closely associated with pathogenic microbiomes in the female reproductive tract, and can lead to neonatal septicemia....
BACKGROUND
Preterm premature rupture of membranes (PPROM) is closely associated with pathogenic microbiomes in the female reproductive tract, and can lead to neonatal septicemia. The current study aimed to investigate potential pathogenic microbiomes associated with neonatal septicemia based on DNA metagenome sequencing.
METHODS
In this study, a total of 7 pregnant women with PPROM presenting neonatal septicemia (experimental group) and 3 pregnant women with normal newborns (control group) were enrolled. Vaginal secretions at admission and before parturition as well as placental tissues after parturition were collected for DNA metagenome sequencing using whole genome shotgun method on the Illumina NovaSeq/HiSeq platform. Raw data were processed by BioBakery workflow, and MetaPhlAn4 was implemented for qualitative and quantitative analyses of microbiome. Lactobacillus crispatus, Gardneralla vaginalis, Fannyhessea vaginae and Streptococcus suis were specifically detected from the experimental group. The two groups were compared using Student's t-tests.
RESULTS
The indexes of Chao1 (P=0.00028/P=0.00072), abundance-based coverage estimator (ACE, P=0.00059/P=0.00026), Shannon (P=0.036/P=0.0065) and Simpson (P=0.007/P=0.041) in the experimental group were increased at admission and before parturition as compared with the control group. Several microbiomes, such as Lactobacillus crispatus, Gardneralla vaginalis, Fannyhessea vaginae and Streptococcus suis, were specifically detected in the experimental group. Notably, Gardnerella vaginalis and Streptococcus gallolyticus were identified from the vaginal secretions and placenta tissues of women with neonatal septicemia. Moreover, nucleic acid synthesis and carbohydrate metabolism-related pathways were enriched in the experimental group.
CONCLUSION
This study enhanced the current understanding of the mechanisms underlying pathogenic microbiomes in PPROM-induced neonatal septicemia. The trial registry number is ChiCTR2300070666 (URL: https://www.chictr.org.cn/showproj.html?proj=195648).
PubMed: 37560239
DOI: No ID Found -
Poultry Science Oct 2023Streptococcus gallolyticus (SG) is a Gram-positive cocci found as commensal gut flora in animals and humans. SG has emerged as a cause of disease in young poults between...
Isolation, characterization, and experimental infection of Streptococcus gallolyticus subspecies pasteurianus from commercial turkeys with acute septicemia: a pilot study.
Streptococcus gallolyticus (SG) is a Gram-positive cocci found as commensal gut flora in animals and humans. SG has emerged as a cause of disease in young poults between 1 and 3 wk of age. SG is associated with septicemia resulting in acute mortality with no premonitory signs in turkeys. Three SG isolates were obtained from clinical field cases of acute septicemia of commercial turkeys and used in three independent experiments. In Experiment 1, embryos were inoculated 25 d of embryogenesis with varying concentrations of SG1, SG2, or SG3. In Experiment 2, day of hatch, poults were inoculated with varying concentrations using different routes of administration of SG1, SG2, or SG3. In Experiment 3, day of hatch, poults were inoculated with only isolate SG1 using different paths. Poults were randomly selected for necropsy on d 8 and d 15 and sampled to collect spleen, heart, and liver for SG on d 21, the remaining poults were necropsied and cultured. Samples were plated on Columbia nalidixic acid and colistin agar (CNA) (40°C, 18-24 h). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) confirmed suspect colonies. Data were analyzed using the chi-square test of independence, testing all possible combinations to determine significance (P < 0.05). Weight data were subjected to ANOVA using JMP with significance (P < 0.05). No differences were found in BW or BWG on d 0, 8, 15, or 22. Splenomegaly, focal heart necrosis, and pericarditis were observed in all groups in experiments 1 through 3. In Experiment 3, only airsacculitis was observed in a negative control in separate isolation (P > 0.05). On d 21 of Experiment 3, increased (P < 0.05) recovery of SG from spleens were observed in co-housed negative controls, as well as poults challenged by oral gavage (P > 0.05 for d 7 and d 14). These results confirm numerous previous studies indicating that SG subsp. pasteurianus is a primary infectious microorganism that causes septicemia in young poults.
Topics: Animals; Chickens; Pilot Projects; Poultry Diseases; Sepsis; Streptococcus gallolyticus; Turkeys
PubMed: 37540949
DOI: 10.1016/j.psj.2023.102950 -
Microorganisms Jun 2023The aim of this study was to evaluate whether dietary supplementation with an innovative silage (IS) created using 60% olive mill waste, 20% grape pomace, and 20%...
The aim of this study was to evaluate whether dietary supplementation with an innovative silage (IS) created using 60% olive mill waste, 20% grape pomace, and 20% deproteinised feta cheese waste solids can modulate the composition of the intestinal microbiota in weaned (Exp. 1) and finishing (Exp. 2) pigs. In Exp. 1 (40 day supplementation), forty-five crossbred weaned pigs were randomly assigned to the 0% (Control), 5%, or 10% IS groups (15 replicates/experimental diet). In Exp. 2 (60 day supplementation), eighteen finishing pigs from Exp. 1 were fed the control diet for 8 weeks before being re-assigned to their original experimental groups and fed with the 0% (Control), 5%, or 10% IS diets (six replicates/experimental diet). Performance parameters were recorded. Ileal and caecal digesta and mucosa were collected at the end of each experiment for microbiota analysis using 16S rRNA gene sequencing (five pigs/experimental diet for Exp. 1 and six pigs/experimental diet for Exp. 2). No significant effects on pig growth parameters were observed in both experiments. In Exp. 1, 5% IS supplementation increased the relative abundance of the family, genus, and (OTU_48) and reduced the relative abundance of genus in the caecum compared to the control and/or 10% IS diets ( < 0.05). In Exp. 2, 5% IS supplementation led to compositionally more diverse and different ileal and caecal microbiota compared to the control group ( < 0.05; = 0.066 for β-diversity in ileum). Supplementation with the 5% IS increased the relative abundance of // (OTU_3) in the ileum and caecum and (OTU_17) in the caecum and reduced the relative abundance of / (OTU_2) in the caecum compared to the control diet ( < 0.05). Similar effects on // and / were observed with the 10% IS diet in the caecum ( < 0.05). IS has the potential to beneficially alter the composition of the gastrointestinal microbiota in pigs.
PubMed: 37512895
DOI: 10.3390/microorganisms11071723 -
Microbiology Spectrum Aug 2023Streptococcus gallolyticus subsp. () is an opportunistic bacterial pathogen strongly associated with colorectal cancer. Here, through comparative genomics analysis, we...
Streptococcus gallolyticus subsp. () is an opportunistic bacterial pathogen strongly associated with colorectal cancer. Here, through comparative genomics analysis, we demonstrated that the genetic locus encoding the type VIIb secretion system (T7SSb) machinery is uniquely present in in two different arrangements. UCN34 carrying the most prevalent T7SSb genetic arrangement was chosen as the reference strain. To identify the effectors secreted by this secretion system, we inactivated the gene encoding the motor of this machinery. A comparison of the proteins secreted by UCN34 wild type and its isogenic Δ mutant revealed six T7SSb effector proteins, including the expected WXG effector EsxA and three LXG-containing proteins. In this work, we characterized an LXG-family toxin named herein TelE promoting the loss of membrane integrity. Seven homologs of TelE harboring a conserved glycine zipper motif at the C terminus were identified in different isolates. Scanning mutagenesis of this motif showed that the glycine residue at position 470 was crucial for TelE membrane destabilization activity. TelE activity was antagonized by a small protein TipE belonging to the DUF5085 family. Overall, we report herein a unique T7SSb effector exhibiting a toxic activity against nonimmune bacteria. In this study, 38 clinical isolates of Streptococcus gallolyticus subsp. () were sequenced and a genetic locus encoding the type VIIb secretion system (T7SSb) was found conserved and absent from 16 genomes of the closely related S. gallolyticus subsp. (). The T7SSb is a bona fide pathogenicity island. Here, we report that the model organism strain UCN34 secretes six T7SSb effectors. One of the six effectors named TelE displayed a strong toxicity when overexpressed in Escherichia coli. Our results indicate that TelE is probably a pore-forming toxin whose activity can be antagonized by a specific immunity protein named TipE. Overall, we report a unique toxin-immunity protein pair and our data expand the range of effectors secreted through T7SSb.
Topics: Streptococcus gallolyticus subspecies gallolyticus; Amino Acid Motifs; Glycine; Type VII Secretion Systems
PubMed: 37432124
DOI: 10.1128/spectrum.01481-23 -
Digestive Diseases and Sciences Aug 2023Streptococcus gallolyticus subspecies gallolyticus (SGG) and Fusobacterium (F.) nucleatum have been implicated in colorectal carcinogenesis. Here, the association of...
BACKGROUND
Streptococcus gallolyticus subspecies gallolyticus (SGG) and Fusobacterium (F.) nucleatum have been implicated in colorectal carcinogenesis. Here, the association of immune responses to bacterial exposure with advancing stages of colorectal neoplasia was assessed by multiplex serology.
METHODS
Immunoglobulin (Ig) A and G antibody responses to eleven proteins each of F. nucleatum and SGG were measured in plasma of controls (n = 100) and patients with colorectal cancer (CRC, n = 25), advanced adenoma (n = 82), or small polyps (n = 85). Multivariable logistic regression was used to evaluate the association of bacterial sero-positivity with colorectal neoplasia. In a cohort subset with matched data (n = 45), F. nucleatum sero-positivity was correlated with bacterial abundance in both neoplastic and matched normal tissue.
RESULTS
IgG sero-positivity to Fn1426 of F. nucleatum was associated with an increased CRC risk (OR = 4.84; 95% CI 1.46-16.0), while IgA sero-positivity to any SGG protein or specifically Gallo0272 and Gallo1675 alone was associated with increased advanced adenoma occurrence (OR = 2.02, 95% CI 1.10-3.71; OR = 2.67, 95% CI 1.10-6.46; and OR = 6.17, 95% CI 1.61-23.5, respectively). Only F. nucleatum abundance in the normal mucosa positively correlated with the IgA response to the Fn1426 antigen (Correlation coefficient (r) = 0.38, p < 0.01).
CONCLUSION
Antibody responses to SGG and F. nucleatum were associated with occurrence of colorectal adenomas and CRC, respectively. Further studies are needed to clarify the role these microbes or the immune response to their antigens may have in colorectal carcinogenesis stages.
Topics: Humans; Fusobacterium nucleatum; Streptococcus gallolyticus; Antibody Formation; Colorectal Neoplasms; Bacteria; Adenoma; Carcinogenesis; Fusobacterium Infections
PubMed: 37338617
DOI: 10.1007/s10620-023-08001-4 -
Microbiology Spectrum Aug 2023This study aimed to identify which streptococcal species are closely associated with infective endocarditis (IE) and to evaluate risk factors for mortality in patients...
This study aimed to identify which streptococcal species are closely associated with infective endocarditis (IE) and to evaluate risk factors for mortality in patients with streptococcal IE. We performed a retrospective cohort study of all patients with streptococcal bloodstream infection (BSI) from January 2010 to June 2020 in a tertiary hospital in South Korea. We compared clinical and microbiological characteristics of streptococcal BSIs according to the diagnosis of IE. We performed multivariate analysis to evaluate the risk of IE according to streptococcal species and risk factors for mortality in streptococcal IE. A total of 2,737 patients were identified during the study period, and 174 (6.4%) were diagnosed with IE. The highest IE prevalence was in patients with Streptococcus mutans BSI (33% [9/27]) followed by S. sanguinis (31% [20/64]), S. gordonii (23% [5/22]), S. gallolyticus (16% [12/77]), and S. oralis (12% [14/115]). In multivariate analysis, previous IE, high-grade BSI, native valve disease, prosthetic valve, congenital heart disease, and community-onset BSI were independent risk factors for IE. After adjusting for these factors, S. sanguinis (adjusted OR [aOR], 7.75), S. mutans (aOR, 5.50), and S. gallolyticus (aOR, 2.57) were significantly associated with higher risk of IE, whereas S. pneumoniae (aOR, 0.23) and (aOR, 0.37) were associated with lower risk of IE. Age, hospital-acquired BSI, ischemic heart disease, and chronic kidney disease were independent risk factors for mortality in streptococcal IE. Our study points to significant differences in the prevalence of IE in streptococcal BSI according to species. Our study of risk of infective endocarditis in patients with streptococcal bloodstream infection demonstrated that Streptococcus sanguinis, S. mutans, and S. gallolyticus were significantly associated with higher risk of infective endocarditis. However, when we evaluated the performance of echocardiography in patients with streptococcal bloodstream infection, patients with S. mutans and S. gordonii bloodstream infection had a tendency of low performance in echocardiography. There are significant differences in the prevalence of infective endocarditis in streptococcal bloodstream infection according to species. Therefore, performing echocardiography in streptococcal bloodstream infection with a high prevalence of, and significant association with, infective endocarditis is desirable.
Topics: Humans; Retrospective Studies; Streptococcus; Endocarditis, Bacterial; Endocarditis; Streptococcal Infections; Sepsis
PubMed: 37284757
DOI: 10.1128/spectrum.01049-23 -
Internal Medicine (Tokyo, Japan) Jan 2024Bacterial meningitis is a life-threatening condition that is mainly caused by Streptococcus pneumoniae and Neisseria meningitis. Although Streptococcus gallolyticus...
Bacterial meningitis is a life-threatening condition that is mainly caused by Streptococcus pneumoniae and Neisseria meningitis. Although Streptococcus gallolyticus subsp. pasteurianus (Sgp) is also known to cause meningitis, its frequency is quite low, especially in adults. We herein report the first immunocompetent Japanese adult patient (20-year-old woman) with bacterial meningitis caused by Sgp. The patient showed dramatic improvement after antibiotic treatment. Although previous reports have described an association between Sgp infection and an immunosuppressive status, bowel and hepatobiliary diseases, or strongyloidiasis, our case did not demonstrate any of these conditions, suggesting that Sgp can cause meningitis even in young immunocompetent adults.
Topics: Female; Humans; Young Adult; Adult; Streptococcus gallolyticus; Streptococcal Infections; Streptococcus; Meningitis, Bacterial
PubMed: 37258163
DOI: 10.2169/internalmedicine.1785-23