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Frontiers in Cellular and Infection... 2021The opportunistic pathogen is one of the few intestinal bacteria that has been consistently linked to colorectal cancer (CRC). This study aimed to identify novel...
OBJECTIVE
The opportunistic pathogen is one of the few intestinal bacteria that has been consistently linked to colorectal cancer (CRC). This study aimed to identify novel -induced pathways in colon epithelial cells that could further explain how contributes to CRC development.
DESIGN AND RESULTS
Transcription profiling of cultured CRC cells that were exposed to revealed the specific induction of oxidoreductase pathways. Most prominently, and genes that encode phase I biotransformation enzymes were responsible for the detoxification or bio-activation of toxic compounds. A common feature is that these enzymes are induced through the Aryl hydrocarbon receptor (AhR). Using the specific inhibitor CH223191, we showed that the induction of was dependent on the AhR both using multiple CRC cell lines as using wild-type C57bl6 mice colonized with . Furthermore, we showed that CYP1 could also be induced by other intestinal bacteria and that a yet unidentified diffusible factor from the secretome (SGS) induces CYP1A enzyme activity in an AhR-dependent manner. Importantly, priming CRC cells with SGS increased the DNA damaging effect of the polycyclic aromatic hydrocarbon 3-methylcholanthrene.
CONCLUSION
This study shows that gut bacteria have the potential to modulate the expression of biotransformation pathways in colonic epithelial cells in an AhR-dependent manner. This offers a novel theory on the contribution of intestinal bacteria to the etiology of CRC by modifying the capacity of intestinal epithelial or (pre-)cancerous cells to (de)toxify dietary components, which could alter intestinal susceptibility to DNA damaging events.
Topics: Animals; Biotransformation; Colorectal Neoplasms; Cytochrome P-450 CYP1A1; Epithelial Cells; Mice; Mice, Inbred C57BL; Receptors, Aryl Hydrocarbon; Streptococcus gallolyticus
PubMed: 34778104
DOI: 10.3389/fcimb.2021.740704 -
Journal of Medical Case Reports Oct 2021Streptococcus gallolyticus subspecies gallolyticus is a known pathogen that causes infective endocarditis, and most cases involve the left heart valves. We present the... (Review)
Review
BACKGROUND
Streptococcus gallolyticus subspecies gallolyticus is a known pathogen that causes infective endocarditis, and most cases involve the left heart valves. We present the first reported case of prosthetic tricuspid valve endocarditis caused by this microorganism. Relevant literature is reviewed.
CASE PRESENTATION
A 67-year-old Jewish female with a history of a prosthetic tricuspid valve replacement was admitted to the emergency department because of nonspecific complaints including effort dyspnea, fatigue, and a single episode of transient visual loss and fever. No significant physical findings were observed. Laboratory examinations revealed microangiopathic hemolytic anemia and a few nonspecific abnormalities. Transesophageal echocardiogram demonstrated a vegetation attached to the prosthetic tricuspid valve. The involved tricuspid valve was replaced by a new tissue valve, and Streptococcus gallolyticus subspecies gallolyticus was grown from its culture. Prolonged antibiotic treatment was initiated.
CONCLUSIONS
Based on this report and the reviewed literature, Streptococcus gallolyticus should be considered as a rare but potential causative microorganism in prosthetic right-sided valves endocarditis. The patient's atypical presentation emphasizes the need for a high index of suspicion for the diagnosis of infective endocarditis.
Topics: Aged; Endocarditis; Endocarditis, Bacterial; Female; Humans; Streptococcal Infections; Streptococcus gallolyticus; Tricuspid Valve
PubMed: 34702343
DOI: 10.1186/s13256-021-03125-5 -
Revista Espanola de Quimioterapia :... Dec 2021
Topics: Abscess; Acidaminococcus; Adult; Female; Fournier Gangrene; Humans; Streptococcus gallolyticus
PubMed: 34645128
DOI: 10.37201/req/070.2021 -
Open Forum Infectious Diseases Sep 2021Lack of awareness of the taxonomic revision from the familiar to the less familiar may be associated with a decrease in recommended colon cancer screening in patients...
BACKGROUND
Lack of awareness of the taxonomic revision from the familiar to the less familiar may be associated with a decrease in recommended colon cancer screening in patients with bacteremia from this organism. This could subsequently lead to a delay in diagnosis or underdiagnosis of colon cancer and other serious underlying gastrointestinal diseases. The aim of this study was to determine whether the nomenclature change of to resulted in decreased colon cancer screening.
METHODS
This study was a retrospective, observational, nationwide analysis of patients who had positive blood cultures for / from any Veterans Affairs Medical Center (VAMC) between January 1, 2002, and December 31, 2017.
RESULTS
There was no difference in the primary end point of intent for colonoscopy between the and groups (66.5% [117/176] vs 62.1% [624/1005], respectively; = .26). The overall mortality rate was 33.8% among 1181 patients included in the study, with a significantly lower mortality in patients with evidence of intent for colonoscopy (29.6% vs 42.5%; ≤ .001), gastroenterology (GI) consultation (29.8% vs 41.4%; < .001), infectious diseases (ID) consultation (29.4% vs 39.0%; = .001), or either consultation (31.9% vs 40.7%; = .013), compared to those that did not.
CONCLUSIONS
There was no difference in colon cancer screening rates between patients with episodes of bacteremia reported as and those reported as . Overall mortality was lower in patients who had ID consultation, GI consultation, or evidence of colonoscopy.
PubMed: 34568510
DOI: 10.1093/ofid/ofab426 -
Frontiers in Microbiology 2021Necrotic enteritis (NE), an economically devastating disease of poultry caused by pathogenic , is known to induce small intestinal lesions and dysbiosis. However, the...
Necrotic enteritis (NE), an economically devastating disease of poultry caused by pathogenic , is known to induce small intestinal lesions and dysbiosis. However, the intestinal microbes that are associated with NE severity are yet to be characterized. Here, we investigated the link between the ileal microbiota and disease severity in a chicken model of clinical NE using 16S rRNA gene sequencing. Our results indicated that richness and Shannon Index of the ileal microbiota were drastically reduced (<0.01) as NE was exacerbated. While the relative abundance of increased from 0.02% in healthy chickens to 58-70% in chickens with severe infection, a majority of the ileal microbes were markedly diminished, albeit varying in their sensitivity to NE. Compositionally, a large group of ileal microbes showed a significant correlation with NE severity. Firmicutes, such as group A and B , , , , and as well as two genera of Actinobacteria ( and ) and two highly related Cyanobacteria were progressively declined as NE was aggravated. Other Firmicutes, such as , , , , , and , appeared much more sensitive and were rapidly abolished in chickens even with mild NE. On the other hand, and two / species were only enriched in the ileal microbiota of chickens with extremely severe NE, while several other species such as and remained unaltered by NE. Functionally, secondary bile acid biosynthesis was predicted to be suppressed by NE, while biosynthesis of aromatic and branched-amino acids and metabolism of a majority of amino acids were predicted to be enhanced in the ileum of NE-afflicted chickens. These intestinal microbes showing a strong correlation with NE severity may provide important leads for the development of novel diagnostic or therapeutic approaches to NE and possibly other enteric diseases.
PubMed: 34489892
DOI: 10.3389/fmicb.2021.703693 -
Pathogens (Basel, Switzerland) Aug 2021Kidney transplant recipients (KTRs) tend to develop infections with characteristic epidemiology, presentation, and outcome. While infective endocarditis (IE) is among...
Kidney transplant recipients (KTRs) tend to develop infections with characteristic epidemiology, presentation, and outcome. While infective endocarditis (IE) is among such complications in KTRs, the literature is scarce. We describe the presentation, epidemiology, and factors associated with IE in KTRs. We performed a retrospective case/control study which included patients from two centers. First episodes of definite or possible IE (Duke criteria) in adult KTRs from January 2010 to December 2018 were included, as well as two controls per case, and followed until 31 December 2019. Clinical, biological, and microbiological data and the outcome were collected. Survival was studied using the Kaplan-Meier method. Finally, we searched for factors associated with the onset of IE in KTRs by the comparison of cases and controls. Seventeen cases and 34 controls were included. IE was diagnosed after a mean delay of 78 months after KT, mostly on native valves of the left heart only. Pathogens of digestive origin were most frequently involved (six , three , and one ), followed by (three cases of and each). Among the risk factors evaluated, age, vascular nephropathy, and elevated calcineurin inhibitor through levels were significantly associated with the occurrence of IE in our study. Patient and death-censored graft survival were greatly diminished five years after IE, compared to controls being 50.3% vs. 80.6% ( < 0.003) and 29.7% vs. 87.5% ( < 0.002), respectively. IE in KTRs is a disease that carries significant risks both for the survival of the patient and the transplant.
PubMed: 34451487
DOI: 10.3390/pathogens10081023 -
BMC Infectious Diseases Jul 2021Infective endocarditis (IE) is diagnosed in 7-8% of streptococcal bloodstream infections (BSIs), yet it is unclear when to perform transthoracic (TTE) and...
BACKGROUND
Infective endocarditis (IE) is diagnosed in 7-8% of streptococcal bloodstream infections (BSIs), yet it is unclear when to perform transthoracic (TTE) and transoesophageal echocardiography (TOE) according to different streptococcal species. The aim of this sub-study was to propose a flowchart for the use of echocardiography in streptococcal BSIs.
METHODS
In a population-based setup, we investigated all patients admitted with streptococcal BSIs and crosslinked data with nationwide registries to identify comorbidities and concomitant hospitalization with IE. Streptococcal species were divided in four groups based on the crude risk of being diagnosed with IE (low-risk < 3%, moderate-risk 3-10%, high-risk 10-30% and very high-risk > 30%). Based on number of positive blood culture (BC) bottles and IE risk factors (prosthetic valve, previous IE, native valve disease, and cardiac device), we further stratified cases according to probability of concomitant IE diagnosis to create a flowchart suggesting TTE plus TOE (IE > 10%), TTE (IE 3-10%), or "wait & see" (IE < 3%).
RESULTS
We included 6393 cases with streptococcal BSIs (mean age 68.1 years [SD 16.2], 52.8% men). BSIs with low-risk streptococci (S. pneumoniae, S. pyogenes, S. intermedius) are not initially recommended echocardiography, unless they have ≥3 positive BC bottles and an IE risk factor. Moderate-risk streptococci (S. agalactiae, S. anginosus, S. constellatus, S. dysgalactiae, S. salivarius, S. thermophilus) are guided to "wait & see" strategy if they neither have a risk factor nor ≥3 positive BC bottles, while a TTE is recommended if they have either ≥3 positive BC bottles or a risk factor. Further, a TTE and TOE are recommended if they present with both. High-risk streptococci (S. mitis/oralis, S. parasanguinis, G. adiacens) are directed to a TTE if they neither have a risk factor nor ≥3 positive BC bottles, but to TTE and TOE if they have either ≥3 positive BC bottles or a risk factor. Very high-risk streptococci (S. gordonii, S. gallolyticus, S. mutans, S. sanguinis) are guided directly to TTE and TOE due to a high baseline IE prevalence.
CONCLUSION
In addition to the clinical picture, this flowchart based on streptococcal species, number of positive blood culture bottles, and risk factors, can help guide the use of echocardiography in streptococcal bloodstream infections. Since echocardiography results are not available the findings should be confirmed prospectively with the use of systematic echocardiography.
Topics: Adult; Aged; Aged, 80 and over; Algorithms; Denmark; Echocardiography; Echocardiography, Transesophageal; Endocarditis, Bacterial; Female; Humans; Male; Middle Aged; Predictive Value of Tests; Prevalence; Registries; Sepsis; Streptococcal Infections; Streptococcus
PubMed: 34271874
DOI: 10.1186/s12879-021-06391-2 -
Open Forum Infectious Diseases Jun 2021Although group (SAG) endocarditis is considered a severe disease associated with abscess formation and embolic events, there is limited evidence to support this...
BACKGROUND
Although group (SAG) endocarditis is considered a severe disease associated with abscess formation and embolic events, there is limited evidence to support this assumption.
METHODS
We performed a retrospective analysis of prospectively collected data from consecutive patients with definite SAG endocarditis in 28 centers in Spain and Italy. A comparison between cases due to SAG endocarditis and viridans group streptococci (VGS) or group (SGG) was performed in a 1:2 matched analysis.
RESULTS
Of 5336 consecutive cases of definite endocarditis, 72 (1.4%) were due to SAG and matched with 144 cases due to VGS/SGG. SAG endocarditis was community acquired in 64 (88.9%) cases and affected aortic native valve in 29 (40.3%). When comparing SAG and VGS/SGG endocarditis, no significant differences were found in septic shock (8.3% vs 3.5%, = .116); valve disorder, including perforation (22.2% vs 18.1%, = .584), pseudoaneurysm (16.7% vs 8.3%, = .108), or prosthesis dehiscence (1.4% vs 6.3%, = .170); paravalvular complications, including abscess (25% vs 18.8%, = .264) and intracardiac fistula (5.6% vs 3.5%, = .485); heart failure (34.7% vs 38.9%, = .655); or embolic events (41.7% vs 32.6%, = .248). Indications for surgery (70.8% vs 70.8%; = 1) and mortality (13.9% vs 16.7%; = .741) were similar between groups.
CONCLUSIONS
SAG endocarditis is an infrequent but serious condition that presents a prognosis similar to that of VGS/SGG.
PubMed: 34189163
DOI: 10.1093/ofid/ofab163 -
Access Microbiology Mar 2021) is an uncommon but increasingly recognized cause of neonatal sepsis and meningitis. Liver abscess in neonates is extremely rare. But liver abscess due to SG has never...
) is an uncommon but increasingly recognized cause of neonatal sepsis and meningitis. Liver abscess in neonates is extremely rare. But liver abscess due to SG has never been reported in the literature. We present the first case of liver abscess due to in a late preterm infant. A female infant was born at 36 weeks via normal vaginal delivery to a mother with unremarkable antenatal history. She had progressively worsening respiratory distress since birth and was intubated at 13 h of life. One dose of surfactant was delivered and ventilation continued. Parenteral crystalline Penicillin and Gentamicin were initiated and her blood culture at birth grew . She had a spike of fever on day 5 of life. An ultrasound (US) scan of the abdomen was included in the septic work up. A multi-septated cystic liver abscess was noted in the right lobe of the liver. As there was inadequate response to appropriate intravenous antibiotics, needle aspiration and biopsy were performed on day 35 of life. Aspirate was sterile and histopathology confirmed a liver abscess. The patient continued to be treated with antibiotics for 8 weeks with serial US scans of the liver showing resolution of the abscess. Increasing awareness among paediatric and neonatal fraternity about these new emerging bacterial infections can facilitate early diagnosis and treatment.
PubMed: 34151155
DOI: 10.1099/acmi.0.000200 -
Infectious Agents and Cancer Jun 2021Recent studies have proposed that commensal bacteria might be involved in the development and progression of gastrointestinal disorders such as colorectal cancer (CRC)....
BACKGROUND AND AIM
Recent studies have proposed that commensal bacteria might be involved in the development and progression of gastrointestinal disorders such as colorectal cancer (CRC). Therefore, in this study, the relative abundance of Fusobacterium nucleatum, Bacteroides fragilis, Streptococcus bovis/gallolyticus, and Enteropathogenic Escherichia coli (EPEC) in CRC tissues, and their association with clinicopathologic characteristics of CRC was investigated in Iranian patients. Moreover, the role of these bacteria in the CRC-associated mutations including PIK3CA, KRAS, and BRAF was studied.
METHOD
To these ends, the noted bacteria were quantified in paired tumors and normal tissue specimens of 30 CRC patients, by TaqMan quantitative Real-Time Polymerase Chain Reaction (qPCR). Next, possible correlations between clinicopathologic factors and mutations in PIK3CA, KRAS, and BRAF genes were analyzed.
RESULTS
In studied samples, B. fragilis was the most abundant bacteria that was detected in 66 and 60% of paired tumor and normal samples, respectively. Furthermore, 15% of the B. fragilis-positive patients were infected with Enterotoxigenic B. fragilis (ETBF) in both adenocarcinoma and matched adjacent normal samples. F. nucleatum was also identified in 23% of tumors and 13% of adjacent normal tissue samples. Moreover, the relative abundance of these bacteria determined by 2 was significantly higher in CRC samples than in adjacent normal mucosa (p < 0.05). On the other hand, our findings indicated that S. gallolyticus and EPEC, compared to adjacent normal mucosa, were not prevalent in CRC tissues. Finally, our results revealed a correlation between F. nucleatum-positive patients and the KRAS mutation (p = 0.02), while analyses did not show any association between bacteria and mutation in PIK3CA and BRAF genes.
CONCLUSION
The present study is the first report on the analysis of different bacteria in CRC tissue samples of Iranian patients. Our findings revealed that F. nucleatum and B. fragilis might be linked to CRC. However, any link between gut microbiome dysbiosis and CRC remains unknown.
PubMed: 34108031
DOI: 10.1186/s13027-021-00381-4