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Journal of Microbiology, Immunology,... Dec 2021We report 4 cases of neonatal sepsis caused by Streptococcus gallolyticus. The clinical course was quite similar to early-and late-onset group B streptococcus disease....
We report 4 cases of neonatal sepsis caused by Streptococcus gallolyticus. The clinical course was quite similar to early-and late-onset group B streptococcus disease. None of the mothers had group B streptococcus (GBS) colonization on prenatal screening nor received intrapartum antibiotics. We proposed the sporadic distribution of S. gallolyticus sepsis among neonates was partly due to relatively low colonization rate in adults compared with GBS. Species determination of S. gallolyticus may not be available using conventional microbiological methods and may contribute to underestimation or misclassification. In our series, we highlighted the importance of S. gallolyticus as an important pathogen in neonatal sepsis deserving further surveillance.
Topics: Anti-Bacterial Agents; Female; Humans; Infant, Newborn; Male; Neonatal Sepsis; Streptococcal Infections; Streptococcus agalactiae; Streptococcus gallolyticus; Treatment Outcome
PubMed: 34052145
DOI: 10.1016/j.jmii.2021.05.003 -
Frontiers in Genetics 2021() is an opportunistic Gram-positive, non-motile bacterium, which causes infective endocarditis, an inflammation of the inner lining of the heart. As has acquired...
() is an opportunistic Gram-positive, non-motile bacterium, which causes infective endocarditis, an inflammation of the inner lining of the heart. As has acquired resistance with the available antibiotics, therefore, there is a dire need to find new therapeutic targets and potent drugs to prevent and treat this disease. In the current study, an approach is utilized to link genomic data of species with its proteome to identify putative therapeutic targets. A total of 1,138 core proteins have been identified using pan genomic approach. Further, using subtractive proteomic analysis, a set of 18 proteins, essential for bacteria and non-homologous to host (human), is identified. Out of these 18 proteins, 12 cytoplasmic proteins were selected as potential drug targets. These selected proteins were subjected to molecular docking against drug-like compounds retrieved from ZINC database. Furthermore, the top docked compounds with lower binding energy were identified. In this work, we have identified novel drug and vaccine targets against , of which some have already been reported and validated in other species. Owing to the experimental validation, we believe our methodology and result are significant contribution for drug/vaccine target identification against -caused infective endocarditis.
PubMed: 33841489
DOI: 10.3389/fgene.2021.564056 -
Boletin Medico Del Hospital Infantil de... Mar 2021Introducción: Streptococcus gallolyticus subsp. pasteurianus es un coco grampositivo, catalasa negativo, perteneciente al grupo D de Lancefield, que se encuentra...
Introducción: Streptococcus gallolyticus subsp. pasteurianus es un coco grampositivo, catalasa negativo, perteneciente al grupo D de Lancefield, que se encuentra relacionado con cuadros de sepsis neonatal, específicamente con meningitis. Caso clínico: Se reporta el caso de un paciente de 2 meses con un cuadro de meningitis por S. gallolyticus subsp. pasteurianus. Se describen la sintomatología y el abordaje diagnóstico y terapéutico. Asimismo, se realiza una revisión de la literatura que evidencia el subdiagnóstico de este agente como causa de meningitis en pediatría. Conclusiones: Este caso representa el primer aislamiento de este agente en el Hospital Nacional de Niños de Costa Rica, de la Caja Costarricense de Seguro Social.
Topics: Costa Rica; Humans; Infant, Newborn; Sepsis; Streptococcus; Streptococcus gallolyticus
PubMed: 33784270
DOI: 10.24875/BMHIM.20000101 -
Medicina (Kaunas, Lithuania) Feb 2021: Characterization of patients with endocarditis regarding demographic, clinical, biological and imagistic data, blood culture results and possible correlation between... (Observational Study)
Observational Study
: Characterization of patients with endocarditis regarding demographic, clinical, biological and imagistic data, blood culture results and possible correlation between different etiologic factors and host status characteristics. : This is a retrospective observational descriptive study conducted on patients older than 18 years admitted in the past 10 years, in the Cardiology Clinic of the Clinical County Emergency Hospital Oradea Romania, with clinical suspicion of bacterial endocarditis. Demographic data, clinical, paraclinical investigations and outcome were registered and analyzed. : 92 patients with definite infective endocarditis (IE) according to modified Duke criteria were included. The mean age of patients was 63.80 ± 13.45 years. A percent of 32.6% had health care associated invasive procedure performed in the 6 months before diagnosis of endocarditis. Charlson's comorbidity index number was 3.53 ± 2.029. Most common clinical symptoms and signs were: shortness of breath, cardiac murmur, fever. Sixty-six patients had native valve endocarditis, 26 patients had prosthetic valve endocarditis and one patient was with congenital heart disease. Blood cultures were positive in 61 patients. Among positive culture patient's staphylococcus group was the most frequently involved: (19.6%) and coagulase negative (18.5%). Most frequent complications were heart failure, acute renal failure and embolic events. IE was associated with the presence of large vegetations, prosthetic valve endocarditis and intracardiac abscess. Coagulase negative (CoNS) infection was associated with prosthetic valve dysfunction. etiology correlated with ischemic embolic stroke and the presence of large vegetations. Cardiovascular surgery was recommended in 67.4% of patients but was performed only on half of them. In hospital death occurred in 33.7% of patients and independent predictors of mortality were congestive heart failure and septic shock.
Topics: Aged; Endocarditis; Endocarditis, Bacterial; Heart Valve Prosthesis; Hospital Mortality; Humans; Middle Aged; Retrospective Studies; Romania; Staphylococcal Infections
PubMed: 33578787
DOI: 10.3390/medicina57020158 -
European Review For Medical and... Jan 2021The purpose of this paper is to contextualize the case of a patient with a synchronous diagnosis of colorectal cancer (CRC) and endocarditis from S. gallolyticus subsp.... (Review)
Review
Association between colorectal cancer and Streptococcus gallolyticus subsp. pasteuranus (former S. bovis) endocarditis: clinical relevance and cues for microbiota science. Case report and review of the literature.
OBJECTIVE
The purpose of this paper is to contextualize the case of a patient with a synchronous diagnosis of colorectal cancer (CRC) and endocarditis from S. gallolyticus subsp. pasteuranus (former S. Bovis) within the current evidence, in order to determine if this condition is indicative of an underlying CRC and if it has any pathophysiologic significance.
PATIENTS AND METHODS
First, we describe the clinical case. Then, we review the literature focused on the association between infections from the former S. Bovis group and CRC and on the possible role of certain microbiota species on the occurrence of CRC. At last, we discuss the implications of this case considering the current evidence.
RESULTS
There is a strong association between all the species of the former S. Bovis group and CRC. There is initial evidence that these bacteria may contribute to CRC by a genomic passenger mechanism.
CONCLUSIONS
There are two main conclusions for this paper. The first one is that CRC neoplasms and endocarditis from all species of the former S. bovis group have a strong association. Any case of infection by these subspecies should prompt to a diagnostic completion by colonoscopy. The second one is that there is an increased need for detailed reports/series and original articles based on the evaluation of gut microbiota in patients with CRC, with the aim to clarify if the association between bacteria and CRC is causative or sporadic and to better understand the possible causative mechanism of specific bacteria in initiating and promoting CRC.
Topics: Colorectal Neoplasms; Endocarditis; Humans; Male; Middle Aged; Streptococcal Infections; Streptococcus gallolyticus
PubMed: 33506939
DOI: 10.26355/eurrev_202101_24417 -
3 Biotech Feb 2021Probiotics inspired by host-microbe interactions in the natural ecosystem are propitious in controlling bacterial infections in aquaculture and veterinary systems. Here...
UNLABELLED
Probiotics inspired by host-microbe interactions in the natural ecosystem are propitious in controlling bacterial infections in aquaculture and veterinary systems. Here we report the isolation and characterization of pathogenic spp. and lactic acid bacteria from an intensive culture system of and natural ecosystem, respectively. The pathogen isolated from the gut of showing the symptoms of white gut disease were identified as and . Both the pathogens expressed the virulence genes, rtxA, and tcpA and were showing multiple antibiotic resistance (MAR) index of more than 0.5. The lactic acid bacteria isolated from the sediment and gut of benthic organisms (shrimp and polychaetes) collected from a tropical estuary were classified as member of 9 OTUs such as , and . Majority of these isolates were facultative in nature and were able to tolerate gastric juice and bile salt. Out of 83 bacteria isolated from sediment and gut, 36 showed abilities to reduce the pH of culture medium to less than five. Many of these isolates (34 Nos.) showed production of hydrolytic enzymes and secondary metabolites with antagonistic activity against both the pathogens (1 No.) or separately toward (9 Nos.) and (11 Nos.). Overall, the current study proposes a natural ecosystem as a potential source of lactic acid bacteria with probiotic potentials to prevent the vibriosis disease outbreaks in shrimp aquaculture systems. Further studies are required to understand the abilities of lactic acid bacteria to colonize shrimp intestine, stimulate immune system and manipulate microbiome.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s13205-020-02618-2.
PubMed: 33489684
DOI: 10.1007/s13205-020-02618-2 -
PLoS Pathogens Jan 2021Streptococcus gallolyticus subspecies gallolyticus (Sgg) has a strong clinical association with colorectal cancer (CRC) and actively promotes the development of colon...
Streptococcus gallolyticus subspecies gallolyticus (Sgg) has a strong clinical association with colorectal cancer (CRC) and actively promotes the development of colon tumors. However, the molecular determinants involved in Sgg pathogenicity in the gut are unknown. Bacterial type VII secretion systems (T7SS) mediate pathogen interactions with their host and are important for virulence in pathogenic mycobacteria and Staphylococcus aureus. Through genome analysis, we identified a locus in Sgg strain TX20005 that encodes a putative type VII secretion system (designated as SggT7SST05). We showed that core genes within the SggT7SST05 locus are expressed in vitro and in the colon of mice. Western blot analysis showed that SggEsxA, a protein predicted to be a T7SS secretion substrate, is detected in the bacterial culture supernatant, indicating that this SggT7SST05 is functional. Deletion of SggT7SST05 (TX20005Δesx) resulted in impaired bacterial adherence to HT29 cells and abolished the ability of Sgg to stimulate HT29 cell proliferation. Analysis of bacterial culture supernatants suggest that SggT7SST05-secreted factors are responsible for the pro-proliferative activity of Sgg, whereas Sgg adherence to host cells requires both SggT7SST05-secreted and bacterial surface-associated factors. In a murine gut colonization model, TX20005Δesx showed significantly reduced colonization compared to the parent strain. Furthermore, in a mouse model of CRC, mice exposed to TX20005 had a significantly higher tumor burden compared to saline-treated mice, whereas those exposed to TX20005Δesx did not. Examination of the Sgg load in the colon in the CRC model suggests that SggT7SST05-mediated activities are directly involved in the promotion of colon tumors. Taken together, these results reveal SggT7SST05 as a previously unrecognized pathogenicity determinant for Sgg colonization of the colon and promotion of colon tumors.
Topics: Animals; Cell Proliferation; Colonic Neoplasms; Gastrointestinal Microbiome; Gastrointestinal Tract; Humans; Mice; Mice, Inbred A; Streptococcal Infections; Streptococcus gallolyticus subspecies gallolyticus; Type VII Secretion Systems
PubMed: 33406160
DOI: 10.1371/journal.ppat.1009182 -
MBio Jan 2021subsp. is an emerging opportunistic pathogen responsible for septicemia and endocarditis in the elderly. Invasive infections by subsp. are strongly linked to the...
subsp. is an emerging opportunistic pathogen responsible for septicemia and endocarditis in the elderly. Invasive infections by subsp. are strongly linked to the occurrence of colorectal cancer (CRC). It was previously shown that increased secondary bile salts under CRC conditions enhance the bactericidal activity of gallocin, a bacteriocin produced by subsp. , enabling it to colonize the mouse colon by outcompeting resident enterococci (L. Aymeric, F. Donnadieu, C. Mulet, L. du Merle, et al., Proc Natl Acad Sci U S A 115:E283-E291, 2018, https://doi.org/10.1073/pnas.1715112115). In a separate study, we showed that subsp. produces and secretes a 21-mer peptide that activates bacteriocin production (A. Proutière, L. du Merle, B. Périchon, H. Varet, et al., mBio 11:e03187-20, 2020, https://doi.org/10.1128/mBio.03187-20). This peptide was named CSP because of its sequence similarity with competence-stimulating peptides found in other streptococci. Here, we demonstrate that CSP is a bona fide quorum sensing peptide involved in activation of gallocin gene transcription. We therefore refer to CSP as GSP (gallocin-stimulating peptide). GSP displays some unique features, since its N-terminal amino acid lies three residues after the double glycine leader sequence. Here, we set out to investigate the processing and export pathway that leads to mature GSP. Heterologous expression in of the genes encoding GSP and the BlpAB transporter is sufficient to produce the 21-mer form of GSP in the supernatant, indicating that subsp. BlpAB displays an atypical cleavage site. We also conducted the first comprehensive structure-activity relationship (SAR) analysis of subsp. GSP to identify its key structural features and found that unlike many other similar streptococci signaling peptides (such as CSPs), nearly half of the mature GSP sequence can be removed (residues 1 to 9) without significantly impacting the peptide activity. subsp. is an opportunistic pathogen associated with colorectal cancer (CRC) and endocarditis. subsp. utilizes quorum sensing (QS) to regulate the production of a bacteriocin (gallocin) and gain a selective advantage in colonizing the colon. In this article, we report (i) the first structure-activity relationship study of the subsp. QS pheromone that regulates gallocin production, (ii) evidence that the active QS pheromone is processed to its mature form by a unique ABC transporter and not processed by an extracellular protease, and (iii) supporting evidence of interspecies interactions between streptococcal pheromones. Our results revealed the minimal pheromone scaffold needed for gallocin activation and uncovered unique interactions between two streptococcal QS signals that warrant further study.
Topics: ATP-Binding Cassette Transporters; Bacterial Proteins; Bacteriocins; Bodily Secretions; Gene Expression Regulation, Bacterial; Membrane Transport Proteins; Peptide Hydrolases; Peptides; Pheromones; Quorum Sensing; Signal Transduction; Streptococcus gallolyticus; Transcriptome
PubMed: 33402540
DOI: 10.1128/mBio.03189-20 -
MBio Jan 2021Bacteriocins are natural antimicrobial peptides produced by bacteria to kill closely related competitors. The opportunistic pathogen subsp. was recently shown to...
Bacteriocins are natural antimicrobial peptides produced by bacteria to kill closely related competitors. The opportunistic pathogen subsp. was recently shown to outcompete commensal enterococci of the murine microbiota under tumoral conditions thanks to the production of a two-peptide bacteriocin named gallocin. Here, we identified four genes involved in the regulatory control of gallocin in subsp. UCN34 that encode a histidine kinase/response regulator two-component system (BlpH/BlpR), a secreted peptide (GSP [gallocin-stimulating peptide]), and a putative regulator of unknown function (BlpS). While BlpR is a typical 243-amino-acid (aa) response regulator possessing a phospho-receiver domain and a LytTR DNA-binding domain, BlpS is a 108-aa protein containing only a LytTR domain. Our results showed that the secreted peptide GSP activates the dedicated two-component system BlpH/BlpR to induce gallocin transcription. A genome-wide transcriptome analysis indicates that this regulatory system (GSP-BlpH/BlpR) is specific for bacteriocin production. Importantly, as opposed to BlpR, BlpS was shown to repress gallocin gene transcription. A conserved operator DNA sequence of 30 bp was found in all promoter regions regulated by BlpR and BlpS. Electrophoretic mobility shift assays (EMSA) and footprint assays showed direct and specific binding of BlpS and BlpR to various regulated promoter regions in a dose-dependent manner on this conserved sequence. Gallocin expression appears to be tightly controlled in subsp. by quorum sensing and antagonistic activity of 2 LytTR-containing proteins. Competition experiments in gut microbiota medium and 5% CO to mimic intestinal conditions demonstrate that gallocin is functional under these -like conditions. subsp. , formerly known as biotype I, is an opportunistic pathogen causing septicemia and endocarditis in the elderly often associated with asymptomatic colonic neoplasia. Recent studies indicate that subsp. is both a driver and a passenger of colorectal cancer. We previously showed that subsp. produces a bacteriocin, termed gallocin, enabling colonization of the colon under tumoral conditions by outcompeting commensal members of the murine microbiota such as Here, we identified and extensively characterized a four-component system that regulates gallocin production. Gallocin gene transcription is activated by a secreted peptide pheromone (GSP) and a two-component signal transduction system composed of a transmembrane histidine kinase receptor (BlpH) and a cytosolic response regulator (BlpR). Finally, a DNA-binding protein (BlpS) was found to repress gallocin genes transcription, likely by antagonizing BlpR. Understanding gallocin regulation is crucial to prevent subsp. colon colonization under tumoral conditions.
Topics: Bacterial Proteins; Bacteriocins; DNA-Binding Proteins; Gastrointestinal Microbiome; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Genes, Bacterial; Genome, Bacterial; Histidine Kinase; Quorum Sensing; Streptococcal Infections; Streptococcus gallolyticus; Transcriptome
PubMed: 33402539
DOI: 10.1128/mBio.03187-20 -
Indian Journal of Critical Care... Oct 2020is an important cause of bacteremia and infective endocarditis in adults. Studies from other parts of the world have shown a strong association between bacteremia and...
INTRODUCTION
is an important cause of bacteremia and infective endocarditis in adults. Studies from other parts of the world have shown a strong association between bacteremia and colonic neoplasia. The profile of bacteremia is understudied in Indian population.
MATERIALS AND METHODS
We retrospectively analyzed the data of 16 patients with bacteremia obtained from microbiology registry. BacT/ALERT positive samples were inoculated into blood agar, chocolate agar, and MacConkey agar. Organisms were identified by the VITEK 2 microbial identification system, and susceptibility was done by the microbroth dilution method as per Clinical and Laboratory Standards Institute (CLSI) M100 guidelines. Clinical details were obtained from electronic medical records.
RESULTS
Majority of our isolates were subspecies . Total 16 patients had isolated from blood over a 1 year period. The median age was 58 years (IQR: 46.5-66). Eleven were males; type II diabetes mellitus and chronic liver disease were the common comorbidities observed in our patients. None of our patients had underlying infective endocarditis or colonic malignancy. Penicillin sensitivity was 81.2% while all the isolates were susceptible to ceftriaxone. Ampicillin resistance was seen in only one of the isolates. In-hospital mortality was 12.5%.
CONCLUSION
subsp. is the commonest subspecies of isolated in our population. Unlike previous studies, colonic neoplasia and infective endocarditis were rare in our patients. Type II diabetes mellitus and chronic liver disease were the commonest risk factors identified in patients with bacteremia.
HOW TO CITE THIS ARTICLE
Niyas VKM, Arjun R, Sasidharan A, Palakunnath GA. Bacteremia: An Experience from a Tertiary Center in South India. Indian J Crit Care Med 2020;24(10):943-945.
PubMed: 33281319
DOI: 10.5005/jp-journals-10071-23569