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Internal Medicine (Tokyo, Japan) Nov 2021A 77-year-old man developed peritoneal dialysis-related peritonitis caused by Streptococcus oralis, a rare pathogen causing the disease. The infection, which was not... (Review)
Review
A 77-year-old man developed peritoneal dialysis-related peritonitis caused by Streptococcus oralis, a rare pathogen causing the disease. The infection, which was not controlled by one-week intraperitoneal administration of cefazolin and ceftazidime, was cured only after switching to two-week intravenous administration of cefazolin and ceftazidime. The patient had no major dental disease or recent history of dental intervention. This case suggests that S. oralis might cause peritoneal dialysis-related peritonitis with persistent systemic inflammation via an extra-oral infection route. The clinical course is discussed along with a review of the literature.
Topics: Aged; Anti-Bacterial Agents; Humans; Male; Peritoneal Dialysis; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Streptococcus oralis
PubMed: 34024849
DOI: 10.2169/internalmedicine.6234-20 -
Journal of the Pediatric Infectious... Jul 2023Levofloxacin prophylaxis (LVXp) is often used for patients with underlying leukemia and severe neutropenia to reduce the risk of fever and bacteremia. This study...
BACKGROUND
Levofloxacin prophylaxis (LVXp) is often used for patients with underlying leukemia and severe neutropenia to reduce the risk of fever and bacteremia. This study evaluated trends in viridans group streptococci (VGS) antibiotic susceptibilities over time and clinical outcomes of children with VGS bloodstream infections (BSIs) during institutional adoption of LVXp.
METHODS
VGS blood culture isolates between 1/1/2010 and 12/31/2021 with susceptibility testing reported were included. Available isolates were re-identified to the species level and additional susceptibility testing was performed. Demographic and clinical data were abstracted from medical records.
RESULTS
A total of 264 VGS BSI isolates were identified in immunocompromised (IC, n = 125) and non-immunocompromised subjects, (non-IC, n = 139). IC subjects had lower rates of VGS isolates susceptible (S) to LVX and higher minimum inhibitory concentration (MICs) to LVX (p = 0.004) and ciprofloxacin (p = 0.0005) compared with non-IC subjects. No other evaluated antibiotic had increased MICs in either group. Fifteen of 19 (74%) LVX not susceptible (NS) isolates occurred in IC subjects, 13 represented breakthrough infections. IC subjects had higher rates of VGS-related shock (p = 0.012), need for pressor support (p = 0.039), and longer duration of hospitalization than non-IC subjects (p < 0.001). Clinical outcomes were comparable between subjects with LVX S and NS VGS BSI isolates.
CONCLUSIONS
VGS with reduced susceptibility to LVX emerged during institutional adoption of LVXp in high-risk children with immunocompromising conditions, but did not result in significant differences in clinical outcomes. Ongoing surveillance and susceptibility testing are critical in weighing the utility of LVXp against emerging antimicrobial resistance in this high-risk population.
Topics: Humans; Child; Levofloxacin; Streptococcal Infections; Viridans Streptococci; Anti-Bacterial Agents; Bacteremia; Microbial Sensitivity Tests
PubMed: 37490409
DOI: 10.1093/jpids/piad041 -
Klinicheskaia Laboratornaia Diagnostika Sep 2020The profiles of oral streptococci sensitivity to antibacterial drugs may reflect information about the presence of macroorganism resistance determinants. The aim of the...
The profiles of oral streptococci sensitivity to antibacterial drugs may reflect information about the presence of macroorganism resistance determinants. The aim of the work was to isolate the spectrum of oral streptococci from the microbiota of the oral cavity of patients and to determine their sensitivity to a wide range of antibiotics. A total of 342 microbial streptococcal isolates were isolated from saliva samples and a periodontal pocket and tested for antibiotic sensitivity. Species identification of streptococci was carried out using biochemical API test systems. Evaluation of antibiotic resistance was performed using E-tests. Real-time PCR was used to identify the presence of tetracycline and macrolide resistance genes. The study identified six types of oral streptococci: S. oralis, S. salivarius, S. mitis, S. sanguinis, S. anginosus and S. mutans. All streptococci were sensitive to linezolid and meropenem. The proportion of penicillin-resistant streptococci in the subgroup S. oralis / mitis / mutans was 47,8% versus 23,5% in the subgroup S. salivarius / sanguinis / anginosus (p = 0.020). Significant levels of resistance were revealed to macrolides (erythromycin) - 47,9%, tetracyclines (tetracycline) - 44,4% and quinolones (ofloxacin) - 41%. Multiple drug resistance (MDR) was detected in 31,9% of oral streptococcal isolates, a combination of erythromycin, tetracycline and ofloxacin resistance was prevalent in 79 isolates (23,1%). The most common genotypes of macrolides and tetracycline resistant oral streptococci (in 127 streptococcal isolates with combined resistance) were ermB-mefE + and tetM + tetQ-, respectively. Thus, S. oralis / mitis / mutans group streptococci predominated in the structure of antibiotic-resistant oral streptococci, including MDR. So, being in one of the most densely populated biotopes of a macroorganism, oral streptococci can mediate the transfer of resistance determinants to more pathogenic and clinically significant microorganisms, which requires careful monitoring of their level of susceptibility to antimicrobial agents.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Humans; Macrolides; Microbial Sensitivity Tests; Streptococcal Infections; Viridans Streptococci
PubMed: 33245653
DOI: 10.18821/0869-2084-2020-65-10-632-637 -
Journal of Infection and Chemotherapy :... Dec 2022Viridans group streptococci (VGS) are the most common causative organisms of infective endocarditis. Among VGS, the Streptococcus anginosus group (SAG) is often...
BACKGROUND
Viridans group streptococci (VGS) are the most common causative organisms of infective endocarditis. Among VGS, the Streptococcus anginosus group (SAG) is often associated with abscess formation, and delayed diagnosis leads to increased morbidity and mortality. This study aims to examine the factors associated with SAG bacteremia and develop a predictive scoring method.
METHODS
This single-center retrospective case-control study of patients with VGS bacteremia compared the background and clinical characteristics between the SAG and non-SAG groups. The univariate analysis used the χ test and t-test. The multivariate analysis was conducted using logistic regression.
RESULTS
Out of 161 patients, 95 had SAG and 66 had non-SAG bacteremia. Age >63 years: 2 points (odds ratio [OR] = 3.52, 95% confidence interval [CI]: 1.64-7.54); solid tumor: 2 points (OR = 4.44, 95% CI: 1.42-6.77); C-reactive protein >7.61 mg/dL: 3 points (OR = 5.40, 95% CI: 2.49-11.72), and white blood cell count >8550/μL: 2 points (OR = 2.76, 95% CI: 1.29-2.91) were found to be independently associated with SAG bacteremia. After totaling the above variables and adding 1 point for diabetes mellitus, the area under the receiver operating curve was 0.81 (95% CI: 0.74-0.88). The sensitivity and specificity were 51% and 88%, respectively, at a cut-off of 6 points.
CONCLUSIONS
In patients with VGS bacteremia, a score of 6 points or higher using this method predicts SAG with high specificity.
Topics: Bacteremia; C-Reactive Protein; Case-Control Studies; Humans; Middle Aged; Research Design; Retrospective Studies; Streptococcal Infections; Streptococcus anginosus
PubMed: 36049615
DOI: 10.1016/j.jiac.2022.08.018 -
Journal of Bacteriology Apr 2019Cystic fibrosis (CF) is a genetic disease that causes patients to accumulate thick, dehydrated mucus in the lung and develop chronic, polymicrobial infections due to...
Cystic fibrosis (CF) is a genetic disease that causes patients to accumulate thick, dehydrated mucus in the lung and develop chronic, polymicrobial infections due to reduced mucociliary clearance. These chronic polymicrobial infections and subsequent decline in lung function are significant factors in the morbidity and mortality of CF. and spp. are among the most prevalent organisms in the CF lung; the presence of correlates with lung function decline, and the group (SMG), a subgroup of the viridans streptococci, is associated with exacerbations in patients with CF. Here we characterized the interspecies interactions that occur between these two genera. We demonstrated that multiple laboratory strains and clinical CF isolates promote the growth of multiple SMG strains and oral streptococci in an coculture system. We investigated the mechanism by which enhances growth of streptococci by screening for mutants of PA14 that are unable to enhance growth, and we identified the ::Tn mutant, which failed to promote growth of and Characterization of the Δ mutant revealed that this strain cannot promote growth. Our genetic data and growth studies support a model whereby the Δ mutant overproduces siderophores and thus likely outcompetes for limited iron. We propose a model whereby competition for iron represents one important means of interaction between and spp. Cystic fibrosis (CF) lung infections are increasingly recognized for their polymicrobial nature. These polymicrobial infections may alter the biology of the organisms involved in CF-related infections, leading to changes in growth, virulence, and/or antibiotic tolerance, and could thereby affect patient health and response to treatment. In this study, we demonstrate interactions between and streptococci using a coculture model and show that one interaction between these microbes is likely competition for iron. Thus, these data indicate that one CF pathogen may influence the growth of another, and they add to our limited knowledge of polymicrobial interactions in the CF airway.
Topics: Bacterial Proteins; Gene Deletion; Genetic Testing; Iron; Microbial Interactions; Mutagenesis, Insertional; Pseudomonas aeruginosa; Siderophores; Streptococcus milleri Group
PubMed: 30718303
DOI: 10.1128/JB.00014-19 -
Journal of Periodontology May 2016Previous studies have focused on antibiotic resistance of Gram-negative bacteria before and after periodontal therapy. The purpose of this analysis is to assess changes... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Previous studies have focused on antibiotic resistance of Gram-negative bacteria before and after periodontal therapy. The purpose of this analysis is to assess changes in resistance patterns of the commensal Gram-positive microbiota. The viridans group streptococci (VGS) have been suggested to serve as reservoirs of resistance genes for more pathogenic streptococci and may be implicated in some non-oral infections.
METHODS
In this randomized clinical trial, 80 patients with periodontitis are distributed randomly into two groups. In group A, patients received 375 mg amoxicillin and 500 mg metronidazole three times per day for 7 days during the non-surgical treatment phase (T1). In group B, the antibiotics were administered during the surgical phase (T2). Resistance of VGS to penicillin and erythromycin was determined by the epsilometer test.
RESULTS
At baseline, VGS from 12.5% (group A) and 11.8% (group B) of patients had a minimum inhibitory concentration (MIC) >2 μg/mL to penicillin. Three months after T1, VGS from 15.6% and 16.7% of patients had an MIC >2 μg/mL, respectively. Six months after T2 VGS from 5.9% and 5.9% and 12 months after T2 VGS from 6.1% and 6.3% patients had an MIC >2 μg/mL. There was no effect of therapy with antibiotics, administered either in T1 or T2, on the carriage of penicillin-resistant VGS. Erythromycin resistance was high at baseline and remained unchanged throughout the study. MICs for penicillin and erythromycin were correlated (P <0.05).
CONCLUSION
Amoxicillin plus metronidazole did not significantly affect the resistance pattern of the VGS to penicillin or erythromycin.
Topics: Amoxicillin; Anti-Bacterial Agents; Drug Resistance, Bacterial; Erythromycin; Humans; Metronidazole; Microbial Sensitivity Tests; Penicillins; Periodontitis; Pharynx; Streptococcal Infections; Viridans Streptococci
PubMed: 26654350
DOI: 10.1902/jop.2015.150494 -
Journal of Clinical Pharmacy and... Apr 2015Antibiotic resistance has become a global public health issue. Most antibiotics are prescribed in the community, although there is less stewardship of such agents in the... (Comparative Study)
Comparative Study
WHAT IS KNOWN AND OBJECTIVE
Antibiotic resistance has become a global public health issue. Most antibiotics are prescribed in the community, although there is less stewardship of such agents in the community compared to secondary and tertiary care. Few studies have attempted to examine the prescribing practices in General Practice and its impact on antibiotic resistance and, therefore, a study was performed in order to compare antibiotic susceptibilities of commensal viridans group streptococci (VGS) obtained from patient cohorts in General Practices (GP), who were high and low prescribers of oral antibiotics.
METHOD
Sixty-five patients (<1 month-81 years; 77% female: 23% male) were enrolled onto the study, and viridans group streptococci (n = 5/patient) were collected from each patient's nasal passages and oropharynx region and tested for antibiotic susceptibility against (i) tetracyclines (doxycycline); (ii) macrolides (erythromycin); (iii) β-lactams (penicillin G); and (iv) fluoroquinolones (ofloxacin & levofloxacin).
RESULTS AND DISCUSSION
There were no significant differences in MICs between high and low GP prescribers with doxycycline (P = 0·094), erythromycin (P = 0·122), ofloxacin (P = 0·193) and levofloxacin (P = 0·058). However, there was a significant difference between high and low GP practices with regard to penicillin G (P = 0·031). This finding is important as the β-lactams are the most commonly prescribed oral antibiotic in the community.
WHAT IS NEW AND CONCLUSION
This study demonstrates that high prescribing practices may lead to an altered (higher) level of resistance to these agents in the commensal VGS population, which may be important as reservoirs of antibiotic resistance determinants in subsequent horizontal gene transfer events, particularly with newly colonizing pathogens, including pneumococci. Primary care physicians should be aware that increased prescribing of antibiotics may led to increased level of penicillin resistance.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Child; Child, Preschool; Drug Resistance, Bacterial; Female; Fluoroquinolones; General Practice; Humans; Infant; Infant, Newborn; Macrolides; Male; Microbial Sensitivity Tests; Middle Aged; Practice Patterns, Physicians'; Streptococcal Infections; Tetracyclines; Viridans Streptococci; Young Adult; beta-Lactams
PubMed: 25604860
DOI: 10.1111/jcpt.12245 -
Ocular Immunology and Inflammation 2019To evaluate the effectiveness of prophylactic systemic moxifloxacin in a rabbit model of Streptococcus viridans (S. viridans) endophthalmitis.
PURPOSE
To evaluate the effectiveness of prophylactic systemic moxifloxacin in a rabbit model of Streptococcus viridans (S. viridans) endophthalmitis.
METHODS
Animals (n=60) were divided into three groups. Intravenous moxifloxacin, vancomycin, normal saline was administered to 20 animals in each group and two hours later, 10 colony-forming units (CFU) of S. salivarius were intravitreally injected into the left eye. Intravenous antibiotics injection was repeated on days 1, 2, and 3 after inoculation. The clinical features, bacterial culture from vitreous aspirates of 10 eyes from each group were evaluated on days 1, 3, 5, and 7. On day 7, eyes for clinical feature examination were enucleated for histopathologic examination.
RESULTS
Clinical scores and logCFU/ml values were lower in moxifloxacin group on all examination days. Histopathologic examination showed less inflammation and relatively well-preserved retina in the moxifloxacin group.
CONCLUSIONS
Systemic moxifloxacin may have a prophyactic effect for S. viridans endophthalmitis after intraocular procedure.
Topics: Animals; Anti-Bacterial Agents; Disease Models, Animal; Endophthalmitis; Eye Infections, Bacterial; Injections, Intraventricular; Moxifloxacin; Rabbits; Streptococcal Infections; Treatment Outcome; Viridans Streptococci; Vitreous Body
PubMed: 28981383
DOI: 10.1080/09273948.2017.1353103 -
PloS One 2022Members of the mitis group streptococci are the most abundant inhabitants of the oral cavity and dental plaque. Influenza A virus (IAV), the causative agent of...
Members of the mitis group streptococci are the most abundant inhabitants of the oral cavity and dental plaque. Influenza A virus (IAV), the causative agent of influenza, infects the upper respiratory tract, and co-infection with Streptococcus pneumoniae is a major cause of morbidity during influenza epidemics. S. pneumoniae is a member of mitis group streptococci and shares many features with oral mitis group streptococci. In this study, we investigated the effect of viable Streptococcus oralis, a representative member of oral mitis group, on the infectivity of H1N1 IAV. The infectivity of IAV was measured by a plaque assay using Madin-Darby canine kidney cells. When IAV was incubated in growing culture of S. oralis, the IAV titer decreased in a time- and dose-dependent manner and became less than 100-fold, whereas heat-inactivated S. oralis had no effect. Other oral streptococci such as Streptococcus mutans and Streptococcus salivarius also reduced the viral infectivity to a lesser extent compared to S. oralis and Streptococcus gordonii, another member of the oral mitis group. S. oralis produces hydrogen peroxide (H2O2) at a concentration of 1-2 mM, and its mutant deficient in H2O2 production showed a weaker effect on the inactivation of IAV, suggesting that H2O2 contributes to viral inactivation. The contribution of H2O2 was confirmed by an inhibition assay using catalase, an H2O2-decomposing enzyme. These oral streptococci produce short chain fatty acids (SCFA) such as acetic acid as a by-product of sugar metabolism, and we also found that the inactivation of IAV was dependent on the mildly acidic pH (around pH 5.0) of these streptococcal cultures. Although inactivation of IAV in buffers of pH 5.0 was limited, incubation in the same buffer containing 2 mM H2O2 resulted in marked inactivation of IAV, which was similar to the effect of growing S. oralis culture. Taken together, these results reveal that viable S. oralis can inactivate IAV via the production of SCFAs and H2O2. This finding also suggests that the combination of mildly acidic pH and H2O2 at low concentrations could be an effective method to inactivate IAV.
Topics: Humans; Hydrogen Peroxide; Influenza A virus; Influenza, Human; Influenza A Virus, H1N1 Subtype; Streptococcus mitis; Streptococcus oralis; Viridans Streptococci; Streptococcus gordonii; Acids; Hydrogen-Ion Concentration
PubMed: 36350830
DOI: 10.1371/journal.pone.0276293 -
Caries Research 2022The literature is still scarce on studies describing Streptococcus mutans global gene expression under clinical conditions such as those found on complex biofilms from...
The literature is still scarce on studies describing Streptococcus mutans global gene expression under clinical conditions such as those found on complex biofilms from sound root surfaces (SRS) and carious root surfaces (RC). This study aimed to investigate the S. mutans gene expression and functional profile within the metatranscriptome of biofilms from SRS and from RC in an attempt to identify enriched functional signatures potentially associated with the healthy-to-disease transitioning process. Total RNA was extracted, and prepared libraries (SRS = 10 and RC = 9) were paired-end sequenced using the Illumina HiSeq2500. A read count assigned to each gene of the S. mutans UA159 strain was obtained. Differentially expressed genes (DEG) between SRS and RC were identified using the DESeq2 R package, and weighted gene co-expression network analysis (WGCNA) was performed to explore and identify functional modules related to SRS and RC. We found seventeen DEG between SRS and RC samples, with three overexpressed in RC and related to membrane protein, alanyl-tRNA synthetase, and GTP-binding protein, with the remaining ones overexpressed in SRS samples and related to hypothetical protein, transposon integrase, histidine kinase, putative transporter, bacteriocin immunity protein, response regulator, 6-phospho-beta-galactosidase, purine metabolism, and transcriptional regulator. Key-functional modules were identified for SRS and RC conditions based on WGCNA, being 139 hub genes found on SRS key-module and 17 genes on RC key-module. Functional analysis of S. mutans within the metatranscriptome of biofilms from sound root and from carious root revealed a similar pattern of gene expression, and only a few genes have been differentially expressed between biofilms from SRS and those from root carious lesions. However, S. mutans presented a greater functional abundance in the carious lesion samples. Some functional patterns related to sugar (starch, sucrose, fructose, mannose, and lactose) and heterofermentative metabolisms, to cell-wall biosynthesis, and to acid tolerance stress seem to be enriched on carious root surfaces, conferring ecological advantages to S. mutans. Altogether, the present data suggest that a functional signature may be associated with carious root lesions.
Topics: Biofilms; Dental Caries; Gene Expression; Humans; RNA-Seq; Root Caries; Streptococcus mutans
PubMed: 35367982
DOI: 10.1159/000524196