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Purpose: Blood culture obtainment prior to antibiotic administration, in patients with suspected infection, is considered the best practice in international guidelines. However, there is little data regarding the effect of a single dose of antibiotics on blood culture sterilization. Methods: We conducted a prospective study, enrolling consecutive patients with suspected infection, hospitalized in an internal medicine ward between December 2019 and January 2023. Included patients had a positive blood culture prior to antibiotic administration and a set of blood cultures taken within 24 h after a single dose of antibiotics. The rate of patients with pathogen isolation after antibiotic administration was assessed. Logistic regression was performed to examine factors associated with blood culture positivity. Results: A total of 155 patients were recruited for the study of which 131 (50.8% female 77.5 ± 13.4 years) met the inclusion criteria. The overall rate of patients with a positive blood culture after a single dose of antibiotics was 42.0% (55/131 patients). Increasing time between antibiotic administration and post-antibiotic culture was an independent predictor for blood culture sterilization (odds ratio 0.89 [95% confidence interval, 0.83–0.97; p = 0.006] for every 60 min). Blood culture volume was an independent predictor for blood culture positivity in a sensitivity analysis which included 82 patients (OR = 1.26 [95% CI 1.03–1.57] for every 1 ml increase; p = 0.024). Conclusion: Blood culture positivity is reduced by antimicrobial therapy but remains high after a single dose of antibiotics. If cultures are not obtained prior to antibiotic administration, they should be obtained as soon as possible afterwards. [ABSTRACT FROM AUTHOR]

Background Evidence supporting combination treatment with a beta-lactam plus an aminoglycoside (C-BA) for endocarditis caused by viridans and gallolyticus group streptococci (VGS-GGS) with intermediate susceptibility to penicillin (PENI-I) is lacking. We assessed the clinical characteristics and outcomes of PEN-I VGS-GGS endocarditis and compared the effectiveness and safety of C-BA with third-generation cephalosporin monotherapy. Methods Retrospective analysis of prospectively collected data of a cohort of definite endocarditis caused by penicillin-susceptible and PENI-I VGS-GGS (penicillin minimum inhibitory concentration ranging from 0.25 to 2 mg/L) between 2008 and 2018 in 40 Spanish hospitals. We compared cases treated with monotherapy or with C-BA and performed multivariable analyses of risk factors for in-hospital and 1-year mortality. Results A total of 914 consecutive cases of definite endocarditis caused by VGS-GGS with complete or intermediate susceptibility to penicillin were included. A total of 688 (75.3%) were susceptible to penicillin and 226 (24.7%) were PENI-I. Monotherapy was used in 415 (45.4%) cases (cephalosporin in 331 cases) and 499 (54.6%) cases received C-BA. In-hospital mortality was 11.9%, and 190 (20.9%) patients developed acute kidney injury. Heart failure (odds ratio [OR]: 6.06; 95% confidence interval [CI]: 1.37–26.87; P =.018), central nervous system emboli (OR: 9.83; 95% CI: 2.17–44.49; P =.003) and intracardiac abscess (OR: 13.47; 95% CI: 2.24–81.08; P =.004) were independently associated with in-hospital mortality among PEN-I VGS-GGS cases, while monotherapy was not (OR: 1.01; 95% CI:.26–3.96; P =.982). Conclusions Our findings support the use of cephalosporin monotherapy in PEN-I VGS-GGS endocarditis in order to avoid nephrotoxicity without adversely affecting patient outcomes. [ABSTRACT FROM AUTHOR]

Purpose: The spectrum of causative organisms in infective endocarditis (IE) has changed significantly in the last decades. Reliable pathogen detection is crucial for appropriate antimicrobial therapy for IE. The aim of the study was to evaluate the diagnostic value of microbiological methods for detecting the causative microorganism of IE and to analyze the spectrum of pathogens. Methods: A total of 224 cases (211 unique patients, some with multiple surgeries) were included into this retrospective study. Patients were diagnosed with IE according to the modified Duke criteria from January 2016 to July 2021 and underwent heart valve surgery in a tertiary hospital. Pathogen detection was performed by blood culture, microbiological culture and 16S rDNA PCR of explanted heart valve material. Results: A causative pathogen of IE was detected in 95.5% (n = 214) of cases. Blood cultures were positive in 83.3%, while a pathogen in the examined heart valve samples was identified in 32.6% by culture and in 88.2% by 16S rDNA PCR. A microorganism was identified by 16S rDNA PCR in 61.1% of blood culture negative cases but only in 19.4% by heart valve culture. The most common pathogens were Staphylococcus aureus (27%), viridans group streptococci (20%), enterococci (19%) and coagulase-negative staphylococci (CoNS 8%). Cutibacterium acnes (7%) was detected in prosthetic valve IE cases only. Conclusion: Blood culture as a comparatively non-invasive and straightforward technique remains an important and reliable method for initial detection of the causative organism in IE. Diagnostic stewardship programs should broadly emphasize proper collection of blood cultures, particularly sampling prior to any antibiotic treatment. Additionally, molecular testing using 16S rDNA tissue PCR can be used with culture techniques to increase the diagnostic yield, especially in the case of a negative blood culture. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objectives: Eye infections can be caused by several microorganisms and the most common causative bacterial agents are staphylococci, streptococci, and Pseudomonas aeruginosa. This study aimed to estimate the prevalence of Staphylococcus aureus, Staphylococcus epidermidis, viridans group streptococci, and P. aeruginosa as the cause of ocular infections in Iran. Methods: We conducted a systematic search on the studies published by Iranian authors from January 2000 to December 2020 in Web of Science, PubMed, Scopus, and Embase. Eligible studies were selected according to the defined inclusion/ exclusion criteria. Statistical heterogeneity between and within groups was estimated by the Q-statistic and I² index. The funnel plots, Duval and Tweedie trim, and fill methods were obtained to evaluate the evidence of publication bias. Results: Twenty-seven studies were included in this review. According to the meta-analysis results, the prevalence of S. epidermidis was 19.1% (95% CI: 12.5-28.1). It was estimated 6.9% (95% CI: 4.4-10.6), 6.7% (95% CI: 4.6-9.6), and 3.3% (95% CI: 1.8-5.8) for P. aeruginosa, S. aureus, and viridans streptococci, respectively. Conclusions: S. epidermidis is the prevalent bacterial agents responsible for eye-associated infections in Iran. [ABSTRACT FROM AUTHOR]

Background: Oral streptococci represent the causing microorganism for infective endocarditis (IE) in many patients. The impact of oral infections is questioned, and it has been suggested that bacteraemia due to daily routines may play a bigger part in the aetiology of IE. The aim of this study was to examine the association between oral health and infective endocarditis caused by oral bacteria in comparison with bacteria of other origin than the oral cavity. Methods: A retrospective study was conducted at Haukeland University Hospital from 2006- 2015. All consecutive adult patients admitted to hospital for treatment of IE and subjected to an oral focus screening including orthopantomogram, were included. The clinical, radiological and laboratory characteristics of the patients, collected during oral infectious focus screening, were analysed. Patient survival was calculated using Kaplan–Meier and mortality rates were compared using Cox-regression. Results: A total of 208 patients were included, 77% (n = 161) male patients and 23% (n = 47) female, mean age was 58 years. A total of 67 (32%) had IE caused by viridans streptococci. No statistically significant correlation could be found between signs of oral infection and IE caused by viridans streptococci. The overall mortality at 30 days was 4.3% (95% CI: 1.6–7.0). There was no statistical difference in mortality between IE caused by viridans streptococci or S. aureus (HRR = 1.16, 95% CI: 0.57–2.37, p = 0.680). Conclusion: The study indicates that the association between origin of the IE causing bacteria and findings during oral infection screening might be uncertain and may suggest that the benefit of screening and elimination of oral infections in patients admitted with IE might be overestimated. However, the results should be interpreted with caution and further studies are needed before any definite conclusions can be drawn. [ABSTRACT FROM AUTHOR]

Objective: To describe the clinical characteristics and outcome of Abiotrophia and Granulicatella infective endocarditis and compare them with Viridans group streptococci infective endocarditis.Methods: All patients in the International Collaboration on Endocarditis (ICE) - prospective cohort study (PCS) and the ICE-PLUS cohort were included (n = 8112). Data from patients with definitive or possible IE due to Abiotrophia species, Granulicatella species and Viridans group streptococci was analyzed. A propensity score (PS) analysis comparing the ABI/GRA-IE and VGS-IE groups according to a 1:2 ratio was performed.Results: Forty-eight (0.64%) cases of ABI/GRA-IE and 1,292 (17.2%) VGS-IE were included in the analysis. The median age of patients with ABI/GRA-IE was lower than VGS-IE (48.1 years vs. 57.9 years; p = 0.001). Clinical features and the rate of in-hospital surgery was similar between ABI/GRA-IE and VGS-IE (52.1% vs. 45.4%; p = 0.366). Unadjusted in-hospital death was lower in ABI/GRA-IE than VGS-IE (2.1% vs. 8.8%; p = 0.003), and cumulative six-month mortality was lower in ABI/GRA-IE than VGS-IE (2.1% vs. 11.9%; p<0.001). After PS analysis, in-hospital mortality was similar in both groups, but six-month mortality was lower in the ABI/GRA IE group (2.1% vs. 10.4%; p = 0.029).Conclusions: Patients with ABI/GRA-IE were younger, had similar clinical features and rates of surgery and better prognosis than VGS-IE. [ABSTRACT FROM AUTHOR]

Simple Summary: The intensive chemotherapy that children with acute myeloid leukemia (AML) receive puts them at high risk of infections. Bloodstream infections (BSI) caused by bacteria are common and known for their associated complications but may be prevented by the use of antibacterial agents. Literature on this matter is scarce. We evaluated the effect of different antibacterial prophylaxis regimens on the occurrence of fever and bacterial BSIs in 82 Dutch children with AML. A combination of prophylactic teicoplanin and ciprofloxacin had the best outcomes, resulting in significantly fewer episodes of fever and bacterial BSIs. The combination of teicoplanin and ciprofloxacin was previously suggested by others, but not yet studied. Currently, a randomized trial is ongoing to address and validate the efficacy of teicoplanin prophylaxis in pediatric AML. Bloodstream infections (BSIs), especially those caused by Gram-negative rods (GNR) and viridans group streptococci (VGS), are common and potentially life-threatening complications of pediatric acute myeloid leukemia (AML) treatment. Limited literature is available on prophylactic regimens. We retrospectively evaluated the effect of different antibacterial prophylaxis regimens on the incidence of febrile neutropenic (FN) episodes and bacterial BSIs. Medical records of children (0–18 years) diagnosed with de novo AML and treated at two Dutch centers from May 1998 to March 2021 were studied. Data were analyzed per chemotherapy course and consecutive neutropenic period. A total of 82 patients had 316 evaluable courses: 92 were given with single-agent ciprofloxacin, 138 with penicillin plus ciprofloxacin, and 51 with teicoplanin plus ciprofloxacin. The remaining 35 courses with various other prophylaxis regimens were not statistically compared. During courses with teicoplanin plus ciprofloxacin, significantly fewer FN episodes (43 vs. 90% and 75%; p < 0.0001) and bacterial BSIs (4 vs. 63% and 33%; p < 0.0001) occurred than with single-agent ciprofloxacin and penicillin plus ciprofloxacin, respectively. GNR and VGS BSIs did not occur with teicoplanin plus ciprofloxacin and no bacterial BSI-related pediatric intensive care unit (PICU) admissions were required, whereas, with single-agent ciprofloxacin and penicillin plus ciprofloxacin, GNR BSIs occurred in 8 and 1% (p = 0.004), VGS BSIs in 24 and 14% (p = 0.0005), and BSI-related PICU admissions were required in 8 and 2% of the courses (p = 0.029), respectively. Teicoplanin plus ciprofloxacin as antibacterial prophylaxis is associated with a lower incidence of FN episodes and bacterial BSIs. This may be a good prophylactic regimen for pediatric AML patients during treatment. [ABSTRACT FROM AUTHOR]

Background and Aim: the study of antibacterial properties of resin cements and modified glass ionomers is of great importance. The aim of this study was to determine the antibacterial effect of resinmodified glass ionomers and resin cements on cariogenic bacteria, Streptococcus mutans, Streptococcus sabrinus and Lactobacillus acidophilus. Materials and Methods:In this experimental laboratory study, samples of Streptococcus mutans, Streptococcus sabrinus and Lactobacillus acidophilus were used. 7 samples were prepared from each of glass ionomer and resin cements. After drying and sterilizing the samples, the quality control operations of the samples were performed and cultured in culture media at 37 ° C for 48 hours. According to the antimicrobial halo around each disk, its measurement the growth or non-growth of bacteria was examined. Data were analyzed using t-test and two-way ANOVA Results: The diameter of growth inhibition zone of the three studied bacteria in the presence of three materials SDI seT PP, Natural Elegance and GC Fugi Plus was significantly different (p <0.001). The diameter of GC Fugi Plus stunted halo in all three types of bacteria was larger than other groups and the stagnation halo diameter of Lactobacillus acidophilus was larger than that of Streptococcus mutans without any difference with Streptococcus sabrinus. Conclusion: The antibacterial effects of glass ionomer cement are more than the other two types of resin cements. Also, the antibacterial effects of the investigated cements on Lactobacillus acidophilus were higher than other bacteria. [ABSTRACT FROM AUTHOR]

Brain abscess formation is extremely rare in patients with osteopetrosis. Herein, we report a case of viridans streptococci brain abscess in an immunocompromised child diagnosed with osteopetrosis. The patient presented with a sudden change in mental status and convulsions. Radiological evaluation revealed a temporal lobe brain abscess, and intravenous antibiotherapy was started immediately. The patient underwent abscess drainage, and laboratory investigation of pus material revealed viridans streptococci. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to find the relation of the MS co‐existence with the decayed, missing (Extracted) and filled teeth (DMFT) score and the prevalence of Streptococcus mutans serotypes in the Iranian population. Methods: In this cross‐sectional research conducted in 2018, volunteers aged 10–60< years were measured by population selection criteria. PCR technique was used to screen MS serotypes in the homogenized saliva and plaque samples. Results: 499 subjects met the selection criteria of the study population. Out of 499 samples, 448 samples were finalized for serotype determination and DMFT relation evaluation. From 448, 348 (77.6%) samples harboured only S. mutans, 44 (9.8%) had both S. mutans and S. sobrinus, 6 (1.3%) were positive for S. sobrinus alone, and 94 (20.9%) were free of both specious. The mean DMFT score in people with S. mutans (6.7) was higher than S. mutans negative (4.6) participants (p < 0.05). In people with both S. mutans and S. sobrinus, the mean DMFT did not change significantly. The frequency of c, e, f and k serotypes was 47.7, 22.7, 27.5 and 22.1%, respectively. The mean DMFT score in participants with serotype e was significantly higher than others (p <.05). Conclusions: People can acquire different S. mutans serotypes over a lifetime. The high prevalence rate of serotype k, a systemic S. mutans serotype, calls worldwide studies on the prevalence of serotype k strains. [ABSTRACT FROM AUTHOR]

This study carried out to evaluate the antibacterial effect methanol and chloroform extraction of Olive pomace (OLP) and Pomegranate peels (POP) extracts and mixture of them against different bacteria isolated from clinical specimens include three bacterial isolates of Staphylococcus aureus and two isolates from Staphylococcus epidermidis and one isolate from Streptococcus viridians, Pseudomonas aeruginosa, Escherichia coli, E. aerugenes and Streptococcus pyogens. The results of study showed that methanol extracts effect on all bacterial species. The higher inhibition rate of Pomegranate peels (POP) of staphylococcus aureus3 was (26.1) mm while the lower inhabitation rate was (16.3) mm of Staphylococcus epidermidis1 and methanol extracts of Olive pomace (OLP) extract, the higher inhibition rate of staphylococcus aureus1 was (22.5) mm while the lower inhabitation rate for Staphylococcus epidermidis1 was (16.6)mm while mixture of them showed that the higher inhibition rate of Pseudomonas aeruginosa was (24.0)mm while the lower inhabitation rate for Staphylococcus epidermidis1 was(15.6)mm, While treatment with chloroform extract did not show any effect on bacterial isolates. [ABSTRACT FROM AUTHOR]

We present a 57-year-old man with recent Streptococcus viridans endocarditis on mitral and aortic valves who had a mycotic aneurysm of the left anterior descending (LAD) coronary artery and associated superior mesenteric and cerebral artery aneurysms. The patient had preoperative renal failure and the infection was controlled with ceftriaxone. Mitral and aortic valve replacement were performed using tissue valves and the LAD aortic aneurysm was ligated and the patient had saphenous venous graft to the LAD. The postoperative course was complicated by pleural effusion and the patient had antibiotic therapy for 6 weeks postoperatively. [ABSTRACT FROM AUTHOR]

Background: Although blood cultures (BCs) are the "gold standard" for detecting bacteremia, the utility of BCs in patients with community-acquired pneumonia (CAP) is controversial. This study describes the proportion of patients with CAP and afebrile bacteremia and identifies the clinical characteristics predicting the necessity for BCs in patients who are afebrile.Methods: Bacteremia rates were determined in 4,349 patients with CAP enrolled in the multinational cohort study The Competence Network of Community-Acquired Pneumonia (CAPNETZ) and stratified by presence of fever at first patient contact. Independent predictors of bacteremia in patients who were afebrile were determined using logistic regression analysis.Results: Bacteremic pneumonia was present in 190 of 2,116 patients who were febrile (8.9%), 101 of 2,149 patients who were afebrile (4.7%), and one of 23 patients with hypothermia (4.3%). Bacteremia rates increased with the CURB-65 score from 3.5% in patients with CURB-65 score of 0 to 17.1% in patients with CURB-65 score of 4. Patients with afebrile bacteremia exhibited the highest 28-day mortality rate (9.9%). Positive pneumococcal urinary antigen test (adjusted OR [AOR], 4.6; 95% CI, 2.6-8.2), C-reactive protein level > 200 mg/L (AOR, 3.1; 95% CI, 1.9-5.2), and BUN level ≥ 30 mg/dL (AOR, 3.1; 95% CI, 1.9-5.3) were independent positive predictors, and antibiotic pretreatment (AOR, 0.3; 95% CI, 0.1-0.6) was an independent negative predictor of bacteremia in patients who were afebrile.Conclusions: A relevant proportion of patients with bacteremic CAP was afebrile. These patients had an increased mortality rate compared with patients with febrile bacteremia or nonbacteremic pneumonia. Therefore, the relevance of fever as an indicator for BC necessity merits reconsideration. [ABSTRACT FROM AUTHOR]

Purpose: Although the burden of illness due to Streptococcus pyogenes is widely recognized, other β-hemolytic streptococci are also important causes of invasive infections. The objective of this study was to compare the population-based epidemiology of groups A, B, and C/G β-hemolytic streptococcal bloodstream infection (BSI). Methods: Population-based surveillance was conducted in the western interior of British Columbia, Canada, 2011–2018. Results: A total of 210 episodes were identified for an incidence of 14.4 per 100,000; the incidences of groups A, B and C/G streptococcal BSI were 4.2, 4.7, and 5.5 per 100,000, respectively. There was an increasing annual incidence of β-hemolytic streptococcal BSI from 2011 through to a peak incidence in 2016 that decreased thereafter. Fifty-two percent (110) of BSIs were community associated, 43% (91) were healthcare associated, and 4% (9) were hospital onset. Patients with group A were younger, more likely to be female, and have fewer co-morbidities than patients with groups B and C/G streptococcal BSI. The most common focus of infection was soft tissue (109/52%), followed by primary (33; 16%), and bone and joint (20; 10%) and these varied by streptococcal species (p < 0.001). The 30-day all-cause case fatality rate was 11% (24/210) and did not significantly vary by group (p = 0.7). Conclusion: Although the determinants vary, the overall burden of disease related to BSI is similar amongst groups A, B and C/G β-hemolytic streptococci. [ABSTRACT FROM AUTHOR]

Background Outpatient parenteral antibiotic treatment (OPAT) has proven efficacious for treating infective endocarditis (IE). However, the 2001 Infectious Diseases Society of America (IDSA) criteria for OPAT in IE are very restrictive. We aimed to compare the outcomes of OPAT with those of hospital-based antibiotic treatment (HBAT). Methods Retrospective analysis of data from a multicenter, prospective cohort study of 2000 consecutive IE patients in 25 Spanish hospitals (2008–2012) was performed. Results A total of 429 patients (21.5%) received OPAT, and only 21.7% fulfilled IDSA criteria. Males accounted for 70.5%, median age was 68 years (interquartile range [IQR], 56–76), and 57% had native-valve IE. The most frequent causal microorganisms were viridans group streptococci (18.6%), Staphylococcus aureus (15.6%), and coagulase-negative staphylococci (14.5%). Median length of antibiotic treatment was 42 days (IQR, 32–54), and 44% of patients underwent cardiac surgery. One-year mortality was 8% (42% for HBAT; P <.001), 1.4% of patients relapsed, and 10.9% were readmitted during the first 3 months after discharge (no significant differences compared with HBAT). Charlson score (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.04–1.42; P =.01) and cardiac surgery (OR, 0.24; 95% CI,.09–.63; P =.04) were associated with 1-year mortality, whereas aortic valve involvement (OR, 0.47; 95% CI,.22–.98; P =.007) was the only predictor of 1-year readmission. Failing to fulfill IDSA criteria was not a risk factor for mortality or readmission. Conclusions OPAT provided excellent results despite the use of broader criteria than those recommended by IDSA. OPAT criteria should therefore be expanded. [ABSTRACT FROM AUTHOR]

Background: Recently, there has been an increasing growth in research on medical plant's effect on dental plaque bacteria. The aim of this study was to determine the antibacterial effects of Satureja hortensis extract and its essential oil (EO) on Streptococcus salivarius, Streptococcus sanguis, and Streptococcus mutans as important bacteria in early supragingival dental plaque formation. Materials and Methods: In this in vitro study, different concentrations of S. hortensis extract and its EO were prepared using double dilution method. The disc diffusion method was used to determine antibacterial activity. Based on these measurements, the minimal inhibitory concentration value was reported for each bacterium. Antibiotics used as positive controls in this study were erythromycin (15 μg) and tetracycline (30 μg). t-test and ANOVA were used for statistical analysis (P < 0.05). Results: Aqueous and methanolic extract did not show significant antibacterial activity, but the EO significantly inhibited the growth of the test bacteria compared to positive control (P < 0.05). High concentrations of EO processed greater antimicrobial effects against three oral bacteria than other low concentrations (P < 0.0001). For S. mutans, the inhibition effect of tetracycline 30 μg was similar with 50% (P = 0.789) and 25% (P = 0.158) dosages of the EO. For S. salivarius, the effect of tetracycline 30 μg was similar to 50% dosages of the EO (P = 0.122). For S. sanguis, the effect of erythromycin 15 μg was lower than 50% (P = 0.0006) and 25% (P = 0.003) dosages of the EO. The inhibition effects of all concentrations of EO were higher for S. sanguis. S. salivarius and S. sanguis are more sensitive than S. mutans to S. hortensis EO. Conclusion: Due to the strong antibacterial effect of S. hortensis EO on the oral bacteria growth, it can be served as herbal mouth rinse, while to confirm this antibacterial effect, further clinical studies are necessary. [ABSTRACT FROM AUTHOR]

Background: Infection, one of the complications associated with procedures, can cause fatal outcomes for patients. Although the local anesthetic agent we use is less susceptible to infection due to its antibacterial action, we performed this study to check the change in the antibacterial effect of lidocaine in various clinical conditions. Methods: After exposing lidocaine to five contaminated environments, we checked on whether the bacteria could be cultured in blood agar plate (BAP) media. In each contaminated environment, lidocaine was exposed for 4 h (n = 9) and 8 h (n = 9), and the results were compared. Lidocaine was swabbed with chlorhexidine (group A), brought into contact with saliva (group B), skin (group C), an operating room floor and an outpatient room floor (group D), operating room air for 24 h (group A-a), and outpatient room air for 24 h (group A-b). After exposure, the culture was initiated. Results: In 2 of 9 BAP media where lidocaine was exposed to saliva (group B) for 8 h, growth of a colony was observed. In gram staining, it was found to be Streptococcus viridans. No bacteria were found in any other groups. Conclusions: Though lidocaine has strong antibacterial activity, it has been found that long-term exposure to a contaminated environment reduces its antibacterial activity and that drug contamination can be heavily affected not only by environmental but also human effects. Therefore, the use of aseptic drugs is necessary, and stopping the reuse of the drug is a way to prevent complications, including infection. [ABSTRACT FROM AUTHOR]

Quaternary ammonium compounds constitute a large group of antibacterial chemicals with a potential for inhibiting dental plaque. The aims of this study were to evaluate short-time antibacterial and regulating effects of dimethylaminododecyl methacrylate (DMADDM) on multispecies biofilm viability, reformation, and bacterial composition in vitro. DMADDM, chlorhexidine (CHX), and sodium fluoride (NaF) were chosen in the present study. Streptococcus mutans, Streptococcus sanguinis, and Streptococcus gordonii were used to form multispecies biofilm. Cytotoxicity assay was used to determine the optimal tested concentration. 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and resazurin test of biofilm were conducted to study the biomass changes and metabolic changes of controlled multispecies biofilm. Scanning electron microscopy (SEM) was used to observe biofilm images. TaqMan real-time polymerase chain reaction was performed to evaluate the proportion change in multispecies biofilm of different groups. Cytotoxicity assay showed that there existed a certain concentration application range for DMADDM, CHX, and NaF. MTT assay and resazurin test results showed that DMADDM and CHX groups decreased multispecies biofilm growth and metabolic activity (p < 0.05), no matter after 1 min or 5 min direct contact killing or after 24 h regrowth. The proportion of S. mutans decreased steadily in DMADDM and CHX groups after 1 min and 5 min direct contact killing and 24 h regrowth, compared to control groups. A novel DMADDM-containing solution was developed, achieving effective short-time antibacterial effects and regulation ability of biofilm formation. [ABSTRACT FROM AUTHOR]

Background We conducted a national antimicrobial surveillance study of both gram-positive and gram-negative organisms isolated from hospitalized patients. This report presents data on antimicrobial susceptibility among 4998 organisms collected in China between 2012 and 2014. Method The minimum inhibitory concentrations (MICs) and susceptibilities of ceftaroline/avibactam (CPA), ceftazidime/avibactam (CZA) and a range of comparative agents were determined according to guidelines established by the Clinical and Laboratory Standards Institute (CLSI). Results The highest overall susceptibility levels for all Enterobacteriaceae during the study period were observed for CPA, CZA, doripenem (DOR), meropenem (MEM), and amikacin (AMK), which were all >90%. However, both CPT and CAZ alone and in combination with avibactam showed low activities for Acinetobacter spp. whereas CPA and CZA exhibited MIC90values for Pseudomonas aeruginosa that were reduced by 4- and 8-fold, respectively, compared with those of CPT and CAZ. High susceptibilities of Acinetobacter spp. and P. aeruginosa to colistin and P. aeruginosa to AMK were observed. For the gram-positive strains, no significant activity changes were seen for Enterococcus, Staphylococcu s, and viridans group streptococci to CPT or CAZ alone or in combination with avibactam, whereas Streptococcus pneumoniae and β-hemolytic Streptococcus showed almost 100% susceptibility to both CPT and CPA. Conclusion The addition of 4 mg/L avibactam greatly increased the activities of CPT and CAZ against most Enterobacteriaceae and P. aeruginosa isolates, whereas no significant changes were observed in Acinetobacter spp. or any of the gram-positive strains. [ABSTRACT FROM AUTHOR]

Oral microbiota consists of hundreds of different species of bacteria, fungi, protozoa and archaea, important for oral health. Oral mycoses, mostly affecting mucosae, are mainly caused by the opportunistic pathogen Candida albicans. They become relevant in denture-wearers elderly people, in diabetic patients, and in immunocompromised individuals. Differently, bacteria are responsible for other pathologies, such as dental caries, gingivitis and periodontitis, which affect even immune-competent individuals. An appropriate oral hygiene can avoid (or at least ameliorate) such pathologies: the regular and correct use of toothbrush, toothpaste and mouthwash helps prevent oral infections. Interestingly, little or no information is available on the effects (if any) of mouthwashes on the composition of oral microbiota in healthy individuals. Therefore, by means of in vitro models, we assessed the effects of alcohol-free commercial mouthwashes, with different composition (4 with chlorhexidine digluconate, 1 with fluoride, 1 with essential oils, 1 with cetylpyridinium chloride and 1 with triclosan), on several virulence traits of C. albicans, and a group of viridans streptococci, commonly colonizing the oral cavity. For the study here described, a reference strain of C. albicans and of streptococci isolates from pharyngeal swabs were used. Chlorhexidine digluconate- and cetylpyridinium chloride-containing mouthwashes were the most effective in impairing C. albicans capacity to adhere to both abiotic and biotic surfaces, to elicit proinflammatory cytokine secretion by oral epithelial cells and to escape intracellular killing by phagocytes. In addition, these same mouthwashes were effective in impairing biofilm formation by a group of viridans streptococci that, notoriously, cooperate with the cariogenic S. mutans, facilitating the establishment of biofilm by the latter. Differently, these mouthwashes were ineffective against other viridans streptococci that are natural competitors of S. mutans. Finally, by an in vitro model of mixed biofilm, we showed that mouthwashes-treated S. salivarius overall failed to impair C. albicans capacity to form a biofilm. In conclusion, the results described here suggest that chlorhexidine- and cetylpyridinium-containing mouthwashes may be effective in regulating microbial homeostasis of the oral cavity, by providing a positive balance for oral health. On the other side, chlorhexidine has several side effects that must be considered when prescribing mouthwashes containing this molecule. [ABSTRACT FROM AUTHOR]

Background: The clinical course of Viridans streptococci (VS) peritonitis in patients undergoing peritoneal dialysis (PD) is rarely reported. This study examined the association of clinical factors with VS peritonitis.Methods: We retrospectively reviewed clinical data from patients with VS peritonitis from March 1990 to February 2016 in a PD center in Taiwan and evaluated clinical profiles and treatment outcomes.Results: A total of 109 episodes of VS peritonitis in 71 patients identified. Among these patients, 57 had mono-VS peritonitis and 14 had concurrent polymicrobial infections. The median time interval from PD initiation to the first VS peritonitis episode was 18 months (range, 0.6-144 months). Among clinical outcomes, most VS peritonitis episodes were completely cured regardless of a history of peritonitis. All episodes with catheter removal occurred in those without a history of recent antibiotic use.Conclusion: VS peritonitis in patients undergoing PD typically has favorable treatment outcomes. Antibiotic therapy should be started promptly. [ABSTRACT FROM AUTHOR]

Background: Many infections due to Gram-positive cocci (GPC; staphylococci, streptococci and enterococci) regularly involve prolonged systemic antibiotic use. Dalbavancin has demonstrated activity against GPC isolates and has been approved for the treatment of acute bacterial skin and skin structure infections (ABSSSIs) in adults.Objectives: To evaluate the activity of dalbavancin against GPC isolated from a variety of infection types in the USA and Europe.Methods: A total of 14 319 Staphylococcus aureus, 1992 CoNS, 3269 β-haemolytic streptococci (BHS), 2071 Enterococcus faecalis, 936 Enterococcus faecium, 71 Enterococcus gallinarum/casseliflavus and other Enterococcus spp., 3487 Streptococcus pneumoniae and 1063 viridans group streptococci (VGS) causing clinical infections were consecutively collected (2015-16) and tested for susceptibility by broth microdilution methods.Results: All S. aureus (36.4% MRSA) isolates were susceptible to dalbavancin, teicoplanin and vancomycin, while daptomycin and linezolid showed susceptibility rates of >99.9% (according to CLSI criteria). Dalbavancin MIC results were at least 16-fold lower than these comparators against all S. aureus. Dalbavancin was the most potent agent against CoNS [62.2%/59.6% methicillin-resistant (CLSI/EUCAST)], followed by daptomycin, linezolid and vancomycin. All vancomycin-susceptible E. faecalis isolates were inhibited by dalbavancin at ≤0.25 mg/L (FDA susceptible breakpoint). Dalbavancin was very active against BHS (MIC90 0.03 mg/L) and the most active agent against S. pneumoniae and VGS (highest MIC 0.25 mg/L). Ceftriaxone, daptomycin, levofloxacin and vancomycin were also active (93.5%-100.0% susceptible) against VGS, whereas clindamycin, erythromycin, penicillin and tetracycline had lower activity.Conclusions: Dalbavancin appears to be a viable candidate for treating serious infections caused by GPC. [ABSTRACT FROM AUTHOR]

Background Little is known about the effect of hepatitis C virus (HCV) infection on gut microbiota and the relationship between alteration of gut microbiota and chronic hepatitis C (CHC) progression. We performed a comparative study of gut microbiota composition between CHC patients and healthy individuals. Methods Fecal samples from 166 CHC patients were compared with those from 23 healthy individuals; the gut microbiota community was analyzed using 16S ribosomal RNA gene sequencing. CHC patients were diagnosed with persistently normal serum alanine aminotransferase without evidence of liver cirrhosis (LC) (PNALT, n = 18), chronic hepatitis (CH, n = 84), LC (n = 40), and hepatocellular carcinoma in LC (n = 24). Results Compared with healthy individuals, bacterial diversity was lower in persons with HCV infection, with a decrease in the order Clostridiales and an increase in Streptococcus and Lactobacillus. Microbiota dysbiosis already appeared in the PNALT stage with the transient increase in Bacteroides and Enterobacteriaceae. Predicted metagenomics of microbial communities showed an increase in the urease gene mainly encoded by viridans streptococci during CHC progression, consistent with a significantly higher fecal pH in CH and LC patients than in healthy individuals or those in the PNALT stage. Conclusions HCV infection is associated with gut dysbiosis, even in patients with mild liver disease. Additionally, overgrowth of viridans streptococci can account for hyperammonemia in CH and LC. Further studies would help to propose a novel treatment strategy because the gut microbiome can be therapeutically altered, potentially reducing the complications of chronic liver disease. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study is to investigate the effect of debonding procedures after completion of orthodontic treatments on bacteremia.Materials and Methods: Twenty-eight patients who were treated with fixed orthodontic treatment at the Faculty of Dentistry's Department of Orthodontics at Gaziantep University and who had an indication of debonding were selected for this study, and blood samples were taken from these patients at different times and examined for bacteremia. Blood culture samples were taken from the antecubital veins of the patients prior to debonding (T0), immediately after removing the bracket (T1), and immediately after cleaning the composite residues and plaque deposits on the enamel surface (T2). The blood samples were then inoculated in blood culture bottles and investigated for bacterial growth.Results: The results showed that there was no bacterial growth in the blood samples taken at T0 and T1, whereas 10 of the blood culture samples taken at T2 showed bacterial growth including the following bacteria; Streptococcus viridans, Streptococcus mitis, Streptococcus parasanguinis, Streptococcus salivarius, Streptococcus oralis, Staphylococcus aureus, Actinomyces oris, Actinomyces naeslundii and Klebsiella pneumoniae.Conclusion: It was concluded that patients in the risk group could develop bacteremia during debonding procedures. The presence of these bacteria in sterile blood suggested the possibility of bacterial endocarditis. [ABSTRACT FROM AUTHOR]

Objectives. Leucocyte- and platelet-rich fibrin (L-PRF) membrane can be used in various regenerative treatments. In the case of classical heterologous membrane exposure, microorganisms can be colonized on it and jeopardize the success of treatment. The aim of this study was to compare the antibacterial, mechanical, and histologic characteristics of the L-PRF membrane before and after the addition of silver nanoparticles (SNP). Materials and Method. This study was performed on 10 volunteer men aged 25-35 years. 20 ml whole bloods were collected from each person and L-PRFs were made by routine and SNP modified method. Mechanical, antibacterial, and histological properties were evaluated. Results. The antibacterial efficacy of L-PRF and nanosilver-modified L-PRF was presented as Klebsiella pneumonia had growth on the L-PRF membrane after 12 hours. After 24 hours, Klebsiella pneumonia and Streptococcus viridans had growth on L-PRF and only Klebsiella pneumonia had growth on SNP-L-PRF. The tensile strength and stiffness were significantly higher in the SNP-L-PRF. Precipitation of the SNPs was patchy in the outer layers and quite homogeneous in the inner core. Conclusion. Modification of L-PRF with SNP improves the mechanical properties and antibacterial activity of the L-PRF. It can play an important role in regenerative procedures. [ABSTRACT FROM AUTHOR]

Purpose: The relationship between infective endocarditis (IE) and osteoarticular infections (OAIs) are not well known. We aimed to study the characteristics of patients with IE and OAIs, and the interactions between these two infections.Methods: An observational study (1993-2014) which includes two cohorts: (1) patients with IE (n = 607) and (2) patients with bacteremic OAIs (n = 458; septic arthritis of peripheral and axial skeleton, and vertebral and peripheral osteomyelitis). These two cohorts were prospectively collected, and we retrospectively reviewed the clinical and microbiological variables.Results: There were 70 cases of IE with concomitant OAIs, representing 11.5% of IE cases and 15% of bacteremic OAI cases. Among cases with IE, the associated OAIs mainly involved the axial skeleton (n = 54, 77%): 43 were vertebral osteomyelitis (61%), mainly caused by “less virulent” bacteria (viridans and bovis streptococci, enterococci, and coagulase-negative staphylococci), and 15 were septic arthritis of the axial skeleton (21%), which were mainly caused by Staphylococcus aureus. OAIs with involvement of the axial skeleton were associated with IE (adjusted OR = 2.2; 95% CI 1.1-4.3) independently of age, sex, and microorganisms.Conclusions: Among patients with IE, the associated OAIs mainly involve the axial skeleton. Transesophageal echocardiography should be carefully considered in patients presenting with these bacteremic OAIs. [ABSTRACT FROM AUTHOR]

Abstract: Bacterial tracheobronchitis without lung parenchymal involvement is extremely rare in adults, except in patients who are intubated or mechanically ventilated. We present a case of nodular tracheobronchitis caused by viridans streptococci in a non‐ventilated lymphoma patient. To our knowledge, this is the first report of viridans streptococcal infection that has caused nodular tracheobronchitis. [ABSTRACT FROM AUTHOR]

Introduction: Active infective endocarditis is associated with high morbidity and mortality. Surgery is indicated in high-risk conditions, and the main determinants of mortality in surgical treatment should be evaluated. Objective: To identify mortality predictors in the surgical treatment of active infective endocarditis in a long-term follow-up. Methods: This prospective observational study involved 88 consecutive patients diagnosed with active infective endocarditis, who underwent surgery between January 2005 and December 2015. Fifty-eight (65.9%) patients were male, the mean age was 50.87±16.15 years. A total of 31 (35.2%) patients had a history of rheumatic fever; 48 (54.5%) had had heart surgery with prosthetic valve implantation; 45 (93.8%) had biological prosthetic valve endocarditis and 3 (6.3%) mechanical prosthetic valve; 40 (45.5%) patients had the disease in their native valve. The mean EuroSCORE II was 8.9±6.5%, and the main surgical indication was refractory heart failure in 38 (43.2%) patients. A total of 68 bioprosthesis (36 aortic, 32 mitral) and 29 mechanical prostheses (12 aortic, 17 mitral) were implanted and three mitral valve plasties performed. A total of 25 (28.4%) patients underwent double or triple valve procedures. Aortic annulus reconstruction by abscess was performed in 18 (20.5%) and six (6.81%) patients had combined procedure. The mean surgery time was 359±97.6 minutes. Results: The overall survival in up to a 10-year follow-up period was 79.5%. In the univariate analysis, the main mortality predictors were positive blood cultures (P=0.003), presence of typical microorganisms (P=0.008), most frequently Streptococcus viridans (12 cases; 25%); C-reactive protein (hazard ratio [HR] 1.034, 95% confidence interval [CI] 1.000 to 1.070, P=0.04); creatinine clearance (HR 0.977, 95% CI 0.962 to 0.993, P=0.005); length of surgery: every five minutes multiplies the chance of death 1.005-fold (HR 1.005, 95% CI 1.001 to 1.009, P=0.0307); age (HR 1.060, 95% CI 1.026 to 1.096, P=0.001); and EuroSCORE II (HR 1.089, 95% CI 1.030 to 1.151, P=0.003). Conclusion: A positive blood culture with typical microorganism, C-reactive protein, age, EuroSCORE II, total surgical time and the presence of postoperative complications were the major predictors of mortality and significantly impacted survival in up to a 10-year follow-up period. [ABSTRACT FROM AUTHOR]

Primary immunodeficiencies are often monogenic disorders characterized by vulnerability to specific infectious pathogens. Here, we performed whole-exome sequencing of a patient with disseminated Mycobacterium abscessus, Streptococcus viridians bacteremia, and cytomegalovirus (CMV) viremia and identified mutations in 2 genes that regulate distinct IFN pathways. The patient had a homozygous frameshift deletion in IFNGR2, which encodes the signal transducing chain of the IFN-γ receptor, that resulted in minimal protein expression and abolished downstream signaling. The patient also harbored a homozygous deletion in IFNAR1 (IFNAR1*557Gluext*46), which encodes the IFN-α receptor signaling subunit. The IFNAR1*557Gluext*46 resulted in replacement of the stop codon with 46 additional codons at the C-terminus. The level of IFNAR1*557Gluext*46 mutant protein expressed in patient fibroblasts was comparable to levels of WT IFNAR1 in control fibroblasts. IFN-α-induced signaling was impaired in the patient fibroblasts, as evidenced by decreased STAT1/STAT2 phosphorylation, nuclear translocation of STAT1, and expression of IFN-α-stimulated genes critical for CMV immunity. Pretreatment with IFN-α failed to suppress CMV protein expression in patient fibroblasts, whereas expression of WT IFNAR1 restored IFN-α-mediated suppression of CMV. This study identifies a human IFNAR1 mutation and describes a digenic immunodeficiency specific to type I and type II IFNs. [ABSTRACT FROM AUTHOR]

Aim: This study was to investigate the laboratory and clinical features of patients in whom Streptococcus spp. were isolated from cultures other than throat cultures. Methods: A total of 161 Streptococcus strains isolated from clinical specimens from 101 (64%) hospitalized patients and 65 (36%) outpatients and clinical and laboratory features of patients were investigated retrospectively. Isolated Streptococcus strains were further identified for type and antibiotic susceptibility according to the Clinical and Laboratory Standards Institute guidelines. Results: Streptococcus strains types were determined as follows; group A (9-5.6%), group B (64-39.7%), group C (2-1.2%), group D (2-1.2%), group G (2-1.2%), viridans (57-32.2%), and Streptococcus pneumonia (24-14,9%). Most frequently observed infections were urinary system infections (52-32.2%), skin and soft tissue infections (48-29.8%) and pulmonary infections (25-15.5%). In 87 (54%) of patients, there was more than one comorbid condition. While all group A Streptococcus pyogenes strains were susceptible to penicillin, 13% of Streptococcus pneumonia were resistant to penicillin and 36.3% were resistant to macrolides. Mortality was observed in eight patients. Conclusion: Invasive streptococcal infections may cause serious mortality and morbidity especially in patients with comorbid conditions. Early detection and appropriate antimicrobial therapy are most important parameters for the management of streptococcal infections. [ABSTRACT FROM AUTHOR]

Two matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDITOF- MS)-based methods were compared for their ability to identify viridans streptococci. One approach employed a reference database and software developed in-house. All inhouse measurements were performed using an Autoflex II Instrument (Bruker Daltonics GmbH, Germany). The other system, a VITEK-MS (BioMérieux, France) was operated on the commercially available V2.0 Knowledge Base for Clinical Use database. Clinical isolates of viridans streptococci (n=184) were examined. Discrepant results were resolved by 16S rDNA sequencing. Species-level identification percentages were compared by a chisquare test. The in-house method correctly identified 179 (97%) and 175 (95%) isolates to the group and species level respectively. In comparison, the VITEK-MS system correctly identified 145 (79%) isolates to the group and species level. The difference between the two methods was statistically significant at both group and species levels. Using the Autoflex II instrument combined with an extraction method instead of whole cell analysis resulted in more reliable viridans streptococci identification. Our results suggest that combining extraction with powerful analysis software and the careful choice of well-identified strains included into the database was useful for identifying viridans streptococci species. [ABSTRACT FROM AUTHOR]

Objectives: Among viridans group streptococcal infective endocarditis (IE), the Streptococcus mitis group is the most common aetiological organism. Treatment of IE caused by the S. mitis group is challenging due to the high frequency of β-lactam resistance, drug allergy and intolerability of mainstay antimicrobial agents such as vancomycin or gentamicin. Daptomycin has been suggested as an alternative therapeutic option in these scenarios based on its excellent susceptibility profile against S. mitis group strains . However, the propensity of many S. mitis group strains to rapidly evolve stable, high-level daptomycin resistance potentially limits this approach.Methods: We evaluated the activity of 6 mg/kg/day daptomycin alone or in combination with gentamicin, ceftriaxone or ceftaroline against two daptomycin-susceptible S. mitis group strains over 96 h in a pharmacokinetic/pharmacodynamic model of simulated endocardial vegetations.Results: Daptomycin alone was not bactericidal and high-level daptomycin resistance evolved at 96 h in both organisms. Combinations of daptomycin + ceftriaxone and daptomycin + ceftaroline demonstrated enhanced killing activity compared with each antibiotic alone and prevented emergence of daptomycin resistance at 96 h. Use of gentamicin as an adjunctive agent neither improved the efficacy of daptomycin nor prevented the development of daptomycin resistance.Conclusions: Addition of ceftriaxone or ceftaroline to daptomycin improves the bactericidal activity against S. mitis group strains and prevents daptomycin resistance emergence. Further investigation with combinations of daptomycin and β-lactams in a large number of strains is warranted to fully elucidate the clinical implications of such combinations for treatment of S. mitis group IE. [ABSTRACT FROM AUTHOR]

Background and Aims: Tooth decay has high prevalence in the world. The use of plant material for the prevention and treatment of this disease for various reasons is considered, due to the increasing resistance of bacteria to antibiotics, the high cost and adverse effects of some chemicals used in dentistry. This study was aimed to determine the antimicrobial effect of alcoholic extract of Pepper (Capsicum annuum) and eggplant skin and cap on the cariogenic streptococci. Materials and Methods: In this study, the antimicrobial activity of ethanol extract of Capsicum annuum and eggplant skin and cap on the cariogenic streptococci, including Streptococcus mutans, Streptococcus sobrinus, and Streptococcus sanguis by microtitre plate method for MIC (Minimum Inhibitor Concentration) was performed. Data were analyzed by one-way analysis of variance using Prism 5 Graph Pad software. Results: MIC for the Capsicum annuum and eggplant skin for Streptococcus mutans was 250 mg/ml (SD=0.052), and for the Streptococcus sobrinus and Streptococcus sanguis was 125 mg/ml (SD=0.027). The MIC for the cap eggplant for Streptococcus mutans and Streptococcus sobrinus was 500 mg/ml (SD=0) and for S. sanguis was getting 125 mg/ml (SD=0.159). Conclusion: This study showed that the herbal extracts of Capsicum annuum and eggplant skin and cap had beneficially antimicrobial effects on all three strains of cariogenic streptococci. [ABSTRACT FROM AUTHOR]

Lung cancer (LC) is the most prevalent cancer worldwide, and responsible for over 1.3 million deaths each year. Currently, LC has a low five year survival rates relative to other cancers, and thus, novel methods to screen for and diagnose malignancies are necessary to improve patient outcomes. Here, we report on a pilot-sized study to evaluate the potential of the sputum microbiome as a source of non-invasive bacterial biomarkers for lung cancer status and stage. Spontaneous sputum samples were collected from ten patients referred with possible LC, of which four were eventually diagnosed with LC (LC+), and six had no LC after one year (LC-). Of the seven bacterial species found in all samples, Streptococcus viridans was significantly higher in LC+ samples. Seven further bacterial species were found only in LC-, and 16 were found only in samples from LC+. Additional taxonomic differences were identified in regards to significant fold changes between LC+ and LC-cases, with five species having significantly higher abundances in LC+, with Granulicatella adiacens showing the highest level of abundance change. Functional differences, evident through significant fold changes, included polyamine metabolism and iron siderophore receptors. G. adiacens abundance was correlated with six other bacterial species, namely Enterococcus sp. 130, Streptococcus intermedius, Escherichia coli, S. viridans, Acinetobacter junii, and Streptococcus sp. 6, in LC+ samples only, which could also be related to LC stage. Spontaneous sputum appears to be a viable source of bacterial biomarkers which may have utility as biomarkers for LC status and stage. [ABSTRACT FROM AUTHOR]

Cutaneous polyarteritis nodosa ( CPAN) is a chronic, indolent, single organ arteritis that generally presents with lower extremity nodules and/or livedo racemosa, accompanied by malaise and arthralgias. CPAN is often triggered by infection, commonly Group A streptococcal species, and is considered an autoimmune reaction. Scarring from surgery and obliterative lymphangiitis from bacterial cellulitis are the causes of lymphedema. Lymphedematous skin is predisposed to autoimmune disorders. Herein we report a 53-year-old woman who developed CPAN restricted to a localized area of the right upper arm-shoulder that had undergone multiple surgeries, complicated by episodes of Streptococcus viridans cellulitis. Clinically, a 15 cm diameter plaque exhibited violaceous, reticulate margins, subtle papules and nodules and central livedo racemosa. Biopsy showed numerous foci of arteritis in active, subacute and reparative stages. In addition, a broad zone of fibrosis replaced the deep dermis-subcutis zone and harbored numerous dilated lymphatic vessels scar lymphedema. Treatment consisted of high potency topical corticosteroids under occlusion; remission after 3 months therapy and follow-up. CPAN primarily affects the lower legs, a region of frequently affected by phlebolymphedema. This report of CPAN localized to an area of scar lymphedema underscores the importance of lymphatic function in the pathogenesis of CPAN. [ABSTRACT FROM AUTHOR]

Background: The clinical features of bacteria endocarditis became atypical when consolidated with other conditions such as tuberculosis (TB). Especially, the symptoms of bacteria endocarditis (BE) which were hidden behind the TB fever often lead to misdiagnosis and missed diagnosis.Case Presentation: A 56-year-old male with thoracic vertebra bone TB history presented with low-grade fever, shortness of breath and cardiac souffle. After conventional antibiotic therapy and strengthen anti-tuberculosis treatment condition did not be improved. Further inspection, there were bacteria endocarditis with the vegetation across the mitral valve. But the other valves were not involved. He was treated with intravenous penicillin for 4 weeks in all including during surgery, and following with oral antibiotic for another 2 weeks. The patient improved clinically eventually.Conclusion: It is the first reported case of isolated thoracic vertebra tuberculosis with valve endocarditis caused by streptococcus viridans and was successfully managed by combination therapy of internal medicine and surgery. It was suggested in tuberculosis patients, the possibility of bacterial endocarditis should be considered when came into fever and unexplained cardiac soufflé (in tuberculosis patients). [ABSTRACT FROM AUTHOR]

Intensive chemotherapy directed against acute myeloid leukemia of childhood is followed by profound neutropenia and high risk for bacterial and fungal infections, including viridans group streptococci as a common cause for gram-positive septicemia. Few retrospective studies have shown the efficacy of various antibiotic prophylactic regimens in children. We retrospectively studied 50 pediatric patients treated on the AML-BFM 2004 protocol between 2005 and 2015 at St. Anna Children's Hospital and assessed the effect of antibiotic prophylaxis on the frequency of febrile neutropenia and bacterial sepsis. Fifty pediatric patients underwent 199 evaluable chemotherapy cycles. Viridans sepsis occurred after none of 98 cycles with prophylactic administration of teicoplanin/vancomycin in comparison to 12 cases of viridans sepsis among 79 cycles without systemic antibacterial prophylaxis (0 vs. 15 %, p < 0.0001). In addition, there were significantly fewer episodes of febrile neutropenia in the teicoplanin/vancomycin group (44 % vs. no prophylaxis 82 %, p < 0.0001). Severity of infection seemed to be worse when no antibiotic prophylaxis had been administered with a higher rate of intensive care unit treatment (0/98, 0 %, vs. 4/79, 5 %, p = 0.038). So far, no increase of vancomycin-resistant enterococcus isolates in surveillance cultures was noticed. Antibiotic prophylaxis with teicoplanin (or vancomycin) appears safe and feasible and resulted in eradication of viridans sepsis and decreased incidence of febrile neutropenia in pediatric AML patients. The possibility to administer teicoplanin on alternate days on an outpatient basis or at home could contribute to patient's quality of life and decrease health care costs. [ABSTRACT FROM AUTHOR]

Introduction: The Aloysia citriodora plant from the family of Verbenaceae has many uses in traditional medicine. The aim of the current study was to determine the effects of the aqueous and ethanolic extracts of A. citriodora on Streptococcus mutans and Streptococcus sobrinus, which cause tooth decay. Methods: This 2016 study was performed on standardized strains of S. mutans PTCC1683 and S. sobrinus PTCC1601 and clinical isolates. Twenty clinical samples were obtained from the dental caries of children admitted to the pediatric ward at the Faculty of Dentistry of Babol University of Medical Sciences (Babol, Iran). The aqueous and ethanolic extracts of A. citriodora leaves were prepared in several concentrations ranging from 625-20,000 µg/ml. These concentrations of the extracts were applied to the bacteria by disk diffusion, agar well diffusion, and macrotube dilution. The antibacterial effects of amoxicillin and chlorhexidine digluconate 0.2% (CHX) were also carried out. Data were analyzed by SPSS version 18 software using independent-samples t-test. Results: Streptococcus spp. was successfully isolated from nine out of 20 (45%) specimens. Of the 9 positive samples cultured, 8 (88.8%) were S. mutans and 1 was S. sobrinus (11.2%). No inhibitory zone was observed around the disks and wells containing all concentrations of A. citriodora extracts. The minimum concentrations for inhibition of growth (MIC) resulted in turbidity in all tubes and were negative except for the control tubes. Inhibition zones were observed for amoxicillin and CHX disks (p < 0.001). Conclusion: This study found that all studied bacteria were resistant to both types of the extracts; therefore, they are not a suggested replacement for chemical agents in mouthwash. It also shown that CHX is less effective than amoxicillin. [ABSTRACT FROM AUTHOR]

We report a case of a 46-year-old female who developed infectious crystalline keratopathy (ICK) after Descemet's stripping endothelial keratoplasty (DSEK). She underwent DSEK for pseudophakic corneal edema in her left eye. Ten weeks after the procedure, the patient presented with complaints of blurred vision, redness in eye, and ocular pain. Slit lamp examination revealed white nonsuppurative branching deep stromal infiltrate. Microscopic examination of the Gram-stained smear showed gram-positive cocci. Streptococcus viridans was isolated on cultures. Isolated organism was sensitive to linezolid. Based on antibiotic sensitivity report, fortified linezolid (0.2%) eye drop was started on hourly basis. After 10 weeks of topical fortified linezolid (0.2%) therapy, complete resolution of infiltrate with significant corneal scarring and vascularization was seen. Infectious crystalline keratopathy can occur after DSEK. [ABSTRACT FROM AUTHOR]

Background: The incidence of bacteremia caused by Gram-negative bacteria has increased recently in febrile neutropenic patients with the increase of antibiotic-resistant Gram-negative bacterial infections. This study aimed to identify the distribution of causative bacteria and the proportion of antibiotic-resistant bacteria in bacteremia diagnosed in febrile neutropenic children. Materials and Methods: The medical records of febrile neutropenic children diagnosed with bacteremia between 2010 and 2014 were retrospectively reviewed. The causative bacteria and proportion of antibiotic-resistant bacteria were investigated and compared yearly during the study period. The clinical impact of antibiotic-resistant bacterial infections was also determined. Results: A total of 336 bacteremia episodes were identified. During the entire study period, 181 (53.9%) and 155 (46.1%) episodes were caused by Gram-negative and Gram-positive bacteria, respectively. Viridans streptococci (25.9%), Klebsiella spp. (16.7%), and Escherichia coli (16.4%) were the most frequent causative bacteria. The overall distribution of causative bacteria was not significantly different annually. Antibiotic-resistant bacteria were identified in 85 (25.3%) episodes, and the proportion of antibiotic-resistant bacteria was not significantly different annually. Extended-spectrum β-lactamase-producing E. coli and Klebsiella spp. were most common among antibiotic-resistant Gram-negative bacteria, and they accounted for 30.6% (n = 34) of the identified E. coli and K. pneumoniae. Methicillin-resistant coagulase-negative staphylococci were most common among antibiotic-resistant Gram-positive bacteria, and it accounted for 88.5% (n = 23) of the identified coagulase-negative staphylococci. Antibiotic-resistant bacterial infections, especially antibiotic-resistant Gram-negative bacterial infections, caused significantly higher mortality due to bacteremia compared with non-antibiotic-resistant bacterial infections (P <0.001). Conclusion: Recently, Gram-negative bacteria caused more bacteremia cases than Gram-positive bacteria in febrile neutropenic children, and antibiotic-resistant Gram-negative bacterial infections increased. Antibiotic-resistant bacterial infections caused poorer prognosis compared with non-antibiotic-resistant bacterial infections, and therefore, continuous surveillance for changing epidemiology of antibiotic-resistant bacterial infections and their clinical impact is necessary. [ABSTRACT FROM AUTHOR]

Type IA topoisomerases represent promising antibacterial drug targets. Data exists suggesting that the two bacterial type IA topoisomerase enzymes—topoisomerase I and topoisomerase III—share an overlapping biological role. Furthermore, topoisomerase I has been shown to be essential for the survival of certain organisms lacking topoisomerase III. With this in mind, it is plausible that topoisomerase I may represent a potential target for selective antibacterial drug development. As many reported bacterial topoisomerase I purification protocols have either suffered from relatively low yield, numerous steps, or a simple failure to report target protein yield altogether, a high-yield and high-purity bacterial topoisomerase I expression and purification protocol is highly desirable. The goal of this study was therefore to optimize the expression and purification of topoisomerase I from Streptococcus mutans , a clinically relevant organism that plays a significant role in oral and extra-oral infection, in order to quickly and easily attain the requisite quantities of pure target enzyme suitable for use in assay development, compound library screening, and carrying out further structural and biochemical characterization analyses. Herein we report the systematic implementation and analysis of various expression and purification techniques leading to the development and optimization of a rapid and straightforward protocol for the auto-induced expression and two-step, affinity tag purification of Streptococcus mutans topoisomerase I yielding >20 mg/L of enzyme at over 95% purity. [ABSTRACT FROM AUTHOR]

Background: In the management of bacteremia, positive repeat blood cultures (persistent bacteremia) are associated with increased mortality. However, blood cultures are costly and it is likely unnecessary to repeat them for many patients. We assessed predictors of persistent bacteremia that should prompt repeat blood cultures.Methods: We conducted a retrospective cohort study of bacteremias at an academic hospital from April 2010 to June 2014. We examined variables associated with patients undergoing repeat blood cultures, and with repeat cultures being positive. A nested case control analysis was performed on a subset of patients with repeat cultures.Results: Among 1801 index bacteremias, repeat cultures were drawn for 701 patients (38.9 %), and 118 persistent bacteremias (6.6 %) were detected. Endovascular source (adjusted odds ratio [aOR], 7.66; 95 % confidence interval [CI], 2.30-25.48), epidural source (aOR, 26.99; 95 % CI, 1.91-391.08), and Staphylococcus aureus bacteremia (aOR, 4.49; 95 % CI, 1.88-10.73) were independently associated with persistent bacteremia. Escherichia coli (5.1 %, P = 0.006), viridans group (1.7 %, P = 0.035) and β-hemolytic streptococci (0 %, P = 0.028) were associated with a lower likelihood of persistent bacteremia. Patients with persistent bacteremia were less likely to have achieved source control within 48 h of the index event (29.7 % vs 52.5 %, P < .001), but after variable reduction, source control was not retained in the final multivariable model.Conclusions: Patients with S. aureus bacteremia or endovascular infection are at risk of persistent bacteremia. Achieving source control within 48 h of the index bacteremia may help clear the infection. Repeat cultures after 48 h are low yield for most Gram-negative and streptococcal bacteremias. [ABSTRACT FROM AUTHOR]

Infectious complications in chronic lymphocytic leukemia (CLL) represent a major cause of morbidity and mortality. The aim of the study was to investigate temporal trends in bloodstream infections (BSIs) among patients with CLL. Individuals with blood cultures were linked to Swedish Cancer Registry and divided into three time periods (1988-1993, 1994-1999, and 2000-2006) according to year of CLL diagnosis. CLL patients (n = 275) with 1092 blood culture episodes were identified and linked to the nationwide Cause of Death Registry and Swedish Patient Registry (to retrieve information on splenectomies). The most common causes of BSI among CLL patients were Escherichia coli (11/43, 15/78, and 9/33), Streptococcus pneumoniae (7/43, 13/78, and 6/33), Pseudomonas aeruginosa (2/43, 8/78, and 3/33), Staphylococcus aureus (1/43, 6/78, and 6/33), and Viridans streptococci (5/43, 6/78, and 2/33). Coagulase-negative staphylococci was the most frequent microorganism found in blood cultures (22/70, 23/106, and 5/41, respectively) but is a frequent contaminant. Based on the largest study to date on BSI in CLL patients, we found a stable proportion of Gram-positive to Gram-negative bacteria and no temporal change of distribution was observed for BSIs 1988-2006. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: The development of resistance to penicillin in Viridans Group Streptococci (VGS) during therapy has been reported. However, the in vitro development of resistance to penicillin or other antimicrobial agents in VGS is mostly overlooked and rarely reported. Aim & Objectives: To induce in vitro resistance to penicillin in VGS and to study its effect on susceptibility pattern of other structurally related (Beta-lactams) and unrelated antimicrobial agents. Material and Methods: Four isolates of VGS susceptible to all antimicrobial agents were manipulated in vitro to induce resistance to penicillin by sequential exposure to increasing concentrations of penicillin. Results: Increase in MIC values of penicillin from 0.06-0.12 µg/ml to 2-32 µg/ml was observed indicating development of resistance to penicillin. A significant increase in Minimum Inhibitory Concentration (MIC) values of ampicillin and slight increase in MIC values of other antimicrobial agents in some isolates was also noted. Conclusions: Exposure to increasing concentrations of penicillin can promote the development of resistance to penicillin and cross-resistance to other antimicrobial agents suggesting its mutagenic role. [ABSTRACT FROM AUTHOR]

Acute otitis media and otitis media with effusion (OME) are the main causes of hearing impairment in children which require proper treatment, mainly antibiotic therapy. Patients whom were appropriate candidates for adenoidectomy were divided into two groups regarding the presence of middle ear effusion. Adenoid tissue specimens were cultured in both groups and the bacterial flora and anti-microbial resistance pattern were determined. 72 patients were studied, 42 % had OME while 58 % did not. The following bacteria were isolated and cultured from both groups with no meaningful difference in prevalence: Streptococcus viridans ( p = 0.265), Staphylococcus aureus ( p = 0.72), H. influenza ( p = 0.806), Entrococcus. spp (0.391), Streptococcus pneumonia ( p = 0.391), nonhemolytic Streptococcus ( p = 0.230). Bacterial sensitivity was similar for Amoxicillin-clavulanate ( p = 0.935), Amoxicillin ( p = 0.935), Cephalexin ( p = 0.806), Cefixime ( p = 0.391) and Azithromycin in both groups. The two groups showed no meaningful difference considering the bacterial flora of nasopharynx and their sensitivity. Bacteria in both groups were sensitive to Amoxicillin and Amoxicillin-clavulanate and resistant to Azithromycin, Cefixime and Cephalexin. [ABSTRACT FROM AUTHOR]