Viridans Group Streptococci Research Articles

Bloodstream Infections in Children With Sickle Cell Disease: 2010-2019.

Children with sickle cell disease (SCD) are at increased risk for bloodstream infections (BSIs), mainly because of functional asplenia. Immunizations and antibiotic prophylaxis have reduced the prevalence of invasive bacterial infections, but contemporary analysis of BSI in children with SCD is limited. We conducted a retrospective cohort study of children aged <18 years with SCD who had blood cultures collected at our institution from 2010 to 2019 to identify BSI. Probable contaminant organisms were identified and not included as BSI. We calculated the annual incidence of BSI at our institution with 95% confidence intervals (CIs) and used multivariate logistic regression to evaluate associations. There were 2694 eligible patients with 19 902 blood cultures. Excluding repeated cultures and contaminant cultures, there were 156 BSI episodes in 144 patients. The median age at BSI was 7.5 years. The average incidence rate of BSI was 0.89 per 100 person-years (95% CI 0.45-1.32). The most common pathogens were Streptococcus pneumoniae (16.0%), Streptococcus viridans group (9.0%), Escherichia coli (9.0%), Staphylococcus aureus (7.7%), Bordetella holmesii (7.7%), Haemophilus influenzae (7.1%), and Salmonella species (6.4%). Odds of BSI were higher with sickle cell anemia genotypes (odds ratio [OR] 1.88; 95% CI 1.20-2.94) and chronic transfusions (OR 2.66; 95% CI 1.51-4.69) and lower with hydroxyurea (OR 0.57; 95% CI 0.39-0.84). BSI remains a risk for children with SCD. Overall incidence, risk factors, and spectrum of pathogens are important considerations to guide prevention and empirical treatment of suspected infection in SCD.

Antibiotic prophylaxis with amoxicillin to prevent infective endocarditis in periodontitis patients reconsidered: a narrative review.

To discuss first, the adequacy of the antibiotic prophylaxis regimen currently recommended for the prevention of infective endocarditis in periodontitis patients, and second, preventive measures to decrease the rate of bacteraemia after periodontal treatment. A bibliographic literature search identifying clinical trials between January 1990 and January 2021, focusing on microorganisms in bacteraemia after periodontal treatment and bacteria in infective endocarditis, was performed. Two reviewers independently identified and screened the literature by systematically searching in Medline/Premedline, EMBASE and Cochrane Library. Two hundred and seventy articles were identified, of which twenty-three met the inclusion criteria. Bacteraemia rates after periodontal treatment ranged from 10-94% in the investigated patients. Mainly oral pathogens related to infective endocarditis, such as viridans group streptococci (up to 70%) and HACEK group pathogens (e.g., Aggregatibacter actinomycetemcomitans), were detected. But typical oral and periodontopathogenic species, such as Porphyromonas spp. (P.s gingivalis) (up to 50%), Actinomyces spp. (up to 30%) and Fusobacterium spp. (up to 30%), which do not usually cause infective endocarditis, were also found. Infective endocarditis episodes that might have been in association with a dental treatment were mainly caused by viridans group streptococci. Prophylactic measures like rinse application of chlorhexidine, povidone-iodine or essential oils, diode laser or systemic antibiotic prescription were described as decreasing the bacteraemia rate after periodontal interventions to 5-70%. The currently recommended systemic antibiotic prophylaxis with amoxicillin before periodontal treatment in high-risk cardiovascular patients still covers the most common oral bacteria causing infective endocarditis, namely viridans group streptococci, and therefore seems adequate in this context. Since bacteraemia, not infective endocarditis, is the endpoint in most studies, the causality between bacteraemia after periodontal treatments and infective endocarditis remains difficult to elucidate. Until more evidence is available regarding this, adherence to current guidelines for antibiotic prophylaxis in patients at high risk for infective endocarditis undergoing periodontal treatment remains recommended.

1077. In Vitro Activity of Delafloxacin Agent Against Bacterial Isolates Recovered from Patients with Cancer

Abstract Background Fluoroquinolones have been used for infection prevention in patients with cancer (PWC). They are active against many Gram-negative bacilli (GNB) but are less active against Gram-positive organisms (GPO). Quinolone resistance is increasing and many institutions are using combination regimens for antimicrobial prophylaxis. We evaluated the in vitro activity of delafloxacin (DLX), a novel fluoroquinolone, and selected comparators against 560 bacterial isolates from PWC. Methods Isolates were from recent blood cultures. Susceptibility testing and time kill studies (TKS) were performed using CLSI approved methodology. Appropriate ATCC control strains were used. We calculated MIC50, MIC90, MIC ranges and percent susceptibility using FDA breakpoints when available. TKS were performed on 4 streptococcus mitis isolates at concentrations of MIC, 4x MIC, and 8x MIC. Results DLX was more active than ciprofloxacin (CIP) and levofloxacin (LEV) against methicillin-susceptible (MSSA), and resistant (MRSA) S. aureus, coagulase-negative staphylococci (CoNS), and viridans group streptococci (VGS), and had similar activity against beta-hemolytic streptococci. It also had low MICs for Bacillus species (SPP.), Listeria monocytogenes, Micrococcus spp., and Rothia spp. Overall GPO susceptibility was 73% to DLX, 42% to CIP, and 52% to LEV. The activity of DLX against Enterobacterales was similar to CIP and LEV. All 3 agents had moderate activity against Citrobacter spp., and non-MDR P. aeruginosa. Notably, all 3 quinolones had poor activity against E. coli, P. mirabilis, and MDR P. aeruginosa, all common pathogens in PWC. All 3 had low MICs for Acinetobacter spp. DLX and LEV achieved peak bactericidal activity at 6-8 h against all 4 VGS isolates (maximum activity at 8x MIC) but this was not always sustained at 24 h. Table 1. Percent Susceptibility of selected Gram-positive isolates to Delafloxacin, Ciprofloxacin and Levofloxacin Table 2. Percent Susceptibility of selected Gram-negative isolates to Delafloxacin, Ciprofloxacin and Levofloxacin Figure 1. Bactericidal Activity of DLX at 1x , 4x, and 8x MIC against VGS - Time Kill Study Conclusion DLX is more active than CIP and LEV against many GPO from PWC (including S. aureus and VGS), but like these agents there are significant gaps in its coverage against GNB. It is probably not suitable as a single agent for antimicrobial prophylaxis in high-risk PWC. The current practice of combining a quinolone with a beta-lactam probably still represents the best option in PWC who need prophylaxis. Disclosures Kenneth Rolston, MD, Tetraphase Pharmaceuticals (Grant/Research Support)

683. Epidemiology and Microbiology of Infective Endocarditis: A Six Year Experience

BackgroundThe epidemiology and microbiology of infective endocarditis (IE) is not well studied in India. Studies from developed countries report a culture positivity of more than 90% in IE, while in India it has been lower (40–70%). Viridans Group Streptococci (VGS) are the commonest organism identified from previous Indian studies. The state of Kerala in India has better health indicators compared to the rest of India and it is likely that the epidemiology of IE in Kerala may be different. We therefore studied the epidemiology and microbiology of IE in patients admitted to a tertiary care hospital in Kerala over six years (2015 – 2020).MethodsAn electronic medical record search was conducted to identify patients who satisfied definite or possible IE criteria as per modified Duke criteria. Three sets of blood cultures were sent in BacT/Alert blood culture bottles for all suspected cases of IE. Blood culture was done using BacT-ALERT 3D automated microbial detection system (bioMérieux, France) and organisms were identified using VITEK-2 system. Transthoracic echocardiogram was done for all patients and a transoesophageal echocardiogram was done when indicated.Results70 patients satisfied the inclusion criteria. Majority (70.4%) were male; mean age was 50.7±16.3 years. 71% patients had underlying valvular heart disease. Diabetes mellitus (53.5%) was the most common comorbidity followed by chronic kidney disease (18.3%). Mitral valve was most commonly affected (53.5%) followed by the aortic valve (19.7%) and both valves were involved in 5.7%. Right sided valves were affected in 8.5%. Prosthetic valve endocarditis accounted for 10% of cases. No echocardiographic evidence of endocarditis was seen in 11.3%. Blood culture was positivity was 64.8%. Staphylococcus aureus (20%) was the most common organism isolated, followed by VGS (17.1%). 50% of the Staphylococcus aureus isolated were methicillin resistant. Among 57 patients in whom an outcome was recorded, mortality was 12.2%.Microbiology profile of infective endocarditis ConclusionStaphylococcus aureus has emerged as the most common etiological agent of IE in our study, in contrast to previous studies from India where VGS was predominant. The high prevalence of MRSA is of concern.Disclosures All Authors: No reported disclosures

238. Antimicrobial Activity of Dalbavancin against Gram-Positive Bacteria Isolated from Patients with Bone and Joint Infections from the United States (US) and Europe (2016-2020): Results from the International Dalbavancin Evaluation of Activity (IDEA) Program

238. Antimicrobial Activity of Dalbavancin against Gram-Positive Bacteria Isolated from Patients with Bone and Joint Infections from the United States (US) and Europe (2016-2020): Results from the International Dalbavancin Evaluation of Activity (IDEA) Program

1260. In Vitro Activity of Eravacycline Against Clinically Significant Bacteria Isolated from Patients with Cancer

Abstract Background Bacterial infections are common in patients with cancer (PWC). Many bacteria have developed resistance to currently used antibiotics, posing therapeutic challenges. we evaluated the in vitro activity of eravacycline (a novel fluorocycline) against clinical bacteria recently (2018-2019) isolated from PWC. Methods All 565 isolates tested were from blood cultures. CLSI approved broth microdilution method was used. Appropriate ATCC controls were included. MIC50, MIC90, MIC ranges and percent susceptibility calculations were made using FDA breakpoints when available. Eravacycline susceptibility breakpoint for most Gram-positive organisms (GPO) is ≤ 0.06 mg/L and for Enterobacterales is ≤ 0.5 mg/L. Results Eravacycline had potent activity against Staphylococcus aureus (methicillin-susceptible and resistant strains), oxacillin-susceptible coagulase-negative staphylococci (CoNS) including Staphylococcus lugdunensis, viridans group streptococci, beta-hemolytic streptococci. Streptococcus pneumoniae. Bacillus spp., Corynebacterium spp., and Micrococcus spp. It was slightly less active against oxacillin-resistant CoNS, and vancomycin-susceptible Enterococcus faecalis (MIC90 0,125 mg/L respectively) and was moderately active against vancomycin-resistant Enterococcus faecium (MIC50, 0.06, and MIC90. 0.25 mg/L). Eravacycline had potent activity against Escherichia coli (including ESBL producing strains), Citrobacter spp., and non-ESBL Klebsiella spp. Eravacycline inhibited 83% of ESBL positive K. pneumoniae, 83% of Enterobacter cloacae, and 80% of carbapenem-resistant Enterobacteriaceae (CRE) isolates at ≤ 0.5 mg/L. The presence of ESBLs increased MIC90 value no more than 2 fold. Eravacycline was also active against many non-fermentative GNB (Achromobacter spp., Acinetobacter spp., Sphingomonas paucimobilis, and Stenotrophomonas maltophilia). Table 1. Percent Susceptibility of Gram-negative isolates to Eravacycline Table 2. Percent Susceptibility of Gram-positive isolates to Eravacycline Conclusion Our data demonstrate that eravacycline has promising activity against clinically significant bacterial pathogens isolated from PWC including many drug resistant strains such as CRE and non--fermentative GNB. it might play an important role in the treatment of bacterial infections in PWC and warrants clinical evolution in this setting. Disclosures Samuel L. Aitken, PharmD, MPH, BCIDP, Melinta Therapeutoics (Individual(s) Involved: Self): Consultant, Grant/Research Support Kenneth Rolston, MD, Tetraphase Pharmaceuticals (Grant/Research Support)

267. Therapeutic Management of Bacterial Brain Abscess: An Overview of Diagnosis and Outcomes

BackgroundWe describe and compare the clinical, diagnostic evaluation and outcomes of patients who underwent therapeutic management for pyogenic brain abscess.MethodsWe retrospectively reviewed adults who presented with pyogenic brain abscess from January 1, 2009 through June 30, 2020.Results231 patients were identified during the study period. Sixty-one (26.4%) patients received antibiotic therapy alone, and 170 (73.6%) had a combination of antibiotic therapy and surgical intervention. The median age for the medical and combined therapy group was 59 years and 58 years, respectively. Patients who received medical treatment had a higher prevalence of infective endocarditis than those who received combined therapy (6.6% vs. 0.6%; P=0.005). The medical therapy group was more likely to have brain MRI and cranial CT than the patients with combined therapy (75.4% vs. 63.5%; P=0.041). Midline shift (11.5% vs. 31.2%; P=0.002), a single (21% vs. 83%; P=0.001) and greater size (1.4 cm vs. 2.5 cm; P=0.007) brain abscess was significant when comparing medical vs. surgically managed abscess. Stereotactic surgical technique was the preferred diagnostic approach for the medical group (65.6% vs. 46.5%; P=0.010), and excision/craniotomy for the combined group (31.1% vs. 53.5%; P=0.002). Streptococcus viridans group was the predominant organism (32.8% and 25.9%; P=0.30). Compared to those who received combined therapy, patients with medical therapy alone were most likely to receive cephalosporin (72.1% vs. 41.2%; P=< 0.0001), vancomycin (23% vs. 12.4%; P=0.047) and metronidazole (27.9% vs. 14.7%; P=0.022). In both groups, median duration of antimicrobial therapy was 42 days (P=0.12). Patients with medical therapy alone had a higher mortality rate (18% vs. 7.1%; p=0.014) but less neurologic sequelae (21.3% vs. 30.6%; P=0.16) compared with combined therapy. Medical Management. Organism isolated in the medical management group Combined Management. Organism isolated in the combined management group Demographic and Clinical Characteristics of Patients with Brain Abscess who Underwent Therapeutic Management ConclusionMost patients with pyogenic brain abscess had no identified risk factors, and brain MRI and cranial CT were the diagnostic imaging modalities of choice. Compared to those who received medical therapy alone, patients with combined treatment had a single and greater size fluid collection with the presence of midline shift. A prompt combined surgical and medical approach with prolonged antimicrobial therapy can cure the infection.Outcomes of Patients with Bacterial Brain Abscess Radiologic and Surgical Diagnosis of Patient with Brain Abscess who Underwent Therapeutic Management Disclosures John C. O’Horo, Sr., MD, MPH, Bates College and Elsevier Inc (Consultant) M. Rizwan Sohail, MD, Medtronic Inc., Philips, and Aziyo Biologics, Inc (Consultant) M. Rizwan Sohail, MD, Aziyo Biologics (Individual(s) Involved: Self): Consultant; Philips (Individual(s) Involved: Self): Consultant

195. Duration of Therapy for Streptococcal Bacteremia

BackgroundShorter durations have shown similar clinical outcomes as longer durations for uncomplicated (source-controlled) Gram-negative bloodstream infections (BSI). There is limited data on the outcomes of patients with non-pneumococcal streptococcal BSI receiving shorter durations of therapy compared to usual durations. MethodsThis was a retrospective, multicenter study of adults hospitalized between January 2018 and March 2019 with ≥ 1 blood culture positive for Streptococcus spp. Exposed patients were those who received ≤ 10 days of antibiotics (i.e., short course therapy) and unexposed patients were those who received 11-21 days of antibiotics (i.e., prolonged course therapy). Patients were excluded if they had S. pneumoniae BSI, suspected contamination, did not receive or complete therapy, or treated for > 21 days. The primary outcome was a composite of recurrent bacteremia with the same pathogen, hospital readmission, or all-cause mortality, all within 30 days from completing therapy. The odds of achieving the primary outcome was compared between exposed and unexposed patients using multivariable logistic regression analysis. ResultsA total of 176 patients met eligibility criteria. 35 (20%) received a short course (median 8 days) and 141 (80%) received a prolonged course (median 15 days) of antibiotic therapy. Baseline characteristics were similar between short and long course groups. The most common pathogens were viridans group streptococci (22%) and S. agalactiae (23%). The most common BSI source was skin and soft tissue infection (SSTI) (40%). The primary outcome occurred in 26% (9/35) and 23% (33/141) of patients in the short course and prolonged course groups, respectively (p = 0.774). The proportion of patients in the short course and prolonged course groups who experienced recurrent BSI, hospital readmission, or all-cause mortality were also non-significant. After adjusting for receipt of an infectious diseases consult, Pitt bacteremia score, and SSTI source, the adjusted odds of meeting the composite outcome remained unchanged (aOR 1.41, 95% CI 0.55 – 3.61, p = 0.466). Table 1. Cohort Characteristics Table 2. Source/Microbiology Table 3. Outcomes ConclusionApproximately a week of antibiotic therapy may be associated with similar clinical outcomes as longer antibiotics courses in patients with uncomplicated streptococcal BSI. Disclosures Kate Dzintars, PharmD, Nothing to disclose Sara E. Cosgrove, MD, MS, Basilea (Individual(s) Involved: Self): Consultant Pranita Tamma, MD, MHS, Nothing to disclose

185. Trends in Clinical Presentation and Antibiotic Resistance of Viridans Group Streptococci Bloodstream Infections in Immunocompromised Children

BackgroundLevofloxacin prophylaxis (LVXp) is recommended in children with severe neutropenia from underlying malignancy or hematopoietic cell transplantation (HCT). The impact of LVXp on the epidemiology of viridans group streptococcus bloodstream infections (VGS-BSI) is unknown. At our center, LVXp was prescribed to high-risk children with expected prolonged neutropenia (ANC < 100, > 7 days) as part of a clinical trial (2013-17) and routinely since November 2018. We aim to describe our local epidemiology, antibiotic susceptibilities, and clinical outcomes of VGS-BSI over time.MethodsVGS-BSI from 1/1/10-1/31/21 were identified via the laboratory database. Clinical data of patients followed at NCH with underlying malignancy, severe neutropenia, or HCT were extracted from the electronic health record. Available VGS isolates were subcultured, species identification confirmed by MALDI-ToF or 16s rDNA sequencing and susceptibility to penicillin (PCN), cefepime (CEF), vancomycin (VAN), and LVX performed via Etest per CLSI M100 guidelines. Non-parametric descriptive statistics were applied.ResultsOver a 10-yr period, 111 VGS-BSI occurred in 93 patients (Table 1); 15 (16%) patients had ≥ 2 VGS-BSI. 80 (86%) patients had fever and neutropenia (F&N); 26 (28%) required ICU care for vasopressors (N=17, 18%) or mechanical ventilation (N=10, 11%). Most VGS isolates were S. mitis/oralis group. In total, 15 (16%) patients received LVXp ≤ 6 months before VGS-BSI; 9 (10%) had breakthrough VGS-BSI while receiving LVXp and all isolates were LVX resistant. Figure 1 shows susceptibilities: overall, 24% of isolates had frank resistance to PCN, 19% CEF, 13% LVX; all were VAN susceptible. When evaluating for changes in susceptibilities over time, there was a significant difference in the proportion of LVX-resistant isolates (p=0.009, Cochran-Armitage χ 2), but not CEF (p=0.08) or PCN (p=0.86).Table 1. Demographic and Clinical Characteristics of Immunocompromised Children with Viridans Group Streptococci Bloodstream Infections (VGS-BSI) Figure 1. Antimicrobial Susceptibility Profile of Viridans Group Streptococci Bloodstream Isolates from Immunocompromised children, 2010-2021. Of 111 VGS-BSI reported during the study period from immunocompromised children, 83 (75%) were available for further testing. Antimicrobial susceptibility testing was performed by Etest and interpreted per CLSI M100. Susceptibility profiles to penicillin (PCN), cefepime (CEP) and, levofloxacin (LVX) are shown. Abbreviations: S—susceptible, I—intermediate, R—resistant. ConclusionBreakthrough, LVX-resistant VGS-BSI occurred in 10% of patients, most frequently in children with AML or HCT. Over time, there was a trend towards increased LVX resistance in the cohort. Routine antimicrobial testing and ongoing monitoring for emergence of resistance are warranted to inform local prophylaxis and empirical antibiotic strategies for high-risk children with F&N.Disclosures Monica I. Ardura, DO, MSCS, Shire (Grant/Research Support)

Life-threatening complications of streptococcal sepsis: a PICU contemporary series

BackgroundLife-threatening streptococcal sepsis nowadays represents an uncommon event in previously healthy infants and children. Critically ill patients suffering from severe streptococcal sepsis complications may present with pre-antibiotic era clinical pictures and require a timely clinical approach to achieve restitutio ad integrum.ResultsWe report a series of four patient groups affected by an uncommon life-threatening streptococcal sepsis, each of them exhibiting some distinct features. Streptococcus Agalactiae sepsis was associated with cerebral thrombotic/ischaemic lesions, whereas severe cardiogenic shock was prominent in the Streptococcus Viridans group; Streptococcus Faecalis and β-hemolytic group A Streptococcus patients mostly reported lung complications.ConclusionsPrevious antibiotic treatments should not delay aggressive treatment in the intensive care setting. Early diagnostic suspicion, as well as appropriate and aggressive treatment provided within an intensive care setting are crucial for the clinical outcome.

Performance assessment of ASTA MicroIDSys, a new matrix assisted laser desorption ionization-time of flight mass spectrometry system, for identification of viridans group streptococci.

The performance of the ASTA MicroIDSys system (ASTA), a new matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) system, was evaluated for the identification of viridans group streptococci (VGS) and compared with the results obtained with the Bruker Biotyper system (Bruker Daltonics). A total of 106 Streptococcus reference strains belonging to 24 species from the bacterial strain bank was analyzed using the two MALDI-TOF MS systems. Of the 106 reference strains tested, ASTA MicroIDSys and Bruker Biotyper correctly identified 84.9% and 81.1% at the species level, 100% and 97.2% at the group level and 100% and 98.1% at the genus level, respectively. The difference between the two systems was not statistically significant (P = 0.289). Out of 24 species, 13 species were accurately identified to the species level with 100% accurate identification rates with both systems. The accurate identification rates at the species level of ASTA MicroIDSys and Bruker Biotyper were 100% and 87.5% for the S. anginosus group; 78.4% and 73.5% for the S. mitis group; 91.7% and 91.7% for the S. mutans group; and 100% and 100% for the S. salivarius group, respectively. The ASTA MicroIDSys showed an identification performance equivalent to that of the Bruker Biotyper for VGS. Therefore, it would be useful for the identification of VGS strains in clinical microbiology laboratories.

Clinical and Microbiological Characteristics of Infective Endocarditis at a Cardiac Center in Saudi Arabia

BackgroundInfective endocarditis (IE) is a serious disease with complex pathology and significant mortality. Little information is known regarding clinical and microbiological characteristics in Saudi Arabia. This study surveyed these characteristics at a Cardiac Center in Riyadh, Saudi Arabia over a period of 5 years.MethodsThis retrospective study was done on all infective endocarditis (IE) patients admitted to Prince Sultan Cardiac Center between January 1, 2015, and December 31, 2019. Clinical characteristics, microbiological results, management, and outcomes were assessed.ResultA total of 340 cases of infective endocarditis were identified over the study period.Most patients (64%) were 50 years old or above, and 67% were males. Fever was the most common clinical presentation, and a murmur was audible in a fifth of patients. Blood cultures were positive in 177 (52%) cases. The most common organisms were Staphylococcus aureus, coagulase negative Staphylococcus and viridans group Streptococcus. Most common microbiological organisms causing native valve endocarditis were viridans group Streptococcus (32%) followed by methicillin-susceptible Staphylococcus aureus (21%), and for prosthetic valve endocarditis they were coagulase negative Staphylococcus (32%) followed by methicillin-susceptible Staphylococcus aureus (23%), the most common causes of culture negative endocarditis were Q-fever and brucellosis. Predisposing cardiac conditions were present in 127 (37%) patients, most commonly rheumatic heart disease and congenital heart disease. Surgical intervention was done in 26% of cases, with an overall in-hospital mortality rate of 6.76%.ConclusionWe demonstrate the epidemiological, clinical, and microbiological profile of infective endocarditis in a tertiary care cardiac center in Saudi Arabia. It gives information concerning the prevalence of responsible organisms. This information will be helpful in assessing patients with suspected IE and in planning management of cases knowing the relative frequency of types of microorganisms encountered.

Impact of frailty on elderly patients with infective endocarditis

Abstract Introduction Frailty studies focused on patients with infective endocarditis (IE) are scarce and its potential impact on patient outcomes is not well known. The aim of this study is to describe the clinical profile and prognosis of elderly patients with IE, comparing patients who met the frailty criteria versus those who did not. Methods A total of 121 cases of confirmed IE were consecutively collected in three tertiary hospitals between 2017 and 2019. The patients were classified into two groups: Group I (n=49), patients with IE who met the Frail criteria for frailty, and Group II (n=72), those patients without frailty by this scale. Results The median age of our cohort was 77 years (69–82), and 62.8% were men. Frail patients were older than those in Group II, as shown in Table 1. Regarding comorbidity, chronic anemia (40.8% vs 25%; p&amp;lt;0.060) was more common in Group I, as well as rheumatic manifestations at admission (12.2% vs 1.4%; p=0.014). The most frequently isolated microorganisms were S. aureus (n=25), coagulase negative staphylococci (n=25), viridans group streptococci (n=14), and enterococci (n=14). Enterococci (16.3% vs 8.3%, p=0.177) and non-viridans streptococci (10.2% vs 2.8%); p=0.086) were more frequent in frail patients. Vegetation (79.6% vs 80.6%; p=0.896) and periannular complications (24.5% vs 29.2%; p=0.571) were similar in both groups. No significant differences were found regarding the location of the infection. The incidence of in-hospital complications was similar between both groups. Frail patients underwent surgery less frequently than those in Group II, and had higher predicted mortality on surgical risk scale scores. However, the percentage of patients who met the surgical criteria and were considered inoperable was similar (33.3% vs 26.2%; p=0.415). In-hospital mortality was similar in both groups. When analyzing in-hospital mortality according to the therapeutic strategy in Group I, a mortality of 34.5% was observed in frail patients with conservative medical treatment, compared to 47.1% in those patients who underwent surgery in the same group. One third of our patients received outpatient antibiotic treatment, being significantly more frequent in Group I (39.6% vs 29.0%; p=0.232). Conclusions The elderly patients with IE and frailty criteria were older and more frequently had rheumatic symptoms at admission. Enterococci and non-viridans streptococci were isolated more frequently than in non-frailty patients. Surgery was less performed among frail patients, who had a higher predicted surgical risk. Although complications and in-hospital mortality were similar between both groups, in the group of frail patients, those with conservative management showed lower mortality compared to surgery. Funding Acknowledgement Type of funding sources: None.

Rapid Increase of Oral Bacteria in Nasopharyngeal Microbiota After Antibiotic Treatment in Children With Invasive Pneumococcal Disease.

IntroductionAntibiotics are commonly prescribed to young children for treating bacterial infections such as invasive pneumococcal disease (IPD) caused by Streptococcus pneumoniae. Despite the obvious benefits of antibiotics, little is known about their possible side effects on children’s nasopharyngeal microbiota. In other ecological niches, antibiotics have been described to perturb the balanced microbiota with short- and long-term effects on children’s health. The present study aims to evaluate and compare the nasopharyngeal microbiota of children with IPD and different degree of antibiotic exposure.MethodsWe investigated differences in nasopharyngeal microbiota of two groups of children <18 years with IPD: children not exposed to antibiotics before sample collection (n=27) compared to children previously exposed (n=54). Epidemiological/clinical data were collected from subjects, and microbiota was characterized by Illumina sequencing of V3-V4 amplicons of the 16S rRNA gene.ResultsMain epidemiological/clinical factors were similar across groups. Antibiotic-exposed patients were treated during a median of 4 days (IQR: 3–6) with at least one beta-lactam (100.0%). Higher bacterial richness and diversity were found in the group exposed to antibiotics. Different streptococcal amplicon sequence variants (ASVs) were differentially abundant across groups: antibiotic use was associated to lower relative abundances of Streptococcus ASV2 and Streptococcus ASV11 (phylogenetically close to S. pneumoniae), and higher relative abundances of Streptococcus ASV3 and Streptococcus ASV12 (phylogenetically close to viridans group streptococci). ASVs assigned to typical bacteria from the oral cavity, including Veillonella, Alloprevotella, Porphyromonas, Granulicatella, or Capnocytophaga, were associated to the antibiotic-exposed group. Common nosocomial genera such as Staphylococcus, Acinetobacter, and Pseudomonas were also enriched in the group exposed to antibiotics.ConclusionOur results point toward a reduction of S. pneumoniae abundance on the nasopharynx of children with IPD after antibiotic treatment and a short-term repopulation of this altered niche by oral and nosocomial bacteria. Future research studies will have to evaluate the clinical implications of these findings and if these populations would benefit from the probiotic/prebiotic administration or even from the improvement on oral hygiene practices frequently neglected among hospitalized children.

ANTIMICROBIAL ACTIVITY OF DALBAVANCIN AGAINST GRAM-POSITIVE BACTERIA ISOLATED FROM PATIENTS WITH INFECTIVE ENDOCARDITIS FROM THE UNITED STATES AND EUROPE (2016-2020): RESULTS FROM THE INTERNATIONAL DALBAVANCIN EVALUATION OF ACTIVITY (IDEA) PROGRAM

TOPIC: Chest Infections TYPE: Original Investigations PURPOSE: The management of infective endocarditis (IE) requires aggressive and prolonged antimicrobial treatment. Dalbavancin (DALBA) has demonstrated potent in vitro activity against gram-positive (GP) organisms commonly responsible for IE and is being evaluated for treatment of complicated bacteremia and IE. METHODS: 16,164 GP organisms were consecutively collected from patients with bloodstream infections (BSIs) in the United States (US; 8,807 isolates from 79 hospitals) and Europe (EU; 7,357 isolates from 42 hospitals in 20 countries) from 2016 to 2020 via the IDEA Program. The collection included 323 isolates from patients with a diagnosis of IE. Isolates were tested for susceptibility (S) against DALBA and comparators by the CLSI broth microdilution method. RESULTS: Among IE isolates, the most common organisms were S. aureus (SA; 52.3%), E. faecalis (EF; 18.0%), and viridans group streptococci (VGS; 10.8%). Among BSI isolates, the most common organisms were SA (45.0%), β-hemolytic streptococci (BHS; 11.0%), and EF (10.8%). DALBA and daptomycin (DAPTO) showed complete activity (100.0%S) against SA from IE, but MIC values from DALBA (MIC50/90, 0.03/0.03 mg/L) were 8- to 16-fold lower than DAPTO (MIC50/90, 0.25/0.5 mg/L). Against SA from IE, linezolid (LZD) and teicoplanin (TEI) were active against 100.0% of isolates and ceftaroline was active against 99.0% of isolates. Vancomycin (VAN) inhibited 98.8% of isolates at ≤1 mg/L. Methicillin-resistant SA (MRSA) rates were 43.3% (US) and 27.5% (EU) among SA from IE (n=169), and 41.1% (US) and 24.0% (EU) among SA from BSI (n=7,279). All EF isolates from IE were S to ampicillin and LZD, whereas 98.3% were S to DALBA (MIC50/90, 0.03/0.06 mg/L), DAPTO (MIC50/90, 0.5/1 mg/L), VAN (MIC50/90, 1/2 mg/L), and TEI (MIC50/90, ≤0.5/≤0.5 mg/L). Against EF, DALBA MIC values were 16- to 32-fold lower than DAPTO and VAN. Among EF from BSI (n=1,748), S to DALBA, DAPTO, and VAN was 98.0%, 99.5%, and 97.7%, respectively. All VGS isolates from IE (n=35) were S to DALBA (at ≤0.12 mg/L), VAN, and LZD; 96.6% of VGS were S to DAPTO. All coagulase-negative staphylococci from IE were S to DALBA (MIC50/90, 0.03/0.12 mg/L; highest MIC, 0.12 mg/L), DAPTO (MIC50/90, 0.25/0.5 mg/L), VAN (MIC50/90, 2/2 mg/L), and LZD (MIC50/90, 1/1 mg/L). E. faecium (EFM) was isolated from 5.6% of IE cases. Among EFM isolates from IE, 66.7% were S to VAN and 72.2% were inhibited at ≤0.12 mg/L of DALBA. BHS was S to DALBA (highest MIC, 0.03 mg/L) and most antimicrobial agents tested. CONCLUSIONS: DALBA exhibited potent in vitro activity against a large collection of contemporary GP isolates recovered from patients with BSI, including IE, in US and EU medical centers. CLINICAL IMPLICATIONS: Due to its prolonged half-life and high potency against GP, DALBA may represent a valuable option for treatment of IE. These results support further investigations on the role of DALBA in the treatment of BSI and IE. DISCLOSURES: my employer received research support relationship with AbbVie Please note: 2020-2022 Added 04/20/2021 by Cecilia Carvalhaes, source=Web Response, value=Grant/Research Support No relevant relationships by Mariana Castanheira, source=Web Response no disclosure on file for Rodrigo Mendes;Research Contractor relationship with Allergan Please note: $1001 - $5000 by Helio Sader, source=Web Response, value=Grant/Research Support Research Contractor relationship with AbbVIe (formerly Allergan) Please note: Ongoing Added 04/15/2021 by Helio Sader, source=Web Response, value=Grant/Research Support No relevant relationships by Streit Streit, source=Web Response

Изучение распространенности и резистентности к антимикотикам грибов рода Candida при инфекционных заболеваниях верхних и нижних дыхательных путей

В ходе исследования выявлено, что ведущая роль в этиологии инфекционных заболеваний верхних и нижних дыхательных путей принадлежала Streptococcus viridans и грибам рода Candida. Удельный вес грибов рода Candida составлял 28,8 % у больных фарингитами, 22,6 % — у больных бронхитами и 37,4 % — у больных пневмонией, которые в 77–85,6 % случаев были представлены ассоциациями с бактериями. Отмечался высокий уровень резистентности грибов рода Candida к триазольным антимикотикам.

Children’s head and neck infections caused by Streptococcus intermedius in the Pediatric Otolaryngology Department of Warsaw Medical University

Introduction. Streptococci are commonly known pathogens of the normal bacterial flora of the mouth, pharynx, gastrointestinal tract and genitourinary system. The most common infections are beta-hemolyzing streptococci causing pharyngitis, streptococcal angina, otitis and paranasal sinusitis. But not all streptococcal infections are easy to treat. They are those that forming abscesses in the deep tissues of the body and caused life-treating complications. Aim. The aim of the study is to draw attention to the pathogen of the Streptococcus viridans group, i.e. Streptococcus intermedius, which, being a saprophyte of the upper respiratory tract, may cause life-threatening complications during an infection. Material and methods. The age, sex of children, underlying disease, complications, conservative and surgical treatment of children treated in the Pediatric Otolaryngology Department of the Medical University of Warsaw due Streptococcus intermedius infections were analyzed. Results. 6 children in age from 14 months to 15 years were treated in the ENT Department of Warsaw Medical University due to Streptococcus intermedius infections. There were 5 boys and 1 girl. All children were diagnosed with abscesses in deep tissue as a complication of acute sinusitis in 4 children, pharyngitis in 1 and post trauma nasal bone in 1 child. All children were immunocompetent. The treatment of choice was antibiotic therapy and drainage of abscesses. All children were successfully treated. Conclusions. The isolation of Streptococcus intermedius in cultures taken from infection’s site in the upper respiratory tract is associated with the risk of complications in the form of deep head and neck and central nervous system abscesses. Each patient with an infection of Streptococcus intermedius etiology requires CT or MRI imaging of the craniofacial and brain due to the possibility of deep abscesses. The treatment of choice is antibiotic therapy with ceftriaxone, clindamycin and together with surgical drainage of the abscess. The sensitivity of Streptococcus intermedius to popular antibiotics is the reason for effective treatment despite serious complications.

A New Species-Specific Typing Method for Salivarius Group Streptococci Based on the Dephospho-Coenzyme A Kinase (coaE) Gene Sequencing.

Viridans streptococci are a group of α-hemolytic streptococcal species. They are mainly commensals, most abundant in the mouth supporting oral health. But they also include important human pathogens such as Streptococcus pneumoniae. Identification and molecular typing of viridans group streptococci are challenging, especially for members of the salivarius group. In this study, we developed a single-locus molecular typing method that is able to differentiate among the highly phylogenetically related members of the salivarius group (S. salivarius, S. vestibularis and S. thermophilus) and might support differentiation in other groups as well. This typing approach is based on the amplification and sequence analysis of the housekeeping gene dephospho-coenzyme A kinase (coaE), a gene with unrecognized taxonomic potential to date. Here, we analysed coaE gene sequences of 154 publicly available genomes and of 30 salivarius group isolates of our own collection that together belong to 20 different gram-positive bacterial (sub) species. Our results revealed that the coaE phylogeny distinguished between streptococcal and non-streptococcal genomes and that coaE gene sequences were species-specific. In contrast to MALDI-TOF MS performance, the coaE typing was able to precisely identify the phylogenetically very closely related members of the salivarius group.

Viridans Group Streptococci in Pediatric Leukemia and Stem Cell Transplant: Review of a Risk-stratified Guideline for Empiric Vancomycin in Febrile Neutropenia.

Viridans group streptococci (VGS) are an important cause of sepsis in immunosuppressed children. We reviewed the effectiveness of risk-stratified addition of vancomycin to empiric febrile neutropenia therapy among 107 children with leukemia or undergoing an allogeneic transplant. Of 19 VGS bacteremia episodes, 78.9% were susceptible to risk-stratified antibiotics including 100% from high-risk patients. All blood cultures were flagged positive within 24 hours.

Isolation and Identification of Optochin-Resistant Viridans Group Streptococci from the Sputum Samples of Adult Patients in Jakarta, Indonesia.

Aim To investigate optochin-resistant viridans group streptococci (VGS) strains isolated from the sputum sample of adult patients with different clinical symptoms. Materials and Methods Optochin-resistant VGS isolates were identified by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). recA sequencing was used to confirm identified isolates at the genus level by MALDI-TOF MS. Finding. We identified 79% of tested isolates (148/187) at the species-level identification using the MALDI-TOF MS tool. We identified that the most common species isolated from sputum specimens were S. oralis (44.9%) followed by S. mitis (25.7%), S. infantis (9.1%), S. parasanguinis (7.5%), S. peroris (3.7%), S. anginosus (2.7%), and S. sanguinis (2.1%). Discussion. The S. oralis strains were majority of optochin-resistant VGS isolates obtained from sputum of adult patients in Jakarta, Indonesia. MALDI-TOF MS showed potential for the rapid identification tool to identify optochin-resistant VGS isolates. Although there were discrepancies in identifying isolates at the genus/species level, the performance could be improved by expanding its database.