Viridans Group Streptococci Research Articles

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.

Use of dalbavancin in infective endocarditis: a case series.

BackgroundInfective endocarditis, typically caused by Gram-positive organisms such as viridans group streptococci and Staphylococcus aureus, is associated with high mortality and morbidity and requires aggressive, prolonged antimicrobial treatment and sometimes surgery. Dalbavancin, a lipoglycopeptide active against Gram-positive pathogens, has a long half-life, which allows IV treatment as one dose or two doses with a prolonged interval, offering personalized treatment for complex psychosocial situations or facilitating early discharge. In the absence of randomized controlled trials in infective endocarditis, current evidence derives from real-world case series involving off-licence use. The Austrian Society for Infectious Disease and Tropical Medicine includes dalbavancin as an option for infective endocarditis.ObjectivesThis retrospective case series reports use of dalbavancin in a small cohort of patients with infective endocarditis treated at Lancashire Cardiac Centre, Blackpool Teaching Hospitals Foundation Trust, UK.ResultsThe pharmacy database included 11 patients in whom dalbavancin was used to address either complex psychosocial circumstances or the need for early discharge. The endocarditis multidisciplinary team selected dalbavancin from available treatment options. Structures affected by infective endocarditis included aortic, mitral and tricuspid valves; aortic composite grafts; implantable cardioverter defibrillator leads; and prosthetic aortic valves. Eight patients underwent surgery; three were managed conservatively with antibiotics. Dalbavancin was curative in all but one patient, whose signs and symptoms of infection improved. No patients developed adverse reactions.ConclusionsDalbavancin is an alternative treatment option at hospital discharge when conventional antibiotics may not be suitable due to complex psychosocial issues or early discharge is required.

A Multicenter Comparison of Rates of Central Venous Catheter-Associated Bloodstream Infections By Central Venous Catheter Type Among Pediatric Patients Receiving Treatment for Newly Diagnosed Acute Myeloid Leukemia

▪Therapy for pediatric acute myeloid leukemia (AML) requires long term central vascular access, which puts patients at risk for central line-associated bloodstream infections and their associated morbidity and mortality. Options for central venous catheter (CVC) access include tunneled external catheters, implanted ports, or peripherally inserted central catheters (PICC). Multiple studies provide conflicting reports on which CVC type is least likely to be associated with bloodstream infections in pediatric hematology-oncology patients. This multicenter cohort of pediatric AML patients is the first to investigate the course-specific incidence of positive CVC blood cultures by line type.The study included patients receiving frontline chemotherapy for AML between 1/1/2012 and 6/30/2017 at 12 US institutions. Trained personnel completed manual chart abstraction from 12/1/2015 to 07/15/2017 to obtain information on demographics, diagnosis, treatment, antibacterial prophylaxis, CVC type at the start of each course, neutropenia duration, and blood culture results obtained from CVC. Abstractors followed a standardized protocol and were required to achieve >95% concordance with trainer before starting formal chart review.Course-specific follow-up began the first day absolute neutrophil count (ANC) fell below 200 cells/uL and continued to the earliest of first positive CVC culture (overall and separately for gram-positive and gram-negative species), ANC recovery, start of conditioning for stem cell transplant, relapse, death or start of next course. Per National Healthcare Safety Network guidance, common commensals were not considered true events with the exception of viridans group streptococci (VGS). Nonbacterial pathogens were also excluded. Covariate distributions were compared by CVC type using chi-square tests. Variability in CVC type by site was examined graphically. Incidence rates for CVC positive blood cultures were reported by line type as per 1000 neutropenic days. Multivariate Poisson regression with log of neutropenia duration as offset was used to compute adjusted rate ratios (aIRR) comparing rates of positive CVC blood cultures by line type, controlling for covariates itemized in Table 1. General estimating equation methods were used to account for non-independence of observations from patients from the same institution.The study population included 357 patients who received 1,164 chemotherapy courses. Median course duration was 38 days (IQR: 34-44) with a median neutropenia duration of 19 days (IQR: 14-25). CVC were present in all patients at the start of each course, with the exception of 11 (3.3%) patients lacking a CVC at the start of Induction I. While tunneled CVC were most prevalent representing 59.1% of courses, PICC and implanted ports were utilized in 28.9% and 11.6% of courses, respectively. There was considerable variation in the distribution of CVC type by treating institution (Figure 1). Age, race, and ethnicity distributions varied by line type (Table 1). Antibacterial prophylaxis was utilized in 47% of courses.In total, there were 300 (25.8%) courses in 199 (55.7%) patients complicated by a positive CVC blood culture during the neutropenic period. The overall incidence rate of positive CVC blood cultures was 6.5 per 1000 neutropenic days. Rates increased over the course of frontline treatment from 3.1 per 1000 neutropenic days in Induction I to 9.6 per 1000 neutropenic days in Intensification II. The rate of gram-positive events (4.2 per 1000 neutropenic days) was higher than gram-negative events (2.0 per 1000 neutropenic days). The most common isolated organisms were VGS at 57.3% and less than 1% of events were polymicrobial infections. Overall rates of positive CVC blood cultures were higher for PICC relative to tunneled CVC (aIRR=1.19, 95% CI: 1.02, 1.38), while rates for implanted ports and tunneled CVC were similar (aIRR=1.06, 95% CI: 0.75, 1.51).While bacteremia is an expected complication during post-chemotherapy neutropenia and not always due to the presence of a CVC, the risk for a positive CVC blood culture is significantly increased for children with PICC compared with those with tunneled CVC or implanted port. Also, the risk was higher after Induction I and increased with age. Given the notable practice variation in line choice, these data highlight an opportunity for standardization with a goal to reduce infectious complications. [Display omitted] DisclosuresFisher:Pfizer: Research Funding; Merck: Research Funding. Gramatges:Bristol Meyer Squibb: Research Funding.

Bloodstream Infection Survey in High-Risk Oncology Patients (BISHOP): Preliminary Report

IntroductionBloodstream bacterial infections are a potentially life-threatening complication of cytotoxic chemotherapy, with approximately 10 to 25% of febrile neutropenic (FN) patients having a positive blood culture taken at the time of first fever during neutropenia (Liu et al ., 2011; Gustinett, Mikulska 2016). Empiric antibiotic therapy started promptly at onset of fever and neutropenia will reduce morbidity and mortality and is standard of care. The choice of empiric antibiotics depends on the prevailing bacterial pathogens in a given at-risk population. Accordingly, it is essential know the patterns of bacterial types and antibiotic susceptibilities in the population at risk, especially in the global context of rising bacterial resistance to common antibiotics. Currently, no such data exists from the United States; a national survey of bloodstream isolates from cancer patients was last published in 2003(Wisplinghoff et al ., 2003). The BISHOP study aims to generate a geographically broad data set describing bloodstream isolate epidemiology, antibiotic susceptibility and clinical outcomes of bacteremias in patients with hematologic malignancies (HM) or undergoing allogeneic or autologous HSCT in the United States.MethodsFifteen geographically diverse US cancer centers that perform at least 100 HSCTs yearly are participating, starting from December 2016. Patients are consecutively enrolled at each center if they have a documented bacterial bloodstream infection at the time of first fever and neutropenia within 14 days of receiving cytotoxic chemotherapy for treatment of HM or in preparation for HSCT. Bacterial isolates are shipped to the central lab (UNMC) and frozen; microtiter antibiotic susceptibility testing will be performed in the future. Clinical data collected electronically include patient demographics, clinical course over first 24 hours, empiric antibiotic treatments and outcomes at 30 days. Target collection is 720 bacterial isolates over 18 months.ResultsEleven of 15 participating centers enrolled 187 patients (chemo only 127, HSCT 60), with 213 bacterial bloodstream isolates in the first 8 months of study (Table 1). There were 49% gram negative isolates, with E.coli (22%), Klebsiella pneumoniae (7.5%) and Pseudomonas aeruginosa (7.5%) predominating. Among gram positives (46%) , Viridans group streptococci (21.6%), coagulase negative staphylococci (7.0%) and methicillin-resistant Staph aureus (MRSA) (5.2%), predominated. Anaerobes accounted for 5% of isolates. Table 2 shows types of bacteremias in the 187 patients, with about equal proportions of single gram negative and gram positive isolates. Full susceptibility data have not yet been collated. Ninety seven patients (chemo only 63, HSCT: 19 allo,15 auto) have clinical data available for the initial 24 hours after presentation: 39% were female, median age 59 years (23-73 y), median ANC 0 cells/ul (0-430). Underlying primary diagnoses were AML 59%, NHL 12%, MM 10%, ALL 6%, MDS 3% HL 2%, and other 7%. Antibiotic prophylaxis prior to onset of FN was given in 61%. Complicated presentations were mucositis 29%, pneumonia 13%, altered mental status 7% or hypotension/pressor requirement 9%. Empiric antibiotics included cefepime 58%, pip-tazobactam 19% ,meropenem 10%, ceftazidime 4%, aztreonam 4%, doripenem (1%) and Other 4 %. Vancomycin and tobramycin were included in the initial regimen in 41% and 3% respectively. Median MASCC score was 21 (6-26). Median Pitt bacteremia score was 1.0 (0-7). There were no deaths within the first 24 hours after presentation.ConclusionThe initial data from the BISHOP survey is described here, representing the largest multicenter profile of bloodstream infections among patients with HM or HSCT collected in the US. Gram negative and positive organisms are distributed equally, with E.coli and viridans group streptococci most commonly isolated. MASCC and Pitt score on presentation did not indicate that this patient cohort was at high risk for early complications (first 24h). Susceptibility data, when available, may inform empiric antibiotic choices. Notably, no patients died within the first 24 hours after presentation indicating that current empiric therapy strategies are generally successful in the early period of fever and neutropenia. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Bloodstream infections in patients with transcatheter aortic valve replacement

ObjectiveTo evaluate incidence and risk factors of bloodstream infections (BSI) in patients with transcatheter aortic valve replacement (TAVR). MethodsWe conducted a population-based study in southeastern Minnesota using the expanded Rochester Epidemiology Project (e-REP) for all adult (≥18 years) patients who underwent TAVR from January 1, 2010 to December 31, 2018. ResultsThe incidence of BSI following TAVR was 1300 episodes/100,000 persons per annum. The median time to BSI following TAVR was 610 days and 84% were community-acquired. Forty percent of BSI cases developed infective endocarditis. Viridans group streptococci (VGS) were the most common pathogens and 80% of patients with VGS BSI had IE. ConclusionsThe high incidence of BSI among TAVR patients is alarming and is likely due to advanced age and comorbid conditions. Because 40% of BSI patients also developed IE, further investigation of modifiable risk factors associated with BSI is warranted.

Infective endocarditis in paediatric population.

Infective endocarditis is very uncommon in children; however, when it does arise, it can lead to severe consequences. The biggest risk factor for paediatric infective endocarditis today is underlying congenital heart defects. The most common causative organisms are Staphylococcus aureus and the viridans group of streptococci. The spectrum of symptoms varies widely in children and this produces difficulty in the diagnosis of infective endocarditis. Infective endocarditis in children is reliant on the modified Duke criteria. The use of blood cultures remains the most effective microbiological test for pathogen identification. However, in blood culture-negative infective endocarditis, serology testing and IgG titres are more effective for diagnosis. Imaging techniques used include echocardiograms, computed tomography and positron emission tomography. Biomarkers utilised in diagnosis are C-reactive protein, with recent literature reviewing the use of interleukin-15 and C-C motif chemokine ligand for reliable risk prediction. The American Heart Association (AHA) and European Society of Cardiology (ESC) guidelines have been compared to describe the differences in the approach to infective endocarditis in children. Medical intervention involves the use of antimicrobial treatment and surgical interventions include the repair and replacement of cardiac valves. Quality of life is highly likely to improve from surgical intervention.Conclusion: Over the past decades, there have been great advancements in clinical practice to improve outcomes in patients with infective endocarditis. Nonetheless, further work is required to better investigative and manage such high risk cohort. What is Known: • The current diagnostic techniques including 'Duke's criteria' for paediatric infective endocarditis diagnosis • The current management guidelines utilised for paediatric infective endocarditis What is New: • The long-term outcomes of patients that underwent medical and surgical intervention • The quality of life of paediatric patients that underwent medical and surgical intervention.

Clinical Features and Outcomes of Streptococcus anginosus Group Infective Endocarditis: A Multicenter Matched Cohort Study.

BackgroundAlthough Streptococcus anginosus group (SAG) endocarditis is considered a severe disease associated with abscess formation and embolic events, there is limited evidence to support this assumption.MethodsWe performed a retrospective analysis of prospectively collected data from consecutive patients with definite SAG endocarditis in 28 centers in Spain and Italy. A comparison between cases due to SAG endocarditis and viridans group streptococci (VGS) or Streptococcus gallolyticus group (SGG) was performed in a 1:2 matched analysis.ResultsOf 5336 consecutive cases of definite endocarditis, 72 (1.4%) were due to SAG and matched with 144 cases due to VGS/SGG. SAG endocarditis was community acquired in 64 (88.9%) cases and affected aortic native valve in 29 (40.3%). When comparing SAG and VGS/SGG endocarditis, no significant differences were found in septic shock (8.3% vs 3.5%, P = .116); valve disorder, including perforation (22.2% vs 18.1%, P = .584), pseudoaneurysm (16.7% vs 8.3%, P = .108), or prosthesis dehiscence (1.4% vs 6.3%, P = .170); paravalvular complications, including abscess (25% vs 18.8%, P = .264) and intracardiac fistula (5.6% vs 3.5%, P = .485); heart failure (34.7% vs 38.9%, P = .655); or embolic events (41.7% vs 32.6%, P = .248). Indications for surgery (70.8% vs 70.8%; P = 1) and mortality (13.9% vs 16.7%; P = .741) were similar between groups.ConclusionsSAG endocarditis is an infrequent but serious condition that presents a prognosis similar to that of VGS/SGG.

Early-Onset Sepsis in Neonates - A Population-Based Study in South-West Norway From 1996 to 2018.

Background: The epidemiology of early-onset sepsis (EOS) may change over time. Longitudinal surveillance of causative pathogens, antibiotic susceptibility patterns and antibiotic therapy is important for optimal therapy strategies.Objectives: To describe the incidence of culture-confirmed EOS, causative pathogens, antibiotic susceptibility patterns and antibiotic therapy over a 23-year period.Methods: Retrospective population-based study from a single-center neonatal intensive care unit at Stavanger University Hospital, Norway, covering a population in South-West Norway, during the 23-year period 1996–2018.Results: Of 104,377 live born infants, 101 infants (0.97/1,000) had culture-confirmed EOS; 89 with Gram positive and 12 with Gram-negative bacteria. The EOS-attributable mortality was 6/101 (5.8%). For the three most prevalent pathogens the incidences were; Group B streptococcus (GBS) 0.57/1,000, Escherichia coli 0.11/1,000 and viridans group streptococci (VGS) 0.10/1,000. GBS was the most common pathogen (59/93; 63%) in infants with gestational age (GA) ≥ 28 weeks. In contrast, among extremely preterm infants (GA <28 weeks) the incidence of E. coli infection was higher than for GBS infection. The second most common bacterial pathogens causing EOS among term infants were VGS. There was no change in the incidence of EOS for the entire study period, but from 2000 to 2018 there was a mean decline in EOS by 6% per year (95% CI 1%−10%) (p = 0.019). The incidences of GBS and E. coli did not change during the study period. The initial empirical antibiotic regimen for EOS was in all cases a combination of benzylpenicillin or ampicillin and an aminoglycoside, but in 21/101 (21%) of cases a broad-spectrum antibiotic was either added or substituted this regimen. In 2/101 (2%) EOS cases, the pathogens were nonsusceptible to the empirical antibiotic regimen. All E. coli isolates were susceptible to aminoglycosides.Conclusion: GBS was the most common causative pathogens in EOS, but E. coli dominated in infants with GA <28 weeks. There was no change in the incidence of EOS during the entire study period. The current empiric regimen with benzylpenicillin and gentamicin provides a very high coverage for EOS in our setting.

A Contemporary Population-Based Profile of Infective Endocarditis Using the Expanded Rochester Epidemiology Project

ObjectiveTo develop a contemporary profile of infective endocarditis (IE) among a population in 6 counties of Olmsted, Dodge, Mower, Steele, Waseca, and Freeborn in southern Minnesota between 2014 and 2018. Patients and MethodsAll possible and definite cases of IE (≥18 years) among residents of 6 counties in southern Minnesota, including Olmsted County, diagnosed between January 1, 2014, and December 31, 2018, were included in this retrospective, population-based investigation, using the Expanded Rochester Epidemiology Project (E-REP). ResultsOverall, 137 patients with IE developed incident IE in the 6-county region, corresponding to an age- and sex-adjusted incidence rate of 11.9 per 100,000 person-years. Men had a significantly higher incidence of IE (17.9 vs 6.8 per 100,000 person-years), and rates increased exponentially with age in both sexes. The median age of incident cases was 68.2 years, and 67.9% were male patients. The percentage of patients with histories of injection-drug use was low, at 6.7%. Bicuspid aortic valve was the most common (9.6%) native valve predisposing condition. Staphylococcus aureus was identified as the predominant pathogen in the overall group (34.8%), with viridans-group streptococci accounting for only 19.3% cases. Central nervous system and musculoskeletal complications were common. The 30-day readmission rate was 27.9%, and the 6-month mortality rate was 31.8%. ConclusionTo our knowledge, this is the first time that the population-based E-REP has been used to determine an age- and sex-adjusted IE incidence. Older male patients predominated, and S aureus was the most common pathogen. Based on these findings, it is not surprising that IE complications were frequently seen.

Post-traumatic endophthalmitis caused by streptococcus species in preschool children: clinical features, antibiotic susceptibilities and outcomes

Background/ObjectivesStreptococcus is a common cause of post-traumatic endophthalmitis in children. This study aimed to analyse the clinical features, antibiotic susceptibilities and outcomes of traumatic endophthalmitis caused by streptococcus in preschool children.Subjects/MethodsPatients aged ≤6 years with traumatic streptococcal endophthalmitis seen at Zhongshan Ophthalmic Center between January 2013 and December 2018 were included in this retrospective study.ResultsIn total, 21 patients (21 eyes) were included. The mean age of the patients was 3.3 ± 1.7 years, where 57.1% were males. Scissors (28.6%, n = 6) were the most common cause of injury; 86.7% of patients were injured at home. Zone I (80.9%) was the most common wound site; 90.5% of patients presented with a traumatic cataract. In general, Streptococcus pneumoniae (47.6%) was the most common isolate. Viridans group streptococci accounted for 58.3% of cases in children aged 0–3 years, while S. pneumoniae accounted for 66.7% of cases in children aged 4–6 years. The susceptibility rates of streptococcus to cefuroxime, levofloxacin and ofloxacin were 100%, 95.0% and 90.5%, respectively. Although all the patients underwent vitrectomy combined with silicone oil tamponade, the final visual outcomes were no better than counting fingers.ConclusionsAlthough S. pneumoniae was the most prevalent organism in general, the dominant species varied between different age groups. The commonly used antibiotics, cefuroxime and fluoroquinolone, showed higher antibiotic susceptibility. Despite prompt treatment, the visual outcomes of paediatric post-traumatic endophthalmitis in preschool children were poor.

Infective endocarditis in patients with aortic grafts

BackgroundInfective endocarditis (IE) in patients with a valve-tube ascending aortic graft (AAG) is a rare entity with a challenging diagnosis and treatment. This study describes the clinical features, diagnosis and outcome of these patients. MethodsBetween 1996 and 2019, 1654 episodes of IE were recruited in 3 centres, of which 37 patients (2.2%) had prosthetic aortic valve and AAG-IE (21 composite valve graft, 16 supracoronary graft) and conformed our study group. ResultsPatients with aortic grafts were predominantly male (91.9%) and the mean age was 67.7 years. Staphylococci were the most frequently isolated microorganisms (32%). Viridans group streptococci were only isolated in patients with composite valve graft. TEE was positive in 89.2%. PET/CT was positive in all 15 patients in whom it was performed. Surgical treatment was performed in 62.2% of patients. In-hospital mortality was 16.2%. Heart failure and the type of infected graft (supracoronary aortic graft) were associated with mortality. Mortality among operated patients was 21.7%. Interestingly, 14 patients received antibiotic therapy alone, and only one died. Mortality was lower among patients with a composite valve graft compared to those with a supracoronary graft (4.8% vs 31.3%; p = 0.03). ConclusionsIn patients with AAG and prosthetic aortic valve IE, mortality is not higher than in other patients with prosthetic IE. Multimodality imaging plays an important role in the diagnosis and management of these patients. Heart failure and the type of surgery were risk factors associated with in-hospital mortality. Although surgical treatment is usually recommended, a conservative management might be a valid alternative treatment in selected patients.

Pediatric fever in neutropenia with bacteremia-Pathogen distribution and in vitro antibiotic susceptibility patterns over time in a retrospective single-center cohort study.

BackgroundFever in neutropenia (FN) is a potentially life-threatening complication of chemotherapy in pediatric cancer patients. The current standard of care at most institutions is emergency hospitalization and empirical initiation of broad-spectrum antibiotic therapy.MethodsWe analyzed in retrospect FN episodes with bacteremia in pediatric cancer patients in a single center cohort from 1993 to 2012. We assessed the distribution of pathogens, the in vitro antibiotic susceptibility patterns, and their trends over time.ResultsFrom a total of 703 FN episodes reported, we assessed 134 FN episodes with bacteremia with 195 pathogens isolated in 102 patients. Gram-positive pathogens (124, 64%) were more common than Gram-negative (71, 36%). This proportion did not change over time (p = 0.26). Coagulase-negative staphylococci (64, 32%), viridans group streptococci (42, 22%), Escherichia coli (33, 17%), Klebsiella spp. (10, 5%) and Pseudomonas aeruginosa (nine, 5%) were the most common pathogens. Comparing the in vitro antibiotic susceptibility patterns, the antimicrobial activity of ceftriaxone plus amikacin (64%; 95%CI: 56%-72%), cefepime (64%; 95%CI 56%-72%), meropenem (64%; 95%CI 56%-72), and piperacillin/tazobactam (62%; 95%CI 54%-70%), respectively, did not differ significantly. The addition of vancomycin to those regimens would have increased significantly in vitro activity to 99% for ceftriaxone plus amikacin, cefepime, meropenem, and 96% for piperacillin/tazobactam (p < 0.001).ConclusionsOver two decades, we detected a relative stable pathogen distribution and found no relevant trend in the antibiotic susceptibility patterns. Different recommended antibiotic regimens showed comparable in vitro antimicrobial activity.

Monitoring of opportunistic microflora in secondary respiratory infections of HIV-infected patients

Objective: to evaluate the results of microbiological examination of sputum of HIV-infected patients with pneumonia clinic.Materials and methods. The analysis of microbiological results of sputum in 850 patients who were treated with pneumonia at the Infectious Clinical Hospital № 1 from 01.01.2012 to 01.01.2019.Results and its discussion. Gram-positive cocci were recorded in sputum in patients with HIV infection in 76,7±2,2% of cases. The growth of Staph. aureus noted in 20,1±2,0% of cases and was associated with the presence of sepsis and septic pneumonia. Staphylococcus epidermidis detected in sputum in 0,5±0,4% of HIV-positive patients with angiogenic sepsis. Streptococcus pyogenes was isolated in sputum in 2,3±0,8% of patients with severe community-acquired pneumonia. Str. pneumoniae was detected in 2,6±0,8% of cases. A common finding in the study of sputum in patients with HIV infection were viridans group Streptococci (50,3±2,6%). Gram-negative aerobic non-spore-forming bacterium Pseudomonas aeruginosa was found in 5,2±1,1%, Enterococcus faecalis in 3,1±0,9% of confirmed cases of pneumonia. Klebsiella pneumonia was confirmed in 11,5±1,6% of patients. Microbial association was noted in 24,1±1,7% of isolates; associations in combination with Staph. aureus were more common in 54,5±4,1% of HIV-infected patients with the clinic of community-acquired pneumonia.Conclusion. In patients with HIV infection with lung damage, it is necessary to collect biological material for microbiological examination, which will affect the further tactics of patient management.

Temporal Trends of Infective Endocarditis in Olmsted County, Minnesota, Between 1970 and 2018: A Population-Based Analysis.

BackgroundA population-based study of infective endocarditis (IE) in Olmsted County, Minnesota, provides a unique opportunity to define temporal and seasonal variations in IE incidence over an extended time period.MethodsThis was a population-based review of all adults (≥18 years) residing in Olmsted County, Minnesota, with definite or possible IE using the Rochester Epidemiology Project from January 1, 1970, through December 31, 2018. Poisson regression was used to characterize the trends in IE incidence; models were fitted with age, sex, calendar time, and season, allowing for nonlinearity and nonadditivity of their effects.ResultsOverall, 269 cases of IE were identified over a 49-year study period. The median age of IE cases was 67.2 years, and 33.8% were female. The overall age- and sex-adjusted incidence of IE was 7.9 cases per 100 000 person-years (95% CI, 7.0–8.9), with corresponding rates of 2.4, 2.4, 0.9, and 0.7 per 100 000 person-years for Staphylococcus aureus, viridans group streptococci (VGS), Enterococcus species, and coagulase-negative staphylococci IE, respectively. Temporal trends varied by age, sex, and season, but on average IE incidence increased over time (P = .021). Enterococcal IE increased the most (P = .018), while S. aureus IE appeared to increase but mostly in the winter months (P = .018). Between 1996 and 2018, the incidence of VGS IE was relatively stable, with no statistically significant difference in the trends before and after the 2007 AHA IE prevention guidelines.ConclusionsOverall, IE incidence, and specifically enterococcal IE, increased over time, while S. aureus IE was seasonally dependent. There was no statistically significant difference in VGS IE incidence in the periods before and after publication of the 2007 AHA IE prevention guidelines.

Obrazac antimikrobne osetljivosti oralnih viridans streptokoka kod dece sa rizikom od infektivnog endokarditisa

Infective endocarditis (IE) is an important clinical disease in children with a mortality rate of 11.6%. Prophylaxis with antibiotics is one of the most commonly used methods in children at risk of IE; therefore, the evaluation of antibiotic resistance seems necessary in view of its increasing trend. This study aimed to determine the antibiotic susceptibility pattern of oral viridans group streptococci (VGS) isolated from the dental plaque of children at risk of IE. Fifty-one plaque samples were obtained from children aged 3 to 12 years old in the period from April to July 2018. Samples were obtained with sterile swabs and were transferred to the laboratory in Brain Heart Infusion (BHI) Broth. Samples were immediately cultivated on Columbia blood agar. After identifying VGS, antimicrobial susceptibility test (AST) was performed using Mueller-Hinton agar (MHA) with sheep's blood and E-test strips for selected antibiotics. The minimum inhibitory concentration (MIC) was determined for each isolate and the results were reported as sensitive, intermediate and resistant. Fifty-one VGS bacteria were isolated from children with an average age of 7.3 ± 2.5 years. The highest resistance was observed for azithromycin in 36 (70.6%) isolates and then cefazolin in 35 (68.6%) isolates. The highest susceptibility was observed for amoxicillin in 46 (90.2%) isolates. Based on the findings of this study, amoxicillin is the most effective option for prophylaxis in children. Furthermore, cefazolin should be used with caution because bacteria resistant to this antibiotic can transfer resistance genes to other bacteria.

Effectiveness of daptomycin against infective endocarditis caused by highly penicillin-resistant viridans group streptococci

Penicillin-resistant viridans group streptococci (VGS) infections are an emerging issue in infectious diseases. Here, we present a case of mitral valve infective endocarditis caused by highly penicillin-resistant VGS (minimum inhibitory concentration >4 μg/mL), which was successfully treated with daptomycin. Although the clinical efficacy of daptomycin has not been established, it can be an alternative for the treatment of highly resistant VGS endocarditis.

Assessment of the Optochin Susceptibility Test to Differentiate Streptococcus pneumoniae from other Viridans Group Streptococci.

Streptococcus pneumoniae identification has traditionally been based on two biochemical tests, susceptibility of pneumococci to optochin and solubility in bile-salt solution. Due to slowness and sometimes difficulty in interpretation, the bile solubility test has fallen into disuse. The main objective of this work was to assess the current effectiveness of the optochin susceptibility test in pneumococcal identification in clinical practice. Overall 126 viridans group streptococci consecutively isolated from respiratory samples were analyzed using the optochin susceptibility test by picking one colony from the culture. Sixty-two were initially considered optochin susceptible, and 64 were considered optochin resistant and analyzed with the bile solubility test. If a discrepancy between the tests was observed (i.e., whether an isolate was optochin susceptible and bile insoluble or optochin resistant and bile soluble), then the optochin susceptibility test was repeated, adjusting the inoculum to a McFarland standard of 0.5. Species were identified by sequencing the lytA and recA genes. Twelve discrepancies were initially observed. The result of the repeated optochin test showed that the initial optochin test of 4 isolates had been wrongly interpreted. Of the remaining 8 discrepancies, 2 optochin-resistant bile-soluble isolates were identified by gene sequencing as S. pneumoniae, and of the 6 optochin-susceptible bile-nonsoluble isolates, 3 were identified as Streptococcus mitis and 3 as Streptococcus pseudopneumoniae. The optochin test correctly identified 90.5% of all recent viridans group streptococci clinical isolates which include both optochin susceptible (62/126 = 49.2%) and optochin resistant (64/126 = 50.8%) strains. Of the group of optochin susceptible viridans, 87.5% were correctly identified, and 93.5% of the optochin resistant group were correctly identified. However, this technique does not correctly differentiate between S. pneumoniae from other viridans group streptococci in the clinical setting. Additional testing is needed for that identification.

250. Blood Stream Infections (BSI) in Pediatric Neuroblastoma High Risk: Emphasis on Viridans Group Streptococci (VGS) Bacteremia

BackgroundFebrile neutropenia’s (FN) literature has focused on acute leukemia and undergoing allogeneic stem cell transplantation (SCT) as high risk factors for microbiological documented infection (MDI) and blood stream infection (BSI). Comprehensive studies on in pediatric Neuroblastoma high risk (NB-HR) who receive highly myelosuppressive therapy are lacking.MethodsWe conducted a retrospective medical record review of pediatric patients who received any oncology care at UCM Comer Children’s Hospitals.with a diagnosis of FN who had at least 1 blood culture obtained and one of the following underlying diagnoses (AML, lymphoblastic leukemia ALL), NB-HR, and other solid tumors (ST). SCT patients were excluded from study. We reviewed pathogens isolated from blood cultures (BCx) and determined whether they were pathogens or contaminants using IDSA guidelines. Comparative analyses of BSI rates between NB-HR and other underlying diagnoses were done.ResultsA total of 560 FN episodes (FNEs) were identified in 230 patients. FNEs occurred in NB-HR were 102 in 77 patients. Fifty-seven percent of patients developed one or more BSI or MDI during induction chemotherapy. The mean age was 11.0 (SD=6.5) years. True BSI occurred in 138 (24.6%) of FN episodes. The organisms that were most frequently isolated from were viridans group streptococci (VGS) (25%). The highest rate of BSI occurred among FNEs with AML (44/115, 37%) followed by NB-HR 26/110 (25%) Table1. Overall BSI rate in NB-HR group is higher than other solid tumors (25 vs 17%, P=0.03). In subset analysis, VGS bacteremia was highest among FNEs with AML and NB-HR compared with ALL (8.7 and 8.8 % vs 6%) P< 0.04 and P=0.02 respectively.Notably, the gram positive/ gram negative (GP/GN ratio) in NB-HR compared with ST was significantly higher (OR =2.26, CI 95% 1.5–7.8, P< 0.01), this was likely due to a higher VGS rate (8.8% vs 2%, OR=4.2, P < 0.01). Rate of GN-BSI are same in each of ALL,HR-NB and ST. ConclusionOur large Neuroblastoma cohort showed that NB-HR during induction chemotherapy are higher risk for VGS bacteremia, compared with other solid tumors. Further prospective studies are needed to investigate infection related complication in this high risk group and possible improved morbidity and mortality.Disclosures All Authors: No reported disclosures