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The profile of antimicrobial resistance (ie, antibiogram) may be disparate between children and adults. An infant developed severe deep neck infection with a multidrug‐resistant microbe. The microbe was more drug‐resistant in children than in adults, in our hospital. Treatment of a child should be guided by the antibiogram obtained from children.

Rationale: In the course of endocarditis, the development of antineutrophil cytoplasmic antibody (ANCA)-mediated disease introduces the dilemma of determining the best treatment approach for immune conditions, whether immunosuppressant therapy should be added to antibiotic treatment has remained controversial. Patient concerns: A 33-year-old man presented with progressive fever lasting for 7 months, and swelling, pain, and purpura in the arms and legs. The patient showed multiple autoantibodies including cytoplasmic ANCA, antiproteinase 3, rheumatoid factor, and anti-beta 2 glycoprotein I. Blood culture was positive for viridans streptococcus, and renal biopsy revealed glomerulonephritis and interstitial nephritis. Diagnosis: Endocarditis caused by viridans streptococci, ANCA-associated vasculitis, and congenital ventricular septal defect. Interventions: In addition to effective antibiotics, he also received twice intravenous corticosteroids and intravenous immunoglobulin therapy, and a low dose of cyclophosphamide. At last, the patient received congenital ventricular septal defect repair and debridement. Outcomes: The abnormal clinical manifestations, including renal failure and loss of strength, recovered rapidly with corticosteroid therapy in addition to antibiotic treatment. After 6 months without any medications, he remained asymptomatic and was able to live normally. Lessons: In this case with endocarditis and ANCA-associated vasculitis, we highlighted the importance of biopsy and immunosuppressive therapy. Histopathologic examination is required for diagnosis and treatment in such case. Identifying patients who have endocarditis and ANCA positivity with vasculitis pathologic features will require corticosteroid/immunosuppressives in addition to the antibiotics therapy.

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.

Background Febrile 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. Methods We 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. Results A 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. Conclusion Our 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

Disk diffusion susceptibility testing inoculated directly from positive blood culture bottles (direct Kirby-Bauer; DKB) allows for preliminary susceptibility results approximately a day sooner than standard antimicrobial susceptibility testing (AST). Our current laboratory workflow utilizes non-standardized inoculum from positive blood culture bottles. To minimize errors associated with inoculum variability, we report preliminary susceptibility results using breakpoints as follows: susceptible — standard-CLSI breakpoints; resistant— a cautious zone size of 6 mm; any zone between these extremes are reported as “pending”. DKB results are reported a median of 23.7 hours earlier compared to final sensitivity results. The decrease in turn-around time is consistent across organisms: DKB results for Enterobacteriales are reported a median of 21.6 hours earlier, Pseudomonas aeruginosa 20.8 hours earlier, and viridans group streptococci 21.9 hours earlier than final sensitivity reports. The portion of isolates that have actionable DKB results, however, is limited by a high portion of “pending” DKB results. In order to increase the portion of reportable and actionable DKB results, we sought to reduce the number of pending DKB results for isolates that were ultimately determined to be resistant by final AST. To accomplish this, we retrospectively compared the DKB zone sizes to the final microbroth susceptibility interpretation of ~800 bacterial isolates from the past 3.5 years and assessed the performance characteristics of DKB results across a range of zone sizes. To maximize the reporting of actionable data when antimicrobial escalation may be indicated, we specifically examined broad spectrum agents. Initial analysis focused on Enterobacteriales due to the number of isolates and distribution of resistance phenotypes. By adjusting the resistant cutoff of cefepime from 6mm to £14 mm, we found an increase in sensitivity of detecting resistant isolates from 23% to 100%, categorical agreement (CA) of 97%, no very major errors (VME), major errors (ME) 2.8%, and no minor errors (mE). For ceftriaxone, by changing the resistant breakpoint from 6mm to £17 mm, we found an increase in sensitivity from 43% to 100%, CA 98%, no VME, ME 1.3%, and mE 0.95%. For piperacillin-tazobactam, a change in the breakpoint from 6 mm to £15 mm resulted in an increase in sensitivity from 8% to 100%, CA 95%, no VME, ME 2.4%, and mE 1.6%. By adjusting the non-standard DKB breakpoints for reporting resistance to broad-spectrum beta-lactams in Enterobacteriales, we have increased the overall sensitivity of detecting resistant isolates to 100% for these agents without requiring extra steps of centrifugation and standardization of inoculum necessary to more completely adopt CLSI breakpoints. Retrospectively over the study period, implementing these changes could have resulted in reporting changes for 73 bacterial isolates from 59 unique patients and the corresponding potential for reduced time to appropriate therapy for patients with bacteremia.

Background NHSN Mucosal Barrier Injury-Laboratory Confirmed Bloodstream Infection (MBI-LCBI) includes pathogens likely to cause bloodstream infections (BSI) in some oncology patients. MBI-LCBIs are excluded from central line-associated BSI (CLABSI) reporting to the Centers for Medicare & Medicaid Services. NHSN users have requested other pathogens be added to MBI-LCBI. To make decision, we compared CLABSI pathogen distributions in three NHSN patient location groups. Methods We analyzed CLABSI data from hospitals conducting surveillance for ≥ 1 month from January 2014–December 2018 in ≥ 1 MBI high-risk location (leukemia, lymphoma, and adult and pediatric hematopoietic stem cell transplant wards). We compared CLABSI pathogen distributions and rates in MBI high-risk locations to medium-risk (solid tumor, adult and pediatric general hematology-oncology wards) and low-risk locations (adult and pediatric medical, surgical, and medical-surgical wards), and used χ2 tests to compare percentages with statistical significance at P ≤ 0.05. Results Overall, 122 hospitals reported 23,578 CLABSIs and 12,961,921 central line (CL)-days (1.81 CLABSIs per 1,000 CL-days) (Table). Percentages of CLABSIs due to three MBI-LCBI pathogens (E. coli, E. faecium, Viridans streptococci) were significantly higher in high- versus low-risk locations, while for other MBI-LCBI pathogens (K. pneumoniae/oxytoca, E. faecalis, Candida spp., Enterobacter spp.) percentages were significantly lower in high-risk locations (Figure). For pathogens not currently in MBI-LCBI, coagulase-negative staphylococci caused similar percentages of CLABSIs across locations, S. aureus caused a significantly higher percentage of CLABSIs in low-risk locations, while PA caused a significantly higher percentage of CLABSIs in high-risk locations. Table CLABSIs attributed to MBI high-risk, medium-risk, and low-risk locations, NHSN, 2014–2018 Figure Percentages of top 10 pathogen-specific CLABSIs in MBI high-risk, medium-risk, and low-risk locations, NHSN, 2014–2018 Conclusion Differences in percentages of CLABSIs due to selected pathogens between MBI high-risk and low-risk locations are evident in NHSN data. Lower percentages of Klebsiella and Candida spp. in high-risk locations might be partially due to antimicrobial prophylaxis in oncology patients. Although PA caused a significantly higher percentage of CLABSIs in high-risk locations, the absolute difference was modest. Additional analyses are needed. Disclosures All Authors: No reported disclosures

Background Recurrent central line-associated bloodstream infections (CLABSI) in children present a unique challenge to infection prevention efforts but guidelines for management are lacking. Methods We reviewed CLABSI data at Texas Children’s Hospital (TCH) from fiscal years (FY) 2017-2019. A chart review to characterize clinical features, risk factors, and outcomes of patients with recurrent CLABSIs in FY2019 was performed. Descriptive statistics and Fisher’s exact test were used. Results Recurrent CLABSIs increased from FY 2017-2019 [20% (26/126) to 33% (44/131)] (P=0.03). In FY2019, 15 patients accounted for 44 CLABSIs (Figure 1). Underlying conditions included aplastic anemia (4), hemophagocytic lymphohistiocytosis (3), malignancy (4), genetic disease (2), congenital heart disease (1) and biliary atresia (1). Two-thirds of the CLABSIs occurred in the setting of severe neutropenia (ANC < 100 cells/mm3) though only 16 (36%) were classified as mucosal barrier injury. The median time between line insertion and date of infection was 41 days (range 1-105). Line type included central venous catheters (25, 57%), peripherally inserted central catheters (17, 39%) and implantable ports (2, 5%). Most lines (80%) had double lumens. The most common organisms included: Gram-negative bacilli (15), coagulase negative staphylococci (14), viridans group streptococci (6) Candida spp. (5), Enterococcus faecalis (3) and Staphylococcus aureus (3). Four CLABSIs were polymicrobial. Patients with >2 CLABSIs were more likely to have subsequent infections with the same organism as compared to patients with only 2 CLABSIs (P=0.01). Lines were removed promptly (19, 43%), had delayed removal (removal >72 hours from infection date) (10, 23%) or remained in place (15, 34%). Lines were removed for all episodes of fungemia (5/44) and for most Gram-negative infections (10/12). Six of 7 Escherichia coli CLABSIs were breakthrough fluoroquinolone-resistant infections in patients on levofloxacin. Single Episode and Recurrent CLABSIs at Texas Children’s Hospital for Fiscal Year 2019 Conclusion Recurrent CLABSI accounted for a third of CLABSIs in FY2019. Line mismanagement was not a key contributor to recurrent CLABSI. Breakthrough CLABSIs in patients on levofloxacin prophylaxis need further investigation. For patients with CLABSIs due to Staphylococci decolonization may be considered. Disclosures All Authors: No reported disclosures

BackgroundThe clinical courses and long-term outcomes of viridans streptococcus (VS) peritoneal dialysis (PD) peritonitis remain unclear.MethodsWe conducted a retrospective analysis of all PD patients in a single center with gram-positive cocci (GPC) peritonitis between 2005 and 2011, and divided them into 3 groups: VS, other streptococci and other GPC (apart from VS). Clinical characteristics and outcomes of the VS group were compared with the other streptococci and other GPC groups, with prognostic factors determined.ResultsA total of 140 patients with 168 episodes of GPC peritonitis (44% of all peritonitis) were identified over 7 years. Among these, 18 patients (13%) developed VS peritonitis, while 14 patients (10%) developed other streptococcal peritonitis. Patients with VS peritonitis had a high cure rate by antibiotic alone (94%), despite a high polymicrobial yield frequency (28%). We found that VS peritonitis carried a lower risk of Tenckhoff catheter removal and relapsing episodes than other GPC peritonitis (6% vs 11%), and a lower mortality than other streptococci peritonitis (0% vs 7%). However, after the index peritonitis episodes, VS, other streptococci, and other GPC group had a significantly increased peritonitis incidence compared with the period before the index peritonitis (all p < 0.01). Patients with VS peritonitis had a significantly higher incidence of refractory peritonitis compared with other streptococci or other GPC peritonitis in the long term (both p < 0.01).ConclusionsVS poses a higher risk of subsequent refractory peritonitis after the index episode as compared with other streptococcal or GPC peritonitis. It might be prudent to monitor the technique of these patients with VS peritonitis closely to avoid further peritonitis episodes.

In rats challenged with viridans streptococci poorly susceptible to antibiotic killing, single doses of antibiotics only prevent endocarditis induced by bacterial inoculum sizes that produce disease in 90% of control animals (ID90): additional doses are required to protect against inocula exceeding the ID90. We investigated whether single-dose rifampin would extend the efficacy of single-dose prophylaxis to inocula exceeding the ID90. We used two strains of viridans streptococci highly susceptible to killing by rifampin and two resistant strains. All rats were injected with 10-1,000 times the ID90 of the four strains. Single-dose rifampin successfully prevented endocarditis due to all four strains. A few prophylaxis failures were observed after challenge with the two poorly susceptible strains, but in vivo emergence of resistant variants did not account for these failures. Thus, rifampin was the first antibiotic given as a single dose that successfully prevented experimental streptococcus endocarditis after challenge with high bacterial inocula.

Streptococcus constellatus is a viridans Streptococcus belonging to the Anginosus group. It was associated with abscesses in 37 children, 80% of whom had acute appendicitis with perforation and abscess formation in 50%. None of the children was

Background Distinguishing blood culture (BC) results between common contaminants (CC) and truly pathogenic organisms can be challenging, especially among pediatric patients, but is important for effective clinical care. However, no recent studies have analyzed the true positivity of common BC contaminants in pediatric patients using linked laboratory data from a large national sample of United States hospitals. Methods We conducted a retrospective cohort study among patients ages < 19 using the Premier Healthcare Database (2009–2016), limiting to hospitals reporting ≥ 4 years of BC data and encounters with one of the five most frequent CC among laboratory-confirmed BC. True positivity was defined for each CC as a second positive BC within 48 hours among all BCs. A multivariable logistic regression model including all variables significant in univariate analyses was created comparing encounters: (1) with and without a second BC; and (2) second BC positive vs. negative, with corresponding adjusted odds ratios (aOR) and 95% confidence intervals (CI) reported. Results A total of 5056 isolates corresponding to 4915 encounters with a CC were included in this analysis; 3075 (61%) isolates had a second BC within 48 hours. Adjusted odds of a second BC were higher for encounters from urban (aOR: 1.73, 95% CI: 1.31, 2.29) and ≥ 500 bed hospitals (aOR 1.40, 95% CI: 1.20,1.63). True positivity was 20.2% for coagulase-negative staphylococci (CoNS), 5.9% for Bacillus spp., 5.2% for Viridans group streptococci, 5.0% for Diphtheroids spp., and 3.1% for Micrococcus spp. True positivity for CoNS was higher among neonates but all other organisms were higher for non-neonates (figure). Adjusted odds of true positivity were higher for encounters with chronic conditions (OR 1.44, 95% CI: 1.13, 1.82), a central line in place (OR: 1.65, 95% CI: 1.30, 2.10), per length of stay day (OR: 1.01 (1.01, 1.01), and with an intensive care unit admission (OR: 1.39, 95% CI: 1.08, 1.77). Conclusion True positivity varied substantially by organism, and in most cases was higher among non-neonates. Regional variations for conducting a second BC within 48 hours were found, and more seriously ill patient encounters were more likely to have a common contaminant be pathogenic. Disclosures All authors: No reported disclosures.

Background Patients with suspected urinary tract infection (UTI) are often prescribed an empiric antibiotic treatment due to delays in obtaining results of urine cultures. The BacterioScan System measures the turbidity of incubating urine specimens to provide a qualitative determination of bacteriuria at a density of >5 × 104 colony-forming units (CFU)/mL within approximately 3 hours. We examined the utility of the BacterioScan assay in predicting bacteriuria and assessed the potential impact of this test to reduce the number of urine cultures processed. Methods Urine samples received for culture in the microbiology laboratory of the Cleveland VA Medical Center were collected daily between September 2018 and December 2018. For each specimen, we performed a bacterioscan diagnostic test and compared it with the result of the traditional culture and urinalysis if available. Urinary cultures were categorized into 4 groups as defined in Figure 1. We compared the sensitivity and specificity of the bacterioscan vs. urinalysis (leukocyte esterase and/or pyuria) results. Results 120 urine samples were tested. As shown in Table 1, the BacterioScan had better sensitivity and specificity than the urinalysis for detection of positive urine cultures. The use of the BacterioScan to rule out UTI could have accurately spared 69 of 120 (57.5%) samples from traditional culture and prevented 26 of 120 (21.6%) from possible misinterpretation as infection due to reporting of growth. BacterioScan resulted in 4 of 31 (12.9%) false negatives, but all occurred when positive cultures were due to viridans streptococci or uropathogens in numbers below 100,000 CFU.ml. Conclusion The BacterioScan system is a rapid diagnostic test that provides early information on urine culture results that could help to avoid overuse of empirical antimicrobials in patients with suspected UTI and decrease the workload of the Microbiology Laboratory. Disclosures All authors: No reported disclosures.

Background Durable mechanical circulatory support device (MCSD) use continues to grow. MCSD deep-seated infections are a serious complication. Removal of the infected hardware is not always possible. Methods Single institution retrospective review of all culture-proven deep MCSD infection (pump and/or driveline) from 2009–2019. Patients were managed with intravenous (IV) and oral (PO) antibiotics; definitive surgical interventions included incision and drainage (I&D), device replacement, and heart transplant; and temporizing surgical measures were chronic chest tube (CCT) drainage for pump pocket and mediastinum and antibiotic impregnated bead implantation for driveline infection. Outcomes were analyzed. Results Total of 29 patients identified, 23 (79%) were male. Median age at device implantation was 44 years (20–68). MCSD were 18 (62%) destination therapy and 11 (38%) bridge to transplant. MCSD included 1 Heartmate I, 17 Heartmate II, 1 Heartmate III, 4 Heartware HVAD, and 6 Syncardia TAH. The median time to infection of 258 days (43–1551), affecting pump in 8 (28%), pump + driveline in 13 (44%), and driveline in 8 (28%). Microorganisms were S. aureus in 17 (60%, MRSA 11 and MSSA 6); coag-negative staphylococci in 3 (10%); Viridans streptococci in 1; Serratia marcescens in 3; P. aeruginosa in 2; Klebsiella oxytoca in 1; Mycobacterium abscessus in 1 and C. albicans in 1. Antibiotics are given to 28 patients, 23 (80%) with initial IV for a median of 6 weeks (1–14) and 5 (17%) with initial PO, for a median of 7 weeks (2–20). Nineteen patients (83%) on IV received PO antibiotics after. 17 patients (61%) remained on chronic suppression antibiotics (13 PO, 2 IV, 2 PO and IV). Twenty-six (90%) patients had I&D, 6 (21%) had device replacement and 11 (38%) had transplant. Of 21 patients with pump infection 16 (76%) had CCT drainage of pump pocket site or mediastinum for a median of 116 days (range 10–887 days). Of 21 patients with driveline infections, 6 (29%) had antibiotic impregnated bead implants. Overall survival at 90 days was 28/29 (95%) and 24/29 (83%) at 1 year. Infection-related mortality in Table 1. Conclusion Deep MCSD infection remains a challenging clinical problem. CCT drainage (for pump) and antibiotic-impregnated bead implant (for driveline) may be temporizing options for patients unable to undergo timely device replacement or heart transplant. Disclosures All authors: No reported disclosures.

The role of Streptococcus species as an aetiological microorganism of vertebral osteomyelitis (VO) is considered to be of little relevance. We aimed to describe a large number of cases of streptococcal vertebral osteomyelitis (SVO), to analyze the clinical features associated with different Streptococcus species, and to compare them with a cohort of patients with VO caused by Staphylococcus aureus. An incidence study and a retrospective, multicenter, observational clinical study of cases of SVO (1991–2011) were performed. Statistical comparison of SVO by different species and between them and staphylococcal VO was carried out. Over the whole period there was an increasing incidence in the number of VOs and SVOs per year (p