bacteremias – A 10 year experience at Mayo Clinic, Rochester, MN Poornima Ramanan, M.D.1, Jason N.Barreto, Pharm. D, R.Ph.2,Douglas R.Osmon, M.D.1, Pritish K. Tosh, M.D.1 1Division of Infectious Diseases, 2Department of Pharmacy, Mayo Clinic, Rochester, MN

Abstract (Revised) Background Results Discussion

Rothia species are part of the normal flora of the human We identified 67 adults with Rothia bacteremia. There was no clear temporal oropharynx and upper respiratory tract. The members of this change in the incidence of Rothia bacteremia over 10 years, however the Background: genus are Rothia mucilaginosa, Rothia dentocariosa, Rothia maximum number of cases were seen in the year 2011 (Figure 1). Thirty-nine Rothia are gram positive that are normal flora of the human aeria, Rothia nasimurium and Rothia amarae. They are patients (66%) had a Charlson comorbidity index score of 4 or greater (Figure 2). upper respiratory tract and cause infections in immunocompromised aerobic or facultatively anaerobic, non-motile, non-spore The common sources of bacteremia were line (17,31%) and presumed GI and normal hosts. The epidemiology and clinical significance of forming, gram positive cocco-bacilli that can form translocation (20,28%) . There was no identifiable source in 36 (34%) cases Rothia bacteremia are not well described. filamentous branches.Rothia are commonly associated with (Figure 3). Neutropenics were significantly less likely to have polymicrobial dental caries and . Invasive disease infection (35% vs. 70%, p=0.0068) or single blood culture set positivity (41% vs. Methods: occurs predominantly in immunocompromised hosts but has 90%, p<0.001) than non-neutropenics (Table 2). Susceptibility testing was done in A retrospective cohort study was conducted at Mayo Clinic, rarely been reported in normal hosts. The clinical syndromes only 14(21%) isolates since the growth of the organism was frequently inadequate Rochester, MN of adult patients with blood cultures positive for associated with Rothia include bloodstream infections, in the lab (Figure 4). There was no significant association between receipt of Rothia, January 2002 – December 2012. Medical records were endocarditis, meningitis, peritonitis, bone and joint infections, , levofloxacin, cefepime or vancomycin within the prior month and the reviewed. Descriptive analysis was performed as well as comparative pneumonia, skin and soft tissue infection, endophthalmitis ability to grow the organism for susceptibilities. All tested isolates were susceptible analysis of patients who were neutropenic (absolute neutrophil count and prosthetic device infection among others. Some of the to penicillin, ceftriaxone, ertapenem, meropenem and vancomycin. Four isolates ≤ 1000 /µL) at the time of bacteremia to those who were not risk factors for invasive disease include hematological were resistant to oxacillin (Figure 5).Although there were 10 deaths, only 4 were neutropenic. Fisher’s exact and Kruskal-Wallis tests were used for malignancy, neutropenia, diabetes mellitus, alcoholism, possibly attributable to the Rothia bloodstream infection(Table 2). There was no comparisons of proportions and medians, respectively, with p-values chronic liver disease, AIDS and intravenous drug abuse. The difference between neutropenics and non-neutropenics in need for ICU care, <0.05 considered statistically significant. clinical significance of isolation of Rothia from blood culture mortality and attributable mortality (Table 2). is frequently unclear, especially in the setting of a single Results: blood culture set positivity with polymicrobial infection In total, 67 adults with Rothia bacteremia were found. The median suggesting contamination. age was 60 years (range 19 – 89) with a 2:1 male predominance. A Charlson comorbidity score of 4 or greater was found in 39 (66%) Aims patients; 38 (57%) patients had a hematologic malignancy or bone Conclusions marrow transplant. Although there were 10 deaths, only 4 were  To describe the epidemiology and clinical significance of possibly attributable to Rothia infection. Neutropenia was observed in Rothia blood stream infections in Mayo Clinic, Rochester.  Rothia bacteremia often occurs in patients with significant medical 37 (55%) patients at the time of bacteremia. Due to poor growth,  To evaluate difference in clinical outcomes between comorbidities, most commonly hematologic malignancy, for which in-hospital susceptibility testing was only able to be performed on 14 (21%) neutropenic and non-neutropenic patients. mortality is high. isolates; however all of these isolates were susceptible to beta-  To describe the antimicrobial susceptibility pattern of  Antimicrobial susceptibility testing is often not able to be performed due to its lactams and vancomycin. Neutropenics were significantly less likely to Rothia isolates. poor growth in culture, but when able to be performed suggests susceptibility have polymicrobial infection (35% vs. 70%, p=0.0068) or single blood to most beta-lactam antimicrobials and vancomycin. However, resistance to culture set positivity (41% vs. 90%, p<0.001) than non-neutropenics. penicillin and oxacillin may occur. There was no difference between neutropenics and non-neutropenics Methods  When Rothia is identified in blood culture from neutropenic patients, it is more in need for ICU care, mortality, or attributable mortality. likely to be monomicrobial and less likely to represent contamination compared This is a single-center, retrospective cohort study of adult to non-neutropenic patients.

Conclusions: patients with blood cultures positive for Rothia between Rothia bacteremia occurred in patients with significant medical January 2002 to December 2012 at the Mayo Clinic in comorbidities, most commonly hematologic malignancy, for which in- Rochester. All medical records were reviewed. The Charlson comorbidity index score was used to assess the severity of hospital mortality was high. Antimicrobial susceptibility testing was References infrequently performed due to poor growth, but when able to be underlying diseases. Antimicrobial susceptibility testing of performed revealed susceptibility to penicillin, ceftriaxone, the Rothia isolates was carried out using the agar dilution method. Descriptive analysis was performed as well as 1. Bruminhent J, Tokarczyk MJ, Jungkind D, and Desimone JA, Jr. Rothia mucilaginosa Prosthetic Device ertapenem, meropenem, and vancomycin. Four isolates were Infections: a Case of Prosthetic Valve Endocarditis. J Clin Microbiol 2013; 51(5): 1629-1632. resistant to oxacillin. When Rothia was identified in blood culture from comparative analysis of patients who were neutropenic 2. Quan H, Li B, Couris CM et al. Updating and validating the Charlson comorbidity index and score for risk neutropenic patients, it was more likely to be monomicrobial and less (absolute neutrophil count ≤ 1000 /µL) at the time of adjustment in hospital discharge abstracts using data from 6 countries. Am J Epidemiol 2011; 173(6): bacteremia to those who were not neutropenic. Fisher’s 676-682. likely to represent contamination compared to non-neutropenic 3. Shakoor S, Fasih N, Jabeen K, and Jamil B. Rothia dentocariosa endocarditis with mitral valve prolapse: patients. exact and Kruskal-Wallis tests were used for comparisons of case report and brief review. Infection 2011; 39(2): 177-179. proportions and medians, respectively, with p-values <0.05 4. McWhinney, P.H., et al., Stomatococcus mucilaginosus: an emerging pathogen in neutropenic patients.  2013 Mayo Foundation for Medical Education and Research considered statistically significant. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 1992. 14(3): p. 641-6.