VOLUME XXIX NUMBER 3 November 2014 CONTAGIOUS COMMENTS Department of Epidemiology Bugs and Drugs Elaine Dowell SM MLS (ASCP), Marti Roe SM MLS (ASCP), Sarah Parker MD, Jason Child PharmD, and Samuel R. Dominguez MD PhD Antibiogram Tables The 2013 Microbiology Laboratory antibiogram is also published within the Bugs and Drugs Handbook. Copies are available from Microbiology or Epidemiology (720-777-6412) and internally on the Pathology Webpage at: (http://prdplanetcf02.thechildrenshospital.org/apps/cm/files/21799.pdf). Items of importance from this year s data are highlighted here. With the exception of Stenotrophomonas maltophilia, these changes reflect decreases in susceptibility for the organisms isolated in the CHCO microbiology laboratory. Stenotrophomonas maltophilia demonstrates an increase in trimethoprim-sulfamethoxazole susceptibility. Our percentage matches the rate seen in other institutions nationwide. There is no increase in non-urine ESBL isolation; however a decrease in gentamicin susceptibility is noted among our isolates. Haemophilus influenzae isolates are more ampicillin resistant. Viridans streptococci are significantly more resistant to penicillin. S. anginosus demonstrates a shift to higher MICs with more intermediate interpretations reported. S. aureus susceptibility to clindamycin decreased by about 10% for both MSSA and MRSA. Isolation of VRE increased from one in previous year to five this past year. A footnote was added to Table 2 Indicating that non-meningeal S. pneumoniae infections may be treated with amoxicillin, cefepime, cefotaxime, ceftriaxone, and cefuroxime. Rapid Blood Culture ID Panel (BCID) This spring, the Microbiology Lab implemented the BCID panel which is a multiplex PCR consisting of 8 gram positive targets, 11 gram negative targets, 5 yeast targets and 3 resistance mechanisms. When blood culture bottles arrive in the Microbiology Lab, they are placed on the Bactec blood culture analyzer and continuously monitored during their 5 day incubation. When the blood culture becomes positive, a Gram stain is performed and a phone call is made within 30 minutes to a physician caring for the patient to report the critical value in Microbiology. Then, the blood culture bottle is tested using the BCID panel. Within about an hour, results are reported with a second phone call to the clinician caring for the patient. In many cases, the organism will be definitively identified by BCID. In the case of an organism that is not represented on the panel, a report will be issued that indicates BCID organisms were not identified. In the case of mixed blood cultures, one organism may be detected and a second may not, yielding variable results. The test is kept in preliminary status until the traditional culture result is available. Occasionally, a corrected report may be issued when definitive culture results do not correlate with the BCID. The intent of performing and reporting the BCID is to allow the clinician the fastest results available, allowing for appropriate antimicrobial adjustments so that patients are treated appropriately in the best available time frame. Rapid reporting of organism identification holds the potential to bring savings to the institution through de-escalation of antimicrobials and avoiding readmission of patients with positive blood cultures deemed likely contaminants. VOLUME XXIX NUMBER 3 November 2014 Page 1
Antimicrobial Stewardship Combines Forces with Microbiology Antimicrobial Stewardship works closely with the microbiology laboratory in an effort to improve patient care. The stewards work to decrease antibiotic pressure within CHCO, in order to decrease antimicrobial resistance, C. difficile infections and adverse drug events, and to improve antimicrobial dosing and efficacy. In order to harness maximal benefit from BCID, the second call described above may be placed by one of the antimicrobial stewards; the stewards will report the BCID result, and are available to field general questions on antimicrobial dose and choice. When highly resistant organisms occur, the stewards are available to help with optimal choice and dosing strategies. Sputum Sample Rejection Criteria Criteria for sputum sample rejection criteria are currently in place. When submitted for bacterial culture, sputa that contain >10 squamous epithelial cells observed per oil immersion field are rejected. This criteria was established by our accrediting agency and is a marker for oral flora contamination. Culture results from specimens that are heavily contaminated in this way are unreliable and will not be cultured. Specimens for Cystic Fibrosis Culture are exempt from this protocol by special request because they are surveillance cultures designed to isolate certain types of bacteria and results are not typically affected by normal oral flora contamination. 2013 Annual Antibiogram Tables 1-7 TABLE 1. Antimicrobial Susceptibilities at Children s Hospital Colorado 2013 Staphylococcus (% susceptible) TESTED Oxacillin* Trimethoprim / Sulfa Clindamycin Vancomycin Staph aureus (MSSA) 806 100 99 78 100 Staph aureus (MRSA) 478 R 99 69 100 Staph epidermidis 206 38 72 100 * Includes agents: Nafcillin/Dicloxacillin/Methicillin Oxacillin resistance predicts resistance to ALL beta-lactams (including penicillin, extended spectrum penicillins and cephalosporins (MRSA) Confirmation of MRSA by PBP2 or Microscan Panel Other antimicrobials tested by Microscan panels VOLUME XXIX NUMBER 3 November 2014 Page 2
TABLE 2. Antimicrobial Susceptibilities at Children s Hospital Colorado 2013 Streptococcus (% susceptible) Penicillin Cefotaxime S I R S I R S. pneumoniae 1 Meningeal (2011-2013) (10) 60 40 90 10 100 S. pneumoniae 1 Non-meningeal 137 96 3 1 93 6 1 67 91 68 * 100 Viridans Strep 1 Group - Invasive 81 45 38 17 25 89 83 100 Strep. anginosus Group 1 - Invasive 41 85 13 2 80 88 95 100 Beta Strep Group A 1 Invasive (21) S 100 100 S Beta Strep Group B 1 (10) S 2 S Beta Strep Group B 1 (prenatal screens) 505 S 51 57 100 Enterococcus faecalis 2 145 100 100 Enterococcus faecium 2 54 56 100 Vanc Resistant Enterococcus spp. (VRE) ** 5 R R 1 Testing by E-test. Testing by Microscan panel. ( ) = small numbers S = Always susceptible to penicillin, ampicillin and cephalexin. **Five new VRE patient identified in 2013 for therapy choices, ID consult recommended. * S. pneumoniae isolates that are susceptible to penicillin are also susceptible to ampicillin. S. pneumoniae infections may be treated with amoxicillin, cefotaxime, ceftriaxone and cefepime. Cefotaxime susceptibility does not imply susceptibility to oral cephalosporins. Gentamicin Synergy Screen E. faecalis = 94% Susceptible Gentamicin Synergy Screen E. faecium = 91% Susceptible Gentamicin Synergy Screens on VRE isolates show 100% Susceptible at CHCO Combination therapy should be used in serious Enterococcus spp. infection (endocarditis & bacteremia). Gentamicin synergy screen predicts synergy of aminoglycosides with cell wall active agents. Erythromycin Clindamycin Trimethoprim/Sulfa Cefotaxime Ampicillin/ Amoxicillin Vancomycin VOLUME XXIX NUMBER 3 November 2014 Page 3
TABLE 3. Antimicrobial Susceptibilities at Children s Hospital Colorado 2013 Gram Negative Organisms, non urine (% susceptible) Ampicillin / Amoxicillin Cefazolin Cefotaxime/ Ceftriaxone Gentamicin Trimethoprim / sulfa Ciprofloxacin Meropenem Cefepime Haemophilus species (29) 21 100 69 E. coli 89 43 93 98 91 65 90 100 100 Enterobacter cloacae 48 R R 90 100 88 96 100 100 Klebsiella pneumoniae 42 R 100 100 100 83 100 100 100 Klebsiella oxytoca (24) R 75 100 100 83 92 100 100 Serratia marcescens (20) R R 100 100 85 85 95 100 Citrobacter freundii 35 R R 84 96 84 100 100 100 Salmonella species 54 85 96 96 Shigella species* (25) 70 100 70 ( ) = small numbers * = Data combined 2012 2013 R = Resistant (Intrinsic) Haemophilus spp. tested by E-test. All other testing by Microscan panel. 5 non-urine ESBL producing Enterobacteriaceae were isolated not included in above data. VOLUME XXIX NUMBER 3 November 2014 Page 4
TABLE 4. Antimicrobial Susceptibilities at Children s Hospital Colorado 2013 Gram Negative Organisms isolated from Urine (% susceptible) Ampicillin / Amoxicillin Ampicillin/Sulbactam Cephalothin** Cefuroxime Cefotaxime/ Ceftriaxone Gentamicin Nitrofurantoin Trimethoprim / sulfa Ciprofloxacin Ceftazidime Levofloxacin Cefepime E. coli 1290 55 60 74 99 99 94 99 73 94 E. coli ESBL* (23) R 4 R R R 65 100 39 30 R R Enterobacter cloacae 39 R R R 33 64 97 44 82 100 Klebsiella pneumoniae 104 R R 90 91 100 98 63 88 95 Klebsiella oxytoca 35 R R 74 89 100 100 97 91 100 Proteus mirabilis 60 87 95 95 97 98 92 R 83 97 Pseudomonas aeruginosa 49 61 76 65 76 ( ) Small number of isolates R = Resistant (Intrinsic) Testing by Microscan panel **Cephalothin results can be used as a surrogate to predict susceptibility to the oral cephalosporin agents: cefdinir, cefpodoxime, cephalexin. *Note: Patients with ESBL producing organisms isolated from urine who have uncomplicated UTI may respond to therapy with beta-lactam agents. VOLUME XXIX NUMBER 3 November 2014 Page 5
TABLE 5. Antimicrobial Susceptibilities at The Children s Hospital 2013 Non-Enterobacteriaceae (% susceptible) Ticarcillin/clavulanic acid Ceftazidime Aztreonam Levofloxacin Tobramycin Meropenem Piperacillin / Tazobactam Minocycline Trimethoprim / Sulfa Ciprofloxacin Gentamicin Cefepime Pseudomonas aeruginosa Non CF 2 149 95 83 95 97 89 74 86 CF-mucoid 1 32 81 78 66 75 84 76 CF-nonmucoid 1 44 75 77 70 73 75 77 Stenotrophomonas maltophilia 1 65 18 17 49 R 92 96 1 2 Cystic fibrosis (CF) isolates performed by E-test. Non-CF testing performed by Microscan panel. VOLUME XXIX NUMBER 3 November 2014 Page 6
TABLE 6. Antimicrobial Susceptibilities at Children s Hospital Colorado 2013 Candida species (# of isolates susceptible) Antifungal # Tested # Susceptible # SDD # Resistant Amphotericin 13 13 Micafungin 13 13 Fluconazole 12 12 Voriconazole 13 13 Testing performed by UTHSC at San Antonio Fluconazole comments: SDD - Susceptible Dose Dependent C. glabrata treatment with fluconazole requires maximum dosages when the MIC is < 32 ug/mll, ID consult is recommended. *C. krusei is intrinsically resistant to fluconazole (isolates not tested). Candida spp. isolates included in data: (12 blood isolates) C. albicans 4 C. parapsilosis 5 C. lusitaniae - 2 C. krusei - 0 C. glabrata - 1 C. tropicalis 1 VOLUME XXIX NUMBER 3 November 2014 Page 7
Table 7. Cumulative Antimicrobial Susceptibility Report for Anaerobic Organisms Isolates collected from US hospitals January 1, 2007 December 31, 2009 ANAEROBIC Ampicillin-sulbactam (Unasyn) Piperacillin/tazobactam (Zosyn) Cefoxitin Ertapenem Meropenem Penicillin/ampicillin Clindamycin Metronidazole Percent Susceptible (%S) and %S %R %S %R %S %R %S %R %S %R %S %R %S %R %S %R Percent Resistant (%R) Fusobacterium nucleatum- 44 100 0 100 0 100 0 100 0 * 0 100 0 100 0 100 0 necrophorum Anaerobic gram- positive 168 98 1 100 0 100 0 100 0 * 0 96 3 78 20 98 1 cocci P. acnes 34 100 0 100 0 100 0 100 0 * 0 100 0 91 3 3 97 B. fragilis group 1580 86 4 95 2 65 9 97 1 98 1 50 39 100 0 *% S for meropenem is not reported due to lack of data and breakpoints are not well established. Data adapted from CLSI M100-S23 January 2013. VOLUME XXIX NUMBER 3 November 2014 Page 8
We are modifying our distribution process for Contagious Comments. If you wish to receive this publication please provide us with your E mail address below. Name: E mail Address: Both the Contagious Comments and Bug Watch publications are always posted on Children s Hospital Colorado website at: http://www.childrenscolorado.org/news/publications/index.aspx Please return your E mail address to: Carolyn Brock, Children s Hospital Colorado, Epidemiology Box B276, 13123 E. 16 th Avenue, Aurora, CO 80045 or E mail address: carolyn.brock@childrenscolorado.org. Thank you for your interest in our publication. CONTAGIOUS COMMENTS Department of Epidemiology EDITOR: Carolyn Brock, Program Assistant Children s Hospital Colorado, Dept. of Epidemiology, B 276 13123 E. 16th Avenue, Aurora, CO 80045 Phone: (720) 777 6412; FAX: (720) 777 7295 carolyn.brock@childrenscolorado.org www.childrenscolorado.org ** We Recycle! ** VOLUME XXIX NUMBER 3 November 2014 Page 9