Aberdeen Hospital Antibiotic Susceptibility Patterns For Commonly Isolated s For 2015 Services Laboratory Microbiology Department Aberdeen Hospital Nova Scotia Health Authority 835 East River Road New Glasgow, NS B2H 3S5 Developed with Dr. D Haldane, Director PPHLN
Number of isolates Clindaymcin Erythromycin Levofloxacin Oxacillin Penicillin Trimeth/Sulfa (TMP-SMZ) Vancomycin Number of isolates Amoxicillin\Clavinic Cephalothin Cefazolin Cefixime Cefoxitin Ceftazidime Ceftriaxone Ertapenem Gentamicin Tobramycin Meropenem Piperacillin/Tazobactam Trimeth/sulfa (TMP-SMZ) 2015 Microbiology Susceptibility Report (January 1, 2015- December 31, 2015) IN-PATIENT ISOLATES - % Susceptibility for GRAM NEGATIVE Isolates Escherichia coli 106 73 50 42 78 88 80 89 89 62 100 88 86 99 87 85 69 73 Pseudomonas aeruginosa 24 NT NT NT NT NT NT 88 NT 74 IR 95 100 87 NT 83 NT IR Klebsiella pneumoniae 35 88 IR 88 91 94 89 94 94 89 100 100 94 97 45 94 91 85 Proteus mirabilis 34 100 59 47 47 88 94 88 88 94 100 73 73 97 IR 94 IR 72 NT = Not Tested * For use in Urinary Tract Infection only. IN-PATIENT ISOLATES- % Susceptibility for GRAM POSITIVE isolates Enterococcus species 69 87 33 IR IR 39 80 IR 85 40 IR 100 Staphylococcus aureus MSSA** 42 IR 91 64 57 95 DNU 100 0 100 100 100 Staphylococcus aureus- MRSA *** 14² IR 7 43 14 7 DNU 0 0 100 100 100 NT = Not Tested DNU= Do not use. * For use in Urinary Tract Infection only. NOTE: MSSA/MRSA in urine often reflects systemic infection. **MSSA that is sensitive to Oxacillin is also susceptible to 1 st generation cephalosporins. ***Methicillin Resistant S.aureus is resistant to ALL penicillins, cephalosporins and carbapenems. ² s with less than 20 isolates should be interpreted with caution as results may be biased by particularly resistant or susceptible strains.
Number of isolates Clindamycin Erythromycin Levofloxacin Oxacillin Penicillin Trimeth/sulfa (TMP-SMZ) Number of isolates Amoxicillin\Clavulinic Cephalothin Cefixime Trimeth/Sulfa (TMP-SMZ) COMMUNITY ISOLATES - % Susceptibility for GRAM NEGATIVE Isolates Escherichia coli 1031 82 60 51 91 84 91 80 79 Klebsiella pneumoniae 160 96 IR 93 96 98 38 85 93 Proteus mirabilis 95 100 87 35 95 98 IR IR 71 Pseudomonas aeruginosa 46 IR IR IR NT 93 0 0 IR Klebsiella oxytoca 14 93 IR 21 100 100 50 93 100 Enterobacter cloacae 12 IR IR 0 33 100 8 100 100 NT = Not Tested * For use in Urinary Tract Infection only. COMMUNITY ISOLATES - % Susceptibility for GRAM POSITIVE and Urine isolates Enterococcus species 162 97 61 IR IR 63 94 IR 97 29 IR Staphylococcus aureus- MSSA** 69 IR 88 71 71 91 DNU 100 IR 96 100 Staph aureus MRSA*** 11² IR 0 18 0 0 DNU 0 IR 100 100 Coag Neg Staph 18² NT 67 50 44 67 DNU 67 IR 89 67 NT = Not Tested DNU= Do not use. * For use in Urinary Tract Infection only. NOTE: MSSA/MRSA in urine often reflects systemic infection. **MSSA that is sensitive to Oxacillin is also susceptible to 1 st generation cephalosporins ***Methicillin Resistant Staph aureus is resistant to ALL Penicillins, Cephalosporins and carbapenems. ² s with less than 20 isolates should be interpreted with caution as results may be biased by particularly resistant or susceptible strains.
GUIDELINES FOR INTERPRETATION OF GRAM STAIN RESULTS: Gram-Positive Cocci (GPC) Pairs, chains, clusters: Staphylococcus sp Pairs, chains: Streptococcus sp Enterococcus sp Gram-Negative Cocci (GNC) Diplococci Pairs: Neisseria meningitidis Neisseria gonorrhoeae Moraxella catarrhalis Acinetobacter sp Gram-Positive Bacilli (GPB) Diphtheroids: Small, pleomorphic: > Corynebacterium sp > Propionibacterium (anaerobe) Large, with spores: Clostridium sp Bacillus sp Branching, beaded, rods: Nocardia sp Actinomyces sp (anaerobe) Listeria sp (Blood/cerebrospinal fluid) Lactobacillus sp (Vaginal/blood) Gram-Negative Bacilli (GNB) Enterobacteriaceae: Escherichia coli Serratia sp Klebsiella sp Enterobacter sp Citrobacter spp. Afermenters: Pseudomonas spp. Stenotrophomonas maltophilia Haemophilus influenzae Bacteroides fragilis group (Anaerobe) Fusiform (long, pointed): Fusobacterium sp (anaerobe) Capnocytophaga spp. These guidelines are not definitive but reflect the morphology of common isolates on gram stain. Treatment will depend on the quality of the specimen and appropriate clinical evaluation.
Aberdeen Hospital Microbiology Laboratory Antibiogram Guidelines: 1. Figures for organisms with less than 20 isolates should be interpreted with caution as results may be biased by particularly resistant or susceptible strains. 2. Specific susceptibilities should be consulted when available. When the antibiogram indicates sensitivity to an antibiotic is 85 % or less it is no longer recommended for empiric treatment. 3. Cephalexin may be used in place of cephalothin. 4. Cefazolin may be used in place of cephalexin or cephalothin. 5. Cefotaxime may be used in place of ceftriaxone. 6. is NOT the drug of choice for gram positive organisms. 7. Levofloxacin is effective against most pathogens from respiratory sites. 8. Nitrofurantoin is used for urinary tract infection only. 9. Vancomycin should be used ONLY in serious infections due to beta-lactam/methicillin resistant gram positive organisms or p.o. in Clostridium difficile associated colitis that is severe or unresponsive to metronidazole. Drug Levels should be monitored and levels over 20mg/L should be avoided. 10. Enterococcus spp is always resistant to aminoglycosides, cephalosporins, clindamycin and trimethoprimsulfamethoxazole. Combination therapy of ampicillin, penicillin or vancomycin plus gentamicin is usually indicated for serious enterococcal infections such as endocarditis. 11. Streptococcus pyogenes (Group A Streptococcus): penicillin is the treatment of choice for most infections. 12. Clostridium difficile is susceptible to metronidazole and vancomycin even when relapse occurs. 13. Klebsiella spp is resistant to ampicillin and by extension amoxicillin. 14. MRSA is resistant to all penicillins, cephalosporins and carbapenems. 15. Haemophilus influenzae is about 25% resistant to ampicillin but is susceptible to quinolones, doxycycline and macrolides. 16. Moraxella catarrhalis is generally susceptible to trimethoprim/sulfamethoxazole, erythromycin and tetracycline. 17. Staphylococcus saprophyticus is generally susceptible to nitrofurantoin and trimethoprim/sulfamethazole. 18. Staphylococcus lugdunensis has virulence factors that resemble S. aureus and can cause similarly aggressive infections. 19. Streptococcus agalactiae (Group B Streptococcus) can be considered susceptible to penicillin, ampicillin, amoxicillin and all cephalosporins. For individuals with minor penicillin allergies, cefazolin is the drug of choice. Clindamycin or vancomycin are the preferred agents for patients with a high risk for anaphylaxis. 20. Pasteurella spp: penicillin is effective, and amoxicillin/clavulanate can be used where mixed infections including Pasteurella spp is anticipated (e.g. dog, cat or human bites). Pasteurella spp is resistant to 1 st generation cephalosporins, cloxacillin and clindamycin. 21. Morganella spp, Proteus vulgaris, Providencia spp and Serratia spp are always resistant to ampicillin, cefazolin and nitrofurantoin. 22. Candida albicans is usually susceptible to fluconazole; C. glabrata may be resistant to fluconazole; C. krusei is intrinsically resistant to fluconazole. 23. Most gram negative anaerobes and gram positive anaerobic rods are susceptible to metronidazole. Anaerobic gram positive cocci, e.g. Peptostreptococcus spp, are often resistant, but are usually susceptible to penicillin.