Antimicrobial Susceptibility Summary

2016—Pierce County, Washington

From Jan. 1 to Dec. 31, 2016, Pierce County MultiCare and • MRSA coverage should be considered for purulent skin military hospital labs reported antibiotic susceptibility test and soft tissue infections (SSTI). Non-purulent SSTIs results to Tacoma-Pierce County Health Department. are rarely caused by Staphylococcus aureus and MRSA coverage is usually not necessary. Antibiotic susceptibility test results include inpatient and outpatient data. Data includes only bacterial isolates • The best agents for empiric MRSA coverage include collected for diagnostic purposes. Surveillance cultures were TMP-SMX and tetracycline analogs (i.e., minocycline or not included. Results reflect combinations of different patient doxycycline). populations with different syndromes, infection sites and risk factors for drug-resistant organisms (e.g., adult vs. pediatric, • Due to the risk of renal failure and severe side effects, inpatient vs. outpatient, ICU vs. non-ICU). TMP-SMX should be used with caution in the elderly and those with pre-existing renal dysfunction. Based on this data and established treatment guidelines, Pierce County Antibiotic Resistance Task Force recommends Acute Otitis Media in Pediatric Patients the following. • Consider treating uncomplicated acute otitis media (AOM) without antibiotics to reduce antibiotic resistance. Most Urinary Tract Infection cases of AOM resolve without antibiotics. • Short courses, selecting recommended agents and • When otitis media with effusion (OME) is diagnosed, avoiding fluoroquinolones are important stewardship antibiotics are not the answer. Effusions may take many strategies. weeks to resolve. • (i.e., cephalexin, cefpodoxime, cefdinir) • First line therapy for AOM, when needed, should be and nitrofurantoin (if creatinine clearance (CrCl) > 60 ml/ amoxicillin 90 mg/kg/day divided BID (maximum 2g/day) min) are the best options for empiric urinary tract infection for 5 to 10 days, depending on child’s age and severity of (UTI) treatment. illness. • Avoid sulfamethoxazole-trimethoprim (TMP-SMX, Bactrim) unless susceptibilities are available. Resistance rates for Limitations common gram-negative pathogens causing UTI are rising. Avoid empiric treatment with TMP-SMX where resistance • CHI Franciscan Health System was unable to report. Due rates are 20% or greater. E. coli resistance to TMP-SMX in to the small number of participating hospitals, data from Pierce County was 20% in 2016 and, therefore, should not larger hospitals may disproportionately impact aggregate be used for empiric treatment. results. • Data are the result of single organism-antimicrobial • Patients without urinary symptoms generally do not need treatment for positive urine dipstick or urinalysis testing combinations. They do not show trends in cross- resistance between an organism and multiple drugs. Nor (unless pregnant or undergoing an invasive urological do they reveal synergistic properties of using different procedure). antimicrobials in combination with each other. • Use nitrofurantoin for afebrile cystitis only (not • Organisms can have multiple strains and are not always pyelonephritis). Patient must have CrCl >60 for drug to be homogenous for clinical pathology or drug resistance. excreted into the urinary tract. For example, this report combines all isolates of • Due to the possibility of side effects and rising resistance Staphylococcus aureus, regardless of methicillin-resistance. levels in some parts of the world, reserve fluoroquinolone • We were unable to determine how many Streptococcus use when possible. When prescribing fluoroquinolones, pneumoniae isolates were invasive, meaning they were ciprofloxacin is preferred for gram-negative coverage in obtained from a sterile site within the body. UTI. Avoid moxifloxacin, as it is not renally excreted. • Not all labs use the same methods to test for microbial Methicillin-resistant Staphylococcus aureus resistance or create antibiograms. Inconsistency in methods can mask important differences and trends. • Pierce County’s overall Methicillin-resistant Staphylococcus aureus (MRSA) rate remained at 43%, • Data may not be generalized to specific patient unchanged from 2015. populations or community locations.

Page 1 of 2 Results limited significanttrends. to statistically epidermi epidermi Staphylococcus Staphylococcus aeruginosa Pseudomonas aeruginosa Pseudomonas aeruginosa Pseudomonas mirabilis Proteus mirabilis Proteus mirabilis Proteus mirabilis Proteus pneumoniae Klebsiella coli Escherichia coli Escherichia Enterococcus Enterococcus Enterococcus cloacae Enterobacter aerogenes Enterobacter freundii freundii Citrobacter Organism 2014-2016—Three-Year Trends inAntimicrobialSusceptibility, PierceCounty aureus Staphylococcus Enterococcus Positive Organism Gram nt marcescens Serratia aeruginosa Pseudomonas mirabilis Proteus morganii Morganella pneumoniae Klebsiella coli Escherichia cloacae Enterobacter aerogenes Enterobacter freundii Citrobacter baumanii Acinetobacter Organism Negative Gram 2016—Antimicrobial SusceptibilityofCommonOrganisms,PierceCounty = Not tested. =Not species 18,747 Gentamicin Clindamycin -Tazobactam Levofloxacin Imipenem Ciprofloxacin Trimeth./Sulfa. Tobramycin Levofloxacin Cefazolin Ampicillin Nitrofuratoin Tobramycin Levofloxacin Ampicillin Vancomycin Nitrofuratoin Levofloxacin Ciprofloxacin Ceftriaxone Imipenem Nitrofuratoin Ceftriaxone Drug 6,634 2,426 1,465 1,033 968 204 464 287 No. No. 313 38 51 Tested Tested < 30 < 30 60 98 78 nt nt nt nt nt nt nt % % Penicillin Ampicillin 100 96 99 98 89 85 82 57 87 97 nt nt % % Oxacillin Pip./Taz. n/a 80 89 93 77 nt nt nt nt nt nt nt % % Clindamycin Cefazolin % 96 96 95 95 85 42 79 74 nt nt nt nt % % Susceptibility by Year Susceptibility 2014

100 Erythromycin Ceftriaxone 90 60 80 86 86 69 88 88 88 88 85 85 82 64 92 32 72 57 87 81 71 71 96 96 99 82 97 91 71 nt nt nt nt nt % % Gentamicin Ceftazidime 2015 100 90 96 99 99 92 63 100 72 97 nt nt nt 90 % % 58 88 88 82 94 94 92 84 84 35 49 72 70 67 79 97 73 74 81 81 71 Nitrofuratoin Imipenem 100 100 90 90 96 95 95 86 98 84 97 nt % % 2016

100 100 Levofloxacin Gentamicin 90 90 80 80 40 40 95 95 89 88 < 30 64 94 94 92 78 78 97 97 76 74 81 100 100 96 96 99 95 95 89 92 97 nt % % Tetracycline Tobramycin % < 30 < 30 40 2014 vs. 2016 vs. 2014 98 92 Total Change nt nt nt nt nt nt nt % % Rifampin Nitrofuratoin 90 96 95 95 89 94 94 84 84 76 77 nt % % Trimeth./Sulfa. Ciprofloxacin 100 100 100 -24 90 90 80 89 88 94 35 -17 87 -11 10 16 -6 12 -8 14 17 nt nt -7 % % 11 9 6 6 5 5 8 7 7 7 7 Vancomycin Levofloxacin 100 90 80 98 85 92 92 78 nt nt % Trimeth/sulfa Vancomycin Trimeth./Sulfa. Tetracycline Penicillin Levofloxacin Erythromycin Cefriaxone Ceftazidime isolates 250 pneumoniae Strep Page 2 of2 250 210 No. 192 40 40 40 40 18 Tested 100 100 100 90 98 63 75 78 % Susceptible