Staphylococcus aureus Resistance Patterns in Wisconsin

Abstract

Objective: Surveillance of antimicrobial resistance patterns on a local level can reveal paradigms not obvious on a regional or national scale. Data collection from this perspective may potentially impact local prescribing patterns and empiric treatment guidelines. The objective of this study was to establish a baseline Staphylococcus aureus antibiogram for the state of Wisconsin and to elucidate potential geographic and demographic factors associated with antimicrobial resistance.Design: Multi-center laboratory surveillance, with testing at a single site utilizing standardized media and susceptibility testing protocols.Methods: 309 isolates of clinically-significant S. aureus were collected from hospital microbiology laboratories across Wisconsin in 2018, with distribution across seven geographic regions. Each isolate was tested using reference broth microdilution methods against a panel of 15 antimicrobial agents. Percentage susceptibility data, as well as median and 90th percentile minimum inhibitory concentration (MIC) values, were computed for each antimicrobial agent as a function of geographic region or demographic category.Results: Increased resistance to penicillin (≥ 86.0% of isolates), erythromycin (≥ 56.8%), cefoxitin (≥ 45.5%), levofloxacin (≥ 25.0%), and clindamycin (≥ 20.5%) was observed in the Southcentral, Lake Winnebago, and Southeast regions of Wisconsin. In addition, isolates phenotypically classified as methicillin-resistant S. aureus (MRSA) were found to have increased rates of resistance to clindamycin, erythromycin, and levofloxacin as compared to S. aureus isolates susceptible to cefoxitin. S. aureus isolates demonstrated nearly 100% in vitro susceptibility to ceftaroline, dalbavancin, and telavancin. Statewide S. aureus isolates exhibited a vancomycin MIC 90 of 1 μg/mL. S. aureus isolates from patients aged 20-39 years were more likely to demonstrate cefoxitin resistance when compared to other age groups (P ≤ 0.03), while isolates from patients ≥ 80 years were more likely to exhibit resistance to levofloxacin and clindamycin (P ≤ 0.046). Conclusions:Several antimicrobial agents continue to demonstrate in vitro efficacy against clinical isolates of S. aureus (including MRSA) throughout Wisconsin, including three agents with recentlypublished susceptibility testing guidelines. However, continued surveillance efforts may be necessary in the Lake Winnebago, Southeast, and Southcentral regions to further assess higher rates of resistance to a number of antimicrobial agents.

Antimicrobial Resistance Traits of Escherichia coli Isolated from Dairy Manure and Freshwater Ecosystems Are Similar to One Another but Differ from Associated Clinical Isolates

“…Because of the lack of direct involvement in the collection of specimens and because of the utilization of de-identified isolates from routine clinical care, the Surveillance of Wisconsin Organisms for Trends in Antimicrobial Resistance and Epidemiology (SWOTARE) program was not considered to be actively engaged in human subject research by the Marquette University Institutional Review Board. Additional activities relative to the SWOTARE program have been described [18][19][20][21].…”

Therapeutic Drug Monitoring of Antibiotics in the Elderly: A Narrative Review

“…In a large study from Canada, Adam et al 36 reported that resistance to clindamycin, clarithromycin, and trimethoprim-sulfamethoxazole in the elderly patients was greater when compared with that in adults and children ( P < 0.001 for each antibiotic). Schulte and Munson 50 reported an increased proportion of levofloxacin-resistant S. aureus from patients aged 80 years or older compared with patients aged 0–19 or 40–59 years ( P ≤ 0.046) and an increased percentage of S. aureus resistant to clindamycin (36.3%) compared with 20- to 39-year-old subjects (16.7%, P = 0.026). Similarly, David et al 51 demonstrated increased S. aureus resistance to clindamycin in elderly patients compared with pediatric patients.…”

Emerging strategies and therapeutic innovations for combating drug resistance in Staphylococcus aureus strains: A comprehensive review

“…Methicillin, a semisynthetic penicillin introduced in 1959, efficiently addressed the penicillin‐resistant strains [10]. MRSA strains carry the mecA gene encoding for PBP2a protein (penicillin‐binding protein 2a) [11]. As per the ICMR annual report 2021, S. aureus did not exhibit complete resistance to vancomycin.…”