Surveillance of Antimicrobial Use and Antimicrobial Resistance

Impact of antibiotic usage on extended-spectrum β-lactamase producing Escherichia coli prevalence

An increase in antibiotic usage is considered to contribute to the emergence of antimicrobial resistance. Although experts are counting on the antimicrobial stewardship programs to reduce antibiotic usage, their effect remains uncertain. In this study, we aimed to evaluate the impact of antibiotic usage and forecast the prevalence of hospital-acquired extended spectrum β-lactamase (ESBL)—producing Escherichia coli (E. coli) using time-series analysis. Antimicrobial culture information of E. coli was obtained using a text processing technique that helped extract free-text electronic health records from standardized data. The antimicrobial use density (AUD) of antibiotics of interest was used to estimate the quarterly antibiotic usage. Transfer function model was applied to forecast relationship between antibiotic usage and ESBL-producing E. coli. Of the 1938 hospital-acquired isolates, 831 isolates (42.9%) were ESBL-producing E. coli. Both the proportion of ESBL-producing E. coli and AUD increased over time. The transfer model predicted that ciprofloxacin AUD is related to the proportion of ESBL-producing E. coli two quarters later. In conclusion, excessive use of antibiotics was shown to affect the prevalence of resistant organisms in the future. Therefore, the control of antibiotics with antimicrobial stewardship programs should be considered to restrict antimicrobial resistance.

Changes in Antimicrobial Usage Patterns in Korea: 12-Year Analysis Based on Database of the National Health Insurance Service-National Sample Cohort

National antimicrobial usage and prescription patterns during the 12 years from 2002 to 2013 were analyzed using the National Health Insurance Service-National Sample Cohort. Antimicrobial usage was analyzed by major illness, sex, age, area of residence, income rank, diagnosis, and type of medical institution for each year. Total antimicrobial prescriptions increased from 15.943 daily defined dose (DDD)/1,000 inhabitants/day in 2002 to 24.219 in 2013. In 2013, 72% of total prescriptions were administered in clinics. Antimicrobials were most frequently prescribed to children younger than 10 years, followed by adults aged 70 years or older and those aged 60-69 years. Penicillins and cephems were the most popular classes of antimicrobial used. In 2013, 48% of total antibiotic usage (11.683 DDD/1,000 inhabitants/day) was due to respiratory diseases. After the Korean government has implemented a series of healthcare policies, antibiotic prescription decreased for the treatment of upper respiratory infection, the causative agents are mostly viruses.

Reduced antibiotic prescription rates following physician-targeted interventions in a dental practice

BACKGROUND

The prescription rate for antibiotics in dental clinics is not declining despite the increase in the antibiotic resistance problem. In this study, we observed the change in antibiotic prescription rates by dentists in a Korean dental hospital for various treatments after conducting interventions targeting dentists.

METHODS

The first intervention was to distribute guidelines. The second intervention was to remove the bundled prescription button containing antibiotics from the Electronic Medical Record system. A total of 22,098 treatment records were divided into 12 main treatment categories, and Chi-square tests and logistic regression analyses were performed.

RESULTS

After the interventions were applied, the overall prescription rate for antibiotics dropped. The antibiotic prescription rate decreased by an odds ratio of 0.774 (95% CI: 0.686-0.873) after intervention 1 and by an odds ratio of 0.574 (95% CI: 0.501-0.658) after intervention 2. The treatments with significantly reduced antibiotic prescription rates were extraction for orthodontic treatment, dental implant surgery, extraction of an impacted tooth and general extraction. These treatments are typically performed in patients without an active infection. The prescription rate did not change for periodontal treatments or endodontic treatments, which are usually performed in patients with an infection. The prescription rate also remained constant for minor operations and other basic treatments.

CONCLUSION

The interventions induced behavioural changes in the dentists and were effective in lowering the antibiotic prescription rates in a dental hospital. In particular, there was a significant reduction in the prescription rates for implant surgery and tooth extraction in the absence of infection.

Two variants of staphylococcal cassette chromosome mec type IVA in community-associated meticillin-resistant Staphylococcus aureus strains in South Korea

Meticillin-resistant Staphylococcus aureus (MRSA) strains harbouring staphylococcal cassette chromosome mec (SCCmec) type IVA are known to be more prevalent in South Korea than in other countries. Variations in the SCCmec IVA structure have been identified, including in sequence type (ST) 1 and ST72 strains. This study compared and investigated the genetic characteristics of two subtypes common in South Korea. Type IVA SCCmec of ST1 strains was characterized by type IV features with the linearized pUB110 at the junkyard (J) 3 region. However, that of ST72 strains carried a variant class B mec complex, ccrA2, with an identity of approximately 96 % and the linearized pUB110 at the J3 region. In SCCmec of ST72 strains, the organization of the class B variant and the J3 region may be more similar to that of type IA than to other types, but the ccr type and other J regions seemed to be derived from type IV. These genetic characteristics showed that type IVA appears to result from the dynamic genetic exchange and recombination of SCC DNA.