Serotyping and Antimicrobial Susceptibility of Salmonella Isolated in Korea in 2015 / 대한임상미생물학회지

BACKGROUND: Salmonella is an important pathogen that causes gastroenteritis and sepsis in humans. Recently, changes in serotype prevalence and an increase in antimicrobial resistance have been reported. This study investigated the distribution of Salmonella serotypes and determined the antimicrobial susceptibility of various strains. METHODS: We collected 113 Salmonella isolates other than Salmonella serotype Typhi from 18 university hospitals in 2015. The serotypes were identified by Salmonella antisera O and H according to the Kauffman White scheme. Antimicrobial susceptibility tests for 12 antibiotics were performed using the disk diffusion method or E-test. RESULTS: We identified 22 serotypes. Serotype group B (44.2%) was the most common, followed by groups C (34.5%) and D (21.2%). Salmonella I 4,[5],12:i:- (23.0%), S. Enteritidis (16.8%), and S. Typhimurium (12.4%) were the most common species. Resistance rates for ampicillin, chloramphenicol, ceftriaxone, and trimethoprim/sulfamethoxazole were 46.9%, 18.5%, 8.8%, and 5.3%, respectively. The intermediate resistance rate to ciprofloxacin was 29.2%. Six isolates were extended-spectrum β-lactamase (ESBL) producers, including 5 bla(CTX-M-15) and 1 bla(CTX-M-55). CONCLUSION: There have been changes in the serotype prevalence and antimicrobial resistance of Salmonella in Korea, with a high prevalence of CTX-M 15-positive strains. Continuous monitoring of Salmonella serotypes and antimicrobial resistance is warranted.

Antimicrobial Susceptibility and Genetic Analysis of Campylobacter jejuni Isolated from Diarrhea Patients in Busan / 대한임상미생물학회지

BACKGROUND: Campylobacter jejuni is an important food-borne pathogen that causes human gastroenteritis. This study was conducted to investigate the incidence of isolation, antimicrobial susceptibility pattern, and C. jejuni genotype from diarrhea patients in Busan, Korea. METHODS: A total of 97 C. jejuni were isolated from diarrhea patients during five food-borne outbreaks from 2014 to September 2017. Antimicrobial susceptibility tests were carried out by the broth microdilution method for ciprofloxacin (CIP), nalidixic acid (NAL), tetracycline (TET), chloramphenicol, azithromycin (AZI), erythromycin (ERY), streptomycin (STR), gentamicin, and telithromycin. To investigate C. jejuni genotypes, pulsed-field gel electrophoresis (PFGE) profile analysis was performed. RESULTS: The isolation rate of C. jejuni was 2.0% for the last 4 years and increased annually. Antimicrobial resistance rates of C. jejuni were shown to be in the order of NAL (90.9%), CIP (89.4%), TET (13.6%), AZI (3.0%), ERY (3.0%), and STR (1.5%). The proportion of multidrug-resistance was 18.2%, and they commonly contained quinolones (CIP-NAL). Analysis of PFGE patterns of SmaI-restricted DNA of C. jejuni isolates showed 17 clusters; cluster 11 was the major genotype pattern. CONCLUSION: This study will provide useful data for the proper use of antimicrobials and the management of resistant C. jejuni. Also it will help to provide data for the epidemiological investigation of foodborne diseases caused by C. jejuni, which is expected to increase in the future.

Effects of CYP2C19 Genetic Polymorphisms on PK/PD Responses of Omeprazole in Korean Healthy Volunteers

The aim of this study was to examine the effects of CYP2C19*2 and *3 genetic polymorphisms on omeprazole pharmacokinetic (PK) and pharmacodynamic (PD) responses. Twenty-four healthy Korean volunteers were enrolled and given 20 mg omeprazole orally once daily for 8 days. The genotypes of CYP2C19 single nucleotide polymorphisms (SNPs) (*2, *3, and *17) were screened. The plasma concentrations of omeprazole, omeprazole sulfone, and 5-hydroxy (5-OH) omeprazole were determined by liquid chromatography with tandem mass spectrometry (LC-MS/MS). The noncompartmental method was used for the determination of PK parameters. Change of mean pH and proportion (%) of time of gastric pH above 4.0 were estimated. The poor metabolizer (PM) group had the lowest metabolic ratio and exhibited the highest area under the curve (AUC) for omeprazole among the CYP2C19 phenotype groups. The PM group showed the greatest change of mean pH and the highest % time of gastric pH above 4.0. The relationship between AUC of omeprazole and % time of gastric pH above 4.0 was confirmed. The study demonstrates that CYP2C19*2 and *3 influence the PKs and PDs of omeprazole in Korean healthy volunteers. Clinical trial registry at the U.S. National Institutes of Health (https://clinicaltrials.gov), number NCT02299687.