An Epidemiologic Study on Hosts and Pathogens of Urinary Tract Infection in Urban Children of Korea (2012–2017)

PURPOSE: We aimed to determine characteristics of host, causative organisms, and antibiotic susceptibility of bacteria in pediatric patients with UTI living in metropolitan area of Korea. METHODS: Retrospective investigation was done for the causative organisms of UTI in 683 pediatric cases treated at Ajou University Hospital from 2012 to 2017. Patients were classified into Escherichia coli and non-E.coli group, where E.coli group was subdivided into ESBL(+) and ESBL(−) groups based on whether the bacteria could produce extended spectrum beta-lactamase (ESBL). Antibiotic susceptibility of the causative organism was also determined. RESULTS: A total of 683 UTIs occurred in 550 patients, of which 463 (67.8%) were first-time infection and 87 (32.2%) were recurrent ones (2–7 recurrences, 2.52 average), and 64.9% were male and 35.1% were female. The most common causative organism was E.coli (77.2%) and ESBL(+) E.coli was found in 126 cases. The susceptibility of E.coli to 3rd or 4th generation cephalosporin was relatively higher than that to ampicillin or amoxicillin/clavulanic acid. ESBL(+) E.coli showed higher resistance rate to 3rd or 4th generation cephalosporin than ESBL(−) E.coli . CONCLUSION: New treatment guideline should be considered due to the incidence of ESBL(+) E.coli increased up to one quarter of UTI cases.

Molecular Epidemiologic Analysis of Community-Onset Extended Spectrum Beta-Lactamase (ESBL) Producing Escherichia coli Using Infrequent-Restriction-Site Polymerase Chain Reaction (IRS-PCR) with Comparison by Pulsed-Field Gel Electrophoresis (PFGE) / 감염과화학요법

BACKGROUND: We evaluated the ability of infrequent restriction site-polymerase chain reaction (IRS-PCR) to perform molecular epidemiologic analysis of Community-Onset Extended Spectrum Beta-Lactamase (ESBL) producing Escherichia coli, and also assessed the use of PFGE as an alternative method. MATERIALS AND METHODS: IRS-PCR assay was performed using combinations of adaptors for XbaI and HhaI restriction sites on clinical isolates of E. coli (n=51). We compared the discriminatory power, quality and efficiency of IRS-PCR to PFGE. RESULTS: In E. coli, PFGE discriminated 39 (76.4%) and IRS-PCR discerned 41 (80.3%) of the total 51 strains. It took much less time to complete IRS-PCR (one day) than PFGE (at least 4 days). CONCLUSIONS: IRS-PCR is a more sensitive and rapid alternative to PFGE for molecular epidemiologic analysis of E. coli.

In Vitro Susceptibility of piperacillin/tazobactam Against extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae / 감염과화학요법

Minimal inhibitory concentrations (MIC) of piperacillin/tazobactam were determined on 20 clinical isolates of extended-spectrum beta-lactamase (ESBL)-producing E. coli and 30 isolates of ESBL- producing Klebsiella pneumoniae. MIC50 and MIC90 for ESBL-producing E. coli were 8/4 microg/ml and 256/4 microg/mL, respectively. MIC50 and MIC90 for ESBL-producing K. pneumoniae were 8/4 microg/mL and > 512/4 microg/mL, respectively. The susceptibilities of ESBL-producing E. coli and K. pneumoniae to piperacillin/tazobactam were 80% and 60%, respectively. Of 20 ESBL-producing E. coli strains, 11 (55%) were TEM-and CTX-M-positive, and SHV-negative. Of 30 ESBL-producing K. pneumoniae strains, ten (33%) were PCR positive for SHV and negative for TEM and CTX-M.

In Vitro Susceptibility of piperacillin/tazobactam Against extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae / 감염과화학요법

Minimal inhibitory concentrations (MIC) of piperacillin/tazobactam were determined on 20 clinical isolates of extended-spectrum beta-lactamase (ESBL)-producing E. coli and 30 isolates of ESBL- producing Klebsiella pneumoniae. MIC50 and MIC90 for ESBL-producing E. coli were 8/4 microg/ml and 256/4 microg/mL, respectively. MIC50 and MIC90 for ESBL-producing K. pneumoniae were 8/4 microg/mL and > 512/4 microg/mL, respectively. The susceptibilities of ESBL-producing E. coli and K. pneumoniae to piperacillin/tazobactam were 80% and 60%, respectively. Of 20 ESBL-producing E. coli strains, 11 (55%) were TEM-and CTX-M-positive, and SHV-negative. Of 30 ESBL-producing K. pneumoniae strains, ten (33%) were PCR positive for SHV and negative for TEM and CTX-M.

In vitro activity of ceftobiprole against hospital-acquired bacteria commonly causing infections in hospitalized patients at Siriraj Hospital.

Objective: To determine the in vitro activity of ceftobiprole against resistant bacteria commonly causing infections in hospitalized patients at Siriraj Hospital. Methods: The studied organisms were MRSA (32 isolates), Enterococcus sp. (30 isolates), ESBL-producing E.coli (20 isolates), ESBL-producing K.pneumoniae (20 isolates), MDR P.aeruginosa (30 isolates) and MDR A.baumannii (30 isolates). The susceptibility of ceftobiprole was determined by the disk diffusion test for all 162 isolates and the MIC was determined by the E-test method for 5 isolates of each organism. Results: All isolates of MRSA and 77% of Enterococcus sp. isolates were susceptible to ceftobiprole. All isolates of ESBL-producing E.coli and MDR A.baumannii were not susceptible to ceftobiprole. Only 10% to 20% of ESBL-producing K.pneumoniae and P.aeruginosa were susceptible to ceftobiprole. The MICs of ceftobiprole against all tested organisms were correlated with the inhibition zone diameters. Conclusion: Ceftobiprole is very active against MRSA and is moderately active against Enterococcus sp. Ceftobiprole is considered inactive or less active against ESBL-producing gram negatives, MDR P.aeruginosa and MDR A.baumannii.