• Pediatric Infection and Vaccine
• /
• v.14 no.2
• /
• pp.162-170
• /
• 2007

Purpose : While cases of vancomycin-resistant enterococci (VRE) have increasingly been reported worldwide since it was first reported in the late 1980s, there have been few systemic studies on the pediatric population. The purpose of this study is to contribute to the planning of VRE prevention by investigating the prevalence, risk factors and transmission of VRE infection. Methods : We studied 230 patients under age 15 years who were isolated VRE between January 2001 and December 2006 retrospectively. The patients were classified into the intensive care unit (ICU) and the non-ICU groups. We reviewed the procedures before VRE detection as well as antibiotic sensitivity of detected organisms. Results : The number of VRE-isolation cases was higher in the ICU group than the non-ICU group. Instances of VRE-isolation were also more prevalent in patients who underwent operations or active procedures while taking 3rd-generation cephalosporins or glycopeptides. Almost all antibiotics except tetracycline were resistant to VRE. The proportion of 3rd-generation cephalosporin use was higher than those of any other antibiotics before VRE detection. Additionally, the use of 3rd-generation cephalosporins has increased annually, but that of glycopeptides had decreased in 2006. Also, the rates of VRE isolation have been increasing since 1998. Conclusion : VRE infection is increasing in pediatric population. Strict adherence to appropriate infection control guidelines for the prevention of VRE transmission in hospitals, and tracking of VRE colonization through active surveillance in high risk units are recommended.

• Pediatric Infection and Vaccine
• /
• v.13 no.2
• /
• pp.155-162
• /
• 2006

Purpose : Appropriate use of antimicrobials is an essential factor to treat infectious diseases and prevent acquisition of antimicrobial resistant pathogens. This study was undertaken to search that application of computerized management program for restriction of antimicrobials use in a hospital is helpful to decrease antimicrobial use density. Methods : Antibiotics utilization committee decided to restrict the use of 16 antimicrobials(14 expensive drugs having fear of drug resistance by pathogens and additional two drugs with inappropriate using tendency). Retrospective evaluation of antimicrobial user numbers between May and July of 2004 and 2005(study group) was conducted to compare with previous use density during same period of 2002 and 2003(control group). Results : Inpatients number of control group($823.5{\pm}37.1$ persons) was more than study group($809.2{\pm}39.3$ persons, P<0.001), but, outpatients number and hospitalized duration were equal in two groups. Antimicrobial user number/100 inpatients per day of glycopeptides and antifungal agents was equal in two groups, and study group was significantly higher density than control group in the use of carbapenems, piperacillin-tazobactam and quinolones(P<0.001). But study group was significantly lower density than control group in the use of drugs with inappropriately using tendency and expensive cephalosporins having broad antimicrobial spectrum(P<0.001). Conclusion : Application of computerized management program for restriction of antimicrobials use in a hospital is effective to decrease the use density of antimicrobials with inappropriately using tendency, but it is an insufficient measures for the restricted use of other antimicrobials on the whole.

• Childhood Kidney Diseases
• /
• v.14 no.2
• /
• pp.203-209
• /
• 2010

Purpose : It has been a common medical practice to use prophylactic antibiotics to prevent recurrent urinary tract infections (UTI) in high risk situations such as urinary tract obstruction, vesicoureteral reflux, neurogenic bladder, or urinary stones. But sometimes, we meet difficult situation of breakthrough infections (BI) which might cause new or progressive renal scarring. The clinical characteristics of children contracting breakthrough UTI experienced in a single center were studied. Methods : The study was done retrospectively through medical records of 150 pediatric patients who had been cared in pediatric and urologic clinics of Pusan National University Hospital from Jan. 2001 till June 2006 and had prophylactic antibiotics to prevent recurrent UTI. Results : The starting age of prophylactic antibiotics of 150 patient was 1-76 months, and median age was 5 months. The BI developed 61 times in 43 patients (28.7%), 1.5 times per 100 patient-months. The BI occurred more frequently in patients with higher grade of VUR, and in the cases with abnormal DMSA scan. Co-trimoxazole was more effective than 2nd and 3rd generation cephalosporins to prevent UTI. The distribution of causative organisms was more diverse than usual UTI. The causative organisms were sensitive to the antibiotics used for prophylaxis in 29.5%, and resistant in 59.1%. After experience of BI, 40 percents of patients went to the surgical treatment including endoscopic injection of Deflux, 35% to new antibiotics for prophylaxis, 26% remain on the same antibiotics as the previous one. Conclusion : Based on our study results, preexisting renal scar might be one of the factors which should be considered in favor of early surgical interventions of VUR. Poor compliance and wrong selection of antibiotics such as cephalosporins are important underlying causes of breakthrough UTIs.

• Childhood Kidney Diseases
• /
• v.10 no.1
• /
• pp.18-26
• /
• 2006

Purpose : Empirical antimicrobial treatment is indicated before bacteriological results are available for young children with febrile UTI to minimize renal scarring. To ensure appropriate therapy, knowledge of the prevalence of causative organisms and their susceptibility patterns to antimicrobials is mandatory. We performed a retrospective analysis investigating the local prevalence and resistance patterns of uropathogens, primarily E. coli, isolated from community-acquired UTIs. Methods : A total of 103 positive urine cultures from children with febrile UTI collected at Bundang CHA General Hospital from February 2004 to February 2005 were analyzed. Inclusion criteria were fever higher than $37.5^{\circ}C$, significant bacteriuria with single strain growth of at least 10s colony forming units/mL urine, and leukocyturia >5/HPF. Results : E. coli(89.3%) was the leading uropathogen followed by Enterococcus spp.(3.9%) Klebsiella spp.(2.9%), Citrobctcter spp.(1.9%) and Enterobacter spp.(1.9%). E. coli strains revealed a low proportion of antimicrobial susceptibility to ampicillin(AMP; 27.2%) ampicillinsulbactam(AMS; 34.8%) and trimethoprim-sulfamethoxazole(SXT; 65.2%). Susceptibility patterns to cephalosporins were as follows; cefazolin(1st generation; 91.3%), cefoxitin(2nd; 100%), ceftriaxone(3rd; 97.8%) and cefepime(4th; 97.8%). Three E. coli isolates produced ex tended - spectrum beta-lactamase(ESBL). Conclusion : Empirical treatment with AMP, AMS and SXT, which are commonly used in pediatric clinics, is not recommended for childhood UTI due to high incidence of resistance. The high level of susceptibility to cephalosporins makes these drugs reasonable alternatives. However the emergence of ESBL-producers, even though they are quite few, may have an impact on cephalosporin treatment in the future. (J Korean Soc Pediatr Nephrol 2006;10:18-26)

• Pediatric Infection and Vaccine
• /
• v.9 no.2
• /
• pp.163-174
• /
• 2002

Background : To delineate the changes in the causative agents of neonatal sepsis and their antimicrobial susceptibilities in the neonatal intensive care unit and nursery of Hanyang University Hospital during the past 10 years. Methods : Hospital records of 15,144 patients hospitalized at the NICU and nursery of Hanyang University Hospital from 1989 to 1998 were reviewed and neonates diagnosed of neonatal sepsis were sorted and included in the study. The study period was divided into Period A(the first 5 years) and Period B(the second 5 years) to analyse causative agents and their antimicrobial susceptibilities. Results : Neonatal sepsis was diagnosed in 170 patients(1.1%{Period A 1.2%, Period B 1.0%}) among the total of 15,144 inpatients. Two hundred isolates(Period A 109 isolates, Period B 91 isolates) were identified in 186 blood cultures(Period A 99 cultures, Period B 87 cultures) from 170 patients(Period A 91 patients, Period B 79 patients). The average age at the onset of the disease, when the initial blood culture was drawn, was 12.3 days old(Period A 8.8 days, Period B 16.3 days), and the proportion of the early onset disease was 34.7% in Period A and 23.0% in Period B, indicating that neonatal sepsis developed earlier during Period A. Among the isolated organisms including Gram positive bacteria[132(66.0%)], Gram negative bacteria [60(30.0%)], and fungi[8(4.0%)], coagulase negative Staphylococcus(CNS) was the most common organism(69/34.5%), followed by Staphylococcus aureus(36/18.0%), Klebsiella pneumoniae(17/8.5%), Enterococcus(12/6.0%), Enterobacter cloacae(8/4.0%), Escherichia coli(6/3.0%), and Pseudomonas aeruginosae(5/2.5%). The isolated fungi were Candida parapsilosis, Candida albicans, and Trichosporon pullulans. CNS, S. aureus and Acinetobacter baumannii were isolated more frequently in Period A compared to Period B. Antimicrobial susceptibilities of CNS and S. aureus to methicillin and the first generation cephalo sporins were decreased in Period B compare to Period A, those to aminoglycosides were increased in Period B, and vancomycin resistant strains were not identified. K. pneumoniae, Enterococcus, E. coli, and P. aeruginosa were isolated less frequently in Period B, compared to Period A. For K. pneumoniae, antimicrobial susceptibilities to the first generation cephalosporins were low in both Periods A and B, those to tobramycin and gentamicin were increased in Period B, and those to amikacin, ceftriaxone, and trimethoprim-sulfamethoxazole were high in both Periods A and B. Antimicrobial susceptibilities of Enterococcous to ampicillin, penicillin, and the first generation cephalosporins were decreased in Period B, but vancomycin resistant strains were not identified. Conclusion : The occurrence rate of neonatal sepsis during the past 10 years in the NICU and nursery of the Hanyang University hospital was 1.1%, and the most common causitive agents were CNS and S. aureus, to which the antimicrobial susceptibilities to the first line drugs decreased in the later half of the study period with no vancomycin resistant isolates identified. Group B Streptococcus known to be the most common agent causing neonatal sepsis was not identified, and K. pneumoniae was isolated more commonly during the later half of the study period without decreased antimicrobial susceptibilities.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.10
• /
• pp.1733-1737
• /
• 2007

A total of 2,280 nonduplicate clinical isolates of Pseudomonas aeruginosa, obtained nationwide from Korean non-tertiary care hospitals from 2002 to 2005, were identified and their susceptibilities to aminoglycosides, antipseudomonal penicillins, carbapenems, cephalosporins, monobactams, and quinolones were studied, together with their production of ${\beta}$-lactamases. Using disk diffusion and minimum inhibitory concentration tests, it was found that 2.9% of isolates were multidrug-resistant (MDR) P. aeruginosa. An EDTA-disk synergy test, PCR amplification with specifically designed primers, and direct sequencing of the PCR products showed that the $bla_{OXA-10}$, $bla_{VIM-2}$, $bla_{OXA-2}$, $bla_{OXA-17}$, $bla_{PER-1}$, $bla_{SHV-12}$, and $bla_{IMP-1}$ genes were carried by 34.3%, 26.9%, 3.0%,3.0%, 1.5%, 1.5%, and 1.5% of 67 MDR P. aeruginosa isolates, respectively. The prevalence of MDR P. aeruginosa was three-fold higher, compared with that from the United States. More than two types of ${\beta}$-lactamase genes were carried by 10.4% of isolates. The most prevalent ${\beta}$-lactamase genes were $bla_{VIM-2}$ and $bla_{OXA-10}$. This study is the first description of MDR P. aeruginosa trom non-tertiary care hospitals in Korea and the coexistence of the $bla_{VIM-2}$, $bla_{IMP-1}$, or $bla_{PER-1} in these clinical isolates.

• Journal of Yeungnam Medical Science
• /
• v.34 no.1
• /
• pp.123-127
• /
• 2017

Drug-induced immune hemolytic anemia (DIIHA) is a rare side effect of drugs. DIIHA may cause a systemic inflammatory response that results in acute multi-organ failure and death. Ceftizoxime belongs to the class of third generation cephalosporins, which are the most common drugs associated with DIIHA. Herein, we present a case of a 66-year-old man who developed fatal DIIHA after receiving a second dose of ceftizoxime. He was admitted to receive photodynamic therapy. He had a history of a single parenteral dose of ceftizoxime 3 months prior to admission. On the day of the procedure - shortly after the infusion of ceftizoxime - the patient's mental status was altered. The blood test results revealed hemolysis. Oliguric acute kidney injury developed, and continuous renal replacement therapy had to be applied. On the suspicion of DIIHA, the patient underwent plasmapheresis. Diagnosis was confirmed by a detection of drug-dependent antibody with immune complex formation. Although his hemolysis improved, his liver failure did not improve. He was eventually discharged to palliative care, and subsequently died.

• Korean Journal of Agricultural Science
• /
• v.42 no.1
• /
• pp.29-35
• /
• 2015

This study was performed to analyze the distribution and antimicrobial resistance of pathogenic microorganisms isolated from the carcass and environments of chicken processing plant located in Gyeonggi province from October to November in 2010. Chicken slaughterhouse was visited 3 times and totally 40 samples were collected from chicken carcass before and after washing (n=14), chicken cuts (n=7), cooling water (n=8), brine (n=2), cutting knives (n=7) and working plate (n=2). Whole-chicken rinsing technique (for chicken carcasses) and swab technique (for working plate and knives) were used to analyze the distribution of pathogenic microorganisms. In addition, brine and chilling water from storage tanks were gathered using sterilized tubes and used as samples. The matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) for whole cell fingerprinting in combination with a dedicated bioinformatic software tool was used to identify the isolated microorganisms. The pathogenic microorganisms, such as Bacillus cereus (n=8) and Staphylococcus aureus (n=9), were isolated form the chicken processing process (chicken carcasses of before and after chilling, chicken cuts, and working plate). The antimicrobial susceptibility of those isolated microorganisms was analyzed using 21 antimicrobial agents. In the case of B. cereus, it showed 100% of resistance to subclasses of penicillins and peptides, and it also resistant to cephalothin, a member of critically important antimicrobials (CIA), however there was no resistance (100% susceptible) to vancomycin and chloramphenicol. S. aureus showed 100% resistance to subclasses of peptides and some of penicillins (penicillin and oxacillin), however, it showed 100% susceptibility to cephalosporins (cefazolin and cephalothin). All of the tested pathogens showed multi drug resistance (MDR) more than 4 subclasses and one of B. cereus and S. aureus showed resistance to 9 subclasses. After the ban on using the antimicrobials in animal feed in July 2011, there would be some change in microbial distribution and antimicrobial resistance, and it still has a need to be analyzed.

• Journal of Yeungnam Medical Science
• /
• v.16 no.2
• /
• pp.270-276
• /
• 1999

Background: Extended-spectrum ${\beta}$-lactamases(ESBL) are enzymes that confer resistance to oxyimino-${\beta}$-lactams as well as to penicillins and cephalosporins. Strains of Klebsiella pneumoniae and Escherichia coli that produce ESBL have been increasingly prevalent in many countries. The purpose of this study was to investigate the ESBL production rate of K. pneumoniae and E. coli at the in Yeungnam University Medical Center. Materials and Methods: Thirty-one isolates of K pneumoniae and twenty-five isolates of E. coli were examined for ESBL by double disk synergy test, using 20/$10{\mu}g$ ticarcillin/clavulanic acid and $30{\mu}g$ oxyimino-${\beta}$-lactam(ceftazidime, ceftaxime, ceftriaxone and aztreonam) disks. Results: Fifty-two percent of K. pneumoniae and sixteen percent of E. coli isolates revealed double disk synergism. Majority of ESBL-producing strains(fifty-five percent) were isolated from patients in the intensive care unit. Conclusion: ESBL production of K. pneumoniae and E. coli were also common at the Yeungnam University Medical Center and pose a serious problem for antimicrobial therapy.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.4
• /
• pp.555-562
• /
• 2012

PCR was performed to analyze the ${\beta}$-lactamase genes carried by ampicillin-resistant Vibrio spp. strains isolated from marine environments in Korea between 2006 and 2009. All 36 strains tested showed negative results in PCR with the primers designed from the nucleotide sequences of various known ${\beta}$-lactamase genes. This prompted us to screen new ${\beta}$-lactamase genes. A novel ${\beta}$-lactamase gene was cloned from Vibrio alginolyticus KV3 isolated from the aquaculture water of Geoje Island of Korea. The determined nucleotide sequence (VAK-3 ${\beta}$-lactamase) revealed an open reading frame (ORF) of 852 bp, encoding a protein of 283 amino acids (aa), which displayed low homology to any other ${\beta}$-lactamase genes reported in public databases. The deduced 283 aa sequence of VAK-3, consisting of a 19 aa signal peptide and a 264 aa mature protein, contained highly conserved peptide segments specific to class A ${\beta}$-lactamases including the specific amino acid residues STFK (62-65), SDN (122-124), E (158), and RTG (226-228). Results from PCR performed with primers specific to the VAK-3 ${\beta}$-lactamase gene identified 3 of the 36 isolated strains as V. alginolyticus, Vibrio cholerae, and Photobacterium damselae subsp. damselae, indicating the utilization of various ${\beta}$-lactamase genes including unidentified ones in ampicillin-resistant Vibrio spp. strains from the marine environment. In a mating experiment, none of the isolates transfered the VAK-3 ${\beta}$-lactamase gene to the Escherichia coli recipient. This lack of mobility, and the presence of a chromosomal acyl-CoA flanking sequence upstream of the VAK-3 ${\beta}$-lactamase gene, led to the assumption that the location of this new ${\beta}$-lactamase gene was in the chromosome, rather than the mobile plasmid. Antibiotic susceptibility of VAK-3 ${\beta}$-lactamase was indicated by elevated levels of resistance to penicillins, but not to cephalosporins in the wild type and E. coli harboring recombinant plasmid pKV-3, compared with those of the host strain alone. Phylogenetic analysis showed that VAK-3 ${\beta}$-lactamase is a new and separate member of class A ${\beta}$-lactamases.