BACKGROUND: Extended-spectrum beta -lactamase (ESBL) producing Escherichia coli and Klebsiella spp. isolates are clinically resistant to all the beta -lactams except carapenems and cephamycins. This study was to determine the prevalence of ESBL producing E. coli and Klebsiella spp. and the rates and trends of resistance to extended-spectrum beta -lactams and other antimicrobial agents in ESBL producing E. coli and Klebsiella spp.. METHODS: During the periods of 2002, a total 2,551 clinical isolates of E. coli & Klebsiella spp. were collected from patients of the Samsung medical center, Seoul, Korea. Antimicrobial susceptibility test and determination of ESBL production were performed by Vitek GNS-433 card. RESULTS: 151/1,594 (9.5%) of E. coli isolates, 128/896 (14.3%) of K. pneumoniae isolates and 11/61 (18.0%) of K. oxytica were ESBL producing strains. Resistance to cefoxitin and cefepime were 2.4% and 13.4% in ESBL producing isolates. Imipenem had excellent activity against E .coli and Klebsiella spp. (100% susceptible). CONCLUSION: In this study, ESBL-producing E. coli and Klebsiella spp were more resistant to beta -lactams including cefepime than ESBL non-producing E. coli and Klebsiella spp.. ESBL producing E. coli and Klebsiella spp. showed a high level of co-resistance with aminoglycosides and fluoroquinolones. Imipenem showed the highest level of activity against E. coli and Klebsiella spp..
Aminoglycosides ; Anti-Infective Agents ; Cefoxitin ; Cephamycins ; Escherichia coli* ; Escherichia* ; Fluoroquinolones ; Humans ; Imipenem ; Klebsiella* ; Korea ; Microbial Sensitivity Tests* ; Pneumonia ; Prevalence ; Seoul

BACKGROUND: Among Gram-negative pathogens in Korea, the incidence of resistance to thirdgeneration cephalosporins is becoming an ever-increasing problem. This study was designed to determine the prevalence of third-generation cephalosporins-resistant Escherichia coli and Klebsiella pneumoniae isolates from patients in a tertiary care hospital in Busan, Korea, and to characterize the mechanism of resistance. METHODS: A total of 710 E. coli and 237 K. pneumoniae non-duplicate isolates were collected from patients in Kosin Medical Center in 1999. Antimicrobial susceptibilities were tested by the disk diffusion method. Extended-spectrum beta-lactamase (ESBL) production was determined by the double disk synergy test. MICs were determined by the agar dilution method. Searches for blaTEM, blaSHV, and blaCMY genes in cefotaxime-resistant or intermediate isolates were performed by PCR amplification. PCR products were used to determine the sequence of resistance genes by the dideoxy-chain termination method. RESULTS: Seven percent of E. coli and 25% of K. pneumoniae isolates were resistant to cefotaxime. Among the isolates with decreased susceptibility to cefotaxime, 69% (18/26) of E. coli and 80% (20/25) of K. pneumoniae isolates showed positive results in double disk synergy test. Banding patterns of PCR amplification showed that the blaTEM, blaSHV, and blaCMY genes were harboured by 71% (20/28), 86% (24/28) and 14% (4/28) of isolates with decreased susceptibility to cefotaxime,respectively. Seventy-one percent (20/28) of the isolates contained more than two types of beta- lactamase genes. Nucleotide sequence analysis of PCR products revealed that blaSHV-12 and blaTEM-1b were the dominant types of beta-lactamase gene. In addition, we also identified blaTEM-52, blaSHV-5, and a new ESBL gene named blaTEM-17b. CONCLUSIONS: Third-generation cephalosporins-resistant E. coli and K. pneumoniae are wide spread in Kosin Medical Center, Busan, Korea. Most of the isolates with decreased susceptibility to cefotaxime had blaTEM and/or blaSHV, and some isolates harboured blaCMY genes that may confer resistance against cephamycins. The spread of these beta-lactamase genes could compromise the future usefulness of third-generation cephalosporins for the treatment of infections caused by E. coli and K. pneumoniae.
Agar ; Base Sequence ; beta-Lactamases ; Busan ; Cefotaxime ; Cephalosporins ; Cephamycins ; Diffusion ; Escherichia coli* ; Escherichia* ; Humans ; Incidence ; Klebsiella pneumoniae* ; Klebsiella* ; Korea ; Pneumonia ; Polymerase Chain Reaction ; Prevalence* ; Tertiary Healthcare

Sternoclavicular septic arthritis is a rare condition and it is usually related to predisposing conditions like intravenous drug abuse, diabetic mellitus, trauma and so on. A delayed diagnosis of this disease may cause severe complications like mediastinitis and chest wall abscess. Computed tomography or magnetic resonance imaging is needed to evaluate the complications. If the above complications are present, then joint resection should be considered. We report here on a case of a 52-year-old man who was diagnosed with primary sternoclavicular septic arthritis and he had no predisposing conditions. The pathogen on the aspiration-culture was S. aureus and it was susceptible to cefminox. The patient was cured with administering only antibiotic therapy for 6 weeks; intravenous cefminox therapy for 4 weeks followed by oral cefminox therapy for 2 weeks.
Abscess ; Arthritis, Infectious ; Cephamycins ; Delayed Diagnosis ; Humans ; Joints ; Magnetic Resonance Imaging ; Mediastinitis ; Middle Aged ; Sternoclavicular Joint ; Substance Abuse, Intravenous ; Thoracic Wall

BACKGROUND: Recently Escherichia coli isolates with extended-spectrum beta-lactamase(ESBL) have been increased in Korea. ESBLs confer variable levels of resistance to cefotaxime, ceftazidime and other broad-spectrum cephalosporins as well as to monobactams such as aztreonam, but they have no detectable activity against cephamycins and carbapenems. The aim of this study was to characterize the ESBL produced by E. coli strains isolated from clinical specimens. METHODS: From March to July, 1998, a total of 93 clinical isolates of E. coli, which was produced ESBL, were collected from patients of the Asan Medical Center. The isolates flagged as ESBL producers by microbroth dilution antibiotic susceptibility test were confirmed by the double disk synergy test. Minimal inhibitory concentration(MIC) of beta-lactams were determined by agar dilution method. The presence of TEM, SHV or CMY-1 gene was determined by polymerase chain reaction. The types of beta-lactamase gene were determined by isoelectric focusing and nucleotide sequence analysis. RESULTS: Sixty-two strains carried plasmid-mediated TEM-52 gene, which sequence showed the substitution of 3 amino acids compared to that of TEM-1. Seventeen strains produced SHV-12, six strains produced SHV-2a, three strains produced TEM-52 and SHV-12, three strains produced TEM-52 and SHV-2a, and one strain produced SHV-2a and SHV-12. One out of twenty-seven strains of cefoxitin-resistant E. coli was confirmed to have CMY-1 beta-lactamase by PCR and nucleotide sequence analysis. CONCLUSIONS: TEM-52 was the most prevalent in E. coli isolates. The most common SHV-types of ESBL in Korea are SHV-12 and SHV-2a in E. coli isolates. In Korea, widespread use of oxyimino-cephalosporins in the hospitals has dramatically increased the prevalence of ESBL-producers in E. coli. Therefore, more prudent use of antibiotics is necessary to reduce the spread of these resistant organisms.
Agar ; Amino Acids ; Anti-Bacterial Agents ; Aztreonam ; Base Sequence ; beta-Lactamases* ; beta-Lactams ; Carbapenems ; Cefotaxime ; Ceftazidime ; Cephalosporins ; Cephamycins ; Chungcheongnam-do ; Escherichia coli* ; Escherichia* ; Humans ; Isoelectric Focusing ; Korea ; Monobactams ; Polymerase Chain Reaction ; Prevalence

To analyze the regularity in combined medication with Xiyanping injection (Xiyanping for short) in the real world by as- sociation rules. Totally 5 822 patients using Xiyanping injection was collected from the 18 Class III Grade I hospitals nationwide to study the combined medication information of the patient with lung infection and make the analysis by using association rules and Apriori. According to the results, major drugs combined with Xiyanping in treatment of lung infection included compound amino acid, inosine, coenzyme A, cytidine triphosphate, vitamin C. Common drugs combined with Xiyanping can be divided into 5 categories: nutrition support therapy (vitamin C, compound amino acid) , coenzymes (coenzyme A, cytidine triphosphate, inosine), expectorants and antiasthmatics (ambroxol, salbutamol, doxofylline), hormones (dexamethasone, budesonide), antibiotics (mainly cefminox). The main combined medicines mostly conformed to the regularity for drugs treating lung infection. In addition, there were two most common medical combination models: the model for Xiyanping combined a single medicine is Xiyanping + nutrition support therapy, while the model for Xiyanping combined two or more than two medicines is Xiyanping + nutrition support therapy + coenzyme. Pharmacologically, Xiyanping is mostly combined with western medicines with similar pharmacological effects to substitute or supplement the antibiotic effect in treating lung infection. However, further studies shall be conducted for the safety and rationality of the combined medication based on clinical practices, in order to provide reference for clinical medication.
Adult ; Anti-Bacterial Agents ; administration & dosage ; Ascorbic Acid ; administration & dosage ; Cephamycins ; administration & dosage ; Drug Therapy, Combination ; Drugs, Chinese Herbal ; administration & dosage ; Female ; Hospital Information Systems ; Humans ; Lung Diseases ; drug therapy ; Male ; Middle Aged ; Young Adult

Synthetic biology aims to design and build new biological systems with desirable properties, providing the foundation for the biosynthesis of secondary metabolites. The most prominent representation of synthetic biology has been used in microbial engineering by recombinant DNA technology. However, there are advantages of using a deleted host, and therefore an increasing number of biotechnology studies follow similar strategies to dissect cellular networks and construct genome-reduced microbes. This review will give an overview of the strategies used for constructing and engineering reduced-genome factories by synthetic biology to improve production of secondary metabolites.
Biosynthetic Pathways ; genetics ; Cephamycins ; biosynthesis ; Epoxy Compounds ; metabolism ; Escherichia coli ; genetics ; metabolism ; Gene Deletion ; Gene Regulatory Networks ; Genetic Engineering ; methods ; Genetics, Microbial ; Genome ; Sesquiterpenes ; metabolism ; Streptomyces ; genetics ; metabolism ; Streptomycin ; biosynthesis ; Synthetic Biology

BACKGROUND: Periodic monitoring of regional or institutional resistance trends of clinically important anaerobic bacteria is recommended, because the resistance of anaerobic pathogens to antimicrobial drugs and inappropriate therapy are associated with poor clinical outcomes. There has been no multicenter study of clinical anaerobic isolates in Korea. We aimed to determine the antimicrobial resistance patterns of clinically important anaerobes at multiple centers in Korea. METHODS: A total of 268 non-duplicated clinical isolates of anaerobic bacteria were collected from four large medical centers in Korea in 2012. Antimicrobial susceptibility was tested by the agar dilution method according to the CLSI guidelines. The following antimicrobials were tested: piperacillin, piperacillin-tazobactam, cefoxitin, cefotetan, imipenem, meropenem, clindamycin, moxifloxacin, chloramphenicol, metronidazole, and tigecycline. RESULTS: Organisms of the Bacteroides fragilis group were highly susceptible to piperacillin-tazobactam, imipenem, and meropenem, as their resistance rates to these three antimicrobials were lower than 6%. For B. fragilis group isolates and anaerobic gram-positive cocci, the resistance rates to moxifloxacin were 12-25% and 11-13%, respectively. Among B. fragilis group organisms, the resistance rates to tigecycline were 16-17%. Two isolates of Finegoldia magna were non-susceptible to chloramphenicol (minimum inhibitory concentrations of 16-32 mg/L). Resistance patterns were different among the different hospitals. CONCLUSIONS: Piperacillin-tazobactam, cefoxitin, and carbapemems are highly active beta-lactam agents against most of the anaerobes. The resistance rates to moxifloxacin and tigecycline are slightly higher than those in the previous study.
Agar ; Bacteria, Anaerobic* ; Bacteroides fragilis ; Cefotetan ; Cefoxitin ; Chloramphenicol ; Clindamycin ; Gram-Positive Cocci ; Imipenem ; Korea ; Metronidazole ; Piperacillin

BACKGROUND: The aim of this study was to survey the nationwide susceptibilities of E. coli and K. pneumoniae against third generation cephalosporins and aztreonam in order to determine the prevalence of extended-spectrum beta-lactamase (ESBL)-producers and to characterize genotypes of ESBLs. METHODS: A total of 6, 567 E. coli and 2, 652 K. pneumoniae non-duplicate strains were isolated from 13 hospitals in April to June 2002. Antimicrobial susceptibilities were tested by the disk diffusion method. Twenty isolates of E. coli and 20 K. pneumoniae were collected from each hospital. ESBL production was determined by a double-disk synergy test. The ceftazidime-resistance of the ESBL-producers was transferred to azide-resistant E. coli J53 by conjugation. MICs of beta-lactam antibiotics to transconjugants were determined by the agar dilution method. Searches for blaTEM , blaSHV , blaCTX-M and blaCMY genes in transconjugants were performed by PCR amplification. RESULTS: Eighty-nine percents of E. coli and 71% of K. pneumoniae isolates were susceptible to ceftazidime. Nine percents of E. coli (23/249) and 30% (78/260) of K. pneumoniae isolates showed positive results in the double-disk synergy test. Ceftazidime-resistance of 13 (57%) E. coli and 42 (53%) K. pneumoniae isolates were transferred to E. coli J53 by conjugation. Among 55 transconjugants, 46 strains were resistant to ceftazidime, while only 16 strains were resistant to cefotaxime. Twelve transconjugants were also resistant to cefoxitin and cefotetan. Banding patterns of PCR amplification showed that the blaTEM , blaSHV , blaCTX-M and blaCMY genes were harboured by 44, 39, 4 and 5 transconjugants, respectively. CONCLUSIONS: E. coli and K. pneumoniae isolates producing TEM-, SHV-type, or CTX-M-type ESBLs are wide spread in Korean hospitals. The spread of ESBL genes could compromise the future usefulness of 3rd generation cephalosporins and aztreonam for the treatment of E. coli and K. pneumoniae infections.
Agar ; Anti-Bacterial Agents ; Aztreonam ; beta-Lactamases* ; Cefotaxime ; Cefotetan ; Cefoxitin ; Ceftazidime ; Cephalosporins ; Diffusion ; Escherichia coli* ; Genotype ; Klebsiella pneumoniae* ; Pneumonia ; Polymerase Chain Reaction ; Prevalence*

BACKGROUND: Plasmid-mediated AmpC beta-lactamases (PABLs) have been detected in the strains of Escherichia coli, Klebsiella spp., Proteus mirabilis, and Salmonella spp. PABLs may be difficult to detect and might interfere in the therapeutic and infection-control processes. Although several PABL-detection methods based on phenotypes have been reported, the Clinical and Laboratory Standards Institute currently does not recommend a routine detection method for PABLs. The aim of this study is to compare the performances of 3 phenotypic PABL detection methods. METHODS: Total 276 non-duplicated clinical isolates of E. coli (N=97), K. pneumoniae (N=136), and P. mirabilis (N=43) were collected from 14 hospitals in Korea between April and June 2007 in a non-consecutive and non-random manner. Multiplex PCR was performed to detect the PABL genes. Further, 3 phenotypic detection methods-cephamycin-Hodge test, Tris-EDTA (TE) disk test, and combination-disk test with 3-aminophenylboronic acid (BA)-were performed using cefoxitin and cefotetan disks. RESULTS: PABL genes were detected by multiplex PCR in 122/276 isolates, including 14/97 E. coli, 105/136 K. pneumoniae, and 3/43 P. mirabilis isolates. The combination-disk test with BA showed higher sensitivity (98.4%), specificity (92.2%), and efficiency (96.3%) than the cephamycin-Hodge (76.2%, 96.1%, and 88.6%, respectively) and the TE-disk (80.3%, 91.6%, and 87.9%, respectively) tests. CONCLUSIONS: The combination-disk test with BA is a simple, efficient, and interpretable test that can be applicable in clinical laboratories involved in the detection of PABLs in clinical isolates of E. coli, K. pneumoniae, and P. mirabilis.
Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/*analysis ; Cefotetan/pharmacology ; Cefoxitin/pharmacology ; Disk Diffusion Antimicrobial Tests/*methods ; Escherichia coli/genetics/*isolation & purification ; Humans ; Klebsiella pneumoniae/genetics/*isolation & purification ; Phenotype ; Plasmids ; Proteus mirabilis/genetics/*isolation & purification ; Sensitivity and Specificity ; beta-Lactamases/*analysis

Mycobacterium massiliense, an emerging pathogen that is increasingly reported as a causative agent in infections occurring during medical procedures, is difficult to be identified using conventional methods. Here we report the case of a cutaneous M. massiliense infection that was associated with repeated surgical procedures and that was identified via a comparative sequence analysis of rpoB and hsp65. The patient showed a substantial response to treatment with a combination of antimicrobial therapies consisting of clarithromycin, amikacin, and cefoxitin for 6 months.
Amikacin ; Cefoxitin ; Clarithromycin ; Humans ; Mycobacterium ; Sequence Analysis