The aim of this study is to characterize the epidemiological features of typhoid fever, categorized as class 1 notifiable disease in Korea and to analyze the recent change of antimicrobial resistance of Salmonella enterica serotype Typhi isolated nationwide. We retrospectively analyzed the 1,692 culture-proven cases from 1992 to 2000, using the data of the Korean National Institute of Health. The overall incidence of culture-proven typhoid fever was 0.41 per 100,000 population. It occurred all over the country, but the southeastern part of Korean peninsula had the higher incidence rate than other areas. There were several outbreaks suspected, of which two outbreaks were confirmed. The resistance rate against chloramphenicol showed mild increase, but the ampicillin, trimethoprim/sulfamethoxazole, kanamycin, or nalidixic acid resistance remained at the similar levels for the past 9 yr. There were 21 (1.3%) multidrug-resistant (MDR) strains isolated since 1992, and the number of those has increased. Two strains resistant to ciprofloxacin were first identified in Korea.
Ampicillin/pharmacology ; Anti-Bacterial Agents/pharmacology ; Chloramphenicol/pharmacology ; *Drug Resistance, Microbial ; Drug Resistance, Multiple ; Human ; Kanamycin/pharmacology ; Korea ; Nalidixic Acid/pharmacology ; Retrospective Studies ; Salmonella Infections/*epidemiology ; Salmonella enterica/*metabolism ; Seasons ; Serotyping ; Support, Non-U.S. Gov't ; Time Factors ; Trimethoprim/pharmacology

The frequency of antibiotic resistance among Salmonella enterica serovar Typhimurium has increased due to the transfer of multiple resistance factors. We detected the 13 antibiotic resistance genes by multiplex-PCR and compared with the results of phage typing and antibiotic disk diffusion for 49 S. typhimurium isolated from food-poisoning outbreaks in Seoul from 1999 to 2002. Resistance genes for tetracycline, streptomycin, ampicillin, sulfonamide, amino-glycoside-modifying enzyme, chloramphenicol, kanamycin, and trimethoprim were detected in 67.3%, 57.1%, 26.5%, 8.1%, 8.1%, 5%, 2.0%, and 0% of isolates, respectively. Overall 28 isolates (57.1%) possessed two or more antibiotic resistance genes. Class 1 integron carrying multidrug resistace genes, ant(3")-IaB, blaPSE, qacE delta1/sul, and tet G were amplified especially in only DT104 isolates. Among the related resistance genes for same antibiotics, strA and strB for streptomycin resistance were simultaneously detected but tetA and tetB for tetracycline were sporadically detected. DT 104 isolates contained only aadA2 and tetG.
Ampicillin ; Anti-Bacterial Agents ; Bacteriophage Typing ; Chloramphenicol ; Diffusion ; Disease Outbreaks ; Drug Resistance, Microbial ; Humans ; Integrons ; Kanamycin ; R Factors ; Salmonella enterica* ; Salmonella* ; Seoul* ; Streptomycin ; Tetracycline ; Trimethoprim

One hundred and thirty trimethoprim-resistant R plasmids derived from of Escherichia coli isolated from clinical specimens and feces of healthy collegians were examined for incompatibility, EcoRI endonuclease restriction fragment pattern, and Southern hybridization with DHFR I, II, III, V, and VII probe. 1. Most trimethoprim-resistant R plasmids were resistant to ampicillin, tetracycline, chloramphenicol, gentamicin, and kanamycin, and showed multiple drug resistance and various antimicrobial resistance patterns. 2. Trimethoprim-resistant R plasmids ranged from 90 to 50 kilobase and 42.3% of R plasmids tested were classified to incompatibilty group Inc FI, Inc FII or Inc FIV, 3. Among 48 random selected R plasmids from various origin, 14 R plasmids (including 9 of 14 Inc FII plasmids and 3 of 14 Inc FI plasmids) hybridized with DHFR VII oligonucleotide probe but others did not respond to any of DHFR probes used. 4. Most R plasmids showed various EcoRI endonuclease fragments and different reaction sites by Southern hybridization. Six plasmids showed identical or nearly identical molecular weight, EcoRI endonuclease fragment patterns and different sites of Southern hybridization. But 2 Inc FII plasmids derived from urine and feces showed identical pattern. These findings, if confirmed by further studies, suggest that normal flora E. coli can act as reservoir of resistant genes and, consequently, as a factor in the dissemination of these genes among enteric pathogens and need to be examined further.
Ampicillin ; Chloramphenicol ; Deoxyribonuclease EcoRI ; Drug Resistance, Multiple ; Escherichia coli* ; Escherichia* ; Feces ; Gentamicins ; Immunodeficiency Virus, Feline ; Kanamycin ; Molecular Biology* ; Molecular Weight ; Plasmids ; R Factors ; Tetracycline ; Trimethoprim Resistance* ; Trimethoprim*

PURPOSE: As the incidence of non-typhoidal salmonella strains resistant to antibiotics has been increased, we attempted to investigate clinical aspects of non-typhoidal salmonella gastroenteritis and antibiotics resistance. METHODS: From January 2000 to June 2002, 99 children with positive stool culture of non-typhoidal salmonella were studied about clinical features, the incidence of antibiotics and multi-drug resistance and the difference of incidence of antibiotics resistance according to immune status. RESULTS: There were 66 males and 33 females. The majority of them were under 5 years of age (71%). 25 children were immunocompromised due to chemotherapy, steroid or immunosuppressive treatment. Serogroup D was the most common isolates (65%) followed by B (16%), C (8%) and E (8%). Resistance rate of 30% to ampicillin, 12% to chloramphenicol, 20% to trimethoprim- sulfamethoxazole (TMP-SMX), 11% to cefotaxime and 8% to cefixime were obtained. All isolates were susceptible to ciprofloxacine. Resistance rate to cefotaxime and cefixime in immunocompromised patients was 24% and 14.3% respectively, which were significantly higher compared to that in immunocompetent patients (6.8%, 5.6%, p<0.05). 11 isolates were resistant to three or more antibiotics. The incidence of multi-drug resistant isolates was significantly higher in immunocompromised patients (24%) than that of immunocompetent patients (6.8%). CONCLUSION: Because of the high prevalence of non-typhoidal salmonella strains resistant to ampicillin, chloramphenicol and TMP-SMX, third-generation cephalosporin might be the treatment of choice in non-typhoidal salmonella gastroenteritis. In particular, antibiotics should be carefully selected in immunocompromised patients because non-typhoidal salmonellas from them showed the higher incidence of antibiotic resistance and multi-drug resistance.
Ampicillin ; Anti-Bacterial Agents* ; Cefixime ; Cefotaxime ; Child ; Chloramphenicol ; Ciprofloxacin ; Drug Resistance, Microbial ; Drug Resistance, Multiple ; Drug Therapy ; Female ; Gastroenteritis* ; Humans ; Immunocompromised Host ; Incidence ; Male ; Prevalence ; Salmonella* ; Sulfamethoxazole ; Trimethoprim, Sulfamethoxazole Drug Combination

Drug-resistant (including multidrug-resistant) bacteria increase continuously with the wide use of antibiotics, which have seriously threatened the human health. It is an important way to fight against drug-resistance by screening and developing novel drugs based on the various mechanisms of the bacterial drug tolerances. Meanwhile, the basic research related to the new drug R. & D. and studies on the new screening methods for the antimicrobial agents should be taken seriously and strengthened, so as to accelerate the process of finding new drugs and meet the challenge of new pathogens and new drug-resistant strains.
Anti-Bacterial Agents ; biosynthesis ; chemical synthesis ; pharmacology ; Bacteria ; drug effects ; genetics ; Bacterial Physiological Phenomena ; drug effects ; Drug Design ; Drug Evaluation, Preclinical ; Drug Resistance, Multiple, Bacterial ; genetics ; physiology ; Humans ; Peptides

The emergence and spread of antimicrobial resistance among the pathogenic and commensal Enterobacteriaceae are of great concern worldwide. We characterized the antimicrobial resistance and integrons found in commensal Escherichia coli from healthy humans in the community. Class 1 integrase (intl1) and class 2 integrase (intl2) genes were identified in 22 (13.3%) and 2 (1.2%) of 165 E. coli isolates, respectively. dfrA17-aadA5 and dfrA1-aadA2 were the most common class 1 integrons. The prevalence of each type of class 1 integron among commensal E. coli isolates during 2001~2003 was similar to that of clinical E. coli isolates from hospital-acquired infections during 1994~1999. The resistant rates of commensal E. coli isolates carrying intl1 to ampicillin, streptomycin, gentamicin, sulfamethoxazole, trimethoprim, chloramphenicol, and tetracycline were significantly higher than those of intl1-negative E. coli isolates (p<0.05). Integrons were directly associated with multidrug resistance in commensal E. coli isolates. It is hypothesized that multidrug-resistant Enterobacteriaceae from hospital-acquired infections are a potential reservoir for integrons associated with resistance genes found in commensal E. coli isolates in the community
Ampicillin ; Chloramphenicol ; Drug Resistance, Multiple ; Enterobacteriaceae ; Escherichia coli* ; Escherichia* ; Gentamicins ; Humans* ; Integrases ; Integrons* ; Prevalence ; Streptomycin ; Sulfamethoxazole ; Tetracycline ; Trimethoprim

BACKGROUND: Staphylococcus aureus is a well-known microbe that colonizes or infects the skin in atopic dermatitis (AD). The prevalence of methicillin-resistant S. aureus (MRSA) in AD has recently been increasing. OBJECTIVE: This study aimed to determine the antimicrobial susceptibility patterns in AD skin lesions and evaluate the prevalence of MRSA in Korea. We also recommend proper first-line topical antibiotics for Korean patients with AD. METHODS: We studied S. aureus-positive skin swabs (n=583) from the lesional skin of infants, children, and adults who presented to our outpatient clinic with AD from July 2009 to April 2012. RESULTS: S. aureus exhibited high susceptibility against most antimicrobial agents. However, it exhibited less susceptibility to benzylpenicillin, erythromycin, clindamycin, and fusidic acid. The prevalence of MRSA was 12.9% among 583 S. aureus isolates, and the susceptibility to oxacillin was significantly lower in infants in both acute and chronic AD lesions. CONCLUSION: S. aureus from AD has a high prevalence of MRSA and multidrug resistance, especially in infants. In addition, the rate of fusidic acid resistance is high among all age groups, and mupirocin resistance increases with age group regardless of lesional status. This is the first study comparing the antimicrobial susceptibility rates of S. aureus isolates from AD cases with respect to age and lesion status in Korea.
Adult ; Ambulatory Care Facilities ; Anti-Bacterial Agents ; Anti-Infective Agents ; Child ; Clindamycin ; Colon ; Dermatitis, Atopic* ; Drug Resistance, Multiple ; Erythromycin ; Fusidic Acid ; Humans ; Infant ; Korea* ; Methicillin Resistance* ; Methicillin-Resistant Staphylococcus aureus* ; Mupirocin ; Oxacillin ; Penicillin G ; Prevalence* ; Skin ; Staphylococcus aureus* ; Staphylococcus*

PURPOSE: Infections of methicillin-resistant Staphylococcus aureus (MRSA) are becoming an increasingly concerning clinical problem. The aim of this study was to assess the development of MRSA in urine cultures in a major public university-affiliated hospital and the therapeutical and hygiene-related possibilities for reducing resistance. MATERIALS AND METHODS: This study included 243 samples from patients diagnosed with MRSA infection over a period of 6 years. An agar diffusion test measured the effects of antimicrobial agents against bacteria grown in culture. The analyses were based on the guidelines of the Clinical and Laboratory Standards Institute. RESULTS: A regression analysis was performed, which showed 100% resistance to the following antibiotics throughout the entire testing period: carbapenem, cephalosporin (1st-4th generation), penicillin G, aminopenicillin, beta-lactamase, and isoxazolyl penicillin. However, a significant decrease in resistance was found for amikacin, gentamicin, clindamycin, levofloxacin, erythromycin, and mupirocin. CONCLUSIONS: MRSA showed a decreasing trend of antimicrobial resistance, except against carbapenem, cephalosporin (1st-4th generation), penicillin G, aminopenicillin, beta-lactamase, and isoxazolyl penicillin, for which complete resistance was observed.
Agar ; Amikacin ; Anti-Bacterial Agents ; Anti-Infective Agents ; Bacteria ; beta-Lactamases ; Clindamycin ; Diffusion ; Drug Resistance, Multiple* ; Erythromycin ; Gentamicins ; Humans ; Levofloxacin ; Methicillin-Resistant Staphylococcus aureus* ; Mupirocin ; Penicillin G ; Penicillins

OBJECTIVETo investigate the molecule epidemic for 7 genes interrelated penicillin, erythromycin, tetracycline, vancomycin resistance of isolated Streptococcus pneumoniae (SP) in children at Suzhou area.

METHODS(1) Thirty-one pneumococcal isolates were collected from respiratory tract secretions of children with respiratory diseases from Nov 2002 to Apr 2003 at the Children's Hospital of Suzhou University (reference strain ATCC49619). (2) Penicillin susceptibility was determined by E-test, while erythromycin, tetracycline, vancomycin were determined by K-B disk. (3) The detecting of pbp2B, ermA/B, mefA, tetM, vanA, vanB genes by PCR, Sequencing pbp2B genes, Contrasting pbp2B DNA sequences among pneumococcal isolates and SP R6 [penicillin sensitive (www.ncbi.nlm.gov/nucleotide, NC-003098)].

RESULTSOf thirty-one isolates studied, the results were shown as follows; (1) Penicillin sensibility 38.7% (n = 12), penicillin resistance 61.3% (n = 19), pbp2B mutation 64.5% (n = 20); (2) Erythromycin sensibility 9.7% (n = 3), erythromycin resistance 90.3% (n = 28), ermA/B 71% (n = 22), mefA 32.1% (n = 10), ermA/B + mefA 87.1% (n = 27); (3) Tetracycline sensibility 9.7% (n = 3), tetracycline resistance 90.3% (n = 28), tetM 90.3% (n = 28); (4) Vancomycin sensibility 100% (n = 31), vanA, vanB all 0%.

CONCLUSIONAmong pneumococcal isolates at our area, penicillin, erythromycin, tetracycline resistance were high, vancomycin was sensitive. Detecting 7 genes interrelated penicillin, erythromycin, tetracycline, vancomycin resistance expressed genotypies for antibiotic resistances in pneumococcal isolates.

Anti-Bacterial Agents ; pharmacology ; Child ; China ; epidemiology ; DNA, Bacterial ; genetics ; Drug Resistance, Multiple, Bacterial ; genetics ; Erythromycin ; pharmacology ; Female ; Humans ; Male ; Microbial Sensitivity Tests ; Molecular Epidemiology ; Penicillin Resistance ; genetics ; Pneumococcal Infections ; epidemiology ; microbiology ; Streptococcus pneumoniae ; drug effects ; genetics ; isolation & purification ; Tetracycline Resistance ; genetics ; Vancomycin ; pharmacology

BACKGROUND: Impetigo is mostly caused by either Staphylococcus aureus(S. aureus) or group A beta-hemolytic Streptococcus(Streptococcus pyogenes). As the relative preponderance of each microorganism varies greatly, so reports have been contradictory. Recently, S. aureus has been reported as the principal causative microorganism of impetigo and shown variable degrees of antimicrobial resistance. OBJECTIVE: The purpose of this study is to find out the main causative microorganism and the antibiotic susceptibility of causative organism in impetigo. METHOD: Bacterial cultures and antimicrobial susceptibility test were done in 55 patients with impetigo. RESULTS: S. aureus was cultured from 49 patients of 55 patients(89.1%), and the remains were coagulase negative Staphylococcus, Streptococcus, Citrobacter braakii and Klebsiella. The resistant rates of S. aureus against antibiotics were as follows ; penicillin: 98.0%, gentamicin: 69.2%, tobramycin: 65.0%, tetracycline: 62.5%, erythromycin: 57.1%, piperacillin: 36.0%, clindamycin: 17.4%, cefazolin: 9.5%, ciprofloxacin: 8.1%, imipenem: 5.0%, oxacillin: 3.9%, trimethoprim-sulfamethoxazole: 3.7%, cefuroxime: 0%, nobobiocin: 0%, teicoplanin: 0%, and vancomycin: 0%. Methicillin-resistant S. aureus(MRSA) and oxacillin-resistant S. aureus(ORSA) were cultured in three of 20 patients(15%) and one of 26 patients(3.9%), respectively. The resistant rates of MRSA or ORSA against other antibiotics were as follows ; cefazolin, ciprofloxacin, erythromycin, and penicillin: 100%, tobramycin: 67%, trimethoprim-sulfamethoxazole: 25%, and teicoplanin, vancomycin, and nobobiocin: 0%. CONCLUSION: S. aureus was the most prominent pathogen in impetigo in this study and sensitive to cefuroxime, nobobiocin, teicoplanin, vancomycin and oxacillin, but not to penicillin, gentamicin, tobramycin, tetracycline and erythromycin. The effective antibiotics in the treatment of MRSA or ORSA were vancomycin, nobobiocin, teicoplanin and trimethoprim-sulfamethoxazole.
Anti-Bacterial Agents ; Cefazolin ; Cefuroxime ; Ciprofloxacin ; Citrobacter ; Clindamycin ; Coagulase ; Erythromycin ; Gentamicins ; Humans ; Imipenem ; Impetigo* ; Klebsiella ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus ; Oxacillin ; Penicillins ; Piperacillin ; Staphylococcus ; Staphylococcus aureus ; Streptococcus ; Teicoplanin ; Tetracycline ; Tobramycin ; Trimethoprim, Sulfamethoxazole Drug Combination ; Vancomycin