Cancer resistance to treatment ; Peninsular Malaysia ; Tetracyclines ; Salmonella typhi ; Chloramphenicol

BACKGROUND: This study is designed to provide data on the trend of resistance by year of isolation in the clinical isolates of group B streptococci(GBS) during recent eight years and to elucidate the relationship between serotypes and antimicrobial resistance patterns. METHODS: The minimal inhibitory concentrations (MIC) of seven antimicrobial agents and serotypes for 150 strains of GBS isolated from clinical specimens between 1990 and 1997 were investigated. RESULTS: The resistance rate of 150 clinical isolates of GBS were 20.0% to clindamycin, 16.0% to erythromycin, 4.0% to chloramphenicol, and 95.3% to tetracycline. None was resistant to penicillin, ceftriaxone, or vancomycin. Of the 24 isolates resistant to erythromycin, 20 (83.3%) were resistant to clindamycin. Resistance rates of erythromycin according to serotypes in decreasing order were 69.2% (V), 23.2% (III), and 3.5% (Ib). All serotypes Ia and II were susceptible to erythromycin and clindamycin. CONCLUSIONS: Striking emergence of resistant strains to erythromycin and clindamycin in our clinical isolates of GBS was mainly due to sudden increase of serotype V and III which shows multi-drug resistance phenotype.
Anti-Infective Agents ; Ceftriaxone ; Chloramphenicol ; Clindamycin ; Drug Resistance, Multiple ; Erythromycin ; Penicillins ; Phenotype ; Strikes, Employee ; Tetracycline ; Vancomycin

BACKGROUND: Extended-spectrum cephalosporins and fluoroquinolones are important antimicrobials for treating invasive salmonellosis, and emerging resistance to these antimicrobials is of paramount concern. METHODS: A total of 30 Salmonella spp. clinical isolates recovered in Gyeongsangbuk-do from 2012 to 2013 were characterized using antibiotic resistance profiles and pulsed-field gel electrophoresis (PFGE). RESULTS: A high prevalence of multidrug-resistant isolates, mainly showing an ampicillin, nalidixic acid, chloramphenicol resistance pattern, was observed. Four extended-spectrum beta-lactamase (ESBL)-producing isolates (3 CTX-M-15 isolates and 1 CTX-M-27 isolate) were found. The bla(CTX-M-27) gene was carried by an IncF conjugative plasmid in the S. Infantis isolate. The bla(CTX-M-15) gene were carried by an IncF (2 isolates) or IncHI2 (1 isolate) conjugative plasmid in S. Enteritidis. In addition, a single mutation of GyrA, Ser83Thr (1 isolates), Asp87Tyr (9 isolates), Asp87Gly (4 isolates), and Asp87Leu (3 isolates), was detected in nalidixic acid-resistant Salmonella spp. isolates. XbaI PFGE analysis of all isolates revealed more than 19 different pulsotypes. The most common S. Enteritidis PFGE pattern (SEGX01.003) was associated with a larger number of cases of invasive salmonellosis than all other patterns. CONCLUSION: The information from our study can assist in source attribution, outbreak investigations, and tailoring of interventions to maximize disease prevention.
Ampicillin ; beta-Lactamases ; Cephalosporins ; Chloramphenicol Resistance ; Drug Resistance ; Drug Resistance, Microbial ; Electrophoresis, Gel, Pulsed-Field ; Fluoroquinolones ; Gyeongsangbuk-do ; Nalidixic Acid ; Plasmids ; Prevalence ; Salmonella Infections ; Salmonella*

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: Erythromycin is currently recommended as an alternative antibiotic for treatment of streptococcal infections in patients allergic to penicillins. Less than 5% of the group A streptococci are known as resistant to erythromycin but the resistance pattern differs among time and region. The purpose of this study was to determine the antimicrobial susceptibility of beta-emolytic streptococcal strains isolated during 1999 in Wonju. METHODS: A total of 107 beta-emolytic streptococci were isolates from the Wonju Christian Hospital during 1999. The susceptibility to penicillin, erythromycin, tetracycline, vancomycin, ceftriaxone, chloramphenicol, and clindamycin was tested with agar dilution method. RESULTS: No beta-emolytic streptococci strain was resistant to penicillin, ceftriaxone and vancomycin. Among beta-emolytic streptococci strains, 20-1%, 18-0% and 14-7% were resistant to tetracycline, erythromycin and clindamycin, respectively. CONCLUSIONS: It appears prudent that active surveillance of the beta-emolytic streptococci for antibiotic resistance be implemented since there are no currently effective vaccines or other methods for controlling the spread of infections due to these virulent organisms.
Agar ; Ceftriaxone ; Chloramphenicol ; Clindamycin ; Drug Resistance, Microbial ; Erythromycin ; Gangwon-do ; Humans ; Penicillins ; Streptococcal Infections ; Tetracycline ; Vaccines ; Vancomycin

BACKGROUND: Erythromycin is currently recommended as an alternative antibiotic for treatment of streptococcal infections in patients allergic to penicillins. Less than 5% of the group A streptococci are known as resistant to erythromycin but the resistance pattern differs among time and region. The purpose of this study was to determine the antimicrobial susceptibility of beta-emolytic streptococcal strains isolated during 1999 in Wonju. METHODS: A total of 107 beta-emolytic streptococci were isolates from the Wonju Christian Hospital during 1999. The susceptibility to penicillin, erythromycin, tetracycline, vancomycin, ceftriaxone, chloramphenicol, and clindamycin was tested with agar dilution method. RESULTS: No beta-emolytic streptococci strain was resistant to penicillin, ceftriaxone and vancomycin. Among beta-emolytic streptococci strains, 20-1%, 18-0% and 14-7% were resistant to tetracycline, erythromycin and clindamycin, respectively. CONCLUSIONS: It appears prudent that active surveillance of the beta-emolytic streptococci for antibiotic resistance be implemented since there are no currently effective vaccines or other methods for controlling the spread of infections due to these virulent organisms.
Agar ; Ceftriaxone ; Chloramphenicol ; Clindamycin ; Drug Resistance, Microbial ; Erythromycin ; Gangwon-do ; Humans ; Penicillins ; Streptococcal Infections ; Tetracycline ; Vaccines ; Vancomycin

Ninety-two strains of Serratia marcescens isolated from 5 hospitals were analyzed for plasmid profile, antimicrobial drug resistance pattern, biotyping, and production of pigment. Ninety-three percents of strains were resistant to chloramphenicol (Cm), tetracycline (Tc), sulfisoxazole (Su), cefazolin (Cz), ampicillin (Ap), and rifampin (Rf). A majority of strains were susceptible to amikacin (Ak), ciprofloxacin (Ci), and cefotaxim (Ct). Fifty-four resistance patterns were found in 94 strains and the most prevalent resistance pattern was CmTcSuApCzRf. Seventeen (17.4%) isolates could transfer their partial resistance to E. coli or Klebsiella pneumoniae by conjugation. Twenty-seven plasmid profiles in 54 strains (58.7%) were detected, however no predominant patterns were seen in isolates from each hospital. Eleven biotypes were detected. The common types were A3b (29.4%) and A8b (27.1%), predominant types were found in each hospital. Twenty strains from 4 of 5 hospitals showed consistence of 3 types. These results indicate that plasmid profile analysis, Grimont biotyping, and resistance pattern type of strains in combination are useful as an epidemiological tool for S. marcescens isolates and some of isolates were confirmed as nosocomial strains.
Amikacin ; Ampicillin ; Cefazolin ; Cefotaxime ; Chloramphenicol ; Ciprofloxacin ; Drug Resistance, Microbial ; Epidemiologic Studies* ; Klebsiella pneumoniae ; Plasmids ; Rifampin ; Serratia marcescens* ; Serratia* ; Sulfisoxazole ; Tetracycline

Chloramphenicol-resistant gene was cloned and analyzed by constructing genomic DNA library of Serratia marcescens KMR-3. It showed that cloned chloramphenicol-resistant gene encoded a protein product of 397 amino acids. The protein belonged to PRK10473 protein, and it showed 92% similarity to drug resistance transporter, Bcr/CflA subfamily of Serratia proteamaculans 568. Regulation elements including promoter, terminator, Shine-Dalgarno (SD) sequence and transcription start site also were identified.
Amino Acid Sequence ; Base Sequence ; Chloramphenicol Resistance ; genetics ; Cloning, Molecular ; Molecular Sequence Data ; Serratia marcescens ; classification ; genetics

Nine strains (6%) were confirmed as resistant (MIC=20ug/ml) to methicillin (MT) among 150 isolates of staphylococcus aureus. These MT-resistant staphylococcus aureus (MRSA) strains were also turned out to be more less resistant to other antibiotics tested, such as penicillin, chloramphenicol, tetracycline, and gentamicin except for cephaloridine. It was noteworthy, however, that strain MRSA 5 showed a relatively susceptible attitude toward most of the antibiotics tested, while being extremely resistant to MT only. Salt (NaC1) containing (5-3%) media did not have any significant effect on the degree of MT-resistance of MRSA strains. There was, however, such a tendency as that by the addition of salt the degree of MT-resistance was lowered in the highly MT-resistant strains while enhanced in MT-susceptible ones. It was confirmed that penicillinase did not have any effect on the MT-resistance while most of the penicillin- resistant strains produced the enzyme.
Anti-Bacterial Agents ; Cephaloridine ; Chloramphenicol ; Gentamicins ; Methicillin Resistance ; Methicillin ; Methicillin-Resistant Staphylococcus aureus ; Penicillinase ; Penicillins ; Staphylococcus aureus ; Staphylococcus ; Tetracycline

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*