RESUMO
Carbapenemase-producing Enterobacterales (CPE) are not always resistant to carbapenem antimicrobial susceptibility testing (AST) and can be difficult to detect. With the newly created VITEK2 AST-XN17 card, the types of antibiotics measured in AST can be increased. In this study, we evaluated the detectability of CPE using the results of AST with multiple antimicrobial agents with additional measurements of the AST-XN17 card. In addition, we evaluated the CPE detectability of comments on CPE using the VITEK2 Advance Expert System (AES). In total, 169 Enterobacterales samples, including 76 non-CPE and 93 CPE, collected from multiple medical institutions in the Kinki region of Japan, were used in this investigation. AST with VITEK2 was performed by adding the AST-XN17 card in addition to the AST-N268 or AST-N404 card. Measurement results were identified using cutoff values, primarily Clinical and Laboratory Standards Institute breakpoints, and the CPE detection capability of each antibiotic was evaluated in several terms, including sensitivity and specificity. The drugs highly sensitive to CPE detection were faropenem (FRPM) > 2 µg/mL at 100% and meropenem > 0.25 µg/mL at 98.9%; the highest specificity to CPE detection was for avibactam/ceftazidime (AVI/CAZ) > 8 µg/mL at 100%. The sensitivity and specificity of each card in the AES output were 86.2% and 94.7% for AST-N404 and AST-XN17 and 91.5% and 90.8% for AST-N268 and AST-XN17, respectively. AST using the VITEK2 AST-XN17 card is a useful test method of screening for CPE.
Assuntos
Proteínas de Bactérias , beta-Lactamases , Antibacterianos/farmacologia , Humanos , Meropeném , Testes de Sensibilidade MicrobianaRESUMO
INTRODUCTION: The carbapenem inactivation method test (CIM) was developed as a method for detecting carbapenemase-producing Gram-negative bacilli, and the modified CIM (mCIM) was recommended by the CLSI for as an improved method in M100-S27. However, few studies have evaluated the influence of bacterial species and genotype on its sensitivity and specificity. In this study, we evaluate the performance of these improved modified CIM methods with mCIM. METHODS: As strains, clinical isolates from Naga Municipal Hospital and stored strains from the Study of Bacterial Resistance in the Kinki Region of Japan were used. The mCIM, CIM-Tris, and simple CIM (sCIM) test methods were applied to 120 Enterobacterales, 40 Pseudomonas aeruginosa, and 37 Acinetobacter spp. The procedure and criteria for each method were based on the original papers and the CLSI M - 100 S27 documents. RESULTS: The sensitivity of the test methods in the detection of carbapenemase in Enterobacterales, Pseudomonas spp., and Acinetobacter spp. was as follows: mCIM, 98.9%, 90.0%, and 76.5%, respectively; CIM-Tris, 94.4%, 100%, 100%; and sCIM 98.9%, 85.0%, 76.5%. All methods showed 100% specificity in Enterobacterales, Pseudomonas spp., and Acinetobacter spp. Each method performed well in the detection of metallo ß-lactamase-producing strains, however, the sensitivity tended to be low in the detection of the organisms producing serine-type carbapenemase, such as GES, OXA-23, and OXA-51. CONCLUSIONS: Care must be taken when selecting test methods because the sensitivity of the detection differs depending on the bacterial species and genotype.
Assuntos
Carbapenêmicos , beta-Lactamases , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Carbapenêmicos/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Sensibilidade e Especificidade , beta-Lactamases/genéticaRESUMO
Carbapenemase-producing Enterobacteriaceae (CPE) are increasing worldwide. Rapid and accurate detection of CPE is necessary for appropriate antimicrobial treatment and hospital infection control. However, CPE contains some strains that are difficult to detect depending on genotype and MIC value of carbapenem, and a detection method has not been established. The recently reported modified carbapenem inactivation method (mCIM) has been developed in CLSI M100-S27 as a phenotypic technique for detecting carbapenemase activity. In the present study, we examined mCIM as a new CPE detection method using 207 Enterobacteriaceae isolates in comparison with the three existing screening methods of modified Hodge test, Carba NP test and carbapenem inactivation method and evaluated its performance. Consequently, both the sensitivity and specificity of mCIM were 100%, indicating better results than the conventional screening methods. The mCIM is a useful tool for microbiology laboratories due to its simplicity, clear criteria, cost-effectiveness and availability at any laboratory.
Assuntos
Proteínas de Bactérias/metabolismo , Técnicas de Tipagem Bacteriana/métodos , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Carbapenêmicos/farmacologia , Ensaios Enzimáticos/métodos , beta-Lactamases/metabolismo , Técnicas de Tipagem Bacteriana/economia , Enterobacteriáceas Resistentes a Carbapenêmicos/classificação , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacteriáceas Resistentes a Carbapenêmicos/enzimologia , Infecções por Enterobacteriaceae/microbiologia , Ensaios Enzimáticos/economia , Testes de Sensibilidade Microbiana , Sensibilidade e EspecificidadeRESUMO
The 7-valent pneumococcal conjugate vaccine (PCV7) was introduced among children in Japan in 2010. There are no long-term multicenter surveillance studies of antimicrobial resistance in S. pneumoniae before and after the introduction of PCV7. Therefore, we examined chronological trends in antimicrobial resistance among 4534 strains of S. pneumoniae isolated from both children and adults in the Kinki region of Japan during 2001-2015. High-level penicillin and third-generation cephalosporin resistance in S. pneumoniae increased among both children and adults during the period before the introduction of PCV7 (2001-2010). Besides penicillin and cephalosporin, pneumococcal carbapenem and macrolide resistance increased among children. The rate of resistance to these antibiotics was higher among children than among adults. The introduction of PCV7 decreased the rate of non-susceptibility to ß-lactam antibiotics and the rate of multidrug resistant S. pneumoniae among children, but not among adults.
Assuntos
Farmacorresistência Bacteriana Múltipla , Vacina Pneumocócica Conjugada Heptavalente/administração & dosagem , Infecções Pneumocócicas/microbiologia , Infecções Pneumocócicas/prevenção & controle , Streptococcus pneumoniae/isolamento & purificação , Adulto , Carbapenêmicos/uso terapêutico , Cefalosporinas/uso terapêutico , Criança , Monitoramento Epidemiológico , Humanos , Japão/epidemiologia , Macrolídeos/uso terapêutico , Penicilinas/uso terapêutico , Infecções Pneumocócicas/tratamento farmacológico , Infecções Pneumocócicas/epidemiologia , Estudos Retrospectivos , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/imunologiaRESUMO
Six Klebsiella pneumoniae clinical isolates resistant to various cephalosporins and cephamycins were identified in a Japanese general hospital, a tertiary care hospital, between November 2009 and April 2010. All K. pneumoniae isolates carried blaGES-4 and blaSHV-1, while 2 K. pneumoniae isolates also harbored blaCTX-M-15. The pulsed-field gel electrophoresis patterns revealed that these 6 K. pneumoniae isolates were almost identical, suggesting their clonal relatedness. Plasmid profiles and conjugation assays revealed that these blaGES-4 genes were located on similar conjugative plasmids. These data indicate that nosocomial spread caused by K. pneumoniae isolates producing blaGES-4 carbapenemase occurred at a Japanese general hospital. K. pneumoniae isolate harboring blaGES-4 is rarely reported in Japan, and, to the best of our knowledge, this is the second report of K. pneumoniae isolates harboring blaGES-4 that occurred nosocomial spread in Japan.
Assuntos
Proteínas de Bactérias/metabolismo , Infecção Hospitalar/microbiologia , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/isolamento & purificação , Klebsiella pneumoniae/metabolismo , beta-Lactamases/metabolismo , Idoso , Idoso de 80 Anos ou mais , Cefalosporinas/metabolismo , Eletroforese em Gel de Campo Pulsado/métodos , Feminino , Hospitais , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Plasmídeos/metabolismoRESUMO
We determined the complete nucleotide sequence of a self-transmissible IncL/M plasmid, pKOI-34, from a Klebsiella oxytoca isolate. pKOI-34 possessed the core structure of an IncL/M plasmid found in Erwinia amylovora, pEL60, with two mobile elements inserted, a transposon carrying the arsenic resistance operon and a Tn21-like core module (tnp and mer modules) piggybacking blaIMP-34 as a class 1 integron, In808, where blaIMP-34 confers a resistance to carbapenems in K. oxytoca and Klebsiella pneumoniae.
Assuntos
Klebsiella oxytoca/genética , Plasmídeos/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Elementos de DNA Transponíveis/genética , Japão , Klebsiella oxytoca/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Testes de Sensibilidade MicrobianaRESUMO
A study was conducted of the 1,225 Pseudomonas aeruginosa strains that were isolated at 20 medical institutions in the Kinki district between 2011 and 2013 to determine their antimicrobial susceptibility and to characterize the strains of multidrug-resistant Pseudomonas aeruginosa (MDRP) and the metallo-ß-lactamase (MBL) -producing strains. The MIC50/MIC90 values (µg/mL) of the various antimicrobial agents were as follows: imipenem, 2/>8; meropenem, 1/>8; doripenem, 0.5/8; biapenem, 1/>8; tazobactam/piperacillin, 8/>64; piperacillin, 8/>64; sulbactam/cefoperazone, 8/64; cefepime, 4/16; cefozopran, 2/>16; aztreonam, 8/>16; amikacin, 4/16; levofloxacin, 1/>4; and ciprofloxacin, 0.25/>2. From the viewpoint of the annual changes in the susceptibility rates (according to the CLSI guidelines [M100-S22]), the susceptibility to tazobactam/piperacillin, piperacillin, cefepime, cefozopran and aztreonam decreased in 2013. On the other hand, two antimicrobial agents showed high susceptibility rates each year; amikacin (94.0-95.6%) showed the highest rate, followed by doripenem (80.3-82.6%). With the exception of amikacin, there were substantial inter-institutional differences in antimicrobial susceptibility. In comparison to the previous CLSI guidelines (M100-S21), the new CLSI guidelines (M100-S22) on the use of carbapenems and penicillins show that the MIC80 has been affected. The MDRP detection rates in 2011, 2012 and 2013 were 1.8% (8 strains), 1.8% (8 strains), and 2.8% (10 strains), respectively. The MBL detection rates were as follows: bla(VIM-2), 0.2% (1 strain) in 2011; bla(IMP-1), 0.9% (4 strains) in 2012, and 1.7% (6 strains, including bla(IMP-1) [3 strains], bla(IMP-2) [2 strains] and bla(VIM-2) [1 strain]) in 2013.
Assuntos
Antibacterianos/farmacologia , Pseudomonas aeruginosa/isolamento & purificação , Farmacorresistência Bacteriana Múltipla , Humanos , Japão , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacosRESUMO
We have determined the DNA sequence of Klebsiella pneumoniae multidrug resistance plasmid pKPI-6, which is a self-transmissible IncN-type plasmid. pKPI-6 harboring blaIMP-6 and blaCTX-M-2 confers a stealth-type carbapenem resistance phenotype on members of the family Enterobacteriaceae that is not detectable with imipenem. pKPI-6 is already epidemic in Japan, favoring the dissemination of IMP-6 and CTX-M-2 in members of the family Enterobacteriaceae.
Assuntos
Enterobacteriaceae/enzimologia , beta-Lactamases/metabolismo , Enterobacteriaceae/efeitos dos fármacos , Imipenem/farmacologia , Japão , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Plasmídeos/genéticaRESUMO
With the increase in extended spectrum ß-lactamase (ESBL)-producing bacteria in the community, cases are often seen in which treatment of infectious diseases with oral antimicrobial agents is difficult. Therefore, we measured the antimicrobial activities of 14 currently available oral antimicrobial agents against ESBL-producing Escherichia coli and Klebsiella pneumoniae. Based on the standard of the Clinical and Laboratory Standards Institute (CLSI), E. coli showed high susceptibility rates of 99.4% to faropenem (FRPM). In terms of fluoroquinolones, the susceptibility rate of E. coli to levofloxacin (LVFX) was low at 32.2%, whereas it showed a good susceptibility rate of 93.1% to sitafloxacin (STFX). With respect to other antimicrobial agents, susceptibility rates to fosfomycin (FOM) and colistin (CL) were more than 90% each, whereas rates of the two antimicrobial agents expected as therapeutic agents, minocycline (MINO) and sulfamethoxazole-trimethoprim (ST), were low at 62.4% and 44.3%, respectively. Based on the CLSI standard, K. pneumoniae showed high susceptibility rates to ceftibuten (CETB) (91.89%), LVFX (86.49%), and STFX (94.6%), indicating that K. pneumoniae showed higher rates than those of E. coli, particularly to fluoroquinolones. Comparison of susceptibility rates according to E. coli genotype showed that many antimicrobial agents existed to which the CTX-M-9 group showed high susceptibility rates. However, there were many agents to which the CTX-M-1 group showed low susceptibility rates, particularly to CETB (51.1%) and LVFX (17.0%). Although there was no significant difference by genotype between FRPM, STFX, and FOM, a significant difference was observed between LVFX, MINO, and ST. Antibiotic-resistant bacteria with highly pathogenic strains have spread in the community, appropriate use of oral antimicrobial agents is required.
Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , beta-Lactamases/metabolismo , Escherichia coli/metabolismo , Klebsiella pneumoniae/metabolismo , Testes de Sensibilidade Microbiana/métodosRESUMO
The antimicrobial activity of 18 antimicrobial agents were measured for the 500 Pseudomonas aeruginosa strains that had been isolated from various clinical specimens in 17 medical institutions in the Kinki district from April to July of 2008. The antimicrobial activity was excellent in the order of tobramycin (TOB), arbekacin (ABK), doripenem (DRPM), gentamicin (GM) and amikacin (AMK). Susceptible rate that was interpreted by Clinical and Laboratory Standards Institute (CLSI) was high in the order of AMK, TOB, tazobactam/piperacillin (TAZ/PIPC), DRPM, ABK. Also, the difference in susceptible rate was observed between departments, materials and institutions. Multidrug resistant strains were only 12 (2.4%) but strains that had resistance to 2 agents were 48 (9.6%), therefore, implementation of further surveillance should be continued.
Assuntos
Antibacterianos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , Sangue/microbiologia , Sistema Digestório/microbiologia , Farmacorresistência Bacteriana , Pacientes Internados , Japão , Pacientes Ambulatoriais , Sistema Respiratório/microbiologia , Sistema Urinário/microbiologiaRESUMO
Extended-spectrum beta-lactamases, plasmid-mediated AmpC beta-lactamases (PABLs), and plasmid-mediated metallo-beta-lactamases confer resistance to many beta-lactams. In Japan, although several reports exist on the prevalence of extended-spectrum beta-lactamases and metallo-beta-lactamases, the prevalence and characteristics of PABLs remain unknown. To investigate the production of PABLs, a total of 22,869 strains of 4 enterobacterial species, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, and Proteus mirabilis, were collected during six 6-month periods from 17 clinical laboratories in the Kinki region of Japan. PABLs were detected in 29 (0.13%) of 22,869 isolates by the 3-dimensional test, PCR analysis, and DNA sequencing analysis. PABL-positive isolates were detected among isolates from 13 laboratories. Seventeen of 13,995 (0.12%) E. coli isolates, 8 of 5,970 (0.13%) K. pneumoniae isolates, 3 of 1,722 (0.17%) K. oxytoca isolates, and 1 of 1,182 (0.08%) P. mirabilis isolates were positive for PABLs. Of these 29 PABL-positive strains, 20 (69.0%), 6 (20.7%), 2 (6.9%), and 1 (3.4%) carried the genes for CMY-2, DHA-1, CMY-8, and MOX-1 PABLs, respectively. Pattern analysis of randomly amplified polymorphic DNA and pulsed-field gel electrophoretic analysis revealed that the prevalence of CMY-2-producing E. coli strains was not due to epidemic strains and that 3 DHA-1-producing K. pneumoniae strains were identical, suggesting their clonal relatedness. In conclusion, the DHA-1 PABLs were predominantly present in K. pneumoniae strains, but CMY-2 PABLs were predominantly present in E. coli strains. The present findings will provide significant information to assist in preventing the emergence and further spread of PABL-producing bacteria.
Assuntos
Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Infecções por Enterobacteriaceae/microbiologia , Escherichia coli/enzimologia , Klebsiella/enzimologia , Plasmídeos/análise , Proteus mirabilis/enzimologia , beta-Lactamases/biossíntese , beta-Lactamases/genética , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Impressões Digitais de DNA , DNA Bacteriano/química , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Humanos , Japão , Klebsiella/efeitos dos fármacos , Klebsiella/genética , Klebsiella/isolamento & purificação , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Reação em Cadeia da Polimerase , Proteus mirabilis/efeitos dos fármacos , Proteus mirabilis/genética , Proteus mirabilis/isolamento & purificação , Técnica de Amplificação ao Acaso de DNA Polimórfico , Análise de Sequência de DNA , beta-Lactamas/farmacologiaRESUMO
Guiana extended-spectrum (GES) ß-lactamases are emerging in Japan. The GES family can be classified into 2 groups, one with extended-spectrum ß-lactamase (ESBL)-like activity, which hydrolyzes penicillins and cephalosporins, and the other with carbapenemase-like activity with an extended spectrum toward carbapenems. This difference is mediated by variations in a specific amino acid in the GES protein: G170â¯N or G170S substitutions. We developed an amplification refractory mutation system (ARMS) PCR assay that enabled rapid identification of these variant genes without sequencing.
Assuntos
Técnicas Bacteriológicas/métodos , Bactérias Gram-Negativas/enzimologia , Reação em Cadeia da Polimerase Multiplex/métodos , beta-Lactamases/genética , Bactérias Gram-Negativas/isolamento & purificação , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Japão , Fatores de Tempo , beta-Lactamases/análise , beta-Lactamases/classificaçãoRESUMO
We studied the susceptibility to penicillin G (PCG) and other antimicrobiotics in 235 clinical isolates of Streptococcus pneumoniae. Samples were collected between April 1 and June 30, 2000 from nine medical institutions of the Kinki Region of Japan. We classified the minimum inhibitory concentration (MIC) of PCG according to the National Committee for Clinical Laboratory Standards (NCCLS) criteria. The overall rate of all types of S. pneumoniae resistance was 53.2% (penicillin-susceptible S. pneumoniae (PSSP): 46.8%, penicillin-intermediate S. pneumoniae (PISP): 42.6%, penicillin-resistant S. pneumoniae (PRSP): 10.6%). In other antimicrobiotics, the resistance (R)/intermediate susceptibility (I) rates (R/I%) were as follows: ceftriaxone, 28.9%; cefotaxime, 7.7%; imipenem, 8.9%; meropenem, 9.8%; clarithromycin, 82.6%; clindamycin, 42.1%; levofloxacin, 0.4%; vancomycin, 0%. We used the polymerase chain reaction to study the mutations of the penicillin-binding proteins pbp1 a, pbp2b, and pbp2x in 140 strains of S. pneumoniae in the MIC for PCG was < 0.5 microgram/ml. Among the 109 strains of PSSP, 32 (29.4%) had no mutation and 77 (70.6%) showed mutation of more than one of the pbp mutations. Among the 31 strains of PISP, only 1 strain (3.2%) was not mutated. Since 70.6% of the strains classified as PSSP had pbp mutations, S. pneumoniae clearly can acquire resistance to anti-microbiotics. In the future, a comprehensive surveillance of S. pneumoniae is necessary.
Assuntos
Aminoaciltransferases , Antibacterianos/farmacologia , Proteínas de Bactérias , Proteínas de Transporte/genética , Hexosiltransferases , Muramilpentapeptídeo Carboxipeptidase/genética , Peptidil Transferases , Streptococcus pneumoniae/genética , Lactamas , Mutação , Resistência às Penicilinas/genética , Proteínas de Ligação às Penicilinas , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/isolamento & purificação , Resistência beta-Lactâmica/genéticaRESUMO
We studied antimicrobial susceptibility and beta-lactamase types among clinical isolates in the Kinki area of Japan. Eight hundreds isolates of eight organisms were collected by seven medical institutions during January and February 2000. The rates of beta-lactamase producing by using the chromogenic nitrocephin test were 68.0% against Staphylococcus aureus isolates, 6.0% against Haemophilus influenzae isolates, 98.0% against Moraxella catarrhalis isolates. The rate of beta-lactamase negative ampicillin-resistant H. influenzae was 4.0% (4 out of 100). The result of beta-lactamase producing by using the acid-metric method were as follows the penicillinase and cephalosporinase: 27.0% and 37.0% against Escherichia coli isolates, 37.0% and 1.0% against Klebsiella pneumoniae isolates, 21.8% and 100% against Enterobacter cloacae isolates, 24.2% and 96.0% against Serratia marcescens isolates, 7.0% and 22.0% against Pseudomonas aeruginosa isolates. We identified beta-lactamase type of each isolate detected by polymerase chain reaction: SHV-derived extended-spectrum beta-lactamase (ESBLs) (1 isolate of E. coli and 1 isolate of K. pneumoniae), CTX-M-1-derived ESBLs (1 isolate of K. pneumoniae, 1 of E. cloacae and 4 of S. marcescens), and IMP-1-derived metallo beta-lactamases (2 isolates of S. marcescens).
Assuntos
Bactérias/efeitos dos fármacos , Bactérias/enzimologia , beta-Lactamases/biossíntese , Farmacorresistência Bacteriana , Enterobacter cloacae/efeitos dos fármacos , Enterobacter cloacae/enzimologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Haemophilus influenzae/efeitos dos fármacos , Haemophilus influenzae/enzimologia , Japão , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Testes de Sensibilidade Microbiana , Moraxella catarrhalis/efeitos dos fármacos , Moraxella catarrhalis/enzimologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/enzimologia , Serratia marcescens/efeitos dos fármacos , Serratia marcescens/enzimologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/enzimologiaAssuntos
Citrobacter freundii/enzimologia , Infecções por Enterobacteriaceae/microbiologia , Pseudomonas aeruginosa/enzimologia , beta-Lactamases/genética , Citrobacter freundii/genética , Citrobacter freundii/isolamento & purificação , Infecções por Enterobacteriaceae/epidemiologia , Humanos , Japão/epidemiologia , Plasmídeos/genética , Pseudomonas aeruginosa/genéticaRESUMO
We investigated 5 metallo-ß-lactamase (MBL)-positive Klebsiella isolates from Japan showing intermediate resistance to imipenem. Sequencing of the MBL gene identified a novel variant of IMP-1 with a single amino acid substitution, Glu87Gly. This variant is designated as IMP-34 where blaIMP-34 is located on a transmissible plasmid.
Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Imipenem/farmacologia , Klebsiella/enzimologia , beta-Lactamases/genética , Japão , Klebsiella/efeitos dos fármacos , Klebsiella/genética , Klebsiella/isolamento & purificação , Testes de Sensibilidade Microbiana , PlasmídeosRESUMO
In the present study, nonduplicate, clinical isolates of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli, Klebsiella spp, and Proteus mirabilis were collected during a 10-year period from 2000 to 2009 at several hospitals in the Kinki region, Japan. The detection rate of E coli markedly increased from 0.24% to 7.25%. The detection rate of Klebsiella pneumoniae increased from 0% to 2.44% and that of P mirabilis from 6.97% to 12.85%. The most frequently detected genotypes were the CTX-M9 group for E coli, the CTX-M2 group for K pneumoniae, and the CTX-M2 group for P mirabilis. E coli clone O25:H4-ST131 producing CTX-M-15, which is spreading worldwide, was first detected in 2007. The most common replicon type of E coli was the IncF type, particularly FIB, detected in 466 strains (69.7%). Of the K pneumoniae strains, 47 (55.3%) were of the IncN type; 77 P mirabilis strains (96.3%) were of the IncT type. In the future, the surveillance of various resistant bacteria, mainly ESBL-producing Enterobacteriaceae, should be expanded to prevent their spread.
Assuntos
Infecções por Escherichia coli/epidemiologia , Escherichia coli/genética , Infecções por Klebsiella/epidemiologia , Klebsiella/genética , Infecções por Proteus/epidemiologia , Proteus mirabilis/genética , beta-Lactamases/genética , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/microbiologia , Humanos , Japão/epidemiologia , Klebsiella/isolamento & purificação , Infecções por Klebsiella/genética , Infecções por Klebsiella/microbiologia , Epidemiologia Molecular , Infecções por Proteus/genética , Infecções por Proteus/microbiologia , Proteus mirabilis/isolamento & purificaçãoRESUMO
Extended-spectrum beta-lactamase (ESBL)-producing bacteria are known to be resistant to penicillins, cephalosporins, and monobactams because of their substrate specificity, and these bacteria are sensitive only to a narrow range of antimicrobial agents. The present study was undertaken to evaluate the efficacy of carbapenems and the new quinolones against ESBL-producing Escherichia coli, using a Monte Carlo simulation based on the pharmacokinetic/pharmacodynamic (PK/PD) theory. The time above MIC (TAM, %) served as the PK/PD parameter for carbapenems, with the target level set at 40%. The AUC/MIC served as the PK/PD parameter for the new quinolones, with the target level set at more than 125. In the analysis of drug sensitivity, the MIC50 of all carbapenems other than imipenem was low (0.03 microg/ml), while the MIC50 of the new quinolones was higher (1-2 microg/ml). The probability of achieving the PK/PD target with carba penems after two doses at the usual dose level, as determined by the Monte Carlo simulation, was high for each of the carbapenems tested (99.0% for biapenem, 99.60% for meropenem, and 95.03% for doripenem), except for imipenem. Among the new quinolones, the highest probability of achieving the PK/PD target was obtained with pazufloxacin (42.90%). Thus, the results of the present study have revealed that carbapenems are effective at the regular dose and can be used as the first-choice antibiotics for ESBL-producing E. coli because the resistance ratios for carbapenems are low compared to those of the new quinolones.
Assuntos
Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Escherichia coli/efeitos dos fármacos , Método de Monte Carlo , Quinolonas/farmacologia , beta-Lactamases/metabolismo , Antibacterianos/farmacocinética , Carbapenêmicos/farmacocinética , Escherichia coli/enzimologia , Humanos , Masculino , Testes de Sensibilidade Microbiana , Modelos Biológicos , Quinolonas/farmacocinética , Resistência beta-LactâmicaRESUMO
We studied the antimicrobial susceptibility of AmpC beta-lactamase-producing Escherichia coli isolates collected at ten medical institutions in the Kinki area of Japan during a 6-month period (November 2002 through April 2003). Of 2845 E. coli isolates tested, 29 (1.0%) showed a minimum inhibitory concentration (MIC) for cefazolin of more than 8 microg/ml and were three-dimensional extract test positive. In standard inoculum susceptibility tests against these 29 strains, the MIC90s for the four carbapenems tested ranged from 0.06 microg/ml to 0.5 microg/ml, and these compounds were more active than the other beta-lactams, with meropenem being the most active. The MIC90s for beta-lactams, except carbapenems, ranged from 4 microg/ml to 32 microg/ml, with cefepime being the most active. In high inoculum susceptibility tests against these strains, the MIC90s for the four carbapenems and cefepime were 8 microg/ml or less, and these compounds were more active than other beta-lactams. The MIC90s for beta-lactams, except carbapenems and cefepime, were 32 microg/ml or more. The MIC90s for the five quinolones tested ranged from 4 microg/ml to 16 microg/ml, and the order of increasing susceptibility was ciprofloxacin > levofloxacin, gatifloxacin and pazufloxacin > prulifloxacin.
Assuntos
Antibacterianos/farmacologia , Cefazolina/farmacologia , Escherichia coli/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Infecção Hospitalar , Escherichia coli/metabolismo , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Hospitais , Humanos , Japão , Testes de Sensibilidade Microbiana , Quinolonas/farmacologia , beta-Lactamases/metabolismoRESUMO
The aim of this study was to research the distribution in the Kinki region of Japan of Enterobacteriaceae and Pseudomonas aeruginosa that produce extended-spectrum beta-lactamase (ESBL) and metallo beta-lactamase (MBL). One thousand isolates, 200 of each of four enterobacterial species (i.e. Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae and Serratia marcescens) and 200 of P. aeruginosa, were collected from seven different laboratories during two 2 month periods, one in 1998 and one in 2000. A double-disc synergy test (DDST) and 2-mercaptopropionic acid inhibition test (2-MPAT) were used to confirm beta-lactamase-producing isolates. The DDST was positive for one isolate of E. coli, five of K. pneumoniae, two of E. cloacae and 14 of S. marcescens. The 2-MPAT was positive for five isolates of S. marcescens and two of P. aeruginosa. We identified the beta-lactamase type of each isolate by molecular confirmatory tests (isoelectric focusing, PCR and DNA sequencing): CTX-M-3 ESBLs (three isolates of K. pneumoniae, two of E. cloacae and 13 of S. marcescens), CTX-M-2 ESBL (one isolate of K. pneumoniae), SHV-12 ESBLs (one isolate of E. coli and one of S. marcescens), CTX-M-3 and SHV-12 combination ESBL (one isolate of K. pneumoniae) and IMP-1 MBLs (five isolates of S. marcescens and two of P. aeruginosa). In conclusion, many species of Gram-negative bacilli that produce CTX-M-3 ESBLs and IMP-1 MBLs were disseminated widely in different hospitals of the Kinki region of Japan. Therefore, monitoring of laboratory bacterial ecology seems important to stop the spread of these strains through nosocomial outbreaks.