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1.
Front Microbiol ; 7: 1830, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27895637

RESUMO

The aim of this work was to investigate the epidemiological and genetic characteristics of ESBL-producing Klebsiella pneumoniae (ESBL-Kp) causing community-onset infections. K. pneumoniae isolates were collected from 31 Chinese secondary hospitals between August 2010 and 2011. Genes encoding ESBL and AmpC beta-lactamases were detected by PCR. The isolates were assigned to sequence types (STs) using multi-locus sequence typing (MLST). Eleven ESBL-Kp strains were selected for whole-genome sequencing (WGS) for investigating the genetic environment and plasmids encoding ESBL genes. A total of 578 K. pneumoniae isolates were collected, and 184 (31.8%) carried ESBL genes. The prevalence of ESBL-Kp varied from different geographical areas of China (10.2-50.3%). The three most prevalent ESBL genes were blaCTX-M-14 (n = 74), blaCTX-M-15 (n = 60), and blaCTX-M-3 (n = 40). MLST assigned 127 CTX-M-14 and CTX-M-15 producers to 54 STs, and CC17 was the most prevalent population (12.6%). STs (23, 37, and 86) that were known frequently associated with hypervirulent K. pneumoniae (hvKP) account for 14.1% (18/127). Phylogenetic analysis by concatenating the seven loci of MLST revealed the existence of ESBL-producing K. quasipneumoniae (two strains) and K. varricola (one strain), which was further confirmed by WGS. This study highlights the challenge of community-onset infections caused by ESBL-Kp in China. The prevalence of STs frequently associating with hvKP should be of concern. Surveillance of ESBL-KP causing community-onset infections now appears imperative.

2.
Int J Infect Dis ; 38: 108-14, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26255892

RESUMO

OBJECTIVE: Clinical treatment for blaKPC-positive Klebsiella pneumoniae isolates is challenging because the recommended antibiotic options are limited and are extraordinarily expensive. This study aimed to explore a new therapy for infection caused by KPC-producing K. pneumoniae. METHODS: Patients with blaKPC-positive K. pneumoniae infection, were prospectively screened and were categorised into two groups: patients in the study group received a combination-based therapy of cefepime and amoxicillin/clavulanic acid and the control group received tigecycline-based therapy. The pathogen clearance rate, 28-day mortality and cost of the antibiotic treatment were compared between the two groups. Moreover, the checkerboard microdilution method was performed to determine the synergy between cefepime and amoxicillin/clavulanic acid in vitro. RESULTS: Twenty-six and 25 cases were enrolled in the study and control groups. The mortality and the overall pathogen clearance rate showed no significant differences (P=0.311 and P=0.447). Both the total cost and the portion of the cost not covered by insurance were higher for the control group compared to the study group (both P<0.001). Consistently, synergy (65.4%) and partial synergy (26.9%) were the main effects. CONCLUSIONS: In contrast to the currently recommended tigecycline-based therapy, cefepime and amoxicillin/clavulanic acid combination was an effective and economical option to KPC-KP infection in China.


Assuntos
Combinação Amoxicilina e Clavulanato de Potássio/uso terapêutico , Antibacterianos/uso terapêutico , Cefalosporinas/uso terapêutico , Infecções por Klebsiella/tratamento farmacológico , Klebsiella pneumoniae , Adulto , Idoso , Antibacterianos/economia , Proteínas de Bactérias/biossíntese , Cefepima , Quimioterapia Combinada , Feminino , Humanos , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/mortalidade , Klebsiella pneumoniae/enzimologia , Masculino , Pessoa de Meia-Idade , Minociclina/análogos & derivados , Minociclina/uso terapêutico , Tigeciclina , beta-Lactamases/biossíntese
3.
BMC Infect Dis ; 15: 161, 2015 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-25886859

RESUMO

BACKGROUND: Klebsiella pneumoniae has been the dominant pathogen for liver abscesses in several Asian countries. Although the prevalence of K. pneumoniae liver abscess (KLA) in mainland China is increasing recently, the clinical and microbiological characteristics of KLA in China have not been elucidated. METHODS: Clinical and microbiology characteristics of 45 consecutive patients with KLA from a tertiary teaching hospital in China between June 2008 and June 2012 were retrospectively evaluated. RESULTS: Vast majority of the strains were susceptible to main antimicrobial agents. Most of K. pneumoniae strains from pyogenic liver abscess patients belonged to K1/K2 serotype (68.9% for K1 serotype and 20% for K2 serotype). All K. pneumoniae strains were rmpA positive, and 68.9% of these strains were magA positive. Overall, 57.8% (26/45) of K. pneumoniae strains belonged to ST23. Twenty-five of 26 ST23 K. pneumoniae isolates (96.2%) from KLA patients were magA-positive and K1 serotype. Only 28.9% (13/45) of KLA isolates exhibited hypermucoviscous phenotype, which is clinically used as the characteristic of hypervirulent K. pneumoniae (hvKP). Liver abscess sizes in patients infected with hvKP were tend to be larger than those in patients infected with cKP. There was no significant association between the microbiological and clinical characteristics including serotypes, magA and rmpA genotypes, and STs with the metastatic infection and prognosis of KLA. CONCLUSIONS: Neither the serotypes, magA and rmpA genotypes, nor the STs of K. pneumoniae were associated with the metastatic infection and prognosis of KLA. However, further studies with larger sample are needed in the future.


Assuntos
Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/genética , Abscesso Hepático Piogênico/microbiologia , Adolescente , Adulto , China/epidemiologia , DNA Bacteriano/genética , Feminino , Genótipo , Humanos , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/isolamento & purificação , Abscesso Hepático Piogênico/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Sorogrupo , Adulto Jovem
4.
Microbes Infect ; 17(6): 417-25, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25708671

RESUMO

The purpose of this study was to survey antibacterial resistance in outpatients of Chinese county hospitals. A total of 31 county hospitals were selected and samples continuously collected from August 2010 to August 2011. Drug sensitivity testing was conducted in a central laboratory. A total of 2946 unique isolates were collected, including 634 strains of Escherichia coli, 606 Klebsiella pneumoniae, 476 Staphylococcus aureus, 308 Streptococcus pneumoniae, and 160 Haemophilus influenzae. Extended-spectrum ß-lactamases were detected in E. coli (42.3% strains), K. pneumoniae (31.7%), and Proteus mirabilis (39.0%). Ciprofloxacin-resistance was detected in 51.0% of E. coli strains. Salmonella spp. and Shigella spp. were sensitive to most antibacterial agents. Less than 8.0% of Pseudomonas aeruginosa isolates were resistant to carbapenem. For S. aureus strains, 15.3% were resistant to methicillin, and some strains of S. pneumoniae showed resistance to penicillin (1.6%), ceftriaxone (13.0%), and erythromycin (96.4%). ß-lactamase was produced by 96.5% of Moraxella catarrhalis strains, and 36.2% of H. influenzae isolates were resistant to ampicillin. Azithromycin-resistant H. influenzae, imipenem-resistant but meropenem-sensitive Proteus, and ceftriaxone- and carbapenem non-sensitive M. catarrhalis were recorded. In conclusion, cephalosporin- and quinolone-resistant strains of E. coli and Klebsiella pneumonia and macrolide-resistant Gram-positive cocci were relatively prominent in county hospitals. The antibacterial resistance profiles of isolates from different geographical locations varied significantly, with proportions in county hospitals lower than those in their tertiary counterparts in the central cities, although the difference is diminishing.


Assuntos
Assistência Ambulatorial , Infecções Bacterianas/microbiologia , Farmacorresistência Bacteriana/genética , Hospitais de Condado/estatística & dados numéricos , Antibacterianos/farmacologia , Infecções Bacterianas/epidemiologia , China/epidemiologia , Geografia , Humanos , Testes de Sensibilidade Microbiana
5.
J Med Microbiol ; 64(Pt 3): 209-216, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25596117

RESUMO

The purpose of this study was to evaluate the risk factors, outcomes and epidemiology associated with Clostridium difficile infection (CDI) in patients with haematological malignancies in a tertiary care hospital in China. C. difficile screening was performed on patients admitted for chemotherapy or haematopoietic stem cell transplantation between 2009 and 2013. C. difficile isolates were analysed by multilocus sequence typing, and a retrospective chart review was performed on all patients with a positive toxin assay. CDI was diagnosed in 21 haematology-oncology ward patients and 14 marrow transplantation service patients for a cumulative incidence of 1.89/1000 and 3.69/1000 patient-days, respectively. Univariate analyses showed that patients who received etoposide had an increased risk of CDI (odds ratio 4.25, 95 % confidence interval 1.32-13.64). There was only one patient death, for which CDI was not the primary cause. Ten sequence types (STs) were identified, of which ST-3 and ST-54 were the most common; the hypervirulent ST-1 (ribotype 027) and ST-11 (ribotype 078) C. difficile strains were not detected in the patients in this study. The incidence of CDI did not differ between patients receiving chemotherapy and those receiving haematopoietic stem cell transplantation. The only risk factor for chemotherapy patients was treatment with etoposide.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Clostridioides difficile/isolamento & purificação , Infecções por Clostridium/epidemiologia , Etoposídeo/uso terapêutico , Neoplasias Hematológicas/complicações , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Adolescente , Adulto , Idoso , Anti-Infecciosos/uso terapêutico , China/epidemiologia , Clostridioides difficile/classificação , Clostridioides difficile/genética , Infecções por Clostridium/sangue , Infecções por Clostridium/tratamento farmacológico , Infecções por Clostridium/microbiologia , Infecção Hospitalar , Enterocolite Pseudomembranosa/sangue , Enterocolite Pseudomembranosa/tratamento farmacológico , Enterocolite Pseudomembranosa/epidemiologia , Enterocolite Pseudomembranosa/microbiologia , Fezes/microbiologia , Feminino , Neoplasias Hematológicas/tratamento farmacológico , Neoplasias Hematológicas/terapia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Tipagem de Sequências Multilocus , Estudos Retrospectivos , Ribotipagem , Fatores de Risco , Centros de Atenção Terciária , Adulto Jovem
6.
Int J Antimicrob Agents ; 45(1): 66-70, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25450805

RESUMO

Fosfomycin has been proposed as an adjunct to other active agents for treating KPC-producing Klebsiella pneumoniae infections. This study aimed to investigate the prevalence of fosfomycin resistance and plasmid-mediated resistance determinants among KPC-producing K. pneumoniae isolates from clinical samples in China. In total, 278 KPC-producing and 80 extended-spectrum ß-lactamase (ESBL)-producing (non-KPC-producing) clinical K. pneumoniae isolates were collected in 12 hospitals from 2010 to 2013. Fosfomycin susceptibility testing was carried out using the agar dilution method. Phylogenetic clonal patterns were revealed by pulsed-field gel electrophoresis (PFGE). Isolates were screened for plasmid-mediated fosfomycin resistance genes (fosA, fosA3 and fosC2) by PCR amplification. A plasmid was completely sequenced by next-generation sequencing. The fosfomycin resistance rate in KPC-producers (60.8%; 169/278) was significantly higher than in ESBL-producers (12.5%; 10/80). In addition, 94 KPC-producing isolates were positive for fosA3 and most of them were clonally related. A 23939-bp plasmid (pFOS18) co-harbouring fosA3 and bla(KPC-2) was completely sequenced, revealing that the fosA3 gene was flanked by two copies of IS26; however, bla(KPC-2) was located on a Tn3-Tn4401 integration structure. Although the fosA3 and blaKPC-2 genes are located on different transposon systems, they are able to spread together worldwide through plasmid transfer. Dissemination of the clone carrying the fosA3-harbouring plasmid mediates the high fosfomycin resistance rate of KPC-producing K. pneumoniae in China. Fosfomycin as an alternative option for treating infections caused by KPC-producing K. pneumoniae should not be recommended in hospitals in which fosfomycin-resistant clonal dissemination is emerging.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Fosfomicina/farmacologia , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/efeitos dos fármacos , beta-Lactamases/metabolismo , China/epidemiologia , DNA Bacteriano/química , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Genótipo , Hospitais , Humanos , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Dados de Sequência Molecular , Plasmídeos , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
7.
J Clin Microbiol ; 53(3): 766-70, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25520451

RESUMO

The high frequency of fluoroquinolone resistance in Escherichia coli is a feature of clinical bacteriology in China, where the molecular epidemiology and genetic characteristics of this resistance in county hospitals remain unclear. A total of 590 nonduplicate E. coli isolates from 30 county hospitals located across seven Chinese regions were examined for plasmid-mediated quinolone resistance (PMQR) genes and mutations in quinolone resistance-determining regions (QRDRs). Multilocus sequence typing (MLST) and phylogenetic analysis of fluoroquinolone-resistant isolates were used to determine their genetic relatedness. The ciprofloxacin resistance rate of community-onset E. coli was 51.2%, and at least one PMQR gene was carried by 220 (37.3%) isolates. These included qnr (3.7%), aac(6')-Ib-cr (19.7%), qepA (14.4%), and oqxAB (3.8%). Two novel oqxB mutants were identified and named oqxB20 and oqxB29. From 60 sequence types (STs) isolated, 5 novel STs (ST4499 to ST4503) were identified. ST1193 (7.9%) was the second most abundant ST among fluoroquinolone-resistant isolates (ST131 was the most common, with 14.6%), and this is the first report of it in China. This is also the first report of ST2115 and ST3014 isolates from human samples. Ciprofloxacin-resistant E. coli isolates fell mainly into phylogroups B2 and D. The rates of fluoroquinolone resistance and the prevalence of PMQR genes in community-onset E. coli isolates from Chinese county hospitals were high. The wide-ranging molecular epidemiology of E. coli isolates from scattered locations across China indicates that fluoroquinolone resistance evolved from different sources.


Assuntos
Antibacterianos/farmacologia , Infecções Comunitárias Adquiridas/epidemiologia , Farmacorresistência Bacteriana , Infecções por Escherichia coli/epidemiologia , Escherichia coli/efeitos dos fármacos , Fluoroquinolonas/farmacologia , Variação Genética , China/epidemiologia , Análise por Conglomerados , Infecções Comunitárias Adquiridas/microbiologia , DNA Bacteriano/química , DNA Bacteriano/genética , Escherichia coli/classificação , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Genes Bacterianos , Genótipo , Hospitais de Condado , Humanos , Epidemiologia Molecular , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Proteínas Mutantes/genética , Filogenia , Plasmídeos/análise
8.
BMC Infect Dis ; 14: 659, 2014 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-25466590

RESUMO

BACKGROUND: In order to investigate the epidemiology, molecular characteristics, and distribution of extended-spectrum ß-lactamase (ESBL)- and AmpC-producing Escherichia coli from community-onset infections in Chinese county hospitals. METHODS: E. coli isolates were collected from patients with community-onset infections in 30 county hospitals. ESBL activity was confirmed by double-disc diffusion. Genetic confirmation and molecular typing of ESBL- and AmpC-producing isolates was determined by PCR and DNA sequencing. ESBL-positive isolates were further characterised by multi-locus sequence typing. RESULTS: Of 550 E. coli isolates, 256 (46.5%) carried ESBL genes and all were of the CTX-M type. The prevalence of ESBL-producing strains varied from 30.2% to 57.0% across different regions of China. Overall, 12 bla CTX-M subtypes were detected; the most abundant were bla CTX-M-14 (163/256 isolates, 64.5%), bla CTX-M-55 (47/256, 18.4%), and bla CTX-M-15 (31/256, 12.1%). CMY-2-like AmpC ß-lactamases were detected in 11 strains, three of which co-existed with bla CTX-M. A total of 64 sequence types (STs) were detected in 256 ESBL-producing strains, including nine that were new. ST131 was the most abundant type (27 isolates, 12.7%), followed by ST69 (14 isolates, 6.6%), ST405 (14 isolates, 6.6%), and ST38 (12 isolates, 5.6%). CONCLUSIONS: This study revealed that the widespread prevalence of ESBLs among outpatient infections has reached a high level in county hospitals. The CTX-M genotype was most dominant, comprising a variety of subtypes. This is the first time the incidence of CTX-M-55 has exceeded that of CTX-M-15 in China. No predominant ST was detected, suggesting that ESBL-producing E. coli strains originate in different clones.


Assuntos
Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Escherichia coli/classificação , beta-Lactamases/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Técnicas de Tipagem Bacteriana , China/epidemiologia , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , DNA Bacteriano/análise , Escherichia coli/enzimologia , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Proteínas de Escherichia coli/metabolismo , Feminino , Marcadores Genéticos , Genótipo , Hospitais de Condado , Humanos , Masculino , Pessoa de Meia-Idade , Tipagem de Sequências Multilocus , Reação em Cadeia da Polimerase , Prevalência , Análise de Sequência de DNA , Adulto Jovem , beta-Lactamases/metabolismo
9.
PLoS One ; 9(2): e89235, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24586619

RESUMO

We report a case of necrotizing pneumonia in a young patient caused by community acquired-methicillin resistant Staphylococcus aureus (CA-MRSA) in a teaching hospital in the People's Republic of China. The patient had a typical clinical presentation and was successfully treated with antibiotics and intravenous immunoglobulin. A CA-MRSA strain, named SA268, was isolated from the blood of the patient. The isolate was susceptible to most antimicrobial agents, except cephalosporins, penicillins, and ß-lactamase inhibitor combinations. Multi-locus sequence typing (MLST) assigned SA268 to ST59, a clone widely spread in eastern Asia. The strain was positive for Panton Valentine Leukocidin (PVL)-encoding genes and SCCmec type V. We sequenced the complete genome of the SA268 isolate. The genome of SA268 was almost identical to that of the Taiwanese ST59 CA-MRSA strains M013 and SA957. However, we observed several differences in gene composition, which included differences in the SCCmec element and several lipoprotein genes that were present in the Taiwanese strains but absent from SA268.


Assuntos
Infecções Comunitárias Adquiridas/genética , Genoma Bacteriano/genética , Staphylococcus aureus Resistente à Meticilina/genética , Pneumonia Estafilocócica/genética , Sepse/genética , Infecções Estafilocócicas/genética , Adolescente , Antibacterianos/administração & dosagem , China , Infecções Comunitárias Adquiridas/tratamento farmacológico , Infecções Comunitárias Adquiridas/microbiologia , DNA Bacteriano/genética , Humanos , Imunoglobulinas Intravenosas/administração & dosagem , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Filogenia , Pneumonia Estafilocócica/tratamento farmacológico , Pneumonia Estafilocócica/microbiologia , Sepse/tratamento farmacológico , Sepse/microbiologia , Análise de Sequência de DNA , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia
10.
Chin Med J (Engl) ; 127(3): 528-31, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24451962

RESUMO

BACKGROUND: Klebsiella pneumoniae carbapenemase (KPC)-producing Escherichia (E.) coli has been reported in China since 2008. However, there is no information about the molecular epidemiology of KPC-producing E. coli in China. In this study, we aimed to investigate the sequence type (ST) and characteristics of KPC-producing E. coli isolates in China. METHODS: Three carbapenem-resistant isolates of E. coli (E1, E2, and E3) from one teaching hospital in Hangzhou covering a one year period were analyzed. Antibiotic susceptibility was determined by Etest. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used for epidemiological analysis. The genetic structure around blaKPC, the major plasmid incompatibility typing, and the identification of ß-lactamase gene types were performed by PCR and the positive products were subsequently sequenced. Plasmids were analyzed by transformation, restriction, and Southern blotting. RESULTS: PFGE demonstrated that patterns of isolates E1 and E2 were clonally-related and designated as patterns A1 and A2; pattern of isolate E3 was different and designated as pattern B. MLST analysis showed that the three isolates displayed one common sequence type ST131. The identification of bla gene types by PCR and sequencing showed that blaKPC-2, blaCTX-M-14, and blaTEM-1 were detected in all three isolates. All three isolates carried a KPC-2-encoding plasmid of the IncN replicon. Plasmid analysis and hybridization experiments showed that the isolates were found simultaneously to carry two or four plasmids. The blaKPC-2 gene in E1 and E2 was located in a plasmid with size of ca. 50 kb. However, the blaKPC-2 gene in E3 was located in a plasmid with size of ca. 130 kb. CONCLUSIONS: E. coli ST131 with KPC-2 ß-lactamase has emerged in China, which enlarges the geographical area where the ST131 KPC-producing E. coli strains have diffused.


Assuntos
Proteínas de Bactérias/genética , Escherichia coli/enzimologia , Klebsiella pneumoniae/enzimologia , beta-Lactamases/genética , China , Eletroforese em Gel de Campo Pulsado , Escherichia coli/genética , Tipagem de Sequências Multilocus
11.
Int J Antimicrob Agents ; 43(4): 361-5, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24388115

RESUMO

The presence and characterisation of plasmid-mediated fosfomycin resistance determinants were investigated among 45 clinical vancomycin-resistant enterococci (VRE) isolated in Zhejiang Province, China. In total, 19 VRE were resistant to fosfomycin, of which 18 isolates had conjugative fosfomycin resistance and were positive for fosB. No reported fos genes were detected in the remaining isolate. Among the 18 fosB-carrying isolates, the fosB gene was always flanked by tnpA, suggesting the same novel fosB transposon. In 10 of the 18 fosB-carrying isolates, the fosB and tnpA genes were found reversely inserted in the vanA transposon Tn1546. In the remaining eight isolates the fosB and vanA genes were located on different plasmids. These findings indicate that acquisition of the conjugative plasmid harbouring the novel fosB transposon (ISL3-like transposon) and the Tn1546-like transposon (containing vanA and fosB) may explain, at least in part, the recent increase in fosfomycin-resistant Enterococcus faecium in China.


Assuntos
Enterococcus/genética , Fosfomicina/farmacologia , Plasmídeos/genética , Proteínas Proto-Oncogênicas c-fos/genética , Resistência a Vancomicina/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Carbono-Oxigênio Ligases/genética , Conjugação Genética , Elementos de DNA Transponíveis , Farmacorresistência Bacteriana/genética , Enterococcus/efeitos dos fármacos , Enterococcus/isolamento & purificação , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Plasmídeos/efeitos dos fármacos , Transposases/genética , Vancomicina/farmacologia
12.
J Med Microbiol ; 63(Pt 4): 562-569, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24344206

RESUMO

Clostridium difficile infection (CDI) is caused by toxin-producing strains. It accounts for 20-30 % of antibiotic-associated diarrhoea and particularly accounts for 90 % of pseudomembranous colitis. The epidemiological study of C. difficile is thus important. In this study, we report the molecular epidemiology and ward distribution of C. difficile in a tertiary hospital of China. A total of 161 toxigenic strains were isolated from 1845 patients originating from different wards and the strains were characterized based on toxin profile and multilocus sequence typing. Variable isolation rates were observed in different wards and the occurrence was higher in intensive care unit and geriatric wards. Toxin gene profiling revealed that, out of the 161 isolates, 134 (83.2)% were positive for both toxin A (tcdA) and toxin B (tcdB) (A+B+) followed by toxin A-negative and B-positive (A-B+) (16.8 %) isolates. However, only three of the toxigenic strains (1.9 %) were positive for both the cdtA and cdtB genes. Based on the molecular epidemiology study, a total of 30 different sequence types (STs), including one new ST (ST-220), were distinguishable. ST-54 was the most prevalent (23.0 %), followed by ST-35 (19.3 %) and ST-37 (10.0 %). None of the isolates belonged to ST-1 (ribotype 027) or ST-11 (ribotype 078). Taken together, the toxin profile and the molecular epidemiological data showed that all the ST-37 clades were of toxin type A-B+, which accounted for 59.3 % of all type A-B+ isolates. Meanwhile the clade 1 genotype, ST-54, was widely distributed among the geriatric, infection and haematology wards. There was no outbreak of C. difficile infection during our study; however the possibility of prolonged outbreaks cannot be completely ignored.


Assuntos
Clostridioides difficile/classificação , Clostridioides difficile/genética , Infecções por Clostridium/epidemiologia , Infecção Hospitalar/epidemiologia , Diarreia/epidemiologia , Toxinas Bacterianas/genética , China/epidemiologia , Clostridioides difficile/isolamento & purificação , Infecções por Clostridium/microbiologia , Infecção Hospitalar/microbiologia , Diarreia/microbiologia , Feminino , Genótipo , Humanos , Masculino , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Ribotipagem , Centros de Atenção Terciária
13.
Microb Drug Resist ; 18(2): 183-8, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22257297

RESUMO

Forty-seven vancomycin-resistant Enterococcus (VRE) strains were isolated from clinical samples in 13 Zhejiang hospitals and fecal samples from ICU patients in a large teaching hospital in China. No VRE isolates were detected in healthy human subjects. CC17 was the main clonal complex in clinical Enterococcus faecium isolates but not in isolates from healthy human subjects. Novel vancomycin-resistance transposons were detected among VRE strains. This is the first report demonstrating insertion of tnpA and fosB genes in the vanRS-vanH intergenic region of Tn1546 leading to coresistance to vancomycin and fosfomycin. The four plasmid replicon types (pRUM, pRE25, pEF418, and pB82) were more common in VRE isolates, suggesting their association with vancomycin resistance and nosocomial transmission. The prevalence rate of vancomycin-resistant Staphylococcus aureus-related Inc18-like plasmid, pIP501, in VRE was 21.3%. The prevalence of the esp gene among VRE isolates was high (76.6%). In several VRE strains, the esp and hyl genes were cotransferred with the vanA gene by conjugation. Although the frequency of VRE is low in Chinese hospitals, its association with virulence determinants, the vancomycin-resistance transposon with other resistance gene insertions or plasmids may lead to multidrug resistance and the evolution of pathogenic VRE.


Assuntos
Elementos de DNA Transponíveis/genética , Enterococcus/efeitos dos fármacos , Infecções por Bactérias Gram-Positivas/epidemiologia , Plasmídeos/genética , Resistência a Vancomicina/genética , Fatores de Virulência/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , China/epidemiologia , Conjugação Genética , Enterococcus/genética , Enterococcus/isolamento & purificação , Enterococcus/patogenicidade , Fosfomicina/farmacologia , Infecções por Bactérias Gram-Positivas/microbiologia , Hospitais de Ensino , Humanos , Incidência , Testes de Sensibilidade Microbiana , Replicon
14.
Braz. j. infect. dis ; 15(5): 486-489, Sept.-Oct. 2011. ilus, tab
Artigo em Inglês | LILACS | ID: lil-612711

RESUMO

Nocardia infection is rare but potentially fatal. Therapy of Nocardia infection remains difficult. Linezolid, a novel oxazolidinone antibiotic, has proven to be effective, but clinical data are limited. Here we describe a case of a 45-year-old man with pulmonary N. farcinica infection following a liver transplantation. The initial therapy was trimethoprim-sulfamethoxazole, which showed no effect. According to susceptibility test, linezolid was administered with clearly improving the patient's condition. The treatment was stopped for anemia as drug related adverse event, and the therapy lasted for as long as 5 months. At the end of treatment clinical cure was confirmed and anemia reversed after discontinuation of linezolid. We also analyzed the clinical data of previously published reports by literature review, focusing on the efficacy and safety of linezolid treatment for Nocardia infection.


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Acetamidas/uso terapêutico , Anti-Infecciosos/uso terapêutico , Nocardiose/tratamento farmacológico , Oxazolidinonas/uso terapêutico , Nocardiose/diagnóstico , Tomografia Computadorizada por Raios X , Resultado do Tratamento
15.
Drug Resist Updat ; 14(4-5): 236-50, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21807550

RESUMO

A comprehensive surveillance system for bacterial resistance in tertiary hospitals has been established in China that involves tertiary hospitals in distinct regions nationwide, enabling the collection of a large amount of antimicrobial surveillance data. Antimicrobial resistance in China has become a serious healthcare problem, with high resistance rates of most common bacteria to clinically important antimicrobial agents. Methicillin-resistant S. aureus, ESBL-producing Enterobacteriaceae and carbapenem-resistant Acinetobacter baumannii represent more than 50% of microbial isolates. Additionally, bacterial resistance to fluoroquinolones, macrolides and third-generation cephalosporins is of serious concern. The molecular epidemiology and resistance mechanisms of the antimicrobial strains in China exhibited regional specificity, as well as the influence of dissemination of international clonal complexes. The molecular characteristics of MRSA, ESBL- and carbapenemase-producing Enterobacteriaceae, and macrolide-resistant gram-positive Streptococci in China were significantly different from those in other countries and regions, while S. pneumoniae serotypes appear to have been affected by the global spread of prevalent clones in other parts of the world. Moreover, important antimicrobial resistant bacteria such as community-acquired-MRSA, multidrug-resistant P. aeruginosa and extensive-resistant A. baumannii, and the antimicrobial resistance in primary healthcare and outpatient setting should be intensely monitored and investigated in the future.


Assuntos
Antibacterianos/uso terapêutico , Infecções Bacterianas/epidemiologia , Farmacorresistência Bacteriana/fisiologia , Farmacoepidemiologia , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Infecções Bacterianas/tratamento farmacológico , China/epidemiologia , Farmacorresistência Bacteriana Múltipla/genética , Farmacorresistência Bacteriana Múltipla/fisiologia , Humanos , Testes de Sensibilidade Microbiana
18.
Braz J Infect Dis ; 15(5): 486-9, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22230859

RESUMO

Nocardia infection is rare but potentially fatal. Therapy of Nocardia infection remains difficult. Linezolid, a novel oxazolidinone antibiotic, has proven to be effective, but clinical data are limited. Here we describe a case of a 45-year-old man with pulmonary N. farcinica infection following a liver transplantation. The initial therapy was trimethoprim-sulfamethoxazole, which showed no effect. According to susceptibility test, linezolid was administered with clearly improving the patient's condition. The treatment was stopped for anemia as drug related adverse event, and the therapy lasted for as long as 5 months. At the end of treatment clinical cure was confirmed and anemia reversed after discontinuation of linezolid. We also analyzed the clinical data of previously published reports by literature review, focusing on the efficacy and safety of linezolid treatment for Nocardia infection.


Assuntos
Acetamidas/uso terapêutico , Anti-Infecciosos/uso terapêutico , Nocardiose/tratamento farmacológico , Oxazolidinonas/uso terapêutico , Humanos , Linezolida , Masculino , Pessoa de Meia-Idade , Nocardiose/diagnóstico , Tomografia Computadorizada por Raios X , Resultado do Tratamento
19.
J Antimicrob Chemother ; 66(2): 307-12, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21131324

RESUMO

OBJECTIVES: Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae has spread rapidly in China. In this study, we aimed to investigate the molecular epidemiology of KPC-producing K. pneumoniae isolates in China. METHODS: Ninety-five carbapenem-resistant K. pneumoniae isolates from 13 hospitals in nine cities covering five provinces in China were analysed. Antibiotic susceptibility was determined by the Etest. Multilocus sequence typing (MLST) and PFGE were used for epidemiological analysis. The genetic structure around bla(KPC) and the encoding genes of extended-spectrum ß-lactamases and plasmid-mediated AmpC enzymes were detected by PCR and sequencing. Plasmids were analysed by transformation, restriction and Southern blot. RESULTS: All isolates harboured the bla(KPC-2) gene. Seven sequence types (STs) were obtained. The dominant clone was ST11 (61/95), which was identified in isolates from Zhejiang province (four hospitals in Hangzhou and one hospital in Ningbo), Jiangsu province (one hospital in Nanjing) and Anhui province (one hospital in Hefei). Isolates with ST11 showed >80% similarity in PFGE patterns. Plasmids from 14 selected transformants, their original isolates representing different STs and/or regions, had a diversity of HindIII restriction maps. CONCLUSIONS: The dominant clone of KPC-producing K. pneumoniae in China is ST11, which is closely related to ST258, which has been reported worldwide.


Assuntos
Proteínas de Bactérias/genética , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/genética , beta-Lactamases/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Proteínas de Bactérias/biossíntese , Técnicas de Tipagem Bacteriana , Southern Blotting , China/epidemiologia , Farmacorresistência Bacteriana Múltipla/genética , Humanos , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Plasmídeos/efeitos dos fármacos , Plasmídeos/genética , Reação em Cadeia da Polimerase , Mapeamento por Restrição , beta-Lactamases/biossíntese
20.
Antimicrob Agents Chemother ; 54(9): 3967-9, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20547789

RESUMO

The Klebsiella pneumoniae multidrug resistance plasmid pKP048 was completely sequenced. This plasmid carries several important resistance determinants, such as bla(KPC-2), bla(DHA-1), qnrB4, and armA, which confer resistance to carbapenems, cephalosporins, fluoroquinolones, and aminoglycosides, respectively. Analysis of the finished 151,188-bp sequence data revealed 163 putative genes, 108 of which were assigned functions such as replication, stable inheritance, antibiotic resistance, a mobile element, conjugal transfer, and a restriction-modification system, showing the strong phylogenetic mosaicism and plasticity of the plasmid.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Plasmídeos/genética , Aminoglicosídeos/farmacologia , Sequência de Bases , Carbapenêmicos/farmacologia , Cefalosporinas/farmacologia , Fluoroquinolonas/farmacologia , Modelos Genéticos , Dados de Sequência Molecular
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