Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Anesth Analg ; 137(6): 1289-1301, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36753440

RESUMO

BACKGROUND: The microtubule-stabilizing drug paclitaxel (PTX) is an important chemotherapeutic agent for cancer treatment and causes peripheral neuropathy as a common side effect that substantially impacts the functional status and quality of life of patients. The mechanistic role for NIMA-related kinase 2 (NEK2) in the progression of PTX-induced neuropathic pain has not been established. METHODS: Adult male Sprague-Dawley rats intraperitoneally received PTX to induce neuropathic pain. The protein expression levels in the dorsal root ganglion (DRG) of animals were measured by biochemical analyses. Nociceptive behaviors were evaluated by von Frey tests and hot plate tests. RESULTS: PTX increased phosphorylation of the important microtubule dynamics regulator NEK2 in DRG neurons and induced profound neuropathic allodynia. PTX-activated phosphorylated NEK2 (pNEK2) increased jumonji domain-containing 3 (JMJD3) protein, a histone demethylase protein, to specifically catalyze the demethylation of the repressive histone mark H3 lysine 27 trimethylation (H3K27me3) at the Trpv1 gene, thereby enhancing transient receptor potential vanilloid subtype-1 (TRPV1) expression in DRG neurons. Moreover, the pNEK2-dependent PTX response program is regulated by enhancing p90 ribosomal S6 kinase 2 (RSK2) phosphorylation. Conversely, intrathecal injections of kaempferol (a selective RSK2 activation antagonist), NCL 00017509 (a selective NEK2 inhibitor), NEK2-targeted siRNA, GSK-J4 (a selective JMJD3 inhibitor), or capsazepine (an antagonist of TRPV1 receptor) into PTX-treated rats reversed neuropathic allodynia and restored silencing of the Trpv1 gene, suggesting the hierarchy and interaction among phosphorylated RSK2 (pRSK2), pNEK2, JMJD3, H3K27me3, and TRPV1 in the DRG neurons in PTX-induced neuropathic pain. CONCLUSIONS: pRSK2/JMJD3/H3K27me3/TRPV1 signaling in the DRG neurons plays as a key regulator for PTX therapeutic approaches.


Assuntos
Antineoplásicos , Neuralgia , Humanos , Ratos , Masculino , Animais , Paclitaxel/efeitos adversos , Paclitaxel/metabolismo , Hiperalgesia/induzido quimicamente , Hiperalgesia/genética , Ratos Sprague-Dawley , Gânglios Espinais , Fosfatos/efeitos adversos , Fosfatos/metabolismo , Histonas/metabolismo , Qualidade de Vida , Canais de Cátion TRPV , Neuralgia/induzido quimicamente , Neuralgia/genética , Neuralgia/metabolismo , Antineoplásicos/efeitos adversos , Neurônios/metabolismo , Epigênese Genética , Quinases Relacionadas a NIMA/genética , Quinases Relacionadas a NIMA/metabolismo
2.
J Gen Virol ; 97(9): 2411-2420, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27435237

RESUMO

Increasing evidence suggests that human cytomegalovirus (HCMV) plays an oncomodulatory role in human cancers. In colorectal cancer (CRC), presence of HCMV in tumours has been associated with a poor outcome in elderly patients. This study aimed to investigate the association between HCMV and the outcome of non-elderly patients with CRC. In tumour samples, HCMV DNA was detected by PCR. Viral transcript and protein were detected by in situ hybridization (ISH) and immunohistochemical staining (IHC), respectively. Clinical, pathological and survival data were compared between patients with HCMV-positive and -negative tumours. Quantitative reverse transcription PCR (qRT-PCR) was used to analyse the expression levels of cellular signals related to CRC progression and metastasis. Among 89 CRC non-elderly patients aged <65 years, HCMV was detected in 31 (34.8 %) tumour samples by PCR. By ISH and IHC, viral transcript and protein specifically localized to the cytoplasm of neoplastic mucosal epithelium. Outcome analysis revealed a more favourable disease-free survival (DFS) rate in patients with HCMV-positive tumours (P<0.01), specifically in patients with stage III disease. In a multivariate Cox proportional-hazard model, tumoural presence of HCMV independently predicted a higher DFS rate (hazard ratio 0.22; 95 % confidence interval 0.075-0.66, P<0.01). By qRT-PCR, the tumoural levels of interleukin-1 were relatively lower in samples positive for HCMV. The results suggest that HCMV may influence the outcome of CRC in an age-dependent manner and possibly has a dual oncomodulatory effect. How the virus interacts with the tumour microenvironment should be further studied.


Assuntos
Neoplasias Colorretais/virologia , Citomegalovirus/isolamento & purificação , Neoplasias Colorretais/patologia , DNA Viral/análise , DNA Viral/genética , Humanos , Imuno-Histoquímica , Hibridização In Situ , Gradação de Tumores , Reação em Cadeia da Polimerase , RNA Viral/análise , RNA Viral/genética , Análise de Sobrevida , Resultado do Tratamento , Proteínas Virais/análise , Proteínas Virais/imunologia
3.
Antimicrob Agents Chemother ; 58(7): 3983-90, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24798276

RESUMO

The role of carbapenem-resistant Acinetobacter baumannii (CRAb) in polymicrobial infection remains elusive. Having observed the ability of CRAb to shelter other susceptible bacteria from carbapenem killing, we sought to determine the factors contributing to this sheltering effect by transforming different recombinant plasmids into recipient A. baumannii cells. The sheltering effects of CRAb were reproduced in recipient A. baumannii cells that highly expressed carbapenem-hydrolyzing class D ß-lactamases (CHDLs) through their associated strong promoter. With the use of Western blot analysis and a bioassay, the highly expressed CHDLs were found to be extracellularly released and led to hydrolysis of carbapenem. The level of extracellular CHDLs increased after challenge with a higher concentration of CHDL substrates, such as carbapenem and ticarcillin. This increased CHDL may, in part, be attributed to cell lysis, as indicated by the presence of extracellular gyrase. In the planktonic condition, the sheltering effect for the cocultured susceptible bacteria might represent an indirect and passive effect of the CRAb self-defense mechanism, because coculture with the susceptible pathogen did not augment the amount of the extracellular CHDLs. Polymicrobial infection caused by CRAb and a susceptible counterpart exerted higher pathogenicity than monomicrobial infection caused by either pathogen alone in mice receiving carbapenem therapy. This study demonstrated that CHDL-producing CRAb appears to provide a sheltering effect for carbapenem-susceptible pathogens via the extracellular release of CHDLs and, by this mechanism, can enhance the pathogenesis of polymicrobial infection in the presence of carbapenem therapy.


Assuntos
Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/genética , Infecções Bacterianas/microbiologia , Farmacorresistência Bacteriana , Infecções por Acinetobacter/tratamento farmacológico , Acinetobacter baumannii/enzimologia , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Anticorpos Antibacterianos/análise , Anticorpos Antibacterianos/biossíntese , Infecções Bacterianas/patologia , Técnicas de Cocultura , Contagem de Colônia Microbiana , Camundongos , Camundongos Endogâmicos C57BL , Testes de Sensibilidade Microbiana , Plasmídeos , Pneumonia Bacteriana/tratamento farmacológico , Pneumonia Bacteriana/microbiologia , beta-Lactamases/metabolismo
4.
Biomarkers ; 19(2): 109-13, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24446591

RESUMO

OBJECTIVE: Investigate the latent cytomegalovirus (CMV) infection as a biomarker of oxidative stress and atherosclerosis. METHODS: Latent CMV infection was diagnosed in healthy individuals with PCR-evidence of CMV DNA in peripheral leucocytes. Oxidative stress and atherosclerosis were measured by mitochondrial DNA oxidative damage index (mtDNA(ΔCT)) and intima media thickness (IMT). RESULTS: The CMV DNA positive subjects had a higher mean mtDNA(ΔCT) and greater IMT than subjects in the control group. CONCLUSIONS: Presence of CMV DNA in leucocytes, as a marker of latent CMV infection, was associated with increased levels of oxidative stress and subclinical atherosclerosis in healthy adults.


Assuntos
Aterosclerose/sangue , Infecções por Citomegalovirus/sangue , Citomegalovirus/genética , DNA Viral/sangue , Leucócitos Mononucleares/virologia , Aterosclerose/diagnóstico por imagem , Aterosclerose/virologia , Biomarcadores/sangue , Espessura Intima-Media Carotídea , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo , Latência Viral
5.
PLoS One ; 8(4): e61921, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23613973

RESUMO

BACKGROUND: Among members of Cryptococcus neoformans- Cryptococcus gattii species complex, C. neoformans is distributed worldwide whereas C. gattii is considered to be more prevalent in the subtropics and tropics including Taiwan. This nationwide study was undertaken to determine the distribution of genotypes, clinical characteristics and outcomes of 219 patients with proven cryptococcosis at 20 hospitals representative of all geographic areas in Taiwan during 1997-2010. METHODS AND FINDINGS: Of 219 isolates analyzed, C. neoformans accounted for 210 isolates (95.9%); nine isolates were C. gattii (4.1%). The predominant genotype was VNI (206 isolates). The other genotypes included VNII (4 isolates), VGI (3 isolates) and VGII (6 isolates). Antifungal minimal inhibition concentrations higher than epidemiologic cutoff values (ECVs) were found in nine VNI isolates (7 for amphotericin B). HIV infection was the most common underlying condition (54/219, 24.6%). Among HIV-negative patients, liver diseases (HBV carrier or cirrhosis) were common (30.2%) and 15.4% did not have any underlying condition. Meningoencephalitis was the most common presentation (58.9%), followed by pulmonary infection (19.6%) and "others" (predominantly cryptococcemia) (18.7%). The independent risk factors for 10-week mortality, by multivariate analysis, were cirrhosis of liver (P = 0.014) and CSF cryptococcal antigen titer ≥ 512 (P = 0.020). All except one of 54 HIV-infected patients were infected by VNI genotype (98.1%). Of the 13 isolates of genotypes other than VNI, 12 (92.3%) were isolated from HIV-negative patients. HIV-infected patients compared to HIV-negative patients were more likely to have meningoencephalitis and serum cryptococcal antigen ≥ 1:512. Patients infected with C. gattii compared to C. neoformans were younger, more likely to have meningoencephalitis (100% vs. 57%), reside in Central Taiwan (56% vs. 31%), and higher 10-week crude mortality (44.4% vs. 22.2%). CONCLUSIONS: Cryptococcus neoformans in Taiwan, more prevalent than C. gatii, has a predominant VNI genotype. Isolates with antifungal MIC higher than ECVs were rare.


Assuntos
Criptococose/epidemiologia , Criptococose/microbiologia , Adolescente , Adulto , Idoso , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Criança , Criptococose/tratamento farmacológico , Criptococose/mortalidade , Cryptococcus neoformans/efeitos dos fármacos , Cryptococcus neoformans/genética , Cryptococcus neoformans/isolamento & purificação , Impressões Digitais de DNA , Feminino , Genótipo , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Filogenia , Fatores de Risco , Taiwan/epidemiologia , Resultado do Tratamento , Adulto Jovem
6.
PLoS One ; 7(9): e45083, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23028773

RESUMO

BACKGROUND: A mouse brain transmigration assessment (MBTA) was created to investigate the central nervous system (CNS) pathogenesis of cryptococcal meningoencephalitis. METHODOLOGY/PRINCIPAL FINDINGS: Two cryptococcal mutants were identified from a pool of 109 pre-selected mutants that were signature-tagged with the nourseothricin acetyltransferase (NAT) resistance cassette. These two mutants displayed abnormal transmigration into the central nervous system. One mutant displaying decreased transmigration contains a null mutation in the putative FNX1 gene, whereas the other mutant possessing a null mutation in the putative RUB1 gene exhibited increased transmigration into the brain. Two macrophage adhesion-defective mutants in the pool, 12F1 and 3C9, showed reduced phagocytosis by macrophages, but displayed no defects in CNS entry suggesting that transit within macrophages (the "Trojan horse" model of CNS entry) is not the primary mechanism for C. neoformans migration into the CNS in this MBTA. CONCLUSIONS/SIGNIFICANCE: This research design provides a new strategy for genetic impact studies on how Cryptococcus passes through the blood-brain barrier (BBB), and the specific isolated mutants in this assay support a transcellular mechanism of CNS entry.


Assuntos
Sistema Nervoso Central/citologia , Sistema Nervoso Central/microbiologia , Cryptococcus neoformans/genética , Cryptococcus neoformans/fisiologia , Genes Fúngicos/genética , Migração Transendotelial e Transepitelial/genética , Acetiltransferases/metabolismo , Animais , Barreira Hematoencefálica/microbiologia , Adesão Celular , Cryptococcus neoformans/crescimento & desenvolvimento , Células Endoteliais/citologia , Células Endoteliais/microbiologia , Estudos de Associação Genética , Testes Genéticos , Camundongos , Microvasos/citologia , Modelos Biológicos , Mutação/genética , Reação em Cadeia da Polimerase , Reprodutibilidade dos Testes , Temperatura , Transcitose
7.
J Clin Virol ; 54(3): 240-4, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22595308

RESUMO

BACKGROUND: It has long been suggested that human cytomegalovirus (HCMV) might be involved in human oncogenesis. However, whether HCMV was associated with colorectal cancer (CRC) was still controversial. OBJECTIVE: To clarify whether HCMV specifically infects the tumorous tissue of CRC. STUDY DESIGN: Paired tumor and adjacent non-neoplastic CRC specimens were collected from 163 patients. HCMV DNA was detected and quantified through PCR and quantitative real-time PCR. Virus location was determined by in situ hybridization (ISH) of formalin-fixed paraffin-embedded tissue sections with an HCMV-specific probe. RESULTS: By PCR, HCMV DNA was detected in 42.3% (69/163) of the tumor specimens, while only 5.6%(14/163) samples of adjacent non-neoplastic tissue were positive for HCMV (p<0.0001). Quantitative real-time PCR in 54 sample pairs revealed significantly higher viral copies in the tumor specimens than the adjacent non-neoplastic tissue specimens (p<0.001). By ISH, the nucleic acids of HCMV were detected in the cytoplasm of neoplastic epithelium. No hybridization was detected in the inflammatory infiltrates, submucosa, or other stromal tissues. CONCLUSIONS: HCMV preferentially infects the tumor epithelium of CRC. How the virus subsists in and interacts with the microenvironment of tumor epithelium of CRC should be studied.


Assuntos
Neoplasias Colorretais/complicações , Neoplasias Colorretais/virologia , Infecções por Citomegalovirus/complicações , Infecções por Citomegalovirus/virologia , Citomegalovirus/isolamento & purificação , Citomegalovirus/patogenicidade , Epitélio/virologia , Citomegalovirus/genética , DNA Viral/genética , DNA Viral/isolamento & purificação , Humanos , Hibridização In Situ , Reação em Cadeia da Polimerase em Tempo Real , Carga Viral
8.
J Biol Chem ; 287(19): 15298-306, 2012 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-22418440

RESUMO

Cryptococcus neoformans is a pathogenic yeast that can invade the brain and cause meningoencephalitis. Our previous in vitro studies suggested that the interaction between C. neoformans hyaluronic acid and human brain endothelial CD44 could be the initial step of brain invasion. In this report, we used a CD44 knock-out (KO or CD44(-/-)) mouse model to explore the importance of CD44 in C. neoformans brain invasion. Our results showed that C. neoformans-infected CD44 KO mice survived longer than the infected wild-type mice. Consistent with our in vitro results, the brain and cerebrospinal fluid fungal burden was reduced in CD44-deficient mice. Histopathological studies showed smaller and fewer cystic lesions in the brains of CD44 KO mice. Interestingly, the cystic lesions contained C. neoformans cells embedded within their polysaccharide capsule and were surrounded by host glial cells. We also found that a secondary hyaluronic acid receptor, RHAMM (receptor of hyaluronan-mediated motility), was present in the CD44 KO mice. Importantly, our studies demonstrated an in vivo blocking effect of simvastatin. These results suggest that the CD44 and RHAMM receptors function on membrane lipid rafts during invasion and that simvastatin may have a potential therapeutic role in C. neoformans infections of the brain.


Assuntos
Encéfalo/metabolismo , Criptococose/metabolismo , Cryptococcus neoformans/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Receptores de Hialuronatos/metabolismo , Animais , Western Blotting , Encéfalo/efeitos dos fármacos , Encéfalo/microbiologia , Criptococose/líquido cefalorraquidiano , Criptococose/microbiologia , Cryptococcus neoformans/patogenicidade , Cryptococcus neoformans/fisiologia , Proteínas da Matriz Extracelular/genética , Feminino , Interações Hospedeiro-Patógeno , Receptores de Hialuronatos/genética , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia de Fluorescência , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Neuroglia/microbiologia , Ligação Proteica , Interferência de RNA , Sinvastatina/farmacologia , Virulência
9.
J Microbiol Immunol Infect ; 45(1): 43-51, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22169123

RESUMO

BACKGROUND AND PURPOSE: To investigate the clinical and molecular epidemiology of the imipenem-resistant Acinetobacter calcoaceticus-Acinetobacter baumannii (IRAcb) complex during an outbreak in an intensive care unit (ICU). METHODS: Forty-six clinical and 11 environmental isolates of the IRAcb complex were collected from the ICU of Taipei Veterans General Hospital, Taiwan between December 2003 and March 2004. These isolates were genotyped using pulsed-field gel electrophoresis (PFGE). Carbapenemase genes and their associated genetic structures were analyzed using PCR. Clinical data obtained from the patients were also reviewed and analyzed. RESULTS: The isolates were identified at the genomic species level as A. baumannii (42 clinical and five environmental isolates) and Acinetobacter genomic species 13TU (four clinical and six environmental isolates). Both species were comprised of two pulsotypes, but those of A. baumannii were closely related (83% similar). IS1008-ΔISAba3-bla(OXA-58-like) and ISAba1-bla(OXA-51-like) were identified in 22 and 21 clinical isolates of A. baumannii, respectively (one isolate contained both). The ISAba3-bracketed bla(OXA-58-like) gene was detected in all isolates of Acinetobacter genomic species 13TU. Patient transfers between different sections of the ICU were important factors that contributed to the spread of the two pulsotypes of A. baumannii. However, among the A. baumannii isolates identified, only those carrying IS1008-ΔISAba3-bla(OXA-58-like) could be found in the environment, indicating an additional route of transmission. The prior use of carbapenem or cefepime was associated with the subsequent infection with A. baumannii carrying the ISAba1-bla(OXA-51-like) gene, while prior piperacillin/tazobactam use was associated with the subsequent infection with A. baumannii carrying the IS1008-ΔISAba3-bla(OXA-58-like) gene. CONCLUSION: A. baumannii isolates carrying different carbapenemase genes and their associated genetic structures might be transmitted or selected in different ways.


Assuntos
Infecções por Acinetobacter/epidemiologia , Acinetobacter baumannii/isolamento & purificação , Acinetobacter calcoaceticus/isolamento & purificação , Proteínas de Bactérias/genética , Infecção Hospitalar/epidemiologia , Surtos de Doenças , Imipenem/farmacologia , beta-Lactamases/genética , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/classificação , Acinetobacter baumannii/enzimologia , Acinetobacter baumannii/genética , Acinetobacter calcoaceticus/classificação , Acinetobacter calcoaceticus/enzimologia , Acinetobacter calcoaceticus/genética , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Análise por Conglomerados , Infecção Hospitalar/microbiologia , Eletroforese em Gel de Campo Pulsado , Microbiologia Ambiental , Feminino , Genes Bacterianos , Variação Genética , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Tipagem Molecular , Reação em Cadeia da Polimerase , Taiwan/epidemiologia , Resistência beta-Lactâmica , beta-Lactamases/metabolismo
10.
J Chin Med Assoc ; 74(8): 369-71, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21872818

RESUMO

We report a case of nasal myiasis caused by Sarcophaga spp., noted during hospitalization. A 74-year-old man was admitted with non-ST-elevation myocardial infarction. The patient underwent coronary arterial bypass surgery and was then mechanically ventilated by means of a nasotracheal tube for the next 8 days. After extubation, a total of seven maggots were retrieved from both nostrils. The larvae were removed and reared to mature flies, which were identified as Sarcophaga peregrina. From the clinical course and the fly's life cycle, it was concluded that the infestation was hospital-acquired.


Assuntos
Infecção Hospitalar/etiologia , Miíase/etiologia , Nariz/parasitologia , Sarcofagídeos , Idoso , Animais , Humanos , Intubação Intratraqueal , Masculino , Tomografia Computadorizada por Raios X
11.
Antimicrob Agents Chemother ; 54(8): 3107-12, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20516281

RESUMO

The contribution of the blaOXA-58 gene and its promoter to beta-lactam resistance has not been validated in Acinetobacter spp. other than Acinetobacter baumannii. We identified a multidrug-resistant (including carbapenem resistance) Acinetobacter genomic species 13TU in which blaOXA-58 was the only detected carbapenemase gene. The blaOXA-58 gene was plasmid located, flanked by ISAba3 (downstream) and an ISAba3-like element (upstream). An IS1006 element was inserted into ISAba3-like (IS1006-DeltaISAba3-like) to generate a hybrid promoter for blaOXA-58, with a -35 promoter located in IS1006 and a -10 promoter in ISAba3-like. The reference strain of Acinetobacter genomic species 13TU, ATCC 17903, revealed higher MICs of amoxicillin, ticarcillin, and piperacillin and heteroresistance to imipenem and meropenem when it was transformed with a shuttle vector containing a fragment encompassing DeltaISAba3-like-blaOXA-58, compared to the same host containing only blaOXA-58. When the fragment was changed from DeltaISAba3-like-blaOXA-58 to IS1006-DeltaISAba3-like-blaOXA-58, the ATCC 17903 transformant revealed a markedly higher level of blaOXA-58 transcription (12-fold), increased cefuroxime and piperacillin-tazobactam MICs, and homoresistance to imipenem and meropenem. Different roles of the insertion elements preceding the blaOXA-58 gene in Acinetobacter genomic species 13TU are demonstrated. The ISAba3-like--blaOXA-58 construct can mediate resistance to penicillin derivatives but only heteroresistance to carbapenems. The insertion of IS1006 into ISAba3-like, generating a hybrid promoter, could further enhance the transcription of blaOXA-58 and mediate homoresistance to carbapenems and also enhanced resistance to piperacillin-tazobactam.


Assuntos
Acinetobacter/efeitos dos fármacos , Elementos de DNA Transponíveis/genética , Plasmídeos/genética , Regiões Promotoras Genéticas/genética , Recombinação Genética , Resistência beta-Lactâmica/genética , beta-Lactamases/genética , Acinetobacter/classificação , Acinetobacter/enzimologia , Acinetobacter/genética , Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Farmacorresistência Bacteriana Múltipla , Genoma Bacteriano , Humanos , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Ácido Penicilânico/análogos & derivados , Ácido Penicilânico/farmacologia , Piperacilina/farmacologia , Análise de Sequência de DNA , Especificidade da Espécie , Tazobactam
12.
J Chemother ; 21(5): 514-20, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19933042

RESUMO

Bla(OXA-51-like), the intrinsic carbapenemase gene in Acinetobacter baumannii previously found only in this species, was detected in a clinical isolate of Acinetobacter genomic species 13tU. this study aimed to characterize this gene in the isolate. Genomic species identification was confirmed by amplified ribosomal DNA restriction analysis and sequence analysis of 16S-23S ribosomal DNA intergenic spacer, rpoB and recA. The bla(OXA-51-like) gene, with an upstream ISAba1 insertion, was plasmid-encoded and the surrounding sequences suggested that its origin was from A. baumannii. Transformation of Acinetobacter genomic species 13TU AtCC 17903 with recombinant plasmid bearing ISAba1-bla(OXA-51-like) from the isolate increased the minimum inhibitory concentrations (MICs) of meropenem and imipenem 256-fold. This is the first report of bla(OXA-51-like) in an organism other than A. baumannii. This plasmid-borne bla(OXA-51-like) gene with an upstream ISAba1 insertion confers a high level of carbapenem resistance to Acinetobacter genomic species 13TU.


Assuntos
Acinetobacter baumannii/genética , Acinetobacter/genética , Proteínas de Bactérias/genética , beta-Lactamases/genética , Acinetobacter/isolamento & purificação , Acinetobacter baumannii/isolamento & purificação , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Southern Blotting , DNA Bacteriano/genética , DNA Ribossômico/genética , Farmacorresistência Bacteriana , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , beta-Lactamases/metabolismo
13.
J Microbiol Immunol Infect ; 42(3): 210-9, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19812854

RESUMO

BACKGROUND AND PURPOSE: Acinetobacter baumannii isolates containing class 1 integrons belong to different clones, but only a few strains are successful at causing infection. This study was conducted to compare the characteristics among these clones with different epidemicity. METHODS: Eighty eight bacteremic isolates of A. baumannii were collected in a medical center in Taiwan during a 3-year period. The gene cassettes and antibiotic susceptibilities of the bacterial isolates were delineated and the patients' characteristics were compared. RESULTS: Class 1 integrons were detected in 75 isolates (85.2%). Most of the isolates belonged to 2 major clones, but only 1 of the 2 clones caused outbreaks in several hospitals in Taiwan. Restriction analyses of variable regions of the integron revealed identical gene cassettes among isolates within the same clone. The cassette arrays of the 3 clones were aacA4, catB8, aadA1 (clone I, epidemic clone); dhfr XII, unknown open reading frame (orfF), aadA2 (clone II, endemic clone); and aacC1, 2 unknown open reading frames (orfX, orfX'), aadA1a (clone III). The epidemic and endemic strains were multidrug resistant, but the former presented a higher resistance rate to ampicillin-sulbactam. Infections with epidemic strains were significantly associated with prior use of cephalosporins, but didn't contribute to a higher mortality rate. CONCLUSIONS: Judicious use of cephalosporins and rapid identification using the integron typing method might be helpful for the prevention of further spread of strains with epidemic potential.


Assuntos
Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/genética , Bacteriemia/microbiologia , Infecção Hospitalar/microbiologia , Infecções por Acinetobacter/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Bacteriemia/epidemiologia , Infecção Hospitalar/epidemiologia , Farmacorresistência Bacteriana , Feminino , Humanos , Integrons/genética , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Análise Multivariada , Ribotipagem , Fatores de Risco , Estatísticas não Paramétricas
14.
Int J Antimicrob Agents ; 34(6): 580-4, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19733035

RESUMO

In this study, we investigated the distribution of genes encoding various carbapenemases as well as their association with carbapenem resistance in clinical isolates of Acinetobacter genomic species from Taiwan. A total of 129 imipenem-non-susceptible and 79 imipenem-susceptible isolates were examined, of which 185 (88.9%) were Acinetobacter baumannii. Among the 185 A. baumannii isolates, imipenem non-susceptibility was more common in isolates with ISAba1-bla(OXA-51-like) (72/75; 96%), bla(OXA-58-like) (33/33; 100%) or bla(OXA-24-like) (7/7; 100%) than in isolates with only bla(OXA-51-like) (4/72; 5.6%). A metallo-beta-lactamase (MBL) gene was present in two isolates of imipenem-resistant A. baumannii, and bla(OXA-58-like) was also present in these isolates. A total of 18% and 1% of imipenem-non-susceptible isolates of A. baumannii were resistant to tigecycline and colistin, respectively. Among the 23 isolates of non-baumannii Acinetobacter spp., bla(OXA-58-like) and MBL genes were widely disseminated in the imipenem-resistant isolates, and isolates with bla(OXA-58-like) and MBL genes had higher imipenem minimum inhibitory concentrations than those with bla(OXA-58-like) alone. Although the rate of non-susceptibility to colistin was 26.7% among the imipenem-non-susceptible isolates of non-baumanniiAcinetobacter, 93.3% and 100% were susceptible to ciprofloxacin and tigecycline, respectively. In conclusion, different isolates of imipenem-non-susceptible A. baumannii and non-baumanniiAcinetobacter contained different carbapenemases and had different antimicrobial susceptibilities.


Assuntos
Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/classificação , Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Variação Genética , Imipenem/farmacologia , Acinetobacter baumannii/genética , Acinetobacter baumannii/fisiologia , Proteínas de Bactérias/genética , DNA Bacteriano/genética , Humanos , Testes de Sensibilidade Microbiana , Taiwan , beta-Lactamases/genética
15.
J Microbiol Immunol Infect ; 42(1): 47-53, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19424558

RESUMO

BACKGROUND AND PURPOSE: Acinetobacter junii is a human pathogen but A. junii infection is rarely reported. This study aimed to delineate the characteristics of A. junii infection. METHODS: The medical records of 34 patients who were treated at Taipei Veterans General Hospital, Taipei, Taiwan, from May 1999 to May 2007 and had A. junii isolated from sterile sites were reviewed. Isolates of A. junii were identified by using API ID 32 GN and were confirmed by analysis of the 16S-23S rRNA intergenic spacer region. RESULTS: Thirty five infections with A. junii were identified. The most common underlying conditions included prior antibiotic use (56%), central venous catheterization (50%), and malignancy (38%). Systemic inflammatory response syndrome and shock developing within 1 week were observed in 27 (77%) and 8 (23%) episodes, respectively. Eighty percent of the infectious episodes were hospital acquired. The infections were primary bacteremia (n = 32), empyema (n = 1), peritonitis (n = 1), and keratitis (n = 1). Polymicrobial infection was present in 9 episodes (26%). A. junii isolates remained susceptible to most of the tested antimicrobial agents, but the hospital-acquired isolates had higher resistance rates than the community-acquired isolates. Four patients (11.4%) died of A. junii infection despite appropriate antimicrobial therapy for 3 patients. Shock that developed within 1 week of bacteremia was associated with a poor outcome (p = 0.01). CONCLUSIONS: A. junii is an opportunistic pathogen that mainly affects patients who have had prior antimicrobial therapy, invasive procedures, or malignancy. Newly emerging infections caused by A. junii and the increasing antimicrobial resistance among hospital-acquired A. junii isolates should be monitored.


Assuntos
Infecções por Acinetobacter , Acinetobacter/isolamento & purificação , Infecções por Acinetobacter/complicações , Infecções por Acinetobacter/diagnóstico , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/epidemiologia , Adulto , Idoso , Análise de Variância , Antibacterianos/uso terapêutico , Criança , Eletroforese em Gel de Campo Pulsado , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Taiwan
16.
J Clin Microbiol ; 46(9): 2938-44, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18632910

RESUMO

There are no previous reports of human infection due to Acinetobacter baylyi. In this study, we report on six patients with bacteremia due to A. baylyi, based on analysis of the 16S-23S rRNA intergenic spacer and the 16S rRNA gene. All six patients had multiple underlying diseases. The infection was nosocomially acquired in five patients. The six clinical isolates had similar ribopatterns, suggesting a clonal relationship. Compared to the reference strain, the clinical isolates were more resistant to antimicrobial agents, especially beta-lactam antibiotics. In three of the isolates, they may have undetermined plasmid mediated class C type beta-lactamases because of the positive results in a double-disk synergy test using 3-aminophenylboronic acid. Two of the clinical isolates retained a level of natural transformability similar to that of the reference strain. None of the patients died, although only three of them received appropriate antimicrobial therapy. This study demonstrates that A. baylyi is a potential human pathogen that can cause nosocomial infection in immunocompromised patients.


Assuntos
Infecções por Acinetobacter/microbiologia , Acinetobacter , Infecções Oportunistas/microbiologia , Acinetobacter/genética , Adolescente , Idoso , Idoso de 80 Anos ou mais , Bacteriemia/microbiologia , Feminino , Genótipo , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Fenótipo , Filogenia
17.
J Microbiol Immunol Infect ; 41(3): 222-6, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18629417

RESUMO

BACKGROUND AND PURPOSE: Blastocystis hominis is an intestinal protozoan. The pathogenic role of this organism in human beings is still controversial and has varied among reports from different geographic areas. The purpose of this study was to determine the clinical significance of B. hominis in northern Taiwan. METHODS: A total of 100 patients who had a positive B. hominis stool examination during the period April to December of 2001 were retrospectively identified from Taipei Veterans General Hospital. The demographic and clinical characteristics of these patients were reviewed from the medical records. RESULTS: All of the patients were adults. Fifty nine patients had more than one underlying diseases, including malignancies. Twenty one patients presented with fever and 10 patients had gastrointestinal symptoms, including diarrhea and/or abdominal pain. However, all of the patients had other conditions that might have contributed to the clinical presentation, and they improved without specific treatment for B. hominis. Furthermore, there were no significant differences in clinical symptoms and white blood cell count between patients with malignancy or diabetes mellitus and those without. Six patients had hypereosinophilia that could not be attributed to other causes. Among 34 patients who had a further stool examination within one year, B. hominis was undetectable in 31 patients (91.2%), despite their having no specific antiprotozoal treatment. CONCLUSIONS: The association of clinical symptoms and B. hominis could not be delineated from our study, even in immunocompromised patients. All of the patients improved without receiving any specific therapy. More studies from different areas are needed in order to delineate the clinical significance B. hominis.


Assuntos
Infecções por Blastocystis/epidemiologia , Infecções por Blastocystis/fisiopatologia , Blastocystis hominis/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Infecções por Blastocystis/parasitologia , Fezes/parasitologia , Feminino , Hospitais , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taiwan
18.
BMC Infect Dis ; 8: 84, 2008 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-18573219

RESUMO

BACKGROUND: Because the outcomes and sequelae after different types of brain injury (BI) are variable and difficult to predict, investigations on whether enhanced expressions of BI-associated biomarkers (BIABs), including transforming growth factor beta1 (TGF-beta1), S100B, glial fibrillary acidic protein (GFAP), neurofilament light chain (NF-L), tissue transglutaminases (tTGs), beta-amyloid precursor proteins (AbetaPP), and tau are present as well as whether impairment of the ubiquitin-proteasome system (UPS) is present have been widely used to help delineate pathophysiological mechanisms in various BIs. Larvae of Toxocara canis can invade the brain and cause BI in humans and mice, leading to cerebral toxocariasis (CT). Because the parasitic burden is light in CT, it may be too cryptic to be detected in humans, making it difficult to clearly understand the pathogenesis of subtle BI in CT. Since the pathogenesis of murine toxocariasis is very similar to that in humans, it appears appropriate to use a murine model to investigate the pathogenesis of CT. METHODS: BIAB expressions and UPS function in the brains of mice inoculated with a single dose of 250 T. canis embryonated eggs was investigated from 3 days (dpi) to 8 weeks post-infection (wpi) by Western blotting and RT-PCR. RESULTS: Results revealed that at 4 and 8 wpi, T. canis larvae were found to have invaded areas around the choroid plexus but without eliciting leukocyte infiltration in brains of infected mice; nevertheless, astrogliosis, an indicator of BI, with 78.9~142.0-fold increases in GFAP expression was present. Meanwhile, markedly increased levels of other BIAB proteins including TGF-beta1, S100B, NF-L, tTG, AbetaPP, and tau, with increases ranging 2.0~12.0-fold were found, although their corresponding mRNA expressions were not found to be present at 8 wpi. Concomitantly, UPS impairment was evidenced by the overexpression of conjugated ubiquitin and ubiquitin in the brain. CONCLUSION: Further studies are needed to determine whether there is an increased risk of CT progression into neurodegenerative disease because neurodegeneration-associated AbetaPP and phosphorylated tau emerged in the brain.


Assuntos
Biomarcadores/análise , Encéfalo/parasitologia , Helmintíase do Sistema Nervoso Central/metabolismo , Toxocara canis/patogenicidade , Toxocaríase/metabolismo , Animais , Anticorpos Anti-Helmínticos , Western Blotting , Encéfalo/metabolismo , Encéfalo/patologia , Helmintíase do Sistema Nervoso Central/parasitologia , Helmintíase do Sistema Nervoso Central/patologia , Modelos Animais de Doenças , Proteína Glial Fibrilar Ácida , Larva , Camundongos , Fatores de Crescimento Neural/análise , Proteínas do Tecido Nervoso/análise , Proteínas de Neurofilamentos/análise , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Serina-Treonina Quinases/análise , Subunidade beta da Proteína Ligante de Cálcio S100 , Proteínas S100/análise , Toxocara canis/imunologia , Toxocaríase/patologia , Fator de Crescimento Transformador beta1/análise , Transglutaminases/análise , Ubiquitina/metabolismo , Proteínas tau/análise
19.
J Virol Methods ; 151(1): 161-4, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18499272

RESUMO

Studies of the human cytomegalovirus (HCMV) glycoprotein N (gpUL73-gN) showed that genotypic variations exist in different geographic areas, with gN-2 unidentified in Chinese population. The purpose of this study was to determine the HCMV gN variants in the Chinese population of Taiwan. Primers were designed and a polymerase chain reaction (PCR) was carried out on the UL73 gene. The PCR products were subjected to restriction fragment length polymorphism (RFLP) analysis. The same PCR-RFLP assay was repeated using primers published previously to demonstrate the influence of primer design. Of the 48 clinical HCMV isolates, 33 were positive for PCR products by both primer sets. Fifteen were positive only by the "in-house" PCR. The distribution of gN-1, gN-2, gN-3, and gN-4 by RFLP analysis was 14:11:7:17, with one isolate positive for both gN-1 and gN-2. The published primers detected the four genotypes with the number of 14:0:2:17. The under-representation of gN-2 and gN-3 by the method published previously may be due to inappropriate primer design when re-examining the sequences. On the basis of the results of this study, gN-2 is not the rarest gN genotype in the Chinese population of Taiwan. The design of primers used for PCR-RFLP genotyping may have a great influence on the frequency distribution of HCMV genomic variants.


Assuntos
Infecções por Citomegalovirus/epidemiologia , Citomegalovirus/isolamento & purificação , Primers do DNA , Variação Genética , Proteínas do Envelope Viral/genética , Povo Asiático , Citomegalovirus/classificação , Citomegalovirus/genética , Infecções por Citomegalovirus/etnologia , Infecções por Citomegalovirus/virologia , Primers do DNA/genética , Humanos , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Taiwan/epidemiologia , Taiwan/etnologia
20.
Antimicrob Agents Chemother ; 52(7): 2573-80, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18443121

RESUMO

The oxacillinase gene was reported to confer limited resistance to carbapenem in Acinetobacter baumannii. In this study, we have demonstrated that an A. baumannii clinical isolate harboring a plasmid, pTVICU53, has 11,037 bp encoding 13 open reading frames. A bla(OXA-58) gene with an upstream insertion of truncated ISAba3 (DeltaISAba3) and IS1008 was found in this plasmid. DeltaISAba3and IS1008 provided two independent promoters for the transcription control of the bla(OXA-58) gene. The transformation of pTVICU53 or a shuttle vector bearing IS1008-DeltaISAba3-bla(OXA-58) to different A. baumannii recipients can increase their MICs of carbapenem 64- to 256-fold. The deletion of promoters provided by IS1008 resulted in dramatic decreases in bla(OXA-58) transcription and a 32- to 64-fold reduction in the carbapenem MIC. These findings highlight that A. baumannii might develop carbapenem resistance with a single transformation step, taking up a plasmid containing a genetic construct with a potentially high level of transcription of the bla(OXA-58) gene.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/genética , Carbapenêmicos/farmacologia , Genes Bacterianos , Resistência beta-Lactâmica/genética , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/enzimologia , Sequência de Bases , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/microbiologia , Primers do DNA/genética , Elementos de DNA Transponíveis/genética , DNA Bacteriano/genética , Humanos , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Plasmídeos/genética , Regiões Promotoras Genéticas , Transformação Genética , beta-Lactamases/biossíntese , beta-Lactamases/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...