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1.
Microbiol Immunol ; 65(12): 542-550, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34581451

RESUMO

Extended spectrum ß-lactamase (ESBL)-producing Escherichia coli have been found in healthy individuals in Indonesia and Vietnam. The ISEcp1-blaCTX-M transposition unit of ESBL-producing bacterial isolates has been considered responsible for the production of CTX-M type ESBL and it is important for the dissemination of blaCTX-M . This study aimed to characterize the upstream genetic structure (UGS) of E. coli isolates possessing blaCTX-M-1 group and/or blaCTX-M-9 group genes obtained from healthy individuals in Indonesia and Vietnam. A total of 501 CTX-M type ESBL-producing E. coli isolates possessing blaCTX-M-1 group and/or blaCTX-M-9 group genes were obtained from healthy individuals of the two countries in 2018. The UGSs of the ISEcp1-blaCTX-M transposition unit of the 501 ESBL-producing E. coli isolates were amplified by barcode-adaptor-ligation-mediated PCR and analyzed using the Nanopore sequencer. The obtained sequence information was used to classify the UGSs of the ISEcp1-blaCTX-M transposition unit. From the 501 ESBL-producing E. coli isolates, 502 UGSs were obtained, which were classified into 85 UGS types based on the sequence. ISEcp1 of 359 (71.5%) of the 502 UGSs was disrupted by gene insertion, and ISEcp1-blaCTX-M transposition unit of most (87.1%) of the determined UGSs was confirmed as plasmidic. Only 6 (7.1%) of the 85 UGS types were common to both countries. Our results indicated that many different UGSs of ISEcp1-blaCTX-M transposition units were detected in Indonesia and Vietnam; hence, we suggest that structurally different kinds of plasmids harboring blaCTX-M were separately distributed in the two countries.


Assuntos
Infecções por Escherichia coli , Escherichia coli , beta-Lactamases , Antibacterianos , Povo Asiático , Escherichia coli/genética , Humanos , Indonésia , Plasmídeos , Vietnã , beta-Lactamases/genética
2.
J Infect Chemother ; 27(9): 1288-1294, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33840596

RESUMO

INTRODUCTION: Because blaCTX-M is responsible for resistance of bacteria to the third generation cephalosporins, location of blaCTX-M could be a good indicator for classifying bacterial isolates harboring blaCTX-M in molecular epidemiology. However, determination of blaCTX-M location has been difficult when multiple copies of ISEcp1 were found on bacterial genome. We aimed to establish a high-throughput analytical method for upstream genetic structures (UGS) of ISEcp1 to facilitate determination of blaCTX-M location. METHODS: Extracted DNA samples obtained from 168 Escherichia coli isolates possessing blaCTX-M were digested by restriction enzyme, HaeIII, and the digested DNA fragments were ligated with homemade barcode adaptors. Then, DNA fragments containing UGS of ISEcp1 were amplified and subjected to the Nanopore sequencer. RESULTS: Nucleotide sequences and locations of 168 UGSs obtained from the examined E. coli isolates were determined. Among the 168 determined UGSs, 150 (89.3%) UGS were confirmed on plasmid and classified into eight types. Interestingly, coding sequence of ISEcp1 transposase gene in seven of the eight types were disrupted by IS26 insertion. The remaining 18 (10.7%) UGSs were observed in identical chromosomal region. The obtained nucleotide sequences the locations of UGSs were confirmed by conventional capillary sequencer and Southern blotting, respectively, and any discrepant result was not observed with these confirmation procedures. CONCLUSIONS: Our results indicated that the established method was efficient for simultaneously determining at least 100 different UGS, and suggested that the determined UGSs of ISEcp1-blaCTX-M transposition unit was useful for classification of bacterial isolates harboring blaCTX-M.


Assuntos
Infecções por Escherichia coli , Escherichia coli , Antibacterianos/farmacologia , Escherichia coli/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Plasmídeos/genética , beta-Lactamases/genética
3.
Int J Urol ; 28(6): 623-628, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33811389

RESUMO

OBJECTIVES: To compare antibiotic susceptibilities between chromosomal and plasmid blaCTX-M-15 locations in urinary tract infection-causing extended-spectrum ß-lactamases-producing Escherichia coli blaCTX-M-15 isolated in Indonesia. METHODS: A total of 84 strains identified as extended-spectrum ß-lactamases-producing E. coli were isolated from patients with urinary tract infection in Indonesia in 2015. Antimicrobial susceptibility tests were performed on these strains using 18 antibiotics, and extended-spectrum ß-lactamase bla genes were detected by polymerase chain reaction. Gene localization of blaCTX-M-15 -positive strains was confirmed by Southern blot hybridization, and epidemiological typing was conducted using multilocus sequence typing. RESULTS: Of 54 strains harboring the blaCTX-M-15 gene, 27 showed localization on chromosome, 20 on plasmid, and seven on chromosome and plasmid. Most multilocus sequence typing sequence types of the 27 strains with chromosomal blaCTX-M-15 were ST405 (25.9%) and ST131 (22.2%) strains, whereas the 20 strains with plasmid-blaCTX-M-15 were mostly ST410 (55.0%). CONCLUSIONS: Extended-spectrum ß-lactamases-producing E. coli blaCTX-M-15 with plasmid genes show significantly higher resistant rates against piperacillin-tazobactam but lower resistant rates against chloramphenicol compared to chromosomal strains in Indonesian patients with urinary tract infection. Mechanistic investigations will be necessary to advance our knowledge of antimicrobial resistance in urinary tract infection.


Assuntos
Infecções por Escherichia coli , Infecções Urinárias , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Cromossomos , Escherichia coli/genética , Infecções por Escherichia coli/tratamento farmacológico , Humanos , Indonésia/epidemiologia , Plasmídeos/genética , Infecções Urinárias/tratamento farmacológico , beta-Lactamases/genética
4.
Int J Med Microbiol ; 310(2): 151395, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31959579

RESUMO

Mostly, blaCTX-M is found on transferable plasmids as a component of the blaCTX-M transposition unit containing an insertion sequence, ISEcp1, which exists on the upstream region of blaCTX-Ms. Several recent studies conducted in clinical and community settings have reported the presence of chromosomally located blaCTX-M in extended spectrum ß-lactamase (ESBL)-producing bacterial isolates. In this study, we observed the frequency and molecular nature of the ISEcp1-mediated transposition of blaCTX-M-14 from a plasmid to a chromosome by using an experimental strain of Escherichia coli. We determined 102 different chromosomal transposition sites of blaCTX-M-14 in 126 E. coli isolates following five independent screening procedures. The characterization of the 102 different chromosomal transposition sites of blaCTX-M-14 observed in this study revealed the presence of 5-bp direct repeat (DR) sequences and identical left terminal inverted sequences in 80 E. coli isolates. However, 5'-flanking sequences of the right terminal DR sequences in the 80 E. coli isolates were highly diverse, and consensus sequences of the right terminal inverted repeat sequences were not observed. In case of our E. coli experimental strain, the frequency of the ISEcp1-mediated transposition of blaCTX-M-14 from a plasmid to a chromosome was determined to be 0.51% (SD = 0.37). Collectively, the molecular nature of ISEcp1 could plausibly be a factor contributing to the high detection rates of E. coli possessing chromosomally located blaCTX-M-14 in both clinical and community settings.


Assuntos
Cromossomos Bacterianos/genética , Elementos de DNA Transponíveis/genética , Escherichia coli/genética , Plasmídeos/genética , Análise de Sequência de DNA , beta-Lactamases
5.
J Infect Chemother ; 26(6): 575-581, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32151495

RESUMO

Enterobacteriaceae isolates producing CTX-M-type extended-spectrum ß-lactamase (ESBL) has been found in hospitalized patients and healthy individuals in communities of the Southeast Asian countries. Medical students might have more risk of ESBL-producing Enterobacteriaceae contagion, because medical students who belong to communities have direct and indirect contacts with workers and patients in healthcare facilities. The aim of this study was to collect information for evaluation of the potential risk of ESBL-producing Enterobacteriaceae contagion in Indonesian undergraduate medical students by characterizing genotypic properties of Escherichia coli isolates-producing CTX-M-type ESBL. A total 141 fecal samples collected from 207 medical students of a university in Surabaya, Indonesia were subjected to PCR, XbaI and S1 nuclease-pulsed-field gel electrophoresis (PFGE), Southern blotting, and sequencing analysis. Eighty-two ESBL-producing Enterobacteriaceae, including 75 E. coli and 7 Klebsiella pneumoniae were isolated from 79 (56.0%) students. Among 75 ESBL-producing E. coli, blaCTX-M-15 was the most prevalent type (44.0%). Although XbaI-PFGE results showed genetic background of the E. coli isolates producing CTX-M-type ESBL were diverse, five clonal spread cases of certain E. coli producing CTX-M-type ESBL isolates were observed among the medical students. Our results suggested that ESBL-producing Enterobacteriaceae might be circulating among the medical students through contaminated environment such as in a university or communities they belonged.


Assuntos
Enterobacteriaceae/genética , Enterobacteriaceae/isolamento & purificação , Proteínas de Escherichia coli/genética , Escherichia coli/isolamento & purificação , Klebsiella pneumoniae/isolamento & purificação , beta-Lactamases/genética , Antibacterianos/farmacologia , DNA Bacteriano , Farmacorresistência Bacteriana/genética , Enterobacteriaceae/enzimologia , Escherichia coli/genética , Infecções por Escherichia coli/microbiologia , Fezes/microbiologia , Humanos , Indonésia , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Estudantes de Medicina/estatística & dados numéricos
6.
J Infect Chemother ; 25(4): 314-317, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30292768

RESUMO

This study was performed to characterize CTX-M type extended spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae carriage in asymptomatic health individuals, which has not been well investigated, in a community of the Okinawa prefecture, Japan. Fecal samples were voluntary collected from asymptomatic healthy individuals who were going to take a routine medical checkup. The collected fecal samples were inoculated on MacConkey agar supplemented with 2 µg/ml of cefotaxime and incubated at 37 °C. Randomly selected three lactose-fermented colonies per each sample were analyzed. Genetic relatedness among the CTX-M type ESBL-producing Enterobacteriaceae isolates were performed by pulsed-field gel electrophoresis (PFGE) after confirmation of ESBL phenotype and determination of bacterial species. Location of blaCTX-M was confirmed by S1-PFGE, I-CeuI-PFGE and the Southern blotting hybridization. ESBL-producing Enterobacteriaceae was isolated from 32 (12.2%) of the collected 263 fecal samples, and 96 ESBL-producing Enterobacteriaceae isolates were obtained. CTX-M type ESBL-producing Escherichia coli B2 were major (67 isolates, 72.0%) and 40 (59.7%) of the 67 CTX-M type ESBL -producing E. coli B2 were E. coli B2-ST131. Three CTX-M type ESBL-producing E. coli B2-ST131 isolates from asymptomatic healthy individuals showed similar PFGE band patterns as five CTX-M type ESBL -producing E. coli B2-ST131 isolates from a hospital locates in the same area of the target community. Chromosomally-transferred blaCTX-M was observed in 10.0% of the examined CTX-M type ESBL-producing Enterobacteriaceae isolates. We report current situation CTX-M type ESBL-producing Enterobacteriaceae carriage in asymptomatic healthy individuals of the Okinawa prefecture, Japan. In addition, our results indicated that worldwide distributed CTX-M type ESBL-producing E. coli B2-ST131 has been spread in a community. Therefore monitoring of ESBL-producing Enterobacteriaceae in healthy individuals is important.


Assuntos
Infecções por Enterobacteriaceae/microbiologia , Enterobacteriaceae/isolamento & purificação , Escherichia coli/isolamento & purificação , beta-Lactamases/metabolismo , Antibacterianos/farmacologia , Infecções Assintomáticas/epidemiologia , Farmacorresistência Bacteriana , Enterobacteriaceae/metabolismo , Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/prevenção & controle , Monitoramento Epidemiológico , Escherichia coli/metabolismo , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/prevenção & controle , Fezes/microbiologia , Voluntários Saudáveis , Humanos , Japão/epidemiologia , Testes de Sensibilidade Microbiana
7.
J Infect Chemother ; 22(5): 281-6, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26898665

RESUMO

Enterobacteriaceae producing extended spectrum ß-lactamase (ESBL) are distributed worldwide. In this study, 114 ESBL-producing Enterobacteriaceae were isolated by analyzing 1672 clinical isolates of Enterobacteriaceae collected from an Okinawa prefectural hospital in Japan between June 2013 and July 2014. The overall prevalence of ESBL-producing Enterobacteriaceae was 6.8%; the prevalence of different bacterial species among the ESBL-producing isolates was as follows: 11.5% Escherichia coli (90 of 783 isolates), 6.2% Klebsiella pneumoniae (19 of 307 isolates), and 11.1% Proteus mirabilis (5 of 45 isolates). The ESBL types blaCTX-M-1, -3, -15, -2, -14, -27, and mutants of blaSHV-1 were detected. Among them, blaCTX-M-15 (33.3%), blaCTX-M-14 (27.8%) and blaCTX-M-27 (33.3%) were dominant in the E. coli isolates, whereas a blaSHV mutant which possessed four mutations (Tyr7Phe, Leu35Gln, Gly238Ser and Glu240Lys) in the amino acid sequence of SHV-1 dominated in the K. pneumoniae isolates (11 of 19, 57.9%). The pandemic E. coli ST131 clone was found to constitute 3.3% of the overall examined isolates and 62.2% of the ESBL-producing E. coli isolates. Our results suggest that the genetic combination of blaCTX-M, and blaSHV and antibiotics-resistant profile were different from that in other regions such as other areas of Japan, Asia, Europe, and North America, especially in the ESBL-producing K. pneumoniae isolates and in the E. coli B2-O25b-ST131 isolates possessing blaCTX-M-15 (40.7% of the E. coli B2-O25b-ST131 isolates). Taken together, our results indicate that the ESBL-producing Enterobacteriaceae in Okinawa, Japan, might be of a unique nature.


Assuntos
Antibacterianos/farmacologia , Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/microbiologia , Enterobacteriaceae/efeitos dos fármacos , Farmacorresistência Bacteriana , Enterobacteriaceae/enzimologia , Enterobacteriaceae/patogenicidade , Humanos , Japão/epidemiologia , Testes de Sensibilidade Microbiana , Prevalência , beta-Lactamases
8.
Environ Health Prev Med ; 21(5): 287-294, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27075357

RESUMO

OBJECTIVES: The genus Aeromonas is known to causes diseases such as food poisoning, sepsis, and wound infection. However, the mode of Aeromonas transmission from environment to humans is not clearly understood. To evaluate the health risks of Aeromonas spp. in environmental freshwater, the number, proportion and putative virulence factors of Aeromonas species were investigated in Okinawa Prefecture, Japan. METHODS: Environmental freshwater samples were collected from three dams, two springs and three private wells. Aeromonas strains were identified by the biochemical method and the viable count was calculated. The production of extracellular enzymes and the virulence genes were investigated for possessing putative virulence factors using representative isolates. RESULTS: At least seven species of already-known Aeromonas isolates as well as unidentified Aeromonas spp. with/without arginin dehydrolase (ADH) exist in water at these sites. Aeromonas spp. was found to exist at over 1000 CFU/100 ml in one spring and two wells. A. veronii biovar sobria and A. jandaei were the predominant species in dams, and A. hydrophila and/or A. eucrenophila were predominant in wells. Almost all the sampled Aeromonas species produced protease, gelatinase, lipase, esterase and DNase, but A. caviae, A. caviae-like bacteria, and A. eucrenophila had low hemolytic activity. Most sampled A. hydrophila strains possessed both aerolysin gene (aer) and hemolysin gene (hlyA), but A. caviae and A. eucrenophila strains did not possess either gene. CONCLUSIONS: Since these results indicated that several Aeromonas species having potential pathogenicity exist in environmental water in Okinawa, surveys are recommended as a public health measure.


Assuntos
Aeromonas/isolamento & purificação , Água Potável/microbiologia , Água Doce/microbiologia , Aeromonas/classificação , Japão , Nascentes Naturais/microbiologia , Fatores de Virulência , Abastecimento de Água , Poços de Água
9.
Antimicrob Agents Chemother ; 59(6): 3574-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25779573

RESUMO

We examined whether Escherichia coli isolates that produce CTX-M-9-type extended-spectrum ß-lactamases (ESBL) are transferred between humans and chickens in a Vietnamese community. The phylogenetic group compositions, sequence types, antimicrobial resistance profiles, the prevalence of plasmid antibiotic resistance genes, and the plasmid replicon types generally differed between the human and chicken E. coli isolates. Our results suggest that transmission of the bla(CTX-M-9)-positive E. coli between humans and poultry was limited.


Assuntos
Proteínas de Escherichia coli/metabolismo , Escherichia coli/enzimologia , beta-Lactamases/metabolismo , Animais , Antibacterianos/farmacologia , Galinhas , Escherichia coli/efeitos dos fármacos , Proteínas de Escherichia coli/genética , Humanos , Plasmídeos/genética , Vietnã , beta-Lactamases/genética
10.
Antimicrob Agents Chemother ; 59(10): 6611-4, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26195526

RESUMO

Healthy carriage of CTX-M-type extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli was examined by thrice collecting fecal samples from the same 199 healthy Vietnamese subjects every 6 months. Using pulsed-field gel electrophoresis (PFGE), identical PFGE patterns throughout the three samplings were not observed, although prevalence of E. coli in the subjects was around 50% in the three samplings. Our results suggested a short carriage period of the CTX-M-type ESBL-producing E. coli in healthy Vietnamese subjects.


Assuntos
Escherichia coli/enzimologia , beta-Lactamases/genética , Povo Asiático , Eletroforese em Gel de Campo Pulsado , Escherichia coli/genética , Humanos , Testes de Sensibilidade Microbiana
11.
J Clin Microbiol ; 53(6): 1848-53, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25809972

RESUMO

Genotyping and characterization of bacterial isolates are essential steps in the identification and control of antibiotic-resistant bacterial infections. Recently, one novel genotyping method using three genomic guided Escherichia coli markers (GIG-EM), dinG, tonB, and dipeptide permease (DPP), was reported. Because GIG-EM has not been fully evaluated using clinical isolates, we assessed this typing method with 72 E. coli collection of reference (ECOR) environmental E. coli reference strains and 63 E. coli isolates of various genetic backgrounds. In this study, we designated 768 bp of dinG, 745 bp of tonB, and 655 bp of DPP target sequences for use in the typing method. Concatenations of the processed marker sequences were used to draw GIG-EM phylogenetic trees. E. coli isolates with identical sequence types as identified by the conventional multilocus sequence typing (MLST) method were localized to the same branch of the GIG-EM phylogenetic tree. Sixteen clinical E. coli isolates were utilized as test isolates without prior characterization by conventional MLST and phylogenetic grouping before GIG-EM typing. Of these, 14 clinical isolates were assigned to a branch including only isolates of a pandemic clone, E. coli B2-ST131-O25b, and these results were confirmed by conventional typing methods. Our results suggested that the GIG-EM typing method and its application to phylogenetic trees might be useful tools for the molecular characterization and determination of the genetic relationships among E. coli isolates.


Assuntos
Infecções por Escherichia coli/microbiologia , Escherichia coli/genética , Técnicas de Genotipagem/métodos , Tipagem Molecular/métodos , DNA Bacteriano/análise , DNA Bacteriano/genética , Escherichia coli/classificação , Fezes/microbiologia , Marcadores Genéticos/genética , Humanos , Filogenia
12.
Foodborne Pathog Dis ; 12(8): 719-25, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26110236

RESUMO

BACKGROUND: Contamination of food with multiantibiotic-resistant bacteria, particularly extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae, is considered a potential source for the wide dissemination of ESBL-producing bacteria in communities. However, little is known about the extent of contamination of food with ESBL-producing bacteria in Vietnam. OBJECTIVE: This study was conducted to assess the characteristics of ESBL-producing Escherichia coli isolated from retail meats and shrimp in Nha Trang, Vietnam. MATERIALS AND METHODS: A total of 350 food samples (poultry [n=143], pork [n=147], and shrimp [n=60]) were purchased in July and November 2013 from a local market. ESBL-producing E. coli were isolated, and ESBL genotypes, phylogenetic groups, and antibiotic resistance profiles were determined. RESULTS: The prevalence of ESBL-producing E. coli in retail foods was 40.6%. ß-Lactamase-encoding genes of the CTX-M-1 (50.7%), CTX-M-9 (41.5%), TEM (59.9%), and SHV (2.8%) groups were detected singly or in combination. The percentages of single ESBL isolates harboring CTX-M-1 or -9 plus TEM groups were 35.2% and 16.2%, respectively. B1 was the most prevalent phylogroup in ESBL isolates from pork (44.7%), poultry (55.9%), and shrimp (72.7%). B2 was the least prevalent (4.2% and 4.8% for pork and poultry isolates, respectively). The prevalence of multidrug resistance (MDR; resistance to ≥ 3 antimicrobial groups) in ESBL-producing E. coli isolated from food was 85.9%. DISCUSSION AND CONCLUSIONS: This is the first report of the characteristics of ESBL-producing E. coli in retail foods in a local city in Vietnam. Our findings indicate that retail foods are contaminated with ESBL-producing E. coli, of which many were MDR. Further monitoring and public health efforts targeting food administration are needed to control the spread of ESBL-producing bacteria in communities.


Assuntos
Escherichia coli/isolamento & purificação , Genes Bacterianos , Carne/microbiologia , Aves Domésticas/microbiologia , Alimentos Marinhos/microbiologia , Animais , Galinhas , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Contaminação de Alimentos , Microbiologia de Alimentos , Filogenia , Suínos , Vietnã
14.
Environ Sci Pollut Res Int ; 30(5): 11740-11754, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36098923

RESUMO

The flagellin A gene (flaA) sequences, swimming motility, and biofilm forming ability were investigated in order to reveal the genetic and functional differences of flagella between clinical and environmental isolates of Aeromonas species. Twenty-eight clinical and 48 environmental strains of Aeromonas species isolated in Okinawa Prefecture of Japan were used in this study. The full-length flaA genes of these strains were sequenced and aligned, and a phylogenetic tree was constructed. In addition, swimming motility and biofilm forming ability were evaluated by conventional methods. Aeromonas veronii biovar sobria and A. hydrophila clearly divided into clinical and environmental strain clusters in the flaA phylogenetic classification, and the six and 13 specific amino acids respectively, of FlaA of both species were different in clinical and environmental strains. Furthermore, the flaA size of the clinical strain of A. veronii bv. sobria was mainly 909, 924, and 939 bp, and the size of A. hydrophila was 909 bp. The swimming motility of clinical isolates of both species was lower than the environmental isolates; however, the biofilm forming ability of the clinical isolates was high. Thus, the clinical isolates of A. veronii bv. sobria and A. hydrophila had different genetic and functional characteristics of flagellin than the environmental isolates. The characteristics of flagellin could serve as indicators to distinguish between clinical and environmental isolates of the both species. It may contribute to diagnosis of these diseases and the monitoring of clinical strain invasion into the natural environment.


Assuntos
Aeromonas , Aeromonas/genética , Flagelina/genética , Flagelina/metabolismo , Natação , Filogenia , Biofilmes
15.
Biochem Biophys Res Commun ; 423(4): 867-72, 2012 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-22713454

RESUMO

The global spread of the four dengue virus serotypes (DENV-1 to -4) has made this virus a major and growing public health concern. Generally, pre-existing neutralizing antibodies derived from primary infection play a significant role in protecting against subsequent infection with the same serotype. By contrast, these pre-existing antibodies are believed to mediate a non-protective response to subsequent heterotypic DENV infections, leading to the onset of dengue illness. In this study, we prepared hybridomas producing human monoclonal antibodies (HuMAbs) against DENV using peripheral blood mononuclear cells (PBMCs) from patients in the acute phase (around 1 week after the onset of illness) or the convalescent phase (around 2weeks after the onset of illness) of secondary infection. Interestingly, a larger number of hybridoma clones was obtained from patients in the acute phase than from those in the convalescent phase. Most HuMAbs from acute-phase infections were cross-reactive with all four DENV serotypes and showed significant neutralization activity to all four DENV serotypes. Thus, secondary DENV infection plays a significant role in stimulating memory cells to transiently increase the number of antibody-secreting plasma cells in patients in the early phase after the secondary infection. These HuMAbs will enable us to better understand the protective and pathogenic effects of DENV infection, which could vary greatly among secondarily-infected individuals.


Assuntos
Anticorpos Monoclonais/biossíntese , Anticorpos Neutralizantes/biossíntese , Vírus da Dengue/imunologia , Dengue/imunologia , Linfócitos/imunologia , Proteínas Virais/imunologia , Adulto , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Chlorocebus aethiops , Coinfecção , Feminino , Imunofluorescência , Humanos , Hibridomas , Masculino , Testes de Neutralização , Sorotipagem , Células Vero , Adulto Jovem
16.
J Antimicrob Chemother ; 67(7): 1769-74, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22514260

RESUMO

OBJECTIVES: To determine the prevalence of CTX-M ß-lactamase-producing Enterobacteriaceae and to study the risk factors associated with faecal carriage in asymptomatic rural Thai people. METHODS: In all, 417 stool samples were obtained from rural Thai people and screened for extended-spectrum ß-lactamases (ESBLs) using MacConkey agar supplemented with 2 mg/L cefotaxime. Results were confirmed using cefotaxime and ceftazidime with and without clavulanic acid. The bla(CTX-M) genes were identified and genotyped using PCR with bacterial DNA samples. Multivariate analysis was performed to investigate risk factors associated with the faecal carriage of CTX-M producers. RESULTS: The prevalence of CTX-M-type ESBL-producing Enterobacteriaceae was 65.7%. The CTX-M-9 group (60.6%) was dominant, followed by the CTX-M-1 group (38.7%). Most of the bacteria were Escherichia coli (85.4%) and Klebsiella pneumoniae (4.7%). Of a total of 234 E. coli strains, 48.7% belonged to phylogenetic group A, 28.6% to group B1, 15.8% to group D and 6.8% to group B2. Most CTX-M producers were susceptible to carbapenems and amikacin, but resistant to tetracycline and gentamicin. In a multivariate logistic regression model, better education status (OR 2.245; 95% CI 1.297-3.884), history of hospitalization (OR 1.643; 95% CI 1.036-2.603) and the use of antibiotics within the last 3 months (OR 1.883; 95% CI 1.221-2.903) were independently associated with faecal carriage. CONCLUSIONS: Faecal carriage of CTX-M-type ESBL-producing Enterobacteriaceae among asymptomatic individuals in rural Thailand remains alarmingly high, and previous antibiotic use and a history of hospitalization may contribute to its dissemination.


Assuntos
Portador Sadio/epidemiologia , Infecções por Enterobacteriaceae/epidemiologia , Enterobacteriaceae/enzimologia , beta-Lactamases/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Portador Sadio/microbiologia , Cefotaxima/farmacologia , Ceftazidima/farmacologia , Meios de Cultura/química , DNA Bacteriano/genética , Enterobacteriaceae/genética , Enterobacteriaceae/isolamento & purificação , Infecções por Enterobacteriaceae/microbiologia , Fezes/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prevalência , Fatores de Risco , População Rural , Tailândia/epidemiologia , Adulto Jovem , beta-Lactamases/genética
17.
Microb Pathog ; 53(1): 1-11, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22516802

RESUMO

Chlamydia trachomatis L2 invasively attacks lymphatic and subepithelial tissues of the genital tract during the formation of primary lesions. This subsequently results in lymphadenopathy, and suggests a greater propensity for systemic dissemination. However, whether lymphocytes are a potential vehicle cell for the dissemination of this infection remains unknown. We therefore assessed the growth properties of C. trachomatis L2 in lymphoid Jurkat cells compared with those observed in epithelial HeLa cells. Both cells supported the growth of C. trachomatis with a similar increase in infective progenies. Enriched human-blood lymphocytes also supported the C. trachomatis growth as well as Jurkat cells. Bacteria infecting the Jurkat cells were more susceptible to antibiotics (doxycycline, azithromycin, ofloxacin) than those in HeLa cells. Of the sphingomyelin biosynthesis inhibitors tested, both myriocin and fumonisin B1 significantly inhibited bacterial growth in both cells types. A Jurkat cell mutant that impaired bacterial growth was established using ethylmethanesulfonate treatment. DNA microarray analysis with real-time reverse transcription-polymerase chain reaction revealed that the mutant cells over-expressed granzyme K gene. Immunofluorescence staining also indicated that granzyme K irregularly over-expressed among the mutant cells as compared with that of the wild cells, suggesting a possible mechanism refractory to C. trachomatis infection. Thus, we concluded that C. trachomatis L2 could infect Jurkat cells with lymphoid properties, providing a new tool for studying C. trachomatis dissemination to tissues via lymphocyte movement.


Assuntos
Chlamydia trachomatis/patogenicidade , Linfócitos T/microbiologia , Antibacterianos/farmacologia , Chlamydia trachomatis/efeitos dos fármacos , Chlamydia trachomatis/crescimento & desenvolvimento , Ácidos Graxos Monoinsaturados/farmacologia , Fumonisinas/farmacologia , Perfilação da Expressão Gênica , Células HeLa , Humanos , Células Jurkat , Análise em Microsséries , Modelos Biológicos , Reação em Cadeia da Polimerase em Tempo Real
18.
Microb Drug Resist ; 28(1): 48-55, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34348048

RESUMO

Objectives: The incidence of healthy individuals carrying multidrug resistant Enterobacteriaceae, including extended-spectrum ß-lactamase producing Enterobacteriaceae (ESBL-E), especially extended-spectrum ß-lactamase producing Escherichia coli (ESBL-EC) and extended-spectrum ß-lactamase producing Klebsiella pneumoniae (ESBL-KP), is increasing worldwide. Although ESBL-E causes early or late onset of neonatal sepsis, the prevalence of ESBL-E carriage among pregnant women in Indonesia is not clear. In the present study, we compared the occurrence of carriage of ESBL-E among pregnant women in a primary health center (PHC) versus two hospitals. Materials and Methods: We collected rectal swab samples from 200 pregnant women who visited a PHC or were admitted to two hospitals in Surabaya, Indonesia from July to October 2018. The ESBL-E strains were isolated from the samples and phenotypically and genotypically analyzed. Results: ESBL-E strains were isolated from 25 (24.8%) pregnant women who visited the PHC and 49 (49.5%) pregnant women who were admitted to the hospitals. The rate of ESBL-E carriage of pregnant women in the hospitals was significantly higher than that in the PHC. Among the 74 isolated ESBL-E strains, ESBL-EC was most frequently isolated (62 strains), followed by ESBL-KP (12 strains). In addition, blaCTX-M-15 was the most frequent ESBL gene type of the isolated ESBL-E strains. Conclusions: Our results revealed the high occurrence of ESBL-E carriage in pregnant women, especially those who were admitted to the hospitals.


Assuntos
Antibacterianos/farmacologia , Portador Sadio/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/genética , Adulto , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Fezes/microbiologia , Feminino , Genes Bacterianos , Genótipo , Humanos , Indonésia/epidemiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , Fenótipo , Gravidez , Atenção Primária à Saúde , Adulto Jovem , beta-Lactamases/genética
20.
Microb Pathog ; 51(3): 209-16, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21511028

RESUMO

This study investigated the proteoglycan (PG)-dependent mechanism of Chlamydophila pneumoniae attachment to lymphocytic cells. Lymphoid Jurkat cells and epithelial HEp-2 cells were statically infected with C. pneumoniae (TW183). Transmission electron microscopy and assessment of inclusion-forming units indicated that the bacteria grew normally in Jurkat cells and were capable of producing secondary infection; however, they grew at a slower rate than in HEp-2 cells. RT-PCR analysis indicated that HEp-2 cells strongly expressed PG-core protein encoding genes, thereby sustaining glycosaminoglycans (GAGs), such as heparin, on the cellular surface. Similar gene expression levels were not observed in Jurkat cells, with the exception of glypican-1. Immunofluorescence analysis also supported strong heparin expression in HEp-2 cells and minimal expression in Jurkat cells, although heparan sulfate pretreatment significantly inhibited bacterial attachment to both cell types. Immunofluorescent co-staining with antibodies against chlamydial LPS and heparin did not identify bacterial and heparin co-localization on Jurkat cells. We also confirmed that when C. pneumoniae was statically infected to human CD4(+) peripheral blood lymphocytes known not expressing detectable level of heparin, the bacteria attached to and formed inclusion bodies in the cells. Thus, the attachment mechanism of C. pneumoniae to Jurkat cells with low PG expression is unique when compared with HEp-2 cells and potentially independent of GAGs such as heparin.


Assuntos
Aderência Bacteriana , Chlamydophila pneumoniae/patogenicidade , Células Jurkat/microbiologia , Proteoglicanas/metabolismo , Linhagem Celular , Chlamydophila pneumoniae/crescimento & desenvolvimento , Células Epiteliais/microbiologia , Humanos , Corpos de Inclusão/microbiologia , Corpos de Inclusão/ultraestrutura , Células Jurkat/metabolismo , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência
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