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1.
J Med Microbiol ; 73(2)2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38305344

RESUMO

The coronavirus disease 2019 pandemic accelerated developments in biotechnology that underpin infection science. These advances present an opportunity to refresh the microbial forensic toolkit. Integration of novel analytical techniques with established forensic methods will speed up acquisition of evidence and better support lines of enquiry. A critical part of any such investigation is demonstration of a robust causal relationship and attribution of responsibility for an incident. In the wider context of a formal investigation into agency, motivation and intent, the quick and efficient assembly of microbiological evidence sets the tone and tempo of the entire investigation. Integration of established and novel analytical techniques from infection science into a systematic approach to microbial forensics will therefore ensure that major perspectives are correctly used to frame and shape the evidence into a clear narrative, while recognizing that forensic hypothesis generation, testing and refinement comprise an iterative process. Development of multidisciplinary training exercises that use this approach will enable translation into practice and efficient implementation when the need arises.


Assuntos
Bioterrorismo , Microbiologia Forense , Técnicas Microbiológicas/métodos
2.
J Med Microbiol ; 72(6)2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37503929
4.
Sci Rep ; 8(1): 6697, 2018 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-29686361

RESUMO

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

5.
Sci Rep ; 7(1): 1903, 2017 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-28507322

RESUMO

The expanding global distribution of multi-resistant Klebsiella pneumoniae demands faster antimicrobial susceptibility testing (AST) to guide antibiotic treatment. Current ASTs rely on time-consuming differentiation of resistance and susceptibility after initial isolation of bacteria from a clinical specimen. Here we describe a flow cytometry workflow to determine carbapenem susceptibility from bacterial cell characteristics in an international K. pneumoniae isolate collection (n = 48), with a range of carbapenemases. Our flow cytometry-assisted susceptibility test (FAST) method combines rapid qualitative susceptible/non-susceptible classification and quantitative MIC measurement in a single process completed shortly after receipt of a primary isolate (54 and 158 minutes respectively). The qualitative FAST results and FAST-derived MIC (MICFAST) correspond closely with broth microdilution MIC (MICBMD, Matthew's correlation coefficient 0.887), align with the international AST standard (ISO 200776-1; 2006) and could be used for rapid determination of antimicrobial susceptibility in a wider range of Gram negative and Gram positive bacteria.

6.
New Microbes New Infect ; 8: 171-3, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27257499

RESUMO

The facultative anaerobic Gram-negative species Escherichia albertii has been isolated from human faeces in gastrointestinal infection and from a range of wild bird species. Here we report the first case of a febrile infection associated with E. albertii bacteraemia in a 76-year-old woman with gastric dysplasia.

7.
New Microbes New Infect ; 2(4): 132-3, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25356359

RESUMO

A 30-year-old man developed an infected knee wound 2 days after jumping his bicycle into a freshwater dam. He required repeated debridement and tissue grew bright green colonies typical of the alga Chlorella plus Aeromonas hydrophila. This, and one previously reported case, responded to surgical debridement and careful wound management.

8.
Eur J Clin Microbiol Infect Dis ; 33(11): 1889-95, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24859908

RESUMO

We evaluated the pathogenic potential of 98 clinical and 31 environmental Aeromonas isolates by detecting the presence of 13 virulence genes using a polymerase chain reaction (PCR)-based method. The majority (96 %) of the strains contained at least one of the virulence genes. The overall distribution was aerA/haem (77 %), alt (53 %), lafA (51 %), ast (39 %), flaA (32 %), aspA (29 %), vasH (26 %), ascV (16 %) and aexT (13 %). No amplification products were detected for the genes encoding a bundle-forming pilus (BfpA and BfpG) or a Shiga-like toxin (stx-1 and stx-2). Five or more virulence genes were detected in 42 % of environmental and 24 % of clinical isolates. Among the major species, 48 % of A. hydrophila and 42 % of A. dhakensis isolates harboured five or more virulence genes compared with 19 % in A. veronii bv. sobria and none in A. caviae isolates. Our results suggest that, in Western Australia, strains of A. dhakensis and A. hydrophila are potentially more virulent than those of A. veronii bv. sobria and A. caviae, although the pathogenic potential of Aeromonas spp. is probably strain- rather than species-dependent.


Assuntos
Aeromonas/genética , Aeromonas/isolamento & purificação , Microbiologia Ambiental , Infecções por Bactérias Gram-Negativas/microbiologia , Fatores de Virulência/genética , Adolescente , Adulto , Aeromonas/classificação , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , DNA Bacteriano/genética , Feminino , Genes Bacterianos , Genótipo , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Virulência , Austrália Ocidental , Adulto Jovem
9.
Int J Syst Evol Microbiol ; 64(Pt 5): 1635-1640, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24510975

RESUMO

A facultatively anaerobic, Gram-reaction-positive, catalase- and oxidase-negative, rod-shaped bacterium isolated from an infected human wound caused by a dog bite was characterized by phenotypic and molecular genetic methods. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain IMMIB Q2029717T was a member of the order Micrococcales of the class Actinobacteria, displaying 91.6% to 96% sequence similarity with members of the family Microbacteriaceae. Phylogentic trees generated by different algorithms indicated that the strain forms an independent phylogenetic line of descent that consistently clustered proximal to the base of the genus Leucobacter. Chemical studies revealed the presence of a cell-wall murein based on L-lysine (type B1α), major menaquinone (MK-10) and a DNA G+C content of 56.9 mol%. The distinct phylogenetic position, ribotyping and matrix-assisted laser desorption/ionization time-of-flight MS profiles and the significant phenotypic differences clearly separate strain IMMIB Q2029717T from its nearest phylogenetic neighbour and support its classification as a representative of a novel genus and species, with the suggested name Canibacter oris gen. nov., sp. nov. The type strain is IMMIB Q2029717T (=DSM 27064T=CCUG 64069T).


Assuntos
Actinomycetales/classificação , Mordeduras e Picadas/microbiologia , Cães , Filogenia , Actinomycetales/genética , Actinomycetales/isolamento & purificação , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Feminino , Humanos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Peptidoglicano/química , RNA Ribossômico 16S/genética , Ribotipagem , Análise de Sequência de DNA , Vitamina K 2/química
10.
Syst Appl Microbiol ; 35(7): 421-6, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23010576

RESUMO

A Gram-reaction-negative bacterium, strain IMMIB L-12475(T), was isolated from blood cultures of a human with septicaemia. The yellowish orange pigmented strain contained flexirubin pigment. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain IMMIB L-12475(T) belonged to the family Flavobacteriaceae, forming a distinct phyletic line that is distantly related (79.1-89.4% sequence similarity) to described genera of this family. Membership to the family was confirmed by a fatty acid profile consisting of branched-chain and 3-hydroxy fatty acids with major amounts of iso-C(17:0) 3-OH and iso-C(15:0), by the presence of menaquinone MK-6 as the only respiratory quinone and a polyamine pattern that contained sym-homospermidine as major component. The phospholipids consisted of phosphatidylethanolamine and an unknown phospholipid. The genomic DNA mol% G+C content was 45.6%. The distant phylogenetic position as compared to other representative of the family and the significant phenotypic properties such as pigment composition, morphology, and physiology support the proposal of a novel genus and species Cruoricaptor ignavus gen. nov., sp. nov. The type strain is IMMIB L-12475(T) (=DSM 25479(T)=CCUG 62025(T)).


Assuntos
Bacteriemia/microbiologia , Sangue/microbiologia , Infecções por Flavobacteriaceae/microbiologia , Flavobacteriaceae/classificação , Flavobacteriaceae/isolamento & purificação , Adulto , Técnicas de Tipagem Bacteriana , Composição de Bases , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Flavobacteriaceae/genética , Flavobacteriaceae/fisiologia , Humanos , Masculino , Dados de Sequência Molecular , Fosfolipídeos/análise , Filogenia , Pigmentos Biológicos/metabolismo , Poliaminas/análise , Quinonas/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
11.
Br J Biomed Sci ; 68(1): 1-4, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21473254

RESUMO

Pseudomonas aeruginosa is an important pathogen in humans, particularly in the context of nosocomial infection and infections of the cystic fibrosis (CF) lung. In order to provide clinicians with information about the likely effectiveness of specific antimicrobial treatment for P. aeruginosa infections, clinical laboratories employ in vitro antimicrobial susceptibility testing. Two commonly employed methods are the CLSI disc-diffusion and Etest methods. The purpose of this study is to compare the accuracy of susceptibility results generated by these two methods against agar dilution as the reference method. Susceptible or nonsusceptible (resistant and intermediate) results of the Etest and CLSI disc-diffusion methods are compared with CLSI agar dilution results for a large cohort of clinical cystic fibrosis (n = 71) and non-cystic fibrosis (n = 83) isolates using CLSI interpretive criteria. An unacceptable number of major and very major errors were observed for various antimicrobials tested against both CF and non-CF isolates when using the Etest and CLSI disc-diffusion methods. The potential for error in standard laboratory antimicrobial susceptibility testing should be considered by clinicians when being guided by the results of such tests in the prescription of antimicrobial agents for P. aeruginosa infection.


Assuntos
Anti-Infecciosos/farmacologia , Fibrose Cística/microbiologia , Testes de Sensibilidade Microbiana/métodos , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/isolamento & purificação , Valor Preditivo dos Testes , Estatística como Assunto
12.
J Hosp Infect ; 76(1): 60-5, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20451300

RESUMO

Multi-resistant Pseudomonas aeruginosa (MRPa) has been isolated from patients in a Western Australian teaching hospital with increasing frequency since first encountered in 2006. Between 2006 and 2008 the number of patients with MRPa increased from three to nine per annum, and their location shifted from intensive care to a high dependency unit. A novel water-saving device (aerator) in a staff hand basin was identified as a likely disseminator, with MRPa being isolated from biofilm in the basin's plumbing. The disposal of patient waste, surplus intravenous antibiotic infusions and solid items via hand basins were possible contributory factors. Genotyping of MRPa from patients in other hospitals showed distinct genotypic lineages. The third seasonal cluster persisted for longer, indicating adaption to environment. More effective environmental control of P. aeruginosa is urgently needed.


Assuntos
Antibacterianos/farmacologia , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana Múltipla , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Técnicas de Tipagem Bacteriana , Impressões Digitais de DNA , Genótipo , Hospitais de Ensino , Humanos , Pseudomonas aeruginosa/isolamento & purificação , Microbiologia da Água , Austrália Ocidental
13.
Epidemiol Infect ; 134(4): 768-79, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16436218

RESUMO

In order to identify subtyping methods able to contribute to the surveillance or investigation of Australian Campylobacter infection, six genotypic and three phenotypic subtyping methods were evaluated on a collection of 84 clinical isolates collected over a 30-month period from one region in Australia. The aim was to compare the logistics of various subtyping methods and examine their ability to assist in finding outbreaks or common sources of sporadic infection. The genotypic subtyping methods used were sequencing of the short variable region of the flaA gene, two methods using restriction fragment length polymorphism (RFLP) of the flaA gene using either DdeI or EcoRI with PstI, automated ribotyping, pulsed field gel electrophoresis and multilocus sequence typing. The phenotypic methods employed included Laboratory of Enteric Pathogens serotyping, Lior biotyping and antibiotic resistotyping. The level of agreement between subtyping results was determined. Phenotypic methods showed little agreement whereas genotypic typing methods showed a high level of agreement. Using the premise that five of the six genotypic typing methods were in agreement 15 genotypic groupings were identified. Sequencing of the short variable region of the flaA gene, RFLP of the flaA gene or automated ribotyping in conjunction with multilocus sequence typing best identified genotypic groupings. An alternative combination of RFLP of the flaA gene followed by ribotyping was equally satisfactory. RFLP of the flaA gene appeared to be suitable as a preliminary typing method based on ease of operation, equipment availability and cost.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Infecções por Campylobacter/epidemiologia , Campylobacter/classificação , Austrália/epidemiologia , Campylobacter/genética , Campylobacter/isolamento & purificação , Surtos de Doenças , Eletroforese em Gel de Campo Pulsado , Genótipo , Humanos , Fenótipo , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Ribotipagem , Sensibilidade e Especificidade , Sorotipagem
14.
Epidemiol Infect ; 132(5): 813-20, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15473143

RESUMO

An environmental surveillance programme was developed to determine whether water supplies could be a source of Burkholderia pseudomallei as noted during previous melioidosis outbreak investigations. Water supplies to communities in the three northern Australian jurisdictions (Western Australia, Northern Territory and Queensland) were sampled periodically during 2001 and 2002. Water and soil samples were collected from communities known to have had recent culture-positive melioidosis cases and nearby communities where no cases had been diagnosed. Clinical isolates of B. pseudomallei obtained from northern Australian patients during 2001 and 2002 were compared with the environmental B. pseudomallei isolates by ribotyping and pulsed-field gel electrophoresis. B. pseudomallei was isolated from 11 distinct locations, all in the Northern Territory, seven of which were associated with culture-positive melioidosis cases (>1 case at three locations). Water was implicated as a possible environmental source of melioidosis in six locations. A variety of free-living amoebae including Acanthamoeba and Hartmannella spp. that are potential hosts to B. pseudomallei were recovered from environmental specimens. Culturable B. pseudomallei was not found to be widely dispersed in the environments sampled.


Assuntos
Burkholderia pseudomallei/isolamento & purificação , Monitoramento Ambiental/métodos , Melioidose/epidemiologia , Melioidose/prevenção & controle , Microbiologia do Solo , Microbiologia da Água , Animais , Austrália/epidemiologia , Burkholderia pseudomallei/genética , DNA Bacteriano/análise , Cães , Eletroforese em Gel de Campo Pulsado , Monitoramento Epidemiológico , Cabras , Humanos , Melioidose/etiologia , Ribotipagem , Solo , Suínos , Abastecimento de Água
15.
Antimicrob Agents Chemother ; 48(8): 2999-3005, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15273112

RESUMO

The effect of the two antibiotics ceftazidime and meropenem on a collection of 46 Burkholderia pseudomallei isolates representing clinical and environmental sources across northern Australia was investigated by using a series of in vitro test methods. The susceptibility testing methods used included Kirby-Bauer disk diffusion, Etest MIC, broth microdilution MIC, and a modification of the microdilution method in which Acanthamoeba cells were added to simulate the effect of a professional phagocytic cell on test outcome. In a semiquantitative validation coculture series, the majority of bacteria were intracellular up to a multiplicity of infection of 10 bacteria to one ameba. The optical density and bacterial count (log10 CFU/ml) correlated across the range tested (r2 = 0.77; P < 0.0001). Susceptibility test results were compared against clinical outcomes. The MICs of ceftazidime were consistently higher than those of meropenem by all three methods. The MICs of both agents were significantly higher when Acanthamoeba trophozoites were added to the broth microdilution method. Conventional and intracellular MIC results were consistent for clinical isolates from the Western Australian outbreak cluster despite the wide variety of clinical outcomes. Further development of the intracellular MIC method is expected to help assess the efficacy of antimicrobial agents on this bacterial species in an intracellular setting.


Assuntos
Burkholderia pseudomallei/efeitos dos fármacos , Ceftazidima/farmacologia , Cefalosporinas/farmacologia , Tienamicinas/farmacologia , Acanthamoeba/microbiologia , Animais , Ceftazidima/uso terapêutico , Cefalosporinas/uso terapêutico , Surtos de Doenças , Humanos , Técnicas de Diluição do Indicador , Indicadores e Reagentes , Melioidose/tratamento farmacológico , Melioidose/microbiologia , Meropeném , Testes de Sensibilidade Microbiana , Reprodutibilidade dos Testes , Tienamicinas/uso terapêutico , Resultado do Tratamento , Austrália Ocidental
16.
Epidemiol Infect ; 131(1): 637-45, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12948362

RESUMO

A cluster of three cases of listeriosis cases occurred against a background of endemic listeriosis in Western Australia. Human and environmental isolates of Listeria monocytogenes obtained during the outbreak investigation were rapidly subtyped by automated ribotyping using an EcoRI protocol and a RiboPrinter. DNA macrorestriction analysis by pulsed-field gel electrophoresis (PFGE) was used to confirm the relatedness of isolates. Serogroup 1/2 predominated among the food samples and the four clinical isolates from the outbreak cluster were also of this serogroup. All isolates from chicken material were serogroup 1/2 and indistinguishable by ribotype pattern. PFGE subdivided strains of this ribotype into four subtypes. The preliminary analysis had an immediate impact on hypothesis generation, environmental health investigations, environmental specimen collection and initial control measures. Sufficient typing data to guide environmental health and disease control initiatives was generated in less than one week by combining automated ribotyping with PCR-based detection of L. monocytogenes in suspect foodstuffs and an L. monocytogenes DNA probe. There were no further cases of bacteriologically confirmed listeriosis in Western Australia for six months after completion of the investigation.


Assuntos
DNA Bacteriano/análise , Surtos de Doenças , Listeria monocytogenes/genética , Listeria monocytogenes/patogenicidade , Listeriose/epidemiologia , Listeriose/genética , Automação , Eletroforese em Gel de Campo Pulsado , Saúde Ambiental , Contaminação de Alimentos , Humanos , Controle de Infecções , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Ribotipagem , Austrália Ocidental/epidemiologia
17.
J Clin Microbiol ; 41(7): 3312-6, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12843080

RESUMO

Isolation of Burkholderia pseudomallei currently relies on the use of Ashdown's selective agar (ASA). We designed a new selective agar (Burkholderia pseudomallei selective agar [BPSA]) to improve recovery of the more easily inhibited strains of B. pseudomallei. B. pseudomallei, Burkholderia cepacia, and Pseudomonas aeruginosa were used to determine the selectivity and sensitivity of BPSA. BPSA was more inhibitory to P. aeruginosa and B. cepacia and should make recognition of Burkholderia species easier due to distinctive colony morphology. BPSA also inhibited Enterococcus, Escherichia, Staphylococcus, and Streptococcus: These results indicate that BPSA is a potential replacement for ASA.


Assuntos
Burkholderia pseudomallei/crescimento & desenvolvimento , Burkholderia pseudomallei/isolamento & purificação , Melioidose/microbiologia , Ágar , Técnicas Bacteriológicas , Meios de Cultura , Humanos
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