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1.
Antimicrob Agents Chemother ; 60(12): 7313-7320, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27671073

RESUMO

The distinct epidemiology of original hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) and early community-associated MRSA (CA-MRSA) is largely unexplained. S. aureus carries either five or six rRNA operon copies. Evidence is provided for a scenario in which MRSA has adapted to the hospital environment by rRNA operon loss (six to five copies) due to antibiotic pressure. Early CA-MRSA, in contrast, results from wild-type methicillin-susceptible S. aureus (MSSA) that acquired mecA without loss of an rRNA operon. Of the HA-MRSA isolates (n = 77), 67.5% had five rRNA operon copies, compared to 23.2% of the CA-MRSA isolates (n = 69) and 7.7% of MSSA isolates (n = 195) (P < 0.001). In addition, 105 MSSA isolates from cystic fibrosis patients were tested, because these patients are repeatedly treated with antibiotics; 32.4% of these isolates had five rRNA operon copies. For all subsets, a correlation between resistance profile and rRNA copy number was found. Furthermore, we showed that in vitro antibiotic pressure may result in rRNA operon copy loss. We also showed that without antibiotic pressure, S. aureus isolates containing six rRNA copies are more fit than isolates with five copies. We conclude that HA-MRSA and cystic fibrosis isolates most likely have adapted to an environment with high antibiotic pressure by the loss of an rRNA operon copy. This loss has facilitated resistance development, which promoted survival in these niches. However, strain fitness decreased, which explains their lack of success in the community. In contrast, CA-MRSA isolates retained six rRNA operon copies, rendering them fitter and thereby able to survive and spread in the community.


Assuntos
Infecções Comunitárias Adquiridas/epidemiologia , Infecção Hospitalar/epidemiologia , Staphylococcus aureus Resistente à Meticilina/genética , RNA Bacteriano/genética , Infecções Estafilocócicas/epidemiologia , Óperon de RNAr/genética , Antibacterianos/uso terapêutico , Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana , Infecções Comunitárias Adquiridas/microbiologia , Infecção Hospitalar/microbiologia , Fibrose Cística/microbiologia , Genoma Bacteriano/genética , Humanos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Proteínas de Ligação às Penicilinas/genética , Polimorfismo Genético/genética , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia
2.
Appl Environ Microbiol ; 81(1): 124-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25326300

RESUMO

After the first isolation of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in 2003, this MRSA variant quickly became the predominant MRSA obtained from humans as part of the Dutch national MRSA surveillance. Previous studies have suggested that human-to-human transmission of LA-MRSA, compared to that of other MRSA lineages, rarely occurs. However, these reports describe the transmission of LA-MRSA based on epidemiology and limited molecular characterization of isolates, making it difficult to assess whether transmission actually occurred. In this study, we used whole-genome maps (WGMs) to identify possible transmission of LA-MRSA between humans. For this, we used LA-MRSA isolates originating from a 2-year prospective longitudinal cohort study in which livestock veterinarians and their household members were repeatedly sampled for the presence of S. aureus. A considerable degree of genotypic variation among LA-MRSA strains was observed. However, there was very limited variability between the maps of the isolates originating from the same veterinarian, indicating that each of the veterinarians persistently carried or had reacquired the same LA-MRSA strain. Comparison of WGMs revealed that LA-MRSA transmission had likely occurred within virtually every veterinarian household. Yet only a single LA-MRSA strain per household appeared to be involved in transmission. The results corroborate our previous finding that LA-MRSA is genetically diverse. Furthermore, this study shows that transmission of LA-MRSA between humans occurs and that carriage of LA-MRSA can be persistent, thus posing a potential risk for spread of this highly resistant pathogen in the community.


Assuntos
Características da Família , Saúde da Família , Gado , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/transmissão , Infecções Estafilocócicas/veterinária , Médicos Veterinários , Animais , Portador Sadio/epidemiologia , Genoma Bacteriano , Humanos , Estudos Longitudinais , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/genética , Epidemiologia Molecular , Tipagem Molecular , Países Baixos , Estudos Prospectivos , Zoonoses/epidemiologia , Zoonoses/transmissão
3.
Eur J Clin Microbiol Infect Dis ; 34(1): 115-122, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25079513

RESUMO

The diagnosis of invasive pneumococcal pneumonia is based mainly on bacteraemia. Episodes without bacteraemia, but with a positive urinary antigen test (UAT), are considered non-invasive. We determined differences in outcome between patients with bacteraemic and non-bacteraemic/UAT-positive pneumococcal community-acquired pneumonia (CAP). Adult patients with clinical and radiological evidence of CAP with blood cultures and UAT tests performed at presentation in three Dutch laboratories between June 2008 and May 2010 were included. Clinical characteristics were retrospectively extracted from hospital records. Overall, 168 patients had non-bacteraemic/UAT-positive pneumococcal CAP and 123 had bacteraemic pneumococcal CAP. The day-30 mortality was 9% and 13% for non-bacteraemic/UAT-positive and bacteraemic pneumococcal CAP patients, respectively [risk difference -4%, 95% confidence interval (CI) -11% to +3%, p = 0.28]. In a multivariable logistic regression model, age ≥ 65 years, admission to the intensive care unit/coronary care unit (ICU/CCU) and presence of an immunocompromising condition were associated with day-30 mortality. A non-significant association with mortality was found for bacteraemia [odds ratio (OR) 2.21, 95% CI 0.94-5.21, p = 0.07). No such trend was found for UAT positivity. The median lengths of hospital stay were 8 [interquartile range (IQR) 5-14] and 10 (IQR 6-18) days for non-bacteraemic/UAT-positive and bacteraemic pneumococcal CAP patients, respectively (p = 0.05). As compared to non-bacteraemic/UAT-positive pneumococcal CAP, bacteraemic pneumococcal CAP has a stronger association with day-30 mortality.


Assuntos
Antígenos de Bactérias/urina , Infecções Comunitárias Adquiridas/patologia , Pneumonia Pneumocócica/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bacteriemia/microbiologia , Bacteriemia/mortalidade , Bacteriemia/patologia , Infecções Comunitárias Adquiridas/microbiologia , Feminino , Humanos , Masculino , Pneumonia Pneumocócica/complicações , Pneumonia Pneumocócica/mortalidade , Estudos Retrospectivos , Análise de Sobrevida , Adulto Jovem
4.
Epidemiol Infect ; 142(9): 1996-9, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24229845

RESUMO

Analysis of the Dutch national invasive pneumococcal disease (IPD) surveillance data by sex reveals an increase in the incidence of serotype-1 disease in young female adults in The Netherlands after the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in the national immunization schedule. This has led to an overall increase in IPD in women aged 20-45 years, which was not observed in men of the same age. No other differences in serotype shifts possibly induced by the introduction of PCV7 were observed between the sexes in this age group. Serotype 1 is a naturally fluctuating serotype in Europe and it has been associated with disease in young healthy adults before. It remains uncertain whether or not there is an association between the observed increase in serotype-1 disease in young female adults and the implementation of PCV7 in The Netherlands.


Assuntos
Infecções Pneumocócicas/microbiologia , Streptococcus pneumoniae/classificação , Adulto , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Infecções Pneumocócicas/epidemiologia , Sorotipagem , Adulto Jovem
5.
Euro Surveill ; 19(49)2014 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-25523972

RESUMO

Staphylococcus aureus is one of the most important human pathogens and meticillin-resistant S. aureus (MRSA) presents a major cause of healthcare- and community-acquired infections. This study investigated the spatial and temporal changes of S. aureus causing bacteraemia in Europe over a five-year interval and explored the possibility of integrating pathogen-based typing data with epidemiological and clinical information at a European level. Between January 2011 and July 2011, 350 laboratories serving 453 hospitals in 25 countries collected 3,753 isolates (meticillin-sensitive S. aureus (MSSA) and MRSA) from patients with S. aureus bloodstream infections. All isolates were sent to the national staphylococcal reference laboratories and characterised by quality-controlled spa typing. Data were uploaded to an interactive web-based mapping tool. A wide geographical distribution of spa types was found, with some prevalent in all European countries. MSSA was more diverse than MRSA. MRSA differed considerably between countries with major international clones expanding or receding when compared to a 2006 survey. We provide evidence that a network approach of decentralised typing and visualisation of aggregated data using an interactive mapping tool can provide important information on the dynamics of S. aureus populations such as early signalling of emerging strains, cross-border spread and importation by travel.


Assuntos
Infecções Estafilocócicas/microbiologia , Proteína Estafilocócica A/genética , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Coleta de Dados , Europa (Continente) , Feminino , Variação Genética , Genótipo , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Infecções Estafilocócicas/sangue , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação
6.
Euro Surveill ; 18(4): 20385, 2013 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-23369388

RESUMO

Genotyping of important medical or veterinary prokaryotes has become a very important tool during the last decades. Rapid development of fragment-separation and sequencing technologies has made many new genotyping strategies possible. Among these new methods is multilocus variable-number tandem repeat analysis (MLVA). Here we present an update on the use of MLVA in eight European countries (Denmark, France, Germany, Ireland, Italy, the Netherlands, Norway and Sweden). Researchers in Europe have been active in developing and implementing a large array of different assays. MLVA has been used as a typing tool in several contexts, from aiding in resolving outbreaks of foodborne bacteria to typing organisms that may pose a bioterrorist threat, as well as in scientific studies.


Assuntos
Variação Genética , Bactérias Gram-Negativas/genética , Bactérias Gram-Positivas/genética , Repetições Minissatélites , Tipagem de Sequências Multilocus , Análise por Conglomerados , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Europa (Continente) , Genótipo , Bactérias Gram-Negativas/classificação , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Positivas/classificação , Bactérias Gram-Positivas/isolamento & purificação , Humanos , Filogenia , Análise de Sequência de DNA
7.
Clin Microbiol Infect ; 26(10): 1412.e7-1412.e12, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32006688

RESUMO

OBJECTIVES: Carbapenem resistance mediated by mobile genetic elements has emerged worldwide and has become a major public health threat. To gain insight into the molecular epidemiology of carbapenem resistance in The Netherlands, Dutch medical microbiology laboratories are requested to submit suspected carbapenemase-producing Enterobacterales (CPE) to the National Institute for Public Health and the Environment as part of a national surveillance system. METHODS: Meropenem MICs and species identification were confirmed by E-test and MALDI-TOF and carbapenemase production was assessed by the Carbapenem Inactivation Method. Of all submitted CPE, one species/carbapenemase gene combination per person per year was subjected to next-generation sequencing (NGS). RESULTS: In total, 1838 unique isolates were received between 2014 and 2018, of which 892 were unique CPE isolates with NGS data available. The predominant CPE species were Klebsiella pneumoniae (n = 388, 43%), Escherichia coli (n = 264, 30%) and Enterobacter cloacae complex (n = 116, 13%). Various carbapenemase alleles of the same carbapenemase gene resulted in different susceptibilities to meropenem and this effect varied between species. Analyses of NGS data showed variation of prevalence of carbapenemase alleles over time with blaOXA-48 being predominant (38%, 336/892), followed by blaNDM-1 (16%, 145/892). For the first time in the Netherlands, blaOXA-181, blaOXA-232 and blaVIM-4 were detected. The genetic background of K. pneumoniae and E. coli isolates was highly diverse. CONCLUSIONS: The CPE population in the Netherlands is diverse, suggesting multiple introductions. The predominant carbapenemase alleles are blaOXA-48 and blaNDM-1. There was a clear association between species, carbapenemase allele and susceptibility to meropenem.


Assuntos
Proteínas de Bactérias/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Infecções por Enterobacteriaceae/epidemiologia , beta-Lactamases/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacter cloacae/efeitos dos fármacos , Enterobacter cloacae/genética , Enterobacter cloacae/isolamento & purificação , Infecções por Enterobacteriaceae/tratamento farmacológico , Infecções por Enterobacteriaceae/microbiologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Humanos , Sequências Repetitivas Dispersas/genética , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Meropeném/farmacologia , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Países Baixos/epidemiologia , beta-Lactamases/metabolismo
8.
Eur J Clin Microbiol Infect Dis ; 28(1): 39-45, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18663501

RESUMO

This study investigates aspects of the general assumption that, in bacteria, genetic variation in functionally-constrained genomic regions accumulates at a lower rate than in regions of hypermutability such as DNA repeat loci. We compared whole genome polymorphism (using high-throughput amplified fragment length polymorphism [ht-AFLP]) as well as short sequence repeat length variation (using multi-locus variable number of tandem repeat analysis [MLVA]) for 994 Staphylococcus aureus strains isolated from both healthy carriers and invasive infections. MLVA and ht-AFLP minimum spanning trees (MSTs) were similar in their identification of totally different types of genetic variants. This suggests that, despite the enhanced inherent variability of repeats, clusters of strains remain traceable. Finally, no specific molecular marker of epidemicity or virulence was identified in this large strain collection by the MLVA approach. We demonstrate that there is a difference in the rates of cross-genome mutation versus regional repeat variability in the clonal bacterial pathogen S. aureus. Despite these dynamic differences, a conservation of type assignments as based upon these two inherently different typing techniques was observed.


Assuntos
Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Técnicas de Tipagem Bacteriana , Impressões Digitais de DNA , Repetições Minissatélites , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , Idoso , Portador Sadio/epidemiologia , Portador Sadio/microbiologia , Criança , Análise por Conglomerados , DNA Bacteriano/genética , Genótipo , Humanos , Epidemiologia Molecular/métodos , Polimorfismo Genético , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação
9.
Eur J Clin Microbiol Infect Dis ; 27(10): 985-92, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18493804

RESUMO

To improve the timeliness of health care delivery to patients with meningococcal disease, the early disease evolution and clinical manifestation at admission were studied in all 752 patients with invasive meningococcal disease in the Netherlands in 2003-2005. Eighty-eight percent (88%) had serogroup B disease. The case fatality rate (CFR) was 6.7% overall, but reached 16% among adults over 50 years of age. The CFR was similar for serogroups B (6.3%) and C (5.2%). Admission followed 17 h (median) after the onset of symptoms. The CFR in patients admitted within 12 h, 12-18 h, 18-36 h or >36 h after the first symptoms was 10.2, 7.8, 3.5 and 2.2%, respectively. Only 60% of patients had skin lesions, and admission followed 2 h (median) later. Earlier recognition can be achieved when non-petechial clues are included in the diagnosis. A short duration of disease before admission is a simple tool in the recognition of patients with severe disease.


Assuntos
Meningite Meningocócica/diagnóstico , Meningite Meningocócica/terapia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Estudos Epidemiológicos , Feminino , Hospitalização , Humanos , Lactente , Recém-Nascido , Masculino , Meningite Meningocócica/mortalidade , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Estudos Prospectivos , Fatores de Risco , Fatores de Tempo
10.
Ned Tijdschr Geneeskd ; 151(3): 172-6, 2007 Jan 20.
Artigo em Holandês | MEDLINE | ID: mdl-17288341

RESUMO

All infants in the Netherlands, which are born after March 2006, receive additional vaccinations at the age of 2, 3, 4 and 11 months to protect them against pneumococcal infections. During the same visit to a consultation bureau, the children also receive a combination vaccine against diphtheria, pertussis, tetanus, poliomyelitis and Haemophilus influenzae (DTPa-IPV-Hib). Children of which at least one parent was born in a country where hepatitis B occurs relatively often are also vaccinated in the Netherlands against hepatitis B. This currently pertains to about 15% of all newborns. These children now receive a new combination vaccine in which a hepatitis B component has been added to the DTPa-IPV-Hib components. They will receive this combination vaccine 4 times. This combination vaccine is given during the same visit as the pneumococcal vaccination. Although pneumococcal vaccination may have a somewhat negative effect on the immune response to hepatitis B, it is expected that the new 4-fold vaccination schedule will induce good and long-lasting protection against hepatitis B in the vast majority of the children. About 700 children are born out of mothers infected with hepatitis B each year in the Netherlands. In the new vaccination schedule, they now receive 5 active vaccinations against hepatitis B and are examined serologically on an individual basis in order to detect breakthrough infections. This will also generate greater insight into the efficacy of the different vaccination schemes and intervention programmes to prevent vertical transmission of the virus.


Assuntos
Vacinas contra Hepatite B , Programas de Imunização , Vacinas Pneumocócicas , Vacina contra Difteria, Tétano e Coqueluche/administração & dosagem , Vacina contra Difteria, Tétano e Coqueluche/imunologia , Feminino , Vacinas Anti-Haemophilus/administração & dosagem , Vacinas Anti-Haemophilus/imunologia , Vacinas contra Hepatite B/administração & dosagem , Vacinas contra Hepatite B/imunologia , Humanos , Esquemas de Imunização , Lactente , Masculino , Países Baixos , Vacinas Pneumocócicas/administração & dosagem , Vacinas Pneumocócicas/imunologia , Vacina Antipólio de Vírus Inativado/administração & dosagem , Vacina Antipólio de Vírus Inativado/imunologia , Vacinas Combinadas
11.
Ned Tijdschr Geneeskd ; 151(26): 1454-7, 2007 Jun 30.
Artigo em Holandês | MEDLINE | ID: mdl-17633974

RESUMO

Despite the availability of antibiotics and the care offered by intensive-care units, invasive pneumococcal disease still causes serious illness with high morbidity and mortality. Currently, two vaccines are available in the Netherlands that offer protection against invasive pneumococcal disease: a 7-valent conjugated vaccine and a 23-valent polysaccharide vaccine. Case reports and pharmaceutical use as registered by the Foundation for Pharmaceutical Statistics (SFK) show that general practitioners and pharmacists are not always aware of the appropriate use of both vaccines. For vaccination against pneumococci in children aged 0-5 years, general practitioners should prescribe only the conjugated vaccine. The non-conjugated polysaccharide vaccine is intended especially for the elderly and specific groups at risk. Pharmacists should verify that the pneumococcal vaccines they hand out on prescription are recommended for the age-group of the individuals to whom the vaccine will be administered.


Assuntos
Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/administração & dosagem , Fatores Etários , Idoso , Pré-Escolar , Feminino , Vacina Pneumocócica Conjugada Heptavalente , Humanos , Lactente , Masculino , Vacinas Meningocócicas/administração & dosagem , Vacinas Meningocócicas/efeitos adversos , Países Baixos , Vacinas Pneumocócicas/efeitos adversos , Fatores de Risco , Vacinas Conjugadas/administração & dosagem , Vacinas Conjugadas/efeitos adversos
12.
Clin Infect Dis ; 43(7): 884-91, 2006 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-16941370

RESUMO

BACKGROUND: The factors behind the reemergence of severe, invasive group A streptococcal (GAS) diseases are unclear, but it could be caused by altered genetic endowment in these organisms. However, data from previous studies assessing the association between single genetic factors and invasive disease are often conflicting, suggesting that other, as-yet unidentified factors are necessary for the development of this class of disease. METHODS: In this study, we used a targeted GAS virulence microarray containing 226 GAS genes to determine the virulence gene repertoires of 68 GAS isolates (42 associated with invasive disease and 28 associated with noninvasive disease) collected in a defined geographic location during a contiguous time period. We then employed 3 advanced machine learning methods (genetic algorithm neural network, support vector machines, and classification trees) to identify genes with an increased association with invasive disease. RESULTS: Virulence gene profiles of individual GAS isolates varied extensively among these geographically and temporally related strains. Using genetic algorithm neural network analysis, we identified 3 genes with a marginal overrepresentation in invasive disease isolates. Significantly, 2 of these genes, ssa and mf4, encoded superantigens but were only present in a restricted set of GAS M-types. The third gene, spa, was found in variable distributions in all M-types in the study. CONCLUSIONS: Our comprehensive analysis of GAS virulence profiles provides strong evidence for the incongruent relationships among any of the 226 genes represented on the array and the overall propensity of GAS to cause invasive disease, underscoring the pathogenic complexity of these diseases, as well as the importance of multiple bacteria and/or host factors.


Assuntos
Infecções Estreptocócicas/metabolismo , Streptococcus/patogenicidade , Fatores de Virulência/metabolismo , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Infecções Estreptocócicas/fisiopatologia , Streptococcus/genética , Streptococcus/isolamento & purificação , Virulência , Fatores de Virulência/genética
13.
J Hosp Infect ; 93(4): 366-74, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27105754

RESUMO

BACKGROUND: In The Netherlands, efforts to control meticillin-resistant Staphylococcus aureus (MRSA) in hospitals have been largely successful due to stringent screening of patients on admission and isolation of those that fall into defined risk categories. However, Dutch hospitals are not free of MRSA, and a considerable number of cases are found that do not belong to any of the risk categories. Some of these may be due to undetected nosocomial transmission, whereas others may be introduced from unknown reservoirs. AIM: Identifying multi-institutional clusters of MRSA isolates to estimate the contribution of potential unobserved reservoirs in The Netherlands. METHODS: We applied a clustering algorithm that combines time, place, and genetics to routine data available for all MRSA isolates submitted to the Dutch Staphylococcal Reference Laboratory between 2008 and 2011 in order to map the geo-temporal distribution of MRSA clonal lineages in The Netherlands. FINDINGS: Of the 2966 isolates lacking obvious risk factors, 579 were part of geo-temporal clusters, whereas 2387 were classified as MRSA of unknown origin (MUOs). We also observed marked differences in the proportion of isolates that belonged to geo-temporal clusters between specific multi-locus variable number of tandem repeat analysis (MLVA) clonal complexes, indicating lineage-specific transmissibility. The majority of clustered isolates (74%) were present in multi-institutional clusters. CONCLUSION: The frequency of MRSA of unknown origin among patients lacking obvious risk factors is an indication of a largely undefined extra-institutional but genetically highly diverse reservoir. Efforts to understand the emergence and spread of high-risk clones require the pooling of routine epidemiological information and typing data into central databases.


Assuntos
Infecção Hospitalar/epidemiologia , Infecção Hospitalar/transmissão , Transmissão de Doença Infecciosa , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Tipagem Molecular , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/transmissão , Análise por Conglomerados , Infecção Hospitalar/microbiologia , Monitoramento Epidemiológico , Variação Genética , Humanos , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/genética , Epidemiologia Molecular , Países Baixos/epidemiologia , Análise Espaço-Temporal , Infecções Estafilocócicas/microbiologia , Inquéritos e Questionários
14.
Clin Microbiol Infect ; 22(1): 60.e1-60.e8, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26344334

RESUMO

To compare the genetic population structure of Staphylococcus aureus from China and Europe, 1294 human isolates were characterized by multiple-locus variable number tandem repeat analysis (MLVA). In total, MLVA identified 17 MLVA complexes (MCs), comprising 260 MLVA types (MTs) among the Chinese isolates and 372 MTs among the European isolates. The five most frequent MCs among the Chinese isolates belonged to MC398, MC5 subclade a, MC8, MC437 and MC7 and made up 55% of the sample. For the European isolates, the five most frequent MCs consisted of MC5 subclade a, MC45, MC8, MC30 and MC22, which accounted for 64% of the sample. Phylogeographic analysis of the major MCs shared between China and Europe points to a European origin of MC8 but cannot provide a consistent signal for MC5 subclade a, probably indicating a different origin. Diversity and frequency distributions of other lineages were also compared. Altogether, this study provides the first snapshot of two extant populations of S. aureus from Europe and China, and important clues on the emergence and dissemination of different lineages of S. aureus.


Assuntos
Genótipo , Repetições Minissatélites , Tipagem Molecular , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , China/epidemiologia , Transmissão de Doença Infecciosa , Europa (Continente)/epidemiologia , Humanos , Epidemiologia Molecular , Filogeografia , Infecções Estafilocócicas/transmissão , Staphylococcus aureus/isolamento & purificação
15.
Clin Microbiol Infect ; 11(3): 226-31, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15715721

RESUMO

A nationwide laboratory-based surveillance study of invasive group A streptococcal (GAS) infections was conducted in The Netherlands from May 1994 until December 2003 (average population during this period was 15 729 704). Microbiologically invasive isolates were obtained from 1504 patients, with most (70%) isolates cultured from blood. There was a clear seasonal pattern in invasive streptococcal infections, with an estimated annual incidence that peaked in 1996 (4.0 cases/100 000 individuals/year) and was at its lowest in 1999 (2.0 cases/100 000 individuals/year). Twenty-eight different M-types were identified, of which the most frequent were M1 (339/1504, 23%), M3 (187/1504, 12%), M89 (174/1504, 12%), M28 (164/1504, 11%), M12 (109/1504, 7%) and M6 (55/1504, 4%). There was a high degree of variation in the relative annual contributions of the predominant M-types, but variations in M1 and M3 combined correlated with overall changes in the annual incidence. The contribution of the patient group aged > or = 56 years to all cases of invasive GAS disease increased during the study period, whereas that of the group aged 0-20 years decreased. A peak in the incidence of invasive GAS disease among the patient group aged 30-34 years did not vary during the study period, indicating that the high incidence of invasive GAS disease in this age group was age-specific rather than cohort-related.


Assuntos
Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/isolamento & purificação , Adolescente , Adulto , Fatores Etários , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Vigilância da População , Fatores de Tempo
16.
Res Microbiol ; 149(8): 577-83, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9795995

RESUMO

A procedure in which the "Invitrogen Easy-DNA" kit was followed by a silica-based method for the isolation of DNA was developed for extraction of PCR-inhibitor-free DNA from up to 300 mg of human vessel wall tissue. Optimally designed PCR assays were developed for the detection of at least one infected cell in this amount of tissue. Details of the procedure are given for the detection of DNA of Chlamydia pneumoniae, cytomegalovirus and herpes simplex virus type 1 and type 2 in human vessel walls. The procedure can serve as a reference method or as a gold standard when a high-performance method is needed.


Assuntos
Aorta Abdominal/microbiologia , Chlamydophila pneumoniae/isolamento & purificação , Herpesviridae/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Aorta Abdominal/virologia , Chlamydophila pneumoniae/genética , Citomegalovirus/genética , Citomegalovirus/isolamento & purificação , Primers do DNA , DNA Bacteriano/isolamento & purificação , DNA Viral/isolamento & purificação , Herpesviridae/genética , Herpesvirus Humano 1/genética , Herpesvirus Humano 1/isolamento & purificação , Herpesvirus Humano 2/genética , Herpesvirus Humano 2/isolamento & purificação , Humanos , Sondas de Oligonucleotídeos
17.
Res Microbiol ; 143(6): 641-7, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1475524

RESUMO

The detailed characterization of various proteins from spirochetes using molecular biology techniques has made possible new approaches to vaccine and diagnostic development that are described in this session. The importance of animal models was emphasized and illustrated.


Assuntos
Vacinas Bacterianas/uso terapêutico , Grupo Borrelia Burgdorferi/imunologia , Doença de Lyme/prevenção & controle , Animais , Vacinas Bacterianas/imunologia , Modelos Animais de Doenças , Cães , Doença de Lyme/diagnóstico , Camundongos , Sífilis/prevenção & controle , Sorodiagnóstico da Sífilis , Treponema pallidum/imunologia
18.
FEMS Microbiol Lett ; 119(1-2): 19-25, 1994 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-8039659

RESUMO

Because of the allelic variations within the M protein gene (emm gene) of group A streptococci, reliable typing of this important human pathogen can be accomplished by the use of emm gene-specific oligonucleotide probes. Two technical modifications (a reverse dot blot and a reverse line blot hybridization assay) of a novel approach for the type-specific identification of emm genes have been developed. Both procedures involved amplification of an emm gene by polymerase chain reaction. The non-radioactively labeled amplicon was subsequently hybridized to a membrane carrying an array of immobilized emm gene-specific oligonucleotide probes, thus allowing the simultaneous analysis of the gene polymorphism in a single hybridization reaction. The feasibility of these rapid and easy to perform methods was shown for the unequivocal identification of reference strains and clinical isolates belonging to 16 different M serotypes.


Assuntos
Antígenos de Bactérias , Proteínas da Membrana Bacteriana Externa , Técnicas de Tipagem Bacteriana , Proteínas de Transporte , Sondas de Oligonucleotídeos , Reação em Cadeia da Polimerase , Streptococcus pyogenes/classificação , Alelos , Proteínas de Bactérias/genética , Sequência de Bases , Dados de Sequência Molecular , Streptococcus pyogenes/genética
19.
J Med Microbiol ; 49(1): 55-62, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10628826

RESUMO

A collection of 297 clinically documented 'Streptococcus milleri' strains, identified to the genotype level by 16S rRNA gene hydridisation, was screened for haemolysis of human and animal red blood cells. Forty-nine strains (65%) of the S. intermedius genotype displayed haemolysis restricted to human blood; they were named 'exclusive human haemolytic' (EHH) S. intermedius strains. The 26 remaining S. intermedius strains were named S. intermedius non-EHH strains. Quantitative studies on the haemolysis indicated that intermedilysin was the factor involved. The S. intermedius EHH strains represented the S. intermedius phenotype, whereas the S. intermedius non-EHH strains were phenotypically characteristic of S. constellatus. The complete 16S rRNA sequences of the S. intermedius EHH strains exhibited identity with S. intermedius strains ATCC 27335 (= NCDO 2227, NCTC 11324); the 16S rRNA sequences of the S. intermedius non-EHH strains were identical to S. constellatus strain ATCC 27823 (= NCDO 2226, NCTC 11325) except for positions 228 and 229 that carried an S. intermedius sequence signature. The 16S sequence similarities between the non-EHH strains and the S. constellatus and the S. intermedius type strains were 99.5% and 98.6%, respectively. Hybridisations of the complete 16S rRNA genes with oligonucleotide probes indicated a 16S rRNA homogeneity within the S. intermedius EHH and the non-EHH strains respectively. The S. intermedius EHH strains were isolated most frequently from infection- and abscess-related specimens. The present data emphasise the genetic variability within the S. constellatus species and redefine the S. intermedius species as a homogeneous group at the 16S rRNA level.


Assuntos
Hemólise , Streptococcus/patogenicidade , Animais , Bovinos , Feminino , Variação Genética , Genótipo , Cavalos , Humanos , Masculino , Fenótipo , Filogenia , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genética , Coelhos , Ovinos , Especificidade da Espécie , Streptococcus/classificação , Streptococcus/genética , Suínos
20.
Int J Tuberc Lung Dis ; 6(11): 959-65, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12475141

RESUMO

SETTING: Cetrangolo Hospital, Vicente Lopez, Argentina, 1995-1999. OBJECTIVE: To describe a home-made reverse-line blot hybridisation assay for the detection of rifampicin resistance-associated mutations in the rpoB gene of Mycobacterium tuberculosis, and to evaluate the usefulness of this rifampicin oligonucleotide, or 'RIFO' assay, to predict rifampicin resistance. DESIGN: A total of 135 M. tuberculosis isolates from the Cetrangolo Hospital were tested using the RIFO assay, the proportion method and the Mycobacterial Growth Indicator Tube (MGIT 960). In addition, 120 drug-susceptible isolates from the Netherlands were included. RESULTS: The results obtained with the proportion method and the MGIT 960 system were in full agreement. In the RIFO assay, 90 of the 97 rifampicin-resistant isolates were correctly identified (sensitivity 92.8%, positive predictive value 100%). All of the drug-susceptible isolates were correctly predicted by the RIFO assay. CONCLUSIONS: With this home-made molecular test, rifampicin resistance in M. tuberculosis can be predicted in colonies isolated in culture in only 1 day, and can therefore shorten the laboratory turn around time for rifampicin susceptibility testing by weeks. In principle the test can also be applied directly to Zichl-Neelsen slides and clinical material, as has been demonstrated for another reverse-line blot-based assay for M. tuberculosis, spoligotyping.


Assuntos
Antibióticos Antituberculose/uso terapêutico , RNA Polimerases Dirigidas por DNA/genética , Mycobacterium tuberculosis/isolamento & purificação , Hibridização de Ácido Nucleico/métodos , Rifampina/uso terapêutico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Tuberculose Pulmonar/microbiologia , DNA Bacteriano/análise , Humanos , Testes de Sensibilidade Microbiana/métodos , Mycobacterium tuberculosis/genética , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Pulmonar/tratamento farmacológico
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