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1.
J Hosp Infect ; 150: 26-33, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38782059

RESUMO

BACKGROUND: Serratia marcescens is known to cause outbreaks in neonatal intensive care units (NICUs). Traditionally epidemiological data, antimicrobial resistance patterns and epidemiological typing have been used to guide infection prevention methods. Whole-genome sequencing (WGS) applications such as core-genome multi-locus sequence typing (cgMLST) applied during an outbreak would potentially yield more information. AIM: To use cgMLST to acquire detailed information on the source and spread of bacteria, enabling more efficient control measures during an S. marcescens outbreak at a NICU. METHODS: Neonates admitted to the NICU of the Leiden University Medical Center (LUMC) during an outbreak between September 2023 and January 2024, with S. marcescens being cultured, were included. Environmental samples were taken to search for a common source, antibiotic susceptibility testing was performed, and antimicrobial resistance genes were analysed. FINDINGS: S. marcescens strains from 17 of the 20 positive patients were available for molecular typing. The cgMLST scheme revealed five different complex types consisting of four separate clusters. Multiple clusters made an unidentified persistent environmental source as cause of the outbreak less likely, leading to a quick downscaling of infection prevention measures. Differences were shown in aminoglycoside resistance patterns of isolates within the same complex types and patients. CONCLUSION: The use of ad-hoc cgMLST provided timely data for rational decision-making during an S. marcescens outbreak at the NICU. Antibiotic phenotyping alone was found not to be suitable for studying clonal spread during this outbreak with S. marcescens.

2.
J Hosp Infect ; 141: 3-8, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37611696

RESUMO

BACKGROUND: It was shown previously that changing the design of a hospital neonatal intensive care unit (NICU) from open bay units (OBUs) to single room units (SRUs) was not associated with a reduction in Gram-negative multi-drug-resistant organism (MDRO) colonization rates. It was therefore hypothesized that colonization mainly occurs vertically, or through parents and healthcare workers, and not through environmental factors, and that transition to SRUs would not decrease the number of clusters of MDROs with an epidemiological link. To investigate this, core-genome multi-locus sequence typing (cgMLST) was applied on MDROs cultured from infants at the study hospital. METHODS: This retrospective cohort study included all infants carrying MDROs admitted to the NICU of a tertiary care academic hospital 2 years prior to the transition from OBUs to SRUs in May 2017, and 1.5 years after the transition (2018-2020). RESULTS: In total, 55 infants were diagnosed with MDRO carriership. Isolates were available from 49 infants for cgMLST. In the OBU period, one cluster involving four of 20 (20%) infants was identified, and in the SRU period, four clusters involving nine of 29 (31%) infants were identified. It was possible to make an epidemiological link in all four SRU MDRO clusters, but this was not possible for the OBU cluster. In the latter case, transmission from an environmental source on the ward seemed likely. CONCLUSION: After transition to SRUs, there was no decrease in the number of clusters of MDROs with an epidemiological link, suggesting that nursing infants in an NICU with an SRU design is not, in itself, protective against the acquisition of MDROs.


Assuntos
Gammaproteobacteria , Unidades de Terapia Intensiva Neonatal , Recém-Nascido , Lactente , Humanos , Estudos Retrospectivos , Tipagem de Sequências Multilocus , Bactérias Gram-Negativas , Enterococcus , Hospitais
3.
J Clin Virol ; 160: 105376, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36640531

RESUMO

BACKGROUND: Viral load (VL) determination in patients with human immunodeficiency virus type 1 (HIV-1), hepatitis B virus (HBV) and hepatitis C virus (HCV) is essential for proper patient management and follow-up. New molecular platforms have been developed to fully automate these diagnostic assays. OBJECTIVE: Evaluation of the clinical performance of HIV-1, HBV and HCV VL assays on the Alinity m (Abbott) and NeuMoDx (Qiagen) molecular platforms. METHOD: Test panels of the three viruses have been compiled of 100 plasma and/or serum samples per target containing non-detectable, non-quantifiable and quantifiable VLs. All samples were retrospectively tested on the Alinity m and NeuMoDx platforms according to manufacturers' instructions. RESULTS: A total of 74, 86 and 66 samples with valid results for both platforms were included in the HIV-1, HBV and HCV analysis respectively. Overall qualitative agreement of the assays on both platforms was 78% for HIV-1, 93% for HBV and 100% for HCV. Quantitative agreement (less than 0.5 log difference) was shown to be 68% for HIV-1, 68% for HBV and 94% for HCV. CONCLUSION: The Alinity m and NeuMoDx HCV assay have a comparable performance. Quantification differences in the HIV-1 assay were mostly apparent in the lower VLs and under-quantification of the NeuMoDx HBV assay was observed.


Assuntos
Infecções por HIV , HIV-1 , Hepatite B , Hepatite C , Humanos , Vírus da Hepatite B , Carga Viral/métodos , Estudos Retrospectivos , Hepatite C/diagnóstico , Hepacivirus , Infecções por HIV/diagnóstico , Hepatite B/diagnóstico , Sensibilidade e Especificidade
4.
J Clin Virol ; 149: 105122, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35299100

RESUMO

BACKGROUND: The detection and follow up of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) viral loads (VL) are crucial in the management of immunocompromised patients. Recently, molecular CE-IVD assays for detection and quantification of CMV and EBV have been launched for use on the random-access and sample-to-result NeuMoDx 96 and 288 platforms (Qiagen). OBJECTIVE: Evaluating the qualitative and quantitative performance of the NeuMoDx CMV and EBV assays in clinical specimens compared to a lab developed tests (LDT) and the CE-IVD assays on the Abbott m2000 system. METHOD: Both a prospective and a retrospective panel, compiled of non-detectable (ND), non-quantifiable (NQ) and quantifiable VLs in plasma samples have been evaluated for both CMV and EBV: NeuMoDx versus LDT and NeuMoDx versus Abbott m2000. Quantitative agreement was determined for samples with a quantifiable VL on both systems. RESULTS: Qualitative and quantitative agreement between the NeuMoDx and LUMC's LDT CMV assays was 88%. Qualitative agreement between the NeuMoDx and Abbott m2000 CMV assays was 92% and quantitative agreement was 87%. Qualitative and quantitative agreement between the NeuMoDx and the LDT EBV assays was 87%. Qualitative agreement between the NeuMoDx and Abbott m2000 EBV assays was 91% and quantitative agreement was 0%. CONCLUSION: These data show that the NeuMoDx assays are suitable for both detection and quantification of CMV and EBV in a medium- to high throughput diagnostic setting, but that differences in sensitivity and quantification (for EBV, NeuMoDx versus Abbott m2000) warrant an extensive transition period when using the respective assays for following VL in patient samples.


Assuntos
Infecções por Citomegalovirus , Infecções por Vírus Epstein-Barr , Citomegalovirus/genética , Infecções por Citomegalovirus/diagnóstico , DNA Viral , Infecções por Vírus Epstein-Barr/diagnóstico , Herpesvirus Humano 4/genética , Humanos , Estudos Prospectivos , Estudos Retrospectivos , Carga Viral
5.
Int J Antimicrob Agents ; 52(3): 407-410, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29772393

RESUMO

Pseudomonas aeruginosa is one of the most important causes of infection in intensive care units (ICUs). It is intrinsically resistant to many antimicrobials and easily acquires additional resistance genes via horizontal gene transfer of mobile genetic elements. In this study, 1528 P. aeruginosa isolates obtained from a Dutch national surveillance programme between the years 1998-2011 were analysed for the presence of extended-spectrum ß-lactamase (ESBL) genes (blaCTX-M, blaSHV, blaTEM, blaBEL, blaPER, blaVEB and blaOXA-10) and metallo-ß-lactamase (MBL) genes (blaIMP, blaVIM and blaNDM). Of the ceftazidime-resistant isolates, 6.2% tested phenotypically positive for ESBL. Moreover, a Verona integron-encoded MBL (VIM) gene was found in 3.1% of isolates that were phenotypically resistant to imipenem and/or meropenem. Multilocus sequence typing (MLST) of ESBL-positive isolates indicated ST1216, ST111 and ST622, with all blaVIM-positive isolates belonging to the ST111 clone. Although the prevalence of ESBL and MBL phenotypes in this Dutch national surveillance collection of >1500 ICU P. aeruginosa isolates was very low, all VIM-producing isolates belonged to the high risk-associated, international, clonal complex CC111, and most ESBL-producing isolates belonged to clonal complexes known for their successful spread, e.g. CC111 and CC235. These data indicate that high-risk clones of P. aeruginosa were present in the Netherlands between 1998-2011 and probably spread unnoticed throughout Dutch hospitals.


Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Infecções por Pseudomonas/epidemiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , beta-Lactamases/genética , Antibacterianos/farmacologia , Ceftazidima/farmacologia , Infecção Hospitalar/microbiologia , Transferência Genética Horizontal , Humanos , Imipenem/farmacologia , Unidades de Terapia Intensiva , Meropeném/farmacologia , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Países Baixos/epidemiologia , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/genética
7.
J Microbiol Methods ; 106: 19-22, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25119380

RESUMO

A variety of molecular typing techniques have been developed to investigate the clonal relationship among bacterial isolates, including those associated with nosocomial infections. In this study, the authors evaluated whole-genome mapping as a tool to investigate the genetic relatedness between Pseudomonas aeruginosa isolates, including metallo beta-lactamase-positive outbreak isolates.


Assuntos
Genoma Bacteriano , Tipagem Molecular/métodos , Pseudomonas aeruginosa/classificação , Pseudomonas aeruginosa/genética , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Genótipo , Humanos , Epidemiologia Molecular/métodos , Infecções por Pseudomonas/epidemiologia , Infecções por Pseudomonas/microbiologia
8.
Dis Aquat Organ ; 108(3): 201-9, 2014 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-24695233

RESUMO

Vibrio vulnificus is a potentially zoonotic bacterial pathogen of fish, which can infect humans (causing necrotic fasciitis). We analysed 24 V. vulnificus isolates (from 23 severe eel disease outbreaks in 8 Dutch eel farms during 1996 to 2009, and 1 clinical strain from an eel farmer) for genetic correlation and zoonotic potential. Strains were typed using biotyping and molecular typing by high-throughput multilocus sequence typing (hiMLST) and REP-PCR (Diversilab®). We identified 19 strains of biotype 1 and 5 of biotype 2 (4 from eels, 1 from the eel farmer), that were subdivided into 8 MLST types (ST) according to the international standard method. This is the first report of V. vulnificus biotype 1 outbreaks in Dutch eel farms. Seven of the 8 STs, of unknown zoonotic potential, were newly identified and were deposited in the MLST database. The REP-PCR and the MLST were highly concordant, indicating that the REP-PCR is a useful alternative for MLST. The strains isolated from the farmer and his eels were ST 112, a known potential zoonotic strain. Antimicrobial resistance to cefoxitin was found in most of the V. vulnificus strains, and an increasing resistance to quinolones, trimethoprim + sulphonamide and tetracycline was found over time in strain ST 140. Virulence testing of isolates from diseased eels is recommended, and medical practitioners should be informed about the potential risk of zoonotic infections by V. vulnificus from eels for the prevention of infection especially among high-risk individuals. Additional use of molecular typing methods such as hiMLST and Diversilab® is recommended for epidemiological purposes during V. vulnificus outbreaks.


Assuntos
Anguilla , Surtos de Doenças/veterinária , Doenças dos Peixes/microbiologia , Vibrioses/veterinária , Vibrio vulnificus/genética , Animais , Antibacterianos/farmacologia , Aquicultura , Farmacorresistência Bacteriana , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/patologia , Variação Genética , Países Baixos/epidemiologia , Vibrioses/epidemiologia , Vibrioses/microbiologia , Vibrioses/patologia , Vibrio vulnificus/isolamento & purificação
9.
Eur J Clin Microbiol Infect Dis ; 33(2): 279-84, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24019162

RESUMO

Generally accepted laboratory methods that have been used for decades do not reliably distinguish between H. influenzae and H. haemolyticus isolates. H. haemolyticus strains are often incorrectly identified as nontypeable Haemophilus influenzae (NTHi). To distinguish H. influenzae from H. haemolyticus we have created a new database on the matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) bio-typer 2 and compared the results with routine determination of Haemophilus (growth requirement for X and V factor), and multilocus sequence typing (MLST). In total we have tested 277 isolates, 244 H. influenzae and 33 H. haemolyticus. Using MLST as the gold standard, the agreement of MALDI-TOF MS was 99.6 %. MALDI-TOF MS allows reliable and rapid discrimination between H. influenzae and H. haemolyticus.


Assuntos
Técnicas Bacteriológicas/métodos , Haemophilus/química , Haemophilus/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Infecções por Haemophilus/diagnóstico , Humanos
10.
Eur J Clin Microbiol Infect Dis ; 32(8): 1017-22, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23430195

RESUMO

Legionnaires' disease (LD) is an acute pneumonia caused by the inhalation or aspiration of aerosols contaminated with Legionella bacteria. The watery environment is considered to be the natural habitat for these bacteria. Therefore, drinking water legislation is used in the primary prevention of LD, focussing on the different water sources to which the general public is exposed. For 10 years, secondary prevention of LD in the Netherlands has been organised using an outbreak detection programme that eliminates potential sources of infection that LD patients have been exposed to during their incubation period. To evaluate the two prevention strategies, we compared the distribution of Legionella pneumophila serogroup 1 genotypes isolated from patient material (n = 179) with the distribution resulting from primary (n = 182) and secondary (n = 60) prevention actions, respectively. The sequence type profiles were generated using the HiMLST method that employs next generation sequencing. We found that genotypes collected during primary prevention differ to a large extent from those isolated from patients. Genotypes collected during secondary prevention efforts had a greater similarity to that of patient isolates, but could be further improved. Our results suggest that primary prevention is not aiming at the correct reservoir, whereas secondary prevention is only partially focussed. It seems that there is a still unknown reservoir.


Assuntos
Surtos de Doenças/prevenção & controle , Legionella pneumophila/genética , Doença dos Legionários/microbiologia , Doença dos Legionários/prevenção & controle , Distribuição de Qui-Quadrado , Reservatórios de Doenças/estatística & dados numéricos , Microbiologia Ambiental , Genótipo , Humanos , Legionella pneumophila/classificação , Legionella pneumophila/isolamento & purificação , Doença dos Legionários/epidemiologia , Países Baixos/epidemiologia
11.
Burns ; 37(5): 808-13, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21334826

RESUMO

Here we report an outbreak among 17 patients caused by a single strain of a multiresistant methicillin-susceptible Staphylococcus aureus (MR-MSSA) in a burn centre. The MR-MSSA strains were resistant to penicillin, ciprofloxacin, erythromycin, clindamycin and co-trimoxazole. Further analysis showed an increased prevalence of MR-MSSA carriership in S. aureus colonized patients admitted to the burn centre, from 0% in 2005 (0/118), 3.3% in 2006 (4/121), 6.1% in 2007 (6/99), to 7.8% in 2008 (7/90). Molecular typing with amplified fragment length polymorphism showed that all MR-MSSA isolates derived from burn centre patients had a unique genotype, and was different compared to isolates derived from other hospital patients. All healthcare workers (HCWs) who worked in the burn centre during the outbreak were screened for nasal carriage with MR-MSSA. One HCW tested positive for a genotype of MR-MSSA that was indistinguishable from the genotype found in samples of the burned patients. No new cases of MR-MSSA colonization or infection were identified after the colonized HCW stopped working at the burn centre. The routine practice of molecular typing of collected S. aureus strains from both patients and HCWs will help to detect nosocomial spread in a burn centre, and opens the possibility of a rapid, almost pre-emptive response.


Assuntos
Surtos de Doenças , Resistência a Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/genética , Infecções Estafilocócicas/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Unidades de Queimados , Criança , Pré-Escolar , DNA Bacteriano/análise , Feminino , Genótipo , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Prevalência , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Adulto Jovem
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