Laboratory for Medical Microbiology and Public Health

Enschede, Netherlands

Laboratory for Medical Microbiology and Public Health

Enschede, Netherlands

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Parwati I.,Padjadjaran University | Alisjahbana B.,Padjadjaran University | Apriani L.,Padjadjaran University | Ottenhoff T.H.,Leiden University | And 4 more authors.
Journal of Infectious Diseases | Year: 2010

Animal studies have shown that the globally emerging Beijing genotype strains of Mycobacterium tuberculosis are more virulent than other strains. We examined whether Beijing strains increase treatment failure in a prospective cohort study in Indonesia. Among 818 tuberculosis cases, positive sputum culture results after 6 months of treatment were more common among patients infected with Beijing strains (33.4%) than among those infected with non-Beijing strains (relative risk, 1.94 [95% confidence interval, 1.26-3.00]), even after adjustment for differences in drug resistance. These data suggest that M. tuberculosis Beijing genotype strains have a higher capacity to withstand tuberculosis treatment, even in the absence of drug resistance. © 2010 by the Infectious Diseases Society of America. All rights reserved.


Al-Hajoj S.A.M.,King Faisal Specialist Hospital And Research Center | Akkerman O.,Spectrum | Parwati I.,Padjadjaran University | Al-Gamdi S.,Hera General Hospital | And 5 more authors.
Journal of Clinical Microbiology | Year: 2010

Five Mycobacterium tuberculosis isolates were obtained from three body sites from a Dutch patient. The isolates displayed a single genotype by 24-locus MIRU-VNTR typing (except for a single locus not amplified from one isolate) but were differentiated by small variations in IS6110 fingerprints, spoligotypes, 6 hypervariable MIRU-VNTR loci, and/or DiversiLab profiles, revealing patterns of microevolution in a clonal infection. Copyright © 2010, American Society for Microbiology. All Rights Reserved.


De Beer J.L.,National Institute for Public Health and the Environment RIVM | Akkerman O.W.,University of Groningen | Schurch A.C.,National Institute for Public Health and the Environment RIVM | Schurch A.C.,Radboud University Nijmegen | And 8 more authors.
Journal of Clinical Microbiology | Year: 2014

Variable-number tandem-repeat (VNTR) typing with a panel of 24 loci is the current gold standard in the molecular typing of Mycobacterium tuberculosis complex isolates. However, because of technical problems, a part of the loci often cannot be amplified by multiplex PCRs. Therefore, a considerable number of single-locus PCRs have to be performed for the loci with missing results, which impairs the laboratory work flow. Therefore, the original in-house method described by Supply et al. in 2006 was reevaluated. We modified seven primers and the PCR master mixture and obtained a strongly optimized in-house 24-locus VNTR typing method. The percentage of instantly complete 24-locus VNTR patterns detected in the routine flow of typing activities increased to 84.7% from the 72.3% obtained with the typing conducted with the commercially available Genoscreen MIRU-VNTR typing kit. The analytical sensitivity of the optimized in-house method was assessed by serial dilutions of M. tuberculosis in bronchoalveolar lavage fluid. A 1:10 dilution of the different strains tested was the lowest dilution for the detection of a complete 24-locus VNTR pattern. The optimized in-house 24-locus VNTR typing method will reduce the turnaround time of typing significantly and also the financial burden of these activities. © 2014, American Society for Microbiology. All Rights Reserved.


Halaby T.,Laboratory for Medical Microbiology and Public Health | Naiemi N.A.,Laboratory for Medical Microbiology and Public Health | Naiemi N.A.,VU University Amsterdam | Kluytmans J.,VU University Amsterdam | And 4 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2013

Selective decontamination of the digestive tract (SDD) selectively eradicates aerobic Gram-negative bacteria (AGNB) by the enteral administration of oral nonabsorbable antimicrobial agents, i.e., colistin and tobramycin. We retrospectively investigated the impact of SDD, applied for 5 years as part of an infection control program for the control of an outbreak with extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae in an intensive care unit (ICU), on resistance among AGNB. Colistin MICs were determined on stored ESBL-producing K. pneumoniae isolates using the Etest. The occurrence of both tobramycin resistance among pathogens intrinsically resistant to colistin (CIR) and bacteremia caused by ESBL-producing K. pneumoniae and CIR were investigated. Of the 134 retested ESBL-producing K. pneumoniae isolates, 28 were isolated before SDD was started, and all had MICs of <1.5 mg/liter. For the remaining 106 isolated after starting SDD, MICs ranged between 0.5 and 24 mg/liter. Tobramycin-resistant CIR isolates were found sporadically before the introduction of SDD, but their prevalence increased immediately afterward. Segmented regression analysis showed a highly significant relationship between SDD and resistance to tobramycin. Five patients were identified with bacteremia caused by ESBL-producing K. pneumoniae before SDD and 9 patients thereafter. No bacteremia caused by CIR was found before SDD, but its occurrence increased to 26 after the introduction of SDD. In conclusion, colistin resistance among ESBL-producing K. pneumoniae isolates emerged rapidly after SDD. In addition, both the occurrence and the proportion of tobramycin resistance among CIR increased under the use of SDD. SDD should not be applied in outbreak settings when resistant bacteria are prevalent. Copyright © 2013, American Society for Microbiology.


Huijskens E.G.W.,St Elisabeth Hospital | Huijskens E.G.W.,Albert Schweitzer Hospital | Rossen J.W.A.,University of Groningen | Kluytmans J.A.J.W.,St Elisabeth Hospital | And 5 more authors.
Influenza and other Respiratory Viruses | Year: 2014

Background: For the detection of respiratory pathogens, the sampling strategy may influence the diagnostic yield. Ideally, samples from the lower respiratory tract are collected, but they are difficult to obtain. Objectives: In this study, we compared the diagnostic yield in sputum and oropharyngeal samples (OPS) for the detection of respiratory pathogens in patients with community-acquired pneumonia (CAP), with the objective to optimize our diagnostic testing algorithm. Methods: Matched sputum samples, OPS, blood cultures, serum, and urine samples were taken from patients (>18 years) with CAP and tested for the presence of possible respiratory pathogens using bacterial cultures, PCR for 17 viruses and five bacteria and urinary antigen testing. Results: When using only conventional methods, that is, blood cultures, sputum culture, urinary antigen tests, a pathogen was detected in 49·6% of patients (n = 57). Adding molecular detection assays increased the yield to 80%. A pathogen was detected in 77 of the 115 patients in OPS or sputum samples by PCR. The sensitivity of the OPS was lower than that of the sputum samples (57% versus 74%). In particular, bacterial pathogens were more often detected in sputum samples. The sensitivity of OPS for the detection of most viruses was higher than in sputum samples (72% versus 66%), except for human rhinovirus and respiratory syncytial virus. Conclusion: Addition of PCR on both OPS and sputum samples significantly increased the diagnostic yield. For molecular detection of bacterial pathogens, a sputum sample is imperative, but for detection of most viral pathogens, an OPS is sufficient. © 2013 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.


Boersma M.N.,ZGT Hospital | Van Der Zanden A.,Laboratory for Medical Microbiology and Public Health | Laverman G.D.,ZGT Hospital | Sanders J.S.,University of Groningen | De Vries P.A.M.,ZGT Hospital
Transplant International | Year: 2012

A 43-year-old female developed an Epstein-Barr virus (EBV)-positive post-transplant lymphoproliferative disorder (PTLD) in the central nervous system (CNS), 14 years after renal transplantation. One year prior to presentation, the patients' treatment regimen was altered from cyclosporine, azathioprine, and prednisone to mycophenolate mofetil and prednisone. Magnetic resonance imaging of the brain revealed lesions suspect for malignant lymphoma. The EBV real-time polymerase chain reaction (PCR) on peripheral blood was negative, but highly positive on cerebrospinal fluid. EBV-positive PTLD was confirmed using histological analysis of cerebral biopsies. Despite tapering of immune suppressive medication and treatment with rituximab and chemotherapy, the patient deceased 50 days after presentation. This case illustrates that vigilance is required when presented with a negative EBV PCR result on peripheral blood when PTLD of the CNS is suspected. This late presentation suggests a relation to the switch in immunosuppressive regimen 1 year earlier. © 2012 The Authors. Transplant International © 2012 European Society for Organ Transplantation.


Hartwig N.G.,Erasmus MC Sophia Childrens Hospital | Warris A.,Radboud University Nijmegen | Van De Vosse E.,Leiden University | Van Der Zanden A.G.M.,Laboratory for Medical Microbiology and Public Health | And 3 more authors.
Journal of Clinical Microbiology | Year: 2011

"Mycobacterium tilburgii" is a nontuberculous mycobacterium that cannot be cultured by current techniques. It is described as causing disseminated disease in adults. We present the first cases of disseminated disease in 2 immunocompromised children. This paper stresses the importance of molecular techniques for correct mycobacterial identification and guidance to immunological diagnosis. Copyright © 2011, American Society for Microbiology. All Rights Reserved.


Bruijnesteijn van Coppenraet L.E.S.,Laboratory for Medical Microbiology and Infectious Diseases | Dullaert-de Boer M.,Laboratory for Medical Microbiology and Public Health | Ruijs G.J.H.M.,Laboratory for Medical Microbiology and Infectious Diseases | van der Reijden W.A.,Regional Laboratory for Medical Microbiology and Public Health | And 3 more authors.
Clinical Microbiology and Infection | Year: 2015

The introduction of molecular detection of infectious organisms has led to increased numbers of positive findings, as observed for pathogens causing gastroenteritis (GE). However, because little is known about the prevalence of these pathogens in the healthy asymptomatic population, the clinical value of these additional findings is unclear. A case-control study was carried out in a population of patients served by general practitioners in the Netherlands. A total of 2710 fecal samples from case and matched control subjects were subjected to multiplex real-time PCR for the 11 most common bacterial and four protozoal causes of GE. Of 1515 case samples, 818 (54%) were positive for one or more target organisms. A total of 49% of the controls were positive. Higher positivity rates in cases compared to controls were observed for Campylobacter spp., Salmonella spp., Clostridium difficile, enteroinvasive Escherichia coli/. Shigella spp., enterotoxigenic E.coli, enteroaggregative E.coli, atypical enteropathogenic E.coli (EPEC), Cryptosporidium parvum/hominis, and Giardia lamblia. However, Dientamoeba fragilis and Shiga-like toxigenic E.coli were detected significantly less frequent in cases than in controls, while no difference in prevalence was found for typical EPEC and enterohemorrhagic E.coli. The association between the presence of microorganisms and GE was the weakest in children aged 0 to 5 years. Higher relative loads in cases further support causality. This was seen for Campylobacter spp., Salmonella spp., enterotoxigenic E.coli, and C.parvum/hominis, and for certain age categories of those infected with C.difficile, enteroaggregative E.coli, and atypical EPEC. For D.fragilis and Shiga-like toxigenic E.coli/enterohemorrhagic E.coli, pathogen loads were lower in cases. Application of molecular diagnostics in GE is rapid, sensitive and specific, but results should be interpreted with care, using clinical and additional background information. © 2015 The Authors.


Reuland E.A.,VU University Amsterdam | al Naiemi N.,VU University Amsterdam | al Naiemi N.,Laboratory for Medical Microbiology and Public Health | Raadsen S.A.,VU University Amsterdam | And 4 more authors.
European Journal of Clinical Microbiology and Infectious Diseases | Year: 2014

To determine whether extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) are present in retail raw vegetables in Amsterdam, the Netherlands, we collected 119 samples of 15 different types of vegetables from various sources. After culture, strain identification and susceptibility testing, ESBL-encoding genes were characterised by a microarray. Four of the 15 vegetable types were contaminated with ESBL-E. Seven samples (6 %) yielded ESBL-E. Three blaCTX-M-15, one blaCTX-M-1, two genes of the CTX-M-9 group and one SHV ESBL-encoding gene were found. The ESBL genes were similar to what is found in enterobacterial strains from human origin. Therefore, raw vegetables might be a source of resistance genes for the enterobacterial strains found in humans. © 2014, The Author(s).


Reuland E.A.,VU University Amsterdam | Overdevest I.T.M.A.,Amphia Hospital | Overdevest I.T.M.A.,St Elisabeth Hospital | al Naiemi N.,VU University Amsterdam | And 11 more authors.
Clinical Microbiology and Infection | Year: 2013

Clin Microbiol Infect The aim of this study was to determine the rate of carriage of ESBL-producing Enterobacteriaceae (ESBL-E) in the community in the Netherlands and to gain understanding of the epidemiology of these resistant strains. Faecal samples from 720 consecutive patients presenting to their general practitioner, obtained in May 2010, and between December 2010 and January 2011, were analysed for presence of ESBL-E. Species identification and antibiotic susceptibility testing were performed according to the Dutch national guidelines. PCR, sequencing and microarray were used to characterize the genes encoding for ESBL. Strain typing was performed with amplified fragment length polymorphism (AFLP) and multilocus sequence typing (MLST). Seventy-three of 720 (10.1%) samples yielded ESBL-producing organisms, predominantly E. coli. No carbapenemases were detected. The most frequent ESBL was CTX-M-15 (34/73, 47%). Co-resistance to gentamicin, ciprofloxacin and cotrimoxazole was found in (9/73) 12% of the ESBL-E strains. AFLP did not show any clusters, and MLST revealed that CTX-M-15-producing E. coli belonged to various clonal complexes. Clonal complex ST10 was predominant. This study showed a high prevalence of ESBL-producing Enterobacteriaceae in Dutch primary care patients with presumed gastrointestinal discomfort. Hence, also in the Netherlands, a country with a low rate of consumption of antibiotics in humans, resistance due to the expansion of CTX-M ESBLs, in particular CTX-M-15, is emerging. The majority of ESBL-producing strains do not appear to be related to the international clonal complex ST131. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.

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