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Jan Kluytmans

Publications and source records attributed to Jan Kluytmans.

13 recordsLinked to original sources
PubMed2007

Appropriateness of antimicrobial therapy measured by repeated prevalence surveys.

Prudent use of antibiotics is mandatory to control antibiotic resistance. The objective of this study was to determine if prevalence surveys are useful tools to determine the appropriateness of antimicrobial therapy (AMT) and determinants of inappropriate AMT. The study was performed in a 1,350-bed teaching hospital including all medical specialties. Six consecutive 1-day prevalence surveys of in-patients were performed twice yearly from 2001 to 2004. Data on the demographics, infections, and AMT were gathered. The appropriateness of AMT was assessed according to a standardized algorithm based on the local AMT prescription guidelines. On average, 684 patients were included in each survey (total, 4,105). The use of AMT as determined in the prevalence survey corresponded to the annual data from the pharmacy department. Nine hundred thirty-eight (22.9%) of the patients received AMT, and in 351 (37.4%) of these patients AMT was inappropriate. Only 25 (0.6%) patients did not receive AMT, although it was indicated. After multivariate analysis, the use of quinolones was the only statistically significant variable associated with inappropriate use. Prevalence surveys proved to be useful tools to judge the appropriateness of AMT and to identify determinants of inappropriate use. This study shows that in a setting with a low use of AMT, there are few patients who inadvertently do not receive AMT. On the other hand, a substantial number of the patients are treated inappropriate.

Adult↗
PubMed2005

Loss of the mecA gene during storage of methicillin-resistant Staphylococcus aureus strains.

The mecA gene was lost in 36 (14.4%) of 250 methicillin-resistant Staphylococcus aureus isolates after 2 years of storage at -80 degrees C with the Microbank system (Pro-lab Diagnostics, Austin, Tex.). Further analysis of 35 of these isolates confirmed loss of the mecA gene in 32 isolates. This finding has important implications for the management of strain collections.

Bacterial Proteins↗
PubMed2005

Performance of CHROMagar MRSA medium for detection of methicillin-resistant Staphylococcus aureus.

CHROMagar MRSA was evaluated for its ability to identify methicillin-resistant Staphylococcus aureus (MRSA). A well-defined collection consisting of 216 MRSA strains and 241 methicillin-susceptible Staphylococcus aureus isolates was used. The sensitivity of CHROMagar MRSA after 24 h of incubation was 95.4%, increasing to 100% after 48 h. The specificity was already 100% after 24 h.

Chromogenic Compounds↗
PubMed2004

Is the perceived association between Chlamydia pneumoniae and vascular diseases biased by methodology?

Inter- and intralaboratory inconsistencies in detection rates of Chlamydia pneumoniae in vascular specimens have been demonstrated. In this study, 66 vascular tissue specimens from 66 patients with vascular disease were tested by three PCR assays: a 16S PCR-based reverse line blot (RLB) assay, a single-step PCR, and a nested PCR. Also, we explored the impacts of different DNA polymerase enzymes on the results based on gel electrophoresis and hybridization. The PCR results by gel electrophoresis in the single-step PCR depended on which DNA polymerase was used. All samples were negative with AmpliTaq Gold DNA polymerase, and 54.5% (36 of 66) were positive with the conventional Taq DNA polymerase. All samples were negative after hybridization with a C. pneumoniae-specific probe. In the nested PCR, all specimens were negative by gel electrophoresis and after hybridization. The RLB assay failed to detect C. pneumoniae in any specimen; however, 20 specimens were Chlamydia sp. positive. The sequence analysis of six of these samples demonstrated Chlamydia-like organisms. RLB detected Chlamydia sp. DNA in water and in the elution buffer after passage of the Qiagen columns (11 of 40). This study identified factors that may influence the detection of C. pneumoniae DNA in vascular tissues and consequently bias the perception of a link between C. pneumoniae and vascular diseases. The following are strongly recommended: to use DNA polymerases that have to be activated, to decontaminate with dUTP-uracil-DNA glycosylase, to hybridize with specific probes, to include sufficient controls, and to use molecular grade water.

Base Sequence↗
PubMed2003

High percentage of methicillin-resistant Staphylococcus aureus isolates with reduced susceptibility to glycopeptides in The Netherlands.

While testing the in vitro activities of 14 antimicrobial agents against 107 methicillin-susceptible Staphylococcus aureus (MSSA) and 250 methicillin-resistant S. aureus (MRSA) isolates collected in The Netherlands, we found to our surprise that 19 (7.6%) MRSA isolates were suspected of having reduced susceptibilities to the glycopeptides when the Etest system (AB Biodisk, Solna, Sweden) was used with a large inoculum (no. 2 McFarland standard) and an extended incubation time (48 h) on brain heart infusion agar for MIC testing. Eventually, 15 of these isolates were classified as heterogeneously resistant to glycopeptides (heterogeneously glycopeptide-intermediate S. aureus [hGISA] isolates) according to the population analysis profile-area under the curve analysis. The MICs at which 50 and 90% of isolates are inhibited obtained with the Etest system with the large inoculum were as follows: for MSSA isolates, 3.0 and 4.0 micro g/ml, respectively, for both teicoplanin and vancomycin; for MRSA isolates, 3.0 and 8.0 micro g/ml, respectively, for teicoplanin, and 3.0 and 4.0 micro g/ml, respectively, for vancomycin. This is the first report of hGISA isolates in The Netherlands.

Acetamides↗
PubMed2002

Intercenter reproducibility of binary typing for Staphylococcus aureus.

The reproducibility of the binary typing (BT) protocol developed for epidemiological typing of Staphylococcus aureus was analyzed in a biphasic multicenter study. In a Dutch multicenter pilot study, 10 genetically unique isolates of methicillin-resistant S. aureus (MRSA) were characterized by the BT assay as presented by van Leeuwen et al. [J. Clin. Microbiol. 2001 39 (1) 328]. The BT assay, including a standardized DNA extraction protocol was performed in duplicate in eleven medical microbiology laboratories. Two different hybridization detection procedures were applied and a prelabeled DNA sample as process control was included. Only three laboratories accurately identified all strains. Divergence in technical procedures resulted in misinterpretation due to an increasing number of faint or absent hybridization signals in combination with high background staining. The binary type of the process control was determined correctly by all participating laboratories. The feasibility of the BT protocol was related directly to the skill of the laboratory personnel. On the basis of the national study, we concluded that the DNA extraction protocol needed modification to improve DNA yield and purity. Subsequently, seven European laboratories participated in an international study to determine the reproducibility of the modified BT protocol. Each center was asked to analyze 10 DNA samples previously extracted from 10 MRSA strains (phase 1) and, additionally, to analyze 10 MRSA strains, using the standardized or their in-house DNA isolation protocol (phase 2). A prelabeled DNA process control sample was included again. The binary types of all DNA samples were identified correctly by all but one laboratories. This latter laboratory diverged from the protocol by adding an excess of labeled DNA to the hybridization mixture, resulting in a high background and, therefore, noninterpretable BT results. All centers produced identical BT results for the process control. Five of the seven centers correctly identified the binary types of all 10 MRSA strains in phase 2 of the international study. Three of these centers used their in-house DNA extraction protocol. Divergence from the standard BT protocol in the remaining two centers resulted in no interpretable BT data for the 10 MRSA strains. The study demonstrated that each center that followed the BT protocol to the letter could generate reproducible results, irrespective whether or not an in-house DNA isolation protocol was used. The current BT protocol thus represents a simple method generating robust, reproducible genotype data for S. aureus strains.

Bacterial Typing Techniques↗
PubMed2002

Prevention of postsurgical infections: some like it hot.

PURPOSE OF THE REVIEW: The present review covers the literature on prevention of surgical site infections published during 2001. Only papers that offer new insights or question current recommendations are included. RECENT FINDINGS: The most interesting advances have been made in the preoperative preparation of the patient. In particular, the effects of preoperative warming of the patient, either generally or locally at the incision site, on the rate of surgical site infections are impressive and warrant further investigation. Also, the effects of strict control of perioperative blood glucose levels and of preoperative eradication of nasal carriage of Staphylococcus aureus should be studied in greater detail. SUMMARY: The protective effect of local and systemic warming before surgical procedures has been described in two well designed studies. Although a final judgement regarding effectiveness can only be made after more extensive investigations have been conducted, there appear to be few arguments against application of this cheap and safe measure. Thus, implementation of preoperative warming can be justified in settings associated with high rates of surgical site infections.

Humans↗
PubMed2002

Performance of CHROMagar selective medium and oxacillin resistance screening agar base for identifying Staphylococcus aureus and detecting methicillin resistance.

Two new selective media, oxacillin resistance screening agar base (ORSAB) and CHROMagar Staph aureus (CSA), were evaluated for identification of Staphylococcus aureus and for screening of methicillin resistance by addition of antimicrobial agents to these media. A well-defined collection consisting of 1,140 staphylococci was used. A total of 624 were S. aureus, of which 358 were methicillin susceptible and 266 were methicillin resistant, and 516 were coagulase-negative staphylococci. The methicillin-resistant S. aureus (MRSA) strains were selected based on the results of phage typing; 247 different types were included in the analysis. For identification of S. aureus, both media performed better after 24 h than after 48 h. The sensitivities at 24 h were comparable (CSA, 98.6%; ORSAB, 97.1%), but the specificity of CSA was significantly higher (CSA, 97.1%; ORSAB, 92.1%). For screening of methicillin resistance, antibiotic supplements were added to both media. The sensitivity was lower after 24 h (CSA, 58.6%; ORSAB, 84.2%) and increased significantly after 48 h (CSA, 77.5%; ORSAB, 91.4%). At both time intervals ORSAB was significantly more sensitive than CSA. However, the specificities of both media were high after 24 h (CSA, 99.1%; ORSAB, 98.3%) and decreased significantly after 48 h of incubation (CSA, 94.7%; ORSAB, 95.5%). In conclusion, for identification of S. aureus, CSA is more accurate than ORSAB because of a significantly higher specificity. For screening of MRSA, ORSAB performs better than CSA, but the usefulness in clinical practice is limited because a significant number of strains are not detected.

Agar↗
PubMed1997

Two clones of methicillin-resistant Staphylococcus aureus in Poland.

OBJECTIVE: To evaluate relatedness among methicillin-resistant Staphylococcus aureus (MRSA) strains isolated in Poland. METHODS: Ninety-three MRSA hospital isolates were collected from different regions in Poland from 1990 to 1992. Strains were analyzed with respect to heterogeneity of methicillin resistance, phage types, resistance patterns, crystal violet staining, chromosomal DNA SmaI restriction patterns by PFGE, ERIC1 and ERIC2 AP-PCR types and DNA repeat polymorphism within the protein A gene. Resistance to methicillin was confirmed by the detection of the mecA gene by PCR. RESULTS: The combined results of typing methods demonstrate that all MRSA strains analyzed could be easily divided into two distinct clones (clonally related strains). The first consisted of strains with clear heterogeneous expression of resistance to methicillin (34 isolates) and the second showed more homogeneous resistance (59 isolates). In this study the best method for epidemiologic analysis of MRSA was found to be PFGE. A good correlation between the epidemic behavior of MRSA and a high number of repetitive DNA units within the protein A gene was observed. CONCLUSIONS: Results show that in Poland two distinct clones of epidemic MRSA have circulated in the past, easily discriminated by pheno- and genotyping methods, and both could be found together in a single hospital.

Journal Article↗
PubMedDate not supplied

The burden of Staphylococcus aureus infections on hospitals in the United States: an analysis of the 2000 and 2001 Nationwide Inpatient Sample Database.

BACKGROUND: Previous studies have investigated the impact of Staphylococcus aureus infections on individual hospitals, but to date, no study using nationally representative data has estimated this burden. METHODS: This is a retrospective analysis of the 2000 and 2001 editions of the Agency for Healthcare Research and Quality's Nationwide Inpatient Sample database, which represents a stratified 20% sample of hospitals in the United States. All inpatient discharge data from 994 hospitals in 28 states during 2000 and from 986 hospitals in 33 states during 2001, representing approximately 14 million inpatient stays, were analyzed to determine the association of S aureus infections with length of stay, total charges, and in-hospital mortality. RESULTS: Staphylococcus aureus infection was reported as a discharge diagnosis for 0.8% of all hospital inpatients, or 292 045 stays per year. Inpatients with S aureus infection had, on average, 3 times the length of hospital stay (14.3 vs 4.5 days; P<.001), 3 times the total charges (48,824 US dollars vs 14,141 US dollars; P<.001), and 5 times the risk of in-hospital death (11.2% vs 2.3%; P<.001) than inpatients without this infection. Even when controlling for hospital fixed effects and for patient differences in diagnosis-related groups, age, sex, race, and comorbidities, the differences in mean length of stay, total charges, and mortality were significantly higher for hospitalizations associated with S aureus. CONCLUSIONS: Staphylococcus aureus infections represent a considerable burden to US hospitals, particularly among high-risk patient populations. The potential benefits to hospitals in terms of reduced use of resources and costs as well as improved outcomes from preventing S aureus infections are significant.

Age Factors↗