Comparison of in-house and commercial real time-PCR based carbapenemase gene detection methods in Enterobacteriaceae and non-fermenting gram-negative bacterial isolates.

BACKGROUND: Carbapenemase-producing gram-negative bacteria are increasing globally and have been associated with outbreaks in hospital settings. Thus, the accurate detection of these bacteria in infections is mandatory for administering the adequate therapy and infection control measures. This study aimed to establish and evaluate a multiplex real-time PCR assay for the simultaneous detection of carbapenemase gene variants in gram-negative rods and to compare the performance with a commercial RT-PCR assay (Check-Direct CPE). METHODS: 116 carbapenem-resistant Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii isolates were genotyped for carbapenemase genes by PCR and sequencing. The defined isolates were used for the validation of the in-house RT-PCR by use of designed primer pairs and probes. RESULTS: Among the carbapenem-resistant isolates the genes bla KPC, bla VIM, bla NDM or bla OXA were detected. Both RT-PCR assays detected all bla KPC, bla VIM and bla NDM in the isolates. The in-house RT-PCR detected 53 of 67 (79.0%) whereas the commercial assay detected only 29 (43.3%) of the OXA genes. The in-house sufficiently distinguished the most prevalent OXA types (23-like and 48-like) in the melting curve analysis and direct detection of the genes from positive blood culture vials. CONCLUSION: The Check-Direct CPE and the in-house RT-PCR assay detected the carbapenem resistance from solid culture isolates. Moreover, the in-house assay enabled the identification of carbapenemase genes directly from positive blood-culture vials. However, we observed insufficient detection of various OXA genes in both assays. Nevertheless, the in-house RT-PCR detected the majority of the OXA type genes in Enterobacteriaceae and A. baumannii.

MALDI-TOF MS based carbapenemase detection from culture isolates and from positive blood culture vials.

BACKGROUND: Antibiotic resistance in bacteria leads to massive health problems. Incidence of carbapenem and multidrug resistance in Gram-negative bacteria are increasing globally and turn out to be a very urgent challenge in health care. Resistant bacteria play an important clinical role during hospital outbreaks as well as in sepsis. Rapid diagnostic tests are necessary to provide immediate information for antimicrobial treatment and infection control measures. METHODS: Our mass spectrometry-based assay was validated with 63 carbapenemase-producing Gram-negative bacterial isolates, and 35 carbapenem-resistant Gram-negative species with no carbapenemase production. These were analyzed from solid culture media and positive blood culture vials. After 4 h of incubation the carbapenemase products were analyzed with the MALDI-TOF MS. All the isolates were genotyped for carbapenemase genes by PCR and sequencing. RESULTS: For culture isolates the concordance of hydrolysis assay to genetic results was 98 % for OXA variants, KPC, VIM, IMP, GIM, and NDM. In contrast, only 14 of 29 Acinetobacter baumannii isolates carrying the OXA and NDM genes could be identified from blood culture. However, from blood culture vials our method allowed the detection of carbapenemases in 98 % of Pseudomonas and Enterobacteriaceae isolates harboring different genes. CONCLUSIONS: This MALDI-TOF MS-based assay permitted the detection of carbapenemases either from solid culture media (98-100 %) or blood culture vials (96 %) for all non-A. baumannii isolates within 4 h. In case of A. baumannii isolates the assay was highly sensitive for the detection of carbapenemases directly from solid culture media.

Enhanced International Prognostic Index (NCCN-IPI), Charlson Comorbidity Index and absolute lymphocyte count as predictors for survival of elderly patients with diffuse large B cell lymphoma treated by immunochemotherapy.

Diffuse large B cell lymphoma (DLBCL) affects more commonly patients over 60 years. These patients have vast number of comorbidities which can modify survival as well as other clinical parameters. The aim of this study was to evaluate prognostic significance of the National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI), absolute lymphocyte count (ALC), absolute monocyte count (AMC), lymphocyte-to-monocyte ratio (LMR) and comorbidities expressed with Charlson Comorbidity Index (CCI). A total of 182 DLBCL patients 60 years old and older were included, focusing on whole group and patients older than 70. All patients were treated with immunochemotherapy.Overall treatment response was achieved in 84.6% of patients. The NCCN-IPI was of highly prognostic value in the analyzed group (p<0.0001). Survival analysis showed that ALC>1.1x109/L, AMC≤0.59x109/L, and LMR>2.8 were associated with more favorable outcome (p=0.029, p=0.019, p=0.028, respectively). The patients with CCI≥2 had poorer outcome (p=0.008) compared to the patients with CCI 0-1. Multivariate analysis showed that among ALC, AMC, LMR, NCCN-IPI and CCI, the NCCN-IPI was the critical parameter that significantly affected survival (p<0.0001). Furthermore, comorbidities were also valuable independent factors which influenced survival (p=0.031) as well as the ALC (p=0.024). In elderly DLBCL patients, NCCN-IPI and ALC proved their prognostic validity, while poorer outcome could be expected in older patients with high CCI (≥2). Furthermore, mentioned prognostic parameters retained their prognostic value in the group of patients older than 70.

Do trees respond to pollution? A network study of the impact of pollution on spruce growth from Europe.

Tree rings have been reliably used as an environmental proxy over the past decades for environmental reconstructions, simulations and forecasting. In our study, we investigated whether tree-ring chronologies are impacted by pollution. We chose sites in the Krusné hory and the Krkonose Mountains in the Czech Republic which have a known history of pollution. We sampled Norway spruce (Picea abies [L.] Karst) in both ranges and compared their chronologies. We found no significant difference in the overall radial growth in the chronologies from both regions. However, we observed an increased heterogeneity in the growth of trees from the 1970s till the 1990s. Coherently, a severe reduction in tree growth from the late 1970s and a recovery towards the early 1990s was evident. We collected and analysed soil samples for pH and exchangeable element concentrations. All seven sampling sites' soils were strongly acidic (pHCaCl2 = 3.3 ± 0.4). The average soil base saturation at Krusné hory was higher than at Krkonose (39% versus 12%), likely due to more intensive liming. Further, we compared these chronologies to other sites in Europe. Analysing 89 sites, we found that most (9 out of 14) of the sites with significantly reduced radial tree growth were located within the former 'Black Triangle', an area which was subjected to heavy industrialisation and pollution from the 1960s to the 1990s. Atmospheric sulphur deposition was found to negatively affect radial tree-growth, while limited quantities of oxidised nitrogen appeared to have a positive effect. Our results are consistent with previous research, indicating that atmospheric SO2 pollution and subsequent acid fog and rime have led to a reduction in annual radial tree growth across the Black Triangle.

Recent progress in the development of advanced support materials for electrocatalysis.

Electrocatalytic materials are pivotal for clean chemical production and energy conversion in devices like electrolyzers and fuel cells. These materials usually consist of metallic nanoparticles which serve as active reaction sites, and support materials which provide high surface area, conductivity and stability. When designing novel electrocatalytic composites, the focus is often on the metallic sites, however, the significance of the support should not be overlooked. Carbon materials, valued for their conductivity and large surface area, are commonly used as support in benchmark electrocatalysts. However, using alternative support materials instead of carbon can be beneficial in certain cases. In this minireview, we summarize recent advancements and key directions in developing novel supports for electrocatalysis, encompassing both carbon and non-carbon materials.

Orbital and ocular adnexal Mucosa-Associated Lymphoid Tissue (MALT) lymphomas: a single-center 10-year experience.

Orbital and ocular andexal Mucosa-Associated Lymphoid Tissue Lymphoma (MALT) or ocular adnexal MALT lymphoma (OAML) is the most common of all eye non-Hodgkin lymphomas. Autoimmune inflammatory disorders and chronic infections are important etiological factors and CD5 and CD43 (sialophorin) tumor markers are significant negative prognostic factors. Disease signs and symptoms can occur a long time before diagnosis. Varieties of treatment options are available. The aim of this retrospective analysis was to compare the efficiency of different treatment options and to investigate disease outcome. Twenty OAML patients, diagnosed in the Clinic of Hematology, Clinical Centre of Serbia, between 2003 and 2013, were enrolled. In most cases, OAML developed in the eighth decade with greater incidence in the male population. Median age was 67.5 years. The median period between the appearance of local signs and symptoms and diagnosis was 7 months. The dominant sign at presentation was swelling of involved tissue (40%). The most common was orbital involvement (55%). All patients had localized disease. Observed laboratory parameters on presentation showed low disease activity. Sialophorin prognostic significance was not registered. Our patients were initially treated differently but there was no significant difference in progression-free survival (PFS) due to initial treatment option (p = 0.2957). Median PFS was 22 months (3-89), and 5-year PFS was 60%. Median overall survival (OS) was 43 months (1-105) and 5-year OS 95%. Eight patients (40%) relapsed and one patient died due to non-hematological complications. In our experience, most modern induction treatment options appear to result in the same, favorable outcome.