Medycyna doświadczalna i mikrobiologia最新文献

{"title":"Evaluation of in-house ELISA and 11 commercial ELISA kits in the serological diagnosis of COVID-19","authors":"W. Rastawicki, Klaudia Płaza, Adam Pietrusiński","doi":"10.32394/mdm.73.04","DOIUrl":"https://doi.org/10.32394/mdm.73.04","url":null,"abstract":"Introduction: ELISA-Immunoassays can complement the molecular diagnostic methods, and can be one of the important tools of sero-surveillance and vaccine evaluation. The aim of the presented study was to develop in-house ELISA and evaluate 11 commercial ELISA tests for detection of anti-SARS-CoV-2 antibodies in serum samples collected from COVID patients.\u0000Methods: In total, 237 serum samples obtained from 165 people with COVID-19 with RT-PCR confirmed SARS-CoV-2 virus infection were used for the study. The specificity of the developed in-house ELISA kit was tested using 170 serum samples obtained from patients with various bacterial and viral infections. The study used an in-house ELISA and 11 commercial ELISA kits developed by various manufacturers.\u0000Results: The presented study showed high sensitivity (81.0%) and specificity (97.2%) of the developed in-house kit in relation to the RT-PCR method. The sensitivity of the inhouse test significantly increased (98.1%) when only convalescents - persons at least 3 weeks after COVID-19 were examined. Commercial ELISA kits most frequently detected IgG antibodies (from 44.9% to 89.4%), especially in samples obtained later in the disease, and the least frequent detection of IgM antibodies (from 4.2% to 42.4%).\u0000Conclusions: All the presented ELISA kits may be used in serodiagnosis of COVID-19 however the detection of antibodies in individual tests differed quite significantly and was dependent on the period of the disease, on the class of immunoglobulins and the type of antigen used. The sensitivity of serological tests in the IgG class is clearly higher when examining samples obtained at least 2-3 weeks from the onset of clinical symptoms.\u0000Searching for IgA antibodies may be useful mainly in the early phase of the disease while IgM antibodies does not provide significant additional information. In the case of asymptomatic or mild infection, the level of antibodies is low which may be the cause problems with the correct interpretation of epidemiological surveys","PeriodicalId":18566,"journal":{"name":"Medycyna doświadczalna i mikrobiologia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133132603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Human gut microbiota – its diversity and impact on our health","authors":"S. Wardak","doi":"10.32394/mdm.73.06","DOIUrl":"https://doi.org/10.32394/mdm.73.06","url":null,"abstract":"The human digestive tract is the living environment for billions of cells of various microorganisms that are part of the human microflora. The use of modern molecular biology techniques, such as NGS (Next Generation Sequencing), made it possible to study the microorganisms inhabiting the intestines and to understand their impact on human health. The gut microbiota plays a significant role in the synthesis and metabolism of many nutrients and metabolites, including short-chain fatty acids (SCFA), amino acids, lipids, bile acids and vitamins. Many factors such as diet, age, climate, and socioeconomic conditions influence the diversity of the microbiota. Rapid changes in the composition of the microbiota (disturbance of homeostasis) can lead to dysbiosis - a condition associated not only with intestinal disorders, but also with numerous extraintestinal diseases. The present work is a review of current reports on: research techniques used to analyze microbiota, the impact of various factors on its diversity and the impact of microbiota on our health.","PeriodicalId":18566,"journal":{"name":"Medycyna doświadczalna i mikrobiologia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126385321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Staphylococcus prettenkoferi – biochemical properties, methods of species identification and clinical significance","authors":"","doi":"10.32394/mdm.73.01","DOIUrl":"https://doi.org/10.32394/mdm.73.01","url":null,"abstract":"Staphylococcus pettenkoferi was first isolated from blood culture a 25-years-old patient with fever of unknown etiology. Based on the literature analysis, it was found that it is an opportunistic microorganism. It causes blood stream infections and was an causative agent of osteomyelitis. Staphylococcus pettenkoferi is a component of the human microbiome, was found in a hospital environment and was also isolated from animals and their surroundings.","PeriodicalId":18566,"journal":{"name":"Medycyna doświadczalna i mikrobiologia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127466288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"AmpC cephalosporinases in Escherichia coli","authors":"Magdalena Anna Nowakowska","doi":"10.32394/mdm.73.05","DOIUrl":"https://doi.org/10.32394/mdm.73.05","url":null,"abstract":"Escherichia coli is an important pathogen causing nosocomial infections. A significant problem in the treatment of infections caused by these microorganisms is their increasing resistance to β-lactam antibiotics, including third and fourth generation cephalosporins. The production of β-lactamases enzymes such as extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamases is among the main mechanisms for resistance to third generation cephalosporins. The genes encoding AmpC cephalosporinases are chromosomal (cAmpC) or plasmid-mediated (pAmpC). In E. coli, the expression of the ampC genes may be conditioned by the constitutive expression of low level ampC chromosomal genes. These strains remain susceptible to β-lactam antibiotics. However, mutations in the promoter region of the ampC may result in increased level of expression of chromosomal ampC genes. This can leads to resistance to cephalosporins. Resistance to cephalosporins in E. coli can be also associated with plasmid-mediated AmpC β−lactamases (pAmpC). In E. coli the presence of one or more plasmid-mediated AmpC β−lactamases along with the neglible expression of chromosomal encoded AmpC enzyme can leads to resistance to broad-spectrum cephalosporins. This review is focused on a resistance mechanisms associated with the production of AmpC cephalosporinases in clinical E. coli isolates.","PeriodicalId":18566,"journal":{"name":"Medycyna doświadczalna i mikrobiologia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129007151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the occurrence of genetic determinants of multi-drug resistance among Acinetobacter baumannii strains","authors":"","doi":"10.32394/mdm.73.02","DOIUrl":"https://doi.org/10.32394/mdm.73.02","url":null,"abstract":"Introduction: The aim of the study was the analysis of occurrence of genetic determinants of multi-drug resistance and the assessment of genetic relationship among Acinetobacter baumannii strains.\u0000Methods: Multiplex-PCR method was performed in order to: (1) confirm the phenotypic identification and (2) detect the presence of CHDL oxacillinases in the group of thirty A.baumannii strains. Further PCR studies included the analysis of the occurrence of genetic determinants associated with efflux pump, insertion sequence and biofilm formation. The relationship between bacterial strains was assayed using 6 primers in RAPD-PCR method.\u0000Results: Detection of the blaOXA-51-like gene confirmed that the strains belong to the A. baumannii species. In the multiplex-PCR, the presence of the blaOXA-23-like and blaOXA-40-like genes was detected in 3 (10%) and 27 (90%) isolates, respectively. Moreover, some strains showed the coexistence of the blaOXA-51-like and blaOXA-23-like genes (10%, n=3) or blaOXA-51-like and blaOXA-40-like (90%, n=27). In the group of analysed strains the presence of the efflux pump gene (adeA) and the insertion sequence ISAba1 were demonstrated in all tested isolates. Biofilm-related genes (abaI, csuE) were found in 100% and 97% (n=29) tested strains adequately. The RAPD-PCR studies revealed the presence of 10 unrelated genotypes.\u0000Conclusions: The obtained results suggest that the phenomenon of multi-drug resistance in the studied A. baumannii strains could be attributed to the occurrence of CHDL oxacillinases, AdeABC efflux pump, insertion sequence ISAba1 and the biofilm formation.","PeriodicalId":18566,"journal":{"name":"Medycyna doświadczalna i mikrobiologia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124591093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of rapid, cassette immunochromatographic tests in the serological diagnosis of COVID-19","authors":"W. Rastawicki, Klaudia Płaza, Adam Pietrusiński","doi":"10.32394/mdm.73.03","DOIUrl":"https://doi.org/10.32394/mdm.73.03","url":null,"abstract":"Introduction: Lateral flow assays (LFIA) are the technology behind low-cost, simple, rapid and portable detection devices popular in biomedicine. Lately, they are very common used in serodiagnosis of SARS-CoV-2 infections. The aim of the presented study was to assess the usefulness of selected LFIA in serological diagnosis of COVID-19.\u0000Methods: The usefulness of seven lateral flow assays in the serodiagnosis of COVID-19 was evaluated (VAZYME, DIAGNOSIS, PCL, INGEZIM, BIOSENSOR, ACCU-TELL, NOVAtest). The study used 107 serum samples obtained from 74 individuals with current SARS-CoV-2 infection confirmed by RT-PCR. The ELISA-IgG (Euroimmun) was used as the reference assay for sensitivity and specificity testing.\u0000Results: The highest percentage of positive results was obtained when searching for IgG antibodies with the NOVAtest (40.6%) and DIAGNOSIS (39.2%) sets and the lowest detection for the PCL set - 25.5%. In the case of searching for IgM antibodies in all sets, significantly lower percentages of positive results compared to the IgG class were recorded. In general, all lateral flow assays showed low sensitivity in relation to the Euroimmun ELISA-IgG. The DIAGNOSIS kit (64.5%) was characterized by the highest sensitivity, and the PCL kit was the lowest (38.7%). On the other hand, the specificity of all kits was very high, almost 100% in almost all cases.\u0000Conclusions: Lateral flow assays due to their low sensitivity are not suitable for quick diagnosis of the current SARS-CoV-2 infections and cannot be an alternative to genetic or even antigen tests. They may be used only to retrospectively test the presence of IgG antibodies. However, a negative results of LFIA in suspected disease or after vaccination should be confirmed by more sensitive serological tests.","PeriodicalId":18566,"journal":{"name":"Medycyna doświadczalna i mikrobiologia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130489637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Avidity of IgG class antibodies to Francisella tularensis in the course of tularemia in humans","authors":"W. Rastawicki, K. Śmietańska, N. Rokosz-Chudziak, Urszula Roguska","doi":"10.32394/MDM.71.05","DOIUrl":"https://doi.org/10.32394/MDM.71.05","url":null,"abstract":"Introduction: Tularemia is a highly infectious zoonotic disease caused by Gram-negative bacterium Francisella tularensis. The microbiological diagnosis of tularemia is based mainly on serological investigations. The present study was undertaken to determine the avidity of IgG class antibodies to Francisella tularensis in the course of tularemia in humans and to evaluate its value for estimation of the phase of diseases.\u0000Methods: Fifty two serum samples obtained from 40 patients with tularemia were tested by in-house ELISA in duplicate in the same plate, without and after the 0.5 h incubation with 8M urea. The age of the subjects was between 6 and 77 years. From one patient, a 9-years-old girl with oculoglandular form of tularemia, five serum samples were taken, respectively after 0.5, 1.5, 3, 6 and 12 months from the beginning of the first clinical symptoms.\u0000Results: The results of the study showed higher values of the avidity index (AI) of IgG antibodies for F. tularensis, often exceeding the value of 0.9, in children and adolescents than in adults. The examination of serum samples obtained 2-3 times in the course of tularemia from few patients did not show significant differences in the level of avidity index depending on the period of the disease. However, in five serum samples obtained from a 9-years-old girl in the different phases of tularemia the avidity index showed increasing values (0.51, 0.80, 0.92, 0.90 and 0.94, respectively).\u0000Conclusions: The avidity index of IgG may be helpful in excluding recent infection, but its usefulness in detecting an active phase of invasion requires further research.","PeriodicalId":18566,"journal":{"name":"Medycyna doświadczalna i mikrobiologia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128687764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of colloidal silver and copper nanoparticles on generation of radical oxygen species (ROS) in human neutrophils","authors":"Maja Kosecka-Strojek, P. Kaszycki, Kinga Regdos, K. Guzik, D. Ropek, J. Międzobrodzki","doi":"10.32394/MDM.71.03","DOIUrl":"https://doi.org/10.32394/MDM.71.03","url":null,"abstract":"Introduction: Silver and copper nanoparticles (AgNPs, CuNPs) applied as hydronanocolloids are known to produce strong antibacterial and antifungal activities. They are extensively used in a number of applications including pharmacy, medicine and cosmetology (especially for surface-applied treatment of skin lesions) as well as agriculture, industry (paint, construction, etc.) and home or office (mainly disinfection applications). Moreover, there is a promising perspective of an intra-systemic NP use, especially to optimize targeted drug delivery. For the above reasons NPs cause risk of penetrating human body and exerting toxic effects and/or stress reactions. This issue has inspired the authors to launch studies on the influence of colloidal AgNPs and CuNPs on physiological potential of neutrophils, blood-cells acting as the first line of immunological defense.\u0000Methods: Physiological activity of neutrophils was evaluated by measuring their ability to generate oxygen radicals (radical oxygen species, ROS) due to the respiratory (oxidative) burst mechanism. Human, peripheral blood-isolated neutrophils were stimulated with a standard activating agent (polystyrene latex particles) to develop high physiological potential revealed by enhanced ability to produce oxygen radicals. The cells were treated with silver and copper hydronanocolloids (each applied at concentrations ranging from 0.4 to 50 mg/kg) alternatively: in the absence and presence of the mentioned activator. The level of generated ROS upon oxidative burst was monitored chemiluminometrically.\u0000Results: The tested Ag and Cu-nanocolloids were not toxic against neutrophils although they hampered mitochondrial dehydrogenase activities when applied at higher levels. At lower concentrations they tended to stimulate ROS generation; however the treatment did not launch the oxidative burst. In the case of the latex-stimulated neutrophils, both types of nanoparticles in all experimental variants did not influence the levels of produced ROS.\u0000Conclusions: The obtained results indicate that the exposure of human neutrophils to colloidal AgNPs and CuNPs does not lead to an enhanced ROS generation, which may enable direct intra-blood application of the tested nanostructures, provided further necessary toxicological studies are carried out.","PeriodicalId":18566,"journal":{"name":"Medycyna doświadczalna i mikrobiologia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129331793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Absorption of non-specific antibodies with Salmonella Enteritidis and Salmonella Typhimurium suspensions from tested serum samples as a useful method in serodiagnosis of salmonellosis carried out by ELISA for epidemiological surveillance","authors":"W. Rastawicki, N. Rokosz-Chudziak, K. Śmietańska, Urszula Roguska","doi":"10.32394/MDM.71.02","DOIUrl":"https://doi.org/10.32394/MDM.71.02","url":null,"abstract":"Introduction: Diagnosis of salmonellosis is usually made by stool culture however in many laboratories ELISA for the detection of human serum antibodies against mixture of LPS antigens of the two predominant serovars of Salmonella was developed. We present the method of absorbing non-specific antibodies with S. Enteritidis (serovars D) and S. Typhimurium (serovars B) suspensions from serum samples as a useful method in serodiagnosis of salmonellosis carried out by ELISA. This simple, cost-efficient and effective method of absorption may be used in the epidemiological investigations.\u0000Methods: We used in-house ELISA three different antigens: LPS of the S. Enteritidis, LPS of the S. Typhimurium and 1:1 mixture of LPS of both serovars. Serum samples collected from 14 patients with salmonellosis, were absorbed with 20% bacterial suspensions obtained from S. Enteritidis, S. Typhimurium and mixture of both serovars (serovars B+D). The non-absorbed sera and sera after particular absorptions were tested separately in ELISA with all three antigens.\u0000Results: The all 14 non-absorbed serum samples showed a high positive results in the IgA, IgG and IgM ELISA with all three LPS antigens. Absorption of the 13 from 14 tested samples with the Salmonella B suspension resulted in a significant decrease in the level of antibodies to Salmonella B antigen, but only a very slight decrease in the levels of Salmonella B + D and Salmonella D antigen. On the other hand, the absorption of the same sera with Salmonella D suspension, caused a significant decrease in the level of antibodies for serovars D, B and B + D antigens. Such a test result clearly shows that the 13 serum samples were obtained from patients with an infection caused by S. Enteritidis (serogroup D). A opposite picture of the humoral response was obtained in the case of one serum sample obtained from a subject with an infection caused by S. Typhimurium (serogroup B).\u0000Conclusions: The presented work demonstrates the usefulness of absorption of non-specific antibodies with S. Enteritidis and S. Typhimurium suspensions in serodiagnosis of salmonellosis carried out by ELISA.","PeriodicalId":18566,"journal":{"name":"Medycyna doświadczalna i mikrobiologia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116373754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of survival of Candida albicans on PVC surfaces in the test of yeasticidal activity of disinfectant","authors":"A. Chojecka","doi":"10.32394/mdm.72.06","DOIUrl":"https://doi.org/10.32394/mdm.72.06","url":null,"abstract":"Introduction: Candida albicans survival tests on PCV carriers are necessary for the proper determination of the effectiveness yeasticidal activity of disinfectants. C. albicans is a pathogenic microorganism that causes fungal diseases and therefore its spread in the medical and non-medical areas should be limited by disinfection.\u0000Methods: Survival of C. albicans was estimated with using principles of PN-EN 16615 standard. Suspension of C. albicans with interfering substances (0,3 g/l bovine albumin) was dry on PCV carriers under a laminar chamber without fan, at the ambient temperature for no longer than 60 minutes. C. albicans was recovered from the carriers immediately after drying and after contact time (1; 5, 10, 20, 40; 60 minutes).\u0000Results: The drying conditions applied reduced the recovery of C. albicans from 1.21 to 2.07 on a logarithmic decimal scale with respect to the test suspension with interfering substances. The difference between the recovery immediately after drying and the recovery after the tested contact times (up to 60 minutes) was insignificant.\u0000Conclusions: Achieving the number of C. albicans after the drying process, as provided for in PN-EN 16615, requires further improvement of the drying conditions or an increase of C. albicans suspension density before drying.","PeriodicalId":18566,"journal":{"name":"Medycyna doświadczalna i mikrobiologia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131045002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}