Medycyna doswiadczalna i mikrobiologia最新文献

Introduction: Cytomegalovirus infection (CMV) is one of the most common viral infections during pregnancy and one of the most common causes of birth defects in newborns. CMV infection occurs mostly through close contact with small children who can secrete the virus in saliva and urine. Children, especially in preschool and early school can also be a source of infection with other herpesviruses. The aim of the study was to determine the prevalence of active infections caused by viruses from the family Herpesviridae (CMV, EBV, VZV) among members of families with children.

Material and methods: The study included 24 families raising children aged from 2 to 18 years. From all members of the families (46 adults and 39 children) saliva samples were collected from which DNA was extracted. The isolated DNA samples were tested for the presence of CMV, EBV, VZV genetic material by nested PCR. In addition, each family carried out a survey.

Results and conclusions: The presence of CMV DNA in saliva samples were detected in members of 7 families and the presence of EBV DNA were detected in members of 11 families. Total DNA of CMV was detected in 8/85 samples of saliva (9.41%), of which 1/46 adults (2.17%) and 7/39 children (17.95%) and EBV DNA was detected in 18/85 tested saliva samples (21,18%) - 13/46 samples from adults (28,26%) and 5/39 samples from children (12,82%). VZV DNA was not detected in any of the tested saliva samples. The obtained results indicate that the active, asymptomatic infections with lymphotropic herpesviruses are common and affect more than 10% (CMV) and 20% (EBV) subjects.

Introduction: The objective of this study was to analyze the fungal infections in patients of an intensive care unit (ICU) in a long period (2002-2012) on the example of the Lodz Medical University Hospital No 1. This analysis was focused on the study of the effect of antimicrobial therapy on the level of these infections.

Methods: A total of 291 strains of fungi were isolated from blood, tips of central intravenous catheters, lower respiratory tract, urine, wounds, pressure sores, and cerebrospinal fluid of 3177 patients. An automatic system Bactec 9050, Yeast ID Phoenix BD panels and E-tests (BioMerieux) were used for the fungi analysis.

Results: The studies were mainly concentrated on the Candida infections, distinguishing cases caused by C. albicans and C. non-albicans pathogens. Changes in the number of these infections in consecutive years have been associated with epidemiological and therapeutic activities in the ICU. Particularly, relationships between the number of infections and the use ofceftazidime were discussed. A statistically significant positive correlation of the count of Candida infections and the ceftazidime consumption was found in the period to 2006. In the later years, the correlation was destroyed as a result of other important therapeutic factors (eg, immunosuppressive drugs).

Conclusions: It has been found that the number of Candida infections in the ICU depends on the consumption of antimicrobial drugs. This conclusion is based on quantitative example of ceftazidime. Only close cooperation between the ICU and microbiologists is able to provide a reduction in nosocomial fungal infections.

Campylobacter jejuni is one of the most common causes of bacterial diarrhea worldwide. Various virulence factors of C. jejuni contribute to survival and participate in the induction of infection in the human body. The virulence mechanisms such as motility, toxin production or invasive properties allow the bacteria to survive in the human body. The article presents the current knowledge on selected virulence mechanisms of C. jejuni.

Introduction: In recent years, nosocomial fungal infections are becoming an increasingly serious problem. More and more complications are observed in patients with high-risk groups resulting from the colonization of the skin and mucous membranes by Candida species. Thus, rapid and effective treatment of superficial fungal infections caused by Candida is a very important task for modern medicine. Unfortunately, with a clear increase in the number of fungal infections, the resistance to currently used antifungal drugs also increases seriously limited the effectiveness of treatment. An intensive search for new therapeutic solutions is therefore necessary. One of the promising solutions is the use of cold atmospheric plasma. The aim of this paper is to investigate the influence of this type of plasma on survival of Candida albicans.

Methods: As a source of cold atmospheric plasma, a linear microdischarge jet, called plasma razor, was used. Plasma was generated at 13.56 MHz, using He as a reactive gas. The gas flow rate and the discharge power were 1.9 L/min and 17 W, respectively. A schematic view of the experimental system is shown in Fig. 1. The reference strain of Candida albicans ATCC 10231 was used as a model material for investigations. The culture was prepared by spreading uniformly 100 μL phosphate buffered saline solution containing 5 x10(7) cells/mL on the surface of a Petri dish. Such a culture was exposed to the plasma at various times. The size of the zone of inhibition of fungal growth was estimated by densitometric method (Fig. 3). For more complete information about the plasma the optical emission spectra were measured.

Results: It was found that with increasing time of plasma treatment, the zone of inhibition clearly increases (Fig. 2). In Fig. 4, the experimental results of the size of the inhibition zone versus the treatment time are shown. These results were successfully fitted (p = 0.0058, r2 = 0.944) by a theoretical curve (Fig. 4), plotted according to Eq. (5), which was derived on the basis of a simple model of the spread of a killing agent from the plasma center. The study of the optical emission spectra confirmed a large variety of possible killing agents generated in the cold atmospheric plasma, such as UV, radicals, ions and energetic electrons. Further research will be focused on the determination of the main agent responsible for the process of the cell killing, and to determine the mechanism of this process.

Conclusions: Cold atmospheric plasma generated by the plasma razor turns out to be a very effective tool for the killing of pathogenic fungi. Although the presented studies are only the initial stage of work on the effects of cold atmospheric microplasma on fungal cells, they provide hope for the possibility of using this technique as a method of eradication of superficial fungal infections.

Introduction: Salmonella is significant etiological agent of bacterial intestinal infections in Poland and other European Union countries. Since the 90's increasing incidence of monophasic Salmonella antigenic formula 1,4,[5],12:i:-has been observed, which are divided into two lineages: Spanish and European. More common European lineage are characterized by antimicrobial resistance ASSuT and DT193 phagetype. In many European countries, these organisms have become one of the most commonly isolated serovars. The aim of this study was to analyze strains of Salmonella enterica subsp. enterica strains with antigenic formula 1,4,[5],12: i:-, isolated in Poland in 2007-2012 years.

Material and methods: The material for the study was 146 Salmonella strains initially identified as Salmonella antigenic formula 1,4,[5],12:i,-, isolated in 2007-2012 from clinical, food and animal samples. All strains has been reidentified according to the methodology routinely used in the laboratory. Serovar has been identified using classical method--slide agglutination for somatic and flagellar antigens and using Check&Trace Salmonella microarray. The fljB gene,fliB-fliA intergenic region, selected Salmonella Pathogenicity Islands' (SPIs) genes and spvC has been detected using PCR. For all strains PFGE typing with HindIII enzyme has been performed and phagetyping also. Moreover antimicrobial resistance has been evaluated by establishing of MIC according EUCAST recommendation.

Results: 110 (75%) strains were S. enterica 1,4,[5],12:i,-. In this group for 17 strains in Check&Trace Salmonella microarray result of identification "Salmonella Typhimurium" have been obtained. All 110 strains have 1000 bp size DNA fragment with IS200 sequence, characteristic for S. Typhimurium. Only in case of 4 strains fljB gene has been detected. All strains harbor avrA, ssaQ, mgtC and siiD genes. For 6 strains spvC gene has been not detected. 92 strains (83.6%) have been typed as DT193, but in case of 40 strains additional reaction with phage no 18 has been observed. For 104 (94.5%) strains resistance for at least one antimicrobial have been detected. Most frequent (44 strains - 40%) resistance pattern was ASSuT. Among all strains 11 pulsotypes, which group two or more strains have been recognized, which contain 37 strains. The rest of strains have unique REA-PFGE patterns.

Conclusions: To this time epidemiological situation of S. enterisa 1,4,[5],12:i:- isolated from human cases in Poland has been not recognized. Results of current studies show, that studied strains belong to european non-spanish lineage of monophasic S. Typhimurium and problem of infection caused by those strains is unrecognized and probably increase.

Introduction: Toll-like receptors (TLRs) are an important component of a innate immune system. Stimulation of TLRs, through action with helper T cells, could change Th1/Th2 balance and thus affect adaptive immune response. The aim of this work was to optimize the stimulation of the peripheral blood mononuclear cells (PBMC) and the validation of real-time RT-PCR method for determination of Toll-like gene expression in these cells.

Methods: PBMCs from healthy donors were stimulated with measles viruses and ligands for TLR2 and TLR4. For examinations the real time RT-PCR (QuantiFast Assay, Qiagen) was used. Fold change of TLRs expression was normalized to GAPDH and estimated by 2(-deltadeltaCt) method. Validation of real-time RT-PCR method was performed for repeatability and efficiency.

Results: The level of gene expression varies between individuals and was dose and time of incubation dependent. The efficiency ofreal-time RT-PCR was 90.4% +/- 10.2 for GAPDH, 87.0% +/- 8.2 for TLR2 and 44.5% +/- 9.2 for TLR4. Repeatability, expressed as relative standard deviation (RSD) for Ct values was less than 0.70% for GAPDH, < 3.2% for TLR2 and < 2.84% for TLR4.

Conclusions: Based on obtained results, the optimal conditions for stimulation were: 10 microg/ml/24h for LPS, 1 microg/ml/6h for Pam3CSK4 and 1250 MeV infectious particles/24h.

Introduction: Enterococci belong to the normal bacterial flora of the gastrointensinal tract of humans. Enterococci are regarded as harmless commensal, and are even believed to have probiotic characteristics. However, they can cause variety of infections, including endocarditis, bloodstream infections and urinary tract infections. During the past several decades, enterococci, and particularly Enterococcus faecalis and E. faecium, have been identified as an important cause of nosocomial infections. Enterococci are intrinsically resistant to a broad range of antimicrobials. Infection caused by resistant strains are difficult to treat. Iron is an essential element for bacteria, but is not easily available in host organisms. Enterococci are iron dependent bacteria. Competition for iron between the host and bacteria is an important factor determining the course of bacterial infections. A common strategy among bacteria living in iron-limited environments is the secretion of siderophores, which can bind poorly soluble iron and make it available to cells via active transport mechanisms. The aim of the presented study was to evaluate the correlation between antibiotic resistance and siderophore production of bacteria of the genus Enterococcus.

Methods: The study included 55 bacterial strains from genus Enterococcus belonging to two species--Enterococcus faecalis and E. faecium. Antimicrobial susceptibility tests were carried out using disc diffusion methods with guidelines of European Committee on Antimicrobial Susceptibility Testing (EUCAST). Total siderophore activity in the culture supernatants was measured using chrome azurol S. Hydroxamate siderophores were assayed using a chemical-specific assay.

Results: Antibacterial susceptibility pattern reveals that E. faecium is more resistant than E. faecalis. A significant correlation was found between resistance to fluoroquinolnes and siderophores production. Ciprofloxacin- and norfloxacin-resistant enterococal strains produced siderophores in large quantity.

Conclusions: One of the most common infections caused by enterococci are urinary tract infections. Fluoroquinolones are an important group of antimicrobial agents used in this type of infection. Fluoroquinolones resistance of enterococci associated with increased synthesis of siderophores result in the increased virulence that may decide on the severity of the infection and the effectiveness of the treatment.

Introduction: The aim of our study was to determine the antibacterial activity of cinnamon bark oil against Gram-positive and Gram-negative isolates belonging to Staphylococcus, Enterococcus, Enterobacter and Acinetobacter genera come from different clinical specimens.

Methods: The microdilution method was used to determine the minimum inhibitory concentration--MIC for cinnamon bark oil. Susceptibility testing to antibiotics was carried out using disc-diffusion method.

Results: Our investigations showed that the tested cinnamon bark oil was inhibiting activity against all isolates. The MIC for Gram-positive bacteria were between 01.25 and 1.5 μl/ml and for Gram-negative between 1.0 and 1.75 μl/ml. The tested bacteria come from Staphylococcus, Enterococcus, Enterobacter and Acinetobacter genera were susceptible to essential oil obtained from Cinnamomum zeylanicum Ness in low concentrations, despite the fact that the bacteria characterized the high resistance to recommended antibiotics. No correlation was found between the antibiotic resistance of the bacterial strains and their sensitivity to essential oil.

Conclusions: The cinnamon bark oil due to the strong activity can be used as alternative antibacterial agents in cosmetics, toiletries and disinfectants applied in hospital environment.

Introduction: Whooping cough is still a significant disease with regular outbreaks despite the decades of mass vaccination and good immunization coverage. The aim of this study was to evaluate the capacity of Bordetella pertussis toxicity testing among strains harbouring different alleles of the pertussis toxin promoter ptxP using hamster ovary cell line CHO (Hamster Ovary).

Methods: The study assessed the limits of detection of high and low Ptx levels producing strains using a reference preparation ofpertussis toxin and B. pertussis strains that increased toxicity in vitro has been previously correlated with ptxP3 allele presence.

Results: The presence of the strong agglomerates on CHO cell line confirmed the higher toxicity of B. pertussis strains isolated in France. Preliminary toxicity study with use of selected strains of B. pertussis differing by ptxP1 and ptxP3 promdter alleles with respect to relevant reference preparation indicate lower toxicity of strains B. pertussis isolated in Poland.

Conclusions: The toxicity measured on CHO line will be used to assess the virulence of all available B. pertussis strains isolated in Poland.

Introduction: Ciprofloxacin is commonly used in Poland specially for the treatment of urinary tract infections including urethritis. Patients are often treated without pathogen identification and antimicrobial resistance tests. Neisseria gonorrhoeae infection is one of the most common causes of urethritis in Poland. The resistance of bacteria to a wide range of antibiotics including ciprofloxacine makes the therapy of gonorrhoea more difficult. The mechanism of ciprofloxacine action depends on inactivation of bacterial topoisomerase II (gyrase) and topoisomerase IV. A resistance to ciprofloxacine occurring in Neisseria gonorrhoeae is mainly due to mutations in bacterial gyrA (encoding topoisomerase II) and/or parC (encoding topoisomerase IV ) genes. High level resistance is an effect of combination of three or four mutations. Another, less important mechanism of ciprofloxacin resistance, that can coexist with mutations in gyrA and parC genes related to the overproduction of membrane pumps proteins.

Material and methods: 65 Neisseria gonorrhoeae strains isolated from patients of Department of Dermatology and Wenereology in Warsaw in the second half of 2012 and first of 2013 was investigated. The strains were cultured on chocolate agar plates in a 5% CO2 atmosphere at 37 degrees C and identified by colony morphology, Gram stain and oxidase reaction, followed by carbohydrate utilization test. Ciprofloxacin susceptibility was determined by E-Tests (bioMerieux). Bacteria were incubated at 35 degrees C in 5% CO2 for 24 h on chocolate agar plates. Tests were performed according to producers recommendations. The results (sensitive or resistant) were interpreted according to EUCAST recommendations.

Results: The MIC (Minimal inhibitory concentration) of Ciprofloxacin in investigated strains ranged from 0,002 to > 32 mg/L, MIC50 = 8 mg/L, MIC90 = > 32 mg/L. It was shown that only 38.5% of the strains were sensitive to ciprofloxacin according to EUCAST criteria from 2013 year.

Conclusions: Due to the high percentage of ciprofloxacin resistant Neisseria gonorrhoeae strains (more than 61%) the antibiotic should not be used for the treatment of gonorrhoea in Poland.