Synthesis of novel sulphamethoxazole derivatives and exploration of their anticancer and antimicrobial properties.

A series of new derivatives based on sulfamethoxazole were designed and synthesized in this study. The structures of the new compounds were confirmed based on a comprehensive characterization of spectral data by applied IR and 1H as well as 13C NMR spectroscopy. The prepared compounds were tested for their anticancer and antimicrobial properties. Hydrazone 16b demonstrated convincing anticancer effect against all tested cell cultures such as human prostate carcinoma PPC-1 and human kidney carcinoma CaKi-1 cell lines, and human fibroblasts HF, n = 3. The most promising compound 16b showed higher activity against CaKi-1 cell line than the anticancer drugs axitinib and pazopanib used to treat renal cancer. Also, it was more active in the PPC-1 cell line compared to the approved PARP inhibitor Olaparib. Hydrazone 16b was also found to possess good antimicrobial properties against gram-positive bacteria strains of Staphylococcus aureus, Staphylococcus epidermidis, as well as Bacillus cereus.

Application of Antiviral, Antioxidant and Antibacterial Glycyrrhiza glabra L., Trifolium pratense L. Extracts and Myristica fragrans Houtt. Essential Oil in Microcapsules.

Viruses and bacteria can disrupt normal human functions; therefore, ways to use the beneficial properties of plants to promote health are constantly being researched. Plant materials that accumulate biologically active compounds can be used to create a new pharmaceutical form. This study aimed to investigate the biological activity of selected plant extracts and essential oil and to produce microcapsules. The main compounds in extracts and essential oil were determined using chromatographic methods, antioxidant activity was evaluated spectrophotometrically, antimicrobial activity was assessed by monitoring the growth of nine pathogens, and the antiviral effect on infected bird cells with coronavirus was evaluated. Trifolium pratense L. extract had the highest antioxidant (26.27 ± 0.31 and 638.55 ± 9.14 µg TE/g dw by the DPPH and ABTS methods, respectively) and antiviral activity (56 times decreased titre of virus). Liquorice extract expressed antibacterial activity against Gram-positive pathogens and the highest antioxidant activity using the FRAP method (675.71 ± 4.61 mg FS/g dw). Emulsion stability depended on excipients and their amount. Microcapsules with extracts and essential oil were 1.87 mm in diameter, and their diameter after swelling was increased more than two times in intestinal media, while less than 0.5 times in gastric media.

Formulation and Characterization of Potential Antifungal Oleogel with Essential Oil of Thyme.

The aim of this research was to formulate oleogel with thyme essential oil with potential antimicrobial activity, design optimal formulation, and evaluate the influence of ingredients on texture parameters of preparation. Central composite design was applied to statistical optimization of colloidal silica and paraffin oil mixture for the modeling of oleogel delivery system. The influence of designed formulations on response variables (texture parameters), firmness, cohesiveness, consistency, and index of viscosity, was evaluated. Quality of essential oil of thyme was assessed by determinate concentration of thymol and carvacrol using gas chromatography with flame ionization detection (GC-FID). Microbiological tests have shown that oleogel with thyme essential oil affects Candida albicans microorganism when thyme essential oil's concentration is 0,05% in oleogel mixture.

Perennial legumes as a source of ingredients for healthy food: proximate, mineral and phytoestrogen composition and antibacterial activity.

ABSTRACT: Perennial legumes have been used as edible or medicinal plants since ancient times. The focus of the current study are perennial legumes-Trifolium pratense L., T. medium L., Medicago sativa L., M. lupulina L., Onobrychis viciifolia Scop., Astragalus glycyphyllos L. and A. cicer L.-of branching stage as a potential source of value-added ingredients for healthy food. Freeze-dried samples were analysed for proximal composition, mineral, isoflavone and coumestrol contents as well as for antimicrobial activity. Legumes were protein-rich (23.0/100 g on average). Mineral contents in 100 g of plant dry matter averaged: K 2.64 g, Ca 1.81 g, Mg 0.475 g, P 0.324 g, Zn 2.76 mg and Fe 37.8 mg. According to the total amount of phytoestrogens, the species ranked as follows: T. medium (34.4 mg/g) â‰« T. pratense â‰« O. viciifolia ≥ M. sativa = A. cicer = M. lupulina ≥ A. glycyphyllos (0.207 mg/g). Extracts of legumes, especially that of O. viciifolia, exhibited noticeable potency to inhibit the growth of Gram-positive and Gram-negative bacteria. Perennial legumes of branching stage can be used as protein, mineral and phytoestrogen rich source for food ingredients and supplements.

Prevalence of O25b-ST131 clone among Escherichia coli strains producing CTX-M-15, CTX-M-14 and CTX-M-92 ß-lactamases.

BACKGROUND: Dissemination of multidrug-resistant Escherichia coli is closely associated with the worldwide spread of a single clone ST131, which is the main cause of urinary tract and bloodstream infections in patients from nursing homes and immunocompromised patients. The aim of our study was to determine the prevalence of ST131 clone and the replicons involved in the spread of blaCTX-M genes among O25b-ST131 CTX-M-producing E. coli isolates in Lithuania. METHODS: The strains included in this study were screened for CTX-M ß-lactamase-encoding genes, phylogenetic groups and ST131 clone by PCR. Bacterial conjugation was performed to identify plasmid replicon types responsible for blaCTX-M genes dissemination. RESULTS: A total of 158 E. coli clinical non-duplicate ESBL isolates were analyzed. Nearly half (n = 67, 42.4%) of the investigated E. coli isolates belonged to phylogenetic group B2. The isolates producing CTX-M-92 ß-lactamases were identified to be the ST131 clone more frequently than the non-ST131 clone (11.5% vs. 3.1%, p = .035). The CTX-M-15 isolates were identified as ST131 isolates less frequently than non-ST131 isolates (50.8% vs. 71.1%; p = .015). The ST131 clone isolates contained type L/M and A/C replicons; a fused FII/FIB replicon was found in four isolates (23.5%). Type HI1 replicon was identified in ST131 E. coli isolates producing CTX-M-15 ß-lactamases. CONCLUSIONS: This study demonstrates the predominance of the ST131 clone among CTX-M ß-lactamase-producing E. coli isolates. Dissemination of blaCTX-M genes in ST131 strains can be linked not only to highly adapted IncF plasmids such as FII/FIB and FII, but also to plasmid replicon types A/C, L/M and HI1.

Formation and Biopharmaceutical Characterization of Electrospun PVP Mats with Propolis and Silver Nanoparticles for Fast Releasing Wound Dressing.

Antibacterial, antiviral, antifungal, antioxidant, anti-inflammatory, and anticancer activities of propolis and its ability to stimulate the immune system and promote wound healing make it a proper component for wound dressing materials. Silver nanoparticles are recognized to demonstrate strong antiseptic and antimicrobial activity; thus, it also could be considered in the development of products for wound healing. Combining propolis and silver nanoparticles can result in improved characteristics of products designed for wound healing and care. The aim of this study was to formulate electrospun fast dissolving mats for wound dressing containing propolis ethanolic extract and silver nanoparticles. Produced electrospun nano/microfiber mats were evaluated studying their structure, dissolution rate, release of propolis phenolic compounds and silver nanoparticles, and antimicrobial activity. Biopharmaceutical characterization of electrospun mats demonstrated fast release of propolis phenolic compounds and silver nanoparticles. Evaluation of antimicrobial activity on Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Bacillus subtilis, Bacillus cereus, and Candida albicans strains confirmed the ability of electrospun mats to inhibit the growth of the tested microorganisms.

Alternative preparation of propolis extracts: comparison of their composition and biological activities.

BACKGROUND: Propolis is the bee product noted for multiple biological effects, and therefore it is widely used for the prevention and treatment of a variety of diseases. The active substances of propolis are easily soluble in ethanol. However ethanolic extracts cannot be used in treatment of certain diseases encountered in ophthalmology, pediatrics, etc. Unfortunately, the main biologically active substances of propolis are scarcely soluble in water, oil and other solvents usually used in pharmaceutical industry. The aim of this study was to investigate chemical composition, radical scavenging and antimicrobial activity of propolis extracts differently made in nonethanolic solvents. METHODS: Total content of phenolic compounds in extracts was determined using Folin-Ciocalteu method. Chemical composition and radical scavenging activity of extracts were determined using HPLC system with free radical reaction detector. Antimicrobial activity of examined preparations was evaluated using the agar-well diffusion assay. RESULTS: Total amount of phenolic compounds in extracts made in polyethylene glycol 400 (PEG) and water mixture or in PEG, olive oil and water mixture at 70 °C was comparable to that of ethanolic extract. Predominantly identified compounds were phenolic acids, which contribute ca. 40 % of total radical scavenging activity. Investigated nonethanolic extracts inhibited the growth and reproduction of all tested microrganisms. Antimicrobial activity of some extracts was equal or exceeded the antimicrobial effect of ethanolic extract. Extracts made in pure water or oil only at room temperature, contained more than 5 - 10-fold lower amount of phenolic compounds, and demonstrated no antimicrobial activity. CONCLUSIONS: Nonethanolic solvent complex and the effect of higher temperature allows more effective extraction of active compounds from propolis. Concentration of total phenolic compounds in these extracts does not differ significantly from the concentration found in ethanolic extract. Propolis nonethanolic extracts have radical scavenging and antimicrobial activity.

Viability changes: microbiological analysis of dental casts.

BACKGROUND: This study evaluated the survival of the most prevalent oral bacteria and fungi (Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, and Candida albicans) in dental casts, and compared changes in the amounts of these microorganisms at different time intervals to determine how long dental casts may pose threat to the health of dental personnel and patients. MATERIAL AND METHODS: When manufacturing the casts, regular water was replaced with sterile distilled water, where suspensions of the studied bacteria or the fungus at certain concentrations were prepared. When the dental casts were fully set (solidified), plaster shavings were examined immediately after the contact of the studied microorganism with the plaster, as well as after 1, 2, 24, 48, 72, 96, and 120 hours. Following that, we measured how the amount of the studied bacteria and fungi in 1 gram of the plaster changed within the studied period of time. RESULTS: Klebsiella pneumoniae survived in plaster for up to 4 days, and the reduction in the number of these bacteria became statistically significant after 1 day (p<0.05). Staphylococcus aureus remained viable in plaster for up to 4 days, and the number of these bacteria dropped after 1 day (p<0.05). Escherichia coli disappeared after 2 days, and a reduction was already observed after 2 hours (p<0.05). Candida albicans in plaster models died within 2 days, and a reduction in their number was observed after 1 day (p<0.05). CONCLUSIONS: The microorganisms did not multiply in the gypsum casts and their number significantly dropped instead of increasing.

A combination of grapefruit seed extract and concentrated cranberry juice as a potential antimicrobial preservative for the improvement of microbiological stability of hypromellose gel.

Aqueous hypromellose gels are not microbiologically stable - they show signs of microorganism growth during storage. To extend the shelf-life of the gels, antimicrobial preservatives are needed. Some substances of plant origin are known for their antimicrobial properties, and thus they may be used as an alternative to synthetic preservatives. Therefore, the aim of this study was to evaluate the microbiological stability of aqueous hypromellose gel and the effectiveness of natural substances - grapefruit seed extract (GSE), concentrated cranberry juice, and a combination thereof - on the antimicrobial protection of the gel. The evaluation of the antimicrobial activity of GSE and cranberry juice showed that their antimicrobial effects differed. Both cranberry juice and GSE inhibited the growth of the standard gram-positive and gram-negative bacteria, but the effect of GSE was significantly stronger. Candida albicans was sensitive only to GSE. For this reason, in order to affect all the microorganisms studied, either a combination of 0.7% GSE and 10% cranberry juice, or 5% GSE alone may be used. The combination of GSE and cranberry juice was effective only in acidic medium (pH being 2.5-5), while the antimicrobial effect of GSE was not dependent on the pH value.

CTX-M-producing Escherichia coli in Lithuania: associations between sites of infection, coresistance, and phylogenetic groups.

Increasing resistance of Escherichia coli (E. coli) to antibiotics, especially to the third-generation cephalosporins, has prompted studies on widespread resistance genes such as blaCTX-M and differentiation of E. coli to phylogenetic groups. The aim of this study was to determine the associations between the CTX-M type and the phylogenetic group, the site of infection, and coresistance in Lithuanian E. coli isolates producing ß-lactamases. MATERIAL AND METHODS. A total of 90 E. coli ESBL strains were recovered from the lower respiratory tract, the urinary tract, sterile body sites, wounds, and other body sites between 2008 and 2012. The E. coli isolates resistant to at least 2 antibiotics with different modes of action along with resistance to cefotaxime were considered as multiresistant. The blaCTX-M, blaTEM, blaOXA-1, and blaSHV genes, the phylogenetic groups, and the resistance profiles were analyzed. RESULTS. Of the 90 isolates, 84 (93.3%) were classified as multiresistant and 6 (6.6%) as resistant. The blaCTX-M-15 gene was the most prevalent gene followed by the blaCTX-M-14 and blaCTX-M-92 genes. The logistic regression analysis revealed the associations between CTX-M-15 and resistance to ceftriaxone, between CTX-M-14 and resistance to cefoxitin, aztreonam, ampicillin/sulbactam, ticarcillin/clavulanic acid, and tobramycin, and between CTX-M-92 and resistance to cefepime, piperacillin/tazobactam, gentamicin, and tobramycin. CONCLUSIONS. The results of this study showed a significant association between CTX-M-15, CTX-M-14, and CTX-M-92 ß-lactamases and resistance to some antibiotics as well as CTX­M-14 ß-lactamase and phylogenetic group A in the Lithuanian population. The associations between the CTX-M type and the site of infection were not determined.

Synthesis and antimicrobial properties of naphthylamine derivatives having a thiazolidinone moiety.

OBJECTIVE: The aim of this study was to evaluate the influence of pharmacophores having naphthylamine and nitro groups on the antimicrobial (antibacterial and antifungal) activity of thiazolidinone derivatives. MATERIALS AND METHODS: The initial 5-substituted-2-methylmercaptothiazolidin-4-ones were subjected to S-demethylation to yield 2-amino-substituted thiazolidinones. 4-Nitro-1-naphthylamine, nitrofuran aldehydes, and nitrobenzene aldehydes were used as pharmacophoric compounds having amino or aldehyde groups. Antimicrobial (antibacterial and antifungal) activity of the new compounds was tested in vitro against bacterial cultures - Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae - and fungal cultures - Candida albicans, Candida glabrata, Candida krusei, Candida kefyr, Candida tropicalis, and Candida parapsilosis. RESULTS: Microbiological analysis showed that all new thiazolidinone derivatives with nitronaphthylamine substituent possessed antibacterial and antifungal properties. New compounds 2a-b showed similar antibacterial activity in vitro against S. aureus and B. subtilis as aminopenicillins. The lowest antibacterial activity of all newly synthesized compounds was against capsule-forming bacteria K. pneumoniae and against gram-negative bacteria E. coli (minimum inhibitory concentration range, 500-1000 µg/mL). CONCLUSIONS: The minimum inhibitory concentration of naphthylamine derivatives varied in the range of 0.4-1000 µg/mL, and activity of some newly synthesized compounds was similar to the activity of aminopenicillins and fluconazole, an antifungal preparation. Based on the results, it is possible to separate the perspective group of potential antimicrobial compounds.

Antibiotic resistance mechanisms of clinically important bacteria.

Bacterial resistance to antimicrobial drugs is an increasing health and economic problem. Bacteria may be innate resistant or acquire resistance to one or few classes of antimicrobial agents. Acquired resistance arises from: (i) mutations in cell genes (chromosomal mutation) leading to cross-resistance, (ii) gene transfer from one microorganism to other by plasmids (conjugation or transformation), transposons (conjugation), integrons and bacteriophages (transduction). After a bacterium gains resistance genes to protect itself from various antimicrobial agents, bacteria can use several biochemical types of resistance mechanisms: antibiotic inactivation (interference with cell wall synthesis, e.g., ß-lactams and glycopeptide), target modification (inhibition of protein synthesis, e.g., macrolides and tetracyclines; interference with nucleic acid synthesis, e.g., fluoroquinolones and rifampin), altered permeability (changes in outer membrane, e.g., aminoglycosides; new membrane transporters, e.g., chloramphenicol), and "bypass" metabolic pathway (inhibition of metabolic pathway, e.g., trimethoprim-sulfamethoxazole).

Investigation of the antimicrobial activity of Rhaponticum (Rhaponticum carthamoides D.C. Iljin) and shrubby cinquefoil (Potentilla fruticosa L.).

The aim of the study was to determine antimicrobial activity of rhaponticum and shrubby cinquefoil extracts. MATERIAL AND METHODS. Ethanol extract from the leaves of rhaponticum (Rhaponticum carthamoides D.C. Iljin) and shrubby cinquefoil (Potentilla fruticosa L.) was produced at the Department of Food Technology, Kaunas University of Technology. The antimicrobial activity of the viscous extract or rhaponticum and shrubby cinquefoil was evaluated using standard microorganism cultures (bacteria Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 33499, Pseudomonas aeruginosa ATCC 27853, Proteus mirabilis ATCC 12459, Bacillus subtilis ATCC 6633, Bacillus cereus ATCC 8035 and fungi Candida albicans ATCC 60193). The minimum inhibitory concentration (MIC) of the examined preparations was determined. RESULTS. Both studied preparations - rhaponticum (Rhaponticum carthamoides D.C. Iljin) and shrubby cinquefoil (Potentilla fruticosa L.) - demonstrated similar antimicrobial activity. The highest sensitivity to the studied preparations was observed in microbes with eukaryotic cell structure: Candida albicans, which is a fungus, and a spore-forming prokaryotic bacterium, Bacillus cereus. The highest resistance was observed in Escherichia coli and Klebsiella pneumoniae. CONCLUSIONS. The studied preparations - viscous extracts of rhaponticum and shrubby cinquefoil - are substances with antimicrobial activity against gram-positive (Staphylococcus aureus and Enterococcus faecalis) and gram-negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus mirabilis) bacteria, spore-forming bacteria (Bacillus subtilis and Bacillus cereus), and fungi (Candida albicans).

Transferable class 1 and 2 integrons in Escherichia coli and Salmonella enterica isolates of human and animal origin in Lithuania.

Antibiotic-resistant Escherichia coli (n = 191) and Salmonella enterica (n = 87) isolates of human and animal origin obtained in Lithuania during 2005-2008 were characterized for the presence and diversity of class 1 and 2 integrons. E. coli isolates were obtained from patients with urinary tract infections (UTIs) (n = 59) and both healthy and diseased farm animals, including poultry (n = 54), swine (n = 35), and cattle (n = 43). Isolates of non-typhoidal S. enterica were recovered from salmonellosis patients (n = 37) and healthy animals, including poultry (n = 31) and swine (n = 19). The presence of integrons, their gene cassette structure, and genome location were investigated by polymerase chain reaction, restriction fragment-length polymorphism, DNA sequencing, Southern blot hybridization, and conjugation experiments. Forty percent of the E. coli and 11% of the S. enterica isolates carried class 1 integrons, whereas class 2 integrons were found in E. coli isolates (9%) only. The incidence of integrons in human UTIs and cattle isolates was most frequent (p < 0.01). A total of 23 different gene cassettes within 15 different variable regions were observed. Seven different integron types, all of them transferable by conjugation, were common for isolates from human infections and for one or more groups of animal isolates. The most prevalent integron types contained arrays dfrA1-aadA1 (36%), dfrA17-aadA5 (23%), and dfrA1-sat1-aadA1 (78%). Two E. coli isolates from humans with UTIs harbored class 1 integron on conjugative plasmid with the novel array type of 4800 bp/dfrA17-aadA5Δ-IS26-ΔintI1-aadB-aadA1-cmlA residing on the Tn21-like transposon. Three S. enterica isolates from swine contained class 1 integron with the newly observed array type of 1800 bp/aadA7-aadA7. Integrons of 10 different types of both classes were located on transferable plasmids in E. coli and S. enterica. Our study demonstrated the existence of a considerable and common pool of transferable integrons in E. coli and S. enterica present in clinical and livestock environment in Lithuania.

Tigecycline - how powerful is it in the fight against antibiotic-resistant bacteria?

Tigecycline is a semisynthetic analogue of earlier tetracyclines and represents the first member of a novel class of antimicrobials - glycylcyclines - recently approved for clinical use. It is active against a broad range of gram-negative and gram-positive bacterial species including clinically important multidrug-resistant nosocomial and community-acquired bacterial pathogens. The exact molecular basis of tigecycline action is not clear at present, although similarly to the tetracyclines, it has been shown to inhibit the translation elongation step by binding to the ribosome 30S subunit and preventing aminoacylated tRNAs to accommodate in the ribosomal A site. Importantly, tigecycline overcomes the action of ribosomal protection proteins and is not a substrate for tetracycline efflux pumps of most bacteria - well-known and prevalent cellular mechanisms of microbial tetracycline resistance. The present review summarizes current knowledge on the molecular mechanism of the tigecycline action, antibacterial activity against various bacteria, clinical application, development of resistance to glycylcyclines.

Prevalence of trimethoprim resistance genes in Escherichia coli isolates of human and animal origin in Lithuania.

A total of 456 non-repetitive Escherichia coli isolates from human clinical specimens (urinary, n=134; cervix, vagina and prostate, n=52; blood, pus and wounds, n=45), healthy animals (cattle, n=45; poultry, n=20) and diseased animals (cattle, n=53; swine, n=64; poultry, n=43) obtained in Lithuania during the period 2005-2008 were studied for trimethoprim (TMP) resistance and the prevalence of dfr genes. A TMP resistance rate in the range of 18-26 % respective to the origin was found in clinical isolates, 23-40 % in isolates from diseased animals and 9-20 % in isolates from healthy animals. Of 112 TMP-resistant isolates, 103 carried at least one of the six dfrA genes (dfrA1, dfrA5, dfrA8, dfrA12, dfrA14 and dfrA17) as determined by multiplex PCR and RFLP. The dfrA1 and dfrA17 genes were found most frequently in clinical isolates (17 and 19 isolates, respectively), whilst dfrA1 and dfrA14 genes dominated in isolates of animal origin (25 and 13 isolates, respectively). The dfrA5, dfrA12 and dfrA8 genes were detected at lower frequencies. The association with class 1/class 2 integrons was confirmed for 73-100 % of dfr genes found in most groups of isolates, except for the isolates from diseased swine. In this group, the majority of dfr-positive isolates (67 %, 8/12) carried dfrA8 (6/12) or dfrA14 genes (2/12) that were not associated with integrons. Non-integron location was also confirmed for the remaining dfrA8 genes (six clinical isolates and one isolate from diseased cattle) and for dfrA14 genes (two isolates from diseased cattle and swine each). All cassette-independent dfrA14 genes were found to be located within the strA gene. This study on the prevalence and distribution of TMP resistance genes among E. coli isolates of human and animal origin in Lithuania demonstrates that dfr genes are carried most frequently as gene cassettes within class 1 and/or class 2 integrons. However, TMP resistance in some of the isolates was found to be mediated by non-integron-associated dfrA8 and dfrA14 genes, indicating the existence of alternative sources for the spread of resistance.

Reduction of nosocomial infections and mortality attributable to nosocomial infections in pediatric intensive care units in Lithuania.

OBJECTIVE: The aim of the study was to identify the most important risk factors for nosocomial infections, evaluate the incidence rates and risk changes after the multimodal intervention, and to assess mortality attributable to nosocomial infections. MATERIAL AND METHODS: This was a prospective surveillance study. Data were collected from January 2005 until December 2007 in three pediatric intensive care units. All patients aged between 1 month and 18 years hospitalized in units for more than 48 hours were included in the study. The patients were divided into preintervention (2006) and postintervention (2007) groups. The multimodal intervention included education of the staff and implementation of evidence-based infection control measures. RESULTS: A total of 755 children were included in the study. Major risk factors for nosocomial infections were identified: mechanical ventilation, central line, intracranial pressure device, and tracheostomy. Overall, the incidence rate (15.6 vs. 7.5 cases per 100 patients, P=0.002), incidence density (19.1 vs. 10.4 cases per 1000 patient-days, P=0.015), and the incidence of pneumonia (5.6 vs. 1.9 per 100 patients, P=0.016) have decreased in the postintervention as compared with the preintervention group. The relative risk reduction, absolute risk reduction, and number needed to treat were statistically significant for ventilator-associated pneumonia (66.5%, 3.7%, 27, respectively; P=0.016). There was no significant difference in survival time by the presence of nosocomial infection (83.67 patient-days without vs. 74.33 patient-days with infection, P>0.05) CONCLUSIONS: The most important risk factors for nosocomial infections were mechanical ventilation, central line, intracranial pressure device, and tracheostomy. After the multimodal intervention, there was a statistically significant decrease in the incidence rates of nosocomial infections and the risk reduction for ventilator-associated pneumonia. No significant impact of nosocomial infections on mortality was determined.

[Staphylococcus aureus prevalence among hospitalized patients]. / Staphylococcus aureus paplitimas hospitalizavimo laikotarpiu.

OBJECTIVE. To determine the prevalence of Staphylococcus aureus strains among hospitalized patients at the beginning of their hospitalization and during their treatment and the resistance of strains to antibiotics, and to evaluate epidemiologic characteristics of these strains. PATIENTS AND METHODS. Sixty-one patients treated at the Department of Cardiac, Thoracic and Vascular Surgery were examined. Identification of Staphylococcus aureus strains was performed using plasmacoagulase and DNase tests. The resistance of Staphylococcus aureus to antibiotics, beta-lactamase production, phagotypes, and phagogroups were determined. The isolated Staphylococcus aureus strains were tested for resistance to methicillin by performing disc diffusion method using commercial discs (Oxoid) (methicillin 5 microg per disk and oxacillin 1 microg per disk). RESULTS. A total of 297 Staphylococcus aureus strains were isolated. On the first day of hospitalization, the prevalence rate of Staphylococcus aureus strains among patients was 67.3%, and it statistically significantly increased to 91.8% on days 7-10 of hospitalization (P<0.05). During hospitalization, patients were colonized with Staphylococcus aureus strains resistant to cephalothin (17.6% of patients, P<0.05), cefazolin (14.6%, P<0.05), tetracycline (15.0%, P<0.05), gentamicin (37.7%, P<0.001), doxycycline (30.7%, P<0.001), and tobramycin (10.6%, P>0.05). Three patients (4.9%) were colonized with methicillin-resistant Staphylococcus aureus strains, belonging to phage group II phage type 3A and phage group III phage types 83A and 77; 22.6-25.5% of Staphylococcus aureus strains were nontypable. During hospitalization, the prevalence rate of phage group II Staphylococcus aureus strains decreased from 39.6% to 5.7% (P<0.05) and the prevalence rate of phage group III Staphylococcus aureus strains increased to 29.5% (P<0.001). CONCLUSIONS. Although our understanding of Staphylococcus aureus is increasing, well-designed community-based studies with adequate risk factor analysis are required to elucidate further the epidemiology of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus. Surveillance of methicillin-resistant Staphylococcus aureus provides relevant information on the extent of the methicillin-resistant Staphylococcus aureus epidemic, identifies priorities for infection control and the need for adjustments in antimicrobial drug policy, and guides intervention programs.

[Antimicrobial activity of soft and purified propolis extracts]. / Tirstojo ir isgryninto propolio ekstrakto antimikrobinis aktyvumas.

OBJECTIVE: To evaluate the antimicrobial activity of soft and purified propolis extracts. STUDY OBJECT AND METHODS: Antimicrobial activity of soft and purified propolis extracts was determined with reference cultures of Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 33499, Pseudomonas aeruginosa ATCC 27853, Proteus mirabilis ATCC 12459, Bacillus subtilis ATCC 6633, Bacillus cereus ATCC 8035, and fungus Candida albicans ATCC 60193. Microbiological tests were performed under aseptic conditions. Minimum inhibitory concentration (MIC)--the highest dilution of preparation (the lowest concentration of preparation) that suppresses growth of reference microorganisms--was determined. RESULTS: Concentration of phenolic compounds in soft propolis extract that possesses antimicrobial activity against gram-positive (Staphylococcus aureus, Enterococcus faecalis) and gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis) is 0.587+/-0.054 mg and 0.587+/-0.054-0.394+/-0.022 mg (P>0.05) and in purified propolis extract--0.427+/-0.044 mg and 0.256+/-0.02 mg (P>0.05). Klebsiella pneumoniae is most resistant to soft propolis extract when the concentration of phenolic compounds is 1.119+/- 0.152 mg and to purified propolis extract when the concentration of phenolic compounds is 1.013+/-0.189 mg (P>0.05). Spore-forming Bacillus subtilis bacteria are more sensitive to soft and purified propolis extracts when the concentration of phenolic compounds is 0.134+/-0.002 mg and 0.075+/-0.025 mg, respectively, and Bacillus cereus--when the concentration is 0.394+/-0.022 mg and 0.256+/-0.02 mg (P>0.05). Sensitivity of fungus Candida albicans to soft and purified propolis extracts is the same as Bacillus subtilis. Encapsulated bacterium Klebsiella pneumoniae is most resistant to antimicrobial action of soft and purified propolis extracts as compared with gram-positive Staphylococcus aureus and Enterococcus faecalis bacteria (P<0.05), gram-negative Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis (P<0.05), spore-forming Bacillus subtilis and Bacillus cereus bacteria (P<0.05), and fungus Candida albicans (P<0.05). There is no statistically significant difference between antimicrobial effect of soft propolis extract and purified propolis extract on gram-positive bacteria, gram-negative bacteria, spore-forming bacteria, encapsulated bacteria, and Candida fungus. CONCLUSIONS: Soft and purified propolis extracts possess antimicrobial activity. They could be recommended as natural preservatives in the manufacture of pharmaceutical products.