The influence of biologically active compounds on oxidative stress markers and antioxidant system

Nicolae Testemitanu State University of Medicine and Pharmacy, Republic of MoldovaIntroduction. The development of degenerative processes relates to the presence of excessive harmful free radicals, which cause damaging oxidative processes within the body. Various defense mechanisms protect cells from the destructive potential of free radicals. These include antioxidant enzymes: superoxide dismutase, catalase, glutathione S-transferase, glutathione peroxidase and glutathione reductase. These enzymes play a significant role in reducing oxidative stress, by preventing the spread of harmful free radicals. Material and methods. The present study used the {N- (prop-2-en-1-yl) -2 - [(pyridin-2- yl) -methylidene] hydrazine-1-carbothioamide} aquacupper (II) chemical compound and the MX1 extract – a biological compound, which is a pigment of Myxoxanthophyll carotenoids, obtained from Spirulina platensis biomass at a concentration of 0.214 mg/ml in 80% aqueous solution of ethyl alcohol. The study also determined both the separate and combined effects of chemical and biological compounds on the spontaneous production of biochemical parameters, which was carried out in vitro according to the method described by Rîjcova S. et al. with some modifications. To assess the oxidative stress, the malondialdehyde (MDA) concentration and the advanced oxidation protein products (AOPP) were determined, whereas the antioxidant system was assessed via the identification of the activity of superoxide dismutase (SOD), total antioxidant (TAA), glutathione-S-transferase (GST), catalase (CT), glutathione peroxidase (GPX) and glutathione reductase (GR). The blood tests were collected from 10 healthy people aged 25 to 35 years. Results. The research findings showed that the biological compound under study had positive effects on all the studied parameters, reducing both the MDA, µM/L (p=0.0085) and AOPP values, µM/L (p=0.018) on the one hand and increasing the potential antioxidant (SOD, u/c (p=0.0035), CT, µM/L (p=0.0029), TAA, µM/L (p=0.0059), GST, nM/sL (p=0.024), GPX, nM/sL (p=0.0041) and GR, nM/sL (p=0.0064)) on the other hand. The tested chemical compound exhibited negative effects, which led to higher MDA, µM/L (p=0.0085) and AOPP, µM/L (p=0.027) values. However, the chemical compound favored the antioxidant system (SOD, u/c (p=0.0035), CT, µM/L (p=0.0248), TAA, µM/L (p=0.0173), GST, nM/sL (p=0.023), GPX, nM/sL (p=0.0365) and GR, nM/sL (p=0.0076)). While studying the activity results of the tested combined compounds, we found that the biological compound determines positive effects, particularly on the oxidative stress markers, though no expected effect potentiation was found. Conclusions. Based on the obtained research findings regarding the biological compound with optimal effects on the studied systems, further relevant studies should be carried out. At the same time, the obtained results require confirmation under in vivo study conditions, thus not allowing concluding on the quantitative effect of the investigated substances, the argument being the relatively small number of respondents, determining wide confidence intervals and being one of the study limitations

Antibiotic susceptibility and some persistence factors of Gram-negative bacilli isolated from trophic ulcers

Department of Microbiology and Immunology, Nicolae Testemitsanu State University of Medicine and Pharmacy, Chisinau, the Republic of MoldovaAbstract Background: Infections that are difficult to treat might lead to high morbidity and mortality rates. In some infections, however, despite a proper antibiotic therapy, microorganisms might persist, under certain circumstances, and produce recurrent or chronic infections. It is a well-known fact that the persistence of microorganisms might influence their viability within the macro-organism, whereas the suppression of the microbial persistence via drug preparations might greatly reduce therapeutic duration. This study is aimed at assessing the antibiotic sensitivity and some factors, contributing to persistence of Gram-negative bacilli strains isolated from trophic ulcers. Material and methods: Data were collected and examined from 128 samples of patients with trophic ulcers. The bacteriological examinations, factors determining the persistence and the antibiotic susceptibility of the isolated strains were carried out in accordance with the current method. Results: 211 microbial strains were isolated. The identified microorganisms revealed a high taxonomic diversity, whereas Gram-negative bacilli made up 50.2%. Isolates showed multiple resistances to antimicrobial drugs in 76.4% of cases, 43.4% strains showed hemolytic, 88.7% – anti-lysozyme and 93.4% – anti-complementary activities, whereas 70.8% strains produced a detectable biofilm. The strains isolated from mixed infections exhibited a higher percentage of pathogenicity factors compared to those isolated from monoinfections. Conclusions: Gram-negative bacteria showed great resistance to the antimicrobial drug tests and multiple persistence factors. The results of the study proved that trophic ulcers are difficult to treat, thus being a major problem, which requires coherent monitoring and control

The bacterial strains isolated from trophic ulcers and their persistence factors

Background: Recently, a particular attention has been drawn to the study of the microbial persistence properties and their correlation with the rate of elimination from the source of infection, as well as the prognosis of the disease progression. Material and methods: There were examined 44 samples taken from patients with trophic ulcers. The bacteriological examination, as well as tests on determining both the persistence factors and the antibiotic susceptibility of the isolated strains were carried out according to the current method. Results: There were determined 80 isolated bacterial strains. Two and more strains were isolated in over half of these cases (52.3%). The most commonly involved strains were the genus Staphylococcus, followed by Enterobacter spp., Pseudomonas spp., Candida spp., and enterococci. Both gram-negative and gram-positive species exhibited a high-level antimicrobial resistance. The study of the persistence factors revealed that the strains isolated in mixed culture showed a higher rate of virulence (1.0-1.5 times higher) compared to isolates in pure culture. Conclusions: The main bacterial strains isolated from trophic ulcers are the genus Staphylococcus and the Enterobacteriaceae family. Isolated strains showed higher level of antimicrobial resistance and multiple persistence factors. The study results proved that treatment of trophic ulcers is still a major problem, requiring rational monitoring and management strategies

Antibiotic susceptibility and factors involved in virulence and persistence of Acinetobacter baumannii strains

Department of Microbiology and Immunology, Nicolae Testemitanu State University of Medicine and Pharmacy, Chisinau, the Republic of MoldovaAbstract. Background: Acinetobacter baumannii has emerged as a medically important pathogen because of the increasing number of infections produced by this organism over the preceding three decades and the global spread of strains with resistance to multiple antibiotic classes. Recently, a particular attention has been drawn to the study of the microbial persistence properties and their correlation with the rate of elimination from the source of infection, as well as the prognosis of the disease progression. Material and methods: There were examined 53 strains of A. baumannii, isolated from patients with trophic ulcers. The bacteriological examination, as well as tests on determining both the persistence factors and the antibiotic susceptibility of the isolated strains were carried out according to the current method. Results: A. baumannii strains were highly resistant to all antibiotics tested, 38 (71.7%) showed multidrug resistance. The studies regarding the persistence factors of A. baumannii strains, revealed that 100% exhibited an antilysosyme activity, 78.0% – anticomplementary activity, 73.6% – produce biofilms, 58.5% – hemolytic activity, 28.3% and 13.2% – lecithinase and plasma coagulation activity, respectively. Conclusions: Isolated strains showed higher level of antimicrobial resistance and multiple persistence factors. The study results proved that treatment of trophic ulcers is still a major problem, requiring rational monitoring and management strategies

Antibiotic resistance and biofilm formation of strains isolated from trophic ulcers

Nicolae Testemitanu State University of Medicine and Pharmacy, Republic of MoldovaIntroduction. The advancement of biomedical science has enabled to study the microorganisms in their natural environment, whereas over 95% of microorganisms existing in nature are in biofilms. Biofilm formation is an important strategy by which microorganisms survive and adapt in natural environments. Bacteria living in a biofilm usually have significantly different properties from free-floating bacteria of the same species, being protected by a dense biofilm structure, which allows them to cooperate and interact in different manners. The main features of the biofilms are their high resistance to disinfectants and antimicrobial drugs, whereas the thick extracellular matrix and the outer layer cells protect the interior of the community. It is estimated that microbial biofilms play a major role in over 80% of infections. Sixty percent of healthcare-associated infections are due to biofilm formation on medical implants. Moreover, many chronic diseases are associated with biofilms, such as infectious endocarditis, cystic fibrosis pneumonia, periodontitis, chronic rhinosinusitis, trophic ulcers and otitis media. Material and methods. The study was carried on 128 samples isolated from trophic ulcers. The microbial strains involved in the process were isolated in pure cultures, under laboratory conditions, and subsequently identified by classical microbiological methods and Vitek2 Compact system (BioMerieux), based on the morpho-biological, coloring and biochemical properties. The antimicrobial susceptibility and biofilm-forming ability testing was performed using the Kirby-Bauer disk diffusion technique and the quantitative adhesion test, respectively. Strains that showed resistance to three or more antibiotic groups were considered poly-resistant ones. Results. Bacteriological examination was carried out on 128 samples collected from patients with trophic ulcers. A single species of microorganisms was isolated in 35.9% of cases, two and more species in 53.1% and no microorganisms were isolated in 10.9% of cases. A total of 211 microbial strains were isolated and identified. The antibiotic susceptibility tests of strains isolated from trophic ulcers showed a high level of resistance to drug preparations. Of the 211 microbial strains isolated from trophic ulcers, 147 (69.7%) strains produced detectable biofilms (OD>0.112). As regarding the biofilm status, 58 (39.5%) isolates produced strong biofilms (OD>0.220), 67 isolates (45.6%) – moderate biofilms (OD 0.112-0.220) and 22 isolates (14.9%) – weak biofilms. The antibiotic resistance of biofilmforming compared to non-biofilm-forming strains showed that biofilm-forming strains had a higher resistance to all groups of drugs tested. Conclusions. The study results revealed a higher biofilm formation capacity at the strains isolated from trophic ulcers, as well as higher rates of antimicrobial resistance in biofilmproducing strains compared to non-producing ones. The obtained data proves a strong correlation between biofilm formation capacity and antimicrobial resistance patterns. The implementation of the relevant antimicrobial susceptibility testing of biofilm-producing strains will improve the management of infections caused by these microorganisms, as well as provide feasible strategies to prevent their spread

Этиологический спектр и терапевтические трудности раневых инфекций

Universitatea de Stat de Medicină şi Farmacie Nicolae Testemiţanu, Centrul Naţional de Sănătate Publică, Conferinţa știinţifico-practică naţională cu participare internaţională Sănătatea ocupaţională: probleme și realizări prima ediţie 5-7 iunie 2014Wound infections still represent one of the major issues of medicine due to the high morbidity and even mortality and to the economic consequences on patients and hospitals involved. The aim of our study is to determine the etiological spectrum and the therapeutically difficulties of the wound infections. Our stady has included 346 bacterial strains isolated from wounds secretion. The etiological spectrum was dominated by S. aureus and E. coli. The isolated bacterial strains have presented different levels of resistance to antibiotics.Раневые инфекции по-прежнему являются серьезной проблемой в медицине из-за высокой заболеваемости и смертности, а также из-за экономических последствий для больных и медицинских учреждений. Цель исследования заключается в определении этиологического спектра и терапевтических трудностей раневых инфекций. В исследование были включены 346 штаммов бактерий, выделенных из ран. В этиологическом спектре преобладали S. aureus и E. coli. Выделенные штаммы показали различные уровни устойчивости к антибиотикам

Грамотность населения в отношении применения антибиотиков в Республике Молдова

The purpose of this research was to study the attitudes and practices of people in the country associated with antibiotic use, assess the level of knowledge of general concepts, destination, and the resistance of microorganisms to these preparations. As a result we were able to highlight some important features to prevent progression of this phenomenon.Целью данного исследования было изучение привычек и практики населения республики, связанных с применением антибиотиков, чтобы оценить уровень знания общих понятий, правил назначения, а также представление о развитии устойчивости микроорганизмов к этим препаратам. В результате мы смогли выделить некоторые особенности, важные для предотвращения прогрессирования этого явления

Antimicrobial susceptibility and biofilm production among Staphylococcus and Candida species

Department of Microbiology and Immunology, Nicolae Testemitsanu State University of Medicine and Pharmacy, Department of Laboratory Diagnostic in Public Health, National Agency for Public Health, Chisinau, the Republic of MoldovaBackground: Biofilms are surface-attached groups of microbial cells that are embedded in an extracellular matrix. One of the main features of biofilms is their resistance to antimicrobial drugs; therefore, the biofilm-based infections are extremely difficult to treat. This study aimed to investigate the biofilmforming capacity of Staphylococcus spp. and Candida spp. strains isolated from collected clinical samples, as well as to assess their antibiotic susceptibility. Material and methods: The study was conducted on 134 strains of Staphylococcus spp. and 147 strains of Candida spp. isolated from various clinical specimens. Both biofilm formation and antibiotic susceptibility of the isolated strains were studied using contemporary standardized microbiological methods. Results: The results of the study showed a high biofilm-forming capacity among the clinical strains of Staphylococcus spp. and Candida spp., as well as a higher level of antibiotic resistance in biofilm-producing strains compared to biofilm non-producing ones. Conclusions: The high rates of antibiotic resistance and biofilm-forming capacity of strains represent a major public health challenge. The study showed a strong correlation between biofilm formation and antimicrobial resistance patterns

Rezistenţa la antibiotice şi factorii de persistenţă a tulpinilor de Staphylococcus aureus izolat din ulcere trofice

Background. The high antibiotic resistance of Staphylococcus aureus strains, together with the resistance to methicillin, the inducible resistance to clindamycin and the formation of biofilms present major problems in the therapy of infections caused by this species. Objective of the study. The aim of the study was to determine the antibiotic resistance and biofilm production capacity of Staphylococcus aureus strains isolated from trophic ulcers. Material and Methods. 138 S. aureus strains isolated from trophic ulcers were included in the study. Antibiotic susceptibility testing was performed by the diffusion method, and the ability to form biofilms by the quantitative adhesion test. Results. 93 (67.4%) S.aureus strains isolated from trophic ulcers were polyresistant to antibiotics, 69 (43.7%) were methicillin resistant, 31 (19.6%) were positive by D test and 81 ( 58.7%) produced biofilms. S. aureus strains were more sensitive to vancomycin (100%) and linezolid (90.6%). A higher rate of inducible clindamycin resistance was observed among methicillin-resistant strains (36.2%) compared to methicillin-sensitive S. aureus (6.7%). Similarly, higher rates of polyresistance and methicillin resistance were recorded among biofilm-producing strains compared to non-biofilm-producing strains (p <0.01). Conclusion. For a good management of S.aureus infections, it is important to include in the routine diagnosis the D test for the detection of inducible resistance to clindamycin, as well as the detection of biofilm production. Introducere. Rezistența înaltă la antibiotice a tulpinilor de Staphylococcus aureus, împreună cu rezistența la meticilină, rezistența inductibilă la clindamicină și formarea de biofilme prezintă problemele majore în terapia infecţiilor provocate de această specie. Scopul lucrării. Scopul studiului a fost determinarea rezistenţei la antibiotice și a capacității de producere a biofilmelor de către tulpinile de Staphylococcus aureus izolate din ulcere trofice. Material și Metode. Au fost incluse în studiu 138 de tulpini S. aureus izolate din ulcere trofice. Testarea sensibilităţii la antibiotice s-a efectuat prin metoda difuzimetrică, iar capacitatea de formare a biofilmelor prin testul cantitativ de aderență. Rezultate. 93 (67,4%) tulpini de S.aureus izolate din ulcere trofice au fost polirezistente la antibiotice, 69 (43,7%) au fost meticilin rezistente, 31(19,6%) au fost pozitive prin testul D şi 81 (58,7%) au produs biofilme. Tulpinile de S. aureus au prezentat sensibilitate sporită față de vancomicină (100%) și linezolid (90,6%). O rată înaltă de rezistență inductibilă la clindamicină a fost observată la tulpini rezistente la meticilină (36,2%) în comparație cu S. aureus sensibil la meticilină (6,7%). Similar, au fost înregistrate rate mai mari de polirezistență și rezistență la meticilină printre tulpinile producătoare de biofilme comparativ cu tulpinile non-producătoare de biofilme (p<0,01). Concluzii. Pentru un management bun al infecţiilor provocate de S.aureus este important de inclus în diagnosticul de rutină testul D pentru detectarea rezistenței inductibile la clindamicină, dar şi detectarea producerii de biofilme

Мониторинг устойчивых к антибиотикам штаммов сальмонелл, циркулирующих на территории Республики Молдова

Universitatea de Stat de Medicină şi Farmacie Nicolae Testemițanu, Centrul Național de Sănătate Publică, Conferința științifico-practică cu participare internațională Centrul de Sănătate Publică din municipiul Chișinău – 70 de ani la straja sănătăţii 23 octombrie 2014A correct choice of antibacterial treatment must be based on real knowledge of the bacterial sensibility/resistance to antibiotics. The aim of this study was evaluation of the present sensibility to antibiotics of Salmonella spp., isolated between January 2011 – December 2013 in Republic of Moldova. The results of the study show a high sensibility of Salmonella spp. to meropenem and to ciprofloxacin and the decrease of sensibility to nalidixic acid, usually used in fi rst treatment of acute diarrhea. Соответствующий выбор антибактериальной терапии должен быть основан на реальных знаниях о чувствительности/устойчивости бактерий к антибиотикам. Целью данного исследования было оценить текущюю восприимчивость к антибиотикам штаммов бактерии рода Salmonella, выделенных с января 2011 года по декабрь 2013 года в Молдове. Результаты показывают высокую чувствительность сальмонелл к меропенему и ципрофлоксацину и снижение чувствительности к налидиксовой кислоте, обычно используемой в первичном лечении острой диареи