Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Ograniczanie wyników
Czasopisma help
Lata help
Autorzy help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 83

Liczba wyników na stronie
first rewind previous Strona / 5 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  pathogenic bacteria
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 5 next fast forward last
EN
Water is a basic human requirement that is required in many processes, particularly those performed in households. However, in most circumstances, this critical product does not fulfill commonly recognized safety criteria. Various anthropogenic activities cause various forms of pollution; as a result, their physicochemical and biological components can pose major hazards to the environment and human health. The objective of this research was to evaluate the microbiological parameters along the Inaouene wadi and its tributaries, as well as their correlation with the physicochemical characteristics. In spring 2020, the following physicochemical and microbiological studies were conducted: ICP-AES was used to assess metals. The most polluted stations are located upstream (S1, S3, S4, S5, and S6). The highest concentrations of sulfate, orthophosphate, BOD5 , and nitrogen compounds are found at these stations. Illegal solid and liquid discharges from the tributaries S1 and S5, as well as urban settlements built on the banks of the Inaouen River, are to blame for this pollution, which has a direct and significant impact on water quality throughout the wadi. Furthermore, heavy metals (Zn, Fe, Co, Cr, Ag, and Cu) are abundant upstream of Inaouen and pass downstream. The monitoring of the evolution of microbiological pollution of wastewater has revealed a significant contamination of these waters upstream of the Wadi by the 3 groups of germs indicative of a fecal contamination and the presence of Listeria monocytogenes and salmonella in the upstream stations and especially S1, S3 and S5. The PCA revealed that the indicator bacteria of fecal contamination present negative correlations with dissolved oxygen, thus the lack of dissolved oxygen leads to a proliferation of germs in the water.
PL
Niniejsza praca przedstawia wyniki badań ilościowych i jakościowych drobnoustrojów potencjalnie chorobotwórczych z rodzaju Staphylococcus w wodzie kąpielisk jeziora Wigry, usytuowanego na terenie Polski Północno-Wschodniej. Próby do badań pobierano od czerwca 1995 do września 1999, w odstępach jednomiesięcznych. Do badań wytypowano osiem najbardziej uczęszczanych kąpielisk jeziora Wigry, usytuowanych w pobliżu miejsc kempingowych oraz ośrodków wczasowych. Próby wody pobierane ze stanowisk sytuowanych na terenie Plosa Północnego charakteryzowały się wyższą liczebnością drobnoustrojów rodzaju Staphylococcus w porównaniu z próbami wody pobieranymi na pozostałych stanowiskach. Spośród bakterii z rodzaju Staphylococcus najliczniej reprezentowane były gatunki: Staphylococcus capitis, Staphylococcus cohnii, Staphylococcus lentus oraz Staphylococcus xylosus. W 10% badanych prób wody stwierdzano obecność bakterii z gatunku Staphylococcus aureus przy braku bakterii z grupy pałeczki okrężnicy typu kałowego w 100 cm3 badanej wody. Rzeka Czarna Hańcza, która wprowadza duże ilości oczyszczonych cieków z Oczyszczalni Ścieków w Suwałkach do północnej części jeziora Wigry, ma ogromny wpływ na zanieczyszczenie tej części jeziora
EN
The paper presents the results of studies on detection, occurrence and differentiation of the waterborne bacterial potential pathogens from Staphylococcus genus in the water of Wigry Lake watering places in 3rth-eastern Poland. The samples of water were collected from June 1995 to September 1999 at one-month intervals, during bathing season. Eight sampling stations were selected in the most attended watering places of the lake, situated near landing stages, camping sites and holiday resorts were investigated. The watering places in the northern part of Lake Wigry (called Ploso Northern) showed the highest number of waterborne bacterial pathogens from Staphylococcus genus. The most numerous were species: Staphylococcus capitis, Staphyloccus cohnii, Staphylococcus lentus and Staphylococcus xylosus. Pathogens from Staphylococcus aureus species identified in 10% of water samples in the absence of faecal bacteria from Escherichia coli species (in 100 cm3 of water). The Czarna Hańcza River, which brought a lot of purified sewage from Wastewater Treatment Plant in Suwałki to northern part of Wigry Lake has immense influence on the pollution of this part Wigry Lake.
EN
The aim of this study was to evaluate the bioactivity of flavonoids extracted from sweet-cherry stems which are often used by a traditional system of medicine to treat gastro-intestinal and urinary tract infections but lacking any consistent scientific evidence; moreover the information about the class of phenolics, their content and the potential bioactivity of such material is very scarce. Thus, in this context, we have set a research study in which we evaluated the profile and content of phenolics extracted from sweet-cherry stems through a conventional (70ºC and 20 min) and ultrasound assisted extraction (40 kHz, room temperature and 20 min). The extracts were phytochemically characterized by using an HPLC-DAD-UV/VIS system and assayed by an in vitro minimum inhibitory concentration (MIC) bioassay against Escherichia coli isolates. Simultaneously, the total antioxidant activities were measured using the 2,2'-azinobis-3-ethylbenzothiazoline-6-sulphonate (ABTS•+) radical cation assay. Our results indicate that sweet-cherry stems have a high content of sakuranetin, ferulic acid, p-coumaric acid, p-coumaroylquinic acid, chlorogenic acid and its isomer neochlorogenic acid. Their average levels were highly affected by the extraction method used (p<0.001). The same trend was observed for total antioxidant activity and MIC values. The extracts produced with ultrasounds presented both, a higher total antioxidant activity and a lower minimum inhibitory concentration. Statistical analyses of our results showed a significant correlation (p<0.01) of total antioxidant activity and minimum inhibitory concentration with phenolics present in the extracts studied. Thus, we can conclude that cherry stems can be further exploited to purify compounds and produce coproducts with enhanced biologically added value for pharmaceutical industry.
EN
The role of the genus Acanthamoeba in the process of maintaining, multiplying and transmitting human pathogens has not been well recognized. The aim of our study was to evaluate the association of potentially pathogenic Acanthamoeba spp. with bacteria in strains recently isolated from Lake Malta near the city of Poznań, Poland. Most of the isolated amoebae belonged to the species A. castellanii and A. rhysodes. The majority of the isolates were pathogenic for mice and amoebae could be recovered from their brains and lungs. In those cases when amoebae could not be recovered from the autopsy material histopathological analysis showed changes in tissues indicating bacterial infection. We found that approximately 50% of the isolates were associated with endosymbiotic or endocytobiotic bacteria, e.g., Proteus sp., Micrococcus sp., Chryseobacterium meningosepticum, Clostridium perfringens, Escherichia coli, Salmonella sp., Legionella pneumophila and other species. The presence of bacteria residing inside free-living amoebae possess a great challenge in terms of disease control and sanitation of contaminated water sources.
EN
The application of random amplified polymorphic DNA- polymerase chain reaction (RAPDPCR) was found to be a simple, cheap and rapid tool to discriminate human pathogenic bacterial isolates especially at intraspecific level. This molecular biological technique relies on the use of random oligonucleotide primers that arbitrarily amplifies specific regions of the genome which gives rise to a unique genomic fingerprint of the strains under investigations. With continued development of novel molecular-based technologies for rapid, high-throughput detection of food borne pathogenic bacteria, the future of conventional microbiological methods such as viable cell enumeration, selective isolation of bacteria on commercial media, and immunoassays seems tenuous. Approaches that enhance recovery of sub lethally injured bacteria, differentiation among species, differentiation among bacteria of interest using biochemical profiling, enumeration using impedance technology, techniques to confirm the presence of target pathogens using immunological methods, and bioluminescence applications for hygiene monitoring are of utmost need in identifying and combating the human pathogenic isolates. The aim of this study is to estimate the efficiency of RAPD-PCR technique in assessing the genetic diversity of diseases causing bacterial isolates. The use of RAPD-PCR in evaluating the genomic variability among the pathogenic strains belonging to different genus are also been discussed in the present report.
EN
INTRODUCTION: Under natural conditions, airways are exposed to various microorganisms present in the environ¬ment. The development of an infection occurs through an imbalance between the defense capabilities and the virulence of microorganisms. Respiratory tract infections caused by bacteria lead to mild and severe inflammation of the air¬ways. The group of microorganisms occurring as an etiological factor of bacterial respiratory infections, in addition to frequently occurring Gram (-) rod-shaped bacteria, includes Gram (+) microorganisms, among them: Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes. In recent years, there has been an increase in the re¬sistance of microorganisms, isolated from infections, to many antibiotics. Therefore, analysis of the pathogenic species Gram (+) as well as the profiles of their resistance during a period of 5 years became expedient. MATERIALS AND METHODS: 3810 results of bacteriological tests of sputum and bronchial lavage were evaluated, which were collected from patients hospitalized in the Department of Lung Diseases and Tuberculosis of the Inde¬pendent Public Clinical Hospital No. 3 in Zabrze. The study was conducted in the Microbiological Laboratory of the Department of Microbiology and Immunology in Zabrze, Medical University of Silesia in Katowice. RESULTS: 1263 strains of pathogenic bacteria were cultured, including 445 strains of Gram (+) rod-shaped bacteria, which comprised 35.2% of the total amount of pathogenic bacteria. The predominant pathogen in Gram (+) bacteria over 5 years was S. aureus MSSA from sputum and bronchial lavage. Gram (+) microorganisms, in 2008–2012, showed the highest percentage of resistance in relation to tetracyclines, then to macrolides, sulfonamides, trimethoprim and lincosamides. The percentage of resistance in relation to quinolones and aminoglycosides was at a similar level. Emergency microorganisms Gram (+) showed the highest percentage of resistance over 5 years compared to macro¬lides and lincosamides.
PL
WSTĘP: W naturalnych warunkach drogi oddechowe narażone są na działanie różnych drobnoustrojów znajdujących się w środowisku. Do rozwoju zakażenia dochodzi poprzez zaburzenie równowagi między zdolnościami obronnymi a zjadliwością drobnoustrojów. Zakażenia układu oddechowego wywołane przez bakterie prowadzą do łagodnych i ciężkich zapaleń dróg oddechowych. Do grupy drobnoustrojów występujących jako czynnik etiologiczny bakteryjnych zakażeń układu oddechowego, oprócz licznie występujących pałeczek Gram (-), zalicza się drobnoustroje Gram (+), a wśród nich Staphylococcus aureus, Streptococcus pneumoniae i Streptococcus pyogenes. W ostatnich latach obserwowany jest wzrost oporności drobnoustrojów, izolowanych z zakażeń, na wiele antybiotyków. Celowa stała się zatem analiza chorobotwórczych gatunków drobnoustrojów Gram (+), a także profili ich oporności w ciągu 5 lat. MATERIAŁ I METODY: Ocenie poddano 3810 wyników badań bakteriologicznych plwociny i popłuczyn oskrzelowych, które pobrano od pacjentów hospitalizowanych w Klinice Chorób Płuc i Gruźlicy Samodzielnego Publicznego Szpitala Klinicznego Nr 3 w Zabrzu. Badania przeprowadzono w Laboratorium Mikrobiologicznym Katedry i Zakładu Mikrobiologii i Immunologii w Zabrzu Śląskiego Uniwersytetu Medycznego w Katowicach. WYNIKI: Wyhodowano 1263 szczepy bakterii chorobotwórczych, w tym 445 szczepów pałeczek Gram (+), które stanowiły 35,2% ogólnej liczby bakterii patogennych. Patogenem dominującym w grupie bakterii Gram (+) uzyska¬nym z plwocin i popłuczyn oskrzelowych w ciągu 5 lat był S. aureus MSSA. Drobnoustroje Gram (+) w latach 2008–2012 wykazały najwyższy odsetek oporności w stosunku do tetracyklin, następnie do makrolidów, sulfonamidów, trimetoprymu i linkozamidów. Odsetek oporności w stosunku do chinolonów i aminoglikozydów kształtował się na podobnym poziomie. Alarmowe drobnoustroje Gram (+) wykazały najwyższy odsetek oporności w ciągu 5 lat w sto¬sunku do makrolidów i linkozamidów.
PL
Omówiono znaczenie występowania bakterii chorobotwórczych w żywności oraz podano warunki umożliwiające ich rozwój. Przedstawiono sytuację epidemiologiczną w zakresie zatruć i zakażeń pokarmowych w ostatnich latach w Polsce. Przedstawiono również wyniki badań monitoringowych występowania Salmonella i Bacillus cereus w wybranych środkach spożywczych oraz w zakresie zanieczyszczenia ogólnego i pałeczkami Enterobacteriaeae mleka pasteryzowanego, które wykonały laboratoria Państwowej Inspekcji Sanitarnej.
EN
The paper discusses importance of the presence of pathogenic bacteria in food, providing the minimum conditions for their development. Presented is the epidemiological situation in the field of food poisoning and infections in recent years in Poland. The results of monitoring, carried out by the laboratories of the State Sanitary Inspection, the presence of Salmonella and Bacillus cereus in selected foods, and the general contamination as well as colony count of Enterobacteriaeae of pasteurized milk are also presented.
14
Content available remote Frequency of Helicobacter pylori infection in children under 4 years of age
63%
|
|
tom 57
|
nr 3
113-122
EN
The work aimed at establishment of frequency of Helicobacter pylori (Hp) infection in children under 4 years of age. One hundred ninety-eight children (6 month to 4 year) were tested using urea breath test (UBT) with the non-radioactive isotope 13C (50 mg of urea). The air was collected before and in the 20th and 30th minute after standard meal. The results of measurements (mass spectrometry IRMS) were given as a quotient 13CO2 /CO2 (), and a positive value was set at >3,5‰. Parents of tested children were asked to fill in a questionnaire on a somatic development, the digestive tract symptoms of a child and family members as well as socioeconomic conditions. The data were analyzed to establish the risk factors in Hp infection in children. Hp infection was found in 18,38% of children. It was not related to child’s sex nor age. The statistical significance was found in the occurrence of Hp infection among children whose family members had infection and among those attending créches or kindergartens. Non-radioactive 13C UBT is very useful and easy method to use in epidemiological studies even in youngest children. The course of infection was asymptomatic and had no impact on their somatic development. Factors increasing the risk of Hp infection were occurrence of Hp among other family members and contact with other children in educational facilities.
EN
Leptospirosis, caused by pathogenic Leptospira, is one of the most important zoonoses in the world. Several molecular techniques have been developed for detection and differentiation between pathogenic and saprophytic Leptospira spp. The aim of this study was to develop a rapid and simple assay for specific detection and differentiation of pathogenic Leptospira spp. by multiplex real-time PCR (TaqMan) assay using primers and probes targeting Leptospira genus specific 16S ribosomal RNA gene, the pathogen specific ligA/B genes and non-pathogen Leptospira biflexa specific 23S ribosomal RNA gene. Sixteen reference strains of Leptospira spp. including pathogenic and nonpathogenic and ten other negative control bacterial strains were used in the study. While the 16S primers amplified target from both pathogenic and non-pathogenic leptospires, the ligA/B and the 23S primers amplified target DNA from pathogenic and non-pathogenic leptospires, respectively. The multiplex real-time PCR (TaqMan) assay detection limit, that is, the sensitivity was found approximately 1 x 10² cells/ml for ligA/B gene and 23S ribosomal RNA gene, and 10 cells/ml 16S ribosomal RNA. The reaction efficiencies were 83-105% with decision coefficients of more than 0.99 in all multiplex assays. The multiplex real-time PCR (TaqMan) assay yielded negative results with the ten other control bacteria. In conclusion, the developed multiplex real-time PCR (TaqMan) assay is highly useful for early diagnosis and differentiation between pathogenic and non-pathogenic leptospires in a reaction tube as having high sensitivity and specificity.
18
Content available remote Bakterie i wirusy w wodzie wodociągowej
63%
PL
Wyprodukowanie w stacji uzdatniania wody do spożycia, spełniającej obowiązujące standardy jakościowe, nie daje gwarancji, iż woda pobierana przez odbiorców jest równie dobrej jakości. Przyczynia się do tego wtórny rozwój mikroorganizmów zachodzący w wodzie rozprowadzanej w sieci wodociągowej i na powierzchni osadów, który jest związany m.in. z obecnością biodegradowalnych substancji organicznych i pierwiastków biogennych. Znaczna część mikroorganizmów rozwijających się w sieci wodociągowej należy do nieszkodliwych heterotrofów, lecz wśród nich mogą występować bakterie oportunistyczne, zagrażające zdrowiu ludzi, głównie osób z uszkodzonym systemem immunologicznym. Zgodnie z raportem Światowej Organizacji Zdrowia, w procesie oczyszczania wody priorytet ma usuwanie z wody mikroorganizmów chorobotwórczych (np.: E. coli, Salmonella, Shigella, Campylobacter jejuni), a ponadto bakterii oportunistycznych chorobotwórczych dla ludzi (np.: Pseudomonas aeruginosa, Aeromonas spp., Legionella spp., Mycobacterium spp.), zdolnych do rozmnażania się w wodzie. Natomiast w mikrobiologicznych badaniach rutynowych kontrolowana jest jedynie obecność bakterii wskaźnikowych, których obecność wskazuje na zanieczyszczenie wody materiałem pochodzenia kałowego, a zatem na potencjalną możliwość występowania organizmów chorobotwórczych pochodzenia jelitowego, przenoszonych drogą wodną. W pracy scharakteryzowano najgroźniejsze wirusy, bakterie chorobotwórcze oraz bakterie oportunistyczne chorobotwórcze dla ludzi, pochodzenia wodnego, ich rozprzestrzenianie w wodzie wodociągowej, a także potencjalne zagrożenie spowodowane spożyciem zanieczyszczonej mikrobiologicznie wody. Podkreślono, że w celu zapobiegania gromadzeniu się mikroorganizmów konieczne jest maksymalne ograniczenie liczby cząstek oraz stężenia substancji organicznych w wodzie produkowanej w stacjach uzdatniania, usuwanie osadów i błony biologicznej gromadzących się w przewodach sieci oraz utrzymanie odpowiedniego stężenia środka dezynfekcyjnego.
EN
Regardless of the fact, that drinking water produced at the water treatment plants fulfils the admissible quality standards, the water received by the consumers usually is not of the same good quality. A drinking-water distribution system provides a habitat for microorganisms, which are sustained by organic and inorganic nutrients present in the pipe and in the conveyed water. The multiplication of bacteria in the distribution system negatively influences on the water quality. Excessive microbial activity can lead to deterioration in aesthetic quality (e.g. taste, odours, turbidity and colour). Most microorganisms developing within the distribution network are harmless heterotrophs but some of them are opportunistic pathogens which are presenting potential health concern to consumers. Opportunistic pathogens are creating risks for vulnerable individuals (e.g. people with acquired immune deficiency syndrome (AIDS) and other immunocompromised individuals). According to the World Health Organization report, the highest attention in the water treatment process should be paid to the removal of not only pathogenic bacteria (E. coli, Salmonella spp., Shigella spp., C. jejuni), as well opportunistic pathogenic bacteria which are able to multiply in water in favourable conditions ((s. aeruginosa, Aeromonas spp., Legionella spp., Mycobacterium spp.). During routine microbiological tests only the presence of indicator bacteria is tested. Presence of these microorganisms indicates pollution of water with faecal material, and potential presence of pathogenic waterborne microorganisms of enteric origin. The most dangerous, waterborne viruses (Adenoviruses, Calciviruses, Coxackieviruses, Echoviruses), pathogenic bacteria (Escherichia coli, Salmonella spp., Yersinia enterocolitica, Campylobacter jejuni, Helicobacter pylori) and opportunistic pathogens (Legionella spp., Aeromonas spp., Pseudomonas aeruginosa, Mycobacterium spp.) are characterized, their presence in the distribution system and relationship to public health is described. The general recommendations on the inhibition of bacterial proliferation in the distribution systems are: the minimizing the number of particles and the restriction on the biodegradable organic content in water leaving the treatment works, together with preventing the accumulation of deposits and biofilms in the distribution system. Additionally, in countries where it is usual to maintain a disinfectant residual to control bacterial multiplication in distributed drinking water, minimizing the factors causing the consumption of residual disinfectant is necessary.
19
Content available remote Heat shock response in gastrointestinal tract
63%
first rewind previous Strona / 5 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.