Search Results

You are looking at 61 - 70 of 282 items for :

  • "bacterium" x
Clear All

Absztrakt:

A szerzők egy gennyes meningitisben szenvedő férfi beteg esetét ismertetik, akinél az infekció hátterében a Streptococcus suis kóroki szerepét igazolták. A baktérium kolonizáló ágensként megtalálható különböző állatok (sertések, kérődzők, macskák, kutyák, szarvasok, lovak) felső légutaiban, tápcsatornájában, nemi szervein. A kórokozó elsősorban állatpatogén, de humán esetek is előfordulnak zoonoticus eredettel. A megbetegedés elsősorban szepszis, meningitis képében jelentkezik mind az állati, mind a humán esetekben. A betegség prevalenciája földrészenként igen eltérő, a legmagasabb Ázsiában. A megbetegedések kialakulásában alapvető különbség figyelhető meg az ázsiai, illetve európai és amerikai régiók között, melyet eltérő kulturális és étkezési szokások befolyásolnak. A baktérium megjelenésére hazánkban elsősorban foglalkozási megbetegedésként kell számítani, de a fellendülő turizmus következtében behurcolt esetek is előfordulhatnak. A kórokozó pontos mikrobiológiai diagnosztikájához elengedhetetlen a modern identifikálómódszerek megléte. A szerzők szeretnék felhívni a figyelmet erre a súlyos infekciót okozó baktériumra, ezért fontosnak tartják a szakirodalomban fellelhető ismeretek összefoglalását és közlését. Orv Hetil. 2019; 160(1): 30–34.

Open access
Orvosi Hetilap
Authors: Balázs Nemes, Fanni Gelley, Eszter Dabasi, György Gámán, Imre Fehérvári, Dénes Görög, László Kóbori, János Fazakas, Eszter Vitális, Attila Doros, Zsuzsanna Gálffy and Zoltán Máthé

Absztrakt

Bevezetés: A szerzők a májátültetést követően kialakult mikrobás fertőzéseket, a mintavételek eredményeit, a multidrug-rezisztencia incidenciáját vizsgálták a hazai betegek körében. Célkitűzés: Tanulmányozták a bakteriális fertőzés kialakulásának kockázati tényezőit, az infekciókhoz kapcsolódó szövődmények előfordulását, lefolyását, és részletes kórokozó-spektrumelemzést végeztek. Módszer: 2003–2012 között májátültetett 408 beteg adatait (281 bakteriológiai tenyésztést) vizsgálták. Eredmények: A 408 beteg közül 70 betegnél (17%) észleltek klinikai tünetekkel járó fertőzést. A tenyésztési lelet 58 betegnél (14,2%) pozitív, 12 betegnél (2,9%) negatív volt. Hét esetben (12,1%) alakult ki cholangitis, 17 esetben (29,3%) fordult elő hasűri és 28 esetben (48,3%) pulmonalis eredetű fertőzés. Posztoperatív fertőzés gyakrabban lépett fel kezdeti csökkent graftműködés, akut veseelégtelenség, epeúti szövődmény és hasűri vérzés mellett. Infekció kialakulása esetén az 1, 3 és 5 éves betegtúlélés 70%, 56% és 56% volt, míg infekció nélkül ez 94%, 87%, 85% volt (p<0,001). A kitenyészett baktériumok 56%-ánál találtak multidrug-rezisztenciát, viszont nem volt szignifikáns különbség a multidrug-rezisztencia pozitív és negatív baktériummal fertőzött csoportok egyéves betegtúlélése között (70,2% mindkettő). Következtetések: Az infekciókontroll, a multidrug-rezisztens kórokozók menedzselése a preventív, higiéniai, izolációs elvek kialakítását, betartását, valamint műtéttechnikai, transzfúziós, antibiotikus stratégiák, folyamatok fejlesztését kell, hogy megcélozza, szakmai csapatmunka keretén belül. Orv. Hetil., 2015, 156(34), 1366–1382.

Open access

. Zhai , L. , Ma , Y. , Xue , Y. , Ma , Y. : Bacillus alkalicola sp. nov., an alkaliphilic, Gram-positive bacterium isolated from Zhabuye lake in Tibet, China . Curr Microbiol 69 , 311 – 316 ( 2014 ). 18

Restricted access
Acta Biologica Hungarica
Authors: Mónika Magony, Ildikó Kákonyi, Anna Gara, P. Rapali, Katalin Perei, K. Kovács and G. Rákhely

A bacterium capable to grow on sulfanilic acid as sole carbon, nitrogen and sulfur source has been isolated. A unique feature of this strain is that it contains the full set of enzymes necessary for the biodegradation of sulfanilic acid. Taxonomical analysis identified our isolate as Sphingomonas subarctica SA1 sp. The biodegradation pathway of sulfanilic acid was investigated at the molecular level. Screening the substrate specificity of the strain disclosed its capacity to degrade six analogous aromatic compounds including p -aminobenzoic acid. Moreover, the strain was successfully used for removal of oil contaminations. S. subarctica SA1 seemed to use distinct enzyme cascades for decomposition of these molecules, since alternative enzymes were induced in cells grown on various substrates. However, the protein patterns appearing upon induction by sulfanilic acid and sulfocatechol were very similar to each other indicating common pathways for the degradation of these substrates. Cells grown on sulfanilic acid could convert p -aminobenzoic acid to some extent and vice versa. Two types of ring cleaving dioxygenases were detected in the cells grown on various substrates: one preferred protocatechol, while the other had higher activity with sulfocatechol. This latter enzyme, named as sulfocatechol dioxygenase was partially purified and characterized.

Restricted access

Clostridium (Clostridioides) difficile is a Gram-positive anaerobic rod-shaped bacterium and the main cause of nosocomial diarrhoea in humans. In recent years, the transmission of C. difficile from environmental reservoirs (e.g. food) to humans has become a major focus of research. The aim of this study was to investigate the prevalence and corresponding toxin genes of C. difficile in faecal samples and meat of quails. Thirty samples of packed quail meat in Mashhad, Iran and 500 faecal samples (pooled to n = 5) were collected on quail farms in the Northeastern Khorasan region for further investigation. Of 100 pooled quail faecal samples 10% showed cultural growth of C. difficile. In meat samples two out of 30 specimens (7%) showed cultural growth. In six of ten isolates from faecal samples toxin genes (tcdB and tcdA) were present, while four isolates harboured no toxin genes. However, in meat isolates no toxin genes were present. Mutations in the tcdC gene were not detected, indicating that ‘hypervirulent’ strains such as RT027 and RT078 were not present. The data suggest that quail and quail products might hold a potential for the spread of C. difficile.

Restricted access
Acta Biologica Hungarica
Authors: A. Waśko, Monika Kordowska-Wiater, M. Podleśny, Magdalena Polak-Berecka, Z. Targoński and Agnieszka Kubik-Komar

The central composite design was developed to search for an optimal medium for the growth of Lactobacillus rhamnosus OXY. The effect of various media components, such as carbon sources, simple and complex nitrogen sources, mineral agents, and growth factors (vitamins B, amino acids) was examined. The first-order model based on Plackett-Burman design showed that glucose, sodium pyruvate, meat extract and mineral salts significantly influenced the growth of the examined bacteria. The second-order polynomial regression confirmed that maximum biomass production could be achieved by the combination of glucose (12.38 g/l), sodium pyruvate (3.15 g/l), meat extract (4.08 g/l), potassium phosphate (1.46 g/l), sodium acetate (3.65 g/l) and ammonium citrate (1.46 g/l).The validation of the predicted model carried out in bioreactor conditions confirmed the usefulness of the new medium for the culture of L. rhamnosus OXY in large scale. The optimal medium makes the culture of the probiotic bacterium L. rhamnosus OXY more cost effective.

Restricted access
Acta Veterinaria Hungarica
Authors: Boglárka Sellyei, Zsuzsanna Varga, Katalin Szentesi-Samu, Éva Kaszanyitzky and Tibor Magyar

Pasteurella multocida causes infectious diseases in a wide range of animal species. Antimicrobial therapy is still an effective tool for treatment. Generally, P. multocida isolates are susceptible to most of the widely used commercial antimicrobial agents but their excessive and unjustified use accelerates the emergence of resistant strains. We defined the antimicrobial sensitivity pattern of 56 P. multocida strains isolated from poultry (20) and swine [16 P. multocida toxin (PMT) positive and 20 PMT negative] to 16 widely applied antibiotics (apramycin, cefquinome, chloramphenicol, colistin, doxycycline, enrofloxacin, erythromycin, florfenicol, flumequine, neomycin, oxolinic acid, penicillin, trimethoprim potentiated sulphamethoxazole, sulphonamide compounds, tetracycline, tulathromycin) by the disk diffusion method. The majority of the strains was susceptible to most of the antimicrobial agents tested. However, the resistance to sulphonamides, tetracyclines, first-generation quinolones and aminoglycosides was remarkable, and thus the use of these compounds for the treatment of infection caused by P. multocida is not recommended. On the other hand, the antimicrobial activity of the classical penicillin, the newer macrolide (tulathromycin), the third-generation fluoroquinolone (enrofloxacin) and the fourth-generation cephalosporin (cefquinome) proved to be satisfactory against this bacterium.

Restricted access

The tuf gene of “Candidatus Phytoplasma mali”, the causal agent of apple proliferation was PCR cloned in an expression vector and expressed in Escherichia coli. First, phytoplasma DNA extracted from periwinkle was amplified using primers designed on the basis of the tuf gene and the PCR product was cloned into pGEM-T (Promega). In the next step specific primers were constructed containing some plasmid sequences and restriction enzyme sites. With this primers the sequence in pGEM-T was amplified, the product was digested with restriction enzymes, and inserted into the pQE40 expression vector (Qiagen). In this plasmid the tuf gene was fused to the 6xHIS tag, and DHFR. The production of 6xHIS-DHFR-Tu fusion protein protein was induced with IPTG and expressed in E. coli M15. The new fusion protein was found in the insoluble fraction of the bacterium. The identity of the protein was verified with polyacrylamid gel-electrophoresis and Western blot analysis using antiserum raised against the 6xHIStag of the fusion protein.

Restricted access

The development of local early basal resistance (EBR), is a form of non-specific general defence response of plants to bacteria, greatly depending on temperature. This symptomless defence mechanism is easily detected by its inhibitory action on the hypersensitive response (HR) caused by a subsequent incompatible pathogenic bacterium. Both EBR and HR were investigated at different temperatures ranging from 30 °C to 5 °C. At normal temperatures (30-20 °C) both heat-killed Pseudomonas syringae pv. syringae 61 (polyvirulent to many plants) and Pseudomonas savastanoi pv. phaseolicola S21 (pathogenic to bean) induced EBR in tobacco leaves within a few hours, but below 10 °C it was greatly delayed and at 5 °C usually no EBR response could be detected within 2-3 days. The time required for development of EBR did not depend on the bacterial pathovars or strains. However, the induction time of HR was not as sensitive to low temperatures as that of EBR, instead, it depended on the bacterial pathovars used.

Restricted access

The aim of this study was to investigate the effect of some food additives used in foods on cold tolerance of Clostridium perfringens at pH close to neutral.Maximal concentrations recommended for foods of sodium benzoate, potassium sorbate, sodium nitrite, monosodium glutamate, or mixtures of those were added to cultures and their effects on C. perfringens tolerance to 10 °C were evaluated. The effect of a previous shock at 28 °C was also determined. Growth of C. perfringens was not inhibited by the substances examined. Sodium nitrite, applied at maximal permitted concentrations, increased C. perfringens survival at 10 °C. Mixtures of GRAS compounds had either no clear effect, or increased tolerance to 10 °C. A pre-shock (28 °C) of the cultures treated with sodium benzoate, sodium nitrite or monosodium glutamate increased survival and stimulated growth of the cultures treated at 10 °C.We conclude that the addition of these compounds including sodium benzoate, potassium sorbate, sodium nitrite and monosodium glutamate to cultures of C. perfringens can influence their cold tolerance. In some cases, the substances that would normally eliminate microorganisms at lower pH, can increase tolerance of this bacterium, permitting survival at low temperatures.

Restricted access