Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 22

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  food-borne pathogen
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

The effect of acid adaptation conditions on heat resistance of Escherichia coli O157:H7

100%
Tosun H., Gonul S. A.
Polish Journal of Microbiology
|
2005
|
tom 54
|
nr 4
The objective of this study was to determine the effect of acid adaptation conditions on heat resistance of E. coli 0157: H7 932. E. coli 0157: H7 was adapted to acid by exposing the cells to pH 4.5 (2h), pH 5.0 (lh), and pH 5.5 (1h) in tryptic soy broth. D and z values of the acid adapted and control cultures at 54°C, 56°C, and 58°C were determined in E buffer. The heat resistance of E. coli 0157: H7 increased significantly (p<0.05) after acid adaptation at pH 4.5 or pH 5.0. E. coli 0157: H7 adapted to acid at pH 4.5 for 2 h had the highest D values at all temperatures tested (20.3-10.7-3.3 min) while D values of culture adapted to acid at pH 5.0 for 1h were 18.2, 7.9, and 2.6 min at 54°C, 56°C and 58°C, respectively. Heat resistance of culture adapted to acid at pH 5.5 for 1h and the control culture was not significantly different (P<0.05). Culture adapted to acid at pH 4.5 had the highest z value (5.10°C), whereas control culture had the lowest z value (4.33°C). This study showed that the magnitude of heat tolerance changed with the adaptation pH and at low adaptation pH, E. coli 0157: H7 showed maximum heat resistance. Acid adaptation at pH 4.5 or 5.0 provides E. coli 0157: H7 with cross-protection against heat treatments, and that this factor must be considered to estimate this pathogen's thermal tolerance accurately.
2
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Antimicrobial resistance of Salmonella spp. isolated from food

86%
Maka L., Popowska M.
Roczniki Państwowego Zakładu Higieny
|
2016
|
tom 67
|
nr 4
This review summarizes current data on resistance among Salmonella spp. isolates of food origin from countries in different regions of the world. The mechanisms of resistance to different groups of antimicrobial compounds are also considered. Among strains resistant to quinolones and/or fluoroquinolones the most prevalent mechanism is amino acid substitutions in quinolone resistance-determining region (QRDR) of genes gyrA, parC but mechanism of growing importance is plasmid-mediated quinolone resistance (PMQR) associated with genes qnrA, qnrB, qnrC, qnrD, qnrS but frequency of their detection is different. Resistance to sulfonamides is mostly associated with genes sul1 and sul2, while resistance to trimethoprim is associated with various variants of dhfr ( dfr) genes. Taking into account Salmonella spp. strains isolated from food, resistance to β-lactams is commonly associated with β-lactamases encoding by blaTEM genes. However strains ESBL and AmpC – positive are also detected. Resistance to aminoglicosides is commonly result of enzymatic inactivation. Three types of aminoglycoside modifying enzyme are: acetyltransferases (AAC), adenyltransferases (ANT) and phosphotransferases (APH). Resistance to tetracyclines among Salmonella spp. isolated from food is most commonly associated with active efflux. Among numerous genetic determinants encoding efflux pumps tetA, tetB, tetC, tetD, tetE and tetG are reported predominatingly. One of the most common mechanisms of resistance against chloramphenicol is its inactivation by chloramphenicol acetyltrasferases (CATs), but resistance to this compound can be also mediated by chloramphenicol efflux pumps encoded by the genes cmlA and floR. It is important to monitor resistance of Salmonella isolated from food, because the globalization of trade, leading to the long-distance movement of goods, animals and food products, encourages the spread of resistant pathogens around the world.
3
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Morphostructural damage of foodborne bacterial pathogens influenced by swamp cranberry (Vaccinium oxycoccos L.) pomace extract treatment as revealed by transmission electron microscopy (TEM)

86%
Stobnicka-Kupiec A., Gniewosz M.
Zeszyty Problemowe Postępów Nauk Rolniczych
|
2019
|
tom 598
4

Report on overcoming the poor quality of ApaI pulsotypes with a short review on PFGE for Listeria monocytogenes

86%
Kusar D., Kavalic M., Ocepek M., Zdovc I.
Polish Journal of Microbiology
|
2013
|
tom 62
|
nr 3
Since listeriosis, caused by Listeria monocytogenes, is one of the important concerns of public health in Europe related to foodborne zoonoses, an efficient protocol for isolate typing is necessary when performing epidemiological studies. Three standardized PFGE protocols available for L. monocytogenes were briefly reviewed. Since observing a poor-quality of ApaI pulsotypes in our laboratory, enzymes from three different manufacturers were compared. The obtained pulsotypes showed that restriction digestion with ApaI from New England BioLabs should be complemented with a subsequent overnight incubation of PFGE plugs in TE buffer for better performance.
5

Analysis of the peptidoglycan hydrolases of Listeria monocytogenes: multiple enzymes with multiple functions

86%
Popowska M.
Polish Journal of Microbiology
|
2004
|
tom 53
|
nr Suppl.
Listeria monocytogenes is a ubiquitous gram-positive, rod-shaped, widespread in nature, facultative intracellular human and animal pathogen that causes infections collectively termed listeriosis. L. monocytogenes EGD encodes a total of 133 surface proteins, the abundance of which, as well as the variety of anchoring systems, probably reflects the ability of this bacterium to survive in diverse environments and to interact with many kinds of eukaryotic cells. The group of surface proteins also includes proteins with murein hydrolase activity-autolysins. To date, five L. monocytogenes autolysins have been identified: p60, P45, Ami, MurA and Auto. These enzymes are involved in numerous cellular processes including cell growth, cell wall turnover, peptidoglycan maturation, cell division and separation, formation of flagella, sporulation, chemotaxis and biofilm formation, genetic competence, protein secretion, the lytic action of some antibiotics and pathogenicity. We have recently identified a putative sixth listerial peptidoglycan-degrading enzyme, which has surprisingly been identified as FlaA, a flagellar protein of L. monocytogenes.
6

Molecular diagnostics of Shiga toxin-producing Escherichia coli strains found in animals and food products

86%
Nawrotek P., Gackowska I.
Advances in Agricultural Sciences
|
2002
|
tom 08
|
nr 1
7

The impact of environmental stress on Listeria monocytogenes virulence

72%
Walecka E., Molenda J., Bania J.
Polish Journal of Veterinary Sciences
|
2009
|
tom 12
|
nr 4
Listeria monocytogenes, a significant food-borne pathogen, must defy a variety of conditions encountered in the food environment and during the infection process. In reaction to adverse conditions, the bacteria significantly change their metabolism, inducing a stress response which is mediated by a range of alternative sigma factors. The extent of the response to stress was shown to vary in the L. monocytogenes population. According to recent evidence a major L. monocytogenes alternative sigma factor, designated sigma B (σB), regulates some virulence genes in response to stress, which supports an older hypothesis that stress-resistant strains should be more pathogenic. The induction of σB-dependent genes may also be important from the point of view of food hygiene. It seems that stress response activation can paradoxically enhance resistance to agents used in food preservation. Therefore, monitoring the expression of σB-dependent genes can serve as a useful marker to assess the innate resistance of L. monocytogenes strains. This knowledge will allow the design of new methods with sequential preservation steps that could inactivate the bacteria without inducing their stress response.
8

The impact of high hydrostatic pressure on inactivation and sublethal injury of foodborne pathogens in beetroot juice

72%
Nasilowska J., Sokolowska B., Fonberg-Broczek M.
Postępy Nauki i Technologii Przemysłu Rolno-Spożywczego
|
2016
|
tom 71
|
nr 1
High hydrostatic pressure (HHP) is a well known method currently used for food preservation. Nevertheless this treatment can also cause sublethal injury of foodborne pathogen cells, which could repair and become potentially dangerous for consumers. The survival of Listeria innocua CIP80.11T, Escherichia coli ATCC 8739 and the wild strains isolated from beetroot juice after HHP treatment (200 MPA, 300 MPa and 400 MPa) as well as the level of sublethal injuries in the surviving cells were investigated in this study. Lethal effect was reported after treatment at 400 MPa for the most of strains. The maximum level of sublethal injuries was reported after 5 minutes under pressure 300 MPa (L. innocua) and 400 MPa (E.coli).
9

Electrochemical sensors for fast detection of foodborne pathogens

72%
Tichoniuk M.
Towaroznawcze Problemy Jakości. Polskie Towarzystwo Towaroznawcze
|
2017
|
nr 4
10

Evidence for probiotic potential of a capsular-producing Streptococcus thermophilus CHCC 3534 strain

72%
Khalil R.
Polish Journal of Microbiology
|
2009
|
tom 58
|
nr 1
49-55
The purpose of this research was to evaluate the probiotic potential of an capsulated Streptococcus thermophilus CHCC 3534 strain. The strain tolerates 0.4% oxgall (bile) and was sufficiently resistant to pH as low as 2.5 for 3 hours of exposure. The strain demonstrated high adherence to human intestinal mucus, and showed unique resistance to different antibiotics. Crude extracts of S. thermophilus CHCC 3534 contained a diffusible antimicrobial compound "bacteriocin" with a broad spectrum that inhibited the growth of closely related lactic acid bacteria and a number of food spoilage bacteria including Salmonella typhimurium and Staphylococcus aureus. The bacteriocin was heat stable, resistant to pH, inactivated by proteolytic enzymes, and resistant to á-amylase and lipase. A SDS-PAGE analysis of the partially purified bacteriocin revealed one component with a molecular weight ranging from 14.4 to 18.4 kDa. The strain may have industrial significance and represents an interesting candidate for use in biopreservation, probiotic food formulations and in the control of spoilage caused by food borne pathogens.
11

Comparison of arbitrary primer [AP] PCR and pulsed-field gel electrophoresis methods for genotypic differentiation of Escherichia coli O157 strains

72%
Weiner M., Osek J.
Bulletin of the Veterinary Institute in Puławy
|
2003
|
tom 47
|
nr 2
12

Insertional knock-out of protein translocation systems common for Yersinia enterocolitica and Listeria monocytogenes

72%
Wisniewski J., Hrebenda J., Bielecki J.
Acta Microbiologica Polonica
|
2000
|
tom 49
|
nr 1
13

Molecular aspects of Listeria monocytogenes infection

72%
Krawczyk-Balska A., Bielecki J.
Polish Journal of Microbiology
|
2004
|
tom 53
|
nr Suppl.
Listeria monocytogenes, a food-borne intracellular animal and human pathogen, interacts with infected host cells both prior to entry and during the intracellular phase of infection. This review is focused on the role of secreted proteins including listeriolysin O and two distinct phospholipases C, in modulating the signal transduction of infected cells.
14

Susceptibility of Listeria monocytogenes strains isolated from dairy products and frozen vegetables to antibiotics inhibiting murein synthesis and to disinfectants

72%
Popowska M., Olszak M., Markiewicz Z.
Polish Journal of Microbiology
|
2006
|
tom 55
|
nr 4
The susceptibility of 96 strains of Listeria monocytogenes isolated from food to antibiotics and disinfectants currently used in human therapy, veterinary, medicine and food industry was determined by a standard operating procedure - broth dilution method. Antimicrobial agents included the β-lactams ampicillin and penicillin, the lantibiotic nisin, and the disinfectants benzalkonium chloride and chlorhexidine gluconate. Among the studied strains we found 13 strains with 8-fold, 7 strains with 16-fold and 2 strains with 32-fold decreased susceptibility to ampicillin, as determined by MIC, compared to wild type reference strain. Interestingly, the mentioned strains were isolated from frozen vegetables and soups, none of the isolates from dairy products showed any elevated resistance to the studied antimicrobial agents. The occurrence in food products of strains with increased resistance to ampicillin is disquieting, especially since β-lactams are the most frequent antibiotic of choice in the therapy of infections caused by the pathogen.
15

Detection of Escherichia coli O157:H7 in raw meat by immunomagnetic separation and multiplex PCR

72%
Lekowska-Kochaniak A., Czajkowska D., Popowski J.
Acta Microbiologica Polonica
|
2002
|
tom 51
|
nr 4
16

Severe diarrhoea caused by Aeromonas veronii biovar sobria in a patient with metastasised GIST

72%
Grobner S., Bissinger A. L., Raible A., Heeg P., Autenrieth I. B., Schmidt S. M.
Polish Journal of Microbiology
|
2007
|
tom 56
|
nr 4
This report describes the isolation of Aeromonas veronii biovar sobria as the causative enteropathogen of diarrhoea in an oncological patient after failure of detection of other infectious agents. The case points out the severe and long course of the infection, the diagnostic dilemma, and the prompt recovery after antibiotic treatment.
17

Development of a PCR internal amplification control for the detection of Shiga toxin-producing Escherichia coli

72%
Wieczorek K., Osek J.
Bulletin of the Veterinary Institute in Puławy
|
2004
|
tom 48
|
nr 4
18
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Simultaneous occurrence of selected food-borne bacterial pathogens on bovine hides, carcasses and beef meat

58%
Wieczorek K., Osek J.
Polish Journal of Veterinary Sciences
|
2010
|
tom 13
|
nr 4
The aim of this study was to determine the simultaneous occurence of Salmonella spp., L. monocytogenes, verotoxigenic E. coli (VTEC), and Campylobacter spp. in slaughtered cattle and in beef meat subjected for human consumption. A total of 406 bovine hides and 406 corresponding carcasses were used to collect the samples with a swab method after exsanguination and evisceration of animals, respectively. Furthermore, 362 beef meat samples were purchased in local retail shops over the same period of time as for the bovine samples. Food-borne bacterial pathogens were identified with standard ISO methods with some modification by the use of PCR for VTEC. The isolated bacteria were then molecularly speciated (Campylobacter), serotyped (L. monocytogenes) and characterized for the presence of several virulence marker genes (VTEC and Campylobacter). It was found that 49 hide (12.1%) and 3 (0.7%) carcass samples were contaminated with more than one bacterial pathogen tested. Most of the hides were positive for Campylobacter spp. and VTEC (27 samples) and Campylobacter spp. together with L. monocytogenes (12 samples). Eight bovine hides contained L. monocytogenes and VTEC while L. monocytogenes and Salmonella spp. were detected in one sample. Furthermore, 3 pathogens (Campylobacter spp., L. monocytogenes and VTEC) were simultaneously identified in one bovine hide tested. In case of bovine carcasses 2 samples contained Campylobacter spp. and VTEC whereas one carcass was positive for L. monocytogenes and VTEC. On the other hand, 10 out of 362 (2.8%) minced beef samples were contaminated with at least two pathogens tested. The majority of these samples were contaminated with L. monocytogenes and Salmonella spp. (6 samples). It was noticed that equal number of C. jejuni and C. coli were found, irrespective of the origin of the samples. Most of the strains possessed more than one pathogenic factor as identified by PCR. Molecular serotyping of L. monocytogenes revealed that the majority of the isolates (27 out of 31; 87.1%) belonged to 1/2a serogroup. It was found that most of the VTEC isolates possessed the Shiga toxin stx2 gene (12 strains) whereas only 2 strains were stx1-positive. The eneterohemolysin and intimin markers were identified only in 7 and 2 isolates, respectively. PCR analysis revealed that 4 VTEC belonged to O91 serogroup, 2 strains were O145 and 1 isolate was identified as O113. None of the VTEC detected in the study was O157 serogroup.
19

Integrin receptors play a role in the internalin B-dependent entry of Listeria monocytogenes into host cells

58%
Auriemma C., Viscardi M., Tafuri S., Pavone L. M., Capuano F., Rinaldi L., Della Morte R., Iovane G., Staiano N.
Cellular and Molecular Biology Letters
|
2010
|
tom 15
|
nr 3
496-506
Listeria monocytogenes enters non-phagocytic cells by binding its surface proteins inlA (internalin) and inlB to the host’s E-cadherin and Met, respectively. The two internalins play either separate or cooperative roles in the colonization of infected tissues. Here, we studied bacterial uptake into HeLa cells using an L. monocytogenes mutant strain (ΔinlA) carrying a deletion in the gene coding for inlA. The ΔinlA mutant strain showed the capability to invade HeLa cells. The monoclonal anti-β3- and anti-β1-integrin subunit antibodies prevented bacterial uptake into the cells, while the anti-β2- and anti-β4-integrin subunit antibodies failed to affect L. monocytogenes entry into HeLa cells. Three structurally distinct disintegrins (kistrin, echistatin and flavoridin) also inhibited bacterial uptake, showing different potencies correlated to their selective affinity for the β3- and β1-integrin subunits. In addition to inducing Met phosphorylation, infection of cells by the L. monocytogenes ΔinlA mutant strain promoted the tyrosine phosphorylation of the focal adhesion-associated proteins FAK and paxillin. Our findings provide the first evidence that β3- and β1-integrin receptors play a role in the inlB-dependent internalization of L. monocytogenes into host cells.
20

Determination of E. coli 0157 in raw and cooked Doner kebabs by using IMS technique

58%
Arun O. O., Aydin A., Vural A., Ciftcioglu G., Aksu H.
Medycyna Weterynaryjna
|
2007
|
tom 63
|
nr 10
1181-1183
Escherichia coli O157 is one of the major threats to public health due to the consumption of meat and meat products. The microorganism is known as a food-borne pathogen even in the presence of low levels. Therefore, a more sensitive method is required to be used for the detection of the microorganism. Immunomagnetic separation (IMS) is a technique used to improve the sensitivity of the detection. IMS has been used to determine the presence of E. coli O157 in raw and cooked Doner samples in this study. 3 out of 30 raw Doner samples have been found to be contaminated with E. coli O157. None of the cooked samples were carrying the agent.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.