Home About us Contact
|
Home About us Contact | ||
|
|
||
Agar Media (agar + media)
Selected AbstractsContribution of ethylamine degrading bacteria to atrazine degradation in soilsFEMS MICROBIOLOGY ECOLOGY, Issue 2 2006Daniel Smith Abstract Bacterial communities that cooperatively degrade atrazine commonly consist of diverse species in which the genes for atrazine dechlorination and dealkylation are variously distributed among different species. Normally, the first step in degradation of atrazine involves dechlorination mediated by atzA, followed by stepwise dealkylation to yield either N -ethylammelide or N -isopropylammelide. As the liberated alkylamine moieties are constituents of many organic molecules other than atrazine, it is possible that a large number of alkylamine-degrading bacteria other than those previously described might contribute to this key step in atrazine degradation. To examine this hypothesis, we isolated 82 bacterial strains from soil by plating soil water extracts on agar media with ethylamine as a sole carbon source. Among the relatively large number of isolates, only 3 were able to degrade N -ethylammelide, and in each case were shown to carry the atzB gene and atzC genes. The isolates, identified as Rhizobium leguminosarum, Flavobacterium sp., and Arthrobacter sp., were all readily substituted into an atrazine-degrading consortium to carry out N -ethylammelide degradation. The distribution of these genes among many different species in the soil microbial population suggests that these genes are highly mobile and over time may lead to generation of various atrazine-degrading consortia. [source] The effect of nitrogen fertilization on fungistatic phenolic compounds in roots of beech (Fagus sylvatica) and Norway spruce (Picea abies)FOREST PATHOLOGY, Issue 4 2005L. Tomova Summary The effect of nitrogen fertilization on fungistatic phenolic compounds in fine roots of beech and Norway spruce growing in afforestation plots was analysed. The plots were situated at two sites in Switzerland on acidic soil with low base saturation. For 9 years, the trees have been treated with dry ammonium nitrate to give 0, 10, 20, 40, 80, 160 kg N ha,1 year,1, respectively. The phenolic compounds responded differently to fertilization. Fine roots of beech showed a significant decrease of (,)-epicatechin and piceatannol with increasing nitrogen fertilization. The concentration of protocatechuic acid was increased with fertilization. Roots of fertilized Norway spruce showed significantly decreased concentrations of 4-hydroxyacetophenone and piceatannol. The mycelial growth of three isolates each of Heterobasidion annosum s.l. and Cylindrocarpon destructans was tested on agar media containing various phenolic compounds in concentrations found in fine roots of Norway spruce (Picea abies) and beech (Fagus sylvatica). All three H. annosum isolates were inhibited by p-coumaric acid and (,)-epicatechin. Two isolates were inhibited by another four phenolic compounds (p-hydroxybenzoic acid, 4-hydroxyacetophenone, piceatannol and protocatechuic acid), one by (+)-catechin. Two of three C. destructans isolates were inhibited by all phenolic compounds except for (+)-catechin which affected only one isolate, one isolate did not respond at all. Résumé L'effet d'une fertilisation azotée sur les composés phénoliques fongistatiques des racines fines de Hêtre (Fagus sylvatica) et d'Epicea (Picea abies) a été analysé dans des parcelles de reboisement. Ces parcelles sont situées dans deux localités de Suisse sur sol acide, avec un faible taux de saturation en bases. Pendant neuf ans, les arbres ont été traités par apports secs de nitrate d'ammonium à raison de 0, 10, 20, 40, 80, 160 kg N par hectare et par an, respectivement. La réponse des composés phénoliques à la fertilisation est variable. Les racines fines de hêtres ont montré une baisse significative d'épicatèchine (,) et de piceatannol avec l'augmentation de la fertilisation azotée. Les concentrations d'acide protocatéchique ont augmenté avec la fertilisation. Les racines d'épicèas fertilisés ont montré une baisse significative des concentrations de 4-hydroxyacétophénone et de piceatannol. La croissance mycélienne de trois isolats de chacune des espèces H .annosum s.l. et Cylindrocarpon destructans a été testée sur milieu agar contenant les différents composés phénoliques aux concentrations trouvées dans les racines fines d'épicèas (Picea abies) et de hêtres (Fagus sylvatica). Les trois isolats d'Heterobasidion annosum s.l. ont été inhibés par l'acide p-coumarique et l'épicatèchine (,). Deux isolats ont été inhibés par quatre autres composés phénoliques (acide p-hydroxybenzoïque, 4-hydroxyacétophénone, piceatannol et acide protocatéchique) et un par la catéchine (+). Deux des trois isolats de Cylindrocarpon destructans ont été inhibés par tous les composés phénoliques à l'exception de la catéchine (+) pour l'un des deux, le dernier isolat ne répondant à aucun composé. Zusammenfassung In einer Aufforstungs-Versuchsfläche wurde der Einfluss einer Stickstoffdüngung auf die fungistatischen phenolischen Verbindungen in Feinwurzeln von jungen Buchen und Fichten untersucht. Die Versuchsflächen befanden sich an zwei Standorten in der Schweiz mit sauren, basenarmen Bodenverhältnissen. Die Bäume wurden über neun Jahre mit 0, 10, 20, 40, 80 und 160 kg N ha,1 a,1 in Form von Ammoniumnitrat gedüngt. Die phenolischen Verbindungen reagierten unterschiedlich auf die Düngung. Die Feinwurzeln von Buchen zeigten mit zunehmender Stickstoffdüngung eine signifikante Abnahme von (,) Epicatechin und Piceatannol, während die Konzentration von Protocatechinsäure durch die Düngung erhöht wurde. Die Feinwurzeln gedüngter Fichten wiesen ebenfalls signifikant tiefere Konzentrationen von 4-Hydroyacetophenon und Piceatannol auf. In in-vitro-Tests wurde das Myzelwachstum von allen drei geprüften Isolaten von Heterobasidion annosum s. l. durch die in den Wurzeln gefundenen Konzentrationen von p-Coumarinsäure und (,)Epicatechin gehemmt. Zwei Pilzisolate zeigten zudem eine Hemmung durch vier weitere in den Wurzeln gefundene phenolische Verbindungen, nämlich p-Hydroxybenzoesäure, 4-Hydroxyacetophenon, Piceatannol und Protocatechinsäure, und eines wurde auch durch (+)-Catechin gehemmt. Bei zwei von drei geprüften Isolaten von Cylindrocarpon destructans wurde das Myzelwachstum durch alle untersuchten phenolischen Verbindungen gehemmt, mit Ausnahme von (+)-Catechin, welches sich nur auf ein Isolat negativ auswirkte. Ein Isolat von C. destructans reagierte auf keine der genannten Substanzen. [source] New media for the semiselective isolation and enumeration of Xanthomonas campestris pv. mangiferaeindicae, the causal agent of mango bacterial black spotJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2005O. Pruvost Abstract Aims:, Mango bacterial black spot, caused by Xanthomonas campestris pv. mangiferaeindicae, is a potentially severe disease in several tropical and subtropical areas. Data describing the life cycle of the pathogen are needed for improving integrated pest management strategies. Because of the important bacterial microflora associated with mango leaves, isolation of the pathogen is often difficult using nonselective agar media. Methods and Results:, A previously developed medium, BVGA, failed to inhibit several Gram-negative saprophytic bacteria, especially those belonging to Enterobacteriaceae. Two new semiselective media were developed. The selectivity of KC and NCTM3 media was achieved using cephalexin 40 mg l,1, kasugamycin 20 mg l,1 and neomycin 1 mg l,1, cephalexin 100 mg l,1, trimethoprime 5 mg l,1, pivmecillinam 100 mg l,1 respectively. Plating efficiencies ranged from 76 to 104% and from 78 to 132% for KC and NCTM3 respectively. Conclusions:, The new media allowed the growth of X. campestris pv. mangiferaeindicae whatever its country of isolation. The pathogen was repeatedly isolated with these media from asymptomatic leaves sampled in growth chamber experiments. Significance and Impact of the Study:, This work provides a description of new semiselective media, which should be valuable tools to study the ecology and epidemiology of X. campestris pv. mangiferaeindicae. [source] EFFECT OF MARINADE AND DRYING TEMPERATURE ON INACTIVATION OF ESCHERICHIA COLI O157:H7 ON INOCULATED HOME DRIED BEEF JERKYJOURNAL OF FOOD SAFETY, Issue 3 2002SUSAN N. ALBRIGHT ABSTRACT Beef slices were inoculated (5.7,7.5 log CFU/cm2) with a 4-strain composite of E. coli O157:H7, stored (4C, 24 h), marinated (4C, 24 h), dried for 10 h at 62.5C or 68.3C, and stored for 90 days at 21C. Unmarinated beef slices dried for 10 h at 62.5C were used to determine the relative contribution of the marinate versus temperature treatment in the 62.5C trials. Samples were analyzed (bacterial enumeration with selective and nonselective agar media, pH, and aw) following inoculation, marinating, at 4, 6, 8 and 10 h of drying, and after 30, 60 and 90 days of storage. Marination resulted in slight changes in bacterial populations (,0.3 to + 0.6 log CFU/cm2), but did not enhance bacterial reduction during drying. For all treatments, most bacterial reductions occurred in the first 4 h of drying, with little reduction thereafter. After 10 h of drying, bacterial reductions were 3.2,3.4 log CFU/cm2 for unmarinated beef slices dried at 62.5C. Reductions of 2.2 and 3.0,4.6 log CFU/cm2 were achieved in marinated jerky slices dried at 62.5C and 68.3C, respectively. No treatment resulted in the recommended 5-log reduction at the end of 10 h drying. However, bacteria did become undetectable by direct plating (<10 CFU/cm2) following 30 days of storage in all treatments except the unmarinated beef slices plated on tryptic soy agar (TSA). Additional work is needed to develop procedures for adequate destruction of E. coli O157:H7 during drying of beef jerky. [source] EVALUATION OF SURVIVAL PATTERNS AND CELLULAR INJURY OF PSEUDOMONAS AERUGINOSA IN DIFFERENT BOTTLED WATERS STORED UNDER VARIOUS CONDITIONSJOURNAL OF FOOD SAFETY, Issue 3 2001PAULA TEIXEIRA ABSTRACT Pseudomonas aeruginosa cells were inoculated into different waters and sampled after different periods of starvation in order to evaluate the influences of storage under daylight or dark conditions, the presence or absence of the autochthonous flora, the chemical composition of the water and the storage temperature, on survival Survival was investigated by plate counts on selective and nonselective agar media. Light, low temperature (4C) and presence of the autochthonous flora negatively influenced the survival of P. aeruginosa during starvation in water. Higher survival rates were observed in waters with high mineral content. During starvation, cells developed sensitivity to the selective medium demonstrating that research is needed in the development of new media, or improvement in the existing ones, for the enumeration of P. aeruginosa in water. Current selective media/methodologies for detecting P. aeruginosa in mineral waters may seriously underestimate the levels of or presence of this organism which might represent, in some cases, a hazard to the public health. [source] Lack of O -polysaccharide enhances biofilm formation by Bradyrhizobium japonicumLETTERS IN APPLIED MICROBIOLOGY, Issue 5 2010Y.-W. Lee Abstract Aims:, To reveal the effects of the O -polysaccharide antigen of Bradyrhizobium japonicum LPS on biofilm formation and motility. Methods and Results:, Wild type and O-antigen-deficient mutant strains of B. japonicum were tested for biofilm formation on polyvinyl chloride (PVC) surfaces and motility on semi-solid (0·3%) agar media. After 7 days of incubation, the amount of biofilms formed by the mutant was c. 3·5-fold greater than that of the wild type. Unlike biofilm formation, the motility assay revealed that the mutant strain was less motile than the wild type. Conclusions:, This study shows enhanced biofilm formation and decreased motility by the O-antigen-deficient mutant, suggesting that the lack of the O -polysaccharide of the rhizobial LPS is associated with biofilm-forming ability and movement. Significance and Impact of the Study:, LPS plays an important role in both pathogenic and beneficial bacteria. It has also been reported that LPS deficiency negatively affects biofilm formation. However, our results demonstrate that the O-antigen-deficient mutant enhances biofilm formation, presumably through a significant increase in hydrophobicity. It is notable that the hydrophobicity of cell walls might be a key regulator in controlling biofilm development in B. japonicum. [source] Recognition of anaerobic bacterial isolates in vitro using electronic nose technologyLETTERS IN APPLIED MICROBIOLOGY, Issue 5 2002A. Pavlou Aims: Use of an electronic nose (e.nose) system to differentiation between anaerobic bacteria grown in vitro on agar media. Methods and Results: Cultures of Clostridium spp. (14 strains) and Bacteroides fragilis (12 strains) were grown on blood agar plates and incubated in sampling bags for 30 min before head space analysis of the volatiles. Qualitative analyses of the volatile production patterns was carried out using an e.nose system with 14 conducting polymer sensors. Using data analysis techniques such as principal components analysis (PCA), genetic algorithms and neural networks it was possible to differentiate between agar blanks and individual species which accounted for all the data. A total of eight unknowns were correctly discriminated into the bacterial groups. Conclusions: This is the first report of in vitro complex volatile pattern recognition and differentiation of anaerobic pathogens. Significance and Impact of the Study: These results suggest the potential for application of e.nose technology in early diagnosis of microbial pathogens of medical importance. [source] Direct fluconazole susceptibility testing of positive Candida blood cultures by flow cytometryMYCOSES, Issue 3 2008Bernard Rudensky Summary The standard methods for yeast susceptibility testing require 24,48 h of incubation. As there has been an increase in incidence of non- albicans Candida species, the clinician is very often wary of initiating therapy with fluconazole until a final susceptibility report is generated, especially when treating very sick patients. A rapid reliable susceptibility testing method would enable the clinician to prescribe fluconazole, thus avoiding more toxic or expensive therapy. To determine the feasibility of direct susceptibility testing of Candida species to fluconazole by a rapid flow cytometric method, 50 Candida strains were seeded into blood culture bottles and were tested for susceptibility to fluconazole directly from the bottles after their being flagged as positive by the blood culture instrument. Minimal inhibitory concentration (MIC) determined by fluorescent flow cytometry (FACS) showed excellent agreement to that determined by macrodilution. Following the seeding experiments, 30 true patient specimens were tested directly from positive blood cultures, and MIC determined by both methods showed excellent agreement. Antifungal susceptibility testing by FACS directly from positive blood culture bottles is a reliable, rapid method for susceptibility testing of Candida to fluconazole. The method allows same-day results, does not require subculture to agar media, and can greatly assist in the selection of appropriate antifungal therapy. [source] Patterns of Interaction between Populus Esch5 and Piriformospora indica: A Transition from Mutualism to AntagonismPLANT BIOLOGY, Issue 2 2005M. Kaldorf Abstract: Piriformospora indica (Sebacinaceae, Basidiomycota) is an axenically cultivable, plant growth promoting root endophyte with a wide host range, including Populus. Rooting of Populus Esch5 explants started within 6 days after transfer to WPM medium. If such plantlets with roots were inoculated with P. indica, there was an increase in root biomass, and the number of 2nd order roots was increased significantly. A totally different observation was recorded when the explants were placed into WPM with pre-grown P. indica. The interaction led to complete blocking of root production and severely inhibited plant growth. Additionally, branched aerial roots appeared which did not penetrate the medium. On contact with the fungal colony or the medium, the ends of the aerial roots became inflated. Prolonged incubation stimulated the fungus to colonize aerial parts of the plant (stem and leaves). Mycelium not only spread on the surface of the aerial parts, but also invaded the cortical tissues inter- and intracellularly. Detached Populus leaves remained vital for 4 - 5 weeks on sterile agar media or on AspM medium with pre-grown P. indica. When the fungus was pre-grown on culture media such as WPM, containing ammonium as the main source of nitrogen, leaves in contact with the cultures turned brownish within 4 - 12 h. Thereafter, the leaves bleached, and about one day later had become whitish. Thus, cultural conditions could alter the behaviour of the fungus drastically: the outcome of the interaction between plant and fungus can be directed from mutualistic to antagonistic, characterized by fungal toxin formation and extension of the colonization to Populus shoots. [source] In vitro quantification of barley reaction to leaf stripePLANT BREEDING, Issue 5 2003M. I. E. Arabi Abstract An in vitro technique was used to quantify the infection level of leaf stripe in barley caused by Pyrenophora graminea. This pathogen penetrates rapidly through subcrown internodes during seed germination of susceptible cultivars. Quantification was based on the percentage of the pieces of subcrown internodes that produced fungal hyphae cultured on potato dextrose agar media. The disease severity was evaluated among five cultivars with different infection levels and numerical values for each cultivar were obtained. A significant correlation coefficient (r = 0.91, P < 0.02) was found among the in vitro and field assessments. In addition, the results were highly correlated (r = 0.94, P < 0.01) among the different in vitro experiments, indicating that this testing procedure is reliable. The method presented facilitates a rapid preselection under uniform conditions which is of importance from a breeder's point of view. Significant differences (P < 0.001) were found for the length of subcrown internodes between inoculated and non-inoculated plants with leaf stripe. Isolate SY3 was the most effective in reducing the subcrown internode length for all genotypes. [source] In vitro quantification of the reaction of barley to common root rotPLANT BREEDING, Issue 5 2001M. I. Arabi Abstract An in vitro technique was used to quantify the infection level of common root rot. This disease produces a brown to black discoloration of the subcrown internodes of barley. Quantification was based on the percentage of germinated infected pieces (1.5 mm) of subcrown internodes cultured on potato dextrose agar media. The disease severity was apparent among four different visually classified categories and numerical values for each category were applied. The results were highly correlated (r = 0.97, P < 0.01) among the different in vitro experiments, indicating that this testing procedure is repeatable. Highly significant differences (P < 0.001) were found for the length of first leaf and fresh weight between plants inoculated and uninoculated with common root rot. However, the effect of inoculation on fresh weight only differed significantly (P < 0.02) among the genotypes. [source] A high throughput membrane BIO-PCR technique for ultra-sensitive detection of Pseudomonas syringae pv. phaseolicolaPLANT PATHOLOGY, Issue 1 2007N. W. Schaad Molecular-based methods such as PCR have greatly improved detection of bacteria in environmental samples. However, the sensitivity of PCR is not high when compared to agar plating assays, and inhibitors from plants are often a problem. Pre-enriching bacteria on agar media (BIO-PCR) can increase the sensitivity of PCR by more than 100% and reduce the effects of inhibitors. To further increase the sensitivity and also reduce the labour needed for BIO-PCR, a high throughput 96-well membrane BIO-PCR technique is described for ultra-sensitive detection of Pseudomonas syringae pv. phaseolicola (PSP) (syn. P. phaseolicola) in washings of seeds and leaves of Phaseolus vulgaris, using available classical PCR primers and newly designed real-time primers and probe. The primers and probe, designed from a tox-argK chromosomal cluster of the PSP-specific phaseolotoxin gene, were confirmed to be specific to PSP. Samples (1·2 mL) were filtered under vacuum in 96-well membrane plates. After incubating on soft agar medium for 48,52 h, each well is washed with 200 µL of sterile water and used immediately for nested (two-step) PCR or real-time PCR or stored at ,20°C. Results of assaying spiked seed washings showed that classical PCR was unable to detect PSP at mean concentrations of 40 colony forming units (cfu) mL,1. BIO-PCR detected PSP in five out of six samples at 40 mean cfu mL,1 but none at mean concentrations of 4·2 and 0·4 mean cfu mL,1. In contrast, membrane BIO-PCR detected the bacterium in all six samples tested containing as few as 0·4 mean cfu mL,1. The sensitivity of detection from leaf washings was lower but the results were similar, classical and BIO-PCR were negative from all three levels of inoculum while membrane BIO-PCR detected three out of three samples at 80 mean cfu mL,1 and one out of three at 40 mean cfu mL,1. [source] A combined agar-absorption and BIO-PCR assay for rapid, sensitive detection of Xylella fastidiosa in grape and citrusPLANT PATHOLOGY, Issue 1 2005M. Fatmi Application of the polymerase chain reaction (PCR) to disease diagnosis is limited in part by the presence of PCR inhibitors. Inhibition can be overcome and sensitivity increased by culturing bacteria on agar media prior to PCR (termed BIO-PCR). However, Xylella fastidiosa grows slowly, requiring 10,14 days for visible colonies to appear. In this study an agar-absorption BIO-PCR method for detecting X. fastidiosa in grape and citrus plants was developed. Optimum lengths of time for absorption of inhibitors by the agar medium or enrichment of bacteria on the medium were determined for Pierce's disease of grape and citrus variegated chlorosis. When petioles of grape and citrus leaves with symptoms were spotted onto agar media, the spots washed after various time intervals and assayed for X. fastidiosa by real-time PCR, 97% (31 out of 32) and 100% (six out of six) of spots were positive after 2 days and 4 h for grape and citrus, respectively. With direct PCR, only 12·5% (four out of 32) and 33% (two out of six) of spots were positive, respectively, and visible X. fastidiosa colonies were evident after 10 and 14 days, respectively. In a separate experiment with samples from a different vineyard, 46% (13 out of 28) of the grape samples (agar spots) were positive after 1 day and 93% (26 out of 28) after 5 days using agar-absorption PCR. In contrast, all samples were negative by direct PCR. Viable X. fastidiosa were recovered from all samples after 14 days. Further tests with eight randomly selected grape petioles from three Texas vineyards known to have Pierce's disease resulted in 50% being positive by a simple 24 h agar-absorption PCR assay, whereas none was positive by direct PCR. Overall, 10 out of 16 (63%) vines from five vineyards (two in California and three in Texas) were positive after the 24 h agar-absorption PCR assay. In contrast, only one vine was positive by direct PCR. This simple agar absorption-based PCR assay protocol should prove useful for the routine detection of X. fastidiosa and other slow-growing bacteria in the presence of PCR inhibitors. [source] Antibacterial Activity of an Atmospheric Pressure Plasma Jet Against Relevant Wound Pathogens in vitro on a Simulated Wound EnvironmentPLASMA PROCESSES AND POLYMERS, Issue 3-4 2010Georg Daeschlein Abstract The aim of the study was to test the efficacy of a hand-held atmospheric pressure plasma jet (APPJ) toward typical wound pathogens in vitro simulating antisepsis on wound surfaces. The plasma jet has been proved to be highly effective in vitro against the most commonly encountered pathogenic species of acute and chronic wounds reaching nearly the power of antiseptics. The following bacteria and fungi were treated on half rigid media (agar) imitating wound colonization: methicillin-sensitive Staphylococcus aureus ATCC 1924 (MSSA), Enterococcus faecium ATCC 6057 (EF), Pseudomonas aeruginosa ATCC 15442 (PA), Candida albicans ATCC 10231 (CA), and , -hemolyzing Streptococci of the Lancefield serogroup A (HSA). Highest reduction factor (RF) was obtained treating PA (RF 4.0) followed by HSA (3.2), MSSA (2.7), CA (2.0), and EF (1.9). Consequently, simulating wound surfaces with moist environment using semisolid agar media, the APPJ allowed bactericidal treatment of highly contaminated surfaces of 55,cm2 imitating skin and wound colonization within 6,min. This antibacterial reduction power together with its handsome flexibility of the APPJ could be a suited therapeutic option in the therapy of infected or colonized wounds. [source] In situ localisation and quantification of surfactins in a Bacillus subtilis swarming community by imaging mass spectrometryPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 18 2008Delphine Debois Abstract Surfactins are a family of heptacyclopeptides in which the C-terminal carbonyl is linked with the ,-hydroxy group of a fatty acid acylating the N-terminal function of a glutamic acid residue. The fatty acyl chain is 12,16 carbon atoms long. These compounds, which are secreted by the Gram-positive bacterium Bacillus subtilis in stationary phase in liquid cultures, play an important role in swarming communities on the surface of agar media in the formation of dendritic patterns. TOF secondary ion MS (TOF-SIMS) imaging was used to map surfactins within 16,17,h swarming patterns, with a 2,,m spatial resolution. Surfactins were mainly located in the central mother colony (the site of initial inoculation), in a ,ring' surrounding the pattern and along the edges of the dendrites. In the mother colony and the interior of the dendrites, surfactins with shorter chain lengths are present, whereas in the ring surrounding the swarm community and between dendrites, surfactins with longer fatty acyl chain lengths were found. A quantitative analysis by MALDI-TOF MS showed a concentration gradient of surfactin from the mother colony to the periphery. The concentration of surfactin was ,400,pmol/mL in the mother colony and ,10,pmol/mL at the base of the dendrites, decreasing to 2,pmol/mL at their tips. [source] Salmonella importance and current status of detection and surveillance methodsQUALITY ASSURANCE & SAFETY OF CROPS & FOOD, Issue 3 2009Hanna-Leena Alakomi Abstract Salmonella, a genus within Enterobacteriaceae, remains as an important human pathogen and it has been reported to be the most common food-borne bacterial disease in the world. Although majority of the Salmonella cases are sporadic, outbreaks occur frequently. Salmonella can be associated with many kinds of foods and the presence of Salmonella in ready-to-eat foods is considered significant regardless of the level of the contamination. Therefore isolation is carried out by enrichment culture of a defined weight or volume of the food (normally 25 g). The traditional and time-consuming detection and isolation of Salmonella spp. from food and feed utilizes a multistep protocol with nonselective pre-enrichment, followed by a selective enrichment step, isolation on selective agar media and a preliminary biochemical and serological confirmation. Several rapid methods have been developed to speed up the detection of Salmonella. This paper aims to give an overview of the occurrence and current status of Salmonella detection and surveillance methods. [source] | ||||||||||||||||||||||