OXYRASETM ENZYME AND MOTILITY ENRICHMENT FUNG‐YU TUBE FOR RAPID DETECTION OF LISTERIA MONOCYTOGENES AND LISTERIA SPECIES1

The effect of different concentrations of Oxyrase in brucella broth supplemented with hematin solution and FBP supplement on growth of five strains of Campylobacter jejuni and one strain of C. coli at 42C under shaking and nonshaking condition was evaluated, and the generation times were calculated. The growth of Campylobacter increased as the amount of Oxyrase (0 to 0.8 unit/ml) in the broth increased. Fastest growth and shortest generation time were achieved with 0.6 unit/ml of Oxyrase in brucella broth both under shaking and nonshaking condition. All strains had higher growth and shorter generation times in the Oxyrase treated samples compared to nontreated controls. Growth kinetics of 5 strains of C. jejuni and one strain of C. coli (different level of initial population of inocula) in brucella broth with (0.6 unit/ml) and without Oxyrase at 42C in a gyrotory water bath shaker were studied. Growth curves were constructed and generation times were calculated. For all strains, growth rates were significantly (P 0.05) higher and generation times were significantly (P 0.05) shorter in the Oxyrase treated samples (0.6 unit/ml) compared to controls (0 unit/ml). The effect of Oxyrase on growth of Campylobacter strains was more profound at low initial inoculum levels. Oxyrase had a greater stimulatory effect on growth of Campylobacter strains in exponential growth phase than in stationary phase of growth.

Section: Dose Response Of Campylobacter Strains To Oxyrasetmsupporting

confidence: 87%

“…Time in hours after incubation in a 42 C gyrotory water bath shaker (100 gyrationshin) of Listeriu, and reported that Oxyrase was more beneficial to the slower growing strains.The effect of Oxyrase on growth of facultative anaerobes in nonselective broth media was studied byYu (1991). She showed that all of the facultative anaerobes…”

mentioning

confidence: 99%

EFFECT OF OXYGEN REDUCING MEMBRANE FRAGMENTS ON GROWTH OF CAMPYLOBACTER SPP.¹

Niroomand

Fung

1993

“…from other organism5 by development of a black color. Yu and Fung (1991 ) and Fung and Yu (1993) reported that the use of Fraser broth containing a membrane fraction (Oxyrase) in association with modified Oxford agar (MOX) in the Fung-Yu U-shaped tube. This system enables rapid detection of Listeriti r,iorioc'!…”

Section: Introductionmentioning

confidence: 99%

“…It creates anaerobiosis in a variety of bacteriological media. The activity of the membrane fraction is due to the presence of an active cytochrome-based electron transport system (Yu and Fung 1991). Tuitemwong (1993) reported that membrane fractions derived from Escherichia coli E-8 and acetic acid bacteria demonstrated oxygen-scavenging activities equivalent to that of Oxyrase in a buffer solution and in yogurt and buttermilk mixes.…”

Section: Introductionmentioning

confidence: 99%

RAPID DETECTION OF LISTERIA MONOCYTOGENES USING A REFLECTANCE COLORBMETRIC METHOD WITH MEMBRANE FRACTIONS FROM OXIDATIVE BACTERIA

Tuitemwong

Fung

Tuitemwong

1995

Membrane fractions obtained from Escherichia coli, Gluconobacter oxydans, and Acetobacter xylinum significantly stimulated rapid growth of Listeria monocytogenes (strains 101, 103, and Scott A) under atmospheric conditions of the OmniSpec Bioactivity System. L. monocytogenes demonstrated a shorter lag phase and faster growth compared to culture systems without the membrane fractions as determined by shorter color detection times, the durations of time for a significant color change to occur. The growth stimulating effect increased as the concentrations of membrane fractions increased. The use of membrane fractions to recover facultative Listeria spp. also lowered the detection limit of the method to < 10 cells/ml by increasing small cell numbers to the detectable level (107 cells/m) faster under aerobic conditions. The application of membrane fractions with the OmniSpec Bioactivity System shortened the detection time for the bacteria by 0.5–10 h, depending on the specific membrane and initial cell concentrations, compared to the conventional OmniSpec method. This method is very useful as a tool for studying food microbiology. Membrane fractions produced in our laboratory effectively dissipated oxygen in Fraser broth and had growth‐enhancing activities comparable to that of commercial OxyraseTM.

“…Consequently, selective methods for campylobacter isolation are involved which are time consuming. A method has been developed (Yu and Fung 1991;Yu and Fung 1992) for isolation of certain bacteria involving the use of the membrane bound oxyrase enzyme system of Escherichiu coli as a media supplement. They found that by using oxyrase in the media, special atmospheric conditions were not needed.…”

Section: Introductionmentioning

confidence: 99%

EVALUATION OF OXYRASE METHOD FOR CAMPYLOBACTER ISOLATION FROM CHICKEN CARCASSES¹

Raben

Slavik

1993

One hundred fresh chickens were purchased from an area grocery store and assayed for campylobacters by comparing four different isolation methods. In all methods, recovery of campylobacter involved pre‐enrichment in broths for 18–24 h and selective plating for isolation. The four campylobacter isolation methods evaluated included: (1) FSIS method, (2) FDA‐BAM method, (3) modified FDA‐BAM method, and (4) oxyrase‐supplemented Brucella broth enrichment method. Each of the four methods detected campylobacters in over 90% of the chicken carcasses tested. The oxyrase method, however, was found to be more rapid and less labor intensive than the other three methods.