bluuebunny/crossref_metadata_2025 huggingface dataset:
VITAMIN E SUPPLEMENTATION OF AWASSI FAT‐TAILED MALE LAMBS1
Authors: YAPRAK M. , EMSEN E. , AKSAKAL V. , OCKERMAN H.W.
Published: May 2007

Lambs were divided into two groups consisting of a control (n=4) and an experimental (n=4) treatment starting at the beginning of the fattening period. The vitamin E‐ treated group (SUP) received an additional 45 mg of vitamin E (DL‐α tocopheryl acetate) with a diet given to the control (CON) per lamb per day for 75 days. The effect of vitamin E supplementation on most meat quality traits was not statistically significant. L* and +a* values were measured on the M. longissimus dorsi (LM) and M. semimembranosus (SM) muscles obtained from vitamin E treated lamb groups which had been stored for a period of 12 days at 4C. The +a* (redness) for the freshly sliced SM muscle was significantly higher than the control (CON) at 4, 7 and 12 days of storage. TBARS (thiobarbituric acid) values in the LD muscle obtained from the control group were found to be higher than those obtained from the vitamin E supplementation group (P<0.01) on day 7 of storage.
INFLUENCE OF BREED AND DIET ON CARCASS AND ORGANOLEPTIC PROPERTIES OF MALE RED KARAMAN AND TUSHIN FAT‐TAILED LAMBS1
Authors: EMSEN E. , EMSEN H. , YAPRAK M. , OCKERMAN H.W.
Published: May 2007

Red‐Karaman (n = 24) and Tushin (n = 24) male fat‐tailed lambs were allocated to three groups and were fed basic diet plus dried alfalfa (Group I), barley grain plus dried alfalfa hay (Group II) and oat grain plus dried alfalfa hay (Group III) for 6 weeks before slaughter. Longissimus and Semimembranosus samples were removed from each carcass and examined by a sensory panel of 10 individuals. Red Karaman lambs had larger Longissimus area values than Tushin lambs. Dressing percentage in groups I, II and III were 52.40 ± 0.62%, 50.57 ± 0.61%, and 49.27 ± 0.63%, respectively (P < 0.05). Samples from Tushin fat‐tailed lambs had higher (P < 0.05) acceptability scores than those of Red Karaman and less (P < 0.05) intense mutton flavor than the other genotype x diet experimental groups. The effects of breed and diet on the other chemical, physical and organoleptic traits investigated in this study were not significant.
INSTRUMENTAL TEXTURE ASSESSMENT AND CONSUMER ACCEPTABILITY OF COOKED BROILER BREASTS EVALUATED USING A GEOMETRICALLY UNIFORM‐SHAPED SAMPLE
Authors: SCHILLING M.W. , SCHILLING J.K. , CLAUS J.R. , MARRIOTT N.G. , DUNCAN S.E. , WANG H.
Published: May 2007

The objective of this study was to determine the relationship of Warner‐Bratzler shear values obtained from sample chicken strips cut to a standard geometric configuration with consumer tenderness acceptability. A relationship with deboning time was also evaluated. One breast from each bird, alternating right and left, were sous vide cooked (78C internal) and an average WBS value (kg) was determined. The remaining companion breasts were sorted into one of five ranges (1.1–2.0, 2.1–3.1, 3.2–4.0, 4.2–5.0, 5.2–6.7 kg) based on shear value. Consumer sensory evaluation was affected (P<0.05) by shear value range, but deboning time and the interaction between the two measurements were not significant (P>0.05). Logistic regression was incorporated to predict the probability that a chicken breast in a specific shear value category would receive each consumer acceptability score.
INFLUENCE OF RABBIT AGE, DEBONER DRUM APERTURE, AND HIND/FORE CARCASS HALF ON MINCE COMPONENTS OF MECHANICALLY SEPARATED RABBIT
Authors: MCNITT J.I. , NEGATU Z. , MCMILLIN K.W.
Published: May 2007

Ninety‐one fryers sacrificed at 8, 12, 16 or 20 weeks were deboned. Mince recovery was highest (P<0.01) for 12 and 16 weeks and lowest at 20 weeks. Recovery with 2.0 mm apertures was greater (P<0.01) than with 1.3 mm and was 71.5% for rear halves and 63.0% for fore halves. Age and carcass half did not affect percentage bone in the mince. Bone content was higher with the 2.0 mm aperture (P<0.01). Deboning time (1.4 0.0s) of eight week carcasses was half the other ages (P<0.01). Hind halves deboned faster. Age and carcass half had no effect on bone fragments <0.5 mm. Percentage fragments >0.85 mm were less (P<0.05) for 12 week carcasses than for other ages but were not affected by carcass half. Mechanical separation of rabbit carcasses is fast and efficient. Further refinement is required to meet the USDA standards for bone size in mince.
STORAGE STABILITY OF PORK FROM BERKSHIRE AND HAMPSHIRE SIRED PIGS FOLLOWING DIETARY SUPPLEMENTATION WITH VITAMIN E
Authors: VAN HEUGTEN E. , HASTY J.L. , SEE M.T. , LARICK D.K.
Published: May 2007

Effects of vitamin E supplementation on pork quality of two genotypes were evaluated using 240 pigs (initial body weight was 87 0.35 kg). Berkshire or Hampshire sired pigs were fed either 12, 55, 99, 174, and 351 IU/kg of vitamin E for 6 weeks prior to slaughter. Loins from Hampshire sired pigs had increased (P < 0.001) levels of drip loss, were paler, more red, and more yellow than loins from Berkshire sired pigs following refrigerated display storage for up to 8 days or vacuum packaged storage for up to 55 days. Vitamin E supplementation did not improve fresh pork quality in either genotype. However, results indicate that vitamin E supplementation improved oxidative stability of pork chops during refrigerated display storage and this effect was more pronounced in the leaner Hampshire sired pigs. Therefore, vitamin E supplementation could be strategically applied to improve storage stability in select genotypes.
A NEW RAPID TECHNIQUE FOR SALMONELLA ANTIGEN DETECTION USING A PARTICLE CONCENTRATION FLUORESCENCE IMMUNOASSAY (PCFIA)
Authors: BLORE PAMELA J. , SLAVIK MICHAEL F.
Published: May 2007

A fluorescent assay employing polystyrene beads coated with antibody to a common structural antigen (CSA) of salmonellae has been developed to detect the presence of Salmonella. This sensitive technique is very fast, relatively simple and with further testing may be suitable for screening food products as well as clinical diagnostics. Comparison was made with a commercially available Salmonella antigen capture enzyme immunoassay (EIA). As little as one single colony‐forming unit (CFU) could be detected by fluorescence after only 16 h of enrichment. the procedure requires only 1 h to run and uses proportionately smaller volumes of sample and reagents than EIA.
A RAPID PCR METHOD FOR DIRECT DETECTION of LOW NUMBERS of CAMPYLOBACTER JEJUNI1
Authors: WANG RONG‐FU , SLAVIK MICHAEL F. , CAO WEL‐WEN
Published: May 2007

A rapid polymerase chain reaction (PCR) method was developed for detection of low numbers of Campylobacter jejuni. In this method, PCR was run directly from lysed C. jejuni cells and used a short denaturing and annealing time, a rapid transition, and an increased number of cycles to obtain good sensitivity. Only 3 h were required for PCR and 1 h for electrophoresis. Additional time for DNA isolation and DNA hybridization was not needed. This system was positive for C. jejuni but negative for C. coli and C. fetus. the method detected as few as two cells in original liquid ofC. jejuni in pure cultures. an internal probe hybridization test confirmed that the PCR products were from C. jejuni.
IMMUNOENZYME FOR RAPID SCREENING of CLOSTRIDIUM BOTULINUM TYPE A CELLS
Authors: SMITH C. , HAMDY M.K.
Published: May 2007

A staining procedure was developed for screening Clostridium botulinum type A (tox+) cells fixed (smear) on glass slides. the method is based on reaction between cells and an immunoenzyme‐conjugate consisting of antibody against type A toxin linked to horseradish peroxidase (HRPO) enzyme. Fixed smears were stained for perioxidase activity (30 min), using one drop of 3,3′‐diaminobenzidine‐hydrogen peroxide solution (pH 7.6) as oxidizable substrate, followed by washing, drying and microscopic examination (1000 X). the cell‐walls of vegetative C. botulinum type A appeared reddish brown and periphery of spores (if present), stained dark brown. However, C. botulinum type B (tox+) cross‐reacted (faint brown) with the same antibody‐HRPO‐conjugate. Specificity and sensitivity of this procedure compared well with the immunodiffusion method of Ferreira et al. (1981, 1983). Factors affecting cell‐staining were: fixation time and type used, incubation time of antibody‐HRPO‐conjugate with cells, growth medium, culture age, and crowding of cells in smears. Ethanol fixation (5 min) of logarithmic and/or stationary phase cells and 30 min incubation with antibody‐HRPO‐conjugate were optimal and yielded the most appropriate procedure for detecting cells containing type A botulinum toxin.
USE of an ELECTRONIC HGMF INTERPRETER SYSTEM FOR ENUMERATION of NALIDIXIC ACID RESISTANT SALMONELLAE IN CHICKEN CAECA
Authors: PETERKIN P.I. , LANGFORD C.F. , CHAMBERS J.R. , SHARPE A.N.
Published: May 2007

An electronic counting system using hydrophobic grid‐membrane filters (HGMF) and the HGMF Interpreter was evaluated for its usefulness in enumerating nalidixic acid resistant Salmonella in frozen chicken caeca. Salmonella recovery was equivalent on both Hektoen Enteric and EF‐18 agars. However, the color of the Salmonella growth on EF‐18 agar was more easily differentiated by the HGMF Interpreter electronic counting system. the study showed that a 4 h resuscitation on a nonselective medium was required in order to maximize the subsequent recovery on Hektoen Enteric agar, though not on EF‐18 agar. Using the EF‐18 agar as the Salmonella selective medium, a method was established that recorded counts of nalidixic acid resistant Salmonella rapidly and easily in electronic data files, for subsequent retrieval and manipulation.
A MINIATURIZED ENRICHMENT SEROLOGY METHOD FOR RAPID DETECTION of SALMONELLA FROM POULTRY MEAT and REARING FARMS ENVIRONMENT
Authors: SALVAT G. , HUMBERT F. , LALANDE F. , COLIN P. , LAHELLEC C.
Published: May 2007

A miniaturization of the enrichment serology method for the detection of Salmonella was improved in order to make the technique more reliable, cheaper, and faster. the miniaturized method (“Micromethod”) was compared to the Sperber and Deibel's method (“Macromethod”) and with a classical isolation method; 1062 samples including 700 rearing farms environment samples, 247 poultry meat samples, and 115 nonfat dry milk samples were analyzed. Specificity of both enrichment serology methods was about 92–99.4%. Sensitivity of Micromethod was better than that of the Macromethod for the environmental samples (86.8 and 74.1%, respectively) and the poultry meat samples (87.5 and 77.5%, respectively) but was the same for the nonfat dry milk samples (82.5%). the costs of both methods were respectively 0.43 US $ for the Macromethod and 0.20 US $ for the Micromethod. This “Micromethod” could be proposed for the screening of Salmonella positive batches in the food industries.
BACILLUS CEREUS PATHOGENICITY: A REVIEW
Authors: FERMANIAN CHRISTOPHE , FREMY JEAN‐MARC , LAHELLEC CECILE
Published: May 2007

Pathogenic Bacillus cereus can be routinely isolated and identified in the laboratory from foods and other sources. Typing of B. cereus strains implicated in food poisoning outbreaks is helpful for confirmation of the origin of the outbreak and for epidemiological studies. Data concerning vegetative growth and spores are given. Different types of toxin are produced by B. cereus in the course of its growth: a so‐called diarrheal enterotoxin and an emetic heat‐stable toxin; their biochemical characteristics and the systems used for their detection are reviewed. Different types of hemolysins and phospholipases C are also produced and may play a role in pathogenicity. Nongastrointestinal infections were also traced to this species.
IMMUNOCYTOCHEMICAL LOCALIZATION OF ANTIGENS IN B. CEREUS T SPORES1
Authors: CHANG Y.H. , FOEGEDING P.M.
Published: May 2007

The application of immunogold labeling for the localization of antigens on Bacillus cereus T spores is described. Ultrathin cryosections of B. cereus T spores were labeled with rabbit anti‐B. cereus T spore serum and protien A‐gold conjugate, and viewed in a transmission electron microscope. Antigens were located throughout the spore exosporium and also in the spore coat and protoplast. The higher density of gold particles in the exosporium indicates that the exosporium is very antigenic and was the major antigen when whole, formalin‐treated, spores were injected into rabbits. The presence of label in the interior structure suggests spores may have been degraded by the animal upon injection, permitting exposure of interior antigens.
AFFINITY CONCENTRATION OF LISTERIA MONOCYTOGENES CELLS ON CONCANAVALIN A‐COATED POLYESTER CLOTH AND SUBSEQUENT DETECTION BY THE POLYMERASE CHAIN REACTION
Authors: BLAIS BURTON W. , PHILLIPPE LUCILLE M.
Published: May 2007

The Canavalia ensiformis lectin concanavalin A (con A) was immobilized on macroporous polyester cloth to form an inexpensive high surface area adsorbent (con A‐cloth) for the affinity concentration of bacterial cells in aqueous suspensions. When the con A‐cloth was packed into a 1 ml pipette tip, the resulting mini‐column could be used to concentrate large volumes of dilute L. monocytogenes cell suspensions, followed by the polymerase chain reaction (PCR) amplification of L. monocytogenes‐specific hly A sequences from lysates of the captured cells. This improved the effective sensitivity of the PCR as compared to the assay of L. monocytogenes in unconcentrated suspensions. Several enrichment broths (Fraser Broth, Listeria Enrichment Broth and Brain Heart Infusion Broth) were found to be inhibitory to the PCR of L. monocytogenes when introduced directly into the reaction mixture. This inhibitory effect was completely eliminated when the L. monocytogenes cells were captured on the con A‐cloth and washed to remove the enrichment broth components prior to performing the PCR. Since the lectin con A is reactive with a broad variety of Gram positive and Gram negative bacteria, this simple and inexpensive affinity concentration method should be applicable to the PCR detection of other pathogens in enrichment cultures.
COMPARISON OF A MEMBRANE FILTRATION PROCEDURE AND A MPN PROCEDURE FOR ENUMERATING SALMONELLA IN WHOLE CARCASS RINSE SAMPLES1
Authors: YAMAGUCHI WAKAKO , KOPEK J. MIKE , WALDROUP AMY L.
Published: May 2007

A membrane filtration method using hydrophobic grid membrane filters was developed to enumerate salmonellae in postchill chicken carcass rinse samples. The entire sample volume (100 ml) was filtered utilizing a 0.1% peptone/1% Tween 80 rinse solution which was digested prior to filtration with 2% trypsin. Samonella colonies were countable on XLD agar supplemented with 20 ppm novobiocin and 1% sodium pyruvate after 24 to 30 h of incubation. The filtration method was compared to a modified 3‐tube MPN procedure (utilizing volumes of 30 ml, 3 ml, 0.3 ml, and 0.03 ml) for recovery of thermally stressed salmonellae that had been inoculated into carcass rinse fluid. Presumptive Salmonella levels were obtained in 30 h by membrane filtration method and in 72 h using the MPN procedure. Membrane filtration did not allow for complete recovery of the inoculated, thermally‐stressed Salmonella. The MPN method recovered significantly higher levels of the inoculated organism, however, levels recovered using this procedure were extremely varied from sample to sample.
A RAPID METHOD FOR THE DETERMINATION OF BACTERIAL GROWTH KINETICS 1
Authors: BREIDT F. , ROMICK T.L. , FLEMING H.P.
Published: May 2007

We have developed a rapid method for the determination of lag times and specific growth rates for bacteria. This method involves the use of a Bio‐Tek model EL312 microtiter plate (MP) reader, controlled by KinetiCalc software, and uses a computer program that processes absorbance data from a 96‐well MP. The program reads an ASCII file consisting of optical density readings generated by the MP reader, sorts the data into individual growth curves, and determines growth kinetics. No statistically significant difference (P > 0.88) was found between the MP method and standard batch methods. This method allows up to 95 growth curves to be carried out simultaneously. The MP method automates the difficult task of determining growth kinetics for bacterial strains under conditions that result in slow growth rates or long lag times. Using this method we determined the effect of NaCl on the growth kinetics of Listeria monocytogenes and the effects of NaCl and temperature on the growth kinetics of Leuconostoc mesenteroides.
DETECTION OF LISTERIA MONOCYTOGENES BY ADSORPTION AND ELUTION FROM HYDROPHOBIC MATRICES
Authors: SHARMA S. , KASATIYA S. , FARBER J.M.
Published: May 2007

The binding of L. monocytogenes Scott A strain to three hydrophobic matrices, octyl, phenyl and butyl Sepharose, was investigated. Optimal adsorption of L. monocytogenes to octyl Sepharose was obtained at pH 3.5 and 4 M NaCl. However, it was difficult to elute the bacteria from octyl Sepharose, even after changing the pH and lowering the salt concentration. Good adsorption of L. monocytogenes to phenyl Sepharose at pH 3.5 and 4 M NaCl was also observed. L. monocytogenes was found to adsorb weakly to butyl Sepharose, which is less hydrophobic than phenyl Sepharose. Bacteria were eluted under various conditions. The best elution was obtained with 10 mM sodium phosphate, followed by an increasing gradient of ethylene glycol. To test the potential application of hydrophobic chromatography for separating L. monocytogenes from food matrices, milk was inoculated with L. monocytogenes and then passed through a column of phenyl Sepharose at pH 3.5 and 4 M NaCl. Nearly all L. monocytogenes were bound to the hydrophobic gel and were eluted in a pure and viable form by changing the pH and lowering the salt concentration, and by using a polar reducing agent, ethylene glycol. This study shows that hydrophobic interaction chromatography can be used to separate L. monocytogenes from milk and may be applicable to other food suspensions. It is a gentle method that makes use of the hydrophobic surface properties of Listeria for attachment to hydrophobic gels, as well as using mild elution conditions to avoid inactivation of the organism.
RAPID DETECTION OF LISTERIA MONOCYTOGENES USING A REFLECTANCE COLORBMETRIC METHOD WITH MEMBRANE FRACTIONS FROM OXIDATIVE BACTERIA
Authors: TUITEMWONG K. , FUNG D.Y.C. , TUITEMWONG P.
Published: May 2007

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.
USE OF BLUE LAKE AS AN INDICATOR OF BACTERIAL PENETRATION INTO EGGS
Authors: KIM JEONG‐WEON , SLAVIK MIKE F.
Published: May 2007

Blue Lake, an insoluble dye, was evaluated as an indicator of potential bacterial penetration into eggs. Various groups of eggs (fresh‐laid; commercial; water‐washed) were dipped in 0.25% (w/v) Blue Lake in 0.1% Triton X‐100 solution for 2 min and incubated at room temperature up to 1 ± 24 h. Penetration was detected by counting the blue dots on shell membranes after breaking the eggs. Commercial eggs allowed the easiest penetration. All commercial eggs showed blue dots even at 2 min incubation and the average count reached 111/egg at 1 h. Water‐washed eggs allowed much less penetration than commercial eggs and the counts of blue dots on those eggs were 10/egg at 2 min and 22 at 1 h. Fresh‐laid eggs did not allow any penetration up to 24 h. Above results corresponded very well with the penetration study with Salmonella enteritidis and also with the morphological study of eggshell surfaces using electron microscopy where fresh‐laid eggs had intact cuticle layers, but commercial eggs did not. Thus, Blue Lake dye might be used as a rapid indicator of bacterial penetration through eggshells.
IMAGE ANALYSIS AS A RAPID PATHOGEN DETECTION METHOD FOR USE IN POULTRY INDUSTRY
Authors: SINGH N. , SLAVIK M.F. , WANG X. , LI Y.
Published: May 2007

An image analysis system was developed and evaluated as a method for rapid detection of Salmonella typhimurium in pure culture and in chicken washes. A direct immunomagnetic separation and immunofluorescent staining technique was developed to capture and identify target cells. Digital images were acquired and segmented into background and bacteria. Bacteria were enumerated using a custom designed image analysis software. The image analyses results were compared with manual enumeration. A correlation coefficient of 0.78 was established between manual and image analysis counts. In addition, the difference between the manual and the image analysis bacterial counts in individual images was low. Image analysis took an average of 15 s to analyze an image. The results indicate that the proposed system has the potential to be used as a rapid screening procedure for bacterial detection in the food industry.
INDIGENOUS POULTRY FEED MICROFLORA RESPONSE TO ETHYL ALCOHOL AND BUFFERED PROPIONIC ACID ADDITION
Authors: HA S.D. , MACIOROWSKI K.G. , KWON Y.M. , RICKE S.C.
Published: May 2007

The present study was designed to compare ethyl alcohol with buffered propionic acid feed treatment on the survival of indigenous poultry feed bacteria and fungi. The aerobic bacterial poultry feed populations were not substantially reduced by either ethyl alcohol or buffered propionic acid treatments. Likewise, indigenous poultry feed fungal populations also were not markedly reduced by buffered propionic acid treatment of the feed but fungal poultry feed populations exposed to ethyl alcohol treatments were significantly lower (P<0.05) than fungal populations recovered from either control and buffered propionic acid treated feeds. Ethyl alcohol treatment may have potential for reducing fungal contamination in poultry feed.
RAPID DETECTION OF MICROBIAL CONTAMINATION IN TRICLOSAN AND HIGH FLUORIDE DENTIFRICES USING AN ATP BIOLUMINESCENCE ASSAY
Authors: IGNAR RAYMOND , ENGLISH DONALD , JIMENEZ LUIS
Published: May 2007

Abstract The Celsis ATP Bioluminescence method was optimized and validated to detect the presence of microbial contamination in High Fluoride and Triclosan dentifrice formulations. Several enrichment broths were evaluated by using a 24–27 h incubation period. The ATP concentrations of the enrichment broths were found to a range from 0.012 to 0.040 nM. None of the tested enrichment broths were found to exhibit any sample inhibition/enhancement effects on the ATP Bioluminescence reaction. Dentifrice suspensions were inoculated with bacteria, yeast, and mold. All test microorganisms (ca. 1–15 CFU/g) were detected within a 24–27 h incubation period by using TAT Broth Base enrichment broths containing different concentrations of the following ingredients: Tween 20, Neopeptone, Dextrose, Triton X‐100, Thiosulfate, Sodium Dibasic Phosphate, and Glycine. Negative ATP response after 24–27 h of incubation at 35C indicates the absence of contamination from these products.
RAPD AS A RAPID METHOD FOR QUALITY ASSURANCE TESTING IN THE FOOD MICROBIOLOGY LABORATORY
Authors: PHANG S.T.W. , NG H.H. , LUAR A.L. , CHEW S.T.
Published: May 2007

The application of RAPD as a rapid tool for quality assurance testing in the food microbiology laboratory is discussed in this paper, using Vibrio cholerae as a specific case study. Nine V. cholerae strains isolated during a one month period from environmental, seafood and shellfish samples were typed using the Random Amplified Polymorphic DNA (RAPD) method. Using this technique, distinct DNA fingerprint patterns were generated for all 9 strains tested. A particular 80% GC‐content RAPD primer, VC80‐10, was evaluated for its possible use in the differentiation among V. cholerae strains. Although the results presented are only very preliminary observations, it is shown that it is possible to use RAPD as an additional tool for quality assurance testing in the food microbiology laboratory, albeit only in a rather limited capacity.
CATALASE ACTIVITY AS AN INDEX OF MICROBIAL LOAD AND END‐POINT COOKING TEMPERATURE OF FISH
Authors: BIN JASASS FAHAD M.R. , FUNG DANIEL Y.C.
Published: May 2007

Psychrotrophs that are responsible for spoilage of many aerobically cold‐stored foods are strongly catalase positive. This study was conducted to ascertain the feasibility of using the Pasteur pipette catalase test developed by Fung (1985) to estimate the microbial population in raw fish during aerobic cold storage and to determine the end‐point cooking temperature of fish. Fish samples (cod fillets, catfish, halibut fillets, rainbow trout, and salmon fillets in three replications each) were stored at 7C and monitored at 0, 6, 12, 24, 48, and 72 h and up to 7 days. Fish surface, fish juice, and fish meat samples were obtained by conventional microbiological methods and were serially diluted in 0.1% of peptone water to a final 1:100 dilution. To perform the catalase test 0.1 mL of the 1:10 or 1:100 dilution of the sample was placed into the wider portion of the heat‐sealed Pasteur pipette followed by 0.1 mL of 3% H2O2. The liquid mixture then was shaken into the heat‐sealed capillary portion. The pipette was then inverted and after 5 min, the lengths of the gas column and the liquid column were measured in mm; the gas column was expressed as a percentage of the total, which was considered as the percentage catalase activity (% CA). Viable cell counts (VCCs) of these samples also were made. As VCCs increased on fish surface, in fish juice, and in fish meat samples, concomitant increases occurred in % CA. The lowest level detect by this method was about 103‐4 CFU/cm2, mL, or g. Catalase activities of 0.0‐0.5% on fish surface, <4.3% in fish juice, and <2% in fish meat, corresponded to low total counts of 104‐5 CFU/cm2, 105 CFU/mL, and 103‐4 CFU/g, respectively. Catalase activities of 0.6‐1.5% on fish surface, 4.3‐8.2% in fish juice, and 2.3‐5% in fish meat, corresponded to high total counts of 106 CFU/cm2, 106 CFU/mL, and 105‐6 CFU/g, respectively. Catalase activities of 1.7‐2.5% on fish surface, 8.3‐12.4% in fish juice, and 5–6% in fish meat, indicated that fish was unacceptable for consumption. Fish samples were cooked at temperatures of 40C, 50C, 55C, 60C, 65C, 70C, and 75C to determine the end‐point temperature. Each sample was heated at each temperature for: 36 s, 1 min, 2 min, 3 min, and 5 min in a temperature‐controlled water bath. Samples that had reached an internal temperature of 65C showed no catalase activity in the test tube method or very little activity in the capillary tube method and contained no live bacteria, indicating that fish was safe for consumption.
DETECTION OF IMMUNOMAGNETICALLY CAPTURED, 4′,6‐DIAMIDINO‐2‐PHENYLINDOLE (DAPI)‐LABELED E. COLI O157:H7 BY FLUORESCENT MICROSCOPE IMAGING 1
Authors: TU S.‐I , UKNALIS J. , PATTERSON D. , GEHRING A.G.
Published: May 2007

Live cells of E. coli O157:H7 were treated with 4′,6‐diamidino‐2‐phenylindole (DAPI), a nucleic acid stain, for observation by epifluorescent microscopy. The treated bacteria, which exhibited minimal growth activity and partially retained respiratory function, were captured by goat anti‐E. coli O157 serum coated on the surface of polystyrene based immunomagnetic beads (IMB). The beads with captured bacteria were then concentrated by magnetic separators. The efficiency of this magnetic concentration step was less than that of using high speed centrifugation. The antibody‐captured and IMB‐immobilized bacteria were then applied on HF‐treated, bovine serum albumin (BSA)‐coated microscope slides mounted on an automated stage, and magnetically aligned before fluorescence distribution was measured by a cooled CCD attached to an inverted microscope. Since the beads were concentrated and linearly aligned along the edge of the magnetic field, image capture along the edge for a few field widths was sufficient to account for most of captured bacteria. This approach could reduce the enumeration time for and increase the efficiency of bacteria counting by manual efforts. The developed procedure of capturing, concentrating and enumerating E. coli O157:H7 exhibited a similar applicability in buffer, pork carcass wash solution and apple juice as described in this study. The presence of about 100 cells/mL of the bacteria could be detected in 30 min with developed procedure.
IMMEDIATE DIFFERENTIATION OF SALMONELLA‐RESEMBLING COLONIES ON BRILLIANT GREEN AGAR
Authors: JENSEN A.N. , HOORFAR J.
Published: May 2007

A rapid biochemical system (OBIS) based on immediate enzymatic differentiation of Citrobacter, Proteus, Providencia, Hafnia and Morganella spp. from Salmonella on brilliant green agar was evaluated. A total of 96 field isolates from various Salmonella serotypes, 18 Citrobacter freundii and 25 isolates of other Enterobacteriaceae were tested. All Salmonella isolates were identified correctly by the kit, and none of the Enterobacteriaceae isolates were identified as Salmonella. The results indicate complete specificity for Salmonella colonies on brilliant green agar.
NEW APPROACH FOR MODELING GENERALIZED MICROBIAL GROWTH CURVES USING ARTIFICIAL NEURAL NETWORKS1
Authors: HAJMEER M.N. , BASHEER I.A. , MARSDEN J.L. , FUNG D.Y.C.
Published: May 2007

Microbial growth curves are essential components in microbiological studies and are modeled conventionally by nonlinear fitting to one analytical expression such as the modified Gompertz equation. This paper discusses the potential of artificial neural networks (ANNs) for modeling bacterial growth curves. These ANNs are efficient approximators for highly dimensional complex functions because of their high nonlinearity and tolerance to noisy data. Therefore, ANNs can provide great flexibility in developing generalized models by extracting the real behavior directly from the experimental data. Such models can be designed to include the effect of time as well as a multitude of parameters pertaining to experimental conditions. The approach was applied to modeling time‐dependent growth curves of Escherichia coli O157:H7 as affected by sodium chloride concentration and of Shigella flexneri as affected by incubation temperature, pH, and initial count. The developed ANNs were able to approximate the experimental growth curves with high accuracy. The advantages as well as limitations of the proposed methodology are presented.
COMPILATION OF INTERVENTION METHODS AND CONDITIONS, AND INGREDIENT LIMITS, FOR CONTROLLING CAMPYLOBACTER JEJUNI IN MEAT AND POULTRY PRODUCTS1
Authors: HENDRICKS REBECCA A. , BOYLE ELIZABETH A.E. , KASTNER CURTIS L. , FUNG DANIEL Y.C.
Published: May 2007

Foodborne disease caused by Campylobacter jejuni has been associated with raw meats, poultry, milk, water, and other foods. Animals can harbor this pathogen among the intestinal flora, and it potentially can contaminate carcasses during dressing procedures. Therefore, it is virtually impossible to completely prevent contamination of meat and poultry. Hazards associated with contamination, survival and, subsequent growth during production, transportation, processing, and preparation must be considered. However, demonstrating C. jejuni presence and control is challenging because it is difficult to culture and maintain in laboratory conditions. Campylobacter jejuni has been exhibited to be extremely vulnerable to a wide variety of antimicrobial treatments, food processing methods, and environmental stress. Effective, validated methods for controlling this pathogen would be of immense value to consumers by reducing exposure. Relevant literature regarding the various techniques for the prevention, control, and inactivation of C. jejuni in meat and poultry is reviewed and their potential assessed.
GROWTH OF PATHOGENIC BACTERIA IN UNIVERSAL PREENRICHMENT BROTH SUPPLEMENTED WITH OXYRASETM AND FERRIOXAMINE E1
Authors: VICHIENROJ K. , FUNG D.Y.C.
Published: May 2007

The effect of OxyraseTM at 0.4 unit/mL and Ferrioxamine E at 1.0 μg/mL supplemented to Universal Preenrichment medium alone or combined on the growth of Salmonella typhimurium, Yersinia enterocolitica, Escherichia coli O157:H7, and Listeria monocytogenes were evaluated. Addition of OxyraseTM at 0.4 unit/mL enhanced the growth of all four organisms. Addition of Ferrioxamine E enhanced the growth of Salmonella typhimurium and Yersinia enterocolitica but did not affect the growth of Escherichia coli O157:H7 and Listeria monocytogenes. OxyraseTM in conjunction with Ferrioxamine E gave the greatest enhancement of growth of Salmonella typhimurium and Yersinia enterocolitica.
PCR REACTION PARAMETER TITRATION AS AN APPROACH TO DEVELOP SHORTENED REACTION TIMES IN A CONVENTIONAL THERMAL CYCLER
Authors: SHAW W.K. , McLANDSBOROUGH L.A.
Published: May 2007

A shortened PCR procedure was developed in a conventional thermal cycler. Overnight cultures of E. coli were used for PCR to amplify fragments of the uidA and slxII genes. A standard PCR program (30 cycles of 1 m denaturation at 94C, 1 m annealing at 54C or 60C, and 2.5 m elongation at 72C) required 3.5 h to complete and was able to detect a product from 1 × 103 PCR template cells in an agarose gel. The shortened PCR program (35 cycles of 17 s denaturation at 94C, 20 s annealing at 54C or 60C and 23 s elongation at 72C) required 1.5 h time and was able to detect PCR product from 5×10 PCR template cells. The results show that it is possible to shorten the time of each PCR cycle producing a more rapid method for the detection of E. coli while still using a conventional thermal cycler. This approach was successful using different primer pairs, indicating other researchers could use this approach to significantly shorten their PCR reaction times.
THE USE OF STREPTAVIDIN COATED MAGNETIC BEADS FOR DETECTING PATHOGENIC BACTERIA BY LIGHT ADDRESSABLE POTENTIOMETRIC SENSOR (LAPS)
Authors: TU SHU‐I , UKNALIS JOSEPH , IRWIN PETER , YU LINDA S.L.
Published: May 2007

A modified procedure for magnetic capture of antibody‐conjugated bacteria for light addressable potentiometric sensor (LAPS) detection using the Threshold System was developed. Streptavidin coated magnetic beads, partially labeled with biotinylated anti Escherichia coli O157 antibodies, were used to capture Escherichia coli O157:H7. Captured bacteria were further labeled with fluorescein‐conjugated anti ‐E. coli O157:H7 antibodies and urease‐labeled. anti‐fluorescein antibody. Magnetically concentrated bacteria‐containing complexes were then immobilized through streptavidin‐biotin interactions on 0.45 μ biotinylated nitro‐cellulose membranes assembled as sample sticks for the Threshold instrument. The rate of pH change associated with the production of NH3 by the urease in urea‐containing solution was measured by a LAPS incorporated in the Threshold instrument. This approach allowed us to detect 103 to 104 CPU of cultured E. coli O157:H7 in PBS solutions. Furthermore, detectable LAPS signals of the sample sticks remained relatively constant for at least 24 h at 4C. The developed approach was applied to detect the E. coli in beef hamburger spiked with the bacteria. After a 5 to 6‐h enrichment at 37C, as low as 1 CFU/g of E. coli O157:H7 in beef hamburger could be detected.
EFFECT OF VOLUME OF LIQUID ENRICHMENT MEDIUM CONTAINING OXYRASE® ON GROWTH OF CAMPYLOBACTER JEJUNI1
Authors: WONGLUMSOM W. , VISHNUBHATLA A. , FUNG D.Y.C.
Published: May 2007

The effect of volume of liquid medium (Hunt broth) supplemented with Oxyrase® on growth of Campylobacter jejuni was evaluated by using four sizes of containers and two concentrations of Oxyrase® (0.15 units/mL and 0.6 units/mL). We used 13×100 mm screw‐capped tubes containing 1, 3, and 6 mL of medium; 18x150 mm screw‐capped tubes containing 1, 5, 10, and 20 mL of medium; 45x45x120 mm bottles containing 25, 50, and 100 mL of medium; and Stomacher® 400 bags containing 250 mL of medium. Counts of four strains of C. jejuni were determined on blood agar plates at 0, 6, 12, 20, and 28 h of incubation. For 13×100 mm tubes, 3 mL of broth resulted the highest bacterial counts with increases of 4–5 log CFU/mL at 12 h and 7–8 log CFU/mL at 20 h. For 18x150 mm tubes, 10 mL and 20 ml of broth both provided increases of 3–4 log CFU/mL and of 6–7 log CFU/mL at 12 h and 20 h, respectively. Increases of 3.5 log CFU/mL at 12 h and of 7–8 log CFU/mL at 20 h were found in bottles containing 100 mL of broth. Overall, 0.15 units/mL Oxyrase® enhanced Campylobacter growth as effectively as 0.6 units/mL in all containers with no significant differences (p>0.05). However, supplementation with 0.6 units/mL of Oxyrase® gave slightly higher bacterial counts than addition of 0.15 units/mL in containers with high ratios of head space volume to medium volume (H:M). Ratios between 1.0 and 3.0 generally gave better results with all strains. The dissolved oxygen levels in each container were lower with high medium volume than with low medium volume. This study positively supported the efficiency of using Oxyrase® for recovery of C. jejuni under normal atmospheric conditions. In addition, various sizes of containers could be used for culturing campylobacters by maintaining the H:M ratio between 1.0 and 3.0.
A MACHINE VISION SYSTEM USING IMMUNO‐FLUORESCENCE MICROSCOPY FOR RAPID RECOGNITION OF SALMONELLA TYPHIMURIUM
Authors: TRUJILLO O. , GRIFFIS C. , LI Y. , SLAVIK M.
Published: May 2007

The objective of this research was to develop an automated system using image processing and statistical modeling techniques to identify and enumerate bacteria on slides containing Salmonella typhimurium. Pictures of bacterial cells were acquired with a CCD camera attached to a motorized fluorescence microscope. A shape boundary modeling technique, based on the use of circular autoregressive model parameters, was used. A minimum‐distance classifier was trained with ten images belonging to each shape class (rod shape and circle shape). Experimental results showed that the model parameters could be used as descriptors of shape boundaries detected in digitized binary images of bacterial cells. In spite of the advantages of human vision, the differences between the computer and a bacteriologist in recognizing and counting of Salmonella cells were less than 8%. The computer analyzed each image in approximately 5 s (a total of 2 h including sample preparation), while the bacteriologist spent an average of 1 min for each image.
EVALUATION OF 5’NUCLEASE BASED DETECTION ASSAYS TO DETECTESCHERICHIA COLIO157:H7 FROM FOOD PRODUCTS
Authors: BOHRA L.K. , OBERST R.D. , PHEBUS R.K. , HAYS M.P. , GREEN R.L. , SARGEANT J.M.
Published: May 2007

Two 5’nuclease‐based PCR methods (PCR‐LS‐50B and PCR‐7200) were evaluated to determine their sensitivity for detecting Escherichia coli O157:H7 from pure cultures and in food samples enriched in different media and after different incubation periods. The PCR‐7200 method was able to detect E. coli O157:H7 at ± 102CFU/mL in pure culture in both mECB and EEB. In spiked meat samples, the PCR‐7200 procedure was capable of detecting the eaeA gene at lower concentrations than the PCR‐LS‐50B procedure, regardless of the meat type or enrichment medium. Escherichia coli O157:H7 spiked at 0.3 CFU/mL was detectable after 9 h in EEB, but it was not detected in mECB within 24 h. An enrichment time of 4 h in mECB was needed to detect E. coli O157:H7 when spiked at higher levels (41 CFU/mL). The detection levels reported in this study are similar with other reported PCR‐based detection techniques for E. coli O157:H7, however, the 5’nuclease‐based assays are less labor intensive and capable of higher sample throughput because of their automated detection and analysis steps.
EVALUATION OF KANG‐FUNG‐SOL MEDIUM FOR SELECTIVITY OF LACTIC ACID BACTERIA FROM LABORATORY MEDIUM AND GROUND BEEF1
Authors: KIM SOL , FUNG DANIEL Y.C. , KANG DONGHYUN
Published: May 2007

deMan Rogosa Sharpe (MRS) medium has usually been used for the recovery of lactic acid bacteria (LAB) from various food products. However, it also allows non‐LAB to grow due to its nutritive ingredients. Three kinds of agar media, MRS, Kang‐Fung (KF), and Kang‐Fung‐Sol (KFS), were evaluated for selective growth of LAB from mixed cultures. All bacteria tested grew well on MRS medium. KF medium was effective for the inhibition of gram‐negative bacteria, but not for some gram‐positive bacteria. KFS medium completely inhibited the growth of all non‐LAB tested. Furthermore, the growth of LAB tested on KFS medium was not significantly different from that on MRS or KF medium. Microbial counts from inoculated ground beef of Pediococcus pentosaceus, Escherichia coli O157:H7, Pseudomonas aeruginosa, and Salmonella arizonae did not show a significant difference between MRS and KF medium. However, no non‐LAB were recovered from ground beef using KFS medium. The recovery of Pediococcus pentosaceus was not significantly different on all three media tested. This research shows that KFS medium can be used to isolate and enumerate LAB in liquid medium or ground beef in the presence of other microorganisms.
DIRECT DETECTION OF ESCHERICHIA COLI 0157:H7 IN UNPASTEURIZED APPLE JUICE WITH AN EVANESCENT WAVE BIOSENSOR
Authors: DeMARCO DANIEL R. , LIM DANIEL V.
Published: May 2007

An evanescent wave biosensor was used to detect Escherichia coli O157:H7 in unpasteurized apple juice. Light is launched from a 635 nm laser diode into silica or polystyrene optical waveguides, generating an evanescent field which extends from the waveguide surface. Fluorescent molecules within the evanescent field are excited resulting in an emission signal that the biosensor then detects and quantifies. A sandwich immunoassay was performed on the waveguides using cyanine 5 dye‐labeled anti‐E. coli O157:H7 antibodies for generation of the specific fluorescent signal. The lower limit of detection was between 6.0 × 102 and 6.0 × 104 CFU/mL with silica waveguides and between 3.2 × 104 and 3.2 × 104 CFU/mL using polystyrene waveguides. One‐hundred percent correct identification of true positive samples occurred at 6.0 × 104 and 3.2 × 104 CFU/mL for silica and polystyrene waveguides, respectively. Signals from a variety of non‐E. coli O157 bacteria, including closely related enterotoxigenic strains of E. coli at concentrations of ˜ 106 CFU/mL, were below the limits of detection. Assays were conducted in near real‐time with results obtained within 15 min of sample processing.
COMPARING ATTACHMENT, HEAT TOLERANCE AND ALKALI RESISTANCE OF PATHOGENIC AND NONPATHOGENIC BACTERIAL CULTURES ON ORANGE SURFACES
Authors: PAO STEVEN , DAVIS CRAIG L.
Published: May 2007

Trials were conducted to compare surrogate organisms (PSO) to human pathogens (Salmonella spp. and Escherichia coli O157:H7) on the surface of orange fruit. Among the six evaluated PSO, E. coli ATCC 8739 and E. coli ATCC 35218 showed a significantly lower attachment (SR) on fruit in comparison to Salmonella spp. In thermal tolerance studies, the D70C values of the evaluated PSO were either no different from or greater than those of the pathogens. However, the D80C ofE. coli ATCC 25922 was significantly lower than that of the E. coli O157:H7. In general, E. coli ATCC 11229 exhibited a higher level of alkali sensitivity than both pathogens; whereas Lactobacillus plantarum ATCC 14917 and, to a lesser extent, Lactobacillus fermentum ATCC 538 showed a significantly greater tolerance to the alkali treatments. The results suggest that nonpathogenic cultures ofE. coli ATCC 11229, L. fermentum ATCC 538, and L. plantarum ATCC 14917 may be utilized in fresh fruit research as surrogates for pathogens to evaluate the efficacy of thermal decontamination. In addition, E. coli ATCC 25922, L. fermentum ATCC 538, and L. plantarum ATCC 14917 cultures may be used to represent pertinent pathogens for validating fruit decontamination by alkaline cleaners.
RAPID ENUMERATION OF CLOSTRIDIAL SPORES IN RAW MILK SAMPLES USING AN IMPEDIMETRIC METHOD
Authors: FONTANA MAURO , BUSIELLO STEFANO , BISOTTI STEFANO , DALLORTO GIUSTO , UNGER GABRIELE , SCHWAMEIS GERLINDE , JUTERSCHNIG UDO , UNGER BRIGITTE , MASANIGER HERBERT , SCHINKINGER MANFRED
Published: May 2007

Late spoilage of cheese is due to gas formation during lactic acid fermentation by spore‐forming, gram‐positive, anaerobic clostridia of the species Ciostridium tyrobutyricum, Clostridium butyricum and Clostridium sporogenes. Since small numbers of such clostridial spores readily cause considerable losses in cheese production, spore numbers of fewer than 100 spores/liter must be determined reliably. Until recently, the only reliable method available was the time‐consuming (7 days) and cumbersome Most Probable Number Method (MPN). The objective of this study was to examine the feasibility of using impedance technology as an alternative method for the enumeration of clostridial spores. Three to fifteen replicates of 7.5–12.0 mL samples were tested using an impedimetric method with and without the addition of Oxyrase to generate anaerobic conditions within the impedance measurement cells. Results were obtained in less than 48 h. Data derived from the rapid impedance method were statistically comparable to those obtained using the reference method (MPN).
IMPACTION‐BASED SAMPLER FOR DETECTING MALE‐SPECIFIC COLIPHAGES IN BIOAEROSOLS
Authors: ESPINOSA ISABEL Y. , PILLAI SURESH D.
Published: May 2007

Air quality within and around confined animal housing operations is important from both occupational exposure and environmental quality perspectives. Appropriate sampling equipment should be available so that bioaerosols are adequately characterized in terms of their component microbial populations. In this study the efficacy of a commercially available impaction‐based bioaerosol sampler (SAS‐100) was evaluated in terms of its ability to detect male‐specific coliphages within and around poultry broiler houses. In addition to the manufacturer recommended agar medium, cellulose and cellulose‐acetate filter media were also used as the collection surface. The agar medium and the cellulose ester filters provided very high recoveries of phages as compared to the cellulose filter (P<0.05). There was a wide range of recoveries ranging from 0–100% when the cellulose acetate filter was used to detect phages in bioaerosols within and around broiler houses. The results suggest that the sampler is capable of concentrating male‐specific coliphages from bioaerosols. However, further studies are still needed to accurately determine the collection efficiencies of viruses.