bluuebunny/crossref_metadata_2025_split huggingface dataset:
ENUMERATION OF AEROMONAS FOR VERIFICATION OF THE HYGIENIC ADEQUACY OF SWINE CARCASS DRESSING PROCESSES1
Authors: YU SHEW‐LING , PALUMBO SAMUEL A. 
Published: April 2007

ABSTRACT Populations of Aeromonas spp. and aerobic bacteria from dehairing equipment and from carcasses passing through different processing steps in a swine slaughtering plant were evaluated to identify the hygienic risks of each operation. Sponge samples were taken from the scraper flails in dehairing machines and the surface of the shackling table at pre‐ and post‐operation times, with 20 samples from each location being collected at each time. Increased post‐operation levels of Aeromonas spp. indicated a buildup and possible spread of these bacteria to carcasses. The belly skins of 40 dehaired carcasses were each sampled at five points along the process line which were after the shackling, after the final singeing, after the final polishing, after the final wash and after chilling. The levels of microbial contaminants on carcasses varied at each processing step. The heaviest contamination of carcasses with Aeromonas (1.88 log CFU/cm2) and aerobic bacteria (2.66 log CFU/cm2) occurred after shackling. Counts were reduced at other steps as a result of singeing, washing and chilling operations. However, singed carcasses were recontaminated with Aeromonas and aerobic bacteria during the polishing operation. Aeromonas hydrophila were the most prominent motile aeromonads (74.1%) recovered at the plant. The findings for Aeromonas spp. were similar to those for aerobic bacteria (r2= 0.9995) which suggested that Aeromonas spp. are appropriate indicators for assessing carcass dressing processes.
WHIPPLE'S DISEASE: IS TROPHERYMA WHIPPELII (WHIPPLE'S BACILLUS) FOODBORNE?1
Authors: SMITH JAMES L. 
Published: April 2007

ABSTRACT Whipple's disease is a rare systemic disease with symptoms dominated by diarrhea, weight loss, arthralgia or arthritis and abdominal pain. Whipple's disease is limited to humans and the disease is caused by infection with the grampositive bacterium, Tropheryma whippelii. PCR determinations suggest that T. whippelii is an environmental actinomycete but studies on the organism have been limited due to the inability to culture the organism in vitro. Most patients are male Caucasians older than 50 years of age living in North and South America, England, continental Europe and Australia. The cellular immune system appears to control T. whippeliiand patients with cellular immune defects appear to be more susceptible to Whipple's disease. The disease affects the gastrointestinal tract, the central nervous system, cardiovascular system and musculoskeletal system; however, other organs also may be affected. Whipple's disease can be treated with antibiotics effective against gram‐positive bacteria but relapses are common. Untreated Whipple's disease is usually fatal. Although the mode of transmission of T. whippelii in humans is unclear, it possibly occurs through the fecal‐oral route and food and/or water may be the source of the organism.
ISOLATION AND CHARACTERIZATION OF BACTERIOCIN‐PRODUCING MICROORGANISMS FROM AGOS‐OS
Authors: TAN JULIE D. , GALVEZ FLOR CRISANTA F. , TOMITA FUSAO 
Published: April 2007

ABSTRACTAgos‐os, a fermented meat and sweetpotato mixture, was produced and analyzed for its microbial characteristics. pH decreased during fermentation. Mold and anaerobic bacterial counts increased while yeasts and aerobic bacterial counts decreased during the third and seventh day of fermentation. Six isolates with the widest zones of inhibition on the indicator lawn were selected for bacteriocin production. These isolates had exactly the same morphological, physiological and biochemical characteristics. The ribosomal RNA sequence was 99.5% identical with Enterococcus faecalis VRE 1492. The identification was confirmed through DNA homology test by the EMBL Genbank, Canada. This bacterium produced the L‐isomer lactic acid. The amount of bacteriocin produced by the bacterium was optimized by growing the bacterium at different growth media, initial pH and fermentation time. Maximum production of bacteriocin was achieved in MRS (De Man Rugosa and Sharpe) medium (with glucose) at pH 7.50. The crude bacteriocin inhibited the growth of gram‐positive bacteria such as Lactobacillus sake 15521 and Listeria innocua. The gram‐negative bacteria such as Escherichia coli DH 5‐alpha (with plasmid, PUC), Salmonella typhii and Staphylococcus aureus were weakly inhibited. Other microorganisms such as Lactobacillus curvatus D31685, Lactobacillus confusius M23036, Lactococcus lactis MG1363, Leuconostoc paramesenteroides S67831, Pediococcus pentosaceus M58834, Saccharomyces cerevisiae SS553 (wild type) and Escherichia coli JM109 (no plasmid) were not inhibited.
SURVIVAL OF CAMPYLOBACTER JEJUNI IN MARINATED AND NONMARINATED CHICKEN PRODUCTS
Authors: PERKO‐MÄKELÄ PÄIVIKKI , KOLJONEN MARI , MIETTTNEN MAIJA , HÄNNINEN MARJA‐LIISA 
Published: April 2007

ABSTRACT Consumption of chicken products has been increasing. Most of these products in Finland are sold as fresh marinated pieces in consumer packages. The impact of marination on the survival of enteric pathogens is not known. We studied the survival of Campylobacter jejuni on marinated chicken drumsticks and sliced breast strips stored at a refrigerator temperature of +4C. The marinade was an emulsion of vegetable oil and water with spices, NaCl (5.9% wt/wt) and its pH was adjusted to 4.5 with lactic and acetic acid. The survival of C. jejuni was similar in marinated and nonmarinated chicken drumsticks and strips. The organisms were detected for at least nine days at the higher inoculum level (101– 102 CFU/mL) and for at least five days at the lower inoculum level (101– 102 CFU/mL). C. jejuni, inoculated into plain marinade and stored at 4C, was detected after 24 h but not after 48 h. Our results revealed that marination procedure used to reduce and prevent the growth of spoilage organisms does not significantly decrease the survival of Campylobacter jejuni in chicken products.
BACTERICIDAL EFFICIENCIES OF COMMERCIAL DISINFECTANTS AGAINST LISTERIA MONOCYTOGENES ON SURFACES
Authors: AARNISALO KAARINA , SALO SATU , MIETTINEN HANNA , SUIHKO MAIJA‐LIISA , WIRTANEN GUN , AUTIO TIINA , LUNDÉN JANNE , KORKEALA HANNU , SJÖBERG ANNA‐MAIJA 
Published: April 2007

ABSTRACT The efficiencies of potassium persulphate, isopropanol, hydrogen peroxide and peracetic acid, quaternary ammonium compound, hypochlorite, sodium dichloroisocyanurate, ethanol and phenol derivatives, tertiary alkylamines and dimethyl alamine betaine‐based disinfectants and a hypochlorite‐based disinfecting cleaning agent were evaluated against eight Listeria monocytogenes strains representing three different ribotypes. All the disinfectants were effective in a suspension test with an exposure time of 30 s at the lowest concentrations recommended by the manufacturer. The efficiencies on surfaces were reduced. However, on clean surfaces all the agents were considered effective when the exposure time was 5 min and the concentration was the average recommended by the manufacturer. Five of nine disinfectants and the disinfecting cleaning agent were considered effective in soiled conditions in the surface test. The most efficient agent was isopropanol‐based and the least effective was the disinfectant containing tertiary alkylamine and dimethyl alamine betaine. Differences in bactericidal efficiencies of disinfectants against different L. monocytogenes strains on meat soiled surfaces were found.
DECONTAMINATION OF A MULTILAMINATED ASEPTIC FOOD PACKAGING MATERIAL AND STAINLESS STEEL BY OZONE
Authors: KHADRE MOHAMMED A. , YOUSEF AHMED E. 
Published: April 2007

ABSTRACT A multilaminated aseptic food packaging material and stainless steel were treated with ozone to inactivate natural contaminants, bacterial biofilms and dried films of Bacillus subtilis spores and Pseudomonas fluorescens. Sterility of the multilaminated packaging material was achieved when 1.0 x 2.0 cm‐pieces of the naturally‐contaminated material were treated with ozone in water (5.9 μg/mL) for 1 min. Dried films of spores (108/6.3–cm2 surface) were eliminated by 13 μg/mL of ozone in water for the multilaminated packaging material and 8 μg/mL in case of the stainless steel. Ozone inactivated Pseudomonas fluorescens in biofilms more effectively on stainless steel than on the multilaminated packaging material. Repeated exposure to ozone ofPseudomonas fluorescens in biofilms on the multilaminated packaging material eliminated up to ∼108 cfu/12.5 cm2. In conclusion, ozone is an effective sanitizer with potential applications in the decontamination of packaging materials and equipment food‐contact surfaces.
INFLUENCE OF WASHING TREATMENT ON NATIVE MICROFLORA AND ESCHERICHIA COLI POPULATION OF INOCULATED CANTALOUPES
Authors: UKUKU DIKE O. , PILIZOTA VLASTA , SAPERS GERALD M. 
Published: April 2007

ABSTRACT The influence of chlorine or hydrogen peroxide treatment on populations of Escherichia coli 25922 on the external surface of inoculated cantaloupe was investigated. Surface treatment with 70% EtOH, followed by immersion in 108 CFU/mL E. coli inoculum deposited an average of 4.4 log10CFU/cm2 cell population on the cantaloupe surface. The efficncy of washing inoculated cantaloupe was dependent on storage interval between inoculation and treatment. Dipping the cantaloupes in solutions containing 1000 mg/L chlorine or 5% peroxide for 5 min, within 24 h of inoculation, caused a 2 log10 CFU/cm2 reduction of the indigenous surface microflora and a 3–4.0 log10 CFU/cm2 reduction in E. coli. The efficacy was less when the interval between inoculation and treatment exceeded 24 h. Chlorine appeared in be a better antimicrobial agent than hydrogen peroxide against F. coli ATCC 25922 inoculated on cantaloupe surfaces while hydrogen peroxide was better in reducing surface microflora of cantaloupe.
INFECTIVE DOSE OF FOODBORNE PATHOGENS IN VOLUNTEERS: A REVIEW
Authors: KOTHARY MAHENDRA H. , BABU UMA S. 
Published: April 2007

ABSTRACT Risk assessment and impact of foodborne pathogens on the health of different populations was one of the goals identified in the Presidential Food Safety Initiative three‐year plan. This entailed estimation of dose‐response relationship for foodborne pathogens to humans, either by feeding studies or from outbreaks. For certain pathogens, such as Listeria monocytogenes and Escherichia coli O157:H7, there are no feeding studies due to ethical reasons, and the results from outbreaks are normally used to estimate the infectious dose. The focus of this review is to compile dose‐response information in volunteers for several foodborne pathogens including Salmonella, Shigella spp., Campylobacter jejuni, Vibrio spp., Escherichia coli, Cryptosporidium parvum and Entamoeba coli. The infectious dose for different serovars of Salmonella and strains of E. coli was quite large (> 105 organisms), while the infectious dose for some Shigella spp. seemed to be as low as less than 10 organisms. Toxigenic V. cholerae (O1 and O139 serotypes) were infective at a dose of 104 organisms; a non‐O1 strain was infective at a much higher dose (106 organisms). C. jejuni, C. parvum and Entamoeba coli appeared to have infectious doses as low as 500 organisms, 10 oocysts, and 1 cyst, respectively. The infectious dose and the dose response are dependent upon the strains used, and the age and physical condition of the individuals, and can therefore show wide variations. In addition, since many of the volunteer studies are carried out by feeding the organisms in a nonfood matrix after neutralizing the stomach acidity, results obtained may not reflect the true dose response.
HEAT RESISTANCE OF CLOSTRIDIUM PERFRINGENS VEGETATIVE CELLS AS AFFECTED BY PRIOR HEAT SHOCK1
Authors: JUNEJA V.K. , NOVAK J.S. , EBLEN B.S. , MCCLANE B.A. 
Published: April 2007

ABSTRACT This study quantified the heat resistance and the effects of a heat shock on the subsequent heat resistance of 10 strains of Clostridium perfringens. Beef gravy samples inoculated with vegetative cells of the pathogen were subjected to sublethal heating at 48C for 10 min, and then heated to a final temperature of 58C using a submerged‐coil heating apparatus. Heat‐treated samples were spiral plated on Shahidi‐Ferguson Perfringens agar to determine surviving bacterial population. No correlation between the heat resistance and the origin of the C. perfringens could be established due to significant variations in the heat resistance among strains. Inactivation kinetics of both heat‐shocked and nonheat‐shocked samples exhibited log‐linear decline in the number of surviving cells with time. D‐values at 58C for C. perfringens vegetative cells ranged from 1.21 to 1.60 min. Heat shocking allowed the organism to survive longer and the increase in heat resistance was as high as 1.5 fold. Also, heat shock resulted in the overexpression of proteins exhibiting epitopic and size similarity to E. coli GroEL and B. subtilis small acid soluble proteins. Increased heat resistance due to heat shock must be considered while designing cooking/reheating regimes that ensure safety of ready‐to‐eat foods contaminated with high numbers of C. perfringens vegetative cells.
CHANGES IN QUALITY ATTRIBUTES DURING STORAGE OF TOGWA, A LACTIC ACID FERMENTED GRUEL
Authors: MUGULA J.K. , NNKO S.A.M. , SØRHAUG T. 
Published: April 2007

ABSTRACT Microbiological, physicochemical and sensory quality changes in togwa during storage at ambient tropical temperatures were monitored in unpasteurized and pasteurized samples with added sodium benzoate, potassium sorbate, propionic acid or a combination of sodium benzoate and potassium sorbate. The untreated samples were unacceptable within 48 h after production. Organic acids, volatile flavor compounds and fermentable sugars were monitored in untreated samples for up to 96 h. Ethanol, 2‐methyl‐1‐propanol, 2‐methyl‐1‐propanal, 3‐methyl‐1‐butanol, 3‐methyl‐1‐butanal, acetone, acetoin, lactic, succinic and formic acid increased significantly within 48 h. Pyroglutamic and pyruvic acid decreased and then increased, while uric acid and sugars decreased within 96 h. Sodium benzoate, potassium sorbate or their combination extended the shelf‐life of the control samples by four days. Pasteurization at 97C/10 min reduced the total mesophilic bacteria, lactic acid bacteria, yeasts and Enterobacteriaceae counts to nil and maintained the pH, titratable acidity, specific gravity, and total soluble content constant, and the products were mildly acceptable during storage for up to 60 days. Pasteurization alone was comparable to the combined effects of pasteurization and treatment with preservatives on the quality of the product. Pasteurization alone may therefore be appropriate for small‐scale production and increased commercialization.
DETECTION OF ANTIMICROBIAL DRUG RESIDUES IN KENYAN MILK
Authors: SHITANDI ANAKALO , STERNESJÖ ÅSE 
Published: April 2007

ABSTRACT The improved Dutch tube diffusion test was used to study the occurrence of inhibitory substances in raw bulk milk samples within the Nakuru District in Kenya. Initially the detection limits of the method were verified using milk standards spiked with selected antibiotics. Addition of penicillinase to inhibitor‐positive samples was used for preliminary identification of penicillin G‐type antibiotics and residue levels were estimated against a standard curve constructed by means of a B. stearothermophilus disc assay. The two‐tube test was used to screen 1109 field samples of which 229 (21%) were suspect positive. The identification procedure confirmed 165 samples (14.9%) to contain penicillin G‐type residues of which 118 contained levels exceeding the established EU MRL for penicillin G (4 μg/kg). This study indicates that antibiotic residues are prevalent in milk within the Nakuru district of Kenya. It suggests that the improved tube diffusion test in combination with a multiplate system could be useful for qualitative and quantitative identification of antimicrobial drug residues in milk.
MICROBIAL ENUMERATION IN READY‐TO‐EAT FOODS AND THEIR RELATIONSHIP TO GOOD MANUFACTURING PRACTICE
Authors: DE SOUSA G.B. , TAMAGNINI L.M. , OLMOS P. , GONZÁLEZ R.D. 
Published: April 2007

ABSTRACT As a contribution to Good Manufacturing Practice (GMP) programs, we have analyzed products produced and offered by ready‐to‐eat food stores. Two hundred and seventy four samples of a wide variety of foods from 19 different shops were analyzed. Aerobic counts, total coliforms and yeast and molds were enumerated in each sample. Food stores were evaluated using a GMP check‐list. They were grouped in three classes: Class III, nonsatisfactory GMP; Class II, partially satisfactory GMP; and Class I, satisfactory GMP. From the results of microorganism counts in the Class I food shops the following maximum counts are proposed for cooked ready‐to‐eat foods: aerobic colony count: 105 cfu g−1. It is coincident with satisfactory microbiological quality of many category 3 foods drawn up by Public Health Laboratory Service (PHLS).
EXAMINATION OF THE MICROBIAL STATUS OF SELECTED INDIGENOUS FERMENTED FOODS IN NIGERIA
Authors: OLASUPO N.A. , SMITH S.I. , AKINSINDE K.A. 
Published: April 2007

ABSTRACT Four Nigerian traditionally fermented foods (wara, nono, ogi and kununzaki) were evaluated for the presence of some microorganisms of public health concern. Among the dairy foods, Staphylococcus aureus and Klebsiella sp. were isolated from wara while Escherichia coli, Salmonella sp. and Klebsiella sp. were isolated from nono. The cereal‐based fermented foods (ogi and kunu‐zaki) contained Bacillus subtilis, E. coli, S. aureus, Klebsiella sp. and Enterococcus faecalis. The mesophilic aerobic counts were: 5 × 105 for wara; nono, 1.53 × 107; ogi, 3.6 × 106 and kunu‐zaki, 2.6 × 106 cfu/mL. The enterobacteriaceae counts on nono, wara, ogi and kunu‐zaki were 1.79 × 107, 4.5 × 105, 4.0 × 105 and 1.2 × 106 cfu/mL, respectively. No Vibrio count (detection limit: <10 cfu/mL) was recorded in all the food samples considered. The yeast and mold counts ranged from 1.0 × 105– 3.31 × 107 among the food products. The antimicrobial susceptibility patterns of the organisms isolated from dairy products (nono and wara) revealed that they were resistant to ampicillin (100%) and sensitive to gentamicin (100%) and nalidixic acid (100%). Most isolates from cereal based products (ogi and kunu‐zaki) were 100% resistant to penicillin, ampicillin and chloramphenicol. This work highlights the need to maintain hygienic standards in the preparation of our locally fermented cereal and dairy foods.
EFFECT OF MARINADE AND DRYING TEMPERATURE ON INACTIVATION OF ESCHERICHIA COLI O157:H7 ON INOCULATED HOME DRIED BEEF JERKY
Authors: ALBRIGHT SUSAN N. , KENDALL PATRICIA A. , AVENS JOHN S. , SOFOS JOHN N. 
Published: April 2007

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.
INTERACTION BETWEEN POTASSIUM SORBATE, OIL AND TWEEN 20: ITS EFFECT ON THE GROWTH AND INHIBITION OF Z BAILII IN MODEL SALAD DRESSINGS
Authors: CASTRO M. , GARRO O. , GERSCHENSON L.N. , CAMPOS C.A. 
Published: April 2007

ABSTRACTThe effect of the interaction between potassium sorbate (KS), oil and Tween® 20 on the growth and inhibition of Z bailii in model salad dressings was studied. Z. bailii grew in emulsions containing 110 and 230 g/kg of oil and the addition of 0.5 g/kg of KS inhibited growth. When the oil content was raised to 460 g/kg, a steep death rate curve was observed and the effect of KS addition was hidden by the inhibitory action of the high oil level. Tween® 20 action depended on oil level: for emulsions containing 110 or 230 g/kg, a depression in the activity of KS was observed. This behavior was attributed to the decrease in the free form of the preservative due to the partition between surfactant micelles and the water. In contrast, when the oil content was 460 g/kg, KS activity was enhanced in spite of the decrease in the amount of its free form. These results highlight the importance of considering ingredient interactions when evaluating shelf‐life.
BEHAVIOR OF LISTERIA MONOCYTOGENES IN RECONSTITUTED INFANT CEREALS
Authors: ABUSHELAIBI A.A. , SOFOS J.N. , SAMELIS J. , KENDALL P.A. 
Published: April 2007

ABSTRACTListeria monocytogenes may contaminate and grow in reconstituted infant cereals refrigerated or temperature abused before consumption. To assess this risk, a 5‐strain composite of the pathogen was inoculated in rice, oatmeal, and wheat‐rice‐oatmeal infant cereals, hydrated (1/6, w/v) with apple juice, pasteurized milk (2% fat) or water, and stored at 4, 15, or 25C for 0, 8 and 24 h to simulate potential advance home preparation and abuse. L. monocytogenes survived with minimal (<0.6 log cfu per mL) or no growth in all cereal preparations at 4C, but it increased in cereals hydrated with water or milk by 2.4–3.3 and 5.3–6.4 log cfu per mL in 24 h at 15 and 25C, respectively. Reconstitution of cereals with water or milk supported growth (P < 0.05) even at 8 h of abuse. In cereals hydrated with apple juice and stored at 15 or 25C, populations of L. monocytogenes were maintained below 3.0 log cfu per mL at 24 h. These results indicate that refrigeration and/or reconstitution with an acid fruit juice may inhibit growth of L. monocytogenes in infant cereal meal preparations. However, in order to ensure prevention of growth, such meals should preferably be consumed soon after preparation or held at 4C for less than 8 h.
BACTERIOCIN EXPOSURE AND FOOD INGREDIENTS INFLUENCE ON GROWTH AND VIRULENCE OF LISTERIA MONOCYTOGENES IN A MODEL MEAT GRAVY SYSTEM
Authors: ALVES VIRGÍNIA FARIAS , SICCHIROLI LAVRADOR MARCO AURÉLIO , PEREIRA DE MARTINIS ELAINE CRISTINA 
Published: April 2007

ABSTRACTThe antilisterial activity of bacteriocin‐producing Lactobacillus sakei 1 bac+ alone and combined with food ingredients (sodium chloride, D‐glucose, oregano, black pepper) was studied in a model meat gravy (1.8% proteose peptone, 1.2% meat extract, 0.6% yeast extract, 2.0% corn starch) kept under refrigeration for 10 days. Two strains of L. monocytogenes (serotypes 4b and 1/2a) were employed in coinoculation experiments and Lactobacillus sakei ATCC 15521 was used as a negative control for bacteriocin production. The LAB bac+ strain was more effective in inhibiting both L. monocytogenes serotypes than the LAB bac− strain. The serotype 4b was more sensitive to bacteriocin than serotype 1/2a. The effect of the ingredients on inhibition of L. monocytogenes was serotype dependent. Bacteriocin exposure did not affect sensitivity to ampicilin and rifampicin. However, L. monocytogenes partially lost their hemolytic activity after exposure to bacteriocin‐producing Lb. sakei 1 and food ingredients.