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PubMed1990

Growth of bacteria in prefilled syringes stored in home refrigerators.

Insulin was examined for the rate of bacterial growth after being stored in prefilled syringes in home refrigerators and in a controlled laboratory refrigerator. Home refrigerators were used to simulate conditions that exist in client homes to establish the safety of storing insulin in prefilled syringes in uncontrolled environments. Insulin from each source was inoculated on three different media and incubated at three temperatures in three oxygen environments. A total of 768 cultures were examined. It was found that temperature had a significant effect on the incidence of bacteria. The difference in incident of bacteria between syringes stored in the controlled versus uncontrolled environments was not statistically significant.

Bacteria↗
PubMed1978

A study of bacteria contaminating refrigerated cooked chicken; their spoilage potential and possible origin.

Cooked chicken was allowed to spoil in a normal kitchen refrigerator (variable temperature) and at a standard 4C. After 10 days' storage, bacteria were isolated from the chicken. It was found that the numbers of organisms at variable refrigeration temperature were tenfold higher than those at a uniform 4C. In an attempt to find the sources of contamination, swabs were made of different areas of the kitchen. Many of the bacteria isolated from the spoiled chicken, were also isolated from the kitchen environment. When pure cultures of organisms isolated from spoiled chicken were inoculated into sterile cooked chicken and held at 4C, the main spoilage organisms were found to be Pseudomonas putida and Aeromonas hydrophila, which were also isolated from the refrigerator where the chickens were stored in the kitchen. Aeromonas hydrophila was found in significantly high numbers on plates, cutting knives, chopping boards and cold water taps.

Aeromonas↗
PubMed2002

Isolation and characterization of Lactococcus piscium strains from vacuum-packaged refrigerated beef.

AIMS: To characterize gram-positive, catalase-negative, psychrotrophic, lactic acid-homofermentative, non-motile cocci isolated from vacuum-packaged refrigerated beef using phenotypic and genotypic methods. METHODS AND RESULTS: A total of 89 strains was isolated at 2 and 6 weeks as one of the predominant microflora of five samples of vacuum-packaged beef stored at 2 degrees C. The strains were compared with reference strains of some gram-positive, catalase-negative cocci using SDS-PAGE whole-cell protein pattern analysis, biochemical characterization and 16S rDNA sequencing. The biochemical and physiological characteristics of the isolates resembled those of Lactococcus piscium GTC 552(T). Numerical analysis of the SDS-PAGE whole-cell protein patterns resulted in close clustering of the strains with L. piscium GTC 552(T) (r > 0.68). Other Lactococcus and Leuconostoc species could be distinguished from the isolates using SDS-PAGE whole-cell protein patterns (r < 0.58) and biochemical characteristics. The 16S rDNA sequencing of four randomly selected strains showed that the strains differed from L. piscium GTC 552(T) by two to three bases in the highly variable region of the sequence. This is the first report on the isolation of L. piscium from vacuum-packaged beef. CONCLUSIONS: The gram-positive catalase-negative cocci isolated from vacuum-packaged refrigerated beef have been identified as L. piscium. SIGNIFICANCE AND IMPACT OF THE STUDY: The findings of this work contribute to the knowledge of the microflora of vacuum-packaged refrigerated beef.

Animals↗
PubMedDate not supplied

The use of frozen intravenous crystalloid solutions as the refrigerant for shipping blood.

The authors studied whether cooled sterile intravenous crystalloid solutions could be used to refrigerate red cells during shipment. Six 1000-ml bags of 0.9 percent normal saline and lactated Ringers (RL) solutions were supercooled and tested separately at temperatures ranging from 1 to -78 degrees C, with either 5 or 30 units of packed red cells (PRBCs). The PRBCs were shipped in a standard military container that permitted separation of the supercooled solutions from the PRBCs. Cooling RL solutions to 6 degrees C and to -22 degrees C maintained acceptable storage temperatures of the PRBC for 36 and 50 hours, respectively, and did not cause visible damage to the units. No significant changes were observed in various biochemical measurements of the cells and plasma. Cooling the RL solution to -78 degrees C caused a significant (p less than 0.05) increase in plasma potassium concentration. The effectiveness of the crystalloid solutions in refrigerating blood varied with the ratio of the number of PRBCs to the volume of cooled solutions and with the ambient temperature surrounding the container. The results of this study suggest that cooled intravenous crystalloid solutions can be used as refrigerants for PRBCs during shipment.

Blood Preservation↗
PubMed2001

Pseudo-outbreak of Mycobacterium gordonae associated with water from refrigerated fountains.

Between March 1997 and December 1997, acid-fast bacilli (AFB) were detected on sputum and/or gastric aspirates smears from five patients hospitalized in the chest medicine department. These specimens grew M. gordonae. Based on AFB-positive smear and clinical presentation, four out of five patients received antituberculous treatment until species identification was known. Epidemiological investigation revealed a heavy contamination of water collected from refrigerated fountains located on the same floor as the patient cases. Strains isolated from four patients and the refrigerated fountain exhibited the same pulsed gel electrophoresis pattern (using DraI and XbaI enzymes) suggesting that positive smears were related to drinking water from the refrigerated fountain. This cluster of pseudo-infections underlines the necessity for a proper maintenance of water supply equipment in order to avoid inappropriate decisions deleterious for patients.

Aged↗
PubMed1987

Effect of refrigeration on microbial growth in the Blairex Water Purifier.

The Blairex Water Purifier is designed to make tap water into purified water that can be used to make saline solution for soft contact lens disinfection and rinsing. The micropore filters of eight Purifiers were perforated to allow a controlled contamination by either Pseudomonas aeruginosa or Serratia marcescens. The bacterial growth was evaluated in these altered Blairex Water Purifiers under refrigerated and unrefrigerated conditions. Those Purifiers that were refrigerated showed significantly less bacterial growth than those Purifiers that were kept at room temperature between samplings. Our findings imply that soft contact lens wearers may reduce the level of microbial growth in undamaged Purifiers by refrigerating the Purifiers between uses.

Contact Lenses, Hydrophilic↗
PubMed1998

The survival of human skin stored by refrigeration at 4 degrees C in McCoy's 5A medium: does oxygenation of the medium improve storage time?

To establish the viable storage time of human skin stored by refrigeration at 4 degrees C in McCoy's 5A medium and to establish whether oxygenating the medium improves the viable storage time, the following experiment was conducted. Eighty discs of human split-thickness skin graft, each 3 mm in diameter, were stored in 40 sterile sealable containers under four different conditions: in 0.9% saline, in McCoy's 5A medium, in oxygenated McCoy's 5A medium, and in carbon dioxide supplemented McCoy's 5A medium. Skin graft viability was assessed using tissue culture. Skin stored in saline was viable for only 1 week, whereas skin stored in McCoy's 5A medium and in oxygenated McCoy's 5A medium was viable for 4 weeks. Skin stored in carbon dioxide supplemented McCoy's 5A solution did not even survive the first week. These findings show that McCoy's 5A medium allows at least 4 weeks of viable human skin storage by refrigeration at 4 degrees C. Furthermore, oxygenating the medium does not seem to improve the viable storage time, and carbon dioxide supplementation is detrimental. The advantages of skin storage by refrigeration and the implications of the above findings are discussed. A clinical case in which split-thickness skin was stored for approximately 5 weeks and still resulted in good graft take is quoted as an example of our experience with the use of McCoy's 5A medium.

Aged↗
PubMed1980

Overnight refrigeration of urine specimens for culture.

Some authorities state that urine may be refrigerated overnight and still be satisfactory for quantitative bacteriologic evaluation. The papers cited appear to us to be inadequate. Four hundred and fourteen urine cultures were evaluated comparing colony count before and after overnight refrigeration. Overnight refrigeration appears to be a satisfactory means of urine preservation for culture.

Humans↗
PubMed1999

A predictive model that describes the effect of prolonged heating at 70 to 90 degrees C and subsequent incubation at refrigeration temperatures on growth from spores and toxigenesis by nonproteolytic Clostridium botulinum in the presence of lysozyme.

Refrigerated processed foods of extended durability such as cook-chill and sous-vide foods rely on a minimal heat treatment at 70 to 95 degrees C and then storage at a refrigeration temperature for safety and preservation. These foods are not sterile and are intended to have an extended shelf life, often up to 42 days. The principal microbiological hazard in foods of this type is growth of and toxin production by nonproteolytic Clostridium botulinum. Lysozyme has been shown to increase the measured heat resistance of nonproteolytic C. botulinum spores. However, the heat treatment guidelines for prevention of risk of botulism in these products have not taken into consideration the effect of lysozyme, which can be present in many foods. In order to assess the botulism hazard, the effect of heat treatments at 70, 75, 80, 85, and 90 degrees C combined with refrigerated storage for up to 90 days on growth from 10(6) spores of nonproteolytic C. botulinum (types B, E, and F) in an anaerobic meat medium containing 2,400 U of lysozyme per ml (50 microg per ml) was studied. Provided that the storage temperature was no higher than 8 degrees C, the following heat treatments each prevented growth and toxin production during 90 days; 70 degrees C for >/=2,545 min, 75 degrees C for >/=463 min, 80 degrees C for >/=230 min, 85 degrees C for >/=84 min, and 90 degrees C for >/=33.5 min. A factorial experimental design allowed development of a predictive model that described the incubation time required before the first sample showed growth, as a function of heating temperature (70 to 90 degrees C), period of heat treatment (up to 2,545 min), and incubation temperature (5 to 25 degrees C). Predictions from the model provided a valid description of the data used to generate the model and agreed with observations made previously.

Botulinum Toxins↗
PubMed1997

Reconstituted botulinum toxin type A does not lose potency in humans if it is refrozen or refrigerated for 2 weeks before use.

Botulinum toxin type A (BTX-A) (Botox, Allergan, Irvine, CA) labeling recommends its use within 4 hours of reconstitution. Since BTX-A is available only in 100-unit vials, a substantial quantity is often discarded. Using eight volunteers, we measured the percent decline in extensor digitorum brevis (EDB) M-wave amplitude (percent paralysis) following injection of freshly reconstituted BTX (right EDB) and compared this with the decline following injection of BTX that was refrozen (-20 degrees C) or refrigerated (+4 degrees C) for 2 weeks (left EDB) after reconstitution. When analyzed as paired data, there was essentially no difference in the muscle paralysis resulting from fresh BTX compared with refrozen or refrigerated BTX, and no statistical difference between groups was noted. Reconstituted BTX-A that is subsequently refrigerated or refrozen for 2 weeks does not lose potency in humans.

Adult↗
PubMedDate not supplied

Influence of refrigeration and formalin on the floatability of Giardia duodenalis cysts.

Giardia duodenalis cysts obtained from fresh fecal samples, fecal samples kept under refrigeration and fecal samples treated with formalin were studied as to their floatability on sucrose solutions with the following specific gravities: 1,040 kg/m3; 1,050 kg/m3; 1, 060 kg/m3; 1,070 kg/m3; 1,080 kg/m3; 1,090 kg/m3; 1,100 kgm3; 1,150 kg/m3; 1,200 kg/m3; and 1,250 kg/m3, contained within counting-chambers 0.17 mm high. Cysts that floated on and those settled down as sediments were counted, and had their percentages estimated. Sucrose solutions of 1,200 kg/m3 specific gravity (the average specific gravity of diluting liquids employed in floatation techniques) caused to float 77.7%, 78.4% and 6.6% of the G. duodenalis cysts obtained, respectively, from fresh fecal samples, fecal samples kept under refrigeration, and fecal samples treated with formalin. Cysts obtained both from fresh fecal samples and fecal samples kept under refrigeration presented similar results concerning floatability. It was observed, however, that the treatment of feces with formalin diminished the cysts floatability under the various specific gravities studied. This results should influence, the recommendations for transport and storage of fecal samples used for parasitological coproscopy.

Animals↗
PubMed1998

Microbiological and chemical changes in high-pressure-treated milk during refrigerated storage.

The microbiological and biochemical changes during storage of high-pressure-treated (400 MPa at 25 degrees C, for 30 min) whole (3.5% fat) and skim (0.3% fat) milk at refrigeration temperatures (7 degrees C) were studied. From a microbiological point of view, high-pressure treatment of milk led to an increase in the shelf life because, after 45 days of refrigerated storage, the psychotrophic and pseudomonad counts of the pressurized milk were lower than those of the unpressurized milk after 15 days. Capillary electrophoresis of the case in fraction showed that proteolysis by bacterial proteinases was not relevant in high-pressure-treated milk, as evidenced by a negligible degradation of kappa-casein. However, since the pressure conditions assayed did not lead to plasmin inactivation, considerable beta-, alpha-s1-casein hydrolysis took place during refrigerated storage, which can be responsible for flavor defects. No significant differences were found between skim and whole high-pressure-treated-milks.

Animals↗
PubMed2001

Efficacy of trisodium phosphate solutions in reducing Listeria monocytogenes populations on chicken skin during refrigerated storage.

Chicken skin inoculated with l0(8) CFU/ml of Listeria monocytogenes was dipped for 15 min in sterile water (control) and in 8, 10, or 12% trisodium phosphate (TSP) solutions. Skin samples were stored at 2 degrees C for 5 days, with microbial monitoring on days 0, 1, 3, and 5 after treatment. Compared to the water dip, all TSP treatments significantly (P < 0.05) reduced L monocytogenes populations on chicken skin. The concentration of the TSP was a significant factor in reducing the populations of the bacteria at days 0, 1, 3, and 5 of refrigerated storage. For all sampling times, the best outcomes were attained with the highest TSP concentration studied (12%). Bacterial reductions in counts during the first day of storage were between 1.52 and 2.70 log10 cycles for 8 and 12% TSP-treated samples, respectively. Significantly greater reductions were observed from the third day of refrigerated storage onward. This occurred largely because populations of L. monocytogenes on control samples increased somewhat, but on TSP-treated samples the pathogen remained practically constant. Differences between L monocytogenes counts in skin samples immersed in water and those treated with TSP ranged from 2.10 (8% TSP-treated samples) and 3.63 (12% TSP-treated samples) log10 cycles on day 5 of storage. These results indicated that TSP is effective against L. monocytogenes in chicken meat, especially after several days of refrigerated storage.

Animals↗
PubMed2003

Filament formation by Salmonella spp. inoculated into liquid food matrices at refrigeration temperatures, and growth patterns when warmed.

In this study, the formation of multicellular filamentous Salmonella cells in response to low temperatures was investigated by using isolates of Salmonella enterica serovar Enteritidis PT4 and S. enterica serovar Typhimurium DT104 as the inocula. The formation of filamentous cells in two liquid food matrices at the recommended maximum temperature for refrigeration (8 degrees C) was monitored and compared with that in tryptone soya broth. Giemsa staining was performed to locate nuclear material within the filaments. Single filaments were warmed on agar at 37 degrees C, and the subsequent rate of septation was quantified. For all strains tested, > 70% of the Salmonella cells inoculated had become filamentous after 4 days in media at 8 degrees C, indicating that filamentation could occur during the shelf life of most refrigerated foods. Strains with impaired RpoS expression were able to form filaments at 8 degrees C, although these filaments tended to be shorter and less numerous. All strains also formed filamentous cells at 8 degrees C in retail milk or chicken meat extract. Filaments often exceeded 100 microm in length and appeared straight-sided under the microscope in media and in foods, and Giemsa staining demonstrated that regularly spaced nucleoids were present. This phenotype indicates that an early block in cell septation is probably responsible for filamentation. When filaments were warmed on agar at 37 degrees C, there was a rapid completion of septation, and for one filament, a >200-fold increase in cell number was observed within 4 h. There are clear public health implications associated with the filamentation of Salmonella in contaminated foods at refrigeration temperatures, especially when the possibility of rapid septation of filamentous cells upon warming is considered.

Animals↗
PubMed2004

Sodium lactate addition on the quality and shelf life of refrigerated sliced poultry sausage packaged in air or nitrogen atmosphere.

The aim of this study was to determine the effect of sodium lactate addition on shelf-life extension of sliced poultry sausage packaged both in air and nitrogen atmospheres and stored in refrigerated conditions. Basic chemical composition, pH, and malonaldehyde content were assayed and color measurement using the reflection method was carried out. Microbiological examination consisted of determination of total number of aerobic psychrotrophic bacteria and number of lactic acid bacteria. Sensory evaluation of products was performed. Microbiological and sensory quality of sliced poultry meat sausage was dependent on the addition during production of sodium lactate and the composition of gases (air or nitrogen) used in packaging. Slices of poultry sausage with 1% as well as 2% of sodium lactate maintained their initial quality of evaluated sensory attributes longer, irrespective of the applied gases. Sodium lactate inhibited growth of aerobic psychrotrophic bacteria and lactic acid bacteria during refrigerated storage. Sodium lactate also inhibited the formation of malonaldehyde in sliced poultry sausage during refrigerated storage. The effectiveness of this process depended on the concentration of sodium lactate addition. It was concluded that 1% as well as 2% addition of sodium lactate could extend the shelf life of sliced poultry sausage packaged in air atmosphere and stored at 5 to 7 degrees C by 3 or 4 times, respectively. Sliced poultry sausage treated with 2% sodium lactate packed in nitrogen had the longest (35-day) shelf life. This was a sevenfold increase in the shelf life of sliced poultry sausage compared with the control.

Air↗
PubMed2005

Shelf-life extension of refrigerated Mediterranean mullet (Mullus surmuletus) using modified atmosphere packaging.

The present work evaluated the quality and freshness characteristics and the effect of modified atmosphere packaging (MAP) on the shelf-life extension of refrigerated Mediterranean mullet using microbiological, biochemical, and sensory analyses. Fresh open sea red mullet (Mullus surmuletus) were packaged in four different atmospheres: M1, 10%/20%/70% (O2/ CO2/N2); M2, 10%/40%/50% (O2/CO2/N2); M3, 10%/60%/30% (O2/CO2/N2); identical fish samples were packaged in air. All fish were kept under refrigeration (4 +/- 0.5 degrees C) for 14 days. Of the three gas atmospheres, the 10%/40%/50% (M2) and 10%/ 60%/30% (M3) gas mixtures were the most effective for inhibiting growth of aerobic microflora in mullet samples until day 10 of refrigerated storage. H2S-producing bacteria and pseudomonads were part of the mullet microflora and their growth was partly inhibited under MAP conditions. Between these two bacterial groups, H2S-producing bacteria (including Shewanella putrefaciens) were dominant toward the end of the storage period, regardless of the packaging conditions. Brochothrix thermosphacta and lactic acid bacteria were found to be members of the final microbial flora of MAP and air-packaged mullet, whereas the Enterobacteriaceae population was lower than other bacterial groups. Of the chemical freshness indices determined, thiobarbituric acid values were variable in mullet samples irrespective of packaging conditions indicative of no specific oxidative rancidity trend. Based on sensorial data and aerobic plate count, trimethylamine nitrogen and total volatile basic nitrogen limit values in the range of ca. 15 to 23 and 52 to 60 mg N/100 g of fish muscle were obtained, respectively, for mullet packaged under modified atmosphere and air. Sensory analyses (odor and taste attributes) showed that the limit of sensorial acceptability was reached after ca. 6 days for the samples packaged in air, 8 days for the M1 and M3 samples, and after 10 days for the M2 samples. Respective shelf-life extension for fresh whole mullet was ca. 2 days (M1 and M3 gas mixtures), and 4 days (M2 gas mixture).

Animals↗
PubMed2000

AANA journal course: update for nurse anesthetists--refrigerated anesthesia-related medications.

Medications have strength, expiration date, and storage conditions printed on the medication bottle or package. Some anesthesia medications require refrigeration to maintain the stated strength and safety until the expiration date. These medications may expire in days rather than years when left at room temperature in anesthesia carts or emergency boxes. The following AANA Journal course discusses anesthesia-related medications that require refrigeration and how long potency and safety is maintained out of the refrigerator and provides a chart for future referral.

Anesthetics↗
PubMed1989

[The hygiene of refrigerated and frozen foods].

Health and spoilage hazards arising from refrigerated and deep frozen foods may be due to - raw materials, e.g. pathogenic microorganisms which come from infected living animals or contaminate raw foods during handling. Psychrotrophic organisms have particular significance as pathogens or spoilage organisms as they can multiply also during refrigeration; - improper processing. Temperature abuse and incorrect time/temperature relations are main causes for microorganisms being not destroyed at the expected rate or even getting a chance of multiplying. Proper handling after refrigeration or frozen storage of foods ("hygiene of thawing") deserves also particular attention. - contamination, i.e. initial contamination of raw products which are ready for consumption without further processing (fruits, raw salads). Recontamination which follows a heat process is much more important and occurs before, during and after application of cold. In those cases, again, one has to distinguish between products which (a) are ready for consumption without a process (bakery and confectionary goods, ice cream, drinking milk) and (b) have to pass a process which reduces the bacterial load before consuming the food (ready to eat dishes or other foods ready for reheating in the home). Sites of increased hygienic hazard are a) lack of partitioning "clean" and "unclean" areas and processes, b) defects of sanitation and hygiene of personnel, c) defects of packaging, d) leakage during aseptic filling. Hazards are controlled through product and plant specific analysis of the process flow followed by continuous monitoring the "Critical Control Points". As an example, a report is given on a study on random samples taken from 180.000 prepackaged deep frozen menus which had been produced for a mass meeting. Microbiological monitoring of the process revealed time/temperature relations as critical control points of primary importance. Particular problems arose from any stoppage at the production line. Reliable means to assure food safety and protect consumer's health are HACCP concept based in plant control programs rather than sporadic microbiological monitoring of end products.

Animals↗