Efficacy of antimicrobial interventions in reducing Salmonella enterica, Shiga toxin-producing Escherichia coli, Campylobacter, and Escherichia coli biotype I surrogates on non-chilled and chilled, skin-on and skinless pork

Effect of various antimicrobial interventions on pork carcass cuts - skin-on and skinless, non-chilled and chilled - was studied. Carcass pieces were inoculated with Salmonella enterica, Shiga toxin-producing Escherichia coli (STEC), Escherichia coli pathogen surrogates or Campylobacter spp. Inoculated pieces were assigned to one of the following antimicrobial treatments: 2.5% and 5.0% room temperature lactic acid, 2.5% and 5.0% warm (55 °C) lactic acid, 400 ppm (0.4 mg/mL) room temperature peroxyacetic acid (PAA) or warm (55 °C) water. Treated pieces were sampled before antimicrobial treatment of non-chilled pork tissue, then at 30 m and 24 h post-treatment. For chilled pork, samples were collected after 24 h chilling and 30 m post-treatment. Lactic acid and PAA treatments reduced (P < 0.05) pathogenic and surrogate bacteria; warm water did not produce similar results. Objective and sensory color evaluations on treated pork indicated minimal negative impacts on pork color. Various antimicrobial interventions were effective in reducing surrogates on pork without diminishing quality.

Does Treating Beef Subprimals with UV-Light Reduce Pathogens and Impact Quality?

ObjectivesTo evaluate reduction of pathogens and impact on quality parameters of beef strip loins treated with pulsed-UV light.Materials and MethodsInoculum was prepared as a cocktail of three non-pathogenic, rifampicin-resistant E. coli Biotype I surrogates. Strip loins were halved, inoculated, individually vacuum packaged, and assigned to one of three pulsed-light UV treatments: (1) light height 5 cm, belt speed 15 Hz; (2) light height 28 cm, belt speed 15 Hz; and (3) light height 28 cm, belt speed 25 Hz. Microbiological samples were obtained and enumerated pre- and post-treatment (n = 90; 3 UV treatments × 5 strip loin halves per treatment × 2 sampling times (pre/post treatment) × 3 replications).To evaluate quality parameters, a control group was added to the three UV treatments. Uninoculated strip loin halves (n = 48) were fabricated, packaged, and assigned (n = 12 strip loins halves per treatment) to one of the four treatment groups. Within each group, n = 3 strip loin halves were assigned a storage time (0, 7, 14, or 21 d). After treatment, three steaks from each strip loin half (approximately 2.54-cm thick; n = 192 total steaks) were cut and individually packaged for analyses: (1) trained aroma and color panel, (2) steak surface pH, purge pH, purge quantification, and objective color, and (3) aerobic plate counts.Data were analyzed using JMP Pro (SAS Institute Inc., Cary, NC). The fit model function was used for analysis of variance, and least squares means comparisons were conducted when appropriate using Student’s t test with an α-level 0.05.ResultsNo differences were seen (P > 0.05) in reductions of E. coli surrogates among the three UV treatments, with all reductions less than 1-log. No differences (P > 0.05) in aroma scores among treatment groups were noted, although differences in aroma attribute scores occurred between aging times. Panelists scored samples highest (P < 0.001) for bloody/serumy on d 0 than any other aging time. Conversely, sour dairy and spoiled intensified over time with d 21 samples receiving the highest scores (P < 0.001). Although trained panelists’ responses for lean color score did not differ (P = 0.277) among UV treatments, scores for percent discoloration did (P = 0.014). Notably, percent discoloration scores for d 0 were statistically higher than other aging times, meaning that discoloration diminished as aging continued. No statistical differences were identified for L*, a*, or b* values across UV treatments. Between aging times, differences were seen (P < 0.001) for a* and b* values, with d 0 having the lowest values for both. For purge and pH, the surface pH of steaks was higher on Days 0 and 7 and began to decrease, showing statistical similarities on Days 14 and 21. The amount of purge (g) steadily increased as steaks aged. APC counts were not found to differ due to UV treatment but generally tended to increase as storage times lengthened.ConclusionPulsed-UV light on chilled subprimals resulted in low microbial reductions, however, this technology could be beneficial if used in addition to other antimicrobial interventions. Initial discoloration was identified but improved as steaks aged. While APCs tended to increase over the course of storage, as did purge, no differences due to UV treatments were seen. Further research is warranted to determine if different treatment parameters would result in greater microbial reductions.

Comparison of Salmonella Prevalence Rates in Bovine Lymph Nodes across Feeding Stages

Peripheral lymph nodes (LNs) located in the fatty tissues of beef carcasses have been shown to harbor Salmonella and, thus, potentially contaminate ground beef. Salmonella prevalence within LNs is known to differ among feedlots. Two South Texas feeding operations (identified as locations A and B) known to harbor salmonellae in the feedlot environment, while historically producing cattle with opposing rates (one "high" and one "low") of Salmonella prevalence in LNs, were used in this study. To determine whether this difference was due to cattle source or factors associated with different stages of feeding, weanling steers of common and known origin were followed through normal feeding stages at both operations. Eighty Angus-sired beef steers were harvested at each of four feeding stages: 1, postweaning; 2, background or stocker; 3, 60 days on feed; and 4, 120 days on feed. Left and right subiliac and superficial cervical LNs ( n = 304) were collected from each carcass, and similar node types were pooled by animal ( n = 152). Results showed a difference ( P < 0.05) in prevalence of Salmonella in bovine lymph nodes between location A and location B and among feeding stages in location B. Salmonella was not isolated from any feeding stage 1 (postweaning) or location A LN samples. Within location B, there was an increase in Salmonella prevalence as cattle moved into later stages of feeding: at 22.2% (4 of 18), 77.8% (14 of 18), and 94.4% (17 of 18) for feeding stages 2, 3, and 4, respectively. Although the reasons for the differences seen between feeding operations and for increased Salmonella prevalence in LNs at later feeding stages remain unexplained, these results indicate that factors other than cattle source are likely influencing Salmonella prevalence in LNs.

Energy storage

The world is moving in the direction of using electricity derived from renewable sources. With the mass production of devices to enable the production of energy from such sources (wind, solar and tides), peak power capacity is competitive with that of deriving the electricity from fossil fuel. The problem is that the profile of power production does not match that of the requirements. This problem is not new, but it has become more acute: due to the extremely peaky nature of the power from the new sources, unless there is efficient energy storage, it is necessary to maintain the capacity to generate power to cover the full load in certain climatic conditions. While nuclear power is clean and would be ideal for satisfying the requirements of base load, the capital cost of nuclear plants (which should include that of decommissioning) makes the real cost of such power more expensive than that which can now obtained from renewables (and from burning gas or coal, of course). Ever since there have been electrical grids, companies have looked for ways to efficiently store energy so that power can be delivered on demand with minimum capital investment. A wide range of technologies is employed, and is being developed, so that everyday needs can be met. Energy storage is resource neutral: it allows us to use electricity from any power source more efficiently. However, it involves considerable capital investment, and can occupy a lot of space. The idea of moving towards reliance on renewable sources of energy has been taken up by a large segment of the population but there is technically still a lot to do, especially with regard to the essential corollary of energy storage. In addition to the challenge of producing the means to store energy, many other issues must be addressed. These include maintainability and longevity of the equipment (both for producing the energy and storing it). In this report we explore and compare the different methods available for storing energy and investigate trends.

Evaluation of novel micronized encapsulated essential oil-containing phosphate and lactate blends for growth inhibition of Listeria monocytogenes and Salmonella on poultry bologna, pork ham, and roast beef ready-to-eat deli loaves

Essential oils and their constituents are reported to possess potent antimicrobial activity, but their use in food processing is limited because of low solubility in aqueous systems and volatilization during processing. Two proprietary noncommercial essential oil-containing phosphate blends were evaluated for antimicrobial activity against Salmonella enterica cocktail (SC)-and Listeria monocytogenes (Lm)-inoculated deli meat products made from pork, poultry, or beef. Four treatments were tested on restructured cured pork ham, emulsified chicken bologna, and restructured beef loaf: nonencapsulated essential oil with phosphate version 1 at 0.45% of final batch (EOV145; chicken and pork, or EEOV245 beef), micronized encapsulated essential oil with phosphate version 2 at 0.60% of final batch (EEOV260), a 2.0% potassium lactate (PL) control, and a negative control (CN) with no applied antimicrobial agent. Compared with the CN, none of the antimicrobial agents (EEOV260, EOV145, PL) successfully limited Lm or SC growth to <2.0 log cycles over 49 days or 35 days of refrigerated storage, respectively. The PL and EEOV260-treated ham loaves did show Lm growth limiting ability of up to 1 log cycle by days 35 and 42. On formed roast beef, the EEOV260 was able to extend the lag phase and inhibited the growth of Lm in the same manner as the PL. For SC-treated samples, the following effects were observed: in poultry bologna treated with EEOV260, a lag-phase extension was observed through 35 days of storage compared with the other samples. For pork deli loaves, the EEOV260 inhibited growth of SC at days 21 and 28 to the same level of efficacy as PL (0.5 log cycle). In roast beef samples, on day 35, the SC growth was inhibited ca. 0.5 log CFU/g by EEOV260 when compared with the CN. In conclusion the EEOV260 can function to replace PL to limit Salmonella and Lm growth in ready-to-eat deli products. Further testing is needed to ensure consumer acceptability.

Glycerol inhibition of ruminal lipolysis in vitro

Supplemental glycerol inhibits rumen lipolysis, a prerequisite for rumen biohydrogenation, which is responsible for the saturation of dietary fatty acids consumed by ruminant animals. Feeding excess glycerol, however, adversely affects dry matter digestibility. To more clearly define the effect of supplemental glycerol on rumen lipolysis, mixed populations of ruminal bacteria were incubated with 6 or 20% glycerol (vol/vol). After 48-h anaerobic incubation of mixed culture rumen fluid, rates of free fatty acid production (nmol/mL per h) for the 6 and 20% glycerol-supplemented samples were decreased by 80 and 86%, respectively, compared with rates from nonsupplemented control cultures (12.4±1.0; mean ± SE). Conversely, assay of the prominent ruminal lipase-producing bacteria Anaerovibrio lipolyticus 5S, Butyrivibrio fibrisolvens 49, and Propionibacterium species avidum and acnes revealed no effect of 2 or 10% (vol/vol) added glycerol on lipolytic activity by these organisms. Supplementing glycerol at 6% on a vol/vol basis, equivalent to supplementing glycerol at approximately 8 to 15% of diet dry matter, effectively reduced lipolysis. However, the mechanism of glycerol inhibition of ruminal lipolysis remains to be demonstrated.

Effect of the use of a neutralizing step after antimicrobial application on microbial counts during challenge studies for orange disinfection

The effects of using a neutralizer after applying antimicrobial treatments and the effect of time lapse between treatment application and subsequent recovery and enumeration of Escherichia coli O157:H7 and Salmonella were investigated in Valencia oranges. Inoculated oranges surfaces were washed with distilled water for 15 s and then sprayed with a solution containing 200 mg/liter sodium hypochlorite (pH 6.5) for 15 s; they were then dipped in L-lactic acid (2.0% at 55°C) for 1 min or in distilled water at 80°C for 1 min. Posttreatment, oranges were divided into two groups. In the first group, oranges were dipped in neutralization treatment: 270 ml of buffered peptone water for 2 min for lactic acid-treated oranges, 270 ml of Dey-Engley broth for 2 min for chlorine-treated oranges, or 3.7 liters of tap water (25°C) for 10 s for hot water-treated oranges. The second group of treated oranges was not subjected to any neutralizer. All oranges then were kept at room temperature (average 26.2°C) and sampled at 0, 7.5, and 15 min for enumeration of surviving Salmonella and E. coli O157:H7. The orange surface (30 cm(2)) was excised for pathogen enumeration. The presence of free chlorine and changes in pH and temperature on the orange surface were determined in uninoculated, treated oranges. Free chlorine was detected on oranges after treatment; the change in temperature of orange surfaces was greater during treatment with hot water than with lactic acid. Nevertheless, pathogen enumeration did not show any impact of neutralizer use on the residual activity of antimicrobials or any impact of the time elapsed between antimicrobial treatment and recovery of bacterial pathogens from inoculated oranges (P ≥ 0.05). The results of this study indicate that the lack of a neutralizing step before enumeration of pathogens is not likely to affect the accuracy of results during challenge studies to test pathogen reduction strategies on oranges.

Addition of a surfactant to tryptic soy broth allows growth of a lactic acid bacteria food antimicrobial, Escherichia coli O157:H7, and Salmonella enterica

AIMS

  This study aimed to determine the survival and growth of Escherichia coli O157:H7 and Salmonella enterica subsp. enterica in a medium supporting the growth of a Lactic Acid Bacteria (LAB) food antimicrobial culture.

METHODS AND RESULTS

  Foodborne pathogens and LAB were cultured individually in tryptic soy broth (TSB), tryptic soy broth supplemented with one g l(-1) Tween 80(®) (TSB-T80), and de Man, Rogosa and Sharpe (MRS) broth. Growth of E. coli O157:H7 and Salmonella was similar in TSB and TSB-T80 but was significantly less in MRS. Conversely, LAB growth was similar in MRS and TSB-T80 but was significantly less in TSB.

CONCLUSIONS

  Supplementation of TSB with Tween 80(®) allows growth of LAB to levels similar to that observed with MRS but does not inhibit the growth of E. coli O157:H7 and Salmonella. We present the formulation of a medium useful in studies useful for evaluating competitive inhibition of foodborne pathogens by LAB in vitro.

SIGNIFICANCE AND IMPACT OF THE STUDY

  This study reports the utility of TSB-T80 for the completion of in vitro competitive inhibition assays incorporating a Lactic Acid Bacteria food safety culture.

Severe iron deficiency anaemia as a manifestation of silent coeliac disease: case report and literature review

Coeliac disease (CD) occurs in individuals sensitive to gluten protein contained in wheat products. It affects at least 1:100 children and may present with extra-intestinal manifestations such as iron deficiency anaemia, short stature and delay in puberty. A case of severe iron deficiency anaemia as a manifestation of CD is described here. There is a need to raise awareness among health professionals about CD and its extra-intestinal presentations. Suspicion of CD should lead to antibody screening tests and positive results should be followed by an intestinal biopsy for a definitive diagnosis. Involvement of a paediatric dietitian is vital in the management of CD and lifelong adherence to a gluten-free diet is necessary. We hope this article leaves the reader with a heightened awareness about CD and will lead to appropriate early referral to the paediatric services.

Decontamination of fluid milk containing Bacillus spores using commercial household products

Although commercial sanitizers can inactivate bacterial spores in food processing environments, relatively little data exist as to the decontamination of products and surfaces by consumers using commercial household products. Should a large scale bioterrorism incident occur in which consumer food products were contaminated with a pathogenic sporeformer such as Bacillus anthracis, there may be a need to decontaminate these products before disposal as liquid or solid waste. Studies were conducted to test the efficacy of commercial household products for inactivating spores of Bacillus cereus (used as a surrogate for B. anthracis) in vitro and in fluid milk. Validation of the resistance of the B. cereus spores was confirmed with B. anthracis spores. Fifteen commercial products, designed as either disinfectants or sanitizers or as potential sanitizers, were purchased from retail markets. Products selected had one of the following active compounds: NaOCl, HCl, H2O2, acetic acid, quaternary ammonium compounds, ammonium hydroxide, citric acid, isopropanol, NaOH, or pine oil. Compounds were diluted in water (in vitro) or in 2% fat fluid milk, and spores were exposed for up to 6 h. Products containing hypochlorite were most effective against B. cereus spores. Products containing HCl or H2O2 also reduced significant numbers of spores but at a slower rate. The resistance of spores of surrogate B. cereus strains to chlorine-containing compounds was similar to that of B. anthracis spores. Therefore, several household products on the market may be used to decontaminate fluid milk or similar food products contaminated by spores of B. anthracis.

Treating first episode psychosis--the service users' perspective: a focus group evaluation

UK national guidance has prioritized developing specialist services for first episode psychosis. Such services are in the early stages of development and a definitive treatment model has yet to be established. The aim of this study was to explore service users' experiences of a first episode intervention designed along evidence-based 'best practice' guidelines and to establish specific elements seen as effective to help inform future service planning and provision. Twelve users of a specialist first episode service participated in focus groups. These were then analyzed using Interpretative Phenomenological Analysis, a specialized form of content analysis. Key elements identified by the service users included the 'human' approach as a key to the recovery process, being involved in treatment decisions, flexibility of appointments, high nurse to patient ratio, reduction in psychotic symptoms, increased confidence and independence and the provision of daily structure. To our knowledge, this is the first systematic qualitative evaluation of users' experience of a specialist first episode treatment intervention. Our findings indicate that adherence to best practice guidelines was appreciated. Regular focus groups provide a continuous audit cycle incorporating service improvements in line with government recommendations, centrally informed by the service users' and caregivers' perspective.

Trends in cigar smoking and perceptions of health risks among Massachusetts adults

OBJECTIVE

To track trends in cigar smoking and assess perceptions of cigar related health risks among Massachusetts adults.

DESIGN

A random digit dial telephone survey conducted in 1993 and a subsequent monthly random digit dial survey conducted March 1995 to June 2000.

PARTICIPANTS

4733 adults who completed the 1993 survey and 14 868 adults who completed the monthly survey between 1995 and 2000.

MAIN OUTCOME MEASURES

Trends in current and experimental cigar use and perceptions of health risks.

RESULTS

Current cigar usage increased significantly among men aged 18-34 years between 1993 (5.8%) and 1997-98 (18.2%), but began to decrease in 1999-2000 (13.5%). Young men were much more likely than older men or women of any age to have experimented with cigars in the year before interview, but this trend appears to have decreased slightly since 1998. Young male cigar smokers were increasingly those who never smoked cigarettes. Former cigarette smokers were not smoking cigars in greater numbers. Cigar smokers were roughly three times as likely as those who do not smoke cigars to believe cigars are a safer alternative to cigarettes, and that perception did not appear to change much over time.

CONCLUSION

Cigar usage increased dramatically among young men in Massachusetts in conjunction with national increases in sales and marketing of cigars, but now appears to be decreasing.

Watching the clock: boredom and vigilance performance

The current study investigated the relationship between a measure of trait boredom, Boredom Proneness, and vigilance performance on a variation of Mackworth's original clock test. Performance, assessed as Sensory Efficiency, was negatively correlated with Boredom Proneness scores early in the vigil but not during later trials. The results suggested that the trait of Boredom Proneness is predictive of performance on monotonous tasks within the first 10-min. block of trials; however, no differences in performance occurred on subsequent blocks, suggesting that as state boredom increases, differences between individuals diminish, e.g., a ceiling effect. The authors discuss the importance of examining Boredom Proneness as a multidimensional construct. Practical implications for these results are presented, particularly in terms of using Sensory Efficiency as a measure of performance during vigilance tasks.

Bidi Smoking among Massachusetts Teenagers

OBJECTIVES

This article presents the prevalence of bidi use among Massachusetts adolescents.

METHODS

Questions on bidi use were included in a statewide telephone survey of a population-based sample of youth 14 to 17 years of age (N = 733).

RESULTS

Past-month use rates were below 2.0% for all demographic subgroups. Minority respondents were more likely than white respondents to have ever smoked a bidi. Males and current cigarette smokers were more likely than their female and nonsmoking counterparts to have ever smoked a bidi or to have smoked one in the past year.

CONCLUSIONS

The demographic distributions of bidi smoking suggest the need for monitoring bidi use trends among adolescent subgroups.

General practitioner access to gastroscopy: is 'censorship' valuable?

An audit was carried out on the activities of a one stop clinic where patients referred by GPs for endoscopy are first interviewed by a gastroenterologist, directly before the procedure. Such a barrier to open access endoscopy did not seem to reduce the workload or the rate of normal examinations.

Plasma prolactin, adrenocorticotrophic hormone and cortisol after administration of d-fenfluramine or placebo to healthy subjects

Hormonal responses following single doses of the racemic drug d,l-fenfluramine have been used as an index of central 5-hydroxytryptamine (5-HT) function. We wished to evaluate normal responses to d-fenfluramine, which is more specific at stimulating 5-HT pathways. Twelve healthy volunteers were given 30 mg oral d-fenfluramine and placebo in a randomized single-blind crossover design. Following d-fenfluramine there was a rise in plasma prolactin, but no ACTH response. Cortisol levels did not rise above baseline values, but d-fenfluramine diminished the circadian fall in cortisol output, and cortisol levels were slightly higher after d-fenfluramine than after placebo. Unlike d,l-fenfluramine, d-fenfluramine is not a potent stimulus for ACTH and cortisol release. Hormonal responses following d-fenfluramine provide a more accurate assessment of the functional integrity of central 5-HT activity.

Rapid dissociation of platelet-rich fibrin clots in vitro by a combination of plasminogen activators and antiplatelet agents

Thrombin promotes the formation of arterial thrombi by converting fibrinogen to fibrin and by causing platelets to aggregate. We have examined the combined effects of plasminogen activators and inhibitors of platelet aggregation on the lysis of platelet-rich fibrin clots formed by alpha-thrombin in citrated platelet-rich plasma. The extent of platelet aggregation and clot formation were measured by recording light transmission in an aggregometer. Immediately after the formation of platelet-rich fibrin clots, addition of 2,000 U/ml streptokinase or 50 micrograms/ml recombinant tissue-type plasminogen activator alone resulted in the degradation of polymerized fibrin and the release of trapped platelet aggregates without causing significant platelet deaggregation. Preincubation of the platelet-rich plasma with 20 microM indomethacin for 1 min before thrombin stimulation or simultaneous addition of prostaglandin E1 (10 microM) with the plasminogen activators after thrombin stimulation resulted in spontaneous platelet deaggregation. Because platelet aggregation is, in part, mediated by the binding of Arg-Gly-Asp-containing adhesive proteins to activated platelets, the effect of Arg-Gly-Asp peptides on platelet deaggregation was examined. By itself, Gly-Arg-Gly-Asp-Ser-Pro specifically caused dose- and time-dependent deaggregation of platelet aggregates formed by ADP or by thrombin in the presence of 1 mM Gly-Pro-Arg-Pro, but had no effect on the dissociation of thrombin-induced platelet-rich fibrin clots. In combination with streptokinase or recombinant tissue-type plasminogen activator, Gly-Arg-Gly-Asp-Ser-Pro enhanced the rate of lysis of platelet-rich fibrin clots. The control Gly-Arg-Gly-Glu-Ser-Pro peptide was completely ineffective.(ABSTRACT TRUNCATED AT 250 WORDS)

Cooling Facilities of Rubber Equipment

Proper maintenance of rubber processing equipment is a necessary and important phase of production. If management is to maintain maximum overall production it must allow the engineering and maintenance organization sufficient authority, time and money to keep equipment operating at top efficiency. When the pressure of production jobs that have to be completed “yesterday” interferes repeatedly with repairs that should have been made last week, the chances are very good that a condition will soon exist where the rush job can not be completed until next month. The first rule, then, in maintenance work is, “Do it now.” A small repair job today may prevent a costly shutdown tomorrow. In addition to the mechanical difficulties regularly occurring, there are a number of little things that frequently cause production delays and hidden extra costs. One of the most important of these concerns the cooling of mills, Banbury mixers, calender rolls and tubing machines. Early in the history of the rubber industry it was learned that some means of carrying off heat occasioned by friction of the stock working on the equipment was necessary. It was learned later that the same facilities could be used to control temperatures within the ranges suited best for a given stock or processing operation. The methods in use today have altered little since the first installations were made, but it is doubtful that full use is always made of the facilities available. In ordinary times this was foolish and expensive. Today it approaches sabotage by interfering with production, increasing the percentage of seconds, and wasting vital raw materials. Most causes of inadequately cooled processing equipment are obvious, and their correction is generally inexpensive and elementary. However, as is often the case, the obvious little things are all too frequently overlooked and unsatisfactory conditions tolerated. It is hoped that, by pointing out potential trouble spots and emphasizing both the processing difficulties due to poor cooling and the ease with which they may be corrected, much future trouble may be avoided.