Sensitivity of Campylobacter spp. to irradiation in poultry meat

β-Resorcylic Acid, a Phytophenolic Compound, Reduces Campylobacter jejuni in Postharvest Poultry

Human Campylobacter infections, a leading foodborne illness globally, has been linked with the high prevalence of this bacterium on raw retail chicken products. Reduction of Campylobacter counts on poultry products would greatly reduce the risk of subsequent infections in humans. To this end, this study investigated the potential of the phytophenolic compound β-resorcylic acid (BR) to reduce Campylobacter counts on postharvest poultry (chicken skin or meat). Four trials in total, two each on thigh skin or breast meat, were conducted in which chicken skin or meat samples (2 ± 0.1 g; 10 samples per treatment) were inoculated with 50 μL (∼10⁶ CFU per sample) of a cocktail of four wild strains of C. jejuni. After 30 min of attachment, inoculated samples were dipped in a 0, 0.5, 1, or 2% BR solution for 30 s immediately followed by vigorously vortexing the samples in Butterfield's phosphate diluent and plating the supernatant for Campylobacter enumeration. In addition, the effect of BR on the color of skin and meat samples was studied. Moreover, the change in the expression of survival and virulence genes of C. jejuni exposed to BR was evaluated. Data were analyzed by the PROC MIXED procedure of SAS (P < 0.05; SAS Institute Inc., Cary, NC). All BR treatments significantly reduced Campylobacter populations on both chicken or meat samples by 1 to 3 log CFU/g compared with non-BR-treated washed controls. No significant difference in the lightness, redness, and yellowness of skin and meat samples was observed on exposure to BR wash (P > 0.05). Real-time PCR results revealed that BR treatment down-regulated expression of select genes coding for motility (motA, motB) and attachment (cadF, ciaB) in the majority of C. jejuni strains. Stress response genes (sodB, katA) were upregulated in C. jejuni S-8 (P < 0.05). Overall, our results suggest that BR could be effectively used as antimicrobial dip treatment during poultry processing for reducing Campylobacter on chicken carcasses.

Effect of Physical and Chemical Treatments onCampylobacterSpiked into Food Samples

Campylobacter spp. were isolated from rivers Mula, Mutha and Pavana by preT-Kapadnis Baseri and Preston enrichment-modified charcoal cefoperazone deoxycholate agar methods. Survival studies were conducted in fresh skim cow milk, chicken meat extract and mushroom extract at various temperatures. The sensitivity of Campylobacter strains inoculated in the food samples, to chemical preservatives, gamma radiation, microwave heating and water bath heating was studied. Campylobacter strains survived well in milk and chicken extract; however, temperature significantly affected their survival in those food samples. Although most of the chemical preservatives were effective against Campylobacter isolates, the sub-inhibitory values of acetic acid and lactic acid were relatively lower against these isolates. All the strains investigated for the effect of gamma radiation, were sensitive to doses less than 3 kGy. In case of heat preservation, around 9 min was required to eliminate Campylobacter spp. by heating in water bath at 50°C while approximately 13 s from food samples exposed to heating in a microwave oven. The effect of food preservation techniques on Campylobacter varied with the temperature and type of the food. Microwave treatment appeared to be much more effective than water bath heating and that chicken meat extract conferred an additional protection to Campylobacter as compared to milk or PBS.

Control of Campylobacter jejuni in chicken breast meat by irradiation combined with modified atmosphere packaging including carbon monoxide

Campylobacter is one of the leading causes of human foodborne illnesses originating from meat and poultry products. Cross-contamination of this organism occurs in many poultry processing plants, and can occur in the kitchens and refrigerators of consumers. Therefore, new intervention strategies are needed for meat and poultry products to better protect consumers from this pathogen. Vacuum or modified atmosphere packaging is a common packaging technique used by the meat and poultry industry to extend the shelf life of meat products. In addition, irradiation has been well established as an antibacterial treatment to reduce pathogens on meat and poultry products. Irradiation in combination with high-CO(2) + CO modified atmosphere packaging (MAP) was investigated in this study for the control of Campylobacter jejuni in chicken breast meat. The radiation sensitivity (D(10)-value) of this foodborne pathogen in chicken breast meat was similar in vacuum or high-O(2) MAP (0.31 ± 0.01 kGy in vacuum packaging and 0.29 ± 0.03 kGy in MAP). C. jejuni survived in both vacuum and high-CO(2) MAP through 6 weeks of refrigerated storage. Irradiation was effective for eliminating C. jejuni from meat or poultry packaged in vacuum or MAP, and should reduce the chance of cross-contamination in retail stores or home kitchens. However, irradiated off-odor and sour aroma were observed for raw, irradiated chicken breast packaged with either vacuum or MAP. Therefore, additional means to mitigate quality changes appear necessary for these products.

Outbreaks where food workers have been implicated in the spread of foodborne disease. Part 6. Transmission and survival of pathogens in the food processing and preparation environment

This article, the sixth in a series reviewing the role of food workers in foodborne outbreaks, describes the source and means of pathogen transfer. The transmission and survival of enteric pathogens in the food processing and preparation environment through human and raw food sources is reviewed, with the main objective of providing information critical to the reduction of illness due to foodborne outbreaks. Pathogens in the food preparation area can originate from infected food workers, raw foods, or other environmental sources. These pathogens can then spread within food preparation or processing facilities through sometimes complex pathways and may infect one or more workers or the consumer of foods processed or prepared by these infected workers. The most frequent means of worker contamination is the fecal-oral route, and study results have indicated that toilet paper may not stop transmission of pathogens to hands. However, contact with raw foods of animal origin, worker aerosols (from sneezes), vomitus, and exposed hand lesions also have been associated with outbreaks. Transfer of pathogens has been documented through contaminated fabrics and carpets, rings, currency, skin surfaces, dust, and aerosols and though person-to-person transmission. Results of experiments on pathogen survival have indicated that transmission depends on the species, the inoculum delivery route, the contact surface type, the duration and temperature of exposure, and the relative humidity. Generally, viruses and encysted parasites are more resistant than enteric bacteria to adverse environmental conditions, but all pathogens can survive long enough for transfer from a contaminated worker to food, food contact surfaces, or fellow workers.

Impact of irradiation on the safety and quality of poultry and meat products: a review

For more than 100 years research on food irradiation has demonstrated that radiation will make food safer and improve the shelf life of irradiated foods. Using the current food safety technology, we may have reached the point of diminishing returns even though recent figures from the CDC show a significant drop in the number of foodborne illnesses. However, too many people continue to get sick and die from eating contaminated food. New and under utilized technologies such as food irradiation need to be re-examined to achieve new levels of safety for the food supply. Effects of irradiation on the safety and quality of meat and poultry are discussed. Irradiation control of the principle microbial pathogens including viruses, the differences among at-risk sub-populations, factors affecting the diminished rate of improvement in food safety and published D values for irradiating raw meat and poultry are presented. Currently permitted levels of irradiation are probably not sufficient to control pathogenic viruses. Typical gram-negative spoilage organisms are very sensitive to irradiation. Their destruction leads to a significant increase in the acceptable shelf life. In addition, the destruction of these normal spoilage organisms did not provide a competitive growth advantage for irradiation injured food pathogens. Another of the main focuses of this review is a detailed compilation of the effects of most of the food additives that have been proposed to minimize the negative quality effect of irradiation. Most of the antimicrobials and antioxidants used singly or in combination produced an increased lethality of irradiation and a decrease in oxidation by-products. Combinations of dosage, temperature, dietary and direct additives, storage temperature and packaging atmosphere can produce meats that the average consumer will find indistinguishable from non-irradiated meats. A discussion of the production of unique radiological by-products is also included.

Campylobacters as zoonotic pathogens: a food production perspective

Campylobacters remain highly important zoonotic pathogens worldwide which infect an estimated 1% of the population of Western Europe each year. Certain campylobacters are also important in infections of animals, particularly of the reproductive tract, and some are involved in periodontal disease. This paper focuses, however, on the two species which are most important in food-borne infections of humans, Campylobacter (C.) jejuni and C. coli. Infection with these campylobacters is serious in its own right but can also have long-term sequelae such as reactive arthritis and Guillain-Barré syndrome. The pathogens are ubiquitous in nature and in domestic animals and, as a consequence, are found frequently in the environment and on many raw foods, of both plant and animal origin and bacterial numbers can be very high on certain key foods like raw poultry meat. Although all commercial poultry species can carry campylobacters, the risk is greater from chicken because of the high levels of consumption. Campylobacters are relatively 'new' zoonotic pathogens as routine culture from clinical specimens only became possible in the late 1970s. As a consequence there is much that still needs to be understood about the behaviour and pathogenicity of these highly important bacteria. In particular, and from a food industry/food safety perspective, it is important to better understand the behaviour of C. jejuni and C. coli in the food production environment, and how this affects their ability to survive certain food production processes. There is a belief that campylobacters are much more sensitive to hostile conditions than either salmonellas or Escherichia coli. Much of data to support this view have been derived from laboratory experiments and may not fully represent the natural situation. Studies are showing that campylobacters may be more robust than previously thought and thus may represent a greater challenge to food safety. We recommend that research is undertaken to better understand how campylobacters behave in the food chain and how responses to relevant conditions affect their ability to survive processing and their virulence. There is also a need to better understand the reasons why campylobacters are capable of frequent change, particularly in the expression of surface antigens.

Reduction of Campylobacter jejuni on chicken wings by chemical treatments

Eight chemicals, including glycerol monolaurate, hydrogen peroxide, acetic acid, lactic acid, sodium benzoate, sodium chlorate, sodium carbonate, and sodium hydroxide, were tested individually or in combination for their ability to inactivate Campylobacter jejuni at 4 degrees C in suspension. Results showed that treatment for up to 20 min with 0.01% glycerol monolaurate, 0.1% sodium benzoate, 50 or 100 mM sodium chlorate, or 1% lactic acid did not substantially (< or = 0.5 log CFU/ml) reduce C. jejuni populations but that 0.1 and 0.2% hydrogen peroxide for 20 min reduced C. jejuni populations by ca. 2.0 and 4.5 log CFU/ml, respectively. By contrast, treatments with 0.5, 1.0, 1.5, and 2.0% acetic acid, 25, 50, and 100 mM sodium carbonate, and 0.05 and 0.1 N sodium hydroxide reduced C. jejuni populations by >5 log CFU/ml within 2 min. A combination of 0.5% acetic acid plus 0.05% potassium sorbate or 0.5% acetic acid plus 0.05% sodium benzoate reduced C. jejuni populations by >5 log CFU/ml within 1 min; however, substituting 0.5% lactic acid for 0.5% acetic acid was not effective, with a reduction of C. jejuni of <0.5 log CFU/ml. A combination of acidic calcium sulfate, lactic acid, ethanol, sodium dodecyl sulfate, and polypropylene glycol (ACS-LA) also reduced C. jejuni in suspension by >5 log CFU/ml within 1 min. All chemicals or chemical combinations for which there was a >5-log/ml reduction of C. jejuni in suspension were further evaluated for C. jejuni inactivation on chicken wings. Treatments at 4 degrees C of 2% acetic acid, 100 mM sodium carbonate, or 0.1 N sodium hydroxide for up to 45 s reduced C. jejuni populations by ca. 1.4, 1.6, or 3.5 log CFU/g, respectively. Treatment with ACS-LA at 4 degrees C for 15 s reduced C. jejuni by >5 log CFU/g to an undetectable level. The ACS-LA treatment was highly effective in chilled water at killing C. jejuni on chicken and, if recycled, may be a useful treatment in chill water tanks for poultry processors to reduce campylobacters on poultry skin after slaughter.

Applications of Ozone, Bacteriocins and Irradiation in Food Processing: A Review

An article is presented describing the background information on the use of ozone, bacteriocins and irradiation for destroying pathogens in food products. Their effectiveness on some pathogens of importance in food processing systems and issues of concern are highlighted. It could be concluded that although each one has the potential for use as an alternative preservation technology in specific food processing applications, no single method, except irradiation, is likely to be effective against all food spoilage and food poisoning microorganisms in all food matrices. However, the synergistic effect of one of these methods and other 'hurdles' or modes of food preservations could be used to ensure the microbial safety and prevention of the development of undesirable sensory and chemical changes in some food products. Bacteriocins may contribute an additional barrier in the 'hurdle concept' of food safety.

Reduction of Campylobacter spp. by commercial antimicrobials applied during the processing of broiler chickens: a review from the United States perspective

A reduction in Campylobacter spp. has been associated with use of commercial antimicrobial technologies during the processing of broiler chickens. This review is focused on commercial interventions that have received approval by both the U.S. Food and Drug Administration and the U.S. Department of Agriculture for use on raw poultry in the United States. Most of these interventions are currently applied prechill. The limited number of publications on the topic suggests that the application of antimicrobials in commercial settings results in Campylobacter reduction of 1 to 2 log CFU/ml of carcass rinse. However, postchill counts of 0.5 to 1 log CFU/ml of carcass rinse (approximately 4,000 CFU per carcass) are still common. Thus, antimicrobial interventions are not a complete solution for the control of Campylobacter on raw poultry. New postchill interventions are needed, as are (i) improvements in the methodology for detection and enumeration of Campylobacter, (ii) additional surveys on the contamination of processed poultry, and (iii) an understanding of possible resistance to antimicrobials by Campylobacter spp. Research addressing these topics will lead to better control of Campylobacter in commercial poultry carcasses.

Effect of electron beam irradiation on poultry meat safety and quality

The purpose of this study was to determine the effectiveness of electron beam irradiation at doses of 1.0 and 1.8 kGy on the elimination of bacteria from boneless, skinless chicken breasts without significantly altering product quality. Microbial testing was conducted in triplicate using a whole carcass rinse method with each nonirradiated control group and an irradiation treatment group consisting of 10 samples. Results indicated that mean counts for coliforms, generic Escherichia coli, and psychrotrophs were 3.13, 3.26, and 1.92 log10 cfu/200 mL rinsate, respectively, in the control samples. However, these populations were not detected after the samples were irradiated with 1.0 or 1.8 kGy. Mean count of 4.60 log10 cfu/200 mL rinsate was detected for aerobic bacteria in the control samples. Irradiation doses of 1.0 and 1.8 kGy reduced the levels to 2.23 and 1.62 log10 cfu/200 mL rinsate, respectively. Irradiation also rendered the fillets free of Salmonella and Campylobacter. Consumer taste panels (product stored for 0, 14, and 28 d at 0 C) indicated that, at Day 0, there were no differences among controls and treatment groups for any of the quality attributes tested. At Day 14, texture and flavor attributes were lower for the irradiated groups. At Day 28, samples irradiated with 1.0 and 1.8 kGy were less desirable with decreased texture, flavor, and overall acceptability. Degree of lipid oxidation also increased as storage time and level of irradiation increased. Irradiated samples also had higher a* values, indicating they were pinker in color.

Campylobacter jejuni--an emerging foodborne pathogen

Campylobacter jejuni is the most commonly reported bacterial cause of foodborne infection in the United States. Adding to the human and economic costs are chronic sequelae associated with C. jejuni infection--Guillian-Barré syndrome and reactive arthritis. In addition, an increasing proportion of human infections caused by C. jejuni are resistant to antimicrobial therapy. Mishandling of raw poultry and consumption of undercooked poultry are the major risk factors for human campylobacteriosis. Efforts to prevent human illness are needed throughout each link in the food chain.