Prevalence of Campylobacter, Salmonella, and Escherichia coli on the external packaging of raw meat

Integrating meta-analysis with a quantitative microbial risk assessment model to investigate Campylobacter contamination of broiler carcasses

This study investigated the prevalence and associated risk factors of Campylobacter in South Korean broilers using a random-effects meta-analysis. Subsequently, to facilitate the design of preventive measures, the prevalence estimate from the meta-analysis was incorporated into a stochastic risk assessment model to quantify the Campylobacter contamination levels on broiler carcasses. The baseline model was developed based on the most common practices along the South Korean broiler processing line, with no interventions. Meta-analysis results revealed Campylobacter prevalence across the chicken supply chain in the following order: farms (60.6 % [57.3-63.4]), retail markets (43.90 % [24.81-64.99]), slaughterhouses (27.71 % [18.56-39.21]), and processing plants (14.50 % [3.96-41.09]). The model estimated a 52 % (36.1-70.8) Campylobacter prevalence at the end of chilling, with an average contamination level of 4.62 (2.50-6.74) log CFU/carcass. Sensitivity analysis indicated that Campylobacter fecal shedding (r = 0.95) and the amount of feces on bird exteriors (r = 0.17) at pre-harvest were the main factors for carcass contamination, while soft scalding (r = -0.22) and air chilling (r = -0.12) can serve as critical control points (CCPs) at harvest. Scenario analysis indicated that a combination of hard scalding, inside-outside bird washing, spray washing, and chlorinated water immersion chilling can offer a 30.9 % reduction in prevalence and a reduction of 2.23 log CFU/carcass in contamination levels compared to the baseline model. Apart from disinfection and sanitation interventions carried out during meat processing, the implementation of robust control measures is indispensable to mitigate Campylobacter prevalence and concentration at broiler farms, thereby enhancing meat safety and public health. Furthermore, given the high Campylobacter prevalence in the retail markets, future studies should explore the potential risk of cross-contamination at post-harvest stage.

Antimicrobial resistant bacteria recovered from retail ground meat products in the US include a Raoultella ornithinolytica co-harboring blaKPC-2 and blaNDM-5

Retail beef and pork, including processed products, can serve as vehicles for the zoonotic foodborne transmission of pathogens and antimicrobial resistant bacteria. However, processed and seasoned products like sausages, are not often included in research and surveillance programs. The objective of this study was to investigate retail ground beef and pork, including processed products, for the presence of common foodborne pathogens and antimicrobial resistant bacteria. We purchased 763 packages of fresh and fully cooked retail meat products during 29 visits to 17 grocery stores representing seven major grocery chains located in west and central Ohio. Each package of meat was evaluated for contamination with methicillin-resistant Staphylococcus aureus (MRSA), Salmonella spp., Enterobacteriaceae expressing extended-spectrum cephalosporin resistance, and carbapenemase-producing organisms (CPO). Only 3 of the 144 (2.1%) packages of fully cooked meat products contained any of these organisms, 1 with an extended-spectrum β-lactamase-producing (ESBL) Enterobacteriaceae and 2 with CPO. Among the 619 fresh meat products, we found that 85 (13.7%) packages were contaminated with MRSA, 19 (3.1%) with Salmonella, 136 (22.0%) with Enterobacteriaceae expressing an AmpC (blaCMY) resistance genotype, 25 (4.0%) with Enterobacteriaceae expressing an ESBL (blaCTX-M) resistance genotype, and 31 (5.0%) with CPO, primarily environmental organisms expressing intrinsic carbapenem resistance. However, one CPO, a Raoultella ornithinolytica, isolated from pork sausage co-harbored both blaKPC-2 and blaNDM-5 on IncN and IncX3 plasmids, respectively. Our findings suggest that fresh retail meat, including processed products can be important vehicles for the transmission of foodborne pathogens and antimicrobial resistant bacteria, including those with epidemic carbapenemase-producing genotypes.

Management Strategies for Prevention of Campylobacter Infections Through the Poultry Food Chain: A European Perspective

Numerous studies point out that at present, a complete elimination of Campylobacter species in the poultry food chain is not feasible. Thus, the current aim should be to establish control measures and intervention strategies to minimize the occurrence of Campylobacter spp. in livestock (esp. poultry flocks) and to reduce the quantitative Campylobacter burden along the food chain in animals and subsequently in foods. The most effective measures to mitigate Campylobacter focus on the primary production stage. Nevertheless, measures applied during slaughter and processing complement the general meat hygiene approaches by reducing fecal contamination during slaughtering and processing and as a consequence help to reduce Campylobacter in poultry meat. Such intervention measures at slaughter and processing level would include general hygienic improvements, technological innovations and/or decontamination measures that are applied at single slaughter or processing steps. In particular, approaches that do not focus on a single intervention measure would need to be based on a thorough process of evaluation, and potential combinatory effects have to be modeled and tested. Finally, the education of all stakeholders (including retailers, food handlers and consumers) is required and will help to increase awareness for the presence of foodborne pathogens in raw meat and meat products and can thus aid in the development of the required good kitchen hygiene.

Fate of Listeria monocytogenes in the Presence of Resident Cheese Microbiota on Common Packaging Materials

Literature data regarding the survival of microorganisms on materials used for food package purposes are scarce. The aim of the current study is to assess the survival of Listeria monocytogenes on different packaging materials for dairy products during extended storage at different temperatures. Three packaging materials (5 × 5 cm) were contaminated with a cocktail of five strains of Listeria monocytogenes suspended in a cheese homogenate, including the cheese's native microbial population. Contaminated samples were incubated at 37°, 12°, and 4°C and periodically analyzed up to 56 days. The evolution of the total viable count and pathogen population was evaluated. At 37°C, the results showed that Listeria monocytogenes was no longer detected on polyethylene-coated nylon (B) by day 4 and on polyethylene-coated parchment (A) and greaseproof paper (C) by day 7. Interestingly, the initial cell population (ranging between 2.5 and 2.7 log CFU/cm2) of Listeria monocytogenes increased to 3 log CFU/cm2 within 4 days of storage at 12°C on A and C. During storage, the number remained fairly constant at 12°C and 4°C on two materials (A-C) and decreased slowly on the third one (B). This study shows that survival of Listeria monocytogenes on packaging materials for dairy products will be higher when stored at 4 or 12°C compared to 37°C. The survival of Listeria monocytogenes on the packaging materials raises concerns of cross-contamination during food handling and preparation at catering and retail premises and within the home, highlighting the importance of treating the packaging materials as a potential source of cross-contamination. These initial findings may aid in quantifying risks associated with contamination of food packaging materials.

Prevalence of Salmonella, Campylobacter, and Shiga Toxin-Producing Escherichia coli on the Surfaces of Raw Poultry Packages

Contamination on the exterior surfaces of raw poultry packages can be transmitted to hands and food contact surfaces during shopping and handling. This study compared the level of microbial contamination and prevalence of foodborne pathogens on the surfaces of raw poultry packages as related to the types of products, types of packaging, and packaging conditions. Packages of whole chicken, cut-up chicken (breast and leg quarter), and ground turkey were purchased from retail stores. Aerobic plate counts (APCs) were significantly different ( P < 0.05) among types of products and packaging materials, with ground turkey packages and the heat-sealed, high-walled containers being the lowest. APCs were significantly lower ( P < 0.05) when the packages were intact and tight compared with intact and loose. Of the 105 packages, there were 10 (9.5%) with the presence of either Shiga toxin-producing Escherichia coli (STEC) or Campylobacter; of those packages, 6 (5.7%) were positive for STEC, 7 (6.7%) were positive for Campylobacter, and 3 (2.9%) were positive for both pathogens on the surfaces. Salmonella was not detected on the surfaces of all tested packages. Surfaces of whole chicken packages were significantly ( P < 0.001) more likely to have detectable levels of Campylobacter and STEC than those of cut-up chicken packages. Packages that were positive for Campylobacter and/or STEC had significantly ( P < 0.005) higher APCs than negative packages. The results suggested that STEC is another significant pathogen present on the surfaces of poultry packages in addition to Campylobacter. The presence of STEC on the external packaging of raw poultry raises a concern because consumers may not expect such pathogens on the surfaces of poultry packages.

Contamination by Meat Juice When Shopping for Packages of Raw Poultry

Raw poultry products often are contaminated with Salmonella and Campylobacter, and these bacteria can be transmitted through meat juice on the packages. An observational study was conducted to assess consumer exposure to meat juice during shopping and to quantify the transmission of meat juice from poultry packages to hands and other surfaces. Ninety-six participants completed the shopping study; 402 swabs were collected and analyzed for the presence of meat juice by an immunoassay. Overall, meat juice was detected on 61% of poultry package surfaces, 34% of shoppers' hands, 41% of grocery bags, 60% of kitchen surfaces, and 51% of food item surfaces. When meat juice was detected on the purchased poultry packages, the chance of the meat juice being on the shopper's hands, grocery bags, food items, and kitchen surfaces was significantly higher ( P < 0.005) compared with packages on which meat juice was not present. Shoppers who had poultry wrapped separately during checkout had a significantly lower ( P < 0.05) chance of meat juice on the food items. However, using plastic bags and wrapping poultry separately did not significantly reduce the likelihood of meat juice on kitchen surfaces at home due to consumers' practices of repackaging before storage. Results suggested that the transfer of meat juice through direct contact with the poultry packages is a major concern during shopping and should be prevented.

Prevalence and Characterization of Campylobacter jejuni Isolated from Retail Chicken in Tianjin, China

Campylobacter jejuni is an important foodborne pathogen worldwide; however, there is a lack of information on the prevalence and antibiotic-resistant profile of C. jejuni in the People's Republic of China. We determined the prevalence and characteristics of C. jejuni on the retail level in Tianjin, one of the five national central cities in China. A total of 227 samples of chicken wings, legs, and breasts were collected from supermarkets and wet markets; 42 of these samples were confirmed to be positive for Campylobacter contamination. The contamination rates of C. jejuni and other Campylobacter species were 13.7% (31 of 227 samples) and 5.7% (13 of 227 samples), respectively. A group of 31 C. jejuni isolates was subjected to antimicrobial susceptibility testing. All (100%) the selected isolates were resistant to ciprofloxacin and nalidixic acid; 77.4% were resistant to tetracycline, 67.7% to doxycycline, 35.5% to gentamicin, 25.8% to clindamycin and florfenicol, 19.4% to chloramphenicol, and 12.9% to erythromycin and azithromycin. A remarkably high proportion (41.9%) of multidrug-resistant isolates was identified. Multilocus sequence typing was conducted to study the population structure of the C. jejuni strains and their relationship to human isolates. The correlation between antimicrobial resistance traits and certain sequence types (STs) or clonal complexes was determined as well. A great genetic diversity of poultry isolates was identified, with 11 STs belonging to 6 clonal complexes and 11 singleton STs. The novel STs accounted for 40.9% (n = 9) of the 22 STs. ST-21, ST-353, ST-354, ST-443, ST-607, and ST-828 complexes had been previously identified from human isolates. This study revealed an extensive level of antimicrobial resistance and genetic diversity in C. jejuni isolated from chicken products in Tianjin, highlighting the necessity of performing enforced interventions to reduce Campylobacter prevalence in China.

Risk factors and spatial distribution of extended spectrum β-lactamase-producing- Escherichia coli at retail poultry meat markets in Malaysia: a cross-sectional study

Background

The significant role of retail poultry meat as an important exposure pathway for the acquisition and transmission of extended spectrum β-lactamase-producing Escherichia coli (ESBL-EC) into the human population warrants understanding concerning those operational practices associated with dissemination of ESBL-EC in poultry meat retailing. Hence, the objective of this study was to determine the prevalence, spatial distribution and potential risk factors associated with the dissemination of ESBL-EC in poultry meat retail at wet-markets in Selangor, Malaysia.

Methods

Poultry meat (breast, wing, thigh, and keel) as well as the contact surfaces of weighing scales and cutting boards were sampled to detect ESBL-EC by using culture and disk combination methods and polymerase chain reaction assays. Besides, questionnaire was used to obtain data and information pertaining to those operational practices that may possibly explain the occurrence of ESBL-EC. The data were analysed using logistic regression analysis at 95 % CI.

Results

The overall prevalence of ESBL-EC was 48.8 % (95 % CI, 42 – 55 %). Among the risk factors that were explored, type of countertop, sanitation of the stall environment, source of cleaning water, and type of cutting board were found to be significantly associated with the presence of ESBL-EC.

Conclusions

Thus, in order to prevent or reduce the presence of ESBL-EC and other contaminants at the retail-outlet, there is a need to design a process control system based on the current prevailing practices in order to reduce cross contamination, as well as to improve food safety and consumer health.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3377-2) contains supplementary material, which is available to authorized users.

Consumer Poultry Handling Behavior in the Grocery Store and In-Home Storage

Considerable work on consumers' food safety habits has highlighted issues associated with home food preparation. However, consumer handling of foods, such as poultry, during shopping and storage has not been noted. The objective of this study was to determine consumer behaviors during purchasing and initial storage of raw poultry to determine potential cross-contamination issues. A shop-along observational study was conducted to determine actual shopping, transportation, and storage behavior of consumers who purchase raw poultry products. Neither hand sanitizer nor wipes were observed in 71% of grocery store meat sections of stores visited. Plastic bags could be found in the meat section 85% of the time, but only 25% of shoppers used the bag for their raw poultry purchases. During checkout, the poultry was bagged separately from other products 71% of the time. A majority of shoppers stored raw poultry in the original package without an additional container or overwrap. Overall, there needs to be an increase in food safety education on the handling of poultry during purchasing, transportation, and storage.

Bacterial contamination in Saeng-go-gi, a ready-to-eat fresh raw beef dish sold in restaurants in South Korea

This study investigated the bacterial contamination levels in ready-to-eat fresh raw beef, Saeng-go-gi in Korean, sold in restaurants. A total of 462 samples were analyzed by performing an aerobic bacterial plate count, a coliform count, and an Escherichia coli O157:H7 count. Aerobic bacterial plate counts of fresh raw beef obtained from Seoul, Cheonan, Daegu, Gunsan, and Gwangju retail store restaurants were 6.46, 6.89, 6.39, 6.58, and 6.67 log CFU/g, respectively, and coliforms were 4.05, 4.97, 4.76, 3.62, and 3.32 log CFU/g, respectively. Among the 462 assessed samples, suspected E. coli O157:H7 colonies were found in 32, 24, 20, 22, and 16 samples obtained from Seoul, Cheonan, Daegu, Gunsan, and Gwangju, respectively. The identity of these isolated colonies was further assessed by using a latex agglutination kit. The agglutination assay data showed that the isolates were not E. coli O157:H7. The data from this study could be used to design better food handling practices for reducing foodborne illnesses linked to fresh raw beef consumption.

Method-dependent variability in determination of prevalence of Campylobacter jejuni and Campylobacter coli in Canadian retail poultry

Campylobacter is the most frequent cause of bacterial gastroenteritis in Canada, and the illness is commonly associated with poultry consumption. Whereas Canadian retail poultry is often contaminated with campylobacters, studies on the prevalence of this organism are inconsistent due to variability in sampling and microbiological methodology. To determine the current microbiological status of Canadian poultry, and to evaluate two commonly used microbiological methods, 348 raw poultry samples were collected at retail across Canada over a period of 3 years (2007 to 2010) and were analyzed for the presence of thermophilic Campylobacter species. The overall prevalence of Campylobacter spp. was found to be 42.8% by a combination of the two testing methods, with 33.9% of the samples positive for C. jejuni, 3.7% of the samples positive for C. coli, and 5.2% of the samples positive for both. Variability in Campylobacter spp. prevalence was observed in samples obtained from different regions across Canada and from poultry with or without skin, but this was not statistically significant. In co-contaminated samples, C. jejuni was preferentially recovered from Preston agar compared with mCCDA and Campy-Cefex agar, with an increase in recovery of C. coli on all selective media after 48 h of enrichment. A subset of 214 of the poultry rinses were analyzed by both Health Canada's standard method, MFLP-46 (enrichment in Park and Sanders broth), and a second method requiring enrichment in Bolton broth. Significantly more positive samples were obtained with the MFLP-46 method (40.6%) than with the alternate method (35.0%). This improved recovery with MFLP-46 may be due to the omission of cycloheximide from this method. These results demonstrate that determination of prevalence of Campylobacter spp. on poultry products may be significantly impacted by the choice of microbiological methods used. Canadian poultry continues to be a source of exposure to Campylobacter spp.

Detection of thermophilic Campylobacter sp. in raw chicken sausages by methods ISO 10272: 2006 in Curitiba - Parana State - Brazil

The aim of this study was the detection of Campylobacter sp. in raw chicken sausages using the methods ISO 10272-1 and ISO 10272-2. The overall prevalence of Campylobacter sp. in the samples tested was 16.67%, representing a serious risk to the health of consumers, particularly if measures guaranteeing proper cooking of foods and prevention of cross-contamination are not adopted. Furthermore, the majority of campylobacteriosis cases in humans are caused by consumption or improper handling of contaminated raw or undercooked poultry meat, which constitute the main vehicle of this infection.

Hygienic quality and antibiotic resistance profile of sliced butchery

In order to investigate the microbiological quality of different meat products on the Greek market, 200 samples were collected from the following preparations: boiled turkey (n=50), boiled pork ham (n=50), smoked turkey (n=50) and smoked pork ham (n=50). In all cold meat preparations Clostridium perfringens vegetative and spore forms, Staphylococcus aureus, Escherichia coli and other Clostridium sp lec(-), as well as Lactobacillus, Bacillus sp. and Salmonella sp. were recovered. For instance Bacillus cereus was present in 6% of the samples. L. monocytogenes, Campylobacter jejuni and Campylobacter coli were rarely present (1-4%) while Yersinia enterocolitica and Campylobacter lari were absent. Differences in the occurrence of S. aureus, Salmonella sp., E. coli and spore forms of C. perfringens in boiled and smoked samples, reflects either the differences in the processing of the foods or could be associated to the extensive handling by the personnel during the purchasing (storage, slicing, wrapping). Antibiotic resistance on specific antibiotics for each pathogen was also studied. A multiresistance antibiotic profile was effective for most bacterial strains, and pronounced resistance profiles were observed for the commonly used antibiotics as ampicillin, penicillin, cephalothin, streptomycin followed by ceftriaxone and gentamycin. Albeit this high observed resistance profile, the tested strains generally conserved their susceptibility to amikacin, aztreonam, chloramphenicol and tylosin conserved an almost absent resistance. Antibiotics commonly used for therapeutic purposes, as well as antibiotics added to feed stuff of animals for increasing animal flesh production should contribute to the extensive spreading of antibiotic resistance in food and the environment. Systematically monitoring of the microbiological quality of cold butchery preparations must be done, in order to preserve food quality, optimizing the processing and elaboration methods of the product and safeguard the public health.

Efficacy of UV light treatment for the microbiological decontamination of chicken, associated packaging, and contact surfaces

UV light was investigated for the decontamination of raw chicken, associated packaging, and contact surfaces. The UV susceptibilities of a number of Campylobacter isolates (seven Campylobacter jejuni isolates and three Campylobacter coli isolates), Escherichia coli ATCC 25922, and Salmonella enterica serovar Enteritidis ATCC 10376 in liquid media were also investigated. From an initial level of 7 log CFU/ml, no viable Campylobacter cells were detected following exposure to the most intense UV dose (0.192 J/cm(2)) in liquid media (skim milk subjected to ultrahigh-temperature treatment and diluted 1:4 with maximum recovery diluent). Maximum reductions of 4.8 and 6.2 log CFU/ml were achieved for E. coli and serovar Enteritidis, respectively, in liquid media. Considerable differences in susceptibilities were found between the Campylobacter isolates examined, with variations of up to 4 log CFU/ml being observed. UV treatment of raw chicken fillet (0.192 J/cm(2)) reduced C. jejuni, E. coli, serovar Enteritidis, total viable counts, and Enterobacteriaceae by 0.76, 0.98, 1.34, 1.76, and 1.29 log CFU/g, respectively. Following UV treatment of packaging and surface materials, reductions of up to 3.97, 4.50, and 4.20 log CFU/cm(2) were obtained for C. jejuni, E. coli, and serovar Enteritidis, respectively (P < 0.05). Overall, the color of UV-treated chicken was not significantly affected (P ≥ 0.05). The findings of this study indicate that Campylobacter is susceptible to UV technology and that differences in sensitivities exist between investigated isolates. Overall, UV could be used for improving the microbiological quality of raw chicken and for decontaminating associated packaging and surface materials.

Efficacy of high-intensity pulsed light for the microbiological decontamination of chicken, associated packaging, and contact surfaces

The efficacy of high-intensity light pulse (HILP) technology (3 Hz, maximum of 505 J/pulse, and a pulse duration of 360 μs) for the decontamination of raw chicken and associated packaging and surface materials was investigated. Its ability to reduce microbial counts on raw chicken through plastic films was also examined. Complete inactivation of Campylobacter spp., Escherichia coli, and Salmonella Enteritidis in liquid was achieved after 30 sec HILP treatment. Reductions of 3.56, 4.69, and 4.60 log₁₀ cfu/cm²) were observed after 5 sec HILP treatment of Campylobacter jejuni, E. coli, and Salmonella Enteritidis inoculated onto packaging materials and contact surfaces, respectively. The greatest reductions on inoculated chicken skin were 1.22, 1.69, and 1.27 log₁₀ cfu/g for C. jejuni, E. coli, and Salmonella Enteritidis, respectively. Corresponding reductions on inoculated skinless breast meat were 0.96, 1.13, and 1.35 log₁₀ cfu/g. The effectiveness of HILP treatment for reducing microbial levels on chicken increased as the film thickness decreased. HILP treatments of 2 sec did not significantly affect the color of raw chicken although treatments of 30 sec impacted color. This study has shown HILP to be an effective method for the decontamination of packaging and surface materials. Additionally, it has demonstrated the potential of HILP to be used as a decontamination method for packaged chicken.

Riding in shopping carts and exposure to raw meat and poultry products: prevalence of, and factors associated with, this risk factor for salmonella and campylobacter infection in children younger than 3 years

Riding in a shopping cart next to raw meat or poultry is a risk factor for Salmonella and Campylobacter infections in infants. To describe the frequency of, and factors associated with, this behavior, we surveyed parents of children aged younger than 3 years in Foodborne Disease Active Surveillance Network sites. We defined exposure as answering yes to one of a series of questions asking if packages of raw meat or poultry were near a child in a shopping cart, or if a child was in the cart basket at the same time as was raw meat or poultry. Among 1,273 respondents, 767 (60%) reported that their children visited a grocery store in the past week and rode in shopping carts. Among these children, 103 (13%) were exposed to raw products. Children who rode in the baskets were more likely to be exposed than were those who rode only in the seats (odds ratio [OR], 17.8; 95% confidence interval [CI], 11.0 to 28.9). In a multivariate model, riding in the basket (OR, 15.5; 95% CI, 9.2 to 26.1), income less than $55,000 (OR, 1.8; 95% CI, 1.0 to 3.1), and Hispanic ethnicity (OR, 2.3; 95% CI, 1.2 to 4.5) were associated with exposure. Our study shows that children can be exposed to raw meat and poultry products while riding in shopping carts. Parents should separate children from raw products and place children in the seats rather than in the baskets of the cart. Retailer use of leak-proof packaging, customer placement of product in a plastic bag and on the rack underneath the cart, use of hand sanitizers and wipes, and consumer education may also be helpful.

Examination of the source and extended virulence genotypes of Escherichia coli contaminating retail poultry meat

Extraintestinal pathogenic Escherichia coli (ExPEC) are major players in human urinary tract infections, neonatal bacterial meningitis, and sepsis. Recently, it has been suggested that there might be a zoonotic component to these infections. To determine whether the E. coli contaminating retail poultry are possible extraintestinal pathogens, and to ascertain the source of these contaminants, they were assessed for their genetic similarities to E. coli incriminated in colibacillosis (avian pathogenic E. coli [APEC]), E. coli isolated from multiple locations of apparently healthy birds at slaughter, and human ExPEC. It was anticipated that the retail poultry isolates would most closely resemble avian fecal E. coli since only apparently healthy birds are slaughtered, and fecal contamination of carcasses is the presumed source of meat contamination. Surprisingly, this supposition proved incorrect, as the retail poultry isolates exhibited gene profiles more similar to APEC than to fecal isolates. These isolates contained a number of ExPEC-associated genes, including those associated with ColV virulence plasmids, and many belonged to the B2 phylogenetic group, known to be virulent in human hosts. Additionally, E. coli isolated from the crops and gizzards of apparently healthy birds at slaughter also contained a higher proportion of ExPEC-associated genes than did the avian fecal isolates examined. Such similarities suggest that the widely held beliefs about the sources of poultry contamination may need to be reassessed. Also, the presence of ExPEC-like clones on retail poultry meat means that we cannot yet rule out poultry as a source of ExPEC human disease.

A baseline survey of the microbiological quality of chicken portions and carcasses at retail in two Australian states (2005 to 2006)

Raw poultry products were purchased from the retail market place in two Australian states, New South Wales (n = 549) and South Australia (n = 310). The products sampled on a proportional volume basis were chicken portions with the skin off or skin on, in bulk or tray packs, and whole carcasses. They were collected from butcher shops, supermarkets, and specialty stores from urban areas during the winter (2005) and summer (2006) months. The samples were analyzed to determine the prevalence and concentration of Escherichia coli, Salmonella, and Campylobacter spp. in addition to total viable counts. Salmonella was found in 47.7 and 35.5% of retail chicken samples (35.3 and 21.9% were the less virulent Salmonella Sofia), at mean counts of -1.42 and -1.6 log MPN/cm2 in New South Wales and South Australia, respectively. Campylobacter was found in 87.8 and 93.2% of samples at mean counts of 0.87 and 0.78 log CFU/cm2, respectively. In both states in both seasons, the mean total viable count was 5 log CFU/cm2. On whole birds, E. coli was detected in all winter samples and on 92.9 and 85.7% of summer samples in New South Wales and South Australia, respectively; the log of the geometric mean per square centimeter was 0.5 in winter and slightly lower in summer. On chicken portions, E. coli was detected in around 90% of winter samples in both states, and in summer on 75.1 and 59.6% of samples in New South Wales and South Australia, respectively. The log of the geometric mean CFU per square centimeter for E. coli was 0.75 and 0.91 in winter, and 0.66 and 0.5 in summer in New South Wales and South Australia, respectively.

New information about pediatric foodborne infections: the view from FoodNet

PURPOSE OF REVIEW

Diarrheal illness is a significant burden to children and their parents. Recent studies describing the etiologic agents that cause diarrheal illness and examining the risk factors for the most common bacterial enteric pathogens are presented.

RECENT FINDINGS

The most common bacterial causes of diarrheal illness among children are Campylobacter spp., Salmonella spp., Shigella spp. and Shiga toxin-producing Escherichia coli. The highest incidence of both Campylobacter and Salmonella is among infants. Risk factors for campylobacteriosis in this group include traveling outside the US, having a pet in the home with diarrhea and visiting or living on a farm. Risk factors for salmonellosis include traveling outside the US, exposure to reptiles and attending day-care with another child with diarrhea. Breastfeeding is a factor that protects against infection.

SUMMARY

Despite a limited diet, infants are at risk of acquiring enteric pathogens that are commonly associated with consumption of contaminated food. Exposure to these pathogens may be through cross-contamination in the home or the environment. Educational measures that focus on improving prevention of exposure to infectious agents and an emphasis on eliminating cross-contamination are needed for parents and care-takers of this vulnerable population.

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.

Sporadic campylobacter infection in infants: a population-based surveillance case-control study

BACKGROUND

Campylobacter is an important cause of foodborne illness in infants (younger than 1 year of age), but little is known about the sources of infection in this age group.

METHODS

Eight sites in the Foodborne Diseases Active Surveillance Network (FoodNet) participated in a 24-month population-based case-control study conducted in 2002-2004. Cases were infants with laboratory-confirmed Campylobacter infection ascertained through active laboratory surveillance, and controls were infants in the community.

RESULTS

We enrolled 123 cases and 928 controls. Infants 0-6 months of age with Campylobacter infection were less likely to be breast-fed than controls [odds ratio (OR); 0.2; 95% confidence interval (CI), 0.1-0.6]. Risk factors for infants 0-6 months of age included drinking well water (OR 4.4; CI, 1.4-14) and riding in a shopping cart next to meat or poultry (OR 4.0; CI, 1.2-13.0). Risk factors for infants 7-11 months of age included visiting or living on a farm (OR 6.2; CI, 2.2-17), having a pet with diarrhea in the home (OR 7.6; CI, 2.1-28) and eating fruits and vegetables prepared in the home (OR 2.5, CI 1.2-4.9). Campylobacter infection was associated with travel outside the United States at all ages (OR 19.3; CI, 4.5-82.1).

CONCLUSIONS

Several unique protective and risk factors were identified among infants, and these risk factors vary by age, suggesting that prevention measures be targeted accordingly. Breast-feeding was protective for the youngest infants and should continue to be encouraged.

A case-control study of the epidemiology of sporadic Salmonella infection in infants

OBJECTIVE

Rates of Salmonella infection are highest in infants, but little is known about potential sources of infection in this high-risk population. We performed a case-control study to identify dietary and environmental risk factors for sporadic salmonellosis among infants.

PATIENTS AND METHODS

In 2002-2004, the Foodborne Diseases Active Surveillance Network conducted a population-based, case-control study of sporadic salmonellosis among infants <1 year of age in 8 states. Cases were identified via active laboratory-based surveillance. Healthy controls were frequency matched by age and identified through birth registries or published birth announcements. We assessed diet and environmental exposures in the 5 days before illness onset or interview. Data were analyzed by using logistic regression adjusting for age.

RESULTS

The study enrolled 442 subjects and 928 controls. Compared with healthy controls, infants with Salmonella infection were less likely to have been breastfed and more likely to have had exposure to reptiles, to have ridden in a shopping cart next to meat or poultry, or to have consumed concentrated liquid infant formula during the 5-day exposure period. Travel outside the United States was associated with illness in infants 3 to 6 and >6 months of age. Attending day care with a child with diarrhea was associated with salmonellosis in infants >6 months of age.

CONCLUSIONS

We identified a number of modifiable protective and risk factors for salmonellosis in infants. Attention should be directed at developing effective preventive measures for this high-risk population.

Prevalence and antimicrobial resistance of Campylobacter jejuni and Campylobacter coli isolated from raw chicken meat and human stools in Korea

Prevalence of Campylobacter in raw chicken meat and human stools and subsequent antibiotic resistance profiles of the pathogenic isolates obtained from 2000 through 2002 were investigated. Campylobacter jejuni and Campylobacter coli were isolated from 570 of the 923 raw chicken meat samples collected from traditional markets, large retail stores, or department stores in Korea, resulting in the isolation rate of 61.8%. A total of 579 Campylobacter isolates were obtained from raw chicken (36.3% for C. jejuni and 26.4% for C. coli) with the average population of 335.6 CFU/g. From 513 human stool samples, 15 isolates of Campylobacter were detected. Seasonal variation in the quantification of C. coli was not noticeable throughout the year, while the isolation rate of C. jejuni was the highest in September through October (840 CFU/g) followed by that of July through August and May through June in decreasing order, showing a significant seasonal effect (P < 0.05). Contamination of Campylobacter was more severe in raw chicken meat sold in traditional markets than in those sold in large retail stores and department stores. Prevalence of Campylobacter in raw chicken sold in traditional markets was significantly influenced by seasonal changes (P < 0.05), whereas the samples obtained from other places was less affected by the seasonal changes. Susceptibilities of the 594 chicken isolates to ciprofloxaxin, chloramphenicol, erythromycin, kanamycin, nalidixic acid, and tetracycline were determined by an E-test. Campylobacter isolates were the most resistant to nalidixic acid (91.4%) followed by ciprofloxaxin (87.9%), tetracycline (87.2%), kanamycin (30.6%), erythromycin (19.4%), and chloramphenicol (1.3%). Human isolates showed a similar resistance to the six antibiotics tested. The proportion of Campylobacter isolates with multidrug resistance to four or more antimicrobials obtained from 2000 through 2002 ranged from 28 to 43.5%, indicating that it could be a serious health-threatening factor. This study suggests that it is prudent to establish an effective National Monitoring Program in Korea for the prevention and control of Campylobacter spp.

Pathogens on meat and infection in animals - Establishing a relationship using campylobacter and salmonella as examples

A high proportion of human campylobacter and salmonella infections is likely to originate from farm animals, usually directly from the consumption of contaminated meat or milk. Surveillance shows that campylobacter and salmonella genotypes are shared between human case isolates, farm animals and foods, although with the latter there can be marked differences between infection frequency in live animals and contamination rates in raw foods. This is supported by a variety of data from around the world, using a range of different methods. In this paper the evidence for farm animals being the reservoir of human salmonella and campylobacter infection is presented. However, a note of caution is sounded about the complex nature of zoonotic diseases caused by these two pathogens. Thus, many salmonellas and campylobacter types found routinely in food animals do not appear to cause human infections. Is this and artefact of the surveillance and/or microbiological methods used or are some strains of these bacteria genuinely non-pathogenic in man?

Attachment strength to pork skin and resistance to quaternary ammonium salt and heat of Escherichia coli isolates recovered from a pork slaughter line

The aim of this study was to determine whether the attachment strength to pork skin, quaternary ammonium salt resistance, and thermal inactivation kinetics (at 65 degrees C) of a range of Escherichia coli isolates could be correlated with their temporal stability (persistence) within a pork slaughter line. The genetic lineage of the E. coli isolates was determined using enterobacterial repetitive intergenic consensus-PCR. The genotypes were divided into transient and endemic populations based on the number of times they were recovered within and across sampling visits made to a pork slaughterhouse. No significant variation in the D-value at 65 degrees C (0.27 to 0.51 min) was observed among the genotypes tested. However, differences in D-values were found for 100 ppm quaternary ammonium salt (3.0 to 6.0 min). All of the E. coli genotypes attached strongly to pork skin, and a high proportion of cells were irreversibly bound (39 to 42% of the initial inoculum). However, variation among genotypes was found with respect to loose attachment (21 to 33% of inoculated cells). No correlation between persistence of E. coli genotypes within the slaughter line and attachment strength or quaternary ammonium salt resistance was found. Variation in either physiological attribute could not be predicted based on genetic lineage. Additional or alternative factors may contribute to the ability of E. coli populations to become endemic within pork processing facilities. More studies should be conducted to elucidate the underlying factors that promote the formation of endemic populations of E. coli and other enteric bacteria (e.g., Salmonella) within slaughter lines.