Current aspects of Salmonella contamination in the US poultry production chain and the potential application of risk strategies in understanding emerging hazards.

PubMed

Rajan, Kalavathy; Shi, Zhaohao; Ricke, Steven C

2017-05-01

One of the leading causes of foodborne illness in poultry products is Salmonella enterica. Salmonella hazards in poultry may be estimated and possible control methods modeled and evaluated through the use of quantitative microbiological risk assessment (QMRA) models and tools. From farm to table, there are many possible routes of Salmonella dissemination and contamination in poultry. From the time chicks are hatched through growth, transportation, processing, storage, preparation, and finally consumption, the product could be contaminated through exposure to different materials and sources. Examination of each step of the process is necessary as well as an examination of the overall picture to create effective countermeasures against contamination and prevent disease. QMRA simulation models can use either point estimates or probability distributions to examine variables such as Salmonella concentrations at retail or at any given point of processing to gain insight on the chance of illness due to Salmonella ingestion. For modeling Salmonella risk in poultry, it is important to look at variables such as Salmonella transfer and cross contamination during processing. QMRA results may be useful for the identification and control of critical sources of Salmonella contamination.

Use of enrichment real-time PCR to enumerate salmonella on chicken parts.

PubMed

Oscar, T P

2014-07-01

Salmonella bacteria that survive cooking or that cross-contaminate other food during meal preparation and serving represent primary routes of consumer exposure to this pathogen from chicken. In the present study, enrichment real-time PCR (qPCR) was used to enumerate Salmonella bacteria that contaminate raw chicken parts at retail or that cross-contaminate cooked chicken during simulated meal preparation and serving. Whole raw chickens obtained at retail were partitioned into wings, breasts, thighs, and drumsticks using a sterilized knife and cutting board, which were then used to partition a cooked chicken breast to assess cross-contamination. After enrichment in buffered peptone water (400 ml, 8 h, 40°C, 80 rpm), subsamples were used for qPCR and cultural isolation of Salmonella. In some experiments, chicken parts were spiked with 0 to 3.6 log of Salmonella Typhimurium var. 5- to generate a standard curve for enumeration by qPCR. Of 10 raw chickens examined, 7 (70%) had one or more parts contaminated with Salmonella. Of 80 raw parts examined, 15 (19%) were contaminated with Salmonella. Of 20 cooked chicken parts examined, 2 (10%) were cross-contaminated with Salmonella. Predominant serotypes identified were Typhimurium (71%) and its variants (var. 5-, monophasic, and nonmotile) and Kentucky (18%). The number of Salmonella bacteria on contaminated parts ranged from one to two per part. Results of this study indicated that retail chicken parts examined were contaminated with low levels of Salmonella, which resulted in low levels of cross-contamination during simulated meal preparation and serving. Thus, if consumers properly handle and prepare the chicken, it should pose no or very low risk of consumer exposure to Salmonella.

Salmonella enterica serovar Enteritidis and Listeria monocytogenes in mango (Mangifera indica L.) pulp: growth, survival and cross-contamination.

PubMed

Penteado, Ana L; de Castro, M Fernanda P M; Rezende, Ana C B

2014-10-01

This study examined the ability of Salmonella enterica serovar Enteritidis and Listeria monocytogenes to grow or survive in mango pulp stored at -20°C, 4°C, 10°C and 25°C, as well as to cross-contaminate mangoes by means of a knife contaminated with different levels of these pathogens. At 25°C lag phase durations of 19 h and 7.2 h and generation times of 0.66 and 1.44 were obtained, respectively, for S. Enteritidis and L. monocytogenes. At 10°C only the growth of L. monocytogenes was observed. At 4°C both bacteria survived for 8 days. At -20°C S. Enteritidis was able to survive for 5 months while L. monocytogenes survived for 8 months. Cross-contamination was observed for knives contaminated with 10⁶, 10⁵ and 10⁴ CFU mL⁻¹ of S. Enteritidis and 10⁶ and 10⁵ CFU mL⁻¹ of L. monocytogenes. Both microorganisms can grow well in mango pulp at 25°C, thus lower temperatures for the maintenance of the pulps are crucial to avoid growth of these microorganisms. A refrigeration temperature of 10°C will avoid only the growth of S. Enteritidis. Thus good handling practices should be rigidly enforced to avoid any contamination as even at refrigeration and freezing temperatures survival of these pathogens may occur. © 2014 Society of Chemical Industry.

Modeling of Salmonella Contamination in the Pig Slaughterhouse.

PubMed

Swart, A N; Evers, E G; Simons, R L L; Swanenburg, M

2016-03-01

In this article we present a model for Salmonella contamination of pig carcasses in the slaughterhouse. This model forms part of a larger QMRA (quantitative microbial risk assessment) on Salmonella in slaughter and breeder pigs, which uses a generic model framework that can be parameterized for European member states, to describe the entire chain from farm-to-consumption and the resultant human illness. We focus on model construction, giving mathematical formulae to describe Salmonella concentrations on individual pigs and slaughter equipment at different stages of the slaughter process. Variability among individual pigs and over slaughterhouses is incorporated using statistical distributions, and simulated by Monte Carlo iteration. We present the results over the various slaughter stages and show that such a framework is especially suitable to investigate the effect of various interventions. In this article we present the results of the slaughterhouse module for two case study member states. The model outcome represents an increase in average prevalence of Salmonella contamination and Salmonella numbers at dehairing and a decrease of Salmonella numbers at scalding. These results show good agreement when compared to several other QMRAs and microbiological studies. © 2016 Society for Risk Analysis.

Higher Storage Temperature Causes Greater Salmonella enterica Serovar Typhimurium Internal Penetration of Artificially Contaminated, Commercially Available, Washed Free Range Eggs.

PubMed

Whiley, Alice; Fallowfield, Howard; Ross, Kirstin; McEvoy, Vanessa; Whiley, Harriet

2016-07-01

Foodborne salmonellosis is a major public health concern, with contaminated eggs identified as a significant source of infection. In Australia, the most prevalent cause of salmonellosis from eggs is Salmonella enterica subsp. enterica serovar Typhimurium. This study explored the effect of temperature after 1, 7, 14, 21, and 28 days of storage on commercially available washed free range eggs, artificially contaminated with Salmonella Typhimurium on the external surface. At each time point, the external surface of the egg, the crushed eggshell, and the internal egg yolk and albumen were analyzed for Salmonella. After 28 days of storage, 25% of eggs stored at 4°C, 50% of eggs stored at 14°C, and 100% of eggs stored at 23 and 35°C were internally contaminated with Salmonella. After 1 day of storage, more than 50% of all eggs had Salmonella present in the crushed shell after the external surface had been disinfected with ethanol. This is the first study to demonstrate that refrigeration reduced the potential for Salmonella Typhimurium to penetrate the eggshell membrane and internally contaminate table eggs commercially available in Australia. It also suggests that the processes of cracking eggs may be a source of cross-contamination within the kitchen.

Analysis of Salmonella sp bacterial contamination on Vannamei Shrimp using binary logit model approach

NASA Astrophysics Data System (ADS)

Oktaviana, P. P.; Fithriasari, K.

2018-04-01

Mostly Indonesian citizen consume vannamei shrimp as their food. Vannamei shrimp also is one of Indonesian exports comodities mainstay. Vannamei shrimp in the ponds and markets could be contaminated by Salmonella sp bacteria. This bacteria will endanger human health. Salmonella sp bacterial contamination on vannamei shrimp could be affected by many factors. This study is intended to identify what factors that supposedly influence the Salmonella sp bacterial contamination on vannamei shrimp. The researchers used the testing result of Salmonella sp bacterial contamination on vannamei shrimp as response variable. This response variable has two categories: 0 = if testing result indicate that there is no Salmonella sp on vannamei shrimp; 1 = if testing result indicate that there is Salmonella sp on vannamei shrimp. There are four factors that supposedly influence the Salmonella sp bacterial contamination on vannamei shrimp, which are the testing result of Salmonella sp bacterial contamination on farmer hand swab; the subdistrict of vannamei shrimp ponds; the fish processing unit supplied by; and the pond are in hectare. This four factors used as predictor variables. The analysis used is Binary Logit Model Approach according to the response variable that has two categories. The analysis result indicates that the factors or predictor variables which is significantly affect the Salmonella sp bacterial contamination on vannamei shrimp are the testing result of Salmonella sp bacterial contamination on farmer hand swab and the subdistrict of vannamei shrimp ponds.

21 CFR 500.35 - Animal feeds contaminated with Salmonella microorganisms.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Animal feeds contaminated with Salmonella microorganisms. 500.35 Section 500.35 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Decisions § 500.35 Animal feeds contaminated with Salmonella microorganisms. (a) Investigations by the Food...

Examination of predictors of Salmonella enterica contamination in cattle feedlot environments

USDA-ARS?s Scientific Manuscript database

Objective: To identify a “predictor” or “environmental marker” that can be used to estimate Salmonella prevalence in a given feedlot environment. Further, to examine the correlation between environmental Salmonella contamination, Salmonella fecal shedding status, and prevalence of Salmonella in per...

Incidence of Salmonella contamination in broiler chickens in Saskatchewan.

PubMed

Bhargava, K K; O'Neil, J B; Prior, M G; Dunkelgod, K E

1983-01-01

The incidence of Salmonella contamination in ten Saskatchewan broiler flocks varying in size from 6 200 to 14 000 was investigated from February, 1977 to April, 1979. Prior to the initial chick placement, brooding equipment, feed, water and fresh litter samples were found to be free of Salmonellae. Samples obtained from the clean and disinfected processing plant equipment before the commencement of daily operation were negative except the isolation for Salmonella anatum from the fingers of the defeathering machine in flock 4. There was no evidence of Salmonella contamination in flocks 5, 6, 8 and 10. The incidence of Salmonella was lower when cloacal swabs were taken from day old chicks fasted for 48 hours than for the same groups of chicks when carcasses were blended in nutrient broth (flocks 7 and 9). The blending of such chicks appears to be a more critical test. The serotypes isolated from eviscerated birds were the same as those isolated from used litter samples. Salmonella saintpaul was isolated from a water sample at 53 days in flock 1 and the same serotype was recovered from the intestinal contents and skin of eviscerated birds. Salmonella typhimurium was recovered from the eviscerated birds and neck samples in flock 3. In flock 4, S. saintpaul and S. anatum were isolated from 13% of the eviscerated birds sampled. Salmonella thompson, Salmonella agona and Salmonella heidelberg were recovered from 61%, 5% and 1%, respectively, of the processed carcasses sampled in flock 7.

Incidence of Salmonella Contamination in Broiler Chickens in Saskatchewan

PubMed Central

Bhargava, K.K.; O'Neil, J.B.; Prior, M.G.; Dunkelgod, K.E.

1983-01-01

The incidence of Salmonella contamination in ten Saskatchewan broiler flocks varying in size from 6 200 to 14 000 was investigated from February, 1977 to April, 1979. Prior to the initial chick placement, brooding equipment, feed, water and fresh litter samples were found to be free of Salmonellae. Samples obtained from the clean and disinfected processing plant equipment before the commencement of daily operation were negative except the isolation for Salmonella anatum from the fingers of the defeathering machine in flock 4. There was no evidence of Salmonella contamination in flocks 5, 6, 8 and 10. The incidence of Salmonella was lower when cloacal swabs were taken from day old chicks fasted for 48 hours than for the same groups of chicks when carcasses were blended in nutrient broth (flocks 7 and 9). The blending of such chicks appears to be a more critical test. The serotypes isolated from eviscerated birds were the same as those isolated from used litter samples. Salmonella saintpaul was isolated from a water sample at 53 days in flock 1 and the same serotype was recovered from the intestinal contents and skin of eviscerated birds. Salmonella typhimurium was recovered from the eviscerated birds and neck samples in flock 3. In flock 4, S. saintpaul and S. anatum were isolated from 13% of the eviscerated birds sampled. Salmonella thompson, Salmonella agona and Salmonella heidelberg were recovered from 61%, 5% and 1%, respectively, of the processed carcasses sampled in flock 7. PMID:6831304

Oral immunisation of laying hens with the live vaccine strains of TAD Salmonella vac E and TAD Salmonella vac T reduces internal egg contamination with Salmonella Enteritidis.

PubMed

Gantois, Inne; Ducatelle, Richard; Timbermont, Leen; Boyen, Filip; Bohez, Lotte; Haesebrouck, Freddy; Pasmans, Frank; van Immerseel, Filip

2006-09-11

Eggs are a major source of human infections with Salmonella. Therefore controlling egg contamination in laying hen flocks is one of the main targets for control programmes. A study was carried out to assess the effect of oral vaccination with TAD Salmonella vac E, TAD Salmonella vac T and with both vaccines TAD Salmonella vac E and TAD Salmonella vac T, on colonization of the reproductive tract and internal egg contamination of laying hens with Salmonella Enteritidis. Three groups of 30 laying hens were vaccinated at 1 day, 6 weeks and 16 weeks of age with either one of the vaccine strains, or a combination of both vaccine strains, while a fourth group was left unvaccinated. At 24 weeks of age, the birds were intravenously challenged with 0.5 ml containing 5 x 10(7)cfu Salmonella Enteritidis PT4 S1400/94. The number of oviducts from which Salmonella was isolated, was significantly lower in the vaccinated than in the non-vaccinated hens at 3 weeks post-challenge. Significantly less egg contents were Salmonella positive in the birds vaccinated with TAD Salmonella vac E or TAD Salmonella vac T (12/105 batches of eggs in both groups) than in the unvaccinated birds (28/105 batches of eggs). Internal egg contamination in the hens vaccinated with both TAD Salmonella vac E and TAD Salmonella vac T was even more reduced, as over the whole experiment, only one batch of eggs was positive. In conclusion, these data indicate that vaccination of laying hens with these live vaccines could be considered as a valuable tool in controlling internal egg contamination.

Impact of Transport Crate Reuse and of Catching and Processing on Campylobacter and Salmonella Contamination of Broiler Chickens

PubMed Central

Slader, J.; Domingue, G.; Jørgensen, F.; McAlpine, K.; Owen, R. J.; Bolton, F. J.; Humphrey, T. J.

2002-01-01

The influence of transport, catching, and processing on contamination of broiler chickens with Salmonella and Campylobacter was investigated. Transport crates were reused with high frequency and were often still contaminated with Salmonella and Campylobacter when they arrived at the farm despite the fact that they were washed at the factory, and thus they were a potential route of infection. These organisms contaminated the feathers of previously Campylobacter- and Salmonella-negative birds going to the processing plant and were isolated from processed carcasses, albeit at a low frequency. The Campylobacter types which were the predominant organisms on the live birds when they arrived at the processing plant were not necessarily the types that were most frequently isolated from processed carcasses. This finding may reflect cross-contamination that occurred during processing or differences in the tolerance of the strains to the hostile environments that the bacteria experienced. The process of catching and putting the birds in crates significantly increased the chance of contamination with Campylobacter (P < 0.001). PMID:11823211

Role of systemic infection, cross contaminations and super-shedders in Salmonella carrier state in chicken.

PubMed

Menanteau, Pierrette; Kempf, Florent; Trotereau, Jerome; Virlogeux-Payant, Isabelle; Gitton, Edouard; Dalifard, Julie; Gabriel, Irene; Rychlik, Ivan; Velge, Philippe

2018-06-19

Carriage of Salmonella is often associated with a high level of bacterial excretion and generally occurs after a short systemic infection. However, we do not know whether this systemic infection is required or whether the carrier-state corresponds to continuous reinfection or real persistence in caecal tissue. The use of a Salmonella Enteritidis bamB mutant demonstrated that a carrier-state could be obtained in chicken in the absence of systemic infection. The development of a new infection model in isolator showed that a marked decrease in animal reinfection and host-to-host transmission between chicks led to a heterogeneity of S. Enteritidis excretion and colonization contrary to what was observed in cages. This heterogeneity of infection was characterized by the presence of super-shedders, which constantly disseminated Salmonella to the low-shedder chicks, mainly through airborne movements of contaminated dust particles. The presence of super-shedders, in the absence of host-to-host transmission, demonstrated that constant reinfection was not required to induce a carrier-state. Finally, our results suggest that low-shedder chicks do not have a higher capability to destroy Salmonella but instead can block initial Salmonella colonization. This new paradigm opens new avenues to improve understanding of the carrier-state mechanisms and to define new strategies to control Salmonella infections. This article is protected by copyright. All rights reserved. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

Improving Food Safety by Understanding the Evolution of Egg-contaminating Salmonella Enteritidis

USDA-ARS?s Scientific Manuscript database

Improving Food Safety by Understanding the Evolution of Egg-contaminating Salmonella Enteritidis Jean Guard, Veterinary Medical Officer U. S. Department of Agriculture, Athens, GA USA (jean.guard@ars.usda.gov) The curious case of egg contamination by Salmonella enterica serovar Enteritidis S. ...

Qualitative map of Salmonella contamination on the chicken carcass

USDA-ARS?s Scientific Manuscript database

Salmonella contamination of poultry is a global public health problem. The objective of this study was to map the distribution of Salmonella on the chicken carcass for the purpose of improving poultry inspection and food safety. Young chickens (n = 70) in the Cornish game hen class were obtained a...

Risk factors associated with Salmonella and Listeria monocytogenes contamination of produce fields.

PubMed

Strawn, Laura K; Gröhn, Yrjo T; Warchocki, Steven; Worobo, Randy W; Bihn, Elizabeth A; Wiedmann, Martin

2013-12-01

Identification of management practices associated with preharvest pathogen contamination of produce fields is crucial to the development of effective Good Agricultural Practices (GAPs). A cross-sectional study was conducted to (i) determine management practices associated with a Salmonella- or Listeria monocytogenes-positive field and (ii) quantify the frequency of these pathogens in irrigation and nonirrigation water sources. Over 5 weeks, 21 produce farms in New York State were visited. Field-level management practices were recorded for 263 fields, and 600 environmental samples (soil, drag swab, and water) were collected and analyzed for Salmonella and L. monocytogenes. Management practices were evaluated for their association with the presence of a pathogen-positive field. Salmonella and L. monocytogenes were detected in 6.1% and 17.5% of fields (n = 263) and 11% and 30% of water samples (n = 74), respectively. The majority of pathogen-positive water samples were from nonirrigation surface water sources. Multivariate analysis showed that manure application within a year increased the odds of a Salmonella-positive field (odds ratio [OR], 16.7), while the presence of a buffer zone had a protective effect (OR, 0.1). Irrigation (within 3 days of sample collection) (OR, 6.0), reported wildlife observation (within 3 days of sample collection) (OR, 6.1), and soil cultivation (within 7 days of sample collection) (OR, 2.9) all increased the likelihood of an L. monocytogenes-positive field. Our findings provide new data that will assist growers with science-based evaluation of their current GAPs and implementation of preventive controls that reduce the risk of preharvest contamination.

Risk Factors Associated with Salmonella and Listeria monocytogenes Contamination of Produce Fields

PubMed Central

Gröhn, Yrjo T.; Warchocki, Steven; Worobo, Randy W.; Bihn, Elizabeth A.; Wiedmann, Martin

2013-01-01

Identification of management practices associated with preharvest pathogen contamination of produce fields is crucial to the development of effective Good Agricultural Practices (GAPs). A cross-sectional study was conducted to (i) determine management practices associated with a Salmonella- or Listeria monocytogenes-positive field and (ii) quantify the frequency of these pathogens in irrigation and nonirrigation water sources. Over 5 weeks, 21 produce farms in New York State were visited. Field-level management practices were recorded for 263 fields, and 600 environmental samples (soil, drag swab, and water) were collected and analyzed for Salmonella and L. monocytogenes. Management practices were evaluated for their association with the presence of a pathogen-positive field. Salmonella and L. monocytogenes were detected in 6.1% and 17.5% of fields (n = 263) and 11% and 30% of water samples (n = 74), respectively. The majority of pathogen-positive water samples were from nonirrigation surface water sources. Multivariate analysis showed that manure application within a year increased the odds of a Salmonella-positive field (odds ratio [OR], 16.7), while the presence of a buffer zone had a protective effect (OR, 0.1). Irrigation (within 3 days of sample collection) (OR, 6.0), reported wildlife observation (within 3 days of sample collection) (OR, 6.1), and soil cultivation (within 7 days of sample collection) (OR, 2.9) all increased the likelihood of an L. monocytogenes-positive field. Our findings provide new data that will assist growers with science-based evaluation of their current GAPs and implementation of preventive controls that reduce the risk of preharvest contamination. PMID:24077713

Salmonella transfer during pilot plant scale washing and roller conveying of tomatoes.

PubMed

Wang, Haiqiang; Ryser, Elliot T

2014-03-01

Salmonella transfer during washing and roller conveying of inoculated tomatoes was quantified using a pilot scale tomato packing line equipped with plastic, foam, or brush rollers. Red round tomatoes (2.3 kg) were dip inoculated with Salmonella enterica serovar Typhimurium LT2 (avirulent) (4 log CFU/g), air dried for 2 h, and then washed in sanitizer-free water for 2 min. Inoculated tomatoes were then passed single file over a 1.5-m conveyor equipped with plastic, foam, or brush rollers followed by 25 previously washed uninoculated tomatoes. Tomato samples were collected after 2 min of both washing and roller conveying, with all 25 uninoculated tomatoes collected individually after conveying. Roller surface samples were collected before and after conveying the uninoculated tomatoes. Both tomato and surface samples were quantitatively examined for Salmonella by direct plating or membrane filtration using xylose lysine Tergitol 4 agar. Regardless of the roller type, Salmonella populations on inoculated tomatoes did not significantly (P < 0.05) decrease during contact with the roller conveyors. After conveying uninoculated tomatoes over contaminated foam rollers, 96% of the 25 tomatoes were cross-contaminated with Salmonella at >100 CFU per tomato. With plastic rollers, 24 and 76% of tomatoes were cross-contaminated with Salmonella at 10 to 100 and 1 to 10 CFU per tomato, respectively. In contrast, only 8% of 25 tomatoes were cross-contaminated with brush rollers with Salmonella populations of 1 to 10 CFU per tomato. Overall, cross-contamination was greatest with foam, followed by plastic and brush rollers (P < 0.05). Adding peroxyacetic acid or chlorine to the wash water significantly decreased cross-contamination during tomato conveying, with chlorine less effective in controlling Salmonella on foam compared with plastic and brush rollers.

Drinking water from dug wells in rural ghana--salmonella contamination, environmental factors, and genotypes.

PubMed

Dekker, Denise Myriam; Krumkamp, Ralf; Sarpong, Nimako; Frickmann, Hagen; Boahen, Kennedy Gyau; Frimpong, Michael; Asare, Renate; Larbi, Richard; Hagen, Ralf Matthias; Poppert, Sven; Rabsch, Wolfgang; Marks, Florian; Adu-Sarkodie, Yaw; May, Jürgen

2015-03-27

Salmonellosis is an important but neglected disease in sub-Saharan Africa. Food or fecal-oral associated transmissions are the primary cause of infections, while the role of waterborne transmission is unclear. Samples were collected from different dug wells in a rural area of Ghana and analyzed for contamination with bacteria, and with Salmonella in particular. In addition, temporal dynamics and riks factors for contamination were investigated in 16 wells. For all Salmonella isolates antibiotic susceptibility testing was performed, serovars were determined and strains from the same well with the same serovar were genotyped. The frequency of well water contamination with Gram-negative rod-shaped bacteria was 99.2% (n = 395). Out of 398 samples, 26 (6.5%) tested positive for Salmonella spp. The serovar distribution was diverse including strains not commonly isolated from clinical samples. Resistance to locally applied antibiotics or resistance to fluoroquinolones was not seen in the Salmonella isolates. The risk of Salmonella contamination was lower in wells surrounded by a frame and higher during the rainy season. The study confirms the overall poor microbiological quality of well water in a resource-poor area of Ghana. Well contamination with Salmonella poses a potential threat of infection, thus highlighting the important role of drinking water safety in infectious disease control.

Cold plasma rapid decontamination of food contact surfaces contaminated with Salmonella biofilms.

PubMed

Niemira, Brendan A; Boyd, Glenn; Sites, Joseph

2014-05-01

Cross-contamination of foods from persistent pathogen reservoirs is a known risk factor in processing environments. Industry requires a rapid, waterless, zero-contact, chemical-free method for removing pathogens from food contact surfaces. Cold plasma was tested for its ability to inactivate Salmonella biofilms. A 3-strain Salmonella culture was grown to form adherent biofilms for 24, 48, or 72 h on a test surface (glass slides). These were placed on a conveyor belt and passed at various line speeds to provide exposure times of 5, 10, or 15 s. The test plate was either 5 or 7.5 cm under a plasma jet emitter operating at 1 atm using filtered air as the feed gas. The frequency of high-voltage electricity was varied from 23 to 48 kHz. At the closer spacing (5 cm), cold plasma reduced Salmonella biofilms by up to 1.57 log CFU/mL (5 s), 1.82 log CFU/mL (10 s), and 2.13 log CFU/mL (15 s). Increasing the distance to 7.5 cm generally reduced the efficacy of the 15 s treatment, but had variable effects on the 5 and 10 s treatments. Variation of the high-voltage electricity had a greater effect on 10 and 15 s treatments, particularly at the 7.5 cm spacing. For each combination of time, distance, and frequency, Salmonella biofilms of 24, 48, and 72 h growth responded consistently with each other. The results show that short treatments with cold plasma yielded up to a 2.13 log reduction of a durable form of Salmonella contamination on a model food contact surface. This technology shows promise as a possible tool for rapid disinfection of materials associated with food processing. Pathogens such as Salmonella can form chemical-resistant biofilms, making them difficult to remove from food contact surfaces. A 15 s treatment with cold plasma reduced mature Salmonella biofilms by up to 2.13 log CFU/mL (99.3%). This contact-free, waterless method uses no chemical sanitizers. Cold plasma may therefore have a practical application for conveyor belts, equipment, and other food contact

Estimation of the rate of egg contamination from Salmonella-infected chickens.

PubMed

Arnold, M E; Martelli, F; McLaren, I; Davies, R H

2014-02-01

Salmonella enterica serovar Enteritidis (S. Enteritidis) is one of the most prevalent causes for human gastroenteritis and is by far the predominant Salmonella serovar among human cases, followed by Salmonella Typhimurium. Contaminated eggs produced by infected laying hens are thought to be the main source of human infection with S. Enteritidis throughout the world. Although previous studies have looked at the proportion of infected eggs from infected flocks, there is still uncertainty over the rate at which infected birds produce contaminated eggs. The aim of this study was to estimate the rate at which infected birds produce contaminated egg shells and egg contents. Data were collected from two studies, consisting of 15 and 20 flocks, respectively. Faecal and environmental sampling and testing of ovaries/caeca from laying hens were carried out in parallel with (i) for the first study, testing 300 individual eggs, contents and shells together and (ii) for the second study, testing 4000 eggs in pools of six, with shells and contents tested separately. Bayesian methods were used to estimate the within-flock prevalence of infection from the faecal and hen post-mortem data, and this was related to the proportion of positive eggs. Results indicated a linear relationship between the rate of contamination of egg contents and the prevalence of infected chickens, but a nonlinear (quadratic) relationship between infection prevalence and the rate of egg shell contamination, with egg shell contamination occurring at a much higher rate than that of egg contents. There was also a significant difference in the rate of egg contamination between serovars, with S. Enteritidis causing a higher rate of contamination of egg contents and a lower rate of contamination of egg shells compared to non-S. Enteritidis serovars. These results will be useful for risk assessments of human exposure to Salmonella-contaminated eggs. © 2013 Crown copyright. This article is published with the

Drinking Water from Dug Wells in Rural Ghana — Salmonella Contamination, Environmental Factors, and Genotypes

PubMed Central

Dekker, Denise Myriam; Krumkamp, Ralf; Sarpong, Nimako; Frickmann, Hagen; Boahen, Kennedy Gyau; Frimpong, Michael; Asare, Renate; Larbi, Richard; Hagen, Ralf Matthias; Poppert, Sven; Rabsch, Wolfgang; Marks, Florian; Adu-Sarkodie, Yaw; May, Jürgen

2015-01-01

Salmonellosis is an important but neglected disease in sub-Saharan Africa. Food or fecal-oral associated transmissions are the primary cause of infections, while the role of waterborne transmission is unclear. Samples were collected from different dug wells in a rural area of Ghana and analyzed for contamination with bacteria, and with Salmonella in particular. In addition, temporal dynamics and riks factors for contamination were investigated in 16 wells. For all Salmonella isolates antibiotic susceptibility testing was performed, serovars were determined and strains from the same well with the same serovar were genotyped. The frequency of well water contamination with Gram-negative rod-shaped bacteria was 99.2% (n = 395). Out of 398 samples, 26 (6.5%) tested positive for Salmonella spp. The serovar distribution was diverse including strains not commonly isolated from clinical samples. Resistance to locally applied antibiotics or resistance to fluoroquinolones was not seen in the Salmonella isolates. The risk of Salmonella contamination was lower in wells surrounded by a frame and higher during the rainy season. The study confirms the overall poor microbiological quality of well water in a resource-poor area of Ghana. Well contamination with Salmonella poses a potential threat of infection, thus highlighting the important role of drinking water safety in infectious disease control. PMID:25826395

Bacteriophages safely reduce Salmonella contamination in pet food and raw pet food ingredients.

PubMed

Soffer, Nitzan; Abuladze, Tamar; Woolston, Joelle; Li, Manrong; Hanna, Leigh Farris; Heyse, Serena; Charbonneau, Duane; Sulakvelidze, Alexander

2016-01-01

Contamination of pet food with Salmonella is a serious public health concern, and several disease outbreaks have recently occurred due to human exposure to Salmonella tainted pet food. The problem is especially challenging for raw pet foods (which include raw meats, seafood, fruits, and vegetables). These foods are becoming increasingly popular because of their nutritional qualities, but they are also more difficult to maintain Salmonella -free because they lack heat-treatment. Among various methods examined to improve the safety of pet foods (including raw pet food), one intriguing approach is to use bacteriophages to specifically kill Salmonella serotypes. At least 2 phage preparations (SalmoFresh® and Salmonelex™) targeting Salmonella are already FDA cleared for commercial applications to improve the safety of human foods. However, similar preparations are not yet available for pet food applications. Here, we report the results of evaluating one such preparation (SalmoLyse®) in reducing Salmonella levels in various raw pet food ingredients (chicken, tuna, turkey, cantaloupe, and lettuce). Application of SalmoLyse® in low (ca. 2-4×10 6 PFU/g) and standard (ca. 9×10 6 PFU/g) concentrations significantly ( P < 0.01) reduced (by 60-92%) Salmonella contamination in all raw foods examined compared to control treatments. When SalmoLyse®-treated (ca. 2×10 7 PFU/g) dry pet food was fed to cats and dogs, it did not trigger any deleterious side effects in the pets. Our data suggest that the bacteriophage cocktail lytic for Salmonella can significantly and safely reduce Salmonella contamination in various raw pet food ingredients.

Bacteriophages safely reduce Salmonella contamination in pet food and raw pet food ingredients

PubMed Central

Soffer, Nitzan; Abuladze, Tamar; Woolston, Joelle; Li, Manrong; Hanna, Leigh Farris; Heyse, Serena; Charbonneau, Duane; Sulakvelidze, Alexander

2016-01-01

ABSTRACT Contamination of pet food with Salmonella is a serious public health concern, and several disease outbreaks have recently occurred due to human exposure to Salmonella tainted pet food. The problem is especially challenging for raw pet foods (which include raw meats, seafood, fruits, and vegetables). These foods are becoming increasingly popular because of their nutritional qualities, but they are also more difficult to maintain Salmonella-free because they lack heat-treatment. Among various methods examined to improve the safety of pet foods (including raw pet food), one intriguing approach is to use bacteriophages to specifically kill Salmonella serotypes. At least 2 phage preparations (SalmoFresh® and Salmonelex™) targeting Salmonella are already FDA cleared for commercial applications to improve the safety of human foods. However, similar preparations are not yet available for pet food applications. Here, we report the results of evaluating one such preparation (SalmoLyse®) in reducing Salmonella levels in various raw pet food ingredients (chicken, tuna, turkey, cantaloupe, and lettuce). Application of SalmoLyse® in low (ca. 2–4×106 PFU/g) and standard (ca. 9×106 PFU/g) concentrations significantly (P < 0.01) reduced (by 60–92%) Salmonella contamination in all raw foods examined compared to control treatments. When SalmoLyse®-treated (ca. 2×107 PFU/g) dry pet food was fed to cats and dogs, it did not trigger any deleterious side effects in the pets. Our data suggest that the bacteriophage cocktail lytic for Salmonella can significantly and safely reduce Salmonella contamination in various raw pet food ingredients. PMID:27738557

Sources of Salmonella on broiler carcasses during transportation and processing: modes of contamination and methods of control.

PubMed

Corry, Janet E L; Allen, V M; Hudson, W R; Breslin, M F; Davies, R H

2002-01-01

The prevalence and types of salmonella in broiler chickens during transportation and during slaughter and dressing were studied. This was part of a comprehensive investigation of salmonellas in two UK poultry companies, which aimed to find the origins and mechanisms of salmonella contamination. Salmonellas were isolated using cultural methods. Serovars of Salmonella detected during rearing were usually also found in a small proportion of birds on the day of slaughter and on the carcasses at various points during processing. There was little evidence of salmonellas spreading to large numbers of carcasses during processing. Many serovars found in the feedmills or hatcheries were also detected in the birds during rearing and/or slaughter. Transport crates were contaminated with salmonellas after washing and disinfection. Prevalence of salmonellas fell in the two companies during this survey. A small number of serovars predominated in the processing plants of each company. These serovars originated from the feed mills. Reasons for transport crate contamination were: (1) inadequate cleaning, resulting in residual faecal soiling; (2) disinfectant concentration and temperature of disinfectant too low; (3) contaminated recycled flume water used to soak the crates. Efforts to control salmonella infection in broilers need to concentrate on crate cleaning and disinfection and hygiene in the feed mills.

[Study on simultaneous contamination of Salmonella and Campylobacter in retail chicken carcasses in Beijing].

PubMed

Hu, Yujie; Wang, Yeru; Li, Fengqin

2015-01-01

To elucidate the simultaneous contamination of Salmonella and Campylobacter in retail chicken carcasses in Beijing and to carry out the serological typing of all Salmonella isolates as well as the identification of Campylobacter at the species level. A total of 33 chicken carcasses were collected from Beijing supermarkets and farm's trade markets from May to July. All samples were enumerated for Salmonella and Campylobacter. All Salmonella isolates obtained were further serotyped and Campylobacter were identified at the species level. Totally, 19 samples (19/33, 57.6%) and 5 samples (5/33, 15.2%) were positive for Salmonella with the mean level of 119.4 MPN/100g and Campylobacter with the mean level of 58.6 CFU/g, respectively. In terms of Salmonella, 166 isolates with 14 serotypes were obtained. Salmonella Enteritidis was the most common serovar detected followed by S. Indiana. Serovar diversity was very high in all Salmonella isolates and various Salmonella serovars were detected in the same chicken carcass. A total of 11 serovar distribution spectrums were found and S. Enteritidis in combination with S. Indiana was the predominant. The retail chicken carcasses in Beijing collected from May to July were heavily contaminated by Salmonella with high serovar diversity.

Assessing tissue colonization and egg contamination by Salmonella Oranienburg in laying hens

USDA-ARS?s Scientific Manuscript database

Transmission of Salmonella into table eggs could be via trans-ovarian (vertical) or trans-shell (horizontal) routes. CDC reported a multi state outbreak in the Midwest (2016) from consumption of eggs contaminated with Salmonella Oranienburg (SO), and this strain was closely related genetically to a ...

Salmonella and raw shell eggs: results of a cross-sectional study of contamination rates and egg safety practices in the United Kingdom catering sector in 2003.

PubMed

Elson, R; Little, C L; Mitchell, R T

2005-02-01

This study was prompted by epidemiological investigations of the unusual number of Salmonella Enteritidis outbreaks associated with the use of eggs in catering premises in England and Wales during 2002. The aims of the study, performed between April and May 2003, were to establish the rate of Salmonella contamination in raw shell eggs from catering premises, investigate any correlation between the origin and type of eggs and the presence of particular serotypes or phage types (PTs) of Salmonella, and examine the use of raw shell eggs in catering premises in the United Kingdom. A total of 34,116 eggs (5,686 pooled samples of six eggs) were collected from 2,104 catering premises, most of which were eggs produced in the United Kingdom (88%). Salmonella was isolated from 17 pools (0.3%) of eggs. Of these, 15 were Salmonella Enteritidis, which were further characterized to PTs as follows: PT6 (0.1%), PT4 (0.07%), PT12 (0.04%), PT1 (0.04%), and PT14b (0.02%). Salmonella Livingstone and Salmonella Typhimurium definitive type 7 resistant to ampicillin, streptomycin, sulfonamides, and tetracycline were also isolated. The Salmonella contamination rate of eggs produced in the United Kingdom appears to have decreased significantly since 1995 and 1996. This trend is reflected in the decrease of Salmonella Enteritidis and, in particular, Salmonella Enteritidis PT4. The impact of the United Kingdom Food Standards Agency's advice on the use of eggs, issued in January 2003, is discussed.

9 CFR 113.30 - Detection of Salmonella contamination.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Detection of Salmonella contamination. 113.30 Section 113.30 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... collected from the bulk suspension before bacteriostatic or bactericidal agents have been added. When tissue...

9 CFR 113.30 - Detection of Salmonella contamination.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Detection of Salmonella contamination. 113.30 Section 113.30 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... collected from the bulk suspension before bacteriostatic or bactericidal agents have been added. When tissue...

9 CFR 113.30 - Detection of Salmonella contamination.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Detection of Salmonella contamination. 113.30 Section 113.30 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... collected from the bulk suspension before bacteriostatic or bactericidal agents have been added. When tissue...

Application of bacteriophages to reduce Salmonella contamination on workers' boots in rendering-processing environment.

PubMed

Gong, C; Jiang, X; Wang, J

2017-10-01

Workers' boots are considered one of the re-contamination routes of Salmonella for rendered meals in the rendering-processing environment. This study was conducted to evaluate the efficacy of a bacteriophage cocktail for reducing Salmonella on workers' boots and ultimately for preventing Salmonella re-contamination of rendered meals. Under laboratory conditions, biofilms of Salmonella Typhimurium avirulent strain 8243 formed on rubber templates or boots were treated with a bacteriophage cocktail of 6 strains (ca. 9 log PFU/mL) for 6 h at room temperature. Bacteriophage treatments combined with sodium hypochlorite (400 ppm) or 30-second brush scrubbing also were investigated for a synergistic effect on reducing Salmonella biofilms. Sodium magnesium (SM) buffer and sodium hypochlorite (400 ppm) were used as controls. To reduce indigenous Salmonella on workers' boots, a field study was conducted to apply a bacteriophage cocktail and other combined treatments 3 times within one wk in a rendering-processing environment. Prior to and after bacteriophage treatments, Salmonella populations on the soles of rubber boots were swabbed and enumerated on XLT-4, Miller-Mallinson or CHROMagar™ plates. Under laboratory conditions, Salmonella biofilms formed on rubber templates and boots were reduced by 95.1 to 99.999% and 91.5 to 99.2%, respectively. In a rendering-processing environment (ave. temperature: 19.3°C; ave. relative humidity: 48%), indigenous Salmonella populations on workers' boots were reduced by 84.2, 92.9, and 93.2% after being treated with bacteriophages alone, bacteriophages + sodium hypochlorite, and bacteriophages + scrubbing for one wk, respectively. Our results demonstrated the effectiveness of bacteriophage treatments in reducing Salmonella contamination on the boots in both laboratory and the rendering-processing environment. © 2017 Poultry Science Association Inc.

Cross-contamination versus undercooking of poultry meat or eggs - which risks need to be managed first?

PubMed

Luber, Petra

2009-08-31

Epidemiological studies show that poultry meat and eggs are important sources for consumers' exposure to pathogens such as Salmonella and Campylobacter. There is a focus in many countries to reduce the level of human illness from food-borne pathogens. Reduction of the prevalence of contaminated poultry meat or eggs is one major area of focus. The other is risk communication to the consumer, where information aimed at changing the food preparation behaviour has been utilised as a risk management tool. The efficacy of messages such as 'cook poultry meat and eggs thoroughly' or 'wash your hands' will depend both on the ability to change consumer behaviour as well as where the risk can best be mitigated. In order to prioritise what message should be given to the consumer, the relative contribution of different exposure pathways finally leading to ingestion of the pathogens and resulting in illness needs to be known. It is important to know whether cross-contamination events or undercooking are the greatest risk lurking in consumers' kitchens. A review of studies looking at the location of pathogens in food products has been performed and data regarding internal and external (surface) contamination of poultry meat with Salmonella spp. and Campylobacter jejuni and C. coli is presented. In the case of eggs, data on internal contamination with Salmonella and for contamination of egg shells with Salmonella and Campylobacter are discussed. The results from published risk assessments for these pathogen-food commodity combinations have been evaluated and conclusions regarding the relative risk of internal and external contamination of poultry meat and eggs were drawn. In conclusion, cross-contamination events from activities such as use of the same cutting board for chicken meat and salad without intermediate cleaning or spreading of pathogens via the kitchen environment seem to be of greater importance than the risk associated with undercooking of poultry meat or eggs. Risk

Salmonella Enteritidis infections associated with a contaminated immersion blender at a cAMP.

PubMed

Daly, Elizabeth R; Smith, Colleen M; Wikoff, Peter; Seiferth, John; Finnigan, Jayne; Nadeau, Alisha M; Welch, Joyce J

2010-09-01

More than 100 foodborne salmonellosis outbreaks occur each year in the United States. Contaminated food preparation equipment is implicated in approximately 32% of Salmonella outbreaks with a known source. In April 2009, we investigated reported Salmonella infections at a camp in New Hampshire. Camp attendees were contacted to complete a standard questionnaire. The questionnaire asked about foods eaten while at the camp, symptoms of gastrointestinal illness, visits to healthcare providers, and specimen submission for pathogen testing. Laboratory and environmental investigations were conducted, including testing of foods and food preparation equipment. A total of 133 ill persons, including 47 laboratory-confirmed Salmonella Enteritidis infections, were identified during this investigation. A total of 142 (80%) of 178 camp attendees completed a standard questionnaire and 109 cases of gastrointestinal illness and 33 healthy individuals were identified. Statistical analysis of survey data indicated that people who ate pudding were 15 times more likely to become ill with salmonellosis than those who did not eat pudding (risk ratio, 15.2; 95% confidence interval, 2.3-102.3). Salmonella Enteritidis was identified in leftover pudding and in the internal mixing components of the blender used to mix the pudding. All patient, food, and blender isolates exhibited the same pulsed-field gel electrophoresis pattern. This outbreak of Salmonella Enteritidis was caused by a Salmonella-contaminated hand-held immersion blender used to prepare pudding at a camp. A malfunctioning blender shaft seal is suspected to have resulted in contamination of the blender and subsequently pudding prepared using the blender.

A QMRA Model for Salmonella in Pork Products During Preparation and Consumption.

PubMed

Swart, A N; van Leusden, F; Nauta, M J

2016-03-01

As part of a quantitative microbiological risk assessment (QMRA) food chain model, this article describes a model for the consumer phase for Salmonella-contaminated pork products. Three pork products were chosen as a proxy for the entire pork product spectrum: pork cuts, minced meat patties, and fermented sausages. For pork cuts cross-contamination is considered the most important process and therefore it is modeled in detail. For minced meat, both cross-contamination and undercooking are the relevant processes. For those commodities bacterial growth during transport and storage is also modeled. Fermented sausages are eaten raw and the production may be defective. Variability between consumers' behavior and the impact of variability between production processes at the farm and abattoir are taken into account. Results indicate that Salmonella levels on products may increase significantly during transport and storage. Heating is very efficient at lowering concentrations, yet cross-contamination plays an important role in products that remain contaminated. For fermented sausage it is found that drying is important for Salmonella reduction. Sensitivity analysis revealed that cross- contamination factors "knife cleaning" and "preparation of a salad" are important parameters for pork cuts. For minced meat cleaning of the board, salad consumption, refrigerator temperature, and storage time were significant. © 2015 Society for Risk Analysis.

Airborne soil particulates as vehicles for Salmonella contamination of tomatoes.

PubMed

Kumar, Govindaraj Dev; Williams, Robert C; Al Qublan, Hamzeh M; Sriranganathan, Nammalwar; Boyer, Renee R; Eifert, Joseph D

2017-02-21

The presence of dust is ubiquitous in the produce growing environment and its deposition on edible crops could occur. The potential of wind-distributed soil particulate to serve as a vehicle for S. Newport transfer to tomato blossoms and consequently, to fruits, was explored. Blossoms were challenged with previously autoclaved soil containing S. Newport (9.39log CFU/g) by brushing and airborne transfer. One hundred percent of blossoms brushed with S. Newport-contaminated soil tested positive for presence of the pathogen one week after contact (P<0.0001). Compressed air was used to simulate wind currents and direct soil particulates towards blossoms. Airborne soil particulates resulted in contamination of 29% of the blossoms with S. Newport one week after contact. Biophotonic imaging of blossoms post-contact with bioluminescent S. Newport-contaminated airborne soil particulates revealed transfer of the pathogen on petal, stamen and pedicel structures. Both fruits and calyxes that developed from blossoms contaminated with airborne soil particulates were positive for presence of S. Newport in both fruit (66.6%) and calyx (77.7%). Presence of S. Newport in surface-sterilized fruit and calyx tissue tested indicated internalization of the pathogen. These results show that airborne soil particulates could serve as a vehicle for Salmonella. Hence, Salmonella contaminated dust and soil particulate dispersion could contribute to pathogen contamination of fruit, indicating an omnipresent yet relatively unexplored contamination route. Copyright © 2016 Elsevier B.V. All rights reserved.

78 FR 42451 - Animal Feeds Contaminated With Salmonella Microorganisms

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-16

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 500 [Docket No. FDA-2013-N-0253] Animal Feeds Contaminated With Salmonella Microorganisms AGENCY: Food and Drug Administration, HHS. ACTION: Final rule; removal. SUMMARY: The Food and Drug Administration (FDA or Agency) is...

Quantification of contamination levels and particular risk of Salmonella spp. in pigs in slaughterhouses in Chiang Mai and Lamphun provinces, Thailand.

PubMed

Tadee, Pakpoom; Boonkhot, Phacharaporn; Patchanee, Prapas

2014-11-01

Salmonella spp. is one of the important foodborne pathogens, and the slaughtering process is recognized as a potential point of contamination and the spread of the pathogens. The three objectives of this study are first, to quantify the contamination levels of Salmonella spp. in pig skins and carcasses, second, to evaluate the outcomes from different pig supply sources and different practices at three critical steps (scalding, splitting, and washing) for Salmonella spp. contamination, and third, to assess risk of Salmonella spp. contamination in pork products after slaughtering level. The study was performed in three representative slaughterhouses in Chiang Mai and Lamphun provinces, Thailand. Investigation conducted from May 2013 through October 2013 found the overall prevalence and contamination levels mean to be 11.85% and 0.34 MPN/cm2, respectively. There was no statistically significant in Salmonella spp. prevalence and contamination levels detected with different patterns at the slaughterhouses which were supplied pigs from either co-operative or integrated farms. Factors found to reduce Salmonella spp. loads on carcasses included good practices, e.g., regular changing of water in the scalding tank after each batch and the use of chlorine in the washing step. Risk of Salmonella spp. contamination of pork products at the final stage of slaughtering was nearly 10%. Good practices and proper hygiene measures should be applied to minimize the risk of Salmonella spp. exposure in the slaughtering line, which can reduce the contamination pressure downstream at retail shops as well as for end consumers.

Prevalence of Salmonella on retail broiler chicken meat carcasses in Colombia.

PubMed

Donado-Godoy, Pilar; Clavijo, Viviana; León, Maribel; Tafur, Mc Allister; Gonzales, Sebastian; Hume, Michael; Alali, Walid; Walls, Isabel; Lo Fo Wong, Danilo M A; Doyle, M P

2012-06-01

A cross-sectional study was performed to estimate the prevalence of Salmonella on retail market chicken carcasses in Colombia. A total of 1,003 broiler chicken carcasses from 23 departments (one city per department) were collected via a stratified sampling method. Carcass rinses were tested for the presence of Salmonella by conventional culture methods. Salmonella strains were isolated from 27 % of the carcasses sampled. Logistic regression analysis was used to determine potential risk factors for Salmonella contamination associated with the chicken production system (conventional versus free-range), storage condition (chilled versus frozen), retail store type (supermarket, independent, and wet market), poultry company (integrated company versus nonintegrated company), and socioeconomic stratum. Chickens from a nonintegrated poultry company were associated with a significantly (P < 0.05) greater risk of Salmonella contamination (odds ratio, 2.0) than were chickens from an integrated company. Chilled chickens had a significantly (P < 0.05) higher risk of Salmonella contamination (odds ratio, 4.3) than did frozen chicken carcasses.

Evaluation of an enhanced cleaning and disinfection protocol in Salmonella contaminated pig holdings in the United Kingdom

PubMed Central

Lambert, Mark; Butt, Paul; Cheney, Tanya; Tatone, Fabrizio Antonio; Callaby, Rebecca; Rabie, André; Gosling, Rebecca J.; Fordon, Steve; Crocker, Graham; Davies, Robert H.; Smith, Richard Piers

2017-01-01

Salmonella is the second most commonly reported zoonotic gastrointestinal pathogen in the European Union, and a significant proportion of the cases are linked to the consumption of contaminated pork. Reduction of Salmonella at the farm level helps to mininimise the contamination pressure at the slaughterhouse, and therefore the number of Salmonella bacteria entering the food chain. Cleaning and disinfection (C&D) between batches of pigs is an intervention measure that has potential to reduce the transmission of Salmonella contamination within farms. In this study, two pig finisher buildings in each of 10 Salmonella positive farms were sampled pre-C&D, post-C&D, post-restocking with the following batch of pigs, and shortly before these pigs were sent to slaughter. The incoming batch of pigs was also sampled before it reached the study building (pre-restocking). At each visit, pooled and individual faecal samples were collected and Salmonella isolation was carried out according to an ISO 6579:2002 Annex D-based method. One building on each farm (intervention) was cleaned and disinfected according to a rigorous protocol consisting of several steps and a Defra-approved disinfectant used at the General Orders concentration, whilst the other building (control) was cleaned and disinfected as per normal farm routine. At the post-C&D visit, Enterobacteriaceae and total bacterial counts were determined to evaluate residual faecal contamination and general hygiene levels. Rodent specialists visited the farms before and after C&D and rodent carcasses were collected for Salmonella testing. The intervention buildings were significantly less likely (p = 0.004) to be positive for Salmonella after C&D. The pre-restocking pigs had the highest likelihood (p<0.001) of being Salmonella positive (often with multiple serovars) and there was no significant difference between intervention and control buildings in Salmonella prevalence at the post-restocking visit (p = 0.199). However, the

Numbers of Salmonella enteritidis in the contents of naturally contaminated hens' eggs.

PubMed Central

Humphrey, T. J.; Whitehead, A.; Gawler, A. H.; Henley, A.; Rowe, B.

1991-01-01

Over 5700 hens eggs from 15 flocks naturally infected with Salmonella enteritidis were examined individually for the presence of the organism in either egg contents or on shells. Thirty-two eggs (0.6%) were positive in the contents. In the majority, levels of contamination were low. Three eggs, however, were found to contain many thousands of cells. In eggs where it was possible to identify the site of contamination, the albumen was more frequently positive than the yolk. Storage at room temperature had no significant effect on the prevalence of salmonella-positive eggs but those held for more than 21 days were more likely (P less than 0.01) to be heavily contaminated. In batches of eggs where both shells and contents were examined, 1.1% were positive on the former site and 0.9% in the latter. PMID:2050203

Prevalence and molecular profiles of Salmonella collected at a commercial turkey processing plant.

PubMed

Nde, Chantal W; Sherwood, Julie S; Doetkott, Curt; Logue, Catherine M

2006-08-01

In this study, whole carcasses were sampled at eight stages on a turkey-processing line and Salmonella prevalence was determined using enrichment techniques. Recovered Salmonella was further characterized using serotyping and the molecular profiles were determined using pulsed-field gel electrophoresis (PFGE). Prevalence data showed that contamination rates varied along the line and were greatest after defeathering and after chilling. Analysis of contamination in relation to serotypes and PFGE profiles found that on some visits the same serotype was present all along the processing line while on other days, additional serotypes were recovered that were not detected earlier on the line, suggesting that the birds harbored more than one serotype of Salmonella or there was cross-contamination occurring during processing. Overall, this study found fluctuations in Salmonella prevalence along a turkey-processing line. Following washing, Salmonella prevalence was significantly reduced, suggesting that washing is critical for Salmonella control in turkey processing and has significant application for controlling Salmonella at the postdefeathering and prechill stages where prevalence increased.

Integrated farm management to prevent Salmonella Enteritidis contamination of eggs

USDA-ARS?s Scientific Manuscript database

Salmonella Enteritidis (SE) in contaminated eggs is a public health hazard which may cause hospitalization or death in the elderly, infants, and individuals with impaired immune systems. Prevention of SE infection of laying hens is an essential first step in reducing SE outbreaks in humans. Multiple...

Assessment of cleaning and disinfection in Salmonella-contaminated poultry layer houses using qualitative and semi-quantitative culture techniques.

PubMed

Wales, Andrew; Breslin, Mark; Davies, Robert

2006-09-10

Salmonella infection of laying flocks in the UK is predominantly a problem of the persistent contamination of layer houses and associated wildlife vectors by Salmonella Enteritidis. Methods for its control and elimination include effective cleaning and disinfection of layer houses between flocks, and it is important to be able to measure the success of such decontamination. A method for the environmental detection and semi-quantitative enumeration of salmonellae was used and compared with a standard qualitative method, in 12 Salmonella-contaminated caged layer houses before and after cleaning and disinfection. The quantitative technique proved to have comparable sensitivity to the standard method, and additionally provided insights into the numerical Salmonella challenge that replacement flocks would encounter. Elimination of S. Enteritidis was not achieved in any of the premises examined although substantial reductions in the prevalence and numbers of salmonellae were demonstrated, whilst in others an increase in contamination was observed after cleaning and disinfection. Particular problems with feeders and wildlife vectors were highlighted. The use of a quantitative method assisted the identification of problem areas, such as those with a high initial bacterial load or those experiencing only a modest reduction in bacterial count following decontamination.

Survey of Salmonella contamination in chicken layer farms in three Caribbean countries.

PubMed

Adesiyun, Abiodun; Webb, Lloyd; Musai, Lisa; Louison, Bowen; Joseph, George; Stewart-Johnson, Alva; Samlal, Sannandan; Rodrigo, Shelly

2014-09-01

This study was conducted to investigate the demography, management, and production practices on layer chicken farms in Trinidad and Tobago, Grenada, and St. Lucia and the frequency of risk factors for Salmonella infection. The frequency of isolation of Salmonella from the layer farm environment, eggs, feeds, hatchery, and imported day-old chicks was determined using standard methods. Of the eight risk factors (farm size, age group of layers, source of day-old chicks, vaccination, sanitation practices, biosecurity measures, presence of pests, and previous disease outbreaks) for Salmonella infection investigated, farm size was the only risk factor significantly associated (P = 0.031) with the prevalence of Salmonella; 77.8% of large farms were positive for this pathogen compared with 33.3 and 26.1% of medium and small farms, respectively. The overall isolation rate of Salmonella from 35 layer farms was 40.0%. Salmonella was isolated at a significantly higher rate (P < 0.05) from farm environments than from the cloacae. Only in Trinidad and Tobago did feeds (6.5% of samples) and pooled egg contents (12.5% of samples) yield Salmonella; however, all egg samples from hotels, hatcheries, and airports in this country were negative. Salmonella Anatum, Salmonella group C, and Salmonella Kentucky were the predominant serotypes in Trinidad and Tobago, Grenada, and St. Lucia, respectively. Although Salmonella infections were found in layer birds sampled, table eggs appear to pose minimal risk to consumers. However, the detection of Salmonella -contaminated farm environments and feeds cannot be ignored. Only 2.9% of the isolates belonged to Salmonella Enteritidis, a finding that may reflect the impact of changes in farm management and poultry production in the region.

Thermal inactivation of Salmonella Typhimurium on dressed chicken skin previously exposed to acidified sodium chlorite or carvacrol

USDA-ARS?s Scientific Manuscript database

Salmonella is a leading cause of foodborne illness, and live poultry is a main reservoir of this pathogen. Cross-contamination and transportation of contaminated poultry meat act as an important vehicle of Salmonella infections in humans. In this study, we assessed the effect of two antimicrobials:...

Assessment of contamination potential of lettuce by Salmonella enterica serovar Newport added to the plant growing medium.

PubMed

Bernstein, Nirit; Sela, Shlomo; Neder-Lavon, Sarit

2007-07-01

The capacity of Salmonella enterica serovar Newport to contaminate Romaine lettuce (Lactuca sativa L. cv. Nogal) via the root system was evaluated in 17-, 20-, and 33-day-old plants. Apparent internalization of Salmonella via the root to the above-ground parts was identified in 33- but not 17- or 20-day-old plants and was stimulated by root decapitation. Leaves of lettuce plants with intact and damaged roots harbored Salmonella at 500 +/- 120 and 5,130 +/- 440 CFU/g of leaf, respectively, at 2 days postinoculation but not 5 days later. These findings are first to suggest that Salmonella Newport can translocate from contaminated roots to the aerial parts of lettuce seedlings and propose that the process is dependent on the developmental stage of the plant.

Contaminated water delivery as a simple and effective method of experimental Salmonella infection.

PubMed

O'Donnell, Hope; Pham, Oanh H; Benoun, Joseph M; Ravesloot-Chávez, Marietta M; McSorley, Stephen J

2015-01-01

In most infectious disease models, it is assumed that gavage needle infection is the most reliable means of pathogen delivery to the GI tract. However, this methodology can cause esophageal tearing and induces stress in experimental animals, both of which have the potential to impact early infection and the subsequent immune response. C57BL/6 mice were orally infected with virulent Salmonella Typhimurium SL1344 either by intragastric gavage preceded by sodium bicarbonate, or by contamination of drinking water. We demonstrate that water contamination delivery of Salmonella is equivalent to gavage inoculation in providing a consistent model of infection. Furthermore, exposure of mice to contaminated drinking water for as little as 4 h allowed maximal mucosal and systemic infection, suggesting an abbreviated window exists for natural intestinal entry. Together, these data question the need for gavage delivery for infection with oral pathogens.

Bioelectronic Nose Using Odorant Binding Protein-Derived Peptide and Carbon Nanotube Field-Effect Transistor for the Assessment of Salmonella Contamination in Food.

PubMed

Son, Manki; Kim, Daesan; Kang, Jinkyung; Lim, Jong Hyun; Lee, Seung Hwan; Ko, Hwi Jin; Hong, Seunghun; Park, Tai Hyun

2016-12-06

Salmonella infection is the one of the major causes of food borne illnesses including fever, abdominal pain, diarrhea, and nausea. Thus, early detection of Salmonella contamination is important for our healthy life. Conventional detection methods for the food contamination have limitations in sensitivity and rapidity; thus, the early detection has been difficult. Herein, we developed a bioelectronic nose using a carbon nanotube (CNT) field-effect transistor (FET) functionalized with Drosophila odorant binding protein (OBP)-derived peptide for easy and rapid detection of Salmonella contamination in ham. 3-Methyl-1-butanol is known as a specific volatile organic compound, generated from the ham contaminated with Salmonella. We designed and synthesized the peptide based on the sequence of the Drosophila OBP, LUSH, which specifically binds to alcohols. The C-terminus of the synthetic peptide was modified with three phenylalanine residues and directly immobilized onto CNT channels using the π-π interaction. The p-type properties of FET were clearly maintained after the functionalization using the peptide. The biosensor detected 1 fM of 3-methyl-1-butanol with high selectivity and successfully assessed Salmonella contamination in ham. These results indicate that the bioelectronic nose can be used for the rapid detection of Salmonella contamination in food.

Contaminated water delivery as a simple and effective method of experimental Salmonella infection

PubMed Central

O’Donnell, Hope; Pham, Oanh H.; Benoun, Joseph M.; Ravesloot-Chávez, Marietta M.; McSorley, Stephen J.

2016-01-01

Aims In most infectious disease models, it is assumed that gavage needle infection is the most reliable means of pathogen delivery to the gastrointestinal tract. However, this methodology can cause esophageal tearing and induces stress in experimental animals, both of which have the potential to impact early infection and the subsequent immune response. Materials and Methods C57BL/6 mice were orally infected with virulent Salmonella Typhimurium SL1344 either by intragastric gavage preceded by sodium bicarbonate, or by contamination of drinking water. Results We demonstrate that water contamination delivery of Salmonella is equivalent to gavage inoculation in providing a consistent model of infection. Furthermore, exposure of mice to contaminated drinking water for as little as 4 hours allowed maximal mucosal and systemic infection, suggesting an abbreviated window exists for natural intestinal entry. Conclusions Together, these data question the need for gavage delivery for infection with oral pathogens. PMID:26439708

Persistence and internalization of Salmonella on/in organic spinach sprout: exploring the contamination route

USDA-ARS?s Scientific Manuscript database

Purpose: The effects of contamination route, including seed and water, on the persistence and internalization of Salmonella in organic spinach cultivars- Lazio, Space, Emilia and Waitiki were studied. Methods: Seeds (1g) were contaminated with S. Newport using 10 ml of S. Newport-water suspension ov...

The relationship between the numbers of Salmonella Enteritidis, Salmonella Heidelberg, or Salmonella Hadar colonizing reproductive tissues of experimentally infected laying hens and deposition inside eggs.

PubMed

Gast, Richard K; Guraya, Rupa; Guard, Jean; Holt, Peter S

2011-06-01

Contamination of eggs by Salmonella Enteritidis has been a prominent cause of human illness for several decades and is the focus of a recently implemented national regulatory plan for egg-producing flocks in the United States. Salmonella Heidelberg has also been identified as an egg-transmitted pathogen. The deposition of Salmonella strains inside eggs is a consequence of reproductive tract colonization in infected laying hens, but prior research has not determined the relationship between the numbers of Salmonella that colonize reproductive organs and the associated frequency of egg contamination. In the present study, groups of laying hens in two trials were experimentally infected with large oral doses of strains of Salmonella Enteritidis (phage type 13a), Salmonella Heidelberg, or Salmonella Hadar. Reproductive tissues of selected hens were cultured to detect and enumerate Salmonella at 5 days postinoculation, and the interior contents of eggs laid between 6 and 25 days postinoculation were tested for contamination. Significantly more internally contaminated eggs were laid by hens infected with Salmonella Enteritidis (3.58%) than with strains of either Salmonella Heidelberg (0.47%) or Salmonella Hadar (0%). However, no significant differences were observed between Salmonella strains in either isolation frequency or the number of colony-forming units (CFU) isolated from ovaries or oviducts. Salmonella isolation frequencies ranged from 20.8% to 41.7% for ovaries and from 8.3% to 33.3% for oviducts. Mean Salmonella colonization levels ranged from 0.10 to 0.51 log CFU/g for ovaries and from 0.25 to 0.46 log CFU/g for oviducts. Although parallel rank-orders were observed for Salmonella enumeration (in both ovaries and oviducts) and egg contamination frequency, a statistically significant relationship could not be established between these two parameters of infection.

A comparison between broiler chicken carcasses with and without visible faecal contamination during the slaughtering process on hazard identification of Salmonella spp.

PubMed

Jiménez, S M; Salsi, M S; Tiburzi, M C; Pirovani, M E

2002-01-01

A comparison of the prevalence of Salmonella in chicken carcasses with and without visible faecal contamination during commercial slaughter practice was made. The relationship between Enterobacteriaceae, coliform and Escherichia coli counts and Salmonella status was also evaluated to establish the likelihood of using these groups as 'index' organisms to predict the presence of pathogen. Samples were removed immediately after evisceration, after the inside-outside shower and after chilling from the processing line for microbiological analysis. Of the carcasses visibly uncontaminated with faeces after the evisceration step 20% harboured salmonellas and 20.8% of the visibly contaminated carcasses were positive for the pathogen. When E. coli, coliforms and Enterobacteriaceae were used as predictor variables the error rates ranged from 33.3 to 60% for both sample types. There was no indication that any of the groups of organisms analysed could predict the incidence of salmonellas on the samples studied. Positive results for the pathogen were obtained at every tested step of the slaughtering process regardless of whether or not faecal contamination was present. The present study demonstrated that carcasses not visibly contaminated with faeces carried Salmonella as well as the visibly contaminated carcasses.

International outbreak of Salmonella Eastbourne infection traced to contaminated chocolate.

PubMed

Craven, P C; Mackel, D C; Baine, W B; Barker, W H; Gangarosa, E J

1975-04-05

Between Dec. 4, 1973, and Feb. 15, 1974, 80 cases of infection due to Salmonella eastbourne, previously a rare isolated serotype in the United States, were reported from twenty-three States. An additional 39 cases were reported from seven Provinces in Canada during a similar period. A telephone case-control study implicated Christmas-wrapped chocolate balls manufactured by a Canadian company as the vehicle of transmission. S. eastbourne was subsequently isolated from several samples of leftover chocolate balls obtained from homes where cases occurred. Investigation of the factory revealed that the contaminated Christmas and Easter chocolates, and a few chocolate items for year-round sale, had been produced between May and October, 1973. Bacteriological testing of samples taken at the plant implicated cocoa beans as the probable source of the salmonella organisms which, in the low-moisture chocolate, were able to survive heating during production. This outbreak and the finding of salmonella of other serotypes in chocolates produced by another manufacturer suggest that chocolate-related salmonellosis may be a significant public-health problem.

Survival of Salmonella Copenhagen in food bowls following contamination with experimentally inoculated raw meat: Effects of time, cleaning, and disinfection

PubMed Central

Weese, J Scott; Rousseau, J.

2006-01-01

There are concerns regarding the safety of feeding raw meat to household pets. This study demonstrated that Salmonella persists in food bowls that are inoculated with Salmonella-containing raw meat. Standard methods of cleaning and disinfection were minimally effective at eliminating Salmonella contamination. PMID:17017654

Contamination by Salmonella spp., Campylobacter spp. and Listeria spp. of most popular chicken- and pork-sausages sold in Reunion Island.

PubMed

Trimoulinard, A; Beral, M; Henry, I; Atiana, L; Porphyre, V; Tessier, C; Leclercq, A; Cardinale, E

2017-06-05

One of the most popular meat products of the local "cuisine" is sausage composed with 100% chicken or 100% pork. In this study, we aimed to determine the presence of Salmonella spp., Campylobacter spp. and Listeria spp. in chicken- and pork-sausages, quantify Salmonella spp. population and identify the factors that could be associated with contamination in the outlets. Two hundred and three batches of pork and chicken sausages were randomly collected from 67 local outlets (supermarkets, groceries and butcher shops). Salmonella spp. was detected in 11.8% (95% confidence interval (CI): [10.0; 13.5]) of samples, Campylobacter spp. in 1.5% [0.7; 4.2] and Listeria monocytogenes in 5.9% [4.4; 7.3]. Most probable number of Salmonella spp. varied between 6cfu per gram to 320cfu per gram. Salmonella serotypes isolated from pork and chicken sausages were S. Typhimurium (45.8%), S. London (20.8%), S. Derby (16.7%), S. Newport (8.33%), S. Blockley (4.2%) and S. Weltevreden (4.17%). Using a logistic (mixed-effect) regression model, we found that Salmonella spp. contamination was positively associated with sausages sold in papers or plastic bags and no control of rodents. Chicken sausages were associated with a decreasing risk of Salmonella contamination. Listeria monocytogenes contamination was positively associated with the presence of fresh rodent droppings in the outlet and negatively when the staff was cleaning regularly their hands with soap and water or water only. All the sampled outlets of Reunion Island were not equivalent in terms of food safety measures. Increasing awareness of these traders remains a cornerstone to limit the presence of Salmonella spp. and Listeria spp. in sausages, particularly in a tropical context (high temperature and humidity). Copyright © 2017 Elsevier B.V. All rights reserved.

Isolation of Salmonella Virchow from a fruit bat (Pteropus giganteus).

PubMed

Islam, Ausraful; Mikolon, Andrea; Mikoleit, Matthew; Ahmed, Dilruba; Khan, Salah Udddin; Sharker, M A Yushuf; Hossain, M Jahangir; Islam, Ariful; Epstein, Jonathan H; Zeidner, Nord; Luby, Stephen P

2013-12-01

Detection of zoonotic pathogens carried by bats is important both for understanding disease ecology and for developing preventive measures. Pteropus fruit bats have been identified as potential carriers of Salmonella enterica serotype Typhi. A cross-sectional study was conducted to determine the prevalence of Salmonella Typhi and other Salmonella serotypes in Pteropus giganteus fruit bats in Bangladesh. Rectal swabs were collected from 302 bats and cultured for Salmonella species. The bats were trapped in three districts (Faridpur, Rajbari, and Cox's Bazar). Salmonella Typhi was not found but one juvenile female bat from Faridpur district was positive for Salmonella Virchow. Close associations between frugivorous bats, humans, and livestock in rural Bangladesh make it likely that the bat was infected by consuming contaminated water.

Chemical additive to enhance antimicrobial efficacy of chlorine and control cross-contamination during immersion chill of broiler carcasses.

PubMed

Schambach, B T; Berrang, M E; Harrison, M A; Meinersmann, R J

2014-09-01

Immersion chilling of broiler carcasses can be a site for cross-contamination between the occasional highly contaminated carcass and those that are co-chilled. Chlorine is often used as an antimicrobial but can be overcome by organic material. A proprietary chlorine stabilizer (T-128) based on phosphoric acid-propylene glycol was tested as a chill tank additive in experiments simulating commercial broiler chilling. In bench-scale experiments, 0.5% T-128 was compared with plain water (control), 50 ppm of chlorine, and the combination of 0.5% T-128 with 50 ppm of chlorine to control transfer of Salmonella and Campylobacter from inoculated wing drummettes to co-chilled uninoculated drummettes. Both chlorine and T-128 lessened cross-contamination with Salmonella (P < 0.05); T-128 and T-128 with chlorine were significantly more effective (P < 0.05) than the control or plain chlorine for control of Campylobacter. T-128 treatments were noted to have a pH of less than 4.0; an additional experiment demonstrated that the antimicrobial effect of T-128 was not due merely to a lower pH. In commercial broiler chilling, a pH close to 6.0 is preferred to maximize chlorine effectiveness, while maintaining water-holding capacity of the meat. In a set of pilot-scale experiments with T-128, a near-ideal pH of 6.3 was achieved by using tap water instead of the distilled water used in bench-scale experiments. Pilot-scale chill tanks were used to compare the combination of 0.5% T-128 and 50 ppm of chlorine with 50 ppm of plain chlorine for control of cross-contamination between whole carcasses inoculated with Salmonella and Campylobacter and co-chilled uninoculated carcasses. The T-128 treatment resulted in significantly less crosscontamination by either direct contact or water transfer with both organisms compared with plain chlorine treatment. T-128 may have use in commercial broiler processing to enhance the effectiveness of chlorine in processing water.

Evaluation of Salmonella biofilm cell transfer from contact surfaces to beef products

USDA-ARS?s Scientific Manuscript database

Introduction: Meat contamination by Salmonella enterica is a serious food safety concern. One common transmission route that leads to cross contamination in meat plants is bacteria transfer from biofilms on contact surfaces to meat products via direct contact. Many factors could affect biofilm tra...

Factors influencing the growth of Salmonella during sprouting of naturally contaminated alfalfa seeds.

PubMed

Fu, Tong-Jen; Reineke, Karl F; Chirtel, Stuart; VanPelt, Olif M

2008-05-01

In this study, the factors that affect Salmonella growth during sprouting of naturally contaminated alfalfa seeds associated with two previous outbreaks of salmonellosis were examined. A minidrum sprouter equipped with automatic irrigation and rotation systems was built to allow sprouting to be conducted under conditions similar to those used commercially. The growth of Salmonella during sprouting in the minidrum was compared with that observed in sprouts grown in glass jars under conditions commonly used at home. The level of Salmonella increased by as much as 4 log units after 48 h of sprouting in jars but remained constant during the entire sprouting period in the minidrum. The effect of temperature and irrigation frequency on Salmonella growth was examined. Increasing the sprouting temperature from 20 to 30 degrees C increased the Salmonella counts by as much as 2 log units on sprouts grown both in the minidrum and in the glass jars. Decreasing the irrigation frequency from every 20 min to every 2 h during sprouting in the minidrum or from every 4 h to every 24 h during sprouting in the glass jars resulted in an approximately 2-log increase in Salmonella counts. The levels of total aerobic mesophilic bacteria, coliforms, and Salmonella in spent irrigation water closely reflected those found in sprouts, confirming that monitoring of spent irrigation water is a good way to monitor pathogen levels during sprouting.

Survey of Salmonella and Campylobacter contamination of whole, raw poultry on retail sale in Wales in 2003.

PubMed

Meldrum, R J; Tucker, I D; Smith, R M M; Edwards, C

2005-07-01

A survey of the Salmonella and Campylobacter contamination of raw, whole chickens available to consumers in Wales was performed between March and December 2003. In total, 736 samples were taken, and overall contamination rates of 73.1% for Campylobacter and 5.7% for Salmonella were found. This survey follows a survey performed during 2001 to 2002 by Welsh local authorities and the National Public Health Service for Wales that established updated baseline rates for both pathogens in raw, whole chicken available to consumers in Wales. This survey indicated no difference in Campylobacter rates between fresh and frozen samples or between samples taken from retailers and local butchers, but significant differences existed in Salmonella rates between fresh and frozen samples and between those sampled from retailers and butchers, with frozen chickens and samples taken from retailers having significantly higher rates. However, the difference in Salmonella isolation rate between retailers and butchers was found to be due to the differences in the proportions of fresh and frozen chickens sampled from these locations, with a significantly higher number of frozen chickens (with a higher Salmonella rate) being sampled from retailers.

Assessing the Public Health Impact and Effectiveness of Interventions To Prevent Salmonella Contamination of Sprouts.

PubMed

Ding, Hongliu; Fu, Tong-Jen

2016-01-01

Sprouts have been a recurring public health challenge due to microbiological contamination, and Salmonella has been the major cause of sprout-associated outbreaks. Although seed treatment and microbiological testing have been applied as risk reduction measures during sprout production, the extent to which their effectiveness in reducing the public health risks associated with sprouts has not been well investigated. We conducted a quantitative risk assessment to measure the risk posed by Salmonella contamination in sprouts and to determine whether and how mitigation strategies can achieve a satisfactory risk reduction based on the assumption that the risk reduction achieved by a microbiological sampling and testing program at a given sensitivity is equivalent to that achieved by direct inactivation of pathogens. Our results indicated that if the sprouts were produced without any risk interventions, the health impact caused by sprouts contaminated with Salmonella would be very high, with a median annual estimated loss of disability-adjusted life years (DALYs) of 691,412. Seed treatment (with 20,000 ppm of calcium hypochlorite) or microbiological sampling and testing of spent irrigation water (SIW) alone could reduce the median annual impact to 734 or 4,856 DALYs, respectively. Combining seed treatment with testing of the SIW would further decrease the risk to 58 DALYs. This number could be dramatically lowered to 3.99 DALYs if sprouts were produced under conditions that included treating seeds with 20,000 ppm of calcium hypochlorite plus microbiological testing of seeds, SIW, and finished products. Our analysis shows that the public health impact due to Salmonella contamination in sprouts could be controlled if seeds are treated to reduce pathogens and microbiological sampling and testing is implemented. Future advances in intervention strategies would be important to improve sprout safety further.

Salmonella DNA Adenine Methylase Mutants Confer Cross-Protective Immunity

PubMed Central

Heithoff, Douglas M.; Enioutina, Elena Y.; Daynes, Raymond A.; Sinsheimer, Robert L.; Low, David A.; Mahan, Michael J.

2001-01-01

Salmonella isolates that lack or overproduce DNA adenine methylase (Dam) elicited a cross-protective immune response to different Salmonella serovars. The protection afforded by the Salmonella enterica serovar Typhimurium Dam vaccine was greater than that elicited in mice that survived a virulent infection. S. enterica serovar Typhimurium Dam mutant strains exhibited enhanced sensitivity to mediators of innate immunity such as antimicrobial peptides, bile salts, and hydrogen peroxide. Also, S. enterica serovar Typhimurium Dam− vaccines were not immunosuppressive; unlike wild-type vaccines, they failed to induce increased nitric oxide levels and permitted a subsequent robust humoral response to diptheria toxoid antigen in infected mice. Dam mutant strains exhibited a low-grade persistence which, coupled with the nonimmunosuppression and the ectopic protein expression caused by altered levels of Dam, may provide an expanded source of potential antigens in vaccinated hosts. PMID:11598044

Interactions of Salmonella with animals and plants.

PubMed

Wiedemann, Agnès; Virlogeux-Payant, Isabelle; Chaussé, Anne-Marie; Schikora, Adam; Velge, Philippe

2014-01-01

Salmonella enterica species are Gram-negative bacteria, which are responsible for a wide range of food- and water-borne diseases in both humans and animals, thereby posing a major threat to public health. Recently, there has been an increasing number of reports, linking Salmonella contaminated raw vegetables and fruits with food poisoning. Many studies have shown that an essential feature of the pathogenicity of Salmonella is its capacity to cross a number of barriers requiring invasion of a large variety of cells and that the extent of internalization may be influenced by numerous factors. However, it is poorly understood how Salmonella successfully infects hosts as diversified as animals or plants. The aim of this review is to describe the different stages required for Salmonella interaction with its hosts: (i) attachment to host surfaces; (ii) entry processes; (iii) multiplication; (iv) suppression of host defense mechanisms; and to point out similarities and differences between animal and plant infections.

Salmonella contamination: a significant challenge to the global marketing of animal food products.

PubMed

L Plym, Forshell; Wierup, M

2006-08-01

Salmonellosis is the most common food-borne bacterial disease in the world. Salmonella is a significant pathogen for food-producing animals and these animals are the primary source of salmonellosis. It is estimated that herd prevalence varies between 0% and 90%, depending on the animal species and region. The pathogen is spread by trade in animals and non-heated animal food products. The emergence of strains that are resistant to antimicrobials, often as a result of antimicrobial usage in animals, is a public health hazard of great concern. It is increasingly accepted that the prevalence of Salmonella in animal production must be decreased and, in the European Union, plans to achieve this are currently being implemented. In this paper, the authors propose various risk mitigation strategies. Successful control must focus on a range of preventive actions because there is no simple 'silver bullet' solution to reduce Salmonella contamination. The authors conclude that the key to controlling Salmonella is to follow the general rules that have been successfully applied to other infectious diseases.

Salmonella typhimurium contamination of processed broiler chickens after a subclinical infection

PubMed Central

Knivett, V. A.

1971-01-01

A subclinical infection of Salmonella typhimurium in a broiler flock was investigated and attempts were made to eradicate the infection by treatment with furazolidone. One-quarter of the chickens were still infected after they had been through the processing plant. Washing in heavily chlorinated water reduced the number of contaminated carcasses. Infected chickens were also found in four other companion flocks on the same farm. PMID:4937856

Multiple typing for the epidemiological study of the contamination of broilers with Salmonella from the hatchery to the slaughterhouse.

PubMed

Heyndrickx, M; Herman, L; Vlaes, L; Butzler, J P; Wildemauwe, C; Godard, C; De Zutter, L

2007-02-01

Eighteen Belgian broiler flocks were followed from the hatchery to the slaughterhouse by a multiple typing approach (sero-, geno-, and phage types) for the investigation of the transmission of Salmonella and its subtypes. For 12 of the 18 flocks, there was no correlation between the serotypes found preharvest and those isolated from the feces in the transport crates and on the carcasses in the slaughterhouse. Serotypes found in the crates were usually also found on the carcasses. In 5 of the 10 flocks with Salmonella-positive broilers, complex contamination patterns with the involvement of different serotypes, genotypes, or both were revealed. In two of these flocks (flocks 8 and 9), the Salmonella Enteritidis contamination of the broilers could be traced to the hatchery. In flock 9, evidence was found for the acquisition, during rearing, of a megaplasmid in the Salmonella Enteritidis strain. In the other three positive flocks (flocks 6, 7, and 10), the environment and movable material (e.g., footwear) played a determining role in the infection and shedding pattern of the broilers. For flocks 6 and 7, reared consecutively in the same broiler house, a persistent Salmonella Hadar geno/phage type predominated in the preharvest period, while another Salmonella Hadar geno/phage type was found in the house or the environment but never in the broilers. Only for the above-mentioned five flocks were the same strains that were found preharvest also recovered from the carcasses, although these strains were not predominant on the carcasses, with the exception of one flock (flock 10). In conclusion, it can be said that most of the time, Salmonella strains that contaminate Belgian broiler carcasses do not predominate in the preharvest environment.

78 FR 42526 - Salmonella

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-16

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-D-0254] Salmonella Contamination of Dry Dog Food; Withdrawal of Compliance Policy Guide AGENCY: Food and Drug... entitled ``Sec. 690.700 Salmonella Contamination of Dry Dog Food (CPG 690.700)'' on October 1, 1980. CPG...

Transmission and control of Salmonella in the pig feed chain: a conceptual model.

PubMed

Binter, Claudia; Straver, Judith Maria; Häggblom, Per; Bruggeman, Geert; Lindqvist, Per-Anders; Zentek, Jürgen; Andersson, Mats Gunnar

2011-03-01

Infected breeder pigs and contaminated feed represent potential sources of Salmonella introduction to fattening pig herds and may thereby cause human infections acquired via consumption of contaminated pork. Modelling approaches such as quantitative microbial risk assessment could improve the design of strategies for control and tracing of Salmonella in the feed chain. However, the construction of such models requires a thorough understanding of the dynamics of the feed chain, including production processes, microbial processes and transport logistics. The present article illustrates a conceptual model of Salmonella in the pig feed chain and explores the possibilities for quantitative modelling including identifying major gaps in data. Information was collected from peer-reviewed scientific journals, official documents and reports and by means of interviews with experts from authorities and the feed industry. Data on prevalence of Salmonella in different parts of the feed chain are difficult to compare as observed prevalence may be biased by variations in sampling procedures as well as limitations of the detection methods. There are almost no data on numbers of Salmonella in commodities of the feed chain, which often makes it difficult to evaluate risks, intervention strategies and sampling plans in a quantitative manner. Tracing the source of Salmonella contamination is hampered by the risk of cross-contamination as well as various mixing and partitioning events along the supply chain, which sometimes makes it impossible to trace the origin of a lot back to a batch or producer. Available information points to contaminated feed materials, animal vectors and persistent contamination of production environments as important sources of Salmonella in feed production. Technological procedures such as hydrothermal or acid treatment can be used to control Salmonella in feed production. However, a large fraction of pig feed is produced without decontamination procedures

Reduction of salmonella on valencia oranges by cold plasma treatment

USDA-ARS?s Scientific Manuscript database

Orange juice has been the source of recurrent food borne illness outbreaks, primarily associated with Salmonella. There is a need for antimicrobial interventions which can effectively eliminate pathogens from fruit surfaces and reduce the risk of cross-contamination during peeling and processing. To...

Prevention of egg contamination by Salmonella Enteritidis after oral vaccination of laying hens with Salmonella Enteritidis ΔtolC and ΔacrABacrEFmdtABC mutants.

PubMed

Kilroy, Sofie; Raspoet, Ruth; Haesebrouck, Freddy; Ducatelle, Richard; Van Immerseel, Filip

2016-08-12

Vaccination of laying hens has been successfully used to reduce egg contamination by Salmonella Enteritidis, decreasing human salmonellosis cases worldwide. Currently used vaccines for layers are either inactivated vaccines or live attenuated strains produced by mutagenesis. Targeted gene deletion mutants hold promise for future vaccines, because specific bacterial functions can be removed that may improve safety and allow differentiation from field strains. In this study, the efficacy of Salmonella Enteritidis ΔtolC and ΔacrABacrEFmdtABC strains in laying hens as live vaccines was evaluated. The mutants are deficient in either the membrane channel TolC (ΔtolC) or the multi-drug efflux systems acrAB, acrEF and mdtABC (ΔacrABacrEFmdtABC). These strains have a decreased ability for gut and tissue colonization and are unable to survive in egg white, the latter preventing transmission of the vaccine strains to humans. Two groups of 30 laying hens were orally inoculated at day 1, 6 weeks and 16 weeks of age with 10(8) cfu of either vaccine strain, while a third group was left unvaccinated. At 24 weeks of age, the birds were intravenously challenged with 5 × 10(7) cfu Salmonella Enteritidis PT4 S1400/94. The vaccine strains were not shed or detected in the gut, internal organs or eggs, 2 weeks after the third vaccination. The strains significantly protected against gut and internal organ colonization, and completely prevented egg contamination by Salmonella Enteritidis under the conditions of this study. This indicates that Salmonella Enteritidis ΔtolC and ΔacrABacrEFmdtABC strains might be valuable strains for vaccination of layers against Salmonella Enteritidis.

Observations on Salmonella contamination of commercial duck farms before and after cleaning and disinfection.

PubMed

Martelli, Francesca; Gosling, Rebecca J; Callaby, Rebecca; Davies, Rob

2017-04-01

In the European Union, statutory control of Salmonella is in place in the chicken and turkey sectors, but not in the duck sector. In this study, 14 Salmonella-positive duck farms were sampled before and after cleaning and disinfection, and once the houses had been restocked with a new flock. The cleaning and disinfection programmes used were subdivided into two main categories: ones in which a final formaldehyde disinfection step was included (1) and ones in which it was not included (2). Several types of samples were collected during the study, and faecal samples were those more frequently positive (62% of faecal samples were positive for Salmonella in comparison to 2-23% of samples from all the other sample categories) (P < 0.001). Independently of the cleaning and disinfection programme used, there was a statistically significant (P < 0.001) reduction in the percentage of Salmonella-positive samples between before cleaning and disinfection (41.1%) and after cleaning and disinfection (3.1%). After restocking, the number of Salmonella-positive samples increased significantly (P < 0.001), with 65.3% of the samples tested being positive for Salmonella. Farms in which disinfection programme 1 was used were 5.34 times less likely to have samples positive for Salmonella after cleaning and disinfection than farms which implemented programme 2. Formaldehyde acts effectively against Salmonella even in the presence of some residual organic matter. Limited residual contamination on farms after cleaning and disinfection represents a risk of infection for young ducklings, and thorough cleaning and disinfection procedures should be implemented to reduce the carry-over of infection between flocks.

Surveillance of Salmonella prevalence in animal feeds and characterization of the Salmonella isolates by serotyping and antimicrobial susceptibility.

PubMed

Li, X; Bethune, L A; Jia, Y; Lovell, R A; Proescholdt, T A; Benz, S A; Schell, T C; Kaplan, G; McChesney, D G

2012-08-01

This article presents the surveillance data from the Feed Contaminants Program (2002-2009) and Salmonella Assignment (2007-2009) of the U.S. Food and Drug Administration (FDA), which monitor the trend of Salmonella contamination in animal feeds. A total of 2,058 samples were collected from complete animal feeds, feed ingredients, pet foods, pet treats, and supplements for pets in 2002-2009. These samples were tested for the presence of Salmonella. Those that were positive for Salmonella underwent serotyping and testing for antimicrobial susceptibility. Of the 2,058 samples, 257 were positive for Salmonella (12.5%). The results indicate a significant overall Salmonella reduction (p≤0.05) in animal feeds from 18.2% (187 samples tested) in 2002 to 8.0% (584 samples tested) in 2009. Among these samples, feed ingredients and pet foods/treats had the most significant reduction (p≤0.05). Of the 45 Salmonella serotypes identified, Salmonella Senftenberg and Salmonella Montevideo were the top two common serotypes (8.9%). Of the 257 Salmonella isolates obtained, 54 isolates (21%) were resistant to at least one antimicrobial. The findings provide the animal feed industries with Salmonella prevalence information that can be used to address Salmonella contamination problems. Our findings can also be used to educate pet owners when handling pet foods and treats at home to prevent salmonellosis.

Evaluation of PCR detection of Salmonella in alfalfa sprouts and spent irrigation water collected during sprouting of naturally contaminated seed.

PubMed

Maks, Nicole; Fu, Tong-Jen

2013-02-01

This study evaluated the efficacy of a PCR-based system (DuPont Qualicon BAX) for detection of Salmonella in sprouts and spent irrigation water collected during sprouting of seeds naturally contaminated with Salmonella. Alfalfa seeds were grown in Mason jars at 20 and 30°C for 3 days. Levels of Salmonella present in the water and sprouts were determined by most-probable-number (MPN) analysis. Background microflora levels were also determined. Samples of spent irrigation water and sprouts were enriched overnight individually in tetrathionate broth and in buffered peptone water with novobiocin at 42°C and then run in the BAX system. Samples were also enriched according to the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA BAM) method for Salmonella as a comparison. Salmonella levels were lower at 20°C compared with 30°C for some trials, and background microflora levels ranged from 10(7) to 10(8) CFU/g or ml at 20°C and 10(8) to 10(9) CFU/g or ml at 30°C. In trials with a Salmonella level >1.1 MPN/g or ml, both the BAX and FDA BAM methods were able to detect Salmonella in all samples. In trials with lower levels (0.21 MPN/g or ml or lower) of Salmonella, BAX was able to detect more positive samples than FDA BAM. For one trial with <0.003 MPN/g or ml of Salmonella, the presence of the pathogen was not indicated by either the BAX or the FDA BAM method. The results suggest that PCR detected low levels of Salmonella in sprouts or spent irrigation water collected from sprouting of naturally contaminated seeds.

Quantification of Transfer of Salmonella from Citrus Fruits to Peel, Edible Portion, and Gloved Hands during Hand Peeling.

PubMed

Jung, Jiin; Friedrich, Loretta M; Danyluk, Michelle D; Schaffner, Donald W

2017-06-01

Although studies have quantified bacterial transfer between hands and various materials, cross-contamination between the surface of fresh citrus fruit and the edible portions during hand peeling has not been reported. This study quantifies transfer of Salmonella to the edible portion of citrus fruit from a contaminated peel during hand peeling. Citrus fruits used for this study were Citrus sinensis (sweet orange) cultivars 'Valencia' and 'Navel', Citrus unshiu (Satsuma mandarins), Citrus reticulata × Citrus paradisi ('Minneola' tangelo or 'Honeybell'), and C. paradisi (grapefruit) cultivar 'Marsh'. An avirulent Salmonella Typhimurium LT2 (ATCC 700720) resistant to rifampin was used for all experiments. The inoculum containing approximately 9 log CFU/mL (50 μL) was spot inoculated onto the equator, stem, or styler of each fruit and allowed to dry for 24 h. Six volunteers put on single-use latex gloves and peeled inoculated fruit. Peel, edible fruit portion, and gloves were collected and enumerated separately. Three replicates of the study were performed in which each volunteer peeled two inoculated fruit of each variety (n = 36 fruit per variety). Cross-contamination from contaminated surface of citrus fruits to edible portion or gloved hands during peeling was affected by inoculation sites. Average Salmonella transfer to the edible portion ranged from 0.16% (Valencia inoculated at the equator) to 5.41% (navel inoculated at the stem). Average Salmonella transfer to gloved hands ranged from 0.41% (grapefruit inoculated at the stem) to 8.97% (navel inoculated at the stem). Most Salmonella remained on the peel of citrus fruits. The average level of Salmonella remaining on the peel ranged from 5.37% (Minneola inoculated at the equator) to 66.3% (Satsuma inoculated at the styler). When grapefruit was inoculated, the Salmonella that remained on the peel showed a bimodal pattern in which some individuals left almost all Salmonella on the peel, while others left

76 FR 58813 - Guidance for Industry; Measures to Address the Risk for Contamination by Salmonella Species in...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-22

...The Food and Drug Administration (FDA) is announcing the availability of a guidance entitled ``Guidance for Industry: Measures to Address the Risk for Contamination by Salmonella Species in Food Containing a Pistachio-Derived Product as an Ingredient.'' The guidance clarifies for manufacturers who produce foods containing a pistachio- derived product as an ingredient that there is a risk that Salmonella species may be present in the incoming pistachio-derived product, and recommends measures to address that risk.

Cross-sectional Study Examining Salmonella enterica Carriage in Subiliac Lymph Nodes of Cull and Feedlot Cattle at Harvest

PubMed Central

Gragg, Sara E.; Loneragan, Guy H.; Brashears, Mindy M.; Arthur, Terrance M.; Bosilevac, Joseph M.; Kalchayanand, Norasak; Wang, Rong; Schmidt, John W.; Brooks, J. Chance; Shackelford, Steven D.; Wheeler, Tommy L.; Brown, Tyson R.; Edrington, Thomas S.

2013-01-01

Abstract Bovine peripheral lymph nodes (LNs), including subiliac LNs, have been identified as a potential source of human exposure to Salmonella enterica, when adipose trim containing these nodes is incorporated into ground beef. In order to gain a better understanding of the burden of S. enterica in peripheral LNs of feedlot and cull cattle, a cross-sectional study was undertaken in which 3327 subiliac LNs were collected from cattle at harvest in seven plants, located in three geographically distinct regions of the United States. Samples were collected in three seasons: Fall 2010, Winter/Spring 2011, and Summer/Fall 2011. A convenience sample of 76 LNs per day, 2 days per season (approximately 1 month apart), was collected per plant, from carcasses held in the cooler for no less than 24 h. Every 10th carcass half on a rail was sampled, in an attempt to avoid oversampling any single cohort of cattle. Median point estimates of S. enterica contamination were generally low (1.3%); however, median Salmonella prevalence was found to be greater in subiliac LNs of feedlot cattle (11.8%) compared to those of cull cattle (0.65%). Enumeration analysis of a subset of 618 feedlot cattle LNs showed that 67% of those harboring S. enterica (97 of 144) did so at concentrations ranging from <0.1 to 1.8 log10 CFU/g, while 33% carried a higher burden of S. enterica, with levels ranging from 1.9 to >3.8 log10 CFU/g. Serotyping of S. enterica isolated identified 24 serotypes, with the majority being Montevideo (44.0%) and Anatum (24.8%). Antimicrobial susceptibility phenotypes were determined for all isolates, and the majority (86.1%) were pansusceptible; however, multidrug-resistant isolates (8.3%) were also occasionally observed. As Salmonella contained within LNs are protected from carcass interventions, research is needed to define opportunities for mitigating the risk of Salmonella contamination in LNs of apparently healthy cattle. PMID:23566273

Effect of Salmonella vaccination of breeder chickens on contamination of broiler chicken carcasses in integrated poultry operations.

PubMed

Dórea, Fernanda C; Cole, Dana J; Hofacre, Charles; Zamperini, Katherine; Mathis, Demetrius; Doyle, Michael P; Lee, Margie D; Maurer, John J

2010-12-01

While measures to control carcass contamination with Salmonella at the processing plant have been implemented with some success, on-farm interventions that reduce Salmonella prevalence in meat birds entering the processing plant have not translated well on a commercial scale. We determined the impact of Salmonella vaccination on commercial poultry operations by monitoring four vaccinated and four nonvaccinated breeder (parental) chicken flocks and comparing Salmonella prevalences in these flocks and their broiler, meat bird progeny. For one poultry company, their young breeders were vaccinated by using a live-attenuated Salmonella enterica serovar Typhimurium vaccine (Megan VAC-1) followed by a killed Salmonella bacterin consisting of S. enterica serovar Berta and S. enterica serovar Kentucky. The other participating poultry company did not vaccinate their breeders or broilers. The analysis revealed that vaccinated hens had a lower prevalence of Salmonella in the ceca (38.3% versus 64.2%; P < 0.001) and the reproductive tracts (14.22% versus 51.7%; P < 0.001). We also observed a lower Salmonella prevalence in broiler chicks (18.1% versus 33.5%; P < 0.001), acquired from vaccinated breeders, when placed at the broiler farms contracted with the poultry company. Broiler chicken farms populated with chicks from vaccinated breeders also tended to have fewer environmental samples containing Salmonella (14.4% versus 30.1%; P < 0.001). There was a lower Salmonella prevalence in broilers entering the processing plants (23.4% versus 33.5%; P < 0.001) for the poultry company that utilized this Salmonella vaccination program for its breeders. Investigation of other company-associated factors did not indicate that the difference between companies could be attributed to measures other than the vaccination program.

Transfer of Salmonella enterica serovar Typhimurium from contaminated irrigation water to parsley is dependent on curli and cellulose, the biofilm matrix components.

PubMed

Lapidot, Anat; Yaron, Sima

2009-03-01

Enteric pathogens can contaminate fresh produce, and this contaminated produce can be a significant potential source of human illness. The objective of this study was to determine a possible mode of transfer of Salmonella Typhimurium from contaminated irrigation water to mature parsley plants and to investigate the role of bacterial cellulose and curli. Parsley plants were drip irrigated with water containing green fluorescent protein-labeled Salmonella Typhimurium. Stems and leaves were harvested 1 day after the third irrigation and examined for the presence of Salmonella Typhimurium. Three weeks after harvesting, the presence of Salmonella was again confirmed in the regrown plants. During this period, bacterial numbers on leaves declined from 4.1 (+/- 0.3) to 2.3 (+/- 0.1) log CFU g(-1) (P < 0.05). Numbers in the soil were constant (5 log CFU g(-1)). Results demonstrated the ability of Salmonella Typhimurium to transfer from irrigation water to the edible parts of the plants. Confocal laser scanning microscopic images revealed that Salmonella Typhimurium formed aggregates at a depth of 8 to 32 microm beneath the leaf surface. Penetration might be achieved through the roots or the phyllosphere. The importance of the bacterial cellulose and curli was determined by comparing the wild-type strain with its mutants, which lack the ability to synthesize cellulose and curli. Counts of the double mutant were 2-log higher in the soil but 1-log lower in the leaves (P < 0.05). Deletion of the agfBA gene (for curli) was more effective than deletion of bcsA (for cellulose). Thus, curli and cellulose play a role in the transfer or survival of Salmonella Typhimurium in the plant, as they do for plant pathogens.

Survey of Salmonella contamination of non-United Kingdom-produced raw shell eggs on retail sale in the northwest of England and London, 2005 to 2006.

PubMed

Little, C L; Walsh, S; Hucklesby, L; Surman-Lee, S; Pathak, K; Gatty, Y; Greenwood, M; De Pinna, E; Threlfall, E J; Maund, A; Chan, C H

2007-10-01

This survey was prompted by a change in the epidemiology of Salmonella Enteritidis infections in England and Wales and elsewhere in Europe and, to our knowledge, is the first survey to provide information on Salmonella contamination of non-United Kingdom eggs on retail sale. Based on 10,464 non-United Kingdom eggs (1744 pooled samples of six eggs) purchased between March 2005 and July 2006, the total weighted prevalence estimate for all Salmonella detected in non-United Kingdom eggs was 3.3%. Of the eggs sampled, most were produced in Spain (66.3%), France (20.0%), or The Netherlands (7.4%). Salmonella was detected from 4.4 and 0.3% of eggs produced in Spain and France, respectively, with weighted prevalence estimates. Eight different Salmonella serotypes were recovered from non-United Kingdom eggs, of which Salmonella Enteritidis predominated, with an estimated prevalence of 2.6%. Salmonella Enteritidis was obtained only from Spanish eggs. Nine different phage types of Salmonella Enteritidis were identified, with phage type 1 found to be the predominant phage type. Most of the Salmonella Enteritidis isolates obtained from Spanish eggs in the survey were resistant to nalidixic acid with concomitant decreased susceptibility to ciprofloxacin (0.125 to 1.0 mg/liter) or ampicillin (8.0 mg/liter). Salmonella Enteritidis phage type 1 until now had not been detected in eggs examined as part of previous United Kingdom egg surveys but has been detected in eggs of Spanish origin examined during recent national outbreaks of Salmonella Enteritidis non-phage type 4 infections in England and Wales. Eggs are a commonly consumed food that may occasionally be contaminated with Salmonella. The rates of contamination may be linked to the origin of the eggs. Consumers and caterers need to be aware of this continuing hazard, adopt appropriate control measures, and follow advice provided by national food agencies in order to reduce the risk of infection.

Foodborne outbreak of Salmonella subspecies IV infections associated with contamination from bearded dragons.

PubMed

Lowther, S A; Medus, C; Scheftel, J; Leano, F; Jawahir, S; Smith, K

2011-12-01

Approximately 1.4 million Salmonella infections and 400 deaths occur annually in the United States. Approximately 6% of human Salmonella cases are thought to be associated with reptiles; Salmonella enterica subspecies IV is primarily reptile-associated. During 1-4 December, 2009, three isolates of Salmonella IV 6,7:z4,z24:- with indistinguishable pulsed-field gel electrophoresis (PFGE) patterns were identified through Minnesota Department of Health laboratory-based surveillance. None of the three patients associated with the isolates reported reptile contact; however, all had attended the same potluck dinner. Dinner attendees were asked questions regarding illness history, foods they prepared for and consumed at the event, and pet ownership. Cases were defined as illness in a person who had eaten potluck food and subsequently experienced fever and diarrhoea (three or more loose stools in 24 h) or laboratory-confirmed infection with Salmonella IV matching the outbreak PFGE subtype. Nineteen days after the event, environmental samples were collected from a food preparer's house where two pet bearded dragons were kept. Sixty-six of 73 potluck food consumers were interviewed; 19 cases were identified; 18 persons reported illness but did not meet the case definition. Median incubation period was 19 h (range: 3-26 h). Median duration of illness was 5 days (range: 1-11 days). Consumption of gravy, prepared by the bearded dragons' asymptomatic owner, was associated with illness (16/32 exposed versus 1/12 unexposed; risk ratio: 6.0; exact P = 0.02). Salmonella Labadi was recovered from 10 samples, including from one bearded dragon, the bathroom door knob and sink drain, and the kitchen sink drain. The outbreak PFGE subtype of Salmonella subspecies IV was isolated from vacuum-cleaner bag contents. This foodborne outbreak probably resulted from environmental contamination from bearded dragons. Reptiles pose a community threat when food for public consumption is prepared in

Oral vaccination with a live Salmonella Enteritidis/Typhimurium bivalent vaccine in layers induces cross-protection against caecal and internal organ colonization by a Salmonella Infantis strain.

PubMed

Eeckhaut, Venessa; Haesebrouck, Freddy; Ducatelle, Richard; Van Immerseel, Filip

2018-05-01

Salmonella is an important zoonotic agent, and poultry products remain one of the main sources of infection for humans. Salmonella Infantis is an emerging serotype in poultry worldwide, reflected by an increased prevalence in poultry flocks, on broiler meat and in human foodborne illness cases. In the current study, the efficacy of oral administration of a live monovalent Salmonella Enteritidis and a live bivalent Salmonella Enteritidis/Typhimurium vaccine, against a Salmonella Enteritidis and Infantis infection, was determined. Oral administration of the live vaccines to day-old chickens caused a decrease in caecal colonization by Salmonella Enteritidis, but not Infantis, at day 7, when challenged at day 2. Vaccination with the bivalent vaccine at day 1 resulted in a decreased spleen colonization by both Salmonella Infantis and Enteritidis. Twice (at day 1 and week 6) and thrice vaccination (at day 1, week 6 and 16) of laying hens with the bivalent vaccine resulted in a decreased caecal colonization by Salmonella Enteritidis and Infantis, and significantly lower oviduct colonization levels by Salmonella Enteritidis. These data show cross-protection against Salmonella Infantis by oral administration of live vaccine strains belonging to other serogroups. Copyright © 2018 Elsevier B.V. All rights reserved.

Isolation of Salmonella enterica serovar Enteritidis from houseflies (Musca domestica) found in rooms containing Salmonella serovar Enteritidis-challenged hens.

PubMed

Holt, Peter S; Geden, Christopher J; Moore, Randle W; Gast, Richard K

2007-10-01

Houseflies (Musca domestica) released into rooms containing hens challenged with Salmonella enterica serovar Enteritidis (Salmonella serovar Enteritidis) rapidly became contaminated with Salmonella serovar Enteritidis. Forty to 50% of the flies were contaminated at 48 h, and the percentage increased to 50 to 70% at 4 and 7 days postexposure and then decreased to 30% at day 15. Initial attempts at recovering surface organisms for culture using an aqueous rinse were largely unsuccessful, while cultures of internal contents readily recovered Salmonella serovar Enteritidis. However, when 0.5% detergent was incorporated into the rinse, high recovery levels of bacteria were observed from both external and internal culture regimens, indicating equal distribution of the organism on and in the fly and a tighter interaction of the organism with the host than previously thought. Salmonella serovar Enteritidis was isolated routinely from the fly gut, on rare occasions from the crop, and never from the salivary gland. Feeding contaminated flies to hens resulted in gut colonization of a third of the birds, but release of contaminated flies in a room containing previously unchallenged hens failed to result in colonization of any of the subject birds. These results indicate that flies exposed to an environment containing Salmonella serovar Enteritidis can become colonized with the organism and might serve as a source for transmission of Salmonella serovar Enteritidis within a flock situation.

Isolation of Salmonella enterica Serovar Enteritidis from Houseflies (Musca domestica) Found in Rooms Containing Salmonella Serovar Enteritidis-Challenged Hens▿

PubMed Central

Holt, Peter S.; Geden, Christopher J.; Moore, Randle W.; Gast, Richard K.

2007-01-01

Houseflies (Musca domestica) released into rooms containing hens challenged with Salmonella enterica serovar Enteritidis (Salmonella serovar Enteritidis) rapidly became contaminated with Salmonella serovar Enteritidis. Forty to 50% of the flies were contaminated at 48 h, and the percentage increased to 50 to 70% at 4 and 7 days postexposure and then decreased to 30% at day 15. Initial attempts at recovering surface organisms for culture using an aqueous rinse were largely unsuccessful, while cultures of internal contents readily recovered Salmonella serovar Enteritidis. However, when 0.5% detergent was incorporated into the rinse, high recovery levels of bacteria were observed from both external and internal culture regimens, indicating equal distribution of the organism on and in the fly and a tighter interaction of the organism with the host than previously thought. Salmonella serovar Enteritidis was isolated routinely from the fly gut, on rare occasions from the crop, and never from the salivary gland. Feeding contaminated flies to hens resulted in gut colonization of a third of the birds, but release of contaminated flies in a room containing previously unchallenged hens failed to result in colonization of any of the subject birds. These results indicate that flies exposed to an environment containing Salmonella serovar Enteritidis can become colonized with the organism and might serve as a source for transmission of Salmonella serovar Enteritidis within a flock situation. PMID:17675422

Adaptive Resistance to Biocides in Salmonella enterica and Escherichia coli O157 and Cross-Resistance to Antimicrobial Agents

PubMed Central

Braoudaki, M.; Hilton, A. C.

2004-01-01

The mechanisms by which bacteria resist killing by antibiotics and biocides are still poorly defined, although repeated exposure to sublethal concentrations of antibacterial agents undoubtedly contributes to their development. This study aimed both to investigate the potential of Salmonella enterica and Escherichia coli O157 for adaptive resistance to commonly used biocides and to determine any cross-resistance to antibiotics. Strains were repeatedly passaged in media containing increasing concentrations of a biocide or antibiotic until adaptive resistance was obtained. A wide panel of antimicrobial agents was then screened by using the adapted strain to determine cross-resistance, if any. Adaptive resistance was readily achieved for both S. enterica and E. coli O157. Cross-resistance in adaptively resistant S. enterica varied with the serotype; Salmonella enterica serovar Enteritidis expressed cross-resistance to chloramphenicol, whereas Salmonella enterica serovar Typhimurium expressed cross-resistance to chlorhexidine. Benzalkonium chloride-resistant Salmonella enterica serovar Virchow showed elevated resistance to chlorhexidine; however, chlorhexidine-resistant Salmonella serovar Virchow did not demonstrate reciprocal cross-resistance to benzalkonium chloride, suggesting specific rather than generic resistance mechanisms. E. coli O157 strains acquired high levels of resistance to triclosan after only two sublethal exposures and, when adapted, repeatedly demonstrated decreased susceptibilities to various antimicrobial agents, including chloramphenicol, erythromycin, imipenem, tetracycline, and trimethoprim, as well as to a number of biocides. These observations raise concern over the indiscriminate and often inappropriate use of biocides, especially triclosan, in situations where they are unnecessary, whereby they may contribute to the development of microbial resistance mechanisms. PMID:14715734

Colonization of reproductive organs and internal contamination of eggs after experimental infection of laying hens with Salmonella heidelberg and Salmonella enteritidis.

PubMed

Gast, Richard K; Guard-Bouldin, Jean; Holt, Peter S

2004-12-01

Internal contamination of eggs laid by hens infected with Salmonella enteritidis has been a prominent international public health issue since the mid-1980s. Considerable resources have been committed to detecting and controlling S. enteritidis infections in commercial laying flocks. Recently, the Centers for Disease Control and Prevention also reported a significant association between eggs or egg-containing foods and S. heidelberg infections in humans. The present study sought to determine whether several S. heidelberg isolates obtained from egg-associated human disease outbreaks were able to colonize reproductive tissues and be deposited inside eggs laid by experimentally infected hens in a manner similar to the previously documented behavior of S. enteritidis. In two trials, groups of laying hens were orally inoculated with large doses of four S. heidelberg strains and an S. enteritidis strain that consistently caused egg contamination in previous studies. All five Salmonella strains (of both serotypes) colonized the intestinal tracts and invaded the livers, spleens, ovaries, and oviducts of inoculated hens, with no significant differences observed between the strains for any of these parameters. All four S. heidelberg strains were recovered from the interior liquid contents of eggs laid by infected hens, although at lower frequencies (between 1.1% and 4.5%) than the S. enteritidis strain (7.0%).

Salmonella spp. contamination in commercial layer hen farms using different types of samples and detection methods.

PubMed

Soria, M C; Soria, M A; Bueno, D J; Godano, E I; Gómez, S C; ViaButron, I A; Padin, V M; Rogé, A D

2017-08-01

The performance of detection methods (culture methods and polymerase chain reaction assay) and plating media used in the same type of samples were determined as well as the specificity of PCR primers to detected Salmonella spp. contamination in layer hen farms. Also, the association of farm characteristics with Salmonella presence was evaluated. Environmental samples (feces, feed, drinking water, air, boot-swabs) and eggs were taken from 40 layer hen houses. Salmonella spp. was most detected in boot-swabs taken around the houses (30% and 35% by isolation and PCR, respectively) follow by fecal samples (15.2% and 13.6% by isolation and PCR, respectively). Eggs, drinking water, and air samples were negative for Salmonella detection. Salmonella Schwarzengrund and S. Enteritidis were the most isolated serotypes. For plating media, relative specificity was 1, and the relative sensitivity was greater for EF-18 agar than XLDT agar in feed and fecal samples. However, relative sensitivity was greater in XLDT agar than EF-18 agar for boot-swab samples. Agreement was between fair to good depending on the sample, and it was good between isolation and PCR (feces and boot-swabs), without agreement for feed samples. Salmonella spp. PCR was positive for all strains, while S. Typhimurium PCR was negative. Salmonella Enteritidis PCR used was not specific. Based in the multiple logistic regression analyses, categorization by counties was significant for Salmonella spp. presence (P-value = 0.010). This study shows the importance of considering different types of samples, plating media and detection methods during a Salmonella spp. monitoring study. In addition, it is important to incorporate the sampling of floors around the layer hen houses to learn if biosecurity measures should be strengthened to minimize the entry and spread of Salmonella in the houses. Also, the performance of some PCR methods and S. Enteritidis PCR should be improved, and biosecurity measures in hen farms must be

Immunochromatographic strip assay for the rapid and sensitive detection of Salmonella Typhimurium in artificially contaminated tomato samples.

PubMed

Shukla, Shruti; Leem, Hyerim; Lee, Jong-Suk; Kim, Myunghee

2014-06-01

This study was designed to confirm the applicability of a liposome-based immunochromatographic assay for the rapid detection of Salmonella enterica subsp. enterica serovar Typhimurium (Salmonella Typhimurium) in artificially contaminated tomato samples. To determine the detection limit and pre-enrichment incubation time (10, 12, and 18 h pre-enrichment in 1% buffered peptone water), the tests were performed with different cell numbers of Salmonella Typhimurium (3 × 10(0), 3 × 10(1), 3 × 10(2), and 3 × 10(3) CFU·mL(-1)) inoculated into 25 g of crushed tomato samples. The assay was able to detect as few as 30 Salmonella Typhimurium cells per 25 g of tomato samples (1.2 cells·g(-1)) after 12 h pre-enrichment incubation. Moreover, when the developed assay was compared with traditional morphological and biochemical culture-based methods as well as colloidal gold nanoparticle-based commercial test strips, the developed assay yielded positive results for the detection of Salmonella Typhimurium within a shorter period time. These findings confirm that the developed assay may have practical application for the sensitive detection of Salmonella Typhimurium in various food samples, including raw vegetables, with a relatively low detection limit and shorter analysis time.

Consecutive salmonella outbreaks traced to the same bakery.

PubMed Central

Evans, M. R.; Tromans, J. P.; Dexter, E. L.; Ribeiro, C. D.; Gardner, D.

1996-01-01

Two consecutive community outbreaks of Salmonella enteritidis phage type 4 (PT4) traced to the same bakery occurred in Cardiff, Wales during August-September 1992. In the first outbreak, illness was associated with eating custard slices (odds ratio 23.8, 95% confidence interval 6.5-94.4, P < 0.0001), and in the second, with eating fresh cream cakes (odds ratio 15.8, 95% confidence interval 1.6-374, P = 0.004). Environmental investigations implicated cross-contamination during preparation of the cold-custard mix as the cause of the first outbreak, and inadequate cleaning and disinfection of nozzles used for piping cream in the second outbreak. S. enteritidis PT4 was isolated from fresh cream sponge cake retained by a case and from two fresh cream cakes and four environmental swabs obtained at the bakery. This incident illustrates the hazard of widespread environmental contamination with salmonella and the need for thorough environmental cleansing for any premises implicated in an outbreak of food poisoning. PMID:8620907

Mechanisms of survival, responses and sources of Salmonella in low-moisture environments

PubMed Central

Finn, Sarah; Condell, Orla; McClure, Peter; Amézquita, Alejandro; Fanning, Séamus

2013-01-01

Some Enterobacteriaceae possess the ability to survive in low-moisture environments for extended periods of time. Many of the reported food-borne outbreaks associated with low-moisture foods involve Salmonella contamination. The control of Salmonella in low-moisture foods and their production environments represents a significant challenge for all food manufacturers. This review summarizes the current state of knowledge with respect to Salmonella survival in intermediate- and low-moisture food matrices and their production environments. The mechanisms utilized by this bacterium to ensure their survival in these dry conditions remain to be fully elucidated, however, in depth transcriptomic data is now beginning to emerge regarding this observation. Earlier research work described the effect(s) that low-moisture can exert on the long-term persistence and heat tolerance of Salmonella, however, data are also now available highlighting the potential cross-tolerance to other stressors including commonly used microbicidal agents. Sources and potential control measures to reduce the risk of contamination will be explored. By extending our understanding of these geno- and phenotypes, we may be able to exploit them to improve food safety and protect public health. PMID:24294212

Contamination of Carcasses and Utensils in Small Swine Slaughterhouses by Salmonella in the Northwestern Region of the State of Rio de Janeiro, Brazil.

PubMed

Cabral, Claudius Couto; Panzenhagen, Pedro Henrique Nunes; Delgado, Karina Frensel; Silva, Gabriela Rodrigues Alves; Rodrigues, Dália Dos Prazeres; Franco, Robson Maia; Conte-Junior, Carlos Adam

2017-07-01

Salmonella is a major foodborne pathogen that constantly threatens food safety in developed countries and underdeveloped countries such as Brazil, where it is responsible for 38% of notified cases of foodborne illness. Swine are one of the main meat-producing species that may asymptomatically carry Salmonella, periodically shedding the bacteria through feces. The state of Rio de Janeiro is not a major producer of swine meat, but small slaughterhouses are operational and produce meat for consumption within the state, although few studies have been conducted in the region. In this context, this study was designed to evaluate Salmonella contamination in carcasses, lymph nodes, feces, utensils, and the environment of three small slaughterhouses in the state of Rio de Janeiro. A total of 344 samples from carcasses, utensils, equipment, water, and the environment were collected from these slaughterhouses in the northwestern region of Rio de Janeiro. Salmonella was isolated from 36 (10.5%) samples: 10 of 48 carcasses, 19 of 96 lymph nodes, 4 of 48 fecal samples, 2 of 6 water samples, and 1 of 6 bleeding knives; 55 isolates were recovered. Serotyping revealed the predominance of Salmonella Typhimurium (20 isolates) followed by Salmonella Abony (10 isolates), Salmonella Give (7 isolates), Salmonella Heidelberg (4 isolates), and Salmonella Infantis (1 isolate). Ten isolates were only partially typeable, with only their O antigen identified, and three isolates had rough, nontypeable colonies. Despite the overall low prevalence of Salmonella in this study, all three slaughterhouses had poor hygienic and sanitary conditions, providing easy routes for carcass and, consequently, meat contamination. Thus, it is imperative to enforce sanitary inspections in these establishments and to apply good manufacture practices to assure the safety of the produced pork.

Evaluation of two commercially available Salmonella vaccines on Salmonella concentration and prevalance in the peripheral lymph nodes of experimentally infected cattle

USDA-ARS?s Scientific Manuscript database

Bovine peripheral lymph nodes (PLN) may contain Salmonella, and unless contaminated nodes are removed during slaughter, they serve as a source of contamination for ground beef. Utilizing an experimental model of Salmonella inoculation of the PLN, two experiments were conducted to evaluate commercia...

Antimicrobials for reduction of Salmonella contamination in uncooked, surface-browned breaded chicken products.

PubMed

Moschonas, Galatios; Geornaras, Ifigenia; Stopforth, Jarret D; Wach, Damien; Woerner, Dale R; Belk, Keith E; Smith, Gary C; Sofos, John N

2012-06-01

Surface-browned but uncooked frozen breaded chicken products have been associated with salmonellosis outbreaks due to inadequate or no cooking of the products before consumption. This study was conducted to evaluate the effect of three antimicrobials against Salmonella during manufacture of a surface-browned, uncooked frozen breaded chicken meat product. Fresh chicken breast meat portions (5 by 5 by 5 cm) were inoculated (4 to 5 log CFU/g) with Salmonella and mixed with caprylic acid (CAA; 0.5 and 1.0%), carvacrol (CAR; 0.3 and 0.5%), ε-polylysine (POL; 0.125 and 0.25%), or distilled water (control). Sodium chloride (1.2%) and sodium tripolyphosphate (0.3%) were added to all treatments, and the mixtures were ground (5% total moisture enhancement level) and formed into portions (9 by 5 by 3 cm). The products were breaded and surface browned by baking in an oven (208°C for 15 min) or deep frying in vegetable oil (190°C for 15 s), packaged in polyethylene bags, and stored at -20°C for 7 days. Total reductions of inoculated Salmonella in untreated control oven- or fryer-browned products after frozen storage were 1.2 and 0.8 log CFU/g, respectively. In comparison, treatment with CAA, CAR, or POL reduced initial pathogen counts by 3.3 to >4.5, 4.1 to >4.7, and 1.1 to 1.6 log CFU/g, respectively, regardless of the antimicrobial concentration and browning method. Treatment with 1.0% CAA (oven browned) or 0.5% CAR (oven or fryer browned) reduced Salmonella to nondetectable levels (<0.3 log CFU/g) in stored frozen products. These data may be useful for development of suitable antimicrobial treatments to reduce the risk of Salmonella contamination in surface-browned, uncooked frozen breaded chicken products.

Survival of Salmonella on refrigerated chicken carcasses and subsequent transfer to cutting board.

PubMed

Jiménez, S M; Tiburzi, M C; Salsi, M S; Moguilevsky, M A; Pirovani, M E

2009-06-01

To determine the effect of refrigeration time and temperature on Salmonella cell numbers on inoculated chicken carcasses and their transfer to a plastic cutting board. The survival of Salmonella on chicken skin and the transfer to a plastic cutting board when exposed to different refrigeration temperatures (2, 6 or 8 degrees C) for 9 days were the two main issues on which this work focused. Two scenarios were carried out to ascertain these effects: carcasses treated with a decontaminating acetic acid solution and untreated carcasses. All of the contaminated carcasses remained contaminated after 9 days of refrigeration. However, on untreated samples, while Salmonella numbers increased almost 1.5 log at 8 degrees C, the pathogen numbers decreased about 1 log at 2 and 6 degrees C. On acid-treated samples, cell numbers slightly decreased at all of the temperatures studied. Temperature did not affect salmonellae transfer to the cutting board, but time did. Acid decontamination increased cell numbers transferred to the cutting board compared with untreated samples. Proper refrigeration at low temperatures did not allow Salmonella numbers to rise, regardless of which carcasses had been, or had not been, acid treated. Despite the fact that the rate of transfer was not affected by temperature, the acid treatment detached Salmonella cells from the chicken skin and, therefore, the probability of greater cross-contamination should be studied further. The results of this study may provide better information about the refrigeration conditions for fresh chicken storage and also determine if these, along with acetic acid decontamination of broiler chicken, would affect the pathogen transfer to a cutting board.

Survival of Salmonella Typhimurium in poultry-based meat preparations during grilling, frying and baking.

PubMed

Roccato, Anna; Uyttendaele, Mieke; Cibin, Veronica; Barrucci, Federica; Cappa, Veronica; Zavagnin, Paola; Longo, Alessandra; Ricci, Antonia

2015-03-16

The burden of food-borne diseases still represents a threat to public health; in 2012, the domestic setting accounted for 57.6% of strong-evidence EU food-borne Salmonella outbreaks. Next to cross-contamination, inadequate cooking procedure is considered as one of the most important factors contributing to food-borne illness. The few studies which have assessed the effect of domestic cooking on the presence and numbers of pathogens in different types of meat have shown that consumer-style cooking methods can allow bacteria to survive and that the probability of eating home-cooked poultry meat that still contains surviving bacteria after heating is higher than previously assumed. Thus, the main purpose of this study was to reproduce and assess the effect of several types of cooking treatments (according to label instructions and not following label instructions) on the presence and numbers of Salmonella Typhimurium DT 104 artificially inoculated in five types of poultry-based meat preparations (burgers, sausages, ready-to-cook-kebabs, quail roulades and extruded roulades) that are likely to be contaminated by Salmonella. Three contamination levels (10 cfu/g; 100 cfu/g and 1000 cfu/g) and three cooking techniques (grilling, frying and baking) were applied. Cooking treatments performed according to label instructions eliminated Salmonella Typhimurium (absence per 25g) for contamination levels of 10 and 100 cfu/g but not for contamination levels of 1000 cfu/g. After improper cooking, 26 out of 78 samples were Salmonella-positive, and 23 out of these 26 samples were artificially contaminated with bacterial loads between 100 and 1000 cfu/g. Nine out of 26 samples provided quantifiable results with a minimum level of 1.4MPN/g in kebabs (initial inoculum level: 100 cfu/g) after grilling and a maximum level of 170MPN/g recorded in sausages (initial inoculum level: 1000 cfu/g) after grilling. Kebabs were the most common Salmonella-positive meat product after cooking

Immunogenicity of Salmonella enterica serovar Enteritidis virulence protein, InvH, and cross-reactivity of its antisera with Salmonella strains.

PubMed

Dehghani, Behzad; Rasooli, Iraj; Gargari, Seyed Latif Mousavi; Nadooshan, Mohammad Reza Jalali; Owlia, Parviz; Nazarian, Shahram

2013-02-22

Acellular vaccines containing bacterial immunodominant components such as surface proteins may be potent alternatives to live attenuated vaccines in order to reduce salmonellosis risk to human health. invH gene, an important part of needle complex in type three secretion system (TTSS) plays important role in efficient bacterial adherence and entry into epithelial cells. In this work we hypothesize that use of a 15 kDa recombinant InvH as Salmonella enterica serovar Enteritidis surface protein could provoke antibody production in mouse and would help us study feasibility of its potential for diagnosis and/or a recombinant vaccine. The purified InvH provoked significant rise of IgG in mice. Active protection induced by immunization with InvH against variable doses of S. enterica serovar Enteritidis, indicated that the immunized mice were completely protected against challenge with 10(4) LD(50). The immunoreaction of sera from immunized mice with other Salmonella strains or cross reaction with sera of Salmonella strains inoculated mice is indicative of possessing by Salmonella strains of the surface protein, InvH, that can be employed in both prophylactic and diagnostic measures against S. enterica. Bacteria free spleen and ileum of the immunized mice in this study indicate that the invH gene affects bacterial invasion. Efficacy of the virulence protein, InvH, in shuttling into host cells in injectisome of S. enterica serovar Enteritidis and inhibition of this phenomenon by active immunization was shown in this study. In conclusion immunization with InvH protein can develop protection against S. enterica serovar Enteritidis infections. InvH in Salmonella strains can be exploited in protective measures as well as a diagnostic tool in Salmonella infections. Copyright © 2012 Elsevier GmbH. All rights reserved.

The occurrence of Salmonella in airline meals.

PubMed

Hatakka, M; Asplund, K

1993-01-01

The occurrence of Salmonella in airline meals was studied in 1989-1992. Samples were collected from flight kitchens in 29 countries. The material consisted of 400 cold dishes and 1,288 hot dishes as well as salads, cheese plates and deserts. Total number of samples was 2211. Salmonella spp. were isolated from 6 samples; 1 contaminated sample was a cold dish prepared in Bangkok, 1 was a hot dish prepared in Mombasa and the remaining 4 contaminated samples were hot dishes prepared within one week in Beijing. The isolated serotypes were S. ohio, S. manchester and S. braenderup. The contaminated cold dish prepared by a flight kitchen in Bangkok was found to be connected with a Salmonella outbreak which occurred in Finland in 1990. Cold airline dishes containing food of animal origin seems to be more risky as a source of Salmonella infections among airline passengers.

Salmonella Enteritidis organ invasion and egg contamination in experimentally infected laying hens housed in conventional or enriched cages.

USDA-ARS?s Scientific Manuscript database

Both disease surveillance and epidemiologic analyses have confirmed a strong association between human salmonellosis and the prevalence of Salmonella Enteritidis (SE) in commercial egg flocks. The majority of human illnesses caused by this pathogen are attributed to contaminated eggs. Animal welfare...

Initially unrecognized distribution of a commercially cooked meat product contaminated over several months with Salmonella serotype Infantis.

PubMed

Kohl, K S; Farley, T A

2000-12-01

An outbreak of salmonellosis occurred among 63 wedding participants. The outbreak was investigated through cohort, laboratory, and environmental studies. Consumption of rice-dressing made from a commercially cooked, meat-based, rice-dressing mix was strongly associated with illness. Nineteen patient isolates, six company/grocery store isolates cultured from the rice-dressing mix, and one environmental isolate from a pump in the production line were of an identical outbreak strain of Salmonella Infantis characterized by pulsed-field gel electrophoresis. In the production line, cooked rice-dressing mix tested negative for S. Infantis before and positive after contact with the contaminated pump. The dressing-mix had an estimated 200 colony-forming units of salmonella per gram of product, and > 180,000 pounds were distributed in 9 states for > or = 2 months before contamination was recognized. Food manufacturers should be required to use systematic, hazard analysis critical control point risk management practices for all processed meat products, validated by periodic microbiologic monitoring of the end product.

Salmonella Levels Associated with Skin of Turkey Parts.

PubMed

Peng, Ye; Deng, Xiang Y; Harrison, Mark A; Alali, Walid Q

2016-05-01

Turkey skin is used as a source of fat in finished ground turkey products. Salmonella-contaminated skin may potentially disseminate this pathogen to ground turkey. The objective of this study was to determine and compare Salmonella levels (presence and numbers) associated with the skin of turkey parts (i.e., drumstick, thigh, and wing). Over a 10-month period, 20 turkey flocks expected to be highly contaminated with Salmonella based on boot-sock testing data of turkey houses were sampled. A total of 300 samples per type of turkey part were collected postchill and were tested for Salmonella using the most-probable-number (MPN) and enrichment methods. Overall, Salmonella was detected in 13.7, 19.7, and 25.0% of drumstick skin, thigh skin, and wing skin samples, respectively. Salmonella prevalence from wing skin was significantly higher (P < 0.05) than in drumstick skin, but the difference was not significant (P > 0.05) when compared with thigh skin. Salmonella was 2.4 times more likely to be present from thigh skin (odds ratio = 2.4; P < 0.05) when the pathogen was found from wing skin. Salmonella mean numbers from drumstick, thigh, and wing were 1.18, 1.29, and 1.45 log MPN per sample, respectively; these values were not significantly different (P > 0.05). Based on our findings, the high prevalence of Salmonella associated with the skin of turkey parts could be a potential source for ground turkey contamination.

Transmission of Salmonella to broilers by contaminated larval and adult lesser mealworms, Alphitobius diaperinus (Coleoptera: Tenebrionidae).

PubMed

Roche, A J; Cox, N A; Richardson, L J; Buhr, R J; Cason, J A; Fairchild, B D; Hinkle, N C

2009-01-01

The ability of the lesser mealworm, Alphitobius diaperinus (Panzer), commonly known as the darkling beetle, to transmit marker Salmonella Typhimurium to day-of-hatch broiler chicks was evaluated, as well as the spread to nonchallenged pen mates. In trial 1, day-of-hatch chicks were orally gavaged with 4 larval or 4 adult beetles that had been exposed to marker Salmonella-inoculated feed for 72 h. In addition, chicks were gavaged with the marker Salmonella in saline solution. These chicks were then placed into pens to serve as challenged broilers. In trial 2, all pens received 2 challenged chicks that were gavaged with larvae or beetles that had been exposed to marker Salmonella-inoculated feed for 24 h and then removed from the inoculated feed for a period of 7 d. At 3 wk of age, cecal samples from the marker Salmonella-challenged broilers and from 5 pen mates in trial 1, or 10 pen mates in trial 2, were evaluated for the presence of the marker Salmonella in their ceca, and at 6 wk of age, all remaining pen mates were sampled. To monitor the presence of the marker Salmonella within pens, stepped-on drag swab litter samples were taken weekly. For the Salmonella-saline pens, 29 to 33% of the broilers that had been challenged and 10 to 55% of the pen mates were positive at 3 wk of age, and only 2 to 6% had positive ceca at 6 wk. For the pens challenged with adult beetles, 0 to 57% of the challenged broilers and 20 to 40% of the pen mates had positive ceca at 3 wk, and 4 to 7% were positive at 6 wk. The pens challenged with larvae had the greatest percentage of marker Salmonella-positive broilers; 25 to 33% of the challenged broilers and 45 to 58% of pen mates were positive at 3 wk, and 11 to 27% were positive at 6 wk. These results demonstrated that ingestion of larval or adult beetles contaminated with a marker Salmonella could be a significant vector for transmission to broilers.

Testing Feeds for Salmonella.

USDA-ARS?s Scientific Manuscript database

Human salmonellosis outbreaks have been linked to contamination of animal feeds. Thus it is crucial to employ sensitive Salmonella detection methods for animal feeds. Based on a review of the literature, Salmonella sustains acid injury at about pH 4.0 to5.0. Low pH can also alter the metabolism of S...

Salmonella and Campylobacter contamination of ready-to-eat street-vended pork meat dishes in Antananarivo, Madagascar: a risk for the consumers?

PubMed

Cardinale, Eric; Abat, Cédric; Bénédicte, Contamin; Vincent, Porphyre; Michel, Rakotoharinome; Muriel, Maeder

2015-03-01

Street-food vending has been increasing in many developing countries and particularly in Madagascar since 2000. Gastroenteric diseases cause 37% of all deaths each year, and 50% of children <5 years are infected with intestinal pathogens. However, there has been little information regarding the incidence of street-food-related diseases, or foodborne pathogens in pork, which is the most commonly eaten meat, along with chicken. Thus, the aim of this study was to investigate the safety of traditional ready-to-eat street-vended pork dishes and to assess the association of restaurant characteristics and cooking practices with Salmonella and Campylobacter contamination of these meals. Sixty street-restaurants were studied from March 2012 to August 2012 in Antananarivo. A questionnaire was submitted to the managers, and samples of ready-to-eat pork dishes were bought. Salmonella spp. were isolated in 10% of the 60 street-restaurants studied and in 5% samples of pork dishes. The most prevalent serovars isolated were Salmonella Typhimurium (44%) and Senftenberg (33%). Campylobacter was not detected. Only 4 of the 43 variables tested in the screening analysis were significantly associated with Salmonella spp. contamination of the street-restaurants. The risk for a restaurant to be Salmonella positive decreased when there were specific premises for the restaurant and when the staff was wearing specific clothes when working. Conversely, that risk increased when the temperature of ready-to-eat pork was <52 °C and when tablecloths were used in the restaurant.

Persistence of poultry associated Salmonella spp. on spinach plants

USDA-ARS?s Scientific Manuscript database

Introduction: Pre-harvest spinach contamination can occur via irrigation water and can influence the persistence of Salmonella on spinach leaves. Salmonella persistence on spinach plants should be evaluated as nearby poultry farms can be a critical source of contaminated water run-off. Purpose: The...

Salmonella in pork cuttings in supermarkets and butchers' shops in Denmark in 2002 and 2006.

PubMed

Hansen, T B; Christensen, B B; Aabo, S

2010-11-01

The prevalence of Salmonella in fresh pork cuttings in Denmark in the years 2002 and 2006 was investigated at retail and compared with the retail supply pattern. A total of 1025 and 3473 samples were taken in 2002 from butcher's shops and supermarkets, respectively. The corresponding numbers in 2006 were 259 from butchers' shops and 628 from supermarkets. In 2002, 1.2% of all samples were positive for Salmonella; butchers' shops and supermarkets had 1.8% and 1.0% positive samples, respectively. The overall prevalence in 2006 was 4.2%, with prevalence of 8.1% and 2.6% for butchers' shops and supermarkets, respectively. Hence, increases around 3- to 5-fold were found. There was neither observed any parallel increase in Salmonella positive carcasses in Danish slaughterhouses during the study period, nor were any changes in supply routes towards slaughterhouses with higher prevalence observed, which could explain the apparent increase. We hypothesize that hygiene levels and ability to avoid cross-contamination and prevent growth of the organism, in the meat processing chain after slaughter were the most likely responsible factors. Results from this study indicate that the hygiene performance, particularly at retail, has a significant impact on the occurrence of Salmonella. This implies that there is no direct link between slaughterhouse Salmonella surveillance data and the level of Salmonella contamination at retail. To improve risk assessment of Salmonella in fresh pork meat, this study underlines the need for comprehensive retail data. © 2010 Blackwell Verlag GmbH.

Salmonella and eggs: from production to plate.

PubMed

Whiley, Harriet; Ross, Kirstin

2015-02-26

Salmonella contamination of eggs and egg shells has been identified as a public health concern worldwide. A recent shift in consumer preferences has impacted on the egg industry, with a push for cage-free egg production methods. There has also been an increased desire from consumers for raw and unprocessed foods, potentially increasing the risk of salmonellosis. In response to these changes, this review explores the current literature regarding Salmonella contamination of eggs during the production processing through to food handling protocols. The contamination of eggs with Salmonella during the production process is a complex issue, influenced by many variables including flock size, flock age, stress, feed, vaccination, and cleaning routines. Currently there is no consensus regarding the impact of caged, barn and free range egg production has on Salmonella contamination of eggs. The literature regarding the management and control strategies post-collection, during storage, transport and food handling is also reviewed. Pasteurisation and irradiation were identified as the only certain methods for controlling Salmonella and are essential for the protection of high risk groups, whereas control of temperature and pH were identified as potential control methods to minimise the risk for foods containing raw eggs; however, further research is required to provide more detailed control protocols and education programs to reduce the risk of salmonellosis from egg consumption.

Salmonella and Eggs: From Production to Plate

PubMed Central

Whiley, Harriet; Ross, Kirstin

2015-01-01

Salmonella contamination of eggs and egg shells has been identified as a public health concern worldwide. A recent shift in consumer preferences has impacted on the egg industry, with a push for cage-free egg production methods. There has also been an increased desire from consumers for raw and unprocessed foods, potentially increasing the risk of salmonellosis. In response to these changes, this review explores the current literature regarding Salmonella contamination of eggs during the production processing through to food handling protocols. The contamination of eggs with Salmonella during the production process is a complex issue, influenced by many variables including flock size, flock age, stress, feed, vaccination, and cleaning routines. Currently there is no consensus regarding the impact of caged, barn and free range egg production has on Salmonella contamination of eggs. The literature regarding the management and control strategies post-collection, during storage, transport and food handling is also reviewed. Pasteurisation and irradiation were identified as the only certain methods for controlling Salmonella and are essential for the protection of high risk groups, whereas control of temperature and pH were identified as potential control methods to minimise the risk for foods containing raw eggs; however, further research is required to provide more detailed control protocols and education programs to reduce the risk of salmonellosis from egg consumption. PMID:25730295

Advanced Oxidation Process sanitization of hatching eggs reduces Salmonella in broiler chicks.

PubMed

Rehkopf, A C; Byrd, J A; Coufal, C D; Duong, T

2017-10-01

The microbial quality of eggs entering the hatchery is an important critical control point for biosecurity, pathogen reduction, and food safety programs in poultry production. Developing interventions to reduce Salmonella contamination of eggs is important to improving the microbial food safety of poultry and poultry products. The hydrogen peroxide (H2O2) and ultraviolet light (UV) Advanced Oxidation Process (AOP) has been previously demonstrated to be effective in reducing Salmonella on the surface of experimentally contaminated eggs. The objective of this study was to evaluate the effect of treating eggs with an egg-sanitizing apparatus using the H2O2/UV AOP on Salmonella contamination during incubation, hatching, and in broiler chicks during grow-out. Experimentally contaminated eggs were treated using the automated H2O2/UV AOP egg sanitizer and incubated for 21 d. AOP sanitization reduced Salmonella up to 7 log10 cfu egg-1 (P < 0.05) from the surface of experimentally contaminated eggs and reduced the number of Salmonella positive eggs by up to 75% (P < 0.05) when treated 1 h post-inoculation. AOP treatment also reduced the number of Salmonella-positive eggs during incubation. Additionally, Salmonella was recovered from more chicks hatched from untreated eggs than from eggs treated using the H2O2/UV AOP egg sanitizer (P < 0.05) through 14 d posthatch. These data suggest reduction of Salmonella contamination on the surface of eggs using the H2O2/UV AOP egg sanitizer prior to incubation may reduce the gastrointestinal colonization of chicks by Salmonella. © 2017 Poultry Science Association Inc.

Salmonella spp. and Extended-Spectrum Cephalosporin-Resistant Escherichia coli Frequently Contaminate Broiler Chicken Transport Cages of an Organic Production Company.

PubMed

Mollenkopf, Dixie F; De Wolf, Brittany; Feicht, Sydnee M; Cenera, Johana K; King, Christy A; van Balen, Joany C; Wittum, Thomas E

2018-06-06

Antimicrobial resistant bacteria in retail meat pose a health hazard to the public, as does contamination of these products with Salmonella. Our aim was to determine the prevalence of Salmonella as well as Escherichia coli expressing AmpC and extended-spectrum beta-lactamase (ESBL) resistance phenotypes contaminating broiler transport cages and fresh, retail ground chicken meat. Sterile gauze sponges were used to collect duplicate cage floor samples from transport trailers that deliver market-ready birds to a single organic poultry-processing facility. With the exception of the first visit (n = 25), 50 duplicate cage floor samples were collected using moistened sterile gauze sponges on each of nine weekly visits during May, June, and July 2013. Additionally, fresh, retail ground chicken meat was sampled at each weekly visit from an on-site retail store located at the same processing facility. A total of 425 cage swabs and 72 ground chicken aliquots from 24 retail packages were collected and screened for the presence of Salmonella as well as E. coli expressing resistance to extended-spectrum cephalosporins using selective culture. We recovered Salmonella from 26.1% of cage swab samples and 2.8% of retail meat samples. E. coli expressing AmpC and ESBL resistance phenotypes were recovered from 84.9% and 22.6% of cage swabs and 77.8% and 11.1% of fresh, retail ground meat samples, respectively. Our results suggest that transport cages could potentially act as a source of broiler exposure to both Salmonella and enteric bacteria resistant to important antimicrobial drugs as they are transported for entry into the food supply as fresh, retail meat products.

Salmonella in the pork production chain and its impact on human health in the European Union.

PubMed

Bonardi, S

2017-06-01

Salmonella spp. comprise the second most common food-borne pathogens in the European Union (EU). The role of pigs as carriers of Salmonella has been intensively studied both on farm and at slaughter. Salmonella infection in pigs may cause fever, diarrhoea, prostration and mortality. However, most infected pigs remain healthy carriers, and those infected at the end of the fattening period could pose a threat to human health. Contamination of pig carcasses can occur on the slaughter line, and it is linked to cross-contamination from other carcasses and the presence of Salmonella in the environment. Therefore, Salmonella serovars present on pig carcasses can be different from those detected in the same bathes on the farm. In recent years, S. Typhimurium, S. Derby and S. serotype 4,[5],12:i:- (a monophasic variant of S. Typhimurium) have been the most common serovars to be detected in pigs in EU countries, but S. Rissen, S. Infantis, S. Enteritidis and S. Brandenburg have also been reported. In humans, several cases of salmonellosis have been linked to the consumption of raw or undercooked pork and pork products. Among the main serovars of porcine origin detected in confirmed human cases, S. Typhimurium, the monophasic variant S. 4,[5],12:i:- and S. Derby are certainly the most important.

Bovine salmonellosis attributed to Salmonella anatum-contaminated haylage and dietary stress.

PubMed

Glickman, L T; McDonough, P L; Shin, S J; Fairbrother, J M; LaDue, R L; King, S E

1981-06-15

An epizootic of salmonellosis in a dairy herd started 2 days after the feeding of a new shipment of medicinal-smelling soybean meal. Clinical findings consisted of diarrhea or fever (greater than 39 C), or both, and markedly decreased milk production. The attack rate was 73% in lactating cows, 3% in calves, and 0% in nonlactating cows. There were no deaths, but 1 cow aborted a late-term fetus. Salmonella anatum was isolated from feces, milk, pharynx, uterine fluid, haylage, and bird droppings from a hayfield. The epidemiologic findings suggested that haylage contaminated by wild birds and improperly stored in a silo was the source of infection and that the precipitating event was ingestion of spoiled soybean meal.

Salmonella risk to consumers via pork is related to the Salmonella prevalence in pig feed.

PubMed

Rönnqvist, M; Välttilä, V; Ranta, J; Tuominen, P

2018-05-01

Pigs are an important source of human infections with Salmonella, one of the most common causes of sporadic gastrointestinal infections and foodborne outbreaks in the European region. Feed has been estimated to be a significant source of Salmonella in piggeries in countries of a low Salmonella prevalence. To estimate Salmonella risk to consumers via the pork production chain, including feed production, a quantitative risk assessment model was constructed. The Salmonella prevalence in feeds and in animals was estimated to be generally low in Finland, but the relative importance of feed as a source of Salmonella in pigs was estimated as potentially high. Discontinuation of the present strict Salmonella control could increase the risk of Salmonella in slaughter pigs and consequent infections in consumers. The increased use of low risk and controlled feed ingredients could result in a consistently lower residual contamination in pigs and help the tracing and control of the sources of infections. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genetic Diversity of Clinical and Environmental Strains of Salmonella enterica Serotype Weltevreden Isolated in Malaysia

PubMed Central

Thong, K. L.; Goh, Y. L.; Radu, S.; Noorzaleha, S.; Yasin, R.; Koh, Y. T.; Lim, V. K. E.; Rusul, G.; Puthucheary, S. D.

2002-01-01

The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.27 to 1.00), indicating that PFGE is very discriminative and that multiple clones of Salmonella serotype Weltevreden exist among clinical and environmental isolates. Strains of one dominant pulsotype (pulsotype X1/X2) appeared to be endemic in this region, as they were consistently recovered from humans with salmonellosis between 1996 and 2001 and from raw vegetables. In addition, the sharing of similar PFGE profiles among isolates from humans, vegetables, and beef provides indirect evidence of the possible transmission of salmonellosis from contaminated raw vegetables and meat to humans. Furthermore, the recurrence of PFGE profile X21 among isolates found in samples of vegetables from one wet market indicated the persistence of this clone. The environment in the wet markets may represent a major source of cross-contamination of vegetables with Salmonella serotype Weltevreden. Antibiotic sensitivity tests showed that the clinical isolates of Salmonella serotype Weltevreden remained drug sensitive but that the vegetable isolates were resistant to at least two antibiotics. To the best of our knowledge, this is the first study to compare clinical and environmental isolates of Salmonella serotype Weltevreden in Malaysia. PMID:12089269

Genetic diversity of clinical and environmental strains of Salmonella enterica serotype Weltevreden isolated in Malaysia.

PubMed

Thong, K L; Goh, Y L; Radu, S; Noorzaleha, S; Yasin, R; Koh, Y T; Lim, V K E; Rusul, G; Puthucheary, S D

2002-07-01

The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.27 to 1.00), indicating that PFGE is very discriminative and that multiple clones of Salmonella serotype Weltevreden exist among clinical and environmental isolates. Strains of one dominant pulsotype (pulsotype X1/X2) appeared to be endemic in this region, as they were consistently recovered from humans with salmonellosis between 1996 and 2001 and from raw vegetables. In addition, the sharing of similar PFGE profiles among isolates from humans, vegetables, and beef provides indirect evidence of the possible transmission of salmonellosis from contaminated raw vegetables and meat to humans. Furthermore, the recurrence of PFGE profile X21 among isolates found in samples of vegetables from one wet market indicated the persistence of this clone. The environment in the wet markets may represent a major source of cross-contamination of vegetables with Salmonella serotype Weltevreden. Antibiotic sensitivity tests showed that the clinical isolates of Salmonella serotype Weltevreden remained drug sensitive but that the vegetable isolates were resistant to at least two antibiotics. To the best of our knowledge, this is the first study to compare clinical and environmental isolates of Salmonella serotype Weltevreden in Malaysia.

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

PubMed

Burgess, F; Little, C L; Allen, G; Williamson, K; Mitchelli, R T

2005-03-01

During September and October 2002, 3,662 prepackaged raw meat samples were collected to evaluate the extent and nature of microbiological contamination on external surfaces of the packaging, which could potentially cross-contaminate ready-to-eat foods during and after purchase. Salmonella was detected on two (<1%) samples of external packaging (both from raw chicken), and Campylobacter was detected on 41 (1.1%) samples of external packaging. The external packaging of game fowl exhibited the highest Campylobacter contamination (3.6%), followed by raw chicken (3.0%), lamb (1.6%), turkey (0.8%), pork (0.2%), and beef (0.1%); Campylobacter jejuni and Campylobacter coli accounted for 59% (24 of 41) and 24% (10 of 41) of the contaminating Campylobacter species, respectively. C. coli isolates from the external packaging were more multiresistant to antimicrobial drugs, including quinolones such as ciprofloxacin, than was C. jejuni. Escherichia coli (an indicator of fecal contamination) was isolated from the external packaging on 4% of the raw meat samples at levels of 40 to 10(5) CFU per swab. The external packaging of raw meats is a vehicle for potential cross-contamination by Campylobacter, Salmonella, and E. coli in retail premises and consumers' homes. The external surface of heat-sealed packaging was less frequently contaminated with Campylobacter and E. coli compared with other types of packaging (e.g., overwrapping, bag, and tie tape) (P < 0.0001 to 0.01). In addition, external packaging of raw meats was contaminated less frequently with Campylobacter and E. coli when packaging was intact, packaging and display areas were visually clean, display temperatures were below 8 degrees C, and hazard analysis systems were in place.

A rapid Salmonella detection method involving thermophilic helicase-dependent amplification and a lateral flow assay.

PubMed

Du, Xin-Jun; Zhou, Tian-Jiao; Li, Ping; Wang, Shuo

2017-08-01

Salmonella is a major foodborne pathogen that is widespread in the environment and can cause serious human and animal disease. Since conventional culture methods to detect Salmonella are time-consuming and laborious, rapid and accurate techniques to detect this pathogen are critically important for food safety and diagnosing foodborne illness. In this study, we developed a rapid, simple and portable Salmonella detection strategy that combines thermophilic helicase-dependent amplification (tHDA) with a lateral flow assay to provide a detection result based on visual signals within 90 min. Performance analyses indicated that the method had detection limits for DNA and pure cultured bacteria of 73.4-80.7 fg and 35-40 CFU, respectively. Specificity analyses showed no cross reactions with Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Enterobacter aerogenes, Shigella and Campylobacter jejuni. The results for detection in real food samples showed that 1.3-1.9 CFU/g or 1.3-1.9 CFU/mL of Salmonella in contaminated chicken products and infant nutritional cereal could be detected after 2 h of enrichment. The same amount of Salmonella in contaminated milk could be detected after 4 h of enrichment. This tHDA-strip can be used for the rapid detection of Salmonella in food samples and is particularly suitable for use in areas with limited equipment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Direct feeding of microencapsulated bacteriophages to reduce Salmonella colonization in pigs

USDA-ARS?s Scientific Manuscript database

Salmonella shedding often increases in pigs following pre-slaughter transportation and/or lairage. We previously showed that administering anti-Salmonella bacteriophages to pigs by gavage significantly reduced Salmonella colonization when the pigs were exposed to a Salmonella-contaminated pen. In ...

Multidrug-Resistant Salmonella Heidelberg Associated with Mechanically Separated Chicken at a Correctional Facility.

PubMed

Taylor, Amanda L; Murphree, Rendi; Ingram, L Amanda; Garman, Katie; Solomon, Deborah; Coffey, Eric; Walker, Deborah; Rogers, Marsha; Marder, Ellyn; Bottomley, Marie; Woron, Amy; Thomas, Linda; Roberts, Sheri; Hardin, Henrietta; Arjmandi, Parvin; Green, Alice; Simmons, Latoya; Cornell, Allyson; Dunn, John

2015-12-01

We describe multidrug-resistant (MDR) Salmonella Heidelberg infections associated with mechanically separated chicken (MSC) served at a county correctional facility. Twenty-three inmates met the case definition. All reported diarrhea, 19 (83%) reported fever, 16 (70%) reported vomiting, 4 (17%) had fever ≥103°F, and 3 (13%) were hospitalized. A case-control study found no single food item significantly associated with illness. Salmonella Heidelberg with an indistinguishable pulsed-field gel electrophoresis pattern was isolated from nine stool specimens; two isolates displayed resistance to a total of five drug classes, including the third-generation cephalosporin, ceftriaxone. MDR Salmonella Heidelberg might have contributed to the severity of illness. Salmonella Heidelberg indistinguishable from the outbreak subtype was isolated from unopened MSC. The environmental health assessment identified cross-contamination through poor food-handling practices as a possible contributing factor. Proper hand-washing techniques and safe food-handling practices were reviewed with the kitchen supervisor.

Prevalence of salmonella in neck skin and bone of chickens.

PubMed

Wu, Diezhang; Alali, W Q; Harrison, M A; Hofacre, C L

2014-07-01

Bone-in and boneless parts, such as drumsticks, are used in ground chicken production. In addition, neck skin is used as a source of fat in ground products. Contaminated chicken neck skin and bones containing internalized Salmonella are potential sources of this pathogen in ground chicken. This study determined the prevalence of Salmonella and serotype distribution in drumstick bones and neck skin of postchill chicken carcasses. One week prior to slaughter, chicken houses (n = 26) at nine farms were tested for the presence of Salmonella, using the boot sock method. Chicken flocks from these houses originated from Salmonella-positive breeders. Eight Salmonella-positive chicken flocks and one flock with undetermined Salmonella status were monitored through processing. Three hundred postchill drumsticks and 299 neck skin samples were analyzed for Salmonella prevalence. Skin samples were rinsed and stomached prior to analysis. Bones were extracted from the drumsticks, external surfaces were sterilized, and bones were crushed for analysis. One Salmonella isolate from each positive sample was serogrouped. Half of the isolates representing different sample types were serotyped. Overall, Salmonella was found in 0.8, 21.4, and 80.1% of bone marrow, neck skin, and farms, respectively. Prevalence of Salmonella on rinsed skin samples (2.3%) and stomached skin samples (20.7%) differed significantly (P ≤ 0.05). Serogroups B, C2, D, and E were found at 23.4, 31.9, 11.7, and 29.8%, respectively. Six Salmonella serotypes were identified: Liverpool (37.9%), Kentucky (27.6%), and Typhimurium (27.6%) were isolated most frequently from neck skin; the two bone isolates were Kentucky; and more than 50% of the farm isolates were Kentucky and Ouakam. Salmonella-contaminated neck skin might be a more significant source of this contamination in ground chicken than Salmonella internalized in bones.

Inactivation of Salmonella and Escherichia coli O157:H7 on artificially contaminated alfalfa seeds using high hydrostatic pressure.

PubMed

Neetoo, Hudaa; Chen, Haiqiang

2010-05-01

Alfalfa sprouts contaminated with Salmonella and Escherichia coli O157:H7 have been implicated in several outbreaks of foodborne illnesses in recent years. The seed used for sprouting appears to be the primary source of pathogens. Seed decontamination prior to sprouting presents a unique challenge for the sprouting industry since cells of the pathogenic survivors although undetectable after sanitizing treatments, can potentially multiply back to hazardous levels. The focus of this study was to therefore test the efficacy of high hydrostatic pressure to eliminate a approximately 5 log CFU/g load of Salmonella and E. coli O157:H7 on alfalfa seeds. Pressure treatment of 600 MPa for up to 25 min at 20 degrees C could not result in complete inactivation of Salmonella. High-pressure treatment was then carried out either at sub-ambient (4 degrees C) or elevated (40, 45 and 50 degrees C) temperatures to test the ability of high pressure to eliminate Salmonella. Pressure treatment at 4 and 20 degrees C did not deliver any satisfactory inactivation of Salmonella while high pressure at elevated temperatures achieved complete kill. Pre-soaking seeds prior to high-pressure treatment also enhanced pressure inactivation of Salmonella but at the expense of seed viability. High-pressure treatment of 500 MPa for 2 min at 45 degrees C was able to eliminate wild-type Salmonella and E. coli O157:H7 strains without bringing about any appreciable decrease in the seed viability. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

A national outbreak of Salmonella serotype Tennessee infections from contaminated peanut butter: a new food vehicle for salmonellosis in the United States.

PubMed

Sheth, Anandi N; Hoekstra, Mike; Patel, Nehal; Ewald, Gwen; Lord, Cathy; Clarke, Carmen; Villamil, Elizabeth; Niksich, Katherine; Bopp, Cheryl; Nguyen, Thai-An; Zink, Donald; Lynch, Michael

2011-08-01

Salmonella serotype Tennessee is a rare cause of the estimated 1 million cases of salmonellosis occurring annually in the United States. In January 2007, we began investigating a nationwide increase in Salmonella Tennessee infections. We defined a case as Salmonella Tennessee infection in a patient whose isolate demonstrated 1 of 3 closely related pulsed-field gel electrophoresis patterns and whose illness began during the period 1 August 2006 through 31 July 2007. We conducted a case-control study in 22 states and performed laboratory testing of foods and environmental samples. We identified 715 cases in 48 states; 37% of isolates were from urine specimens. Illness was associated with consuming peanut butter more than once a week (matched odds ratio [mOR], 3.5 [95% confidence interval {95% CI}, 1.4-9.9]), consuming Brand X peanut butter (mOR, 12.1 [95% CI, 3.6-66.3]), and consuming Brand Y peanut butter (mOR, 9.1 [95% CI, 1.0-433]). Brands X and Y were produced in 1 plant, which ceased production and recalled products on 14 February 2007. Laboratories isolated outbreak strains of Salmonella Tennessee from 34 Brands X and Y peanut butter jars and 2 plant environmental samples. This large, widespread outbreak of salmonellosis is the first linked to peanut butter in the United States; a nationwide recall resulted in outbreak control. Environmental contamination in the peanut butter plant likely caused this outbreak. This outbreak highlights the risk of salmonellosis from heat-processed foods of nonanimal origin previously felt to be low risk for Salmonella contamination.

Determination of viable Salmonellae from potable and source water through PMA assisted qPCR.

PubMed

Singh, Gulshan; Vajpayee, Poornima; Bhatti, Saurabh; Ronnie, Nirmala; Shah, Nimish; McClure, Peter; Shanker, Rishi

2013-07-01

Resource constrained countries identified as endemic zones for pathogenicity of Salmonella bear an economic burden due to recurring expenditure on medical treatment. qPCR used for Salmonella detection could not discriminate between viable and nonviable cells. Propidium monoazide (PMA) that selectively penetrates nonviable cells to cross-link their DNA, was coupled with ttr gene specific qPCR for quantifying viable salmonellae in source/potable waters collected from a north Indian city. Source water (raw water for urban potable water supply) and urban potable water exhibited viable salmonellae in the range of 2.1×10(4)-2.6×10(6) and 2-7160CFU/100mL, respectively. Potable water at water works exhibited DNA from dead cells but no viable cells were detected. PMA assisted qPCR could specifically detect low numbers of live salmonellae in Source and potable waters. This strategy can be used in surveillance of urban potable water distribution networks to map contamination points for better microbial risk management. Copyright © 2013 Elsevier Inc. All rights reserved.

Bacteriophage cocktail for biocontrol of Salmonella in dried pet food.

PubMed

Heyse, Serena; Hanna, Leigh Farris; Woolston, Joelle; Sulakvelidze, Alexander; Charbonneau, Duane

2015-01-01

Human salmonellosis has been associated with contaminated pet foods and treats. Therefore, there is interest in identifying novel approaches for reducing the risk of Salmonella contamination within pet food manufacturing environments. The use of lytic bacteriophages shows promise as a safe and effective way to mitigate Salmonella contamination in various food products. Bacteriophages are safe, natural, highly targeted antibacterial agents that specifically kill bacteria and can be targeted to kill food pathogens without affecting other microbiota. In this study, we show that a cocktail containing six bacteriophages had a broadspectrum activity in vitro against a library of 930 Salmonella enterica strains representing 44 known serovars. The cocktail was effective against 95% of the strains in this tested library. In liquid culture dose-ranging experiments, bacteriophage cocktail concentrations of ≥10(8) PFU/ml inactivated more than 90% of the Salmonella population (10(1) to 10(3) CFU/ml). Dried pet food inoculated with a mixture containing equal proportions of Salmonella serovars Enteritidis (ATCC 4931), Montevideo (ATCC 8387), Senftenberg (ATCC 8400), and Typhimurium (ATCC 13311) and then surface treated with the six-bacteriophage cocktail (≥2.5 ± 1.5 × 10(6) PFU/g) achieved a greater than 1-log (P < 0.001) reduction compared with the phosphate-buffered saline-treated control in measured viable Salmonella within 60 min. Moreover, this bacteriophage cocktail reduced natural contamination in samples taken from an undistributed lot of commercial dried dog food that tested positive for Salmonella. Our results indicate that bacteriophage biocontrol of S. enterica in dried pet food is technically feasible.

Multistate outbreak of human Salmonella infections caused by contaminated dry dog food--United States, 2006-2007.

PubMed

2008-05-16

During January 1, 2006-December 31, 2007, CDC collaborated with public health officials in Pennsylvania, other states, and the Food and Drug Administration (FDA) to investigate a prolonged multistate outbreak of Salmonella enterica serotype Schwarzengrund infections in humans. A total of 70 cases of S. Schwarzengrund infection with the outbreak strain (XbaI pulsed-field gel electrophoresis [PFGE] pattern JM6X01.0015) were identified in 19 states, mostly in the northeastern United States. This report describes the outbreak investigation, which identified the source of infection as dry dog food produced at a manufacturing plant in Pennsylvania. This investigation is the first to identify contaminated dry dog food as a source of human Salmonella infections. After handling pet foods, pet owners should wash their hands immediately, and infants should be kept away from pet feeding areas.

Natural antimicrobials to control biofilms formed by environmental isolates of Salmonella

USDA-ARS?s Scientific Manuscript database

Fresh produce account for 9.5 million (12%) of the ~76 million U.S. foodborne illnesses annually. Salmonella is the leading causative agent of an estimated 35% hospitalizations and 28% deaths. Fresh produce can be contaminated by Salmonella at farm level via contaminated manure, irrigation water, w...

Prevalence of Salmonella spp. in pet turtles and their environment

PubMed Central

Back, Du-San; Shin, Gee-Wook; Wendt, Mitchell

2016-01-01

Pet turtles are known as a source of Salmonella infection to humans when handled in captivity. Thirty four turtles purchased from pet shops and online markets in Korea were examined to determine whether the turtles and their environment were contaminated with Salmonella spp. Salmonella spp. were isolated from fecal samples of 17 turtles. These isolates were identified as S. enterica through 16S rRNA gene sequencing. The isolation rate of Salmonella spp. from the soil and water samples increased over time. We concluded that a high percentage of turtles being sold in pet shops were infected with Salmonella spp., and their environments tend to become contaminated over time unless they are maintained properly. These results indicate that pet turtles could be a potential risk of salmonellosis in Korea. PMID:27729933

Efficacy of chlorine and calcinated calcium treatment of alfalfa seeds and sprouts to eliminate Salmonella.

PubMed

Gandhi, Megha; Matthews, Karl R

2003-11-01

The efficacy of a 20,000 ppm calcium hypochlorite treatment of alfalfa seeds artificially contaminated with Salmonella was studied. Salmonella populations reached >7.0 log on sprouts grown from seeds artificially contaminated with Salmonella and then treated with 20,000 ppm Ca(OCl)(2). The efficacy of spray application of chlorine (100 ppm) to eliminate Salmonella during germination and growth of alfalfa was assessed. Alfalfa seed artificially contaminated with Salmonella was treated at germination, on day 2 or day 4, or for the duration of the growth period. Spray application of 100 ppm chlorine at germination, day 2, or day 4 of growth was minimally effective resulting in approximately a 0.5-log decrease in population of Salmonella. Treatment on each of the 4 days of growth reduced populations of Salmonella by only 1.5 log. Combined treatment of seeds with 20,000 ppm Ca(OCl)(2) and followed by 100 ppm chlorine or calcinated calcium during germination and sprout growth did not eliminate Salmonella.

Outer membrane vesicles from flagellin-deficient Salmonella enterica serovar Typhimurium induce cross-reactive immunity and provide cross-protection against heterologous Salmonella challenge.

PubMed

Liu, Qiong; Liu, Qing; Yi, Jie; Liang, Kang; Hu, Bo; Zhang, Xiangmin; Curtiss, Roy; Kong, Qingke

2016-10-04

Outer membrane vesicles (OMVs) isolated from Salmonella Typhimurium are potentially useful for developing subunit vaccines because of high immunogenicity and protective efficacy. However, flagella might remain in OMV pellets following OMV purification, resulting in non-essential immune responses and counteraction of bacterial protective immune responses when developing a vaccine against infection of multiple serotypes Salmonella. In this study, a flagellin-deficient S. Typhimurium mutant was constructed. Lipopolysaccharide profiles, protein profiles and cryo-electron microscopy revealed that there were no significant differences between the wild-type and mutant OMVs, with the exception of a large amount of flagellin in the wild-type OMVs. Neither the wild-type OMVs nor the non-flagellin OMVs were toxic to macrophages. Mice immunized with the non-flagellin OMVs produced high concentrations of IgG. The non-flagellin OMVs elicited strong mucosal antibody responses in mice when administered via the intranasal route in addition to provoking higher cross-reactive immune responses against OMPs isolated from S. Choleraesuis and S. Enteritidis. Both intranasal and intraperitoneal immunization with the non-flagellin OMVs provided efficient protection against heterologous S. Choleraesuis and S. Enteritidis challenge. Our results indicate that the flagellin-deficient OMVs may represent a new vaccine platform that could be exploited to facilitate the production of a broadly protective vaccine.

Advanced Oxidation Process sanitation of hatching eggs reduces Salmonella in broiler chicks

USDA-ARS?s Scientific Manuscript database

Reduction of Salmonella contamination of eggs is important in improving the microbial food safety of poultry and poultry products. Developing interventions to reduce Salmonella contamination of eggs is important to improving the microbial quality of eggs entering the hatchery. Previously, the hydr...

Quantification and molecular characterization of Salmonella isolated from food samples involved in salmonellosis outbreaks in Rio Grande do Sul, Brazil

PubMed Central

Mürmann, Lisandra; dos Santos, Maria Cecília; Longaray, Solange Mendes; Both, Jane Mari Corrêa; Cardoso, Marisa

2008-01-01

Data concerning the prevalence and populations of Salmonella in foods implicated in outbreaks may be important to the development of quantitative microbial risk assessments of individual food products. In this sense, the objective of the present study was to assess the amount of Salmonella sp. in different foods implicated in foodborne outbreaks in Rio Grande do Sul occurred in 2005 and to characterize the isolated strains using phenotypic and genotypic methods. Nineteen food samples involved in ten foodborne outbreaks occurred in 2005, and positive on Salmonella isolation at the Central Laboratory of the Health Department of the State of Rio Grande do Sul, were included in this study. Food samples were submitted to estimation of Salmonella using the Most Probable Number (MPN) technique. Moreover, one confirmed Salmonella colony of each food sample was serotyped, characterized by its XbaI-macrorestriction profile, and submitted to antimicrobial resistance testing. Foods containing eggs, mayonnaise or chicken were contaminated with Salmonella in eight outbreaks. Higher counts (>107 MPN.g-1) of Salmonella were detected mostly in foods containing mayonnaise. The isolation of Salmonella from multiple food items in five outbreaks probably resulted from the cross-contamination, and the high Salmonella counts detected in almost all analyzed samples probably resulted from storing in inadequate temperature. All strains were identified as S. Enteritidis, and presented a unique macrorestriction profile, demonstrating the predominance of one clonal group in foods involved in the salmonellosis outbreaks. A low frequency of antimicrobial resistant S. Enteritidis strains was observed and nalidixic acid was the only resistance marker detected. PMID:24031261

Commercially laid eggs vs. discarded hatching eggs: contamination by Salmonella spp.

PubMed

Kottwitz, Luciana B M; Leão, Joice Aparecida; Back, Alberto; Rodrigues, Dalia dos P; Magnani, Marciane; de Oliveira, Tereza C R M

2013-01-01

Salmonella enterica is frequently associated with outbreaks of human salmonellosis, and products of avian origin, such as eggs and chicken meat, are the main vehicles of its transmission. The present study describes the occurrence of different serovars of Salmonella enterica and phagotypes of S. enterica serovar Enteritidis in eggs destined for human consumption. Four thousand eggs obtained from commercial egg laying farms and one thousand discarded hatching eggs from broiler farms, which were acquired at farmers' markets and informal shops, were analyzed. Salmonella spp. was isolated from 52.0% of the discarded hatching eggs, in which the predominant serovar was Enteritidis (84.6%), and the predominant Salmonella Enteritidis phagotype (PT) was PT7 (26.9%). Salmonella spp. was not isolated from eggs obtained from commercial egg laying farms. The antimicrobial resistance profile showed that 23.1% (n = 6) of the SE strains were resistant to nalidixic acid. The results suggest that the consumption of discarded hatching eggs represents an important source of Salmonella transmission to humans.

Large outbreak of Salmonella enteritidis PT8 in Portsmouth, UK, associated with a restaurant.

PubMed

Severi, E; Booth, L; Johnson, S; Cleary, P; Rimington, M; Saunders, D; Cockcroft, P; Ihekweazu, C

2012-10-01

Seventy-five individuals with Salmonella infection were identified in the Portsmouth area during August and September 2009, predominantly Salmonella Enteritidis phage type 8. Five patients were admitted to hospital. A case-case comparison study showed that a local restaurant was the most likely source of the infection with a risk of illness among its customers 25-fold higher than that of those who did not attend the restaurant. A case-control study conducted to investigate specific risk factors for infection at the restaurant showed that eating salad was associated with a threefold increase in probability of illness. Changing from using ready washed lettuces to lettuces requiring washing and not adhering strictly to the 48 hours exclusion policy for food handlers with diarrhoea were likely to have contributed to the initiation and propagation of this outbreak. Possibilities for cross-contamination and environmental contamination were identified in the restaurant.

Sources of Salmonellae in broiler chickens in Ontario.

PubMed Central

Hacking, W C; Mitchell, W R; Carlson, H C

1978-01-01

Sources of Salmonellae infecting broiler chicken flocks in Ontario were investigated from July, 1975 to April, 1976. Three broiler flocks were investigated on each of four farms which received chicks from a common hatchery. Samples of feed and new litter were preenriched in nonselective broth subcultured to Salmonella-selective enrichment broth and plated on Salmonella-selective differential agar.Samples of used litter, water, culled chicks, insects, mice, wild birds and environmental swabs were not cultured initially in the nonselective broth. Fecal samples from principal and occasional flock attendants were examined for Samonellae. Salmonella infection, as judged by contaminated flock litter was detected in six flocks on two of the farms while the flocks on the other farms remained negative. Salmonellae were isolated from 23 of 412 feed samples (nine serotypes), six of 35 new wood shaving samples (four serotypes), one of 29 pools of culled chick viscera (one serotype) and 44 of 267 used litter samples (14 serotypes). These results indicate that broiler chicken flocks were infected with diverse Salmonellae introduced in day old chicks, pelleted feeds, wood shavings and residual contamination from the preceding flock. PMID:743597

Assessment of Meat and Poultry Product Recalls Due to Salmonella Contamination: Product Recovery and Illness Prevention.

PubMed

Seys, Scott A; Sampedro, Fernando; Hedberg, Craig W

2017-08-01

Data from the recalls of meat and poultry products from 2000 through 2012 due to Salmonella contamination were used to assess the factors associated with the recovery of the recalled product and to develop quantitative models to estimate the number of illnesses prevented by recalls. The percentage of product recovered following a recall action was not dependent on establishment size, recall expansions, complexity of the distribution chain, type of distribution, amount of time between the production and recall dates, or number of pounds of product recalled. However, illness-related recalls were associated with larger amounts of recalled product, smaller percentages of recalled product recovered, a greater number of days between the production date and recall date, and nationwide distribution than were recalls that were not illness related. In addition, the detection of recall-associated illnesses appeared to be enhanced in states with strong foodborne illness investigation systems. The number of Salmonella illnesses prevented by recalls was based on the number of illnesses occurring relative to the number of pounds consumed, which was then extrapolated to the number of pounds of recalled product recovered. A simulation using a program evaluation and review technique probability distribution with illness-related recalls from 2003 through 2012 estimated that there were 19,000 prevented Salmonella illnesses, after adjusting for underdiagnosis. Recalls not associated with illnesses from 2000 through 2012 prevented an estimated additional 8,300 Salmonella illnesses, after adjusting for underdiagnosis. Although further improvements to ensure accurate and complete reporting should be undertaken, our study demonstrates that recalls are an important tool for preventing additional Salmonella illnesses. Moreover, additional training resources dedicated to public health agencies for enhancing foodborne illness detection, investigations, and rapid response and reporting would

Attachment of Salmonella serovars and Listeria monocytogenes to stainless steel and plastic conveyor belts.

PubMed

Veluz, G A; Pitchiah, S; Alvarado, C Z

2012-08-01

In poultry industry, cross-contamination due to processing equipment and contact surfaces is very common. This study examined the extent of bacterial attachment to 6 different types and design of conveyor belts: stainless steel-single loop, stainless steel-balance weave, polyurethane with mono-polyester fabric, acetal, polypropylene mesh top, and polypropylene. Clean conveyor belts were immersed separately in either a cocktail of Salmonella serovars (Salmonella Typhimurium and Salmonella Enteritidis) or Listeria monocytogenes strains (Scott A, Brie 1, ATCC 6744) for 1 h at room temperature. Soiled conveyor chips were dipped in poultry rinses contaminated with Salmonella or Listeria cocktail and incubated at 10°C for 48 h. The polyurethane with mono-polyester fabric conveyor belt and chip exhibited a higher (P<0.05) mean number of attached Salmonella serovars (clean: 1.6 to 3.6 cfu/cm2; soiled: 0.8 to 2.4 cfu/cm2) and L. monocytogenes (clean: 4.0 to 4.3 cfu/cm2; soiled: 0.3 to 2.1 cfu/cm2) in both clean and soiled conditions. The stainless steel conveyor belt attached a lower (P<0.05) number of Salmonella serovars (clean: 0 to 2.6 cfu/cm2; soiled: 0.4 to 1.3 cfu/cm2) and L. monocytogenes (clean: 0.4 to 2.9 cfu/cm2; soiled: 0 to 0.7 cfu/cm2) than the polymeric materials, indicating weaker adhesion properties. Plastic conveyor belts exhibited stronger bacterial adhesion compared with stainless steel. The result suggests the importance of selecting the design and finishes of conveyor belt materials that are most resistant to bacterial attachment.

[A quantitative risk assessment model of salmonella on carcass in poultry slaughterhouse].

PubMed

Zhang, Yu; Chen, Yuzhen; Hu, Chunguang; Zhang, Huaning; Bi, Zhenwang; Bi, Zhenqiang

2015-05-01

To construct a quantitative risk assessment model of salmonella on carcass in poultry slaughterhouse and to find out effective interventions to reduce salmonella contamination. We constructed a modular process risk model (MPRM) from evisceration to chilling in Excel Sheet using the data of the process parameters in poultry and the Salmomella concentration surveillance of Jinan in 2012. The MPRM was simulated by @ risk software. The concentration of salmonella on carcass after chilling was 1.96MPN/g which was calculated by model. The sensitive analysis indicated that the correlation coefficient of the concentration of salmonella after defeathering and in chilling pool were 0.84 and 0.34,which were the primary factors to the concentration of salmonella on carcass after chilling. The study provided a quantitative assessment model structure for salmonella on carcass in poultry slaughterhouse. The risk manager could control the contamination of salmonella on carcass after chilling by reducing the concentration of salmonella after defeathering and in chilling pool.

Postharvest transfer and survival of Salmonella enterica serotype enteritidis on living lettuce.

PubMed

Waitt, J A; Kuhn, D D; Welbaum, G E; Ponder, M A

2014-02-01

The potential for postharvest transfer of Salmonella to 'living lettuce' is not well understood. In this study, the transfer of Salmonella enterica Enteritidis (6 log CFU g(-1) ) from worker hands or contaminated roots to leaves of living lettuce was quantified. Transfer rates of Salmonella from contaminated gloves to sequentially handled lettuce heads ranged from 94% to head 1, 82% to head 2 and 69% to head 3. On average, 2.9 ± 0.1 log CFU g(-1) (64%) Salmonella was transferred from inoculated roots to leaves resulting from typical postharvest handling activities for living lettuce. Salmonella persisted on leaves stored at recommended storage temperatures (4°C) and increased 0.5 log CFU g(-1) when stored at temperature abuse conditions (12°C). Salmonella increased 1.6 log CFU g(-1) on roots after 18-day storage at 12°C, emphasizing the need to maintain temperature control to reduce the risk of human illness. Hydroponically grown lettuce packaged in plastic clamshells with intact roots, marketed as 'living lettuce', is increasing in popularity due to its extended shelf life. This study demonstrates the transfer of Salmonella from contaminated worker hands and contaminated roots to leaves where it persisted at 4°C for 18 day. Temperature abuse (12°C) increased Salmonella on roots and leaves. These findings suggest that failure to maintain temperatures below 12°C can pose a risk for consumers purchasing living lettuce at markets where recommended storage temperatures are not maintained. © 2013 The Society for Applied Microbiology.

Outbreaks of Salmonella newport infection in dairy herds and their relationship to management and contamination of the environment.

PubMed

Clegg, F G; Chiejina, S N; Duncan, A L; Kay, R N; Wray, C

1983-06-18

Two outbreaks of Salmonella newport infection in dairy herds are described which were characterised by haemorrhagic enteritis. The history of the outbreaks, the extent of the losses, clinical and laboratory findings and treatment are described. The first herd consisted of 193 cattle, of which seven died, three aborted and another 84 required treatment. Salmonellosis persisted over 14 months throughout the summer on a paddock grazing system and continued during the following winter when the herd was loose housed. The relationship of the commencement of clinical disease to dietary changes and to the time of calving is described, as are the problems in controlling the disease. The second herd consisted of 98 milking cows and a few beef animals. One cow died and two aborted; altogether 18 were clinically affected. The epidemiology of the disease and the geographical relationship between the two farms is described. Extensive contamination of streams occurred and one cow died on a neighbouring third farm. In contact humans were found to be excreting the organism. The public health significance of the outbreak is discussed because bulk milk samples were contaminated with salmonellae for 10 months and local streams were polluted with human sewage.

Detection of Salmonella sp in chicken cuts using immunomagnetic separation

PubMed Central

de Cássia dos Santos da Conceição, Rita; Moreira, Ângela Nunes; Ramos, Roberta Juliano; Goularte, Fabiana Lemos; Carvalhal, José Beiro; Aleixo, José Antonio Guimarães

2008-01-01

The immunomagnetic separation (IMS) is a technique that has been used to increase sensitivity and specificity and to decrease the time required for detection of Salmonella in foods through different methodologies. In this work we report on the development of a method for detection of Salmonella in chicken cuts using in house antibody-sensitized microspheres associated to conventional plating in selective agar (IMS-plating). First, protein A-coated microspheres were sensitized with polyclonal antibodies against lipopolysacharide and flagella from salmonellae and used to standardize a procedure for capturing Salmonella Enteritidis from pure cultures and detection in selective agar. Subsequently, samples of chicken meat experimentally contaminated with S. Enteritidis were analyzed immediately after contamination and after 24h of refrigeration using three enrichment protocols. The detection limit of the IMS-plating procedure after standardization with pure culture was about 2x10 CFU/mL. The protocol using non-selective enrichment for 6-8h, selective enrichment for 16-18h and a post-enrichment for 4h gave the best results of S. Enteritidis detection by IMS-plating in experimentally contaminated meat. IMS-plating using this protocol was compared to the standard culture method for salmonellae detection in naturally contaminated chicken cuts and yielded 100% sensitivity and 94% specificity. The method developed using in house prepared magnetic microespheres for IMS and plating in selective agar was able to diminish by at least one day the time required for detection of Salmonella in chicken products by the conventional culture method. PMID:24031199

Influence of On-farm pig Salmonella status on Salmonella Shedding at Slaughter.

PubMed

Casanova-Higes, A; Andrés-Barranco, S; Mainar-Jaime, R C

2017-08-01

The risk of Salmonella shedding among pigs at slaughter with regard to their previous on-farm Salmonella status was assessed in a group of pigs from a farm from NE of Spain. A total of 202 pigs that had been serologically monitored monthly during the fattening period and from which mesenteric lymph nodes (MLN) and faecal (SFEC) samples were collected at slaughter for Salmonella isolation were included. A repeated-measures anova was used to assess the relationship between mean OD% values during the fattening period and sampling time and bacteriology on MLN and SFEC. Pigs were also grouped into four groups, that is pigs seronegative during the fattening period and Salmonella negative in MLN (group A; n = 69); pigs seronegative during the fattening period but Salmonella positive in MLN (B; n = 36); pigs seropositive at least once and Salmonella positive in MLN (C; n = 50); and pigs seropositive at least once but Salmonella negative in (D; n = 47). Pigs shedding at slaughter seroconverted much earlier and showed much higher mean OD% values than non-shedders pigs. The proportion of Salmonella shedders in groups A and D was high and similar (26.1% and 29.8%, respectively), but significantly lower than that for groups B and C. The odds of shedding Salmonella for groups B and C were 4.8 (95% CI = 1.5-15.5) and 20.9 (3.7-118) times higher, respectively, when compared to A. It was concluded that a large proportion of Salmonella seronegative pigs may shed Salmonella at slaughter, which would be likely associated to previous exposure with contaminated environments (i.e. transport and lairage). For pigs already infected at farm, the likelihood of shedding Salmonella was much higher and may depend on whether the bacterium has colonized the MLN or not. The odds of shedding Salmonella spp. were always much higher for pigs in which Salmonella was isolated from MLN. © 2016 Blackwell Verlag GmbH.

Observations on the distribution and control of Salmonella species in two integrated broiler companies.

PubMed

Davies, R; Breslin, M; Corry, J E; Hudson, W; Allen, V M

2001-08-25

The effectiveness of cleaning and disinfecting broiler farms and the persistence of Salmonella species in two integrated broiler companies was investigated for two years. Both companies used a cleaning and disinfection regime which included the application of a spray of phenolic disinfectant followed by fogging with formaldehyde solution, and this was highly effective in preventing carry-over of infection in the broiler houses. The disinfection of service areas and areas outside the houses was less effective but it had no influence on the Salmonella status of later flocks. Both companies had persistent problems with the contamination of pellet cooling systems in their feedmills with Salmonella 4, 12:d:- in company A, and with Salmonella binza and Salmonella ohio in company B. The hatcher incubators of both companies were also persistently contaminated with Salmonella livingstone and Salmonella thomasville in company A and with Salmonella senftenberg in company B. At both companies sites Salmonella enteritidis and Salmonella typhimurium Tr104 were also isolated occasionally from various locations.

Characterization of the Salmonella enterica Serotype Isangi Isolated from Patients for the First Time in China.

PubMed

Li, Xin-Peng; Gao, Ri-Hong; Hou, Pei-Bin; Ren, Yan-Yan; Zhang, Hua-Ning; Jiang, Kui-Ying; Chen, Yu-Zhen; Qi, Zi-Gang; Xu, Min; Bi, Zhen-Wang

2017-08-01

No studies have reported the isolation of serotype Salmonella Isangi from cases of salmonellosis in mainland China. We investigated an outbreak of foodborne disease with salmonella and collected the samples from the patients and surplus foods. Salmonella strains were isolated and the serotype was identified according to the Kauffmann-White scheme. The relatedness of the isolates was determined using pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). Antimicrobial susceptibility was conducted by the broth microdilution method. There were 74 diners in the case, 33 of which got ill, with an attack rate of 44.6% (33/74). A total of 24 samples were collected from the outbreak cases, six Salmonella Isangi strains were isolated and susceptible to all tested drugs. PFGE and WGS analysis suggested that the pathogen dissemination through a single or limited vector(s), the steamed fish and mixed food (fry spicy chicken, braised pork ribs, and goose leg), may be the source of infection or be cross-contaminated. We first report the characteristics of an outbreak and molecular strain relatedness of Salmonella Isangi in mainland China.

Prevalence and antibiogram study of Salmonella and Staphylococcus aureus in poultry meat

PubMed Central

Akbar, Ali; Anal, Anil Kumar

2013-01-01

Objective To evaluate the presence and antibiogram pattern of Salmonella and Staphylococcus aureus (S. aureus) in retail poultry meat products. Methods Foodborne pathogens (Salmonella and S. aureus) were isolated from poultry meat and confirmed with the help of biochemical and immunological test. Antibiogram of the isolates were examined by following CLSI methods. Results A total number of 209 poultry meat samples were collected and studied in this study. Out of which, 5.26% were found contaminated with Salmonella while 18.18% were found contaminated with S. aureus. All the Salmonella and S. aureus isolates were found resistant to at least one antibiotic. About 72.72% of the Salmonella isolates showed resistance to tetracycline, while S. aureus isolates were also found highly resistant to tetracycline equal to 44.73%. One of the Salmonella isolates showed multi-drug resistance to almost six antibiotics out of nine antibiotics used in the study. Multidrug resistant S. aureus isolates were also found in the study. Conclusions The study confirmed the presence of Salmonella and S. aureus in retail poultry meat. It is a potential threat to consumer health. To reduce the risk of contamination, good hygiene practices are necessary from processing to storage. PMID:23593598

Inactivation of Salmonella, Escherichia coli O157:H7 and non-O157 STEC by hypochlorite solutions with high organic loads

USDA-ARS?s Scientific Manuscript database

Introduction: Salmonella, E. coli O157:H7 and Non-O157 STEC have been recognized as foodborne pathogen concerns for fresh produce. Although chlorinated water (CW) is widely used in fresh produce processing to reduce pathogens and prevent cross-contamination, limited information is available on effic...

Salmonella Questions and Answers

MedlinePlus

... Forms Standard Forms FSIS United States Department of Agriculture Food Safety and Inspection Service About FSIS District ... Inspection Service (FSIS) of the U.S. Department of Agriculture (USDA) is addressing the problems of Salmonella contamination ...

Rodents as a Source of Salmonella Contamination in Wet Markets in Thailand.

PubMed

Ribas, Alexis; Saijuntha, Weerachai; Agatsuma, Takeshi; Prantlová, Veronika; Poonlaphdecha, Srisupaph

2016-08-01

Few studies have been conducted on the presence of Salmonella in the rodents that inhabit the wet markets that play an important role in daily life in Southeast Asia. The results of studies of rodents as carriers of Salmonella vary greatly, ranging from an absence of Salmonella to high prevalences. Previous studies investigated habitats such as farms and urban and wild areas where there is less rodent-human interaction than in wet markets. Consequently, the potential role of rodents as reservoirs and transmitters of Salmonella in wet markets is of great interest. Rodents were trapped in eight traditional wet markets in Thailand and identified to species level. Subsequently, they were screened for Salmonella and isolates were serotyped. A total of 110 rats (Rattus norvegicus and Rattus exulans) were examined. Overall, the prevalence of Salmonella in rats was 49.10%, but varied between 0% and 73.3% among markets. Three serovars were identified: Salmonella Typhimurium (30%), S. Weltevreden (12.7%), and S. 4,[5],12:i:- (6.4%). Our results show that rodents in wet markets are a potential reservoir of Salmonella due to the close contact they have with humans and food. The three isolated serovars, of which serovar S. 4,[5],12:i:- is reported for the first time in rodents, are among the 10 commonest serovars isolated from humans in Thailand. Thus, more attention should be paid to rodents as potential reservoirs of Salmonella.

Potential use of caprylic acid in broiler chickens: effect on Salmonella enteritidis.

PubMed

Skřivanová, Eva; Hovorková, Petra; Čermák, Ladislav; Marounek, Milan

2015-01-01

The effect of dietary caprylic acid (CA) on Salmonella Enteritidis, as well as the surface treatment of chicken skin contaminated with Salmonella Enteritidis was evaluated. To evaluate the dietary effect of CA on Salmonella Enteritidis, the individually housed broiler chickens (n=48) were divided into 4 groups (positive control, negative control, 2.5 g/kg of CA in the feed, and 5 g/kg of CA in the feed). The feed of all groups, except the negative control, was artificially contaminated with Salmonella Enteritidis ATCC 13076 (10(7) colony-forming units/100 g of feed). Both concentrations of dietary CA significantly decreased counts of Salmonella Enteritidis in the crop and cecum of experimental chickens (p<0.05). The effect of CA in the crop contents was more pronounced than in the cecum. Surface treatment of chilled chicken halves with CA at 1.25 and 2.5 mg/mL significantly decreased Salmonella Enteritidis contamination of chicken skin (p<0.05). The sensory evaluation of the skin and meat showed that treatment of the skin with 1.25 mg/mL of CA worsened odor and appearance of the chicken skin, while sensory traits of chicken meat were not significantly affected. Taste and overall acceptability was not influenced by CA in both meat and skin. Treatment of the skin with 2.5 mg/mL of CA resulted in more pronounced changes of the skin odor and appearance. In conclusion, dietary CA reduced carriage of Salmonella Enteritidis in chickens, whereas surface-treatment reduced or eliminated Salmonella Enteritidis contamination in the processed bird.

Survey of Salmonella contamination of raw shell eggs used in food service premises in the United Kingdom, 2005 through 2006.

PubMed

Little, C L; Rhoades, J R; Hucklesby, L; Greenwood, M; Surman-Lee, S; Bolton, F J; Meldrum, R; Wilson, I; McDonald, C; de Pinna, E; Threlfall, E J; Chan, C H

2008-01-01

This survey was launched after an unusual number of Salmonella Enteritidis outbreaks associated with the use of eggs in food service premises in England and Wales. Between November 2005 and December 2006, 9,528 eggs (1,588 pooled samples of 6 eggs) were collected from 1,567 food service premises in the United Kingdom, most of which (89%) were produced in the United Kingdom. Salmonella was isolated from 6 (0.38%) pools of eggs. Of these, 5 (0.31%) were Salmonella Enteritidis, which were further characterized to phage types (PTs): PT 4 (0.19%), PT 8 (0.06%), and PT 12 (0.06%). Salmonella Mbandaka was also isolated (0.06%). Salmonella was detected from five and one of pooled eggs samples that were produced in the United Kingdom and Germany, respectively; these were from different producers. The study showed evidence of poor egg storage and handling practices in food service premises, in that 55% did not store eggs under refrigerated conditions; 20.7% of eggs had expired "best before" dates or were in use after 3 weeks of lay, indicating poor stock rotation; and 37.1% pooled eggs not intended for immediate service. Eggs are a commonly consumed food that may occasionally be contaminated with Salmonella at different rates, according to their country of origin. The food service sector needs to be aware of this continuing hazard, receive appropriate food safety and hygiene training on storage and usage of raw shell eggs, adopt appropriate control measures, and follow advice provided by national food agencies in order to reduce the risk of infection.

A case-control study of domestic kitchen microbiology and sporadic Salmonella infection.

PubMed

Parry, S M; Slader, J; Humphrey, T; Holmes, B; Guildea, Z; Palmer, S R

2005-10-01

The microbiology of domestic kitchens in the homes of subjects who had suffered sporadic Salmonella infection (cases) was compared with control domestic kitchens. Case and control dishcloths and refrigerator swabs were examined for the presence of Salmonella spp., total Enterobacteriaceae counts and total aerobic colony counts. Salmonella spp. were isolated from both case and control dishcloths and refrigerators but there were no significant differences between the two groups. Colony counts were similar in case and control dishcloths and refrigerator swabs. There was no relationship between the total counts and presence of Salmonella . There was no evidence that cases of Salmonella infection were more likely to have kitchens which were contaminated with these bacteria or have higher bacterial counts than controls. Total bacterial counts were poor indicators of Salmonella contamination of the domestic kitchen environment. Further factors which could not be identified by a study of this design may increase risk of Salmonella food poisoning. These factors may include individual susceptibility of the patient. Alternatively, sporadic cases of Salmonella food poisoning may arise from food prepared outside the home.

Electrochemical characterization of an immunosensor for Salmonella spp. detection

USDA-ARS?s Scientific Manuscript database

Immunosensors represent a rapid alternative method for diagnosing Salmonella contamination. The objective of this study was to develop and evaluate the performance of an electrochemical immunosensor for the detection of Salmonella spp., the most common foodborne pathogen worldwide. In the immunosens...

Control and monitoring of Salmonella in egg-laying chickens

USDA-ARS?s Scientific Manuscript database

Contaminated eggs have been internationally significant sources for the transmission of Salmonella infection to humans for several decades. Both the public and private sectors have invested substantial resources in comprehensive risk reduction and monitoring programs for Salmonella in commercial egg...

Inhibition of nalidixic acid-resistant salmonella on marinated chicken skin.

PubMed

Pathania, A; McKee, S R; Bilgili, S F; Singh, M

2010-11-01

Marination is widely used to enhance flavor and increase consumer acceptability of meat and poultry products. The impact of such marination on the safety and shelf life of poultry meat was evaluated in this study. A series of experiments were conducted to determine the efficacy of teriyaki and lemon pepper marinades against multiple strains of nalidixic acid (NAL)-resistant Salmonella. NAL-resistant Salmonella serovar (Typhimurium, Heidelberg, and Senftenberg) cultures were inoculated onto chicken skin at 0.6 to 3.14 log CFU/g in a 12-well titer plate. Inoculated chicken skin was exposed to teriyaki or lemon pepper marinades for up to 32 h and stored at 4 or 25°C to determine the prevalence of Salmonella. To determine Salmonella survival, a three-strain cocktail of Salmonella was inoculated at low (ca. 4 log CFU/g) and high (8 log CFU/g) levels onto chicken skin that was then marinated with either teriyaki or lemon pepper marinade for up to 32 h and stored at 4 or 25°C. Prevalence of Salmonella was significantly reduced (P ≤ 0.05) by teriyaki marinade at all levels of contamination regardless of storage temperature. Lemon pepper marinade reduced Salmonella prevalence (P ≤ 0.05) at low levels of contamination (10¹ and 10² CFU/g), whereas no significant effect (P > 0.05) was observed at higher levels of contamination. Marination of chicken skin with teriyaki marinade greatly reduced Salmonella prevalence and survival (P ≤ 0.05) regardless of the storage temperature, indicating the antimicrobial potential of this marinade for poultry and meat products.

Enjoying Homemade Ice Cream without the Risk of Salmonella Infection

MedlinePlus

... Contaminants Buy, Store & Serve Safe Food Enjoying Homemade Ice Cream without the Risk of Salmonella Infection Share ... it Email Print August 2004 Every year homemade ice cream causes several outbreaks of Salmonella infection with ...

In vitro studies of chicken egg yolk antibody (IgY) against Salmonella enteritidis and Salmonella typhimurium.

PubMed

Lee, E N; Sunwoo, H H; Menninen, K; Sim, J S

2002-05-01

Chicken egg yolk antibody (IgY) raised against Salmonella enteritidis or Salmonella typhimurium was found in highly specific activity levels by ELISA. S. enteritidis- and S. typhimurium-specific IgY powder, prepared by freeze-drying the egg yolk water-soluble fraction, contained 15.5 and 10.0% of specific IgY, respectively. Anti-S. enteritidis IgY cross-reacted 55.3% with S. typhimurium. The cross-reactivity of anti-S. typhimurium IgY with S. enteritidis was 42.4%. Salmonella-specific IgY was demonstrated to inhibit Salmonella growth in liquid medium. The growth rate of S. enteritidis incubated with S. enteritidis-specific IgY was fourfold less than that of the control group during a 4-to-6-h incubation. Cell counts of S. typhimurium incubated with S. typhimurium-specific IgY were reduced by 1.6 log cfu/mL in comparison to that of the control group after 6 h of incubation. The specific binding activity of IgY was further evaluated by using immunofluorescence and immunoelectron microscopy. It was found that Salmonella-specific IgY could bind to the antigens expressed on the Salmonella surface, resulting in structural alterations of the bacterial surface.

Salmonella spp. on chicken carcasses in processing plants in Poland.

PubMed

Mikołajczyk, Anita; Radkowski, Mieczysław

2002-09-01

Chickens at selected points in the slaughter process and after slaughter on the dressing line in poultry plants were sampled and analyzed for Salmonella. These chickens came from the northeast part of Poland. The examinations were carried out in quarters I, II, III, and IV of 1999. All the birds were determined to be healthy by a veterinary inspection. Swab samples were taken from the cloaca after stunning and from the skin surface and body cavity of the whole bird after evisceration, after rinsing at the final rinse station but before chilling in the spin-chiller, and after cooling in the continuous cooling plant at the end of the production day. In 1999, 400 whole chickens were examined. The percentage of these 400 chickens from which Salmonella spp. were isolated was relatively high (23.75%; Salmonella-positive results were observed in 95 cases). Salmonella spp. were found after stunning in 6% of the chickens (6 of 100 samples), after evisceration in 24% (24 of 100), before cooling in 52% (52 of 100), and after cooling in 13% (13 of 100). These results show that Salmonella spp. were found more often at some processing points than at others. The lowest Salmonella spp. contamination rate (6%) for slaughter birds was found after stunning, and the highest contamination rate was found before chilling (52%). The serological types of Salmonella spp. isolated from whole chickens were Salmonella Enteritidis, Salmonella Typhimurium, Salmonella Saintpaul, Salmonella Agona, and Salmonella Infantis. The results of these investigations indicate that Salmonella Enteritidis is the dominant serological type in infections of slaughter chickens, as it is in many countries.

Occurrence and characterization of Salmonella from chicken nuggets, strips, and pelleted broiler feed.

PubMed

Bucher, O; Holley, R A; Ahmed, R; Tabor, H; Nadon, C; Ng, L K; D'Aoust, J Y

2007-10-01

Raw, frozen chicken nuggets and strips have been identified as a significant risk factor in contracting foodborne salmonellosis. Cases of salmonellosis as a result of consuming partly cooked chicken nuggets may be due in part to Salmonella strains originating in broiler feed. This study was undertaken to determine the occurrence and characterize the strains of Salmonella contaminating chicken nuggets, strips, and pelleted feeds, in an attempt to demonstrate whether the same Salmonella strains present in broiler feed could be isolated from raw, frozen chicken nuggets and strips available for human consumption. Salmonellae were recovered using the Health Canada MFHPB-20 method for the isolation and identification of Salmonella from foods. Strains were characterized by serotyping, phage typing, antimicrobial resistance typing (R-typing), and by pulsed-field gel electrophoresis (PFGE). Salmonellae were isolated from 25-g samples in 27% (n=92) of nugget and strip samples, 95% (n=20) of chicken nugget meat samples, and from 9% (n=111) of pelleted feed samples. Salmonella Heidelberg, Salmonella Enteritidis, and Salmonella Orion were the most commonly isolated serovars from chicken nuggets and strips, nugget and strip meat, and pelleted broiler feeds, respectively. Salmonella Enteritidis phage type (PT) 13a with PFGE pattern SENXAI.0006 and R-type sensitive as well as Salmonella Enteritidis PT13a with PFGE pattern SENXAI.0068 and R-type sensitive were isolated from pelleted feed, and chicken nugget and strip meat in two separate instances. Data showed that Salmonella strains isolated from broiler feed were indistinguishable from strains isolated from packaged raw, frozen chicken nuggets and strips. However, results did not rule out the possibility that breeding stock or contamination during processing may have contributed to chicken meat contamination by Salmonella.

Inactivation of Salmonella on Eggshells by Chlorine Dioxide Gas

PubMed Central

Yum, Bora; Yoon, Sung-Sik; Song, Kyoung-Ju; Kim, Jong-Rak

2016-01-01

Microbiological contamination of eggs should be prevented in the poultry industry, as poultry is one of the major reservoirs of human Salmonella. ClO2 gas has been reported to be an effective disinfectant in various industry fields, particularly the food industry. The aims of this study were to evaluate the antimicrobial effect of chlorine dioxide gas on two strains of Salmonella inoculated onto eggshells under various experimental conditions including concentrations, contact time, humidity, and percentage organic matter. As a result, it was shown that chlorine dioxide gas under wet conditions was more effective in inactivating Salmonella Enteritidis and Salmonella Gallinarum compared to that under dry conditions independently of the presence of organic matter (yeast extract). Under wet conditions, a greater than 4 log reduction in bacterial populations was achieved after 30 min of exposure to ClO2 each at 20 ppm, 40 ppm, and 80 ppm against S. Enteritidis; 40 ppm and 80 ppm against S. Gallinarum. These results suggest that chlorine dioxide gas is an effective agent for controlling Salmonella, the most prevalent contaminant in the egg industry. PMID:27499670

Coconut and Salmonella Infection

PubMed Central

Schaffner, Carl P.; Mosbach, Klaus; Bibit, Venuso C.; Watson, Colin H.

1967-01-01

Raw, unprocessed coconut supports the growth of salmonellae as well as that of other enteric bacteria, salmonellae being particularly resistant to subsequent desiccation. Original contamination is not due to carriers or to polluted water supplies, but to contact with bacteria-containing soils followed by dispersion via infected coconut milk and shells. Pasteurization of raw coconut meat in a water bath at 80 C for 8 to 10 min effectively killed such bacteria, did not injure the product, and provided a prophylactic method now widely used by the coconut industry. PMID:5340650

Cross-contamination of foods and implications for food allergic patients.

PubMed

Taylor, Steve L; Baumert, Joseph L

2010-07-01

Cross-contamination presents a risk of unknown magnitude for food allergic consumers. Published cases likely represent the tip of a rather large iceberg. Cross-contamination can occur in homes, restaurants, food manufacturing plants, and on farms. The frequency of cross-contamination as the cause of accidental exposures to allergenic foods is unknown. Food allergic individuals can react to ingestion of trace levels of the offending food, although a highly variable range of threshold doses exist among populations of food allergic individuals. The magnitude of the risk posed to food allergic consumers by cross-contamination is characterized by the frequency of exposure to cross-contaminated foods, the dose of exposure, and the individual's threshold dose. The food and food service industry (and food preparers in homes as well) have the responsibility to provide and prepare foods that are safe for food allergic consumers, but quality of life may be improved with the recognition that safe (though very low) thresholds do exist.

Pooling raw shell eggs: Salmonella contamination and high risk practices in the United Kingdom food service sector.

PubMed

Gormley, F J; Little, C L; Murphy, N; de Pinna, E; McLauchlin, J

2010-03-01

Salmonella contamination of pooled raw shelled egg mix (RSEM) used as an ingredient in lightly cooked or uncooked foods and high-risk kitchen hygiene practices in United Kingdom food service establishments using RSEM were investigated. Samples were collected from 934 premises. Salmonella was found in 1 (0.13%) of 764 RSEM samples, 2 (0.3%) of 726 samples from surfaces where ready-to-eat foods were prepared, and 7 (1.3%) of 550 cleaning cloths. Poor RSEM storage and handling practices were highlighted. Workers in 40% of the premises sampled failed to use designated utensils when RSEM was added to other ingredients, workers in 17% of the premises did not clean surfaces and utensils thoroughly after use with RSEM and before preparing other foods, only 42% of workers washed and dried their hands after handling eggs or RSEM, workers in 41% of the premises did not store RSEM at refrigeration temperature before use, and workers in 8% of the premises added RSEM to cooked rice at the end of cooking when preparing egg fried rice. Take-away premises, especially those serving Chinese cuisine, were least likely to have a documented food safety management system and awareness of the key food safety points concerning the use of RSEM compared with other food service premises (P < 0.0001). Food service businesses using RSEM must be aware of the continuing hazard from Salmonella, must adopt appropriate control measures, and must follow advice provided by national food agencies to reduce the risk of Salmonella infection.

Mathematical modeling and validation of growth of Salmonella Enteritidis and background microorganisms in potato salad – one-step kinetic analysis and model development

USDA-ARS?s Scientific Manuscript database

This study was conducted to examine the growth of Salmonella Enteritidis (SE) in potato salad caused by cross-contamination and temperature abuse, and develop mathematical models to predict its growth. The growth of SE was investigated under constant temperature conditions (8, 10, 15, 20, 25, 30, a...

Salmonella and antimicrobial resistance in an animal-based agriculture river system.

PubMed

Palhares, Julio Cesar Pascale; Kich, Jalusa D; Bessa, Marjo C; Biesus, Luiza L; Berno, Lais G; Triques, Nelise J

2014-02-15

The aim of this study was to examine the Salmonella serovars and antimicrobial resistance within an animal-based agriculture river system. The study area consisted of a 1,345 ha upper part of Pinhal catchment. A total of 384 samples were collected in four years of monitoring. Salmonella was isolated from 241 samples (62.7%), resulting in 324 isolates. The highest number of Salmonella sp. occurred in samples associated with sites with high stoking density animal unit per hectare. It was possible to demonstrate the variability of serovars in the study area: 30 different serovars were found and at least 11 per monitoring site. Thirty-three potentially related isolates were genotyped by PFGE, one major clone was observed in serovar Typhimurium, which occurred in animal feces (swine and bovine), and different sites and samplings proving the cross-contamination and persistence of this specific clone. Among 180 isolates submitted to an antimicrobial susceptibility test, 50.5% were susceptible to all 21 antimicrobials tested and 54 different profiles were found. In the current study, 49.5% of the tested isolates were resistant to at least one antimicrobial, and multi-resistance occurred in 18% of isolates. Results indicate a close interaction between animal-based agriculture, Salmonella, and antimicrobial resistance. Copyright © 2013 Elsevier B.V. All rights reserved.

Salmonella and produce: survival in the plant environment and implications in food safety.

PubMed

Fatica, Marianne K; Schneider, Keith R

2011-01-01

There has been a continuous rise in the number of produce-based foodborne outbreaks in the recent decades despite the perception that foodborne diseases were primarily linked to animal-based products. The Centers for Disease Control and Prevention (CDC) estimates that 95% of Salmonella-based infections originate from foodborne sources, with multiple produce-based salmonellosis outbreaks occurring since 1990. The contamination of produce in both the pre-harvest and post-harvest produce environments is challenging to eliminate since produce is consumed as a raw, fresh commodity. Salmonella spp. contamination is possible through contact with the produce in the field as well as in the processing facility. The field contamination of produce infers the ability of Salmonella spp. to survive on the plant surface. The fitness of Salmonella spp. in the plant habitat is limited as opposed to naturally plant-associated bacteria, but survival is possible. The use of intensive farming practices, globalization of food products, high demand for convenience food products, and increased foodborne disease surveillance also have unknown ramifications in the ascending trends of produce-based outbreaks. A better understanding of the ecology of Salmonella spp. in the plant environment as well as the processing, food handling, and surveillance factors affecting the incidence of foodborne outbreaks will provide a comprehensive view of the etiology and epidemiology of produce-associated foodborne outbreaks. An understanding of the outbreaks and the factors facilitating produce contamination will allow for the development of intervention procedures and strategies to reduce the risk of produce contamination by Salmonella spp.

Salmonella in beef and produce from honduras.

PubMed

Maradiaga, Martha; Miller, Mark F; Thompson, Leslie; Pond, Ansen; Gragg, Sara E; Echeverry, Alejandro; Garcia, Lyda G; Loneragan, Guy H; Brashears, Mindy M

2015-03-01

Salmonella continues to cause a considerable number of foodborne illnesses worldwide. The sources of outbreaks include contaminated meat and produce. The purpose of this study was to establish an initial investigation of the burden of Salmonella in produce and beef from Honduras by sampling retail markets and abattoirs. Retail produce samples (cantaloupes, cilantro, cucumbers, leafy greens, peppers, and tomatoes; n = 573) were purchased in three major cities of Honduras, and retail whole-muscle beef (n = 555) samples were also purchased in four major cities. Additionally, both hide and beef carcass (n = 141) samples were collected from two Honduran abattoirs. Whole-muscle beef samples were obtained using a sponge hydrated with buffered peptone water, and 10 ml of the buffered peptone water rinsate of each produce sample was collected with a dry sponge and placed in a bag to be transported back to the United States. Salmonella was detected using a commercially available, closeplatform PCR system, and positive samples were subjected to culture on selective media to obtain isolates. Overall, the prevalence of Salmonella-positive samples, based on PCR detection in Honduras (n = 555) retail beef was 10.1% (95% confidence interval = 7.8, 12.9), whereas 7.8% (n = 141) of beef carcass and hides samples were positive in both beef plants. The overall Salmonella prevalence for all produce samples (n = 573) collected was 2.1% (95% confidence interval = 1.2, 3.6). The most common serotypes identified in Honduras were Salmonella Typhimurium followed by Derby. These results provide an indication of Salmonella contamination of beef and produce in Honduras. Developing a Salmonella baseline for Latin America through an initial investigation like the one presented here contributes to a broader global understanding of the potential exposure through food, thus providing insight into the needs for control strategies.

Tolerance of Salmonella Enteritidis and Staphylococcus aureus to surface cleaning and household bleach.

PubMed

Kusumaningrum, H D; Paltinaite, R; Koomen, A J; Hazeleger, W C; Rombouts, F M; Beumer, R R

2003-12-01

Effective cleaning and sanitizing of food preparation sites is important because pathogens are readily spread to food contact surfaces after preparation of contaminated raw products. Tolerance of Salmonella Enteritidis and Staphylococcus aureus to surface cleaning by wiping with regular, microfiber, and antibacterial-treated cloths was investigated. Wiping with cleaning cloths resulted in a considerable reduction of microorganisms from surfaces, despite the greater difficulty in removing S. aureus than Salmonella Enteritidis. Depending on the cloth type, S. aureus were reduced on surfaces from initial numbers of approximately 10(5) CFU/100 cm2 to numbers from less than 4 CFU/100 cm2 (below the detection limit) to 100 CFU/100 cm2. Directly after the cloths were used to clean the contaminated surfaces, they contained high numbers of bacteria (10(4) to 10(5) CFU/100 cm2), except for the disposable antibacterial-treated cloths, in which no bacteria could be detected. The tolerance of these pathogens to sodium hypochlorite was studied in the suspension test and in cloths. S. aureus showed a better tolerance for sodium hypochlorite than Salmonella Enteritidis. Inactivation of microorganisms in cloths required a higher concentration of sodium hypochlorite than was needed in the suspension test. Repeated exposure to sodium hypochlorite, however, resulted in an increase in susceptibility to this compound. This study provides essential information about the transfer of bacteria when wiping surfaces and highlights the need for a hygiene procedure with cleaning cloths that sufficiently avoids cross-contamination in the household environment.

Effects of meat juice on biofilm formation of Campylobacter and Salmonella.

PubMed

Li, Jiaqi; Feng, Jinsong; Ma, Lina; de la Fuente Núñez, César; Gölz, Greta; Lu, Xiaonan

2017-07-17

Campylobacter and Salmonella are leading causes of foodborne illnesses worldwide, vastly harboured by raw meat as their common food reservoir. Both microbes are prevalent in meat processing environments in the form of biofilms that contribute to cross-contamination and foodborne infection. This study applied raw meat juice (chicken juice and pork juice) as a minimally processed food model to study its effects on bacterial biofilm formation. Meat juice was collected during the freeze-thaw process of raw meat and sterilized by filtration. In 96-well polystyrene plates and glass chambers, supplementation of over 25% meat juice (v/v) in laboratory media led to an increase in biofilm formation of Campylobacter and Salmonella. During the initial attachment stage of biofilm development, more bacterial cells were present on surfaces treated with meat juice residues compared to control surfaces. Meat juice particulates on abiotic surfaces facilitated biofilm formation of Campylobacter and Salmonella under both static and flow conditions, with the latter being assessed using a microfluidic platform. Further, the deficiency in biofilm formation of selected Campylobacter and Salmonella mutant strains was restored in the presence of meat juice particulates. These results suggested that meat juice residues on the abiotic surfaces might act as a surface conditioner to support initial attachment and biofilm formation of Campylobacter and Salmonella. This study sheds light on a possible survival mechanism of Campylobacter and Salmonella in meat processing environments, and indicates that thorough cleaning of meat residues during meat production and handling is critical to reduce the bacterial load of Campylobacter and Salmonella. Copyright © 2017 Elsevier B.V. All rights reserved.

Biofilm formation, antimicrobial resistance, and sanitizer tolerance of Salmonella entericia strains isolated from beef trim

USDA-ARS?s Scientific Manuscript database

In the beef industry, product contamination by Salmonella enterica is a serious public health concern, which may result in human infection and cause significant financial loss due to product recalls. Currently, the precise mechanism and pathogen source responsible for Salmonella contamination in com...

Salmonella internalization in mung bean sprouts and pre- and postharvest intervention methods in a hydroponic system.

PubMed

Ge, Chongtao; Rymut, Susan; Lee, Cheonghoon; Lee, Jiyoung

2014-05-01

Mung bean sprouts, typically consumed raw or minimally cooked, are often contaminated with pathogens. Internalized pathogens pose a high risk because conventional sanitization methods are ineffective for their inactivation. The studies were performed (i) to understand the potential of internalization of Salmonella in mung bean sprouts under conditions where the irrigation water was contaminated and (ii) to determine if pre- and postharvest intervention methods are effective in inactivating the internalized pathogen. Mung bean sprouts were grown hydroponically and exposed to green fluorescence protein-tagged Salmonella Typhimurium through maturity. One experimental set received contaminated water daily, while other sets received contaminated water on a single day at different times. For preharvest intervention, irrigation water was exposed to UV, and for postharvest intervention-contaminated sprouts were subjected to a chlorine wash and UV light. Harvested samples were disinfected with ethanol and AgNO3 to differentiate surface-associate pathogens from the internalized ones. The internalized Salmonella Typhimurium in each set was quantified using the plate count method. Internalized Salmonella Typhimurium was detected at levels of 2.0 to 5.1 log CFU/g under all conditions. Continuous exposure to contaminated water during the entire period generated significantly higher levels of Salmonella Typhimurium internalization than sets receiving contaminated water for only a single day (P < 0.05). Preintervention methods lowered the level of internalized Salmonella by 1.84 log CFU/g (P < 0.05), whereas postintervention methods were ineffective in eliminating internalized pathogens. Preintervention did not completely inactivate bacteria in sprouts and demonstrated that the remaining Salmonella Typhimurium in water became more resistant to UV. Because postharvest intervention methods are ineffective, proper procedures for maintaining clean irrigation water must be followed

Further research into the possibility of salmonella-free fattening and slaughter of pigs.

PubMed

Oosterom, J; Notermans, S

1983-08-01

At a pig-fattening farm in the south-western Veluwe which was infected with salmonellas it was sought to achieve salmonella-free fattening in a specially adapted piggery. The test piggery was thoroughly cleaned and disinfected and measures were taken to exclude birds, insects and rodents. An attempt was also made to obtain salmonella-free piglets. Clean clothing, special footwear and disinfectants were used when entering the piggery. During the experiment an infection was detected in the test piggery caused by the same salmonella serotypes as had only been found immediately before the test at the breeding farm. Other salmonella serotypes occurring at the fattening farm did not find their way into the test piggery, and therefore it can be concluded that after the pigs had been brought in all the hygienic barriers functioned adequately. The test showed that the hygienic measures taken had a beneficial effect on growth performance, even though salmonellas were not entirely excluded. After fattening the pigs were slaughtered in two groups. The first group was slaughtered in the usual way, but with the second group extra care was taken with the individual singeing of the carcasses and the careful removal of the intestines. Tests on the carcasses showed that 46% of the pigs in the first group were contaminated with salmonellas as against only 7% in the second. From this it can be concluded that slaughter need not lead to further contamination by salmonellas present in the intestines; indeed, carefully carrying out the slaughter process can even reduce the contamination of the surface of pig carcasses by salmonellas.

Detection of Salmonella invA gene in shrimp enrichment culture by polymerase chain reaction.

PubMed

Upadhyay, Bishnu Prasad; Utrarachkij, Fuangfa; Thongshoob, Jarinee; Mahakunkijcharoen, Yuvadee; Wongchinda, Niracha; Suthienkul, Orasa; Khusmith, Srisin

2010-03-01

Contamination of seafood with salmonellae is a major public health concern. Detection of Salmonella by standard culture methods is time consuming. In this study, an enrichment culture step prior to polymerase chain reaction (PCR) was applied to detect 284 bp fragment of Salmonella invA in comparison with the conventional culture method in 100 shrimp samples collected from four different shrimp farms and fresh food markets around Bangkok. Samples were pre-enriched in non-selective lactose broth (LB) and selective tetrathionate broth (TTB). PCR detection limit was 10 pg and 10(4) cfu/ml of viable salmonellae with 100% specificity. PCR assay detected 19 different Salmonella serovars belonging to 8 serogroups (B, C1, C2-C3, D1, E1, E4 and K) commonly found in clinical and environmental samples in Thailand. The detection rate of PCR following TTB enrichment (24%) was higher than conventional culture method (19%). PCR following TTB, but not in LB enrichment allowed salmonella detection with 84% sensitivity, 90% specificity and 89% accuracy. Shrimp samples collected from fresh food markets had higher levels of contaminated salmonellae than those from shrimp farms. The results indicated that incorporation of an enrichment step prior to PCR has the potential to be applied for detection of naturally contaminated salmonellae in food, environment and clinical samples.

Prevalence and characterization of Salmonella serovars isolated from oysters served raw in restaurants.

PubMed

Brillhart, Crystal D; Joens, Lynn A

2011-06-01

To determine if Salmonella-contaminated oysters are reaching consumer tables, a survey of raw oysters served in eight Tucson restaurants was performed from October 2007 to September 2008. Salmonella spp. were isolated during 7 of the 8 months surveyed and were present in 1.2% of 2,281 oysters tested. This observed prevalence is lower than that seen in a previous study in which U.S. market oysters were purchased from producers at bays where oysters are harvested. To test whether the process of refrigerating oysters in restaurants for several days reduces Salmonella levels, oysters were artificially infected with Salmonella and kept at 4°C for up to 13 days. Direct plate counts of oyster homogenate showed that Salmonella levels within oysters did not decrease during refrigeration. Six different serovars of Salmonella enterica were found in the restaurant oysters, indicating multiple incidences of Salmonella contamination of U.S. oyster stocks. Of the 28 contaminated oysters, 12 (43%) contained a strain of S. enterica serovar Newport that matched by pulsed-field gel electrophoresis a serovar Newport strain seen predominantly in the study of bay oysters performed in 2002. The repeated occurrence of this strain in oyster surveys is concerning, since the strain was resistant to seven antimicrobials tested and thus presents a possible health risk to consumers of raw oysters.

Salmonella species isolated from animal feed in Iraq.

PubMed Central

Al-Hindawi, N; Taha, R R

1979-01-01

Of 700 animal feed samples, 32 (4.5%) harbored Salmonella. The highest percentage of contamination was found in sheep feed and local protein. A total of 17 Salmonella serotypes were identified. The most frequent serotypes were Salmonella meleagridis. S. bornum, S. montevideo, and S. drypool. S. bornum was isolated for the first time in Iraq and from both local feed and its ingredients. The common somatic group found was that of Salmonella group C; then came groups E, G, B, and D. Three serotypes (S. enteritidis, S. california, and S. muenchen) seemed to form a link of infection among feed, food, patients, and carriers. PMID:453836

A Mexican restaurant-associated outbreak of Salmonella Enteritidis type 34 infections traced to a contaminated egg farm.

PubMed Central

McNeil, M. M.; Sweat, L. B.; Carter, S. L.; Watson, C. B.; Holloway, J. T.; Manning, R.; Altekruse, S. F.; Blake, P. A.

1999-01-01

In May 1996, the Georgia Division of Public Health was notified about a cluster of persons with Salmonella Enteritidis (SE) infections in Waycross, Georgia. A matched pair case-control study to determine risk factors for illness found a statistically significant association of SE infection with a history of having eaten at Restaurant A during the 5 days before onset of illness (relative risk = 13 [95% confidence interval (CI) = 3-62, P < 0.01]). In a second case-control study, to determine specific food exposures, consumption of a deep-fried Mexican dish (chile relleno) (4 of 21 cases vs. 0 of 26 controls, odds ratio undefined, 95% CI > 1.46, P = 0.034) was found to be significantly associated with SE infection. An environmental investigation found evidence of suboptimal food storage and cooking temperatures at Restaurant A; cross contamination of foods may have contributed to the low attributable risk identified for chile rellenos. Five of 37 Restaurant A food and environment specimens yielded SE strains. All five positive specimens were from chiles rellenos. Of the seven outbreak-associated strains (six patient isolates and one food isolate from Restaurant A) for which phage typing was conducted, all were phage type 34. A FDA traceback investigation through Restaurant A's single-egg supplier identified the potential source as three interrelated farms in South Carolina. Environmental culture from one of these farms yielded SE phage type 34. As a result of this outbreak, FDA helped institute a statewide egg quality-assurance programme in South Carolina to minimize SE contamination of eggs. PMID:10355784

A Mexican restaurant-associated outbreak of Salmonella Enteritidis type 34 infections traced to a contaminated egg farm.

PubMed

McNeil, M M; Sweat, L B; Carter, S L; Watson, C B; Holloway, J T; Manning, R; Altekruse, S F; Blake, P A

1999-04-01

In May 1996, the Georgia Division of Public Health was notified about a cluster of persons with Salmonella Enteritidis (SE) infections in Waycross, Georgia. A matched pair case-control study to determine risk factors for illness found a statistically significant association of SE infection with a history of having eaten at Restaurant A during the 5 days before onset of illness (relative risk = 13 [95% confidence interval (CI) = 3-62, P < 0.01]). In a second case-control study, to determine specific food exposures, consumption of a deep-fried Mexican dish (chile relleno) (4 of 21 cases vs. 0 of 26 controls, odds ratio undefined, 95% CI > 1.46, P = 0.034) was found to be significantly associated with SE infection. An environmental investigation found evidence of suboptimal food storage and cooking temperatures at Restaurant A; cross contamination of foods may have contributed to the low attributable risk identified for chile rellenos. Five of 37 Restaurant A food and environment specimens yielded SE strains. All five positive specimens were from chiles rellenos. Of the seven outbreak-associated strains (six patient isolates and one food isolate from Restaurant A) for which phage typing was conducted, all were phage type 34. A FDA traceback investigation through Restaurant A's single-egg supplier identified the potential source as three interrelated farms in South Carolina. Environmental culture from one of these farms yielded SE phage type 34. As a result of this outbreak, FDA helped institute a statewide egg quality-assurance programme in South Carolina to minimize SE contamination of eggs.

Prevalence and characterization of motile Salmonella in commercial layer poultry farms in Bangladesh.

PubMed

Barua, Himel; Biswas, Paritosh K; Olsen, Katharina E P; Christensen, Jens P

2012-01-01

Salmonella is a globally widespread food-borne pathogen having major impact on public health. All motile serovars of Salmonella enterica of poultry origin are zoonotic, and contaminated meat and raw eggs are an important source to human infections. Information on the prevalence of Salmonella at farm/holding level, and the zoonotic serovars circulating in layer poultry in the South and South-East Asian countries including Bangladesh, where small-scale commercial farms are predominant, is limited. To investigate the prevalence of Salmonella at layer farm level, and to identify the prevalent serovars we conducted a cross-sectional survey by randomly selecting 500 commercial layer poultry farms in Bangladesh. Faecal samples from the selected farms were collected following standard procedure, and examined for the presence of Salmonella using conventional bacteriological procedures. Thirty isolates were randomly selected, from the ninety obtained from the survey, for serotyping and characterized further by plasmid profiling and pulsed-field gel electrophoresis (PFGE). Results of the survey showed that the prevalence of motile Salmonella at layer farm level was 18% (95% confidence interval 15-21%), and Salmonella Kentucky was identified to be the only serovar circulating in the study population. Plasmid analysis of the S. Kentucky and non-serotyped isolates revealed two distinct profiles with a variation of two different sizes (2.7 and 4.8 kb). PFGE of the 30 S. Kentucky and 30 non-serotyped isolates showed that all of them were clonally related because only one genotype and three subtypes were determined based on the variation in two or three bands. This is also the first report on the presence of any specific serovar of Salmonella enterica in poultry in Bangladesh.

Prevalence and Characterization of Motile Salmonella in Commercial Layer Poultry Farms in Bangladesh

PubMed Central

Barua, Himel; Biswas, Paritosh K.; Olsen, Katharina E. P.; Christensen, Jens P.

2012-01-01

Salmonella is a globally widespread food-borne pathogen having major impact on public health. All motile serovars of Salmonella enterica of poultry origin are zoonotic, and contaminated meat and raw eggs are an important source to human infections. Information on the prevalence of Salmonella at farm/holding level, and the zoonotic serovars circulating in layer poultry in the South and South-East Asian countries including Bangladesh, where small-scale commercial farms are predominant, is limited. To investigate the prevalence of Salmonella at layer farm level, and to identify the prevalent serovars we conducted a cross-sectional survey by randomly selecting 500 commercial layer poultry farms in Bangladesh. Faecal samples from the selected farms were collected following standard procedure, and examined for the presence of Salmonella using conventional bacteriological procedures. Thirty isolates were randomly selected, from the ninety obtained from the survey, for serotyping and characterized further by plasmid profiling and pulsed-field gel electrophoresis (PFGE). Results of the survey showed that the prevalence of motile Salmonella at layer farm level was 18% (95% confidence interval 15–21%), and Salmonella Kentucky was identified to be the only serovar circulating in the study population. Plasmid analysis of the S. Kentucky and non-serotyped isolates revealed two distinct profiles with a variation of two different sizes (2.7 and 4.8 kb). PFGE of the 30 S. Kentucky and 30 non-serotyped isolates showed that all of them were clonally related because only one genotype and three subtypes were determined based on the variation in two or three bands. This is also the first report on the presence of any specific serovar of Salmonella enterica in poultry in Bangladesh. PMID:22558269

Impact of litter Salmonella status during feed withdrawal on Salmonella recovery from the broiler crop and ceca.

PubMed

Buhr, R J; Bourassa, D V; Hinton, A; Fairchild, B D; Ritz, C W

2017-12-01

Research was conducted to evaluate the impact of litter Salmonella status during feed withdrawal on Salmonella recovery from the crop and ceca following feed withdrawal. In 4 experiments, pens of broilers in separate rooms were challenged with marker strains of either Salmonella Montevideo or Salmonella Heidelberg. Three d post challenge, a 12-hour feed withdrawal was initiated, and one pen of broilers was switched between rooms for each Salmonella serotype. In experiments 3 and 4, non-challenged broilers also were added to the Salmonella challenge pens. The litter of each pen was sampled before and after the feed withdrawal period, the broilers euthanized, and the crop and ceca aseptically removed for Salmonella isolation. Results showed that only the challenge Salmonella serotype was recovered from the litter in challenge pens where broilers were not moved, while both Salmonella serotypes were recovered from the litter of the switched pens. Salmonella was recovered from 56/80 crops and from 66/80 ceca of challenged broilers that remained in the challenge pens. The challenge Salmonella serotype was recovered from 50/80 crops and from 60/80 ceca, and the switched pens' litter Salmonella serotype was recovered from 19/80 crops but not from the ceca in broilers challenged with Salmonella and then switched between pens. For experiments 3 and 4, Salmonella was recovered from 19/40 crops and from only 2/40 ceca from the non-challenged broilers placed into the Salmonella challenge pens. The results from broilers that were switched between Salmonella challenge pens indicate that the recovery of Salmonella from the crop of broilers following feed withdrawal (on Salmonella-contaminated litter) appears to depend mainly on the initial challenge Salmonella (62%) and less on the litter Salmonella (24%) status during the feed withdrawal period. In contrast, only the initial challenge Salmonella was recovered from the ceca (79%) from broilers that remained in challenge pens or

Effect of storage temperatures and stresses on the survival of Salmonella spp. in halva.

PubMed

Osaili, T M; Al-Nabulsi, A A; Nazzal, D S; Shaker, R R

2017-11-01

The presence of Salmonella spp. in halva has been associated with foodborne illnesses and product recalls from the markets. This study investigated the effect of environmental stresses on the survival of Salmonella spp. in halva during storage for 12 months at 10 and 25°C (log (N 0 /N) g -1 ). Halva samples were inoculated with a cocktail of four strains of unstressed, desiccation stressed or heat stressed Salmonella (10 6 -10 7  CFU per gram). In general, survival of Salmonella spp. in halva decreased significantly (P ˂ 0·05) as storage time and temperature increased. At the end of halva shelf life at 10°C, the initial populations of unstressed, desiccation stressed or heat stressed Salmonella spp. decreased by 2·7, 2·6 or 2·8 log CFU per gram (reduction rate c. 0·2 log CFU per month), respectively. While at 25°C, the populations decreased 5·2, 6·7 or 6·3 log CFU per gram, respectively (reduction rate c. 0·4-0·5 log CFU per month). The populations of stressed Salmonella spp. in halva samples were not significantly different (P ≥ 0·05) from populations of unstressed cells during storage at 10 and 25°C, except during the last 3 months of storage at 25°C when populations of unstressed cells were higher (P < 0·05). Exposing Salmonella spp. to desiccation or heat stress prior product contamination may play a role in Salmonella spp. survival in halva during storage. Contamination of halva (tahini halva) with Salmonella from raw materials or during production was documented. Halva and tahini have been involved in salmonellosis outbreaks in different countries. The study demonstrated enhanced survivability of stressed and unstressed Salmonella spp. in halva over a 12-month storage period at 10 and 25°C with lower log reductions than expected. Exposing Salmonella spp. to desiccation or heat stress prior product contamination may play a role in microbial survival in halva during storage. These findings serve as a model to halva producers to

Salmonella Infections in Childhood.

PubMed

Bula-Rudas, Fernando J; Rathore, Mobeen H; Maraqa, Nizar F

2015-08-01

Salmonella are gram-negative bacilli within the family Enterobacteriaceae. They are the cause of significant morbidity and mortality worldwide. Animals (pets) are an important reservoir for nontyphoidal Salmonella, whereas humans are the only natural host and reservoir for Salmonella Typhi. Salmonella infections are a major cause of gastroenteritis worldwide. They account for an estimated 2.8 billion cases of diarrheal disease each year. The transmission of Salmonella is frequently associated with the consumption of contaminated water and food of animal origin, and it is facilitated by conditions of poor hygiene. Nontyphoidal Salmonella infections have a worldwide distribution, whereas most typhoidal Salmonella infections in the United States are acquired abroad. In the United States, Salmonella is a common agent for food-borne–associated infections. Several outbreaks have been identified and are most commonly associated with agricultural products. Nontyphoidal Salmonella infection is usually characterized by a self-limited gastroenteritis in immunocompetent hosts in industrialized countries, but it may also cause invasive disease in vulnerable individuals (eg, children less than 1 year of age, immunocompromised). Antibiotic treatment is not recommended for treatment of mild to moderate gastroenteritis by nontyphoidal Salmonella in immunocompetent adults or children more than 1 year of age. Antibiotic treatment is recommended for nontyphoidal Salmonella infections in infants less than 3 months of age, because they are at higher risk for bacteremia and extraintestinal complications. Typhoid (enteric) fever and its potential complications have a significant impact on children, especially those who live in developing countries. Antibiotic treatment of typhoid fever has become challenging because of the emergence of Salmonella Typhi strains that are resistant to classically used first-line agents: ampicillin, trimethoprim-sulfamethoxazole, and chloramphenicol. The

Survival of Salmonella Newport on whole and fresh-cut cucumbers treated with lytic bacteriophages

USDA-ARS?s Scientific Manuscript database

Salmonella enterica associated with consumption of cucumbers (Cucumis sativus) has led to foodborne outbreaks in the U.S. Whole and fresh-cut cucumbers are susceptible to Salmonella spp. contamination during growing and harvesting. The application of lytic bacteriophages specific for Salmonella spp...

Quantitative transfer of Salmonella Typhimurium LT2 during mechanical slicing of tomatoes as impacted by multiple processing variables.

PubMed

Wang, Haiqiang; Ryser, Elliot T

2016-10-03

Slicing of fresh produce can readily lead to pathogen cross-contamination with pre-sliced tomatoes having been linked to multistate outbreaks of salmonellosis in the United States. This study aimed to assess the impact of multiple processing variables on quantitative transfer of Salmonella during simulated commercial slicing of tomatoes. One red round tomato was inoculated with Salmonella Typhimurium LT2 at ~5logCFU/g and sliced using a manual or electric slicer, followed by 20 uninoculated tomatoes. Thereafter, the distribution of Salmonella on inoculated and uninoculated tomato slices was evaluated along with the transfer of Salmonella from different parts of the slicer. The impact of multiple processing variables including post-contamination hold time (0 and 30min), tomato wetness (dry and wet), processing room temperature (23, 10 and 4°C), slice thickness (0.48, 0.64, and 0.95cm), tomato variety (Torero, Rebelski, and Bigdena) and pre-wash treatment (no wash, tap water, and chlorine) was also investigated. The data were fitted to a two-parameter exponential decay model (Y=A⋅exp(BX)) with the percentage of Salmonella transferred to 20 uninoculated tomatoes then calculated. Salmonella populations on nine inoculated tomato slices ranged from 4.6±0.2 to 5.5±0.3logCFU/g, with higher populations on slices from the blossom and stem scar ends. However, Salmonella transfer to the previously uninoculated slices was similar (P>0.05), ranging from 2.1±0.2 to 3.4±0.2logCFU/g. Significantly fewer salmonellae transferred from the blade (3.4±0.4 log CFU, P≤0.05) than from the back and bottom plates (4.7±0.3 log CFU) or the whole manual slicer (5.2±0.2 log CFU) to the 20 uninoculated tomatoes. However, the blade was the primary contributor to Salmonella transfer for the electric slicer. Post-contamination hold time, processing temperature and tomato slice thickness did not significantly impact (P>0.05) the Salmonella transfer rate (parameter B) or the overall

Further research into the possibility of salmonella-free fattening and slaughter of pigs.

PubMed Central

Oosterom, J.; Notermans, S.

1983-01-01

At a pig-fattening farm in the south-western Veluwe which was infected with salmonellas it was sought to achieve salmonella-free fattening in a specially adapted piggery. The test piggery was thoroughly cleaned and disinfected and measures were taken to exclude birds, insects and rodents. An attempt was also made to obtain salmonella-free piglets. Clean clothing, special footwear and disinfectants were used when entering the piggery. During the experiment an infection was detected in the test piggery caused by the same salmonella serotypes as had only been found immediately before the test at the breeding farm. Other salmonella serotypes occurring at the fattening farm did not find their way into the test piggery, and therefore it can be concluded that after the pigs had been brought in all the hygienic barriers functioned adequately. The test showed that the hygienic measures taken had a beneficial effect on growth performance, even though salmonellas were not entirely excluded. After fattening the pigs were slaughtered in two groups. The first group was slaughtered in the usual way, but with the second group extra care was taken with the individual singeing of the carcasses and the careful removal of the intestines. Tests on the carcasses showed that 46% of the pigs in the first group were contaminated with salmonellas as against only 7% in the second. From this it can be concluded that slaughter need not lead to further contamination by salmonellas present in the intestines; indeed, carefully carrying out the slaughter process can even reduce the contamination of the surface of pig carcasses by salmonellas. PMID:6886411

78 FR 42526 - Compliance Policy Guide Sec. 690.800 Salmonella

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-16

... withdrawal of ``Compliance Policy Guide Sec. 690.700 Salmonella Contamination of Dry Dog Food.'' The... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2010-D-0378] Compliance Policy Guide Sec. 690.800 Salmonella in Food for Animals; Availability AGENCY: Food and Drug...

Assessment of Salmonella survival in dry-cured Italian salami.

PubMed

Bonardi, S; Bruini, I; Bolzoni, L; Cozzolino, P; Pierantoni, M; Brindani, F; Bellotti, P; Renzi, M; Pongolini, S

2017-12-04

The inactivation of Salmonella during curing of Italian traditional pork salami was investigated. A total of 150 batches of ground raw meat (GRM) used for salami manufacturing by four producers were tested for Salmonella by real-time PCR followed by ISO 6579 cultural confirmation and MPN enumeration. Salami produced with Salmonella positive GRMs were re-tested at the end of their curing period. Aw, pH and NaCl content were also measured. Detection of Salmonella was performed testing both 25 and 50g of the samples. By Real-Time PCR 37% of the GRMs resulted positive, but cultural detection of Salmonella was obtained in 14% of the samples only. Salmonella enumeration ranged from 31 MPN/g to <1.3 MPN/g. The difference between testing 50g and 25g of the samples was statistically significant (p value≤0.01). In particular, ISO-50g detected Salmonella in 100% of all positive samples, vs. 62% of ISO-25g. Salami made of the contaminated GRMs were 29% Salmonella-positive, as most batches of salami produced with Salmonella-positive GRMs resulted negative after regular curing (20-48days). Overall, 13% of salami produced with Salmonella-contaminated GRMs were positive. They belonged to six batches, which turned out negative after prolonged curing ranging between 49 and 86days. Salmonella enumeration in salami ranged from 8.7 MPN/g to <1.3 MPN/g. Unlike GRMs, no significant difference was observed between the ISO-50g and the ISO-25g in detecting Salmonella in cured salami (p value: >0.05). The most common Salmonella serovars in GRMs were Derby (52%), Typhimurium monophasic variant 4, (Barbuti et al., 1993), 12:i:- (19%) and Stanley (10%). Salmonella Derby (56%), London, Branderup, Panama (13%, respectively) and Goldcoast (6%) were most frequent in cured salami. The study showed negative correlation between real-time CT values and cultural confirmation of Salmonella, as well as the importance of sample size for Salmonella detection. Among considered factors with possible effect

Laser cutting eliminates nucleic acid cross-contamination in dried-blood-spot processing.

PubMed

Murphy, Sean C; Daza, Glenda; Chang, Ming; Coombs, Robert

2012-12-01

Dried blood spots (DBS) are useful for molecular assays but are prone to false positives from cross-contamination. In our malaria DBS assay, cross-contamination was encountered despite cleaning techniques suitable for HIV-1. We therefore developed a contact-free laser cutting system that effectively eliminated cross-contamination during DBS processing.

Commonly used disinfectants fail to eradicate Salmonella enterica biofilms from food contact surface materials.

PubMed

Corcoran, M; Morris, D; De Lappe, N; O'Connor, J; Lalor, P; Dockery, P; Cormican, M

2014-02-01

Salmonellosis is the second most common cause of food-borne illness worldwide. Contamination of surfaces in food processing environments may result in biofilm formation with a risk of food contamination. Effective decontamination of biofilm-contaminated surfaces is challenging. Using the CDC biofilm reactor, the activities of sodium hypochlorite, sodium hydroxide, and benzalkonium chloride were examined against an early (48-h) and relatively mature (168-h) Salmonella biofilm. All 3 agents result in reduction in viable counts of Salmonella; however, only sodium hydroxide resulted in eradication of the early biofilm. None of the agents achieved eradication of mature biofilm, even at the 90-min contact time. Studies of activity of chemical disinfection against biofilm should include assessment of activity against mature biofilm. The difficulty of eradication of established Salmonella biofilm serves to emphasize the priority of preventing access of Salmonella to postcook areas of food production facilities.

Evaluation of VIDAS Salmonella (SLM) easy Salmonella method for the detection of Salmonella in a variety of foods: collaborative study.

PubMed

Crowley, Erin; Bird, Patrick; Fisher, Kiel; Goetz, Katherine; Benzinger, M Joseph; Agin, James; Goins, David; Johnson, Ronald L

2011-01-01

The VIDAS Salmonella (SLM) Easy Salmonella method is a specific enzyme-linked fluorescent immunoassay performed in the automated VIDAS instrument. The VIDAS Easy Salmonella method is a simple 2-step enrichment procedure, using pre-enrichment followed by selective enrichment in a newly formulated broth, SX2 broth. This new method was compared in a multilaboratory collaborative study to the U.S. Food and Drug Administration's Bacteriological Analytical Manual, Chapter 5 method for five food matrixes (liquid egg, vanilla ice cream, spinach, raw shrimp, and peanut butter) and the U.S. Department of Agriculture's Microbiology Laboratory Guidebook 4.04 method for deli turkey. Each food type was artificially contaminated with Salmonella at three inoculation levels. A total of 15 laboratories representing government, academia, and industry, throughout the United States, participated. In this study, 1583 samples were analyzed, of which 792 were paired replicates and 791 were unpaired replicates. Of the 792 paired replicates, 285 were positive by both the VIDAS and reference methods. Of the 791 unpaired replicates, 341 were positive by the VIDAS method and 325 were positive by the cultural reference method. A Chi-square analysis of each of the six food types was performed at the three inoculation levels tested. For all foods evaluated, the VIDAS Easy SLM method demonstrated results comparable to those of the reference methods for the detection of Salmonella.

Laser Cutting Eliminates Nucleic Acid Cross-Contamination in Dried-Blood-Spot Processing

PubMed Central

Daza, Glenda; Chang, Ming; Coombs, Robert

2012-01-01

Dried blood spots (DBS) are useful for molecular assays but are prone to false positives from cross-contamination. In our malaria DBS assay, cross-contamination was encountered despite cleaning techniques suitable for HIV-1. We therefore developed a contact-free laser cutting system that effectively eliminated cross-contamination during DBS processing. PMID:23052309

Identification of new loci involved in the host susceptibility to Salmonella Typhimurium in collaborative cross mice.

PubMed

Zhang, Jing; Malo, Danielle; Mott, Richard; Panthier, Jean-Jacques; Montagutelli, Xavier; Jaubert, Jean

2018-04-27

Salmonella is a Gram-negative bacterium causing a wide range of clinical syndromes ranging from typhoid fever to diarrheic disease. Non-typhoidal Salmonella (NTS) serovars infect humans and animals, causing important health burden in the world. Susceptibility to salmonellosis varies between individuals under the control of host genes, as demonstrated by the identification of over 20 genetic loci in various mouse crosses. We have investigated the host response to S. Typhimurium infection in 35 Collaborative Cross (CC) strains, a genetic population which involves wild-derived strains that had not been previously assessed. One hundred and forty-eight mice from 35 CC strains were challenged intravenously with 1000 colony-forming units (CFUs) of S. Typhimurium. Bacterial load was measured in spleen and liver at day 4 post-infection. CC strains differed significantly (P < 0.0001) in spleen and liver bacterial loads, while sex and age had no effect. Two significant quantitative trait loci (QTLs) on chromosomes 8 and 10 and one suggestive QTL on chromosome 1 were found for spleen bacterial load, while two suggestive QTLs on chromosomes 6 and 17 were found for liver bacterial load. These QTLs are caused by distinct allelic patterns, principally involving alleles originating from the wild-derived founders. Using sequence variations between the eight CC founder strains combined with database mining for expression in target organs and known immune phenotypes, we were able to refine the QTLs intervals and establish a list of the most promising candidate genes. Furthermore, we identified one strain, CC042/GeniUnc (CC042), as highly susceptible to S. Typhimurium infection. By exploring a broader genetic variation, the Collaborative Cross population has revealed novel loci of resistance to Salmonella Typhimurium. It also led to the identification of CC042 as an extremely susceptible strain.

Chlorine stabilizer T-128 enhances efficacy of chlorine against cross-contamination by E. coli O157:H7 and Salmonella in fresh-cut lettuce processing.

PubMed

Nou, Xiangwu; Luo, Yaguang; Hollar, LaVonda; Yang, Yang; Feng, Hao; Millner, Patricia; Shelton, Daniel

2011-04-01

During fresh-cut produce processing, organic materials released from cut tissues can rapidly react with free chlorine in the wash solution, leading to the potential survival of foodborne bacterial pathogens, and cross-contamination when the free chlorine is depleted. A reported chlorine stabilizer, T-128, has been developed to address this problem. In this study, we evaluated the ability of T-128 to stabilize free chlorine in wash solutions in the presence of high organic loads generated by the addition of lettuce extract or soil. Under conditions used in this study, T-128 significantly (P<0.001) decreased the rate of free chlorine depletion at the presence of soil. T-128 also slightly decreased the rate of free chlorine depletion caused by the addition of lettuce extract in wash solution. Application of T-128 significantly reduced the survival of bacterial pathogens in wash solutions with high organic loads and significantly reduced the potential of cross-contamination, when contaminated and uncontaminated produce were washed together. However, T-128 did not enhance the efficacy of chlorinated wash solutions for microbial reduction on contaminated iceberg lettuce. Evaluation of several produce quality parameters, including overall visual appearance, package headspace O2 and CO2 composition, and lettuce electrolyte leakage, during 15 d of storage indicated that iceberg lettuce quality and shelf life were not negatively impacted by washing fresh-cut lettuce in chlorine solutions containing 0.1% T-128.   Reported chlorine stabilizer is shown to enhance chlorine efficacy against potential bacterial cross-contamination in the presence of high organic loads without compromising product quality and shelf life.

Plant-Microbe and Abiotic Factors Influencing Salmonella Survival and Growth on Alfalfa Sprouts and Swiss Chard Microgreens

PubMed Central

Reed, Elizabeth; Ferreira, Christina M.; Bell, Rebecca; Brown, Eric W.

2018-01-01

ABSTRACT Microgreens, like sprouts, are relatively fast-growing products and are generally consumed raw. Moreover, as observed for sprouts, microbial contamination from preharvest sources may also be present in the production of microgreens. In this study, two Salmonella enterica serovars (Hartford and Cubana), applied at multiple inoculation levels, were evaluated for survival and growth on alfalfa sprouts and Swiss chard microgreens by using the most-probable-number (MPN) method. Various abiotic factors were also examined for their effects on Salmonella survival and growth on sprouts and microgreens. Community-level physiological profiles (CLPPs) of sprout/microgreen rhizospheres with different levels of S. enterica inoculation at different growth stages were characterized by use of Biolog EcoPlates. In the seed contamination group, the ability of S. enterica to grow on sprouting alfalfa seeds was affected by both seed storage time and inoculation level but not by serovar. However, the growth of S. enterica on Swiss chard microgreens was affected by serovar and inoculation level. Seed storage time had little effect on the average level of Salmonella populations in microgreens. In the irrigation water contamination group, the growth of Salmonella on both alfalfa sprouts and microgreens was largely affected by inoculation level. Surprisingly, the growth medium was found to play an important role in Salmonella survival and growth on microgreens. CLPP analysis showed significant changes in the microbial community metabolic diversity during sprouting for alfalfa sprouts, but few temporal changes were seen with microgreens. The data suggest that the change in rhizosphere bacterial functional diversity was dependent on the host but independent of Salmonella contamination. IMPORTANCE Sprouts and microgreens are considered “functional foods,” i.e., foods containing health-promoting or disease-preventing properties in addition to normal nutritional values. However, the

Plant-Microbe and Abiotic Factors Influencing Salmonella Survival and Growth on Alfalfa Sprouts and Swiss Chard Microgreens.

PubMed

Reed, Elizabeth; Ferreira, Christina M; Bell, Rebecca; Brown, Eric W; Zheng, Jie

2018-05-01

Microgreens, like sprouts, are relatively fast-growing products and are generally consumed raw. Moreover, as observed for sprouts, microbial contamination from preharvest sources may also be present in the production of microgreens. In this study, two Salmonella enterica serovars (Hartford and Cubana), applied at multiple inoculation levels, were evaluated for survival and growth on alfalfa sprouts and Swiss chard microgreens by using the most-probable-number (MPN) method. Various abiotic factors were also examined for their effects on Salmonella survival and growth on sprouts and microgreens. Community-level physiological profiles (CLPPs) of sprout/microgreen rhizospheres with different levels of S. enterica inoculation at different growth stages were characterized by use of Biolog EcoPlates. In the seed contamination group, the ability of S. enterica to grow on sprouting alfalfa seeds was affected by both seed storage time and inoculation level but not by serovar. However, the growth of S. enterica on Swiss chard microgreens was affected by serovar and inoculation level. Seed storage time had little effect on the average level of Salmonella populations in microgreens. In the irrigation water contamination group, the growth of Salmonella on both alfalfa sprouts and microgreens was largely affected by inoculation level. Surprisingly, the growth medium was found to play an important role in Salmonella survival and growth on microgreens. CLPP analysis showed significant changes in the microbial community metabolic diversity during sprouting for alfalfa sprouts, but few temporal changes were seen with microgreens. The data suggest that the change in rhizosphere bacterial functional diversity was dependent on the host but independent of Salmonella contamination. IMPORTANCE Sprouts and microgreens are considered "functional foods," i.e., foods containing health-promoting or disease-preventing properties in addition to normal nutritional values. However, the microbial

Detection of Salmonella species in chicken carcasses using genus specific primer belong to invA gene in Sohag city, Egypt.

PubMed

Abdel-Aziz, Nahed Mahmoud

2016-10-01

This study aimed to detect Salmonella species found as contaminants in chicken carcass (thigh, breast, wings, liver, and gizzard). A total of 75 chicken samples including thigh, breast, wings, liver, and gizzard (15 of each) were collected from different markets in Sohag city for detection of Salmonella species by culture methods, biochemical tests, serology, and polymerase chain reaction. The overall incidence of Salmonella contamination of 75 examined samples was found to be 6.6% with the higher percentage of Salmonella being isolated from liver samples (13.3%) followed by thigh, wings, gizzard (6.6%) while breast show negative result. Results in this study indicate that contamination of chicken carcass with Salmonella needs strict hygienic measures to prevent their transmission to human.

Prevalence and Antimicrobial Resistance of Salmonella Isolates from Chicken Carcasses in Retail Markets in Yangon, Myanmar.

PubMed

Moe, Aung Zaw; Paulsen, Peter; Pichpol, Duangporn; Fries, Reinhard; Irsigler, Herlinde; Baumann, Maximilian P O; Oo, Kyaw Naing

2017-06-01

A cross-sectional investigation was conducted concerning prevalence, antimicrobial resistance, multidrug resistance patterns, and serovar diversity of Salmonella in chicken meat sold at retail in Yangon, Myanmar. The 141 chicken meat samples were collected at 141 retail markets in the Yangon Region, Myanmar, 1 November 2014 to 31 March 2015. Information on hygienic practices (potential risk factors) was retrieved via checklists. Salmonella was isolated and identified according to International Organization for Standardization methods (ISO 6579:2002) with minor modifications. Twelve antimicrobial agents belonging to eight pharmacological groups were used for antimicrobial susceptibility testing (disk diffusion method). Salmonella was recovered from 138 (97.9%) of the 141 samples. The isolates were most frequently resistant to trimethoprim-sulfamethoxazole (70.3% of isolates), tetracycline (54.3%), streptomycin (49.3%), and ampicillin (47.1%). Resistance was also found to chloramphenicol (29.7%), amoxicillin-clavulanic acid (17.4%), ciprofloxacin (9.4%), tobramycin (8.7%), gentamicin (8%), cefazolin (7.2%), lincomycin-spectinomycin (5.8%), and norfloxacin (0.7%). Among the 138 Salmonella isolates, 72 (52.2%) were resistant to three or more antimicrobial agents. Twenty-four serovars were identified among the 138 Salmonella-positive samples; serovars Albany, Kentucky, Braenderup, and Indiana were found in 38, 11, 10, and 8% of samples, respectively. None of the potential risk factors were significantly related to Salmonella contamination of chicken carcasses. This study provides new information regarding prevalence and antimicrobial resistance and Salmonella serovar diversity in retail markets in Yangon, Myanmar.

Odorant binding protein based biomimetic sensors for detection of alcohols associated with Salmonella contamination in packaged beef.

PubMed

Sankaran, Sindhuja; Panigrahi, Suranjan; Mallik, Sanku

2011-03-15

Detection of food-borne bacteria present in the food products is critical to prevent the spread of infectious diseases. Intelligent quality sensors are being developed for detecting bacterial pathogens such as Salmonella in beef. One of our research thrusts was to develop novel sensing materials sensitive to specific indicator alcohols at low concentrations. Present work focuses on developing olfactory sensors mimicking insect odorant binding protein to detect alcohols in low concentrations at room temperature. A quartz crystal microbalance (QCM) based sensor in conjunction with synthetic peptide was developed to detect volatile organic compounds indicative to Salmonella contamination in packaged beef. The peptide sequence used as sensing materials was derived from the amino acids sequence of Drosophila odorant binding protein, LUSH. The sensors were used to detect alcohols: 3-methyl-1-butanol and 1-hexanol. The sensors were sensitive to alcohols with estimated lower detection limits of <5 ppm. Thus, the LUSH-derived QCM sensors exhibited potential to detect alcohols at low ppm concentrations. Copyright © 2011. Published by Elsevier B.V.

Characterization of Salmonella spp. from wastewater used for food production in Morogoro, Tanzania.

PubMed

Mhongole, Ofred J; Mdegela, Robinson H; Kusiluka, Lughano J M; Forslund, Anita; Dalsgaard, Anders

2017-03-01

Wastewater use for crop irrigation and aquaculture is commonly practiced by communities situated close to wastewater treatment ponds. The objective of this study was to characterize Salmonella spp. and their antimicrobial susceptibility patterns among isolates from wastewater and Tilapia fish. A total of 123 Salmonella spp. isolates were isolated from 52 water and 21 fish intestinal samples. Genotyping of Salmonella spp. isolates was done by Pulsed-field Gel Electrophoresis (PFGE). Antimicrobial susceptibility testing was done by the minimal inhibitory concentration (MIC) technique. A total of 123 Salmonella spp. isolates represented 13 different serovars and 22 PFGE groups. Salmonella serovars showed resistance to 8 out of 14 antimicrobials; sulfamethaxazole (94%), streptomycin (61%), tetracycline (22%), ciprofloxacin and nalidixic acid (17%), trimethoprim (11%); gentamycin and chloramphenicol (6%). Salmonella Kentucky, S. Chandans, S. Durban and S. Kiambu showed multiple antimicrobial resistance to 7, 6 and 3 antimicrobials, respectively. This study has demonstrated that wastewater at the study sites is contaminated with Salmonella spp. which are resistant to common antimicrobials used for treatment of diseases in humans. Wastewater may, therefore, contaminate pristine surface water bodies and foodstuffs including fish and irrigated crops as well as food handlers.

Prevalence of Salmonella spp. in environmental samples from table egg barns in Alberta.

PubMed

St Amand, Joan A; Cassis, Rashed; King, Robin K; Annett Christianson, Colleen B

2017-12-01

Some Salmonella spp. are zoonotic, a frequent cause of foodborne illness in Canada, and known to infect humans through contaminated poultry and poultry products. Certain serotypes of Salmonella spp. have been demonstrated to be vertically transmitted from hen to egg. The incidence of Salmonella spp. isolation in the flock has been correlated to its isolation from the environment. Twenty-one producers were enrolled in this study to examine the occurrence of Salmonella spp. in 48 table egg layer flocks housed in 35 barns in Alberta. The purpose of this study was to: (i) identify Salmonella serotypes isolated from the environment of table egg layer facilities in Alberta and (ii) record the prevalence of Salmonella spp. across eight defined environmental sampling points. Salmonella spp. were isolated from the environment of 20/35 barns representing 29/48 flocks. The most common serotypes isolated were S. Heidelberg, S. Kentucky and S. Mbandaka. The order of most to least contaminated sample location was manure belts (54.1%), feeders (47.9%), feed motors (45.8%), egg belts and walls (41.7%), fans (35.0%), cage bottoms (31.3%) and lobbies (27.1%). Salmonella spp. were isolated from 7/7 barns post cleaning and disinfection, demonstrating the persistence of this organism in the environment and the need for effective eradication protocols.

Sources of salmonellae in an uninfected commercially-processed broiler flock.

PubMed

Rigby, C E; Pettit, J R; Baker, M F; Bentley, A H; Salomons, M O; Lior, H

1980-07-01

Cultural monitoring was used to study the incidence and sources of salmonellae in a 4160 bird broiler flock during the growing period, transport and processing in a commercial plant. No salmonellae were isolated from any of 132 litter samples of 189 chickens cultured during the seven-week growing period, even though nest litter samples from four of the eight parent flocks yielded salmonellae and Salmonella worthington was isolated from the meat meal component of the grower ration. On arrival at the plant, 2/23 birds sampled carried S. infantis on their feathers, although intestinal cultures failed to yield salmonellae. Three of 18 processed carcasses samples yielded salmonellae (S. infantis, S. heidelberg, S. typhimurium var copenhagen). The most likely source of these salmonellae was the plastic transport crates, since 15/107 sampled before the birds were loaded yielded salmonellae (S. infantis, S. typhimurium). The crate washer at the plant did not reduce the incidence of Salmonella-contaminated crates, since 16/116 sampled after washing yielded salmonellae (S. infantis, S. typhimurium, S. heidelberg, S. schwarzengrund, S. albany).

Combined Effects and Cross-Interactions of Different Antibiotics and Polypeptides in Salmonella bredeney.

PubMed

Ju, Xiangyu; Zhu, Mengjiao; Han, Jinzhi; Lu, Zhaoxin; Zhao, Haizhen; Bie, Xiaomei

2018-05-24

Salmonella spp. are health-threatening foodborne pathogens. The increasingly common spread of antibiotic-resistant Salmonella spp. is a major public healthcare issue worldwide. In this study, we wished to explore (1) antibiotic or polypeptide combinations to inhibit multidrug-resistant Salmonella bredeney and (2) the regulation of cross-resistance and collateral sensitivity of antibiotics and polypeptides. We undertook a study to select antibiotic combinations. Then, we promoted drug-resistant strains of S. bredeney after 15 types of antibiotic treatment. From each evolving population, the S. bredeney strain was exposed to a particular single drug. Then, we analyzed how the evolved S. bredeney strains acquired resistance or susceptibility to other drugs. A total of 105 combinations were tested against S. bredeney following the protocols of CLSI-2016 and EUCAST-2017. The synergistic interactions between drug pairings were diverse. Notably, polypeptides were more likely to be linked to synergistic combinations: 56% (19/34) of the synergistic pairings were relevant to polypeptides. Simultaneously, macrolides demonstrated antagonism toward polypeptides. The latter were more frequently related to collateral sensitivity than the other drugs because the other 13 drugs sensitized S. bredeney to polypeptides. In an experimental evolution involving 15 drugs, single drug-evolved strains were examined against the other 14 drugs, and the results were compared with the minimal inhibitory concentration of the ancestral strain. Single drug-evolved S. bredeney strains could alter the sensitivity to other drugs, and S. bredeney evolution against antibiotics could sensitize it to polypeptides.

Phenotypic, Genotypic and Pathogenicity assessment of Salmonella Infantis strains isolated from poultry

USDA-ARS?s Scientific Manuscript database

Salmonella enterica subspecies enterica serovar Infantis has been associated with human illnesslinked to contamination of poultry products. In the US, Salmonella Infantis has been recently associated to human cases of salmonellosis linked to live poultry. The presence of multidrug resistant strains ...

Evaluation of gallium maltolate on fecal Salmonella shedding in cattle

USDA-ARS?s Scientific Manuscript database

Salmonella is a major cause of foodborne illness in humans and causes over a third of all cases of gastroenteritis in the United States. Human foodborne outbreaks due to Salmonella have been traced to milk, beef, pork, and poultry. Fecal contamination of the carcass and hide is thought to be a maj...

Ethanol adaptation induces direct protection and cross-protection against freezing stress in Salmonella enterica serovar Enteritidis.

PubMed

He, S; Zhou, X; Shi, C; Shi, X

2016-03-01

Salmonella enterica serovar Enteritidis (Salm. Enteritidis) encounters mild ethanol stress during its life cycle. However, adaptation to a stressful condition may affect bacterial resistance to subsequent stresses. Hence, this work was undertaken to investigate the influences of ethanol adaptation on stress tolerance of Salm. Enteritidis. Salmonella Enteritidis was subjected to different ethanol adaptation treatments (2·5-10% ethanol for 1 h). Cellular morphology and tolerance to subsequent environmental stresses (15% ethanol, -20°C, 4°C, 50°C and 10% NaCl) were evaluated. It was found that 10% was the maximum ethanol concentration that allowed growth of the target bacteria. Ethanol adaptation did not cause cell-surface damage in Salm. Enteritidis as revealed by membrane permeability measurements and electron micrograph analysis. Salmonella Enteritidis adapted with 2·5-10% ethanol displayed an enhanced resistance to a 15%-ethanol challenge compared with an unchallenged control. The maximum ethanol resistance was observed when ethanol concentration used for ethanol adaptation was increased to 5·0%. Additionally, pre-adaptation to 5·0% ethanol cross-protected Salm. Enteritidis against -20°C, but not against 4°C, 50°C or 10% NaCl. Ethanol adaptation provided Salm. Enteritidis direct protection from a high level ethanol challenge and cross-protection from freezing, but not other stresses tested (low temperature, high salinity or high temperature). The results are valuable in developing adequate and efficient control measures for Salm. Enteritidis in foods. © 2016 The Society for Applied Microbiology.

Nutritional strategies to combat Salmonella in mono-gastric food animal production.

PubMed

Berge, A C; Wierup, M

2012-04-01

Nutritional strategies to minimize Salmonella in food animal production are one of the key components in producing safer food. The current European approach is to use a farm-to-fork strategy, where each sector must implement measures to minimize and reduce Salmonella contamination. In the pre-harvest phase, this means that all available tools need to be used such as implementation of biosecurity measures, control of Salmonella infections in animals at the farm as well as in transport and trade, optimal housing and management including cleaning, disinfection procedures as well as efforts to achieve Salmonella-free feed production. This paper describes some nutritional strategies that could be used in farm control programmes in the major mono-gastric food production animals: poultry and pigs. Initially, it is important to prevent the introduction of Salmonella onto the farm through Salmonella-contaminated feed and this risk is reduced through heat treatment and the use of organic acids and their salts and formaldehyde. Microbiological sampling and monitoring for Salmonella in the feed mills is required to minimize the introduction of Salmonella via feed onto the farm. In addition, feed withdrawal may create a stressful situation in animals, resulting in an increase in Salmonella shedding. Physical feed characteristics such as coarse-ground meal to pigs can delay gastric emptying, thereby increasing the acidity of the gut and thus reducing the possible prevalence of Salmonella. Coarse-ground grains and access to litter have also been shown to decrease Salmonella shedding in poultry. The feed can also modify the gastro-intestinal tract microflora and influence the immune system, which can minimize Salmonella colonization and shedding. Feed additives, such as organic acids, short- and medium-chain fatty acids, probiotics, including competitive exclusion cultures, prebiotics and certain specific carbohydrates, such as mannan-based compounds, egg proteins, essential oils

Modeling the survival of Salmonella Enteritidis and Salmonella Typhimurium during the fermentation of yogurt.

PubMed

Savran, Derya; Pérez-Rodríguez, Fernando; Halkman, A Kadir

2018-03-01

The objective of this study was to evaluate the behavior of Salmonella Enteritidis and Salmonella Typhimurium, the two most important serovars of salmonellosis , during the fermentation of yogurt. The microorganisms were enumerated in milk throughout the fermentation process at three initial inoculum levels (3, 5 and 7 log CFU/mL). DMFit software was used in the fitting procedure of the data (IFR, Norwich, UK, Version 3.5). The data provided sigmoidal curves that were successfully displayed with the Baranyi model. The results showed that the initial inoculum level did not affect the growth for both pathogens; thus, the µ max values (maximum specific growth rate) did not significantly differ across all the contamination levels, ranging from 0.26 to 0.38 for S. Enteritidis and from 0.50 to 0.56 log CFU/g/h for S. Typhimurium ( P > 0.05). However, the µ max values significantly differed between the two serovars ( P < 0.05). The λ values (lag time) did not have a clear trend in either of the pathogens. The present study showed that Salmonella can survive the fermentation process of milk even at a low contamination level. In addition, the models presented in this study can be used in quantitative risk assessment studies to estimate the threat to consumers.

Optimized molecular resolution of cross-contamination alerts in clinical mycobacteriology laboratories.

PubMed

Martín, Ana; Herranz, Marta; Lirola, Miguel Martínez; Fernández, Rosa Fernández; Bouza, Emilio; García de Viedma, Darío

2008-02-14

The phenomenon of misdiagnosing tuberculosis (TB) by laboratory cross-contamination when culturing Mycobacterium tuberculosis (MTB) has been widely reported and it has an obvious clinical, therapeutic and social impact. The final confirmation of a cross-contamination event requires the molecular identification of the same MTB strain cultured from both the potential source of the contamination and from the false-positive candidate. The molecular tool usually applied in this context is IS6110-RFLP which takes a long time to provide an answer, usually longer than is acceptable for microbiologists and clinicians to make decisions. Our purpose in this study is to evaluate a novel PCR-based method, MIRU-VNTR as an alternative to assure a rapid and optimized analysis of cross-contamination alerts. MIRU-VNTR was prospectively compared with IS6110-RFLP for clarifying 19 alerts of false positivity from other laboratories. MIRU-VNTR highly correlated with IS6110-RFLP, reduced the response time by 27 days and clarified six alerts unresolved by RFLP. Additionally, MIRU-VNTR revealed complex situations such as contamination events involving polyclonal isolates and a false-positive case due to the simultaneous cross-contamination from two independent sources. Unlike standard RFLP-based genotyping, MIRU-VNTR i) could help reduce the impact of a false positive diagnosis of TB, ii) increased the number of events that could be solved and iii) revealed the complexity of some cross-contamination events that could not be dissected by IS6110-RFLP.

Reduction of Salmonella populations on cucumber fruit by application of lytic bacteriophages

USDA-ARS?s Scientific Manuscript database

Background: Foodborne illness outbreaks of Salmonella enterica associated with consumption of cucumbers (Cucumis sativus) in the U.S. in 2014 and 2015 sickened over 1000 people and caused 5 deaths. Whole and fresh-cut cucumbers are susceptible to Salmonella contamination during growing and harvestin...

Inactivation of Salmonella in Organic Soil by Cinnamaldehyde, Eugenol, Ecotrol, and Sporan

USDA-ARS?s Scientific Manuscript database

Salmonella can survive in soil for months to years; consequently, soil can be a preharvest source of contamination of produce. Elimination of Salmonella with natural products and processes such as essential oils is important to prevent infection among consumers. Essential oils have been mainly eval...

Development of multiplex PCR assay for simultaneous detection of Salmonella genus, Salmonella subspecies I, Salm. Enteritidis, Salm. Heidelberg and Salm. Typhimurium.

PubMed

Park, S H; Ricke, S C

2015-01-01

The aim of this research was to develop multiplex PCR assay that could simultaneously detect Salmonella genus, Salmonella subsp. I, Salm. Enteritidis, Heidelberg and Typhimurium because these Salmonella serovars are the most common isolates associated with poultry products. Five primers were utilized to establish multiplex PCR and applied to Salmonella isolates from chickens and farm environments. These isolates were identified as Salmonella subsp. I and 16 of 66 isolates were classified as Salm. Enteritidis, while Heidelberg or Typhimurium was not detected. We also spiked three Salmonella strains on chicken breast meat to evaluate the specificity and sensitivity of multiplex PCR as well as qPCR to optimize quantification of Salmonella in these samples. The optimized multiplex PCR and qPCR could detect approx. 2·2 CFU of Salmonella per gram after 18 h enrichment. The multiplex PCR and qPCR would provide rapid and consistent results. Also, these techniques would be useful for the detection and quantification of Salmonella in contaminated poultry, foods and environmental samples. The strategy for the rapid detection of Salmonella serovars in poultry is needed to further reduce the incidence of salmonellosis in humans. The optimized multiplex PCR will be useful to detect prevalent Salmonella serovars in poultry products. © 2014 The Society for Applied Microbiology.

Prevalence, molecular and antimicrobial resistance of Salmonella isolated from sausages in Meknes, Morocco.

PubMed

Ed-Dra, Abdelaziz; Filali, Fouzia Rhazi; Karraouan, Bouchra; El Allaoui, Abdellah; Aboulkacem, Amal; Bouchrif, Brahim

2017-04-01

Salmonella is among the most important food borne pathogens worldwide contaminating a wide range of animal products including meat products. The aims of this study go through two steps: The first step is to estimate the proportion of sausages products contaminated with Salmonella in Meknes city (Morocco), which were collected from various shopping sites: butchery, street vendors, supermarket and souk (Weekly market combines the population of the small villages around Meknes city). The second one is to identify serovars, to determine the antimicrobials resistance patterns of isolates and to detect the invA and spvC genes. 34 (21.79%) Salmonella were isolated, recovered 4 serogroups and 12 serotypes. The most prevalent serotypes were Salmonella Corvallis (23.53%) and Salmonella Kentucky (17.65%). All Salmonella isolates were tested for their susceptibility to 18 selected antimicrobials agents, of which 100% were resistant to at least one antimicrobial, 85.30% (29/34) were resistant to two or more antimicrobials and 44.12% (15/34) were resistant to at least three antimicrobials. All Salmonella are resistant to ampicillin, 76.47% to streptomycin, 20.59% to sulfonamides, 17.65% to Tetracycline and 11.77% to Ofloxacin. The "ACSSuT" penta-resistance pattern was observed in tow of the Salmonella Typhimurium strains. In addition, this study showed that all Salmonella strains (34) were positive for invasion gene invA and negative for the virulence gene spvC. Copyright © 2017 Elsevier Ltd. All rights reserved.

Salmonella prevalence and characterization in a free-range pig processing plant: tracking in trucks, lairage, slaughter line and quartering.

PubMed

Hernández, Manuela; Gómez-Laguna, Jaime; Luque, Inmaculada; Herrera-León, Silvia; Maldonado, Alfonso; Reguillo, Lucía; Astorga, Rafael J

2013-03-01

New consumer tendencies are focused on products derived from systems which allow both a high animal welfare condition and a high food safety level. However, sometimes animal welfare regulations make the adoption of adequate bio-security measures difficult, representing a barrier for animal health and food safety. Thus the aim of this study was to determine the prevalence of Salmonella at different points of the pig slaughtering process (Trucks, Lairage, Slaughter line and Quartering, TLSQ) from pigs reared in free-range systems. From eight samplings a total of 126 Salmonella isolates out of 1160 different samples were recovered (10.86%). The highest percentage of isolates was detected at the points of pre-scalding (29/80, 36.25%), trucks (13/56, 23.21%), cecal contents (17/80, 21.25%), tonsils (14/80, 17.50%), ileocecal lymph nodes (13/80, 16.25%) and lairage (9/64, 14.06%). Furthermore, eighteen isolates were obtained from different environmental samples from slaughter line and quartering plant (knives and surface of tables) (5.63%) and three isolates at the quartering plant samples (ham, shoulder and loin) (3.75%). Fourteen different serotypes were isolated: Bredeney, Rissen, Derby, Typhimurium, Montevideo, Israel, Anatum, Emek, Monophasic Salmonella Typhimurium (mST), Choleraesuis, Durban, Kentucky, London and Sandiego. S. Typhimurium phage types U311, 193, 104b and UT were identified. Moreover, mST strain was phage typed as U311. From TLSQ1, TLSQ2 and TLSQ4, different strains of S. Derby, S. Rissen and S. Bredeney serotypes were isolated from pig and environmental samples, pointing to a potential cross contamination. Molecular typing (Pulsed-Field Gel Electrophoresis, PFGE) of these strains confirmed the cross contamination. In the remaining samplings, different serotypes were obtained in each sampled point of the chain, assuming that the isolated serotypes belonged to different epidemiological origins. Our results show the isolation of different serotypes of

Prevalence and Characterization of Salmonella in Animal Meals Collected from Rendering Operations.

PubMed

Jiang, Xiuping

2016-06-01

As part of the Salmonella Education Reduction Program, the Animal Protein Producers Industry initiated a yearlong microbiological survey of animal meals from 1 January to 31 December 2010. The types of animal meals included poultry meal, pork and beef crax, meat meal, meat and bone meal, feather meal, blood meal, and fish meal from a variety of rendering operations (n = 65). Salmonella was positive in 731 (8.3%) of 8,783 analyzed samples, with contamination rates as 1.0, 33.2, and 21.3% from samples collected right after press, being loaded out, or unidentified, respectively. The randomly selected positive Salmonella samples (n = 100) representing 1.1% of the total samples tested were enumerated by the most-probable-number (MPN) method. The Salmonella contamination level ranged from <0.03 (below the detection limit) to 240 MPN/g with a median MPN per gram of 0.036. Among 102 Salmonella isolates from those 100 positive samples, a total of 42 Salmonella serotypes or groups were identified with Montevideo (13%), Senftenberg (11%), Mbandaka (7%), Orion (7%), Livingstone (6%), Tennessee (4%), Infantis (4%), Cerro (4%), and group C1 (4%) as the most predominant ones. Those Salmonella isolates were further analyzed for antimicrobial resistance to the 15 most common antibiotics by using the National Antimicrobial Resistance Monitoring System gram-negative plate. Most Salmonella isolates (n = 94) were sensitive to all antibiotics tested, with seven isolates resistant to one antibiotic and one resistant to seven antibiotics. Clearly, the prevalence of Salmonella in animal meals declined compared with previous surveys, and none of the Salmonella serotypes concerning target animal health were isolated. In addition, most Salmonella isolates remained susceptible to the majority of the 15 most commonly used antibiotics.

Salmonella serotypes in reptiles and humans, French Guiana.

PubMed

Gay, Noellie; Le Hello, Simon; Weill, François-Xavier; de Thoisy, Benoit; Berger, Franck

2014-05-14

In French Guiana, a French overseas territory located in the South American northern coast, nearly 50% of Salmonella serotypes isolated from human infections belong to serotypes rarely encountered in metropolitan France. A reptilian source of contamination has been investigated. Between April and June 2011, in the area around Cayenne, 151 reptiles were collected: 38 lizards, 37 snakes, 32 turtles, 23 green iguanas and 21 caimans. Cloacal swab samples were collected and cultured. Isolated Salmonella strains were identified biochemically and serotyped. The overall carriage frequency of carriage was 23.2% (95% confidence interval: 16.7-30.4) with 23 serotyped strains. The frequency of Salmonella carriage was significantly higher for wild reptiles. Near two-thirds of the Salmonella serotypes isolated from reptiles were also isolated from patients in French Guiana. Our results highlight the risk associated with the handling and consumption of reptiles and their role in the spread of Salmonella in the environment. Copyright © 2014 Elsevier B.V. All rights reserved.

Risk factors for contamination of ready-to-eat street-vended poultry dishes in Dakar, Senegal.

PubMed

Cardinale, E; Perrier Gros-Claude, J D; Tall, F; Guèye, E F; Salvat, G

2005-08-25

Our objective was to investigate the Salmonella and Campylobacter contamination of traditional ready-to-eat street-vended poultry dishes and to assess the association of some restaurant characteristics and cooking practices with the contamination of these meals. One hundred and forty-eight street-restaurants were studied from January 2003 to April 2004 in Dakar. A questionnaire was submitted to the managers, and samples of ready-to-eat poultry dishes were taken. Salmonella spp. was isolated in 20.1% of the 148 street-restaurants studied and in 10.1% samples of poultry dishes. The most prevalent serovars isolated were Salmonella hadar, Salmonella enteritidis and Salmonella brancaster. Campylobacter jejuni was detected in only 3 restaurants and 3 poultry dishes. Not peeling and not cleaning vegetables and other ingredients during meal preparation (OR=3.58), dirty clothing for restaurant employees (OR=4.65), reheating previously cooked foods (OR=5.2), and no kitchen and utensils disinfection (OR=3.47) were associated with an increasing risk of Salmonella contamination. Adequate cooking procedures decreased the risk of Salmonella contamination (OR=0.15).

Salmonella, Escherichia coli and Enterobacteriaceae in the peanut supply chain: From farm to table.

PubMed

Nascimento, M S; Carminati, J A; Silva, I C R N; Silva, D L; Bernardi, A O; Copetti, M V

2018-03-01

Due to recent foodborne outbreaks, peanuts have been considered a potential risk for Salmonella transmission. For this reason, the aim of this study was to determine the prevalence and contamination load of Salmonella, Escherichia coli and Enterobacteriaceae throughout the peanut supply chain in Brazil. Samples of peanuts and peanut-containing processed products from post-harvest (n=129), secondary processing (n=185) and retail market (n=100) were analyzed. The results showed high Enterobacteriaceae counts in the post-harvest samples. At the end of the secondary processing, 16% of the samples remained contaminated by this group of microorganisms. Six peanut samples from primary production and one sample of peanut butter were tested positive for E. coli while Salmonella was detected in nine samples (2.2%): six from post-harvest, two from the initial stage of the secondary processing and one from retail. The Salmonella counts ranged between 0.004 and 0.092MPN/g and five serotypes were identified (Muenster, Miami, Javiana, Oranienburg, Glostrup). The results demonstrated a high prevalence of Enterobacteriaceae and low prevalence of E. coli throughout the peanut supply chain. Furthermore, it was verified that peanuts may become contaminated by Salmonella during different stages of the supply chain, especially at post-harvest. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of Rapid Detection and Genetic Characterization of Salmonella in Poultry Breeder Feeds

PubMed Central

Jarquin, Robin; Hanning, Irene; Ahn, Soohyoun; Ricke, Steven C.

2009-01-01

Salmonella is a leading cause of foodborne illness in the United States, with poultry and poultry products being a primary source of infection to humans. Poultry may carry some Salmonella serovars without any signs or symptoms of disease and without causing any adverse effects to the health of the bird. Salmonella may be introduced to a flock by multiple environmental sources, but poultry feed is suspected to be a leading source. Detecting Salmonella in feed can be challenging because low levels of the bacteria may not be recovered using traditional culturing techniques. Numerous detection methodologies have been examined over the years for quantifying Salmonella in feeds and many have proven to be effective for Salmonella isolation and detection in a variety of feeds. However, given the potential need for increased detection sensitivity, molecular detection technologies may the best candidate for developing rapid sensitive methods for identifying small numbers of Salmonella in the background of large volumes of feed. Several studies have been done using polymerase chain reaction (PCR) assays and commercial kits to detect Salmonella spp. in a wide variety of feed sources. In addition, DNA array technology has recently been utilized to track the dissemination of a specific Salmonella serotype in feed mills. This review will discuss the processing of feeds and potential points in the process that may introduce Salmonella contamination to the feed. Detection methods currently used and the need for advances in these methods also will be discussed. Finally, implementation of rapid detection for optimizing control methods to prevent and remove any Salmonella contamination of feeds will be considered. PMID:22346699

Comparison of the Antimicrobial and Sanitizer Resistance of Salmonella Isolates from Chicken Slaughter Processes in Korea.

PubMed

Youn, So Youn; Jeong, Ok Mi; Choi, Byung Kook; Jung, Suk Chan; Kang, Min Su

2017-03-01

Salmonella is a foodborne pathogen worldwide. Outbreaks of Salmonella are commonly associated with consumption of contaminated foods such as poultry products. Therefore, the objective of this study was to determine the occurrence, biofilm formation, antibiotic resistance, and sanitizer resistance of Salmonella enterica isolated from chicken carcasses. A total of 318 samples were collected from 15 chicken slaughterhouses in 8 provinces of Korea. They were then examined for Salmonella contamination. S. enterica isolates were tested for their susceptibilities to 15 antimicrobials by broth microdilution method. Their biofilm formation ability and resistance to sanitizers were also evaluated. Eighty-two isolates of S. enterica were obtained from the 318 samples. There were 14 serotypes and 2 untypable isolates. Fifty-seven (69.5%) isolates were resistant to at least one antibiotic while 30 (36.6%) isolates were resistant to 5 or more antibiotics. Two S. Senftenberg and 3 S. Montevideo isolates exhibited considerable biofilm formation ability (A 600 >0.2) following incubation in Luria-Bertani (LB) broth for 48 h. Biofilm cell survival and recovery growth assay after sanitization showed that most isolates were highly susceptible to 2.5% lactic acid and 0.1% cetylpyridinium chloride. Therefore, lactic acid and cetylpyridinium chloride might be alternatively or additionally used in addition to chlorine-based sanitizers that are frequently used to reduce Salmonella contamination of chicken carcasses. Our results provide basic information on the distribution of Salmonella serotypes in chicken slaughterhouses. This study also highlights the necessity to improve farming practices and use antimicrobial agents cautiously. This study also suggests that sanitization during the slaughtering process might be necessary to reduce Salmonella contamination of chicken carcasses. © 2017 Institute of Food Technologists®.

Efficiency of organic acid preparations for the elimination of naturally occurring Salmonella in feed material.

PubMed

Axmann, Sonja; Kolar, Veronika; Adler, Andreas; Strnad, Irmengard

2017-11-01

Salmonella can enter animal stocks via feedstuffs, thus posing not only an infection risk for animals, but also threatening to contaminate food of animal origin and finally humans. Salmonella contamination in feedstuffs is still a recurring and serious issue in animal production (especially for the poultry sector), and is regularly detected upon self-monitoring by feed companies (self-checks) and official inspections authorities. Operators within the feed chain in certain cases need to use hygienic condition enhancers, such as organic acids, to improve the quality of feed for animal nutrition, providing additional guarantees for the protection of animal and public health. The present study investigated the efficiencies of five organic acid preparations. The acid products were added to three different feed materials contaminated with Salmonella (contamination occurred by recontamination in the course of the production process) at seven different inclusion rates (1-7%) and analysed after 1, 2, and 7 days' exposure time using culture method (tenfold analysis). A reliable standard was established for defining a successful decontamination under the prevailing test conditions: 10 Salmonella-negative results out of 10 tested samples (0/10: i.e. 0 positive samples and 10 negative samples). The results demonstrated that the tested preparations showed significant differences with regard to the reduction in Salmonella contamination. At an inclusion rate of 7% of the feed materials, two out of five acid preparations showed an insufficient, very small, decontamination effect, whereas two others had a relatively large partial effect. Reliable decontamination was demonstrated only for one acid preparation, however, subject to the use of the highest acid concentration.

Resistance of Strains Producing Extended-Spectrum β-Lactamases Among Salmonella from Duck Carcasses at Slaughterhouses in Three Major Provinces of South Korea.

PubMed

Lee, Soo Kyoung; Choi, Dasom; Chon, Jung Whan; Seo, Kun Ho

2016-03-01

The current study was carried out to estimate Salmonella spp. contamination of duck carcasses and to determine the antibiotic susceptibility profiles and serotype distribution of the isolates. Salmonella spp. was detected in 21.7% (26/120) of fresh raw duck carcasses sampled at different slaughterhouses in South Korea. Eight Salmonella serovars were identified; the most prevalent serovar was S. Typhimurium (34.6%), followed by S. Virchow (30.8%). All isolates were resistant to at least one antibiotic, and five remarkable isolates were resistant to more than 10 antibiotics, including third- and fourth-generation cephalosporins. Additional phenotypic and genetic characterization demonstrated that these isolates harbored resistance genes to broad-spectrum β-lactams, blaCTX-M-15 and blaCMY-2 genes, among the most prevalent β-lactamase enzymes worldwide. Based on molecular subtyping performed using the DiversiLab™ automated repetitive-sequence-based PCR system, isolates were classified into cluster A and cluster B. Among β-lactamase-producing Salmonellas, the isolate showing >98% similarity in their repetitive-sequence-based PCR banding pattern seemed to have acquired the resistance gene (blaCMY-2) and thus a distinct multiresistance profile. Given that antibiotic-resistant genes might be transferred by plasmid-mediated conjugation, periodic microbiological assessment within slaughterhouses is recommended for pathogens not to be transmitted through cross-contamination during slaughtering and dressing.

Presence of Salmonella in the red meat abattoir lairage after routine cleansing and disinfection and on carcasses.

PubMed

Small, A; James, C; James, S; Davies, R; Liebana, E; Howell, M; Hutchison, M; Buncic, S

2006-10-01

Foodborne pathogens, such as Salmonella, may remain in abattoir lairages after cleansing and pose a risk of transfer and contamination from one processing day to the next. These organisms may be transferred to the outer surface of animals held in lairage facilities, and the skin or hide may be a significant source of microbial contamination on the red meat carcasses subsequently produced. Sponge samples were taken from various sites in the lairage (n = 556), and single-pass sponge samples were taken from one side of red meat carcasses (n = 1,050) at five commercial abattoirs in Southwest England and tested for the presence of Salmonella. Of these, 6.5% of lairage samples were positive, containing estimated numbers of up to 10(4) Salmonella organisms per sampled area (50 by 50 cm). Salmonella was found on 9.6% of 240 lamb carcasses, 12.7% of 330 beef carcasses, 31% of 70 pig carcasses, 20% of 80 calf carcasses younger than 14 days of age, and none of 330 cull cow and bull carcasses. Subtyping divided the 137 isolates into seven serogroups and three pulsed-field gel electrophoresis clusters, and sensitivity testing against a bank of 16 antimicrobials indicated that 47 isolates had resistance to one or more antimicrobial agents. These results indicate that Salmonella contamination can persist in the lairage environment from one processing day to the next and that Salmonella is present on red meat carcasses, although the implications of residual lairage contamination on carcass meat microbiology are not clear from this study. Abattoir owners should take steps to reduce the level of contamination in their premises to prevent contamination from being carried over from one processing day to the next.

Salmonella organisms in garden fertilizers of animal origin.

PubMed Central

Smith, H. W.; Tucker, J. F.; Hall, M. L.; Rowe, B.

1982-01-01

Of 120 specimens of garden fertilizers of animal origin purchased in retail shops, 40 (33.3%) were found to be contaminated with salmonella organisms. Untreated bone meal (53.1%) was the most heavily contaminated but 25% of specimens of this product classed as heat-treated or sterilized were positive. In all, 32 serotypes were identified. PMID:6284835

Prevalence and antibiotic resistance pattern of Salmonella serovars in integrated crop-livestock farms and their products sold in local markets.

PubMed

Peng, Mengfei; Salaheen, Serajus; Almario, Jose Alejandro; Tesfaye, Bezait; Buchanan, Robert; Biswas, Debabrata

2016-05-01

Major concern in the Mixed Crop-Livestock (MCL) farms, in which livestock and vegetables grown closely in the same facility, is cross-contamination of zoonotic bacterial pathogens especially Salmonella. To investigate the distribution of Salmonella serovars in MCL and their products, a total of 1287 pre-harvest samples from various farms and 1377 post-harvest samples from retail supermarkets in Maryland and Washington D.C. areas were collected and analysed. A total of 315 Salmonella isolates were recovered, with 17.44% and 5.88%, from MCL and conventional farms samples (P < 0.001). At post-harvest level, the prevalence of Salmonella was 30.95%, 19.83%, and 8.38% in chicken meat (P < 0.001) from farmers, organic, and conventional retail markets respectively, and 16.81% and 6.06% in produce products (P < 0.001) from farmers and organic retail markets, but none from conventional retail markets. From the isolated Salmonella, 34.50% was confirmed S. Typhimurium, followed by S. Heidelberg (10.86%) and S. Enteritidis (9.90%). The overall multi-antibiotic resistance in recovered Salmonella was 23.81% versus 4.55% in conventional and MCL farms (P = 0.004) and 66.67% versus 7.76% in conventional and farmers markets (P < 0.001). Overall the data reveals higher Salmonella risks in MCL farms' environment and their products sold in farmers markets and warrants taking necessary measures to limit Salmonella transmission. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Multigeneration Cross-Contamination of Mail with Bacillus anthracis Spores

PubMed Central

Edmonds, Jason; Lindquist, H. D. Alan; Sabol, Jonathan; Martinez, Kenneth; Shadomy, Sean; Cymet, Tyler; Emanuel, Peter

2016-01-01

The release of biological agents, including those which could be used in biowarfare or bioterrorism in large urban areas, has been a concern for governments for nearly three decades. Previous incidents from Sverdlosk and the postal anthrax attack of 2001 have raised questions on the mechanism of spread of Bacillus anthracis spores as an aerosol or contaminant. Prior studies have demonstrated that Bacillus atrophaeus is easily transferred through simulated mail handing, but no reports have demonstrated this ability with Bacillus anthracis spores, which have morphological differences that may affect adhesion properties between spore and formite. In this study, equipment developed to simulate interactions across three generations of envelopes subjected to tumbling and mixing was used to evaluate the potential for cross-contamination of B. anthracis spores in simulated mail handling. In these experiments, we found that the potential for cross-contamination through letter tumbling from one generation to the next varied between generations while the presence of a fluidizer had no statistical impact on the transfer of material. Likewise, the presence or absence of a fluidizer had no statistically significant impact on cross-contamination levels or reaerosolization from letter opening. PMID:27123934

Contamination of knives and graters by bacterial foodborne pathogens during slicing and grating of produce.

PubMed

Erickson, Marilyn C; Liao, Jean; Cannon, Jennifer L; Ortega, Ynes R

2015-12-01

Poor hygiene and improper food preparation practices in consumers' homes have previously been demonstrated as contributing to foodborne diseases. To address potential cross-contamination by kitchen utensils in the home, a series of studies was conducted to determine the extent to which the use of a knife or grater on fresh produce would lead to the utensil's contamination with Escherichia coli O157:H7 or Salmonella enterica. When shredding inoculated carrots (ca. 5.3 log CFU/carrot), all graters became contaminated and the number of E. coli O157:H7 present on the utensil was significantly greater than Salmonella (p < 0.05). Contamination of knives after slicing inoculated produce (4.9-5.4 log CFU/produce item) could only be detected by enrichment culture. After slicing tomatoes, honeydew melons, strawberries, cucumbers, and cantaloupes, the average prevalence of knife contamination by the two pathogens was 43%, 17%, 15%, 7%, and 3%, respectively. No significant increase in the incidence or level of contamination occurred on the utensils when residues were present (p > 0.05); however, subsequent contamination of 7 produce items processed with the contaminated utensils did occur. These results highlight the necessity of proper sanitization of these utensils when used in preparation of raw produce. Copyright © 2015 Elsevier Ltd. All rights reserved.

Optimizing buffering chemistry to maintain near neutral pH of broiler feed during pre-enrichment for Salmonella

USDA-ARS?s Scientific Manuscript database

Salmonella is a human pathogen that can accompany live broilers to the slaughter plant contaminating fully processed carcasses. Feed is one potential source of Salmonella to growing broilers. Monitoring feed for the presence of Salmonella is part of good agricultural practices. The first step in ...

Antimicrobial resistance of Salmonella enterica isolates from bulk tank milk and milk filters in the United States

USDA-ARS?s Scientific Manuscript database

Non-typhoid Salmonella is frequently associated with dairy cattle and their environment. Despite well-developed milking hygiene protocols, fecal contamination can occur and Salmonella has often been isolated from bulk milk. Salmonella isolates were recovered from US bulk tank milk as part of the NAH...

Salmonella serotype distribution in the Dutch broiler supply chain.

PubMed

van Asselt, E D; Thissen, J T N M; van der Fels-Klerx, H J

2009-12-01

Salmonella serotype distribution can give insight in contamination routes and persistence along a production chain. Therefore, it is important to determine not only Salmonella prevalence but also to specify the serotypes involved at the different stages of the supply chain. For this purpose, data from a national monitoring program in the Netherlands were used to estimate the serotype distribution and to determine whether this distribution differs for the available sampling points in the broiler supply chain. Data covered the period from 2002 to 2005, all slaughterhouses (n = 22), and the following 6 sampling points: departure from hatchery, arrival at the farm, departure from the farm, arrival at the slaughterhouse, departure from the slaughterhouse, and end of processing. Furthermore, retail data for 2005 were used for comparison with slaughterhouse data. The following serotypes were followed throughout the chain: Salmonella Enteritidis, Salmonella Typhimurium, Salmonella Paratyphi B var. Java (Salmonella Java), Salmonella Infantis, Salmonella Virchow, and Salmonella Mbandaka. Results showed that serotype distribution varied significantly throughout the supply chain (P < 0.05). Main differences were found at the farm and at the slaughterhouse (within one stage), and least differences were found between departure from one stage and arrival at the next stage. The most prominent result was the increase of Salmonella Java at farm level. This serotype remained the most prominent pathogen throughout the broiler supply chain up to the retail phase.

Specific Discrimination of Three Pathogenic Salmonella enterica subsp. enterica Serotypes by carB-Based Oligonucleotide Microarray

PubMed Central

Shin, Hwa Hui; Hwang, Byeong Hee; Seo, Jeong Hyun

2014-01-01

It is important to rapidly and selectively detect and analyze pathogenic Salmonella enterica subsp. enterica in contaminated food to reduce the morbidity and mortality of Salmonella infection and to guarantee food safety. In the present work, we developed an oligonucleotide microarray containing duplicate specific capture probes based on the carB gene, which encodes the carbamoyl phosphate synthetase large subunit, as a competent biomarker evaluated by genetic analysis to selectively and efficiently detect and discriminate three S. enterica subsp. enterica serotypes: Choleraesuis, Enteritidis, and Typhimurium. Using the developed microarray system, three serotype targets were successfully analyzed in a range as low as 1.6 to 3.1 nM and were specifically discriminated from each other without nonspecific signals. In addition, the constructed microarray did not have cross-reactivity with other common pathogenic bacteria and even enabled the clear discrimination of the target Salmonella serotype from a bacterial mixture. Therefore, these results demonstrated that our novel carB-based oligonucleotide microarray can be used as an effective and specific detection system for S. enterica subsp. enterica serotypes. PMID:24185846

Specific discrimination of three pathogenic Salmonella enterica subsp. enterica serotypes by carB-based oligonucleotide microarray.

PubMed

Shin, Hwa Hui; Hwang, Byeong Hee; Seo, Jeong Hyun; Cha, Hyung Joon

2014-01-01

It is important to rapidly and selectively detect and analyze pathogenic Salmonella enterica subsp. enterica in contaminated food to reduce the morbidity and mortality of Salmonella infection and to guarantee food safety. In the present work, we developed an oligonucleotide microarray containing duplicate specific capture probes based on the carB gene, which encodes the carbamoyl phosphate synthetase large subunit, as a competent biomarker evaluated by genetic analysis to selectively and efficiently detect and discriminate three S. enterica subsp. enterica serotypes: Choleraesuis, Enteritidis, and Typhimurium. Using the developed microarray system, three serotype targets were successfully analyzed in a range as low as 1.6 to 3.1 nM and were specifically discriminated from each other without nonspecific signals. In addition, the constructed microarray did not have cross-reactivity with other common pathogenic bacteria and even enabled the clear discrimination of the target Salmonella serotype from a bacterial mixture. Therefore, these results demonstrated that our novel carB-based oligonucleotide microarray can be used as an effective and specific detection system for S. enterica subsp. enterica serotypes.

Effects of Domestic Storage and Thawing Practices on Salmonella in Poultry-Based Meat Preparations.

PubMed

Roccato, Anna; Uyttendaele, Mieke; Cibin, Veronica; Barrucci, Federica; Cappa, Veronica; Zavagnin, Paola; Longo, Alessandra; Catellani, Paolo; Ricci, Antonia

2015-12-01

Among consumer food handling practices, time-temperature abuse has been reported as one of the most common contributory factors in salmonellosis outbreaks where the evidence is strong. The present study performed storage tests of burgers, sausages, and kebabs and investigated (i) the effect of refrigerator temperatures (4°C versus 8 or 12°C, which were the temperatures recorded in 33 and 3%, respectively, of domestic refrigerators in Italy), with or without prior temperature abuse (25°C for 2 h, simulating transport of meats from shop to home), and (ii) the impact of the thawing method (overnight in the refrigerator at 8°C versus on the kitchen countertop at 23°C) on the presence and numbers of Salmonella bacteria. Storage tests were carried out on naturally or artificially (Salmonella enterica serovar Typhimurium at ca. 10 CFU/g) contaminated products, while freezing-thawing tests were conducted only on artificially contaminated products (Salmonella Typhimurium at ca. 10, 100, and 1,000 CFU/g). The results from the artificially contaminated products showed significant (P < 0.05) growth of Salmonella Typhimurium at 12°C (i.e., from ca. 8 most probable number [MPN]/g to > 710 MPN/g) in kebabs after 7 and 10 days but more moderate growth in sausages (i.e., from ca. 14 MPN/g to a maximum of 96 MPN/g after 9 days of storage). Storage of naturally contaminated burgers or sausages (contamination at or below 1 MPN/g) at 4, 8, or 12°C and a short time of temperature abuse (2 h at 25°C) did not facilitate an increase in the presence and numbers of Salmonella bacteria. Thawing overnight in the refrigerator led to either a moderate reduction or no change of Salmonella Typhimurium numbers in burgers, sausages, and kebabs. Overall, this study showed that domestic storage and thawing practices can affect food safety and that time-temperature abuse can cause a substantial increase of Salmonella numbers in some types of poultry-based meat preparations, highlighting that

Development of hyperspectral imaging technique for salmonella enteritidis and typhimurium on agar plates

USDA-ARS?s Scientific Manuscript database

Salmonella is a common cause of foodborne disease resulting from the consumption of contaminated food products. Although a direct plating method is widely used for presumptive positive screening of pathogenic Salmonella colonies on agar plates, it is labor-intensive, time-consuming and also prone to...

Quantification, serovars, and antibiotic resistance of salmonella isolated from retail raw chicken meat in Vietnam.

PubMed

Ta, Yen T; Nguyen, Trung Thanh; To, Phuong Bich; Pham, Da Xuan; Le, Hao Thi Hong; Thi, Giang Nguyen; Alali, Walid Q; Walls, Isabel; Doyle, Michael P

2014-01-01

The objectives of this study were to quantify Salmonella counts on retail raw poultry meat in Vietnam and to phenotypically characterize (serovars and antibiotic resistance) the isolates. A total of 300 chicken carcasses were collected from two cities and two provinces in Vietnam. Salmonella counts on the samples were determined according to the most-probable-number (MPN) method of the U.S. Department of Agriculture, Food Safety and Inspection Service (USDA-FSIS). A total of 457 isolates were serotyped and tested for antibiotic susceptibility. Overall, 48.7% of chicken samples were Salmonella positive with a count of 2.0 log MPN per carcass. There were no significant differences (P > 0.05) in log MPN per carcass by the study variables (market type, storage condition, and chicken production system). There was a significant difference (P < 0.05) in Salmonella-positive prevalence by chicken production system. Among the 22 Salmonella serovars identified, Albany was the most frequent (34.1%), followed by Agona (15.5%) and Dabou (8.8%). Resistance to at least one antibiotic was common (i.e., 73.3%), with high resistance to tetracycline (59.1%) and ampicillin (41.6%). Resistance to three antibiotics was the most frequently found multidrug resistance profile (17.7%, n = 81); the profile that was resistant to the highest number of drugs was resistant to nine antibiotics (0.7%, n = 3). Only Salmonella Albany posed phenotypic resistance to ceftriaxone (a drug of choice to treat severe cases of salmonellosis). The data revealed that, whereas Salmonella prevalence on raw poultry was high (48.7%), counts were low, which suggests that the exposure risk to Salmonella is low. However, improper storage of raw chicken meat and cross-contamination may increase Salmonella cell counts and pose a greater risk for infection. These data may be helpful in developing risk assessment models and preventing the transmission of foodborne Salmonella from poultry to humans in Vietnam.

Protein Chips for Detection of Salmonella spp. from Enrichment Culture

PubMed Central

Poltronieri, Palmiro; Cimaglia, Fabio; De Lorenzis, Enrico; Chiesa, Maurizio; Mezzolla, Valeria; Reca, Ida Barbara

2016-01-01

Food pathogens are the cause of foodborne epidemics, therefore there is a need to detect the pathogens in food productions rapidly. A pre-enrichment culture followed by selective agar plating are standard detection methods. Molecular methods such as qPCR have provided a first rapid protocol for detection of pathogens within 24 h of enrichment culture. Biosensors also may provide a rapid tool to individuate a source of Salmonella contamination at early times of pre-enrichment culture. Forty mL of Salmonella spp. enrichment culture were processed by immunoseparation using the Pathatrix, as in AFNOR validated qPCR protocols. The Salmonella biosensor combined with immunoseparation showed a limit of detection of 100 bacteria/40 mL, with a 400 fold increase to previous results. qPCR analysis requires processing of bead-bound bacteria with lysis buffer and DNA clean up, with a limit of detection of 2 cfu/50 μL. Finally, a protein chip was developed and tested in screening and identification of 5 common pathogen species, Salmonella spp., E. coli, S. aureus, Campylobacter spp. and Listeria spp. The protein chip, with high specificity in species identification, is proposed to be integrated into a Lab-on-Chip system, for rapid and reproducible screening of Salmonella spp. and other pathogen species contaminating food productions. PMID:27110786

Atmospheric pressure plasma jet treatment of Salmonella Enteritidis inoculated eggshells.

PubMed

Moritz, Maike; Wiacek, Claudia; Koethe, Martin; Braun, Peggy G

2017-03-20

Contamination of eggshells with Salmonella Enteritidis remains a food safety concern. In many cases human salmonellosis within the EU can be traced back to raw or undercooked eggs and egg products. Atmospheric pressure plasma is a novel decontamination method that can reduce a wide range of pathogens. The aim of this work was to evaluate the possibility of using an effective short time cold plasma treatment to inactivate Salmonella Enteritidis on the eggshell. Therefore, artificially contaminated eggshells were treated with an atmospheric pressure plasma jet under different experimental settings with various exposure times (15-300s), distances from the plasma jet nozzle to the eggshell surface (5, 8 or 12mm), feed gas compositions (Ar, Ar with 0.2, 0.5 or 1.0% O 2 ), gas flow rates (5 and 7slm) and different inoculations of Salmonella Enteritidis (10 1 -10 6 CFU/cm 2 ). Atmospheric pressure plasma could reduce Salmonella Enteritidis on eggshells significantly. Reduction factors ranged between 0.22 and 2.27 log CFU (colony-forming units). Exposure time and, particularly at 10 4 CFU/cm 2 inoculation, feed gas had a major impact on Salmonella reduction. Precisely, longer exposure times led to higher reductions and Ar as feed gas was more effective than ArO 2 mixtures. Copyright © 2017 Elsevier B.V. All rights reserved.

Survival of Salmonella enterica in Freshwater and Sediments and Transmission by the Aquatic Midge Chironomus tentans (Chironomidae: Diptera)

PubMed Central

Moore, Barry C.; Martinez, Edward; Gay, John M.; Rice, Daniel H.

2003-01-01

Survival of a nalidixic acid-resistant strain of Salmonella enterica serovar Typhimurium mr-DT-104 in water and sediments was tested using artificially contaminated aquaria. Water samples remained culture positive for salmonella for up to 54 days. Sediment samples were culture positive up to 119 days. In addition, potential mechanisms for spreading salmonella in the environments by chironomid larvae and adults were tested. We evaluated the acquisition of mr-DT-104 by chironomids from contaminated aquatic sediments and subsequent spread to uncontaminated sediments. Larval chironomids raised in contaminated sediments became culture positive, and the bacteria were carried over to adults after emergence. Contamination of clean sediments by chironomid larvae was not demonstrated. These findings clearly suggest that mr-DT-104 serovar organisms can survive in aquatic sediments for at least several months. Uptake of salmonellae by chironomid larvae and adults suggests that they are possible vectors of mr-DT-104 in both aquatic and terrestrial environments, although the role of larval defecation in movement of bacteria to new sediments was not demonstrated. PMID:12902242

Salmonella survival in manure-treated soils during simulated seasonal temperature exposure.

PubMed

Holley, Richard A; Arrus, Katia M; Ominski, Kimberly H; Tenuta, Mario; Blank, Gregory

2006-01-01

Addition of animal manure to soil can provide opportunity for Salmonella contamination of soil, water, and food. This study examined how exposure of hog manure-treated loamy sand and clay soils to different simulated seasonal temperature sequences influenced the length of Salmonella survival. A six-strain cocktail of Salmonella serovars (Agona, Hadar, Heidelberg, Montevideo, Oranienburg, and Typhimurium) was added to yield 5 log cfu/g directly to about 5 kg of the two soils and moisture adjusted to 60 or 80% of field capacity (FC). Similarly, the Salmonella cocktail was mixed with fresh manure slurry from a hog nursery barn and the latter added to the two soils at 25 g/kg to achieve 5 log cfu/g Salmonella. Manure was mixed either throughout the soil or with the top kilogram of soil and the entire soil volume was adjusted to 60 or 80% FC. Soil treatments were stored 180 d at temperature sequences representing winter to summer (-18, 4, 10, 25 degrees C), spring to summer (4, 10, 25, 30 degrees C), or summer to winter (25, 10, 4, -18 degrees C) seasonal periods with each temperature step lasting 45 d. Samples for Salmonella recovery by direct plating or enrichment were taken at 0, 7, and 15 d post-inoculation and thereafter at 15-d intervals to 180 d. Salmonella numbers decreased during application to soil and the largest decreases occurred within the first week. Higher soil moisture, manure addition, and storage in the clay soil increased Salmonella survival. Salmonella survived longest (> or = 180 d) in both soils during summer-winter exposure but was not isolated after 160 d from loamy sand soil exposed to other seasonal treatments. For all but one treatment decimal reduction time (DRT45d) values calculated from the first 45 d after application were < or = 30 d and suggested that a 30-d delay between field application of manure in the spring or fall and use of the land would provide reasonable assurance that crop and animal contamination by Salmonella would be

Prevalence, Seasonal Occurrence, and Antimicrobial Resistance of Salmonella spp. Isolates Recovered from Chicken Carcasses Sampled at Major Poultry Processing Plants of South Korea.

PubMed

Lee, Soo-Kyoung; Choi, Dasom; Kim, Hong-Seok; Kim, Dong-Hyeon; Seo, Kun-Ho

2016-10-01

The current study was conducted to assess Salmonella spp. contamination in chicken carcasses produced at major poultry processing plants in South Korea. In total, 120 chicken carcasses were collected through 12 individual trials (10 chickens per trial) from six poultry processing plants in the summer of 2014 and the winter of 2015. Eighteen chicken samples (15%) were contaminated with Salmonella, with a higher rate of contamination observed during summer (14 isolates, 11.7%) than during winter (four isolates, 3.3%). Salmonella enterica serotype Typhimurium was the most prevalent, followed by Salmonella Hadar, Salmonella Rissen, Salmonella Bareilly, and Salmonella Virchow. Among five multidrug resistant isolates, a single strain was resistant to 10 antibiotics, including third-generation cephalosporins. This cephalosporin-resistant strain exhibited the extended-spectrum β-lactamase (ESBL) phenotype and harbored the gene encoding CTX-M-15, the most prevalent ESBL enzyme worldwide. Herein, repetitive-sequence-based polymerase chain reaction (rep-PCR) subtyping was conducted to discriminate the isolated Salmonella spp. and the ESBL-producing Salmonella isolate was distinguished by rep-PCR molecular subtyping, showing low genetic similarity in their rep-PCR-banding patterns. Given that poultry processing plants are the last stage in the chicken-production chain, the occurrence of Salmonella spp. including ESBL-producing strain in individually packaged chicken products highlights the necessity for regular monitoring for Salmonella in poultry processing plants.

Fate of Salmonella Typhimurium in laboratory-scale drinking water biofilms.

PubMed

Schaefer, L M; Brözel, V S; Venter, S N

2013-12-01

Investigations were carried out to evaluate and quantify colonization of laboratory-scale drinking water biofilms by a chromosomally green fluorescent protein (gfp)-tagged strain of Salmonella Typhimurium. Gfp encodes the green fluorescent protein and thus allows in situ detection of undisturbed cells and is ideally suited for monitoring Salmonella in biofilms. The fate and persistence of non-typhoidal Salmonella in simulated drinking water biofilms was investigated. The ability of Salmonella to form biofilms in monoculture and the fate and persistence of Salmonella in a mixed aquatic biofilm was examined. In monoculture S. Typhimurium formed loosely structured biofilms. Salmonella colonized established multi-species drinking water biofilms within 24 hours, forming micro-colonies within the biofilm. S. Typhimurium was also released at high levels from the drinking water-associated biofilm into the water passing through the system. This indicated that Salmonella could enter into, survive and grow within, and be released from a drinking water biofilm. The ability of Salmonella to survive and persist in a drinking water biofilm, and be released at high levels into the flow for recolonization elsewhere, indicates the potential for a persistent health risk to consumers once a network becomes contaminated with this bacterium.

Salmon as a food-poisoning vehicle--two successive Salmonella outbreaks.

PubMed Central

Cartwright, K. A.; Evans, B. G.

1988-01-01

Gastroenteritis due to Salmonella montevideo occurred amongst guests attending two social functions held within 24 h, food for both having been provided by the same catering firm. Salmon was the most likely vehicle of infection in each case, although cross-contamination of other foods occurred. There were no deaths; four patients were admitted to hospital, one of whom underwent appendicectomy. A review of salmon-associated food-poisoning outbreaks suggests that fresh salmon is an infrequent cause of food poisoning in the United Kingdom. The two outbreaks described here resulted from a failure of simple kitchen hygiene measures at a time of high ambient temperatures. Some current cooking instructions for salmon are inadequate. PMID:3181309

Culture- and molecular-based detection of swine-adapted Salmonella shed by avian scavengers.

PubMed

Blanco, Guillermo; Díaz de Tuesta, Juan A

2018-09-01

Salmonella can play an important role as a disease agent in wildlife, which can then act as carriers and reservoirs of sanitary importance at the livestock-human interface. Transmission from livestock to avian scavengers can occur when these species consume contaminated carcasses and meat remains in supplementary feeding stations and rubbish dumps. We compared the performance of PCR-based detection with conventional culture-based methods to detect Salmonella in the faeces of red kites (Milvus milvus) and griffon vultures (Gyps fulvus) in central Spain. The occurrence of culturable Salmonella was intermediate in red kites (1.9%, n=52) and high in griffon vultures (26.3%, n=99). These proportions were clearly higher with PCR-based detection (13.5% and 40.4%, respectively). Confirmation cultures failed to grow Salmonella in all faecal samples positive by the molecular assay but negative by the initial conventional culture in both scavenger species, indicating the occurrence of false (non-culturable) positives by PCR-based detection. This suggests that the molecular assay is highly sensitive to detecting viable Salmonella in cultures, but also partial genomes and dead or unviable bacteria from past infections or contamination. Thus, the actual occurrence of Salmonella in a particular sampling time period can be underestimated when using only culture detection. The serovars found in the scavenger faeces were among the most frequently isolated in pigs from Spain and other EU countries, especially those generally recognized as swine-adapted monophasic variants of S. Typhimurium. Because the studied species obtain much of their food from pig carcasses, this livestock may be the primary source of Salmonella via direct ingestion of infected carcasses and indirectly via contamination due to the unsanitary conditions found in supplementary feeding stations established for scavenger conservation. Combining culture- and molecular-based detection is encouraged to understand the

Survival of Salmonella Newport in oysters.

PubMed

Morrison, Christopher M; Armstrong, Alexandra E; Evans, Sanford; Mild, Rita M; Langdon, Christopher J; Joens, Lynn A

2011-08-02

Salmonella enterica is the leading cause of laboratory-confirmed foodborne illness in the United States and raw shellfish consumption is a commonly implicated source of gastrointestinal pathogens. A 2005 epidemiological study done in our laboratory by Brands et al., showed that oysters in the United States are contaminated with Salmonella, and in particular, a specific strain of the Newport serovar. This work sought to further investigate the host-microbe interactions between Salmonella Newport and oysters. A procedure was developed to reliably and repeatedly expose oysters to enteric bacteria and quantify the subsequent levels of bacterial survival. The results show that 10 days after an exposure to Salmonella Newport, an average concentration of 3.7 × 10(3)CFU/g remains within the oyster meat, and even after 60 days there still can be more than 10(2)CFU/g remaining. However, the strain of Newport that predominated in the market survey done by Brands et al. does not survive within oysters or the estuarine environment better than any other strains of Salmonella we tested. Using this same methodology, we compared Salmonella Newport's ability to survive within oysters to a non-pathogenic strain of E. coli and found that after 10 days the concentration of Salmonella was 200-times greater than that of E. coli. We also compared those same strains of Salmonella and E. coli in a depuration process to determine if a constant 120 L/h flux of clean seawater could significantly reduce the concentration of bacteria within oysters and found that after 3 days the oysters retained over 10(4)CFU/g of Salmonella while the oysters exposed to the non-pathogenic strain of E. coli contained 100-times less bacteria. Overall, the results of this study demonstrate that any of the clinically relevant serovars of Salmonella can survive within oysters for significant periods of time after just one exposure event. Based on the drastic differences in survivability between Salmonella and a non

Assessment of Consumer Exposure to Salmonella spp., Campylobacter spp., and Shiga Toxin-Producing Escherichia coli in Meat Products at Retail in the City of Sao Paulo, Brazil.

PubMed

Ristori, Christiane Asturiano; Rowlands, Ruth Estela Gravato; Martins, Cecília Geraldes; Barbosa, Maria Luisa; Dos Santos, Luis Fernando; Jakabi, Miyoko; de Melo Franco, Bernadette Dora Gombossy

2017-08-01

Meat products may be vehicles of bacterial pathogens to humans, and Salmonella spp., Campylobacter spp., and Shiga toxin-producing Escherichia coli (STEC) are the most relevant. The aim of this study was to generate data on prevalence of these three pathogens in 552 samples of meat products (hot dogs, pork sausages, raw ground beef, and raw chicken legs) sold at retail in the city of Sao Paulo, Brazil. Salmonella spp. was detected in 5.8% (32/552) of samples, comprising pork sausages 62.5% (20/32) and chicken legs 37.5% (12/32). The counts of Salmonella spp. were low, ranging from < 0.3 to 9.3 × 10 most probable number per gram and the most frequent serovars were Salmonella Typhimurium (28.1%), Salmonella I 4,[5],12:i:- (15.6%), Salmonella Enteritidis (12.5%), Salmonella Derby, and Salmonella Brandenburg (9.4%). Campylobacter spp. was detected in 33 samples (6.0%), comprising chicken legs (82%) and ground beef (18%). All samples were negative for STEC. These results suggest that meat products when subjected to inadequate cooking and/or cross-contamination with other products ready for consumption can lead to occurrence of outbreaks, highlighting the risks associated with them.

Cold plasma rapid decontamination of food contact surfaces contaminated with Salmonella biofilms

USDA-ARS?s Scientific Manuscript database

Cross-contamination of fresh produce and other foods from persistent pathogen reservoirs is a known risk factor in processing environments. Industry requires a rapid, waterless, zero-contact, chemical-free method for removing pathogens from food-contact surfaces. Cold plasma was tested for its abili...

Efficacy of chemical sprays to eliminate inoculated Salmonella from defeathered broiler breast skin

USDA-ARS?s Scientific Manuscript database

Contamination of poultry with Salmonella is a food safety concern. Because Salmonella-free broilers cannot always be produced on the farm, antimicrobials are used in the processing plant. The objective of this study was to look at the efficacy of several chemicals to eliminate 104 cells of a marker...

Estimation of costs for control of Salmonella in high-risk feed materials and compound feed

PubMed Central

Wierup, Martin; Widell, Stig

2014-01-01

Introduction Feed is a potential and major source for introducing Salmonella into the animal-derived food chain. This is given special attention in the European Union (EU) efforts to minimize human food-borne Salmonella infections from animal-derived food. The objective of this study was to estimate the total extra cost for preventing Salmonella contamination of feed above those measures required to produce commercial feed according to EU regulation (EC) No 183/2005. The study was carried out in Sweden, a country where Salmonella infections in food-producing animals from feed have largely been eliminated. Methods On the initiative and leadership of the competent authority, the different steps of feed production associated with control of Salmonella contamination were identified. Representatives for the major feed producers operating in the Swedish market then independently estimated the annual mean costs during the years 2009 and 2010. The feed producers had no known incentives to underestimate the costs. Results and discussion The total cost for achieving a Salmonella-safe compound feed, when such a control is established, was estimated at 1.8–2.3 € per tonne of feed. Of that cost, 25% relates to the prevention of Salmonella contaminated high-risk vegetable feed materials (mainly soybean meal and rapeseed meal) from entering feed mills, and 75% for measures within the feed mills. Based on the feed formulations applied, those costs in relation to the farmers’ 2012 price for compound feed were almost equal for broilers and dairy cows (0.7%). Due to less use of protein concentrate to fatten pigs, the costs were lower (0.6%). These limited costs suggest that previous recommendations to enforce a Salmonella-negative policy for animal feed are realistic and economically feasible to prevent a dissemination of the pathogen to animal herds, their environment, and potentially to human food products. PMID:24959328

Thermal Inactivation of Desiccation-Adapted Salmonella spp. in Aged Chicken Litter

PubMed Central

Chen, Zhao; Diao, Junshu; Dharmasena, Muthu; Ionita, Claudia; Rieck, James

2013-01-01

Thermal inactivation of desiccation-adapted Salmonella spp. in aged chicken litter was investigated in comparison with that in a nonadapted control to examine potential cross-tolerance of desiccation-adapted cells to heat treatment. A mixture of four Salmonella serovars was inoculated into the finished compost with 20, 30, 40, and 50% moisture contents for a 24-h desiccation adaptation. Afterwards, the compost with desiccation-adapted cells was inoculated into the aged chicken litter with the same moisture content for heat treatments at 70, 75, 80, 85, and 150°C. Recovery media were used to allow heat-injured cells to resuscitate. A 5-log reduction in the number of the desiccation-adapted cells in aged chicken litter with a 20% moisture content required >6, >6, ∼4 to 5, and ∼3 to 4 h of exposure at 70, 75, 80, and 85°C, respectively. As a comparison, a 5-log reduction in the number of nonadapted control cells in the same chicken litter was achieved within ∼1.5 to 2, ∼1 to 1.5, ∼0.5 to 1, and <0.5 h at 70, 75, 80, and 85°C, respectively. The exposure time required to obtain a 5-log reduction in the number of desiccation-adapted cells gradually became shorter as temperature and moisture content were increased. At 150°C, desiccation-adapted Salmonella cells survived for 50 min in chicken litter with a 20% moisture content, whereas control cells were detectable by enrichment for only 10 min. Our results demonstrated that the thermal resistance of Salmonella in aged chicken litter was increased significantly when the cells were adapted to desiccation. This study also validated the effectiveness of thermal processing being used for producing chicken litter free of Salmonella contamination. PMID:24014540

Thermal inactivation of desiccation-adapted Salmonella spp. in aged chicken litter.

PubMed

Chen, Zhao; Diao, Junshu; Dharmasena, Muthu; Ionita, Claudia; Jiang, Xiuping; Rieck, James

2013-11-01

Thermal inactivation of desiccation-adapted Salmonella spp. in aged chicken litter was investigated in comparison with that in a nonadapted control to examine potential cross-tolerance of desiccation-adapted cells to heat treatment. A mixture of four Salmonella serovars was inoculated into the finished compost with 20, 30, 40, and 50% moisture contents for a 24-h desiccation adaptation. Afterwards, the compost with desiccation-adapted cells was inoculated into the aged chicken litter with the same moisture content for heat treatments at 70, 75, 80, 85, and 150°C. Recovery media were used to allow heat-injured cells to resuscitate. A 5-log reduction in the number of the desiccation-adapted cells in aged chicken litter with a 20% moisture content required >6, >6, ∼4 to 5, and ∼3 to 4 h of exposure at 70, 75, 80, and 85°C, respectively. As a comparison, a 5-log reduction in the number of nonadapted control cells in the same chicken litter was achieved within ∼1.5 to 2, ∼1 to 1.5, ∼0.5 to 1, and <0.5 h at 70, 75, 80, and 85°C, respectively. The exposure time required to obtain a 5-log reduction in the number of desiccation-adapted cells gradually became shorter as temperature and moisture content were increased. At 150°C, desiccation-adapted Salmonella cells survived for 50 min in chicken litter with a 20% moisture content, whereas control cells were detectable by enrichment for only 10 min. Our results demonstrated that the thermal resistance of Salmonella in aged chicken litter was increased significantly when the cells were adapted to desiccation. This study also validated the effectiveness of thermal processing being used for producing chicken litter free of Salmonella contamination.

Number of Salmonella on chicken breast filet at retail level and its implications for public health risk.

PubMed

Straver, J M; Janssen, A F W; Linnemann, A R; van Boekel, M A J S; Beumer, R R; Zwietering, M H

2007-09-01

This study aimed to characterize the number of Salmonella on chicken breast filet at the retail level and to evaluate if this number affects the risk of salmonellosis. From October to December 2005, 220 chilled raw filets (without skin) were collected from five local retail outlets in The Netherlands. Filet rinses that were positive after enrichment were enumerated with a three-tube most-probable-number (MPN) assay. Nineteen filets (8.6%) were contaminated above the detection limit of the MPN method (10 Salmonella per filet). The number of Salmonella on positive filets varied from 1 to 3.81 log MPN per filet. The obtained enumeration data were applied in a risk assessment model. The model considered possible growth during domestic storage, cross-contamination from filet via a cutting board to lettuce, and possible illness due to consumption of the prepared lettuce. A screening analysis with expected-case and worst-case estimates for the input values of the model showed that variability in the inputs was of relevance. Therefore, a Monte Carlo simulation with probability distributions for the inputs was carried out to predict the annual number of illnesses. Remarkably, over two-thirds of annual predicted illnesses were caused by the small fraction of filets containing more than 3 log Salmonella at retail (0.8% of all filets). The enumeration results can be used to confirm this hypothesis in a more elaborate risk assessment. Modeling of the supply chain can provide insight for possible intervention strategies to reduce the incidence of rare, but extreme levels. Reduction seems feasible within current practices, because the retail market study indicated a significant difference between suppliers.

Salmonella enterica serovar Typhimurium in Mauritius linked to consumption of marlin mousse.

PubMed

Issack, Mohammad I; Hendriksen, Rene S; Lun, Phimy Lan Keng; Lutchun, Ram K S; Aarestrup, Frank M

2009-01-01

We report the first outbreak of salmonellosis caused by consumption of contaminated marlin mousse. Between 29 October and 5 November 2008, at least 53 persons developed diarrheal illness, all with a history of eating marlin mousse. Salmonella spp. that did not produce gas from glucose was isolated from stools of 26 affected patients and blood culture from one patient. Salmonella sp. isolates with the same phenotype were isolated in three samples of marlin mousse manufactured on 27 October 2008. The constituents of the mousse were smoked marlin, raw eggs, bovine gelatin, oil, and cream. A laboratory investigation of one sample of marlin mousse manufactured 3 days later, and the individual ingredients sampled a week after production of the contaminated batch were all negative for Salmonella. Serotyping and minimum inhibitory concentration determination were performed on 12 patient isolates related to the outbreak and two mousse isolates. All isolates belonged to Salmonella serovar Typhimurium and were pansusceptible to all antimicrobials tested. Pulsed-field gel electrophoresis revealed that all the isolates were indistinguishable, thus implicating the mousse as the vehicle of the outbreak.

The role of home-made ice cream as a vehicle of Salmonella enteritidis phage type 4 infection from fresh shell eggs.

PubMed Central

Morgan, D.; Mawer, S. L.; Harman, P. L.

1994-01-01

A family outbreak of Salmonella enteritidis PT4 infection is described in which home-made ice cream was identified as the vehicle of infection. The ice cream contained approximately 10(5) S. enteritidis PT4 organisms per gm and was probably contaminated by an infected shell egg containing between 10(5)-10(8) organisms. The continued relevance of the Chief Medical Officer's warning on the use of raw shell eggs is highlighted. Home-made ice cream using the same recipe as ice cream that had been incriminated as the cause of the family outbreak of S. enteritidis PT4 infection was used to study the growth of the organism that might have occurred in the 3-4 h it took to prepare the product. When the inoculum was in the stationary phase, as it would be from shell or other cross contamination, there was a lag phase of 3 h before growth occurred at room temperature. Even when actively multiplying organisms were introduced, as may be found in an infected egg, there was less than 3 log(10) increase in the salmonella count in 4 h at room temperature. It was, therefore, given the high S. enteritidis count, unlikely that the ice cream was cross-contaminated. By contrast, raspberry sorbet at pH 3.73 proved to be lethal to a large inoculum of S. enteritidis and may be a relatively safe raw egg containing product. PMID:8062876

Inactivation of Salmonella spp. in ground chicken using High Pressure Processing

USDA-ARS?s Scientific Manuscript database

High pressure processing (HPP) is a safe and effective process for improving the microbial safety and shelf-life of foods. Salmonella is a common contaminant in poultry meat and is frequently responsible for foodborne illness associated with contaminated poultry meat. In this study the inactivation...

Microbiological evaluation of a newly designed dental air-turbine handpiece for anti-cross contaminations.

PubMed

Ohsuka, S; Ohta, M; Masuda, K; Kaneda, T; Ueda, M

1994-01-01

The effectiveness of a newly developed anti-cross contamination device for a dental air-turbine handpiece was tested. The handpiece with or without the anti-cross contamination device was contaminated with two bacterial strains, Staphylococcus aureus and Streptococcus mutans, as well as two bacteriophage strains, T2 and MS2. After contamination with these microorganisms, the handpieces were disinfected with glutaraldehyde or replaced with newly autoclaved ones. Residual microorganisms inside the handpiece or an air/water supply hose line were collected and counted after overnight cultivation. The anti-cross contamination device effectively reduced the contamination level of an air-turbine handpiece to that of the negative control. No microbial contamination in the air/water supply hose line was detected with this device.

Stochastic, compartmental, and dynamic modeling of cross-contamination during mechanical smearing of cheeses.

PubMed

Aziza, Fanny; Mettler, Eric; Daudin, Jean-Jacques; Sanaa, Moez

2006-06-01

Cheese smearing is a complex process and the potential for cross-contamination with pathogenic or undesirable microorganisms is critical. During ripening, cheeses are salted and washed with brine to develop flavor and remove molds that could develop on the surfaces. Considering the potential for cross-contamination of this process in quantitative risk assessments could contribute to a better understanding of this phenomenon and, eventually, improve its control. The purpose of this article is to model the cross-contamination of smear-ripened cheeses due to the smearing operation under industrial conditions. A compartmental, dynamic, and stochastic model is proposed for mechanical brush smearing. This model has been developed to describe the exchange of microorganisms between compartments. Based on the analytical solution of the model equations and on experimental data collected with an industrial smearing machine, we assessed the values of the transfer parameters of the model. Monte Carlo simulations, using the distributions of transfer parameters, provide the final number of contaminated products in a batch and their final level of contamination for a given scenario taking into account the initial number of contaminated cheeses of the batch and their contaminant load. Based on analytical results, the model provides indicators for smearing efficiency and propensity of the process for cross-contamination. Unlike traditional approaches in mechanistic models, our approach captures the variability and uncertainty inherent in the process and the experimental data. More generally, this model could represent a generic base to use in modeling similar processes prone to cross-contamination.

The horizontal transfer of Salmonella between the lesser mealworm (Alphitobius diaperinus) and poultry manure

USDA-ARS?s Scientific Manuscript database

There is a need to determine the nature and extent of residual reservoirs of Salmonella which contribute to perpetual contamination within poultry flocks. The dispersal of Salmonella between birds, litter, and beetles has been established, but the extent that these act as critical components in the...

Assessment of the microbiological safety of edible dried seeds from retail premises in the United Kingdom with a focus on Salmonella spp.

PubMed

Willis, Caroline; Little, Christine L; Sagoo, Satnam; de Pinna, Elizabeth; Threlfall, John

2009-12-01

Sesame seed products have recently been associated with a number of Salmonella outbreaks in the UK and elsewhere. Aside from sesame seeds, there is little published information on the prevalence of Salmonella spp. in edible seeds. A study of 3735 samples of retail edible dried seeds in the UK was therefore carried out between October 2007 and March 2008 to assess their microbiological safety in relation to Salmonella contamination and levels of Escherichia coli, an indicator of faecal contamination. Overall, Salmonella was detected in 23 samples (0.6%), of which over half (57%) were sesame seeds. Other seeds contaminated with Salmonella were linseed (1 sample), sunflower (1 sample), alfalfa (1 sample), melon (4 samples) and mixed seeds (3 samples). E. coli was detected in 9% of samples, with 1.5% containing unsatisfactory levels (> or = 10(2)/g). These included melon, pumpkin, sesame, hemp, poppy, linseed, sunflower and mixed seeds. The UK retailers affected by the detection of Salmonella in their products recalled the contaminated batches, and Food Standards Agency food alerts were issued to advise against the consumption of affected seed products. This study highlights the importance of good hygiene practices and effective decontamination procedures during the production of these products.

Enhanced recovery of Salmonella from apple cider and apple juice with universal preenrichment broth.

PubMed

Hammack, Thomas S; Johnson, Mildred L; Jacobson, Andrew P; Andrews, Wallace H

2002-01-01

A comparison was made of the relative efficiencies of Universal Preenrichment (UP) broth and lactose broth for the recovery of a variety of Salmonella serovars from pasteurized and unpasteurized apple cider and pasteurized apple juice. Bulk portions of juice were contaminated with single Salmonella serovars at high and low levels of 0.4 and 0.04 CFU/mL, respectively. The juice was aged for a minimum of 5 days at 2-5 degrees C. On the day analysis was initiated, each of 20 test portions (25 mL) of the contaminated juice was preenriched in UP broth and in lactose broth. The Bacteriological Analytical Manual Salmonella culture method was followed thereafter. For pasteurized apple cider, UP broth recovered significantly (p < 0.05) more Salmonella-positive test portions than did lactose broth (112 and 75, respectively). For unpasteurized apple cider, UP broth recovered significantly more Salmonella-positive test portions than did lactose broth (326 and 221, respectively). For pasteurized apple juice, UP broth recovered more Salmonella-positive test portions than did lactose broth (93 and 81, respectively). However, this difference was not statistically significant. These results indicate that UP broth should replace lactose broth for the analysis of pasteurized and unpasteurized apple cider and pasteurized apple juice.

Application of loop-mediated isothermal amplification with propidium monoazide treatment to detect live Salmonella in chicken carcasses.

PubMed

Youn, S Y; Jeong, O M; Choi, B K; Jung, S C; Kang, M S

2017-02-01

Raw chicken products are major causes of human foodborne salmonellosis worldwide. In particular, there is a significant risk of human exposure to Salmonella originating from the chicken slaughtering process. Controlling the contamination of chicken carcasses by Salmonella has been a considerable challenge in chicken-slaughtering facilities and involves routine microbiological monitoring using reliable detection methods. Simple and rapid detection methods, particularly those capable of determining cell viability, will significantly facilitate routine monitoring of Salmonella Here, we report an invA-based loop-mediated isothermal amplification method coupled with a simple propidium monoazide treatment (PMA-LAMP) for simple and rapid detection and quantification of viable Salmonella in rinse water of chicken carcasses. In this study, PMA-LAMP consistently gave negative results for isopropanol-killed Salmonella with concentrations up to 8.0 × 10 6 CFU/reaction. The detection limit of PMA-LAMP was 8.0 × 10 1 CFU/reaction with viable Salmonella in both pure culture and rinse water of chicken carcasses, and 10-fold lower than a conventional polymerase chain reaction coupled with PMA (PMA-PCR) targeting invA There was a high correlation (R 2 = 0.99 to 0.976) between LAMP time threshold (T T ) values and viable Salmonella with a quantification range of 1.0 × 10 3 to 1.0 × 10 8 CFU/mL in pure culture and rinse water of chicken carcasses. The PMA-LAMP assay took less than 2 h to detect Salmonella contaminated in test samples. Therefore, this simple and rapid method will be a very useful tool to detect live Salmonella contamination of chicken carcasses without pre-enrichment at the slaughterhouse where sanitizing treatments are commonly used. © 2016 Poultry Science Association Inc.

Use of High Hydrostatic Pressure To Inactivate Escherichia coli O157:H7 and Salmonella enterica Internalized within and Adhered to Preharvest Contaminated Green Onions

PubMed Central

Neetoo, Hudaa; Lu, Yingjian; Wu, Changqing

2012-01-01

Green onions grown in soil and hydroponic medium contaminated with Escherichia coli O157:H7 and Salmonella were found to take up the pathogens in their roots, bulbs, stems, and leaves. Pressure treatment at 400 to 500 MPa for 2 min at 20 to 40°C eliminated both pathogens that were internalized within green onions during plant growth. PMID:22247156

Detection of Salmonella spp. in Retail Raw Food Samples from Vietnam and Characterization of Their Antibiotic Resistance▿

PubMed Central

Van, Thi Thu Hao; Moutafis, George; Istivan, Taghrid; Tran, Linh Thuoc; Coloe, Peter J.

2007-01-01

A study was conducted to examine the levels of Salmonella spp. contamination in raw food samples, including chicken, beef, pork, and shellfish, from Vietnam and to determine their antibiotic resistance characteristics. A total of 180 samples were collected and examined for the presence of Salmonella spp., yielding 91 Salmonella isolates. Sixty-one percent of meat and 18% of shellfish samples were contaminated with Salmonella spp. Susceptibility of all isolates to a variety of antimicrobial agents was tested, and resistance to tetracycline, ampicillin/amoxicillin, nalidixic acid, sulfafurazole, and streptomycin was found in 40.7%, 22.0%, 18.7%, 16.5%, and 14.3% of the isolates, respectively. Resistance to enrofloxacin, trimethoprim, chloramphenicol, kanamycin, and gentamicin was also detected (8.8 to 2.2%). About half (50.5%) of the isolates were resistant to at least one antibiotic, and multiresistant Salmonella isolates, resistant to at least three different classes of antibiotics, were isolated from all food types. One isolate from chicken (serovar Albany) contained a variant of the Salmonella genomic island 1 antibiotic resistance gene cluster. The results show that antibiotic resistance in Salmonella spp. in raw food samples from Vietnam is significant. PMID:17766455

Prevalence of Salmonella in poultry processing environments in wet markets in Penang and Perlis, Malaysia.

PubMed

Nidaullah, Hafiz; Abirami, Nadarajan; Shamila-Syuhada, Ahamed Kamal; Chuah, Li-Oon; Nurul, Huda; Tan, Teik Pei; Abidin, Farah Wahida Zainal; Rusul, Gulam

2017-03-01

The aim of this study was to determine the prevalence of various Salmonella serotypes in chickens, carcass contact surfaces as well as environmental samples collected from wet markets and small scale processing plant. A total of 182 poultry and environmental samples were collected at random on separate occasions from wet markets and small scale processing plant, during the period of October 2014 to July 2015 in Penang and Perlis, Malaysia. The samples were analyzed for the presence of Salmonella using ISO 6579:2002 conventional culture-based method. Presumptive Salmonella colonies were subjected to various biochemical tests (such as triple sugar iron and lysine iron test), serologically confirmed using polyvalent O and H antisera and further serotyped at Public Health Laboratory, Ministry of Health, Perak, Malaysia. Salmonella serotypes were isolated from 161 out of 182 samples (88.46%) with 100% prevalence in the whole chicken carcass and chicken cuts - as well as transport crate, cage, drum, knife, chopping board, display table, floor, bench wash water, wash water, and drain water. Salmonella was isolated from 91.67%, 83.33%, and 66.67% of defeathering machines, drain swabs, and apron, respectively. 17 serotypes were isolated in this study with Salmonella Albany (57/161), Salmonella Corvallis (42/161), and Salmonella Brancaster (37/161) being the predominant serovars. The most carcass contact and environmental samples collected along the wet market chicken processing line were consistently contaminated with Salmonella . This indicates that Salmonella has established itself in poultry processing environments by colonizing the surfaces of the equipment and survives in these environments by establishing biofilms. Our results highlight the need of implementing strict hygiene and sanitation standards to reduce the incidence of Salmonella . The prevalence of Salmonella in poultry can be reduced effectively by identifying and eliminating the sources and contamination

Prevalence of Salmonella in poultry processing environments in wet markets in Penang and Perlis, Malaysia

PubMed Central

Nidaullah, Hafiz; Abirami, Nadarajan; Shamila-Syuhada, Ahamed Kamal; Chuah, Li-Oon; Nurul, Huda; Tan, Teik Pei; Abidin, Farah Wahida Zainal; Rusul, Gulam

2017-01-01

Aim: The aim of this study was to determine the prevalence of various Salmonella serotypes in chickens, carcass contact surfaces as well as environmental samples collected from wet markets and small scale processing plant. Materials and Methods: A total of 182 poultry and environmental samples were collected at random on separate occasions from wet markets and small scale processing plant, during the period of October 2014 to July 2015 in Penang and Perlis, Malaysia. The samples were analyzed for the presence of Salmonella using ISO 6579:2002 conventional culture-based method. Presumptive Salmonella colonies were subjected to various biochemical tests (such as triple sugar iron and lysine iron test), serologically confirmed using polyvalent O and H antisera and further serotyped at Public Health Laboratory, Ministry of Health, Perak, Malaysia. Results: Salmonella serotypes were isolated from 161 out of 182 samples (88.46%) with 100% prevalence in the whole chicken carcass and chicken cuts - as well as transport crate, cage, drum, knife, chopping board, display table, floor, bench wash water, wash water, and drain water. Salmonella was isolated from 91.67%, 83.33%, and 66.67% of defeathering machines, drain swabs, and apron, respectively. 17 serotypes were isolated in this study with Salmonella Albany (57/161), Salmonella Corvallis (42/161), and Salmonella Brancaster (37/161) being the predominant serovars. Conclusion: The most carcass contact and environmental samples collected along the wet market chicken processing line were consistently contaminated with Salmonella. This indicates that Salmonella has established itself in poultry processing environments by colonizing the surfaces of the equipment and survives in these environments by establishing biofilms. Our results highlight the need of implementing strict hygiene and sanitation standards to reduce the incidence of Salmonella. The prevalence of Salmonella in poultry can be reduced effectively by identifying

Prevalence of Salmonella in broilers at retail outlets, processing plants and farms in Malaysia.

PubMed

Rusul, G; Khair, J; Radu, S; Cheah, C T; Yassin, R M

1996-12-01

A study was conducted to estimate the prevalence of Salmonella among broilers retailed at wet-markets and processing plants. Litter and feed samples obtained from both broiler and breeder farms were also examined for Salmonella. A total of 158 out of 445 (35.5%) and 52 out of 104 (50.0%) broiler carcasses obtained from wet-markets and processing plants were contaminated with Salmonella, respectively. Salmonella was isolated from 14 out of 98 (14.3%) samples of intestinal content. Litter samples from broiler and breeder farms were positive for Salmonella, 8/40 (20%) and 2/10 (20%), respectively. Salmonella isolates (230) belonging to 15 different serovars were isolated. Predominant serovars were S. enteritidis, S. muenchen, S. kentucky and S. blockley.

Salmonellae Associated with Further-processed Turkey Products1

PubMed Central

Bryan, Frank L.; Ayres, John C.; Kraft, Allen A.

1968-01-01

“Further-processed” turkey products, prepared from chilled, eviscerated, and thawed carcasses at two commercial turkey-processing plants, were evaluated, for the presence of salmonellae. These organisms were isolated from swab samples from 12% of chilled, eviscerated turkey carcasses, 27% of finished products, and 24% of processing equipment. The same serotypes as those found throughout a plant on any one visit were recovered from 31% of rinse-samples taken from hands and gloves of processing personnel. Salmonellae were found in samples taken on 37 of 48 visits; a greater number of recoveries were made on days when freshly killed turkeys were processed (87%) than when frozen-defrosted carcasses were processed (59%). The predominant serotype isolated from meat and environment usually changed from visit to visit. Salmonella sandiego and Salmonella anatum were the most frequent among 23 serotypes recovered. Most of the isolated serotypes are commonly associated with turkeys and have been incriminated as causative agents of human salmonellosis. The implication is that further-processed turkey products, if inadequately cooked by the consumer and if improperly refrigerated between the time of manufacture and consumption, could directly transmit salmonellae. These same products might also contaminate other foods by introducing salmonellae into food-preparation areas. PMID:5688832

Rapid detection of Salmonella spp. in food by use of the ISO-GRID hydrophobic grid membrane filter.

PubMed Central

Entis, P; Brodsky, M H; Sharpe, A N; Jarvis, G A

1982-01-01

A rapid hydrophobic grid-membrane filter (HGMF) method was developed and compared with the Health Protection Branch cultural method for the detection of Salmonella spp. in 798 spiked samples and 265 naturally contaminated samples of food. With the HGMF method, Salmonella spp. were isolated from 618 of the spiked samples and 190 of the naturally contaminated samples. The conventional method recovered Salmonella spp. from 622 spiked samples and 204 unspiked samples. The isolation rates from Salmonella-positive samples for the two methods were not significantly different (94.6% overall for the HGMF method and 96.7% for the conventional approach), but the HGMF results were available in only 2 to 3 days after sample receipt compared with 3 to 4 days by the conventional method. Images PMID:7059168

Comprehensive analysis of Salmonella sequence polymorphisms and development of a LDR-UA assay for the detection and characterization of selected serotypes.

PubMed

Lauri, Andrea; Castiglioni, Bianca; Mariani, Paola

2011-07-01

Salmonella is a major cause of food-borne disease, and Salmonella enterica subspecies I includes the most clinically relevant serotypes. Salmonella serotype determination is important for the disease etiology assessment and contamination source tracking. This task will be facilitated by the disclosure of Salmonella serotype sequence polymorphisms, here annotated in seven genes (sefA, safA, safC, bigA, invA, fimA, and phsB) from 139 S. enterica strains, of which 109 belonging to 44 serotypes of subsp. I. One hundred nineteen polymorphic sites were scored and associated to single serotypes or to serotype groups belonging to S. enterica subsp. I. A diagnostic tool was constructed based on the Ligation Detection Reaction-Universal Array (LDR-UA) for the detection of polymorphic sites uniquely associated to serotypes of primary interest (Salmonella Hadar, Salmonella Infantis, Salmonella Enteritidis, Salmonella Typhimurium, Salmonella Gallinarum, Salmonella Virchow, and Salmonella Paratyphi B). The implementation of promiscuous probes allowed the diagnosis of ten further serotypes that could be associated to a unique hybridization pattern. Finally, the sensitivity and applicability of the tool was tested on target DNA dilutions and with controlled meat contamination, allowing the detection of one Salmonella CFU in 25 g of meat.

Colonization of internal organs by Salmonella serovars Heidelberg and Typhimurium in experimentally infected laying hens housed in enriched colony cages at different stocking densities

USDA-ARS?s Scientific Manuscript database

Contaminated eggs produced by infected commercial laying flocks are often implicated as sources of human infections with Salmonella Enteritidis, but Salmonella serovars Heidelberg and Typhimurium have also been significantly associated with egg-transmitted illness. Contamination of the edible conten...

Evaluation and comparison of rapid methods for the detection of Salmonella in naturally contaminated pine nuts using different pre enrichment media.

PubMed

Wang, Hua; Gill, Vikas S; Cheng, Chorng-Ming; Gonzalez-Escalona, Narjol; Irvin, Kari A; Zheng, Jie; Bell, Rebecca L; Jacobson, Andrew P; Hammack, Thomas S

2015-04-01

Foodborne outbreaks, involving pine nuts and peanut butter, illustrate the need to rapidly detect Salmonella in low moisture foods. However, the current Bacteriological Analytical Manual (BAM) culture method for Salmonella, using lactose broth (LB) as a pre enrichment medium, has not reliably supported real-time quantitative PCR (qPCR) assays for certain foods. We evaluated two qPCR assays in LB and four other pre enrichment media: buffered peptone water (BPW), modified BPW (mBPW), Universal Pre enrichment broth (UPB), and BAX(®) MP media to detect Salmonella in naturally-contaminated pine nuts (2011 outbreak). A four-way comparison among culture method, Pathatrix(®) Auto, VIDAS(®) Easy SLM, and qPCR was conducted. Automated DNA extraction techniques were compared with manual extraction methods (boiling or InstaGene™). There were no significant differences (P > 0.05) among the five pre enrichment media for pine nuts using the culture method. While both qPCR assays produced significantly (P ≤ 0.05) higher false negatives in 24 h pre enriched LB than in the other four media, they were as sensitive as the culture method in BPW, mBPW, UPB, and BAX media. The VIDAS Easy and qPCR were equivalent; Pathatrix was the least effective method. The Automatic PrepSEQ™ DNA extraction, using 1000 μL of pre enrichment, was as effective as manual extraction methods. Published by Elsevier Ltd.

Orally incoculated Salmonella typhimurium is detected in the lymph nodes and synovial fluid of swine

USDA-ARS?s Scientific Manuscript database

Salmonella is a foodborne pathogen that has been associated with illnesses from the consumption of meat products. Traditional carcass sampling techniques fail to account for contamination via atypical carcass reservoirs such as lymph nodes and synovial fluid that may harbor Salmonella. In this two-p...

Occurrence of Campylobacter and Salmonella in ducks and duck eggs in Selangor, Malaysia.

PubMed

Nor Faiza, S; Saleha, A A; Jalila, A; Fauziah, N

2013-03-01

The importance of Campylobacter and Salmonella as foodborne pathogens is well recognised globally. A recent work in Penang found ducks in commercial farms were infected with these organisms. The aim of the study was to detect the presence of Campylobacter and Salmonella in ducks and Salmonella in duck eggs in farms in a small part of Selangor. Cloacal swabs were obtained from 75 ducks and 30 duck eggs from three farms. The isolation and identification of Campylobacter and Salmonella were done using conventional methods. Twelve percent of Campylobacter and 16.0% of Salmonella were isolated from the ducks sampled. Salmonella was absent on and in eggs. Campylobacter isolates consisted of 22% Campylobacter jejuni and the remaining was Campylobacter coli. Three Salmonella serovars identified were Salmonella Agona, S. Braenderup and S. Corvallis. The presence of Campylobacter and Salmonella in ducks may cause contamination of the meat during processing and handling which can constitute public health hazard. Moreover, the farm workers may be exposed to the organisms through contact with the infected animals.

Prevalence and concentration of Salmonella on raw shelled peanuts in the United States.

PubMed

Calhoun, Stephen; Post, Laurie; Warren, Benjamin; Thompson, Sterling; Bontempo, Ann Rogers

2013-04-01

Recalls and/or outbreaks associated with Salmonella contamination in peanut-containing products were reported over the past several years. There are very limited data available on the prevalence and concentration of Salmonella on raw shelled peanuts in the United States. The objectives of this study were to estimate the prevalence of Salmonella on raw shelled peanuts in the United States and to estimate that concentration of Salmonella. Samples of Runner- and Virginia-type raw shelled peanuts from the 2008, 2009, and 2010 crop years were proportionately sampled from each growing region, based on 2007 production volume. Of 944 raw shelled peanut samples (375 g each), 22 (2.33%) were positive for Salmonella by the VIDAS Salmonella assay. Salmonella serovars identified in this study included Agona, Anatum, Braenderup, Dessau, Hartford, Meleagridis, Muenchen, Rodepoort, Tennessee, and Tornow. The concentration levels of Salmonella in positive samples, as determined by a most-probable-number assay, were <0.03 to 2.4 MPN/g. These data will be useful when designing and validating processes for the reduction or elimination of Salmonella in peanuts and/or peanut-containing products.

Validation of Thermal Lethality against Salmonella enterica in Poultry Offal during Rendering.

PubMed

Jones-Ibarra, Amie-Marie; Acuff, Gary R; Alvarado, Christine Z; Taylor, T Matthew

2017-09-01

Recent outbreaks of human disease following contact with companion animal foods cross-contaminated with enteric pathogens, such as Salmonella enterica, have resulted in increased concern regarding the microbiological safety of animal foods. Additionally, the U.S. Food and Drug Administration Food Safety Modernization Act and its implementing rules have stipulated the implementation of current good manufacturing practices and food safety preventive controls for livestock and companion animal foods. Animal foods and feeds are sometimes formulated to include thermally rendered animal by-product meals. The objective of this research was to determine the thermal inactivation of S. enterica in poultry offal during rendering at differing temperatures. Raw poultry offal was obtained from a commercial renderer and inoculated with a mixture of Salmonella serovars Senftenberg, Enteritidis, and Gallinarum (an avian pathogen) prior to being subjected to heating at 150, 155, or 160°F (65.5, 68.3, or 71.1°C) for up to 15 min. Following heat application, surviving Salmonella bacteria were enumerated. Mean D-values for the Salmonella cocktail at 150, 155, and 160°F were 0.254 ± 0.045, 0.172 ± 0.012, and 0.086 ± 0.004 min, respectively, indicative of increasing susceptibility to increased application of heat during processing. The mean thermal process constant (z-value) was 21.948 ± 3.87°F. Results indicate that a 7.0-log-cycle inactivation of Salmonella may be obtained from the cumulative lethality encountered during the heating come-up period and subsequent rendering of raw poultry offal at temperatures not less than 150°F. Current poultry rendering procedures are anticipated to be effective for achieving necessary pathogen control when completed under sanitary conditions.

Salmonella outbreak among railway and airline passengers.

PubMed

Hatakka, M

1992-01-01

A widespread outbreak by Salmonella infantis, infecting a total of 226 people, occurred in Finland at the beginning of August 1986. Of those infected, 107 were railway passengers, 91 were airline passengers and 28 were employed in a food processing establishment. The outbreak among the railway passengers was caused by egg sandwiches, the airline passengers were infected by a meal served on board and the catering employees by the breakfast served in the establishment. The outbreak was caused by food prepared in the establishment's kitchen. The employees' breakfasts had probably been contaminated by an employee who was a symptom-free Salmonella infantis carrier, and a number of the employees subsequently became infected, leading to widespread contamination of the food prepared in the establishment. The spread of the outbreak was further influenced by a heatwave at the time and by shortcomings in the cold storage facilities. The kitchen's hygiene supervision and the quality control of its output were reorganized after the outbreak.

Salmonella enterica serovar Kentucky flagella are required for broiler skin adhesion and Caco-2 cell invasion

USDA-ARS?s Scientific Manuscript database

Nontyphoidal Salmonella strains are the main source of pathogenic bacterial contamination in the poultry industry. Recently, Salmonella enterica serovar Kentucky has been recognized as the most prominent serovar on carcasses in poultry-processing plants. Previous studies showed that flagella are one...

Salmonella survival during thermal dehydration of fresh garlic and storage of dehydrated garlic products.

PubMed

Zhang, Hongmei; Qi, Yan; Wang, Lei; Zhang, Shaokang; Deng, Xiangyu

2017-12-18

Salmonella survival was characterized and modeled during thermal dehydration of fresh garlic and storage of dehydrated garlic products. In our experiments that simulated commercial dehydration processing at 80±5°C, moderate level of Salmonella contamination (4-5logCFU/g) on fresh garlic was reduced below the enumeration limit (1.7logCFU/g) after 4.5h of dehydration and not detectable by culture enrichment after 7h. With high level of contamination (7-8logCFU/g), the Salmonella population persisted at 3.6logCFU/g after 8h of processing. By increasing the dehydration temperature to 90±5°C, the moderate and high levels of initial Salmonella load on fresh garlic dropped below the enumeration limit after 1.5 and 3.75h of processing and became undetectable by culture enrichment after 2.5 and 6h, respectively. During the storage of dried garlic products, Salmonella was not able to grow under all tested combinations of temperature (25 and 35°C) and water activity (0.56-0.98) levels, suggesting active inhibition. Storage temperature played a primary role in determining Salmonella survival on dehydrated garlic flakes. Under a typical storage condition at 25°C and ambient relative humidity, Salmonella could persist over months with the population gradually declining (4.3 log reduction over 88days). Granular size of dehydrated garlic had an impact on Salmonella survival, with better survival of the pathogen observed in bigger granules. At the early stage of dehydrated garlic storage (until 7days), rising water activity appeared to initially promote but then inhibited Salmonella survival, resulting in a water activity threshold at 0.73 where Salmonella displayed strongest persistence. However, this phenomenon was less apparent during extended storage (after 14days). Copyright © 2017 Elsevier B.V. All rights reserved.

Colonization of internal organs by Salmonella serovars Heidelberg and Typhimurium in experimentally infected laying hens housed in enriched colony cages at different stocking densities

USDA-ARS?s Scientific Manuscript database

Contaminated eggs produced by infected commercial laying flocks are often implicated as sources of human infections with Salmonella Enteritidis, but Salmonella serovars Heidelberg and Typhimurium have also been associated with egg-transmitted illness. Contamination of the edible contents of eggs is ...

Antimicrobial resistance in zoonotic nontyphoidal Salmonella: an alarming trend?

PubMed

Michael, G B; Schwarz, S

2016-12-01

Zoonotic bacteria of the genus Salmonella have acquired various antimicrobial resistance properties over the years. The corresponding resistance genes are commonly located on plasmids, transposons, gene cassettes, or variants of the Salmonella Genomic Islands SGI1 and SGI2. Human infections by nontyphoidal Salmonella isolates mainly result from ingestion of contaminated food. The two predominantly found Salmonella enterica subsp. enterica serovars in the USA and in Europe are S. Enteritidis and S. Typhimurium. Many other nontyphoidal Salmonella serovars have been implicated in foodborne Salmonella outbreaks. Summary reports of the antimicrobial susceptibility patterns of nontyphoidal Salmonella isolates over time suggest a moderate to low level of antimicrobial resistance and multidrug-resistance. However, serovar-specific analyses showed in part a steady state, a continuous decline, or a recent increase in resistance to certain antimicrobial agents. Resistance to critically important antimicrobial agents, e.g. third-generation cephalosporins and (fluoro)quinolones is part of many monitoring programmes and the corresponding results confirm that extended-spectrum β-lactamases are still rarely found in nontyphoidal Salmonella serovars, whereas resistance to (fluoro)quinolones is prevalent at variable frequencies among different serovars from humans and animals in different countries. Although it is likely that nontyphoidal Salmonella isolates from animals represent a reservoir for resistance determinants, it is mostly unknown where and when Salmonella isolates acquired resistance properties and which exchange processes have happened since then. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

The role of defeathering in the contamination of turkey skin by Salmonella species and Listeria monocytogenes.

PubMed

Clouser, C S; Doores, S; Mast, M G; Knabel, S J

1995-04-01

This study was undertaken to determine whether the incidence of either Salmonella spp. or Listeria monocytogenes on turkeys at three commercial processors could be related to the type of defeathering system: 1) conventional, 58 C common bath scald; 2) kosher, 7 C common bath scald; or 3) steam-spray, 62 C nonimmersion scald. Flocks were sampled before defeathering, after defeathering, and after chill at each facility. The incidence of Salmonella-positive turkeys significantly increased subsequent to conventional defeathering (10 positive out of 14) as compared with before defeathering (3/14). The number of Salmonella-positive carcasses following kosher (0/14) and steam-spray (2/14) defeathering were similar to the number of Salmonella-positive carcasses found prior to defeathering (1/14 and 3/14, respectively). The incidence of Salmonella-positive carcasses following chill was slightly lower, but not significantly different than the number of Salmonella-positive carcasses found immediately following defeathering at all processors (8/14, 0/14, 1/14 for conventional, kosher, and steam-spray processors, respectively). Although L. monocytogenes was detected on turkeys sampled before chilling (2/10, kosher) and after chilling (8/14, kosher; 1/14, conventional), no L. monocytogenes was detected on turkeys at any of the processors prior to the evisceration process. Flocks with high aerobic plate counts prior to processing were more likely to contain Salmonella-positive birds throughout processing. Aerobic plate counts of all flocks were similar after chill whether or not Salmonella spp. and L. monocytogenes were detected.

Influence of hard water ions on the growth of salmonella in poultry processing water

USDA-ARS?s Scientific Manuscript database

The influence of magnesium and calcium ions in process water on the growth of Salmonella was evaluated and related to the contamination in process wastewater. Salmonella typhimurium was grown in the laboratory and exposed to 500 mg/kg and 1000 mg/kg of magnesium and calcium ions to simulate hard pr...

Impact on human health of Salmonella spp. on pork in The Netherlands and the anticipated effects of some currently proposed control strategies.

PubMed

Berends, B R; Van Knapen, F; Mossel, D A; Burt, S A; Snijders, J M

1998-11-10

efficient and cost-effective way of reducing the 'Salmonella problem' entailed by the consumption of pork would be to decontaminate carcasses under the precondition that the entire production chain strictly adheres to GMP principles. Therefore, the EU should also allow for more possibilities regarding the decontamination of carcasses than is currently the case. It is also concluded that current EU regulations relying on hazard analysis of critical control points (HACCP)-inspired production in cutting plants will not be effective in reducing the prevalence of Salmonella spp. on pork. This is mainly because (1) there is currently an almost steady stream of Salmonella-positive carcasses that enter the cutting process; (2) when contaminated carcasses are being processed, further cross-contamination during working hours is unavoidable; (3) no steps in the cutting process are intentionally designed to effectively reduce the risks or consequences of cross contamination of cuts and retail-ready products.

Prevalence of Salmonella in diverse environmental farm samples.

PubMed

Rodriguez, Andres; Pangloli, Philipus; Richards, Harold A; Mount, John R; Draughon, F Ann

2006-11-01

The development of suitable intervention strategies to control Salmonella populations at the farm level requires reliable data on the occurrence and prevalence of the pathogen. Previous studies on Salmonella prevalence have focused on acquiring data from specific farm types and/or selected regions. The purpose of this study was to evaluate the distribution of this pathogen across a variety of farm types and regions in order to generate comparative data from a diverse group of environmental samples. Farm samples (n = 2,496) were collected quarterly from 18 different farms across five states (Tennessee, North Carolina, Alabama, California, and Washington) over a 24-month period. The participating farms included beef and dairy cattle operations, swine production and farrowing facilities, and poultry farms (both broiler chicken and turkey). The samples were analyzed for the presence of Salmonella by means of the U.S. Food and Drug Administration's Bacteriological Analytical Manual methods optimized for farm samples. Salmonella isolates were characterized by automated riboprinting. Salmonella serovars were recovered from 4.7% of all samples. The majority of positive findings were isolated from swine farms (57.3%). The occurrence of Salmonella was lower on dairy farms (17.9%), poultry farms (16.2%), and beef cattle farms (8.5%). The most commonly isolated serovar was Salmonella Anatum (48.4%), which was isolated notably more frequently than the next most common Salmonella serovars, Arizonae (12.1%) and Javiana (8.8%). The results of this study suggest that significant reservoirs of Salmonella populations still exist on swine production facilities and to a lesser extent in other animal production facilities. Data showed that the surrounding farm environment could be an important source of contamination.

Rapid detection of food-borne Salmonella contamination using IMBs-qPCR method based on pagC gene.

PubMed

Wang, Jiashun; Li, Yi; Chen, Jia; Hua, Deping; Li, Yi; Deng, Hui; Li, Ying; Liang, Zhixuan; Huang, Jinhai

Detection of Salmonella is very important to minimize the food safety risk. In this study, the recombinant PagC protein and PagC antibody were prepared and coupled with immunomagnetic beads (IMBs) to capture Salmonella cells from pork and milk samples. And then the SYBR Green qualitative PCR was developed to detect the pathogenic Salmonella. The results showed that the PagC polyclonal antiserum is of good specificity and the capture rate of 0.1mg IMBs for Salmonella tended to be stable at the range of 70-74% corresponding to the concentrations between 10 1 and 10 4 CFU/mL. The method developed demonstrated high specificity for the positive Salmonella samples when compared to non-specific DNA samples, such as Escherichia coli, Staphylococcus aureus, Yersinia enterocolitica, and Yersinia pseudotuberculosis. The limit of detection of this assay was 18CFU/mL. Detection and quantitative enumeration of Salmonella in samples of pork or milk shows good recoveries of 54.34% and 52.07%. In conclusion, the polyclonal antibody of recombinant PagC protein is effective to capture Salmonella from detected samples. The developed pagC antibody IMBs-qPCR method showed efficiency, sensitivity and specificity for 30 Salmonella detection, enabling detection within 10h, which is a promising rapid method to detect Salmonella in emergency. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

The effect of urea and ammonia treatments on the survival of Salmonella spp. and Yersinia enterocolitica in pig slurry.

PubMed

Bolton, D J; Ivory, C; McDowell, D A

2013-01-01

The objective of this study was to investigate the survival of Salmonella and Yersinia enterocolitica strains in pig slurry and evaluate urea and ammonia as disinfection strategies. Salmonella Anatum, Salmonella Derby, Salmonella Typhimurium DT19 and Y. enterocolitica bioserotypes 4, O:3, 2, O:5,27 and 1A, O:6,30 were selectively marked by insertion of the plasmid, pGLO encoding for green fluorescent protein and for ampicillin resistance. Strain cocktails were inoculated into fresh pig slurry (control), slurry treated with urea [final concentration 2% w/w, (0.33 mol l(-1) )] and slurry treated with ammonia [final concentration 0.5% w/w, (0.3 mol l(-1) )] and stored at 4, 14 and 25°C. Bacterial counts were determined at regular intervals on xylose lysine deoxycholate agar (XLD), and XLD supplemented with ampicillin (0.1 mg ml(-1) ) and arabinose (0.6 mg ml(-1) ) for Salmonella and cefsulodin-irgasan-novobiocin agar (CIN) and CIN supplemented with ampicillin and arabinose for Y. enterocolitica. The pH of the control-, urea- and ammonia-treated samples ranged from 7.1 to 7.7, 8.8 to 8.9 and 8.0 to 8.3, respectively. Salmonella D(4) values ranged from 2.71 to 21.29 days, D(14) values from 2.72 to 11.62 days and D(25) values from 1.76 to 6.85 days. The equivalent D values ranges for the Y. enterocolitica strains were 3.7-19.23, 1.8-16.67 and 1.63-7.09 days, respectively. Treatment significantly (P < 0.01) affected D values with control > ammonia > urea, as did incubation temperature; 4 > 14 > 25°C. Urea and to a lesser extent ammonia may be used to disinfect Salmonella- and/or Y. enterocolitica-contaminated pig slurry, decreasing the storage time required while increasing its fertilizer value. This study presents data supporting the treatment of pig slurry to kill important zoonotic agents, thereby reducing environmental contamination, cross-infection of other animals and decreasing zoonotic disease in the food chain. © 2012 The Society for Applied Microbiology.

Changes in the Salmonella status of broiler chickens subjected to simulated shipping conditions.

PubMed Central

Rigby, C E; Pettit, J R

1980-01-01

Market-age broiler chickens from flocks infected with Salmonella typhimurium were killed after being placed in crates and subjected to simulated shipping conditions for five, 19 or 24 hours. The cloacal feces, ceca and exteriors of the birds were cultured for salmonellae to identify shedders, cecal carriers and external carriers respectively, and the results compared with those obtained from pen-mates killed at the time the tested birds were put into the crates. Carriage of S. typhimurium was significantly higher among birds placed in clean crates than among the uncrated controls, mainly due to an increase in cecal carriers (from 23.5% to 61.5%). This increase was not related to the time spent in the crate. Twenty-four chickens were placed in crates contaminated with Salmonella alachua and all 24 became carriers of this organism: 22 (91.5%) of these were cecal carriers and 18 (75%) were shedders. This contamination also spread to 15/24 chickens placed in clean crates and "shipped" in the same truck: six of these became cecal carriers and seven were shedders. These results indicated that chickens in shipping crates which are exposed to salmonellae under transport conditions may readily become infected and begin to shed salmonellae within 24 hours. PMID:7004609

Prevalence of antimicrobial resistance of non-typhoidal Salmonella serovars in retail aquaculture products.

PubMed

Zhang, Jianmin; Yang, Xiaowei; Kuang, Dai; Shi, Xianming; Xiao, Wenjia; Zhang, Jing; Gu, Zhen; Xu, Xuebin; Meng, Jianghong

2015-10-01

Aquaculture products can become sources of Salmonella by exposure to contaminated water or through processing practices, thus representing a public health hazard. A study was conducted on Salmonella contamination in aquaculture products sampled from marketplaces and retailers in Shanghai, China. A total of 730 samples (including fish, shellfish, bullfrog, clam, shrimp and others) were obtained from 2006 to 2011. Among them, 217 (29.7%) were positive for Salmonella. Thirty-eight serovars were identified in the 217 Salmonella isolates. The most prevalent were Salmonella Aberdeen (18.4%), S. Wandsworth (12.0%), S. Thompson (9.2%), S. Singapore (5.5%), S. Stanley (4.6%), S. Schwarzengrund (4.6%), S. Hvittingfoss (4.1%) and S. Typhimurium (4.1%). Many resistant isolates were detected, with 69.6% resistant to at least one antimicrobial drug. We observed high resistance to sulfonamides (56.5%), tetracycline (34.1%), streptomycin (28.6%), ampicillin (23.5%) and nalidixic acid (21.2%). Lower levels of resistance were found for gentamicin (3.2%), ciprofloxacin (2.3%), ceftiofur (1.3%), cefotaxime (0.9%), ceftazidime (0.5%) and cefepime (0.5%). A total of 43.3% of the Salmonella isolates were multidrug-resistant and 44 different resistance patterns were found. This study provided data on the prevalence, serovars and antimicrobial resistance of Salmonella from retail aquaculture products in Shanghai, and indicated the need for monitoring programs for microbiologic safety in such projects and for more prudent drug use in aquaculture production in order to reduce the risk of development and spread of antimicrobial resistance. Copyright © 2015 Elsevier B.V. All rights reserved.

Tips to Reduce Your Risk of Salmonella from Eggs

MedlinePlus

... What's this? Submit Button Past Emails Salmonella and Eggs Language: English (US) Español (Spanish) Recommend on Facebook ... Dizziness when standing up. Safe Handling Tips for Eggs from Backyard Poultry Shell eggs may become contaminated ...

Peanut Roaster Temperatures Relative to Salmonella Kill

USDA-ARS?s Scientific Manuscript database

ARS, Market Quality and Handling Research Unit, Raleigh NC 27695 In response to the limited peanut butter contamination incident of 2006/7, studies were initiated to examine the effect of various time and temperature protocols on log kill levels for Salmonella on peanuts. The objective of the work ...

Salmonella enterica Serovar Kentucky Flagella are Required for Broiler Skin Adhesion and Caco-2 Cell Invasion

USDA-ARS?s Scientific Manuscript database

Non-typhoidal Salmonella are the main source of pathogenic bacterial contamination in the poultry industry. Recently, Salmonella enterica serovar Kentucky has been recognized as the most prominent serovar on carcasses in poultry processing plants. Previous studies showed that flagella are one of the...

Reversible synthesis of colanic acid and O-antigen polysaccharides in Salmonella Typhimurium enhances induction of cross-immune responses and provides protection against heterologous Salmonella challenge.

PubMed

Li, Pei; Liu, Qing; Huang, Chun; Zhao, Xinxin; Roland, Kenneth L; Kong, Qingke

2017-05-15

Colanic Acid (CA) and lipopolysaccharide (LPS) are two major mannose-containing extracellular polysaccharides of Salmonella. Their presence on the bacterial surface can mask conserved protective outer membrane proteins (OMPs) from the host immune system. The mannose moiety in these molecules is derived from GDP-mannose, which is synthesized in several steps. The first two steps require the action of phosphomannose isomerase, encoded by pmi (manA), followed by phosphomannomutase, encoded by manB. There are two copies of manB present in the Salmonella chromosome, one located in the cps gene cluster (cpsG) responsible for CA synthesis, and the other in the rfb gene cluster (rfbK) involved in LPS O-antigen synthesis. In this study, it was demonstrated that the products of cpsG and rfbK are isozymes. To evaluate the impact of these genes on O-antigen synthesis, virulence and immunogenicity, single mutations (Δpmi, ΔrfbK or ΔcpsG) and a double mutation (ΔrfbK ΔcpsG) were introduced into both wild-type Salmonella enterica and an attenuated Δcya Δcrp vaccine strain. The Δpmi, ΔrfbK and ΔcpsG ΔrfbK mutants were defective in LPS synthesis and attenuated for virulence. In orally inoculated mice, strain S122 (Δcrp Δcya ΔcpsG ΔrfbK) and its parent S738 (Δcrp Δcya) were both avirulent and colonized internal tissues. Strain S122 elicited higher levels of anti-S. Typhimurium OMP serum IgG than its parent strain. Mice immunized with S122 were completely protected against challenge with wild-type virulent S. Typhimurium and partially protected against challenge with either wild-type virulent S. Choleraesuis or S. Enteritidis. These data indicate that deletions in rfbK and cpsG are useful mutations for inclusion in future attenuated Salmonella vaccine strains to induce cross-protective immunity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Salmonella enteritidis surveillance by egg immunology: impact of the sampling scheme on the release of contaminated table eggs.

PubMed

Klinkenberg, Don; Thomas, Ekelijn; Artavia, Francisco F Calvo; Bouma, Annemarie

2011-08-01

Design of surveillance programs to detect infections could benefit from more insight into sampling schemes. We address the effect of sampling schemes for Salmonella Enteritidis surveillance in laying hens. Based on experimental estimates for the transmission rate in flocks, and the characteristics of an egg immunological test, we have simulated outbreaks with various sampling schemes, and with the current boot swab program with a 15-week sampling interval. Declaring a flock infected based on a single positive egg was not possible because test specificity was too low. Thus, a threshold number of positive eggs was defined to declare a flock infected, and, for small sample sizes, eggs from previous samplings had to be included in a cumulative sample to guarantee a minimum flock level specificity. Effectiveness of surveillance was measured by the proportion of outbreaks detected, and by the number of contaminated table eggs brought on the market. The boot swab program detected 90% of the outbreaks, with 75% fewer contaminated eggs compared to no surveillance, whereas the baseline egg program (30 eggs each 15 weeks) detected 86%, with 73% fewer contaminated eggs. We conclude that a larger sample size results in more detected outbreaks, whereas a smaller sampling interval decreases the number of contaminated eggs. Decreasing sample size and interval simultaneously reduces the number of contaminated eggs, but not indefinitely: the advantage of more frequent sampling is counterbalanced by the cumulative sample including less recently laid eggs. Apparently, optimizing surveillance has its limits when test specificity is taken into account. © 2011 Society for Risk Analysis.

Potential for cross-contamination from use of a needleless injector.

PubMed

Weintraub, A M; Ponce de Leon, M P

1998-08-01

Medical devices that are used on patients in fields containing potentially infectious body fluids can become contaminated and transmit infectious agents to other sites on the patient or to other patients if the devices are not properly cleaned and decontaminated after use on each patient treatment site. One such device is the needleless or jet injector, which is widely used in medicine and dentistry to deliver local anesthetic in procedures such as bone marrow aspirations, lumbar punctures, and cutaneous and intraoral injections. This study was conducted to determine whether cross-contamination can occur on in vitro reuse of a needleless injector and whether a manufacturer's recommended method of injector decontamination (ie, immersion sterilization) is effective in the prevention of cross-contamination. The study was performed with new autoclaved injectors, fluorescein dye, and Streptococcus crista (the bacteria commonly found in saliva) in the field of use to determine whether these devices can become contaminated during use and carry over the contamination to other sites during immediate reuse. Fluorescein dye and bacteria tests with the needleless injectors showed that contamination or carryover does occur. It appeared to reduced to a minimum when a autoclaved, sterile rubber cap used over the head of the device during injection was replaced between each use, although replacement of the rubber cap alone did not prevent carryover. Immersion of the head of the injector in a 2% glutaraldehyde solution for 30 minutes followed by a sterile water rinse and the replacement of the rubber cap with a sterile cap between uses was shown to curtail bacterial growth and prevent cross-contamination on immediate reuse of the device. This study demonstrated that needleless injectors become contaminated during in vitro use and direct contact with contaminated surfaces and that needless injectors carry over the contamination to subsequent sites of release. The replacement of the

Fate of Salmonella enterica and Enterohemorrhagic Escherichia coli Cells Artificially Internalized into Vegetable Seeds during Germination.

PubMed

Liu, Da; Cui, Yue; Walcott, Ronald; Chen, Jinru

2018-01-01

Vegetable seeds contaminated with bacterial pathogens have been linked to fresh-produce-associated outbreaks of gastrointestinal infections. This study was undertaken to observe the physiological behavior of Salmonella enterica and enterohemorrhagic Escherichia coli (EHEC) cells artificially internalized into vegetable seeds during the germination process. Surface-decontaminated seeds of alfalfa, fenugreek, lettuce, and tomato were vacuum-infiltrated with four individual strains of Salmonella or EHEC. Contaminated seeds were germinated at 25°C for 9 days, and different sprout/seedling tissues were microbiologically analyzed every other day. The internalization of Salmonella and EHEC cells into vegetable seeds was confirmed by the absence of pathogens in seed-rinsing water and the presence of pathogens in seed homogenates after postinternalization seed surface decontamination. Results show that 317 (62%) and 343 (67%) of the 512 collected sprout/seedling tissue samples were positive for Salmonella and EHEC, respectively. The average Salmonella populations were significantly larger ( P < 0.05) than the EHEC populations. Significantly larger Salmonella populations were recovered from the cotyledon and seed coat tissues, followed by the root tissues, but the mean EHEC populations from all sampled tissue sections were statistically similar, except in pregerminated seeds. Three Salmonella and two EHEC strains had significantly larger cell populations on sprout/seedling tissues than other strains used in the study. Salmonella and EHEC populations from fenugreek and alfalfa tissues were significantly larger than those from tomato and lettuce tissues. The study showed the fate of internalized human pathogens on germinating vegetable seeds and sprout/seedling tissues and emphasized the importance of using pathogen-free seeds for sprout production. IMPORTANCE The internalization of microorganisms into vegetable seeds could occur naturally and represents a possible pathway of

[Investigation of a water-borne Salmonella ohio outbreak].

PubMed

Molinero, M E; Fernández, I; García-Calabuig, M A; Peiró, E

1998-05-01

The genus Salmonella is one of the main causes of foodborne and waterborne illness worldwide. It is a major public health concern almost entirely due to S. enteritidis. However, outbreaks caused by Salmonella ohio are rare. We have not found any reference about salmonellosis by S. ohio whose origin was water of a drinking fountain. An epidemiological survey was carried out to investigate the origin of the outbreak, and information was sought on personal details, symptoms, contact with others who had ill as well as a history of eating. Fecal specimens and water samples were cultured for bacterial pathogens including Salmonella. Salmonella isolates obtained were characterized by stereotyping. A total of 101 persons were exposed. 87 of these were interviewed, but only 59 of these were affected (attack rate: 67.8%), including 56 children and 3 adults. Syndrome was not severe, in general, persisting for a period of 2 days, in average. S. ohio was isolated from the water and from 2 of the 13 stool specimens analysed. The outbreak was caused by consumption of water from a drinking fountain which was contaminated by S. ohio. This fountain had not a chlorination system. An outbreak due to S. ohio whose origin is the consumption of water from a drinking fountain is described for the first time in this paper. It can be concluded the importance of keeping a good epidemiological control system to investigate and prevent outbreaks. The control of drinking fountains is also important, to prevent its contamination.

Effect of Low Dose of Fumonisins on Pig Health: Immune Status, Intestinal Microbiota and Sensitivity to Salmonella

PubMed Central

Burel, Christine; Tanguy, Mael; Guerre, Philippe; Boilletot, Eric; Cariolet, Roland; Queguiner, Marilyne; Postollec, Gilbert; Pinton, Philippe; Salvat, Gilles; Oswald, Isabelle P.; Fravalo, Philippe

2013-01-01

The objective of this study was to measure the effects of chronic exposure to fumonisins via the ingestion of feed containing naturally contaminated corn in growing pigs infected or not with Salmonella spp. This exposure to a moderate dietary concentration of fumonisins (11.8 ppm) was sufficient to induce a biological effect in pigs (Sa/So ratio), but no mortality or pathology was observed over 63 days of exposure. No mortality or related clinical signs, even in cases of inoculation with Salmonella (5 × 104 CFU), were observed either. Fumonisins, at these concentrations, did not affect the ability of lymphocytes to proliferate in the presence of mitogens, but after seven days post-inoculation they led to inhibition of the ability of specific Salmonella lymphocytes to proliferate following exposure to a specific Salmonella antigen. However, the ingestion of fumonisins had no impact on Salmonella translocation or seroconversion in inoculated pigs. The inoculation of Salmonella did not affect faecal microbiota profiles, but exposure to moderate concentrations of fumonisins transiently affected the digestive microbiota balance. In cases of co-infection with fumonisins and Salmonella, the microbiota profiles were rapidly and clearly modified as early as 48 h post-Salmonella inoculation. Therefore under these experimental conditions, exposure to an average concentration of fumonisins in naturally contaminated feed had no effect on pig health but did affect the digestive microbiota balance, with Salmonella exposure amplifying this phenomenon. PMID:23612754

Public health investigations of Salmonella Enteritidis in catering raw shell eggs, 2002-2004.

PubMed

Little, C L; Surman-Lee, S; Greenwood, M; Bolton, F J; Elson, R; Mitchell, R T; Nichols, G N; Sagoo, S K; Threlfall, E J; Ward, L R; Gillespie, I A; O'Brien, S

2007-06-01

In response to a dramatic change in the epidemiology of Salmonella Enteritidis in England and Wales thought to be associated with raw shell eggs, the Health Protection Agency initiated public health investigations to establish the incidence of Salmonella contamination and origin of eggs used by catering premises implicated in outbreaks of Salm. Enteritidis. Between October 2002 and November 2004, 16 971 eggs were sampled and Salmonella were recovered from 3.4%. Salmonella was isolated from 5.5% and 6.3% of Spanish and eggs of unknown origin, respectively, used in catering premises linked to outbreaks, a level significantly higher than that (1.1%) found in nonLion Quality UK eggs sampled. The small sample of UK Lion Quality eggs tested (reflecting their lack of use in premises visited) did not contain Salmonella. Several phage types of Salm. Enteritidis other than phage type 4 (PT 4) were identified with nonUK eggs. Eggs from Spain were implicated as a major source of infection. Eggs were contaminated more frequently with Salmonella when shells were dirty and/or cracked, and stored at above 8 degrees C. The use of Spanish eggs by the catering sector has been identified as a consistent significant factor in many of the outbreaks caused by Salm. Enteritidis nonPT4 in England and Wales during 2002-2004. Advice to caterers and hospitals that raw shell eggs should not be used in food that will either not be cooked or only lightly cooked should be reinforced.

Persistence of salmonella typhimurium in nopal cladodes

USDA-ARS?s Scientific Manuscript database

Fresh produce associated outbreaks have increased in the last few years. E.coli O157:H7 and Salmonella have been causative agents of infection in these outbreaks. Fresh produce is consumed raw, and in the absence of terminal kill treatment, it is imperative to understand sources of contamination o...

Antimicrobial resistance and resistance genes in Salmonella strains isolated from broiler chickens along the slaughtering process in China.

PubMed

Zhu, Yuanting; Lai, Haimei; Zou, Likou; Yin, Sheng; Wang, Chengtao; Han, Xinfeng; Xia, Xiaolong; Hu, Kaidi; He, Li; Zhou, Kang; Chen, Shujuan; Ao, Xiaolin; Liu, Shuliang

2017-10-16

A1 (19 isolates) and bla OXA-30 -aadA1/drfA1-orfC (2 isolates), were identified in class 1 integron-positive isolates. 97.9% (184/188) of quinolone-resistant isolates had at least one mutation within gyrA or parC. Overall, antimicrobial resistance showed an increasing trend along the slaughtering process. The results showed that broiler chicken products in the slaughterhouse were contaminated with MDR Salmonella, which might originate from food producing animals to some extent, and cross-contamination during slaughter, and facilitate the dissemination of the resistance genes to consumers along the production chain, which suggests importance of controlling Salmonella during slaughter for public health, underlying strict hygiene method and HACCP management to reduce cross-contamination. Copyright © 2017 Elsevier B.V. All rights reserved.

Prevalence of intestinal parasite, Shigella and Salmonella species among diarrheal children in Jimma health center, Jimma southwest Ethiopia: a cross sectional study.

PubMed

Beyene, Getenet; Tasew, Haimanot

2014-02-05

Diarrheal disease continues to be an important cause of morbidity and mortality among young children in developing countries including Ethiopia. Globally, intestinal parasite, Shigella and Salmonella species remain major contributors to acute enteric infections. The study was aimed at determining the frequency of intestinal parasite, Shigella and Salmonella species identified from diarrheic children at Jimma Health Centre, Jimma south west Ethiopia. A health institution based cross sectional study was conducted from March to November 2012. A structured questionnaire was used for collection of data on socio- demographic characteristics. Parasite and bacteria identification as well as susceptibility testing was done using standard parasitological and bacteriological procedures. A total of 260 diarrheal children were included in the study. A total of 129 (49.6%) samples were positive for intestinal parasite, Shigella and Salmonella species. Of these, 107 (41.1%), 6 (2.3%) and 16 (6.2%) samples were positive for intestinal parasite, Shigella and Salmonella species respectively. The dominant isolated parasite was G. lamblia with prevalence of 13.5% followed by A. lumbricoides (11.5%). The least identified parasites were Schistosoma mansoni and Taenia species accounting 0.4% each. Multiple parasitic infections were observed in 19 (7.3%) patients. Shigella species showed hundred percent resistances to ampicillin, amoxacillin, and cotrimoxazole. All Salmonella isolates were resistant against amoxicillin. All Shigella and Salmonella species were susceptible to ceftriaxone, ciprofloxacin and gentamycin. The presence of reasonably high amount of intestinal parasite and Salmonella and Shigella species that are drug resistance to the commonly prescribed drugs is a treat to the children and community at large. Therefore, measures including health education, improvement of safe water supply, sanitation facilities and continuous monitoring of microbiological and antimicrobial

Epidemiological studies on Salmonella in a certain area ("Walcheren project"). I. The presence of Salmonella in man, pigs, insects, seagulls and in foods and effluents.

PubMed

Edel, W; van Schothorst, M; Kampelmacher, E H

1976-08-01

During a certain period various materials (pigs, foods, insects, seagull droppings, chopping-block scrapings from butcher's shops, effluents of sewage treatment plants and stools of patients) were examined for the presence of Salmonella at the same time in a relatively small area (Walcheren). Certain types of Salmonella (S. typhi murium type II 505, S. panama, S. infantis and S. brandenburg) were frequently isolated from almost all materials examined. This may indicate the existence of Salmonella contamination cycles: one may think of the cycle: slaughter animal (infected from the environment and/or by meal) - meat - consumer - patient or healthy carrier - effluent and surface water - insects, birds and rodents - slaughter animal or meat and possibly other foods - consumer.

Administration of a Salmonella Enteritidis ΔhilAssrAfliG strain by coarse spray to newly hatched broilers reduces colonization and shedding of a Salmonella Enteritidis challenge strain.

PubMed

De Cort, W; Haesebrouck, F; Ducatelle, R; van Immerseel, F

2015-01-01

Consumption of contaminated poultry meat is still an important cause of Salmonella infections in humans. Colonization inhibition (CI) occurs when a live Salmonella strain is administered to chickens and subsequently protects against challenge with another Salmonella strain belonging to the same serotype. A Salmonella Enteritidis hilAssrAfliG deletion mutant has previously been proven to reduce colonization and shedding of a wild-type Salmonella Enteritidis strain in newly hatched broilers after experimental infection. In this study, we compared two administration routes for this strain. Administering the Salmonella Enteritidis ΔhilAssrAfliG strain through drinking water on the first day of life resulted in decreased fecal shedding and cecal colonization of a wild-type Salmonella Enteritidis challenge strain administered 24 h later using a seeder-bird model. When administering the CI strain by coarse spray on newly hatched broiler chicks, an even more pronounced reduction of cecal colonization was observed, and fecal shedding of the Salmonella Enteritidis challenge strain ceased during the course of the experiment. These data suggest that administering a Salmonella Enteritidis ΔhilAssrAfliG strain to newly hatched chicks using a coarse spray is a useful and effective method that reduces colonization and shedding of a wild-type Salmonella Enteritidis strain after early challenge. © 2014 Poultry Science Association Inc.

[Epidemic condition and molecular subtyping of ciprofloxacin and cefotaxime co-resistant Salmonella Indiana isolated from retail chicken carcasses in six provinces, China].

PubMed

Hu, Yujie; He, Yingying; Wang, Yeru; Cui, Shenghui; Chen, Qiuxia; Liu, Guihua; Chen, Qian; Zhou, Gang; Yang, Baowei; Huang, Jinlin; Yu, Hongxia; Li, Fengqin

2015-08-01

To elucidate the epidemic condition and molecular subtyping of ciprofloxacin and cefotaxime co-resistant Salmonella Indiana (S. Indiana) isolated from retail chicken carcasses in six provinces of China. A total of 2 647 Salmonella strains isolated from retail chicken carcasses collected from six provinces of China were subjected to antimicrobial susceptibility testing. All Salmonella isolates co-resistant to ciprofloxacin and cefotaxime were further characterized by serotyping, extended-spectrum beta-lactamases (ESBLs) producing strains screening and pulsed field gel electrophoresis (PFGE) typing. Among 2 629 Salmonella isolates tested, 227 (8.52%) isolates were co-resistant to ciprofloxacin and ceftazidime/cefotaxime (Beijing: 11.67% (99/874), Jilin: 8.20% (60/726), Guangdong: 1.39% (7/502), Jiangsu: 15.61% (42/260), Shaanxi: 8.56% (16/186), Inner Mongolia: 0 (0/81)), and 224 of them were identified as S. Indiana. 213 (95.10%) isolates of S. Indiana were ESBLs producing strains. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates developed a multi-drug resistant profile and 17.86% (40/224) of them were resistant to all antibiotics tested except carbapenems, and 50.89% (114/224) of them resistant to 9 antibiotics, additionally, 25.45% (57/224) of them showed multi-drug resistance to 8 antibiotics. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates were divided into 32 PFGE clusters and 150 PFGE patterns. Strains of S. Indiana from same or different sampling site and time seemed to either share the same PFGE patterns or be differential to each other in different regions. The results indicated that chicken carcasses collected from parts of China were heavily contaminated by ciprofloxacin and cefotaxime co-resistant S. Indiana and could serve as an important reservoir of ciprofloxacin and cefotaxime co-resistant Salmonella. Molecular subtyping results indicated that cross contamination or common pollution source might be in these strains.

Effect of Product Dimensions and Surface Browning Method on Salmonella Contamination in Frozen, Surface-Browned, Breaded Chicken Products Treated with Antimicrobials.

PubMed

Moschonas, Galatios; Geornaras, Ifigenia; Stopforth, Jarret D; Woerner, Dale R; Belk, Keith E; Smith, Gary C; Sofos, John N

2015-12-01

Not-ready-to-eat breaded chicken products formulated with antimicrobial ingredients were tested for the effect of sample dimensions, surface browning method and final internal sample temperature on inoculated Salmonella populations. Fresh chicken breast meat portions (5 × 5 × 5 cm), inoculated with Salmonella (7-strain mixture; 5 log CFU/g), were mixed with (5% v/w total moisture enhancement) (i) distilled water (control), (ii) caprylic acid (CAA; 0.0625%) and carvacrol (CAR; 0.075%), (iii) CAA (0.25%) and ε-polylysine (POL; 0.5%), (iv) CAR (0.15%) and POL (0.5%), or (v) CAA (0.0625%), CAR (0.075%) and POL (0.5%). Sodium chloride (1.2%) and sodium tripolyphosphate (0.3%) were added to all treatments. The mixtures were then ground and formed into 9 × 5 × 3 cm (150 g) or 9 × 2.5 × 2 cm (50 g) portions. The products were breaded, browned in (i) an oven (208 °C, 15 min) or (ii) deep fryer (190 °C, 15 s), packaged, and stored at -20 °C (8 d). Overall, maximum internal temperatures of 62.4 ± 4.0 °C (9 × 2.5 × 2 cm) and 46.0 ± 3.0 °C (9 × 5 × 3 cm) were reached in oven-browned samples, and 35.0 ± 1.1 °C (9 × 2.5 × 2 cm) and 31.7 ± 2.6 °C (9 × 5 × 3 cm) in fryer-browned samples. Irrespective of formulation treatment, total (after frozen storage) reductions of Salmonella were greater (P < 0.05) for 9 × 2.5 × 2 cm oven-browned samples (3.8 to at least 4.6 log CFU/g) than for 9 × 5 × 3 cm oven-browned samples (0.7 to 2.5 log CFU/g). Product dimensions did not (P ≥ 0.05) affect Salmonella reductions (0.6 to 2.8 log CFU/g) in fryer-browned samples. All antimicrobial treatments reduced Salmonella to undetectable levels (<0.3 log CFU/g) in oven-browned 9 × 2.5 × 2 cm samples. Overall, the data may be useful for the selection of antimicrobials, product dimensions, and surface browning methods for reducing Salmonella contamination. © 2015 Institute of Food Technologists®

Detection of Salmonella enterica in pigs at slaughter and comparison with human isolates in Italy.

PubMed

Bonardi, Silvia; Alpigiani, Irene; Bruini, Ilaria; Barilli, Elena; Brindani, Franco; Morganti, Marina; Cavallini, Pierugo; Bolzoni, Luca; Pongolini, Stefano

2016-02-02

In 2013-2014, 201 pigs belonging to 67 batches were tested for Salmonella in their mesenteric lymph nodes (MLN) in one abattoir of Northern Italy. For each batch, faecal material was collected at lairage by swabbing the pen floor for approximately 1600 cm(2). The aim of this study was to investigate the prevalence of Salmonella in MLN of pigs at slaughter, to assess Salmonella contamination at lairage and to evaluate the effect of lairage duration on its prevalence. Serotyping, XbaI PFGE typing and antimicrobial testing of the isolates were performed. Pig and human Salmonella isolates of the same region of Italy were compared to evaluate possible correlations. Salmonella enterica was isolated from 19.9% of the MLN and 49.3% of the environmental faecal samples. Nine different serovars were identified among 75 S. enterica isolates. In MLN Salmonella Derby was the most common (52.5%), followed by S. enterica 4,[5],12:i:- (17.5%) and Salmonella Rissen (10.0%). In faecal samples S. Derby was prevalent (51.4%), followed by S. enterica 4,[5], 12:i:- (20.0%) and Salmonella Brandenburg (14.3%). Lairage holding varied between 1 and ≥ 12 h (median value: 2.5h). In pigs held for 1-3h, 14.1% were positive for Salmonella in MLN but the prevalence reached 31.8% when they were held for ≥ 12 h. The contamination of MLN was statistically different (p=0.0045) between the two groups, thus confirming the role of long-lasting lairage in Salmonella contamination of pigs. XbaI PFGE typing detected 36 PFGE types. Twenty-three PFGE types were identified among the 40 MLN isolates and 22 PFGE types among the 35 faecal isolates. A total of 11 PFGE types were shared between the MLN of pigs and the lairage environment. Among S. Derby, 6 shared PFGE types between MLN and faeces were found and among S. enterica 4,[5],12:i:- one PFGE type was common between MLN and the faecal samples. Shared profiles between human and swine isolates of S. Derby, S. enterica 4,[5],12:i:-, S. Rissen, Salmonella

Tracking cross-contamination transfer dynamics at a mock retail deli market using GloGerm.

PubMed

Maitland, Jessica; Boyer, Renee; Gallagher, Dan; Duncan, Susan; Bauer, Nate; Kause, Janell; Eifert, Joseph

2013-02-01

Ready-to-eat (RTE) deli meats are considered a food at high risk for causing foodborne illness. Deli meats are listed as the highest risk RTE food vehicle for Listeria monocytogenes. Cross-contamination in the retail deli market may contribute to spread of pathogens to deli meats. Understanding potential cross-contamination pathways is essential for reducing the risk of contaminating various products. The objective of this study was to track cross-contamination pathways through a mock retail deli market using an abiotic surrogate, GloGerm, to visually represent how pathogens may spread through the deli environment via direct contact with food surfaces. Six contamination origination sites (slicer blade, meat chub, floor drain, preparation table, employee's glove, and employee's hands) were evaluated separately. Each site was inoculated with 20 ml of GloGerm, and a series of standard deli operations were completed (approximately 10 min of work). Photographs were then taken under UV illumination to visualize spread of GloGerm throughout the deli. A sensory panel evaluated the levels of contamination on the resulting contaminated surfaces. Five of the six contamination origination sites were associated with transfer of GloGerm to the deli case door handle, slicer blade, meat chub, preparation table, and the employee's gloves. Additional locations became contaminated (i.e., deli case shelf, prep table sink, and glove box), but this contamination was not consistent across all trials. Contamination did not spread from the floor drain to any food contact surfaces. The findings of this study reinforce the need for consistent equipment cleaning and food safety practices among deli workers to minimize cross-contamination.

Cross-sectional survey of indicator and pathogenic bacteria on vegetables sold from Asian vendors at farmers' markets in northern California.

PubMed

Pan, Fengguang; Li, Xunde; Carabez, Jennifer; Ragosta, Guy; Fernandez, Kristine L; Wang, Elaine; Thiptara, Anyarat; Antaki, Elizabeth; Atwill, Edward R

2015-03-01

A cross-sectional survey was conducted during summer 2013 to determine the occurrence of Escherichia coli, fecal coliforms (FCs), E. coli O157:H7, and Salmonella on raw vegetable commodities common to Asian cuisine from 21 vendors or farmers at six farmers' markets in northern California. Based on 242 samples from six commodities (basil, yardlong beans, bitter squash, okra, squash stems and leaves, cilantro), 100% of samples had detectable FCs and 20% had detectable E. coli. The mean concentrations were 0.67 log CFU/g and 1.26 log CFU per bundle for E. coli and 4.00 log CFU/g and 6.26 log CFU per bundle for FCs. Vegetables irrigated with ground versus surface water contained lower concentrations of FCs, but this difference was not observed for E. coli. Yardlong beans, bitter squash, and okra had lower levels of FCs compared with basil, cilantro, and squash stems and leaves. Sixteen (6.6%) samples had detectable levels of Salmonella serovars (Newport, Enteritidis, Agona, and Worthington), with the majority of positives found in cilantro and squash stems and leaves. There was a twofold higher probability of Salmonella contamination in samples from growers or vendors who stated that they used organic farming practices compared with samples from those using conventional farming practices. Lastly, the concentrations of FC and E. coli bacteria were significantly associated with Salmonella contamination: for each additional 100 CFU/g or bundle, the probability of Salmonella contamination increased by ∼15 and ∼30%, respectively. None of the samples had detectable E. coli O157:H7.

Survival and growth of Salmonella in salsa and related ingredients.

PubMed

Ma, Li; Zhang, Guodong; Gerner-Smidt, Peter; Tauxe, Robert V; Doyle, Michael P

2010-03-01

A large outbreak of Salmonella Saintpaul associated with raw jalapeño peppers, serrano peppers, and possibly tomatoes was reported in the United States in 2008. During the outbreak, two clusters of illness investigated among restaurant patrons were significantly associated with eating salsa. Experiments were performed to determine the survival and growth characteristics of Salmonella in salsa and related major ingredients, i.e., tomatoes, jalapeño peppers, and cilantro. Intact and chopped vegetables and different formulations of salsas were inoculated with a five-strain mixture of Salmonella and then stored at 4, 12, and 21 degrees C for up to 7 days. Salmonella populations were monitored during storage. Salmonella did not grow, but survived on intact tomatoes and jalapeño peppers, whereas significant growth at 12 and 21 degrees C was observed on intact cilantro. In general, growth of Salmonella occurred in all chopped vegetables when stored at 12 and 21 degrees C, with chopped jalapeño peppers being the most supportive of Salmonella growth. Regardless of differences in salsa formulation, no growth of Salmonella (initial inoculation ca. 3 log CFU/g) was observed in salsa held at 4 degrees C; however, rapid or gradual decreases in Salmonella populations were only observed in formulations that contained both fresh garlic and lime juice. Salmonella grew at 12 and 21 degrees C in salsas, except for those formulations that contained both fresh garlic and lime juice, in which salmonellae were rapidly or gradually inactivated, depending on salsa formulation. These results highlight the importance of preharvest pathogen contamination control of fresh produce and proper formulation and storage of salsa.

Transient gut retention and persistence of Salmonella through metamorphosis in the lesser mealworm, Alphitobius diaperinus (Coleoptera: Tenebrionidae)

USDA-ARS?s Scientific Manuscript database

his study was undertaken to determine the retention of Salmonella through Alphitobius diaperinus metamorphosis and the contribution of defecation to external contamination. Adults and larvae were exposed to a tagged Salmonella enterica and evaluated for external elimination. Each day for three wee...

Salmonella prevalence and antimicrobial susceptibility from the National Animal Health Monitoring System Swine 2000 and 2006 Studies

USDA-ARS?s Scientific Manuscript database

Concern over Salmonella contamination of food is compounded by fear that antimicrobials traditionally used to combat the infection will become useless due to rising antibiotic resistance. Livestock, in particular swine, are often blamed for illnesses caused by Salmonella and for increasing antibioti...

[Prevalence and antimicrobial susceptibility of Salmonella isolated from broiler whole production process in four provinces of China].

PubMed

Li, W W; Bai, L; Zhang, X L; Xu, X J; Tang, Z; Bi, Z W; Guo, Y C

2018-04-06

findings indicated that Salmonella contamination was common and serious in commercial broiler whole production process in China, especially in the course of defeathering, precooling and selling. The environment of broiler farm is the important source of Salmonella contamination. Additionally, antibiotic resistance of Salmonella was serious for common antimicrobials and multi-drug resistant strains existed widespread, which can pose potential risk on public health and clinical therapy.

Integrated Food Chain Surveillance System for Salmonella spp. in Mexico1

PubMed Central

Calva, Juan Jose; Estrada-Garcia, Maria Teresa; Leon, Veronica; Vazquez, Gabriela; Figueroa, Gloria; Lopez, Estela; Contreras, Jesus; Abbott, Jason; Zhao, Shaohua; McDermott, Patrick; Tollefson, Linda

2008-01-01

Few developing countries have foodborne pathogen surveillance systems, and none of these integrates data from humans, food, and animals. We describe the implementation of a 4-state, integrated food chain surveillance system (IFCS) for Salmonella spp. in Mexico. Significant findings were 1) high rates of meat contamination (21.3%–36.4%), 2) high rates of ceftriaxone-resistant S. Typhimurium in chicken, ill humans, and swine (77.3%, 66.3%, and 40.4% of S. Typhimurium T isolates, respectively), and 3) the emergence of ciprofloxacin resistance in S. Heidelberg (10.4%) and S. Typhimurium (1.7%) from swine. A strong association between Salmonella spp. contamination in beef and asymptomatic Salmonella spp. infection was only observed in the state with the lowest poverty level (Pearson r = 0.91, p<0.001). Pulsed-field gel electrophoresis analysis of 311 S. Typhimurium isolates showed 14 clusters with 102 human, retail meat, and food-animal isolates with indistinguishable patterns. An IFCS is technically and economically feasible in developing countries and can effectively identify major public health priorities. PMID:18325258

Serotype Distribution of Salmonella Isolates from Turkey Ground Meat and Meat Parts

PubMed Central

Erol, Irfan; Goncuoglu, Muammer; Ayaz, Naim Deniz; Ellerbroek, Lüppo; Bilir Ormanci, Fatma Seda; Iseri Kangal, Ozlem

2013-01-01

The aim of the study was to find out the serotype distribution of 169 Salmonella colonies recovered from 112 Salmonella positive ground turkey (115 colonies) and 52 turkey meat parts (54 colonies). Out of 15 Salmonella serotypes: S. Corvallis, S. Kentucky, S. Bredeney, S. Virchow, S. Saintpaul and S. Agona were identified as the predominant serovars at the rates of 27%, 13%, 12%, 12%, 11%, and 10%, respectively. Other serotypes were below 6% of the total isolates. All S. Kentucky and S. Virchow and most of the S. Corvallis (39/46) and S. Heidelberg (9/9) serotypes were recovered from ground turkey. The results indicate that turkey ground meat and meat parts were contaminated with quite distinct Salmonella serotypes. This is the first study reporting Salmonella serotype distribution in turkey meat and S. Corvallis as predominant serotype in poultry meat in Turkey. PMID:23936785

Toward better control of Salmonella contamination by taking advantage of the egg's self-defense system: a review.

PubMed

Zhang, Wei; Zheng, Jiang-Xia; Xu, Gui-Yun

2011-04-01

Egg-associated salmonellosis is a major problem for food safety. It can be caused by vertical transmission (transovarian transmission) in hens and horizontal transmission though penetration. Despite a series of physical and chemical defense mechanisms naturally found in eggs, they cannot provide complete protection for them. Environmental hygiene, bacteria vectors such as birds, rodent, flies, and beetles along with feed and water contamination are the most frequently reported causes of Salmonella colonization in hens, and finally to eggs. In addition, inappropriate egg handling will cause eggs to lose their self-protection ability, thus resulting in the survival and multiplication of Salmonella in an egg's contents, which contributes to the horizontal dissemination. The routes of Salmonella contamination were discussed, and the effectiveness and shortcomings of different decontamination methods were evaluated in this review. Various studies on egg storage indicated that the low-temperature storage without temperature fluctuation was beneficial for the control of Salmonella. This review, based on an understanding of the stages of Salmonella transmission and an egg's self-protection mechanisms, highlights a comprehensive strategy toward Salmonella control in a process from egg production and handling to human consumption.

Evaluation of 3M molecular detection assay (MDA) Salmonella for the detection of Salmonella in selected foods: collaborative study.

PubMed

Bird, Patrick; Fisher, Kiel; Boyle, Megan; Huffman, Travis; Benzinger, M Joseph; Bedinghaus, Paige; Flannery, Jonathan; Crowley, Erin; Agin, James; Goins, David; Benesh, DeAnn; David, John

2013-01-01

The 3M Molecular Detection Assay (MDA) Salmonella is used with the 3M Molecular Detection System for the detection of Salmonella spp. in food, food-related, and environmental samples after enrichment. The assay utilizes loop-mediated isothermal amplification to rapidly amplify Salmonella target DNA with high specificity and sensitivity, combined with bioluminescence to detect the amplification. The 3M MDA Salmonella method was compared using an unpaired study design in a multilaboratory collaborative study to the U.S. Department of Agriculture/Food Safety and Inspection Service-Microbiology Laboratory Guidebook (USDA/FSIS-MLG 4.05), Isolation and Identification of Salmonella from Meat, Poultry, Pasteurized Egg and Catfish Products for raw ground beef and the U.S. Food and Drug Administration/Bacteriological Analytical Manual (FDA/BAM) Chapter 5 Salmonella reference method for wet dog food following the current AOAC guidelines. A total of 20 laboratories participated. For the 3M MDA Salmonella method, raw ground beef was analyzed using 25 g test portions, and wet dog food was analyzed using 375 g test portions. For the reference methods, 25 g test portions of each matrix were analyzed. Each matrix was artificially contaminated with Salmonella at three inoculation levels: an uninoculated control level (0 CFU/test portion), a low inoculum level (0.2-2 CFU/test portion), and a high inoculum level (2-5 CFU/test portion). In this study, 1512 unpaired replicate samples were analyzed. Statistical analysis was conducted according to the probability of detection (POD). For the low-level raw ground beef test portions, the following dLPOD (difference between the POD of the reference and candidate method) values with 95% confidence intervals were obtained: -0.01 (-0.14, +0.12). For the low-level wet dog food test portions, the following dLPOD with 95% confidence intervals were obtained: -0.04 (-0.16, +0.09). No significant differences were observed in the number of positive

Prevalence, serotype diversity, and antimicrobial resistance of Salmonella in imported shipments of spice offered for entry to the United States, FY2007-FY2009.

PubMed

Van Doren, Jane M; Kleinmeier, Daria; Hammack, Thomas S; Westerman, Ann

2013-06-01

In response to increased concerns about spice safety, the U.S. FDA initiated research to characterize the prevalence of Salmonella in imported spices. Shipments of imported spices offered for entry to the United Sates were sampled during the fiscal years 2007-2009. The mean shipment prevalence for Salmonella was 0.066 (95% CI 0.057-0.076). A wide diversity of Salmonella serotypes was isolated from spices; no single serotype constituted more than 7% of the isolates. A small percentage of spice shipments were contaminated with antimicrobial-resistant Salmonella strains (8.3%). Trends in shipment prevalence for Salmonella associated with spice properties, extent of processing, and export country, were examined. A larger proportion of shipments of spices derived from fruit/seeds or leaves of plants were contaminated than those derived from the bark/flower of spice plants. Salmonella prevalence was larger for shipments of ground/cracked capsicum and coriander than for shipments of their whole spice counterparts. No difference in prevalence was observed between shipments of spice blends and non-blended spices. Some shipments reported to have been subjected to a pathogen reduction treatment prior to being offered for U.S. entry were found contaminated. Statistical differences in Salmonella shipment prevalence were also identified on the basis of export country. Published by Elsevier Ltd.

Growth of Salmonella during sprouting of alfalfa seeds associated with salmonellosis outbreaks.

PubMed

Stewart, D S; Reineke, K F; Ulaszek, J M; Tortorello, M L

2001-05-01

Growth of Salmonella was assessed during sprouting of naturally contaminated alfalfa seeds associated with two outbreaks of salmonellosis. Salmonella was determined daily in sprouts and sprout rinse water samples by a three-tube most probable number (MPN) procedure and a commercial enzyme immunoassay (EIA). Growth of Salmonella in the sprouts was reflected in the rinse water, and the MPNs of the two samples were generally in agreement within approximately 1 log. The results from EIA testing of sprouts and water samples were also in agreement. The pathogen was present in the seed at less than 1 MPN/g, and it increased in number to maximum population levels of 102 to 10(3) MPN/g in one seed lot and 10(2) to 10(4) MPN/ g in the other seed lot. Maximum populations of the pathogen were apparent by day 2 of sprouting. These results show the ability of the pathogen to grow to detectable levels during the sprouting process, and they provide support for the recommendation to test the sprout water for the presence of pathogens 48 h after starting seed sprouting. The effectiveness of a 10-min, 20,0000-microg/ml (ppm) calcium hypochlorite treatment of the outbreak-associated seeds was studied. For both seed lots, the hypochlorite treatment caused a reduction, but not elimination, of Salmonella contamination in the finished sprouts. These results confirm the need to test each production batch for the presence of pathogens, even after 20,000 microg/ml (ppm) hypochlorite treatment of seeds, so that contaminated product is not distributed.

Salmonella spp. in lymph nodes of fed and cull cattle: Relative assessment of risk to ground beef

USDA-ARS?s Scientific Manuscript database

Ground beef products have been implicated as the vehicle for the transmission of Salmonella in a number of outbreaks. Although carcass surface interventions have proven effective, Salmonella contamination in ground beef still occurs. Recent studies indicate that deep tissue lymph nodes (DTLNs) may b...

Diversity of Multi-drug Resistant Salmonella enterica Associated with Cull Cattle at Harvest in the United States

USDA-ARS?s Scientific Manuscript database

Background: Salmonella is an important foodborne pathogen, causing millions of cases of food poisoning in the U.S. each year. While poultry products and contaminated fresh produce are well established vectors for Salmonella, several foodborne disease case studies have shown that undercooked ground b...

Outbreak of food-poisoning caused by Salmonella virchow in spit-roasted chicken.

PubMed

Semple, A B; Turner, G C; Lowry, D M

1968-12-28

Salmonella virchow food-poisoning acquired from eating chicken caused illness in at least 50 people who attended a tennis club function in Liverpool, and in many other people in the Merseyside area. In some cases the illness was severe, with positive blood cultures, and 35 people were admitted to hospital.The source of infection was a retail shop which received deep-frozen chickens already contaminated with S. virchow from a packing-station in Cheshire. These chickens were spit-roasted after inadequate thawing and subsequently handled under unhygienic conditions. The result was a massive build-up of salmonella contamination in the shop and in the chicken portions sold.S. virchow was isolated from over 160 patients and contacts in the Merseyside area during the outbreak and many continued to excrete the organism in the faeces after four months. Antibiotic treatment was not recomended because there was no evidence that it shortened the duration of excretion.A high rate of contamination of chickens from a packing-station by a salmonella type capable of causing serious disease in man is clearly a public health problem which cannot be ignored.The use of rotary spits for roasting chickens requires thorough investigation and appraisal, because as operated at present they evidently constitute a public health hazard.

Outbreak of Food-poisoning Caused by Salmonella Virchow in Spit-roasted Chicken

PubMed Central

Semple, A. B.; Turner, G. C.; Lowry, D. M. O.

1968-01-01

Salmonella virchow food-poisoning acquired from eating chicken caused illness in at least 50 people who attended a tennis club function in Liverpool, and in many other people in the Merseyside area. In some cases the illness was severe, with positive blood cultures, and 35 people were admitted to hospital. The source of infection was a retail shop which received deep-frozen chickens already contaminated with S. virchow from a packing-station in Cheshire. These chickens were spit-roasted after inadequate thawing and subsequently handled under unhygienic conditions. The result was a massive build-up of salmonella contamination in the shop and in the chicken portions sold. S. virchow was isolated from over 160 patients and contacts in the Merseyside area during the outbreak and many continued to excrete the organism in the faeces after four months. Antibiotic treatment was not recomended because there was no evidence that it shortened the duration of excretion. A high rate of contamination of chickens from a packing-station by a salmonella type capable of causing serious disease in man is clearly a public health problem which cannot be ignored. The use of rotary spits for roasting chickens requires thorough investigation and appraisal, because as operated at present they evidently constitute a public health hazard. PMID:5750404

Effect of sample preparation and preenrichment media on the recovery of Salmonella from cantaloupes, mangoes, and tomatoes.

PubMed

Hammack, Thomas S; Johnson, Mildred L; Jacobson, Andrew P; Andrews, Wallace H

2006-01-01

Studies were conducted to determine the relative effectiveness of buffered peptone water (BPW), lactose (LAC) broth, and Universal Preenrichment (UP) broth for the recovery of Salmonella organisms from fruit rinses, whole fruit, and comminuted fruit. In the first phase, the relative effectiveness of the rinse and soak methods for the recovery of Salmonella from surface-contaminated mangoes and tomatoes was examined. Fruits were spot inoculated with single Salmonella serovars and held for 4 days at 2-6 degrees C before analysis was initiated. The contaminated fruit was rinsed in portions of BPW, LAC broth, or UP broth. Portions from each rinse were added to its respective broth (e.g., BPW to BPW). Individual whole fruit, in their remaining broth rinses (soak method), and the fruit rinse/broths (rinse method) were incubated for 24 h at 35 degrees C. The Bacteriological Analytical Manual (BAM) Salmonella culture method was followed thereafter. The soak method produced significantly greater numbers (P < 0.05) of positive test portions than did the rinse method for the analysis of mangoes (93 versus 12) and tomatoes (85 versus 34). The 3 broths were comparable for the recovery of Salmonella for both the soak and the rinse methods for mangoes. For tomatoes, there were no significant differences among the broths for the soak method, but BPW and UP broth were significantly more productive (P < 0.05) than LAC broth by the rinse method. In the second phase, the relative effectiveness of LAC broth, BPW, and UP broth for the recovery of Salmonella from comminuted fruit was examined. Fruits were contaminated with single Salmonella serovars and aged for 4 days at 2-6 degrees C. Twenty 25 g test portions were preenriched in each of the following broths: BPW, LAC broth, and UP broth. The BAM Salmonella culture method was followed thereafter. For cantaloupes, significantly more (P < 0.05) Salmonella-positive test portions were recovered with UP broth (96 Salmonella-positive test

Prevalence of nontyphoidal Salmonella and Salmonella strains with conjugative antimicrobial-resistant serovars contaminating animal feed in Texas

USDA-ARS?s Scientific Manuscript database

The objective of this study was to characterize 365 nontyphoidal Salmonella enterica isolates from animal feed. Among the 365 isolates, 78 serovars were identified. Twenty-four isolates (7.0%) were recovered from three of six medicated feed types. Three of these isolates derived from the medicate...

Salmonella Species' Persistence and Their High Level of Antimicrobial Resistance in Flooded Man-Made Rivers in China.

PubMed

Song, Qifa; Zhang, Danyang; Gao, Hong; Wu, Junhua

2018-05-11

Man-made rivers, owing to proximity to human habitats, facilitate transmission of salmonellosis to humans. To determine the contamination situation by Salmonella in flooded man-made rivers and thereafter the exposure risk to public health, we investigated the prevalence of Salmonella species and their antimicrobial resistance in such rivers, as well as the relationship between the incidence of local infectious diarrhea cases and the number of Salmonella isolates from patients. After a heavy flood, 95 isolates of 13 Salmonella serotypes were isolated from 80 river water samples. The two most prevalent serotypes were Typhimurium and Derby. Eight Salmonella serotypes were newly detected after the flood. Overall, 50 isolates were resistant to ampicillin and/or cefotaxime and carried at least bla TEM . Twelve isolates of serotypes Typhimurium, Derby, Rissen, and Indiana were extended-spectrum β-lactamase (ESBL) producing and carried at least one of bla OXA and bla CTX-M-like genes. Twelve isolates of serotypes Typhimurium, Derby, Agona, Rissen, and Indiana were resistant to ciprofloxacin and had gyrA mutations. Isolates of Typhimurium, Derby, and Indiana were concurrently ciprofloxacin resistant and ESBL producing. Pulsed-field gel electrophoresis illustrates the circulation of two dominant clones of Salmonella Typhimurium isolates among patients, river, and food. High prevalence of various highly pathogenic and antimicrobial-resistant Salmonella serotypes shows that man-made rivers are prone to heavy contamination with Salmonella, and as a result put public health at greater risk.

Survival of Salmonella enterica serovar infantis on and within stored table eggs.

PubMed

Lublin, Avishai; Maler, Ilana; Mechani, Sara; Pinto, Riky; Sela-Saldinger, Shlomo

2015-02-01

Contaminated table eggs are considered a primary source of foodborne salmonellosis globally. Recently, a single clone of Salmonella enterica serovar Infantis emerged in Israel and became the predominant serovar isolated in poultry. This clone is currently the most prevalent strain in poultry and is the leading cause of salmonellosis in humans. Because little is known regarding the potential transmission of this strain from contaminated eggs to humans, the objective of this study was to evaluate the ability of Salmonella Infantis to survive on the eggshell or within the egg during cold storage or at room temperature. Salmonella cells (5.7 log CFU per egg) were inoculated on the surface of 120 intact eggs or injected into the egg yolk (3.7 log CFU per egg) of another 120 eggs. Half of the eggs were stored at 5.5 ± 0.3°C and half at room temperature (25.5 ± 0.1°C) for up to 10 weeks. At both temperatures, the number of Salmonella cells on the shell declined by 2 log up to 4 weeks and remained constant thereafter. Yolk-inoculated Salmonella counts at cold storage declined by 1 log up to 4 weeks and remained constant, while room-temperature storage supported the growth of the pathogen to a level of 8 log CFU/ml of total egg content, as early as 4 weeks postinoculation. Examination of egg content following surface inoculation revealed the presence of Salmonella in a portion of the eggs at both temperatures up to 10 weeks, suggesting that this strain can also penetrate through the shell and survive within the egg. These findings imply that Salmonella enterica serovar Infantis is capable of survival both on the exterior and interior of table eggs and even multiply inside the egg at room temperature. Our findings support the need for prompt refrigeration to prevent Salmonella multiplication during storage of eggs at room temperature.

Antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. isolated from chicken samples.

PubMed

Er, Buket; Demirhan, Burak; Onurdag, Fatma Kaynak; Ozgacar, Selda Özgen; Oktem, Aysel Bayhan

2014-03-01

Salmonella spp. are widespread foodborne pathogens that contaminate egg and poultry meats. Attachment, colonization, as well as biofilm formation capacity of Salmonella spp. on food and contact surfaces of food may cause continuous contamination. Biofilm may play a crucial role in the survival of salmonellae under unfavorable environmental conditions, such as in animal slaughterhouses and processing plants. This could serve as a reservoir compromising food safety and human health. Addition of antimicrobial preservatives extends shelf lives of food products, but even when products are supplemented with adequate amounts of preservatives, it is not always possible to inhibit the microorganisms in a biofilm community. In this study, our aims were i) to determine the minimum inhibitory concentrations (MIC) and minimum biofilm inhibitory concentrations (MBIC) of selected preservatives against planktonic and biofilm forms of Salmonella spp. isolated from chicken samples and Salmonella Typhimurium SL1344 standard strain, ii) to show the differences in the susceptibility patterns of same strains versus the planktonic and biofilm forms to the same preservative agent, and iii) to determine and compare antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. For this purpose, Salmonella Typhimurium SL1344 standard strain and 4 Salmonella spp. strains isolated from chicken samples were used. Investigation of antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. was done according to Clinical and Laboratory Standards Institute M100-S18 guidelines and BioTimer assay, respectively. As preservative agents, pure ciprofloxacin, sodium nitrite, potassium sorbate, sodium benzoate, methyl paraben, and propyl paraben were selected. As a result, it was determined that MBIC values are greater than the MIC values of the preservatives. This result verified the resistance seen in a biofilm community to food

Occurrence of antimicrobial-resistant salmonella species in raw and ready to eat turkey meat products from retail outlets in the midwestern United States.

PubMed

Khaitsa, Margaret L; Kegode, Redempta B; Doetkott, Dawn K

2007-01-01

To investigate occurrence of Salmonella in raw and ready to eat (RTE) turkey from retail outlets, determine factors associated with its occurrence and antimicrobial-resistance patterns. A total of 959 turkey products (raw, n = 345; and RTE, n = 614) were purchased in 3 months from four stores in one city in the midwestern United States. Chi-square and logistic regression analyses were used to test for associations of microbial contamination with product type and brand, expiration date, sampling time, and retail store. Antimicrobial resistance of Salmonellae was determined using a National Antimicrobial Resistance Monitoring System (NARMS) panel of antimicrobials. Overall, 2.2% (21/959) of the samples (4.1% [14/345] raw and 1.1% [7/614] RTE) were contaminated with Salmonella. A significant difference in Salmonella occurrence (p < 0.05), between meat type (raw vs. RTE; OR = 4.2, 95% CI = 1.6, 10.8); and sampling month (p < 0.05) was reported, but not between retail stores and product brands. Salmonellae belonged to 6 serotypes: Hadar, Heidelberg, Typhimurium var. Copenhagen, Newport, Saintpaul, and Agona. Salmonellae from raw turkey exhibited higher antimicrobial resistance (53%) compared to those from RTE products (33%). Multidrug resistance was exhibited by 62% of Salmonellae (86% RTE, 50% raw meats). CONCLUSION AND CLINICAL APPLICATIONS: Turkey (both raw and RTE) may occasionally be contaminated with antimicrobial-resistant Salmonellae whose occurrence was influenced by sampling month and meat type. Continued surveillance of Salmonella occurrence in meat products, in particular RTE ones, is warranted in order to ensure a safe food supply.

Monitoring Salmonella, Campylobacter, Escherichia coli and Staphylococcus aureus in traditional free-range 'Label Rouge' broiler production: a 23-year survey programme.

PubMed

Salvat, G; Guyot, M; Protino, J

2017-01-01

'Label Rouge' broiler free-range carcasses have been monitored since 1991, and broiler flocks since 2010, for contamination by the main foodborne zoonotic bacteria. Initially, the monitoring plan mainly focused on the surveillance of Salmonella, and on indicators of the overall microbiological quality of free-range broiler carcasses such as Staphylococcus aureus and coliforms, but was extended in 2007 to include Campylobacter enumeration on carcasses and in 2010, to Salmonella in the environment of live birds. Salmonella contamination of free-range broiler carcasses rose to a peak of 16% in 1994 but less than 1% of carcasses are now regularly found to be positive. Indicators of the overall microbiological quality of carcasses are also improving. These results correlate with the low prevalence of Salmonella in free-range broiler breeding and production flocks, and with the continuous improvement of hazard analysis and critical control points in slaughterhouses, the implementation of a good manufacturing practice guide since 1997 and the application of EU regulations on Salmonella since 1998 in France. Regarding Campylobacter counts on carcasses, the situation has been improving continuously over the last few years, even if 2·5% of the carcasses are still contaminated by more than 1000 Campylobacter per g of skin. Although the current control system focusing on Salmonella is based on firm epidemiologic data and offers effective means of control (e.g. slaughtering of positive breeder flocks), existing information on Campylobacter makes it more difficult to formulate an effective control plan for free-range broilers, due to their particular exposure to environmental contamination. This long-term surveillance programme provided an extended view of the evolution of the contamination of free-range broilers and a direct measurement of the impact of mandatory and profession-driven interventions on the microbiological quality of carcasses. © 2016 The Society for Applied

Survivability of Salmonella cells in popcorn after microwave oven and conventional cooking.

PubMed

Anaya, I; Aguirrezabal, A; Ventura, M; Comellas, L; Agut, M

2008-01-01

The survivability of Salmonella cells in popcorn preparation was determined for two distinct cooking methods. The first method used a standard microwave oven. The second method used conventional cooking in a pan. Prior to thermal processing in independent experiments, 12 suspensions in a range between 1x10(3) and 8x10(6) colony-forming units (CFU) per gram of Salmonella cells were inoculated in both raw microwave popcorn and conventional corn kernels. The influence of the initial concentration of Salmonella cells in the raw products and the lethal effects on Salmonella by thermal treatments for cooking were studied. Survival of Salmonella cells was determined in the thermally processed material by pre-enrichment and enrichment in selective medium, in accordance with the legislation for expanded cereals and cereals in flakes. Viable experimental contaminants were recovered from the conventionally cooked popcorn with initial inoculation concentrations of 9x10(4)cells/g or greater. Salmonella cell viability was significantly reduced after microwave oven treatment, with recoveries only from initial concentrations of 2x10(6)cells/g or superior.

[Little epidemic caused by Salmonella panama (author's transl)].

PubMed

Kienitz, M; Licht, W; Richter, M

1977-05-06

Between 8. 1. 1976 and 10. 8. 1976 16 new or premature born children got a gastroenteritis due to salmonella panama. All these children were together in one pediatric ward of the hospital. Most of them came directly for the labour ward or from the newborn-ward. They had antibiotic therapy due to the indication of the mother or the child. It was impossible to fine the source of the salmonella infection, therefore, finally the ward was closed. After radical desinfection new patients came to the ward. Again they were infected with salmonella panama. Now it became clear that contaminated milk (Humanan-Heilnahrung) was the source of infections. Most papers mention a mild benign course of the infections. In contrary we could see severe conditions dependent on the pre-damage of the child or his reduced immunity. The minimal number of germs of dietic food products needs to be examinated.

The Salmonella transcriptome in lettuce and cilantro soft rot reveals a niche overlap with the animal host intestine

USDA-ARS?s Scientific Manuscript database

Fresh vegetables have been recurrently associated with salmonellosis outbreaks and Salmonella contamination of retail produce has been correlated positively with the presence of soft rot disease. We observed that Salmonella enterica Typhimurium SL1344 grows to 50-fold greater populations in the pres...

Bacteriological evaluation of a new air turbine handpiece for preventing cross-contamination in dental procedures.

PubMed

Masuda, K; Ohta, M; Ohsuka, S; Matsuyama, M; Ashoori, M; Usami, T; Ito, M; Ueda, M; Kaneda, T

1994-03-01

An autoclavable air turbine handpiece, Air Flushing Clean System (AFCS) (Osada Electric Co., Ltd., Tokyo, Japan) was developed for use in dentistry with the objective of reducing cross-contamination. Its potential for bacterial contamination was investigated in vitro using two bacterial strains (Streptococcus mutants ATCC 25175 and Staphylococcus aureus FDA 209 P). In theory, this device should prevent cross-contamination of the internal water and air lines of the handpiece, by maintaining an internal positive pressure even after the turbine is stopped. In the present study, this AFCS device was found to reduce the bacterial contamination within the air turbine handpiece more effectively than the conventional handpiece used according to accepted protocol. The reduction of such contamination by the AFCS is in keeping with the recent objective of the American Dental Association to reduce cross-contamination during dental procedures.

Global Screening of Salmonella enterica Serovar Typhimurium Genes for Desiccation Survival

PubMed Central

Mandal, Rabindra K.; Kwon, Young M.

2017-01-01

Salmonella spp., one of the most common foodborne bacterial pathogens, has the ability to survive under desiccation conditions in foods and food processing facilities for years. This raises the concerns of Salmonella infection in humans associated with low water activity foods. Salmonella responds to desiccation stress via complex pathways involving immediate physiological actions as well as coordinated genetic responses. However, the exact mechanisms of Salmonella to resist desiccation stress remain to be fully elucidated. In this study, we screened a genome-saturating transposon (Tn5) library of Salmonella Typhimurium (S. Typhimurium) 14028s under the in vitro desiccation stress using transposon sequencing (Tn-seq). We identified 61 genes and 6 intergenic regions required to overcome desiccation stress. Salmonella desiccation resistance genes were mostly related to energy production and conversion; cell wall/membrane/envelope biogenesis; inorganic ion transport and metabolism; regulation of biological process; DNA metabolic process; ABC transporters; and two component system. More than 20% of the Salmonella desiccation resistance genes encode either putative or hypothetical proteins. Phenotypic evaluation of 12 single gene knockout mutants showed 3 mutants (atpH, atpG, and corA) had significantly (p < 0.02) reduced survival as compared to the wild type during desiccation survival. Thus, our study provided new insights into the molecular mechanisms utilized by Salmonella for survival against desiccation stress. The findings might be further exploited to develop effective control strategies against Salmonella contamination in low water activity foods and food processing facilities. PMID:28943871

Research note: Molecular subtyping of Salmonella enterica serovar Tshiongwe recently isolated in Malaysia during 2001-2002.

PubMed

Thong, Kwai Lin; Bakeri, Shamsilawani Ahmad; Lai, Kin Seng; Koh, Yin Tee; Taib, Mohd Zainuldin; Lim, V K E; Yasin, Rohani Md

2004-03-01

Pulsed field gel electrophoresis (PFGE) and antimicrobial susceptibility analysis were undertaken on twenty-three strains of Salmonella enterica serovar Tshiongwe, an unusual serovar, which recently emerged in Malaysia. Antimicrobial susceptibility analysis showed that all the strains were sensitive to ampicilin, chloramphenicol, cotrimoxazole, and kanamycin. Twenty (87%) and 8 (3.5%) strains had resistance to tetracycline and streptomycin respectively. PFGE analysis subtyped 23 strains into 10 profiles (Dice coefficient of similarity, F = 0.7-1.0). The predominant profile, X1 was found in both clinical and environmental isolates and was widely distributed in different parts of Malaysia during the study period. In addition, isolates recovered from food, a hand-towel, apron and the surface of a table-top in one particular location had unique, indistinguishable profiles (X4/4a) and identical antibiograms. Similarly, isolates from cooked meat and a chopping board had PFGE profiles similar to some human isolates. These probably indicated cross-contamination and poor hygiene in food practices, hence contributing to Salmonellosis. Factors causing the emergence of this rare Salmonella serovar being responsible for food poisoning episodes during the study period remained unclear. The study reiterated the usefulness and versatility of PFGE in the molecular subtyping of this rare Salmonella serovar in Malaysia.

Simulation of cross-contamination and decontamination of Campylobacter jejuni during handling of contaminated raw vegetables in a domestic kitchen.

PubMed

Chai, Lay-Ching; Lee, Hai-Yen; Ghazali, Farinazleen Mohd; Abu Bakar, Fatimah; Malakar, Pradeep Kumar; Nishibuchi, Mitsuaki; Nakaguchi, Yoshitsugu; Radu, Son

2008-12-01

Campylobacter jejuni was found to occur at high prevalence in the raw salad vegetables examined. Previous reports describe cross-contamination involving meat; here we investigated the occurrence of cross-contamination and decontamination events in the domestic kitchen via C. jejuni-contaminated vegetables during salad preparation. This is the first report concerning quantitative cross-contamination and decontamination involving naturally contaminated produce. The study was designed to simulate the real preparation of salad in a household kitchen, starting with washing the vegetables in tap water, then cutting the vegetables on a cutting board, followed by slicing cucumber and blanching (heating in hot water) the vegetables in 85 degrees C water. Vegetables naturally contaminated with C. jejuni were used throughout the simulation to attain realistic quantitative data. The mean of the percent transfer rates for C. jejuni from vegetable to wash water was 30.1 to 38.2%; from wash water to cucumber, it was 26.3 to 47.2%; from vegetables to cutting board, it was 1.6 to 10.3%; and from cutting board to cucumber, it was 22.6 to 73.3%. The data suggest the wash water and plastic cutting board as potential risk factors in C. jejuni transmission to consumers. Washing of the vegetables with tap water caused a 0.4-log reduction of C. jejuni attached to the vegetables (most probable number/gram), while rapid blanching reduced the number of C. jejuni organisms to an undetectable level.

Microbial Contamination Level Profiles Attributed to Contamination of Beef Carcasses, Personnel, and Equipment: Case of Small and Medium Enterprise Slaughterhouses.

PubMed

Wambui, Joseph; Lamuka, Peter; Karuri, Edward; Matofari, Joseph; Njage, Patrick Murigu Kamau

2018-04-01

The microbial contamination level profiles (MCLPs) attributed to contamination of beef carcasses, personnel, and equipment in five Kenyan small and medium enterprise slaughterhouses were determined. Aerobic plate counts, Enterobacteriaceae, Staphylococcus, and Salmonella were used to determine contamination at four different slaughter stages, namely, dehiding, evisceration, splitting, and dispatch. Microbiological criteria of the four microorganisms were used to score contamination levels (CLs) as poor (0), poor to average (1), average (2), or good (3). MCLPs were further assigned to carcasses, personnel, and equipment at each stage by summing up the CL scores. The CL score attributed to aerobic plate count contamination was 2 or 3 for carcasses but 0 for personnel and equipment in almost all slaughterhouses. A score of 0 on carcasses was mostly attributed to Enterobacteriaceae at evisceration and to Salmonella at dehiding and evisceration. In addition, a score of 0 was mostly attributed to Staphylococcus contamination of personnel at dehiding. A score of 3 was attributed mostly to Enterobacteriaceae on hands at splitting, whereas a score of 2 was mostly attributed to the clothes at dehiding and evisceration. A CL score of 3 was mostly attributed to Enterobacteriaceae and Salmonella contamination of equipment at dehiding and splitting, respectively. Although CLs attributed to contamination of carcasses, personnel, and equipment ranged from 0 to 3, the maximum MCLP score of 9 was only attained in carcasses from two slaughterhouses at dehiding and from one slaughterhouse at dispatch. There is, therefore, a lot of room for small and medium enterprise slaughterhouses to improve their food safety objectives by improving food safety management systems at the points characterized by low CL scores.

Prevalence of Salmonella among waterfowl along the Texas Gulf coast.

PubMed

Grigar, M K; Cummings, K J; Rankin, S C

2017-12-01

Migratory waterfowl may play a role in the ecology and transmission of zoonotic pathogens, given their ability to travel long distances and their use of varied habitats. Our objectives were to estimate the prevalence of Salmonella among waterfowl along the Texas Gulf coast and to characterize the isolates. Faecal samples were collected from hunter-harvested waterfowl at four wildlife management areas from September through November, 2016. Standard bacteriologic culture methods were used to isolate Salmonella from samples, and isolates were characterized by serotyping and anti-microbial susceptibility testing. The apparent prevalence of faecal Salmonella shedding was 0.5% (2/375). Serotypes identified were Thompson and Braenderup, and both isolates were susceptible to all anti-microbial agents tested. Although faecal contamination of agricultural fields or surface waters could serve as a potential source of zoonotic Salmonella transmission, waterfowl along the Gulf coast during the fall hunting season appear to pose minimal risk. © 2017 Blackwell Verlag GmbH.

Characterization of Salmonella food isolates with concurrent resistance to ceftriaxone and ciprofloxacin.

PubMed

Wong, Marcus Ho Yin; Zeng, Li; Liu, Jian Hua; Chen, Sheng

2013-01-01

Foodborne salmonellosis is an important public health problem worldwide. Most human Salmonella infections occur through the consumption of contaminated food of animal origin. The study reported the first isolation of two Salmonella enterica serovar Oranienburg strains from pork in China with concurrent resistance to ciprofloxacin and ceftriaxone. Both isolates also showed resistance to norfloxacin, trimethoprim-sulfamethoxazole, and chloramphenicol, and an elevated minimal inhibitory concentraton of azithromycin; one strain was also resistant to amikacin, gentamicin, tetracycline, and amoxicillin-clavulanic acid. Salmonella ceftriaxone resistance was due to the production of IncN plasmidborne CTX-M-14 ESBL, and their ciprofloxacin resistance was mediated by target mutations and efflux pump activity. This is the first time that ceftriaxone- and ciprofloxacin-resistant Salmonella was reported in meat products, which may be due to the uses of antibiotics in animal production. The study warrants the continuous surveillance of multidrug-resistant Salmonella in meat products and cautious use of antibiotics in food animals.

Incidence, Antimicrobial Resistance, and Molecular Characteristics of Nontyphoidal Salmonella Including Extended-Spectrum β-Lactamase Producers in Retail Chicken Meat.

PubMed

Choi, Dasom; Chon, Jung-Whan; Kim, Hong-Seok; Kim, Dong-Hyeon; Lim, Jong-Soo; Yim, Jin-Hyeok; Seo, Kun-Ho

2015-11-01

The present study was undertaken to determine the prevalence of Salmonella in 100 chicken carcass samples from five integrated broiler operation brands in Korea. Serotypes, antibiotic resistance patterns, extended-spectrum β-lactamase (ESBL) genotype, and clonal divergence using multilocus sequence typing of the isolated strains were analyzed. A total of 42 chicken samples were contaminated with nontyphoidal Salmonella (NTS) isolates: 16 isolates (38%) were Salmonella Virchow, 9 (21%) were Salmonella Bareilly, and 8 (19%) were Salmonella Infantis. A multidrug resistance (MDR; resistant to more than three classes of antibiotics) phenotype was observed in 29% of the isolates, which were resistant to five or more classes of antibiotics. The dominant MDR type was resistance to classes of penicillin, cephalosporins, aminoglycosides, quinolones, and tetracyclines. All the MDR isolates were positive for ESBL producers, and all but one (with the CTX-M-1 genotype) had the CTX-M-15 genotype. Multilocus sequence typing of the isolates revealed ST16 as the dominant sequence type; Salmonella Virchow, Salmonella Infantis, and Salmonella Richmond were all ST16, indicating a close genetic relationship between these serovars. This is the first study in Korea showing the CTX-M-1 type of NTS and the prevalence of ESBL-producing strains among NTS isolated from retail chicken meat. Our findings suggest that MDR Salmonella contamination is widely prevalent in retail chicken meat, and consumption of inadequately cooked products could lead to dissemination of NTS, which is hazardous to human health.

Microbial cross-contamination by airborne dispersion and contagion during defeathering of poultry.

PubMed

Allen, V M; Hinton, M H; Tinker, D B; Gibson, C; Mead, G C; Wathes, C M

2003-09-01

1. A readily identifiable strain of Escherichia coli K12 was used as a 'marker' organism to determine the sources, routes and patterns of microbial cross-contamination during mechanical defeathering of broiler chicken carcases. 2. Inoculation of scald water with the marker organism led to a relatively even pattern of carcase contamination during subsequent defeathering. Microbial cross-contamination was greater by this route of inoculation than by either surface inoculation of a 'seeder' carcase or oral inoculation of a live bird one day before slaughter. 3. Dispersal of the marker organism was strongly influenced by the mechanical action of the defeathering machines. Forward transmission of the marker occurred by aerosol or large airborne droplets and particulates such as feathers. Moving carcases through the defeathering machines when these were non-operational clearly reduced backward transmission of the marker. 4. Although microbial dispersal was unaffected by increasing the spacing between individual carcases or installing a water curtain at the entry and exit of the defeathering machines, shielding of carcases with aluminium baffles reduced counts of the marker organism from contaminated carcases by > 90%. 5. The results imply that microbial cross-contamination of broiler chicken carcases during defeathering occurs mainly via the airborne route, which could be contained by physical means.

Survival of Salmonella spp. and fecal indicator bacteria in Vietnamese biogas digesters receiving pig slurry.

PubMed

Huong, Luu Quynh; Forslund, Anita; Madsen, Henry; Dalsgaard, Anders

2014-09-01

Small-scale biogas digesters are widely promoted worldwide as a sustainable technology to manage livestock manure. In Vietnam, pig slurry is commonly applied to biogas digesters for production of gas for electricity and cooking with the effluent being used to fertilize field crops, vegetables and fish ponds. Slurry may contain a variety of zoonotic pathogens, e.g. Salmonella spp., which are able to cause disease in humans either through direct contact with slurry or by fecal contamination of water and foods. The objective of this study was to evaluate the survival of Salmonella spp. and the fecal indicator bacteria, enterococci, E. coli, and spores of Clostridium perfringens in biogas digesters operated by small-scale Vietnamese pig farmers. The serovar and antimicrobial susceptibility of the Salmonella spp. isolated were also established. The study was conducted in 12 farms (6 farms with and 6 farms without toilet connected) located in Hanam province, Vietnam. Sampling of pig slurry and biogas effluent was done during two seasons. Results showed that the concentration of enterococci, E. coli, and Clostridium perfringens spores was overall reduced by only 1-2 log10-units in the biogas digesters when comparing raw slurry and biogas effluent. Salmonella spp. was found in both raw slurry and biogas effluent. A total of 19 Salmonella serovars were identified, with the main serovars being Salmonella Typhimurium (55/138), Salmonella enterica serovar 4,[5],12:i:- (19/138), Salmonella Weltevreden (9/138) and Salmonella Rissen (9/138). The Salmonella serovars showed similar antimicrobial resistance patterns to those previously reported from Vietnam. When promoting biogas, farmers should be made aware that effluent should only be used as fertilizer for crops not consumed raw and that indiscriminate discharge of effluent are likely to contaminate water recipients, e.g. drinking water sources, with pathogens. Relevant authorities should promote safe animal manure management

Microbiological contamination in peanut confectionery processing plants.

PubMed

Carminati, J de A; Amorim Neto, D P; Morishita, K N; Takano, L V; Olivier Bernardi, A; Copetti, M V; do Nascimento, M da S

2016-10-01

In order to investigate Enterobacteriaceae, coliforms, Escherichia coli and Salmonella contamination, a survey was conducted at three peanut confectionery processing companies (A, B and C) in Brazil. Samples of different peanut confectionery products (n = 59), peanut raw material (n = 30), manufacturing environment (n = 116) and workers' hand surfaces (n = 12) were analysed. Salmonella and E. coli were not detected in any final product or raw material analysed. Enterobacteriaceae was isolated from 15% of final products. Coliforms were detected in only one sample. Referring to the raw material, six samples showed contamination by Enterobacteriaceae and three samples by coliforms. For the process environment, 19% and 11% of samples presented Enterobacteriaceae and coliforms. Escherichia coli was detected in 5% of samples, and one of these samples tested positive for Salmonella; this strain was serotyping as S. Heidelberg. All food handlers surveyed in Company C showed Enterobacteriaceae and coliforms on their hands. Escherichia coli was isolated from one food worker's hand. The results showed that the manufacturing environment, including food handlers were considered the main sources for possible contamination of peanut confectionery products. This has been the first study to investigate the occurrence of Salmonella and other Enterobacteriaceae throughout peanut confectionery processing lines. The results might be used to assist risk assessment studies and to establish more effective control measures. © 2016 The Society for Applied Microbiology.

Preliminary assessment of the risk of Salmonella infection in dogs fed raw chicken diets.

PubMed

Joffe, Daniel J; Schlesinger, Daniel P

2002-06-01

This preliminary study assessed the presence of Salmonella spp. in a bones and raw food (BARF) diet and in the stools of dogs consuming it. Salmonella was isolated from 80% of the BARF diet samples (P < 0.001) and from 30% of the stool samples from dogs fed the diet (P = 0.105). Dogs fed raw chicken may therefore be a source of environmental contamination.

Preliminary assessment of the risk of Salmonella infection in dogs fed raw chicken diets

PubMed Central

Joffe, Daniel J.; Schlesinger, Daniel P.

2002-01-01

This preliminary study assessed the presence of Salmonella spp. in a bones and raw food (BARF) diet and in the stools of dogs consuming it. Salmonella was isolated from 80% of the BARF diet samples (P < 0.001) and from 30% of the stool samples from dogs fed the diet (P = 0.105). Dogs fed raw chicken may therefore be a source of environmental contamination. PMID:12058569

Estimation of the Rate of Unrecognized Cross-Contamination with Mycobacterium tuberculosis in London Microbiology Laboratories

PubMed Central

Ruddy, M.; McHugh, T. D.; Dale, J. W.; Banerjee, D.; Maguire, H.; Wilson, P.; Drobniewski, F.; Butcher, P.; Gillespie, S. H.

2002-01-01

Isolates from patients with confirmed tuberculosis from London were collected over 2.5 years between 1995 and 1997. Restriction fragment length polymorphism (RFLP) analysis was performed by the international standard technique as part of a multicenter epidemiological study. A total of 2,779 samples representing 2,500 individual patients from 56 laboratories were examined. Analysis of these samples revealed a laboratory cross-contamination rate of between 0.54%, when only presumed cases of cross-contamination were considered, and 0.93%, when presumed and possible cases were counted. Previous studies suggest an extremely wide range of laboratory cross-contamination rates of between 0.1 and 65%. These data indicate that laboratory cross-contamination has not been a common problem in routine practice in the London area, but in several incidents patients did receive full courses of therapy that were probably unnecessary. PMID:12409381

Salmonella Inactivation During Extrusion of an Oat Flour Model Food.

PubMed

Anderson, Nathan M; Keller, Susanne E; Mishra, Niharika; Pickens, Shannon; Gradl, Dana; Hartter, Tim; Rokey, Galen; Dohl, Christopher; Plattner, Brian; Chirtel, Stuart; Grasso-Kelley, Elizabeth M

2017-03-01

Little research exists on Salmonella inactivation during extrusion processing, yet many outbreaks associated with low water activity foods since 2006 were linked to extruded foods. The aim of this research was to study Salmonella inactivation during extrusion of a model cereal product. Oat flour was inoculated with Salmonella enterica serovar Agona, an outbreak strain isolated from puffed cereals, and processed using a single-screw extruder at a feed rate of 75 kg/h and a screw speed of 500 rpm. Extrudate samples were collected from the barrel outlet in sterile bags and immediately cooled in an ice-water bath. Populations were determined using standard plate count methods or a modified most probable number when populations were low. Reductions in population were determined and analyzed using a general linear model. The regression model obtained for the response surface tested was Log (N R /N O ) = 20.50 + 0.82T - 141.16a w - 0.0039T 2 + 87.91a w 2 (R 2 = 0.69). The model showed significant (p < 0.05) linear and quadratic effects of a w and temperature and enabled an assessment of critical control parameters. Reductions of 0.67 ± 0.14 to 7.34 ± 0.02 log CFU/g were observed over ranges of a w (0.72 to 0.96) and temperature (65 to 100 °C) tested. Processing conditions above 82 °C and 0.89 a w achieved on average greater than a 5-log reduction of Salmonella. Results indicate that extrusion is an effective means for reducing Salmonella as most processes commonly employed to produce cereals and other low water activity foods exceed these parameters. Thus, contamination of an extruded food product would most likely occur postprocessing as a result of environmental contamination or through the addition of coatings and flavorings. © 2017 Institute of Food Technologists®.

Evaluation of the association between feeding raw meat and Salmonella enterica infections at a Greyhound breeding facility.

PubMed

Morley, Paul S; Strohmeyer, Rachel A; Tankson, Jeanetta D; Hyatt, Doreene R; Dargatz, David A; Fedorka-Cray, Paula J

2006-05-15

To investigate Salmonella enterica infections at a Greyhound breeding facility. Cross-sectional study. ANIMAL AND SAMPLE POPULATIONS: 138 adult and juvenile dogs and S. enterica isolates recovered from the dogs and their environment. The investigation was conducted at the request of a Greyhound breeder. Observations regarding the environment and population of dogs were recorded. Fecal, food, and environmental specimens were collected and submitted for Salmonella culture. Isolates were serotyped and tested for susceptibility to 16 antimicrobials. Isolates underwent genetic analyses by use of pulsed-field gel electrophoresis and ribotyping. S. enterica was recovered from 88 of 133 (66%) samples of all types and from 57 of 61 (93%) fecal samples. Eighty-three (94.3%) of the isolates were serotype Newport, 77 (87.5%) of which had identical resistance phenotypes. Genetic evaluations suggested that several strains of S. enterica existed at the facility, but there was a high degree of relatedness among many of the Newport isolates. Multiple strains of Salmonella enterica serotype Newport were recovered from raw meat fed on 1 day. S. enterica infections and environmental contamination were common at this facility. A portion of the Salmonella strains detected on the premises was likely introduced via raw meat that was the primary dietary constituent. Some strains appeared to be widely disseminated in the population. Feeding meat that had not been cooked properly, particularly meat classified as unfit for human consumption, likely contributed to the infections in these dogs.

Generation and selection of anti-flagellin monoclonal antibodies useful for serotyping Salmonella enterica.

PubMed

Hiriart, Yanina; Serradell, Maria; Martínez, Araci; Sampaolesi, Sofia; Maciel, Dolores Gonzalez; Chabalgoity, Jose Alejandro; Yim, Lucía; Algorta, Gabriela; Rumbo, Martin

2013-01-01

In developing countries, bacterial acute gastroenteritis continues to be an important cause of morbidity and mortality among young children. Salmonellosis constitutes a major cause of infectious enteritis worldwide, most of them associated to the consumption of contaminated food products. Traditionally, Salmonella has been classified in serovars based on varieties of O and H surface antigens. In the present work we generated and characterized a panel of anti-flagellin monoclonal antibodies (MAbs) in order to select antibodies useful for detecting the H surface antigen. Four different MAbs were obtained by somatic hybridization of splenocytes. We found two MAbs that recognised regions of flagellin conserved among different Salmonella serovars. Other two MAbs recognised structures restricted to Salmonella enterica sv. Typhimurium, being one of them suitable for agglutination tests. Using a diverse panel of S. enterica serovars with different H antigen varieties we confirmed that this MAb agglutinates specifically S. Typhimurium (antigenic formula: 4,12:i:1,2) or other serovars expressing flagellar factor i. In conclusion, we generated a valuable immunochemical tool to be used in simple assays for serotyping of epidemiologically relevant strains. The capacity to characterize specific strains and determine the primary sources of Salmonella contamination generate valuable information of the epidemiology of this microorganism, contributing to the improvement of public health.

Dispersal of Salmonella Typhimurium by rain splash onto tomato plants.

PubMed

Cevallos-Cevallos, Juan M; Danyluk, Michelle D; Gu, Ganyu; Vallad, Gary E; van Bruggen, Ariena H C

2012-03-01

Outbreaks of Salmonella enterica have increasingly been associated with tomatoes and traced back to production areas, but the spread of Salmonella from a point source onto plants has not been described. Splash dispersal by rain could be one means of dissemination. Green fluorescent protein-labeled, kanamycin-resistant Salmonella enterica sv. Typhimurium dispensed on the surface of plastic mulch, organic mulch, or soil at 10⁸ CFU/cm² was used as the point source in the center of a rain simulator. Tomato plants in soil with and without plastic or organic mulch were placed around the point source, and rain intensities of 60 and 110 mm/h were applied for 5, 10, 20, and 30 min. Dispersal of Salmonella followed a negative exponential model with a half distance of 3 cm at 110 mm/h. Dispersed Salmonella survived for 3 days on tomato leaflets, with a total decline of 5 log and an initial decimal reduction time of 10 h. Recovery of dispersed Salmonella from plants at the maximum observed distance ranged from 3 CFU/g of leaflet after a rain episode of 110 mm/h for 10 min on soil to 117 CFU/g of leaflet on plastic mulch. Dispersal of Salmonella on plants with and without mulch was significantly enhanced by increasing rain duration from 0 to 10 min, but dispersal was reduced when rainfall duration increased from 10 to 30 min. Salmonella may be dispersed by rain to contaminate tomato plants in the field, especially during rain events of 10 min and when plastic mulch is used.

Influence of Environmental Factors and Human Activity on the Presence of Salmonella Serovars in a Marine Environment

PubMed Central

Martinez-Urtaza, Jaime; Saco, Montserrat; de Novoa, Jacobo; Perez-Piñeiro, Pelayo; Peiteado, Jesus; Lozano-Leon, Antonio; Garcia-Martin, Oscar

2004-01-01

The temporal and spatial distribution of Salmonella contamination in the coastal waters of Galicia (northwestern Spain) relative to contamination events with different environmental factors (temperature, wind, hours of sunlight, rainfall, and river flow) were investigated over a 4-year period. Salmonellae were isolated from 127 of 5,384 samples of molluscs and seawater (2.4%), and no significant differences (P < 0.05) between isolates obtained in different years were observed. The incidence of salmonellae was significantly higher in water column samples (2.9%) than in those taken from the marine benthos (0.7%). Of the 127 strains of Salmonella isolated, 20 different serovars were identified. Salmonella enterica serovar Senftenberg was the predominant serovar, being represented by 54 isolates (42.5%), followed by serovar Typhimurium (19 isolates [15%]) and serovar Agona (12 isolates [9.4%]). Serovar Senftenberg was detected at specific points on the coast and could not be related to any of the environmental parameters analyzed. All serovars except Salmonella serovar Senftenberg were found principally in the southern coastal areas close to the mouths of rivers, and their incidence was associated with high southwestern wind and rainfall. Using multiple logistic regression analysis models, the prevalence of salmonellae was best explained by environmental parameters on the day prior to sampling. Understanding this relationship may be useful for the control of molluscan shellfish harvests, with wind and rainfall serving as triggers for closure. PMID:15066800

Diversity of Antimicrobial Resistance Phenotypes in Salmonella Isolated from Commercial Poultry Farms.

PubMed

Liljebjelke, Karen A; Hofacre, Charles L; White, David G; Ayers, Sherry; Lee, Margie D; Maurer, John J

2017-01-01

Salmonella remains the leading cause of foodborne illness in the United States, and the dissemination of drug-resistant Salmonellae through the food chain has important implications for treatment failure of salmonellosis. We investigated the ecology of Salmonella in integrated broiler production in order to understand the flow of antibiotic susceptible and resistant strains within this system. Data were analyzed from a retrospective study focused on antimicrobial resistant Salmonella recovered from commercial broiler chicken farms conducted during the initial years of the US FDA's foray into retail meat surveillance by the National Antimicrobial Resistance Monitoring System (NARMS). Sixty-three percentage of Salmonella were pan-susceptible to a panel of 19 antimicrobials used by the NARMS program. Twenty-five antimicrobial resistance phenotypes were observed in Salmonella isolated from two broiler chicken farms. However, Salmonella displaying resistance to streptomycin, alone, and in combination with other antibiotics was the most prevalent (36.3%) antimicrobial resistance phenotype observed. Resistance to streptomycin and sulfadimethoxine appeared to be linked to the transposon, Tn 21 . Combinations of resistance against streptomycin, gentamicin, sulfadimethoxine, trimethoprim, and tetracycline were observed for a variety of Salmonella enterica serovars and genetic types as defined by pulsed-field gel electrophoresis. There were within and between farm differences in the antibiotic susceptibilities of Salmonella and some of these differences were linked to specific serovars. However, farm differences were not linked to antibiotic usage. Analysis of the temporal and spatial distribution of the endemic Salmonella serovars on these farms suggests that preventing vertical transmission of antibiotic-resistant Salmonella would reduce carcass contamination with antibiotic-resistant Salmonella and subsequently human risk exposure.

Diversity of Antimicrobial Resistance Phenotypes in Salmonella Isolated from Commercial Poultry Farms

PubMed Central

Liljebjelke, Karen A.; Hofacre, Charles L.; White, David G.; Ayers, Sherry; Lee, Margie D.; Maurer, John J.

2017-01-01

Salmonella remains the leading cause of foodborne illness in the United States, and the dissemination of drug-resistant Salmonellae through the food chain has important implications for treatment failure of salmonellosis. We investigated the ecology of Salmonella in integrated broiler production in order to understand the flow of antibiotic susceptible and resistant strains within this system. Data were analyzed from a retrospective study focused on antimicrobial resistant Salmonella recovered from commercial broiler chicken farms conducted during the initial years of the US FDA’s foray into retail meat surveillance by the National Antimicrobial Resistance Monitoring System (NARMS). Sixty-three percentage of Salmonella were pan-susceptible to a panel of 19 antimicrobials used by the NARMS program. Twenty-five antimicrobial resistance phenotypes were observed in Salmonella isolated from two broiler chicken farms. However, Salmonella displaying resistance to streptomycin, alone, and in combination with other antibiotics was the most prevalent (36.3%) antimicrobial resistance phenotype observed. Resistance to streptomycin and sulfadimethoxine appeared to be linked to the transposon, Tn21. Combinations of resistance against streptomycin, gentamicin, sulfadimethoxine, trimethoprim, and tetracycline were observed for a variety of Salmonella enterica serovars and genetic types as defined by pulsed-field gel electrophoresis. There were within and between farm differences in the antibiotic susceptibilities of Salmonella and some of these differences were linked to specific serovars. However, farm differences were not linked to antibiotic usage. Analysis of the temporal and spatial distribution of the endemic Salmonella serovars on these farms suggests that preventing vertical transmission of antibiotic-resistant Salmonella would reduce carcass contamination with antibiotic-resistant Salmonella and subsequently human risk exposure. PMID:28691011

DNA hybridization assay for detection of Salmonella in foods: collaborative study.

PubMed

Flowers, R S; Klatt, M J; Mozola, M A; Curiale, M S; Gabis, D A; Silliker, J H

1987-01-01

A collaborative study was performed in 11 laboratories to validate a DNA hybridization (DNAH) procedure for detection of Salmonella in foods. The DNAH procedure was compared to the standard culture method for detection of Salmonella in 6 foods: ground pepper, soy flour, dry whole egg, milk chocolate, nonfat dry milk, and raw deboned turkey. With the exception of turkey which was naturally contaminated, uninoculated and inoculated samples of each food group were analyzed. Results for the DNAH method were significantly better than for the standard culture method at the 5% probability level for the detection of Salmonella in turkey. There was no significant difference between the methods for the other 5 foods. The method has been adopted official first action.

Cantaloupe facilitates transmission of Salmonella typhimurium between adult house flies

USDA-ARS?s Scientific Manuscript database

Salmonella enterica ser. Typhimurium (S. Typhimurium) is a pathogen harbored by livestock that can contaminate fresh produce, such as cantaloupe, and cause food-borne illnesses. We previously demonstrated that house flies acquire and harbor S. Typhimurium after exposure to inoculated cattle manure. ...

A genome-wide screen identifies Salmonella Enteritidis lipopolysaccharide biosynthesis and the HtrA heat shock protein as crucial factors involved in egg white persistence at chicken body temperature.

PubMed

Raspoet, R; Shearer, N; Appia-Ayme, C; Haesebrouck, F; Ducatelle, R; Thompson, A; Van Immerseel, F

2014-05-01

Eggs contaminated with Salmonella Enteritidis are an important source of human foodborne Salmonella infections. Salmonella Enteritidis is able to contaminate egg white during formation of the egg within the chicken oviduct, and it has developed strategies to withstand the antimicrobial properties of egg white to survive in this hostile environment. The mechanisms involved in the persistence of Salmonella Enteritidis in egg white are likely to be complex. To address this issue, a microarray-based transposon library screen was performed to identify genes necessary for survival of Salmonella Enteritidis in egg white at chicken body temperature. The majority of identified genes belonged to the lipopolysaccharide biosynthesis pathway. Additionally, we provide evidence that the serine protease/heat shock protein (HtrA) appears essential for the survival of Salmonella Enteritidis in egg white at chicken body temperature.

Virulence and antimicrobial resistance of Salmonella spp. and Escherichia coli in the beef jerky production line.

PubMed

Fernandes, Fernanda Pereira; Voloski, Flávia Liége Schütz; Ramires, Tassiana; Haubert, Louise; Reta, Giulia Giugliani; Mondadori, Rafael Gianella; Silva, Wladimir Padilha da; Conceição, Rita de Cássia Dos Santos da; Duval, Eduarda Hallal

2017-05-01

Intense manipulation during beef jerky production increases the possibility of contamination with pathogenic microorganisms. This study evaluated the contamination by thermotolerant coliforms, Escherichia coli and Salmonella spp., on processing surfaces and raw materials during beef jerky production, as well as in the final product. Thermotolerant coliforms were found on all surfaces tested and in the raw material. Escherichia coli was identified in 6.7% of the surface samples, while Salmonella spp. was found in 3.3% of the surface samples and 8.6% of raw material samples. Virulence genes were detected in Salmonella spp. isolates. One Salmonella spp. isolate was resistant to sulfonamide, while one E. coli isolate was multiresistant, including the presence of resistance genes sul2, strA, strB, tetA and tetB. The presence of coliforms demonstrates failings in hygienic-sanitary procedures. The presence of pathogenic microorganisms causing foodborne diseases in the production line indicates persistent contamination in the production plant. Although the drying process applied to beef jerky should guarantee the safety of the final product, the presence of multiresistant pathogenic microorganisms, presenting virulence genes, should be a matter of concern. Because beef jerky is a ready-to-eat product, a failure in the production process may cause such microorganisms to pose a public health risk. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effects of Pseudomonas chlororaphis and gaseous chlorine dioxide on the survival of Salmonella enterica on tomatoes

USDA-ARS?s Scientific Manuscript database

Produce contamination incited by Salmonella enterica serovars on tomatoes and various outbreaks of Salmonellisis have been reported periodically. Post-harvest intervention measures applied to limit produce contamination will improve food and consumer safety. The aim of this reserach was to evaluat...

Sampling naturally contaminated broiler carcasses for Salmonella by three different methods

USDA-ARS?s Scientific Manuscript database

Postchill neck skin (NS) maceration and whole carcass rinsing (WCR) are frequently used methods to detect salmonellae from commercially processed broilers. These are practical, nondestructive methods, but they are insensitive and may result in frequent false negatives (20 to 40%). NS samples only ...

Use of FTA Cards for the Transport of DNA Samples of Salmonella spp. from Poultry Products from Southern Brazil.

USDA-ARS?s Scientific Manuscript database

Background: The contamination of products with Salmonella is a major threat to the poultry industry because the possible transmission to humans and animals can produce a huge negative impact. The diversity of Salmonella enterica serotypes complicates the diagnostic systems and the transport of live ...

In vivo and in vitro evaluation of tissue colonization and survival capacity of Salmonella Oranienburg in laying hens

USDA-ARS?s Scientific Manuscript database

Salmonella Oranienburg (SO) was linked to a human salmonellosis outbreak in the Midwest in 2015 and 2016 from consumption of eggs. However, unlike Salmonella Enteritidis (SE), little is known regarding the potential of SO to colonize in laying hens and contaminate eggs. We used in vivo and in vitr...

Listeria monocytogenes cross-contamination of cheese: risk throughout the food supply chain.

PubMed

Sauders, B D; D'Amico, D J

2016-10-01

Listeria monocytogenes has been the most common microbial cause of cheese-related recalls in both the United States and Canada in recent years. Since L. monocytogenes is inactivated by pasteurization, the majority of these cases have been linked to environmental and cross-contamination of fresh-soft, soft-ripened, and semi-soft cheeses. Cross-contamination of foods with L. monocytogenes is a continuous risk throughout the food supply chain and presents unique challenges for subsequent illness and outbreak investigations. Reports on outbreaks of listeriosis attributed to cross-contamination downstream from primary processing help highlight the critical role of epidemiological investigation coupled with coordinated molecular subtyping and surveillance in the recognition and investigation of complex foodborne outbreaks. Despite their complexity, environmental sampling throughout the supply chain coupled with improved genotyping approaches and concomitant analysis of foodborne illness epidemiological exposure data are needed to help resolve these and similar cases more rapidly and with greater confidence.

In situ characterization and analysis of Salmonella biofilm formation under meat processing environments using a combined microscopic and spectroscopic approach.

PubMed

Wang, Huhu; Ding, Shijie; Wang, Guangyu; Xu, Xinglian; Zhou, Guanghong

2013-11-01

Salmonella biofilm on food-contact surfaces present on food processing facilities may serve as a source of cross-contamination. In our work, biofilm formation by multi-strains of meat-borne Salmonella incubated at 20 °C, as well as the composition and distribution of extracellular polymeric substances (EPS), were investigated in situ by combining confocal laser scanning microscopy (CLSM), scanning electron microscope (SEM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and Raman spectroscopy. A standard laboratory culture medium (tryptic soy broth, TSB) was used and compared with an actual meat substrate (meat thawing-loss broth, MTLB). The results indicated that Salmonella grown in both media were able to form biofilms on stainless steel surfaces via building a three-dimensional structure with multilayers of cells. Although the number of biofilm cells grown in MTLB was less than that in TSB, the cell numbers in MTLB was adequate to form a steady and mature biofilm. Salmonella grown in MTLB showed "cloud-shaped" morphology in the mature biofilm, whereas when grown in TSB appeared "reticular-shaped". The ATR-FTIR and Raman analysis revealed a completely different chemical composition between biofilms and the corresponding planktonic cells, and some important differences in biofilms grown in MTLB and in TSB. Importantly, our findings suggested that the progress towards a mature Salmonella biofilm on stainless steel surfaces may be associated with the production of the EPS matrix, mainly consisting of polysaccharides and proteins, which may serve as useful markers of biofilm formation. Our work indicated that a combination of these non-destructive techniques provided new insights into the formation of Salmonella biofilm matrix. © 2013.

Salmonella pollution in ground and surface waters. (Latest citations from Pollution abstracts). Published Search

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1993-04-01

The bibliography contains citations concerning the contamination of ground waters and surface waters by Salmonella bacteria. Articles discuss the occurence, survival, origin, and control of these bacteria in water sources including rivers, reservoirs, swimming pools, wastewater, aquifers, and ground water. Citations also address the use of Salmonella populations as biological indicators of pollution in aquatic systems. (Contains a minimum of 102 citations and includes a subject term index and title list.)

Prevalence of intestinal parasites, salmonella and shigella among apparently health food handlers of Addis Ababa University student's cafeteria, Addis Ababa, Ethiopia.

PubMed

Aklilu, Addis; Kahase, Daniel; Dessalegn, Mekonnen; Tarekegn, Negatu; Gebremichael, Saba; Zenebe, Seyfe; Desta, Kassu; Mulugeta, Gebru; Mamuye, Yeshiwodim; Mama, Mohammedaman

2015-01-24

Food contamination may occur at any point during its journey through production, processing, distribution, and preparation. The risk of food getting contaminated depends largely on the health status of the food handlers, their personal hygiene, knowledge and practice of food hygiene. Food borne diseases are a public health problem in developed and developing countries like Ethiopia. A cross sectional study was conducted among food handlers in Addis Ababa student's cafeteria from January to May 2013. Structured questionnaire was used to collect socio demographic data and associated risk factors. Stool specimens were examined for bacteria and intestinal parasites following standard procedures. Biochemical tests were done to identify the species of bacterial isolates. Sensitivity testing was done using Kirby- Baur disk diffusion method. A total of 172 food handlers were enrolled in the study. The majority of study participants were females 134 (77.9%). About 78 (45.3%) of food handlers were found to be positive for different intestinal parasites with the most abundant parasite of Entameoba histolytica/dispar 68 (70.8%) followed by Giardia lamblia 18 (18.8%), Taenia species 5 (5.2%), Ascaris lumbricoides 2 (2.1%), hookworm 2 (2.1%) and Trichuris trichiura 1 (1.1%). Stool cultures revealed 3.5% of Salmonella isolates (Sero-grouping on Salmonella isolate was not done), while Shigella species was not isolated from any of the stool samples obtained from Food handlers. All isolates of Salmonella were sensitive to ciprofloxacin, amikacin and gentamicin but resistant to ampicillin, clindamycin, and erythromycin. The present study revealed a high prevalence of intestinal parasite in asymptomatic (apparently health) food handlers. Such infected food handlers can contaminate food, drinks and could serve as source of infection to consumers via food chain.

The chain of cross-contamination: link-by-link.

PubMed

Schwartz, Jeanne

2002-01-01

Conscious efforts must be made to break the chain of cross-contamination--link-by-link. Pay attention to detail Avoid being careless Avoid touching objects while wearing soiled gloves Frequently wash hands (15-second hand washing) to remove pathogens--before and after gloving, and before handling food or drink Wear all PPE, and change accordingly.

Effect of oil and dry roasting of peanuts at various temperatures and times on survival of Salmonella and Enterococcus faecium

USDA-ARS?s Scientific Manuscript database

A number of outbreaks of salmonellosis since 2006 associated with the consumption of Salmonella-contaminated peanut butter have increased concerns about this food and the associated processing methods. Laboratory studies were conducted to determine the level of Salmonella reduction associated with o...

Presence and Persistence of Salmonella enterica Serotype Typhimurium in the Phyllosphere and Rhizosphere of Spray-Irrigated Parsley

PubMed Central

Kisluk, Guy

2012-01-01

Salmonella enterica is one of the major food-borne pathogens associated with ready-to-eat fresh foods. Although polluted water might be a significant source of contamination in the field, factors that influence the transfer of Salmonella from water to the crops are not well understood, especially under conditions of low pathogen levels in water. The aim of this study was to investigate the short- and long-term (1 h to 28 days) persistence of Salmonella enterica serotype Typhimurium in the phyllosphere and the rhizosphere of parsley following spray irrigation with contaminated water. Plate counting and quantitative real-time PCR (qRT-PCR)-based methods were implemented for the quantification. By applying qRT-PCR with enrichment, we were able to show that even irrigation with water containing as little as ∼300 CFU/ml resulted in the persistence of S. Typhimurium on the plants for 48 h. Irrigation with water containing 8.5 log CFU/ml resulted in persistence of the bacteria in the phyllosphere and the rhizosphere for at least 4 weeks, but the population steadily declined with a major reduction in bacterial counts, of ∼2 log CFU/g, during the first 2 days. Higher levels of Salmonella were detected in the phyllosphere when plants were irrigated during the night compared to irrigation during the morning and during winter compared to the other seasons. Further elucidation of the mechanisms underlying the transfer of Salmonella from contaminated water to crops, as well as its persistence over time, will enable the implementation of effective irrigation and control strategies. PMID:22447598

Presence and persistence of Salmonella enterica serotype typhimurium in the phyllosphere and rhizosphere of spray-irrigated parsley.

PubMed

Kisluk, Guy; Yaron, Sima

2012-06-01

Salmonella enterica is one of the major food-borne pathogens associated with ready-to-eat fresh foods. Although polluted water might be a significant source of contamination in the field, factors that influence the transfer of Salmonella from water to the crops are not well understood, especially under conditions of low pathogen levels in water. The aim of this study was to investigate the short- and long-term (1 h to 28 days) persistence of Salmonella enterica serotype Typhimurium in the phyllosphere and the rhizosphere of parsley following spray irrigation with contaminated water. Plate counting and quantitative real-time PCR (qRT-PCR)-based methods were implemented for the quantification. By applying qRT-PCR with enrichment, we were able to show that even irrigation with water containing as little as ∼300 CFU/ml resulted in the persistence of S. Typhimurium on the plants for 48 h. Irrigation with water containing 8.5 log CFU/ml resulted in persistence of the bacteria in the phyllosphere and the rhizosphere for at least 4 weeks, but the population steadily declined with a major reduction in bacterial counts, of ∼2 log CFU/g, during the first 2 days. Higher levels of Salmonella were detected in the phyllosphere when plants were irrigated during the night compared to irrigation during the morning and during winter compared to the other seasons. Further elucidation of the mechanisms underlying the transfer of Salmonella from contaminated water to crops, as well as its persistence over time, will enable the implementation of effective irrigation and control strategies.

Prevalence of Salmonella in Cashews, Hazelnuts, Macadamia Nuts, Pecans, Pine Nuts, and Walnuts in the United States.

PubMed

Zhang, Guodong; Hu, Lijun; Melka, David; Wang, Hua; Laasri, Anna; Brown, Eric W; Strain, Errol; Allard, Marc; Bunning, Vincent K; Musser, Steven M; Johnson, Rhoma; Santillana Farakos, Sofia; Scott, Virginia N; Pouillot, Régis; Doren, Jane M Van; Hammack, Thomas S

2017-03-01

Nuts have been identified as a vector for salmonellosis. The objective of this project was to estimate the prevalence and contamination level of Salmonella in raw tree nuts (cashews, pecans, hazelnuts, macadamia nuts, pine nuts, and walnuts) at retail markets in the United States. A total of 3,656 samples of six types of tree nuts were collected from different types of retail stores and markets nationwide between October 2014 and October 2015. These samples were analyzed using a modified version of the Salmonella culture method from the U.S. Food and Drug Administration's Bacteriological Analytical Manual. Of the 3,656 samples collected and tested, 32 were culturally confirmed as containing Salmonella. These isolates represented 25 serotypes. Salmonella was not detected in pecans and in-shell hazelnuts. Salmonella prevalence estimates (and 95% confidence intervals) in cashews, shelled hazelnuts, pine nuts, walnuts, and macadamia nuts were 0.55% [0.15, 1.40], 0.35% [0.04, 1.20], 0.48% [0.10, 1.40], 1.20% [0.53, 2.40], and 4.20% [2.40, 6.90], respectively. The rates of Salmonella isolation from major or big chain supermarkets, small chain supermarkets, discount, variety, or drug stores, and online were 0.64% [0.38, 1.00], 1.60% [0.80, 2.90], 0.00% [0.00, 2.40], and 13.64% [2.90, 35.00], respectively (Cochran-Mantel-Haenszel test: P = 0.02). The rates of Salmonella isolation for conventional and organic nuts were not significantly different. Of the samples containing Salmonella, 60.7% had levels less than 0.003 most probable number (MPN)/g. The highest contamination level observed was 0.092 MPN/g. The prevalence and levels of Salmonella in these tree nut samples were comparable to those previously reported for similar foods.

Applications of microscopy in Salmonella research.

PubMed

Malt, Layla M; Perrett, Charlotte A; Humphrey, Suzanne; Jepson, Mark A

2015-01-01

Salmonella enterica is a Gram-negative enteropathogen that can cause localized infections, typically resulting in gastroenteritis, or systemic infection, e.g., typhoid fever, in humans and many other animals. Understanding the mechanisms by which Salmonella induces disease has been the focus of intensive research. This has revealed that Salmonella invasion requires dynamic cross-talk between the microbe and host cells, in which bacterial adherence rapidly leads to a complex sequence of cellular responses initiated by proteins translocated into the host cell by a type 3 secretion system. Once these Salmonella-induced responses have resulted in bacterial invasion, proteins translocated by a second type 3 secretion system initiate further modulation of cellular activities to enable survival and replication of the invading pathogen. Elucidation of the complex and highly dynamic pathogen-host interactions ultimately requires analysis at the level of single cells and single infection events. To achieve this goal, researchers have applied a diverse range of microscopy techniques to analyze Salmonella infection in models ranging from whole animal to isolated cells and simple eukaryotic organisms. For example, electron microscopy and high-resolution light microscopy techniques such as confocal microscopy can reveal the precise location of Salmonella and its relationship to cellular components. Widefield light microscopy is a simpler approach with which to study the interaction of bacteria with host cells and often has advantages for live cell imaging, enabling detailed analysis of the dynamics of infection and cellular responses. Here we review the use of imaging techniques in Salmonella research and compare the capabilities of different classes of microscope to address specific types of research question. We also provide protocols and notes on some microscopy techniques used routinely in our own research.

Denaturing gradient gel electrophoresis-polymerase chain reaction comparison of chitosan effects on anaerobic cultures of broiler cecal bacteria and Salmonella Typhimurium

USDA-ARS?s Scientific Manuscript database

Salmonella colonization and product contamination are major poultry industry problems. Alternatives to traditional antibiotics against Salmonella offer the potential to lessen the development of resistance to antibiotics of importance to human health. The chitin derivative chitosan has drawn substa...

[Microbiological evaluation of chicken meal "shaverma" as a factor for Salmonella transmission].

PubMed

Sergevnin, V I; Udavikhina, L S; Gorokhova, S V; Istomina, L F; Khasanov, R Kh; Sarmometov, E V; Novoselov, V G

2012-01-01

It has been established that the dish shawarma may be a factor for Salmonella transmission, by involving in sporadic and outbreak cases of Salmonella infection. Chicken fillet grilling when cooking the dish shawarma has been found to ensure its guaranteed freedom from Salmonella only in a piece less than 2 cm thick. Deeper layers of chicken and its juice that accumulates in the grill tray may remain be Salmonella-contaminated throughout the heat treatment. Obviously, for the epidemiological safety of the dish shawarma, it is necessary to cut a not more than 2-cm piece of fillet every time the latter is ready-made, i.e. a white color and a clear juice are produced. At the time one should not use the chicken juice as sauce to the ready-made fillet and to gather and crumble the latter in a separate container rather than in the tray.

Production of recombinant flagellin to develop ELISA-based detection of Salmonella Enteritidis.

PubMed

Mirhosseini, Seyed Ali; Fooladi, Abbas Ali Imani; Amani, Jafar; Sedighian, Hamid

Food-borne diseases, caused by the pathogenic bacteria, are highly prevalent in the world. Salmonella is one of the most important bacterial genera responsible for this. Salmonella Enteritidis (SE) is one of the non-typhoid Salmonellae that can be transmitted to human from poultry products, water, and contaminated food. In recent years, new and rapid detection methods such as enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) have been developed. In this study, recombinant FliC (rFliC) was produced to be used as an antigen. The immunization was conducted in mice with the purified recombinant FliC (rFliC). The mice were subcutaneously immunized with rFliC and elicited significant rFliC specific serum IgG antibodies. An indirect ELISA system was established for the detection of Salmonella Enteritidis. Our results confirmed that the recombinant flagellin can be one of the excellent indicators for the detection of Salmonella Enteritidis. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Applications of immunomagnetic capture and time-resolved fluorescence detection for Salmonella enteriditis in liquid eggs

NASA Astrophysics Data System (ADS)

Tu, Shu-I.; Gehring, Andrew; Paoli, George

2008-04-01

An immuno sandwich method was evaluated for the detection of Salmonella in liquid eggs. Liquid eggs spiked with different out-break strains of Salmonella were mixed with proper enrichment media and incubated at 37 C for 4 to 20 h. After enrichment, immunomagnetic beads (IMB) coated with anti Salmonella antibodies were used to capture the bacteria. Samarium (Sm) labeled anti Salmonella antibodies were then used to form sandwiched complexes with IMB captured bacteria. Sandwiched Salmonella were then treated with Sm-chelator to allow the measurement of the released Sm by time-resolved fluorescence (TRF). The processes ranging from IMB capture to Sm chelation were performed using an automated KingFisher apparatus. With this approach, the presence of ~ 1 CFU of outbreak strains of Salmonella Enteritidis per egg (~50 g of liquid eggs) could be detected after enrichment for 20 h at 37 C. For higher levels of Salmonella Enteritidis contamination, e.g., 10 CFU per 50 g of liquid eggs, the enrichment time could be reduced to 5 h at 37 C. The results demonstrated that a combination of IMB capture and TRF measurement could be a rapid and sensitive method for Salmonella Enteritidis detection in liquid eggs.

[Protagonists of innate immunity during in Salmonella infections].

PubMed

Salez, Laurent; Malo, Danielle

2004-12-01

Salmonella are facultative intracellular Gram-negative bacteria that are found ubiquitously in nature and have the ability to infect a wide range of hosts including humans, domesticated, wild mammals, and birds. The principal clinical manifestations associated with Salmonella infection in humans are enteric fever (typhoid and paratyphoid) and a self-limiting gastroenteritis (salmonellosis). Additionally, silent carriage of this bacterium is frequent and contributes to disease dissemination. Typhoid fever still represents a major public health problem in many developing countries. On the other hand, industrialized countries experience an increased incidence of nontyphoidal Salmonella infections with most cases tracing back to food contamination. Studies using mouse model of infection with a highly virulent Salmonella typhimurium serotype have provided important insight into the complexity of the innate immune response to infection. The players are numerous but emphasis was placed on the genes that were discovered using genetic approaches and in vivo assay with live pathogen and include positional cloning of mouse mutations and manipulation of genes in the context of whole animal either by transgenesis or knockout technologies. Some of the critical genes include those known to play a role in the detection of the bacteria (Cd14, Lbp, Tlr4 and Tlr5) and in microbicidal activity (Slc11a1, Nos2, NADPH oxidase and cryptdins). These discoveries have already initiated the search for the contribution of particular genetic pathways in the innate immune response of humans to infection with Salmonella and other intracellular microorganisms.

Requirement of siderophore biosynthesis for plant colonization by Salmonella enterica

USDA-ARS?s Scientific Manuscript database

Contaminated fresh produce has become the number one vector of non-typhoidal salmonellosis to humans. However, Salmonella enterica genes essential for the life cycle of this organism outside the mammalian host are for the most part unknown. Screening deletion mutants led to the discovery that an aro...

Evaluation of PCR and high-resolution melt curve analysis for differentiation of Salmonella isolates.

PubMed

Saeidabadi, Mohammad Sadegh; Nili, Hassan; Dadras, Habibollah; Sharifiyazdi, Hassan; Connolly, Joanne; Valcanis, Mary; Raidal, Shane; Ghorashi, Seyed Ali

2017-06-01

Consumption of poultry products contaminated with Salmonella is one of the major causes of foodborne diseases worldwide and therefore detection and differentiation of Salmonella spp. in poultry is important. In this study, oligonucleotide primers were designed from hemD gene and a PCR followed by high-resolution melt (HRM) curve analysis was developed for rapid differentiation of Salmonella isolates. Amplicons of 228 bp were generated from 16 different Salmonella reference strains and from 65 clinical field isolates mainly from poultry farms. HRM curve analysis of the amplicons differentiated Salmonella isolates and analysis of the nucleotide sequence of the amplicons from selected isolates revealed that each melting curve profile was related to a unique DNA sequence. The relationship between reference strains and tested specimens was also evaluated using a mathematical model without visual interpretation of HRM curves. In addition, the potential of the PCR-HRM curve analysis was evaluated for genotyping of additional Salmonella isolates from different avian species. The findings indicate that PCR followed by HRM curve analysis provides a rapid and robust technique for genotyping of Salmonella isolates to determine the serovar/serotype.

Antibacterial effect of roselle extracts (Hibiscus sabadariffa), sodium hypochlorite and acetic acid against multidrug-resistant Salmonella strains isolated from tomatoes.

PubMed

Gutiérrez-Alcántara, E J; Rangel-Vargas, E; Gómez-Aldapa, C A; Falfan-Cortes, R N; Rodríguez-Marín, M L; Godínez-Oviedo, A; Cortes-López, H; Castro-Rosas, J

2016-02-01

Antibiotic-resistant Salmonella strains were isolated from saladette and red round type tomatoes, and an analysis done of the antibacterial activity of roselle calyx extracts against any of the identified strains. One hundred saladette tomato samples and 100 red round tomato samples were collected from public markets. Each sample consisted of four whole tomatoes. Salmonella was isolated from the samples by conventional culture procedure. Susceptibility to 16 antibiotics was tested for the isolated Salmonella strains by standard test. The antibacterial effect of four roselle calyx extracts (water, methanol, acetone and ethyl acetate), sodium hypochlorite and acetic acid against antibiotic-resistant Salmonella isolates was evaluated on contaminated tomatoes. Twenty-four Salmonella strains were isolated from 12% of each tomato type. Identified Salmonella serotypes were Typhimurium and Typhi. All isolated strains exhibited resistance to at least three antibiotics and some to as many as 12. Over contaminated tomatoes, the roselle calyx extracts produced a greater reduction (2-2·6 log) in antibiotic-resistant Salmonella strain concentration than sodium hypochlorite and acetic acid. The presence of multidrug-resistant Salmonella in vegetables is a significant public health concern. Multidrug-resistant Salmonella strains were isolated from raw tomatoes purchased in public markets in Mexico and challenged with roselle Hibiscus sabdariffa calyx extracts, sodium hypochlorite and acetic acid. On tomatoes, the extracts caused a greater reduction in the concentration of antibiotic-resistant Salmonella strains than sodium hypochlorite and acetic acid. Roselle calyx extracts are a potentially useful addition to disinfection procedures of raw tomatoes in the field, processing plants, restaurants and homes. © 2015 The Society for Applied Microbiology.

Prevalence and Antimicrobial Resistance of Salmonella Isolates Recovered from Retail Pork in Major Village Markets in Tai'an Region, China.

PubMed

Miao, Zengmin; Li, Song; Qin, Kun; Zhou, Yufa

2017-10-01

The current study was undertaken to evaluate Salmonella contamination in retail pork at major village markets of the Tai'an region, China. In total, 200 retail pork samples were collected from four village markets between June 2015 and February 2016, of which 69 samples (34.5%) were determined to be positive for Salmonella. Eleven serotypes were identified from the 69 Salmonella isolates, and Salmonella Derby was the most common (18 of 69, 26.1%), followed by Typhimurium (17 of 69, 24.6%) and Meleagridis (11 of 69, 15.9%). Antimicrobial susceptibility testing showed that antimicrobial resistance against tetracycline was the most prevalent (42 of 69, 60.9%), but antimicrobial resistance against both ceftriaxone and cefotaxime was 1.4% (1 of 69) and 2.9% (2 of 69), respectively. Multilocus sequence typing revealed that the 69 Salmonella isolates were divided into 11 sequence types (STs), among which ST40 (18 of 69, 26.1%) was the most common, followed by ST34 (15 of 69, 21.7%) and ST64 (13 of 69, 18.8%). Collectively, retail pork at village markets in the Tai'an region has a high Salmonella contamination rate, and these isolates exhibit broad-spectrum antimicrobial resistance. However, the absence of a dominant ST demonstrates that the Salmonella isolates from retail pork may be of diverse origins.

Quantification of hygiene indicators and Salmonella in the tonsils, oral cavity and rectal content samples of pigs during slaughter.

PubMed

Van Damme, Inge; Mattheus, Wesley; Bertrand, Sophie; De Zutter, Lieven

2018-05-01

The tonsils, oral cavity and faeces of 94 pigs at slaughter were sampled to assess the numbers of total aerobic bacteria, Enterobacteriaceae and Escherichia coli in the rectal content, tonsils and oral cavity of pigs at time of evisceration. Moreover, the prevalence, numbers and types of Salmonella spp. were determined. Mean numbers of Enterobacteriaceae in tonsils and the oral cavity differed between slaughterhouses. The proportion of Enterobacteriaceae relative to total aerobic bacteria differed between the different tissues, though large variations were observed between animals. Salmonella spp. were mostly detected in oral cavity swabs (n = 51, 54%), of which six samples were contaminated in numbers over 2.0 log CFU/100 cm 2 . Salmonella spp. were also recovered from 17 tonsillar tissue samples (18%) and 12 tonsillar swabs (13%). Out of the 29 rectal content samples from which Salmonella was recovered (31%), most were lowly contaminated, in the range between -1 and 0 log CFU/g. The predominant serotypes were S. Typhimurium and its monophasic variant, which were recovered from 33 and 13 pigs, respectively. In most cases, the same serotypes and MLVA profiles were found in pigs slaughtered during the same day, thus suggesting a common source of contamination. Copyright © 2017 Elsevier Ltd. All rights reserved.

Isolation, characterization, and application of bacteriophages for Salmonella spp. biocontrol in pigs.

PubMed

Albino, Luiz A A; Rostagno, Marcos H; Húngaro, Humberto M; Mendonça, Regina C S

2014-08-01

Foodborne illness due to Salmonella-contaminated pork products is an important public health problem, causing significant economic losses worldwide. The use of bacteriophages is a potential intervention tool that has attracted interest for the control of foodborne pathogens. The objective of this study was to detect the presence of Salmonella in commercial pig farms and to isolate specific autochthonous bacteriophages against Salmonella Typhimurium, to characterize them and to evaluate their lytic capacity against Salmonella Typhimurium in vivo and in vitro. Salmonella was isolated on 50% (4/8) of the farms, with serotype Typhimurium being the most prevalent, detected in 48.2% of samples (13/27). The isolated Salmonella Typhimurium bacteriophages belong to the Podoviridae family, were active against serotypes Abony, Enteritidis, Typhi, and Typhimurium, but not against serotypes Arizonae, Cholerasuis, Gallinarum, and Pullorum. In in vitro tests, bacteriophage at 10(7) PFU/mL and 10(9) PFU/mL significantly reduced (p<0.05) Salmonella Typhimurium counts in 1.6 and 2.5 log10 colony-forming units (CFU)/mL, respectively, after 24 h. Before the in vivo treatment with bacteriophages, Salmonella was identified in 93.3% (28/30) of the fecal samples from the pigs inoculated with 10(6) CFU/mL, and only in 56.6% (17/30) after the treatment consisting of oral administration of the pool of the bacteriophages after the fasting period, simulating a common preslaughter practice. These results indicate that the pool of bacteriophages administered was capable of reducing the colonization of Salmonella in pigs.