Food Poisoning Incidents Research Articles

In vitro production of diarrhoeal enterotoxin by Bacilus cereus isolates from milk and dairy products

Bacilius cereus is a great safety concern for dairy industry as it is associated with incidences of food poisoning by producing enterotoxins. In the present study, growth temperature profile and enterotoxin production potental of 144 strains of Bacalus cereus isolated from milk and dairy products were investigated. Out of them, 107 (74.36) were able to grow at s7 oC. Presence of such a large number of psychrotolerant/psychotrophic strains in dairy environment is of major concern mainly because of their potential for growth, spoilage and ton production in chilled products. Out of 144 isolates, 134 (93%) exhibited haemalysis. While 98% of the solates from milk and 899% from. cheese were positive for diarhoeal enterotoxin, all the isolates from milk powder, ice cream, paneer and butter were positive. The prevalence of potent producers of enterotoxin among dairy isolates pases a high health risk.

Biochemical and organoleptic changes in some frozen commercially important freshwater fish species in Benin metropolis, Edo state, Nigeria

This study assessed the biweekly comparative changes in the organoleptic and biochemical composition of Nile Tilapia, Oreochromis niloticus , Electric fish, Malapterurus electricus , African knife fish, Xenomystus nigri and Snake fish, Erpetoichthys calabaricus . The Fish samples were procured live from the Ikpoba River in Benin metropolis, Edo State, Nigeria. They were transported to the laboratory, killed, degutted, washed and frozen. Organoleptic assessment with the aid of questionnaire on the basis of eyes, gills, skin and flesh quality was conducted by five (5) trained panelists. The proximate composition was assessed using changes in Moisture, Ash, Protein and Fat contents. Biochemical indices carried out were changes in pH, Total Volatile Base (TVB), Trimethylamine Acid (TMA), Free Fatty Acid (FFA) and Peroxide Value (PV) levels. The data were subjected to Analysis of variance and the means were tested and compared using Duncan multiple range test at 5% level of significance. Organoleptic assessment revealed that there were no significant (p > 0.05) changes in the fish samples during the course of storage. The proximate changes showed that the percentage moisture content of the fish samples increased and that of crude protein decreased but were not significantly different. Crude fat as well as Ash content decreased significantly (p < 0.05) during the time of storage. In general, pH, PV, TMA, FFA as well as TVB increased significantly (p < 0.05) with increase in storage period but the fish samples were all within the limits of acceptability. The levels of these parameters with respect to storage temperature and time may be exploited to minimize the incidence of fresh fish food poisoning and post-harvest losses. Keywords : Organoleptic assessment, chemical composition, Oreochromis niloticus, Malapterurus electricus, Xenomystus nigri, Erpetoichthys calabaricus

Staphylococcus aureus harbouring egc cluster coding for non-classical enterotoxins, involved in a food poisoning outbreak, Romania, 2012 / Staphylococcus aureus purtător de gene codante pentru enterotoxine non-clasice (cluster egc), implicat într-un focar de toxiinfecţie alimentară, România, 2012

Abstract In March 2012, a food poisoning outbreak was reported in a Romanian county, with a total number of 30 children affected. The symptoms (vomiting, diarrhea and abdominal pain), with onset within 1-2 hours after the ingestion of a particular food (milk), suggested a possible staphylococcal aetiology. An outbreak investigation was carried out, in accordance with the national surveillance methodology and 25 samples: stool (n=9), vomit (n=5), nasal swabs (n=9), and milk (n=2) were collected from the affected children, food handlers and suspected food. All isolated strains were sent to the Reference Centre for Staphylococci within the “Cantacuzino” National Institute of Research-Development for Microbiology and Immunology, Bucharest, Romania, for confirmation and further analysis. The aim of this study was to increase the reference laboratory capacity to confirm staphylococcal food poisoning (SFP) outbreak by defining the molecular basis of toxicity of Staphylococcus aureus (S. aureus) isolates and assessing their genetic relatedness. PCR methods have been used to detect 14 enterotoxin genes and the expression of some of these genes was proved by using a reverse transcription real-time PCR. Pulsed-field gel electrophoresis (PFGE) and Staphylococcus protein A coding gene sequence typing (spa typing) have been used to track the origin of the S. aureus contamination and to confirm the food poisoning outbreak. Two enterotoxigenic S. aureus strains isolated from milk, twelve isolated from patients and two from food handlers were of the same spa- type (t902) and revealed an indistinguishable SmaI macrorestriction pattern after a PFGE analysis. All these strains harboured the same toxin genes profile, namely the enterotoxin gene cluster (egc), which strongly supports the evidence that the milk was the incriminated food vehicle of the outbreak and a food-handler was the most likely source of the staphylococcal food poisoning (SFP) incident.

Norovirus genotype diversity in community-based sporadic gastroenteritis incidents: a five-year study.

Although norovirus is a known cause of sporadic gastroenteritis, the incidence and genotypes of norovirus associated with sporadic community-based gastroenteritis are poorly understood. The current study examined this issue by using material from alleged food poisoning incidents in the state of Victoria, Australia, for the period 2008-2012. Norovirus was identified, by either ORF (open reading frame) 1 or ORF 2 RT-PCR methodology, in 159 of 379 (42.0%) sporadic gastroenteritis incidents, thereby showing that norovirus was an important cause of sporadic gastroenteritis. The number of sporadic norovirus incidents did not vary significantly from year to year, indicating that the pool of circulating norovirus remained constant. Norovirus ORF 1 genotypes identified included GI.1, GI.2, GI.3, GI.4, GI.b, GI.d, GII.2, GII.4 (including variants 2006a, 2006b, 2007, and 2009), GII.16, GII.22, GII.b, GII.e, and GII.g. Norovirus ORF 2 genotypes identified included GI.1, GI.2, GI.3, GI.4, GI.6, GII.2, GII.3, GII.4 (variants 2006b, 2009, 2009-like, 2012, and "unknown"), GII.6, GII.7, GII.9, GII.12, and GII.13. Five ORF 1/ORF 2 norovirus recombinant forms were confirmed: GII.b/GII.3, GII.e/GII.4 (2012), GII.e/GII.4 (unknown), GII.g/GII.12 and GII.16/GII.2. Although the incidence of ORF 2 GI.3 was significantly higher in children than in adults, this was not the case for other major ORF 2 genotypes (GII.2, GII.4, and GII.6) which occurred equally in all age groups. The findings demonstrate the importance and diverse nature of norovirus in sporadic community-based gastroenteritis incidents and indicate that the development of successful vaccine strategies may be difficult.

THE POWER OF AN INTEGRATED MONITORING TECHNOLOGY SYSTEM FOR MINIMIZING QUALITY AND FOOD SAFETY RISKS IN FRESH PRODUCE SUPPLY CHAIN

The fresh food industry is plagued with a large percentage of waste and significant food safety issues in its supply chain. About one-third of fresh produce goes to waste because of improper sanitary, temperature and RH handling. Similarly, in the US there are, annually, approximately 76 million incidents of food poisoning, 325,000 hospitalizations and 5,000 deaths with direct economic cost of over USD $ 35 billion. A number of technologies have been developed to deal with waste and food safety risks, e.g., data loggers, gas chromatographs, and pathogen detection devices (e.g., 3M Molecular detection System). Unfortunately all such devices are independent of each other, fragmented in their data stream, and prevent decision makers from having a full view of risks associated with the consumption of perishable goods. To overcome such deficiencies, the Xsense ® technology was designed as a platform for real time data collection, data communication and information. At its core, the technology is conceived as a tag capable of carrying multiple sensor devices, collecting data on temperature, RH, and various volatile and pathogen specific gases. Data collection is in real time, using novel and advanced active RF-based mesh networking communication technology, and transmitting the collected data along with GPS locations through an innovative Communication Device to a centralized data center (server in a cloud) to enable the construction of data mining for the purpose of information generation through analytics processes. The Xsense ® system offers a holistic approach to the mitigation of risks associated with quality, freshness, and food safety in the supply chain. Once the data have been collected and transmitted, the Xsense ® technology generates, among other things, Cold Chain Logistic (CCL) scores and Pallets in Risk (PIR) indicators, thereby enabling the transformation of inventory management from First-in-First-Out (FIFO) to First-Expired-First-Out (FEFO).

Comprehensive study on the prevention of food poisoning through the investigation of an affected hospital food service facility

In Japan, more than 20,000 people suffer from various types of food poisoning annually. In this paper, we discuss the prevention of food poisoning in hospital food service facilities from the perspective of hygiene management and organizational behavior. We inspected the kitchen environment and the meal preparation process in a hospital food service facility in Japan that had been the site of a food poisoning incident. To clarify the present state of hygiene management, interviews were conducted with both the head of the nutrition and food service section and the administrative manager. In addition, questionnaires were distributed to the food service staff to assess their level of satisfaction with the working environment. The facility had been built about 10 years previously and was well maintained. Meal preparations were performed according to the operation manual, and education and training for the food service staff were carried out daily. No problems were evident regarding hygiene management. However, concerning organizational behavior, the satisfaction level of the staff was found to be relatively low, which may have led to a reduction in their organizational commitment and a decrease in their performance. To aid in the prevention of food poisoning incidents in hospital food service facilities, it is essential not only to conduct standard hygiene management and training, but also to consider the organizational behavior of the food service staff.

Risk Assessement Represented by Pathogenic Microorganisms Regarding the Incidence of Foodboorne Ilnesses in a Representative County During 2013

The interest of the competent authorities regarding foodborne ilnesses is increasing this days, although in the last time was managed by the combined effort of the food industry and the monitoring system conducted by the state, the decreasing of the prevalence of pathogens in foods of animal origin, and thus the incidence of food poisoning. Despite the progress aquired in analytical techniques, often remain undiagnosed cases, not knowing the true incidence of these disease. The aim of this paper was to assess microbiological risk represented by the pathogenic germs in different foods of animal origin foods, associated to the incidence of foodborne ilnesses in a representative County during 2013. The research material was represented by 10.947 food of animal origin samples: fresh meat, fresh poultry meat, poultry carcasses, minced meat, meat products, pasteurized liquid milk products, cheese manufactured from pasteurized and unpasteurized milk, butter, icecream, eggs, ready to eat foods and seafoods, collected according to national surveillance programme during 2013. In order to identify the main pathogenic microorganisms, usually involved in outbreaks of foodborne ilnesses ( Salmonella enteritidis , Salmonella typhimurium , Campylobacter jejuni/coli, Echerichia coli , Staphylococcus aureus and Listeria moncytogenes, the samples were processed through standardized methods. Based on the obtained results we identified in 214 samples Salmonella enteritidis/typhimurium , 191 samples Escherichia coli , 18 samples Staphylococcus aureus. We mention that no Campylobacter and Listeria germs were identified. According to the data gathered from the Infectious disease Hospital, during 2013 were confirmed 33 foodborne ilnessess asociated with Salmonella enteritidis/ typhimurium and 18 with Escherichia coli . Microbial risk in case of Salmonella enteritidis/typhimurium was incresed in case of poultry meat. Dairy products, respectively cheese manufactured from unpasteurized milk were the most unsafe food of animal origin regarding the risk with E. coli . Reducing the incidence of  food borne ilnesses is a multifactorial process that requires a comprehensive approach to food safety, along the entire food chain, in which must been involved farmers, industry, distributors, retailers, consumers, and the competent control authorities.

Characterization of three Bacillus cereus strains involved in a major outbreak of food poisoning after consumption of fermented black beans (Douchi) in Yunan, China.

Three Bacillus cereus strains isolated from an outbreak of food poisoning caused by the consumption of fermented black beans (douchi) containing B. cereus is described. The outbreak involved 139 persons who had nausea, vomiting, and diarrhea. The strains were isolated from vomit and the unprepared douchi. Two of the strains produced the emetic toxin cereulide, as evidenced by polymerase chain reaction analysis for the presence of the nonribosomal synthetase cluster responsible for the synthesis of cereulide and by chemical analysis by high-performance liquid chromatography-mass spectrometry. These two strains belong to genetic group III of B. cereus, and multiple locus sequence typing revealed that the type was ST26, as a major part of B. cereus emetic strains. One of these strains produced significantly more cereulide at 37°C than the type cereulide producer (F4810/72), and it was also able to produce the toxin at 40°C and 42°C. The third strain belongs to genetic group IV, and it is a new multiple locus sequence type closely related to strains that are cytotoxic and enterotoxigenic. It possesses genes for hemolysin BL, nonhemolytic enterotoxin, and cytotoxin K2; however, it varies from the majority of strains possessing genes for hemolysin BL by not being hemolytic. Thus, two B. cereus strains producing the emetic toxin cereulide and a strain producing enterotoxins might have been involved in this food-poisoning incident caused by the consumption of a natural fermented food. The ability of one of the strains to produce cereulide at ≥37°C makes it possible that it is produced in the human gut in addition to occurring in the food.

Prevalence of enterotoxins and toxin gene profiles of Staphylococcus aureus isolates recovered from a bakery involved in a second staphylococcal food poisoning occurrence.

The study objective was to characterize and analyse the distribution of enterotoxins and genes encoding enterotoxins in Staphylococcus aureus strains recovered from the 601 environment and ingredient samples obtained during multiple inspections of a bakery implicated in two separate staphylococcal food poisoning incidents. Staphylococcus aureus isolates were evaluated using serological assays for identification of classical staphylococcal enterotoxins (SEs) SEA-SEE and polymerase chain reaction for the detection of newly described SE and SE-like enterotoxin genes seg-seu. Pulsed field gel electrophoresis identified thirteen pattern types. During these investigations, a total of 585 environmental swabs and 16 raw ingredient samples were collected by investigators, 85 of which were confirmed to contain Staph. aureus; of those isolates, 95·3% (81/85) harboured enterotoxin genes and 4·7% (4/85) carried newly described SE and SE-like enterotoxin genes in the absence of classical enterotoxins. Our research demonstrates the prevalence and diversity of classical SEs and the probable underestimated impact of nonclassical SE and SE-like enterotoxins role in domestic staphylococcal food poisoning outbreaks. Given the abundance of SEs and SE-like toxins, these findings illustrate the utilization of PCR for enterotoxin gene identification and its significance in outbreak investigations.

Investigation and analysis of 102 mushroom poisoning cases in Southern China from 1994 to 2012

Mushroom poisoning is the main cause of mortality in food poisoning incidents in China. Although some responsible mushroom species have been identified, some were identified inaccuratly. This study investigated and analyzed 102 mushroom poisoning cases in southern China from 1994 to 2012, which involved 852 patients and 183 deaths, with an overall mortality of 21.48 %. The results showed that 85.3 % of poisoning cases occurred from June to September, and involved 16 species of poisonous mushroom: Amanita species (A. fuliginea, A. exitialis, A. subjunquillea var. alba, A. cf. pseudoporphyria, A. kotohiraensis, A. neoovoidea, A. gymnopus), Galerina sulciceps, Psilocybe samuiensis, Russula subnigricans, R. senecis, R. japonica, Chlorophyllum molybdites, Paxillus involutus, Leucocoprinus cepaestipes and Pulveroboletus ravenelii. Six species (A. subjunquillea var. alba, A. cf. pseudoporphyria, A. gymnopus, R. japonica, Psilocybe samuiensis and Paxillus involutus) are reported for the first time in poisoning reports from China. Psilocybe samuiensis is a newly recorded species in China. The genus Amanita was responsible for 70.49 % of fatalities; the main lethal species were A. fuliginea and A. exitialis. Russula subnigricans caused 24.59 % of fatalities, and five species showed mortality >20 % (A. fuliginea, A. exitialis, A. subjunquillea var. alba, R. subnigricans and Paxillus involutus). Mushroom poisoning symptoms were classified from among the reported clinical symptoms. Seven types of mushroom poisoning symptoms were identified for clinical diagnosis and treatment in China, including gastroenteritis, acute liver failure, acute renal failure, psychoneurological disorder, hemolysis, rhabdomyolysis and photosensitive dermatitis.

Research on Real-Time Localization and Environmental Monitoring Using Sensors and ZigBee for Cold Chain System

As consumers increase the level of quality requirements for foods due to the spread of well-being culture, the demands for safe cold chain have been continuously increased. However, as we can see from the food poisoning incidents that have recently occurred, important issues are how to keep the items (foods) and manage them. Although many people are aware that these issues are important, development and investment for keeping and managing foods are not enough at present. In the existing cold chain system, it is seen that the technologies of ubiquitous sensor networks (USNs), GPS, and CDMA have been used. However, this is only applied to a particular area, and the refrigeration/freezing level is the same as the existing one. In this paper, in order to increase the utilization of the cold chain system, we use both the commercial technologies of sensors and ZigBee for environmental measurements and cellular phone or smart phone with GPS for real-time localization and date transmissions. It is expected that our implementation system that is instantly ready to use leads to the expansion of cold chain system to various fields and the development of USN technologies.

食中毒原因究明のための遺伝子解析によるキノコ鑑別［食衛誌 53(5)，237～242］

食中毒原因究明のための遺伝子解析によるキノコ鑑別［食衛誌 <b>53</b>(5)，237～242］

Application of MALDI-TOF mass spectrometry for the detection of enterotoxins produced by pathogenic strains of the Bacillus cereus group

Enterotoxins produced by different species of the Bacillus cereus group, such as cytotoxin K1 (CytK1) and non-haemolytic enterotoxin (NHE), have been associated with diarrhoeal food poisoning incidents. Detection of CytK1 is not possible with commercial assays while NHE is recognised by an immunological kit (TECRA) that does not specifically target this protein because it is based on polyclonal antibodies. It is evident that the lack of suitable tools for the study of enterotoxins hampers the possibilities for accurate hazard identification and characterisation in microbial food safety risk assessment. We applied matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS) for the detection of CytK1 and NHE produced by pathogenic strains of the B. cereus group using protein digests from 1D gel electrophoresis. Secretion of CytK1 and two of the three components of NHE was confirmed in supernatants of different B. cereus cultures. For each protein, we introduce biomarkers that could be used for the screening of food poisoning or food/environmental isolates that can secrete enterotoxins. For example, tryptic peptides of 2,310.2 and 1,192.5 Da (calculated mass) can be indicators for CytK1 and NheA, respectively, although a simultaneous detection of other enterotoxin-specific peptides is recommended to assure the presence of a toxin in an unknown sample. Comparison of MALDI-TOF/MS with the TECRA kit showed that our methodological strategy performed well and it had the competitive advantage of specifically detecting NheA. Therefore, MALDI-TOF/MS can be successfully incorporated into risk assessment procedures in order to determine the involvement of strains of the B. cereus group in foodborne outbreaks, including the recently described cytK1 producing species, Bacillus cytotoxicus.

Development of a new loop-mediated isothermal amplification assay for prt (rfbS) gene to improve the identification of Salmonella serogroup D

Loop-mediated isothermal amplification (LAMP) is a promising nucleic acid assay for rapid and cost-effective detection of pathogen-specific sequences within a sample. Development of an appropriate taxonomic group-specific LAMP assay highly relies on the design of proper primers to cover all major members of the taxon. Regarding this fact, we designed and evaluated a new LAMP primer set specific to prt (rfbS) gene for rapid identification of Salmonella serogroup D serotypes. Unlike the previously reported LAMP assay for serogroup D which detects solely the non-typhoidal serotypes; the new LAMP primers set detects both typhoidal and non-typhoidal serotypes of this serogroup with a detection limit of 10 CFU/rection. Furthermore, the technique was successfully applied to artificially contaminated meat samples with an inoculation level of 1-5 CFU/250 ml of Salmonella Enteritidis, following a 5-h pre-enrichment step in tryptic soy broth. Overall, the new LAMP assay and its optimized setup would be useful for fast diagnosis of food poisoning incidents caused by these bacteria.

Occurrence, fatality and time distribution of food poisoning in Hunan Province.

To explore the incidence, mortality, trends and time distribution of food poisoning in Hunan Province. The data on food poisoning was derived from the Information Office of Hunan Provincial Health Department. Using the trend-test and circular distribution methods, we have described the current situation of food poisoning and tested the central tendency of the peak time points and the peak time zone of food poisoning in Hunan from 2000 to 2009. On average, the incidence of food poisoning in Hunan from 2000 to 2009 was 0.072 per 100000 population. And the average number of people affected in these incidents was 1.937 per 100000 population. There were no apparent trends in either the number of incidents or people affected between 2000 and 2009 (u=-0.98, P>0.05; u=-1.34, P>0.05, respectively). The average mortality was 0.015 per 100000 population. The trend-test indicated that the average annual mortality decreased significantly from 2000 to 2009 (u=-1.72, P<0.05). Meanwhile the average annual fatality rate was 0.77%. The trend-test revealed statistically significant differences for the average annual fatality rate (u=-1.88, P<0.05). The circular distribution analysis showed that there was a central tendency of the distribution of food poisoning cases, with the average peak time at August 28th and the average peak time zone from June 7th to November 18th for food poisoning from 2000 to 2008. From 2000 to 2009, there is a significant tendency in the average annual mortality and fatality rate of food poisoning in Hunan. Summer and fall are the high seasons for food poisoning. We should pay attention to the peak time zone, especially the peak time point of food poisoning for food safety monitoring, and strengthen the prevention and control on food poisoning.

Antibacterial action of chitosan-arginine against Escherichia coli O157 in chicken juice

The antimicrobial action of chitosan and functionalized chitosan derivatives is well known; however, limited research has been undertaken on its use in meat environments. In this study, the antibacterial activity of a newly-developed arginine-functionalized chitosan was tested against pathogenic Escherichia coli O157 in chicken juice. The chicken juice was representative of the liquid which accumulates in food packaging and which is frequently implicated in food poisoning incidents. Aliquots of chicken juice (50 ml) were inoculated with a lux-marked strain of E. coli O157 to approximately 8.75 log10 CFU ml−1. Samples were subsequently mixed with chitosan-arginine of varying concentrations (0–500 mg l−1) and incubated at 4 or 20 °C to mimic refrigeration and room temperatures, respectively. Pathogen persistence and metabolic activity (indexed by bioluminescence measurements) were subsequently quantified in the liquor at 0 (immediately after mixing), 3, 12, 24, 48, and 72 h post-incubation. The presence of chitosan-arginine significantly reduced both the numbers and metabolic activity of the pathogen in a dose-dependent manner with greater inhibition seen at higher concentration. In addition, it also suppressed the growth of general food spoilage bacteria, reduced malodor and prevented pathogen re-growth up to 72 h. The results imply that incorporating water soluble chitosan-arginine into packaging may help maintain both product shelf life and freshness as well as minimize the risk of food poisoning in both retail outlets and domestic homes.

Tetrodotoxin Poisoning Due to Pufferfish and Gastropods, and Their Intoxication Mechanism

Marine pufferfish generally contain a large amount of tetrodotoxin (TTX) in their skin and viscera, and have caused many incidences of food poisoning, especially in Japan. Edible species and body tissues of pufferfish, as well as their allowable fishing areas, are therefore clearly stipulated in Japan, but still 2 to 3 people die every year due to pufferfish poisoning. TTX is originally produced by marine bacteria, and pufferfish are intoxicated through the food chain that starts with the bacteria. Pufferfish become nontoxic when fed TTX-free diets in a closed environment in which there is no possible invasion of TTX-bearing organisms. On the other hand, TTX poisoning due to marine snails has recently spread through Japan, China, Taiwan, and Europe. In addition, TTX poisoning of dogs due to the ingestion of sea slugs was recently reported in New Zealand. TTX in these gastropods also seems to be exogenous; carnivorous large snails are intoxicated by eating toxic starfish, and necrophagous small-to-medium snails, the viscera of dead pufferfish after spawning. Close attention must be paid to the geographic expansion and/or diversification of TTX-bearing organisms, and to the sudden occurrence of other forms of TTX poisoning due to their ingestion.

Surveillance on Salmonella infection in Guangdong province, 2008 - 2009

To understand the infection of Salmonella (S.) in patients with diarrhea and outbreaks caused by Salmonella to identify the serotypes, resistance to antibiotics and PFGE types of the strains from the surveillance program in Guangdong province. S. strains from patients with diarrhea were detected, and all the positive strains collected in routine and outbreak surveillance programs, were tested by serum agglutination, antibiotic susceptibility and PFGE. 71 S. strains were isolated from 1922 stool samples in 2008, with positive rate as 3.7%. 85 S. strains were isolated from 2110 stool samples in 2009, with positive rate as 4.0%. All the 156 strains were divided into 37 serotypes, with S. serotype typhimurium and enteritidis as the most common serotypes. 10 incidents of food poisoning were detected, of which 4 were caused by enteritidis and 3 by typhimurium. A suspected outbreak by enteritidis was discovered and under epidemiological investigation. The findings indicated that 2 of the 4 patients from this outbreak were infected with identical enteritidis isolates. 80% of the 229 isolates were found susceptible to cephalosporins and quinolone and 59.3% of them were multiresistant to the antibiotics. S. enteritidis and S. typhimurium were the most common serotypes that caused infectious diarrhoea and food poisoning in Guangdong province.

Molecular characterization of the probiotic strain Bacillus cereus var. toyoi NCIMB 40112 and differentiation from food poisoning strains.

Bacillus cereus var. toyoi strain NCIMB 40112 (Toyocerin), a probiotic authorized in the European Union as feed additive for swine, bovines, poultry, and rabbits, was characterized by DNA fingerprinting applying pulsed-field gel electrophoresis and multilocus sequence typing and was compared with reference strains (of clinical and environmental origins). The probiotic strain was clearly characterized by pulsed-field gel electrophoresis using the restriction enzymes Apa I and Sma I resulting in unique DNA patterns. The comparison to the clinical reference strain B. cereus DSM 4312 was done with the same restriction enzymes, and again a clear differentiation of the two strains was possible by the resulting DNA patterns. The use of the restriction enzymes Apa I and Sma I is recommended for further studies. Furthermore, multilocus sequence typing analysis revealed a sequence type (ST 111) that was different from all known STs of B. cereus strains from food poisoning incidents. Thus, a strain characterization and differentiation from food poisoning strains for the probiotic strain was possible.

Pyrrolizidine alkaloids in food: a spectrum of potential health consequences

Contamination of grain with 1,2-dehydropyrrolizidine ester alkaloids (dehydroPAs) and their N-oxides is responsible for large incidents of acute and subacute food poisoning, with high morbidity and mortality, in Africa and in central and south Asia. Herbal medicines and teas containing dehydroPAs have also caused fatalities in both developed and developing countries. There is now increasing recognition that some staple and widely consumed foods are sometimes contaminated by dehydroPAs and their N-oxides at levels that, while insufficient to cause acute poisoning, greatly exceed maximum tolerable daily intakes and/or maximum levels determined by a number of independent risk assessment authorities. This suggests that there may have been cases of disease in the past not recognised as resulting from dietary exposure to dehydroPAs. A review of the literature shows that there are a number of reports of liver disease where either exposure to dehydroPAs was suspected but no source was identified or a dehydroPA-aetiology was not considered but the symptoms and pathology suggests their involvement. DehydroPAs also cause progressive, chronic diseases such as cancer and pulmonary arterial hypertension but proof of their involvement in human cases of these chronic diseases, including sources of exposure to dehydroPAs, has generally been lacking. Growing recognition of hazardous levels of dehydroPAs in a range of common foods suggests that physicians and clinicians need to be alert to the possibility that these contaminants may, in some cases, be a possible cause of chronic diseases such as cirrhosis, pulmonary hypertension and cancer in humans.