Food Poisoning Outbreaks Research Articles

Food-Borne Outbreak Investigation and Molecular Typing: High Diversity of Staphylococcus aureus Strains and Importance of Toxin Detection.

Staphylococcus aureus is an important aetiological agent of food intoxications in the European Union as it can cause gastro-enteritis through the production of various staphylococcal enterotoxins (SEs) in foods. Reported enterotoxin dose levels causing food-borne illness are scarce and varying. Three food poisoning outbreaks due to enterotoxin-producing S. aureus strains which occurred in 2013 in Belgium are described. The outbreaks occurred in an elderly home, at a barbecue event and in a kindergarten and involved 28, 18, and six cases, respectively. Various food leftovers contained coagulase positive staphylococci (CPS). Low levels of staphylococcal enterotoxins ranging between 0.015 ng/g and 0.019 ng/g for enterotoxin A (SEA), and corresponding to 0.132 ng/g for SEC were quantified in the food leftovers for two of the reported outbreaks. Molecular typing of human and food isolates using pulsed-field gel electrophoresis (PFGE) and enterotoxin gene typing, confirmed the link between patients and the suspected foodstuffs. This also demonstrated the high diversity of CPS isolates both in the cases and in healthy persons carrying enterotoxin genes encoding emetic SEs for which no detection methods currently exist. For one outbreak, the investigation pointed out to the food handler who transmitted the outbreak strain to the food. Tools to improve staphylococcal food poisoning (SFP) investigations are presented.

Low cost bioluminescence imaging as an alternative to in vivo bioassays for quantifying biologically active staphylococcal enterotoxin type E

Staphylococcus aureus is a major causative agent implicated in outbreaks of food poisoning. It acts through the production of a range of toxins including staphylococcal enterotoxin type E which has been associated with foodborne outbreaks in the USA, UK and France. While tests such as ELISA exist to detect the toxin’s molecules, existing methods to distinguish active toxin from inactivated are costly and require the use of live animal testing. In this study we constructed and evaluated a low cost CCD camera device in conjunction with a cell based assay for active SEE employing a genetically engineered T-cell line with a luciferase reporter regulated by nuclear factor of activated T-cells combined with a B-cell line for toxin presentation. The emitted light intensity from the T-cells is proportional to SEE concentration over an 8-log range and can discern the active form of toxin that sickens consumers, from toxin inactivated by heat treatment. The assay was verified in sample food matrices by spiking white grape and peach mango juices as well as apple cider. The low cost imaging device compared favorably against the expensive commercial luminometer plate reader using the same cell based assay. The low cost camera device should improve the availability of active toxin testing, especially in resource poor regions.

Cloning, Sequencing and Production of Recombinant Polyclonal Antibodies against Egyptian Staphylococcal Enterotoxin A

Staphylococcus aureus (S.aureus) is the most common pathogen found in hospitals, community-acquired infections and colonizes up to 50% of humans, including mucous membranes and damaged skin. Some strains produce enterotoxins (Ent) as staphylococcal enterotoxin A (SEA) which is involved in 75% of food poisoning outbreaks. Few methods are sensitive and specific enough to confirm the diagnosis of staphylococcal food poisoning. In this study, a segment of Ent A-ORF with molecular weight 774 bp was amplified, cloned, sequenced and aligned with published Ent A-ORFs. Ent A-ORF was subcloned into bacterial expression vector (GST-PGEX4T1 vector) and expressed as a fusion protein with GST-tagged protein. A band size of 27 kDa of purified Ent A protein was cleaved from GST protein by thrombin. The expressed protein of Ent A was identified by strong reaction with commercialized polyclonal antibodies against Ent A. Antiserum against Egyptian recombinant Ent A protein was produced by immunization of Balb/c mice, the produced recombinant polyclonal antibodies had a titre of 1:2500 in direct ELISA. The produced recombinant polyclonal antibody was evaluated and reacted specifically in Western immunoblotting analysis and ELISA test. Finally from the obtained results, the produced recombinant protein of Ent A can be used successfully for production of recombinant polyclonal antibodies and used in large-scale detection of staphylococcal enterotoxin A.

Incidence of some anaerobic bacteria isolated from chicken meat products with special reference to Clostridium perfringens

Anaerobic spore formers, especially Clostridium perfringens, represent one of the most prevalent bacterial food poisoning outbreaks which mostly related to consumption of contaminated meat and meat products, therefore, a total of 125 random raw and half cooked chicken meat samples represented by (breast, thigh, nuggets, panee and frankfurter “25 of each”) were collected from various retail stores and supermarkets in Qualyubia governorate. Results illustrated that, raw thigh samples were the most contaminated with anaerobic bacterial counts in incidence of 84%. The identified strains were C. perfringens, C. sporogenes, C. bifermenants, C. butyricum and C. sordelli in 21.6, 16, 8, 3.2 and 3.2%, respectively. Regarding to the incidence of vegetative and spore of C. perfringens were 24, 32, 20, 16, 16% and 16, 20, 16, 8, 8% in examined raw breast, raw thigh, nuggets, panee and frankfurter, respectively. 33.3% of isolates were lecithinase positive strains and typed as C. perfringens type A (6.4%), type D (0.8%); in absence of neither type B nor D. Experimental heat resistant C. perfringens spores were six heat resistant strains; where all isolates were of type A. The high incidence of these food poisoning microorganisms in chicken meat may indicate defects in sanitary conditions and handling in processing plant.

Outbreak of food poisoning in a working men's hostel: A retrospective cohort study

Introduction: Food poisoning is an acute gastroenteritis caused by ingestion of food or drink contaminated with either living bacteria or their toxins or inorganic chemical substances and poisons derived from plants and animals, commonly occurring as explosive outbreaks. The authors investigated an outbreak of food poisoning reported from a working men's hostel in urban area of Pune, Maharashtra. Materials and Methods: A retrospective cohort study design was adopted to investigate the outbreak. Of the total 170 members, 68 had symptoms of food poisoning. Remaining 102 unexposed members were also interviewed as part of the study. Data for environmental and laboratory parameters were also collected. Results: The point source outbreak indicated cooked chicken as the source with a risk ratio of 3.34 (95% confidence interval: 2.02–5.54) and attributable fraction for chicken was 75.3%. As is the case with 70% of food poisoning outbreaks, laboratory confirmation of causative organism could not be established, due to lack of specimens. However, the clinicoepidemiological profile of the patients displays a median incubation period of 8 h (range 5–17 h), along with the clinical symptomatology of a self-limiting disease of diarrhea, abdominal cramps, and nausea; suggested the implicating organisms to be either Clostridium perfringens or Bacillus cereus. Conclusion: The defaulting environmental parameters of compromised sanitary conditions, inadequate storage in refrigerator, improper storage of raw food, and unsafe cooking practices were enhancing factors, which need to be mandatorily addressed in bulk cooking.

Staphylococcal food poisoning caused by Staphylococcus argenteus harboring staphylococcal enterotoxin genes

Staphylococcal food poisoning (SFP) is caused by staphylococcal enterotoxins (SEs) preformed in food materials. SE genes are encoded on mobile genetic elements and are widely found across Staphylococcus species including S. argenteus, although most SFP cases are caused by S. aureus. S. argenteus, recently discriminated from S. aureus as a novel species, are non-pigmented staphylococci phenotypically related to S. aureus. In 2014 and 2015, two independent food poisoning cases occurred in Osaka, Japan, in which non-pigmented staphylococci were predominantly isolated. Several enterotoxin genes (seb, seg, sei, sem, sen, seo, and selu2) were found in their genome and the production of SEB was confirmed by reverse passive agglutination tests. The non-pigmented isolates from patients, food handlers, food, and cooking utensils all produced the same pulsed-field gel electrophoresis pattern. These non-pigmented isolates were coagulase-positive and biochemically identical to S. aureus. We performed further genetic analysis using nucA sequencing and multi-locus sequence typing, and identified these isolates as S. argenteus. We also found that seb was encoded on the Staphylococcus aureus pathogenicity island, while seg, sei, sem, sen, seo, and selu2 were encoded on the enterotoxin gene cluster. From these results, we concluded that the two food poisoning outbreaks were SFP cases caused by S. argenteus harboring SE genes.

Quality evaluation of selected ice cream samples sold in the market of Bikaner city (Rajasthan)

Dairy products are universally known for their nutritional and therapeutic values. Kulfi is the popular Indian frozen concentrated milk product, which is an ice cream like product, has been quoted in literature in different ways like Kulfi, Kulffi, Kulafi, Kulfy, Kulphy . Kulfi which is one of the most popular and nutritious dairy product can sometimes become a potential source of health hazard, by causing food poisoning outbreaks or by acting as a carrier of pathogens or by adulteration. The present study was attempted to evaluate the quality of Kulfi . For this, samples were collected in triplicates in previously sterilized containers, from five prominent shops of Bikaner city. The average moisture, crude protein, fat, total ash, carbohydrate, energy, calcium and phosphorus content was ranged from 42.36-57.20 g %, 6.56-9.28 g %, 10.13-18.56 g %, 3.35-4.35 g %, 15.01-35.16 g %, 233-273 Kcal, 683-718 mg %, and 736-901 mg %, respectively. Forty per cent and 20 per cent samples were noted to be of satisfactory quality with respect to SPC and faecal streptococcal count, respectively. Presence or absence of adulterants like starch and metanil yellow were also detected, but all the samples were found to be devoid of starch but in 20 per cent samples the inedible color that is metanil yellow was present. With respect to the possibility of adulteration and microbial contamination, quality of Kulfi remains in question.

JAID/JSC Guidelines for Infection Treatment 2015-Intestinal infections.

JAID/JSC Guidelines for Infection Treatment 2015-Intestinal infections.

Food poisoning outbreak in Tokyo, Japan caused by Staphylococcus argenteus

Staphylococcus argenteus is a novel species subdivided from Staphylococcus aureus. Whether this species can cause food poisoning outbreaks is unknown. This study aimed to investigate the enterotoxigenic activities of two food poisoning isolates suspected to be S. argenteus (Tokyo13064 and Tokyo13069). The results for phylogenic trees, constructed via whole genome sequencing, demonstrated that both isolates were more similar to a type strain of S. argenteus (MSHR1132) than any S. aureus strain. Moreover, the representative characteristics of S. argenteus were present in both strains, namely both isolates belong to the CC75 lineage and both lack a crtOPQMN operon. Thus, both were determined to be “S. argenteus.” The compositions of the two isolates' accessory elements differed from those of MSHR1132. For example, the seb-related Staphylococcus aureus pathogenicity island, SaPIishikawa11, was detected in Tokyo13064 and Tokyo13069 but not in MSHR1132. Both isolates were suggested to belong to distinct lineages that branched off from MSHR1132 lineages in terms of accessory elements. Tokyo13064 and Tokyo13069 expressed high levels of s(arg)eb and produced S(arg)EB protein, indicating that both have the ability to cause food poisoning. Our findings suggest that S. argenteus harboring particular accessory elements can cause staphylococcal diseases such as food poisoning, similarly to S. aureus.

Indian Medical Mission at Hajj-2016: Mass-Gathering Medicine Perspectives, Challenges, and Opportunities in a Mission Posture

Introduction: Hajj is an annual mass gathering of over 3.5 million pilgrims congregating from 200 countries in the desert climate of Saudi Arabia. Mass gathering medicine at Hajj is challenged by issues of healthcare accessibility, infection control, on-site treatment, referral, evacuation, and response to disasters and public health emergencies. The Indian Medical Mission at Hajj 2016 established, operated, and coordinated a strategic network of mass gathering medical operations, the proceeds of which are discussed herein. Methods: The mission was designed to provide holistic health security through health intelligence for pre-existing chronic diseases, epidemic intelligence for endemic and exotic diseases, public-health and disaster-health preparedness, and tiered healthcare through mobile medical task forces, static clinics, tent clinics, secondary care hospitals, and evacuation capabilities. Results: Primary care, secondary care, and tertiary care treated 374 475, 930, and 523 patients, respectively. Patients exhibited limited compliance with pre-instituted treatments and precautionary protocols. Respiratory and gastrointestinal infections, cardiorespiratory, trauma, and heat illnesses were seen. Epidemic intelligence revealed an outbreak of food poisoning. Respiratory infections were reported by 90% of the healthcare personnel. Surge capacity was overwhelmed with patient throughput and ambulance transfers. Crude unadjusted mortality was 11.99/10 000. Conclusion: The Indian Medical Mission at Hajj 2016 yielded solutions to the challenges faced during the 2016 Hajj pilgrimage. The mission posture of the Indian Medical Mission in Hajj presents a modus operandi for handling crisis scenarios in mass gathering. The situational analysis of the Hajj health mission calls for dynamic interventions in preparedness, clientele, and health systems.

Analysis of Kudoa septempunctata as a cause of foodborne illness and its associated differential diagnosis.

Objectives Recently kudoa septempuctata in olive flounders is suggested as a cause of food poisoning, however whether kudoa septempuctata can affect human gastrointestinal systems is controversial and its pathogenecity remains unclear. In view of the field epidemiology, food poisonings caused by kudoa septempuctata should be distinguished from those caused by Staphylococcus aureus and bacillus cereus. Methods The statistics of food poisoning investigations published by Korea Centers for Disease Control and Prevention in 2013-2015 were reviewed. The characteristics of kudoa septempuctata food poisoning reported by Korea Centers for Disease Control and Prevention were reviewed. Information regarding clinical symptoms or epidemiology was extracted. Results Total eleven kudoa septempuctata food poisoning cases were analyzed. Food poisonings caused by kudoa septempuctata, Staphylococcus aureus and bacillus cereus have clinical and epidemiological similarities. Forty five percent of food poisoning outbreaks occurred in Korea was concluded as unknown. The food poisoning caused by Staphylococcus aureus and bacillus cereus accounted for 4.5% (50/1,092) of all food poisoning outbreaks in Korea between 2013 and 2015. Conclusions This study suggests the possibilities of misdiagnosis in the investigations of food poisoning by Staphylococcus aureus and bacillus cereus with kudoa septempuctata.

Prevalence and expression of staphylococcal enterotoxin genes in Staphylococcus aureus isolated from food poisoning outbreaks.

Staphylococcus aureus is an important pathogen of foodborne origin. The pathogen produces a variety of toxins that include the staphylococcal enterotoxins (SE). The present study aimed to evaluate the prevalence and expression of 5 SE genes (sea, seb, sec, sed, and see) in S. aureus isolated from outbreaks occurred in the state of Rio Grande do Sul, Brazil. All isolates, with the exception of 2, presented the same or higher transcriptional expression than the reference strains for at least 1 of these genes. The presence of SE genes combined with high levels of transcriptional expression suggests that 1 or more SEs were involved with the staphylococcal food poisoning outbreak analyzed in the present study.

Isolation and Identification of Clostridium perfringens and its Enterotoxin in Food poisoning Patients

Background: Clostridium perfringens enterotoxin (CPE), which is one of the most common cause’s foodborne illnesses and contribute to diarrhea that is associated with broadspectrum antibiotic treatment.Objectives: This study focuses on diagnosis of Clostridium perfringens enterotoxin (CPE) from patients suffering from food poisoning and diarrhea associated with antibiotic treatment cases in stool samples and to determine the resistance of isolated against antibiotics.Methods: Samples were taken during the period of first of June 2015 until the end of April 2016 from Baghdad hospitals. Enzyme Linked Immunosorbent Assay (ELISA) was used to detect Clostridium perfringens enterotoxin in stool samples. Api 20A kit and culture to confirm isolation and identification was used, disk diffusion was performed for antibiotic resistance.Results: The infection cases increased among old adult age group, were (8.7%) and their age range was (64≥) years old,and children (5.3%) their age range was(15≤) years old. Overall positivity was (23%) in present studied groups and infection increased with causes of food poisoning (61.5%).Conclusion: This study revealed that the majority percent from age ≥64year (8.7%) and this percent decreased under this age. The future advances research should explain the epidemiology of enterotoxigenic C. perfringens and also participate to the prevention of C. perfringens food poisoning outbreaks and other CPE-associated human diseases.

عزل وتشخيص جرثومة Clostridium perfringens وسمومها المعوية من مرضى التسمم الغذائي

Background: Clostridium perfringens enterotoxin (CPE), which is one of the most common cause’s foodborne illnesses and contribute to diarrhea that is associated with broadspectrum antibiotic treatment.Objectives: This study focuses on diagnosis of Clostridium perfringens enterotoxin (CPE) from patients suffering from food poisoning and diarrhea associated with antibiotic treatment cases in stool samples and to determine the resistance of isolated against antibiotics.Methods: Samples were taken during the period of first of June 2015 until the end of April 2016 from Baghdad hospitals. Enzyme Linked Immunosorbent Assay (ELISA) was used to detect Clostridium perfringens enterotoxin in stool samples. Api 20A kit and culture to confirm isolation and identification was used, disk diffusion was performed for antibiotic resistance.Results: The infection cases increased among old adult age group, were (8.7%) and their age range was (64≥) years old,and children (5.3%) their age range was(15≤) years old. Overall positivity was (23%) in present studied groups and infection increased with causes of food poisoning (61.5%).Conclusion: This study revealed that the majority percent from age ≥64year (8.7%) and this percent decreased under this age. The future advances research should explain the epidemiology of enterotoxigenic C. perfringens and also participate to the prevention of C. perfringens food poisoning outbreaks and other CPE-associated human diseases.

Evaluations of hotels and restaurants' guests of food risk management quality in Alexandria

The aim of this study is to evaluate the food risk management quality in Alexandria city through hotels and restaurants guests and the food safety knowledge of guests about factors that contribute to food poisoning outbreaks. The data were collected via two questionnaires, distributed to a sample of hotels and restaurants ‘guests. The results generally confirm the importance of these factors, which help explain relative perceptions of well and poorly managed risks.

Biological characteristics of staphylococcal enterotoxin Q and its potential risk for food poisoning.

To elucidate the biological characteristics and stability of a newly identified staphylococcal enterotoxin Q (SEQ) against heating and digestive enzymes and to evaluate the risk of seq-harbouring Staphylococcus aureus in food poisoning. Purified SEQ was treated with heating, pepsin and trypsin which are related to food cooking, stomach and intestine conditions, respectively. Superantigenic activity of SEQ was assessed by determining the ability of IL-2 induction in mouse spleen cells. The emetic activity of SEQ was assessed using house musk shrew, a small emetic animal model. The results revealed that SEQ exhibits a remarkable resistance to heat treatment and pepsin digestion and has significant superantigenic and emetic activities. Furthermore, a sandwich ELISA for detection of SEQ production was developed, and the results showed that seq-harboring S. aureus isolates produce a large amount of SEQ. The newly identified SEQ had remarkable stability to heat treatment and digestive enzyme degradation and exhibited significant superantigenic and emetic activities. In addition, seq-harbouring S. aureus isolated from food poisoning outbreaks produced a large amount of SEQ, suggesting that seq-harbouring S. aureus could potentially be a hazard for food safety. This study found, for the first time, that SEQ, a nonclassical SE, had remarkable stability to heat treatment and enzyme degradation and exhibited significant emetic activity, indicating that SEQ is a high-risk toxin in food poisoning.

The inhibitory effects of Lactobacillus fermentum, Lactobacillus acidophilus and Lactobacillus paracasei isolated from yoghurt on the growth and enterotoxin A gene expression of S. aureus

BACKGROUND: Staphylococcal foodborne intoxication is the most common cause of foodborne illnesses by Staphylococcus aureus strains and most are caused by the enterotoxins of S. aureus. Staphylococcal enterotoxin A (SEA) is the most frequently responsible for staphylococcal food poisoning outbreaks. From a food safety and human health point of view, lactic acid bacteria (LAB) may provide a promising strategy in the fight against S. aureus.OBJECTIVES: Increasing product shelf life, and enhancing the safety of food and human health using natural microflora are the aims of this study. METHODS: In this study we evaluate the inhibitory effects of three lactobacillus strains isolated from yoghurt, namely lactobacillus acidophilus, lactobacillus fermentum and lactobacillus paracasei, on the growth and enterotoxin production of Staphylococcus aureus by co-incubating each strain with enterotoxigenic S. aureus at two temperatures: 25 and 35°C. Expression of the SEA gene of S. aureus was assessed by real-time PCR. RESULTS: All the strains decreased the bacterial count at both temperatures compared to the control. This effect was greater at 25°°C than at 35°C. The production of SEA, SEC and SEE was inhibited by all the isolates tested. Furthermore, expression of the sea gene was significantly suppressed in S. aureus co-cultured with the lactobacillus isolates and the greatest impact was on Lactobacillus acidophilus at 35 ° C. CONCLUSINS: This research highlights the potential of lactic acid bacteria isolated from traditional foods for use as natural preservatives in foodstuffs and suggests a new approach for biocontrol of Staphylococcus aureus.

Analysis of Kudoa septempunctata as a cause of foodborne illness and its associated differential diagnosis.

OBJECTIVESRecently kudoa septempuctata in olive flounders is suggested as a cause of food poisoning, however whether kudoa septempuctata can affect human gastrointestinal systems is controversial and its pathogenecity remains unclear. In view of the field epidemiology, food poisonings caused by kudoa septempuctata should be distinguished from those caused by Staphylococcus aureus and bacillus cereus. METHODSThe statistics of food poisoning investigations published by Korea Centers for Disease Control and Prevention in 2013-2015 were reviewed. The characteristics of kudoa septempuctata food poisoning reported by Korea Centers for Disease Control and Prevention were reviewed. Information regarding clinical symptoms or epidemiology was extracted.RESULTSTotal eleven kudoa septempuctata food poisoning cases were analyzed. Food poisonings caused by kudoa septempuctata, Staphylococcus aureus and bacillus cereus have clinical and epidemiological similarities. Forty five percent of food poisoning outbreaks occurred in Korea was concluded as unknown. The food poisoning caused by Staphylococcus aureus and bacillus cereus accounted for 4.5% (50/1,092) of all food poisoning outbreaks in Korea between 2013 and 2015. CONCLUSIONSThis study suggests the possibilities of misdiagnosis in the investigations of food poisoning by Staphylococcus aureus and bacillus cereus with kudoa septempuctata.

Thermal stability and structural changes in bacterial toxins responsible for food poisoning.

The staphylococcal enterotoxins (SEs) are secreted by the bacteria Staphylococcus aureus and are the most common causative agent in staphylococcal food poisoning. The staphylococcal enterotoxin A (SEA) has been associated with large staphylococcal food poisoning outbreaks, but newer identified SEs, like staphylococcal enterotoxin H (SEH) has recently been shown to be present at similar levels as SEA in food poisoning outbreaks. Thus, we set out to investigate the thermo-stability of the three-dimensional structures of SEA, SEH and staphylococcal enterotoxin E (SEE), since heat inactivation is a common method to inactivate toxins during food processing. Interestingly, the investigated toxins behaved distinctly different upon heating. SEA and SEE were more stable at slightly acidic pH values, while SEH adopted an extremely stable structure at neutral pH, with almost no effects on secondary structural elements upon heating to 95°C, and with reversible formation of tertiary structure upon subsequent cooling to room temperature. Taken together, the data suggests that the family of staphylococcal enterotoxins have different ability to withstand heat, and thus the exact profile of heat inactivation for all SEs causing food poisoning needs to be considered to improve food safety.

Crystal structure and structure-based mutagenesis of actin-specific ADP-ribosylating toxin CPILE-a as novel enterotoxin.

Unusual outbreaks of food poisoning in Japan were reported in which Clostridium perfringens was strongly suspected to be the cause based on epidemiological information and fingerprinting of isolates. The isolated strains lack the typical C. perfringens enterotoxin (CPE) but secrete a new enterotoxin consisting of two components: C. perfringens iota-like enterotoxin-a (CPILE-a), which acts as an enzymatic ADP-ribosyltransferase, and CPILE-b, a membrane binding component. Here we present the crystal structures of apo-CPILE-a, NAD+-CPILE-a and NADH-CPILE-a. Though CPILE-a structure has high similarity with known iota toxin-a (Ia) with NAD+, it possesses two extra-long protruding loops from G262-S269 and E402-K408 that are distinct from Ia. Based on the Ia–actin complex structure, we focused on actin-binding interface regions (I-V) including two protruding loops (PT) and examined how mutations in these regions affect the ADP-ribosylation activity of CPILE-a. Though some site-directed mutagenesis studies have already been conducted on the actin binding site of Ia, in the present study, mutagenesis studies were conducted against both α- and β/γ-actin in CPILE-a and Ia. Interestingly, CPILE-a ADP-ribosylates both α- and β/γ-actin, but its sensitivity towards β/γ-actin is 36% compared with α-actin. Our results contrast to that only C2-I ADP-ribosylates β/γ-actin. We also showed that PT-I and two convex-concave interactions in CPILE-a are important for actin binding. The current study is the first detailed analysis of site-directed mutagenesis in the actin binding region of Ia and CPILE-a against both α- and β/γ-actin.