First Report of Food Poisoning Due to Staphylococcal Enterotoxin Type B in Döner Kebab (Italy)

Staphylococcal food poisoning results from the consumption of food contaminated by staphylococcal enterotoxins. In July 2022, the Turin local health board was notified of a suspected foodborne outbreak involving six children who had consumed döner kebab purchased from a takeaway restaurant. The symptoms (vomiting and nausea) were observed 2-3 h later. A microbiological analysis of the food samples revealed high levels (1.5 × 107 CFU/g) of coagulase-positive staphylococci (CPS). The immunoassay detected a contamination with staphylococcal enterotoxins type B (SEB). The whole genome sequencing of isolates from the food matrix confirmed the staphylococcal enterotoxin genes encoding for type B, which was in line with the SEB detected in the food. This toxin is rarely reported in staphylococcal food poisoning, however, because there is no specific commercial method of detection. The involvement of enterotoxin type P (SEP) was not confirmed, though the corresponding gene (sep) was detected in the isolates. Nasal swabs from the restaurant food handlers tested positive for CPS, linking them to the likely source of the food contamination.

Bacteria of Zoonotic Interest Identified on Edible Freshwater Fish Imported to Australia

Previous research has shown that freshwater edible fish imported into Australia are not compliant with Australian importation guidelines and as a result may be high risk for bacterial contamination. In the present study, the outer surface of imported freshwater fish were swabbed, cultured, confirmatory tests performed and antimicrobial patterns investigated. Channidae fish (Sp. A/n = 66) were contaminated with zoonotic Salmonella sp./Staphylococcus aureus (n = 1/66) and other bacteria implicated in cases of opportunistic human infection, these being Pseudomonas sp. (including P. mendocina and P. pseudoalcaligenes (n = 34/66)); Micrococcus sp. (n = 32/66); Comamonas testosteroni (n = 27/66) and Rhizobium radiobacter (n = 3/66). Pangasiidae fish (Species B/n = 47) were contaminated with zoonotic Vibrio fluvialis (n = 10/47); Salmonella sp. (n = 6/47) and environmental bacteria Micrococcus sp. (n = 3/47). One sample was resistant to all antimicrobials tested and is considered to be Methicillin Resistant S. aureus. Mud, natural diet, or vegetation identified in Sp. A fish/or packaging were significantly associated with the presence of Pseudomonas spp. The study also showed that visibly clean fish (Sp. B) may harbour zoonotic bacteria and that certain types of bacteria are common to fish groups, preparations, and contaminants. Further investigations are required to support the development of appropriate food safety recommendations in Australia.

Characterization of A Staphylococcal Food Poisoning Outbreak in A Workplace Canteen during the Post-Earthquake Reconstruction of Central Italy

In summer 2017, a foodborne outbreak occurred in Central Italy, involving 26 workers employed in the post-earthquake reconstruction. After eating a meal provided by a catering service, they manifested gastrointestinal symptoms; 23 of them were hospitalized. The retrospective cohort study indicated the pasta salad as the most likely vehicle of poisoning. Foods, environmental samples, and food handlers' nasal swabs were collected. Bacillus cereus (Bc) and coagulase-positive staphylococci (CPS) including S. aureus, together with their toxins, were the targets of the analysis. CPS, detected in all the leftovers, exceeded 10⁵ CFU/g in the pasta salad, in which we found Staphylococcal Enterotoxins (SEs) (0.033 ng SEA/g; 0.052 ng SED/g). None of the environmental and human swabs showed contamination. We characterized 23 S. aureus from foods. They all belonged to the human biotype, showed the same toxigenic profile (sea, sed, sej, and ser genes), and had the same Pulsed Field Gel Electrophoresis (PFGE) pattern; none of them harbored mecA or mupA genes. We also detected Bc contamination in the pasta salad but none of the isolates harbored the ces gene for the emetic toxin cereulide. The EU Reference Laboratory for CPS confirmed the case as a strong-evidence outbreak caused by the ingestion of SEs produced by a single strain of S. aureus carried by the same human source. This outbreak was successfully investigated despite the emergency situation in which it occurred.

Investigation of a Staphylococcal Food Poisoning Outbreak from a Chantilly Cream Dessert, in Umbria (Italy)

On August 28, 2015, a staphylococcal food poisoning outbreak occurred in Umbria, Italy, affecting 24 of the 42 customers who had dinner at a local restaurant. About 3 h after ingesting a variety of foods, the customers manifested gastrointestinal symptoms. Within 24 h of notification from the hospital emergency department, Sanitary Inspectors of the local Public Health Unit performed an epidemiological investigation. A retrospective cohort study was conducted among the customers. Food and environmental samples were collected. Due to the rapid onset of symptoms (vomiting, diarrhea), the food samples were analyzed for the presence of toxigenic bacteria and their toxins; nasopharyngeal swabs were collected from the waiters and cooks. Among the food tested, high levels of coagulase-positive staphylococci (CPS) (3.4 × 10⁸ CFU/g) and staphylococcal enterotoxins (2.12 ng SEA/g) were only detected in the Chantilly cream dessert. CPS were also detected on the surface of a kitchen table (10 CFU/swab), and five food handlers were positive for Staphylococcus aureus. In total, five enterotoxigenic S. aureus isolates were recovered from three food handlers, a kitchen surface, and the Chantilly cream dessert. These isolates were further characterized by biotyping, pulsed-field gel electrophoresis, and multiplex polymerase chain reaction assays for the detection of eleven enterotoxin encoding genes (sea, seb, sec, sed, see, seg, seh, sei, sej, sep, and ser) and three genes involved in antibiotic resistance (mecA, mecC, and mupA). Three sea-positive strains, isolated from the dessert, environment, and one of the cooks, had the same pulsed-field gel electrophoresis profile and belonged to the human biotype, suggesting that the contamination causing the outbreak most likely originated from a food handler. Moreover, improper storage of the dessert, at room temperature for about 5 h, permitted microbial growth and SEA production. This study underlines the importance of both laboratory evidence and epidemiological data for outbreak investigation.

Investigation of a staphylococcal food poisoning outbreak combining case-control, traditional typing and whole genome sequencing methods, Luxembourg, June 2014

In June 2014, a staphylococcal food poisoning outbreak occurred at an international equine sports event in Luxembourg requiring the hospitalisation of 31 persons. We conducted a microbiological investigation of patients and buffet items, a case-control study and a carriage study of catering staff. Isolates of Staphylococcus aureus from patients, food and catering staff were characterised and compared using traditional typing methods and whole genome sequencing. Genotypically identical strains (sequence type ST8, spa-type t024, MLVA-type 4698, enterotoxin A FRI100) were isolated in 10 patients, shiitake mushrooms, cured ham, and in three members of staff. The case-control study strongly suggested pasta salad with pesto as the vehicle of infection (p<0.001), but this food item could not be tested, because there were no leftovers. Additional enterotoxigenic strains genetically unrelated to the outbreak strain were found in four members of staff. Non-enterotoxigenic strains with livestock-associated sequence type ST398 were isolated from three food items and two members of staff. The main cause of the outbreak is likely to have been not maintaining the cold chain after food preparation. Whole genome sequencing resulted in phylogenetic clustering which concurred with traditional typing while simultaneously characterising virulence and resistance traits.

Acute infectious diarrhea

Infectious diarrhea is both a local and a global concern. Illnesses can range from mild inconveniences to life-threatening epidemics. Although diarrhea can be caused by a vast array of pathogens, the cornerstone of prevention is provision of a safe food and water supply, application of basic hygiene principles, and the development and administration of vaccines. The cornerstone of treatment is rehydration. Selection of specific antimicrobial therapy should be based on disease presentation and epidemiologic factors.

Risk factors for gastroenteritis: a nested case-control study

This nested case-control study investigated the risk factors for gastroenteritis in a cohort using rainwater as their primary domestic water source. Consumption of beef [odds ratio (OR) 2·74, 95% confidence interval (CI) 1·56–4·80], handling of raw fresh chicken in the household (OR 1·52, 95% CI 1·02–2·29) and animal contact (OR 1·83, 95% CI 1·20–2·83) were found to be significant risk factors (P>0·05). Significant protective effects were observed with raw salad prepared at home (OR 0·33, 95% CI 0·18–0·58), consumption of salami (OR 0·60, 95% CI 0·36–0·98), and shellfish (OR 0·31, 95% CI 0·14–0·67). This study provides novel insight into community-based endemic gastroenteritis showing that consumption of beef was associated with increased odds of illness and with a population attributable fraction (PAF) of 57·6%. Detecting such a high PAF for beef in a non-outbreak setting was unexpected.

A review of gastrointestinal outbreaks in schools: effective infection control interventions

BACKGROUND

The purpose of this study was to review documented outbreaks of gastrointestinal illness in schools, published in the last 10 years, to identify etiology, mode of transmission, the number of children affected, morbidity and mortality patterns, and interventions for control and prevention.

METHODS

Searches of electronic databases, public health publications, and federal, state, and provincial public health Web sites were completed.

RESULTS

Of the 121 outbreaks that met the inclusion criteria, 51% were bacterial, 40% viral, 7% were from Cryptosporidium, and 2% from multiple organisms. Transmission routes recorded in 101 reports included foodborne (45%), person-to-person (16%), waterborne (12%), and animal contact (11%). Actions to control outbreaks included alerting medical and public health authorities or the community to the outbreak (13%), treating cases (12%), enhancing hand washing (11%), and increased vigilance during food preparation (8%). Recommendations to prevent future outbreaks were compared with previously published studies that demonstrated effectiveness.

CONCLUSIONS

The risk of foodborne illness was reduced when food handlers practiced effective hand washing technique and received food safety training and certification. Student training programs on hand hygiene, enhanced cleaning and disinfection of the school, and hepatitis A vaccination were found effective. Children should be supervised on farm visits, hand washing strictly enforced, and food eaten in an area separated from the animals. Staff and students should have a positive, continuous communication with public health authorities including educational sessions and immediate reporting of possible outbreaks.

Inhibitory effect of Eleutherine americana Merr. extract on Staphylococcus aureus isolated from food

About 106 samples of ready-to-eat foods were purchased over a period of 3 mo out of which 76 (71.69%) were contaminated with Staphylococcus aureus. S. aureus isolated from the food samples were characterized phenotypically using traditional biochemical methods. Ninety-four percent of the isolates were mannitol fermenters, 86% positive for coagulase test, while 80% produced lipase enzyme. Antibiotic susceptibility test revealed that 21% and 63% of the food isolates were resistant to oxacillin and penicillin, respectively. The antibacterial activity of the bulb of Eleutherine americana used in Thai cuisine was investigated by agar disc diffusion using 2.5 mg of the crude extract and produced inhibition zone between 14.5 and 15.7 mm, while the minimum inhibitory concentration (MIC) value ranged from 0.06 to 1.00 mg/mL on both food isolates and reference strains. Growth curve in the presence of the crude ethanol extract at 4 MIC showed bacteriostatic effect by 5 log reduction relative to the control. Partially purified fractions tentatively identified by column chromatography were suspected to be responsible for the antibacterial property. This study suggests that E. americana bulb has potential for application as a natural preservative in foods.

[Hygiene tips for kids. Concept and examples of realisation]

Basic hygiene measures aim at promoting and maintaining good health. The necessary routines are most effectively learned and adopted during childhood. These key findings form the basis for the educational programme "Hygiene Tips for Kids" which was initiated at the Department of Hygiene and Public Health at Bonn University under the auspices of WHO Europe in 2003. The programme addresses children, teachers and parents and offers a range of materials and activities tailored to the specific needs of the target groups based on expert advice. The objective is to exert a long-lasting, positive influence on the performance of hygiene routines. Campaigns are usually directed at pre-school, kindergarten and primary school settings, with the public health service personnel playing a crucial role in coordinating and implementing the various activities. Evaluation of a campaign in the federal state of Mecklenburg-Vorpommern has proven a positive effect on hand washing routines in pre-school as well as in the domestic setting. Moreover, Hygiene Tips for Kids has a sustained positive effect on the cooperation and communication between public health authorities and teachers, children and their parents. Teachers implement their own ideas within a framework of standardised information to suit their local needs. A long-term goal would be the obligatory integration of a sensible health education programme in the syllabus of pre-school, kindergarten and primary schools.