Shiga Toxin-Producing E. coli Infections Associated with Flour.

BACKGROUND: In 2016, a multijurisdictional team investigated an outbreak of Shiga toxin-producing Escherichia coli (STEC) serogroup O121 and O26 infections linked to contaminated flour from a large domestic producer. METHODS: A case was defined as infection with an outbreak strain in which illness onset was between December 21, 2015, and September 5, 2016. To identify exposures associated with the outbreak, outbreak cases were compared with non-STEC enteric illness cases, matched according to age group, sex, and state of residence. Products suspected to be related to the outbreak were collected for STEC testing, and a common point of contamination was sought. Whole-genome sequencing was performed on isolates from clinical and food samples. RESULTS: A total of 56 cases were identified in 24 states. Univariable exact conditional logistic-regression models of 22 matched sets showed that infection was significantly associated with the use of one brand of flour (odds ratio, 21.04; 95% confidence interval [CI], 4.69 to 94.37) and with tasting unbaked homemade dough or batter (odds ratio, 36.02; 95% CI, 4.63 to 280.17). Laboratory testing isolated the outbreak strains from flour samples, and whole-genome sequencing revealed that the isolates from clinical and food samples were closely related to one another genetically. Trace-back investigation identified a common flour-production facility. CONCLUSIONS: This investigation implicated raw flour as the source of an outbreak of STEC infections. Although it is a low-moisture food, raw flour can be a vehicle for foodborne pathogens.

Differential Scanning Calorimetry Analysis of the Effects of Heat and Pressure on Protein Denaturation in Soy Flour Mixed with Various Types of Plasticizers.

The effects of heat and pressure on protein denaturation in soy flour were explored by an experimental design that used pressure (atmospheric to 600 MPa), temperature (room to 90 °C), time (1 to 60 min), and type of aqueous plasticizer (NaCl, sucrose, betaine, and lactobionic acid (LBA)) as factors. When 50% (w/w) soy flour-water paste was high hydrostatic pressure (HHP)-treated for 20 min at 25 °C, the treatment at 200 MPa showed a small effect on denaturation of only the 7S soy globulin, but the treatment at 600 MPa showed a significant effect on denaturation of both the 7S and 11S soy globulins. The treatment at 60 °C showed a less-pronounced effect on denaturation of the 11S globulin, even at 600 MPa, but that at 90 °C showed a similar extent of denaturation of the 11S globulin at 600 MPa to that at 25 °C. Chaotropic 2N NaCl, 50% sucrose-, 50% betaine-, or 50% LBA-water solutions showed protective effects on protein denaturation during HHP treatment at 25 °C. Although LBA enhanced the extent of thermostability of soy protein less than did 2N NaCl, LBA exhibited better stabilization against pressure. The results from DSC analysis demonstrated that thermostable soy proteins were not always barostable.

Poisoning due to yam flour consumption in five families in Ilorin, Central Nigeria.

BACKGROUND: Food poisoning is known to occur sporadically from time to time due to poor hygienic preparation. Its occurrence rarely assumes epidemic proportion. OBJECTIVE: To report the ccurrence of food poisoning due to yam flour consumption among five families and to create public awareness about the condition. CASE REPORT: Food poisoning due to yam flour consumption which occurred almost in quick succession between February and July 2005 among five family clusters in Ilorin is reported. They presented variedly with diarrhoea, vomiting, abdominal pain, convulsion and loss of consciousness. They all recovered within 48 hours of admission. Even though we could not carry out toxicological tests, yam flour consumption was highly implicated as the cause. Investigations indicated that the use of certain lethal preservatives for the processing of the yam flour might be responsible. CONCLUSION: Poisoning from consumption of yam flour should be a differential diagnosis of acute seizure disorder or the occurrence of vomiting, diarrhoea and abdominal pain in the tropics. We recommend education on proper processing of all food products in view of the public health implication of doing otherwise.

Cassava cyanogens and konzo, an upper motoneuron disease found in Africa.

Konzo is a distinct form of tropical myelopathy characterised by abrupt onset of spastic paraparesis. Epidemics in East Africa have been attributed to dietary cyanide exposure from insufficiently processed cassava but a study done in Zaire disputed such an aetiology. We investigated a konzo-affected population in rural Zaire and measured the cyanogen content of cassava flour, determined urinary thiocyanate as an indicator of cyanide intake, and compared blood cyanide concentrations in cases and controls. The affected population consumed flour made from short-soaked (one day) cassava roots and thus had high dietary cyanide exposure (urinary thiocyanate in 31 children = 757 mumol/l) compared with the unaffected population (urinary thiocyanate in 46 children = 50 mumol/l) that ate cassava that had been soaked for three days before consumption. 3 konzo patients, but only 2 of 23 controls, had blood cyanide concentrations above 4 mumol/l (p less than 0.01), although serum thiocyanate concentrations were similar. Our findings indicate a causal role in konzo of sustained high blood cyanide concentrations maintained by a deficient sulphur intake impairing cyanide to thiocyanate conversion. The underlying causes of konzo are poverty and food shortage, but a minor improvement of food processing may, as in beri-beri, be preventive.

Fermented corn flour poisoning in rural areas of China. III. Isolation and identification of main toxin produced by causal microorganisms.

Flavotoxin A was isolated from Pseudomonas cocovenenans subsp. farinofermentans culture in semisolid potato-dextrose-agar medium, which was isolated from fermented corn meal that had caused food poisoning outbreaks in China. The isolation, purification, and chemical structure of this toxin were studied. The NMR spectra, the uv spectra, and molar extinction coefficients, and the mass spectra of Flavotoxin A are in good agreement with those reported for bongkrekic acid. Therefore, Flavotoxin A and bongkrekic acid are the same organic chemical compound; the molecular formula is C28H38O7. The oral LD50 of the purified Flavotoxin A in mice was 3.16 mg/kg (1.53-6.15 mg/kg). The existence of bongkrekic acid in toxic fermented corn samples collected during food poisoning outbreaks was also confirmed. It is concluded that bongkrekic acid has played an important role in the outbreaks of fermented corn poisoning.

Studies on fermented corn flour poisoning in rural areas of China. I. Epidemiology, Clinical Manifestations, and Pathology.

An outbreak of a new type of fatal food poisoning has been reported in different parts of the People's Republic of China. Liver, kidney, heart, and brain were the main target organs, and the overall fatality of intoxicated individuals was 38.2%. Evidence obtained from epidemiological studies and animal tests indicates that the food poisoning was caused by the consumption of homemade fermented corn flour products.

Studies on fermented corn flour food poisoning in rural areas of China. II. Isolation and identification of causal microorganisms.

Using potato dextrose agar medium, 40 strains of microorganisms were isolated from leftover fermented corn flour samples involved in outbreaks of food poisoning. All strains produced powerful toxins which caused the same intoxication to mice, dogs, and monkeys as the leftover food samples. On the basis of results obtained from the morphology of this bacteria and its colony, from biochemical tests, and from the G-C mole percentage in DNA, the bacteria was identified as Flavobacterium farinofermentans nov. sp. (Meng, Z. and Wang, D.).

An epidemic of veno-occlusive disease of the liver in Afghanistan. Pathologic features.

A large outbreak of veno-occlusive disease occurred in Afghanistan in which approximately 7,800 in a population of 35,000 subjects were estimated to have been affected. It was caused by consumption of wheat flour heavily contaminated with seeds of a plant of the heliotropium species. These were found to contain pyrrolizidine alkaloids, chiefly heliotrine. Fourteen percutaneous liver biopsies, representing different stages of diseases and liver tissue from eight autopsies were studied. Morphological changes in the liver were characteristic. Centrilobular hemorrhagic necrosis was followed by occlusive changes in the hepatic veins, finally resulting in nonportal cirrhosis. The sequence of changes observed suggests primary parenchymal injury and possibly obstructive lesions at the sinusoidal level. Collagenization of the sinusoids and reorganization of the lobular reticulin begin early in disease. Occlusive changes in the efferent veins apparently follow.