Microbial contamination of food products consumed by infants and babies in Korea

Novel hypothesis for infant methemoglobinemia: Survival and metabolism of nitrite-producers from vegetables under gastrointestinal stress and intestinal adhesion

Infants have digestive environments that are more favorable for microbial proliferation and subsequent endogenous nitrite production than those of adults, but direct evidence of this has been lacking. In this study, we propose a novel epidemiology of infant methemoglobinemia by demonstrating the risk posed by nitrite-producers in the gastrointestinal tract. Nitrite-producers from vegetables (n = 323) were exposed to stress factors of the gastrointestinal environment (gastric pH, intestinal bile salts, anaerobic atmosphere) reflecting 4 different postnatal age periods (Neonate, ≤1 month; Infant A, 1-3 months; Infant B, 3-6 months; Infant C, 6-12 months). "High-risk" strains with a nitrate-to-nitrite conversion rate of ≥1.3 %, the minimum rate corresponding to nitrite overproduction, under the Neonate stress condition were analyzed for intestinal adhesion. Among all the phyla, Pseudomonadota achieved the highest survival (P < 0.05; survival rate of 51.3-71.8 %). Possible cross-protection against bile resistance due to acid shock was observed for all the phyla. All the high-risk strains exhibited moderate autoaggregation (14.0-36.4 %), whereas only a few exhibited satisfactory surface hydrophobicity (>40 %). The Pantoea agglomerans strain strongly adhered to Caco-2 cells (7.4 ± 1.1 %). This study showed the ability of the Pantoea, Enterobacter, and Klebsiella strains to survive under gastrointestinal stress for ≤12 months, to excessively produce nitrite under neonatal stress conditions, and to settle in the human intestine. To our knowledge, this is the first study to reveal the role of the natural flora of vegetables in the epidemiology of infant methemoglobinemia through a multilateral approach.

Microbiological Analysis and Content of Heavy Metals in Different Candies, Chocolates, and Their Wrappers in Bangladesh

Present study investigates 39 brands of candies, chocolate, and litchis, purchased from Dhaka City, Bangladesh, for their moisture content, sulphated ash value, heavy metal, and bacterial contamination. All the brands showed moisture content (0.64%-4.775%) within the BSTI range, but sulphated ash values (18.80%-25.72%) were beyond the accepted value. Pb, Cd, Ni, and Cr ranged from 0.24-2.40 μg/g, 0.071-0.44 μg/g, 0.38-48.10 μg/g, and 0.50-12.79 μg/g, respectively, in the tested brands. Most of the brands contained Pb and Cd beyond the acceptable limits of WHO/FDA. Pb (2.24-2586.75 μg/g) was found in high concentration in the packaging of most brands, and Ni and Cd ranged from 2.10-108.05 μg/g and 1.68-45 μg/g, respectively. Bacterial presence was found in 15 brands, and 4 of them had a total aerobic bacterial count of >1 log CFU/g. Consumption of such contaminated confectionaries holds significant public health risks, specially in children, and demands necessary precautionary steps.

Enterococcus contamination of infant foods and implications for exposure to foodborne pathogens in peri-urban neighbourhoods of Kisumu, Kenya

We collected infant food samples from 714 households in Kisumu, Kenya, and estimated the prevalence and concentration of Enterococcus, an indicator of food hygiene conditions. In a subset of 212 households, we quantified the change in concentration in stored food between a morning and afternoon feeding time. In addition, household socioeconomic characteristics and hygiene practices of the caregivers were documented. The prevalence of Enterococcus in infant foods was 50% (95% confidence interval: 46.1 - 53.4), and the mean log10 colony-forming units (CFUs) was 1.1 (SD + 1.4). No risk factors were significantly associated with the prevalence and concentration of Enterococcus in infant foods. The mean log10 CFU of Enterococcus concentration was 0.47 in the morning and 0.73 in the afternoon foods with a 0.64 log10 mean increase in matched samples during storage. Although no factors were statistically associated with the prevalence and the concentration of Enterococcus in infant foods, household flooring type was significantly associated with an increase in concentration during storage, with finished floors leading to 1.5 times higher odds of concentration increase compared to unfinished floors. Our study revealed high prevalence but low concentration of Enterococcus in infant food in low-income Kisumu households, although concentrations increased during storage implying potential increases in risk of exposure to foodborne pathogens over a day. Further studies aiming at investigating contamination of infant foods with pathogenic organisms and identifying effective mitigation measures are required to ensure infant food safety.

Bacteriological quality and safety of bottle food and associated factors among bottle-fed babies attending pediatric outpatient clinics of Government Health Institutions in Arba Minch, southern Ethiopia

BACKGROUND

Microbial contamination of baby bottle food has been identified as a significant public health concern, especially in developing countries, but it remains overlooked. Therefore, this study aimed to determine microbiological hazards, compliance with hygiene practices, and critical control points of contamination in baby bottle food in Arba Minch, southern Ethiopia.

OBJECTIVE

To evaluate the bacteriological quality and prevalence of foodborne pathogens in baby bottle food and to identify associated factors among bottle-fed babies attending three government health institutions in Arba Minch, southern Ethiopia.

METHODS

A cross-sectional study was conducted between February 24 and March 30, 2022. A total of 220 food samples, comprising four types prepared with different sources of materials, were collected from systematically selected bottle-fed babies attending health facilities. The data on sociodemographic characteristics, food hygiene, and handling practices were solicited by face-to-face interview using a semi-structured questionnaire. Food samples (10 mL) were quantitatively analyzed for total viable counts (TVC) and total coliform count (TCC) and qualitatively for the presence of common foodborne bacterial pathogens. Data were analyzed using SPSS; ANOVA and multiple linear regression analyses were done to identify factors influencing microbial counts.

RESULTS

Results revealed that the means and standard deviations of TVC and TCC were 5.3 ± 2.3 log₁₀ colony forming units (CFU)/mL and 4.1 ± 2.6 log₁₀ CFU/mL, respectively. Of the various food samples analyzed, 57.3 and 60.5% had a TVC and TCC above the maximum acceptable limits, respectively. The result of the ANOVA showed that there was a significant difference in the mean score of TCV and TCC among the four types of food samples (p < 0.001). Enterobacteriaceae were found in the majority of positive food samples (79.13%), followed by Gram-positive cocci (20.8%). Salmonella spp., diarrheagenic Escherichia coli, and Staphylococcus aureus were the common foodborne pathogens detected in 8.6% of tested foods. The regression result revealed that the type of baby food, hand washing practices of mothers or caregivers, and sterilizing and disinfecting procedures of feeding bottles are independent determinants of bacterial contamination (p < 0.001).

CONCLUSION

The high microbial load and the presence of potential foodborne bacterial pathogens in the bottle food samples analyzed indicate unsanitary practices and the potential risk of exposure to foodborne pathogens in bottle-fed babies. Thus, interventions such as educating parents about proper hygiene practices, sterilizing feeding bottles and limiting bottle feeding practices are critical to reducing the risk of foodborne to bottle-fed infants.

The Investigation of Mycotoxins and Enterobacteriaceae of Cereal-Based Baby Foods Marketed in Turkey

In this study, a total of 85 cereal-based baby foods with or without milk (four different brands; A, B, C, and D) collected from Ankara local markets, Turkey were analyzed for mycotoxins, total aerobic mesophilic bacteria (TAMB), and Enterobacteriaceae contamination. Baby foods were analyzed for 12 toxicological important mycotoxins such as aflatoxin B1, B2, G1, and G2; fumonisin B1 and B2; ochratoxin A; sterigmatocystin (STE); deoxynivalenol (DON); zearalenone (ZON); and T-2 toxin and HT-2 toxin by LC-MS/MS multi-mycotoxin method. In addition to these mycotoxins, the presence of aflatoxin M1 (AFM1) was investigated in baby foods containing milk. The classical culture method was used for microbiological analysis. Consequently, at least one mycotoxin was detected in 69.41% of the total samples. The most frequently detected mycotoxins were STE (34.12%) and HT-2 (34.12%). However, AFM1 was not detected in any of the baby foods containing milk. Also, TAMB and Enterobacteriaceae were isolated from 30.59% and 10.59% of samples, respectively. As a result, it was determined that the mycotoxin levels in the analyzed samples were in accordance with the mycotoxin levels specified in the Turkish Food Codex.

Profiling of Microbiota at the Mouth of Bottles and in Remaining Tea after Drinking Directly from Plastic Bottles of Tea

It has been speculated that oral bacteria can be transferred to tea in plastic bottles when it is drunk directly from the bottles, and that the bacteria can then multiply in the bottles. The transfer of oral bacteria to the mouth of bottles and bacterial survival in the remaining tea after drinking directly from bottles were examined immediately after drinking and after storage at 37 °C for 24 h. Twelve healthy subjects (19 to 23 years of age) were asked to drink approximately 50 mL of unsweetened tea from a plastic bottle. The mouths of the bottles were swabbed with sterile cotton, and the swabs and the remaining tea in the bottles were analyzed by anaerobic culture and 16S rRNA gene sequencing. Metagenomic analysis of the 16S rRNA gene was also performed. The mean amounts of bacteria were (1.8 ± 1.7) × 10⁴ colony-forming units (CFU)/mL and (1.4 ± 1.5) × 10⁴ CFU/mL at the mouth of the bottles immediately after and 24 h after drinking, respectively. In contrast, (0.8 ± 1.6) × 10⁴ CFU/mL and (2.5 ± 2.6) × 10⁶ CFU/mL were recovered from the remaining tea immediately after and 24 h after drinking, respectively. Streptococcus (59.9%) were predominant at the mouth of the bottles immediately after drinking, followed by Schaalia (5.5%), Gemella (5.5%), Actinomyces (4.9%), Cutibacterium (4.9%), and Veillonella (3.6%); the culture and metagenomic analyses showed similar findings for the major species of detected bacteria, including Streptococcus (59.9%, and 10.711%), Neisseria (1.6%, and 24.245%), Haemophilus (0.6%, and 15.658%), Gemella (5.5%, and 0.381%), Cutibacterium (4.9%, and 0.041%), Rothia (2.6%, and 4.170%), Veillonella (3.6%, and 1.130%), Actinomyces (4.9%, and 0.406%), Prevotella (1.6%, and 0.442%), Fusobacterium (1.0%, and 0.461%), Capnocytophaga (0.3%, and 0.028%), and Porphyromonas (1.0%, and 0.060%), respectively. Furthermore, Streptococcus were the most commonly detected bacteria 24 h after drinking. These findings demonstrated that oral bacteria were present at the mouth of the bottles and in the remaining tea after drinking.

Emergence of Cronobacter sakazakii in Cases of Neonatal Sepsis in Upper Egypt: First Report in North Africa

Background and Aim

Cronobacter sakazakii (C. sakazakii) has attracted considerable attention as an emerging neonatal pathogen and has been associated with outbreaks of life-threatening septicemia, necrotizing enterocolitis, and meningitis in neonates and infants globally. No data about the role of C. sakazakii as a cause of neonatal sepsis in North Africa is availale. Herein, we aimed to study the incidence of C. sakazakii in cases of neonatal sepsis, its distribution in different food samples in Egypt, antimicrobial profile, and the ability of the strains to form biofilms.

Methods

A total of 100 positive blood cultures from cases of neonatal sepsis admitted to the neonatal ICU at Assiut University Children's Hospital, Egypt, were analyzed. In addition, 1,100 food samples, including 400 powdered infant formula (PIF), 500 herbs, and 200 water samples were screened for the presence of C. sakazakii. We evaluated the antimicrobial profile and the ability of the strains to form biofilms.

Results

Cronobacter sakazakii was detected in 12 out of 100 cases of neonatal sepsis. The organism was also isolated from PIF, herbs, and water in percentages of 17.5, 9.2, and 7.5%, respectively. Regarding the antimicrobial sensitivity, all strains were resistant to ampicillin, amoxicillin, ampicillin/sulbactam, clindamycin, cephalothin, and cephalexin. In addition, C. sakazakii strains showed the ability to form biofilms, but with variable degrees of cell density.

Conclusion

We reported, for the first time, cases of neonatal sepsis caused by the emerging life-threatening pathogen C. sakazakii in Egypt. The organism was also detected in contaminated PIF, herbs, and water, which may be sources of infection for neonates, especially in countries where natural herbs are widely used as an alternative medicine. Finally, collective efforts by the parents, manufacturers of PIF, and healthcare personnel are essential to prevent serious infections caused by C. sakazakii, particularly in infants.

Profiling of microbiota in liquid baby formula consumed with an artificial nipple

It is suspected that oral bacteria are transferred to the liquid baby formula through the artificial nipple and multiply in the bottle after feeding. In the present study, in order to understand the influence of bacteria on liquid baby formula after feeding, the transfer of oral bacteria through artificial nipples and their survival in liquid baby formula were examined immediately after drinking as well as after storage at 4°C for 3 h. Four healthy human subjects (20-23 years old) were asked to drink liquid baby formula (Aptamil^®, ca. 50 mL) from baby bottles using artificial nipples. Samples of the liquid baby formula (immediately after drinking and 3 h later) were inoculated onto blood agar plates and incubated anaerobically at 37°C for 7 days. Salivary samples from each subject and 6 newborn infants were also cultured. Genomic DNA was extracted from individual colonies, and bacterial species were identified by 16S rRNA gene sequencing. The mean amounts of bacteria (CFU/mL) were (3.2 ± 3.0) ×10⁴ and (3.4 ± 3.3) ×10⁴ immediately after drinking and 3 h later, respectively. Streptococcus (41.6 and 40.5%), Actinomyces (24.3 and 21.5%) and Veillonella (16.2 and 11.0%) were recovered from the samples immediately after drinking and 3 h later, respectively. On the other hand, Streptococcus (38.9%), Actinomyces (17.1%), Neisseria (9.1%), Prevotella (6.9%), Rothia (6.9%) and Gemella (5.1%) were predominant in the saliva of adult subjects, and Streptococcus (65.2%), Staphylococcus (18.5%), Gemella (8.2%) and Rothia (5.4%) were predominant in the saliva of infant subjects. From these findings, oral bacteria, e.g., Streptococcus, Gemella and Rothia, were found to transfer into the liquid baby formula through artificial nipples, and the bacterial composition in the remaining liquid baby formula was found to resemble that of human saliva. The bacterial levels were similar between immediately after drinking and when stored at 4°C for 3 h, suggesting that the remaining liquid baby formula may be preserved in a refrigerator for a specified amount of time.

Why be serious about emetic Bacillus cereus: Cereulide production and industrial challenges

Cereulide, a potent toxin produced by Bacillus cereus, is a small, highly heat- and acid-resistant depsipeptide toxin, which confronts food industry with several challenges. Due to the ubiquitous presence of B. cereus in the environment, this opportunistic pathogen can enter food production and processing at almost any stage. Although the bacteria itself might be removed during food processing, the cereulide toxin will most likely not be destroyed or inactivated by these processes. Because of the high toxicity of cereulide and the high incidence rates often observed in connection with foodborne outbreaks, the understanding of the mechanisms of toxin production as well as accurate data on contamination sources and factors promoting toxin formation are urgently needed to prevent contamination and toxin production in food production processes. Over the last decade, considerable progress had been made on the understanding of cereulide toxin biosynthesis in emetic B. cereus, but an overview of current knowledge on this toxin with regards to food industry perspective is lacking. Thus, we aim in this work to summarize data available on extrinsic parameters acting on cereulide toxin synthesis in emetic B. cereus and to discuss the food industry specific challenges related to this toxin. Furthermore, we emphasize how identification of the cardinals in food production processes can lead to novel effective strategies for prevention of toxin formation in the food processing chain and could contribute to the improvement of existing HACCP studies.

A Retrospective Epidemiological Study of the Incidence and Risk Factors of Salmonellosis in Bahrain in Children During 2012⁻2016

Salmonellosis is one of the major public health concerns in Bahrain as it has increased rapidly during the past few years. This study aims to determine the prevalence of salmonellosis in children and the possible risk factors such as age, geographical area, nationality, gender, unsafe drinking water, infant born weight and gastrointestinal disease. The cases of salmonellosis in children reported by the Ministry of Health of Bahrain ranged from 21 to 26 per 100,000 population during the period 2012-2016. Salmonellosis cases were geographically concentrated in the capital and northern regions. Statistical analysis showed a significant difference in the number of salmonellosis cases between Bahrainis and non-Bahrainis based on region, and gender (p < 0.001). In the Bahraini cohort, there was an association between the increase of cases and the number of gastrointestinal disease-related deaths (p < 0.05). In addition, unsafe water (over the level of 2.14%) and low-birth weight (<3.100 g) were associated, but not statistically significant (p = 0.086 and p = 0.126, respectively) with the increase of salmonellosis cases. Despite the decline in the number of cases, the results of this study contribute to the understanding of the epidemiology of Salmonella in humans and this, in turn, will help develop and implement preventative measures.

Riscos microbiológicos de fórmulas para lactentes

Resumo O objetivo desse trabalho foi discorrer sobre os principais perigos biológicos encontrados em fórmulas infantis a partir dos relatos da literatura, especialmente de registros de surtos. Este estudo é de cunho exploratório por meio de revisão bibliográfica, sendo utilizados como fontes de dados sites de busca científica. Dentre os principais micro-organismos causadores de doenças ligadas à ingestão de fórmulas infantis estão o Cronobacter sakazakii e a Salmonella enterica, porém outras bactérias, como Clostridium botulinum, Klebsiella pneumoniae, Staphylococcus aureus e Bacillus cereus, podem ser responsáveis por contaminações destas fórmulas. Visto que lactentes apresentam os sistemas imunológico e metabólico ainda em desenvolvimento, estes representam um público mais vulnerável a contaminantes, fazendo-se fundamental o oferecimento de alimentos seguros desde o processamento na indústria até a administração nas residências e unidades hospitalares.

Underrecognized niche of spore-forming bacilli as a nitrite-producer isolated from the processing lines and end-products of powdered infant formula

Although nitrite in powdered milk formula (PIF) is a recognized health risk for infants, the presence of nitrite in PIF has only been investigated as a chemical contaminant during the inspection of end-products. The risk posed by microbial sources of nitrite during the PIF manufacturing process has not been considered. This is the first study to report the taxonomy and physiological characteristics of nitrite-producing bacteria isolated from PIF processing environments. All isolates identified as nitrite-producers (133 out of 501 strains collected over four years) from work-in-process and end-products of PIF were spore-forming bacilli. Nitrite-producing metabolism under PIF processing conditions was found in not only thermophilic isolates (3 Bacillus, 60 Geobacillus from 63 strains; 100%) but also in mesophilic isolates (65 Bacillus, 1 Anoxybacillus from 70 strains; 65.7%). Geobacillus was the only highly heat-resistant sporeformer and vigorous nitrite-producer exhibiting dramatic increases in nitrite over short periods of incubation (a maximum value within 3 h). High conversions of nitrate to nitrite (up to 88.8%) was also observed, highlighting bacteria as a key source of nitrite in PIF processing lines. Further research into the diversity of metabolic activity observed in this study can facilitate specialized management of nitrite-producers in PIF processing lines.

Assessment of microbiological contamination in saengshik products from the Korean market and identification of the irradiation status

This study investigated the prevalence of microbiological contamination in commercial Saengshik products (samples SP-1 to SP-12) from the Korean market, and identified their irradiation status. SP-2, SP-8, and SP-12 showed less than 3.66 and 1.10 log colony forming units (CFU)/g in total plate and coliforms counts, respectively, while the remaining samples showed more than 4.70 and 2.35 log CFU/g, respectively. Four samples were positive on some of foodborne pathogenic bacteria (Clostridium perfringens, Escherichia coli O157:H7, and Bacillus cereus). SP-2, SP-8, and SP-12 contained no pathogenic bacteria and were suspected to have been irradiated. They were confirmed as positive using photostimulated luminescence (PSL) analysis. PSL positive results on samples SP-2, SP-8 and SP-12 were finally confirmed by the authentic thermoluminescence (TL) analysis on the basis of TL glow curve shape, intensity, temperature range of TL peak maxima and TL ratio (TL₁/TL₂).

Microbiological evaluation of infant foods quality and molecular detection of Bacillus cereus toxins relating genes

A 205 samples representing eight different infant foods with various based materials were collected and analyzed for their microbiological properties. The contamination rate by aerobic spore formers was achieved 100% in milk based infant food with fruit, vegetables, honey, rice and infant milk powder. While, it was detected in 95, 60 and 65% of the infant food with wheat milk based, ready to use (infant food with fruit) and ready to use (infant food with vegetables), respectively. Biochemical Identification and API 50 CHB used to identify the obtained isolates and revealed that B. subtilis was the most frequently occurring Bacillus spp. Followed by B. licheniformis and B. circulans. While B. cereus was detected in 10.20% of the total isolates. Moreover, B. cereus was confirmed in 21.2% of milk based fruit, vegetables (15.7%), honey (17.2%), rice (14.1%) and wheat (12%) and vanished in the infant milk powder samples. Although, B. cereus noted in lower percentage but this strain is considered as the more harmful one in lower numbers. For that, the following part is focused on B. cereus. Forty five isolates obtained from B. Cereus contaminating samples were screened for prevalence of 3 important virulent enterotoxigenic genes using PCR technique. The CYTK gene had the highest presence which detected in 43 isolates (95.5%), followed by NHEC gene detected in 32 isolates. However, the HBLA gene was detected in just 5 isolates. So, many processes should be applied for controlling of pathogens to preserve infant lives.

Cronobacter sakazakii and Microbiological Parameters in Dairy Formulas Associated With a Food Alert in Chile

The objective of this study was to evaluate the presence of Cronobacter sakazakii and microbiological parameters in dairy products associated with a food alert. Ninety dairy product samples were analyzed, including seven commercial brands and two product types (liquid and powdered) from four countries. Aerobic plate count (APC) and Enterobacteriaceae count were performed according to Chilean standards. Cronobacter spp. and C. sakazakii were identified by polymerase chain reaction real time amplification of rpoB and cgcA genes and the genotype by multilocus sequence typing. Eighty-eight percent of dairy products showed APC higher than the detection limit. Fifty percent of liquid commercial brand samples contained APC: 2.6, 2.3, 1.1, and 2.9 CFU/mL in brands A, C, E, and G, respectively. Results for powdered commercial brands were 3.0, 3.6, and 5.7 CFU/g in brands B, D, and F, respectively. Maximum count (5.7 CFU/g) occurred in brand F dairy product manufactured in Chile. Enterobacteriaceae were found in 55% of the samples, 64% in liquid and 51% in powdered commercial brands. In 50% of brands B, D, and E, samples contained 2.9, 2.8, and 2.7 log CFU/g, respectively. Only liquid commercial brands from the United States had Enterobacteriaceae values between 0.1 and 4.5 CFU/mL. Seventeen suspicious strains were isolated and nine were identified as Enterobacter spp. Only eight suspicious strains from four powdered commercial brands (Chile and Singapore) were confirmed as C. sakazakii by rpoB and cgcA gene amplification and fusA sequencing. C. sakazakii prevalence in the analyzed samples was 8.8%. There were 11% of powdered milk brands that contained APC between 4.0 and 4.7 log CFU/g and 55% of the samples contained Enterobacteriaceae. C. sakazakii was found in dairy products manufactured in Chile and Singapore. On the basis of this information, the Chilean Ministry of Health (RSA) decreed a national and international food alert and recalled all the product batches that resulted positive in the present study from supermarkets and pharmacies.

Using PacBio Long-Read High-Throughput Microbial Gene Amplicon Sequencing To Evaluate Infant Formula Safety

Infant formula (IF) requires a strict microbiological standard because of the high vulnerability of infants to foodborne diseases. The current study used the PacBio single-molecule real-time (SMRT) sequencing platform to generate full-length 16S rRNA-based bacterial microbiota profiles of 30 Chinese domestic and imported IF samples. A total of 600 species were identified, dominated by Streptococcus thermophilus, Lactococcus lactis, and Lactococcus piscium. Distinctive bacterial profiles were observed between the two sample groups, as confirmed with both principal coordinate analysis and multivariate analysis of variance. Moreover, the product whey protein nitrogen index (WPNI), representing the degree of preheating, negatively correlated with the relative abundances of the Bacillus genus. This study has demonstrated the application of the PacBio SMRT sequencing platform in assessing the bacterial contamination of IF products, which is of interest to the dairy industry for effective monitoring of microbial quality and safety during production.

Inactivation of Bacillus cereus spores in a tsuyu sauce using continuous ohmic heating with five sequential elbow-type electrodes

AIMS

The effect of ohmic heating (OH) in a pilot plant system which had a zig-zag shaped (elbow-type) ohmic heater with five sequential voltage electrodes was investigated on Bacillus cereus spores in a commercial tsuyu sauce.

METHODS AND RESULTS

The electrical field was fixed at 26·7 V cm(-1) with an alternating current frequency of 25 kHz. Raw tsuyu sauce (50 l) inoculated with B. cereus spores was submitted in a 4 × 3 factorial design to the OH system and heated at 95, 105, 115, and 125°C each for 30, 60, and 90 s. Survival of B. cereus spores and colour change in the commercial tsuyu sauce were both measured before and after treatment. As the treatment temperature and time increased, the number of surviving B. cereus spores decreased. The OH treatment in a bath-type process at 105°C for more than 30 s resulted in the total inactivation of the inoculated B. cereus spores (average 5·4 log reductions to undetectable levels after treatment). The OH protocol of heating at 105°C for 60 s which ensure complete eradication of the inoculated spores without compromising product quality was chosen and investigated for its suitability for commercial application on bulk quantities of samples (500 l). Reliable and reproducible reductions in B. cereus spore counts of 4·7-5·5 log CFU ml(-1) (mean ± standard deviation = 5·1 ± 0·3 CFU ml(-1) ) were achieved by the selected protocol of the continuous OH treatment (105°C for 60 s).

CONCLUSION

This study suggests that OH treatment with five sequential elbow-type electrodes has great potential as an industrial sterilizing method for liquid food contaminated with B. cereus spores.

SIGNIFICANCE AND IMPACT OF THE STUDY

This procedure will enhance the microbiological quality of liquid foods while minimizing quality deterioration.

Evaluation of bacterial contamination in raw milk, ultra-high temperature milk and infant formula using single molecule, real-time sequencing technology

The Pacific Biosciences (Menlo Park, CA) single molecule, real-time sequencing technology (SMRT) was reported to have some advantages in analyzing the bacterial profile of environmental samples. In this study, the presence of bacterial contaminants in raw milk, UHT milk, and infant formula was determined by SMRT sequencing of the full length 16S rRNA gene. The bacterial profiles obtained at different taxonomic levels revealed clear differences in bacterial community structure across the 16 analyzed dairy samples. No indicative pathogenic bacteria were found in any of these tested samples. However, some of the detected bacterial species (e.g., Bacillus cereus, Enterococcus casseliflavus, and Enterococcus gallinarum) might potentially relate with product quality defects and bacterial antibiotic gene transfer. Although only a limited number of dairy samples were analyzed here, our data have demonstrated for the first time the feasibility of using the SMRT sequencing platform in detecting bacterial contamination. Our paper also provides interesting reference information for future development of new precautionary strategies for controlling the dairy safety in large-scale industrialized production lines.

Cronobacter Species Contamination of Powdered Infant Formula and the Implications for Neonatal Health

Cronobacter is a class of Enterobacteriaceae that cause infections in neonates, especially those born prematurely. Over 90% of these infections have been linked epidemiologically to powdered infant formula (PIF). Contamination of PIF can occur at manufacture, reconstitution, or storage of reconstituted product. Intrinsic properties that enable Cronobacter to cause disease include resistance to heat, ultraviolet radiation, oxygen radicals, stomach acids, and pasteurization; an ability to utilize sialic acid (a nutrition additive to PIF that facilitates the organism's growth and survival), and an exceptional affinity for biofilms in enteral feeding tubes. As part of ongoing endeavors to reduce the incidence of neonatal PIF-associated Cronobacter infections, the World Health Organization and the US Food and Drug Administration have established guidelines for PIF production, preparation for infant feeding, and storage of reconstituted product.

Survival of foodborne pathogenic bacteria (Bacillus cereus, Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, Staphylococcus aureus, and Listeria monocytogenes) and Bacillus cereus spores in fermented alcoholic beverages (beer and refined rice wine)

Only limited information is available on the microbiological safety of fermented alcoholic beverages because it is still a common belief that such beverages do not provide a favorable environment for bacterial growth and survival. Thus, in this study, we examined the survival of major foodborne pathogens and spores in fermented alcoholic beverages. Foodborne pathogens (Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica serovar Typhimurium, and Staphylococcus aureus) and B. cereus spores (initial population, 3 to 4 log CFU/ml) were inoculated separately into three types of beer and refined rice wine, which were then stored at 5 and 22°C. Bacterial counts were assayed periodically for up to 28 days. Vegetative B. cereus counts decreased rapidly, whereas B. cereus spore counts remained constant (P > 0.05) for a long period of time in all beverages. Vegetative B. cereus cells formed spores in beer at 5 and 22°C, and the spores survived for long periods. Among vegetative cells, E. coli O157:H7 had the highest survival (only 1.49 to 1.56 log reduction during 28 days in beer at 5°C). Beer and refined rice wine supported microbial survival from several days to several weeks. Our results appear to contradict the common belief that pathogens cannot survive in alcoholic beverages. Long-term survival of pathogens (especially B. cereus and E. coli O157:H7) in beer and refined rice wine should be taken into consideration by the manufacturers of these beverages. This study provides basic information that should help further research into microbial survival in alcoholic beverages and increase the microbiological safety regulation of fermented alcoholic beverages.

Food Safety: Emerging Pathogens

This article presents information related to emerging pathogens that are foodborne or have the potential to be foodborne including bacteria, viruses, and parasites. The phenotypic characteristics of these pathogens, their epidemiology, prevalence in foods, and transmission routes to humans as well as means for their control are also discussed.

Microbial diversity and prevalence of foodborne pathogens in cheap and junk foods consumed by primary schoolchildren

Aerobic plate counts (APC), coliforms, Bacillus cereus, Escherichia coli and eight foodborne pathogens were tested in 1008 cheap and junk foods, including candies, dried cakes, chewing gum, chocolate, dried and seasoned seafood, ice cream, and sugary foods. APCs were positive for 342 samples (33·9%), and the majority of the counts were 2-3 log CFU g(-1) or ml(-1) (average: 1·10 log CFU g(-1) or ml(-1) ). Most samples (97·3%) contained no coliforms (average: 0·07 log CFU g(-1) or ml(-1) ). Bacillus cereus was detected in 68 samples (average: 0·14 log CFU g(-1) or ml(-1) ). Escherichia coli and Listeria monocytogenes were detected in 6 and 1 samples, respectively, whereas other foodborne pathogens were not isolated. The highest bacterial counts were associated with dried and seasoned seafood products and dried cakes, suggesting that appropriate regulations of these food types should be considered. Cheap and junk foods were produced mainly in developing countries, but there were no significant differences in the bacterial counts among different countries of origin. The presence of foodborne pathogens may pose a risk for children. These results suggest that there is cause for deeper concern about the safety of these foods and that effective countermeasures should be established to improve their microbiological safety.

SIGNIFICANCE AND IMPACT OF THE STUDY

Food safety is especially important for children, but only limited information is available about the microbiological quality of cheap and junk foods that are consumed frequently by primary schoolchildren (e.g. dried cakes, candies and chocolates). The present study investigated the microbial quality of cheap and junk foods, and our results indicate that these foods are a potential health risk for children, therefore, deeper concern about the safety of these foods and effective countermeasures should be established to improve their microbiological safety. The present study may contribute to the development of an appropriate child food safety management system.

A rapid and simple screening method of Cronobacter spp. in cell suspension and tofu

BACKGROUND

Cronobacter spp. causes illnesses such as neonatal meningitis, sepsis and necrotising enterocolitis that can be fatal in infants and neonates. Thus it is of great concern to the food industry, which requires a simple and miniaturised method for the rapid detection of Cronobacter spp. in food.

RESULTS

A simple and rapid method was developed for the quantitative estimation of Cronobacter spp. Cell suspension cultures and tofu inoculated with Cronobacter spp. as well as a mixed culture (Cronobacter spp. and other micro-organisms) were serially diluted twofold on microtitre plates. Kim and Rhee broth, containing salicin, was added to each well. After 16-18 h of incubation the colour of broth in the wells changed from purple to yellow owing to salicin fermentation by Cronobacter spp. Bacterial counts were predicted by analysing the end points (the last well number in a series of positive wells). The coefficients of determination (r(2)) between the conventional plating method and the current method had high degrees of correlation (0.954-0.963), suggesting that the latter method offers a reasonable quantification of Cronobacter spp.

CONCLUSION

The simple method developed in this study could be used for the efficient and rapid screening of Cronobacter spp. in the food industry.

Quality and safety aspects of infant nutrition

Quality and safety aspects of infant nutrition are of key importance for child health, but oftentimes they do not get much attention by health care professionals whose interest tends to focus on functional benefits of early nutrition. Unbalanced diets and harmful food components induce particularly high risks for untoward effects in infants because of their rapid growth, high nutrient needs, and their typical dependence on only one or few foods during the first months of life. The concepts, standards and practices that relate to infant food quality and safety were discussed at a scientific workshop organized by the Child Health Foundation and the Early Nutrition Academy jointly with the European Society for Paediatric Gastroenterology, Hepatology and Nutrition, and a summary is provided here. The participants reviewed past and current issues on quality and safety, the role of different stakeholders, and recommendations to avert future issues. It was concluded that a high level of quality and safety is currently achieved, but this is no reason for complacency. The food industry carries the primary responsibility for the safety and suitability of their products, including the quality of composition, raw materials and production processes. Introduction of new or modified products should be preceded by a thorough science based review of suitability and safety by an independent authority. Food safety events should be managed on an international basis. Global collaboration of food producers, food-safety authorities, paediatricians and scientists is needed to efficiently exchange information and to best protect public health.