Diurnal rhythmicity of infant fecal microbiota and metabolites: A randomized controlled interventional trial with infant formula

Microbiota assembly in the infant gut is influenced by diet. Breastfeeding and human breastmilk oligosaccharides promote the colonization of beneficial bifidobacteria. Infant formulas are supplemented with bifidobacteria or complex oligosaccharides, notably galacto-oligosaccharides (GOS), to mimic breast milk. To compare microbiota development across feeding modes, this randomized controlled intervention study (German Clinical Trial DRKS00012313) longitudinally sampled infant stool during the first year of life, revealing similar fecal bacterial communities between formula- and breast-fed infants (N = 210) but differences across age. Infant formula containing GOS sustained high levels of bifidobacteria compared with formula containing B. longum and B. breve or placebo. Metabolite and bacterial profiling revealed 24-h oscillations and circadian networks. Rhythmicity in bacterial diversity, specific taxa, and functional pathways increased with age and was strongest following breastfeeding and GOS supplementation. Circadian rhythms in dominant taxa were further maintained ex vivo in a chemostat model. Hence, microbiota rhythmicity develops early in life and is impacted by diet.

Co-culture of Cronobacter sakazakii and Staphylococcus aureus: Explore the influence of mixed biofilm formation and regulation of Cronobacter sakazakii biofilm formation genes

Bacterial biofilm is a protective matrix composed of metabolites secreted by bacteria that envelop bacteria. By forming a biofilm, bacteria can considerably improve their environmental tolerance. In food-related processing environment, different types of microorganisms are often present in biofilms. The main contaminating strain in the powdered infant formula (PIF) processing environment, Cronobacter sakazakii and Staphylococcus aureus continues to pollute the PIF processing environment after biofilm production. This study selected Cronobacter sakazakii with a weak biofilm-forming ability as one of the test organisms. The coexistence of Cronobacter sakazakii and Staphylococcus aureus on the surface of production equipment was simulated to analyze the interaction. Biofilm formation in the co-culture group was significantly higher than the others. In-depth study of the effect of Staphylococcus aureus on the biofilm formation genes of Cronobacter sakazakii. Results show two bacteria can coexist on the surface of a metal device, forming a more compact hybrid biofilm structure. Under co-culture conditions, S. aureus increased bcsA and fliD expression in Cronobacter sakazakii, whereas decreased bcsC expression. Signaling molecules produced by Staphylococcus aureus (Autoinducer 2) significantly promoted the biofilm formation of Cronobacter sakazakii at the concentration of 0-500 ng/mL (0.099-0.177) and up-regulated the expression of bcsA, filD and flhD genes.

Evaluation of the biocontrol potential of a collagen peptide/trehalose-based Cronobacter sakazakii phage powder in rehydrated powdered infant formula

Cronobacter sakazakii is a major foodborne pathogen that is mainly transmitted through powdered infant formula (PIF) and has a high mortality rate of up to 80%, particularly in fetuses and neonates. Bacteriophages have emerged as an effective biocontrol agent for antibiotic-resistant bacteria. In this study, lytic phage SG01 was newly characterized and loaded into collagen peptide/trehalose-based powders to develop an antibacterial agent against C. sakazakii contamination in PIF. The phage belongs to the Siphoviridae family, has an icosahedral head and a flexible tail, and showed rapid and persistent antibacterial activity up to 17 h. It was specifically active against C. sakazakii and also exhibited effective anti-biofilm properties. The phage was freeze-dried to a collagen peptide/trehalose-based powder and the phage was tested for viability, storage stability, and antibacterial activity. The optimal composition was 5% (w/v) collagen peptides and 1% (w/v) trehalose, which demonstrated the highest phage viability after freeze-drying. The phage remained stable in the collagen peptide/trehalose-based powder for up to four weeks at 4 °C and 25 °C, indicating that this is a desirable formulation for phage protection. Furthermore, the phage powder showed significant antibacterial efficacy in PIF, with a 4-log CFU/mL reduction within 6 h. Overall, the tested phage powder has the potential to be used as an antimicrobial agent in the food industry, particularly in powdered foods such as PIF.

Cronobacter spp. in foods of plant origin: occurrence, contamination routes, and pathogenic potential

Cronobacter is an emerging bacterial pathogen associated with infections such as necrotizing enterocolitis, sepsis, and meningitis in neonates and infants, related to the consumption of powdered infant formula. In addition, this bacterium can also cause infections in adults by the ingestion of other foods. Thus, this review article aims to report the occurrence and prevalence of Cronobacter spp. in foods of plant origin, as well as the possible sources and routes of contamination in these products, and the presence of pathogenic strains in these foods. Cronobacter was present in a wide variety of cereal-based foods, vegetables, herbs, spices, ready-to-eat foods, and foods from other categories. This pathogen was also found in cultivation environments, such as soils, compost, animal feces, rice and vegetable crops, as well as food processing industries, and domestic environments, thus demonstrating possible contamination routes. Furthermore, sequence types (ST) involved in clinical cases and isolates resistant to antibiotics were found in Cronobacter strains isolated from food of plant origin. The identification of Cronobacter spp. in plant-based foods is of great importance to better elucidate the vehicles and routes of contamination in the primary production chain and processing facility, until the final consumption of the food, to prevent infections.

Effects of a Novel Infant Formula on the Fecal Microbiota in the First Six Months of Life: The INNOVA 2020 Study

Exclusive breastfeeding is highly recommended for infants for at least the first six months of life. However, for some mothers, it may be difficult or even impossible to do so. This can lead to disturbances in the gut microbiota, which in turn may be related to a higher incidence of acute infectious diseases. Here, we aimed to evaluate whether a novel starting formula versus a standard formula provides a gut microbiota composition more similar to that of breastfed infants in the first 6 months of life. Two hundred and ten infants (70/group) were enrolled in the study and completed the intervention until 12 months of age. For the intervention period, infants were divided into three groups: Group 1 received formula 1 (INN) with a lower amount of protein, a proportion of casein to whey protein ratio of about 70/30 by increasing the content of α-lactalbumin, and with double the amount of docosahexaenoic acid/arachidonic acid than the standard formula; INN also contained a thermally inactivated postbiotic (Bifidobacterium animalis subsp. lactis). Group 2 received the standard formula (STD) and the third group was exclusively breastfed (BF) for exploratory analysis. During the study, visits were made at 21 days, 2, 4, and 6 months of age, with ±3 days for the visit at 21 days of age, ±1 week for the visit at 2 months, and ±2 weeks for the others. Here, we reveal how consuming the INN formula promotes a similar gut microbiota composition to those infants that were breastfed in terms of richness and diversity, genera, such as Bacteroides, Bifidobacterium, Clostridium, and Lactobacillus, and calprotectin and short-chain fatty acid levels at 21 days, 2 and 6 months. Furthermore, we observed that the major bacteria metabolic pathways were more alike between the INN formula and BF groups compared to the STD formula group. Therefore, we assume that consumption of the novel INN formula might improve gut microbiota composition, promoting a healthier intestinal microbiota more similar to that of an infant who receives exclusively human milk.

Limosilactobacillus reuteri DSM 17938-Containing Infant Formulas and the Associations with Gastrointestinal Tolerance: A Cross-Sectional Observational Study

Limosilactobacillus (L.; previously Lactobacillus) reuteri has been shown to influence gastrointestinal (GI) tolerance. This study was a secondary analysis of GI tolerance data from a multi-country, cross-sectional, observational study in healthy infants using the validated Infant Gastrointestinal Symptom Questionnaire (IGSQ) and a gut comfort questionnaire. Breastfed infants (BFI; n = 760) were compared to formula-fed infants receiving either L. reuteri-containing formula (FFI + LR; n = 470) or standard formula without any probiotic or prebiotic (FFI-Std; n = 501). The IGSQ composite scores (adjusted mean ± SE) in FFI + LR (22.17 ± 0.39) was significantly lower than in FFI-Std (23.41 ± 0.37) and similar to BFI (22.34 ± 0.30;), indicating better GI tolerance in FFI + LR than in FFI-Std. Compared with FFI-Std, FFI + LR had lower reports of difficulty in passing stools (11% vs. 22%; adjusted-odds ratio (OR) (95%CI) = 0.46 (0.31-0.68)), fewer hard stools (mean difference = -0.12 (-0.21, -0.02)) and less physician-confirmed colic (OR = 0.61 (0.45-0.82)), and similar to BFI. Parent-reported crying time (mean difference = -0.15 (-0.28, -0.01)), frequency of spitting-up/vomiting (mean difference = -0.18 (-0.34, -0.03)), volume of spit-up (mean difference = -0.20 (-0.32, -0.08)) and fussiness due to spitting-up/vomiting (mean difference = -0.17 (-0.29, -0.05)) were lower in FFI + LR versus FFI-Std and similar to BFI. In this study, L. reuteri-containing formula was associated with improved digestive tolerance and behavioral patterns.

Emerging of Multidrug-Resistant Cronobacter sakazakii Isolated from Infant Supplementary Food in China

Cronobacter is a foodborne pathogen associated with severe infections in restricted populations and particularly with high mortality in neonates and infants. The prevalence and antimicrobial resistance (AMR) phenotype of Cronobacter cultured from powdered infant formula and supplementary food were studied. The virulence factors, AMR genes, and genomic environments of the multidrug-resistant isolates were further studied. A total of 1,055 Cronobacter isolates were recovered from 12,105 samples of powdered infant formula and supplementary food collected from 29 provinces between 2018 and 2019 in China. Among these, 1,048 isolates were from infant supplementary food and 7 were from powdered infant formula. Regarding antimicrobial resistance susceptibility, 11 (1.0%) isolates were resistant and two showed resistance to four antimicrobials (ampicillin [AMP], tetracycline [TET], sulfamethoxazole-trimethoprim [SXT], and chloramphenicol [CHL]), defined as MDR. These two MDR isolates were subsequently identified as Cronobacter sakazakii sequence type 4 (ST4) (C. sakazakii Crono-589) and ST40 (C. sakazakii Crono-684). Both MDR isolates contain 11 types of virulence genes and 7 AMR genes on their genomes. Meanwhile, the IncFIB plasmids of both MDR C. sakazakii isolates also harbored 2 types of virulence genes. Results of the genomic comparative analysis indicated that food-associated C. sakazakii could acquire antimicrobial resistance determinants through horizontal gene transfer (HGT). IMPORTANCE As a foodborne pathogen, Cronobacter can cause serious infections in restricted populations and lead to death or chronic sequelae. Although a number of investigations showed that Cronobacter isolates are susceptible to most antimicrobial agents, MDR Cronobacter isolates, isolated mainly from clinical cases but occasionally from foods, have been reported in recent years. In this study, we successfully identified two MDR Cronobacter sakazakii isolates from infant foods based on nationwide surveillance and genome sequencing in China. Genomic analysis revealed that these two MDR C. sakazakii strains acquired resistance genes from other species via different evolution and transmission routes. It is important to monitor MDR C. sakazakii isolates in infant foods, and appropriate control measures should be taken to reduce the contamination with and transmission of this MDR bacterium.

Two Cases of Cronobacter Sakazakii Meningitis in Infants: The Importance Of Early Advanced Brain Imaging and Public Health Reporting

We report 2 infants hospitalized with Cronobacter sakazakii meningitis. Each infant had exposure to powdered infant formula at home. Both infants survived, but 1 infant had a subdural empyema drained and developed left sensorineural hearing loss. Early advanced brain imaging is recommended in infants with C. sakazakii meningitis. Reporting to state and federal public health officials may help identify outbreaks.

Influence of Human Milk on Very Preterms' Gut Microbiota and Alkaline Phosphatase Activity

The FEEDMI Study (NCT03663556) evaluated the influence of infant feeding (mother's own milk (MOM), donor human milk (DHM) and formula) on the fecal microbiota composition and alkaline phosphatase (ALP) activity in extremely and very preterm infants (≤32 gestational weeks). In this observational study, preterm infants were recruited within the first 24 h after birth. Meconium and fecal samples were collected at four time points (between the 2nd and the 26th postnatal days. Fecal microbiota was analyzed by RT-PCR and by 16S rRNA sequencing. Fecal ALP activity, a proposed specific biomarker of necrotizing enterocolitis (NEC), was evaluated by spectrophotometry at the 26th postnatal day. A total of 389 fecal samples were analyzed from 117 very preterm neonates. Human milk was positively associated with beneficial bacteria, such as Bifidobacterium, Bacteroides ovatus, and Akkermancia muciniphila, as well as bacterial richness. Neonates fed with human milk during the first week of life had increased Bifidobacterium content and fecal ALP activity on the 26th postnatal day. These findings point out the importance of MOM and DHM in the establishment of fecal microbiota on neonates prematurely delivered. Moreover, these results suggest an ALP pathway by which human milk may protect against NEC.

The Impact of Formula Choice for the Management of Pediatric Cow's Milk Allergy on the Occurrence of Other Allergic Manifestations: The Atopic March Cohort Study

OBJECTIVES

To compare the impact of different formulas on the occurrence of other atopic manifestations and the time of immune tolerance acquisition.

STUDY DESIGN

In a 36-month prospective cohort study, the occurrence of other atopic manifestations (eczema, urticaria, asthma, and rhinoconjunctivitis) and the time of immune tolerance acquisition were comparatively evaluated in immunoglobulin E-mediated children with cow's milk allergy (CMA) treated with extensively hydrolyzed casein formula containing the probiotic L. rhamnosus GG (EHCF + LGG), rice hydrolyzed formula, soy formula, extensively hydrolyzed whey formula (EHWF), or amino acid-based formula.

RESULTS

In total, 365 subjects were enrolled into the study, 73 per formula cohort. The incidence of atopic manifestations was 0.22 (Bonferroni-corrected 95% CI 0.09-0.34) in the EHCF + LGG cohort; 0.52 (0.37-0.67) in the rice hydrolyzed formula cohort; 0.58 (0.43-0.72) in the soy formula cohort; 0.51 (0.36-0.66) in the EHWF cohort; and 0.77 (0.64-0.89) in the amino acid-based formula cohort. The incidence of atopic manifestations in the rice hydrolyzed formula, soy formula, EHWF, and amino acid-based formula cohorts vs the EHCF + LGG cohort was always greater than the prespecified absolute difference of 0.25 at an alpha-level of 0.0125, with corresponding risk ratios of 2.37 (1.46-3.86, P < .001) for rice hydrolyzed formula vs EHCF + LGG; 2.62 (1.63-4.22, P < .001) for soy formula vs EHCF + LGG; 2.31 (1.42-3.77, P < .001) for EHWF vs EHCF + LGG; and 3.50 (2.23-5.49, P < .001) for amino acid-based formula vs EHCF + LGG. The 36-month immune tolerance acquisition rate was greater in the EHCF + LGG cohort.

CONCLUSIONS

The use of EHCF + LGG for CMA treatment is associated with lower incidence of atopic manifestations and greater rate of immune tolerance acquisition.

A Human Milk-Based Protein Concentrate Developed for Preterm Infants Retains Bioactive Proteins and Supports Growth of Weanling Rats

BACKGROUND

Bovine milk-based protein modulars are currently available to nutrient-enrich enteral feedings; however, they have limitations for use in very-low-birth-weight infants.

OBJECTIVES

Our objectives were to develop a human milk-based protein (HMP) concentrate and to conduct a preclinical assessment of the HMP concentrate in weanling rats.

METHODS

An HMP concentrate was produced from donor milk using pressure-driven membrane filtration processes and high hydrostatic pressure processing. Protein and lactoferrin concentrations and lysozyme activity were determined by Kjeldahl, HPLC, and turbidimetric assay, respectively. Male Sprague Dawley rats 24 d old (n = 30) were randomly assigned to 1 of 3 isocaloric AIN-93G diets for 4 wk containing 100% casein (control) or with 50% of the casein replaced with the HMP concentrate (treatment) or a bovine whey protein isolate (treatment). Body weight, food intake, fat mass, plasma amino acid profiles, and organ weights were measured. Data were analyzed using linear regression models.

RESULTS

Raw donor milk contained (mean ± SD) 101 ± 6 g protein/kg and 5 ± 1 g lactoferrin/kg of milk solids. Postprocessing, protein and lactoferrin concentrations were 589 ± 3 g/kg and 29 ± 10 g/kg, respectively. Lysozyme activity was initially 209 ± 4 U/kg and increased to 959 ± 39 U/kg in the HMP concentrate. There were no statistically significant differences in body weight, food intake, fat mass, or plasma amino acid profiles between rats fed diets containing the HMP concentrate and the control diet. Full cecum weights were higher in rats fed the HMP concentrate than in those fed control diets (mean difference: 5.59 g; 95% CI: 4.50, 6.68 g; P < 0.0001), likely reflecting the concentration of human milk oligosaccharides. No differences were found for other organ weights.

CONCLUSIONS

The HMP concentrate retained important bioactive proteins and supported normal rat growth in the preclinical assessment.

Transient Effect of Infant Formula Supplementation on the Intestinal Microbiota

Breastfeeding is the gold standard for feeding infants because of its long-term benefits to health and development, but most infants in the United States are not exclusively breastfed in the first six months. We enrolled 24 infants who were either exclusively breastfed or supplemented with formula by the age of one month. We collected diet information, stool samples for evaluation of microbiotas by 16S rRNA sequencing, and blood samples for assessment of immune development by flow cytometry from birth to 6 months of age. We further typed the Bifidobacterium strains in stool samples whose 16S rRNA sequencing showed the presence of Bifidobacteriaceae. Supplementation with formula during breastfeeding transiently changed the composition of the gut microbiome, but the impact dissipated by six months of age. For example, Bifidobacterium longum, a bacterial species highly correlated with human milk consumption, was found to be significantly different only at 1 month of age but not at later time points. No immunologic differences were found to be associated with supplementation, including the development of T-cell subsets, B cells, or monocytes. These data suggest that early formula supplementation, given in addition to breast milk, has minimal lasting impact on the gut microbiome or immunity.

The Sporobiota of the Human Gut

The human gut microbiome is a diverse and complex ecosystem that plays a critical role in health and disease. The composition of the gut microbiome has been well studied across all stages of life. In recent years, studies have investigated the production of endospores by specific members of the gut microbiome. An endospore is a tough, dormant structure formed by members of the Firmicutes phylum, which allows for greater resistance to otherwise inhospitable conditions. This innate resistance has consequences for human health and disease, as well as in biotechnology. In particular, the formation of endospores is strongly linked to antibiotic resistance and the spread of antibiotic resistance genes, also known as the resistome. The term sporobiota has been used to define the spore-forming cohort of a microbial community. In this review, we present an overview of the current knowledge of the sporobiota in the human gut. We discuss the development of the sporobiota in the infant gut and the perinatal factors that may have an effect on vertical transmission from mother to infant. Finally, we examine the sporobiota of critically important food sources for the developing infant, breast milk and powdered infant formula.

Fates of pathogenic bacteria in time-temperature-abused and Holder-pasteurized human donor-, infant formula-, and full cream cow's milk

This study was conducted to address the dearth in works that simultaneously compare the growth and inactivation behaviors of selected pathogens in different milk products. In worst-case scenarios where hygienic practices are absent and heavy microbiological contaminations occur, Salmonella enterica, Escherichia coli O157:H7, Listeria monocytogenes, Pseudomonas aeruginosa, and Staphylococcus aureus multiplied in all samples at room temperature (27 °C). Most organisms readily proliferated with growth lag (t_lag) values ranging from 0.00 to 5.95 h. Growth rates (K_G) ranged from 0.16 to 0.67 log CFU/h. Sanitary risk times (SRTs) for a 1-log population increase ranged from 1.85 to 6.27 h, while 3.69-12.55 h were the SRTs determined for 2-log population increase. Final populations (Pop_fin) ranged from 7.11 to 9.36 log CFU/mL. Inactivation in heavily contaminated milk during Holder pasteurization revealed biphasic inactivation behavior with total log reduction (TLR) after exposure to 62.5 °C for 30 min ranging from 1.91 (90.8%) to 6.00 (99.9999%). These results emphasize the importance food safety systems in the handling of milk and milk products during manufacture and preparation.

Postbiotics for Preventing and Treating Common Infectious Diseases in Children: A Systematic Review

Postbiotics have recently been tentatively defined as bioactive compounds produced during a fermentation process (including microbial cells, cell constituents and metabolites) that supports health and/or wellbeing. Postbiotics are currently available in some infant formulas and fermented foods. We systematically reviewed evidence on postbiotics for preventing and treating common infectious diseases among children younger than 5 years. The PubMed, Embase, SpringerLink, and ScienceDirect databases were searched up to March 2019 for randomized controlled trials (RCTs) comparing postbiotics with placebo or no intervention. Seven RCTs involving 1740 children met the inclusion criteria. For therapeutic trials, supplementation with heat-killed Lactobacillus acidophilus LB reduced the duration of diarrhea (4 RCTs, n = 224, mean difference, MD, -20.31 h, 95% CI -27.06 to -13.57). For preventive trials, the pooled results from two RCTs (n = 537) showed that heat-inactivated L. paracasei CBA L74 versus placebo reduced the risk of diarrhea (relative risk, RR, 0.51, 95% CI 0.37-0.71), pharyngitis (RR 0.31, 95% CI 0.12-0.83) and laryngitis (RR 0.44, 95% CI 0.29-0.67). There is limited evidence to recommend the use of specific postbiotics for treating pediatric diarrhea and preventing common infectious diseases among children. Further studies are necessary to determine the effects of different postbiotics.

Prevalence and genetic characteristics of Cronobacter spp. from food and human clinical stool samples in Wenzhou, China 2008-2018

Pathogenic Cronobacter species are responsible for life-threatening illness in neonates. A ten-year comprehensive survey was conducted to examine the population structure and antimicrobial resistant patterns of Cronobacter isolates from food (n = 78) and clinical (n = 12) sources in Wenzhou, China. A total of 90 (4.4%) isolates were recovered from 2051 collected samples. The occurrence of Cronobacter spp. was highest in spices with a rate of 22% (26/119), whereas the lowest contamination rate of 1% was found in powered infant and toddler formula (7/494), special medical infant formula (1/95) and human stool samples (12/1024). Cronobacter strains revealed a high degree of genetic diversity among the isolates tested. Pulsed-field gel electrophoresis (PFGE) distinguished 75 clonal groups, and the biggest cluster consisted of four strains. Multilocus sequence typing (MLST) method displayed 43 sequence types (STs), of which ST1, ST4, ST8, ST64, ST148 and ST201 were most frequently identified. Meanwhile, two new sequence types were discovered and added to the PubMLST international database. Resistance to ceftriaxone, cefotaxiv, amoxicillin, ampicillin, cefoxitin, tetracycline, streptomycin, azithromycin, chloramphenicol, as well as multidrug resistance, was noted. Taken together, this large-scale surveillance study highlights the wide dissemination and diverse molecular features of Cronobacter spp. in Wenzhou China.

Validation of the TadpoleTM Campylobacter jejuni Real-Time PCR Identification Kit

Background: The gene-based real-time PCR method for identification of Campylobacter jejuni is more simple, rapid and accurate than the traditional biochemical method. Objective: A performance validation of the Tadpole^TMCampylobacter jejuni Real-Time PCR Identification Kit was performed. Method: The assay uses TaqMan Real-time PCR technology to amplify target genes from isolated colonies. Bacterial deoxyribonucleic acid (DNA) from inclusivity and exclusivity organisms cultured on Columbia Blood Agar, Campy-Cefex agar and modified Charcoal Cefoperazone Deoxycholate was extracted and analyzed on three instruments: Applied Biosystems (ABI) 7500 Fast, ABI StepOne Plus and Bio-Rad CFX96. Results: When 57 distinct strains of C. jejuni were tested for inclusivity, all 57 strains produced positive results on the three instruments. In exclusivity testing, all 35 strains of related organisms, including 7 non-target Campylobacter strains and other common species, produced negative results on the three instruments. The Independent Laboratory validation consisting of an inclusivity and exclusivity evaluation for 10 C. jejuni isolates and 10 nontarget Campylobacter isolates also showed 100% expected results on the three instruments. In addition, in robustness testing, small, deliberate changes to the assay parameters, including cell suspension turbidity, heat lysis time, and DNA template volume in the PCR reaction, did not affect the kit performance. Finally, the combined lot-to-lot and stability study on both the ABI 7500 Fast and the ABI StepOne Plus showed that the 11 C. jejuni strains and 5 nontarget Campylobacter strains can be correctly identified by the three independently manufactured, lots and it supported a shelf life of 9 months when stored at -20°C. Conclusions: The Tadpole method offers a rapid, accurate, and robust alternative for C. jejuni identification. Highlights: Rapid and accurate method to identify C. jejuni, which has a good robustness and high stability. It is flexible and offers the advantages of reduced labor and time saving.

Validation of Biomode S.A. Probe4CronobacterTM for the Identification of Cronobacter spp

Background: Probe4Cronobacter test kit is based on the use of a fluorescence-labeled peptide nucleic acid probe (PNA) allied to fluorescence microscopy. A sample is taken after a 24 h enrichment of rehydrated 30 g portions of powdered infant formula (PIF). The method uses ready to use dropper solutions applied directly in the sample. This simple process takes less than 2 h to provide a result. In the presence of Cronobacter species, bright red rod-shaped cells will be visible under a fluorescence microscope. Objective: Probe4Cronobacter validation as a new method for the detection Cronobacter species in Powdered Infant Formula (PIF) under the AOAC Performance Tested MethodsSM (License No. 081702). Methods: The validation study encompassed matrix comparison study, inclusivity and exclusivity testing and robustness studies (stability, kit variation, and ruggedness). Results: The inclusivity and exclusivity testing (50 and 35 strains, respectively) yielded no false negative or false positive results. Probe4Cronobacter was compared to the ISO/TS 22964:2006 in 30 g of PIF samples within method comparison in an unpaired study. A total of 30 samples with both low and high level of inoculation were analyzed by Probe4Cronobacter and compared to the same number of samples screened by ISO/TS 22964:2006. No statistically significant differences between presumptive and confirmed results or between candidate and reference method results were observed. Robustness studies showed a high level of consistency and integrity of the kit when different parameters were varied. The deviation conditions tested did not affect the performance of the kit. Conclusions: Probe4Cronobacter test kit has shown to be a accurate, highly sensitive and robust methods for the detection of Cronobacter spp. in PIF samples.

Enteral administration of bacteria fermented formula in newborn piglets: A high fidelity model for necrotizing enterocolitis (NEC)

Objective

To develop an animal model which replicates neonatal NEC and characterizes the importance of bacterial fermentation of formula and short chain fatty acids (SCFAs) in its pathogenesis.

Background

NEC is a severe form of intestinal inflammation in preterm neonates and current models do not reproduce the human condition.

Methods

Three groups of newborn piglets: Formula alone (FO), Bacteria alone (E.coli: BO) and E.coli-fermented formula (FF) were anesthetized, instrumented and underwent post-pyloric injection of formula, bacteria or fermented-formula. SCFA levels were measured by gas chromatography-mass spectrometry. At 6 h bowel appearance was assessed, histologic and molecular analysis of intestine were performed. Gut inflammation (p65 NF-κB, TLR4, TNF-α, IL-1β), apoptosis (cleaved caspase-3, BAX, apoptosis) and tight junction proteins (claudin-2, occludin) were measured.

Results

SCFAs were increased in FF. Small bowel from FF piglet’s demonstrated inflammation, coagulative necrosis and pneumatosis resembling human NEC. Histologic gut injury (injury score, mast cell activation) were increased by Bacteria, but more severe in FF piglets. Intestinal expression of p65 NF-κB, NF-κB activation, TNF-α and IL-1β were increased in BO and markedly increased in the FF group (P<0.05 vs. FO). Intestine from Bacteria piglets demonstrated increased apoptotic index, pro-apoptotic protein expression and decreased tight junction proteins. These changes were more severe in FF piglets.

Conclusions

Our piglet model demonstrates the findings of NEC in human neonates: systemic acidosis, intestinal inflammation, pneumatosis and portal venous gas. Bacteria alone can initiate intestinal inflammation, injury and apoptosis, but bacterial fermentation of formula generates SCFAs which contribute to the pathogenesis of NEC.

Use of infant formula in the ELFE study: The association with social and health-related factors

Breastfeeding is recommended until 6 months of age, but a wide range of infant formula is available for nonbreastfed or partially breastfed infants. Our aim was to describe infant formula selection and to examine social- and health-related factors associated with this selection. Analyses were based on 13,291 infants from the French national birth cohort Etude Longitudinale Française depuis l'Enfance. Infant diet was assessed at Month 2 by phone interview and monthly from Months 3 to 10 via internet/paper questionnaires. Infant formulas were categorized in 6 groups: extensively or partially hydrolysed, regular with or without prebiotics/probiotics, and thickened with or without prebiotics/probiotics. Associations between type of infant formula used at 2 months and family or infant characteristics were assessed by multinomial logistic regressions. At Month 2, 58.1% of formula-fed infants were fed with formula enriched in prebiotics/probiotics, 31.5% with thickened formula, and 1.4% with extensively hydrolysed formula. The proportion of formula-fed infants increased regularly, but the type of infant formula used was fairly stable between 2 and 10 months. At Month 2, extensively hydrolysed formulas were more likely to be used in infants with diarrhoea or regurgitation problems. Partially hydrolysed formulas were more often used in families with high income, with a history of allergy, or with infants with regurgitation issues. Thickened formulas were used more with boys, preterm infants, infants with regurgitation issues, or in cases of early maternal return to work. The main factors related to the selection of infant formula were family and infant health-related ones.

Development and Application of a Probabilistic Risk-Benefit Assessment Model for Infant Feeding Integrating Microbiological, Nutritional, and Chemical Components

A probabilistic and interdisciplinary risk-benefit assessment (RBA) model integrating microbiological, nutritional, and chemical components was developed for infant milk, with the objective of predicting the health impact of different scenarios of consumption. Infant feeding is a particular concern of interest in RBA as breast milk and powder infant formula have both been associated with risks and benefits related to chemicals, bacteria, and nutrients, hence the model considers these three facets. Cronobacter sakazakii, dioxin-like polychlorinated biphenyls (dl-PCB), and docosahexaenoic acid (DHA) were three risk/benefit factors selected as key issues in microbiology, chemistry, and nutrition, respectively. The present model was probabilistic with variability and uncertainty separated using a second-order Monte Carlo simulation process. In this study, advantages and limitations of undertaking probabilistic and interdisciplinary RBA are discussed. In particular, the probabilistic technique was found to be powerful in dealing with missing data and to translate assumptions into quantitative inputs while taking uncertainty into account. In addition, separation of variability and uncertainty strengthened the interpretation of the model outputs by enabling better consideration and distinction of natural heterogeneity from lack of knowledge. Interdisciplinary RBA is necessary to give more structured conclusions and avoid contradictory messages to policymakers and also to consumers, leading to more decisive food recommendations. This assessment provides a conceptual development of the RBA methodology and is a robust basis on which to build upon.

[Study on species identification of Cronobacter isolated from infant formula foods and cereal based foods and clinical diarrhea cases in 2012-2014 in China]

OBJECTIVE

To develop a Cronobacter spieces identification PCR method based on RNA polymerase beta subunit( rpo B) gene and identify species of Cronobacter isolated from different sources.

METHODS

A total of 7 primer pairs based on the rpo B were design, and 9 standard strains were set as reference strains to identify species of261 strains isolated from infant formula foods, cereal based foods and clinical diarrhea cases in 2012-2014 in China.

RESULTS

The molecular weight of 9 standard strains were as same as expect, 179 of 216 Cronobacter isolates were C. sakazakii, 56 were C. malonaticus, 13 were C. universalis, 11 were C. dublinensis, 2 were C. turicensis, accounted for 68. 58%, 21. 46%, 4. 98%, 4. 21% and 0. 77% of the total isolates, respectively.

CONCLUSION

The Cronobacter species identification PCR system is specific, convenient, sensitive. This system can provide technical support for Cronobacter risk surveillance and control in China.

Detection of Mycobacterium avium subspecies paratuberculosis in powdered infant formula using IS900 quantitative PCR and liquid culture media

Mycobacterium avium subspecies paratuberculosis (MAP) has been implicated in Crohn's disease in humans resulting in public concern over the presence of MAP in powdered infant formula, which could contribute towards early human exposure to MAP or MAP components. Testing of representative powdered infant formula samples using effective tests is required to provide information on contamination of infant formula with MAP, so that consumers can make informed decisions. This study aimed to test representative powdered infant formula samples for the presence of MAP using a quantitative PCR and liquid culture method. For this purpose, an efficient DNA extraction method was developed and an optimum decontamination protocol for culture method was identified. A total of 122 powdered infant formula samples were tested, comprising 72 brands produced by 12 manufacturers from 9 countries. Powdered infant formula samples were reconstituted and centrifuged to separate the casein pellet, cream layer and whey fraction. A sensitive qPCR test was performed on DNA extracted from the casein pellet. In addition, the cream layer and casein pellet were cultured in liquid media, following decontamination with the optimum protocol. Of the 122 samples tested, 6 were positive for MAP DNA but none were positive for growth in culture at 12 and 20 weeks. The limit of detection of the quantitative PCR was less than 5 MAP organisms per 1.5g milk powder. The methods developed in the study could be used for quality assurance testing for infant formula and calf milk replacers. The low contamination level of MAP and absence of viable forms in our study suggests a relatively low risk of exposure of infants to MAP components.

Surveillance and molecular typing of Cronobacter spp. in commercial powdered infant formula and follow-up formula from 2011 to 2013 in Shandong Province, China

BACKGROUND

Infection with Cronobacter spp. leads to neonatal meningitis, necrotizing enterocolitis and bacteremia. Cronobacter spp. are reported to comprise an important pathogen contaminating powdered infant formula (PIF) and follow-up formula (FUF), although little is known about the contamination level of Cronobacter spp. in PIFs and FUFs in China.

RESULTS

In total, 1032 samples were collected between 2011 and 2013. Forty-two samples were positive, including 1.6% in PIFs and 6.5% in FUFs. The strains were susceptible to most antibiotics except for cefoxitin. Pulsed-field gel electrophoresis after XbaI digestion produced a total of 36 banding patterns. The 38 strains were found in 27 sequence types (STs), of which nine types (ST454 to ST462) had not been reported in other countries. The clinically relevant strains obtained from the 38 isolates in the present study comprised three ST3, two ST4, two ST8 and one ST1.

CONCLUSION

The contamination rate in the PIF and FUF has stayed at a relatively high level. The contamination rate of PIF was significantly lower than FUF. The isolates had high susceptibility to the antibiotics tested, except cefoxitin. There were polymorphisms between the Cronobacter spp. as indicated by pulsed-field gel electrophoresis and multilocus sequence typing. Therefore, contamination with Cronobacter spp. remains a current issue for commercial infant formulas in China. © 2016 Society of Chemical Industry.

Contaminated milk is a common cause of necrotising enterocolitis: A hypothesis

Necrotising enterocolitis (NEC) is the most commonly acquired gastrointestinal disease of neonates, particularly the very preterm (gestation <32 weeks) and/or very low birth weight (<1500g). It is associated with high morbidity and mortality. Despite improvement in neonatal care and increased use of expressed breast milk (EBM), the incidence remains high in many neonatal intensive care units (NICU), and even shows increasing trend in some countries. Numerous studies have pointed to the infective nature of NEC. Some investigators have reported an increase in the incidence of NEC in their NICU when the percentage of infants with pathogens isolated from their gut increased, and decreased when gut colonisation rate was low. Both bacteria and viruses have been reported to be associated with outbreaks of NEC. The majority (>90%) of the NEC cases occurred in neonates on enteral feeding. Studies have shown that milk (whether EBM or formula) fed to neonates was not sterile and were further contaminated during collection, transport, storage and/or feeding. Other investigators have reported a reduction in the incidence of NEC when they improved infection control measures and hygienic procedures in handling milk. It is, therefore, hypothesised that the most common cause of NEC is due to the feeding of neonates, particularly the vulnerable very preterm small neonates, with milk heavily contaminated during collection at source, transport, storage and/or feeding. Because of the immaturity of the immune system of the neonates, excessive inflammatory response to the pathogen load in the gut leads to the pathogenesis of NEC.

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.

Exposure Assessment of Infants to Aflatoxin M₁ through Consumption of Breast Milk and Infant Powdered Milk in Brazil

Aflatoxin M₁ (AFM₁) is an important biomarker that can be used to evaluate aflatoxin exposure in both humans and animals. The aim of this study was to evaluate the exposure degree of infants to AFM₁ through consumption of breast milk and infant powdered milk in Brazil. For this purpose, the estimated daily intake (EDI) for infants was calculated based on the AFM₁ levels analyzed in 94 breast milk (BM) samples collected in Southern Brazil, and 16 infant powdered milk (IPM) samples commonly commercialized in Brazil. AFM₁ was detected in 5.3% (n = 5) and 43.8% (n = 7) of BM and IPM samples, with mean levels of 0.003 ng/g and 0.011 ng/g, respectively. All the IPM samples showed AFM₁ levels lower than those established by the Brazilian guidelines (5 ng/g), and in most of the samples (81.25%) levels were below the maximum limit tolerated by the European Commission (0.025 ng/g). The EDI of AFM₁ for infants aged zero to 12 months old showed values from 0.018 to 0.069 ng/kg body weight/day for BM, and 0.078 to 0.306 ng/kg body weight/day for IPM. Hazard index (HI) values for BM and IPM were less than one, except for IPM intended for infants up to one month. In conclusion, the exposure of infants to AFM₁ was low, but continuous monitoring of mycotoxin levels is essential to minimize infant health risk.

Evaluation of a Commercial Real-Time PCR Kit for the Detection of Mycobacterium avium subspecies paratuberculosis in Milk

There are several commercial test kits for Mycobacterium avium subspecies paratuberculosis (MAP) detection, each with different advantages, disadvantages, and applications. In the present study, a real-time PCR kit targeting the unique transposon sequence ISMAP02 was evaluated. The analytical sensitivity was determined using the type strain ATCC 19698, and the specificity was validated by testing fifteen MAP isolates, thirteen non-MAP Mycobacterium isolates, and eight non-Mycobacterium isolates. Six spiking experiments were performed using raw milk and reconstituted infant milk artificially contaminated with dilutions containing 10(0)-10(5) MAP cells mL(-1). Sensitivity and specificity were at 100 %. The detection probabilities in raw milk and reconstituted infant milk for the samples (containing 1.4 × 10(1) and 1.7 × 10(1) MAP cell 50 mL(-1)) were 16.6 and 91.6 %, respectively. Thus, the tested kit yielded satisfying results to detect MAP in milk.

The Survey of Cronobacter spp. (formerly Enterbacter sakazakii) in Infant and Follow-up Powdered Formula in China in 2012

OBJECTIVE

To determine Cronobacter spp. contamination in infant and follow-up powdered formula in China.

METHODS

All of 2282 samples were collected from the retail markets in China from January 2012 to December 2012, and analyzed for Cronobacter spp. by the Chinese National Food Safety Standard. Characterization of the isolates was analyzed by pulsed-field gel electrophoresis (PFGE) with XbaI and SpeI restriction enzymes.

RESULTS

Cronobacter spp. strains were isolated from 25 samples, and the positive rates in infant powdered formulas and follow-up powdered formulas were 0.90% (10/1011) and 1.18% (15/1271), respectively. Analysis of variable data regarding different purchasing store formats, seasonality, and production locations as well as comparison of infant versus follow-up formulas did not reveal statistically significant factors. During the sampling period, one of six surveillance zones did exhibit a statistically significant trend towards higher positive rate. PFGE characterization of Cronobacter spp. to elucidate genetic diversity revealed only three pairs of Cronobacter spp. out of 25 having the same PFGE patterns.

CONCLUSION

The current investigation indicated a lower positive rate of Cronobacter spp. in the powdered formula in China. This evidence suggested contamination originating from multiple different sources during the manufacturing process.

Isolation and Identification Enterobacter asburiae from Consumed Powdered Infant Formula Milk (PIF) in the Neonatal Intensive Care Unit (NICU)

Enterobacter asburiae (E. asburiae) is a facultative anaerobic, non-spore-forming gram-negative rod-shaped bacterium belonging to the family of Enterobacteriaceae. It is an opportunistic pathogen that its strains are isolated from a variety of clinical and environmental specimens. Since powdered infant formula milk (PIF) is not a sterile product, it is an excellent medium for bacterial growth. The aim of this study was to isolate and identify E. asburiae from PIF in the neonatal intensive care unit (NICU) and determine antimicrobial susceptibility patterns of this bacterium. A total 125 PIF samples were purchased from drug stores between June 2011 to March 2012. E. asburiae was isolated according to FDA method. For final confirmation, biochemical tests embedded in the API-20E system were used. The drug susceptibility test was performed using the disc diffusion method according to CLSI recommendations. Out of the 125 PIF samples investigated, 2 (1.6%) samples were positive for E. asburiae. All isolated strains were uniformly susceptible to aztreonam, cefotaxim, amikacin, streptomycin, nalidixic acid, meropenem, tetracycline, ceftazidime, and colistin. Variable susceptibility was seen to the some antimicrobial agents tested. Each country should categorize its own designed guidelines for the preparation and handling of PIF adapted to the local environment. Moreover, the pathogenesis of the E. asburiae in infants hospitalized in NICU and other groups such as immunosuppressed patients and HIV infected individuals is uncertain and requires further study.

[Effect of Lactobacillus acidophilus on metabolizing lactic acid in formula milk: a quantitative analysis of the effect of erythritol]

OBJECTIVE

To evaluate the lactic acid productivity of Lactobacillus acidophilus (La) exposed to formula milk containing different concentration of erythritol.

METHODS

La was cultured under anaerobic condition (80% N(2), 10% CO(2), 10% H(2)) at 37 °C in five experimental groups (formula milk mixed with different concentrations of erythritol). The five experimental groups contained 1%, 2%, 4%, 6%, and 8% erythritol, respectively (groups 1% E-M, 2% E-M, 4% E-M, 6% E-M, 8% E-M). Formula milk served as control group (group M). The lactic acid was analyzed by high performance liquid chromatography (HPLC) at 4 h intervals during 24 h. The peak-area of lactic acid was recorded and used to calculate the concentration of lactic acid through the equation of a standard curve (y = 590 244x + 67 507). ANOVA and Tukey HDS analysis were used to analyze the data.

RESULTS

The concentration of lactic acid at 24 h was group M [(4.693 ± 0.105) g/L], group 1% E-M[(4.114 ± 0.186) g/L], group 2% E-M[(3.720 ± 0.158) g/L], group 4% E-M[(3.045 ± 0.152) g/L], group 6% E-M[(2.971 ± 0.086) g/L], group 8% E-M[(2.789 ± 0.142) g/L]. Statistically significant differences in lactic acid concentrations were found between different time points (P < 0.05) and between different groups (F = 187.448, P < 0.05). Moreover, the concentrations of lactic acid in each experimental group was lower than that in control group (P < 0.05). The difference among groups 4% E-M, 6% E-M, and 8% E-M were not statistically significant (P > 0.05).

CONCLUSIONS

Erythritol showed the inhibition potential against La in metabolizing lactic acid in formula milk. The effect of erythritol was concentration depended. The higher concentration of erythritol contained in the milk, the better the inhibition potential against La in metabolizing lactic acid.

Comparative Genotypic and Phenotypic Analysis of Cronobacter Species Cultured from Four Powdered Infant Formula Production Facilities: Indication of Pathoadaptation along the Food Chain

Cronobacter species are opportunistic pathogens commonly found in the environment. Among the seven Cronobacter species, Cronobacter sakazakii sequence type 4 (ST-4) is predominantly associated with recorded cases of infantile meningitis. This study reports on a 26-month powdered infant formula (PIF) surveillance program in four production facilities located in distinct geographic regions. The objective was to identify the ST(s) in PIF production environments and to investigate the phenotypic features that support their survival. Of all 168 Cronobacter isolates, 133 were recovered from a PIF production environment, 31 were of clinical origin, and 4 were laboratory type strains. Sequence type 1 (n = 84 isolates; 63.9%) was the dominant type in PIF production environments. The majority of these isolates clustered with an indistinguishable pulsotype and persisted for at least an 18-month period. Moreover, DNA microarray results identified two phylogenetic lineages among ST-4 strains tested. Thereafter, the ST-1 and -4 isolates were phenotypically compared. Differences were noted based on the phenotypes expressed by these isolates. The ST-1 PIF isolates produced stronger biofilms at both 28°C and 37°C, while the ST-4 clinical isolates exhibited greater swimming activity and increased binding to Congo red dye. Given the fact that PIF is a low-moisture environment and that the clinical environment provides for an interaction between the pathogen and its host, these differences may be consistent with a form of pathoadaptation. These findings help to extend our current understanding of the epidemiology and ecology of Cronobacter species in PIF production environments.

Microbiological quality of enteral feeding and infant formula produced in dietary units, according to the triad of Donabedian

INTRODUCTION AND AIMS

Microbial contamination of enteral feeding and infant formulas can result in a risk of worsening of the clinical condition of the patients, who are already weakened and susceptible to pathogens. The objective was to evaluate aspects of the management of quality hygienic - sanitary of enteral feeding and infant formulas in hospitals, focusing on the structure, process and outcome.

METHODS

An observational, descriptive, prospective, with quantitative and qualitative variables study was done. The survey was conducted for 12 months and 227 samples of enteral feeding and 176 of infant formula were collected in Nutrition and Dietetic Services of Health Secretary / Federal District. In evaluating the operating conditions, the Tool 2 was applied to: Enteral Nutrition Preparation. Data were analyzed from the unified Donabedian's triad for evaluation of health services.

RESULTS

The results obtained with the Tool 2 demonstrated that the Storage Block complies with legal requirements. Moreover, Dressing Block is a risk factor for the contamination. From the 403 samples, 56% corresponded to samples of Enteral Nutrition and 44% to samples of Infant Formulas. The data indicate that from 227 samples of Enteral Nutrition, 6.2% were in disagreement with the legislation, while from 176 samples of Infant Formulas, 4.6% were also in disagreement with the legislation.

CONCLUSION

The ineffective implementation of the sanitary and hygienic requirements during the preparation results in a microbiologically unsafe product to patients in debilitated health state, and the count of mesophilic microorganisms can be a good indicator of microbiological safety.

Functional Screening of the Cronobacter sakazakii BAA-894 Genome reveals a role for ProP (ESA_02131) in carnitine uptake

Cronobacter sakazakii is a neonatal pathogen responsible for up to 80% of fatalities in infected infants. Low birth weight infants and neonates infected with C. sakazakii suffer necrotizing enterocolitis, bacteraemia and meningitis. The mode of transmission most often associated with infection is powdered infant formula (PIF) which, with an aw of ∼0.2, is too low to allow most microorganisms to persist. Survival of C. sakazakii in environments subject to extreme hyperosmotic stress has previously been attributed to the uptake of compatible solutes including proline and betaine. Herein, we report the construction and screening of a C. sakazakii genome bank and the identification of ProP (ESA_02131) as a carnitine uptake system.

Plant compounds enhance the assay sensitivity for detection of active Bacillus cereus toxin

Bacillus cereus is an important food pathogen, producing emetic and diarrheal syndromes, the latter mediated by enterotoxins. The ability to sensitively trace and identify this active toxin is important for food safety. This study evaluated a nonradioactive, sensitive, in vitro cell-based assay, based on B. cereus toxin inhibition of green fluorescent protein (GFP) synthesis in transduced monkey kidney Vero cells, combined with plant extracts or plant compounds that reduce viable count of B. cereus in food. The assay exhibited a dose dependent GFP inhibition response with ~25% inhibition at 50 ng/mL toxin evaluated in culture media or soy milk, rice milk or infant formula, products associated with food poisonings outbreak. The plant extracts of green tea or bitter almond and the plant compounds epicatechin or carvacrol were found to amplify the assay response to ~90% inhibition at the 50 ng/mL toxin concentration greatly increasing the sensitivity of this assay. Additional studies showed that the test formulations also inhibited the growth of the B. cereus bacteria, likely through cell membrane disruption. The results suggest that the improved highly sensitive assay for the toxin and the rapid inactivation of the pathogen producing the toxin have the potential to enhance food safety.