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 Spe I 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.

Detection and Molecular Characterization of <i>Cronobacter sakazakii</i>Isolated from Powdered Infant Formula (PIF) from North Central Region, Nigeria

Cronobacter sakazakii is an emerging ubiquitous and opportunistic pathogen that currently contaminates a wide spectrum of foods including powdered milk and poses a lethal threat to neonates, the elderly and persons with immune deficiencies. They cause life threatening neonatal meningitis, septicemia, and necrotizing enterocolitis. A total of 360 samples of powdered infant formula were collected from postnatal hospital attendees reconstituting the PIF for their children in the North Central region of Nigeria where cases of infant mortality are very high and presenting as enterocolitis and diarrhea. Pre-enriched samples were cultured in chromogenic Cronobacter broth and were then further sub-cultured into a chromogenic Cronobacter sakazakii agar. They were positive, exhibiting yellowish cultures typical of Cronobacter sakazakii. Biochemical tests of the isolates were also carried out and indicated the presence of Cronobacter sakazakii. The isolates were then characterized molecularly using specie specific PCR detection of Cronobacter sakazakii. The targeted genes of interest were ompA gene and CPA gene. The isolates tested showed bands for ompA gene on electrophoresis imager and were confirmed as Cronobacter sakazakii. In Nigeria, majority of infants are still fed with PIF. There is no existing data on the detection of Cronobacter sakazakii previously reported in the North central region of Nigeria hence the need to carry out the present study. The result of the study demonstrated the need for effective prevention and control measures as contamination of PIF with Cronobacter sakazakii constituted potential public health risk to neonates and infants.

A Survey on Occurrence of Melamine and Its Analogues in Tainted Infant Formula in China

Objective To investigate the occurrence and concentrations of melamine and its analogues in tainted infant formula and to identify the etiologic factors for the urinary stones epidemic in infants and young children in China in 2008. Methods Sanlu infant formula samples were collected from families of the affected children in Gansu province, and markets in Gansu and Hebei provinces and Beijing city. Melamine and its analogues, including cyanuric acid, ammeline, and ammelide were measured by gas chromatography/tandem mass spectrometry. Results High prevalence and concentrations of melamine were found in Sanlu infant formula samples, with low concentrations of cyanuric acid, ammeline and ammelide. Melamine were detected in 87 out of 111 Sanlu infant formula samples with a range of 118 to 4 700 mg/kg, Conclusion The results provide strong evidence for melamine as the etiological factor for the urinary stones epidemic in infants and young children in China in 2008.

Molecular and Epidemiological Characterization of Infant Botulism in Beijing, China

Laboratory-based pathogen isolation, identification, and toxicity determination were performed on samples from a suspected case of infant botulism. Mice injected with cultures generated from the enema sample and ingested Powered infant formula （PIF） presented typical signs of botulism. Antitoxins to polyvalent botulinum neurotoxins （BoNTs） and monovalent BoNT type B antitoxin had protective effects. Clostridium botulinum isolated from the enema and residual PIF samples were positive for type B toxin. Pulsed-field gel electrophoresis （PFGE） revealed that the two strains of C. botulinum isolated from the two samples produced indistinguishable pulsotypes. These findings confirmed this case of type B infant botulism associated with the ingestion of PIF contaminated bv type B C. botulinum spores.

Screening for Enterobacteriaceae Bacteria in Infant Formula Powder

A total of 151 infant formula powder samples were tested for the screening of the Enterobacteriaceae bacteria, and it had been contaminated by the conditioned pathogen like Enterobacter sakazakii, Klebsiella pneumoniae, Klebsiella oxytoca, and Enterobacter cloacae. The results showed that six samples were separated Enterobacter sakazakii, 24 samples were separated Enterobacteriaceae by using the traditional validation and real-time fluorescence quantitative PCR. Then the result identified by API20E biochemistry test and VITEC2 identification system. Through the study we concluded the potential safety hazard of the current infant formula powder and should regard Enterobacteriaceae as an indicator to carry out effective management, the neglected mild and discontinuity contamination could be easily found, thus to guarantee the safety of the special group.