scholarly journals Thermal Inactivation of Mycobacterium avium subsp. paratuberculosis in Artificially Contaminated Milk by Direct Steam Injection

2016 ◽  
Vol 82 (9) ◽  
pp. 2800-2808 ◽  
Author(s):  
Mats Peterz ◽  
Sophie Butot ◽  
Balamurugan Jagadeesan ◽  
Douwe Bakker ◽  
John Donaghy
Keyword(s):  
Infant Formula ◽  
Mycobacterium Avium ◽  
Dairy Products ◽  
Thermal Inactivation ◽  
Steam Injection ◽  
Process Conditions ◽  
Powdered Infant Formula ◽  
Content Type ◽  
Direct Steam ◽  
Direct Steam Injection

ABSTRACTThe efficiency of direct steam injection (DSI) at 105°C for 3 s to inactivateMycobacterium aviumsubsp.paratuberculosisin milk at a pilot-plant scale was investigated. Milk samples were artificially contaminated withM. aviumsubsp.paratuberculosisand also with cow fecal material naturally infected withM. aviumsubsp.paratuberculosis. We also tested milk artificially contaminated withMycobacterium smegmatisas a candidate surrogate to compare thermal inactivation betweenM. smegmatisandM. aviumsubsp.paratuberculosis. Following the DSI process, no viableM. aviumsubsp.paratuberculosisorM. smegmatiswas recovered using culture methods for both strains. For pureM. aviumsubsp.paratuberculosiscultures, a minimum reduction of 5.6 log10was achieved with DSI, and a minimum reduction of 5.7 log10was found withM. smegmatis. The minimum log10reduction for wild-typeM. aviumsubsp.paratuberculosisnaturally present in feces was 3.3. In addition, 44 dairy and nondairy powdered infant formula (PIF) ingredients used during the manufacturing process of PIF were tested for an alternate source forM. aviumsubsp.paratuberculosisand were found to be negative by quantitative PCR (qPCR). In conclusion, the results obtained from this study indicate that a >7-fold-log10reduction ofM. aviumsubsp.paratuberculosisin milk can be achieved with the applied DSI process.IMPORTANCEM. aviumsubsp.paratuberculosisis widespread in dairy herds in many countries.M. aviumsubsp.paratuberculosisis the causative agent of Johne's disease in cattle, and infected animals can directly or indirectly (i.e., fecal contamination) contaminate milk. Despite much research and debate, there is no conclusive evidence thatM. aviumsubsp.paratuberculosisis a zoonotic bacterium, i.e., one that causes disease in humans. The presence ofM. aviumsubsp.paratuberculosisor its DNA has been reported in dairy products, including pasteurized milk, cheese, and infant formula. In light of this, it is appropriate to evaluate existing mitigation measures to inactivateM. aviumsubsp.paratuberculosisin dairy products. The work conducted in this study describes the efficacy of direct steam injection, a thermal process commonly used in the dairy industry, to eliminateM. aviumsubsp.paratuberculosisand a surrogate bacterium in milk, thus ensuring the absence ofM. aviumsubsp.paratuberculosisin dairy products subject to these process conditions.

scholarly journals Draft Genome Sequences of Seven Cronobacter sakazakii Strains Carrying the mcr 9.1 Gene Isolated in Chile

2021 ◽  
Vol 10 (28) ◽  
Author(s):  
Julio Parra-Flores ◽  
Ondrej Holý ◽  
Francisca Riffo ◽  
Sarah Lepuschitz ◽  
Werner Ruppitsch ◽  
...  
Keyword(s):  
Infant Formula ◽  
Necrotizing Enterocolitis ◽  
Dairy Products ◽  
Draft Genome ◽  
Powdered Infant Formula ◽  
Cronobacter Sakazakii ◽  
Genome Sequences ◽  
Content Type

Cronobacter sakazakii is a pathogen that causes severe diseases such as meningitis and necrotizing enterocolitis in infants under 12 months, associated with the consumption of contaminated rehydrated powdered infant formula (PIF). We present seven C. sakazakii genome sequences isolated from PIF and dairy products in Chile in 2017.

scholarly journals RNA Sequencing-Based Transcriptional Overview of Xerotolerance inCronobacter sakazakiiSP291

2018 ◽  
Vol 85 (3) ◽  
Author(s):  
Shabarinath Srikumar ◽  
Yu Cao ◽  
Qiongqiong Yan ◽  
Koenraad Van Hoorde ◽  
Scott Nguyen ◽  
...  
Keyword(s):  
Infant Formula ◽  
Mortality Rates ◽  
Secondary Response ◽  
Ecological Niches ◽  
Infant Food ◽  
Powdered Infant Formula ◽  
Cronobacter Sakazakii ◽  
Rna Seq ◽  
Production Environment ◽  
Content Type

ABSTRACTCronobacter sakazakiiis a xerotolerant neonatal pathogen epidemiologically linked to powdered infant food formula, often resulting in high mortality rates. Here, we used transcriptome sequencing (RNA-seq) to provide transcriptional insights into the survival ofC. sakazakiiin desiccated conditions. Our RNA-seq data show that about 22% of the totalC. sakazakiigenes were significantly upregulated and 9% were downregulated during desiccation survival. When reverse transcription-quantitative PCR (qRT-PCR) was used to validate the RNA-seq data, we found that the primary desiccation response was gradually downregulated during the tested 4 hours of desiccation, while the secondary response remained constitutively upregulated. The 4-hour desiccation tolerance ofC. sakazakiiwas dependent on the immediate microenvironment surrounding the bacterial cell. The removal of Trypticase soy broth (TSB) salts and the introduction of sterile infant formula residues in the microenvironment enhanced the desiccation survival ofC. sakazakiiSP291. The trehalose biosynthetic pathway encoded byotsAandotsB, a prominent secondary bacterial desiccation response, was highly upregulated in desiccatedC. sakazakii.C. sakazakiiSP291 ΔotsABwas significantly inhibited compared with the isogenic wild type in an 8-hour desiccation survival assay, confirming the physiological importance of trehalose in desiccation survival. Overall, we provide a comprehensive RNA-seq-based transcriptional overview along with confirmation of the phenotypic importance of trehalose metabolism inCronobacter sakazakiiduring desiccation.IMPORTANCECronobacter sakazakiiis a pathogen of importance to neonatal health and is known to persist in dry food matrices, such as powdered infant formula (PIF) and its associated production environment. When infections are reported in neonates, mortality rates can be high. The success of this bacterium in surviving these low-moisture environments suggests thatCronobacterspecies can respond to a variety of environmental signals. Therefore, understanding those signals that aid the persistence of this pathogen in these ecological niches is an important step toward the development of strategies to reduce the risk of contamination of PIF. This research led to the identification of candidate genes that play a role in the persistence of this pathogen in desiccated conditions and, thereby, serve as a model target to design future strategies to mitigate PIF-associated survival ofC. sakazakii.

scholarly journals Whole-Genome Sequences of Five Geobacillus stearothermophilus Strains Isolated from Processing Lines of Powdered Infant Formula

2019 ◽  
Vol 8 (4) ◽  
Author(s):  
Tae Jin Cho ◽  
Dongmin Yang ◽  
Byeonghyeok Park ◽  
In-Geol Choi ◽  
Min Suk Rhee
Keyword(s):  
Infant Formula ◽  
Safety Management ◽  
Whole Genome ◽  
Powdered Infant Formula ◽  
Geobacillus Stearothermophilus ◽  
Genome Sequences ◽  
Content Type ◽  
Manufacturing Plants ◽  
Work In Process ◽  
Concentrated Milk

Geobacillus stearothermophilus is the thermophile present in processing lines of powdered infant formula (PIF). We report the whole-genome sequences of G. stearothermophilus strains isolated from work-in-process products (sterilized and concentrated milk) of manufacturing plants. Understanding the genomic basis governing the metabolism of G. stearothermophilus can contribute to the safety management of PIF during its manufacture.

Sensory and Microbial Quality of Milk Processed for Extended Shelf Life by Direct Steam Injection†

1995 ◽  
Vol 58 (9) ◽  
pp. 1007-1013 ◽  
Author(s):  
M. R. BLAKE ◽  
B. C. WEIMER ◽  
D. J. MCMAHON ◽  
P. A. SAVELLO
Keyword(s):  
Shelf Life ◽  
Lipase Activity ◽  
Storage Time ◽  
Consumer Preference ◽  
Steam Injection ◽  
Distribution Area ◽  
Direct Steam ◽  
Off Flavors ◽  
Direct Steam Injection

Heat treatments of milk between 100 and 145°C produce a new type of product with a shelf life of 15 to 30 days at 7°C, which is termed extended shelf life (ESL) milk. Little information is available on the safety and sensory qualities of this product. Extended shelf life milk is being processed commercially to expand the distribution area of fluid milk products. After arrival at market, this product still has the shelf life of a pasteurized product. In this study milk was processed by direct steam injection at temperatures between 100 and 140°C for 4 or 12 s. Holding time did not significantly affect the sensory quality of the milk. A trained taste panel found cooked flavor and other off flavors varied significantly with increasing processing temperature and storage time. There were no significant differences noted in cooked or off flavors between 132 and 140°C. Psychrotrophic Bacillus species were isolated from milk processed at and below 132°C, while no organisms were isolated from milk processed at temperatures at or above 134°C. Consumer preference panels indicated consumers preferred milk processed at 134°C for 4 s to ultrahigh-temperature (UHT) processed milk, although there was a slight preference for high-temperature short-time processed (HTST) milk compared to milk processed at 134°C for 4 s. Higher temperatures had a less destructive effect on lipase activity, while storage time did not significantly affect lipase activity.

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