Toxinogenic and spoilage potential of aerobic spore-formers isolated from raw milk

Jonghe, Valerie De; Coorevits, An; Block, Jan De; Coillie, Els Van; Grijspeerdt, K.; Herman, Lieve; Vos, Paul De; Heyndrickx, Marc

doi:10.1016/j.ijfoodmicro.2009.11.007

Cited by 168 publications

(113 citation statements)

References 40 publications

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“…Previous work has shown that the majority of dairy-associated Paenibacillus subtypes are ␤-galactosidase positive, whereas the majority of Bacillus subtypes are not (5,21). However, as some dairy-associated Bacillus isolates have expressed positive or weakly positive ␤-Gal activity, this phenotypic test cannot be completely relied upon to distinguish Paenibacillus from other sporeformers (21).…”

Section: Discussionmentioning

confidence: 98%

“…Therefore, pasteurized milk contamination with Pseudomonas and other non-spore-forming bacteria can be controlled or eliminated by adhering to pasteurization specifications for minimum time and temperature combinations (8) and by adhering to proper sanitation and equipment maintenance protocols, particularly with respect to milk filler sites (33). Conversely, Grampositive psychrotolerant sporeformers can survive pasteurization as spores, germinate, and then grow during refrigerated storage to numbers capable of causing off flavors or curdling of milk (5,20,34,36).…”

mentioning

confidence: 99%

“…and Paenibacillus spp. have been isolated from farm environments (e.g., soil, water, and feed), raw milk, dairy-processing plants, and pasteurized milk (5,19,38,42). In HTST pasteurized milk, when postpasteurization contamination is excluded, Bacillus spp.…”

mentioning

confidence: 99%

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Real-Time PCR Detection of Paenibacillus spp. in Raw Milk To Predict Shelf Life Performance of Pasteurized Fluid Milk Products

Ranieri

Ivy

Mitchell

et al. 2012

Appl Environ Microbiol

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Psychrotolerant sporeformers, specifically Paenibacillus spp., are important spoilage bacteria for pasteurized, refrigerated foods such as fluid milk. While Paenibacillus spp. have been isolated from farm environments, raw milk, processing plant environments, and pasteurized fluid milk, no information on the number of Paenibacillus spp. that need to be present in raw milk to cause pasteurized milk spoilage was available. A real-time PCR assay targeting the 16S rRNA gene was designed to detect Paenibacillus spp. in fluid milk and to discriminate between Paenibacillus and other closely related spore-forming bacteria. Specificity was confirmed using 16 Paenibacillus and 17 Bacillus isolates. All 16 Paenibacillus isolates were detected with a mean cycle threshold (C T ) of 19.14 ؎ 0.54. While 14/17 Bacillus isolates showed no signal (C T > 40), 3 Bacillus isolates showed very weak positive signals (C T ‫؍‬ 38.66 ؎ 0.65). The assay provided a detection limit of approximately 3.25 ؋ 10 1 CFU/ml using total genomic DNA extracted from raw milk samples inoculated with Paenibacillus. Application of the TaqMan PCR to colony lysates obtained from heat-treated and enriched raw milk provided fast and accurate detection of Paenibacillus. Heat-treated milk samples where Paenibacillus (>1 CFU/ml) was detected by this colony TaqMan PCR showed high bacterial counts (>4.30 log CFU/ ml) after refrigerated storage (6°C) for 21 days. We thus developed a tool for rapid detection of Paenibacillus that has the potential to identify raw milk with microbial spoilage potential as a pasteurized product. Despite advances in food preservation techniques, bacterial spoilage remains a leading cause of global food loss (14). Nearly one-third of all food produced worldwide is estimated to be lost postharvest, and much of this loss can be attributed to microbial spoilage (16). Dairy products constitute one of the leading sectors impacted by food loss in the United States, as nearly 20% of conventionally pasteurized (high temperature, short time [HTST]) fluid milk is discarded prior to consumption each year (23). In the United States, the shelf life of fluid milk ranges from approximately 1 to 3 weeks. Most consumer complaints result from the growth of psychrotolerant bacteria, typically, either nonspore-forming Gram-negative rods or Gram-positive sporeforming bacteria (12,18,19,28,34,39). The presence of psychrotolerant, non-spore-forming bacteria (e.g., Pseudomonas) in pasteurized milk indicates either inadequate heating of the milk or, more commonly, postpasteurization contamination (6). Therefore, pasteurized milk contamination with Pseudomonas and other non-spore-forming bacteria can be controlled or eliminated by adhering to pasteurization specifications for minimum time and temperature combinations (8) and by adhering to proper sanitation and equipment maintenance protocols, particularly with respect to milk filler sites (33). Conversely, Grampositive psychrotolerant sporeformers can survive pasteurization as spores, germinate, and then grow ...

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Section: Discussionmentioning

confidence: 98%

mentioning

confidence: 99%

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Real-Time PCR Detection of Paenibacillus spp. in Raw Milk To Predict Shelf Life Performance of Pasteurized Fluid Milk Products

Ranieri

Ivy

Mitchell

et al. 2012

Appl Environ Microbiol

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“…A previous study showed that isolates from milk were capable of causing spoilage, but no toxin gene was detected among them (18). In this study, few cheese samples from low temperature were in spoilage state and were positive for B. cereus, demonstrating that rarely isolates could grow at this temperature (2 -8°C) (18). Other studies also showed that B. cereus strains were mesophiles and that they rarely grew at this temperature as psychrotolerant strains.…”

Section: Discussionmentioning

confidence: 45%

“…According to Langeveld (17), these concentrations place in range of spoilage ability, showing a threshold value of B. cereus. A previous study showed that isolates from milk were capable of causing spoilage, but no toxin gene was detected among them (18). In this study, few cheese samples from low temperature were in spoilage state and were positive for B. cereus, demonstrating that rarely isolates could grow at this temperature (2 -8°C) (18).…”

Section: Discussionmentioning

confidence: 48%

Detection of hblA and bal Genes in Bacillus cereus Isolates From Cheese Samples Using the Polymerase Chain Reaction

Kohneshahri¹,

Khiabani²,

Ghasemian³

et al. 2016

Avicenna J Clin Microbiol Infect

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Background: Bacillus cereus is a Gram-positive spore-forming bacterium, which causes food poisoning. Spores enable the persistence of B. cereus in the environment, and B. cereus strains can tolerate adverse environmental conditions, such as temperature and insufficient nutrients. B. cereus causes food poisoning via the production of two enterotoxins. Most isolates produce toxins leading to diarrhea (enterotoxins) and vomiting (emetic forms). Diarrhea is caused by the production of three different heat-labile enterotoxins: HBL, NHE, and cytotoxin K. A heat-stable toxin, cereulide, is responsible for emesis. Objectives: This study aimed to detect enterotoxigenic B. cereus isolates in cheese samples using the polymerase chain reaction (PCR). Materials and Methods: Two-hundred pasteurized (n = 100) and nonpasteurized (n = 100) cheese samples were collected. The initial isolation was performed on PEMBA specific medium. Antibiotic susceptibility testing was performed using several antibiotic disks, according to the guidelines of the Clinical Laboratory and Standards Institute. Specific primers amplifying the hblA enterotoxinencoding gene and bal hemolysin-encoding gene were used for the molecular detection of the toxins. Results: Ten samples were positive for the presence of B. cereus, with both Gram staining and biochemical reactions. All the isolates were resistant to penicillin and ampicillin but susceptible to vancomycin, erythromycin, and ciprofloxacin. Six and three isolates were resistant to tetracycline and trimethoprim-sulfamethoxazole, respectively. The hblA and bal genes were amplified in all the B. cereus isolates. Conclusions:The prevalence of B. cereus among the cheese samples was low. All the isolates were positive for genes encoding the hblA enterotoxin and bal toxin.

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The GenusBacillus

Ehling‐Schulz

Messelhäußer²

2014

DNA Methods in Food Safety

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Toxinogenic and spoilage potential of aerobic spore-formers isolated from raw milk

Cited by 168 publications

References 40 publications

Real-Time PCR Detection of Paenibacillus spp. in Raw Milk To Predict Shelf Life Performance of Pasteurized Fluid Milk Products

Real-Time PCR Detection of Paenibacillus spp. in Raw Milk To Predict Shelf Life Performance of Pasteurized Fluid Milk Products

Detection of hblA and bal Genes in Bacillus cereus Isolates From Cheese Samples Using the Polymerase Chain Reaction

The GenusBacillus

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