scholarly journals Detection and quantification of Bacillus cereus and its spores in raw milk by qPCR, and distinguish Bacillus cereus from other bacteria of the genus Bacillus

2022 ◽  
Author(s):  
Lijiao Liang ◽  
Ping Wang ◽  
Tianming Qu ◽  
Xiaomei Zhao ◽  
Yiqiang Ge ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Pathogenic Bacteria ◽  
High Sensitivity ◽  
Raw Milk ◽  
Raw Material ◽  
Amplification Efficiency ◽  
Genus Bacillus ◽  
Application Range ◽  
Spoilage Bacteria ◽  
Qpcr Method

Abstract Introduction The raw milk is the basic raw material of dairy products, Bacillus cereus is a typical conditional pathogenic bacteria and cold-phagocytic spoilage bacteria in raw milk. This study established a qPCR method for detecting B. cereus in raw milk Materials and Methods In this study, a qPCR method for detecting B. cereus in raw milk was established. The specificity of the method was verified by using other Bacillus bacteria and pathogenic bacteria, the sensitivity of the method was evaluated by preparing recombinant plasmids and simulated contaminated samples, and the applicability of the method was verified by using pure spore DNA. The actual sample detection was completed by using the established qPCR method Results The qPCR established in this study can specifically detect B. cereus in raw milk. The LOD of the method was as low as 200 CFU/mL, and the LOQ ranged from 2 × 10 2 to 2 × 10 8 CFU/ml, the amplification efficiency of qPCR was 96.6% Conclusins The method established in this study can distinguish B. cereus from other Bacillus bacteria, and spore DNA can be used as the detection object. This method has the advantages of strong specificity, high sensitivity, wide application range and short detection time, which is expected to be applied in the dairy industry.

scholarly journals Newly isolated lactic acid bacteria from silage targeting biofilms of foodborne pathogens during milk fermentation

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Elizaveta Gavrilova ◽  
Elizaveta Anisimova ◽  
Alsu Gabdelkhadieva ◽  
Elena Nikitina ◽  
Adel Vafina ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Foodborne Pathogens ◽  
Pathogenic Bacteria ◽  
Starter Culture ◽  
Raw Milk ◽  
Raw Material ◽  
Plant Materials ◽  
Organoleptic Characteristics ◽  
Milk Fermentation

Abstract Background Raw milk, meat and plant materials are subjected to high risks of contamination by various pathogenic bacteria and thus their growth prevention is a great challenge in the food industry. Food fermentation by lactic acid bacteria (LAB) besides changing its organoleptic characteristics also helps to eliminate unfavorable microflora and represses growth of pathogens. To the date only few LABs has been reported to exhibit activity against bacteria embedded in the biofilms characterized by extreme resistance to antimicrobials, high exchange rate with resistance genes and represent high risk factor for foodborne disease development. Results Six novel LAB strains isolated from the clover silage exhibited pronounced antibacterial activity against biofilm embedded pathogens. We show explicitly that these strains demonstrate high acidification rate, completely repress the growth of E. coli, S. aureus and to a lesser extent P. aeruginosa as well as exhibit appropriate probiotic and milk-fermenting properties. Moreover, in contrast to the approved probiotic strain Lactobacillus plantarum 8PA3, the new isolates were able to efficiently eradicate preformed biofilms of these pathogens and prevent bacterial spreading originating from the biofilm. We suggest these strains as potential additives to the pre-cultures of conventional LAB strains as efficient tools targeting foodborne pathogens in order to prevent food contamination from either seeded raw material or biofilm-fouled equipment. Conclusions The AG10 strain identified as L. plantarum demonstrate attractive probiotic and milk fermentation properties as well as high resistance to simulated gastric conditions thus appearing perspective as a starter culture for the prevention of bacterial contamination originating from fouled equipment during milk fermentation.

scholarly journals Study About Pathogenic Bacteria Associated With Bovine

2004 ◽  
Vol 28 (1) ◽  
pp. 227-234
Author(s):  
Safana A. S. AL-Taan ◽  
Asmaa H. AL-Jobori ◽  
Anton S. AL-Bana.
Keyword(s):  
Bacillus Cereus ◽  
Pathogenic Bacteria ◽  
Raw Milk ◽  
Viable Count ◽  
Coliform Bacteria ◽  
Milk Samples ◽  
Different Types ◽  
High Level ◽  
Living Bacteria

Out of 100 raw milk samples collected from one hundred cows infected with mastitis, thirty three isolates of different types of pathogenic bacteria were isolated using different types of selective media.  On the basis of traditional bacteriological tests, these isolates were identified as the following: 13 isolates of Staphylococcus aureus, 9 isolates of B-haemolytic Streptococci, 6 isolates of Coliform bacteria, 4 isolates of Corynebacterium pyogenes, and only one isolate Bacillus cereus.  In addition to these isolates, a number of non-pathogenic bacteria were recovered during the isolation and they were considered as contaminants of milk such as S. epidermidis, C. bovis and B. subtilus.  The total number of living bacteria present in milk samples was measured and it was ranged from (1400 to 1800) bact./ml.  The isolates of pathogenic bacteria were tested for their sensitivity to different types of antibiotics and the results were: 100% of these isolates were sensitive to Gentamycin and Tetracycline, 11 (84.6%) isolates of S. aureus, 6(66.2%) isolates of B-hacmolytic Streptococci , 4(66.2%) isolates of Coliform bacteria and 3(75%)  es of C. pyogenes were sensitive to Ampicillin, Penicillin, Erythromycin and Cepholexin. While Bacillus cereus isolate was resistant to all these antibiotics.  As a result of this work, generally the bacteriological quality of this milk is acceptable due to the low number of viable count of bacteria in   milk and the isolates showed high level of sensitivity to the antibiotics used in this study.

scholarly journals Integrated qPCR and Staining Methods for Detection and Quantification of Enterocytozoon hepatopenaei in Shrimp Litopenaeus vannamei

2020 ◽  
Vol 8 (9) ◽  
pp. 1366
Author(s):  
Lijun Wang ◽  
Qing Lv ◽  
Yantong He ◽  
Ruocheng Gu ◽  
Bingqian Zhou ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Shrimp Farming ◽  
Economic Losses ◽  
Amplification Efficiency ◽  
Qpcr Method ◽  
Staining Methods ◽  
Microscopy Method ◽  
Optimum Annealing Temperature ◽  
Enterocytozoon Hepatopenaei ◽  
Sensitivity Specificity

Enterocytozoon hepatopenaei (EHP) is an obligate, intracellular, spore-forming parasite, which mainly infects the gastrointestinal tract of shrimp. It significantly hinders the growth of shrimp, which causes substantial economic losses in farming. In this study, we established and optimized a SYBR Green I fluorescent quantitative PCR (qPCR) assay based on the polar tube protein 2 (PTP2) gene for the quantitative analysis of EHP-infected shrimp. The result showed that the optimum annealing temperature was 60 °C for the corresponding relation between the amplification quantitative (Cq) and the logarithmic of the initial template quantity (x), conformed to Cq = −3.2751x + 31.269 with a correlation coefficient R2 = 0.993. The amplification efficiency was 102%. This qPCR method also showed high sensitivity, specificity, and repeatability. Moreover, a microscopy method was developed to observe and count EHP spores in hepatopancreas tissue of EHP-infected shrimp using Fluorescent Brightener 28 staining. By comparing the PTP2-qPCR and microscopy method, the microscopic examination was easier to operate whereas PTP2-qPCR was more sensitive for analysis. And we found that there was a correspondence between the results of these two methods. In summary, the PTP2-qPCR method integrated microscopy could serve for EHP detection during the whole period of shrimp farming and satisfy different requirements for detecting EHP in shrimp farming.

scholarly journals Study About Pathogenic Bacteria Associated With Bovine Mastitis

2004 ◽  
Vol 28 (1) ◽  
pp. 227-234
Author(s):  
Safana A. S. AL-Taan ◽  
Asmaa H. AL-Jobori ◽  
Anton S. AL-Bana.
Keyword(s):  
Bacillus Cereus ◽  
Pathogenic Bacteria ◽  
Bovine Mastitis ◽  
Raw Milk ◽  
Viable Count ◽  
Coliform Bacteria ◽  
Milk Samples ◽  
Different Types ◽  
High Level

Out of 100 raw milk samples collected from one hundred cows infected with mastitis, thirty three isolates of different types of pathogenic bacteria were isolated using different types of selective media.  On the basis of traditional bacteriological tests, these isolates were identified as the following: 13 isolates of Staphylococcus aureus, 9 isolates of B-haemolytic Streptococci, 6 isolates of Coliform bacteria, 4 isolates of Corynebacterium pyogenes, and only one isolate Bacillus cereus.  In addition to these isolates, a number of non-pathogenic bacteria were recovered during the isolation and they were considered as contaminants of milk such as S. epidermidis, C. bovis and B. subtilus.  The total number of living bacteria present in milk samples was measured and it was ranged from (1400 to 1800) bact./ml.  The isolates of pathogenic bacteria were tested for their sensitivity to different types of antibiotics and the results were: 100% of these isolates were sensitive to Gentamycin and Tetracycline, 11 (84.6%) isolates of S. aureus, 6(66.2%) isolates of B-hacmolytic Streptococci , 4(66.2%) isolates of Coliform bacteria and 3(75%)  es of C. pyogenes were sensitive to Ampicillin, Penicillin, Erythromycin and Cepholexin. While Bacillus cereus isolate was resistant to all these antibiotics.  As a result of this work, generally the bacteriological quality of this milk is acceptable due to the low number of viable count of bacteria in  milk and the isolates showed high level of sensitivity to the antibiotics used in this study.

scholarly journals Efficacy of Bacteriocin Extracted from Lactobacillus acidophilus (LAK) against Bacillus cereus in cow raw milk

2015 ◽  
Vol 39 (2) ◽  
pp. 91-97
Author(s):  
Thikra M. Ali
Keyword(s):  
Bacillus Cereus ◽  
Lactobacillus Acidophilus ◽  
Pathogenic Bacteria ◽  
Inhibitory Concentration ◽  
Bovine Milk ◽  
Raw Milk ◽  
Bactericidal Effect ◽  
Gram Stain ◽  
Zone Of Inhibition ◽  
High Potency

     Fifty seven out of ninety bovine milk samples were collected from different areas inside and nearby Baghdad which were positive for Bacillus cereus. The isolates were checked on chromogenic Bacillus cereus agar which was specific for detection of B. cereus colonies. The colony appearance, gram stain, spore stain and oxidase lipase monitol catalase tests were carried out to identify this bacterium. Bacteriocin extracted from Lactobacillus acidophilus was used as a tool to control the growth of undesirable B. cereus growth as spoilage and pathogenic bacteria as well as to keep the food more acceptable and safe to consumer. The results of this study showed that bacteriocin (LAK) had 8 a bactericidal effect against B. cereus in refrigeration and room temperatures at pH 4, 7 and 9, respectively. High potency of bacteriocin (LAK) was confirmed by minimum inhibitory concentration at 30, 60 and 120 minutes. It was found that the zone of inhibition of B. cereus by bacteriocin at 4°C and pH 7 was 26 mm. The present study revealed that bacteriocin was highly effective against locally isolated B. cereus.

scholarly journals Incidence and characterisation of Bacillus cereus bacteriophages from Thua Nao, a Thai fermented soybean product

2021 ◽  
Vol 12 (1) ◽  
pp. 85-93
Author(s):  
Wallapat Phongtang ◽  
Ekachai Chukeatirote
Keyword(s):  
Bacillus Cereus ◽  
Food Industry ◽  
Pathogenic Bacteria ◽  
Morphological Analysis ◽  
Food Poisoning ◽  
Fermented Soybean ◽  
Foodborne Pathogenic Bacteria ◽  
Ph Range ◽  
Potential Use

Abstract Bacillus cereus is considered to be an important food poisoning agent causing diarrhea and vomiting. In this study, the occurrence of B. cereus bacteriophages in Thai fermented soybean products (Thua Nao) was studied using five B. cereus sensu lato indicator strains (four B. cereus strains and one B. thuringiensis strain). In a total of 26 Thua Nao samples, there were only two bacteriophages namely BaceFT01 and BaceCM02 exhibiting lytic activity against B. cereus. Morphological analysis revealed that these two bacteriophages belonged to the Myoviridae. Both phages were specific to B. cereus and not able to lyse other tested bacteria including B. licheniformis and B. subtilis. The two phages were able to survive in a pH range between 5 and 12. However, both phages were inactive either by treatment of 50°C for 2 h or exposure of UV for 2 h. It should be noted that both phages were chloroform-insensitive, however. This is the first report describing the presence of bacteriophages in Thua Nao products. The characterization of these two phages is expected to be useful in the food industry for an alternative strategy including the potential use of the phages as a biocontrol candidate against foodborne pathogenic bacteria.

The potentials of secondary metabolites from Bacillus cereus SN7 and Vagococcus fluvialis CT21 against fish pathogenic bacteria

2021 ◽  
pp. 105062
Author(s):  
Feli Feliatra ◽  
Ummi Mardhiah Batubara ◽  
Yuana Nurulita ◽  
Iesje Lukistyowati ◽  
Jarot Setiaji
Keyword(s):  
Secondary Metabolites ◽  
Bacillus Cereus ◽  
Pathogenic Bacteria

scholarly journals Isolation and Characterization of Bacteriophage ZCSE6 against Salmonella spp.: Phage Application in Milk

Biologics ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 164-176
Author(s):  
Abdallah S. Abdelsattar ◽  
Anan Safwat ◽  
Rana Nofal ◽  
Amera Elsayed ◽  
Salsabil Makky ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Raw Milk ◽  
Salmonella Spp ◽  
Isolation And Characterization ◽  
Food Borne ◽  
Wide Range ◽  
Almost All ◽  
And Control ◽  
Milk And Dairy Products

Food safety is very important in the food industry as most pathogenic bacteria can cause food-borne diseases and negatively affect public health. In the milk industry, contamination with Salmonella has always been a challenge, but the risks have dramatically increased as almost all bacteria now show resistance to a wide range of commercial antibiotics. This study aimed to isolate a bacteriophage to be used as a bactericidal agent against Salmonella in milk and dairy products. Here, phage ZCSE6 has been isolated from raw milk sample sand molecularly and chemically characterized. At different multiplicities of infection (MOIs) of 0.1, 0.01, and 0.001, the phage–Salmonella interaction was studied for 6 h at 37 °C and 24 h at 8 °C. In addition, ZCSE6 was tested against Salmonella contamination in milk to examine its lytic activity for 3 h at 37 °C. The results showed that ZCSE6 has a small genome size (<48.5 kbp) and belongs to the Siphovirus family. Phage ZCSE6 revealed a high thermal and pH stability at various conditions that mimic milk manufacturing and supply chain conditions. It also demonstrated a significant reduction in Salmonella concentration in media at various MOIs, with higher bacterial eradication at higher MOI. Moreover, it significantly reduced Salmonella growth (MOI 1) in milk, manifesting a 1000-fold decrease in bacteria concentration following 3 h incubation at 37 °C. The results highlighted the strong ability of ZCSE6 to kill Salmonella and control its growth in milk. Thus, ZCSE6 is recommended as a biocontrol agent in milk to limit bacterial growth and increase the milk shelf-life.

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