scholarly journals Growth inhibition of foodborne pathogens in camel milk: Staphylococcus aureus, Listeria monocytogenes, Salmonella spp. and E. coli O157:H7

2017 ◽  
Vol 35 (No. 4) ◽  
pp. 311-320 ◽  
Author(s):  
Abusheliabi Aisha ◽  
Al-Holy Murad A ◽  
Al-Rumaithi Hind ◽  
Al-Khaldi Sufian ◽  
Al-Nabulsi Anas A ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Growth Inhibition ◽  
Foodborne Pathogens ◽  
Bovine Milk ◽  
Growth Patterns ◽  
Camel Milk ◽  
Salmonella Spp ◽  
E Coli ◽  
Milk Samples

The growth behaviour of foodborne pathogens (Staphylococcus aureus, Listeria monocytogenes, E. coli O157:H7 and Salmonella spp.) was investigated in pasteurised camel milk and compared with pasteurised bovine milk at different incubation temperatures. This study also aimed to compare the growth patterns of these four foodborne pathogens in pasteurised and raw camel milk. Pasteurised or raw camel milk and pasteurised bovine milk were separately inoculated with a cocktail of three strains of each foodborne pathogen. The inoculated milk samples were incubated at 10, 25, and 37°C. The total bacterial count (TBC) in raw milk and the total thermoduric bacteria count (TDB) in pasteurised milk samples were monitored. Greater growth inhibition rates of four pathogens were obtained for the pasteurised camel milk compared to the pasteurised bovine milk. Raw and pasteurised camel milk exerted bacteriostatic effect against all tested pathogens, particularly for the first 8 h of incubation in milk at the different temperatures. Pasteurised camel milk exerted an inhibitory activity that was equivalent to that of raw camel milk.

Inhibition and Inactivation of Five Species of Foodborne Pathogens by Chitosan

1992 ◽  
Vol 55 (11) ◽  
pp. 916-919 ◽  
Author(s):  
GUANG-HUA WANG
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Acetic Acid ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Yersinia Enterocolitica ◽  
Foodborne Pathogens ◽  
E Coli ◽  
No Inhibition

Inhibition and inactivation of five species of foodborne pathogens (Staphylococcus aureus, Escherichia coli, Yersinia enterocolitica, Listeria monocytogenes, and Salmonella typhimurium) by chitosan were studied. Nutrient broths were supplemented with 0, 0.5, 1.0, 1.5, 2.0, and 2.5% chitosan, adjusted to pH 6.5 or 5.5 with 2% acetic acid, and incubated at 30°C. The outgrowths of these bacteria were observed. At pH 6.5, in general, antibacterial activity of chitosan was relatively weak. The effectiveness of chitosan against S. aureus was greatest, followed by S. typhimurium, E. coli, and Y. enterocolitica. As the concentration of chitosan increased, the effectiveness of chitosan against these four species of pathogens also increased. No inhibition of L. monocytogenes by chitosan occurred. At pH 5.5, presence of chitosan inactivated these pathogens except that 0.5% chitosan did not affect the growth of S. typhimurium. Thus, the antibacterial activity of chitosan was stronger at pH 5.5 than at pH 6.5.

scholarly journals Baseline composition and microbial quality assessment of raw milk from endemic small ruminants and Maghrebi camels in the oasis area of Tunisia

2022 ◽  
Author(s):  
Zahran Khaldi ◽  
Mounir Nafti ◽  
Mohamed Tabarek Jilani
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Small Ruminants ◽  
Goat Milk ◽  
Camel Milk ◽  
Microbial Quality ◽  
Protein Ratio ◽  
E Coli ◽  
Milk Samples ◽  
Casein Protein

Abstract Characteristics and quality aspects of milk from native ovine queue fine de l’Ouest (QFO) and the local goat population were investigated and compared with those of the local Maghrebi camel. A total of 378 individual milk samples were collected from lactating animals reared in the continental oasis region of Tunisia. Samples were analyzed for physical parameters (pH, density, and acidity), chemical composition (dry matter, fat, protein, lactose, casein, ash, and casein-protein ratio), mineral concentrations (Ca, P, Na, and K) and microbiological features (total mesophilic aerobic bacteria (TMAB), total coliform count (TCC), lactic acid bacteria (LAB), sulphite-reducing Clostridium (CSR), yeast and molds (Y/M), Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Salmonella) according to standard methods. The results obtained for milk characteristics revealed noticeable disparities between the three species. The mean values of pH, density, and acidity in milk collected from sheep appeared higher than those in milk collected from goat species. Compared to the camel populations, sheep species produced milk with similar pH but higher density and acidity. Between camel and goat species, pH and acidity were higher in Negga, while the density was similar. For milk composition, the results showed a remarkable variation among all studied species and an obvious superiority of the ovine species over the caprine and camel populations in all the chemical contents being studied, except for the casein-protein ratio, which is in favor of goat species. The milk of QFO sheep, the richest in casein and protein, was expressed with significantly higher levels of calcium and phosphorus than goat and camel milk. Compared to small ruminants, milk from camels is the richest in Na and K. Additionally, more Ca is present in milk from camels than goats. Goat milk, the poorest type of milk in Ca and Na, contains on average more P than camel milk and more K than sheep's milk. The poor bacteriological quality was that of camel milk for all microbial counts. The microbial quality of goat milk was higher than that of ewe milk based on TMAB, TCC, and E. coli counts, while ovine milk was of better quality, referring to LAB, Y/M, and S. aureus values. No significant differences were found for Staphylococcus aureus and Escherichia coli between the examined species. The obtained results highlighted the complete absence of the two dangerous pathogens Salmonella and CSR in all investigated milk samples. The microbiological examination evidenced that the milk of small ruminant species complies with standard criteria required by Tunisian legislation on the hygiene of milk and dairy products. Regarding camel milk, the microbial analysis revealed poor quality that exceeds standard criteria.

Safety and Quality of Romain Lettuce Accessible to Low Socioeconomic Populations Living in Houston, TX

2021 ◽  
Author(s):  
Sujata Sirsat ◽  
Zahra H Mohammad ◽  
Isabella M Raschke
Keyword(s):  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Personal Hygiene ◽  
Low Ses ◽  
Rt Pcr ◽  
Salmonella Spp ◽  
Low Socioeconomic ◽  
E Coli ◽  
Leafy Greens

Previous empirical evidence has demonstrated that low socioeconomic status (SES) communities have higher rates of gastroenteritis; however, there is a paucity of literature on the safety and quality of food (fresh produce) accessible to these communities. The overarching goal of this study was to investigate the microbial safety and quality of fresh leafy greens from low and high SES neighborhoods in the Houston, Texas area. Fresh greens were purchased from low and high SES neighborhood retailers and APC, coliform, E. coli , yeast, and mold assays were conducted. In addition, enrichment was performed on all samples for Listeria monocytogenes , Staphylococcus aureus, Salmonella spp., and E. coli O157:H7 and RT-PCR analysis was carried out. The results showed that generic E. coli , coliform, yeast, and mold were present in significantly higher counts ( P < 0.05) in produce obtained from low SES neighborhoods as compared to high SES neighborhoods. The RT-PCR results showed that 38% of samples from high SES areas were positive for Staphylococcus aureus versus 87% of samples from low SES areas. None of the samples from high SES areas were positive for the other pathogens. The samples from low SES areas were positive for E. coli O157:H7 (4%), Salmonella spp. (53%), Listeria monocytogenes (13%), and Staphylococcus aureus (87%). Based on these results, the most common challenges are associated with poor personal hygiene, cross contamination, and time/temperature abuse, all of which are most likely to occur in the retail setting. These results demonstrate a significant disparity in the quality and safety of fresh leafy greens accessible to low versus high SES populations. Future studies can be designed to identify the specific cause of this challenge by investigating the food supply chain.

Survival of Bacterial Pathogens in Pasteurized Process Cheese Slices Stored at 30°C

1998 ◽  
Vol 61 (3) ◽  
pp. 290-294 ◽  
Author(s):  
KATHLEEN A. GLASS ◽  
KRISTINE M. KAUFMAN ◽  
ERIC A. JOHNSON
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Salmonella Serotypes ◽  
Sterile Plastic ◽  
Process Cheese ◽  
Plastic Sample

Six lots of commercial pasteurized process cheese slices were evaluated for the ability to support the growth of four foodborne pathogens, Listeria monocytogenes, Staphylococcus aureus, Salmonella serotypes, and Escherichia coli O157:H7, during 4 days of storage at 30°C. Individual cheese slices were inoculated separately with each pathogen to yield ca. 103 CFU/g. Slices were packaged in sterile plastic sample bags and stored at 30°C for up to 96 h. Populations of Salmonella serotypes and Escherichia coli O157:H7 decreased an average of 1.3 and 2.1 log10 CFU/g, respectively, by 36 h and Salmonella serotypes decreased an additional 0.6 logi0 CFU/g during the remaining 60 h. Populations of Listeria monocytogenes also decreased, although to a lesser extent, exhibiting approximately a 0.6-log10 CFU/g reduction in 96 h. Staphylococcus aureus levels remained relatively constant during the testing period, and were below levels that support detectable enterotoxin production. The process cheese slices tested allowed survival but did not support rapid growth of S. aureus, whereas populations of L. monocytogenes, E. coli O157:H7, and Salmonella serotypes decreased during the 96-h storage at 30°C.

scholarly journals Antimicrobial Activity and Chemical Composition of Pistachia Atlantica Gum Sub Sp. Kurdica. Essential Oil

2019 ◽  
Author(s):  
Hasan Ellahi ◽  
Elham Khalili Sadrabad ◽  
Seyed Hossein Hekmatimoghaddam ◽  
Ali Jebali ◽  
Jalal Sadeghizadeh-yazdi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Chemical Composition ◽  
Essential Oil ◽  
Foodborne Pathogens ◽  
Salmonella Enterica ◽  
Diffusion Method ◽  
E Coli ◽  
Significant Difference

Background: Staphylococcus aureus, Salmonella enterica, Escherichia Coli (E. Coli) and Listeria monocytogenes are considered as important foodborne pathogens. Pistachia atlantica sub sp. Kurdica, called wild pistachio, has been known as an antimicrobial compound. The aim of this study was to determine the antimicrobial activity and chemical composition of this essential oil (EO) on some of foodborne pathogens. Methods: The EO of Pistachia atlantica was obtained by hydro-distillation and analyzed by GC-MASS. The antibacterial effects of Pistachia atlantica were evaluated at two concentrations of 10 and 15 µL against Staphylococcus aureus, E. Coli, Salmonella enterica, and Listeria monocytogenes using disk diffusion method. The analysis was done by SPSS. Results: In the current study, α-pinene (92.5%) and ß-pinene (1.62%) were the main components of Pistachia atlantica EO. The EO was most effective on Salmonella enterica, whereas, its effect on Listeria monocytogenes was the weakest. The results showed a significant difference in reducing Salmonella enterica in comparison to others (P < 0.05). Conclusion: The EO has inhibitory effects on the studied bacteria. Therefore, this EO can be used as a natural preservative to extend the shelf life of foods.

scholarly journals Molecular characterization of foodborne pathogenic bacteria recovered from fermented meat products

2021 ◽  
Vol 3 (2) ◽  
pp. 1-10
Author(s):  
Naeima M. H. Yousef ◽  
Doaa M. Abd El- Aziz ◽  
Martina A. Mansour
Keyword(s):  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Pathogenic Bacteria ◽  
Meat Products ◽  
Salmonella Spp ◽  
E Coli ◽  
Two Samples ◽  
Control And Prevention ◽  
Foodborne Pathogenic Bacteria ◽  
Meat Samples

Foodborne pathogenic bacteria are causing diseases with a significant effect on human health and the economy. The four most common bacterial foodborne pathogens were isolated from different fermented meat products and characterized molecularly in the current study. A total of 20 random samples of fermented meat products, including Hotdog, pepperoni, salami, sausage, and luncheon (4 from each), were collected from different markets to be examined bacteriologically for detection of foodborne pathogenic bacteria. The samples were tested by culture for the presence of bacteria. PCR was used as a diagnostic tool for the proper identification of foodborne pathogenic bacteria. So, the pure isolates were identified and confirmed by PCR- based method using specific primers for each genus. The isolated pathogenic bacteria were identified as Escherichia coli 0157:H7, Listeria monocytogenes, Salmonella sp. and Staphylococcus aureus. Out of 20 samples, only one sample contains E. coli 0157:H7. Listeria monocytogenes and Salmonella spp. were isolated from two samples. At the same time, S. aureus was found in 6 samples, one of which was mecA positive. The results revealed the presence of foodborne pathogenic bacteria in fermented meat samples. So, to decrease the human hazard risk and a major public health threat associated with foodborne pathogenic bacteria and their toxins, a greater emphasis should be applied in control and prevention of contamination during processing and manipulation.

scholarly journals Wpływ procesu zamrażania i rozmrażania na bezpieczeństwo mikrobiologiczne mleka kobiecego

2020 ◽  
Vol 124 (3) ◽  
pp. 40-51
Author(s):  
Elżbieta Rosiak ◽  
Mateusz Gemba ◽  
Aleksandra Wesołowska
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Cronobacter Sakazakii ◽  
Salmonella Spp ◽  
E Coli

Mleko kobiece uznawane jest za „złoty standard” żywienia dla noworodków ze względu na unikatowe właściwości odżywcze i immunologiczne oraz źródło mikroflory stanowiącej podstawę do kształtowania mikrobiomu człowieka. Działalność Banków Mleka przyczynia się do racjonalizacji dostępności mleka kobiecego. Metodą utrwalania mleka w celu jego przechowywania jest zamrażanie. W pracy podjęto próbę oceny jakości mikrobiologicznej mleka kobiecego nieutrwalonego oraz mleka poddanego zamrażaniu i rozmrażaniu z zastosowaniem metody w nawiewie powietrza o temp. 37 ºC. Analizy wykonano w kierunku: ogólnej liczby drobnoustrojów tlenowych mezofilnych (OLD), Escherichia coli, Staphylococcus aureus, Cronobacter sakazakii, Listeria monocytogenes, Salmonella spp. Na podstawie uzyskanych wyników stwierdzono, że w przypadku ogólnej liczby drobnoustrojów tlenowych mezofilnych 30 % próbek mleka kobiecego przed zamrożeniem przekraczało maksymalną akceptowaną liczbę drobnoustrojów, natomiast w przypadku mleka rozmrożonego było to 5 % prób. Liczba Staphylococcus aureus została przekroczona w 10 % próbek mleka przed zamrożeniem i w 5 % próbek mleka rozmrożonego. Stwierdzono, że proces zamrażania i prawidłowo przeprowadzony proces rozmrażania mogą stanowić istotny element kształtowania jakości mikrobiologicznej mleka kobiecego. W próbkach mleka kobiecego poddanych analizie nie wykryto bakterii patogennych: Listeria monocytogenes, Salmonella, Cronobacter sakazakii. Bakterie E. coli również były nieobecne, co świadczy o dobrym stanie higieny i przestrzeganiu instrukcji higieny postępowania z mlekiem.

scholarly journals Assessment of listeria monocytogenes, staphylococcus aureus and salmonella SPP. Contamination in dairy samples collected in Gia Lam and Ba Vi, Hanoi early 2019

2019 ◽  
Vol 2 (4) ◽  
pp. 22-32
Author(s):  
Minh Huyen Nguyen Thi ◽  
Hoa Tran Thi ◽  
Tuyet Lan Ninh Thi ◽  
Hien Tran Thi ◽  
◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Dairy Products ◽  
Pathogenic Bacteria ◽  
Raw Milk ◽  
Accurate Method ◽  
Salmonella Spp ◽  
Pasteurized Milk ◽  
Milk Samples ◽  
Milk And Dairy Products

Milk and dairy products from dairy farms around Hanoi greatly contribute to the consumed milk quantity in Hanoi. The use of fresh milk or pasteurized milk becomes more and more popular in the daily life of local people. Milk and dairy products were widely sold in numerous stores, particularly in Xuan Mai, Ba Vi, Phu Dong and Gia Lam. However, there have not yet been any studies to assess the pathogenic bacterial contamination of these products. In our study, 49 samples including 23 raw milk samples, 12 pasteurized milk samples, and 14 yogurt samples were collected in order to examine the presence of food&shy;born pathogenic bacteria such as Listeria monocytogenes, Staphylococcus aureus, Salmonella spp. using PCR method. This fast and accurate method works based on the specific amplification of tested bacterial DNA. The results showed that one of the samples may contain Staphylococcus aureus while another may be contaminated with Listeria monocytogenes. None of the samples was contaminated with Salmonella spp. The results were confirmed by gene sequencing.

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