Investigation of Enterotoxigenic Coagulase-negative Staphylococci Isolated from Local and Imported Dairy Products; a Microbiological Study

2020 ◽  
pp. 82-98
Author(s):  
Niyaz Sirwan Ali ◽  
Huner Hiwa Arif
Keyword(s):  
Dairy Products ◽  
Virulence Genes ◽  
Food Poisoning ◽  
Bacterial Activity ◽  
Coagulase Negative Staphylococci ◽  
The Past ◽  
Nacl Concentration ◽  
Staphylococcus Equorum ◽  
Growth Limits ◽  
Staphylococcus Gallinarum

    Coagulase negative staphylococci (CNS) have been recorded as a conveying vector for virulence genes and have been implicated in some cases of food poisoning. Research interest in CNS has increased over the past decade following their implication in infections in animals and humans. This study was aimed to detect CNS isolated from 150 dairy products (yoghurt, several types of cheese, Lork, and Serezh) in Sulaimani and Halabja governorate. Thirteen isolates out of 150 samples were identified as CNS using the VITEK® 2 system as an identification method. Results revealed that the most common isolates species including Staphylococcus saprophyticus, Staphylococcus sciuri and Staphylococcus xylosus each species have been identified in 3 samples separately (23%), followed by Staphylococcus vitulinus was in 2 samples (15%), Staphylococcus equorum found in 1 sample (8%), and Staphylococcus gallinarum also was in one sample (8%). The isolated CNS did not have enterotoxins type A to E according to RIDASCREEN kit test. Studying the growth limits of S. saprophyticus and S. vitulinus results showed that S. saprophyticus grew better at pH levels (5,6,7) at (25℃,37℃) and low NaCl concentration (5%), while low bacterial activity was observed at pH 4 at all temperatures and NaCl concentrations and also at 4℃ at all pH and NaCl levels. S. vitulinus behaviour was almost the same as S. saprophyticus but, S. vitulinus was able to tolerate different NaCl concentrations and overall had higher bacterial activity in all parameter’s interactions than S. saprophyticus. Investigating the effect of acetic acid and lactic acid on the growth of previous species where studied, S. saprophyticus grew better in different concentrations of L.A but S. vitulinus showed more activity than S. saprophyticus in A.A and the growth of both species inhibited at 0.4% of L.A at the first 24 hours of incubation.

scholarly journals Multi-locus sequence typing and virulence profile in Bacillus cereus sensu lato strains isolated from dairy products

2021 ◽  
Vol 9 (4) ◽  
Author(s):  
Angelica Bianco ◽  
Loredana Capozzi ◽  
Angela Miccolupo ◽  
Simona Iannetti ◽  
Maria Luisa Danzetta ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Bacillus Cereus ◽  
Dairy Products ◽  
Virulence Genes ◽  
Food Poisoning ◽  
Important Food ◽  
Food Contaminants ◽  
Bacillus Cereus Group ◽  
Mlst Analysis ◽  
Sequence Types

Members of Bacillus cereus group are important food contaminants and they are of relevant interest in food safety and public heath due to their ability to cause two distinct forms of food poisoning, emetic and diarrhoeal syndrome. In the present study, 90 strains of B. cereus isolated from dairy products, have been typed using Multilocus Sequence Typing (MLST) analysis and investigated for the occurrence of 10 enterotoxigenic genes (hblA, hblC, hblD, nheA, nheB, nheC, cytK, entFM, entS and bceT) and one emetogenic gene (ces), to determine their genetic diversity. A total of 58 sequence types were identified and among these 17 were signalled as new profiles. Among the virulence genes, the majority of our strains carried the entS (92%), entFM (86%), nhe (82%) and cytK (72%) genes. All remaining genes were identified in at least one strain with different prevalence, stressing the genetic diversity, how even the different grade of pathogenicity of B. cereus isolated from dairy products.

Small-colony Variants (SCVs) of Staphylococci: A Role in Foreign Body-associated Infections

2007 ◽  
Vol 30 (9) ◽  
pp. 778-785 ◽  
Author(s):  
C. Von Eiff ◽  
K. Becker
Keyword(s):  
Foreign Body ◽  
Defense Mechanisms ◽  
Susceptibility Testing ◽  
Slow Growth ◽  
Clinical Laboratory ◽  
Coagulase Negative Staphylococci ◽  
Small Colony Variants ◽  
The Past ◽  
Small Colony ◽  
Antibacterial Chemotherapy

Staphylococci have various strategies for resisting therapy that extend beyond classic mechanisms. Clinical experience with device-associated infections as well as with infections due to small-colony variants (SCVs) clearly shows that both antibacterial chemotherapy and host defense mechanisms are often unable to eliminate the pathogens and cure these infections. Of particular interest is the fact that in the past few years an increasing number of various foreign body-related infections due to staphylococcal SCVs have been reported. In this overview, the characteristics of SCVs recovered from clinical specimens and of defined mutants displaying the SCV phenotype are described. Their slow growth and changing biochemical and physiological features represent a challenge to clinical laboratory personnel, because recovery, identification, as well as susceptibility testing of these variants need particular efforts. In addition, the reduced susceptibility to aminoglycosides and the ability of SCVs to persist intracellularly require specific attention for the treatment of these infections. Thus, special efforts to search for these variants formed by Staphylococcus aureus or by coagulase-negative staphylococci should be considered when an infection is particularly resistant to therapy, persists for a long period or fails to respond to apparently adequate therapy with antimicrobial compounds.

THE HORMONAL COMPOSITION OF MILK IN PRODUCTIVE ANIMALS AND ITS SAFETY FOR HUMANS

2020 ◽  
Vol 1 (3) ◽  
pp. 313-321
Author(s):  
P.A. Popov ◽  
◽  
V.S. Babunova ◽  
Keyword(s):  
Trace Elements ◽  
Growth Factor ◽  
Dairy Products ◽  
The Body ◽  
The Other ◽  
Raw Material ◽  
Important Food ◽  
The Past ◽  
Highly Sensitive ◽  
And Control

Hormones are an integral part of milk and throughout lactation, the content of certain hormones is unstable. Hormones regulate the process of starting lactation of animals, the lactation process itself, and also the other functions of the body. Milk is of great importance for the growth of young animals and the formation of immunity. Milk is a special product in the diet and is an important food and raw material for the production of dairy products for people. It contains a large amount of protein, fat, carbohydrates, vitamins and trace elements in biologically available form. But at the same time, over the past few years, more and more evidence has emerged that hormones in dairy products can impact on human health. Thus, some estrogens and insulin-like growth factor IGF-1 are involved in the initiation and provocation of breast, prostate and endometrial tumors. That’s why, it is necessary to normalize and control the content of certain hormones in milk with highly sensitive methods.

Staphylococcus aureus: Production of Extracellular Compounds and Behavior in Foods - A Review

1989 ◽  
Vol 52 (4) ◽  
pp. 267-282 ◽  
Author(s):  
MARGARET I. HALPIN-DOHNALEK ◽  
ELMER H. MARTH
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Products ◽  
Food Poisoning ◽  
Water Soluble ◽  
Bakery Products ◽  
Single Chain ◽  
Poultry Products ◽  
Heat Stable ◽  
And Behavior ◽  
Red Meats

Growth of Staphylococcus aureus is accompanied by production of such extracellular compounds as hemolysins, nuclease, coagulase, lipase, and enterotoxins. Enterotoxins that can cause food poisoning are produced by about one-third of the coagulase-positive strains of S. aureus. The enterotoxins are a heterogeneous group of heat-stable, water-soluble, single-chain globular proteins having a molecular weight between 28,000 and 35,000 daltons. Production of enterotoxin by appropriate strains of S. aureus is affected by the nutritional quality and pH of the substrate, temperature, atmosphere, sodium chloride (and hence water activity), other chemicals, and competing microorganisms. Outbreaks of staphylococcal food poisoning most often are associated with processed red meats, poultry products (especially chicken salad), sauces, dairy products (especially cheeses), and custard- or cream-filled bakery products. Ham and associated products often are involved in as many as 30% of outbreaks of staphylococcal food poisoning. Most outbreaks result from the combined effects of contamination of the food, often through unsanitary handling, with S. aureus and holding the food at the wrong temperature thus allowing growth and synthesis of enterotoxin by the pathogen.

Mathematical Modeling and Assessment of Microbial Migration during the Sprouting of Alfalfa in Trays in a Nonuniformly Contaminated Seed Batch Using Enterobacter aerogenes as a Surrogate for Salmonella Stanley

2007 ◽  
Vol 70 (11) ◽  
pp. 2602-2605 ◽  
Author(s):  
BIN LIU ◽  
DONALD W. SCHAFFNER
Keyword(s):  
Irrigation Water ◽  
Membrane Filtration ◽  
Microbial Contamination ◽  
Food Poisoning ◽  
Enterobacter Aerogenes ◽  
Probability Of Detection ◽  
Microbial Populations ◽  
Water Sampling ◽  
The Past ◽  
Low Concentrations

Raw seed sprouts have been implicated in several food poisoning outbreaks in the past 10 years. The U.S. Food and Drug Administration recommends that sprout growers use interventions (such as testing of spent irrigation water) to control the presence of pathogens in the finished product. During the sprouting process, initially low concentrations of pathogen may increase, and contamination may spread within a batch of sprouting seeds. A model of pathogen growth as a function of time and distance from the contamination spot during the sprouting of alfalfa in trays has been developed with Enterobacter aerogenes. The probability of detecting contamination was assessed by logistic regression at various time points and distances by sampling from sprouts or irrigation water. Our results demonstrate that microbial populations and possibility of detection were greatly reduced at distances of ≥20 cm from the point of contamination in a seed batch during tray sprouting; however, the probability of detecting microbial contamination at distances less than 10 cm from the point of inoculation was almost 100% at the end of the sprouting process. Our results also show that sampling irrigation water, especially large volumes of water, is highly effective at detecting contamination: by collecting 100 ml of irrigation water for membrane filtration, the probability of detection was increased by three to four times during the first6hof seed germination. Our findings have quantified the degree to which a small level of contamination will spread throughout a tray of sprouting alfalfa seeds and subsequently be detected by either sprout or irrigation water sampling.

Food Safety: Problems of the Past and Perspectives of the Future1

1982 ◽  
Vol 45 (7) ◽  
pp. 658-660 ◽  
Author(s):  
E. M. FOSTER
Keyword(s):  
United States ◽  
Food Poisoning ◽  
Food Service ◽  
The United States ◽  
Red Tides ◽  
Animal Products ◽  
The Past ◽  
Processing Plants ◽  
Market Areas ◽  
Bacterial Food

Historically, most bacterial food poisoning in the United States is associated with mishandling, either in the home or in the food service establishment. Outbreaks traceable to errors in processing plants are rare. When they do occur they are often associated with changes in processing or packaging technology whose effect is not determined before the product is on the market. Areas of future concern that need research include (1) a better understanding of the mycotoxins; (2) how to minimize Salmonella contamination in animal products; (3) how to prevent, or at least predict, red tides; (4) better bactericidal agents that can be applied to foods; (5) an understanding of the nature and significance of mutagenic agents that are produced in foods during cooking.

scholarly journals Exposure to Bacillus cereus in Water Buffalo Mozzarella Cheese

Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1899
Author(s):  
Angela Michela Immacolata Montone ◽  
Federico Capuano ◽  
Andrea Mancusi ◽  
Orlandina Di Maro ◽  
Maria Francesca Peruzy ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Dairy Products ◽  
Water Buffalo ◽  
Diarrheal Disease ◽  
Food Poisoning ◽  
Mozzarella Cheese ◽  
Food Borne ◽  
Genes Encoding ◽  
Spoilage Bacterium ◽  
Hemolysin Bl

Bacillus cereus is a spoilage bacterium and is recognized as an agent of food poisoning. Two food-borne illnesses are caused by B. cereus: a diarrheal disease, associated with cytotoxin K, hemolysin BL, non-hemolytic enterotoxin and enterotoxin FM, and an emetic syndrome, associated with the cereulide toxin. Owing to the heat resistance of B. cereus and its ability to grow in milk, this organism should be considered potentially hazardous in dairy products. The present study assessed the risk of B. cereus poisoning due to the consumption of water buffalo mozzarella cheese. A total of 340 samples were analyzed to determine B. cereus counts (ISO 7932:2005); isolates underwent molecular characterization to detect the presence of genes encoding toxins. Eighty-nine (26.1%) samples harbored B. cereus strains, with values ranging from 2.2 × 102 to 2.6 × 106 CFU/g. Isolates showed eight different molecular profiles, and some displayed virulence characteristics. Bacterial counts and the toxin profiles of isolates were evaluated both separately and jointly to assess the risk of enteritis due to B. cereus following the consumption of buffalo mozzarella cheese. In conclusion, the results of the present study showed that the risk of poisoning by B. cereus following the consumption of this cheese was moderate.

scholarly journals Characterization of Bacillus cereus in Dairy Products in China

Toxins ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 454 ◽  
Author(s):  
Xiao-Ye Liu ◽  
Qiao Hu ◽  
Fei Xu ◽  
Shuang-Yang Ding ◽  
Kui Zhu
Keyword(s):  
Bacillus Cereus ◽  
Virulence Factors ◽  
Prevalence Rate ◽  
Dairy Products ◽  
Foodborne Pathogen ◽  
Food Poisoning ◽  
Intervention Strategies ◽  
Epidemiological Characteristics ◽  
Shed Light

Bacillus cereus is a common and ubiquitous foodborne pathogen with an increasing prevalence rate in dairy products in China. High and unmet demands for such products, particularly milk, raise the risk of B. cereus associated contamination. The presence of B. cereus and its virulence factors in dairy products may cause food poisoning and other illnesses. Thus, this review first summarizes the epidemiological characteristics and analytical assays of B. cereus from dairy products in China, providing insights into the implementation of intervention strategies. In addition, the recent achievements on the cytotoxicity and mechanisms of B. cereus are also presented to shed light on the therapeutic options for B. cereus associated infections.

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