Staphylococcus aureus —A Foodborne Pathogen

2018 ◽  
pp. 3-10 ◽  
Author(s):  
Delia Grace ◽  
Alexandra Fetsch
Keyword(s):  
Staphylococcus Aureus ◽  
Foodborne Pathogen

Humectant Permeability Influences Growth and Compatible Solute Uptake by Staphylococcus aureus Subjected to Osmotic Stress

2002 ◽  
Vol 65 (6) ◽  
pp. 1008-1015 ◽  
Author(s):  
ODDUR VILHELMSSON ◽  
KAREN J. MILLER
Keyword(s):  
Staphylococcus Aureus ◽  
Sodium Chloride ◽  
Water Activity ◽  
Glycine Betaine ◽  
Compatible Solutes ◽  
Foodborne Pathogen ◽  
Compatible Solute ◽  
Solute Uptake ◽  
Stressed Cells ◽  
Carnitine Uptake

The effects of different humectants (sodium chloride, sucrose, and glycerol) on the growth of and compatible solute (glycine betaine, proline, and carnitine) uptake by the osmotolerant foodborne pathogen Staphylococcus aureus were investigated. While growth in the presence of the impermeant humectants sodium chloride and sucrose induced the accumulation of proline and glycine betaine by cells, growth in the presence of the permeant humectant glycerol did not. When compatible solutes were omitted from low-water-activity media, growth was very poor in the presence of impermeant humectants. In contrast, the addition of compatible solutes had essentially no effect on growth when cells were grown in low-water-activity media containing glycerol as the humectant. Carnitine was found to accumulate to high intracellular levels in osmotically stressed cells when proline and glycine betaine were absent, making it a potentially important compatible solute for this organism.

scholarly journals Effects of Staphylococcus aureus hemolysin toxins on blood cells and association with skin and soft tissue infections

2021 ◽  
pp. 152-160
Author(s):  
Adnan Shahid ◽  
Afsheen Rafiq
Keyword(s):  
Staphylococcus Aureus ◽  
Soft Tissue ◽  
Foodborne Pathogen ◽  
Soft Tissue Infections ◽  
Accessory Gene ◽  
Alpha Hemolysin ◽  
Accessory Gene Regulator ◽  
Keywords Mrsa ◽  
The Family ◽  
Enhanced Expression

Staphylococcus aureus (S. aureus) is gram positive, catalase positive cocci which belongs to the family of Staphylococcaceae and is long known as clinical and foodborne pathogen. The emergence of multidrug resistance strain of S. aureus which is methicillin resistant S. aureus (MRSA) challenges the health care system because it can cause wide variety of hospital and community acquired skin and soft tissue infections which are difficult to treat. The virulence of S. aureus is because of different factors which includes toxins, enzymes and superantigens. S. aureus produce variety of exotoxins, enterotoxins and exfoliative toxins which contributes to the virulence of S. aureus. Hemolysin toxins produce by S. aureus strains are associated with different skin and soft tissue infections (SSTIs) and can cause the lysis of RBCs. Hemolysins are regulated by accessory gene regulator (agr) and is required for the enhanced expression of virulence factors secreted by S. aureus. Hemolysins have leucolytic activity and can help in iron scavenging from host. The most important toxin is alpha hemolysin which can induce the apoptosis and cause the lysis of epithelial cells, erythrocytes and keratinocytes. Human immune cells are affected by beta hemolysin and gamma hemolysin is a biocomponent toxin. Delta hemolysin is low molecular weight exotoxin which belongs to the class of phenol soluble modulins. Keywords: MRSA, Exotoxins, Hemolysins, SSTIs

Effect of gamma irradiation on the expressed proteins in the foodborne pathogen Staphylococcus aureus

2012 ◽  
Vol 81 (8) ◽  
pp. 1181-1184 ◽  
Author(s):  
Karine Trudeau ◽  
Khanh Dang Vu ◽  
François Shareck ◽  
Monique Lacroix
Keyword(s):  
Staphylococcus Aureus ◽  
Gamma Irradiation ◽  
Foodborne Pathogen

scholarly journals Pathogenic and Virulence Factor Detection on Viable but Non-culturable Methicillin-Resistant Staphylococcus aureus

2021 ◽  
Vol 12 ◽  
Author(s):  
Hua Jiang ◽  
Kan Wang ◽  
Muxia Yan ◽  
Qian Ye ◽  
Xiaojing Lin ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Limit Of Detection ◽  
Foodborne Pathogen ◽  
Food Poisoning ◽  
Clinical Settings ◽  
Analytical Sensitivity ◽  
Vbnc State ◽  
Methicillin Resistant ◽  
Staphylococcal Enterotoxins ◽  
Sensitivity Specificity

Food safety and foodborne infections and diseases have been a leading hotspot in public health, and methicillin-resistant Staphylococcus aureus (MRSA) has been recently documented to be an important foodborne pathogen, in addition to its recognition to be a leading clinical pathogen for some decades. Standard identification for MRSA has been commonly performed in both clinical settings and food routine detection; however, most of such so-called “standards,” “guidelines,” or “gold standards” are incapable of detecting viable but non-culturable (VBNC) cells. In this study, two major types of staphylococcal food poisoning (SFP), staphylococcal enterotoxins A (sea) and staphylococcal enterotoxins B (seb), as well as the panton-valentine leucocidin (pvl) genes, were selected to develop a cross-priming amplification (CPA) method. Limit of detection (LOD) of CPA for sea, seb, and pvl was 75, 107.5, and 85 ng/μl, indicating that the analytical sensitivity of CPA is significantly higher than that of conventional PCR. In addition, a rapid VBNC cells detection method, designated as PMA-CPA, was developed and further applied. PMA-CPA showed significant advantages when compared with PCR assays, in terms of rapidity, sensitivity, specificity, and accuracy. Compared with conventional VBNC confirmation methods, the PMA-CPA showed 100% accordance, which had demonstrated that the PMA-CPA assays were capable of detecting different toxins in MRSA in VBNC state. In conclusion, three CPA assays were developed on three important toxins for MRSA, and in combination with PMA, the PMA-CPA assay was capable of detecting virulent gene expression in MRSA in the VBNC state. Also, the above assays were further applied to real samples. As concluded, the PMA-CPA assay developed in this study was capable of detecting MRSA toxins in the VBNC state, representing first time the detection of toxins in the VBNC state.

scholarly journals NEK7-Mediated Activation of NLRP3 Inflammasome Is Coordinated by Potassium Efflux/Syk/JNK Signaling During Staphylococcus aureus Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Ruiqing Liu ◽  
Yashan Liu ◽  
Chang Liu ◽  
Aijiao Gao ◽  
Lin Wang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Nlrp3 Inflammasome ◽  
Critical Role ◽  
Foodborne Pathogen ◽  
Inflammasome Activation ◽  
Mrna Levels ◽  
Potassium Efflux ◽  
Pyrin Domain ◽  
Subsequent Activation

Staphylococcus aureus (S. aureus) is a foodborne pathogen that causes severe diseases, such as endocarditis, sepsis, and bacteremia. As an important component of innate immune system, the NLR family pyrin domain-containing 3 (NLRP3) inflammasome plays a critical role in defense against pathogen infection. However, the cellular mechanism of NLRP3 inflammasome activation during S. aureus infection remains unknown. In the present study, we found that spleen tyrosine kinase (Syk) and c-Jun N-terminal kinase (JNK) were rapidly phosphorylated during S. aureus infection. Moreover, a Syk/JNK inhibitor and Syk/JNK siRNA not only reduced NLRP3 inflammasome-associated molecule expression at the protein and mRNA levels, apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) speck formation, and interleukin-1β (IL-1β), and IL-18 release but also rescued the decreased NIMA-related kinase 7 (NEK7) expression level following suppression of the NEK7-NLRP3 interaction in macrophages. Interestingly, Syk/JNK phosphorylation levels and NLRP3 inflammasome-associated molecule expression were decreased by blockade of K+ efflux. Furthermore, activation of the NLRP3 inflammasome and a lower NEK7 protein level were found in vivo upon S. aureus infection. Taken together, our data indicated that S. aureus infection induces a K+ efflux/Syk/JNK/NEK7-NLRP3 signaling pathway and the subsequent activation of the NLRP3 inflammasome for the release of proinflammatory cytokines. This study expands our understanding of the basic molecular mechanism regulating inflammation and provides potential value for anti-infective drug development against S. aureus infection.

scholarly journals Prevalence and Susceptibility Patterns Associated with Staphylococcus Aureus Presence in Marketed Milk and Milk Products.

2020 ◽  
Author(s):  
JOHN MACHARIA MACHARIA ◽  
Zsolt Kaposztas ◽  
Cheruiyot Richard ◽  
Nyerere K. Andrew ◽  
Mathenge J. Muriithi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Susceptibility ◽  
Foodborne Pathogen ◽  
Raw Milk ◽  
Penicillin G ◽  
Antibiotic Resistant ◽  
Milk Products ◽  
Resistance To Penicillin ◽  
Different Sources ◽  
Susceptibility Patterns

Abstract Introduction: Staphylococcus aureus is a major foodborne pathogen that poses a serious threat to public health. Indiscriminate use of antibiotics increases evolution of antibiotic resistant strains. This study aimed to determine the presence of Staphylococcus aureus in milk and milk products and their antimicrobial susceptibility patterns. Methods: A total of 334 samples were collected for analysis in the laboratories. To determine antimicrobial susceptibility patterns, selected antibiotics from different classes were used: Penicillin G, Erythromycin, Vancomycin, Chloramphenicol, Tetracycline, Gentamycin, Methicillin, and Ciprofloxacin. Results: The presence of S. aureus in milk and milk products was found occurring in 21.56% of all the samples. In raw milk analyzed, 64.81% of samples were contaminated by Staphylococcus aureus, 20.54% in pasteurized milk, 10.71% in yogurt, and 3.57% in ice cream. All isolates were found to be 100 % sensitive to Tetracycline, Ciprofloxacin, Erythromycin, and Methicillin. Infrequent sensitivity was found in Gentamicin and Vancomycin. Resistance to Penicillin G was occasionally observed across the different sources of milk and milk products. Resistance to Gentamicin (42 %) and Vancomycin (11 %) was seldom observed in isolates, hence occurring in yogurt samples only. Conclusion and Recommendation: The research hypothesis was rejected based on the presence of pathogenic Staphylococcus aureus across the different samples analyzed. It is recommended that Tetracycline, Ciprofloxacin, Methicillin, and Erythromycin antibiotics should be used for the treatment of Staphylococcus aureus infections based on the susceptibility test outcome.

scholarly journals Livestock-Associated Meticillin-Resistant Staphylococcus aureus—Current Situation and Impact From a One Health Perspective

2021 ◽  
Author(s):  
Alexandra Fetsch ◽  
Danai Etter ◽  
Sophia Johler
Keyword(s):  
Staphylococcus Aureus ◽  
One Health ◽  
Animal Health ◽  
Foodborne Pathogen ◽  
Invasive Disease ◽  
Asia Pacific ◽  
True Incidence ◽  
Geographical Regions ◽  
The Impact

Abstract Purpose of Review In this article, we aim to provide an overview of the occurrence and characteristics of livestock-associated (LA-) meticillin-resistant Staphylococcus aureus (MRSA). We further question the role of LA-MRSA as a potential foodborne pathogen. We investigate recent findings and developments from a One Health perspective also highlighting current strategies and initiatives aiming to improve reporting, control, and prevention of LA-MRSA. Recent Findings While the overall number of invasive MRSA infections in humans is decreasing (in most European countries and the USA) or steadily increasing (in the Asia-Pacific region), the role of LA-MRSA as causative agent of invasive disease and as potential foodborne pathogen is still poorly understood. LA-MRSA prevalence in livestock remains high in many geographical regions and the acquisition of new virulence and resistance determinants constitutes a growing threat for human health. Summary The true incidence of LA-MRSA infections due to occupational exposure is unknown. Improved MRSA monitoring and tracking procedures are urgently needed. Strain typing is crucial to enable improved understanding of the impact of LA-MRSA on human and animal health.

Prevalence of Staphylococcus aureus in Imported Fish and Correlations between Antibiotic Resistance and Enterotoxigenicity

2015 ◽  
Vol 78 (11) ◽  
pp. 1999-2005 ◽  
Author(s):  
MOHAMMAD M. OBAIDAT ◽  
ALAA E. BANI SALMAN ◽  
SHAWKAT Q. LAFI
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Meca Gene ◽  
Foodborne Pathogen ◽  
Multidrug Resistant ◽  
Fresh Fish ◽  
Low Resistance ◽  
Fish Samples ◽  
Amoxicillin Clavulanic Acid ◽  
Resistance To Penicillin

A total of 156 Staphylococcus aureus isolates were obtained from 330 imported fresh fish samples from three countries. Selective media were used for the isolation of S. aureus, and the isolates were confirmed by PCR. The isolates were tested for mecA gene, antibiotic resistance, and enterotoxin genes (sea, seb, sec, sed, see, seg, seh, and sei). Most isolates carried sea, seg, and sei genes, and seg-sei was the most frequent enterotoxin profile. About 88.5% of the S. aureus exhibited resistance to at least one antibiotic. High resistance to penicillin and ampicillin; low resistance to tetracycline, erythromycin, rifampin, and clindamycin; and very low resistance to cefotaxime, amoxicillin–clavulanic acid, gentamicin, and ciprofloxacin were exhibited by S. aureus from the three countries. In addition, some antibiotic resistance exhibited a strong correlation (P ≤ 0.01) with enterotoxigenicity in S. aureus. The study concluded that the large amount of globally traded fish increases the possibility of intercontinental transmission of enterotoxigenic and multidrug-resistant S. aureus through fish and highlights the potential influence of local fish handling and processing on consumer health worldwide. The introduction of periodic training in food safety and hygiene is essential to increase fish handlers' awareness of good hygienic practices in handling fish. These findings also enrich the ongoing debate about the risk of methicillin- and multidrug-resistant S. aureus as a foodborne pathogen compared with drug-susceptible S. aureus.

Staphylococcus aureus as a Foodborne Pathogen

2018 ◽  
Vol 5 (2) ◽  
pp. 88-96 ◽  
Author(s):  
Alexandra Fetsch ◽  
Sophia Johler
Keyword(s):  
Staphylococcus Aureus ◽  
Foodborne Pathogen
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