scholarly journals Staphylococcus aureus Exotoxins and Their Detection in the Dairy Industry and Mastitis

Toxins ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 537 ◽  
Author(s):  
Ana G. Abril ◽  
Tomás G. Villa ◽  
Jorge Barros-Velázquez ◽  
Benito Cañas ◽  
Angeles Sánchez-Pérez ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Industry ◽  
Food Poisoning ◽  
Microbial Colonization ◽  
Economic Losses ◽  
Human Consumption ◽  
Negative Effects ◽  
Virulence Proteins ◽  
Causative Agents ◽  
Best Medical Therapy

Staphylococcus aureus constitutes a major food-borne pathogen, as well as one of the main causative agents of mastitis in dairy ruminants. This pathogen can produce a variety of extracellular toxins; these include the shock syndrome toxin 1 (TSST-1), exfoliative toxins, staphylococcal enterotoxins (SE), hemolysins, and leukocidins. S. aureus expresses many virulence proteins, involved in evading the host defenses, hence facilitating microbial colonization of the mammary glands of the animals. In addition, S. aureus exotoxins play a role in the development of both skin infections and mastitis. Indeed, if these toxins remain in dairy products for human consumption, they can cause staphylococcal food poisoning (SFP) outbreaks. As a result, there is a need for procedures to identify the presence of exotoxins in human food, and the methods used must be fast, sensitive, reliable, and accurate. It is also essential to determine the best medical therapy for human patients suffering from S. aureus infections, as well as establishing the relevant veterinary treatment for infected ruminants, to avoid economic losses in the dairy industry. This review summarizes the role of S. aureus toxins in the development of mastitis in ruminants, their negative effects in the food and dairy industries, and the different methods used for the identification of these toxins in food destined for human consumption.

Isothermal Target and Probe Amplification Assay for the Real-Time Rapid Detection of Staphylococcus aureus

2015 ◽  
Vol 78 (4) ◽  
pp. 723-727 ◽  
Author(s):  
HYEWON SHIN ◽  
MINHWAN KIM ◽  
EUNJU YOON ◽  
GYOUNGWON KANG ◽  
SEUNGYU KIM ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Real Time ◽  
Rapid Detection ◽  
Food Poisoning ◽  
Detection Methods ◽  
Economic Losses ◽  
Fluorescence Detector ◽  
The Real ◽  
Robust Detection ◽  
Advantages And Disadvantages

Staphylococcus aureus, the species most commonly associated with staphylococcal food poisoning, is one of the most prevalent causes of foodborne disease in Korea and other parts of the world, with much damage inflicted to the health of individuals and economic losses estimated at $120 million. To reduce food poisoning outbreaks by implementing prevention methods, rapid detection of S. aureus in foods is essential. Various types of detection methods for S. aureus are available. Although each method has advantages and disadvantages, high levels of sensitivity and specificity are key aspects of a robust detection method. Here, we describe a novel real-time isothermal target and probe amplification (iTPA) method that allows the rapid and simultaneous amplification of target DNA (the S. aureus nuc gene) and a fluorescence resonance energy transfer–based signal probe under isothermal conditions at 61°C or detection of S. aureus in real time. The assay was able to specifically detect all 91 S. aureus strains tested without nonspecific detection of 51 non–S. aureus strains. The real-time iTPA assay detected S. aureus at an initial level of 101 CFU in overnight cultures of preenriched food samples (kiwi dressing, soybean milk, and custard cream). The advantage of this detection system is that it does not require a thermal cycler, reducing the cost of the real-time PCR and its footprint. Combined with a miniaturized fluorescence detector, this system can be developed into a simplified quantitative hand-held real-time device, which is often required. The iTPA assay was highly reliable and therefore may be used as a rapid and sensitive means of identifying S. aureus in foods.

scholarly journals In vitro antimicrobial susceptibility of Staphylococcus aureus strains from dairy herds in KwaZulu-Natal

2011 ◽  
Vol 82 (2) ◽  
Author(s):  
T. Schmidt
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Susceptibility ◽  
Bacterial Resistance ◽  
Bovine Mastitis ◽  
Dairy Industry ◽  
Economic Losses ◽  
Beta Lactam ◽  
Treatment Regimens ◽  
High Level

Staphylococcus aureus is 1 of the most important causes of bovine mastitis and is responsible for significant economic losses to the dairy industry worldwide. One of the principal approaches used in treating intramammary infections is the administration of antimicrobials. Due to the propensity of S. aureus to develop resistance, antimicrobial susceptibility monitoring is necessary to ensure that treatment regimens are effective. As part of this investigation, 90 S. aureus strains isolated from mastitis cases submitted to Allerton Provincial Veterinary Laboratory during 2008 and 2009 were evaluated for their susceptibility to a panel of 10 antimicrobials. Only 8 of the 90 S. aureus isolates tested (8.9 %) were found to be susceptible to all of the antimicrobials evaluated. A very high level of resistance to the beta-lactam antibiotics was noted: 47.8 % of the isolates were resistant to penicillin and 65.6 % were resistant to ampicillin. Minimal resistance to oxacillin, cephalothin and trimethoprim-sulfamethoxazole (1.1 %) was found. Seventeen (18.9 %) of the isolates tested were found to be resistant to 3 or more antimicrobials. The need for vigilant monitoring of bacterial resistance trends in the dairy industry is warranted as the potential public health implications are significant.

scholarly journals Chemical and bacteriological risks of shrimp and clams (Gandofly) from Suez Gulf

Food Research ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 281-288
Author(s):  
A.N. Amin ◽  
A.M. Ahemd ◽  
Ahmed O.M.
Keyword(s):  
Staphylococcus Aureus ◽  
Storage Temperature ◽  
Food Poisoning ◽  
Thiobarbituric Acid ◽  
Human Consumption ◽  
Thiobarbituric Acid Reactive Substance ◽  
Total Volatile ◽  
Total Volatile Basic Nitrogen ◽  
Basic Nitrogen ◽  
And Staphylococcus Aureus

Shellfish including shrimp and clams are consumed allover the world for their nutritional value, however, handling in seafood markets may challenge their safety and quality. Shellfish products in the fish markets in Suez Governorate were evaluated throughchemical analysis of total volatile basic nitrogen value, thiobarbituric acid, histamine content, and some heavy metals residues. As well as, microbiological estimation of the total aerobic counts, Enterobacteriaceae counts, Escherichia coli counts, and Staphylococcus aureus counts, in addition of Salmonella detection. Results declared that more than half of the examined samples of shrimp and clams (gandofly) were fit for human consumption based on the permissible limits of the Egyptian standard. Otherwise, some gandofly samples contain high levels of total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substance (TBA), and may cause scombroid food poisoning with elevated histamine level. The levels of cadmium, lead, and zinc in shellfish samples under study was different with the sequence: Zn>Pb>Cd. Bacteria including E. coli and Staphylococcus aureus were identified. The analysed samples in this study were judged as medium/good quality market samples as more than half of the examined samples were within the Egyptian standard and may indicate that trading of shellfish at Suez markets went under abuse storage temperature.

PCR Primers for the Detection of Staphylococcal Enterotoxins K, L, and M and Survey of Staphylococcal Enterotoxin Types in Staphylococcus aureus Isolates from Food Poisoning Cases in Taiwan

2006 ◽  
Vol 69 (5) ◽  
pp. 1072-1079 ◽  
Author(s):  
YU-CHENG CHIANG ◽  
LI-TUNG CHANG ◽  
CHIA-WEI LIN ◽  
CHI-YEA YANG ◽  
HAU-YANG TSEN
Keyword(s):  
Staphylococcus Aureus ◽  
Food Poisoning ◽  
Pcr Primers ◽  
Enterotoxin Gene ◽  
Bacterial Strains ◽  
Staphylococcal Enterotoxins ◽  
Reverse Transcription Pcr ◽  
Causative Agents ◽  
Expression Potential ◽  
Positive Results

Staphylococcal enterotoxins (SEs) are important causative agents in gastroenteritidis and food poisoning cases. They are serologically grouped into five major classical types, i.e., SEA, SEB, SEC, SED, and SEE. In addition, new SEs, such as SEG through SEM, have recently been identified and characterized. In an attempt to survey the distribution of classical and new SEs in organisms responsible for staphylococcal infections in Taiwan, we developed PCR primers for the genes that define the SEK, SEL, and SEM types. Bacterial strains other than sek, sel, and sem Staphylococcus aureus, including strains of other Staphylococcus species, did not generate any false-positive results when examined with these primers. The expression potential for the sek, sel, and sem types were also determined by reverse transcription–PCR. Together with the PCR primers specific for the classical SEs and other new SEs, including SEG, SEH, SEI, and SEJ, we surveyed the SE genes in S. aureus strains isolated from food poisoning cases. For 147 S. aureus isolates originating from food poisoning cases, 109 (74.1%) were positive for one or more SE genes. Of them, the major classical enterotoxin type was sea (28.6%), followed by seb (20.4%), sec (8.2%), and sed (2.0%). For the new SE types, sei (30.6%) was detected the most often, followed by sek (18.4%), sem (12.9%), and sel (8.2%). Also, 64 (43.5%) of the total bacterial strains had more than one enterotoxin gene.

Phylogeny Characterization of Seb Gene Encoding Enterotoxins in Staphylococcus aureus Isolated from Raw Milk and Cheese

2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
Fatima N. Aziz ◽  
Laith Abdul Hassan Mohammed-Jawad
Keyword(s):  
Staphylococcus Aureus ◽  
Food Poisoning ◽  
Raw Milk ◽  
Staphylococcal Enterotoxin B ◽  
Human Pathogen ◽  
Conventional Pcr ◽  
Biochemical Tests ◽  
Specific Primers ◽  
Gene Encoding

Food poisoning due to the bacteria is a big global problem in economically and human's health. This problem refers to an illness which is due to infection or the toxin exists in nature and the food that use. Milk is considered a nutritious food because it contains proteins and vitamins. The aim of this study is to detect and phylogeny characterization of staphylococcal enterotoxin B gene (Seb). A total of 200 milk and cheese samples were screened. One hundred ten isolates of Staphylococcus aureus pre-confirmed using selective and differential media with biochemical tests. Genomic DNA was extracted from the isolates and the SEB gene detects using conventional PCR with specific primers. Three staphylococcus aureus isolates were found to be positive for Seb gene using PCR and confirmed by sequencing. Sequence homology showed variety range of identity starting from (100% to 38%). Phylogenetic tree analyses show that samples (6 and 5) are correlated with S. epidermidis. This study discovered that isolates (A6-RLQ and A5-RLQ) are significantly clustered in a group with non- human pathogen Staphylococcus agnetis.

scholarly journals Complement Inactivation Strategy of Staphylococcus aureus Using Decay-Accelerating Factor and the Response of Infected HaCaT Cells

2021 ◽  
Vol 22 (8) ◽  
pp. 4015
Author(s):  
Kyoung Ok Jang ◽  
Youn Woo Lee ◽  
Hangeun Kim ◽  
Dae Kyun Chung
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Cells ◽  
Respiratory Infections ◽  
Food Poisoning ◽  
Surface Expression ◽  
Host Cells ◽  
Hacat Cells ◽  
Decay Accelerating Factor ◽  
Ligand Expression ◽  
The Complement System

Staphylococcus aureus is a species of Gram-positive staphylococcus. It can cause sinusitis, respiratory infections, skin infections, and food poisoning. Recently, it was discovered that S. aureus infects epithelial cells, but the interaction between S. aureus and the host is not well known. In this study, we confirmed S. aureus to be internalized by HaCaT cells using the ESAT-6-like protein EsxB and amplified within the host over time by escaping host immunity. S. aureus increases the expression of decay-accelerating factor (CD55) on the surfaces of host cells, which inhibits the activation of the complement system. This mechanism makes it possible for S. aureus to survive in host cells. S. aureus, sufficiently amplified within the host, is released through the initiation of cell death. On the other hand, the infected host cells increase their surface expression of UL16 binding protein 1 to inform immune cells that they are infected and try to be eliminated. These host defense systems seem to involve the alteration of tight junctions and the induction of ligand expression to activate immune cells. Taken together, our study elucidates a novel aspect of the mechanisms of infection and immune system evasion for S. aureus.

scholarly journals Optimal Nitrogen Fertilization to Reach the Maximum Grain and Stover Yields of Maize (Zea mays L.): Tendency Modeling

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1354
Author(s):  
Sergio E. Medina-Cuéllar ◽  
Deli N. Tirado-González ◽  
Marcos Portillo-Vázquez ◽  
Sergio Orozco-Cirilo ◽  
Marco A. López-Santiago ◽  
...  
Keyword(s):  
Nitrogen Fertilization ◽  
Zea Mays L ◽  
N Fertilization ◽  
Human Consumption ◽  
Alluvial Soils ◽  
Grain Production ◽  
Negative Effects ◽  
Maize Stover ◽  
The Individual ◽  
Quadratic Models

Utilization of maize stover to the production of meat and milk and saving the grains for human consumption would be one strategy for the optimal usage of resources. Variance and tendency analyses were applied to find the optimal nitrogen (N) fertilization dose (0, 100, 145, 190, 240, and 290 kg/ha) for forage (F), stover (S), cob (C), and grain (G) yields, as well as the optimal grain-to-forage, cob-to-forage, and cob-to-stover ratios (G:F, C:F, and C:S, respectively). The study was performed in central Mexico (20.691389° N and −101.259722° W, 1740 m a.m.s.l.; Cwa (Köppen), 699 mm annual precipitation; alluvial soils). N-190 and N-240 improved the individual yields and ratios the most. Linear and quadratic models for CDM, GDM, and G:F ratio had coefficients of determination (R2) of 0.20–0.46 (p < 0.03). Cubic showed R2 = 0.30–0.72 (p < 0.02), and the best models were for CDM, GDM, and the G:F, C:F, and C:S DM ratios (R2 = 0.60–0.72; p < 0.0002). Neither SHB nor SDM negatively correlated with CDM or GDM (r = 0.23–0.48; p < 0.0001). Excess of N had negative effects on forage, stover, cobs, and grains yields, but optimal N fertilization increased the proportion of the G:F, C:F, and C:S ratios, as well as the SHB and SDM yields, without negative effects on grain production.

scholarly journals Diversity of Colletotrichum Species Associated with Anthracnose Disease in Tropical Fruit Crops—A Review

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 297
Author(s):  
Latiffah Zakaria
Keyword(s):  
Management Strategies ◽  
Economic Losses ◽  
Fruit Crops ◽  
Tropical Fruit ◽  
Colletotrichum Species ◽  
Adequate Knowledge ◽  
Dragon Fruit ◽  
Causative Agents ◽  
Colletotrichum Spp ◽  
Fruit Plantations

In tropical fruit crops, anthracnose is mainly caused by species belonging to the fungal genus, Colletotrichum. These phytopathogens can infect several parts of the fruit crops; however, infection during postharvest or ripening stages is responsible for major economic losses. Due to the formation of black to dark brown sunken lesions on the fruit surface, anthracnose reduces fruit quality and marketability. Among the most common tropical fruit crops susceptible to anthracnose are mango, papaya, banana, avocado, guava, and dragon fruit; these are economically relevant products in many developing countries. It is important to document that the newly recorded Colletotrichum spp. associated with fruit anthracnose can infect multiple hosts, but some species may be host-specific. By using multiple markers, many phylogenetic species of Colletotrichum have been reported as anthracnose-causing pathogens. Taking into account that disease management strategies strongly rely on adequate knowledge of the causative agents, updated information on Colletotrichum species and the hazard posed by the most recently identified species in tropical fruit plantations and harvested fruits becomes vital. Besides, the newly recorded species may be important for biosecurity and should be listed as quarantine pathogens, considering that tropical fruits are traded worldwide.

scholarly journals Poult Enteritis and Mortality Syndrome in Turkey Poults: Causes, Diagnosis and Preventive Measures

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2063
Author(s):  
Awad A. Shehata ◽  
Shereen Basiouni ◽  
Reinhard Sting ◽  
Valerij Akimkin ◽  
Marc Hoferer ◽  
...  
Keyword(s):  
Preventive Measures ◽  
Clinical Signs ◽  
Accurate Diagnosis ◽  
Economic Losses ◽  
Turkey Poults ◽  
Causative Agents ◽  
Enteric Disorders ◽  
And Control ◽  
Enteropathogenic Viruses ◽  
Poult Enteritis

Poult enteritis and mortality syndrome (PEMS) is one of the most significant problem affecting turkeys and continues to cause severe economic losses worldwide. Although the specific causes of PEMS remains unknown, this syndrome might involve an interaction between several causative agents such as enteropathogenic viruses (coronaviruses, rotavirus, astroviruses and adenoviruses) and bacteria and protozoa. Non-infectious causes such as feed and management are also interconnected factors. However, it is difficult to determine the specific cause of enteric disorders under field conditions. Additionally, similarities of clinical signs and lesions hamper the accurate diagnosis. The purpose of the present review is to discuss in detail the main viral possible causative agents of PEMS and challenges in diagnosis and control.

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