scholarly journals Molecular Methods for the Detection of Toxoplasma gondii Oocysts in Fresh Produce: An Extensive Review

2021 ◽  
Vol 9 (1) ◽  
pp. 167
Author(s):  
Iva Slana ◽  
Nadja Bier ◽  
Barbora Bartosova ◽  
Gianluca Marucci ◽  
Alessia Possenti ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Method Development ◽  
Fresh Produce ◽  
Foodborne Pathogen ◽  
Human Infection ◽  
Detection Methods ◽  
Extensive Literature ◽  
Oocyst Wall ◽  
Online Questionnaire ◽  
Validation Data

Human infection with the important zoonotic foodborne pathogen Toxoplasma gondii has been associated with unwashed raw fresh produce consumption. The lack of a standardised detection method limits the estimation of fresh produce as an infection source. To support method development and standardisation, an extensive literature review and a multi-attribute assessment were performed to analyse the key aspects of published methods for the detection of T. gondii oocyst contamination in fresh produce. Seventy-seven published studies were included, with 14 focusing on fresh produce. Information gathered from expert laboratories via an online questionnaire were also included. Our findings show that procedures for oocyst recovery from fresh produce mostly involved sample washing and pelleting of the washing eluate by centrifugation, although washing procedures and buffers varied. DNA extraction procedures including mechanical or thermal shocks were identified as necessary steps to break the robust oocyst wall. The most suitable DNA detection protocols rely on qPCR, mostly targeting the B1 gene or the 529 bp repetitive element. When reported, validation data for the different detection methods were not comparable and none of the methods were supported by an interlaboratory comparative study. The results of this review will pave the way for an ongoing development of a widely applicable standard operating procedure.

scholarly journals Current Trends and Challenges for Rapid SMART Diagnostics at Point-of-Site Testing for Marine Toxins

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2499
Author(s):  
Michael Dillon ◽  
Maja A. Zaczek-Moczydlowska ◽  
Christine Edwards ◽  
Andrew D. Turner ◽  
Peter I. Miller ◽  
...  
Keyword(s):  
Method Development ◽  
Regulatory Control ◽  
Detection Methods ◽  
Control Individual ◽  
Mouse Bioassay ◽  
Future Market ◽  
Site Testing ◽  
Wide Range ◽  
Development And Validation ◽  
Analytical Standards

In the past twenty years marine biotoxin analysis in routine regulatory monitoring has advanced significantly in Europe (EU) and other regions from the use of the mouse bioassay (MBA) towards the high-end analytical techniques such as high-performance liquid chromatography (HPLC) with tandem mass spectrometry (MS). Previously, acceptance of these advanced methods, in progressing away from the MBA, was hindered by a lack of commercial certified analytical standards for method development and validation. This has now been addressed whereby the availability of a wide range of analytical standards from several companies in the EU, North America and Asia has enhanced the development and validation of methods to the required regulatory standards. However, the cost of the high-end analytical equipment, lengthy procedures and the need for qualified personnel to perform analysis can still be a challenge for routine monitoring laboratories. In developing regions, aquaculture production is increasing and alternative inexpensive Sensitive, Measurable, Accurate and Real-Time (SMART) rapid point-of-site testing (POST) methods suitable for novice end users that can be validated and internationally accepted remain an objective for both regulators and the industry. The range of commercial testing kits on the market for marine toxin analysis remains limited and even more so those meeting the requirements for use in regulatory control. Individual assays include enzyme-linked immunosorbent assays (ELISA) and lateral flow membrane-based immunoassays (LFIA) for EU-regulated toxins, such as okadaic acid (OA) and dinophysistoxins (DTXs), saxitoxin (STX) and its analogues and domoic acid (DA) in the form of three separate tests offering varying costs and benefits for the industry. It can be observed from the literature that not only are developments and improvements ongoing for these assays, but there are also novel assays being developed using upcoming state-of-the-art biosensor technology. This review focuses on both currently available methods and recent advances in innovative methods for marine biotoxin testing and the end-user practicalities that need to be observed. Furthermore, it highlights trends that are influencing assay developments such as multiplexing capabilities and rapid POST, indicating potential detection methods that will shape the future market.

scholarly journals Neospora caninum and/or Toxoplasma gondii Seroprevalence: Vaccination against PCV2 and Muscle Enzyme Activity in Seropositive and Seronegative Pigs

2021 ◽  
Vol 9 (5) ◽  
pp. 1097
Author(s):  
Labrini V. Athanasiou ◽  
Vasileios G. Papatsiros ◽  
Victoria M. Spanou ◽  
Eleni G. Katsogiannou ◽  
Anna Dedousi
Keyword(s):  
Enzyme Activity ◽  
Toxoplasma Gondii ◽  
Neospora Caninum ◽  
Human Infection ◽  
Porcine Circovirus ◽  
Muscle Enzyme ◽  
Blood Samples ◽  
Zoonotic Pathogen ◽  
Muscle Enzyme Activity ◽  
Immunofluorescence Antibody

Neospora caninum and Toxoplasma gondii affect both humans and animals worldwide. To investigate their seroprevalence and differences in seropositivity between pigs vaccinated and unvaccinated against porcine circovirus 2 (PCV2), as well as differences in muscle enzyme activity between seropositive and seronegative pigs, blood samples were collected from 380 sows. Antibodies against T. gondii and N. caninum were detected by an indirect immunofluorescence antibody (IFA) assay, while the activities of creatine kinase (CK) and aspartate aminotransferase (AST) were biochemically assessed. Out of the 364 sows finally included in the study, 4.4%, 3.5%, and 0.5% were seropositive to T. gondii, N. caninum, or both. A significantly higher percentage of seropositivity against T. gondii and/or N. caninum in PCV2 unvaccinated pigs compared with vaccinated pigs was observed. Increased serum activities of CK and AST were detected in 71.43% and 100% of only against T. gondii (T+) and 63.64% and 90.91% of only against N. caninum (N+) seropositive sows, respectively, and were significantly higher compared to seronegative animals. T. gondii and N. caninum seropositivity, especially in presumed immunocompromised pigs, and the evidence of muscle damage highlight their importance as a zoonotic pathogen and animal model of human infection, respectively.

scholarly journals Survival characteristics of Salmonella enterica serovar Enteritidis in chicken egg albumen

2006 ◽  
Vol 134 (5) ◽  
pp. 967-976 ◽  
Author(s):  
H. KANG ◽  
C. LOUI ◽  
R. I. CLAVIJO ◽  
L. W. RILEY ◽  
S. LU
Keyword(s):  
Salmonella Enterica ◽  
Iron Acquisition ◽  
Foodborne Pathogen ◽  
Human Infection ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Factors Affecting ◽  
Chicken Egg ◽  
Egg Albumen ◽  
High Concentrations ◽  
Incubation Temperatures

Salmonella enterica serovar Enteritidis (SE) is a major foodborne pathogen primarily causing human infection through contaminated chicken eggs. To understand how SE survives in chicken egg albumen, we systematically and quantitatively analysed the survival properties of SE in egg albumen and identified factors affecting its survival. Survival assays of SE in egg indicate that egg albumen restricted the growth of SE. A major factor that controlled SE's growth in egg albumen was iron restriction, since egg albumen supplemented with iron allowed SE to grow, and iron acquisition mutants of SE showed decreased survival in egg albumen. In addition, low pH of albumen, high concentrations of bacteria and low incubation temperatures of bacteria with albumen facilitates the survival of SE. Our results suggest that egg albumen uses multiple mechanisms to control SE including iron limitation, surface interaction and possible enzymatic activities.

scholarly journals Prevalence and risk factors for Toxoplasma gondii infection in certified and non-certified pig breeding farms in the Toledo microregion, PR, Brazil

2010 ◽  
Vol 19 (3) ◽  
pp. 152-156 ◽  
Author(s):  
Piassa Franciele Rossandra ◽  
Jacqueline Baptista de Araújo ◽  
Ronaldo César da Rosa ◽  
Rodrigo José Mattei ◽  
Rodrigo Costa da Silva ◽  
...  
Keyword(s):  
Risk Factors ◽  
Toxoplasma Gondii ◽  
Human Infection ◽  
Control Measures ◽  
Rodent Control ◽  
Reproductive Disorders ◽  
Toxoplasma Infection ◽  
Pork Products ◽  
Toxoplasma Gondii Infection ◽  
Breeding Farms

Toxoplasma gondii infection has been diagnosed in pigs all over the world. Economical losses are generally related to reproductive disorders. Toxoplasma infection is also a matter of public health because tissue cysts of the parasite may remain in pork and pork products, and become sources of human infection. The objective of this study was to evaluate the frequency and risk factors associated with Toxoplasma infection in certified and non-certified pig breeding farms in the Toledo microregion, in the State of Paraná, Brazil which includes the cities of Toledo, Nova Santa Rosa, Sao José das Palmeiras and Sao Pedro do Iguaçu. Relative frequency of infection was 13.4%, independently of the type of farm. Logistic regression analysis showed that the following factors were associated with infection: absence of workers exclusive for each area of the farm, access of other animals to feeders and drinkers, lack of lids in drinkers, lack of rodent control measures, mean piglet number and weight at weaning per female.

scholarly journals Seroprevalence of Toxoplasma gondii in dogs of riverside communities of Mato Grosso Pantanal, Brazil

2016 ◽  
Vol 25 (4) ◽  
pp. 531-535 ◽  
Author(s):  
Juliana Yuki Rodrigues ◽  
Arleana do Bom Parto Ferreira de Almeida ◽  
Eveline da Cruz Boa Sorte ◽  
Naiani Domingos Gasparetto ◽  
Felipe Augusto Constantino Seabra da Cruz ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Antibody Test ◽  
Human Infection ◽  
Mato Grosso ◽  
Exact Test ◽  
Worldwide Distribution ◽  
Significant Difference ◽  
Chi Squared ◽  
Immunofluorescence Antibody Test ◽  
Immunofluorescence Antibody

Abstract Toxoplasma gondii is an intracellular protozoan with worldwide distribution and dogs act as sentinels of human infection. This search aimed to determine the occurrence of antibodies against T. gondii in dogs of the communities on the Cuiabá River, Mato Grosso and variables associated with infection. The dogs of the riverside communities in Cuiabá River, which includes Barranco Alto, Praia do Poço, Engenho Velho, Varginha, Bom Sucesso, Passagem da Conceição and São Gonçalo Beira Rio, were evaluated for the presence of T. gondii antibodies by indirect immunofluorescence antibody test (IFAT). The prevalence and factors associated with infection were calculated by chi-squared test (χ2) or Fisher’s exact test, and univariate and multiple analysis. Of the 248 dogs surveyed, 107 (43.1%) were seropositive for T. gondii. The seroprevalence ranged from 25.6% to 64.3%. There was no statistically significant difference between the communities studied (p > 0.05). As for the associated factors, the only statistically significant factor was that of dogs living with cats (p = 0.02), with approximately twice the risk of acquiring infection. In conclusion, the seroprevalence in dogs of riverside communities in the Baixada Cuiabana demonstrated that high rates of infection, being the factor associated with infection, contact with domestic cats.

scholarly journals Detection of Viable Toxoplasma gondii in Free-Range Pigs from the Special Nature Reserve of Zasavica

2016 ◽  
Vol 65 (3-4) ◽  
pp. 1-6 ◽  
Author(s):  
Ljiljana Kuruca ◽  
Ivana Klun ◽  
Aleksandra Uzelac ◽  
Aleksandra Nikolić ◽  
Branko Bobić ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Nature Reserve ◽  
Heart Tissue ◽  
Human Infection ◽  
Serological Screening ◽  
Free Range ◽  
Modified Agglutination Test ◽  
Successful Isolation ◽  
Polymerase Chain ◽  
Great Appreciation

SummaryToxoplasma gondii is considered one of the most successful parasites of humans and animals. The ingestion of viable cysts through the consumption of undercooked pork is recognized as a significant route of human infection with T. gondii. The aim of this study was to investigate the presence of viable parasite in tissues of free-range pigs from the Zasavica Special Nature Reserve. All pigs were of the Mangulica breed, raised in a traditional way. The serological screening was performed using a modified agglutination test (MAT). The isolation of viable T. gondii was attempted by a bioassay of pig heart tissue in mice, while the real-time polymerase chain reaction (qPCR) targeted at the 529 bp repetitive element of T. gondii was used to detect parasitic DNA in digested hearts. Specific antibodies were detected in 12 out of 18 pigs examined. The bioassay was performed for five MAT-positive and one MAT-negative pig, and a total of three isolates were obtained. qPCR was performed for all samples, including one MAT-negative sample that was not bioassayed. The presence of T. gondii DNA was confirmed in all hearts with a positive bioassay as well as in one originating from seropositive and one from seronegative pig whose hearts were not bioassayed. The successful isolation of viable cysts, presence of risk factors (such as older age at the time of slaughter) and increased contact with the environment, along with the great appreciation of Serbian consumers towards home-cured Mangulica’s meat, make this breed worthy of consideration as a potentially important reservoir of human infection.

scholarly journals RP-HPLC Method Development and Validation for Cleaning Residue Determination of Tofacitinib Citrate in Tofacitinib Tablets

2021 ◽  
pp. 262-276
Author(s):  
Thaticherla Kaleswararao ◽  
Duvvuri Suryakala
Keyword(s):  
Method Development ◽  
Drug Product ◽  
Hplc Method ◽  
Solution Stability ◽  
Sample Analysis ◽  
Validation Data ◽  
Manufacturing Equipment ◽  
Rp Hplc ◽  
Hplc Method Development ◽  
Development And Validation

A novel, Specific, and precise RP-HPLC method was developed to determine the residue content of Tofacitinib citrate left on the surface of equipment used in the manufacturing process. The manufacturing equipment considered in assessment of cleaning has been verified and found the tools assembled to the equipment are made up of Stainless steel, Glass, Teflon and plastic. Hence, these surfaces of manufacturing equipment that come in contact with the drug product during manufacturing are considered for evaluation of the cleaning procedure. By developing and validating an analytical method for residue estimation, the manufacturing equipment can be evaluated for efficient cleaning and to release the manufacturing equipment for further intended use by minimizing the cross contaminations. The stationary phase suited for the well separation of components is CAPCELL PAK C18 150 x 4.6 mm, 3 μm; 0.4 % perchloric acid and acetonitrile in the ratio of 85:15 % v/v is the mobile phase pumped at a flow rate of 1.2 mL/min through the column at temperature of 40 ºC. Each run extended for 10 min as the Tofacitinib peak elutes at RT of 5.2 min. The method has been validated successfully for Specificity, Precision, Linearity, Accuracy, Ruggedness and Filter validation of both rinse and swab methods. The LOD, LOQ concentrations found to be 0.006, 0.019 µg/mL for swab method and 0.03 and 0.1 µg/mL for rinse method respectively. The correlation coefficient is 0.999 and method found linear from LOQ to 500% for swab method and LOQ to 200% for rinse method. Solution stability has been established to ensure the test solution get tested within the stable time (4 Days). Based on the filter validation data, it is concluded that PVDF filter is not suitable for cleaning sample analysis and 2 mL sample should be discarded when 0.45 µm Nylon filter is used for cleaning sample analysis.

scholarly journals Outbreaks, Germination, and Inactivation of Bacillus cereus in Food Products: A Review

2020 ◽  
Vol 83 (9) ◽  
pp. 1480-1487
Author(s):  
WON CHOI ◽  
SANG-SOON KIM
Keyword(s):  
Food Safety ◽  
Bacillus Cereus ◽  
Food Processing ◽  
Rapid Detection ◽  
Foodborne Pathogen ◽  
Present Review ◽  
Detection Methods ◽  
Processing Technologies ◽  
Foodborne Outbreaks ◽  
Food Commodity

ABSTRACT Bacillus cereus has been reported as a foodborne pathogen worldwide. Although food processing technologies to inactivate the pathogen have been developed for decades, foodborne outbreaks related to B. cereus have occurred. In the present review, foodborne outbreaks, germination, inactivation, and detection of B. cereus are discussed, along with inactivation mechanisms. B. cereus outbreaks from 2003 to 2016 are reported based on food commodity, number of cases, and consequent illnesses. Germination before sporicidal treatments is highlighted as an effective way to inactivate B. cereus, because the resistance of the pathogen increases significantly following sporulation. Several germinants used for B. cereus are listed, and their efficacies are compared. Finally, recently used interventions with sporicidal mechanisms are identified, and rapid detection methods that have been developed are discussed. Combining two or more interventions, known as the hurdle technology concept, is suggested to maximize the sporicidal effect. Further study is needed to ensure food safety and to understand germination mechanisms and sporicidal resistance of B. cereus. HIGHLIGHTS

scholarly journals Advances in Foodborne Pathogen Analysis

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1635
Author(s):  
Arun K. Bhunia ◽  
Bledar Bisha ◽  
Andrew G. Gehring ◽  
Byron F. Brehm-Stecher
Keyword(s):  
Point Of Care ◽  
Foodborne Pathogen ◽  
Test Methods ◽  
Detection Methods ◽  
World Population ◽  
Future Production ◽  
Dietary Choices ◽  
Critical Issues ◽  
User Friendly ◽  
Face Time

As the world population has grown, new demands on the production of foods have been met by increased efficiencies in production, from planting and harvesting to processing, packaging and distribution to retail locations. These efficiencies enable rapid intranational and global dissemination of foods, providing longer “face time” for products on retail shelves and allowing consumers to make healthy dietary choices year-round. However, our food production capabilities have outpaced the capacity of traditional detection methods to ensure our foods are safe. Traditional methods for culture-based detection and characterization of microorganisms are time-, labor- and, in some instances, space- and infrastructure-intensive, and are therefore not compatible with current (or future) production and processing realities. New and versatile detection methods requiring fewer overall resources (time, labor, space, equipment, cost, etc.) are needed to transform the throughput and safety dimensions of the food industry. Access to new, user-friendly, and point-of-care testing technologies may help expand the use and ease of testing, allowing stakeholders to leverage the data obtained to reduce their operating risk and health risks to the public. The papers in this Special Issue on “Advances in Foodborne Pathogen Analysis” address critical issues in rapid pathogen analysis, including preanalytical sample preparation, portable and field-capable test methods, the prevalence of antibiotic resistance in zoonotic pathogens and non-bacterial pathogens, such as viruses and protozoa.

scholarly journals Comanaging fresh produce for nature conservation and food safety

2015 ◽  
Vol 112 (35) ◽  
pp. 11126-11131 ◽  
Author(s):  
Daniel S. Karp ◽  
Sasha Gennet ◽  
Christopher Kilonzo ◽  
Melissa Partyka ◽  
Nicolas Chaumont ◽  
...  
Keyword(s):  
Food Safety ◽  
Fresh Produce ◽  
Foodborne Pathogen ◽  
The United States ◽  
Livestock Grazing ◽  
Central Coast ◽  
E Coli ◽  
Vegetation Removal ◽  
Pathogen Prevalence ◽  
Coast Region

In 2006, a deadly Escherichia coli O157:H7 outbreak in bagged spinach was traced to California’s Central Coast region, where >70% of the salad vegetables sold in the United States are produced. Although no definitive cause for the outbreak could be determined, wildlife was implicated as a disease vector. Growers were subsequently pressured to minimize the intrusion of wildlife onto their farm fields by removing surrounding noncrop vegetation. How vegetation removal actually affects foodborne pathogens remains unknown, however. We combined a fine-scale land use map with three datasets comprising ∼250,000 enterohemorrhagic E. coli (EHEC), generic E. coli, and Salmonella tests in produce, irrigation water, and rodents to quantify whether seminatural vegetation surrounding farmland is associated with foodborne pathogen prevalence in California’s Central Coast region. We found that EHEC in fresh produce increased by more than an order of magnitude from 2007 to 2013, despite extensive vegetation clearing at farm field margins. Furthermore, although EHEC prevalence in produce was highest on farms near areas suitable for livestock grazing, we found no evidence of increased EHEC, generic E. coli, or Salmonella near nongrazed, seminatural areas. Rather, pathogen prevalence increased the most on farms where noncrop vegetation was removed, calling into question reforms that promote vegetation removal to improve food safety. These results suggest a path forward for comanaging fresh produce farms for food safety and environmental quality, as federal food safety reforms spread across ∼4.5 M acres of US farmland.

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