scholarly journals Role of Clostridium perfringens Necrotic Enteritis B-like Toxin in Disease Pathogenesis

Vaccines ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 61
Author(s):  
Kyung-Woo Lee ◽  
Hyun S. Lillehoj
Keyword(s):  
Clostridium Perfringens ◽  
Large Scale ◽  
Scientific Evidence ◽  
Short Review ◽  
Complex Nature ◽  
Necrotic Enteritis ◽  
Toxin A ◽  
Commercial Broiler ◽  
Large Scale Field

Necrotic enteritis (NE) is a devastating enteric disease caused by Clostridium perfringens type A/G that impacts the global poultry industry by compromising the performance, health, and welfare of chickens. Coccidiosis is a major contributing factor to NE. Although NE pathogenesis was believed to be facilitated by α-toxin, a chromosome-encoded phospholipase C enzyme, recent studies have indicated that NE B-like (NetB) toxin, a plasmid-encoded pore-forming heptameric protein, is the primary virulence factor. Since the discovery of NetB toxin, the occurrence of NetB+ C. perfringens strains has been increasingly reported in NE-afflicted poultry flocks globally. It is generally accepted that NetB toxin is the primary virulent factor in NE pathogenesis although scientific evidence is emerging that suggests other toxins contribute to NE. Because of the complex nature of the host-pathogen interaction in NE pathogenesis, the interaction of NetB with other potential virulent factors of C. perfringens needs better characterization. This short review will summarize the primary virulence factors involved in NE pathogenesis with an emphasis on NetB toxin, and a new detection method for large-scale field screening of NetB toxin in biological samples from NE-afflicted commercial broiler flocks.

Total Productive Maintenance: Competing or Complementary to other Initiatives?

2013 ◽  
Vol 315 ◽  
pp. 472-476
Author(s):  
Adnan Hj. Bakri ◽  
Abdul Rahman Abdul Rahim ◽  
Noordin Mohd Yusof
Keyword(s):  
Large Scale ◽  
Manufacturing Industry ◽  
Short Review ◽  
The Other ◽  
Total Quality ◽  
Total Productive Maintenance ◽  
Quality Initiatives ◽  
Practical Applications ◽  
Manufacturing Organization

The objective of this short review paper is to examine the practical applications of Total Productive Maintenance (TPM) in the manufacturing industry. In this short review, an attempt was made to critically discuss the previous literatures related to TPM with the other established quality initiatives in the manufacturing, such as Total Quality Management (TQM) and Just-In-Time practice (JIT). This literature review-based research revealed an important research gaps related to TPM. The significance role of TPM as an important complementary to either TQM or JIT initiative is observed not been well addressed in the available literatures. Most of the researches available investigate these initiatives separately, focuses on the other element rather than addressing on the significant role of TPM as one of the main thrust. The separate implementation of such quality initiatives in the manufacturing organization means the requirement of large scale human, financial and technical resources as well the associated problems of running competing project in the company. The outcomes from this review justify the needs of further research in the area of TPM integration with other available initiatives, to further enhance its methodology aimed at solidifying its philosophy towards more realistic practical applications.

scholarly journals Role of Clostridium perfringens Toxins in Necrotic Enteritis in Poultry

2016 ◽  
pp. 1-16 ◽  
Author(s):  
M Flores-Díaz ◽  
E Barquero-Calvo ◽  
M Ramírez ◽  
A Alape-Girón
Keyword(s):  
Clostridium Perfringens ◽  
Necrotic Enteritis

scholarly journals The Agr-Like Quorum Sensing System Is Required for Pathogenesis of Necrotic Enteritis Caused by Clostridium perfringens in Poultry

2017 ◽  
Vol 85 (6) ◽  
Author(s):  
Qiang Yu ◽  
Dion Lepp ◽  
Iman Mehdizadeh Gohari ◽  
Tao Wu ◽  
Hongzhuan Zhou ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Clostridium Perfringens ◽  
Global Gene Expression ◽  
Toxin Production ◽  
Phospholipid Metabolism ◽  
Necrotic Enteritis ◽  
Content Type ◽  
Protein Levels ◽  
Global Gene Expression Analysis

ABSTRACT Clostridium perfringens encodes at least two different quorum sensing (QS) systems, the Agr-like and LuxS, and recent studies have highlighted their importance in the regulation of toxin production and virulence. The role of QS in the pathogenesis of necrotic enteritis (NE) in poultry and the regulation of NetB, the key toxin involved, has not yet been investigated. We have generated isogenic agrB-null and complemented strains from parent strain CP1 and demonstrated that the virulence of the agrB-null mutant was strongly attenuated in a chicken NE model system and restored by complementation. The production of NetB, a key NE-associated toxin, was dramatically reduced in the agrB mutant at both the transcriptional and protein levels, though not in a luxS mutant. Transwell assays confirmed that the Agr-like QS system controls NetB production through a diffusible signal. Global gene expression analysis of the agrB mutant identified additional genes modulated by Agr-like QS, including operons related to phospholipid metabolism and adherence, which may also play a role in NE pathogenesis. This study provides the first evidence that the Agr-like QS system is critical for NE pathogenesis and identifies a number of Agr-regulated genes, most notably netB, that are potentially involved in mediating its effects. The Agr-like QS system thus may serve as a target for developing novel interventions to prevent NE in chickens.

scholarly journals Investigation of Clostridium perfringens in small-scale commercial broiler flocks in Mymensingh district of Bangladesh

2021 ◽  
pp. 2809-2816
Author(s):  
Arunima Oarin Tresha ◽  
Mohammad Arif ◽  
Sk Shaheenur Islam ◽  
A. K. M. Ziaul Haque ◽  
Md. Tanvir Rahman ◽  
...  
Keyword(s):  
Risk Factors ◽  
Clostridium Perfringens ◽  
Antimicrobial Agents ◽  
Structured Interview ◽  
Economic Losses ◽  
Small Scale ◽  
Necrotic Enteritis ◽  
Cross Sectional Survey ◽  
Level Data ◽  
Commercial Broiler

Background and Aim: Necrotic enteritis (NE) is one of the most prevalent diseases in broiler poultry caused by Clostridium perfringens connected with significant economic losses. A cross-sectional survey was conducted in Mymensingh district of Bangladesh to assess the prevalence of C. perfringens through toxinotyping molecular assay and confirm the risk factors for NE, including antimicrobial-resistant (AMR) status of the isolates. Materials and Methods: We included 40 small-scale commercial broiler farms randomly selected from two subdistricts of Mymensingh district of Bangladesh. As an individual sample, 240 cloacal swabs, and as a pooled sample, 40 drinking water, 40 workers' hand washing, 40 litter swab, and 40 feed samples were collected and evaluated by culture, biochemical, and molecular assays. A pretested semi-structured interview questionnaire was employed to capture flock-level data on risk factors from the farm owners. The flock-level data on risk factors were assessed through univariable and multivariable logistic regression analyses with p<0.05 was considered statistically significant. Results: Overall flock-level prevalence of C. perfringens was estimated to be 10.3% (95% confidence interval [CI] 7.5- 13.6%). Litter swab (pooled) was found to be highly contaminated with C. perfringens (25.0%, 95% CI: 12.7-41.2%) followed by the cloacal swab (10.4%, 95% CI: 6.9-15.0%) and feed sample (5.0%, 95% CI: 0.6-16.9%). History of coccidia infection (Adjusted odds ratio =33.01, 95% CI: 2.14-507.59, p=0.01) was significantly associated with flock-level C. perfringens infection status. In this study, 78.1% isolates were found as multidrug-resistant as they demonstrated resistance to 3-5 antimicrobial agents. Conclusion: Evidence-based control options need to be taken through the uses of prebiotics and probiotics, biosecurity, and hygienic measurement, including control of coccidia infection, is needed to lessen the NE infection and AMR related to this pathogen in small-scale commercial broiler poultry.

scholarly journals The Role of Mindset in Education : A Large-Scale Field Experiment in Disadvantaged Schools

2021 ◽  
Author(s):  
Elise Huillery ◽  
Adrien Bouguen ◽  
Axelle Charpentier ◽  
Yann Algan ◽  
Coralie Chevallier
Keyword(s):  
Field Experiment ◽  
Experimental Evidence ◽  
Large Scale ◽  
Cost Effective ◽  
Growth Mindset ◽  
Disadvantaged Schools ◽  
Scale Field ◽  
Large Scale Field ◽  
The Impact

This article provides experimental evidence of the impact of a four-year inter-vention aimed at developing students’ growth mindset and internal locus ofcontrol in disadvantaged middle schools. We find a 0.07 standard deviationincrease in GPA, associated with a change in students’ mindset, improved be-havior as reported by teachers and school registers, and higher educational andprofessional aspirations. International empirical benchmarks reveal that theintervention is at least ten times more cost-effective than the typical educa-tional intervention. However, while reducing between-school inequality whentargeted to disadvantaged schools, the program benefits less to more fragilestudents, therefore increasing within-school inequality.

scholarly journals ROLE OF CLOSTRIDIUM PERFRINGENS IN PATHOGENICITY OF SOME DOMESTIC ANIMALS

2017 ◽  
Vol 7 (3) ◽  
pp. 1117-1121 ◽  
Author(s):  
Mohammad Reza Mohammadabadi
Keyword(s):  
Clostridium Perfringens ◽  
Gastrointestinal Disease ◽  
Food Poisoning ◽  
Small Ruminants ◽  
Necrotic Enteritis ◽  
Economic Stability ◽  
Native Breed ◽  
The World ◽  
The Tropics

Clostridium perfringens, is an anaerobic, gram-positive, pathogenic and spore-forming bacillus and broadly gave out in our territory. This bacterium has spore formation capability and creating gangrene and gastrointestinal disease, for example food poisoning and necrotic enteritis in human, whilst in other animals, gastrointestinal and enterotoxemic diseases more happening. Prevalence of necrotic enteritis, created by C. perfringens, has been often stated in sheep, chickens and ostrich throughout the world. The most critical problem for epidemiological investigations and vaccines improvement is accurate recognition of C. perfringens variants. Moreover, Small ruminants, especially native breed types, play an important role to the livelihoods of a considerable part of human population in the tropics from socio-economic aspects. Therefore, integrated attempt in terms of management and genetic improvement to enhance production is of crucial importance. Poultry provide humans with companionship, food and fiber in the form of eggs, meat and feathers. Many people love to raise and show chickens and other poultry species at fairs and other poultry shows. Others just love to raise them for backyard pets and for fresh eggs every day. In the last few years, ostrich farming has progressed dramatically and the world ostrich industry has achieved some economic stability. There is considerable scope for improvement in the areas of artificial incubation, chick nutrition, environmental requirements and selective breeding. Hence, the aim of this paper was to study role of Clostridium perfringens in pathogenicity of sheep, broilers and Ostrich. In conclusion, recognition of toxins producing by C. perfringens is very momentous because their toxin types are related to particular gastric and intestinal animal sickness and PCR has become an essential research and diagnostic tool, being a powerful technique with a vast and increasing range of applications. Hence, it is better that animal breeders identify different types of C. perfringens using PCR technique to prevent the damage caused by this bacterium.  

scholarly journals Disaster Ergonomics: Human Factors in COVID-19 Pandemic Emergency Management

2020 ◽  
Vol 62 (7) ◽  
pp. 1061-1068 ◽  
Author(s):  
Farzan Sasangohar ◽  
Jason Moats ◽  
Ranjana Mehta ◽  
S. Camille Peres
Keyword(s):  
Human Factors ◽  
Emergency Management ◽  
Large Scale ◽  
Extended Period ◽  
Short Review ◽  
Propagation Rate ◽  
Training Methods ◽  
Expert Review ◽  
Enhance Efficiency

Objective We aimed to identify opportunities for application of human factors knowledge base to mitigate disaster management (DM) challenges associated with the unique characteristics of the COVID-19 pandemic. Background The role of DM is to minimize and prevent further spread of the contagion over an extended period of time. This requires addressing large-scale logistics, coordination, and specialized training needs. However, DM-related challenges during the pandemic response and recovery are significantly different than with other kinds of disasters. Method An expert review was conducted to document issues relevant to human factors and ergonomics (HFE) in DM. Results The response to the COVID-19 crisis has presented complex and unique challenges to DM and public health practitioners. Compared to other disasters and previous pandemics, the COVID-19 outbreak has had an unprecedented scale, magnitude, and propagation rate. The high technical complexity of response and DM coupled with lack of mental model and expertise to respond to such a unique disaster has seriously challenged the response work systems. Recent research has investigated the role of HFE in modeling DM systems’ characteristics to improve resilience, accelerating emergency management expertise, developing agile training methods to facilitate dynamically changing response, improving communication and coordination among system elements, mitigating occupational hazards including guidelines for the design of personal protective equipment, and improving procedures to enhance efficiency and effectiveness of response efforts. Conclusion This short review highlights the potential for the field’s contribution to proactive and resilient DM for the ongoing and future pandemics.

scholarly journals Developing an experimental necrotic enteritis model in turkeys - the impact of Clostridium perfringens, Eimeria meleagrimitis and host age on frequency of severe intestinal lesions

2019 ◽  
Author(s):  
Simon P. Hardy ◽  
Sylvie L. Benestad ◽  
Inger Sofie Hamnes ◽  
Torfinn Moldal ◽  
Bruce David ◽  
...  
Keyword(s):  
Clostridium Perfringens ◽  
Scoring System ◽  
In Vivo Model ◽  
Necrotic Enteritis ◽  
Intestinal Lesions ◽  
Gross Lesions ◽  
Successful Establishment ◽  
The Impact

Abstract Background: Necrotic enteritis is a significant problem to the poultry industry globally and, in Norway up to 30 % of Norwegian turkey grow-outs can be affected. However, despite an awareness that differences exist between necrotic enteritis in chickens and turkeys, little information exists concerning the pathogenesis, immunity, microbiota or experimental reproduction of necrotic enteritis in turkeys. In particular, it is important to determine the appearance of the gross lesions, the age dependency of the disease and the role of netB toxin of Clostridium perfringens . To this end, we report our findings in developing an in vivo experimental model of necrotic enteritis in turkeys. Results: A four tier (0-3) scoring system with clearly defined degrees of severity of macroscopic intestinal lesions was developed, based on 2312 photographic images of opened intestines from 810 B.U.T. 10 or B.U.T. Premium turkeys examined in nine experiments. Loss of macroscopically recognizable villi in the anterior small intestine was established as the defining lesion qualifying for a score 3 (severe intestinal lesions). The developed scoring system was used to identify important factors in promoting high frequencies of turkeys with severe lesions: a combined Eimeria meleagrimitis and Clostridium perfringens challenge, challenge at five rather than three weeks of age, the use of an Eimeria meleagrimitis dose level of at least 5 000 oocysts per bird and finally, examination of the intestines of 5-week-old turkeys at 125 to 145 hours after Eimeria meleagrimitis inoculation. Numbers of oocysts excreted were not influenced by Clostridium perfringens inoculation or turkey age. Among three different lesion score outcomes tested, frequency of severe lesions proved superior in discriminating between impact of four combinations of Clostridium perfringens inoculation and turkey age at challenge. Conclusions: This study provides details for the successful establishment of an in vivo model of necrotic enteritis in turkeys.

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