2.6 GENOME PLASTICITY AND EVOLUTION OF ESCHERICHIA COLI
Like all life forms, new strains of E. coli evolve through the natural biological processes of mutation, gene duplication, and horizontal gene transfer; in particular, 18% of the genome of the laboratory strain MG1655 was horizontally acquired since the divergence from Salmonella. E. coli K-12 and E. coli B strains are the most frequently used varieties for laboratory purposes. Some strains develop traits that can be harmful to a host animal. These virulent strains typically cause a bout of diarrhea that is often self-limiting in healthy adults but is frequently lethal to children in the developing world. (Futadar et al., 2005). More virulent strains, such as O157:H7, cause serious illness or death in the elderly, the very young, or the immunocompromised.
The genera Escherichia and Salmonella diverged around 102 million years ago (credibility interval: 57–176 mya), which coincides with the divergence of their hosts: the former being found in mammals and the latter in birds and reptiles. (Wang et al., 2009). This was followed by a split of an Escherichia ancestor into five species (E. albertii, E. coli, E. fergusonii, E. hermannii, and E. vulneris). The last E. coli ancestor split between 20 and 30 million years ago.
The long-term evolution experiments using E. coli, begun by Richard Lenski in 1988, have allowed direct observation of genome evolution over more than 65,000 generations in the laboratory. For instance, E. coli typically do not have the ability to grow aerobically with citrate as a carbon source, which is used as a diagnostic criterion with which to differentiate E. coli from other, closely, related bacteria such as Salmonella. In this experiment, one population of E. coli unexpectedly evolved the ability to aerobically metabolize citrate, a major evolutionary shift with some hallmarks of microbial speciation.
2.7 INCUBATION PERIOD
The time between ingesting the STEC bacteria and feeling sick is called the “incubation period”. The incubation period is usually 3–4 days after the exposure, but may be as short as 1 day or as long as 10 days. The symptoms often begin slowly with mild belly pain or non-bloody diarrhea that worsens over several days. HUS, if it occurs, develops an average of 7 days after the first symptoms, when the diarrhea is improving.
2.7.1 DISCOVERY OF ANTIBIOTICS
• History of antibiotics – 1
19th century:Louis Pasteur & Robert Koch
• History of antibiotics – 2
– Quinine (against malaria)
– Ipecacuanha root (emetic, e.g. in dysentery)
– Mercury (against syphilis)
– Arsenic (Atoxyl, against Trypanosoma)
– Trypan Blue (Ehrlich)
– Prontosil (azo-dye, Domagk, 1936)
• History of antibiotics – 3
• started science of chemotherapy
• Systematic chemical modifications
(“Magic Bullet”) no. 606 compound = Salvarsan (1910)
• Selective toxicity.
• Developed the Chemotherapeutic Index
• History of antibiotics – 4
Penicillin- the first antibiotic – 1928• Alexander Fleming observed the
killing of staphylococci by a fungus (Penicillium notatum)
• observed by others – never exploited
• Florey & Chain purified it by freeze-drying (1940) – Nobel prize 1945
• First used in a patient: 1942
• World War II: penicillin saved 12-15% of lives
• History of antibiotics – 5
Selman Waksman – Streptomycin (1943), was the first scientist who discovered antibiotic active against all Gram-negatives for examples; Mycobacterium tuberculosis
– Most severe infections were caused by Gram-negatives and Mycobacterium
tuberculosis, extracted from Streptomyces – extracted from Streptomyces
– 20 other antibiotics include. neomycin, actinomycin
2.8 CHARACTERISTICS OF ANTIBIOTICS
According to the Oxford Dictionary, the term Antibiotics encompasses medicines (such as penicillin or its derivatives) that inhibit the growth of or destroys microorganisms. Antibiotics are naturally occurring substances that exhibit inhibitory properties towards microbial growth at high concentrations. (Zaffiri, et al., 2012).
-Antibiotics are selective in their effect on different microorganisms, being specific in their action not only against genera and species but even against strains and individual cells. Some of these agents act mainly on gram-positive bacteria, while others inhibit only gram-negative ones.
-Some antibiotics are produced by some organism, from different strains of penicillin.
-Bacteria are sensitive to the antibiotic which enable them to developed resistance after contact, for several periods.
2.9 ROLE OF ANTIBIOTICS
Based on the clinical use of antibiotics, it may appear that these compounds play a similar role as microbial weapons in nature, yet this seems unlikely due to the fact that the concentrations used in the clinical setting are significantly higher than that produced in nature (Fajardo et al., 2008). Due to experimental evidence, it makes more sense to see antibiotics as small, secreted molecules involved in cell-to-cell communication within microbial communities.
(Martinez, 2008). Diverse Studies have been conducted in which different antibiotics and antibiotic-like structures were administered to different bacterial species at levels below the compounds minimum inhibitory concentrations (MIC). (Fajardo et al., 2008). that was
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Poul¬try industry, intensive farming practice and irrational use of medicated feeds in broiler and layer operations to improve feed efficiency has made poultry as a major reservoir of antimicrobial resistant strains of Salmonella and E. coli (Crump et al., 2002)
Foodborne diseases and poisoning in the contemporary world are emerging and great public health concerns. Foodborne infections are widely spread in both developed and developing countries. (Akbar et al., 2011)
Poultry is an important farm species in almost all countries, it can be raised with limited cap¬ital and is an important cheap source of animal protein, Birds are intensively reared for meat and egg purpose. (Okorie-kanu et al., 2016)
Escherichia coli and serovars of S. enterica. dominant members of Enterobacteriaceae, are responsible for major cause of foodborne infections worldwide. (Helmy et al., 2017).
Aetiology, History and Background Escherichia coli
Escherichia coli is a gram-negative facultative bacteria belongs to the family Enterobacteriaceae. It is ubiquitous, commensal in animals, strains of E.coli food- and waterborne zoonotic infection (Dhama et al., 2013).
Pathogenic strains of E.coli associated with diarrhea are Enterotoxigenic E. coli (ETEC), Enteopathogenic E. coli (EPEC), Enterohemorrhagic E. coli (EHEC) or Shiga toxin-producing E. coli (STEC), Enteroinvasive E. coli (EIEC), Enteroaggregative E. coli (EAEC) and Diffusely adherent E. coli (DAEC). Enteropathogenic E. coli and certain Enterotoxigenic E. coli strains of E. coli, are significant are the main cause of global health burden of diarrheal disease (croxen et al., 2013).
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Strains of E.coli are potential of causing either intestinal or extra-intestinal form of diseases. In humans strain of E. coli O157:H7 has been reported to be pathogenic causing hemorrhagic gastroenteritis and hemolytic uremic syndrome. In Poultry houses, rodent droppings, water, litter, fecal matter, and dust and feeds have been implicated as possible sources of E. coli. (Moawad et al., 2017).
(Geidam et al 2012) reported the high prevalence of multidrug resistant E.coli over other microbial infection among poultry farms.
(Okorie-kanu et al., 2016) analyzed 68 composite samples of eggs obtained from farms and retail outlets in the study area, 37 (54.4%) were positive for pathogenic E. coli and reported that Eggs from farms recorded higher contamination with pathogenic E. coli than eggs obtained from retail outlets
Diagnosis of E.coli
Escherichia coli gram –ve rod-shaped organism belongs to Enterobacteriaceae family coliform group which ferments lactose and produces acid and gas. uidA gene which encodes for ?-D-glucuronidase is routinely used to specifically identify E. coli. ( Feng et al., 1991)
Probability of detecting target organisms of low concentrations enhanced by PCR which results in exponential amplification of specific DNA sequences and reduces the time required to obtain results. (Molina et al., 2015)
Salmonella enterica subtype Enteritidis major serotype of Salmonella responsible for food borne infection worldwide possess serious economic impact.
Salmonella is the common inhabitant in poultry harbours in gastrointestinal tract, reproductive organs, and birds will shed the organisms during defecation and egg laying. In poultry houses feces, litter, water acts as a source of infection to humans. (Frederick et al., 2011)
Salmonella Typhimurium, Salmonella Enteritidis serotypes of Salmonella spp. are reported to be pathogenic for both human and animal.
Diagnosis of Salmonella
PCR targeting invA gene for Salmonella is rapid, sensitive and specific for detection of Salmonella in many clinical samples. The invA gene encodes for protein membrane of bacteria, which is necessary for invasion to epithelial cells. (Lampel et al., 2000)
Salmonella detection by conventional methods are time consuming which includes selective enrichment and plating followed by biochemical characterization. Polymerase Chain
Reaction (PCR) found to be rapid and reliable method for detection Salmonella and other food borne pathogens (Rodulfo et al., 2012)
(Davies et al 2003) carried out an investigation about distribution of Salmonella in layer breeding and egg production system and they found that Salmonella enterica serovar Enteritidis PT6 serovar established and infects the chicks.
ANTIBIOTIC SUSCEPTIBILITY OF ENTERIC BACTERIA IN POULTRY
Antimicrobial agents continuously fed to poultry as a antimicrobial growth promoters (AMGP) has resulted in emergence of resistant bacteria in poultry and accordinly their faecal ?ora also contains a relatively high proportion of resistant bacteria (Van den Bogaard et al., 1999)
Indiscriminate antibiotic usage is considered as the influencing factor results in selection, emergence and dissemination of antibiotic-resistant microorganisms, in both veterinary and human medicine. (Van den Bogaard et al., 2001)
(Mayrhofer et al., 2004) studied the Antimicrobial resistance profile of five major food-borne pathogens isolated from beef, pork and poultry and E.coli isolates stx1 positive strains obtained from poultry characterized phenotypically, exhibited a multiple drug resistance against tetracycline, kanamycin, sulfonamides, ampicillin and streptomycin antibiotics under disc diffusion method.
Salmonella and E. coli spp. resistance rates among food animals to antibiotics are reported to be high in most of countries (Mayrhofer et al., 2004)
Extended spectrum beta lactamases
Extended spectrum beta-lactamases (ESBLs) are enzymes commonly inhibited by inhibitors of Class A ?-lactamases such as clavulanic acid and others, such as sulbactam and tazobactam. Confers decreased susceptibility or resistance to Narrow spectrum and Expanded-spectrum cephalosporins, but do not affects cephamycin and carbapenem compounds. (Poirel et al., 2005)
Extended spectrum beta-lactamases (ESBL) incurring resistance to 3rd generation cephalosporins a specific type of antibiotic resistance contemporarily represents a major public health concern (Canton et al., 2008)
Most widely distributed enzymes of ESBL includes TEM and SHV with more than 160 and100 variants which has been recognised mostly associated with Enterobacteriaceae species,mainly K. pneumoniae and Enterobacter spp. isolates and recently with Pseudomonas aeruginosa and Acinetobacter baumannii. (Oliver et al., 2005)
CTX-M, ESBL enzyme confer resistance predominantly to cefotaxime rather than ceftazidime have been detected in many species (Canton et al., 2008).
The spread of TEM and SHV plasmid-mediated enzymes dissemination provided a major impetus for the development of ‘?-lactamase-stable ?-lactams’. TEM-1,TEM-2 and SHV-1 types, broad-spectrum enzymes, categorized in group III, which are rapidly disseminating and became major sources of acquired resistance to the broad-spectrum penicillins (Livermore et al., 2008).
(Bortolaia et al., 2010) reported prevalence of 2 (3%) out of 60 cloacal swabs collected from were positive for CTX-M ESBL-producing E. coli in ?ocks of chicken egg layers reared in Danish organic systems
(Chauvin et al., 2013) reported that blaCTX-M-1 was along with blaCTX-M-15, are the most frequent ESBL genes harbored by E. coli in fecal samples
(Wasyl et al., 2013) reported that 42.3% of isolates from layers in Poland and other European countries, contained 3G Cephelosporin resistant E. coli which is significant and delineated that poultry and pigs might be a reservoir of third-generation cephalosporin-resistant E. coli.
2.1 Theoretical Frameworks
The paragraphs below I plagiarized (100%) from the paper –Exploring financing decision making in Swedish family firms!! Being Sew, Five dimensions and FIBER
2.1.1 SEW, Five dimensions
The Socioemotional Wealth by Gomez-Mejia et al. (2007) have been constructed as a differentiator of family firms to better be able to explain why such firms behave differently. The model derives from the behavioral agency theory as a general extension, where the earlier theory by Gomez-Mejia, Welbourne, and Wiseman (2000) comprise and integrate behavioural theory of a firm, agency theory and the prospect theory. Arguing when family owners facing an issue affecting the socioemotional endowment the economic logic is not the main consideration or guidance, hence decisions may be taken leading to higher risks for the firm in order to protect the socioemotional endowment. Therefore Berrone, Cruz and Gomez-Mejia (2012) have generated a five dimensional model named FIBER of SEW to provide a more intuitive understanding to why family firms make diverse strategic choices compared to non-family firms. Even though the SEW is considered still as a quite new concept it has been widely used to explain “non-financial aspect of the firm that meets the families affected needs such as identity, the ability to exercise family influence, and the perpetuation of the family dynasty” (Gómez-Mejia et al., 2007, p. 106).
Therefore the SEW is used as a framework to give the reader a better understanding of the nature of family firms in their decision making process. Hence the five dimensions that SEW is composed of is provided in section 2.6.1 to provide a profound insight.
(F) Family control and influence: Strategic decisions and control are made by family members that have great influence over the firm in order to contain both the direct and indirect influence of the business, regardless of the financial considerations (Gomez-Mejia et al., 2007) Therefore the power to control from an owners perspective is prominent regarding the types of decisions that are to be made and at what time. Control itself can be utilized from different hieratical levels within the family firm, most common is the direct control implying a family member being CEO or chairman of the board (Villalonga & Amit, 2010). Having key positions within the firm allows the decision makers to appoint the top management team (TMT) members, hence being able to influence the future control of the business, but it is not unusual owners engage in multiple roles as a way to gain information and exercise authority (Sciascia, Mazzola & Chirico, 2012). The control and election of the TMT is commonly held and taken by the founder or a superior family coalition mostly to preserve the ownership and influence by the family (Bjuggren & Sund, 2012), enabling the handover to the next generation with greater ease since passing on the business is a vital long-term goal for family firms (Berrone et al., 2010), strongly linked to the fifth dimensions of SEW.
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(I) Family members’ identification with the firm: The second dimension acknowledge the close identification of family members and the business. Where the owner of a family firm, especially the founder, is often inseparable linked with the identification of the firm, which also often shares the family’s name (Matherne, Waterwall, Ring & Credo, 2017).
Implying from a stakeholder’s perspective that the family firm have both internal and external interests to attain, mainly driven by the intrinsic motives (Carrigan ; Buckley, 2008). Neubaum, Dibrell and Craig (2012) comprises internal stakeholder commonly as employees, managers, shareholders, and owners that is the actors depending on the success of the business and potentially rewarded thereafter. Due to the strong identification with the firm, internally the owner and family top managers not only seek to influence the attitude of employees but also the internal processes and service management towards customers and the products the firms provide (Teal, Upton ; Seaman, 2003). Family members identifying strongly with the firm tend to be concerned to maintain a professional image to external stakeholders such as customers, suppliers, community and government (Micelotta ; Raynard, 2011), also strengthen by Gallucci,
Santulli and Calabrò (2015) stressing the importance for family members to build a strong family brand. Findings by Campopiano and Massis (2014) and Stanley and McDowell (2014) provides insights of family firms’ higher attention to corporate social responsibility (CSR) to increase their esteem from the community. But the authors also conclude that family firms are more likely to be more committed to pursue long term sustainability goals compared to non-family firms in order to enhancing the reputation and marketing from sustainable and environmental friendly actions.
(B) Binding social ties: The third dimension emphasize the social relationship and the joint benefits provided by SEW that evolves and captured in the ceased network. Where the feeling of social capital, relational trust, closeness, and interpersonal solidarity (Coleman, 1990) is considered more important compared to the financial gains that is a more common driving factor within non-family firms (Gomez-Mejia et al. 2007). Meaning that family firms consider close business partners within the supply chain as an extended part of the family ties itself (de Kok et al., 2006), since commitment, belonging, and identifying with the firm is fundamental for family members (Miller & Le Breton-Miller, 2005). Even though there is no direct economic benefit of engender a strong social relationship with members of the extended family this may explain why family firms are more engaged in their communities trying to improve the welfare in their surroundings in exchange of receiving recognition of generosity (Berrone et al., 2012).
(E) Emotional attachment: Is useful to better understand why members of a family firm acts unselfish to each other as to some extent stated in the social ties but this dimension refers rather to the emotions, moods, and attitudes from the family business aspect. Holt and Popp (2013) argues that family firms are more emotional driven by the deeper affective familial relationship, greater intimacy leading to greater individual freedom, and emotions functions as a vehicle of the succession of dynastic ambition and virtue. Berrone et al. (2010) reasons that family businesses are emotional attached and can to some extent be explained by the unclear boundaries between family life and the professional life. Therefore both positive and negative emotions emerge and affects events in the daily situations within the family business system (Gersick, Davis, Hampton &Lansberg, 1997). Emotions in family business settings have prior been studied in terms of the issues and the negative impacts of the subject and where the issues indirectly have
been focused on the family conflicts, personal relationships, and family culture. Researchers have noted that emotions in the context of family firms have long been understudied (Holt & Popp, 2013), nevertheless emotions for SEW’s fourth dimension is highly relevant to explain the decision making process within family business in order to understand why family members are altruistic to each other and why they most likely consider other family members to be trustworthy (Cruz, Gomez-Mejia ; Becerra, 2010). Berrone et al. (2010) mentions another difference between family and non-family firms regarding the dysfunctional aspect between the two. In a non-family organisation a dysfunctional relationship or negative conflicts often ends with a termination of the employee, but in a family firm where the emotions attachment is of greater impact the persistence and hope that the situation by time will eventually return to harmony between the parties involved (Fletcher, 2000).
(R) Renewal of family bonds to the firm through dynastic succession: Berrone, Gomez and Mejia’s (2010) last dimension involves the intention of handing over the business to future generations. The dynasty continuum is an important factor for family firms where owners may extract private benefits of preserving the control of the company within the family (Sacristán-Navarro, Cabeza-García& Gómez-Ansón, 2015). Making it even harder for family business owners to sell the company since they are strongly linked with family pride, heritage, and traditions (Byrom& Lehman, 2009). Also strengthened by Kellermanns and Eddleston, (2007) stating that a common goal for family firms is to maintain the business for future generations to inherit and run.
Depending on the shareholder structure and family influence the long-term view may lead to implications and conflicts within the owners regarding the succession of the business for the continuous of the dynasty (Sacristán-Navarro, Cabeza-García& Gómez-Ansón, 2015), Berrone at al. (2010) adds to the literature of the intentions to pass on the business and preserve the family values by foster a strategy of investing in the future generation to build capabilities, and learning.
2.2 Crowd-funding- I inserted this title and the paragraphs were done by Samarie using the research paper: Exploring financing decision making in Swedish family firms. However, my research questions did not cover any aspect of crowd-funding so I am not sure if we will use all – however some sections do touch base on SEW & FIBER.
In Henrik Johansson and David Tingaker’s research analysis, family firm’s financial decision making are not only monetarily considered but also considers the frameworks of Social Emotional Wealth (SEW) and values of the owners. In other words, the culture of family firms are seen both internally and externally to be driven by principles that “preserve emotional capital” (Tingaker& Johansson, 2018). Both the emotional ties and other technological, political and economic changes within a family firm are factors that helps to preserve the values of ownership and keeps the idea that there are other financing methods used in reference to family firms’ decision making. To demonstrate the theory, Tigaker; Johansson’s study looked at a different approach to financial decision making in the form of crowd-funding based on the values and social emotional wealth of the firm. According to Mollick, crowd-funding is a term used to describe funds being raised from a large number of individuals who contribute into a family firm. In order to achieve crowd equity from crowd-funding, the basis of Social Emotional Wealth (SEW) must be utilized.
Since the decision making rights are privileged to the owners/creators of the family firm, the basis of their values are implemented into the reputation of the firm. However, the term “values” in Tingaker& Johansson’s research is very broad, therefore, making it difficult to fully interpret the exact motive to crowd-funding using values. In addition, Social Emotional Wealth in Tigaker; Johansson’s research was also utilized for family firm’s decision making but still creates a limited amount of analysis since SEW is a fairly new paradigm in the family business field. Nevertheless, both values and SEW of the firm are still shown by the research to have a great non-financial motive in financial decision making, not solely on monetary gains. For instance, since one of the aspects of financial decision making is “concentrated on family culture and value to meet their goals” (Feltham, Felthan; Barnett, 2005), one of the ways decisions can be accomplished within the firm would through long term networking/relationships from other firms and also the family firm itself being trustworthy and committed within their networking/relationships to other firms. Having a close relationship using the values of the firm enables firms to “succeed in the market with a strong business brand identity linked with the family” (Le Breton-Miller ; Miller, 2006).
Although financial decision making considers plenty of other financing and economic methods, Tingaker; Johansson’s research still considers non-monetary financial decision making methods using the values of the firm’s internal personnel (such as owners and managers). This research opens the path for other methods to be considered into the financing mix of an organization.
2.2 Problem Relevant Studies
2.4 Research Framework (MindMap)
CHAPTER III – METHODOLOGY
For the purposes of this research, the research methodologies and their definitions will be constructed and referenced from the Research Onion by Saunders, et al (2009). It is an instrumental way to select an adequate approach and strategy for this research and also provides steps to follow in the process of writing this methodology.