Keywords

1 Introduction

Research on children’s ideas about microorganisms reveals that children frequently hold alternative ideas about aspects such as microorganisms’ size and morphology, their status as living entities, the location where they can be found, and their activity (Byrne, 2011). For example, researching the ideas of students aged 11–14, Bandiera (2007) reported that when asked about the presence of microorganisms indoors, half of her study participants placed microorganisms in specific rooms of the home, primarily the bathroom and the kitchen. Furthermore, when asked whether microorganisms could be found in a healthy human body, 38% of them answered that healthy humans are free of microorganisms. When asked where microorganisms can be found, students aged 7–14 in Byrne’s (2011) study largely focused on the human body. The same finding is reported by Jones and Rua (2006) as well; among their participants, high school and middle school students believed that microorganisms could be present in the mouth or on the hands, whereas elementary school students thought that germs were located in particular areas of the body, such as saliva and skin. Other areas where microorganisms may be found according to students are filthy and unsanitary places, such as waste, dustbins, sewage treatment plants, compost piles and soil (Byrne, 2011).

According to Byrne et al. (2009), the most frequently mentioned microbial activity by students of various ages was as agents of human disease. In another study, Byrne (2011) found that students 7–14 years old held similar beliefs about microorganisms, such as the belief that they are the cause of disease. Byrne and Grace (2010) also acknowledged that negative aspects of microbial activity dominated children’s ideas. They noted that the participants of their study appeared to know substantially more about the connection between microorganisms and disease or food spoilage than they did about the beneficial functions that they serve in matter cycling, food production and medicine. The lack of knowledge of these aspects of microbial activity among children is alarming; learning about these applications would not only serve as a foundation for later lessons on more complex microbial technology and biotechnology, but it might also help to balance out the students’ largely unfavourable views of microorganisms (Byrne & Grace, 2010).

In an effort to track the origin of students’ thoughts about microorganisms, Simonneaux (2000) noted that the media appear to have a crucial part in forming students’ relevant understanding, along with school lessons, personal experience, and family life. According to Mafra and Lima (2009), children often develop their understanding of microorganisms as a result of the diseases that they, their parents or other family members experience; thus the concept of microorganisms is associated with a negative meaning. Questioning 836 primary school students on their major source of information about microorganisms, Karadon and Şahin (2010) reported that the most common response was the media, such as TV shows (39.2%), with school being the main source of information about microorganisms for 21.1% of students. Simard (2021) suggested that since the 1990s, the media have emphasized the association of microorganisms with disease, while ignoring information on their beneficial roles and functions. The media greatly fuel prejudices against microorganisms by focusing on human illnesses in the news; the public gets the impression that microorganisms are only causes of disease and mortality as a result of the focus on illnesses such as SARS, AIDS and H1N1 (Simard, 2021).

Thus, it seems that (a) students considerably express negative ideas about microorganisms, mainly related to the threat they pose to human health, (b) it is of paramount importance for students to build an understanding of the positive activities of microorganisms, and (c) students’ ideas about microorganisms are significantly influenced by the media, and school seems to play a rather important role as well. Focusing on school education, we note that it relies heavily on the usage of textbooks, which are essential for both teaching and learning (Liu & Khine, 2016). Over 90% of secondary science teachers in the United States use textbooks to help them plan and deliver lessons (Weiss et al., 2001). Abd-El-Khalick et al. (2008) argue that textbooks may influence what is taught and learned in the classroom to a greater extent than what educators would like.

Considering the above, we decided to explore Greek school textbooks in regard to the representation of microorganisms. Therefore, the research question addressed here is: How are microorganisms represented in Greek school textbooks?

2 Methods

For this study, we investigated the textbooks used for the teaching of biology in secondary education (six textbooks) and the textbooks used for the teaching of natural sciences in primary education (two textbooks) in Greece. We note here that there are no courses specialized in biology in the curriculum of Greek primary schools; thus biological concepts are discussed in natural sciences classes for Grade 5 and Grade 6 students. The textbooks investigated were the following:

  • Natural Sciences for the fifth grade of Primary School (Apostolakis et al., 2015a) – Grade 5.

  • Natural Sciences for the sixth grade of Primary School (Apostolakis et al., 2015b) – Grade 6.

  • Biology for the first grade of Gymnasium (Mavrikaki et al., 2017a) – Grade 7.

  • Biology for the second and third grade of Gymnasium (Mavrikaki et al., 2017b) – Grades 8–9.

  • Biology for the first grade of Lyceum (Kastorinis et al., 2011) – Grade 10.

  • Biology for the second grade of General Lyceum-General Education (Kapsalis et al., 2013) – Grade 11.

  • Biology for the second and third grade of General Lyceum (Adamantiadou et al., 2013) – Grades 11–12.

  • Biology for the third grade of General Lyceum-Health Studies Specialization (Aleporou-Marinou et al., 2013) – Grade 12.

The first author identified the words “microorganism/microorganisms” (in Greek: mikroorganismos/mikroorganismoi) and “microbe/microbes” (in Greek: microvio/mikrovia) in the textual corpus of the study – i.e. the whole text included in the eight textbooks of interest, apart from illustrations legends, tables of contents, chapter titles and assessment activities. We note that we transliterated the Greek terms to Latin characters above according to ELOT 743 standard which is equivalent to ISO 843 standard. For the reader’s convenience, we will refer to the English words in the rest of the text, i.e. microorganism/s and microbe/s. Each paragraph including the word “microorganism/s” and/or the word “microbe/s” at least once was determined as unit of analysis.

Taking into consideration the above, our analysis resulted in 187 relevant paragraphs included in seven of the textbooks investigated:

  1. 1.

    Natural Sciences for the sixth grade of Primary School.

  2. 2.

    Biology for the first grade of Gymnasium.

  3. 3.

    Biology for the second and third grade of Gymnasium.

  4. 4.

    Biology for the first grade of Lyceum.

  5. 5.

    Biology for the second grade of General Lyceum-General Education.

  6. 6.

    Biology for the second and third grade of General Lyceum.

  7. 7.

    Biology for the third grade of General Lyceum-Health Studies Specialization.

The paragraphs were coded in mutually exclusive categories formed by drawing on a scheme proposed by Mafra and Lima (2009). As shown in Table 7.1, the coding scheme consists of four categories:

  • Microorganisms as a part of the living world: the text refers to ideas, such as the variety of living organisms on earth, the different environments that microorganisms are found in, and elements of their physiology.

  • Microorganisms and health: the text refers to microorganisms as human pathogens or part of the human microbiome, as well as their role as pathogens of organisms other than humans.

  • Microorganisms and food: the text refers to the role of microorganisms in food production (e.g. yeasts involved in bread, yoghurt and alcohol production).

  • Microorganisms in industry and technology: the text refers to the role of microorganisms in industrial and technological applications, such as the production of enzymes, antibiotics, vaccines or serum, and cleaning water.

Table 7.1 The coding scheme
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In contrast to Mafra and Limas’s (2009) scheme, we decided to include subordinate categories as shown in Table 7.1. The main reasons for this decision were (a) to distinguish between the positive and negative roles of microorganisms concerning health (i.e. microorganisms as pathogens and microorganisms as part of the microbiome) and (b) to illustrate the different technological and industrial applications linked with microbial activity in the textbooks investigated. We also have to note that, while Mafra and Lima (2009) classified the role of microorganisms in vaccine development under the “Microorganisms and health” category, we decided to classify relevant paragraphs under the “Microorganisms in industry and technology” category, arguing that in this case their role in the application of technology should be highlighted.

Both authors coded independently 93 (i.e. about 50%) randomly chosen paragraphs and the rater agreement was about 90%. The cases of disagreement were reviewed and discussed by the two coders and the rest of the analysis was carried out by the first author. We should note that our research may not be considered an exhaustive account of how microorganisms are represented in the textbooks investigated, since our results are limited by the methodology used to collect our data. For instance, searching for the words “microorganism/s” and “microbe/s”, we do not trace appearances of microorganisms mentioned by the name of specific taxa (e.g. bacteria, fungi) or the name of specific species.

3 Results

As shown in Table 7.2, in most cases microorganisms are mentioned in relation to health (94/187). More specifically, in 85/187 paragraphs microorganisms are mentioned as human pathogens. For example, in textbook-4 we read: “Pathogenic microorganisms are transmitted from person to person, by coughing, sneezing, etc. The respiratory tract, of course, is protected by the mucus and cilia of the epithelial tissue. However, if the number of pathogenic microorganisms is high and/or the body’s resistance is reduced, then these microorganisms (bacteria and viruses) can cause various diseases such as pneumonia, tuberculosis and acute bronchitis. To reduce the possibility of contracting such diseases, we must avoid indoor spaces where many people are crowded together” (Kastorinis et al., 2011, p. 83).

Table 7.2 Frequencies of categories of microorganisms’ representations
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Moreover, 6/187 paragraphs refer to microorganisms as pathogens of organisms different than humans. For instance (textbook-2): “If, for example, we are interested in studying how water affects the growth of a plant, we should experiment with identical plants keeping all other known factors constant. That is, the plants should have the same height, we should place them in similar pots, with the same quality soil, we should provide them with the same lighting and in general we should keep all the necessary conditions constant except for the amount of water we pour on them. Of course, there are other factors that may affect the growth of the plant, but which cannot be precisely controlled, such as some microorganisms found in the soil of the pot or some insects that may harm them” (Mavrikaki et al., 2017a, p. 13).

Under the “Microorganisms and health” category we traced 3/187 paragraphs where a positive role of microorganisms is mentioned. What follows is an excerpt discussing microorganisms as part of the human microbiome (textbook-6): “Other microorganisms, such as the bacterium Escherichia coli that lives in the intestines, are beneficial for humans when they are in small numbers and do not migrate to other tissues and organs; they constitute the microbiome of humans, which produce useful chemical substances that humans cannot synthesize on their own (e.g. vitamin K from E. coli) or contribute to the body’s defense” (Adamantiadou et al., 2013, p. 11).

The second most popular category is “Microorganisms in industry and technology” (41/187). In 12/187 paragraphs the cultivation of microorganisms is discussed without focusing on particular applications. For instance, in textbook-7 we read: “Biotechnology is a combination of science and technology aimed at using living organisms to produce useful products on a large scale. It relies mainly on recombinant DNA and microorganisms’ cultivation techniques. Microorganisms grow under controlled conditions in which a range of suitable nutrients is available. In a large-scale cultivation, suitable devices, called bioreactors, are used” (Aleporou-Marinou et al., 2013, p. 116).

Moreover, 11/187 paragraphs refer to the production of antibiotics or enzymes through the treatment of microorganisms. For instance (textbook-7): “Microorganisms’ products are usually produced in small quantities, sufficient to cover their metabolic needs. It is obvious that for a microorganism to be practically useful, its products, such as enzymes or antibiotics, must be produced in large quantities. This is achieved in two main ways: by regulating the cultivation conditions and by genetically modifying the organisms” (Aleporou-Marinou et al., 2013, p. 151).

Furthermore, 11/187 paragraphs refer to the development of vaccines or serum through treating microorganisms. What follows is an excerpt discussing the role of microorganisms in the development of vaccines and serum (textbook-3): “A small amount of dead or inactive microorganisms or their parts is introduced into our body with vaccination. The content of the vaccine is sufficient to activate the immune system response while it is usually not capable of causing disease. In this way, the organism develops ‘memory’ cells for the particular microorganism” (Mavrikaki et al., 2017b, p. 86–87).

Under the “Microorganisms in industry and technology” category we finally traced 11/187 paragraphs referring to the role of microorganisms in cleaning water e.g. from oil. The following text is an example of such a reference (textbook-7): “Marine microorganisms can contribute in breaking down oil spills: After the volatile fractions of the oil evaporate, its organic chemical compounds are broken down by bacteria and fungi belonging to more than 70 genera, resulting in their metabolism into carbon dioxide” (Aleporou-Marinou et al., 2013, p. 162).

The number of paragraphs classified under the “Microorganisms as a part of the living world” category is 40/187. Most of them (24/187) deal with elements of microorganisms’ physiology. For example, in textbook-5 we read: “Many microorganisms perform anaerobic respiration, that is glucose is oxidized to produce ATP in the absence of oxygen. Of course, there are also cells of multicellular organisms, which occasionally, when they are forced to produce energy and there is not enough oxygen in their environment, also perform anaerobic respiration. Muscle cells are a typical example” (Kapsalis et al., 2013, p. 110).

The rest of the paragraphs classified under the “Microorganisms as a part of the living world” category mention microorganisms through discussing the diversity of living organisms or their habitat. For instance (textbook-1): “A trip to the countryside or a walk in the forest is enough to feel the relaxation and pleasure offered by observing the natural environment, but also to see the great variety of microorganisms, plants and animals, as well as the relationships that these living organisms develop among themselves” (Apostolakis et al., 2015b, p. 74).

Finally, 12/187 paragraphs refer to the role of microorganisms in food and drink production. The following excerpt of textbook-3 is an example of such a reference: “For thousands of years, humans have been taking advantage of the properties of certain organisms, with the aim of improving their lives. They grow plants, breed animals and, by the method of selective breeding, create organisms with desirable properties-phenotypes. They use various organisms (e.g. herbs) as raw material for the preparation of medicines and cosmetics. In addition, with the help of specific microorganisms, they develop various useful products (food and drinks), such as bread, beer, wine, cheese and yogurt” (Mavrikaki et al., 2017b, p. 120).

As shown in Fig. 7.1, microorganisms are mostly mentioned in relation to health in 4/7 textbooks. The category “Microorganisms and health” is the second most popular in textbook-1, the least popular in textbook-7, while in textbook-5 the microorganisms’ link with health is not mentioned at all. The category “Microorganisms as a part of the living world” is the most popular in 2/7 textbooks, while the category “Microorganisms in industry and technology” is the most popular in 1/7 textbooks.

Fig. 7.1
A grouped bar graph of the frequencies of 4 microorganism categories as represented in 7 textbooks, 1 to 7. Microorganisms and health tops in 2, 3, 4, and 6. Microorganisms as a part of the living world tops in 1 and 5. Microorganisms in industry and technology tops in 7.

Frequencies of categories of microorganisms’ representations in textbooks

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In most textbooks some categories are not represented. In 2/7 textbooks there are paragraphs classified under all four categories, 3/7 textbooks include paragraphs classified under three of the categories, in 1/7 textbooks two categories are represented, while in 1/7 textbooks microorganisms are mentioned only in regard to their link with health. In sum, the category “Microorganisms as a part of the living world” appears in 5/7 textbooks, the category “Microorganisms and health” appears in 6/7 textbooks, the category “Microorganisms and food” appears in 4/7 textbooks and the category “Microorganisms in industry and technology” appears in 5/7 textbooks.

4 Discussion

Reviewing eight textbooks used in biology and natural sciences classes in secondary and primary education in Greece respectively, we noticed that microorganisms are most frequently mentioned in relation to health; about 50% of the paragraphs including the word “microorganism/s” and/or “microbe/s” are classified under the “Microorganisms and health” category. It should be noted that this is not the case for each textbook separately; in 3/7 textbooks microorganisms are not mostly mentioned in relation to health. For instance, in textbook-7 the most popular category is the “Microorganisms in industry and technology”, while in textbook-1 and textbook-5 the most popular category is the “Microorganisms as a part of the living world”. We argue that this is because of curriculum priorities. For instance, textbook-5 focuses on cell biology, thus discussing the physiology and anatomy of unicellular organisms, while textbook-7 is a specialization textbook which focuses on applications of biotechnology. Specific curriculum priorities are also the reason why microorganisms are not mentioned in “Natural Sciences for the fifth grade of Primary School”, which focuses on concepts of physics and chemistry rather than biology.

At this point we should discuss two methodological choices we made. The first one is distinguishing between pathogens of humans and pathogens of organisms other than humans. Today there is an increased awareness of the possibility and essential need to address health concerns and to attain health objectives by refocusing health management more on the interaction between ecosystem health, animal health, and human health (Evans & Leighton, 2014). The One Health concept, which is defined as the “collaborative effort of multiple health science professions, together with their related disciplines and institutions – working locally, nationally, and globally – to attain optimal health for people, domestic animals, wildlife, plants, and our environment” (One Health Commission, as cited in Gibbs, 2014), is receiving attention. Although health tends to be approached in a holistic way, we decided to distinguish between human and other organisms’ pathogens in our analysis in order to get a better understanding of the role of textbooks in the conceptualization of microorganisms as a threat to human health.

The second choice we should discuss is, unlike Mafra and Lima (2009), distinguishing between the role of microorganisms as pathogens and their role as part of the human microbiome. Microorganisms have several positive roles as part of the human microbiome. For instance, the gut microbiome is known to contribute to the renewal of gut epithelial cells, the development of the immune system, harvesting nutrients that would not otherwise be available and synthesizing vitamins (Turnbaugh et al., 2007). By illustrating the presentation of microorganisms as part of the human microbiome in the textbooks we investigated, we intended to trace possible instances of mentioning microorganisms in a positive way that would otherwise go unnoticed.

Returning to the results of our analysis, we noted that microorganisms are presented in a negative way in 91/187 paragraphs (subcategories: “Human pathogens” and “Pathogens of organisms other than humans”), while they are presented in a positive way in 56/187 paragraphs (subcategories: “Human microbiome”, “Cultivation”, “Enzymes and antibiotics production”, “Vaccines and serum production”, “Cleaning water”). There are 40/187 paragraphs where microorganisms are presented in neither a positive, nor negative way (subcategories: “Biological diversity” and “Physiology”). It seems that the instances where microorganisms are presented in an unfavorable way (i.e. as pathogens for humans and other organisms) are more frequent than the instances where microorganisms are presented in a favorable way (i.e. as part of the human microbiome or as having a role in beneficial applications and procedures).

All public and private schools in Greece use the same textbooks. Textbooks are government mandated and the curriculum relies heavily on their use by the teachers of all grades. Thus, in our research we are looking at textbooks as a reflection of what is taught in the Greek classroom. To the best of our knowledge, the representation of microorganisms in Greek textbooks of biology and natural sciences currently in use has not been investigated before. The discussion of our analysis findings (a) contributes to the literature on how students think and learn about microorganisms, and (b) suggests that certain actions should be taken regarding textbooks currently in use in Greek primary and secondary education, in order to improve microorganisms teaching and learning. A conceptual shift to a representation of microorganisms that integrates their diversity and beneficial contributions seems to be an essential goal for science education, according to Simard (2021), who argued that education should emphasize the importance that microorganisms have in human lives, as well as their role in the ecosystem and industry. This may be much more crucial and difficult to accomplish today, i.e. after the SARS-CoV-2 virus spread in early 2020 which caused a global pandemic. Students have seen disproportionately negative effects from COVID-19 in terms of their wellbeing, educational possibilities, and physical and mental health (Valadez et al., 2020). Their daily routines have been severely disrupted, and the limitations they have been subjected to, along with the changes to their families’ routines and practices, have had a significant psychological impact on them (Mukherjee, 2021). This could result in even stronger representations of microorganisms as “enemies” (Bonoti et al., 2022) or “always bad” (Ergazaki et al., 2010). Thus, the COVID-19 post-pandemic period will be important for the conceptualization of microorganisms. Due to a certain consolidation of pre-existing unfavourable perceptions, a considerable educational barrier must be anticipated; as a result, a knowledgeable education, based on textbooks promoting a more balanced understanding of microorganisms, will be necessary to prevent the crystallization of negative ideas of microorganisms in students (Simard, 2021).