Investing in the STEM workforce: microbiological safety in Australian secondary schools

Some experiments that might seem innocuous in the classroom setting, can be catastrophic for some students if there is a lack of knowledge and risk assessments are not performed. An example of this is the seemingly simple ‘mould bread experiment’ in which bread is placed in a resealable sandwich bag and placed in a warm incubator or room. If there is heavy growth of fungal species and the sample does not remain sealed and is removed from the bag, countless fungal conidiospores are released, which may cause allergic reactions, asthma or other respiratory problems for those in proximity.⁷ Importantly, in secondary schools, laboratories are likely to be used by multiple classes, so this risk may be spread across the school community throughout the day. Accordingly, this type of experiment is not recommended in schools (closed culture is fine, but the growth container must remain closed during evaluation and proper disposal of containers must occur).

There is nothing better for student learning and engagement than for students to undertake their own experiments in the classroom.^8,9 Many school science laboratories are not at Physical Containment Level 1 (PC1), which precludes many microbiological practical activities. However, if PC1 standards are in place and safety can be maintained, students and staff can work safely with microorganisms without resorting to demonstration-only experiments. Risk assessments must be carried out to identify the potential hazards and protocols should be modified to reduce risk where possible. All methodology should be clearly explained to the students, and their understanding of the associated risk should be assessed. To assist both LTs and teachers, Science ASSIST provides risk assessment templates (e.g. https://assist.asta.edu.au/resource/2298/risk-assessment-template) and a risk-severity matrix may be useful (an example is provided in Fig. 2). Points of risk will usually involve the creation of aerosols (e.g. sub-optimal use of a loop and Bunsen burner, opening and transferring liquid cultures with spillage and aerosol risks). Coordination between trained teachers and LTs is important to ensure that instruction is clear and that students understand how to remain safe during these activities and what to do if things go wrong. Physical means of risk reduction (e.g. using racks to reduce accidental spillage of liquid samples) are effective and the provision of microbiology-specific spill kits need to be carefully considered (as there are also risks associated with quantities of 70% ethanol and bleach). The increasing impacts of antimicrobial resistance should also be considered as a potential risk as skin flora are potentially highly resistant to antibiotics, underscoring the importance of not subculturing from plates derived from environmental or personal samples.¹⁰ It is also important that schools effectively decontaminate and sterilise items from practical classes, as this waste will ultimately be discarded in the standard rubbish stream. The incorrect handling of microorganisms could lead to possible laboratory-acquired infections, or the release of unwanted microorganisms outside of the laboratory.

Fig. 2. 

Risk severity matrix. This matrix allows an evaluation of the risk level of an activity to be calculated. Points of risk are identified and the likelihood of them occurring is multiplied with the likely effect. For example, an activity containing a highly unlikely event that has a potentially severe outcome is a medium risk activity. Risk for an activity should be no greater than low or medium. Note that microbiological risk will always be increased where participants are undergoing treatments such as immunosuppressive therapy or have health concerns such as respiratory disease (e.g. cystic fibrosis). The affected participant should receive medical advice before being allowed to undertake any microbiological activity. This simple example of a risk severity matrix was adapted from https://www.smartsheet.com/content/risk-assessment-forms.

In addition to the growth and culture of microorganisms, more recently, concepts such as bacterial transformation, previously the domain of tertiary education, are being introduced into the broad upper secondary school curriculum. It is important in these instances to think about why such experiments would need to be included as student activities – do they fit within the curriculum? Do they help the students to understand and retain the content? Are the students able to understand these concepts? By performing these experiments, risks associated with the potential release of genetically modified (usually penicillin-resistant) microbes emphasise the importance of appropriate technique and optimal disinfection and sterilisation practises. Schools failing to adequately disinfect and sterilise products from these experiments theoretically may have to answer to the Office of the Gene Technology Regulator (https://www.ogtr.gov.au/). This agency assumes not only that school decontamination regimes are sufficient, but that due diligence is performed checking that the organisms in GMO kits are suitable for PC1 laboratories.¹¹ Schools undertaking these higher risk activities need to keep good records of the kits used and the sterilisation undertaken.

Science ASSIST is a national online advisory service for school science educators and LTs that has provided support since 2013. This service supplies expert advice on all aspects of school laboratory safety, management, and design as well as high-quality teaching and learning resources. Science ASSIST began as a stand-alone service funded by a federal grant and is now part of the Australian Science Teachers Association and operates under a subscription model. Members of subscribing schools can ask questions and receive answers from professionals with experience teaching science in secondary schools. This service has developed the ‘Guidelines for Best Practice for Teaching Microbiology in Australian Schools’, which was prepared with the contribution of members of the ASM Education Special Interest Group.¹²

It is important that secondary school science technicians and teachers are upskilled and feel confident in the execution of microbiology practical activities in the secondary school setting. One of the ways this could occur is through professional development, specifically microbiology training courses. Currently, although there are some industry-focussed microbiology short certification courses (microcredentials) available in Australia, these are not context-specific and practical exercises do not reflect the equipment or even the physical containment present in most school classroom settings. Although microcredentials would need to be operated and administered through tertiary institutions, they should have carefully selected, contextualised content that upskills teachers and LTs with a focus on risk analysis and safety, the reasoning underpinning restrictions to microbiological activities in schools, and theory and hands-on practical activities based on current curricula. A wholly online microcredential would not be sufficient to develop the hands-on skill set needed to deliver microbiology practical activities safely and effectively. Building on current practice, it would be logical to integrate Science ASSIST into the development of LT and science teacher-focussed microcredentials, and to ensure sufficient funding for this service to answer new questions, to oversee and detect when new protocols are being trialled by schools (through questions submitted to the website) and potentially to allow new hazards to be dealt with quickly, through bulletins and alerts (for example, making hand sanitiser without checking the percentage of ethanol, potentially making an ineffective product). Upskilling science teachers and LTs should be recognised by school administrators as being critically important for maintaining student safety and microbiology teaching microcredentials could form part of formal professional development for all participants.