Sterile halo: Using burners to create sterile zones

We count with two types of burners, nevertheless, they are used when working in an open bench. Having a burner in the working area is excellent to create a sterile zone, this to prevent cross-contamination among the samples we are working with.

Lab Access and Waste Management

The labs we work in are categorized as Containment Level 2 Laboratories. They count with lockable doors. These labs are for Biotechnology alumni and teachers exclusive use.

Usually we have to dispose of four types of wastes. They should be appropriately disposed in order to avoid every possible accident a confusion might cause. Sharp objects go in a thick red plastic bottle, biological wastes, such as fluids and organic tissues go in a yellow hermetic bottle. The solid wastes should be disposed in a yellow bag and all of the other materials that were in contact with bacteria or infectious agents, in general, go in a red bag.

Trying to develop an effective treatment for the American and European Foulbrood diseases has brought us to work with its causative agents: Paenibacillus larvae and Melissococcus plutonius. Getting to know the main characteristics of these bacteria and developing the right containment methods to avoid accidental release has become indispensable for the correct development of our project.

Paenibacillus larvae is an endospore-forming, facultative anaerobe, gram-positive bacteria; Melissococcus plutonius is described as an obligate anaerobe, gram-positive bacteria. Both microorganisms are characterized for having an important host specificity, being honey bee larvae their principal target organism. Although this turns them into non-human pathogens, they are still the cause of an important infection in honey bee colonies and, consequently, the standard bacteriological procedures were considered during its manipulation in the laboratory.

Biological safety and biocontainment practices included wearing laboratory coat, gloves and eye protection, regular cleaning of work clothes, washing our hands after working with the pathogens and before leaving the laboratory, decontaminating work surfaces after completion of work and after any spill of the bacteria, leaving our personal belongings and food away from the lab when handling infectious materials and regular decontamination of laboratory equipment and materials. It should be noted that handling of these bacteria was done by lighting a burner in the working area or in an ESCO Class II biosafety cabinet. This cabinet was only used after its cleaning with ethanol 70% (v/v) and exposition to UV light for fifteen minutes. The same procedure was always done after the manipulation of the pathogens.

It is important to mention that the strains of these bacteria were supplied by the Research Center in Food and Development (CIAD), located in Cuauhtémoc, Chihuahua. At this center, the correct handling of these pathogens has already been standardized and all the containment methods and protocols were provided to the team.