How clean is clean enough?

Last changed: 20 November 2023
Photo from sampling with settle plates in an operating room

The overall aim of the PhD project is to improve infection prevention and control (IPC) in veterinary healthcare. Cleaning and disinfection are important IPC measures to decrease the amount of environmental bacteria. In this PhD project the bacterial contamination in the environment and on equipment before and after cleaning and disinfection is evaluated.

Pathogen bacteria and other microorganisms on near-patient surfaces pose a risk for indirect infection transmission. Gathering many animals in a small area like a veterinary hospital or clinic increases the risk for infection transmission. In recent years outbreak with resistant bacteria has been reported from veterinary healthcare.  

By studying occurring bacteria in the veterinary healthcare environment and the amount of them we get a picture of i.a. the effect of the hygiene routines. That also gives us some basic data to start investigate potential risks different parts of the veterinary healthcare facilities pose for infection transmission. For frequent bacterial species whole genome sequencing can show if there is a house flora or different strains. To study spreading pattern is extra important when it comes to potentially pathogen and resistant bacteria. In this way possible sources of infection can be traced, i.e. if the strain was spread from equipment, a patient, staff or in another way.

Cleaning is important to decrease the amount of soil and microorganisms on surfaces. For cleaning to have good effect it is important to use mechanical force by e.g. scrubbing the surface. For the disinfectant to have effect it is important that the surface is clean. It is important to study the effect of cleaning and disinfection of near-patient surfaces and equipment to evaluate if cleaning and disinfection methods used in veterinary healthcare today have desired effect. By measuring the amount of bacteria before and after cleaning and/or disinfection the methods ability to lower the amount of bacteria on a surface can be evaluated. The amount of bacteria on the surface can be compared with threshold values, used in human healthcare, for bacterial contamination.   


The project is partially financed by Stiftelsen Djursjukhus i Stor-Stockholm, Jan Skogsborgs stiftelse and Gymn. dir Stina Johansson i Fränsta Scholarship for research in veterinary medicine

The research group

PhD student Todd Alsing Johansson, MSc Veterinary Medicine, MSc Infectious Disease Control, Faculty of Veterinary Medicine and Animal Science, Department of Clinical Sciences, SLU.

Associate Professor Johanna Penell, MSc Veterinary Medicine, Faculty of Veterinary Medicine and Animal Science, Department of Clinical Sciences, SLU.

Associate Professor Anna Bergh, MSc Veterinary Medicine, BSc Physical Therapy, Faculty of Veterinary Medicine and Animal Science, Department of Clinical Sciences, SLU. 

VMD Karin Bergström, MSc Veterinary Medicine, Department of Animal Health and Antimicrobial Strategies, SVA. 

Professor Susanna Sternberg Lewerin, Faculty of Veterinary Medicine and Animal Science, Department of Biomedicine and Veterinary Public Health, SLU.   


Todd Alsing Johansson

Doctoral Student, Lecturer at the Department of Clinical Sciences;
Division of Veterinary Nursing

Telephone: +4618671841
E-mail: Todd Alsing Johansson