A Robust Incubator to Improve Access to Microbiological Culture in Low Resource Environments

Abstract

To help address the limitations of operating conventional microbiological culture incubators in low resource environments, a new incubator design was developed and tested to meet the requirements of operation in laboratories without reliable power (power outages up to 12 contiguous hours) or climate control (ambient indoor temperatures from 5 °C to 45 °C). The device is designed to enable adherence to incubation temperatures recommended for growth detection, identification, and drug susceptibility testing (DST) of human pathogenic bacteria. During power outages, stable temperatures are maintained in the device's internal sample compartment by employing phase change material (PCM) as a bi-directional thermal battery to maintain incubation temperature. Five prototypes were tested in a laboratory setting using environmental test chambers and programmable power supplies, and three were field tested in the Lao PDR in situations of intended use. The prototypes successfully held their temperature to within ±1 °C in both laboratory environmental chamber testing as well as during the field test. The results indicate that the device will maintain stable culture temperatures across periods of intermittent power supply, while enabling normal workflow of this could greatly increase the availability of microbiological culture for diagnosis and antimicrobial resistance (AMR) monitoring.

Moving microcapillary antibiotic susceptibility testing (mcAST) towards the clinic: unravelling kinetics of detection of uropathogenic E. coli, mass-manufacturing and usability for detection of urinary tract infections in human urine

“…† Increasingly, more designs for portable and affordable incubation for field microbiology have been developed. [52][53][54] Since the mcAST devices are low profile they can be effectively heated from below, without needing a large incubator volume. The incubation stage was prototyped using a heated bed designed for 3D printers, comprising a simple resistive heating element on a printed circuit board (PCB).…”

AMR in low-resource settings: Médecins Sans Frontières bridges surveillance gaps by developing a turnkey solution, the Mini-Lab

“…All equipment was selected based on its safety, low maintenance needs, and robustness in tropical conditions where power outages, dust, humidity, and other challenges are common. The Incudigit SV30 incubators (JP Selecta Co., Ltd,, Barcelona, Spain) can withstand 12 hours without electricity without dropping more than 1°C from initial baseline set temperatures [43]. The autoclave (Tuttnauer Co., Ltd, Breda, The Netherlands) includes a predefined cycle for waste sterilization and J o u r n a l P r e -p r o o f has safety measures that prevent it from opening when the electricity is out.…”

MicroMI: A portable microbiological mobile incubator that uses inexpensive lithium power banks for field microbiology

“…Transport to laboratories can also increase cost of testing. To help address those issues, several recent studies have reported low cost mobile incubators based on widely available materials and construction methods, convenience for use in low resources environments, and for integration into automated novel technology [3] , [5] , [6] , [8] , [11] .…”