Persistence of Legionella in Routinely Disinfected Heater-Cooler Units and Heater Units assessed by Propidium Monoazide qPCR

Background: Evidence to date indicates that heater–cooler units (HCUs) and heater units (HUs) can generate potentially infectious aerosols containing a range of opportunistic pathogens such as Mycobacterium chimaera, other non-tuberculous mycobacterial (NTM) species, Pseudomonas aeruginosa and Legio...

Full description

Saved in:
Bibliographic Details
Published in:Pathogens (Basel) 2020-11, Vol.9 (11), p.978
Main Authors: Ditommaso, Savina, Giacomuzzi, Monica, Memoli, Gabriele, Garlasco, Jacopo, Zotti, Carla M.
Format: Article
Language:English
Subjects:
Aerosols
Aquatic bacteria
Bacteria
Circuits
Contamination
Deoxyribonucleic acid
Devices
Disinfectants
DNA
Health care
Heart surgery
heater–cooler unit
Infections
Legionella
NTM
Opportunist infection
Pathogens
Patients
Precautionary principle
propidium monoazide qPCR
Pseudomonas aeruginosa
Respiratory distress syndrome
Sampling
Surveillance
Systems design
Tuberculosis
Ventilation
Ventilators
Water analysis
Water sampling
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Background: Evidence to date indicates that heater–cooler units (HCUs) and heater units (HUs) can generate potentially infectious aerosols containing a range of opportunistic pathogens such as Mycobacterium chimaera, other non-tuberculous mycobacterial (NTM) species, Pseudomonas aeruginosa and Legionella spp. Our purpose was to determine the extent of Legionella contamination and total viable count (TVC) in HCUs and HUs and to analyze the relationship by water system design of devices of two different brands (LivaNova vs. Maquet). Methods: Legionella spp. were detected and quantified by our optimized PMA-qPCR protocol; TVCs were assessed according to ISO protocol 6222. Analyses were performed in the first sampling round and after six months of surveillance. Results: Overall, Legionella spp. was detected in 65.7% of devices. In the second sampling round, Legionella positivity rates were significantly lower in water samples from the Maquet devices compared to the LivaNova ones (27.3% vs. 61.5%). LivaNova HCUs also yielded more Legionella, and aquatic bacteria counts than Maquet in both first and second-round samples. Conclusions: We recommend that all surgical patients and staff exposed to aerosols from thermoregulatory devices should be followed up for Legionella infection and that microbiological surveillance on such devices should be conducted regularly as precautionary principle.
ISSN:2076-0817
2076-0817
DOI:10.3390/pathogens9110978