Characterisation of common environmental healthcare associated infection pathogens and their genetic relatedness to isolates causing severe infection in a neonatal care unit at a tertiary level hospital in Soweto

Abstract

Introduction: Multidrug-resistant (MDR) healthcare associated infections (HAI) cause debilitating and life-threatening infections in hospitalised patients. Neonates are at high-risk for HAI. The environment may act as a reservoir for MDR HAI organisms, and evaluation for relatedness between MDR environmental organisms and clinical specimens is vital. Molecular techniques provide the best method for assessing relatedness.

Setting: Neonatal unit at a tertiary academic institution in Gauteng, South Africa

Objective: To sample high-touch environmental surfaces to determine microbial bioburden, isolate multidrug-resistant organisms (MDROs) and determine genetic relatedness of MDR environmental organism and clinical MDROs by macrorestriction analysis

Methods: In a point-prevalence environmental sampling survey of the neonatal unit, 112 environmental samples were taken and processed for microbial bioburden and the presence of MDROs. Neonatal blood culture samples of MDROs were collected over four weeks. Macro-restriction analysis was performed to determine genetic relatedness of environmental and clinical isolates

Results: Microbial bioburden demonstrated variation in the unit. Greater microbial bioburden was recorded in overcrowded cubicles. Environmental sample isolates included 52 MDROs: 5 MRSA; 4 CRE; 19 ESBL Enterobacterales, and 24 XDR A. baumannii. Isolation of a MDR ESKAPE organism was not related to the microbial bioburden of the surface sampled (p-value= 0.22). Genetic relatedness of environmental and clinic XDR A. baumannii isolates was found, however a temporal relationship was unable to be demonstrated.

Conclusion: Microbial bioburden and distribution of MDR ESKAPE organisms was described. The microbial burden and isolation of MDR ESKAPE organisms do not correlate. Organisms are transferred from high touch surfaces to infants in the unit, most likely via health care worker and caregiver hands. Genetic relatedness of environmental and clinical isolates emphasises the importance of infection prevention and control measures.