Think Pink – Serratia marcescens strikes again

Occasionally a paper pops up which raises a red flag of concern – or in this case pink.  Serratia marcescens belongs to the Enterobacteriacae family and is a common water dweller.  There have been reports of hospital-acquired infection and outbreak, including multi-drug-resistant epidemic events, in immunocompromised, critically ill patients, those undergoing haemodialysis and those in long term care.  Infection can take many forms including keratitis, conjunctivitis, urinary tract infections, pneumonia, surgical site infections, sepsis and meningitis. The most common site of infection is bloodstream followed by lung followed by gastrointestinal.

Often the source of infection is not found.  This is not helpful when investigating an outbreak.  However water sources, sink traps and drains are often overlooked when undertaking environmental examinations.  Serratia marcescens is adaptive and tenacious, persisting in environmental niches and displaying high levels of antibiotic resistance.  It often appears alongside Pseudomonas spp colonisation.

A recent paper by Liu et al, in-press with the Journal of Hospital Infection, shares their experience of a Serratia marcescens outbreak, investigation and termination over a 2 month period in a large hospital (3,500 beds) within a group of neurosurgical patients.  Breakdown of surgical wounds and purulent discharge were seen, alongside fever in the patients.

Serratia marcescens was isolated from cerebrospinal fluid, wound discharge and other patient secretions – these isolates underwent antibiotic resistance testing (with 21 antimicrobial agents tested) and this paper reports the first whole genome sequencing undertaken in a Serratia investigation.

Environmental investigations were conducted, initially in the surgical theatres, and then the relevant ICUs.  Nothing found.  However this team then followed the patient pre-op activities and exposures to water sources and the bacteria was found – the source was the hospital hairdresser’s equipment including haircutting clippers and razors.  All isolates exhibited identical antibiotic resistance patterns – resistant to cefazolin and intermediately sensitive to tobramycin.  The authors highlight the risks related to pre-operative skin preparation, and the need for continuous education as an holistic infection prevention tool.  Infection control teams supported pre-operative skin preparation training, and the hospital adopted disposable clippers as part of the remediation.

This is not the first Serratia marcescens outbreak linked to the hospital barber, nor the first contaminated component (ultrasonography probes have also been associated with an outbreak).  Indeed even within this paper the author believes the 2022 outbreak was linked to a cluster of Serratia infections seen in 2021. 

If you have concerns regarding Serratia marcescens contamination, related infections, or environmental investigations to find the source, please include in your Water Safety Group discussions.  Beware the pinkish tinge on sanitary ware!  For further information, discussion or support, please contact us:

Supporting References

Cristina ML, Sartini M, Spagnolo AM. Serratia marcescens Infections in Neonatal Intensive Care Units (NICUs). Int J Environ Res Public Health. 2019 Feb 20;16(4):610. doi: 10.3390/ijerph16040610. PMID: 30791509; PMCID: PMC6406414.

Diorio-Toth L, Wallace MA, Farnsworth CW, Wang B, Gul D, Kwon JH, Andleeb S, Burnham CD, Dantas G. Intensive care unit sinks are persistently colonized with multidrug resistant bacteria and mobilizable, resistance-conferring plasmids. mSystems. 2023 Aug 31;8(4):e0020623. doi: 10.1128/msystems.00206-23. Epub 2023 Jul 13. PMID: 37439570; PMCID: PMC10469867.

Dunne EM, Hylsky D, Peterson E, Voermans R, Ward A, Turner K, Hahn C, Arduino M, Ball C, Carter KK, Lee JR. A cluster of Achromobacter xylosoxidans led to identification of Pseudomonas aeruginosa and Serratia marcescens contamination at a long-term-care facility. Am J Infect Control. 2021 Oct;49(10):1331-1333. doi: 10.1016/j.ajic.2021.04.004. Epub 2021 Apr 19. PMID: 33887423.

Leng P, Huang WL, He T, Wang YZ, Zhang HN. Outbreak of Serratia marcescens postoperative infection traced to barbers and razors. J Hosp Infect. 2015 Jan;89(1):46-50. doi: 10.1016/j.jhin.2014.09.013. Epub 2014 Oct 24. PMID: 25465310.

Liu X, Yan Z, Ye L, Wang K, Li J, Lin Y, Liao C, Liu Y, Li P, Du M. Genomic epidemiological investigation of an outbreak of Serratia marcescens neurosurgical site infections associated with contaminated haircutting toolkits in a hospital barbershop. J Hosp Infect. 2023 Sep 27:S0195-6701(23)00312-2. doi: 10.1016/j.jhin.2023.09.013. Epub ahead of print. PMID: 37774927.

Novosad SA, Lake J, Nguyen D, Soda E, Moulton-Meissner H, Pho MT, Gualandi N, Bepo L, Stanton RA, Daniels JB, Turabelidze G, Van Allen K, Arduino M, Halpin AL, Layden J, Patel PR. Multicenter Outbreak of Gram-Negative Bloodstream Infections in Hemodialysis Patients. Am J Kidney Dis. 2019 Nov;74(5):610-619. doi: 10.1053/j.ajkd.2019.05.012. Epub 2019 Jul 30. PMID: 31375298.

Regev-Yochay G, Smollan G, Tal I, Pinas Zade N, Haviv Y, Nudelman V, Gal-Mor O, Jaber H, Zimlichman E, Keller N, Rahav G. Sink traps as the source of transmission of OXA-48-producing Serratia marcescens in an intensive care unit. Infect Control Hosp Epidemiol. 2018 Nov;39(11):1307-1315. doi: 10.1017/ice.2018.235. Epub 2018 Oct 4. PMID: 30284524.

Tavares-Carreon F, De Anda-Mora K, Rojas-Barrera IC, Andrade A. Serratia marcescens antibiotic resistance mechanisms of an opportunistic pathogen: a literature review. PeerJ. 2023 Jan 5;11:e14399. doi: 10.7717/peerj.14399. PMID: 36627920; PMCID: PMC9826615.

Yeo KT, Octavia S, Lim K, Lin C, Lin R, Thoon KC, Tee NWS, Yung CF. Serratia marcescens in the neonatal intensive care unit: A cluster investigation using molecular methods. J Infect Public Health. 2020 Jul;13(7):1006-1011. doi: 10.1016/j.jiph.2019.12.003. Epub 2019 Dec 26. PMID: 31883745.

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