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https://doi.org/10.11613/BM.2019.030801

Escherichia coli spheroplasts in a Croatian patient misclassified by two urine sediment analysers as erythrocytes: case report

Ana Nikler orcid.org/0000-0001-6624-863X ; Department of Medical Laboratory Diagnostics, University Hospital “Sveti Duh”, Zagreb, Croatia
Vanja Radišić Biljak ; Department of Medical Laboratory Diagnostics, University Hospital “Sveti Duh”, Zagreb, Croatia
Helena Čičak ; Department of Medical Laboratory Diagnostics, University Hospital “Sveti Duh”, Zagreb, Croatia
Nikolina Marić ; Department of Emergency and Intensive Medicine, University Hospital “Sveti Duh”, Zagreb, Croatia
Danijela Bejuk ; Department of Clinical Microbiology and Hospital Infections, University Hospital “Sveti Duh”, Zagreb, Croatia
Jose Antonio Ana-Maria Simundic1,7 Tesser Poloni ; Carlos Franco Voegeli Clinical Analysis Laboratory, Santa Casa de Misericórdia de Porto Alegre, Porto Alegre, Brazil; Universidade do Vale do Rio dos Sinos, São Leopoldo, Brazil; Controllab, Rio de Janeiro, Brazil
Ana-Maria Simundic ; Department of Medical Laboratory Diagnostics, University Hospital “Sveti Duh”, Zagreb, Croatia; Faculty of Pharmacy and Biochemistry, University of Zagreb, Zagreb, Croatia

Abstract

Introduction: It has already been reported that subinhibitory concentrations of β-lactam antibiotics can cause abnormal changes of bacterial
forms, such as spheroplasts. Herein we report a case of Croatian male patient with Escherichia coli spheroplasts present in urine after treatment with
tazobactam, on the tenth day of hospitalization. The aim of this report is to emphasize the inability of imaging based automated urine analysers to
recognize some relatively uncommon forms of bacterial presentation in urine sediment.
Materials and methods: During routine urine analysis, unusual particles were observed in patient urine. Urine sediment was examined by two
urine analysers: Atellica 1500 (Siemens, Germany) and Iris iQ200 (Beckman Coulter, USA). Additionally, urine was sent for culture testing to Microbiology
department.
Results: Both urine analysers didn’t indicate presence of bacteria in urine sediment. Unusual particles observed on the tenth day were classified as
erythrocytes by both instruments. Dipstick test showed blood trace and microscopic analysis revealed bacteria in urine. Urine culture was positive
for Escherichia coli. Careful examination of urine sediment has confirmed that shapes present in urine were abnormal bacterial forms called spheroplasts.
Conclusions: Imaging based automated urine analysers are not able to recognize bacterial spheroplasts in urine sediment misclassifying it as erythrocytes.
Microscopic examination remains the gold standard for urines with blood trace or negative blood, in which erythrocytes are reported by
urine analyser in urine sediment. Failure to identify and follow up such cases may lead to inaccurate treatment decisions and puts patient safety at risk.

Keywords

spheroplasts; bacterial forms; urinalysis; misclassification

Hrčak ID:

226460

URI

https://hrcak.srce.hr/226460

Publication date:

15.10.2019.

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