Comparison of the certified Copan eSwab system with commercially available cotton swabs for the detection of multidrug-resistant bacteria in rectal swabs

• Published in: American journal of infection control 2022-10, Vol.50 (10), p.1145-1149
• Main Authors: Lippmann, Norman, Wendt, Sebastian, Stîngu, Catalina-Suzana, Wiegand, Johannes, Lübbert, Christoph
• Format: Article
• Language: English
• Subjects: COVID-19 - diagnosis; Escherichia coli; Humans; Klebsiella pneumoniae; Pandemics; Prospective Studies; SARS-CoV-2; Vancomycin; Vancomycin-Resistant Enterococci
• ISSN: 0196-6553; 1527-3296
• DOI: 10.1016/j.ajic.2022.02.002

Rectal swabs are well-implemented screening tools for multidrug-resistant bacteria (MDRB). Since certified swabs such as the Copan eSwab system experienced a delivery bottleneck during the COVID-19 pandemic, commercially available alternatives such as commonly used double-tipped cotton swabs had to be investigated, especially considering their similarity to professional cotton swabs for microbiological purposes. Diagnostic properties of commercial cotton swabs (comparable to Q-tips) and Copan eSwabs were qualitatively compared in a prospective single-center study using microbiological standard cultures and PCR methods for the detection of multidrug-resistant Gram-negative bacteria and vancomycin-resistant enterococci (VRE). A total of 196 swab pairs were collected from 164 participants. MDRB were detected in 36 of 164 cases (22%). There were neither false-negative nor false-positive results using commercial cotton swabs. In 8 of 196 samples (4.1%) MDRB species were detected only by using cotton swabs, including vancomycin-resistant Enterococcus faecium, OXA-48 producing Escherichia coli, ESBL-producing Klebsiella pneumoniae and ESBL-producing Escherichia coli. Commercial cotton swabs turned out to be a reliable alternative to Copan eSwabs. For practical use as a screening tool, relevant storage- and manufacturer-related contamination must be ruled out beforehand. Commonly available double-tipped cotton swabs can be used for rectal MDRB screening in the event of supply shortages of certified swabs. Further studies should clarify their suitability as a sampling system for nasopharyngeal MRSA carriage or even for the molecular biological detection of SARS-CoV-2.