Abstract
A small-colony variant (SCV) of carbon dioxide-dependent Escherichia coli was isolated from a patient with acute bacterial cystitis. After the urine sample
was inoculated on 5% sheep blood agar and incubated overnight at 35 °C in ambient
air, no colony formation was observed. However, after overnight incubation at 35 °C
in 5% CO2-enhanced ambient air, numerous colonies were obtained. We failed to characterize
or identify the SCV isolate using the MicroScan WalkAway-40 System because the isolate
did not grow in the system. Matrix-assisted laser desorption/ionization time-of-flight
mass spectrometry and 16S rRNA sequencing were useful for identifying this SCV isolate.
Genome sequencing analysis of the isolates revealed the presence of an 11-bp deletion
mutation leading to premature translational truncation in the carbonic anhydrase gene,
can, and the presence of 10 known antimicrobial resistance genes. The results of the antimicrobial
susceptibility tests performed under CO2-enhanced ambient air were consistent with the presence of antimicrobial resistance
genes. Our results also showed that Can is important to grow E. coli in ambient air, and that antimicrobial susceptibility testing of carbon dioxide-dependent
SCVs should be performed in 5% CO2-enhanced ambient air. A revertant strain was obtained by passaging the SCV isolate,
but the deletion mutation in can remained. To the best of our knowledge, this is the first case in Japan of acute
bacterial cystitis caused by carbon dioxide-dependent E. coli with a deletion mutation in can.
Keywords
Abbreviations:
SCV (Small-colony variant), ST (sequence type), MLST (multilocus sequence typing)To read this article in full you will need to make a payment
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References
- Small colony variants: a pathogenic form of bacteria that facilitates persistent and recurrent infections.Nat Rev Microbiol. 2006; 4: 295-305https://doi.org/10.1038/nrmicro1384
- Carbon dioxide-dependent Escherichia coli.Br Med J. 1978; 1: 576https://doi.org/10.1136/bmj.1.6112.576-b
- Isolation of a carbon dioxide-dependent strain of E. coli from the urine of a patient with chronic pyelonephritis (author's transl).Zentralbl Bakteriol Orig A. 1979; 244: 229-232
- Urinary tract infection caused by capnophilic Escherichia coli.Emerg Infect Dis. 2008; 14: 1163-1164https://doi.org/10.3201/eid1407.071053
- Capnophilic Enterobacteriaceae.Diagn Microbiol Infect Dis. 2017; 87: 318-319https://doi.org/10.1016/j.diagmicrobio.2017.01.010
- Molecular characterization of a carbon dioxide-dependent Escherichia coli small-colony variant isolated from blood cultures.Int J Med Microbiol. 2020; 310151431https://doi.org/10.1016/j.ijmm.2020.151431
- Sex and virulence in Escherichia coli: an evolutionary perspective.Mol Microbiol. 2006; 60: 1136-1151https://doi.org/10.1111/j.1365-2958.2006.05172.x
- Crystal structure of E. coli beta-carbonic anhydrase, an enzyme with an unusual pH-dependent activity.Protein Sci. 2001; 10: 911-922https://doi.org/10.1110/ps.46301
- Bacterial carbonic anhydrases.EXS. 2000; : 547-565https://doi.org/10.1007/978-3-0348-8446-4_29
- Why is carbonic anhydrase essential to Escherichia coli.J Bacteriol. 2003; 185: 6415-6424https://doi.org/10.1128/JB.185.21.6415-6424.2003
- Enteroaggregative Escherichia coli have evolved independently as distinct complexes within the E. coli population with varying ability to cause disease.PLoS One. 2014; 9e112967https://doi.org/10.1371/journal.pone.0112967
- Comparative genetic characterization of Enteroaggregative Escherichia coli strains recovered from clinical and non-clinical settings.Sci Rep. 2016; 624321https://doi.org/10.1038/srep24321
- Whole genome analyses of CMY-2-producing Escherichia coli isolates from humans, animals and food in Germany.BMC Genom. 2018; 19: 601https://doi.org/10.1186/s12864-018-4976-3
- Chromosomally encoded ESBL genes in Escherichia coli of ST38 from Mongolian wild birds.J Antimicrob Chemother. 2017; 72: 1310-1313https://doi.org/10.1093/jac/dkx006
- Molecular typing of CTX-M-producing Escherichia coli isolates from environmental water, swine feces, specimens from healthy humans, and human patients.Appl Environ Microbiol. 2013; 79: 5988-5996https://doi.org/10.1128/AEM.01740-13
Article info
Publication history
Published online: May 01, 2023
Accepted:
April 17,
2023
Received in revised form:
April 3,
2023
Received:
September 9,
2022
Publication stage
In Press Corrected ProofIdentification
Copyright
© 2023 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
