Susceptibility of Escherichia coli to L-selenaproline and other L-proline analogues in laboratory culture media and normal human urine.

Abstract

AIMS:

The aims of this study were to identify analogues of L-proline which inhibit the growth of Escherichia coli in both laboratory culture media and normal human urine and to study their mechanisms of uptake.

METHODS AND RESULTS:

The susceptibility of E. coli to L-proline analogues was studied by radial streak assays on agar plates and by minimal inhibitory concentration determinations in liquid media. Only L-selenaproline (SCA) inhibited growth in Mueller-Hinton medium and human urine as well as in glucose minimal medium. L-Proline did not prevent the inhibition of growth by SCA and strains defective in L-proline transport were as susceptible to SCA as wild-type strains. However, E. coli was resistant to SCA in the presence of L-cysteine and L-cystine. Spontaneous mutants selected for resistance to SCA or L-selenocystine were resistant to the other compound and had reduced growth in minimal medium containing L-cysteine or L-cystine as the sole sulfur source.

CONCLUSIONS:

L-selenaproline inhibited the growth of E. coli under conditions that may occur in the urinary tract and appeared to be taken up by the L-cystine transport system.

SIGNIFICANCE AND IMPACT OF THE STUDY:

Although urinary tract infections caused by E. coli can be treated with sulfamethoxazole/trimethoprim and quinolones, resistance to these antibiotics has been increasing. These results suggest that L-selenaproline may represent a new class of compounds that could be used to treat these infections.

• Authors: C E Deutch, M E Arballo, L N Cooks, J M Gomes, T M Williams, T Aboul-Fadl, J C Roberts
• Journal: Letters in applied microbiology (Lett Appl Microbiol) Vol. 43 Issue 4 Pg. 392-8 (Oct 2006) ISSN: 0266-8254 [Print] England
• PMID: 16965369 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Culture Media
• Organoselenium Compounds
• selenaproline
• Proline
• Cysteine

Topics

• Bacteriological Techniques (methods)
• Culture Media (metabolism, pharmacology)
• Cysteine (metabolism)
• Escherichia coli (drug effects, genetics, growth & development)
• Humans
• Microbial Sensitivity Tests
• Organoselenium Compounds (chemistry, pharmacology, urine)
• Proline (analogs & derivatives, chemistry, pharmacology, urine)