Emerging of multidrug-resistant Pseudomonas guariconensis with blaVIM-2 in an asymptomatic bacteriuria patient: A rare clinical presentation

This case presents the clinical and genomic aspects of a rare and multidrug-resistant Pseudomonas guariconensis isolate carrying blaVIM-2 and highlights the need for heightened awareness in healthcare facilities. A 63-year-old woman underwent surgery for the diagnosis of a paraspinal abscess and infectious spondylitis. During hospitalization, the patient was diagnosed with heart failure exacerbation. The patient had no symptoms of urinary tract infection and met the criteria for asymptomatic bacteriuria. In urine culture, colonies of the organism grew >105 CFU/mL on blood agar and on MacConkey agar. The Bruker Biotyper mass spectrometry showed P. guariconensis. Based on the 16S rRNA gene sequence showed that a 99.79 % match with as P. guariconensis LMG 27394T. The average nucleotide identity with P. guariconensis LMG 27394T was 91.53 %. Antimicrobial susceptibility testing showed that the isolate was not susceptible to most of the antibiotics. Antimicrobial resistance genes identified were aph(6)-Id, aph(3″)-Ib, aac(6')-Ib3, aac(3)-If, gyrA mutation (T83I) and blaVIM-2.

Molecular cloning, overexpression, characterization, and In silico modelling analysis of a novel GDSL autotransporter-dependent outer membrane lipase (OML) of Pseudomonas guariconensis

The outer membrane lipase (oml) gene, encoding a novel autotransporter-dependent lipase from Pseudomonas guariconensis, was cloned and sequenced. The oml gene has an open reading frame of 1866 bp. It encodes the 621 amino acid autotransporter-dependent GDSL lipase (OML), which has the highest sequence similarity (64.08 %) with the EstA of Pseudomonas aeruginosa (PDB:3kvn.1. A). OML was expressed and purified, which showed a purified band of approximately 70 kDa. The purified enzyme showed maximum activity at pH 9 and 40 °C. Substrate specificity studies and kinetic study by Lineweaver-Burk plot of purified OML showed Km of 1.27 mM and Vmax of 333.33 U/mL with p-nitrophenyl palmitate. The purified enzyme showed good stability in the presence of hexane, methanol, and ethanol, while the presence of the metal ion Mg2+ showed maximum lipase activity. Bioinformatics analysis supported the in vitro findings by predicting enzyme substrate specificity towards long-chain fatty acids and fatty acids with shorter chain lengths. The stability of the interaction of the protein-ligand complex (OML-ricinoleic acid) was confirmed using MDS and castor oil bioconversion using purified OML was confirmed using High-Performance Liquid Chromatography (HPLC).

Pseudomonas guariconensis Necrotizing Fasciitis, United Kingdom

We describe a case of necrotizing fasciitis in the United Kingdom in which Pseudomonas guariconensis was isolated from multiple blood culture and tissue samples. The organism carried a Verona integron-encoded metallo-β-lactamase gene and evidence of decreased susceptibility to β-lactam antimicrobial agents. Clinicians should use caution when treating infection caused by this rare pathogen.