Distinct carbapenems susceptibility profiles in isogenic isolates of Klebsiella pneumoniae presenting Ompk36 disruption and expression of down-regulated blaKPC-2

The isolation of multidrug-resistant Klebsiella pneumoniae in hospitals is a major public health threat, increasing patient hospitalization costs, morbidity and mortality. Therefore, this work investigated the resistance mechanisms that produced different carbapenems susceptibility profiles in two isogenic strains of K. pneumoniae isolated from the same patient in a public hospital in Recife, Pernambuco. The genes that encode the main porins in K. pneumoniae, ompK35 and ompK36, and several beta-lactamase genes were analyzed. The expression of these genes was evaluated by quantitative real time PCR (polymerase chain reaction) with reverse transcriptase (RT-qPCR). SDS-PAGE (sodium dodecyl sulphate-polyacrylamide gel electrophoresis) was performed to analyze the outer membrane proteins. The analysis of the ompK36 genetic environment disclosed an IS903 insertion sequence disrupting this gene in the ertapenem resistant isolate (KPN133). The blaKPC-2 gene showed down-regulated expression in both isolates. Our findings show that changes in porins, especially OmpK36, are more determinant to carbapenems susceptibility profile of bacterial isolates than variations in blaKPC gene expression.

Proteomic profile of vitrified in vitro-produced bovine embryos (Bos taurus indicus)

BACKGROUND

The proteomic profile of cryopreserved in vitro produced bovine embryos is little known but can provide insights on the successful application of cryo procedures in support of animal breeding.

OBJECTIVE

To identify embryonic proteins and biomarkers related to improved cryotolerance of vitrified in vitro produced bovine embryos.

MATERIALS AND METHODS

Proteins were isolated from embryo pools (n = 25 embryos per replicate) and analyzed using the nanoLC - MS/MS system. Further, the UniProtKB database (Uniprot -http://www.uniprot.org/) was used for protein identification. Proteins were classified based on their molecular mass, isoelectric point, and enzymatic activity. Post-translational modification predictions and functional gene ontology analysis were performed as well. Finally, a protein-protein interaction network was created to shed light on the embryo interactome.

RESULTS

Based on the MS/MS approach, 66 proteins were identified from vitrified Bos taurus embryos. The retrieved proteins were presumably annotated, which allowed a description of the qualitative and functional aspects of the embryo proteome after the vitrification process.

CONCLUSION

These findings allowed us to conclude that in vitro-produced vitrified embryos expressed proteins that underlie biological processes related to reproduction, stress and lipid metabolic process, which are essential to maintain embryo viability. doi.org/10.54680/fr22410110512.