Background and aim: Multidrug resistant Klebsiella pneumoniae is associated with nosocomial infections in both outbreak and non-outbreak situations. The study intends to evaluate the potential of enterobacterial repetitive intergenic consensus- polymerase chain reaction (ERIC-PCR), a genomic based typing and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) proteomic-based typing techniques for clonal relatedness among multidrug resistant Klebsiella pneumoniae isolates. Methodology: Multidrug resistant clinical isolates of Klebsiella pneumoniae (n = 137) were collected from March 2019 to February 2020. Identification and protein-based phylogenetic analysis were performed by MALDI-TOF MS. Genomic typing was done by ERIC-PCR and analyzed by an online data analysis service (PyElph). Dice method with unweighted pair group method with arithmetic mean (UPGMA) program was used to compare the ERIC profiles. The samples were also evaluated by PCR for the presence of genes encoding carbapenemases, extended spectrum beta lactamases (ESBLs) and mobile colistin resistance-1 (mcr1). Result and conclusion: The study presents ERIC-PCR as more robust and better discriminatory typing tool in comparison to MALDI-TOF for clonal relatedness in multidrug resistant K. pneumoniae clinical isolates. Isolates were typed into 40 ERIC types, and six groups by MALDI-TOF-MS. PCR-based analysis revealed that all the strains harbored two or more ESBL and carbapenemase genes. None of the isolates revealed the presence of the plasmid mediated mcr-1 gene for colistin resistance.

Aim: The aim of the study was to assess and evaluate the antimicrobial effectiveness of chitosan nanoparticles (CSNPs) with calcium hydroxide in the elimination of Enterococcus faecalis . Materials and Methods: Using the broth microdilution method, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of calcium hydroxide and CSNPs were measured. The antibiofilm effect of calcium hydroxide and CSNPs against E. faecalis biofilm was qualitatively analyzed using a crystal violet assay. A 7-day-old biofilms of E. faecalis grown on dentine discs were assigned to the following three groups ( n = 11 dentine discs), normal saline (group I), calcium hydroxide (group II), and CSNPs (group III). Quantification of live and dead cells using confocal microscopy was done to evaluate the antibiofilm efficacy of the medicaments included in the study. Results: MIC of calcium hydroxide and CSNPs against E. faecalis was observed at 2.5 mg/mL and 0.31 mg/mL, respectively. MBC of calcium hydroxide and CSNPs was observed at 2.5 mg/mL and 0.31 mg/mL, respectively. Using Crystal Violet (CV) assay, calcium hydroxide and CSNPs showed biofilm inhibition at concentrations of 2.5 mg/mL and 0.625 mg/mL, respectively. Confocal laser scanning microscopy analysis found that both calcium hydroxide and CSNPs showed a significant decrease in viable cells at their MBC values compared to the control group’s normal saline. CSNPs showed a significantly lower percentage of live cells than calcium hydroxide ( P < 0.05). Conclusion: The study results reveal that the antimicrobial efficacy of CSNPs is better than calcium hydroxide and normal saline against E. faecalis biofilm.

The rise in multidrug resistance in Klebsiella pneumoniae is an alarming issue, especially in invasive infections among patients with co-morbidities. With the gain of hypervirulence traits, multidrug-resistant K. pneumoniae has led to a significant increase in chronic infections and associated mortality. This study aims to explore the distribution of multidrug-resistant and hypervirulent (hv) K. pneumoniae in invasive infections in a tertiary care hospital. A total of 231 K. pneumoniae isolates were collected over a period of six months from invasive infections. These isolates were tested phenotypically and genotypically for the presence of antimicrobial resistance, along with molecular detection of hypervirulence determinants (iucA, rmpA, rmpA2, peg344, iroB). High levels of resistance to β-lactams, fluoroquinolones, and aminoglycosides were observed. Carbapenemase-encoding genes were widely distributed, and 22% showed the presence of at least one hypervirulence gene, most commonly iucA and rmpA. Co-carriage of resistance and hypervirulence determinants in K. pneumoniae was observed in nearly 20% of the isolates, indicating the emergence of MDR-hvKP phenotypes in the hospital setting. Mortality was significantly higher among patients infected with MDR isolates, whereas hypervirulence markers were not independently associated with mortality. The presence of MDR–hypervirulent strains remains clinically concerning and underscores the need for continued genomic surveillance.