Detection of Carbapenem Resistance of Proteus mirabilis Strains Isolated from Foxes, Raccoons and Minks in China

Genetic characteristics of chromosomally integrated carbapenemase gene (blaNDM-1) in isolates of Proteus mirabilis

OBJECTIVE

This study aims to conduct an in-depth genomic analysis of a carbapenem-resistant Proteus mirabilis strain to uncover the distribution and mechanisms of its resistance genes.

METHODS

The research primarily utilized whole-genome sequencing to analyze the genome of the Proteus mirabilis strain. Additionally, antibiotic susceptibility tests were conducted to evaluate the strain's sensitivity to various antibiotics, and related case information was collected to analyze the clinical distribution characteristics of the resistant strain.

RESULTS

Study on bacterial strain WF3430 from a tetanus and pneumonia patient reveals resistance to multiple antibiotics due to extensive use. Whole-genome sequencing exposes a 4,045,480 bp chromosome carrying 29 antibiotic resistance genes. Two multidrug-resistant (MDR) gene regions, resembling Tn6577 and Tn6589, were identified (MDR Region 1: 64.83 Kb, MDR Region 2: 85.64 Kbp). These regions, consist of integrative and conjugative elements (ICE) structures, highlight the intricate multidrug resistance in clinical settings.

CONCLUSION

This study found that a CR-PMI strain exhibits a unique mechanism for acquiring antimicrobial resistance genes, such as blaNDM-1, located on the chromosome instead of plasmids. According to the results, there is increasing complexity in the mechanisms of horizontal transmission of resistance, necessitating a comprehensive understanding and implementation of targeted control measures in both hospital and community settings.

Key biological processes and essential genes for Proteus mirabilis biofilm development inhibition by protocatechuic acid

Proteus mirabilis is an opportunistic pathogen linked to human urinary tract infections, and is potentially present as a foodborne pathogen within poultry products, including broiler chickens. This report outlines the inhibitory impacts of protocatechuic acid (PCA) on P. mirabilis isolated from a broiler slaughterhouse in China as well as its biofilm. This investigation encompasses assays related to motility and adhesion, bacterial metabolic activity, extracellular polymer (EPS) production, and scavenging capacity. The findings demonstrated that PCA reduced biofilm formation by 61 %. Transcriptomics findings identified that PCA limited the expression of genes like PstS that promote adhesin formation, rbsA and RcsB that alter bacterial chemotaxis, lipopolysaccharide synthesis genes LpxA and EptB, and cell wall synthesis genes MurF and MrdA, and affects the Regulator of Capsule Synthesis (RCS) two-component modulation system. Weighted gene co-expression network analysis (WGCNA) was conducted to identify the core genes. Furthermore, the binding sites of PCA to cytochrome oxidases cydA and cydB, two subunits of ATP synthase atpI and atpH, and ftsZ, which regulate bacterial division, were predicted via molecular docking. Metabolome analysis determined that PCA critically influenced coenzyme A biosynthesis, nucleotide metabolism, alanine, aspartic acid, and glutamate metabolic pathways of P. mirabilis. Therefore, PCA impacts metabolism within bacteria via various pathways, limiting the levels of extracellular polymer and bacterial viability to hinder biofilm formation. Additionally, we prepared an antibacterial plastic film containing protocatechuic acid using PVA as the monomer and CNC as the reinforcing agent. We examined the mechanical and antibacterial properties of this film. When used to wrap chicken, it reduced the total number of colonies, slowed the deterioration of chicken, and maintained the freshness of chicken. In conclusion, the information outlined in this study complements our comprehension of P. mirabilis inhibition by PCA and provides clues for the reduction of foodborne infections associated with P. mirabilis.

Multidrug-Resistant Proteus mirabilis Infections and Clinical Outcome at Tertiary Hospital in Riyadh, Saudi Arabia

Background

Proteus mirabilis (P. mirabilis) is known to cause various infections, most commonly urinary tract infections, and is a threat to hospitalized patients, especially in long-stay departments that utilize invasive devices. This study aims to fill the knowledge gap regarding P. mirabilis epidemiology and antimicrobial resistance in Saudi Arabia. It investigates epidemiological patterns, resistance characteristics, and clinical outcomes among P. mirabilis patients at King Fahad Medical City in Riyadh from 2019 to 2021.

Methods

A total of 598 P. mirabilis isolated from diverse clinical specimens, including the clinical information of 78 intensive care unit (ICU) patients, were included in the current study. The Phoenix BD instrument was used for complete identification and sensitivity testing of Proteus spp. Demographic, clinical, and outcome data were reported and compared using statistical analysis.

Results

Pan-drug-resistant isolates were identified in 2019 (n = 6), although multi- and extensively drug-resistant isolate frequencies were greatest among all patients in 2019. The highest susceptibility levels were observed for piperacillin-tazobactam, carbapenems, and cephalosporins antibiotics. In contrast, Cephalothin, trimethoprim-sulfamethoxazole, and ampicillin had the lowest susceptibilities. Urine infections with a positive culture of P. mirabilis were significantly higher in females and non-ICU patients (p <0.001), but respiratory infections were significantly higher in ICU patients (p <0.001). Moreover, ICU patients infected with P. mirabilis and undergoing renal dialysis have a 7.2-fold (P 0.034) higher risk of death than those not receiving dialysis.

Conclusion

Hospitalized patients are at risk of fatal consequences due to P. mirabilis infection. It is crucial to conduct further investigation to fully understand the severity of this issue and take necessary measures to prevent it.