Detection of Proteus mirabilis urease gene in urinary calculi by polymerase chain reaction

A correlation study between virulence factors and multidrug resistance among clinical isolates of Proteus mirabilis

Treatment of Proteus mirabilis infections is a challenge due to the high abundance of virulence factors and the high intrinsic resistance to antimicrobials. Multidrug resistance (MDR) and extensive drug resistance (XDR) further challenge the control of P. mirabilis infection. This study aimed to investigate the correlation between virulence determinants and multidrug resistance in 100 clinical isolates of P. mirabilis collected in Alexandria from December 2019 to June 2021. Susceptibility to antimicrobials was tested by the Kirby Bauer method. Detection of swarming, urease, protease, hemolysin, and biofilm formation was performed phenotypically and by PCR amplification of zapA, flaA, ureC, mrpA, atfA, ucaA, hpmA, and luxS. MDR and XDR were detected in 34% and 5%, respectively. All isolates were positive for motility, swarming, urease, and protease production. Ninety percent were positive for hemolysin production, while 73% formed biofilm. All isolates possessed the ureC and zapA genes. The luxS, flaA, ucaA, hpmA, mrpA, and atfA genes were detected in 99%, 98%, 96% 90%, 89%, and 84%, respectively. The presence of a single biofilm-related gene was statistically correlated with non-biofilm production (P= 0.018). It was concluded that P. mirabilis isolates from catheterized-urine samples were significantly associated with biofilm formation. MDR and virulence were not statistically correlated. A significant positive correlation was detected between some virulence genes in P. mirabilis. Non-MDR isolates of P. mirabilis had a high abundance of virulence factors with no statistically significant difference from MDR. Most of the MDR and all XDR isolates could produce biofilm.

Development of a multiplex PCR assay for the simultaneous and rapid detection of six pathogenic bacteria in poultry

Escherichia coli, Pasteurella multocida, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella spp. and Staphylococcus aureus are six bacterial pathogens of avian. However, these pathogens may cause many similar pathological changes, resulting in clinical isolates that are difficult to quickly and simultaneously detect and identify. Here, a multiplex polymerase chain reaction (m-PCR) assay is reported to rapidly identify targets genes (phoA, KMT1, ureR, toxA, invA, and nuc) of these six pathogens in clinical samples. Six pairs of specific primers were designed. The optimal reaction conditions, specificity, and sensitivity of the m-PCR assay were investigated. The results showed that betaine remarkably improved amplification of the target genes. Specific test results showed that all six pathogens were detected by the proposed m-PCR protocol without cross-amplification with viruses or parasites. Sensitivity test results showed that the m-PCR system could amplify the six target genes from bacterial genomes or cultures with template amounts of 500 pg or 2.8-8.6 × 10³ colony forming units, respectively. Furthermore, the six bacterial pathogens isolated from the infected tissue samples were successfully identified. The proposed m-PCR assay is a useful tool to monitor and diagnose bacterial infection in birds with high specificity, sensitivity and throughput.

First report of the plasmid-borne colistin resistance gene (mcr-1) in Proteus mirabilis isolated from a toddler in non-clinical settings

We report the detection of a plasmid-borne mobile colistin-resistance-gene, mcr-1, in Proteus mirabilis, a known community and hospital pathogen, that was isolated from a toddler (2 years old) in the community in Lebanon. To our knowledge, this is the first report of the occurrence of mcr-1 in human-associated P. mirabilis as well as mcr-1 in humans in the Lebanese community.

From Catheter to Kidney Stone: The Uropathogenic Lifestyle of Proteus mirabilis

Proteus mirabilis is a model organism for urease-producing uropathogens. These diverse bacteria cause infection stones in the urinary tract and form crystalline biofilms on indwelling urinary catheters, frequently leading to polymicrobial infection. Recent work has elucidated how P. mirabilis causes all of these disease states. Particularly exciting is the discovery that this bacterium forms large clusters in the bladder lumen that are sites for stone formation. These clusters, and other steps of infection, require two virulence factors in particular: urease and MR/P fimbriae. Highlighting the importance of MR/P fimbriae is the cotranscribed regulator, MrpJ, which globally controls virulence. Overall, P. mirabilis exhibits an extraordinary lifestyle, and further probing will answer exciting basic microbiological and clinically relevant questions.