Proteus mirabilis is a Gram-negative bacterium with exclusive molecular and biological features. It is a versatile pathogen acclaimed for its distinct urease production, swarming behavior, and rapid multicellular activity. Clinically, P. mirabilis is a frequent pathogen of the human urinary system where it causes urinary tract infections (UTIs) and catheter-associated urinary tract infections (CAUTIs). This review explores the epidemiology, risk factors, clinical manifestations, and treatment of P. mirabilis infections, emphasizing its association with UTIs. The bacterium's genome analysis revealed the presence of resistance genes against commonly used antibiotics, an antibiotic-resistant phenotype that poses a serious clinical challenge. Particularly, the emergence of extended-spectrum β-lactamases (ESBLs) and carbapenemases resistant P. mirabilis strains. On a molecular level, P. mirabilis possesses a wide array of virulence factors including the production of fimbriae, urease, hemolysins, metallophores, and biofilm formation. This review thoroughly tackles a substantial gap in understanding the role of metallophores in shaping the virulence factors of P. mirabilis virulence. Siderophores, iron metal chelating and transporting metallophores, particularly contribute to the complex pathogenic strategies, displaying a potential target for therapeutic intervention.

Rectal prolapse is a protrusion of rectal mucosa through the anal sphincter. Although uncommon, it is seen more often in children, younger than 4 years of age. The last data analysis of rectal prolapse and its clinical characteristics in children was performed over 30 years ago. Since that time, many medical advances have occurred that may alter our workup and management of this disease in children. We performed a chart review to reassess the clinical characteristics of rectal prolapse and its management.

This was a retrospective descriptive analysis study, assessing children less than 18 years of age that were diagnosed with rectal prolapse from 1999 to 2014 at a single tertiary care center. The onset of presentation, demographics, etiology, clinical characteristics, and management were analyzed.

A total of 158 patients were diagnosed with rectal prolapse, with mean age of onset being 3 years. Constipation was the leading cause, with straining being the most common complaint. Stool consistencies with constipation varied. Many patients diagnosed with idiopathic recurrent rectal prolapse had either a social stressor or were described as having unusual behaviors associated with prolapse. Cystic fibrosis was only diagnosed in 4 patients. Thirty-four patients (22%) required surgical correction.

Constipation remains the main cause of rectal prolapse. Cystic fibrosis is no longer a common etiology for rectal prolapse, because of the implementation of newborn screening. Patients with social stressors or atypical behavior may be at risk for recurrent rectal prolapse.

Proteus mirabilis is a Gram-negative bacterium and is well known for its ability to robustly swarm across surfaces in a striking bulls'-eye pattern. Clinically, this organism is most frequently a pathogen of the urinary tract, particularly in patients undergoing long-term catheterization. This review covers P. mirabilis with a focus on urinary tract infections (UTI), including disease models, vaccine development efforts, and clinical perspectives. Flagella-mediated motility, both swimming and swarming, is a central facet of this organism. The regulation of this complex process and its contribution to virulence is discussed, along with the type VI-secretion system-dependent intra-strain competition, which occurs during swarming. P. mirabilis uses a diverse set of virulence factors to access and colonize the host urinary tract, including urease and stone formation, fimbriae and other adhesins, iron and zinc acquisition, proteases and toxins, biofilm formation, and regulation of pathogenesis. While significant advances in this field have been made, challenges remain to combatting complicated UTI and deciphering P. mirabilis pathogenesis.

Rectal prolapse is a herniation of the rectum through the anus. It is rare in children. When it does occur, it is usually prior to 4 years of age and due to anatomical variants. A few conditions predispose children to rectal prolapse, the most common being constipation. Cystic fibrosis used to be commonly associated with rectal prolapse, but with the advent of cystic fibrosis newborn screening, this association is no longer as frequently seen. Many recent case reports, detailed in this chapter, describe conditions previously unknown to be associated with rectal prolapse. Management is usually supportive; however, rectal prolapse requires surgical management in certain situations. This review details the presentation of rectal prolapse, newly described clinical manifestations, and associated conditions, and up-to-date medical and surgical management.