-
Microbiology Spectrum Oct 2015Proteus 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... (Review)
Review
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.
Topics: Animals; Catheter-Related Infections; Disease Models, Animal; Humans; Locomotion; Proteus Infections; Proteus mirabilis; Urinary Tract Infections; Virulence; Virulence Factors
PubMed: 26542036
DOI: 10.1128/microbiolspec.UTI-0017-2013 -
EcoSal Plus Feb 2018, a Gram-negative rod-shaped bacterium most noted for its swarming motility and urease activity, frequently causes catheter-associated urinary tract infections (CAUTIs)... (Review)
Review
, a Gram-negative rod-shaped bacterium most noted for its swarming motility and urease activity, frequently causes catheter-associated urinary tract infections (CAUTIs) that are often polymicrobial. These infections may be accompanied by urolithiasis, the development of bladder or kidney stones due to alkalinization of urine from urease-catalyzed urea hydrolysis. Adherence of the bacterium to epithelial and catheter surfaces is mediated by 17 different fimbriae, most notably MR/P fimbriae. Repressors of motility are often encoded by these fimbrial operons. Motility is mediated by flagella encoded on a single contiguous 54-kb chromosomal sequence. On agar plates, undergoes a morphological conversion to a filamentous swarmer cell expressing hundreds of flagella. When swarms from different strains meet, a line of demarcation, a "Dienes line," develops due to the killing action of each strain's type VI secretion system. During infection, histological damage is caused by cytotoxins including hemolysin and a variety of proteases, some autotransported. The pathogenesis of infection, including assessment of individual genes or global screens for virulence or fitness factors has been assessed in murine models of ascending urinary tract infections or CAUTIs using both single-species and polymicrobial models. Global gene expression studies performed in culture and in the murine model have revealed the unique metabolism of this bacterium. Vaccines, using MR/P fimbria and its adhesin, MrpH, have been shown to be efficacious in the murine model. A comprehensive review of factors associated with urinary tract infection is presented, encompassing both historical perspectives and current advances.
Topics: Animals; Bacterial Vaccines; Catheter-Related Infections; Disease Models, Animal; Fimbriae, Bacterial; Host-Pathogen Interactions; Humans; Mice; Proteus Infections; Proteus mirabilis; Urinary Tract Infections; Virulence
PubMed: 29424333
DOI: 10.1128/ecosalplus.ESP-0009-2017 -
Annals of Clinical Microbiology and... Apr 2021Multi-Drug Resistant (MDR) uropathogenic bacteria have increased in number in recent years and the development of new treatment options for the corresponding infections... (Review)
Review
Multi-Drug Resistant (MDR) uropathogenic bacteria have increased in number in recent years and the development of new treatment options for the corresponding infections has become a major challenge in the field of medicine. In this respect, recent studies have proposed bacteriophage (phage) therapy as a potential alternative against MDR Urinary Tract Infections (UTI) because the resistance mechanism of phages differs from that of antibiotics and few side effects have been reported for them. Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis are the most common uropathogenic bacteria against which phage therapy has been used. Phages, in addition to lysing bacterial pathogens, can prevent the formation of biofilms. Besides, by inducing or producing polysaccharide depolymerase, phages can easily penetrate into deeper layers of the biofilm and degrade it. Notably, phage therapy has shown good results in inhibiting multiple-species biofilm and this may be an efficient weapon against catheter-associated UTI. However, the narrow range of hosts limits the use of phage therapy. Therefore, the use of phage cocktail and combination therapy can form a highly attractive strategy. However, despite the positive use of these treatments, various studies have reported phage-resistant strains, indicating that phage-host interactions are more complicated and need further research. Furthermore, these investigations are limited and further clinical trials are required to make this treatment widely available for human use. This review highlights phage therapy in the context of treating UTIs and the specific considerations for this application.
Topics: Animals; Bacteria; Bacteriophages; Biofilms; Drug Resistance, Multiple, Bacterial; Glycoside Hydrolases; Host Specificity; Humans; Klebsiella pneumoniae; Phage Therapy; Proteus mirabilis; Urinary Tract Infections; Uropathogenic Escherichia coli
PubMed: 33902597
DOI: 10.1186/s12941-021-00433-y -
The Lancet. Microbe Nov 2022TMexCD1-TOprJ1, which is associated with phenotypic resistance to multiple classes of antibiotics, is a transmissible resistance-nodulation-division (RND) family efflux...
BACKGROUND
TMexCD1-TOprJ1, which is associated with phenotypic resistance to multiple classes of antibiotics, is a transmissible resistance-nodulation-division (RND) family efflux pump. However, the prevalence and genomic and phenotypic characteristics of clinical isolates with this important resistance determinant are poorly understood. In this study, we aimed to survey tmexCD-toprJ among clinical Gram-negative isolates collected from hospitals in China between 1991 and 2020 and characterise tmexCD-toprJ-positive clinical isolates.
METHODS
We conducted online data retrieval and active nationwide surveillance in China to screen tmexCD-toprJ-positive strains. We characterised tmexCD-toprJ-positive clinical strains for their antimicrobial susceptibility, genetic and functional characteristics, and the potential inter-species transmission route of tmexCD-toprJ with whole genome sequencing and bioinformatics analyses. The function of tmexCD-toprJ in Pseudomonas sp and Proteus sp was investigated by tmexD gene knockdown using an isopropylthio-β-galactoside-inducible CRISPR interference system.
FINDINGS
Data retrieval obtained 53 strains carrying tmexCD-toprJ, comprising 32 Pseudomonas spp, 11 Klebsiella pneumoniae, one Aeromonas spp, one Citrobacter freundii, and one uncultured bacterium from diverse niches. 48 (0·64%) of 7517 clinical isolates from China, including seven Klebsiella spp, one Proteus mirabilis, and 40 Pseudomonas spp, carried tmexCD-toprJ. These isolates exhibited multidrug resistance phenotypes and co-harboured resistance genes, such as mcr and carbapenemases genes. tmexCD-toprJ was encoded on both plasmids and chromosomes in all Klebsiella spp that carried plasmid-borne tmexCD-toprJ (n=7), P mirabilis carried chromosome-borne tmexCD-toprJ, and Pseudomonas spp carried either plasmid-borne (n=19) or chromosome-borne (n=21) ones. tmexCD-toprJ had undergone clonal and horizontal transmission among clinical pathogens. Eight different types of genetic context of tmexCD-toprJ were identified, each of which was associated with different mobile elements, including IntI, IS6100, TnAs1-like, ISRor5, ISVsa3, ISCfr-like, Tn5393, and IS222-like, which might facilitate its transmission. Knockdown of tmexD led to a four times decrease in tigecycline minimum inhibitory concentrations in both Pseudomonas spp and Proteus spp.
INTERPRETATION
Our study provides evidence to suggest that tmexCD-toprJ contributes to the antimicrobial resistance phenotypes in different bacterial species. tmexCD-toprJ has disseminated among diverse species of clinical pathogens, which warrants timely monitoring in clinical pathogens.
FUNDING
National Natural Science Foundation of China, Guangdong Major Project of Basic and Applied Basic Research, Natural Science Foundation of Jiangsu Province.
Topics: Drug Resistance, Bacterial; Gram-Negative Bacteria; Microbial Sensitivity Tests; Anti-Bacterial Agents; Proteus mirabilis; Multigene Family
PubMed: 36202114
DOI: 10.1016/S2666-5247(22)00221-X -
Frontiers in Cellular and Infection... 2022The genera and were independently described in 1885. These Gram-negative rods colonize the human intestinal tract regarded as the main reservoir of these opportunistic... (Review)
Review
The genera and were independently described in 1885. These Gram-negative rods colonize the human intestinal tract regarded as the main reservoir of these opportunistic pathogens. In favorable conditions they cause infections, often hospital-acquired ones. The activity of and , the leading pathogens within each genus, results in infections of the urinary (UTIs) and respiratory tracts, wounds, bacteremia, affecting mainly immunocompromised patients. and cause polymicrobial UTIs, which are often persistent due to the catheter biofilm formation or increasing resistance of the bacteria to antibiotics. In this situation a need arises to find the antigens with features common to both species. Among many virulence factors produced by both pathogens urease shows some structural similarities but the biggest similarities have been observed in lipids A and the core regions of lipopolysaccharides (LPSs). Both species produce capsular polysaccharides (CPSs) but only in these antigens play a crucial role in the serological classification scheme, which in spp. is based on the structural and serological diversity of LPS O-polysaccharides (OPSs). Structural and serological similarities observed for spp. and spp. polysaccharides are important in the search for the cross-reacting vaccine antigens.
Topics: Humans; Proteus mirabilis; Klebsiella pneumoniae; Virulence Factors; Coinfection; Urinary Tract Infections; Lipopolysaccharides
PubMed: 36339335
DOI: 10.3389/fcimb.2022.991657 -
BMJ Case Reports Aug 2019A 62-year-old man was admitted to the emergency department due to fever and acute heart failure. A transthoracic echocardiogram revealed severe aortic valve obstruction....
A 62-year-old man was admitted to the emergency department due to fever and acute heart failure. A transthoracic echocardiogram revealed severe aortic valve obstruction. He was an hepatic transplant recipient and was medicated with everolimus. He underwent mitral and aortic valve replacement with prosthetic valves 4 years ago. Due to his medical background, therapy and clinical presentation, empirical therapy for infective endocarditis was started. Transoesophageal echocardiogram showed severe aortic valve regurgitation but no other findings suggestive of endocarditis. Computed tomography (CT) revealed pulmonary infiltrates compatible with infection and no evidence of septic embolisation. Multiple sets of blood cultures were negative. was isolated in bronchial lavage and antibiotic therapy was adjusted. The patient underwent aortic valve replacement, with no macroscopic findings suggestive of endocarditis. was isolated in the surgically removed valve. Dual antibiotic therapy was successfully administered for 6 weeks.
Topics: Acute Disease; Anti-Bacterial Agents; Aortic Valve Insufficiency; Bronchoalveolar Lavage Fluid; Bronchoscopy; Diagnosis, Differential; Echocardiography, Transesophageal; Endocarditis, Bacterial; Heart Failure; Heart Valve Diseases; Heart Valve Prosthesis; Humans; Lung; Male; Middle Aged; Proteus mirabilis; Tomography, X-Ray Computed; Treatment Outcome
PubMed: 31466989
DOI: 10.1136/bcr-2019-230575 -
Frontiers in Cellular and Infection... 2020is a Gram negative bacterium that is a frequent cause of catheter-associated urinary tract infections (CAUTIs). Its ability to cause such infections is mostly related... (Review)
Review
is a Gram negative bacterium that is a frequent cause of catheter-associated urinary tract infections (CAUTIs). Its ability to cause such infections is mostly related to the formation of biofilms on catheter surfaces. In order to form biofilms, expresses a number of virulence factors. Such factors may include adhesion proteins, quorum sensing molecules, lipopolysaccharides, efflux pumps, and urease enzyme. A unique feature of biofilms that build up on catheter surfaces is their crystalline nature owing to their ureolytic biomineralization. This leads to catheter encrustation and blockage and, in most cases, is accompanied by urine retention and ascending UTIs. Bacteria embedded in crystalline biofilms become highly resistant to conventional antimicrobials as well as the immune system. Being refractory to antimicrobial treatment, alternative approaches for eradicating biofilms have been sought by many studies. The current review focuses on the mechanism by which biofilms are formed, and a state of the art update on preventing biofilm formation and reduction of mature biofilms. These treatment approaches include natural, and synthetic compounds targeting virulence factors and quorum sensing, beside other strategies that include carrier-mediated diffusion of antimicrobials into biofilm matrix. Bacteriophage therapy has also shown successful results for combating biofilms either merely through their lytic effect or by acting as facilitators for antimicrobials diffusion.
Topics: Biofilms; Humans; Proteus mirabilis; Quorum Sensing; Urease; Urinary Tract Infections
PubMed: 32923408
DOI: 10.3389/fcimb.2020.00414 -
Journal of Molecular Biology Nov 2015Flagella propel bacteria during both swimming and swarming, dispersing them widely. However, while swimming bacteria use chemotaxis to find nutrients and avoid toxic... (Review)
Review
Flagella propel bacteria during both swimming and swarming, dispersing them widely. However, while swimming bacteria use chemotaxis to find nutrients and avoid toxic environments, swarming bacteria appear to suppress chemotaxis and to use the dynamics of their collective motion to continuously expand and acquire new territory, barrel through lethal chemicals in their path, carry along bacterial and fungal cargo that assists in exploration of new niches, and engage in group warfare for niche dominance. Here, we focus on two aspects of swarming, which, if understood, hold the promise of revealing new insights into microbial signaling and behavior, with ramifications beyond bacterial swarming. These are as follows: how bacteria sense they are on a surface and turn on programs that promote movement and how they override scarcity and adversity as dense packs.
Topics: Anti-Bacterial Agents; Bacillus subtilis; Bacterial Physiological Phenomena; Chemotaxis; Drug Resistance, Bacterial; Escherichia coli; Flagella; Proteus mirabilis; Salmonella; Vibrio parahaemolyticus
PubMed: 26277623
DOI: 10.1016/j.jmb.2015.07.025 -
Journal of the American Association For... May 2022The exclusion of opportunistic pathogens is important for protecting animal health and ensuring desired research outcomes in highly immunodeficient mice. has been...
The exclusion of opportunistic pathogens is important for protecting animal health and ensuring desired research outcomes in highly immunodeficient mice. has been associated with gastrointestinal tract lesions, septicemia, pyelonephritis, splenomegaly, and hepatitis and can influence select mouse models. To inform health-surveillance practices after we experienced difficulty in excluding from our mouse colony, we aimed to determine the likelihood of detecting -positive immunocompromised (SRG), immunovague (), and immunocompetent (CD1) colony mice through culture and PCR testing; to evaluate transmission via 2 sentinel-based approaches (direct contact and indirect dirty-bedding transfer); and to further characterize associated pathology. We hypothesized that immunocompromised mice would be better detectors and transmitters of . Multiple logistic regression models were used for analysis and included PCR copy number, repeated testing, age, sex, and antibiotic-treated (trimethoprim-sulfamethoxazole) diet as covariates. Repeated testing over 10 wk showed that -colonized immunocompromised colony mice were 95 times more likely than immunocompetent mice to test positive by culture and 30 times more likely by PCR assay. Sentinel mice were 15 times more likely to test positive by PCR assay for when exposed by direct contact compared with dirty bedding and 18 times more likely to test positive when exposed to positive immunocompromised as compared with immunocompetent colony mice. After 10 wk of exposure, 3.8% of dirty-bedding sentinel PCR tests were positive, as compared with 30.7% of contact sentinels. Only immunocompromised mice on antibiotic diet (37.5%) developed lesions of the urogenital tract and abdominal cavity consistent with known pathology of . Our findings suggest that PCR testing of dirty-bedding sentinels alone is not sufficient for the detection of in mouse colonies. Direct-contact sentinels and testing of colony mice-especially if immunocompromised-with adjunct culture may facilitate successful bioexclusion.
Topics: Animals; Anti-Bacterial Agents; Bedding and Linens; Housing, Animal; Mice; Proteus mirabilis
PubMed: 35277210
DOI: 10.30802/AALAS-JAALAS-21-000104