Host‐Pathogen Interactions Mediating Pain of Urinary Tract Infection (original) (raw)
Uropathogenic Escherichia coli induces chronic pelvic pain
Infection and immunity, 2011
Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a debilitating syndrome of unknown etiology often postulated, but not proven, to be associated with microbial infection of the prostate gland. We hypothesized that infection of the prostate by clinically relevant uropathogenic Escherichia coli (UPEC) can initiate and establish chronic pain. We utilized an E. coli strain newly isolated from a patient with CP/CPPS (strain CP1) and examined its molecular pathogenesis in cell culture and in a murine model of bacterial prostatitis. We found that CP1 is an atypical isolate distinct from most UPEC in its phylotype and virulence factor profile. CP1 adhered to, invaded, and proliferated within prostate epithelia and colonized the prostate and bladder of NOD and C57BL/6J mice. Using behavioral measures of pelvic pain, we showed that CP1 induced and sustained chronic pelvic pain in NOD mice, an attribute not exhibited by a clinical cystitis strain. Furthermore, pain was observed to ...
Asymptomatic Bacteriuria Escherichia coli Are Live Biotherapeutics for UTI
PLoS ONE, 2014
Urinary tract infections (UTI) account for approximately 8 million clinic visits annually with symptoms that include acute pelvic pain, dysuria, and irritative voiding. Empiric UTI management with antimicrobials is complicated by increasing antimicrobial resistance among uropathogens, but live biotherapeutics products (LBPs), such as asymptomatic bacteriuria (ASB) strains of E. coli, offer the potential to circumvent antimicrobial resistance. Here we evaluated ASB E. coli as LBPs, relative to ciprofloxacin, for efficacy against infection and visceral pain in a murine UTI model. Visceral pain was quantified as tactile allodynia of the pelvic region in response to mechanical stimulation with von Frey filaments. Whereas ciprofloxacin promoted clearance of uropathogenic E. coli (UPEC), it did not reduce pelvic tactile allodynia, a measure of visceral pain. In contrast, ASB E. coli administered intravesically or intravaginally provided comparable reduction of allodynia similar to intravesical lidocaine. Moreover, ASB E. coli were similarly effective against UTI allodynia induced by Proteus mirabilis, Enterococccus faecalis and Klebsiella pneumoniae. Therefore, ASB E. coli have anti-infective activity comparable to the current standard of care yet also provide superior analgesia. These studies suggest that ASB E. coli represent novel LBPs for UTI symptoms.
Mediators of inflammation, 2017
Urinary tract infection (UTI) is an extremely common infectious disease. Uropathogenic (UPEC) is the predominant etiological agent of UTI. Asymptomatic bacteriuric (ABEC) strains successfully colonize the urinary tract resulting in asymptomatic bacteriuria (ABU) and do not induce symptoms associated with UTI. Oxylipids are key signaling molecules involved in inflammation. Based on the distinct clinical outcomes of colonization, we hypothesized that UPEC triggers the production of predominantly proinflammatory oxylipids and ABEC leads to production of primarily anti-inflammatory or proresolving oxylipids in the urinary tract. We performed quantitative detection of 39 oxylipid mediators with proinflammatory, anti-inflammatory, and proresolving properties, during UTI and ABU caused by genetically distinct strains in the murine urinary bladder. Our results reveal that infection with UPEC causes an increased accumulation of proinflammatory oxylipids as early as 6 h postinoculation, compa...
Scientific reports, 2018
Patients with interstitial cystitis/bladder pain syndrome (IC/BPS) can potentially develop symptom flares after exposure to minor bladder irritants such as subclinical bacterial infection. To reproduce this symptom onset, we intravesically instilled a sub-noxious dose of uropathogenic E. coli component lipopolysaccharide (LPS) in young URO-OVA/OT-I mice, a transgenic autoimmune cystitis model that spontaneously develops bladder inflammation at ≥10 weeks of age. Female URO-OVA/OT-I mice (6-weeks old) were treated intravesically with phosphate-buffered saline (PBS) or PBS containing a sub-noxious dose (1 μg) of LPS. Mice were evaluated for bladder inflammation, pelvic pain, and voiding dysfunction at days 1, 7, and 14 post-treatment. Mice treated with LPS but not PBS developed early bladder inflammation with increased macrophage infiltration. Accordingly, the inflamed bladders expressed increased levels of mRNA for proinflammatory cytokines (IL-1β and IL-6) and pain mediator (substanc...
Uropathogenic Escherichia coli Superinfection Enhances the Severity of Mouse Bladder Infection
PLoS Pathogens, 2015
Urinary tract infections (UTIs) afflict over 9 million women in America every year, often necessitating long-term prophylactic antibiotics. One risk factor for UTI is frequent sexual intercourse, which dramatically increases the risk of UTI. The mechanism behind this increased risk is unknown; however, bacteriuria increases immediately after sexual intercourse episodes, suggesting that physical manipulation introduces periurethral flora into the urinary tract. In this paper, we investigated whether superinfection (repeat introduction of bacteria) resulted in increased risk of severe UTI, manifesting as persistent bacteriuria, high titer bladder bacterial burdens and chronic inflammation, an outcome referred to as chronic cystitis. Chronic cystitis represents unchecked luminal bacterial replication and is defined histologically by urothelial hyperplasia and submucosal lymphoid aggregates, a histological pattern similar to that seen in humans suffering chronic UTI. C57BL/6J mice are resistant to chronic cystitis after a single infection; however, they developed persistent bacteriuria and chronic cystitis when superinfected 24 hours apart. Elevated levels of interleukin-6 (IL-6), keratinocyte cytokine (KC/CXCL1), and granulocyte colony-stimulating factor (G-CSF) in the serum of C57BL/6J mice prior to the second infection predicted the development of chronic cystitis. These same cytokines have been found to precede chronic cystitis in singly infected C3H/ HeN mice. Furthermore, inoculating C3H/HeN mice twice within a six-hour period doubled the proportion of mice that developed chronic cystitis. Intracellular bacterial replication, regulated hemolysin (HlyA) expression, and caspase 1/11 activation were essential for this increase. Microarrays conducted at four weeks post inoculation in both mouse strains revealed upregulation of IL-1 and antimicrobial peptides during chronic cystitis. These data suggest a mechanism by which caspase-1/11 activation and IL-1 secretion could predispose certain women to recurrent UTI after frequent intercourse, a predisposition predictable by several serum biomarkers in two murine models.
Microbes and Infection, 2008
Urinary tract infections are a major source of morbidity among women, with the majority caused by uropathogenic Escherichia coli. Our objective was to test if uropathogenic E. coli suppress the innate immune response of bladder epithelial cells. We found that bladder epithelial cells secrete interleukin-6 and interleukin-8 in response to non-pathogenic E. coli, whereas they failed to do so in response to uropathogenic E. coli. Uropathogenic E. coli prevented interleukin-6 secretion in response to non-pathogenic E. coli and a panel of Toll-like receptor agonists, as well as to interleukin-1b, but not to tumor necrosis factor a. These results indicate that receptors with a Toll/interleukin-1 receptor domain are specifically targeted, and that suppression is not a consequence of toxicity. One candidate for mediating immune suppression is bacterial lipopolysaccharide. However, lipopolysaccharide isolated from either uropathogenic or non-pathogenic E. coli stimulated interleukin-6 secretion to similar levels. In addition, uropathogenic E. coli did not stimulate interleukin-6 secretion from cells expressing a dominant negative Toll-like receptor 4, and prevented cells lacking Toll-like receptor 4 from secreting interleukin-6 in response to synthetic lipoprotein. We conclude that uropathogenic E. coli suppress the innate immune response through a pathway partially independent of lipopolysaccharide and Toll-like receptor 4.
Scientific Reports, 2020
The NLRP3 inflammasome and IL-1β have recently been linked to the severity of uropathogenic Escherichia coli (UPEC)-mediated urinary tract infection (UTI). However, not much is known about the contribution of NLRP3 to the antimicrobial properties of neutrophils and the release of IL-1β during UPEC infection. The purpose of this study was to elucidate the mechanisms behind UPECinduced IL-1β release from human neutrophils, and to investigate the contribution of the NLRP3 inflammasome in neutrophil-mediated inhibition of UPEC growth. We found that the UPEC strain CFT073 increased the expression of NLRP3 and increased caspase-1 activation and IL-1β release from human neutrophils. The IL-1β release was mediated by the NLRP3 inflammasome and by serine proteases in an NF-κB-and cathepsin B-dependent manner. The UPEC virulence factors α-hemolysin, type-1 fimbriae and p-fimbriae were all shown to contribute to UPEC mediated IL-1β release from neutrophils. Furthermore, inhibition of caspase-1 and NLRP3 activation increased neutrophil ROSproduction, phagocytosis and the ability of neutrophils to suppress UPEC growth. In conclusion, this study demonstrates that UPEC can induce NLRP3 and serine protease-dependent release of IL-1β from human neutrophils and that NLRP3 and caspase-1 can regulate the antimicrobial activity of human neutrophils against UPEC. Urinary tract infection (UTI) is one of the most common infections in humans. It is known that approximately 30% of all women will have at least one episode of UTI by the age of 24, and 60% will have at least one UTI during their lifetime 1 . Uropathogenic Escherichia coli (UPEC), expressing an array of virulence factors crucial for host adherence, nutrition acquisition, mobility and modulation of host immune responses 2,3 , is the predominant cause of UTI . One fourth of women with UTI will have a recurring infection within six months, which leads to exaggerated consumption of antibiotics. This in combination with the increased number of multidrug-resistant UPEC isolates have made treatment options limited 6 . Understanding the host-pathogen interaction and the mechanisms behind a successful colonization of the urinary tract by UPEC, could provide valuable clues in the search for alternative treatment strategies. During UTI, release of chemokines, e.g. IL-8, CXCL1 and CXCL2, cause recruitment of neutrophils to the superficial epithelium and the bladder lumen to target the infection . Within two hours after infection, the first neutrophils are found in the urinary tract of mice, and the influx of neutrophils has been found to be proportional to the bacterial load 9 . Neutrophils are the main effector cells of the innate immune response during UTI, and they are critical for UPEC clearance 8 . Activated neutrophils can kill UPEC through reactive oxygen species (ROS), antibacterial granular agents, phagocytosis and neutrophil extracellular traps (NETs) . Mice with defective neutrophil response have been shown to be more susceptible to UTI, and they have a decreased ability to clear the
Frontiers in Microbiology
Background: Inflammatory response during urinary tract infection (UTI) is mediated by innate immune defense. Nod like receptors (NLRs) have been proposed to work simultaneously beside TLR pathways to mediate pro-inflammatory response and maintain tissue homeostasis. Some in vitro reports have showed the involvement of NLRP3 inflammasome during uropathogenic Escherichia coli (UPEC) mediated UTI. So we have sought to determine the status of various inflammasomes and their components in UPEC mediated UTI. Methods: A total of 186 females experiencing the first episode of UTI were recruited for the study and forty were found to be positive for UPEC (≥10 5 CFU/ml) in their urine (N = 40). Further, we analyzed the expression of NLRP3, NLRC4, NAIP, AIM2, ASC, CASPASE-4, and CASPASE-1 gene at mRNA and protein level in the blood of UPEC confirmed study subjects through real time qPCR and immunoblotting. Healthy females (N = 40) visiting the OPD for health checkups, family planning advice and subjects undergoing routine medical examinations, were recruited as healthy control subjects. Pro-inflammatory cytokines (IL-6, IL-8, IFN-γ, TNF-α and MCP-1) were measured in the plasma of patients and controls through ELISA. For investigation of the involvement of NLRC4 and NLRP3 inflammasome, in vitro studies were performed using co-immunoprecipitation and confocal microscopy. Results: Most of the inflammatory regulators studied (i.e., NLRP3, NAIP, NLRC4, ASC, and CASPASE-1) were found to be up-regulated at both mRNA and protein levels in the UPEC infected UTI patients. Also, pro-inflammatory cytokines (IL-6, IL-8, IFN-γ, TNF-α, and MCP-1) were found to be up-regulated in the patients group. However, no significant difference was observed in the expression of AIM2 and CASPASE-4 genes at both mRNA and protein levels. Further, in vitro studies have shown the involvement of NLRC4 inflammasome in UPEC infected THP1 derived macrophages.
Urinary tract infections: new insights into a common problem
Postgraduate Medical Journal, 2005
U rinary tract infection (UTI) is one of the most common bacterial infections encountered in clinical practice in Europe and North America. It is estimated that 150 million cases of UTI occur on a global basis per year resulting in more than 4 billion pounds (6 billion dollars) in direct health care expenditure. 1 Young, otherwise healthy, women are commonly affected with an estimated incidence of 0.5-0.7 infections per year. 2 Of the women affected 25%-30% will go on to develop recurrent infections not related to any functional or anatomical urinary tract abnormality. Although uncomplicated infections do not result in long term sequelae, for example renal scarring, they cause significant morbidity, particularly when recurrent.
Urinary tract infections: epidemiology, mechanisms of infection and treatment options
Nature reviews. Microbiology, 2015
Urinary tract infections (UTIs) are a severe public health problem and are caused by a range of pathogens, but most commonly by Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterococcus faecalis and Staphylococcus saprophyticus. High recurrence rates and increasing antimicrobial resistance among uropathogens threaten to greatly increase the economic burden of these infections. In this Review, we discuss how basic science studies are elucidating the molecular details of the crosstalk that occurs at the host-pathogen interface, as well as the consequences of these interactions for the pathophysiology of UTIs. We also describe current efforts to translate this knowledge into new clinical treatments for UTIs.
O-Antigen Modulates Infection-Induced Pain States
PLoS ONE, 2012
The molecular initiators of infection-associated pain are not understood. We recently found that uropathogenic E. coli (UPEC) elicited acute pelvic pain in murine urinary tract infection (UTI). UTI pain was due to E. coli lipopolysaccharide (LPS) and its receptor, TLR4, but pain was not correlated with inflammation. LPS is known to drive inflammation by interactions between the acylated lipid A component and TLR4, but the function of the O-antigen polysaccharide in host responses is unknown. Here, we examined the role of O-antigen in pain using cutaneous hypersensitivity (allodynia) to quantify pelvic pain behavior and using sacral spinal cord excitability to quantify central nervous system manifestations in murine UTI. A UPEC mutant defective for O-antigen biosynthesis induced chronic allodynia that persisted long after clearance of transient infections, but wild type UPEC evoked only acute pain. E. coli strains lacking O-antigen gene clusters had a chronic pain phenotype, and expressing cloned O-antigen gene clusters altered the pain phenotype in a predictable manner. Chronic allodynia was abrogated in TLR4-deficient mice, but inflammatory responses in wild type mice were similar among E. coli strains spanning a wide range of pain phenotypes, suggesting that O-antigen modulates pain independent of inflammation. Spinal cords of mice with chronic allodynia exhibited increased spontaneous firing and compromised short-term depression, consistent with centralized pain. Taken together, these findings suggest that O-antigen functions as a rheostat to modulate LPS-associated pain. These observations have implications for an infectious etiology of chronic pain and evolutionary modification of pathogens to alter host behaviors.
Correlation Study between Urinary Tract Bacterial Infection and Some Acute Inflammatory Responses
Wolters Kluwer - Medknow, 2019
Background: There is no population in the world clear from urinary tract infection (UTI), especially among women. Urinary tract disease is a general term alluding to the bacterial infection anyplace in the urinary tract. It is commonly acknowledged that contamination of the upper urinary tract puts the patient in danger for kidney damage. The aim of the study was to identify the type of bacteria that cause UTI beside elevates the correlation between UTI and some inflmmatory markers such as erythrocyte sedimentation rate, white blood cell, C‑reactive protein (CRP), and hemoglobin for the UTI among patients in various sex and age groups. Methods: The study was carried in Baghdad Teaching Hospital during July 7, 2017–October 15, 2017. A sum of 45 UTI patients and 20 control group was collected. Results: The study showed that UTI increased in female than in male with 62.2% and 37.8%, respectively, and high risk at age 30–49 years with 42.2%. The microorganisms identifid in this study were Escherichia coli (42.2%), followed by Enterobacter (8.9%), Pseudomonas and Klebsiella (6.7% for each), Proteus spp and Serratia spp (4.4% for each), and mixed culture (E. coli + Proteus and E. coli + Pseudomonas with 2.2% for each one). Conclusion: This study showed highly signifiant correlation between CRP and bacterial isolation.
Infection and Immunity, 2003
The gram-negative bacterium Escherichia coli is the leading cause of urinary tract infection. The interaction between type 1 piliated E. coli and bladder epithelial cells leads to the rapid production of inflammatory mediators, such as interleukin-6 (IL-6) and IL-8. Conflicting reports have been published in the literature regarding the mechanism by which uroepithelial cells are activated by type 1 piliated E. coli. In particular, the role of lipopolysaccharide (LPS) in these responses has been an area of significant debate. Much of the data arguing against LPS-mediated activation of bladder epithelial cells have come from studies using a renal epithelial cell line as an in vitro model of the urinary epithelium. In this report, we analyzed three bladder epithelial cell lines and demonstrated that they all respond to LPS. Furthermore, the LPS responsivity of the cell lines directly correlated with their ability to generate IL-6 after E. coli stimulation. The LPS receptor complex utilized by the bladder epithelial cell lines included CD14 and Toll-like receptors, and signaling involved the activation of NF-B and p38 mitogen-activated protein kinase. Also, reverse transcription-PCR analysis demonstrated that bladder epithelial cells express CD14 mRNA. Thus, the molecular machinery utilized by bladder epithelial cells for the recognition of E. coli is very similar to that described for traditional innate immune cells, such as macrophages. In contrast, the A498 renal epithelial cell line did not express CD14, was hyporesponsive to LPS stimulation, and demonstrated poor IL-6 responses to E. coli.
Bactofection with Toll-Like Receptor 4 in a Murine Model of Urinary Tract Infection
Current Microbiology, 2011
The role of innate immunity in the prevention of urinary tract infection is well-documented. Toll-like receptor 4 (TLR4) is a major determinant of innate immune response. In an animal model of urinary tract infection, bactofection-mediated gene transfer of TLR4 was tested in a preventive approach. Bactofection with TLR4 reduced the colonization with uropathogenic Escherichia coli by 91% in the kidney and by 41% in the bladder. Reduced colonization was associated with lower oxidative stress and expression of monocyte chemoattractant protein-1 and myeloperoxidase in the kidney. Bactofection with TLR4 was successful in the prevention of ascending pyelonephritis. Further studies should focus on long-term effects, the dose response and the potential therapeutic use in models of chronic urinary tract infection.
The Journal of infectious diseases, 2015
CD14, a co-receptor for several pattern recognition receptors and a widely used monocyte/macrophage marker, plays a key role in host responses to Gram-negative bacteria. Despite its central role in the inflammatory response to lipopolysaccharide and other microbial products, and in dissemination of bacteria in some infections, the signaling networks controlled by CD14 during urinary tract infection (UTI) are unknown. We used uropathogenic Escherichia coli (UPEC) infection of wild-type (WT) C57BL/6 and Cd14-deficient mice and RNA-sequencing (RNA-seq) to define the CD14-dependent transcriptional signature, and role of CD14, in host defense against UTI in the bladder. UPEC-induced the up-regulation of Cd14 and monocyte/macrophage related genes Emr1/F4/80 and Csf1r/c-fms, which was associated with lower UPEC burdens in WT compared to Cd14-deficient mice. Exacerbation of infection in Cd14-deficient mice was associated with the absence of a 491-gene transcriptional signature in the bla...