Impact of Proinflammatory Cytokines on the Virulence of Uropathogenic Escherichia coli

Comprehensive analysis of multiple cytokines to stratify uropathogenic Escherichia coli pathogenesis in mouse model of urinary tract infection

PURPOSE

Urinary tract infection (UTI) is one of the most common human bacterial infections primarily caused by uropathogenic E. coli (UPEC). Empiric treatment in UTI cause emergence of multidrug resistance and limit treatment options. Understanding UTI at the molecular level with respect to the causative pathogen as well as subsequent host response pose an absolute necessity towards appropriate clinical management. This study aimed to investigate host cytokine response in mouse UTI model with respect to bacterial colonization and associated virulence gene expression upon infection.

METHOD

Mouse UTI model was established with two clinical UPEC isolates E. coli NP105 and E. coli P025. UPEC colonization in bladder and kidney was evaluated by bacterial culture (CFU/ml). Histopathology of the tissues were examined by hematoxylin and eosin staining. PCR and real time PCR were used to detect the incidence and expression of respective bacterial genes. Cytokine concentrations in tissues and sera were evaluated using ELISA. GraphPad prism version 8.0.2 was used for statistical interpretation.

RESULT

Highest bacterial colonization was observed on 7th and 9th day post infection (p.i). in bladder and kidney of mouse infected with E. coli P025 and E. coli NP105 respectively with a distinct difference in relative expression of fimH and papC adhesin genes in vivo. IL-1β level in tissues and sera of E. coli NP105 and E. coli P025 infected mouse was significantly different but the IL-17A, GCSF, TGF-β levels were comparable.

CONCLUSION

These findings show a role of IL1β to stratify pathogenicity of UPEC in mouse UTI model.

Testosterone increases the virulence traits of uropathogenic Escherichia coli

Uropathogenic Escherichia coli (UPEC) is the most common cause of urinary tract infections (UTIs) in humans. Testosterone negatively impacts UTIs by affecting the immune response, leading to higher susceptibility of chronic cystitis in individuals with elevated testosterone levels, regardless of gender. Current research is mostly focused on how testosterone affects the host response to UPEC, but not so much is known about how testosterone directly affect UPEC virulence. The aim of the present study was to investigate the impact of testosterone exposure on the virulence of UPEC. We found that testosterone directly increases UPEC growth, endotoxin release and biofilm formation. We also found that testosterone-stimulated CFT073 increased colonization and invasion of bladder epithelial cells. Testosterone-stimulated CFT073 also increased the release of IL-1β and LDH from bladder epithelial cells. Additionally, by using a Caenorhabditis elegans survival assay we also showed that testosterone decreased the survival of CFT073 infected C. elegans worms. Taken together, our findings show that testosterone directly increases the virulence traits of UPEC.

The Role of NLRP3 in Regulation of Antimicrobial Peptides and Estrogen Signaling in UPEC-Infected Bladder Epithelial Cells

The NLRP3 inflammasome, estrogen and antimicrobial peptides have all been found to have a vital role in the protection of the bladder urothelium. However, the interdependence between these protective factors during a bladder infection is currently unknown. Our aim was to investigate the role of NLRP3 in the regulation of antimicrobial peptides and estrogen signaling in bladder epithelial cells during a UPEC infection. Human bladder epithelial cells and CRISPR/Cas9-generated NLRP3-deficient cells were stimulated with the UPEC strain CFT073 and estradiol. The gene and protein expression were evaluated with microarray, qRT-PCR, western blot and ELISA. Microarray results showed that the expression of most antimicrobial peptides was reduced in CFT073-infected NLRP3-deficient cells compared to Cas9 control cells. Conditioned medium from NLRP3-deficient cells also lost the ability to suppress CFT073 growth. Moreover, NLRP3-deficient cells had lower basal release of Beta-defensin-1, Beta-defensin-2 and RNase7. The ability of estradiol to induce an increased expression of antimicrobial peptides was also abrogated in NLRP3-deficient cells. The decreased antimicrobial peptide expression might be linked to the observed reduced expression and activity of estradiol receptor beta in NLRP3-deficient cells. This study suggests that NLRP3 may regulate the release and expression of antimicrobial peptides and affect estrogen signaling in bladder epithelial cells.

Antibacterial and Analgesic Properties of Beta-Caryophyllene in a Murine Urinary Tract Infection Model

Beta-caryophyllene has demonstrated anti-inflammatory effects in a variety of conditions, including interstitial cystitis. These effects are mediated primarily via the activation of the cannabinoid type 2 receptor. Additional antibacterial properties have recently been suggested, leading to our investigation of the effects of beta-caryophyllene in a murine model of urinary tract infection (UTI). Female BALB/c mice were intravesically inoculated with uropathogenic Escherichia coli CFT073. The mice received either beta-caryophyllene, antibiotic treatment using fosfomycin, or combination therapy. After 6, 24, or 72 h, the mice were evaluated for bacterial burden in the bladder and changes in pain and behavioral responses using von Frey esthesiometry. In the 24 h model, the anti-inflammatory effects of beta-caryophyllene were also assessed using intravital microscopy. The mice established a robust UTI by 24 h. Altered behavioral responses persisted 72 h post infection. Treatment with beta-caryophyllene resulted in a significant reduction in the bacterial burden in urine and bladder tissues 24 h post UTI induction and significant improvements in behavioral responses and intravital microscopy parameters, representing reduced inflammation in the bladder. This study demonstrates the utility of beta-caryophyllene as a new adjunct therapy for the management of UTI.

Application of metagenomic next-generation sequencing in the diagnosis of urinary tract infection in patients undergoing cutaneous ureterostomy

Objective

Urinary tract infection (UTI) is an inflammatory response of the urothelium to bacterial invasion and is a common complication in patients with cutaneous ureterostomy (CU). For such patients, accurate and efficient identification of pathogens remains a challenge. The aim of this study included exploring utility of metagenomic next-generation sequencing (mNGS) in assisting microbiological diagnosis of UTI among patients undergoing CU, identifying promising cytokine or microorganism biomarkers, revealing microbiome diversity change and compare virulence factors (VFs) and antibiotic resistance genes (ARGs) after infection.

Methods

We performed a case-control study of 50 consecutive CU patients from December 2020 to January 2021. According to the clinical diagnostic criteria, samples were divided into infected group and uninfected group and difference of urine culture, cytokines, microorganism, ARGs and VFs were compared between the two groups.

Results

Inflammatory responses were more serious in infected group, as evidenced by a significant increase in IFN-α (p=0.031), IL-1β (0.023) and IL-6 (p=0.018). Clinical culture shows that there is higher positive rate in infected group for most clinical pathogens like Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Candida auris etc. and the top three pathogens with positive frequencies were E. coli, K. pneumoniae, and Enterococcus faecalis. Benchmarking clinical culture, the total sensitivity is 91.4% and specificity is 76.3% for mNGS. As for mNGS, there was no significant difference in microbiome α- diversity between infected and uninfected group. Three species biomarkers including Citrobacter freundii, Klebsiella oxytoca, and Enterobacter cloacae are enriched in infected group based on Lefse. E. cloacae were significantly correlated with IL-6 and IL-10. K. oxytoca were significantly correlated with IL-1β. Besides, the unweighted gene number and weighted gene abundance of VFs or ARGs are significantly higher in infected group. Notablely, ARGs belonging to fluoroquinolones, betalatmas, fosfomycin, phenicol, phenolic compound abundance is significantly higher in infected group which may have bad effect on clinical treatment for patients.

Conclusion

mNGS, along with urine culture, will provide comprehensive and efficient reference for the diagnosis of UTI in patients with CU and allow us to monitor microbial changes in urine of these patients. Moreover, cytokines (IL-6, IL-1β, and IFN-a) or microorganisms like C. freundii, K. oxytoca or E. cloacae are promising biomarkers for building effective UTI diagnostic model of patients with CU and seriously the VFs and ARGs abundance increase in infected group may play bad effect on clinical treatment.

Battle royale: Immune response on biofilms – host-pathogen interactions

The research interest of the scientific community in biofilm-forming microorganisms is growing due to the problems caused by their infections affecting humans and animals, mainly because of the difficulty of the host immune system in eradicating these microbial complex communities and the increasing antimicrobial resistance rates worldwide. This review describes the virulence factors and their interaction with the microbial communities of four well-known and highly biofilm-forming pathogens, more exactly, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus spp., and Candida spp. The innate and adaptive immune responses caused by the infection with these microorganisms and their evasion to the host immune system by biofilm formation are discussed in the present work. The relevance of the differences in the expression of certain virulence factors and the immune response in biofilm-associated infections when compared to planktonic infections is usually described as the biofilm architecture protects the pathogen and alters the host immune responses, here we extensively discussed these mechanisms.

Interaction of Neutrophils and Biofilm Formed by Uropathogenic Escherichia coli Strains with Different Pathogenic Potential

The biofilm formation by uropathogenic E. coli (UPEC) allows bacteria to avoid the influence of the host immune system that determines the pathogenesis of persistent urinary tract infections. The purpose of this work was to evaluate the mutual influence of neutrophils and biofilms formed by UPEC with different set of virulence-associated genes (VAGs). E. coli R11 and R32 strains with a wide range of virulence factors were characterized by low biofilm biomass that did not change after interaction with neutrophils. The biomass index decreased after interaction with neutrophils for strains with a limited set of pathogenicity factors (R33, R36, R45, and R44) and a "thick" biofilm. Bacterial cells and biofilm supernatants of all UPEC strains reduced viability (DiOC₆(3)⁺/PI^-) and stimulated early apoptosis (DiOC₆(3)^-/PI^-) of neutrophils. The number of viable neutrophils was higher, while the number of apoptotic and necrotic (DiOC₆(3)^-/PI⁺) cells was lower under the action of supernatants of strains R44, R36, R45 in comparison with bacterial cells. Thus, modulation of the innate cell functions depends on the realization of the pathogenic potential of UPEC bacteria in urinary tract biofilms that determines the development of recurrent urinary tract infections.

Association between anti-seizure medication and the risk of lower urinary tract infection in patients with epilepsy

PURPOSE

The aim of this retrospective study was to analyze the incidence of lower urinary tract infections (LUTI) and antibiotic prescriptions within 12 months after initial prescription of anti-seizure medication (ASM) between January and December 2020 (index date) and to investigate the association between a broad spectrum of ASMs and the risk of LUTI in patients with epilepsy.

METHODS

This retrospective cohort study included a total of 9186 adult patients (≥18 years) with an initial diagnosis of epilepsy and a prescription of an ASM treated in 1284 general practices in Germany between January 2010 and December 2020 (index date). Six frequently prescribed ASMs with at least 1000 available patients were analyzed. Patients treated with one of six ASMs were matched to each other by propensity scores based on sex, age, and secondary diagnoses. Cox regression models were used to analyze the association between the use of ASM and LUTI risk.

RESULTS

The cumulative LUTI incidence 12 months after the start of therapy was highest in patients treated with pregabalin (16.7%), followed by valproate (11.6%) and gabapentin (10.2%). A similar trend was observed for LUTI with antibiotic prescription (9.2% pregabalin, 6.8% valproate, 6.8% gabapentin). Conditional regression analyses revealed that pregabalin therapy was significantly positively associated with LUTI (HR: 1.76; 95% CI 1.29-2.39) and LUTI-based antibiotic prescription (HR: 2.16; 95% CI 1.43-3.27). Carbamazepine was associated with a significantly lower incidence of LUTI in women (HR: 0.47; 95% CI: 0.30-0.75), but not in men. No significant associations were observed for other ASMs.

CONCLUSION

The present study identifies a significant positive association between ASM and LUTI incidence and antibiotic prescriptions in patients with epilepsy treated with pregabalin, whereas a protective effect was found for carbamazepine in women only. No significant associations were observed for the four remaining ASMs.

Gut bacteria, bacteriophages, and probiotics: Tripartite mutualism to quench the SARS-CoV2 storm

Patients with SARS-CoV-2 infection, exhibit various clinical manifestations and severity including respiratory and enteric involvements. One of the main reasons for death among covid-19 patients is excessive immune responses directed toward cytokine storm with a low chance of recovery. Since the balanced gut microbiota could prepare health benefits by protecting against pathogens and regulating immune homeostasis, dysbiosis or disruption of gut microbiota could promote severe complications including autoimmune disorders; we surveyed the association between the imbalanced gut bacteria and the development of cytokine storm among COVID-19 patients, also the impact of probiotics and bacteriophages on the gut bacteria community to alleviate cytokine storm in COVID-19 patients. In present review, we will scrutinize the mechanism of immunological signaling pathways which may trigger a cytokine storm in SARS-CoV2 infections. Moreover, we are explaining in detail the possible immunological signaling pathway-directing by the gut bacterial community. Consequently, the specific manipulation of gut bacteria by using probiotics and bacteriophages for alleviation of the cytokine storm will be investigated. The tripartite mutualistic cooperation of gut bacteria, probiotics, and phages as a candidate prophylactic or therapeutic approach in SARS-CoV-2 cytokine storm episodes will be discussed at last.

Effects of estradiol on the virulence traits of Porphyromonas gingivalis

Porphyromonas gingivalis has been strongly associated to active periodontitis sites. A number of studies have tried to elucidate the association between female steroid sex hormones and gingival health. However, until now, there is limited knowledge on estradiol effects on the virulence traits of P. gingivalis. The aim of the study was to investigate the impact of estradiol exposure on the virulence characteristics of P. gingivalis strain W50. We found that a pre- and postmenopausal concentration of estradiol increased the growth and biofilm formation of P. gingivalis W50. We also found that estradiol increased the release of lysine and arginine gingipains from W50. We then showed that IL-1β, CXCL10 and TGF-β1 release from gingival epithelial cells was significantly lowered by W50 pre-exposed to estradiol compared to W50 alone. Real time-qPCR showed that the gene expression of IL-18, IL-6, IL-8, TGF-β1 and NLRP3 in gingival epithelial cells was significantly lowered by W50 pre-exposed to estradiol compared to W50 alone. We also found that estradiol in a dose-dependent manner increased P. gingivalis colonization and invasion of gingival epithelial cells. Taken together, our findings show that estradiol has the ability to alter the virulence traits of P. gingivalis.

The role of uropathogenic Escherichia coli adhesive molecules in inflammatory response- comparative study on immunocompetent hosts and kidney recipients

Background

Urinary tract infections (UTI) represent one of the most common contagious diseases in humans. Uropathogenic Escherichia coli (UPEC) strains are recognized as the most frequent causative agent, and these express a range of virulence factors including the adhesins. Immune response to UPEC under immunosuppression has not been fully understood yet. Interleukin 1β (IL1β), 6 (IL6) and 17 (IL17) represent clinically relevant markers of inflammation.

Aim

The study aimed to investigate the interplay between UPEC genotype and hosts’ immune status in shaping local inflammatory response in the course of an UTI episode. The respective numbers of: 18 kidney recipients with UPEC UTI, 28 immunocompetent hosts with UPEC UTI and 29 healthy controls were involved. Urine IL1β, IL6, and IL17/creatinine ratios in relation to fimH, csgA, papC, tosA, and flu genes presence in UPEC isolated from the urine samples were analyzed. Apart from traditional statistics, also machine learning algorithms were applied.

Results

The urine levels of IL1β and IL 6 were similar in kidney recipients and the immunocompetent hosts. IL1β levels were higher in both kidney recipients and immunocompetent hosts than in controls, while IL6 levels were higher only in immunocompetent hosts than in controls. In the machine learning classification model, high urine IL17 levels were significantly more prevalent in controls, while low IL17 levels in urines infected with Ag43-positive UPEC strains, regardless of the host’s immune status. In the traditional statistical analysis, IL17 levels appeared significantly higher in urine samples from kidney recipients infected with Ag43–negative UPEC strains.

Conclusions

In the UTI- affected patients, the combination of the immune status of an individual and Ag43 status of the UPEC strain determined urine IL17 level in the analyzed group. However, IL17 levels above median were overall more prevalent in controls.

Adaptive strategies of uropathogenic Escherichia coli CFT073: from growth in lab media to virulence during host cell adhesion

Urinary tract infections (UTIs) are a major concern in public health. The prevalent uropathogenic bacterium in healthcare settings is Escherichia coli. The increasing rate of antibiotic-resistant strains demands studies to understand E. coli pathogenesis to drive the development of new therapeutic approaches. This study compared the gene expression profile of selected target genes in the prototype uropathogenic E. coli (UPEC) strain CFT073 grown in Luria Bertani (LB), artificial urine (AU), and during adhesion to host bladder cells by semi-quantitative real-time PCR (RT-PCR) assays. AU effectively supported the growth of strain CFT073 as well as other E. coli strains with different lifestyles, thereby confirming the appropriateness of this medium for in vitro models. Unexpectedly, gene expression of strain CFT073 in LB and AU was quite similar; conversely, during the adhesion assay, adhesins and porins were upregulated, while key global regulators were downregulated with respect to lab media. Interestingly, fimH and papGII genes were significantly expressed in all tested conditions. Taken together, these results provide for the first time insights of the metabolic and pathogenic profile of strain CFT073 during the essential phase of host cell adhesion.

Transcriptomic analyses and experimental verification reveal potential biomarkers and biological pathways of urinary tract infection

Urinary tract infection (UTI) is a common infectious disease. Urinary tract pathogenic Escherichia coli (UPEC) is the main cause of UTIs. At present, antibiotics are mainly used for the treatment of UTIs. However, with the increase of drug resistance, the course of the disease is prolonged. Therefore, identifying the receptors and signal pathways of host cells and tissues will further our understanding of the pathogenesis of UTIs and help in the development of new drug treatments. We used two public microarray datasets (GSE43790, GSE124917) in the Gene Expression Omnibus (GEO) database to identify differentially expressed genes (DEGs) between UTI and normal cell samples. A functional analysis based on Gene Ontology (GO) data, a pathway enrichment analysis based on Kyoto Encyclopedia of Genes and Genomes (KEGG) data and a protein-protein interaction analysis identified the main potential biomarkers and verified them in animal tissues. A total of 147 up-regulated genes and 40 down-regulated genes were identified. GO enrichment analysis showed that these functional changes relate to the terms response to lipopolysaccharide, regulation of cytokine production, and regulation of the inflammatory response. KEGG analysis indicated that urinary tract infections likely involve the TNF-αsignaling pathways. The 20 hub genes were selected from the protein-protein interaction network, and the highly significant hub genes were verified by animal experiments. Our findings provide potential targets for exploring new treatments for urinary tract infections. After a comprehensive analysis of the GEO database, these results may facilitate development of new diagnosis and treatment strategies for urinary tract infections.

Targeting of Uropathogenic Escherichia coli papG gene using CRISPR-dot nanocomplex reduced virulence of UPEC

Urinary tract infections (UTI) are the most common infectious diseases in the world. It is becoming increasingly tough to treat because of emergence of antibiotic resistance. So, there is an exigency to develop novel anti-virulence therapeutics to combat multi-drug resistance pathogenic strains. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) discovery has revolutionized the gene editing technology for targeted approach. The greatest obstacle for CRISPR/Cas9 is cargo delivery systems and both viral and plasmid methods have disadvantages. Here, we report a highly efficient novel CRISPR based gene editing strategy, CRISPR-dots for targeting virulence factor Fimbrial Adhesion (papG gene), the bacterial adhesion molecule. Carbon quantum dots (CQD) were used as a delivery vehicle for Cas9 and gRNA into CFT073, a UPEC strain. CQDs were covalently conjugated to cas9 and papG-targeted guide RNA (gRNA) forming a nanocomplex CRISPR-dots (Cri-dots) as confirmed by DLS and transmission electron microscopy. Cri-dots-papG significantly targeted papG as demonstrated by decrease in the expression of papG.Further papG deficient UPEC had significantly reduced adherence ability and biofilm forming ability as demonstrated by fluorescence microscopy and scanning electron microscopy. Also, papG deficient UPEC had reduced virulence as shown by significantly increased survival of Caenorhabditis elegans (C. elegans) worms compared to UPEC. Our findings suggest that targeting of papG gene using Cri-dots nanocomplexes significantly reduced the pathogenicity of UPEC. Thus, Cri-dots nanocomplex offer a novel anti-bacterial strategy against multi-drug resistant UPEC.

Influenza A virus infection in turkeys induces respiratory and enteric bacterial dysbiosis correlating with cytokine gene expression

Turkey respiratory and gut microbiota play important roles in promoting health and production performance. Loss of microbiota homeostasis due to pathogen infection can worsen the disease or predispose the bird to infection by other pathogens. While turkeys are highly susceptible to influenza viruses of different origins, the impact of influenza virus infection on turkey gut and respiratory microbiota has not been demonstrated. In this study, we investigated the relationships between low pathogenicity avian influenza (LPAI) virus replication, cytokine gene expression, and respiratory and gut microbiota disruption in specific-pathogen-free turkeys. Differential replication of two LPAI H5N2 viruses paralleled the levels of clinical signs and cytokine gene expression. During active virus shedding, there was significant increase of ileal and nasal bacterial contents, which inversely corresponded with bacterial species diversity. Spearman’s correlation tests between bacterial abundance and local viral titers revealed that LPAI virus-induced dysbiosis was strongest in the nasal cavity followed by trachea, and weakest in the gut. Significant correlations were also observed between cytokine gene expression levels and relative abundances of several bacteria in tracheas of infected turkeys. For example, interferon γ/λ and interleukin-6 gene expression levels were correlated positively with Staphylococcus and Pseudomonas abundances, and negatively with Lactobacillus abundance. Overall, our data suggest a potential relationship where bacterial community diversity and enrichment or depletion of several bacterial genera in the gut and respiratory tract are dependent on the level of LPAI virus replication. Further work is needed to establish whether respiratory and enteric dysbiosis in LPAI virus-infected turkeys is a result of host immunological responses or other causes such as changes in nutritional uptake.

Estradiol Alters the Virulence Traits of Uropathogenic Escherichia coli

Uropathogenic Escherichia coli (UPEC) is the most common bacteria to cause urinary tract infection (UTI). Postmenopausal women have an increased risk of recurrent UTI. This is partly explained by estrogenic effects on host defenses against UTI. Current research is mostly focused on how UPEC affects host factors, but not so much is known about how host factors like hormones affect UPEC virulence. The aim of the present study was to investigate the impact of estradiol exposure on the virulence of UPEC. We found that a postmenopausal concentration of estradiol increased CFT073 growth and biofilm formation, but not the premenopausal concentrations. Real-time qPCR showed that estradiol altered the expression of genes associated with the iron acquisition system and metabolic pathways in CFT073. We also found that estradiol in a dose-dependent manner increased the expression of fimH and papC adhesins and increased colonization and invasion of bladder epithelial cells. The premenopausal concentration of estradiol also suppressed cytokine release from bladder epithelial cells. Additionally, we also showed using a Caenorhabditis elegans killing assay that estradiol increased the survival of CFT073-infected C. elegans worms. Taken together, our findings show that estradiol has the ability to alter the virulence traits of UPEC.

Recurrent Urinary Tract Infection: A Mystery in Search of Better Model Systems

Urinary tract infections (UTIs) are among the most common infectious diseases worldwide but are significantly understudied. Uropathogenic E. coli (UPEC) accounts for a significant proportion of UTI, but a large number of other species can infect the urinary tract, each of which will have unique host-pathogen interactions with the bladder environment. Given the substantial economic burden of UTI and its increasing antibiotic resistance, there is an urgent need to better understand UTI pathophysiology - especially its tendency to relapse and recur. Most models developed to date use murine infection; few human-relevant models exist. Of these, the majority of in vitro UTI models have utilized cells in static culture, but UTI needs to be studied in the context of the unique aspects of the bladder's biophysical environment (e.g., tissue architecture, urine, fluid flow, and stretch). In this review, we summarize the complexities of recurrent UTI, critically assess current infection models and discuss potential improvements. More advanced human cell-based in vitro models have the potential to enable a better understanding of the etiology of UTI disease and to provide a complementary platform alongside animals for drug screening and the search for better treatments.

A Synthetic Peptide 2Abz23S29 Reduces Bacterial Titer and Induces Pro-Inflammatory Cytokines in a Murine Model of Urinary Tract Infection

Introduction

A urinary tract infection (UTI), which is often caused by uropathogenic E. coli (UPEC) strains, affects many people worldwide annually. UPEC causes the production of pro-inflammatory cytokines by the bladder epithelial cells; however, it has been proven that the UPEC can inhibit the early activation of the innate immune system.

Methods

This study aimed to examine the antibacterial and immunomodulatory effects of different doses of truncated alpha-defensins (human neutrophil peptide (HNP)-1) analog 2Abz²³S²⁹ on the mouse UTI model. Experimentally uropathogenic E. coli CFT073-infected mice were treated with low-dose 2Abz²³S²⁹ (250µg/mL), high-dose 2Abz²³S²⁹ (750µg/mL), ciprofloxacin (cip) (800µg/mL), or high-dose 2Abz²³S²⁹plus cip once a day 24 h post-infection. The 2Abz²³S²⁹ and cip treatment were given for two consecutive days.

Results

The in vivo results showed that fewer UPEC were recovered from the bladders of mice treated transurethrally with 2Abz²³S²⁹. Moreover, low-dose 2Abz²³S²⁹ significantly decreased the level of the interleukin-6 (IL-6), whereas high-dose 2Abz²³S²⁹ increased pro-inflammatory cytokines including IL-6, macrophage inflammatory protein/2 (MIP/2), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) in infected bladders of mice. Besides, the levels of cytokines IL-6 and MIP/2 in infected mice treated with a combination of high-dose 2Abz²³S²⁹ and cip were significantly higher than the untreated mice. In contrast, CFT073-infected mice treated with a combination of high-dose 2Abz²³S²⁹ and cip showed no changes in cytokines TNF-α and IL-1β levels, indicating that ciprofloxacin may play an anti-inflammatory role.

Conclusion

Collectively, apart from the direct antibacterial role of 2Abz²³S²⁹, our data illustrated that 2Abz²³S²⁹ modulates pro-inflammatory cytokine production of bladder in a dose-dependent manner, which has implications for the development of new anti-infective agents.