Genotypic and phenotypic characterisation of asymptomatic bacteriuria (ABU) isolates displaying bacterial interference against multi-drug resistant uropathogenic E. Coli.

Escherichia coli can colonise the urogenital tract of individuals without causing symptoms of infection, in a condition referred to as asymptomatic bacteriuria (ABU). ABU isolates can protect the host against symptomatic urinary tract infections (UTIs) by bacterial interference against uropathogenic E. coli (UPEC). The aim of this study was to investigate the genotypic and phenotypic characteristics of five ABU isolates from midstream urine samples of adults. Comparative genomic and phenotypic analysis was conducted including an antibiotic resistance profile, pangenome analysis, and a putative virulence profile. Based on the genome analysis, the isolates consisted of one from phylogroup A, three from phylogroup B2, and one from phylogroup D. Two of the isolates, PUTS 58 and SK-106-1, were noted for their lack of antibiotic resistance and virulence genes compared to the prototypic ABU strain E. coli 83,972. This study provides insights into the genotypic and phenotypic profiles of uncharacterised ABU isolates, and how relevant fitness and virulence traits can impact their potential suitability for therapeutic bacterial interference.

Efficacy and safety of preventing catheter-associated urinary tract infection by inhibiting catheter bacterial biofilm formation: a multicenter randomized controlled trial.

BACKGROUND: Catheter-associated urinary tract infection (CAUTI) remains the most significant challenge among hospital-acquired infections (HAIs), yet still unresolved. The present study aims to evaluate the preventive effectiveness of JUC Spray Dressing (name of U.S. FDA and CE certifications, while the medical device name in China is Long-acting Antimicrobial Material) alone for CAUTI without combining with antibiotics and to evaluate the impact of bacterial biofilm formation on CAUTI results on the inserted catheters of patients. METHODS: In this multicenter, randomized, double-blind study, we enrolled adults who suffered from acute urinary retention (AUR) and required catheterization in 6 hospitals in China. Participants were randomly allocated 1:1 according to a random number table to receive JUC Spray Dressing (JUC group) or normal saline (placebo group). The catheters were pretreated with JUC Spray Dressing or normal saline respectively before catheterization. Urine samples and catheter samples were collected after catheterization by trial staff for further investigation. RESULTS: From April 2012 to April 2020, we enrolled 264 patients and randomly assigned them to the JUC group (n = 132) and the placebo group (n = 132). Clinical symptoms and urine bacterial cultures showed the incidence of CAUTI of the JUC group was significantly lower than the placebo group (P < 0.01). In addition, another 30 patients were enrolled to evaluate the biofilm formation on catheters after catheter insertion in the patients' urethra (10 groups, 3 each). The results of scanning electron microscopy (SEM) showed that bacterial biofilm formed on the 5th day in the placebo group, while no bacterial biofilm formed on the 5th day in the JUC group. In addition, no adverse reactions were reported using JUC Spray Dressing. CONCLUSION: Continued indwelling urinary catheters for 5 days resulted in bacterial biofilm formation, and pretreatment of urethral catheters with JUC Spray Dressing can prevent bacterial biofilm formation by forming a physical antimicrobial film, and significantly reduce the incidence of CAUTI. This is the first report of a study on inhibiting bacterial biofilm formation on the catheters in CAUTI patients.

Distribution of chaperone-usher fimbriae and curli fimbriae among uropathogenic Escherichia coli.

BACKGROUND: In the present study, we aimed to determine the frequency of the csgA, fimH, mrkD, foc, papaGI, papGII and papGIII genes, to provide and to design fimbrial adhesin gene (FAG) patterns and profiles for the isolated uropathogenic Escherichia coli (UPEC) strains. METHODS: The enrollment of 108 positive urine samples was performed during seven months, between January 2022 and July 2022. The UPEC strains were confirmed through the standard microbiological and biochemical tests. The antimicrobial susceptibility test was performed through the Kirby-Bauer disc diffusion method. Molecular screening of FAGs was done through the polymerase chain reaction technology. The statistical analyses including chi square and Fisher's exact tests were performed to interpret the obtained results in the present study. RESULTS: As the main results, the antimicrobial resistance (AMR) patterns, multi- (MDR) and extensively drug-resistance (XDR) patterns and FAG patterns were designed and provided. fimH (93.3%), csgA (90.4%) and papG (37.5%) (papGII (30.8%)) genes were recognized as the top three FAGs, respectively. Moreover, the frequency of csgA-fimH gene profile was identified as the top FAG pattern (46.2%) among the others. The isolates bearing csgA-fimH gene profile were armed with a versatile of phenotypic AMR patterns. In the current study, 27.8%, 69.4% and 1.9% of the UPEC isolates were detected as extended-spectrum ß-lactamases (ESBLs) producers, MDR and XDR strains, respectively. CONCLUSIONS: In conclusion, detection, providing and designing of patterns and profiles in association with FAGs, AMR feature in UPEC strains give us an effective option to have a successful and influential prevention for both of UTIs initiation and AMR feature.

Development and evaluation of fermented milk with Lactobacillus acidophilus added to concentrated cranberry (Vaccinium macrocarpon) juice with the potential to minimize the recurrence of urinary tract infections.

Repeated urinary tract infections affect many people worldwide. A potential strategy to reduce the incidence of these infections is to consume probiotics and cranberry fruit regularly. In this context, this study aims to prepare fermented milk with Lactobacillus acidophilus La-5 added with concentrated cranberry juice in two concentrations (5 and 10 %, corresponding to C1 and C2 samples, respectively) and evaluate different technological aspects of the samples after production and during storage, and comparing with the control sample (C). The juice had pH 1.91, 70.09 % of solids, and total proanthocyanidins and A-type proanthocyanidins (PACs) values of 117.03 mg/100 g and 16.38 mg/100 g, respectively. The higher the juice content added to the product, the higher the acidity (1.4 and 2.6 g of lactic acid in 100 g, corresponding to C1 and C2 on day 1 (D1), respectively), the total proanthocyanidin content (1.96 and 4.01 mg/100 g on D1; and 1.31 and 3.05 mg/100 g on day 28 of storage (D28), corresponding to C1 and C2, respectively) and A-type proanthocyanidin (0.56 and 1.26 mg/100 g in Day 1; and 0.54 and 1.19 mg/100 g in D28, corresponding to C1 and C2, respectively), higher the values of the color parameters (L*a* and C*), and lower pH value, probiotic viability, and sensory acceptance. Furthermore, the rheological parameters demonstrated a stronger protein network due to the addition of cranberry. The new formulations, including samples C1 and C2, are alternatives as functional products, which regular consumption probably has the potential to minimize the recurrence of urinary tract infections.

Novel Fabrication of Bio-polymeric Nanogel Loaded with Nalidixic Acid Formulations for the Effective Prevention of Bacterial Pathogens Leading Urinary Tract Infection and Its Biosafety Evaluation.

Management of urinary tract infections (UTI) is a highly challenging process due to the biofilm-forming ability of human-pathogenic bacteria. Here, we designed to fabricate an effective nanogel with a combination of chitosan bio-polymer and nalidixic acid to prevent biofilm-forming bacterial pathogens. Chitosan-coated nalidixic acid nanogel (NA@CS) exhibits outstanding inhibition potential against bacterial strains. In vitro, anti-bacterial analysis methods (well diffusion, colony-forming assay, and anti-biofilm assay) were performed to study the bacterial inhibition potential of prepared nanogel, which reveals that NA@CS nanogel have greater inhibition potential against selected pathogens. The combination of nalidixic acid with chitosan biopolymer decreases the virulence and pathogenicity of biofilm-forming pathogens due to their ability to membrane phospholipids penetration. Furthermore, the fabricated NA@CS nanogel showed reliable in vitro bio-compatibility on L929 fibroblast cells and in vivo compatibility with Artemia salina animal model. Overall, the results demonstrate that NA@CS nanogel could be an effective therapeutic for treating urinary tract infections and urine bladder wound healing.

Investigating the interaction of zno nanoparticles with flagellum and fimbriae in multi-drug resistant uropathogenic bacteria encoding fli and fim genes.

Due to the increasing occurrence of drug resistant urinary tract infections (UTI) among children, there is a need to investigate alternative effective treatment protocols such as nanoparticles. Flagella and fimbriae are primary factors contributing the virulence of urinary tract infecting bacteria. The aim of this study was to assess the antibacterial effects of zinc oxide nanoparticles which have been synthesized using both chemical and green methods on multi-drug resistant (MDR) uropathogenic bacteria encoding fli and fim genes and investigating their binding ability to bacterial appendage proteins. A total of 30 urine culture samples were collected from children under 2 years old diagnosed with urinary tract infection. The isolates underwent antibiotic suseptibility assessment and the isolates demonstrating MDR were subjected to molecular amplification of fimG (fimbrial) and fliD and fliT (flagellal) genes. The confirmation of cellular appendages was achieved through silver nitrate staining. The antibacterial efficacy of the synthetized nanoparticles was assessed using the micro and macrodilution methods. The successful binding of nanoparticles to bacterial appendage proteins was confirmed through mobility shift and membrane filter assays. The dimensions of chemically synthesized ZnO nanoparticles and green nanoparticles were measured at 30 nm and 85 nm, respectively, with the exhibition of hexagonal geometries. The nanoparticles synthesized through chemical and green methods exhibited minimum inhibitory concentrations (MIC) of 0.0062-0.025 g/L and 0.3 g/L, respectively. The ability of ZnO nanoparticles to bind bacterial appendage proteins and to combat MDR uropathogenic bacteria are promising for new treatment protocols against UTI in children in future.

The role of bacterial size, shape and surface in macrophage engulfment of uropathogenic E. coli cells.

Uropathogenic Escherichia coli (UPEC) can undergo extensive filamentation in the host during acute urinary tract infections (UTIs). It has been hypothesised that this morphological plasticity allows bacteria to avoid host immune responses such as macrophage engulfment. However, it is still unclear what properties of filaments are important in macrophage-bacteria interactions. The aim of this work was to investigate the contribution of bacterial biophysical parameters, such as cell size and shape, and physiological parameters, such as cell surface and the environment, to macrophage engulfment efficiency. Viable, reversible filaments of known lengths and volumes were produced in the UPEC strain UTI89 using a variety of methods, including exposure to cell-wall targeting antibiotics, genetic manipulation and isolation from an in vitro human bladder cell model. Quantification of the engulfment ability of macrophages using gentamicin-protection assays and fluorescence microscopy demonstrated that the ability of filaments to avoid macrophage engulfment is dependent on a combination of size (length and volume), shape, cell surface and external environmental factors. UTI89 filamentation and macrophage engulfment efficiency were also found to occur independently of the SOS-inducible filamentation genes, sulA and ymfM in both in vivo and in vitro models of infection. Compared to filaments formed via antibiotic inhibition of division, the infection-derived filaments were preferentially targeted by macrophages. With several strains of UPEC now resistant to current antibiotics, our work identifies the importance of bacterial physiological and morphological states during infection.

Urinary tract infection among people living with human immunodeficiency virus attending selected hospitals in Addis Ababa and Adama, central Ethiopia.

Background: Urinary tract infections (UTIs) and antibacterial resistance (ABR) are important public health problems, but they are not well-studied among people living with human immunodeficiency virus (PLHIV) globally, especially in low-income countries. Therefore, it is important to regularly measure the extent of UTIs and ABR in the most susceptible populations. This study aimed to investigate the prevalence of UTIs, associated factors, bacterial causal agents, and their antibiotic susceptibility profile among PLHIV in central Ethiopia. Methods: A hospital-based cross-sectional study was conducted to recruit 688 PLHIV by a simple random sampling method. Background information was gathered through interviews, while clinical information was gathered from recent information sheets of patient charts using organized, pretested, and validated study tools. Midstream urine was collected aseptically and transported to the Microbiology Laboratory of Aklilu Lemma Institute of Pathobiology within 4 h of collection, maintaining its cold chain. Standard conventional microbial culture methods and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry were used to identify the bacterial isolates at the species level. Kirby Bauer's disk diffusion method was used to determine the antibiotic susceptibility profile of the bacterial isolates based on the interpretation guidelines of the Clinical Laboratory Standard Institute. Logistic regression models were used to examine factors associated with the occurrence of UTIs among PLHIV attending selected hospitals in Addis Ababa, and Adama. Results: Out of 688 PLHIVs involved in the current study, 144 (20.9%) were positive for UTIs, whereas the majority were asymptomatic for UTIs. In the multivariable logistic regression analysis, only HIV RNA ≥ 200 copies/ml [AOR = 12.24 (95% CI, 3.24, 46.20), p < 0.01] and being symptomatic for UTIs during the study period [AOR = 11.57 (95% CI, 5.83, 22.97), p < 0.01] were associated with the occurrence of UTIs. The dominant bacterial species isolated were Escherichia coli (E. coli; n = 65; 43%), followed by Enterococcus faecalis (E. faecalis; n = 16; 10.6%) and Klebsiella pneumoniae (K. pneumoniae; n = 11; 7.3%). Over half of the E. coli isolates were resistant to antibiotics such as gentamicin (GM; n = 44; 67.7%), amikacin (AN; n = 46; 70.8%), nalidixic acid (NA; n = 42; 64.6%), ciprofloxacin (CIP; n = 40; 61.5%), and azithromycin (AZM; n = 45; 69.2%). All of the K. pneumoniae isolates (n = 11; 100%), (n = 6; 54.5%), and (n = 7; 63.6%) were resistant to [amoxicillin as well as amoxicillin + clavulanic acid], ceftriaxone, and sulfamethoxazole + trimethoprim, respectively. All the Staphylococcus aureus (S. aureus) isolates were resistant to cefoxitin, which implies methicillin-resistant S. aureus (MRSA). Conclusion: The high prevalence of UTIs and antibiotic resistance revealed in the current study needs public health interventions such as educating the population about preventive measures and the importance of early treatment of UTIs. Our findings also highlight the need to provide UTI screening services for PLHIV, and healthcare providers should adopt antibiotic stewardship programs to promote and ensure their appropriate and judicious use.

Pathogenic Bacteria and Antimicrobial Resistance in Hospital-Acquired Urinary Tract Infections among Patients with Diabetic Nephropathy.

OBJECTIVE: Hospital-acquired urinary tract infections (UTIs) are common complications in patients with diabetic nephropathy (DN), leading to increased mortality and increased medical resource utilisation. This study investigated hospital-acquired UTIs in patients with DN, focusing on prevalent pathogens and drug resistance to inform clinical management. METHODOLOGY: This retrospective study analysed 141 patients with hospital-acquired UTIs admitted to The Affiliated Hospital of Qingdao University from January 1, 2013 to December 31, 2022, using the Yidu Cloud database. Among them, 109 had DN, and 32 had nondiabetic nephropathy (NDN). Patient demographics, pathogen distribution, and antibiotic resistance were statistically evaluated. RESULTS: The incidence of hospital-acquired UTIs was significantly higher in patients with DN compared to those with NDN (p < 0.0001), with a higher prevalence in women (p = 0.004). Gram-negative bacteria, particularly Escherichia coli (E. coli) and Klebsiella pneumoniae, were the primary pathogens in patients with DN and NDN. E. coli infections were more common in the DN group (p = 0.017). These pathogens exhibited high susceptibility to carbapenems, ß-lactamase inhibitors, amikacin, nitrofurantoin, and minocycline; However, they showed significant resistance to quinolones, cephalosporin, and penicillins. CONCLUSIONS: Preventing hospital-acquired UTIs in patients with DN is crucial. Effective treatment requires selecting antibacterial drugs based on pathogen resistance profiles.

Conformational ensembles in Klebsiella pneumoniae FimH impact uropathogenesis.

Klebsiella pneumoniae is an important pathogen causing difficult-to-treat urinary tract infections (UTIs). Over 1.5 million women per year suffer from recurrent UTI, reducing quality of life and causing substantial morbidity and mortality, especially in the hospital setting. Uropathogenic E. coli (UPEC) is the most prevalent cause of UTI. Like UPEC, K. pneumoniae relies on type 1 pili, tipped with the mannose-binding adhesin FimH, to cause cystitis. However, K. pneumoniae FimH is a poor binder of mannose, despite a mannose-binding pocket identical to UPEC FimH. FimH is composed of two domains that are in an equilibrium between tense (low-affinity) and relaxed (high-affinity) conformations. Substantial interdomain interactions in the tense conformation yield a low-affinity, deformed mannose-binding pocket, while domain-domain interactions are broken in the relaxed state, resulting in a high-affinity binding pocket. Using crystallography, we identified the structural basis by which domain-domain interactions direct the conformational equilibrium of K. pneumoniae FimH, which is strongly shifted toward the low-affinity tense state. Removal of the pilin domain restores mannose binding to the lectin domain, thus showing that poor mannose binding by K. pneumoniae FimH is not an inherent feature of the mannose-binding pocket. Phylogenetic analyses of K. pneumoniae genomes found that FimH sequences are highly conserved. However, we surveyed a collection of K. pneumoniae isolates from patients with long-term indwelling catheters and identified isolates that possessed relaxed higher-binding FimH variants, which increased K. pneumoniae fitness in bladder infection models, suggesting that long-term residence within the urinary tract may select for higher-binding FimH variants.

Exploring the clinical and diagnostic value of metagenomic next-generation sequencing for urinary tract infection: a systematic review and meta-analysis.

BACKGROUND: A new pathogen detection tool, metagenomic next-generation sequencing (mNGS), has been widely used for infection diagnosis, but the clinical and diagnostic value of mNGS in urinary tract infection (UTI) remains inconclusive. This systematic review with meta-analysis aimed to investigate the efficacy of mNGS in treating UTIs. METHODS: A comprehensive literature search was performed in PubMed, Web of Science, Embase, and the Cochrane Library, and eligible studies were selected based on the predetermined criteria. The quality of the included studies was assessed via the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool, and the certainty of evidence (CoE) was measured by the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) score. Then, the positive detection rate (PDR), pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve of the summary receiver operating characteristic curve (AUROC) was estimated in Review Manager, Stata, and MetaDisc. Subgroup analysis, meta-regression, and sensitivity analysis were performed to reveal the potential factors that influence internal heterogeneity. RESULTS: A total of 17 studies were selected for further analysis. The PDR of mNGS was markedly greater than that of culture (odds ratio (OR) = 2.87, 95% confidence interval [CI]: 1.72-4.81, p < 0.001, I2 = 90%). The GRADE score presented a very low CoE. Then, the pooled sensitivity was 0.89 (95% CI: 0.86-0.91, I2 = 39.65%, p = 0.06), and the pooled specificity was 0.75 (95% CI: 0.51-0.90, I2 = 88.64%, p < 0.001). The AUROC of the studies analyzed was 0.89 (95% CI: 0.86-0.92). The GRADE score indicated a low CoE. CONCLUSION: The current evidence shows that mNGS has favorable diagnostic performance for UTIs. More high-quality prospective randomized controlled trials (RCTs) are expected to verify these findings and provide more information about mNGS in UTI treatment and prognosis.

Extensive thigh pyomyositis secondary to cystic fistulae due to anaerobic-bacterial infection in a kidney transplant recipient.

BACKGROUND: Managing infectious complications after kidney transplantation (KT) remains a major challenge. Infections are the leading non-cardiovascular cause of death among kidney transplant recipients (KTr). The urinary tract is particularly vulnerable to infections in this group, leading to high levels of morbidity and mortality, as well as significant economic costs. CASE PRESENTATION: This case report presents the first documented instance of extensive thigh pyomyositis resulting from cystic fistulae in an 84-year-old KTr. The patient was referred to our hospital with acute onset fever, pain in the inner thighs and pyuria. A CT scan revealed bilateral pyomyositis of the thighs, characterized by multiple abscesses in the adductor muscles and hydroaerobic levels. Additionally, cystic fistulae complicated by pubic symphysis osteitis were identified. CONCLUSION: In KTr, lower limb pyomyositis resulting from a urinary tract infection is an extremely rare and significantly worsens the overall prognosis for these patients.

In vitro-antibacterial properties of ten medicinal plants against common uropathogenic organisms and toxicity determination using brine shrimp lethality assay.

BACKGROUND: In recent years, antibiotic resistance has emerged as a global health concern in bacterial infections such as urinary tract infections (UTIs). Uropathogenic Escherichia coli is the most frequent organism responsible for both simple and complex UTIs. Staphylococcus aureus and Pseudomonas aeruginosa are frequently associated with complicated UTIs. Sri Lanka has significant resources of medicinal plants used to cure UTIs in Ayurvedic and traditional medicine. METHODS: Agar well diffusion and broth microdilution methods were used to determine the antibacterial activity of the methanolic extract of ten medicinal plants against P. aeruginosa ATCC27853, S.aureus ATCC25923, E.coli ATCC25922 and their UTI positive strains extracted from positive culture plates. As a preliminary toxicity assay, the Brine Shrimp Lethality Assay (BSLA) was used to determine its cytotoxicity. RESULTS: The methanolic fruits extract of P. emblica demonstrated the highest antibacterial activity against both E. coli ATCC25922 and E. coli UTI-positive strains. B. diffusa roots extract exhibited the highest activity against S. aureus ATCC25923, while T. chebula fruits extract showed the highest activity against the S. aureus UTI-positive strain. T. involucrata roots extract displayed the highest activity against P. aeruginosa ATCC27853, and Z. officinale rhizomes extract showed the highest activity against the P. aeruginosa UTI-positive strain. Moreover, the plant mixture showed the most substantial antibacterial effect against P. aeruginosa ATCC27853. However, the methanolic seed extract of C. melo did not exhibit any antimicrobial effects against the selected organisms. All plant material, including the plant mixture, showed cytotoxicity according to the BSLA. CONCLUSION: All the methanolic extracts including P. emblica fruits, O. tenuiflorum whole plant, T. chebula fruits, Z. officinale rhizome, T. terrestris roots, T. involucrata roots, A. lanata whole plant. B. diffusa roots and A. falcatus roots showed antimicrobial effects against selected strains except C. melo seed extract. The results of the present study evidently supports the traditional and ayurvedic use of these plants for the treatment of UTIs. This paves the way for another praise for new plant-based therapeutic product development for the treatment of UTIs. However, further toxicity studies are needed for medicinal dose determination.

Carbapenem-resistant Acinetobacter baumannii (CRAB): metabolic adaptation and transcriptional response to human urine (HU).

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a major human pathogen and a research priority for developing new antimicrobial agents. CRAB is a causative agent of a variety of infections in different body sites. One of the manifestations is catheter-associated urinary tract infection, which exposes the bacteria to the host's urine, creating a particular environment. Exposure of two CRAB clinical isolates, AB5075 and AMA40, to human urine (HU) resulted in the differential expression levels of 264 and 455 genes, respectively, of which 112 were common to both strains. Genes within this group play roles in metabolic pathways such as phenylacetic acid (PAA) catabolism, the Hut system, the tricarboxylic acid (TCA) cycle, and other processes like quorum sensing and biofilm formation. These results indicate that the presence of HU induces numerous adaptive changes in gene expression of the infecting bacteria. These changes presumably help bacteria establish and thrive in the hostile conditions in the urinary tract. These analyses advance our understanding of CRAB's metabolic adaptations to human fluids, as well as expand knowledge on bacterial responses to distinct human fluids containing different concentrations of human serum albumin (HSA).

Effect of Diabetes Mellitus on the Spectrum of Uropathogens and the Antimicrobial Resistance in Patients with Urinary Tract Infection.

Patients with diabetes mellitus frequently experience urinary tract infections (UTIs). In the present study, we looked at how glycemic control affects diabetic patients' rates of UTI, the causing pathogens, the presence of multi-drug-resistant (MDR) and extensively drug-resistant organisms, and the infections' relation to diabetes. Diabetes patients' midstream urine samples were included, after collecting and identifying the organisms, disc diffusion antibiotic sensitivity tests were conducted. The HbA1c was measured for all patients. A total of 500 diabetic patients provided urine samples for this study, and 189 (37.2%) of them had UTIs. Compared to 59 patients with managed glycemia, 130 individuals in the uncontrolled glycemic group experienced the most UTI cases. In both diabetic groups, females had a significantly higher prevalence of UTI than males (88.4% and 11.6%, respectively). The most common bacterial isolate, E. coli, displayed 58.4% MDR. Regardless of age or gender, glycemic control in diabetes patients is essential for decreasing UTI rates.

Adaptive evolution of carbapenem-resistant hypervirulent Klebsiella pneumoniae in the urinary tract of a single patient.

The emergence of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKp) is a growing concern due to its high mortality and limited treatment options. Although hypermucoviscosity is crucial for CR-hvKp infection, the role of changes in bacterial mucoviscosity in the host colonization and persistence of CR-hvKp is not clearly defined. Herein, we observed a phenotypic switch of CR-hvKp from a hypermucoviscous to a hypomucoviscous state in a patient with scrotal abscess and urinary tract infection (UTI). This switch was attributed to decreased expression of rmpADC, the regulator of mucoid phenotype, caused by deletion of the upstream insertion sequence ISKpn26. Postswitching, the hypomucoid variant showed a 9.0-fold decrease in mice sepsis mortality, a >170.0-fold reduction in the ability to evade macrophage phagocytosis in vitro, and an 11.2- to 40.9-fold drop in growth rate in normal mouse serum. Conversely, it exhibited an increased residence time in the mouse urinary tract (21 vs. 6 d), as well as a 216.4-fold boost in adhesion to bladder epithelial cells and a 48.7% enhancement in biofilm production. Notably, the CR-hvKp mucoid switch was reproduced in an antibiotic-free mouse UTI model. The in vivo generation of hypomucoid variants was primarily associated with defective or low expression of rmpADC or capsule synthesis gene wcaJ, mediated by ISKpn26 insertion/deletion or base-pair insertion. The spontaneous hypomucoid variants also outcompeted hypermucoid bacteria in the mouse urinary tract. Collectively, the ISKpn26-associated mucoid switch in CR-hvKp signifies the antibiotic-independent host adaptive evolution, providing insights into the role of mucoid switch in the persistence of CR-hvKp.

[Nine-year trend in Escherichia coli resistance to ciprofloxacin: cross-sectional study in a hospital in Colombia]. / Nueve años de tendencia en la resistencia a ciprofloxacina por Escherichia coli: estudio transversal en un hospital de Colombia.

Ciprofloxacin is a critically important antibiotic for human health. The increase of Escherichia coli resistance to ciprofloxacin is a global public health problem due to its importance in the treatment of complicated urinary tract infections and other serious infections; however, its prescription is high in the Colombian Caribbean. The objective was to determine the resistance trend of E. coli to ciprofloxacin in a Colombian hospital of high complexity. From antibiogram reports, isolates were categorized according to Clinical and Laboratory Standards Institute criteria for each year studied; proportions were calculated and differences in sensitivity were explored using the χ2 test. The Cochran-Armitage test was used to evaluate the resistance trend. Significance was considered when p-value ≤ 0.05. In total, 6,848 isolates were analyzed, and 49.31% resistance was found. According to origin, the highest resistance was in community samples (51.96% - 95%CI: 50.51; 53.41), and by type of sample, in skin and tissues (61.76% - 95%CI: 56.96; 66.35) and urine (48.97% - 95%CI: 47.71; 50.23). Increasing trends were observed for resistance per year (p < 0.0001), community samples (p = 0.0002) and urine (p < 0.0001). Resistance to ciprofloxacin is high and tends to increase in the community and in urine, exceeding the limit established for its use at the ambulatory level, which is of concern due to the high prescription of fluoroquinolones in the locality.

La ciprofloxacina es un antibiótico de importancia crítica para la salud humana. El aumento de la resistencia de Escherichia coli a ciprofloxacina es un problema de salud pública global por su importancia en el tratamiento de infecciones urinarias complicadas y otras infecciones graves; sin embargo, su prescripción es alta en el caribe colombiano. El objetivo fue determinar la tendencia de resistencia de E. coli a ciprofloxacina en un hospital colombiano de alta complejidad. A partir de reportes de antibiogramas, los aislados fueron categorizados según los criterios del Instituto de Normas Clínicas y de Laboratorio de los Estados Unidos para cada año estudiado; se calcularon proporciones y se exploraron diferencias en la sensibilidad con pruebas χ2. Se utilizó la prueba de Cochran-Armitage para evaluar la tendencia de la resistencia. Valores de p ≤ 0,05 se consideraron significativos. Se analizaron 6.848 aislados, encontrándose una resistencia de 49,31%. Según el origen, la resistencia más alta fue en muestras comunitarias (51,96% - IC95%: 50,51; 53,41), y por tipo de muestra, en piel y tejidos (61,76% - IC95%: 56,96; 66,35) y orina (48,97% - IC95%: 47,71; 50,23). Se halló una tendencia al aumento en la resistencia por año (p < 0,0001), en muestras comunitarias (p = 0,0002) y en orina (p < 0,0001). La resistencia a ciprofloxacina es alta y tiende al aumento en comunidad y en orina, superando el límite establecido para su uso a nivel ambulatorio, lo que es preocupante por la alta prescripción de fluoroquinolonas en la localidad.

A ciprofloxacina é um antibiótico extremamente importante para a saúde humana. O aumento da resistência da Escherichia coli à ciprofloxacina é um problema de saúde pública global devido à sua importância no tratamento de infecções complicadas do trato urinário e outras infecções graves; no entanto, sua prescrição é alta no caribe colombiano. O objetivo foi determinar a tendência de resistência da E. coli à ciprofloxacina em um hospital colombiano de alta complexidade. A partir de relatórios de antibiogramas, os isolados foram categorizados de acordo com os critérios do Instituto de Padrões Clínicos e Laboratoriais dos Estados Unidos para cada ano estudado; as proporções foram calculadas e as diferenças de sensibilidade foram exploradas com os testes χ2. O teste de Cochran-Armitage foi usado para avaliar a tendência de resistência. Os valores de p ≤ 0,05 foram considerados significativos. Um total de 6.848 isolados foi testado e foi encontrada uma taxa de resistência de 49,31%. Por origem, a resistência foi mais alta em amostras comunitárias (51,96% - IC95%: 50,51; 53,41) e, por tipo de amostra, em pele e tecidos (61,76% - IC95%: 56,96; 66,35) e urina (48,97% - IC95%: 47,71; 50,23). Foi encontrada uma tendência de aumento na resistência por ano (p < 0,0001), em amostras da comunidade (p = 0,0002) e na urina (p < 0,0001). A resistência à ciprofloxacina é alta e tende a aumentar na comunidade e na urina, excedendo o limite estabelecido para uso ambulatorial, o que é preocupante, dada a alta prescrição de fluoroquinolonas na localidade.

The bacterial displacement test: an in vitro microbiological test for the evaluation of intermittent catheters and urinary tract infection.

AIMS: Intermittent catheters (ICs) are commonly used in bladder management, but catheter-associated urinary tract infections (CAUTIs) remain challenging. Insertion tips may reduce the risk of CAUTIs by minimizing bacterial transfer along the urinary tract. However, there are few laboratory tests to evaluate such technologies. We describe the use of an adapted in vitro urethra agar model to assess bacterial displacement by ICs. METHODS AND RESULTS: Simulated urethra agar channels (UACs) were prepared with catheter-specific sized channels in selective media specific to the challenge organisms. UACs were inoculated with Escherichia coli and Enterococcus faecalis before insertion of ICs, and enumeration of UAC sections was performed following insertion. Four ICs were evaluated: Cure Catheter® Closed System (CCS), VaPro Plus Pocket™, Bard® Touchless® Plus, and SpeediCath® Flex Set. CCS demonstrated significantly reduced bacterial displacement along the UACs compared to the other ICs and was also the only IC with undetectable levels of bacteria toward the end of the UAC (representing the proximal urethra). CONCLUSION: The bacterial displacement test demonstrated significant differences in bacterial transfer between the test ICs with insertion tips, which may reflect their different designs. This method is useful for evaluating CAUTI prevention technology and may help guide future technology innovations.