High Incidence of Antibiotic Resistance in the Uropathogenic Bacteria Associated with Different Urological Diseases and Metabolic Complications: A Single Center Cross-Sectional Study

Urological diseases affect all age groups and are associated with different urinary complications. Presence of pathogenic bacteria complicates the urological diseases such as chronic kidney disease (CKD), kidney stone disease (KSD), emphysematous pyelonephritis (EPN), and urological cancers (UCs) coinciding with urinary metabolic complications. The One Health concept for preventing the spread of antibiotic resistant opportunistic pathogens necessitates detailed investigation on the virulence and the antibiotic sensitivity patterns of the pathogens from the urinary tract infections (UTIs). This cross-sectional study was aimed to profile the pathogenic bacteria associated with different urological diseases that included urine samples from the patients from a tertiary care hospital. The study included 258 patients representing CKD (15.1%), KSD (28.7%), EPN (15.5%), UC (12.0%), and UTI patients without any urological diseases (28.7%) with overall 70.5% patients showing positive urine culture. Furthermore, other than UTI in patients without any urological diseases (100%), higher culture positive cases were seen in KSD (64.9%), followed by CKD (61.5%), EPN (52.5%), and UC (48.4%). Escherichia coli was the most predominant bacteria in UTI (35.1%) and EPN (66.7%). In KSD, Pseudomonas aeruginosa (41.7%), Staphylococcus aureus (18.8%), and Proteus mirabilis (14.6%) were more common. S. aureus (86.7%) was the most isolated bacteria from the UC cases. Overall rate of multidrug resistance (MDR) was 77.8%. All (100%) E. coli, K. pneumoniae, P. mirabilis, and S. aureus strains were MDR. Among the strains, strong biofilm formation was observed in 73.6%, and 66.7% strains were urease positive. Biofilm was positively correlated with MDR and urease activity. The abundance and distribution of bacteria differed among the urological diseases suggesting their association with the urine metabolite profile. Colonization of MDR pathogens in patients with urological diseases is a serious concern requiring steps to control the emergence of drug resistance and their further spread into the ecosystem.

Circulating metabolite biomarkers: a game changer in the human prostate cancer diagnosis

PURPOSE

Prostate cancer (PCa) is the second most commonly diagnosed cancer in men in Western and Asian countries. Serum prostate-specific antigen (PSA) test has been the routine diagnostic method despite the tremendous research in diagnostic markers for early detection of PCa. A shift towards a promising and potential biomarker for PCa detection is through metabolomic profiling of biofluids, particularly the blood and urine samples. Finding reliable, routinely usable circulating metabolite biomarkers may not be a distant reality.

METHODS

We performed a PubMed-based literature search of metabolite biomarkers in blood and urine for the early detection of prostate cancer. The timeline of these searches was limited between 2007 and 2022 and the following keywords were used: 'metabolomics', 'liquid biopsy', 'circulating metabolites', 'serum metabolite', 'plasma metabolite', and 'urine metabolite' with respect to 'prostate cancer'. We focussed only on diagnosis-based studies with only the subject-relevant articles published in the English language and excluded all of the other irrelevant publications that included prostate tissue biomarkers and cell line biomarkers.

RESULTS

We have consolidated all the blood and urine-based potential metabolite candidates in individual as well as panels, including lipid classes, fatty acids, amino acids, and volatile organic compounds which may become useful for PCa diagnosis.

CONCLUSION

All these metabolome findings unveil the impact of different dimensions of PCa development, giving a promising strategy to diagnose the disease since suspected individuals can be subjected to repeated and largescale blood and urine testing.

Functional outcome of robotic-assisted intracorporeal versus extracorporeal neobladder following radical cystectomy: Initial experience

Introduction:

Worldwide, the seventh most commonly diagnosed cancer in the male population is Bladder cancer (BC), while it drops to eleventh when both genders are considered. Radical cystectomy is the surgical treatment of choice for patients with all muscle-invasive and some nonmuscle invasive BCs. An orthotopic continent diversion (neobladder) is preferred whenever possible to achieve a better postoperative quality of life. We attempt to study the functional outcomes of intracorporeal neobladder (ICNB) versus extracorporeal neobladder (ECNB) (ICNB vs. ECNB).

Materials and Methods:

Forty patients who underwent robot-assisted radical cystectomy with neobladder in our institute during the period of March 2016–March 2018 were included in the study. An orthotopic neobladder (Studer method) was created in all our patients. Our main outcomes of interest were peak flow rates, residual urine, attainment of continence, and Pdet at qmax of the neobladder.

Results:

The mean age of patients in our study group was 54 ± 6 years. The mean body mass index was 23 ± 2 kg/m². The mean follow-up period was 24 ± 5 months. Twenty patients underwent ICNB and 20 patients underwent ECNB. The urodynamic assessment was done 1-year postprocedure. The same parameters applied to an intact bladder are used, and results analyzed by comparing it with other studies. Common in the initial postoperative period was incontinence which reduced substantially over time. After 1-year, 75% of patients did not require pads in the daytime, and a meager, <10% used more than one pad per day. There was no difference in outcome between both the groups, which was statistically significant.

Conclusion:

Both ICNB and ECNB groups achieved urodynamically proven values of adequate bladder capacity and compliance. Daytime continence was excellent, and night time continence was good in both groups. Furthermore, there was no significant difference between both the groups as regards to urodynamic parameters. However, continence is attained little earlier in the ICNB group. There is no perceived superiority of ICNB over ECNB.

Morphological characteristics and microstructure of kidney stones using synchrotron radiation μCT reveal the mechanism of crystal growth and aggregation in mixed stones

Understanding the mechanisms of kidney stone formation, development patterns and associated pathological features are gaining importance due to an increase in the prevalence of the disease and diversity in the presentation of the stone composition. Based on the microstructural characteristics of kidney stones, it may be possible to explain the differences in the pathogenesis of pure and mixed types of stones. In this study, the microstructure and distribution of mineral components of kidney stones of different mineralogy (pure and mixed types) were analyzed. The intact stones removed from patients were investigated using synchrotron radiation X-ray computed microtomography (SR-μCT) and the tomography slice images were reconstructed representing the density and structure distribution at various elevation planes. Infrared (IR) spectroscopes, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to confirm the bulk mineral composition in the thin section stones. Observations revealed differences in the micro-morphology of the kidney stones with similar composition in the internal 3-D structure. Calcium oxalate monohydrate stones showed well-organised layering patterns, while uric acid stones showed lower absorption signals with homogenous inner structure. Distinct mineral phases in the mixed types were identified based on the differential absorption rates. The 3-D quantitative analysis of internal porosity and spatial variation between nine different types of stones were compared. The diversity among the microstructure of similar and different types of stones shows that the stone formation is complex and may be governed by both physiological and micro-environmental factors. These factors may predispose a few towards crystal aggregation and stone growth, while, in others the crystals may not establish stable attachment and/or growth.

Anti-biofilm and cytoprotective activities of quercetin against Pseudomonas aeruginosa isolates

Increase in infection with multidrug resistant Pseudomonas aeruginosa is a serious global challenge in healthcare. Pseudomonas aeruginosa is capable of causing human infection in various sites and complicates the infection due to its virulence factors. This study was aimed to investigate the effect of quercetin, a dietary flavonoid against the virulence factors of P. aeruginosa and its cell protective effects on epithelial cells. Bactericidal activity, anti-biofilm activity and effect on different virulence factors were carried out using standard methods by using five P. aeruginosa isolates. Cytotoxicity and cell protective effect of quercetin was evaluated by trypan blue dye exclusion assay. All the tested isolates were completely inhibited (100%) by quercetin at a concentration of 500 μg ml^-1 . It showed significant (P < 0·05) inhibitory effect on virulence factors including biofilm formation and showed significant protective effect on HEK 293T cells infected with P. aeruginosa strains. This study supports the role of quercetin against P. aeruginosa, by inhibiting virulence factors as well as its cytoprotective activity during bacterial infection either by attenuating the virulence or providing direct protective effect to the host cells. SIGNIFICANCE AND IMPACT OF THE STUDY: The increase in infections caused by opportunistic pathogen Pseudomonas aeruginosa is a serious concern in the health care system. This study describes the beneficial effects of a dietary flavonoid, quercetin against pathogenic P. aeruginosa strains and its protective effect against the P. aeruginosa infection in HEK 293T cells in vitro.

Vitamin C inhibits crystallization of struvite from artificial urine in the presence of Pseudomonas aeruginosa

BACKGROUND

Formation of struvite stones is associated with urinary tract infection by urease-producing bacteria. Biogenic crystal growth in natural and synthetic materials is regulated by the action of inhibitors, ranging from small ions, molecules to large macromolecules.

MATERIALS AND METHODS

We report the dynamics of in vitro crystallization of struvite in presence of vitamin C in synthetic urine using single diffusion gel growth technique. Sodium metasilicate gel of specific gravity 1.05 and the aqueous solution of ammonium dihydrogen phosphate were used as the medium for growing the struvite crystals. The crystallization process was induced by a urease positive struvite stone associated Pseudomonas aeruginosa to mimic the infection leading to stone formation. The grown crystals were characterized by ATR-FTIR and powder XRD. The surface morphology was analysed through FE-SEM for comparison between treatments.

RESULTS

We observed decrease in number, dimension, and growth rate of struvite crystals with the increasing concentrations of vitamin C. Crystals displayed well-defined faces and dendritic morphology of struvite in both control and biogenic systems.

CONCLUSION

The results strongly suggest that, vitamin C can modulate the formation of struvite crystals in the presence of uropathogenic bacteria.

Adaptation and diversification in virulence factors among urinary catheter-associated Pseudomonas aeruginosa isolates

AIM

The aim of this study was to investigate the natural variation in the antibiotic sensitivity, biofilm formation and virulence among Pseudomonas aeruginosa isolated from the catheter-associated urinary tract infection (CAUTI) from a single centre.

METHODS AND RESULTS

Pseudomonas aeruginosa strains were isolated from the patients with CAUTI after obtaining informed consent. These isolates were identified by routine biochemical methods and 16S rRNA gene sequencing. Antibiotic sensitivity and virulence factors were measured using standard protocols. Crystal violet staining, scanning electron microscopy and confocal laser scanning microscopy were used for the biofilm studies. The extent of infectivity of the strains to induce cell lysis was studied in vitro using the Human Embryonic Kidney cells (HEK 293T). Association between virulence factors, biofilm formation and antibiotic resistance among the strains was analysed statistically. Among the 1266 patients admitted during the 2016-2017 period, 98 cases of CAUTI were reported and 18·36% (n = 18) was due to P. aeruginosa infection. Antibiogram showed that 94·4% of isolates were resistant to multiple antibiotics and 73·7% were carbapenem-resistant. All the isolates formed biofilm on different material surfaces with varying intensity (OD₅₈₀ ≥0·20-1·11). The biofilm intensity on silicone-latex material was significantly higher compared to the polystyrene surface (P > 0·05). All the strains were highly virulent and able to cause cell killing of HEK 293T cells with a rate ranging from 69·35 to 100% and showed very low sensitivity to healthy human serum.

CONCLUSIONS

Antibiotic sensitivity and association between the virulence factors and biofilm formation in the P. aeruginosa clinical strains showed complex natural diversity.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates the natural diversity and adaptation in virulence factors, biofilm formation and host-pathogen interaction among catheter-associated P. aeruginosa strains. The findings from the study urge for developing individualized drug strategy for targeting these multidrug-resistant pathogens.

Morphological and micro-tomographic study on evolution of struvite in synthetic urine infected with bacteria and investigation of its pathological biomineralization

Pathological biomineralization in the urinary system leads to urolithiasis. Formation of kidney stones involves a series of events during which they undergo morphological and mineralogical changes. We investigated the mineralization of biogenic struvite (in vitro) and examined the transformation of distinct interior and exterior structure of struvite. In vitro crystallization of struvite was performed in the presence of two bacteria that were originally isolated from the kidney stone patients. Morphological evaluation was carried out using SR-μCT as well as FESEM, XRD and FT-IR. Characteristic internal 3-D morphology and porosity of the stones were studied. For comparison, patient derived struvite stones were used. From the results obtained, we report that the presence of bacteria enhances the crystallization process of struvite in vitro. A series of time-resolved experiments revealed that struvite crystals experienced a significant morphologic evolution from pin pointed structure to X-shaped and tabular morphologies. These X-shaped and unusual tabular habits of struvite resembled biogenic morphologies of struvite. SR-μCT showed similarities between the patient derived and the in vitro derived struvite crystals. In conclusion, these experiments revealed that the bacteria play a major role in the specific morphogenesis of struvite and can able to control the nucleation, modulate crystalline phases, and shape of the growing crystal.

Characteristics of bacterial colonization after indwelling double-J ureteral stents for different time duration

Background

Indwelling Double-J ureteral stenting is commonly used in urological practice and has various complications. This study aimed to assess the frequency of bacterial stent colonization and stent-associated bacteriuria after indwelling it for different time durations and to evaluate the significance of urinary cultures for identification of colonizing microorganisms.

Materials and Methods

A prospective cross-sectional study was conducted. Midstream urine from 72 patients undergoing J stent insertion was investigated microbiologically before stent insertion and on the day of stent removal. The stents were removed by aseptic manipulation, and 1-3 cm of the tip located in the bladder was collected for microbiological study. The urine and stent samples were cultured, and the bacterial pathogens were identified using standard microbiological methods followed by Phoenix automated system. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion method.

Results

Bacterial colonies were found in 47.2% (34 of 72) of the stents. Of the multiple pathogens identified, Escherichia coli (20%) was the most common, followed by Streptococcus sp. (17.5%) and Pseudomonas sp. (12.5%). The bacteria did not colonize within the first 2 weeks of stent placement. Results showed that 55% of the isolates were resistant to erythromycin, 52.5% to ampicillin, 42.5% to piperacillin, and least resistant being 17.5% for tetracycline and imipenem. However, 81.3% and 66.7% of the stents were colonized when placed for 90-120 days and 60-90 days, respectively.

Conclusion

High prevalence of bacterial isolates and risk of bacteriuria and colonization was found in the DJ stent tips, with E. coli being dominant colonizer. Most of the bacteria were resistant to different classes of antibiotics. Bacteriuria and stent colonization gradually increases with the duration of stent retention in the body.