Pharmacokinetic Characteristics of Antimicrobials and Optimal Treatment of Urosepsis

Pharmacokinetics, tissue distribution, bioavailability and excretion of the anti-virulence drug Fluorothiazinon in rats and rabbits

Growing antimicrobial resistance has accelerated the development of anti-virulence drugs to suppress bacterial toxicity without affecting cell viability. Fluorothiazinon (FT), an anti-virulence, type three secretion system and flagella motility inhibitor which has shown promise to suppress drug-resistant pathogens having the potential to enhance the efficacy of commonly prescribed antibiotics when used in combination. In this study we characterized the pharmacokinetics, tissue distribution, bioavailability and excretion of FT in rats and rabbits. FT presented a dose-proportional linear increase in the blood of rats. Tissue distribution profiling confirmed that FT distributes to all organs being substantially higher than in the blood of rats. The bioavailability of FT was higher when administered with starch than with water implying FT should be ideally dosed with food. FT was primarily excreted in the feces in rats and rabbits while negligible amounts are recovered from the urine.

Exploring the Dynamic Role of Bacterial Etiology in Complicated Urinary Tract Infections

Background and Objectives. Numerous studies have been conducted to explore the epidemiological characteristics of urinary tract infections (UTI) and sepsis. However, there is still a lack of relevant bacteriological features and prognostic information regarding urosepsis based on bacteriological etiology. The current study aims to evaluate the bacterial etiology of complicated UTI (cUTI) and bacterial resistance to antibiotics and whether they present an intrinsic risk of developing urosepsis. Materials and Methods. A retrospective study was performed that included 102 patients who were diagnosed with cUTI and admitted to the urology department of the "Sfântul Apostol Andrei" County Emergency Clinical Hospital (GCH) from September 2019 to May 2022. Results. A considerable number of patients, n = 41 (40.2%), were diagnosed with multi drug-resistant (MDR) infection. Escherichia coli (E. coli) was identified as the prevailing pathogen, accounting for 51 patients. Klebsiella manifested itself as the subsequent causative agent in 27 instances. The presence of Enterococcus spp. infection was documented in 13 patients, whereas Pseudomonas emerged as the etiological perpetrator in the clinical context of 8 patients. The current study found a substantial prevalence of resistance to first-line antibiotics. The overall resistance rate was 74.5% for penicillin, 58.82% for trimethoprim-sulfamethoxazole and 49% for fluoroquinolones; cephalosporin resistance displayed an inverse correlation with antibiotic generation with fourth-generation cephalosporins exhibiting a resistance rate of 24.5%, and first-generation cephalosporins demonstrating a resistance rate of 35.29%. Conclusions. Age, comorbidities and indwelling urinary catheters are risk factors for developing MDR infections. While the intrinsic characteristics of the causative bacterial agent in cUTI may not be a risk factor for developing urosepsis, they can contribute to increased mortality risk. For empiric antibiotic treatment in patients with cUTI who are at a high risk of developing urosepsis and experiencing a potentially unfavorable clinical course, broad-spectrum antibiotic therapy is recommended. This may include antibiotics, such as amikacin, tigecycline, carbapenems and piperacillin-tazobactam.

Dynamics of Urinary Extracellular DNA in Urosepsis

Extracellular DNA (ecDNA) is a promising candidate marker for the early diagnosis and monitoring of urinary tract infections (UTIs). The aim of our study is to describe the dynamics of ecDNA in the plasma and urine of patients with urosepsis as well as in a mouse model of UTI. Samples of blood and urine were collected from adult patients with UTIs and obstructive uropathy (n = 36) during the first 3 days at the hospital and during a follow-up. Bacterial burden and urinary ecDNA were evaluated in a mouse UTI model (n = 26) at baseline; 24, 48, and 72 h after UTI induction; and 7 days after UTI induction. The plasma ecDNA did not change during urosepsis, but the plasma DNase activity increased significantly at the follow-up. The urinary ecDNA decreased significantly during hospitalization and remained low until the follow-up (90% lower vs. admission). No change was seen in the urinary DNase activity. C-reactive protein (CRP) and procalcitonin are positively correlated with plasma and urinary ecDNA. A UTI caused sepsis in 23% of mice. The urinary ecDNA decreased by three-fold and remained low until day 7 post-infection. Urinary bacterial burden is correlated with urinary ecDNA. Urinary ecDNA is a potential non-invasive marker for monitoring the effects of treatment during urosepsis and is related to UTI progression in the experimental animal model.

The effect of fluoroquinolones and antioxidans on biofilm formation by Proteus mirabilis strains

Background

Fluoroquinolones are a group of antibiotics used in urinary tract infections. Unfortunately, resistance to this group of drugs is currently growing. The combined action of fluoroquinolones and other antibacterial and anti-biofilm substances may extend the use of this therapeutic option by clinicians. The aim of the study was to determine the effect of selected fluoroquinolones and therapeutic concentrations of ascorbic acid and rutoside on biofilm formation by Proteus mirabilis.

Materials and methods

The study included 15 strains of P. mirabilis isolated from urinary tract infections in patients of the University Hospital No. 1 dr A. Jurasz in Bydgoszcz (Poland). The metabolic activity of the biofilm treated with 0.4 mg/ml ascorbic acid, 0.02 µg/ml rutoside and chemotherapeutic agents (ciprofloxacin, norfloxacin) in the concentration range of 0.125–4.0 MIC (minimum inhibitory concentration) was assessed spectrophotometrically.

Results

Both ciprofloxacin and norfloxacin inhibited biofilm formation by the tested strains. The biofilm reduction rate was correlated with the increasing concentration of antibiotic used. No synergism in fluoroquinolones with ascorbic acid, rutoside or both was found. The ascorbic acid and rutoside combination, however, significantly decreased biofilm production.

Conclusions

Our research proves a beneficial impact of ascorbic acid with rutoside supplementation on biofilm of P. mirabilis strains causing urinary tract infections.

Observational study over 8-year period evaluating microbiological characteristics and risk factor for isolation of multidrug-resistant organisms (MDRO) in patients with healthcare-associated infections (HAIs) hospitalized in a urology ward

Objective: To analyze, in a urology ward, the prevalence and characteristics of healthcare-associated infections (HAIs) due to multidrug-resistant organisms (MDRO). Methods: We carried out an observational study from 2012 to 2019, evaluating MDRO among patients with HAIs, who were hospitalized in the urology ward. MDRO include Pseudomonas spp., resistant to at least three antibiotic groups, extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae or those resistant to carbapenems, and Enterococcus spp. resistant to vancomycin. Results: Among patients with HAIs, MDRO were isolated in 100 out of 438 (22.8%) positive cultures. Univariate and multivariate analyses reported that prior urinary tract infection (UTI) [OR 2.45; 95% CI 1.14-5.36; p=0.021] and immunosuppression [OR 2.13; 95% CI 1.11-4.10; p=0.023] were risk factors for MDRO. A high prevalence of MRDO was found in patients with a catheter in the upper urinary tract; 27.6% for double J stent, 29.6% in those with a nephrostomy tube, and 50% in those with a percutaneous internal/external nephroureteral (PCNU) stent. MDRO were isolated in 28.4% of cultures with Enterobacteriaceae (23.8% and 44.7% in those with E. coli and Klebsiella spp.); 7% of Enterobacteriaceae showed resistance to carbapenems (1.3% and 10% for E. coli and Klebsiella spp., respectively). Three out of 80 Enterococcus spp. were vancomycin-resistant. The rate of Pseudomonas aeruginosa resistant to at least three antibiotic groups was 36.3%. Conclusions: The isolation of MDRO, in up to 25% of positive cultures in a urology ward, constitutes a challenge for the selection of antibiotics. MDRO are more common in immunosuppressed patients, those with previous UTIs, and those with a catheter in the upper urinary tract.

The Urosepsis-A Literature Review

Urosepsis is a very serious condition with a high mortality rate. The immune response is in the center of pathophysiology. The therapeutic management of these patients includes surgical treatment of the source of infection, antibiotic therapy and life support. The management of this pathology is multidisciplinary and requires good collaboration between the urology, intensive care, imaging and laboratory medicine departments. An imbalance of pro and anti-inflammatory cytokines produced during sepsis plays an important role in pathogenesis. The study of cytokines in sepsis has important implications for understanding pathophysiology and for development of other therapeutic solutions. If not treated adequately, urosepsis may lead to serious septic complications and organ sequelae, even to a lethal outcome.

Epidemiology, definition and treatment of complicated urinary tract infections

UTIs are amongst the most frequent bacterial infections. However, the clinical phenotypes of UTI are heterogeneous and range from rather benign, uncomplicated infections to complicated UTIs (cUTIs), pyelonephritis and severe urosepsis. Stratification of patients with UTIs is, therefore, important. Several classification systems exist for the description and classification of UTIs, with the common rationale that cUTIs have a higher risk of recurrence or chronification, progression or severe outcome than uncomplicated UTIs. The pathophysiology and treatment of cUTIs and pyelonephritis are driven more by host factors than by pathogen attributes. cUTIs and pyelonephritis are associated with high antimicrobial resistance rates among causative pathogens. However, antimicrobial resistance rates can differ substantially, depending on the population being studied and whether the data being analysed are from surveillance studies, registry data or interventional studies, in which specific inclusion and exclusion criteria are used for patient selection. For example, antibiotic resistance rates are higher in patients with urosepsis than in those with less severe infections. Thus, treatment outcomes differ substantially among studies, ranging from 50% to almost 100% clearance of infection, depending on the patient population analysed, the UTI entities included and the primary outcome of the study. Pyelonephritis and cUTIs have emerged as infection models for the study of novel antibiotics, including extensive investigation of novel substances active against Gram-negative bacteria.

Calculated parenteral initial treatment of bacterial infections: Infections of the kidneys and the genito-urinary tract

This is the eighth chapter of the guideline "Calculated initial parenteral treatment of bacterial infections in adults - update 2018" in the 2nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience. The chapter deals with the treatment of more severe infections of the kidney and the urogenital tract, including urosepsis. Recommendations for empiric and targeted antibacterial treatment are given.

Clinical Situations of Bacteriology and Prognosis in Patients with Urosepsis

BACKGROUND

Urosepsis and septic shock are a critical situation leading to a mortality rate up to 30% in patients with obstructive diseases of the urinary tract.

AIM

To analyze the bacterial distribution and drug resistance of pathogenic bacteria in patients with urosepsis and to provide a basis for the rational application of antibacterial drugs in clinical practice.

METHODS

A retrospective analysis of 94 hospitalized patients with urosepsis for 6 years was performed. The strain composition, resistance characteristics, and the antibiogram of common bacteria from positive blood and midstream urine culture were analyzed.

RESULTS

A total of 87 strains were isolated, including 65 strains (74.71%) of Gram-negative bacilli, 14 strains (16.09%) of Gram-positive cocci, and 8 strains (9.20%) of fungi. The Gram-negative bacilli included 42 strains of Escherichia coli (E. coli) (64.62%), among which 34 strains (80.95%) were producing ESBLs, and 14 strains (21.84%) of Klebsiella pneumoniae (K. pneumoniae), among which nine strains (64.29%) were producing ESBLs. The most common pathogenic bacteria, ESBL+ E. coli and K. pneumoniae strains, showed sensitivity towards imipenem, ertapenem, piperacillin/tazobactam, amikacin, and cefotetan, but were highly resistant to quinolones. The cure rate of urosepsis was 88.30%, and the susceptibility rate of septic shock was 45.47%.

SIGNIFICANCE

Gram-negative bacterial infections are the main cause of urosepsis. The mild patient group showed more E. coli (ESBL-) infections, and the number of ESBL producing E. coli isolated from the mild group showed higher drug resistance rates for aztreonam and levofloxacin compared with isolates from the severe group.

[Urosepsis. Update on diagnosis and treatment]

BACKGROUND

Sepsis is an acute systemic response to the presence of bacteria and bacterial components in the macroorganism, and urosepsis is defined as sepsis caused by an infection in the urogenital tract. The urogenital tract is considered to be responsible for about 30 % of the cases of septic processes, whereby obstructive uropathy is causative in about 80 % of these cases. Sepsis manifests as an initially predominant proinflammatory response by widespread release of inflammatory mediators as a result of activation of cells responsive to infectious components such as bacterial toxins, which is then accompanied by a counter-regulatory anti-inflammatory response.

DIAGNOSIS AND THERAPY

Prior to antibiotic therapy, blood and urine cultures are recommended, while procalcitonin and lactate can be considered diagnostically relevant biomarkers. Furthermore, early imaging to localize the level of obstruction and infectious focus should be carried out. Treatment is divided into causal therapy (antimicrobial therapy and infectious source), supportive therapy (fluids and oxygen administration), and adjunctive therapy (sepsis-specific therapy).

Urosepsis: Overview of the Diagnostic and Treatment Challenges

Urosepsis is defined as sepsis caused by an infection in the urogenital tract. In approximately 30% of all septic patients the infectious focus is localized in the urogenital tract, mainly due to obstructions at various levels, such as ureteral stones. Urosepsis may also occur after operations in the urogenital tract. In urosepsis, complete bacteria and components of the bacterial cell wall from the urogenital tract trigger the host inflammatory event and act as exogenous pyrogens on eukaryotic target cells of patients. A burst of second messenger molecules leads to several different stages of the septic process, from hyperactivity to immunosuppression. As pyelonephritis is the most frequent cause for urosepsis, the kidney function is therefore most important in terms of cause and as a target organ for dysfunction in the course of the sepsis.Since effective antimicrobial therapy must be initiated early during sepsis, the empiric intravenous therapy should be initiated immediately after microbiological sampling. For the selection of appropriate antimicrobials, it is important to know risk factors for resistant organisms and whether the sepsis is primary or secondary and community or nosocomially acquired. In addition, the preceding antimicrobial therapies should be recorded as precisely as possible. Resistance surveillance should, in any case, be performed locally to adjust for the best suitable empiric treatment. Treatment challenges arise from the rapid increase of antibiotic resistance in Gram-negative bacteria, especially extended-spectrum β-lactamase (ESBL)-producing bacteria. Treatment of urosepsis comprises four basic strategies I) supportive therapy (stabilizing and maintaining blood pressure), II) antimicrobial therapy, III) control or elimination of the complicating factor, and IV) specific sepsis therapy.

Temporal changes in physiological parameters of systemic inflammatory response syndrome during the three days prior to a diagnosis of sepsis: a case-control study

AIMS AND OBJECTIVES

This study was conducted to determine temporal patterns of early changes in physiological parameters of systemic inflammatory response syndrome over three days prior to a diagnosis of sepsis.

BACKGROUND

Early detection and timely management of systemic inflammatory response syndrome are often not implemented due to a failure to recognise or diagnose systemic inflammatory response syndrome.

DESIGN

A retrospective case-control study design was adopted.

METHODS

All 81 study subjects in an intensive care unit were included: 33 case subjects who received a definitive diagnosis of sepsis and 48 control patients who were not diagnosed with systemic inflammatory response syndrome or sepsis. Vital signs (temperatures, heart rates, blood pressures and respiratory rates) and white blood cell count, urine output, serum creatinine concentration, platelet count and serum glucose level data were collected for one, two and three days prior to sepsis diagnosis.

RESULTS

Homogeneity test revealed greater proportions of the aged and subjects with diabetes mellitus, hypertension and wound in the case group. Analysis also showed significant intergroup differences in systemic inflammatory response syndrome criteria score, heart rates, platelet counts and blood glucose levels, but no intergroup differences in body temperatures, blood pressures, respiratory rates, urine outputs or serum creatinine levels. A larger proportion of case subjects were fitted with a central venous or Foley catheter.

CONCLUSIONS

The presence of a wound, hypertension or diabetes mellitus, and the use of an invasive medical device may increase the risk of systemic inflammatory response syndrome. Of the physiological parameters examined, heart rate, platelet counts, and blood glucose levels might serve as significant early signs of systemic inflammatory response syndrome.

RELEVANCE TO CLINICAL PRACTICE

Caution should be observed whenever diabetic or hypertension patients develop sudden and persistent hyperglycaemia or tachycardia, and nurses should also be aware of the potential for systemic inflammatory response syndrome in patients with a central venous or indwelling urinary catheter.

Efficacy of ceftolozane/tazobactam versus levofloxacin in the treatment of complicated urinary tract infections (cUTIs) caused by levofloxacin-resistant pathogens: results from the ASPECT-cUTI trial

OBJECTIVES

Empirical fluoroquinolone therapy is widely used in treating complicated urinary tract infections (cUTIs), even in areas of high fluoroquinolone resistance. While it is believed that high antibiotic concentrations in urine might be sufficient to overcome and effectively treat infections caused by resistant bacteria, clinical trial data validating this assumption are limited. This post hoc analysis evaluated the efficacy of ceftolozane/tazobactam versus levofloxacin in the subgroup of patients with cUTIs caused by levofloxacin-resistant pathogens in a randomized, controlled trial (NCT01345929/NCT01345955).

METHODS

Hospitalized adults with cUTI/pyelonephritis were randomized to 7 days of 1.5 g of ceftolozane/tazobactam every 8 h or 750 mg of levofloxacin once daily, before availability of culture and susceptibility data. A composite of microbiological eradication and clinical cure 5 to 9 days post-therapy was assessed in the microbiological modified ITT (mMITT; n = 800) and microbiologically evaluable (ME; n = 694) populations.

RESULTS

In the mMITT population, there were 212 patients (26.5%) with at least one baseline uropathogen that was resistant to levofloxacin. The majority of uropathogens in this subgroup were Enterobacteriaceae (n = 186) that were susceptible to ceftolozane/tazobactam [MIC ≤2 mg/L, 88.7% (165/186)]. Among patients with levofloxacin-resistant pathogens, ceftolozane/tazobactam demonstrated significantly higher composite cure rates than levofloxacin in both the mMITT [60.0% (60/100) versus 39.3% (44/112); 95% CI for the treatment difference, 7.2%-33.2%] and ME [64.0% (57/89) versus 43.4% (43/99); 95% CI for the treatment difference, 6.3%-33.7%] populations, respectively.

CONCLUSIONS

High urinary levels of levofloxacin did not reliably cure cUTIs. Seven day treatment with ceftolozane/tazobactam was more effective than high-dose levofloxacin treatment in patients with cUTI caused by levofloxacin-resistant bacteria, and it may be an alternative treatment in settings of increased fluoroquinolone resistance.

[Emergency nephrectomies: retrospective monocentric study, about eight cases]

OBJECTIVE

Emergency nephrectomies are rare because of the improvement of the management of urinary tract infections and the development of radio-embolization. Few series of patients have been reported. The objective of our study is to assess the indication, the morbi-mortality and the outcome of the emergency nephrectomy performed in our hospital.

PATIENTS

Between January 2011 and November 2012, eight patients underwent an emergency nephrectomy at the University Hospital Center of Caen. The present review reports the characteristics of this emergency nephrectomy and their morbi-mortality.

RESULTS

Six women and two men were analyzed retrospectively between January 2011 and November 2012. All patients except one needed intensive care for a multiple-organ failure. All these eight emergency nephrectomies concerned a native kidney with a surgical approach as a lombotomy or subcostal laparotomy. Both patients survived. One patient need a renal dialysis support.

CONCLUSION

Emergency nephrectomy are rare. Uncontrolled urinary sepsis represents the main indication. Identifying the population at risk of evolution to the toxic shock is indispensable for a better and faster care and to reduce the mortality bound to the sepsis.

Urinary tract infection

The urinary tract is a common source for life-threatening infections. Most patients with sepsis or septic shock from a urinary source have complicated urinary tract infection. This article explains the epidemiology, risk factors, and treatment. Effective management, appropriate collection of microbiology specimens, prompt initiation of antimicrobial therapy, source control, and supportive therapy are described.

Contemporary Management of recurrent UTI in adult females

The management of recurrent UTI is subject to significant variation and patients may fall under the care of a variety of specialties. We review the pathogenesis, investigation and management of this group of patients. Accurate diagnosis of UTI is the cornerstone of successful management, and careful interpretation of MSU results is needed. Although prophylactic antibiotic regimes are often successful, the emergence of antibiotic resistance mandates the cautious use of antibiotics and consideration of other initial therapies where possible.

Approach to a patient with urosepsis

Urinary tract infections can occur in all age groups and produce an exceptionally broad range of clinical syndromes ranging from asymptomatic bacteriuria to acute pyelonephritis with Gram negative sepsis to septic shock. In approximately one-quarter of all patients with sepsis, the focus of infection is localized to the urogenital tract. This may lead to substantial morbidity and significant economic implications. We present a review of the current approaches to managing urospesis.

Risk factors for fluoroquinolone-resistant Escherichia coli in adults with community-onset febrile urinary tract infection

OBJECTIVES

To assess risk factors for fluoroquinolone resistance in community-onset febrile Escherichia coli urinary tract infection (UTI).

METHODS

A nested case-control study within a cohort of consecutive adults with febrile UTI presenting at primary healthcare centres or emergency departments during January 2004 through December 2009. Resistance was defined using EUCAST criteria (ciprofloxacin MIC >1.0 mg/L). Cases were subjects with fluoroquinolone-resistant E. coli, and controls those with fluoroquinolone-susceptible isolates. Multivariable logistic regression analysis was used to identify potential risk factors for fluoroquinolone resistance.

RESULTS

Of 787 consecutive patients, 420 had E. coli-positive urine cultures. Of these, 51 (12%) were fluoroquinolone resistant. Independent risk factors for fluoroquinolone resistance were urinary catheter [odds ratio (OR) 3.1; 95% confidence interval (CI) 0.9-11.6], recent hospitalization (OR 2.0; 95% CI 1.0-4.3) and fluoroquinolone use in the past 6 months (OR 17.5; 95% CI 6.0-50.7). Environmental factors (e.g. contact with animals or hospitalized household members) were not associated with fluoroquinolone resistance. Of fluoroquinolone-resistant strains, 33% were resistant to amoxicillin/clavulanate and 65% to trimethoprim/sulfamethoxazole; 14% were extended-spectrum β-lactamase (ESBL) positive compared with <1% of fluoroquinolone-susceptible isolates.

CONCLUSIONS

Recent hospitalization, urinary catheter and fluoroquinolone use in the past 6 months were independent risk factors for fluoroquinolone resistance in community-onset febrile E. coli UTI. Contact with animals or hospitalized household members was not associated with fluoroquinolone resistance. Fluoroquinolone resistance may be a marker of broader resistance, including ESBL positivity.

[Urosepsis and treatment]

Urosepsis is one of the most frequent sepsis entities. Mortality from urosepsis is nowadays mostly lower than from other entities. Sepsis syndrome is pathophysiologically characterized by a generalized infection and immune dysregulation. Exogenous microbiological and active or passive endogenous factors released from body cells initiate and accompany the immune dysregulation. Diagnosis and therapy of urosepsis need to be instigated as early as possible (within the first hour), in order to prevent cell and tissue damage in the early phase. For this reason a series of measures is started, aimed at achieving early control of the focus of infection, providing antibiotic treatment, and stabilizing respiratory and cardiovascular function in order to optimize tissue oxygenation. A significant clinical problem ensues due to increasing antibiotic resistance mainly of enterobacteria. The choice of antibiotic therefore is made on the basis of local antibiotic resistance statistics. Dosage is determined on an individual basis, as well as according to current pharmacokinetic/pharmacodynamic knowledge. The intensive care of the septic patient needs to be started as early as on patient admission and, where necessary, continued on the intensive care ward.

Pharmacokinetics/pharmacodynamics of antibacterials in the Intensive Care Unit: setting appropriate dosing regimens

Patients admitted to Intensive Care Units (ICUs) are at very high risk of developing severe nosocomial infections. Consequently, antimicrobials are among the most important and commonly prescribed drugs in the management of these patients. Critically ill patients in ICUs include representatives of all age groups with a range of organ dysfunction related to severe acute illness that may complicate long-term illness. The range of organ dysfunction, together with drug interactions and other therapeutic interventions (e.g. haemodynamically active drugs and continuous renal replacement therapies), may strongly impact on antimicrobial pharmacokinetics in critically ill patients. In the last decade, it has become apparent that the intrinsic pharmacokinetic (PK) and pharmacodynamic (PD) properties are the major determinants of in vivo efficacy of antimicrobial agents. PK/PD parameters are essential in facilitating the translation of microbiological activity into clinical situations, ensuring a successful outcome. In this review, we analyse the typical patterns of antimicrobial activity and the corresponding PK/PD parameters, with a special focus on a PK/PD dosing approach of the antimicrobial agent classes commonly utilised in the ICU setting.