Efficacy of single and multiple oral doses of fosfomycin against Pseudomonas aeruginosa urinary tract infections in a dynamic in vitro bladder infection model

2020 ◽  
Vol 75 (7) ◽  
pp. 1879-1888 ◽  
Author(s):  
Iain J Abbott ◽  
Elke van Gorp ◽  
Rixt A Wijma ◽  
Jordy Dekker ◽  
Peter D Croughs ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Single Dose ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Infection Model ◽  
Post Exposure ◽  
High Level ◽  
Tract Infections ◽  
Emergence Of Resistance

Abstract Objectives We used a dynamic bladder infection in vitro model with synthetic human urine (SHU) to examine fosfomycin exposures to effectively kill, or prevent emergence of resistance, among Pseudomonas aeruginosa isolates. Methods Dynamic urinary fosfomycin concentrations after 3 g oral fosfomycin were simulated, comparing single and multiple (daily for 7 days) doses. Pharmacodynamic response of 16 P. aeruginosa (MIC range 1 to >1024 mg/L) were examined. Baseline disc diffusion susceptibility, broth microdilution MIC and detection of heteroresistance were assessed. Pathogen kill and emergence of resistance over 72 h following a single dose, and over 216 h following daily dosing for 7 days, were investigated. The fAUC0–24/MIC associated with stasis and 1, 2 and 3 log10 kill were determined. Results Pre-exposure high-level resistant (HLR) subpopulations were detected in 11/16 isolates after drug-free incubation in the bladder infection model. Five of 16 isolates had >2 log10 kill after single dose, reducing to 2/16 after seven doses. Post-exposure HLR amplification occurred in 8/16 isolates following a single dose and in 11/16 isolates after seven doses. Baseline MIC ≥8 mg/L with an HLR subpopulation predicted post-exposure emergence of resistance following the multiple doses. A PK/PD target of fAUC0–24/MIC >5000 was associated with 3 log10 kill at 72 h and 7 day-stasis. Conclusions Simulated treatment of P. aeruginosa urinary tract infections with oral fosfomycin was ineffective, despite exposure to high urinary concentrations and repeated daily doses for 7 days. Emergence of resistance was observed in the majority of isolates and worsened following prolonged therapy. Detection of a baseline resistant subpopulation predicted treatment failure.

scholarly journals Oral Fosfomycin Treatment for Enterococcal Urinary Tract Infections in a Dynamic In Vitro Model

2020 ◽  
Vol 64 (6) ◽  
Author(s):  
Iain J. Abbott ◽  
Elke van Gorp ◽  
Aart van der Meijden ◽  
Rixt A. Wijma ◽  
Joseph Meletiadis ◽  
...  
Keyword(s):  
Single Dose ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Treatment Options ◽  
Infection Model ◽  
Urinary Concentration ◽  
Content Type ◽  
Vitro Model ◽  
Tract Infections

ABSTRACT There are limited treatment options for enterococcal urinary tract infections, especially vancomycin-resistant Enterococcus (VRE). Oral fosfomycin is a potential option, although limited data are available guiding dosing and susceptibility. We undertook pharmacodynamic profiling of fosfomycin against E. faecalis and E. faecium isolates using a dynamic in vitro bladder infection model. Eighty-four isolates underwent fosfomycin agar dilution susceptibility testing (E. faecalis MIC50/90 32/64 μg/ml; E. faecium MIC50/90 64/128 μg/ml). Sixteen isolates (including E. faecalis ATCC 29212 and E. faecium ATCC 35667) were chosen to reflect the MIC range and tested in the bladder infection model with synthetic human urine (SHU). Under drug-free conditions, E. faecium demonstrated greater growth restriction in SHU compared to E. faecalis (E. faecium maximal growth 5.8 ± 0.6 log10 CFU/ml; E. faecalis 8.0 ± 1.0 log10 CFU/ml). Isolates were exposed to high and low fosfomycin urinary concentrations after a single dose, and after two doses given over two days with low urinary concentration exposure. Simulated concentrations closely matched the target (bias 2.3%). E. faecalis isolates required greater fosfomycin exposure for 3 log10 kill from the starting inoculum compared with E. faecium. The ƒAUC0-72/MIC and ƒ%T > MIC0-72 for E. faecalis were 672 and 70%, compared to 216 and 51% for E. faecium, respectively. There was no rise in fosfomycin MIC postexposure. Two doses of fosfomycin with low urinary concentrations resulted in equivalent growth inhibition to a single dose with high urinary concentrations. With this urinary exposure, fosfomycin was effective in promoting suppression of regrowth (>3 log10 kill) in the majority of isolates.

scholarly journals Ceftazidime/Avibactam: Who Says You Can’t Teach an Old Drug New Tricks?

2016 ◽  
Vol 19 (4) ◽  
pp. 448 ◽  
Author(s):  
Katie E. Barber ◽  
Jessica K. Ortwine ◽  
Ronda L Akins
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
The United States ◽  
Phase Iii ◽  
In Vitro Susceptibility ◽  
Gram Negative ◽  
Tract Infections ◽  
Abdominal Infections

Purpose: Gram-negative resistance continues to rise with treatment options becoming more limited. Ceftazidime/avibactam was recently approved in the United States and Europe, which combines an established third-generation cephalosporin with a new, unique, non-β-lactam β-lactamase inhibitor. This review conducts a thorough examination of structure, pharmacology, spectrum of activity, pharmacokinetics/pharmacodynamics, in vitro and clinical efficacy and safety/tolerability of ceftazidime/avibactam, as well as detailed future directions for the agent. Methods: Pubmed and clinicaltrials.gov searches, as well as abstracts from the 2015 Interscience Conference on Antimicrobial Agents and Chemotherapy/International Society of Chemotherapy (ICAAC/ICC) and ID Week meetings and the 2016 American Society of Microbiology Microbe meeting, were conducted from January 2004 – September 2016. Relevant search terms included ceftazidime, ceftazidime/avibactam, avibactam, NXL104 and AVE1330A. The US package insert for ceftazidime/avibactam (02/2015) and European public assessment report (06/2016) were also reviewed. Results: In vitro susceptibility for ceftazidime/avibactam displayed potent activity against many Enterobacteriaceae including extended-spectrum-β-lactamase (ESBL) and carbapenemase-producing strains, as well as Pseudomonas aeruginosa. Phase II clinical trials utilized for approval demonstrated comparable safety and efficacy to imipenem/cilistatin for treatment of complicated urinary tract infections (70.4% vs. 71.4%) and combined with metronidazole compared to meropenem in complicated intra-abdominal infections (91.2% vs 93.4%). Phase III data displayed non-inferior efficacy of ceftazidime/avibactam compared to doripenem for complicated urinary tract infections (70.2% vs 66.2%) and combined with metronidazole compared to meropenem in complicated intra-abdominal infections (82.5% vs 84.9%), as well as comparable safety. Ceftazidime/avibactam was well-tolerated but does require renal adjustments. Additionally, 3 case series and a single case report have demonstrated the potential for ceftazidime/avibactam against multidrug resistant organisms for compassionate use or failure after previous therapy. Conclusion: By adding avibactam to ceftazidime, clinicians’ antimicrobial armamentarium is expanded, potentially increasing the ability to combat multi-drug resistant gram-negative pathogens, particularly ESBL and carbapenemase-producing organisms, as well as Pseudomonas aeruginosa. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals Quorum sensing and virulence of Pseudomonas aeruginosa during urinary tract infections

2012 ◽  
Vol 6 (06) ◽  
pp. 501-507 ◽  
Author(s):  
Sezgi Senturk ◽  
Seyhan Ulusoy ◽  
Gulgun Bosgelmez-Tinaz ◽  
Aysegul Yagci
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Urinary Tract ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Urinary Tract Infections ◽  
Clinical Isolates ◽  
Pcr Analysis ◽  
Signal Molecules ◽  
Tract Infections

Introduction: In the opportunistic pathogen Pseudomonas aeruginosa, the production of several virulence factors depends on quorum sensing (QS) involving N-acylhomoserine lactone signal molecules. In vitro studies have suggested that the QS system is crucial in the pathogenesis of P. aeruginosa. However, it is unclear whether QS systems of P. aeruginosa play the same role during infections. Methodology:  In this study, to explore the contribution of QS systems to the pathogenesis of P. aeruginosa during urinary tract infections, we collected 82 clinical isolates. Detection of N-acyl-homoserine lactones (C12-HSL and C4-HSL) was performed on agar plates employing biosensor strains C. violaceum. Elastase and biofilm production were determined spectrophotometrically. QS genes were detected by PCR and subsequently underwent sequencing. Results and conclusion:  Six isolates were found to be negative in the production of both C12-HSL and C4-HSL and all virulence factors tested.  PCR analysis of these isolates revealed that four isolates contained all four QS genes while one isolate was negative for lasR gene, and one isolate negative for lasI, lasR and rhlR genes. Sequence analyses of these isolates showed that the lasR, lasI, rhlR and rhlI genes had point mutations. The combination of these mutations probably explains their C12-HSL, C4-HSL and virulence factor deficiencies. Results of this study suggest that QS deficient clinical isolates occur and are still capable of causing clinical infections in humans. 

scholarly journals Urinary Tract Infections among Indonesian Pregnant Women and Its Susceptibility Pattern

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Yeva Rosana ◽  
Dwiana Ocviyanti ◽  
Melissa Halim ◽  
Friza Yossy Harlinda ◽  
Rahmah Amran ◽  
...  
Keyword(s):  
Single Dose ◽  
Urinary Tract ◽  
Pregnant Women ◽  
Urinary Tract Infections ◽  
Asymptomatic Bacteriuria ◽  
In Vitro Susceptibility ◽  
E Coli ◽  
Fosfomycin Trometamol ◽  
Tract Infections

Pregnant women are usually at risk of urinary tract infections (UTIs) such as asymptomatic bacteriuria. In the current multidrug-resistance era, appropriate diagnosis and treatment should be provided to avoid complications in pregnant women in developing countries, which have limited facilities, such as Indonesia. The aim of this study was to evaluate in vitro susceptibility tests. Urinary isolates were collected from 715 pregnant women who visited eight Community Health Centers in Jakarta, Indonesia, between 2015 and 2017. We identified bacterial uropathogens from samples that were positive for nitrite/leukocyte esterase (LE), using two types of VITEK cards. Since noncompliance among patients is a major problem, fosfomycin-trometamol 3 g single-dose sachets were given to the patients, and the side effects of the medication and neonatal outcomes were reported. Asymptomatic bacteriuria was found in 10.5% of the 715 pregnant women. Escherichia coli was the most common etiological factor (26.7%), followed by Klebsiella pneumoniae (20%), Streptococcus agalactiae (9.3%), Enterobacter cloacae (5.3%), Enterococcus faecalis (5.3%), Staphylococcus saprophyticus (4%), Acinetobacter baumannii (4%), and others. Out of 76 pregnant women who took fosfomycin-trometamol, two complained of diarrhea that subsided without medication and fever that responded to paracetamol. Neonatal outcomes showed 100% full-term and normal-weight babies. E. coli, including extended-spectrum beta-lactamase- (ESBL-) producing E. coli, was 100% susceptible to fosfomycin. Nitrite/LE test results are often used as evidence for empiric antibiotic administration for treating asymptomatic bacteriuria in pregnancy, but the diagnosis should be confirmed using culture tests. Based on in vitro susceptibility patterns and medication outcomes, fosfomycin-trometamol single dose could be administered to noncompliant UTI patients, including pregnant women.

scholarly journals Inhibition of quorum sensing in Pseudomonas aeruginosa by azithromycin and its effectiveness in urinary tract infections

2011 ◽  
Vol 60 (3) ◽  
pp. 300-306 ◽  
Author(s):  
Anju Bala ◽  
Ravi Kumar ◽  
Kusum Harjai
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Urinary Tract ◽  
Quorum Sensing ◽  
Urinary Tract Infections ◽  
Opportunistic Pathogen ◽  
Signal Molecules ◽  
Chronic Infections ◽  
Beneficial Effects ◽  
Tract Infections

Pseudomonas aeruginosa, an opportunistic pathogen, is the third most common pathogen associated with nosocomial urinary tract infections (UTIs). The virulence of this organism is due to its ability to produce quorum-sensing (QS) signal molecules and form biofilms. These biofilms are usually resistant to conventional antibiotics and host immune responses. Recently, beneficial effects of macrolides, especially azithromycin (AZM), have been shown in patients suffering from chronic infections caused by P. aeruginosa. These were due to anti-inflammatory and modulatory effects of AZM on the expression of virulence factors of this pathogen. The present study was designed to evaluate the potential of AZM to inhibit QS signal molecules and its ability to attenuate the virulence of P. aeruginosa in an experimental UTI model. Sub-MIC concentrations of AZM significantly inhibited the production of QS signals, swimming, swarming and twitching motilities, and biofilm formation in vitro. The therapeutic evaluation of AZM in this experimental UTI model showed complete clearance of the organisms from the mouse kidneys. The results of this study highlight the potential effectiveness of AZM in attenuating the virulence of P. aeruginosa in a UTI model.

Detection of tox A gene in Pseudomonas aeruginosa that isolates from different clinical cases by using PCR.

2018 ◽  
pp. 26
Author(s):  
Rana M. Abdullah Al-Shwaikh ◽  
Abbas Falih Alornaaouti
Keyword(s):  
Molecular Weight ◽  
Pseudomonas Aeruginosa ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Otitis Media ◽  
Urinary Tract Infections ◽  
Gel Electrophoresis ◽  
Wound Infections ◽  
Tract Infections

       Current study obtained (75) isolate of Pseudomonas aeruginosa collected from different cases included : 28 isolates from otitis media, 23 isolates from burn infections, 10 isolates from wound infections, 8 isolates from urinary tract infections and 6 isolates from blood, during the period between 1/9/2014 to 1/11/2014        The result revealed that the tox A gene was present in 54 isolates (72%) of Pseudomonas aeruginosa. The gel electrophoresis showed that the molecular weight of tox A gene was 352 bp. The result shows 17 isolates (60.71%) from otitis media has tox A gene, 18 isolates (78.26%) from burn followed by 8 isolate (80%) from wound infection and 5 isolates (62.5%) from urinary tract infection , finally 6 isolates (100%) from blood have this gene.

Sign in / Sign up

Export Citation Format

Share Document