Bacteriological profile, antimicrobial susceptibility, and factors associated with urinary tract infection in pregnant women.

INTRODUCTION: Urinary tract infection (UTI) is a common bacterial complication in pregnancy. The study aimed to estimate the prevalence, risk factors, and bacterial etiology of UTI during pregnancy and determine the efficacy of antimicrobial drugs in treating UTIs. METHODOLOGY: Urine specimens and clinical data were collected from pregnant women who attended primary health centers in Erbil, Iraq. All specimens were cultured on appropriate media and identified by standard microbiological methods. The pregnant women were grouped into symptomatic UTI group, asymptomatic bacteriuria group, and the control group. The agar dilution method was used to determine antimicrobial susceptibility. RESULTS: Among the 5,042 pregnant women included in this study, significant bacteriuria was found in 625 (12.40%) of the cases, and 198 (31.68%) had symptomatic UTI, of which 43.59% were diagnosed during the third trimester. Out of the 643 bacteria isolated, 33.28% were symptomatic UTI, of which 43.59% developed during the third trimester. There was a significant difference in the bacterial etiology between symptomatic UTI and asymptomatic bacteriuria (p = 0.002), as well as between cystitis and pyelonephritis (p = 0.017). The most common bacterial species isolated was Escherichia coli, which was susceptible to fosfomycin (100%), meropenem (99.45%), and nitrofurantoin (97.8%). CONCLUSIONS: Pregnant women are more likely to develop UTI in the third trimester. Escherichia coli is the predominant pathogen. The study suggests the use of fosfomycin, meropenem, and nitrofurantoin for the treatment of UTI. No Gram-positive isolates were resistant to daptomycin.

[Antibacterial prophylaxis with fosfomycin at the time of the urethral catheter removal after radical prostatectomy (prospective randomized trial)].

AIM: To evaluate the effect of antibacterial prophylaxis using oral fosfomycin during the removal of a urethral catheter after radical prostatectomy on the development of urinary tract infection, severity of leukocyturia and bacteriuria, as well as the severity of lower urinary tract symptoms. MATERIALS AND METHODS: A single-center, non-blind, prospective, randomized controlled trial was carried out. The main group included 40 patients, and the control group included 37 patients. In the group 1, patients received two doses of oral fosfomycin, 3 g, namely in the evening on the day of catheter removal (the first dose) and 48 hours after catheter removal (the second dose). In the group 2, patients did not receive any antibacterial prophylaxis after urethral catheter removal. The endpoints of the study were confirmed episodes of urinary tract infection within 1 month after removal of the urethral catheter, leukocyturia and bacteriuria in urinalysis/urine culture) and severity of the lower urinary tract symptoms assessed by IPSS questionnaire. RESULTS: In the group 2, urinary tract infection was noted in 17.1%, while in the group 2 only in 2.6% of patients (p=0.032). Leukocyturia and bacteriuria were significantly less common in the group receiving antibacterial prophylaxis with fosfomycin (18.4% vs. 48.6%, respectively; p=0.006). Positive urine culture was observed in 7.9% vs. 25.7%, respectively (p=0.035). Four weeks after removal of the urethral catheter, the average IPSS score was significantly higher in the group 2 (13.2 vs. 9.5 points; p=0.002). There were no cases of allergic reaction and pseudomembranous colitis associated with C. difficile in both groups. Diarrhea cured with sorbents was noted in 2 patients (5.2%) in fosfomycin group. CONCLUSION: Antibacterial prophylaxis using two oral doses of fosfomycin 3 g on the day of urethral catheter removal and 48 hours after catheter removal after radical prostatectomy appears to be an effective scheme that reduces the incidence of urinary tract infection and the severity of lower urinary tract symptoms, and is characterized by a minimal risk of adverse events. It is necessary to carried out further research and develop clear recommendations for antibacterial prevention in urological interventions requiring prolonged urethral catheterization.

Antibiotics efficacy in clinical and microbiological cure of uncomplicated urinary tract infection: a systematic review and network meta-analysis.

PURPOSE: Fosfomycin has been used more frequently in managing uncomplicated urinary tract infections (UTIs) due to decreased compliance and increased multidrug-resistant bacteria. The aim of this network meta-analysis was to assess the efficacy of Fosfomycin compared to Nitrofurantoin, Trimethoprim-Sulfamethoxazole (TMP-SMX), and Ciprofloxacin in terms of clinical and microbiological cure alongside with other measurements. MATERIALS AND METHODS: We searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL). We included randomized control trials (RCTs) with uncomplicated UTI patients who received Fosfomycin, Nitrofurantoin, TMP-SMX, or Ciprofloxacin and reported the clinical or microbiological cure. We used Cochrane Risk of Bias Assessment Tool to assess the included studies' quality. R-software was used for all statistical analysis. We ranked all antibiotics using the netrank function which yielded P scores. Frequentist network meta-analysis was used to assess the efficacy of all outcomes. RESULTS: We included 13 RCTs with a total number of 3856 patients that showed Fosfomycin ranked the highest among the other antibiotics with respect to clinical cure (P-score = 0.99) and microbiological cure (P-score = 0.99) while Ciprofloxacin ranked the lowest (P-score = 0.11 and 0.02, respectively). Moreover, Ciprofloxacin yielded the highest relapse rate (P-score = 1), whereas TMP-SMX had the lowest relapse rate (P-score = 0.07). As for the adverse events, Ciprofloxacin demonstrated the highest adverse events as opposed to Fosfomycin (P-score = 0.98 and 0.05, respectively). CONCLUSION: The network meta-analysis demonstrated that Fosfomycin is the most effective antibiotic in treating uncomplicated UTIs with respect to clinical cure, microbiological cure, and adverse events profile.

Hydroxamate-Containing Bisphosphonates as Fosmidomycin Analogues: Design, Synthesis, and Proherbicide Activity.

Fosmidomycin (FOS) is a natural product inhibiting the DXR enzyme in the MEP pathway and has stimulated interest for finding more suitable FOS analogues. Herein, two series of FOS analogue hydroxamate-containing bisphosphonates as proherbicides were designed, with bisphosphonate replacing the phosphonic unit in FOS while retaining the hydroxamate (BPF series) or replacing it with retro-hydroxamate (BPRF series). The BPF series were synthesized through a three-step reaction sequence including Michael addition of vinylidenebisphosphonate, N-acylation, and deprotection, and the BPRF series were synthesized with a retro-Claisen condensation incorporated into the reaction sequence. Evaluation on model plants demonstrated several compounds having considerable herbicidal activities, and in particular, compound 8m exhibited multifold activity enhancement as compared to the control FOS. The proherbicide properties were comparatively validated. Furthermore, DXR enzyme assay, dimethylallyl pyrophosphate rescue, and molecular docking verified 8m to be a promising proherbicide candidate targeting the DXR enzyme. In addition, 8m also displayed good antimalarial activities.

Bacterial Persistence in Urinary Tract Infection Among Postmenopausal Population.

IMPORTANCE: Urinary tract infections (UTIs) are common in older-aged women. Our study examined bacterial persistence with commonly prescribed antibiotics. Bacterial growth was demonstrated despite antibiotic treatment. OBJECTIVES: The aims of this study were to quantify the bacterial persister phenotype in urine collected from postmenopausal women with acute and recurrent UTI and to determine the capabilities of first-line antibiotics to effectively treat persister cells. STUDY DESIGN: This was an institutional review board-approved cross-sectional analysis within a large academic referral center. Uropathogens were cultured from postmenopausal women with acute or recurrent UTI and screened for persister cells using persistence assays. Demographic and clinical variables were collected and analyzed. The entire experimental process was repeated in triplicate. Data were analyzed for significance (P < 0.05) between the persister culture and antibiotic treatments using a 1-way analysis of variance with multiple comparisons in Prism 9.3.0. RESULTS: Forty participants were included: 62.5% White, 22.5% Black, 3% Asian, and 2% Hispanic with a mean age of 72.3 ± 11.62 years. The persister phenotype was demonstrated in all of Escherichia coli isolates. Treatment with fosfomycin demonstrated reduced colony-forming units per milliliter compared with control (P < 0.01). Among recurrent isolates, there was a statistically significant decrease in colony-forming units per milliliter after antibiotic treatment with all 4 antibiotics (P < 0.05). CONCLUSIONS: This study demonstrated in vitro bacterial persistence in uropathogens from urogynecology patients despite treatment with commonly prescribed antibiotics. Fosfomycin generated the least amount of persister cells. Results suggest that persistence may be one bacterial defense mechanism involved in UTIs. Further research is needed to understand the clinical implications.

Comparative effectiveness and mortality of colistin monotherapy versus colistin-fosfomycin combination therapy for the treatment of carbapenem-resistant Enterobacteriaceae (CRE) infections: A propensity score analysis.

BACKGROUND: Carbapenem-resistant Enterobacteriaceae (CRE) infections pose a significant threat to global health due to limited treatment options and high mortality rates. Colistin-based regimens have emerged as a primary treatment approach, but the effectiveness and mortality outcomes of colistin monotherapy versus colistin-fosfomycin combination therapy remain uncertain. This study aims to compare the effectiveness and mortality of colistin monotherapy and colistin-fosfomycin combination therapy for CRE infections. Notably, our study is the first to undertake a comprehensive examination of the effectiveness and mortality outcomes between colistin monotherapy and colistin-fosfomycin combination therapy in the context of CRE infections. METHODS: A retrospective cohort study was conducted using data from patients diagnosed with carbapenem-resistant Enterobacteriaceae (CRE) infections at Nakornping Hospital during 2015 to 2022. Inverse probability weighting (IPW) was employed to create balanced cohorts of patients receiving either colistin monotherapy or colistin-fosfomycin combination therapy. The primary outcome measure was treatment effectiveness, assessed by 30-day mortality. Secondary outcome measures included clinical response, mortality at the end of treatment, and microbiologic response. Univariate and multivariate logistic regression analysis were employed after applying propensity score weighting using inverse probability of weighting (IPW). RESULTS: A total of 220 patients were included in the analysis, with 67 receiving colistin monotherapy and 153 receiving colistin-fosfomycin combination therapy. Propensity score weighting using IPW balanced the baseline characteristics between the two groups. The effectiveness of treatment, as measured by 30-day mortality, was not significantly different between the colistin monotherapy group and the colistin-fosfomycin combination therapy group (adjusted odds ratio [aOR] = 1.51, 95% confidence interval [CI]: 0.60-3.78, p = 0.383). Similarly, no significant difference was observed in the mortality at the end of treatment between the two groups (aOR = 1.26, 95% CI: 0.55-2.90, p = 0.576). The clinical response (aOR = 1.48, 95% CI: 0.61-3.59, p = 0.383) and microbiologic response (aOR = 0.66, 95% CI: 0.18-2.38, p = 0.527) were similar between the colistin monotherapy and colistin-fosfomycin combination therapy groups. CONCLUSION: The propensity score analysis among 220 matched patients showed comparable treatment effectiveness and mortality between colistin monotherapy and colistin-fosfomycin combination therapy for CRE infections. These results suggest that colistin monotherapy may be as effective as combination therapy. More prospective randomized controlled trials are needed to confirm these findings and establish optimal CRE treatment strategies.

In vitro and in silico studies of enterobactin-inspired Ciprofloxacin and Fosfomycin first generation conjugates on the antibiotic resistant E. coli OQ866153.

BACKGROUND: The emergence of antimicrobial resistance in bacterial pathogens is a growing concern worldwide due to its impact on the treatment of bacterial infections. The "Trojan Horse" strategy has been proposed as a potential solution to overcome drug resistance caused by permeability issues. OBJECTIVE: The objective of our research was to investigate the bactericidal activity and mechanism of action of the "Trojan Horse" strategy using enterobactin conjugated with Ciprofloxacin and Fosfomycin against the antibiotic-resistant Escherichia coli strain OQ866153. METHODOLOGY: Enterobactin, a mixed ligand of E. coli OQ866153, was conjugated with Ciprofloxacin and Fosfomycin individually to aid active absorption via specific enterobactin binding proteins (FepABCDG). The effectiveness of the conjugates was assessed by measuring their bactericidal activity against E. coli OQ866153, as well as their ability to inhibit DNA gyrase enzyme and biofilm formation. RESULTS: The Fe+3-enterobactin-Ciprofloxacin conjugate effectively inhibited the DNA gyrase enzyme (Docking score = -8.597 kcal/mol) and resulted in a lower concentration (25 µg/ml) required to eliminate supercoiled DNA plasmids compared to the parent drug (35 µg/ml; Docking score = -6.264 kcal/mol). The Fe+3-Enterobactin-Fosfomycin conjugate showed a higher inhibition percentage (100%) of biofilm formation compared to Fosfomycin (21.58%) at a concentration of 2 mg/ml, with docking scores of -5.481 and -3.756 kcal/mol against UDP-N acetylglucosamine 1-carboxyvinyltransferase MurA. CONCLUSION: The findings of this study suggest that the "Trojan Horse" strategy using enterobactin conjugated with Ciprofloxacin and Fosfomycin can effectively overcome permeability issues caused by efflux proteins and enhance the bactericidal activity of these drugs against antibiotic-resistant strains of E. coli.

Pharmacokinetics/pharmacodynamics cut-off determination for fosfomycin using Monte Carlo simulation in healthy horses.

Fosfomycin (FOM) is an approved veterinary medicinal product for large animals in Japan, but Clinical breakpoint (CBP) for antimicrobial susceptibility test (AST) is not defined for animals. This study aimed at conducting a pharmacokinetics/pharmacodynamics (PK/PD) analysis to determine the PK/PD cutoff for the CBP in horses. Drug concentrations following single intravenous administration (IV) of 20 mg/kg body weight (BW) FOM in nine horses were measured using liquid chromatography/mass spectrometry. The data were modelled using a nonlinear mixed-effects model, followed by Monte Carlo simulations. A 90% probability of target attainment for a PK/PD target of the ratio of Area Under the free plasma concentration-time curve divided by the minimal inhibitory concentration (MIC) >24 hr was set as PK/PD cut-off. The PK/PD cutoff for FOM 20 mg/kg BW q12 hr IV was estimated with the MIC value of ≤16.0 mg/L, and this regimen was considered effective against E. coli (MIC90; 16.0 mg/L) in healthy horses based on the MIC90 values of the wild population. Owing to the relevance of FOM to human health, veterinarians should use q 12 hr FOM 20 mg /kg against E. coli infections with an MIC <16 µg/mL, as suggested by our PK/PD cutoff after AST.

Cerebrospinal fluid drain infection caused by pandrug-resistant Staphylococcus epidermidis successfully treated with ceftaroline in combination with fosfomycin and vancomycin.

External ventricular drain-related cerebrospinal fluid infection represents a fearsome complication of neurosurgical interventions. Although vancomycin represents the standard of care for methicillin-resistant CoNS healthcare-associated ventriculitis, resistance phenomena have been described. We reported a case of a persistent external ventricular fluid drain infection after device removal by pandrug-resistant Staphylococcus epidermidis successfully treated with intravenous ceftaroline in combination with fosfomycin and vancomycin. No evidence regarding pandrug-resistant S. epidermidis therapy currently exists to our knowledge. In this case, the S. epidermidis phenotype emerged during the therapy course, possibly due to initial device retention, biofilm formation and the host immune impaired response. Despite being poorly studied in vivo, ceftaroline may be considered an option when other alternatives are unavailable, thanks to its described activity against CoNS in vitro. This case extends the experience with ceftaroline for central nervous system infections suggesting it could also be used in high antimicrobial resistance settings for immunocompromised people.

In vitro susceptibility to fosfomycin in clinical and environmental extended-spectrum beta-lactamase producing and/or ciprofloxacin-non-susceptible Escherichia coli isolates.

Extended-spectrum beta-lactamase producing and ciprofloxacin-non-susceptible Escherichia coli are clinical and environmental issues. We evaluated the susceptibility profile of fosfomycin in non-susceptible E. coli isolated from urine and the environment. We measured the activity of fosfomycin against 319 and 36 E. coli strains from urine and environmental isolates, respectively, collected from rivers. Fosfomycin resistance profiles were investigated using the minimal inhibitory concentration (MIC), according to the Clinical and Laboratory Standards Institute (CLSI) and the European Committee for Antimicrobial Susceptibility Testing (EUCAST) guidelines. Antibiotic susceptibility testing revealed that 5% and 6.6% of urine samples were non-susceptible to fosfomycin according to CLSI and EUCAST guidelines, respectively. The fosfomycin MIC50/90 was 0.5/4 mg/L. Of the 36 E. coli isolates from river water, 11.1% and 13,8% were non-susceptible to fosfomycin according to CLSI and EUCAST, respectively (range ≤0.25 ≥512 mg/L). All the isolates with MIC ≥512 mg/L for fosfomycin showed the fosA3 gene. Fosfomycin resistance was more frequent in the environment than in clinical samples.

Acute Uncomplicated UTIs in Adults: Rapid Evidence Review.

An acute uncomplicated urinary tract infection (UTI) is a bacterial infection of the lower urinary tract with no sign of systemic illness or pyelonephritis in a noncatheterized, nonpregnant adult with no urologic abnormalities or immunocompromise. In women, a self-diagnosis of a UTI with the presence of typical symptoms (e.g., frequency, urgency, dysuria/burning sensation, nocturia, suprapubic pain), without vaginal discharge, is accurate enough to diagnose an uncomplicated UTI without further testing. Urine culture and susceptibility testing should be reserved for women with recurrent infection, treatment failure, history of resistant isolates, or atypical presentation to make a definitive diagnosis and guide antibiotic selection. First-line antibiotics include nitrofurantoin for five days, fosfomycin in a single dose, trimethoprim for three days, or trimethoprim/sulfamethoxazole for three days. Symptomatic treatment with nonsteroidal anti-inflammatory drugs and delayed antibiotics may be considered because the risk of complications is low. Increased fluids, intake of cranberry products, and methenamine hippurate can prevent recurrent infections. Antibiotic prophylaxis is also effective in preventing recurrence but has a risk of adverse effects and antimicrobial resistance. Men with lower UTI symptoms should always receive antibiotics, with urine culture and susceptibility results guiding the antibiotic choice. Clinicians should also consider the possibility of urethritis and prostatitis in men with UTI symptoms. First-line antibiotics for men with uncomplicated UTI include trimethoprim, trimethoprim/sulfamethoxazole, and nitrofurantoin for seven days. Uncomplicated UTIs in nonfrail women and men 65 years and older with no relevant comorbidities also necessitate a urine culture with susceptibility testing to adjust the antibiotic choice after initial empiric treatment; first-line antibiotics and treatment durations do not differ from those recommended for younger adults.

Back to the Future: Intravenous Fosfomycin is Safe and Effective for the Treatment of Complicated Infections in Children.

BACKGROUND: Despite its broad spectrum and excellent safety profile, fosfomycin is still rarely used in pediatrics, with very limited experience from clinicians. METHODS: We retrospectively reviewed the medical records of all children admitted to Bambino Gesù Children's Hospital, IRCCS, Rome, Italy, and treated with fosfomycin for any serious infection. Children with immunodeficiency and oncologic diseases were excluded. Of each, we reported and analyzed demographic and clinical data. RESULTS: The clinical charts of 20 patients were reviewed and analyzed. The mean age was 10.2 years. Most children were males (85%). Most patients treated had an osteo-articular infection (65%). In our sample, 7 patients (35%) had an underlying comorbidity. The causative agent was isolated in 14 cases (70%). All patients were treated with a combination of 2-3 antibiotics, including fosfomycin. The average duration of antibiotic treatment was 18 days. After treatment, 8 patients (40%) experienced a mild adverse reaction, possibly correlated with the administration of fosfomycin. All patients were discharged in good clinical condition. CONCLUSIONS: The present study reports on a sample of pediatric patients with complicated infections where administration of fosfomycin led to eradication of the disease with little or no side effects. Role of the underlying condition and concomitant medication in causing the reaction could not be ruled out. These data suggest that fosfomycin is an effective and safe antibiotic in the pediatric population, particularly for deep-seated infections sustained by multi-drug resistant pathogens.

Comparison of different regimens of short-term antibiotic prophylaxis in transrectal prostate biopsy.

BACKGROUND: Prostate cancer is the most common malignant solid tumour in men aged >70 years and is the second most common cause of death from oncological circumstances. AIM: To evaluate the effect of different short-term prophylactic antibiotic regimens in transrectal prostate biopsy (PB) on the incidence of infectious complications. METHODS: Patients who underwent transrectal ultrasound-guided PB between January 2021 and December 2022 were included in the prospective randomized study. According to the regimen of prophylaxis, patients were randomized into three groups: (1) fosfomycin trometamol 3 g, 3 h before the procedure + ciprofloxacin 500 mg, 2 h before the procedure; (2) fosfomycin trometamol 3 g, 3 h before and 24 h after the procedure; (3) ciprofloxacin 500 mg 12, 2 h before the procedure, and 12 h after the procedure. A rectal swab was performed 1-2 weeks before PB to evaluate the culture findings. Complications were evaluated during follow-up visits within one month after PB. FINDINGS: In the monitored period, 605 PBs were performed, and 544 patients met the inclusion criteria (184, 161, and 199 in groups 1, 2, and 3). Infectious complications occurred in 10 cases (1.83%), namely 3, 4, and 3 according to patient groups. There was no statistically significant difference between the individual groups. None of the patients required hospitalization and all were free of symptoms of sepsis. CONCLUSION: Short-term antibiotic prophylaxis in PB using fosfomycin trometamol, ciprofloxacin, or their combination appears to be effective. Fosfomycin trometamol is a suitable alternative to fluoroquinolone antibiotics.

Beyond the MEP Pathway: A novel kinase required for prenol utilization by malaria parasites.

A proposed treatment for malaria is a combination of fosmidomycin and clindamycin. Both compounds inhibit the methylerythritol 4-phosphate (MEP) pathway, the parasitic source of farnesyl and geranylgeranyl pyrophosphate (FPP and GGPP, respectively). Both FPP and GGPP are crucial for the biosynthesis of several essential metabolites such as ubiquinone and dolichol, as well as for protein prenylation. Dietary prenols, such as farnesol (FOH) and geranylgeraniol (GGOH), can rescue parasites from MEP inhibitors, suggesting the existence of a missing pathway for prenol salvage via phosphorylation. In this study, we identified a gene in the genome of P. falciparum, encoding a transmembrane prenol kinase (PolK) involved in the salvage of FOH and GGOH. The enzyme was expressed in Saccharomyces cerevisiae, and its FOH/GGOH kinase activities were experimentally validated. Furthermore, conditional knockout parasites (Δ-PolK) were created to investigate the biological importance of the FOH/GGOH salvage pathway. Δ-PolK parasites were viable but displayed increased susceptibility to fosmidomycin. Their sensitivity to MEP inhibitors could not be rescued by adding prenols. Additionally, Δ-PolK parasites lost their capability to utilize prenols for protein prenylation. Experiments using culture medium supplemented with whole/delipidated human plasma in transgenic parasites revealed that human plasma has components that can diminish the effectiveness of fosmidomycin. Mass spectrometry tests indicated that both bovine supplements used in culture and human plasma contain GGOH. These findings suggest that the FOH/GGOH salvage pathway might offer an alternate source of isoprenoids for malaria parasites when de novo biosynthesis is inhibited. This study also identifies a novel kind of enzyme related to isoprenoid metabolism.

Assessing prescription of antibiotics after vaccination against pneumococcal pneumonia; using prescription sequence symmetry analysis.

OBJECTIVES: Prescription sequence symmetry analysis (PSSA) is used to detect adverse event signals using administrative claims databases. In this study, we investigated whether PSSA can be applied to gauge the effects of PCV13 vaccination on antibiotic prescription rates in elderly patients. METHODS: We studied prescription records of patients aged 65 or older between 1 January 2014 and 31 December 2020, from the Helsana Swiss claims database. PSSA was performed to explore the relationship between 13-valent pneumococcal conjugate vaccine (PCV13) and six antibiotics recommended by the Swiss Society of Infectious Diseases for community-acquired pneumonia treatment (amoxicillin-clavulanate, azithromycin, clarithromycin, doxycycline, levofloxacin, and moxifloxacin), three additional antibiotics (amoxicillin, ciprofloxacin, and fosfomycin), and ten control drugs. RESULTS: Amoxicillin-clavulanate, clarithromycin, and levofloxacin were more likely to be prescribed before than after vaccination, for all time windows between 25 and 104 weeks. Adjusted sequence ratio (ASR) values ranged from 0.599 to 0.614, 0.508 to 0.568, and 0.514 to 0.752, respectively. Lower prescription rates after vaccination were also observed for azithromycin (all time windows between 38 and 104 weeks, ASR 0.705-0.739) and moxifloxacin (all time windows between 52 and 104 weeks, ASR 0.658-0.772). PCV13 did not have statistically significant associations with doxycycline, amoxicillin, ciprofloxacin, fosfomycin, or any of the ten controls. DISCUSSION: The lower prescription rate of antibiotics for community-acquired pneumonia after vaccination could be attributed to a protective effect of PCV13. This novel application of PSSA can be used to compare the real-world impact of other vaccines on drug consumption.

Pharmacokinetic/pharmacodynamic analysis of ceftazidime/avibactam and fosfomycin combinations in an in vitro hollow fiber infection model against multidrug-resistant Escherichia coli.

IMPORTANCE: Mechanistic understanding of pharmacodynamic interactions is key for the development of rational antibiotic combination therapies to increase efficacy and suppress the development of resistances. Potent tools to provide those insights into pharmacodynamic drug interactions are semi-mechanistic modeling and simulation techniques. This study uses those techniques to provide a detailed understanding with regard to the direction and strength of the synergy of ceftazidime-avibactam and ceftazidime-fosfomycin in a clinical Escherichia coli isolate expressing extended spectrum beta-lactamase (CTX-M-15 and TEM-4) and carbapenemase (OXA-244) genes. Enhanced killing effects in combination were identified as a driver of the synergy and were translated from static time-kill experiments into the dynamic hollow fiber infection model. These findings in combination with a suppression of the emergence of resistance in combination emphasize a potential clinical benefit with regard to increased efficacy or to allow for dose reductions with maintained effect sizes to avoid toxicity.

Synergistic properties of linezolid against Enterococcus spp. isolates: a systematic review from in vitro studies.

PURPOSE: Vancomycin-resistant enterococci (VRE) are a leading cause of hospital-acquired infections with limited therapeutic options. Combination of at least two antimicrobials is a possible strategy to obtain rapid and sustained bactericidal effects and overcome the emergence of resistance. We revised the literature on linezolid synergistic properties from in vitro studies to assess its activity in combination with molecules belonging to other antibiotic classes against Enterococcus spp. METHODS: We performed a systematic review of the literature from three peer-reviewed databases including papers evaluating linezolid synergistic properties in vitro against Enterococcus spp. isolates. RESULTS: We included 206 Enterococcus spp. isolates (92 E. faecalis, 90 E. faecium, 2 E. gallinarum, 3 E. casseliflavus, 19 Enterococcus spp.) from 24 studies. When an isolate was tested with different combinations, each combination was considered independently for further analysis. The most frequent interaction was indifferent effect (247/343, 72% of total interactions). The highest synergism rates were observed when linezolid was tested in combination with rifampin (10/49, 20.4% of interactions) and fosfomycin (16/84, 19.0%, of interactions). Antagonistic effect accounted for 7/343 (2.0%) of total interactions. CONCLUSION: Our study reported overall limited synergistic in vitro properties of linezolid with other antibiotics when tested against Enterococcus spp. The clinical choice of linezolid in combination with other antibiotics should be guided by reasoned empiric therapy in the suspicion of a polymicrobial infection or targeted therapy on microbiological results, rather than on an intended synergistic effect of the linezolid-based combination.

Parenteral Fosfomycin in Gastrointestinal Surgery: A Systematic Review.

BACKGROUND: To investigate if perioperative parenteral administration of fosfomycin given before or during gastrointestinal surgery could protect against postoperative infectious complications and characterise the administration of fosfomycin and its harms. METHODS: This systematic review included original studies on gastrointestinal surgery where parental administration of fosfomycin was given before or during surgery to≥5 patients. We searched three databases on March 24 2023 and registered the protocol before data extraction (CRD42020201268). Risk of bias was assessed with Cochrane Handbook risk of bias assessment tool or the Newcastle-Ottawa Scale. A narrative description was undertaken. For infectious complications, results from emergency and elective surgery were presented separately. RESULTS: We included 15 unique studies, reporting on 1,029 patients that received fosfomycin before or during gastrointestinal surgery. Almost half of the studies were conducted in the 1980s to early 1990s, and typically a dose of 4 g fosfomycin was given before surgery co-administered with metronidazole and often repeated postoperatively. The risk of bias across studies was moderate to high. The rates of infectious complications were low after fosfomycin; the surgical site infection rate was 0-1% in emergency surgery and 0-10% in elective surgery. If reported, harms were few and mild and typically related to the gastrointestinal system. CONCLUSION: There were few postoperative infectious complications after perioperative parenteral administration of one or more doses of 4 g fosfomycin supplemented with metronidazole in various gastrointestinal procedures. Fosfomycin was associated with few and mild harms.

Role of the phosphotransferase system in the transport of fosfomycin in Escherichia coli.

The inducible inner membrane transporters, UhpT and GlpT are considered to be unique fosfomycin transporters. Glucose-6-phosphate, the substrate for UhpT, enhances fosfomycin activity. Previous work indicates that the fructose phosphotransferase system (PTS) might be involved in fosfomycin transport in the bacterial species, Stenotrophomonas maltophilia. Fosfomycin transport in Escherichia coli has been extensively studied and characterised. The current paper addresses the potential fosfomycin transport activity of the fructose PTS in E. coli. Notably, the deletion of both fructose-specific and general PTS proteins in E. coli increases fosfomycin resistance, which indicates that fructose PTS is involved in fosfomycin transport in E. coli. Further, although inactivation of UhpT, the canonical fosfomycin transporter, in E. coli increases fosfomycin resistance by 2-fold, inactivation of genes encoding the PTS increases it by up to 256-fold. Moreover, intracellular accumulation declines in the absence of both transporters, being mutations in the PTS associated with a larger decline. The results presented in this paper re-open the study of fosfomycin transport and reveal the role of the PTS in the transport of this bactericidal antibiotic in E. coli.