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Cell Host & Microbe May 2023Clostridioides difficile infections (CDIs) remain a healthcare problem due to high rates of relapsing/recurrent CDIs (rCDIs). Breakdown of colonization resistance...
Clostridioides difficile infections (CDIs) remain a healthcare problem due to high rates of relapsing/recurrent CDIs (rCDIs). Breakdown of colonization resistance promoted by broad-spectrum antibiotics and the persistence of spores contribute to rCDI. Here, we demonstrate antimicrobial activity of the natural product class of chlorotonils against C. difficile. In contrast to vancomycin, chlorotonil A (ChA) efficiently inhibits disease and prevents rCDI in mice. Notably, ChA affects the murine and porcine microbiota to a lesser extent than vancomycin, largely preserving microbiota composition and minimally impacting the intestinal metabolome. Correspondingly, ChA treatment does not break colonization resistance against C. difficile and is linked to faster recovery of the microbiota after CDI. Additionally, ChA accumulates in the spore and inhibits outgrowth of C. difficile spores, thus potentially contributing to lower rates of rCDI. We conclude that chlorotonils have unique antimicrobial properties targeting critical steps in the infection cycle of C. difficile.
Topics: Animals; Mice; Swine; Vancomycin; Clostridioides difficile; Anti-Bacterial Agents; Clostridium Infections
PubMed: 37098342
DOI: 10.1016/j.chom.2023.04.003 -
ACS Infectious Diseases Jul 2023Traditional antibacterial screens rely on growing bacteria in nutrient-replete conditions which are not representative of the natural environment or sites of infection....
Traditional antibacterial screens rely on growing bacteria in nutrient-replete conditions which are not representative of the natural environment or sites of infection. Instead, screening in more physiologically relevant conditions may reveal novel activity for existing antibiotics. Here, we screened a panel of antibiotics reported to lack activity against the opportunistic Gram-negative bacterium, , under low-nutrient and low-iron conditions, and discovered that the glycopeptide vancomycin inhibited the growth of at low micromolar concentrations through its canonical mechanism of action, disruption of peptidoglycan crosslinking. Spontaneous vancomycin-resistant mutants underwent activating mutations in the sensor kinase of the two-component CpxSR system, which induced cross-resistance to almost all classes of β-lactams, including the siderophore antibiotic cefiderocol. Other mutations that conferred vancomycin resistance mapped to WapR, an α-1,3-rhamnosyltransferase involved in lipopolysaccharide core biosynthesis. A WapR P164T mutant had a modified LPS profile compared to wild type that was accompanied by increased susceptibility to select bacteriophages. We conclude that screening in nutrient-limited conditions can reveal novel activity for existing antibiotics and lead to discovery of new and impactful resistance mechanisms.
Topics: Vancomycin; Pseudomonas aeruginosa; Anti-Bacterial Agents; Glycopeptides; Nutrients
PubMed: 37279282
DOI: 10.1021/acsinfecdis.3c00167 -
Immunity, Inflammation and Disease Aug 2022Early life exposures to antibiotics negatively impact respiratory health and are associated with an increased risk of childhood asthma. It is explained that the lung is...
Early life exposures to antibiotics negatively impact respiratory health and are associated with an increased risk of childhood asthma. It is explained that the lung is inclined to develop chronic inflammatory phenotypes due to early antibiotic alteration in the gut microbiome. We investigated whether a gut-targeted antibiotic has an impact on the lung microbiome and on pulmonary immunity. Fourteen-day old C57BL/6 mice were administered with vancomycin via oral gavage for 3 days (1 time/day). Control groups were treated with clarithromycin and phosphate-buffered saline (PBS), respectively. Five days after treatment, the cecum and lung microbiome, and pulmonary immune response were analyzed. Vancomycin treatment decreased the relative abundance of the genera Clostridium XIVa and Alistipes and the family Lachnospiraceae in the cecum. Furthermore, the relative abundance of the family Parabacteroidetes and the genus Lactobacillus were increased, whereas the abundance of the phylum Firmicutes was decreased. In the lung, vancomycin treatment reduced bacteria belonging to Clostridium XIVa and the family Lachnospiraceae as compared to those in the clarithromycin treated group. Lung cells from the vancomycin-treated mice released higher levels of interleukin (IL)-4 and IL-13 compared to those from the PBS group, and increased levels of IL-6, IFN-γ, and TNFα compared to lung cells from the clarithromycin and PBS treated mice. Our pilot study suggests that alteration in the gut microbiome could affect bacterial composition and immunity of the lung hence proposes a gut-lung microbiome axis in early life.
Topics: Animals; Anti-Bacterial Agents; Bacteria; Clarithromycin; Immunity; Lung; Mice; Mice, Inbred C57BL; Microbiota; Pilot Projects; Vancomycin
PubMed: 35894712
DOI: 10.1002/iid3.675 -
Injury Aug 2022Cannulated screws are often used in the management of open lower extremity fractures. These fractures exhibit broad contamination profiles, necessitating empirical...
Concentrations of co-administered vancomycin and meropenem in the internal dead space of a cannulated screw and in cancellous bone adjacent to the screw - Evaluated by microdialysis in a porcine model.
BACKGROUND
Cannulated screws are often used in the management of open lower extremity fractures. These fractures exhibit broad contamination profiles, necessitating empirical Gram-positive and Gram-negative antibiotic coverage. To ensure full antibiotic protection of the cannulated screw and the bone tissue, it is generally accepted that target tissue antibiotic concentrations, as a minimum, reach and remain above relevant epidemiological cut-off minimal inhibitory concentrations (T>MIC) for a sufficient amount of time.
METHODS
8 female pigs were included. Microdialysis catheters were placed in the internal dead space of a cannulated screw placed in tibial cancellous bone, in tibial cancellous bone adjacent to the screw (mean distance to the screw: 3 mm), and in cancellous bone on the contralateral tibia. Following single-dose simultaneous intravenous administrations of vancomycin (1000 mg) and meropenem (1000 mg), microdialysates and plasma were dynamically sampled over 8 h. The applied MIC targets ranged from 1 to 4 µg/mL for vancomycin and 0.125-2 µg/mL for meropenem RESULTS: For both drugs, and for all MIC targets investigated (except for the high vancomycin target: 4 µg/mL), the internal dead space of the cannulated screw had the shortest T>MIC. At the low MIC targets T>MIC ranged between 88 and 449 min across sampling sites for vancomycin (1 µg/mL), and 148-406 min for meropenem (0.125 µg/mL). For the high MIC targets, T>MIC ranged between 3 and 446 min for vancomycin (4 μg/mL) and 17-181 min for meropenem (2 μg/mL). Vancomycin displayed longer T>MIC (2 and 4 μg/mL), higher area under the concentration time curve (AUC) and peak drug concentration in the proximal tibial cancellous bone without a screw nearby. For meropenem, only the cancellous bone AUC was significantly higher on the side with no screw.
CONCLUSION
We found short T>MIC, particularly for the high MIC targets for vancomycin and meropenem, both inside the cannulated screw and in cancellous bone adjacent to the screw. The presence of a cannulated screw impaired the penetration of especially vancomycin into cancellous bone adjacent to the screw. More aggressive or different vancomycin and meropenem approaches may be considered to encompass contaminating differences and to ensure a theoretically more sufficient antibiotic protection of cannulated screws when used in the management of open lower extremity fractures.
Topics: Animals; Anti-Bacterial Agents; Cancellous Bone; Female; Meropenem; Microdialysis; Swine; Vancomycin
PubMed: 35710595
DOI: 10.1016/j.injury.2022.06.008 -
Journal of Global Antimicrobial... Mar 2021To determine whether an inhaled vancomycin formulation resulting in high intrapulmonary 24-h area under the concentration-time curve (AUC) could be optimised for...
OBJECTIVES
To determine whether an inhaled vancomycin formulation resulting in high intrapulmonary 24-h area under the concentration-time curve (AUC) could be optimised for tuberculosis treatment. We also explored vancomycin synergy and antagonism with d-cycloserine and benzylpenicillin.
METHODS
We determined MICs of two Mycobacterium tuberculosis (Mtb) laboratory strains (H37Ra and H37Rv) and two drug-susceptible and nine multidrug resistant clinical strains. Second, in the hollow fiber system model of TB [HFS-TB] using Mtb H37Ra strain, we recapitulated vancomycin intrapulmonary pharmacokinetics of eight doses administered twice daily over 28 days, mimicking a 6-h half-life. Using the HFS-TB, vancomycin was tested in combination with d-cycloserine and benzylpenicillin to determine synergy or antagonism between drugs targeting the same pathway.
RESULTS
Vancomycin MICs were 12 and 48 mg/L in drug-susceptible clinical isolates but >96 mg/L in all MDR isolates.In the HFS-TB, vancomycin killed 3.9 ± 0.6 log CFU/mL Mtb. The EC was calculated as AUC/MIC of 184.6 ± 106.5. Compared with day 0, 1.0 and 2.0 log CFU/mL kill was achieved by AUC/MIC of 168 and 685, respectively. Acquired vancomycin resistance developed to all vancomycin doses tested in the HFS-TB. In the HFS-TB, vancomycin was antagonistic to benzylpenicillin, which works downstream to glycopeptides in peptidoglycan synthesis, but synergistic with d-cycloserine, which inhibits upstream d-Ala-d-Ala ligase and alanine racemase.
CONCLUSION
Our proof-of-concept studies show that vancomycin optimal exposure target for Mtb kill could be achieved via inhalational drug delivery. Addition of drugs synergistic with vancomycin, e.g. d-cycloserine, may lower the vancomycin concentrations required to kill Mtb.
Topics: Antitubercular Agents; Microbial Sensitivity Tests; Mycobacterium tuberculosis; Vancomycin
PubMed: 33508482
DOI: 10.1016/j.jgar.2021.01.005 -
The Journal of Infectious Diseases Jan 2024Clostridioides difficile infection (CDI) is a common healthcare-associated infection with limited treatment options. Omadacycline, an aminomethylcycline tetracycline,... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Clostridioides difficile infection (CDI) is a common healthcare-associated infection with limited treatment options. Omadacycline, an aminomethylcycline tetracycline, has potent in vitro activity against C difficile and a low propensity to cause CDI in clinical trials. We aimed to assess fecal pharmacokinetics and gut microbiome effects of oral omadacycline compared to oral vancomycin in healthy adults.
METHODS
This was a phase 1, nonblinded, randomized clinical trial conducted in healthy volunteers aged 18-40 years. Subjects received a 10-day course of omadacycline or vancomycin. Stool samples were collected at baseline, daily during therapy, and at follow-up visits. Omadacycline and vancomycin stool concentrations were assessed, and microbiome changes were compared.
RESULTS
Sixteen healthy volunteers with a mean age of 26 (standard deviation [SD], 5) years were enrolled; 62.5% were male, and participants' mean body mass index was 23.5 (SD, 4.0) kg/m2. Omadacycline was well tolerated with no safety signal differences between the 2 antibiotics. A rapid initial increase in fecal concentrations of omadacycline was observed compared to vancomycin, with maximum concentrations achieved within 48 hours. A significant difference in alpha diversity was observed following therapy in both the omadacycline and vancomycin groups (P < .05). Bacterial abundance and beta diversity analysis showed differing microbiome changes in subjects who received omadacycline versus vancomycin.
CONCLUSIONS
Subjects given omadacycline had high fecal concentrations with a distinct microbiome profile compared to vancomycin.
CLINICAL TRIALS REGISTRATION
NCT06030219.
Topics: Adult; Humans; Male; Female; Vancomycin; Gastrointestinal Microbiome; Healthy Volunteers; Anti-Bacterial Agents; Tetracyclines; Clostridium Infections
PubMed: 38051631
DOI: 10.1093/infdis/jiad537 -
Emergence of Clinical Clostridioides difficile Isolates With Decreased Susceptibility to Vancomycin.Clinical Infectious Diseases : An... Jan 2022Clostridioides difficile infection (CDI) is a leading cause of hospital-associated antibiotic-related diarrhea and deaths worldwide. Vancomycin is one of the few...
BACKGROUND
Clostridioides difficile infection (CDI) is a leading cause of hospital-associated antibiotic-related diarrhea and deaths worldwide. Vancomycin is one of the few antibiotics recommended for both nonsevere and severe CDI cases. We sought to determine whether vancomycin nonsusceptible C. difficile strains are circulating in the patient population.
METHODS
Stool samples from patients with CDI were collected from 438 and 98 patients at a large university hospital in Houston, Texas, and Nairobi, Kenya, respectively. The stools were examined for the presence of vancomycin and metronidazole nonsusceptible C. difficile using broth dilution culture, Etest (BioMérieux, France), polymerase chain reaction (PCR), whole-genome sequencing, and in vivo testing in a CDI mouse model.
RESULTS
Of the Houston stool samples, 114/438 (26%) had vancomycin nonsusceptible C. difficile isolates and 128/438 (29%) were metronidazole nonsusceptible. Similarly, 66 out of 98 (67%) and 83/98 (85%) of the Nairobi patients harbored vancomycin and metronidazole nonsusceptible isolates, respectively. Vancomycin treatment of a CDI mouse model infected with a vancomycin nonsusceptible isolate failed to eradicate the infection. Whole-genome sequencing analyses did not identify vanA genes, suggesting a different mechanism of resistance.
CONCLUSIONS
C. difficile strains exhibiting reduced susceptibility to vancomycin are currently circulating in patient populations. The spread of strains resistance to vancomycin, a first-line antibiotic for CDI, poses a serious therapeutic challenge. Routine susceptibility testing may be necessary.
Topics: Animals; Anti-Bacterial Agents; Clostridioides; Clostridioides difficile; Clostridium Infections; Humans; Kenya; Mice; Vancomycin
PubMed: 35016207
DOI: 10.1093/cid/ciaa912 -
Pharmacology & Therapeutics Jun 2023As one of the efficient techniques for TDM, the population pharmacokinetic (popPK) model approach for dose individualization has been developed due to the rapidly... (Review)
Review
Bayesian prediction-based individualized dosing of anti-methicillin-resistant Staphylococcus aureus treatment: Recent advancements and prospects in therapeutic drug monitoring.
As one of the efficient techniques for TDM, the population pharmacokinetic (popPK) model approach for dose individualization has been developed due to the rapidly growing innovative progress in computer technology and has recently been considered as a part of model-informed precision dosing (MIPD). Initial dose individualization and measurement followed by maximum a posteriori (MAP)-Bayesian prediction using a popPK model are the most classical and widely used approach among a class of MIPD strategies. MAP-Bayesian prediction offers the possibility of dose optimization based on measurement even before reaching a pharmacokinetically steady state, such as in an emergency, especially for infectious diseases requiring urgent antimicrobial treatment. As the pharmacokinetic processes in critically ill patients are affected and highly variable due to pathophysiological disturbances, the advantages offered by the popPK model approach make it highly recommended and required for effective and appropriate antimicrobial treatment. In this review, we focus on novel insights and beneficial aspects of the popPK model approach, especially in the treatment of infectious diseases with anti-methicillin-resistant Staphylococcus aureus agents represented by vancomycin, and discuss the recent advancements and prospects in TDM practice.
Topics: Humans; Anti-Bacterial Agents; Bayes Theorem; Methicillin-Resistant Staphylococcus aureus; Drug Monitoring; Vancomycin
PubMed: 37149156
DOI: 10.1016/j.pharmthera.2023.108433 -
International Journal of Antimicrobial... Jan 2024To illustrate the impact of errors in documented dose administration time on therapeutic drug monitoring (TDM)-based target attainment evaluation for vancomycin and...
OBJECTIVES
To illustrate the impact of errors in documented dose administration time on therapeutic drug monitoring (TDM)-based target attainment evaluation for vancomycin and meropenem, and to explore the influence of drug and patient characteristics, and TDM sampling strategies.
METHODS
Bedside observations of errors in documented dose administration times were collected. Population pharmacokinetic simulations were performed for vancomycin and meropenem, evaluating different one- and two-sampling strategies for populations with estimated creatinine clearance (CLcr) of 30, 80 or 130 mL/min. The impact of errors was evaluated as the proportion of individuals incorrectly considered to have reached the target.
RESULTS
Of 143 observed dose administrations, 97% of doses were given within ±30 min of the documented time. For vancomycin, a +30 min error was predicted to result in a 0.1-3.9 percentage point increase of cases incorrectly evaluated as reaching area under the concentration-time curve during a 24-hour period (AUC)/minimum inhibitory concentration (MIC) >400, with the largest increase for patients with augmented renal clearance and peak and trough sampling. For meropenem, a +30 min error resulted in a 1.3-6.4 and 0-20 percentage point increase of cases incorrectly evaluated as reaching 100% T, and 50% T, respectively. Overall, mid-dose and trough sampling was most favourable for both antibiotics.
CONCLUSIONS
For vancomycin, simulations indicate that TDM-based target attainment evaluation is robust with respect to the observed errors in dose administration time of ±30 min; however, the errors had a potentially clinically important impact in patients with augmented renal clearance. For meropenem, extra measures to promote correct documentation are warranted when using TDM, as the impact of errors was evident even in patients with normal renal function.
Topics: Humans; Vancomycin; Meropenem; Drug Monitoring; Anti-Bacterial Agents; Kidney Function Tests; Renal Insufficiency
PubMed: 37956952
DOI: 10.1016/j.ijantimicag.2023.107032 -
Medicine Oct 2019The clinical significance of using vancomycin loading dose remains controversial. A systematic review and meta-analysis were performed to assess the clinical efficacy... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The clinical significance of using vancomycin loading dose remains controversial. A systematic review and meta-analysis were performed to assess the clinical efficacy and safety of vancomycin loading dose in the treatment of infections.
METHODS
The Pubmed, Embase, Web of Science, and Cochrane Library databases were searched from their inception up to 5 May 2019. Randomized controlled trials (RCTs) and other observational studies were included if they provided clinical outcomes or trough concentrations of vancomycin loading dose (20-30 mg/kg) and conventional-dose (10-20 mg/kg) in the treatment of infections. Achievement of therapeutic concentration (serum trough concentrations of vancomycin reached 15-20 mg/L before the second dose), clinical response (clinical improvement or culture-negative), nephrotoxicity (serum creatinine increase ≥0.5 mg/dL or ≥50% increasing from the baseline), other adverse events (including pruritus, flushing, rash, and/or red man syndrome), and mortality were analyzed. Heterogeneity was identified using the Cochrane I statistic, and P-value <.10 or I-values >50% indicated significant heterogeneity. Pooled estimates of the intervention effects were determined by the odds ratios (ORs) and 95% confidence intervals (CIs) in Review Manager program, version 5.3.5.
RESULTS
Two RCTs and 7 cohort studies including 2816 infected patients were selected for the analysis, in which serum trough concentrations of vancomycin following the use of vancomycin loading dose or other outcomes were available. Loading dose group had a significantly higher compliance rate of serum trough concentration of 15 to 20 mg/L (OR = 3.06; 95% CI = 1.15-8.15; P = .03) and significantly lower incidence of nephrotoxicity (OR = 0.59, 95% CI = 0.40-0.87; P = .008; I = 29%) compared with control group. No significant difference was noted between loading dose group and control group in terms of other adverse events and clinical response (OR = 1.98, 95% CI = 0.80-4.93; P = .14; I = 0%). The use of vancomycin loading doses in patients can indeed increase the achievement of therapeutic concentration.
CONCLUSION
Vancomycin loading dose increases the achievement of therapeutic concentration without bringing extra risk of nephrotoxicity. However, well-designed large-scale RCTs remain needed to validate the clinical efficacy of vancomycin loading dose and to further evaluate other adverse reactions and mortality.PROSPERO registration number CRD42018093927.
Topics: Anti-Bacterial Agents; Bacterial Infections; Drug Administration Schedule; Humans; Treatment Outcome; Vancomycin
PubMed: 31651882
DOI: 10.1097/MD.0000000000017639