Tigecycline is unique glycylcycline class of semisynthetic antimicrobial agents developed for the treatment of polymicrobial infections caused by multidrug-resistant Gram-positive and Gram-negative ...pathogens. Tigecycline evades the main tetracycline resistance genetic mechanisms, such as tetracycline-specific efflux pump acquisition and ribosomal protection, via the addition of a glycyclamide moiety to the 9-position of minocycline. The use of the parenteral form of tigecycline is approved for complicated skin and skin structure infections (excluding diabetes foot infection), complicated intra-abdominal infections, and community-acquired bacterial pneumonia in adults. New evidence also suggests the effectiveness of tigecycline for the treatment of severe
Clostridioides difficile
infections. Tigecycline showed in vitro susceptibility to
Coxiella
spp.,
Rickettsia
spp., and multidrug-resistant
Neisseria gonnorrhoeae
strains which indicate the possible use of tigecycline in the treatment of infections caused by these pathogens. Except for intrinsic, or often reported resistance in some Gram-negatives, tigecycline is effective against a wide range of multidrug-resistant nosocomial pathogens. Herein, we summarize the currently available data on tigecycline pharmacokinetics and pharmacodynamics, its mechanism of action, the epidemiology of tigecycline resistance, and its clinical effectiveness.
•Oral administration of metronidazole results in low concentration in stool.•A low concentration of metronidazole prolongs Clostridioides difficile shedding.•Oral vancomycin and fidaxomicin reach ...very high concentrations in the stool.•A high concentration of vancomycin also suppresses gram-negative anaerobes.•Fidaxomicin has a narrow spectrum of antimicrobial activity and persists on spores.
Recently, the recommendations for the treatment of Clostridioides difficile infection (CDI) have been updated. However, in addition to the clinical efficacy data, the drug of choice should ideally represent optimal antimicrobial stewardship, with an emphasis on rapid restoration of the gut microbiota to minimize the risk of infection relapses. Oral administration of metronidazole results in low concentration in stool, and interaction with fecal microbiota reduces its antimicrobial bioactivity. Reported elevated minimum inhibitory concentrations of metronidazole in epidemic C. difficile ribotypes and the emergence of plasmid-mediated resistance to metronidazole represent additional potential risks for clinical failure. If metronidazole is the only CDI treatment option, antimicrobial susceptibility testing on agar containing heme should be performed in C. difficile isolate. Compared with metronidazole, oral vancomycin and fidaxomicin reach very high concentrations in the stool, and therefore can quickly reduce C. difficile shedding. Health care facilities with higher CDI incidence and/or occurrence of epidemic ribotypes should not use metronidazole because prolonged C. difficile shedding can increase the risk for further C. difficile transmission. Only fidaxomicin has a narrow spectrum of antimicrobial activity, which might be, together with persistence on spores, the main contributing factor to reduce the recurrent CDI rates.
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In 2009, the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) published the first treatment guidance document for Clostridioides difficile infection (CDI). This document was ...updated in 2014. The growing literature on CDI antimicrobial treatment and novel treatment approaches, such as faecal microbiota transplantation (FMT) and toxin-binding monoclonal antibodies, prompted the ESCMID study group on C. difficile (ESGCD) to update the 2014 treatment guidance document for CDI in adults.
Key questions on CDI treatment were formulated by the guideline committee and included: What is the best treatment for initial, severe, severe-complicated, refractory, recurrent and multiple recurrent CDI? What is the best treatment when no oral therapy is possible? Can prognostic factors identify patients at risk for severe and recurrent CDI and is there a place for CDI prophylaxis? Outcome measures for treatment strategy were: clinical cure, recurrence and sustained cure. For studies on surgical interventions and severe-complicated CDI the outcome was mortality. Appraisal of available literature and drafting of recommendations was performed by the guideline drafting group. The total body of evidence for the recommendations on CDI treatment consists of the literature described in the previous guidelines, supplemented with a systematic literature search on randomized clinical trials and observational studies from 2012 and onwards. The Grades of Recommendation Assessment, Development and Evaluation (GRADE) system was used to grade the strength of our recommendations and the quality of the evidence. The guideline committee was invited to comment on the recommendations. The guideline draft was sent to external experts and a patients' representative for review. Full ESCMID endorsement was obtained after a public consultation procedure.
Important changes compared with previous guideline include but are not limited to: metronidazole is no longer recommended for treatment of CDI when fidaxomicin or vancomycin are available, fidaxomicin is the preferred agent for treatment of initial CDI and the first recurrence of CDI when available and feasible, FMT or bezlotoxumab in addition to standard of care antibiotics (SoC) are preferred for treatment of a second or further recurrence of CDI, bezlotoxumab in addition to SoC is recommended for the first recurrence of CDI when fidaxomicin was used to manage the initial CDI episode, and bezlotoxumab is considered as an ancillary treatment to vancomycin for a CDI episode with high risk of recurrence when fidaxomicin is not available. Contrary to the previous guideline, in the current guideline emphasis is placed on risk for recurrence as a factor that determines treatment strategy for the individual patient, rather than the disease severity.
•For 271 patients with Clostridioides difficile (CDI) clinical outcome was recorded (sustained clinical cure or recurrence).•Fidaxomicin was a superior treatment to metronidazole or vancomycin in the ...initial episode.•Fidaxomicin was a superior treatment to metronidazole or vancomycin in the first recurrence.•Fidaxomicin was a superior treatment to metronidazole or vancomycin in non-severe CDI.•Fidaxomicin had a similar treatment outcome to vancomycin in severe and multiple recurrent CDI.
We aimed to evaluate the efficacy of different antibiotic regimens for the treatment of Clostridioides difficile infection (CDI) with regard to the CDI episode number and disease severity.
An observation cohort study included 271 CDI patients hospitalised between 2013–2016. Univariate logistic regression was used to evaluate the association between patients’ clinical outcome (sustained clinical cure or recurrence) in a 60-day follow-up and the antibiotic regimen used (oral metronidazole, oral vancomycin, combination of oral vancomycin and metronidazole, oral fidaxomicin). Subgroup analyses, based on CDI episode number and severity, were performed.
In the overall population, fidaxomicin was superior to metronidazole, vancomycin or their combination, for a sustained clinical response and in the prevention of recurrent CDI (rCDI).
In the subgroup analyses, fidaxomicin was superior to vancomycin or metronidazole for a sustained clinical response and in the prevention of rCDI in the initial episode, first recurrence and non-severe cases. In the oral treatment of severe CDI, fidaxomicin had a similar treatment outcome to vancomycin and none of the antibiotic treatments were superior in the prevention of rCDI. Fidaxomicin, vancomycin, or a combination of metronidazole and vancomycin, had similar outcomes for sustained clinical response and prevention of rCDI in patients with multiple rCDI.
Fidaxomicin was superior to metronidazole or vancomycin for the treatment of the initial episode, first recurrence, and non-severe CDI.
Successful treatment of cancer remains a challenge, due to the unique pathophysiology of solid tumors, and the predictable emergence of resistance. Traditional methods for cancer therapy including ...radiotherapy, chemotherapy, and immunotherapy all have their own limitations. A novel approach is bacteriotherapy, either used alone, or in combination with conventional methods, has shown a positive effect on regression of tumors and inhibition of metastasis. Bacteria‐assisted tumor‐targeted therapy used as therapeutic/gene/drug delivery vehicles has great promise in the treatment of tumors. The use of bacteria only, or in combination with conventional methods was found to be effective in some experimental models of cancer (tumor regression and increased survival rate). In this article, we reviewed the major advantages, challenges, and prospective directions for combinations of bacteria with conventional methods for tumor therapy.
In this report, we reviewed the major advantages, challenges, and prospective directions for combination of conventional methods and bacteria for tumor therapy.
We investigated the occurrence of plasmid-mediated colistin resistance in
Enterobacteriaceae
in turkey meat produced in the Czech Republic as well as in turkey meat imported into the Czech Republic ...from other European Union countries. Seventeen samples of raw turkey meat from the Czech Republic (
n
= 4), Hungary (
n
= 2), Poland (
n
= 6) and Germany (
n
= 5) were cultured in peptone water at 37 °C overnight and the enriched cultures were tested for the presence of
mcr-1-5
genes. PCR-positive enriched cultures were inoculated onto selective agar with colistin (3.5 mg/L). A minimal inhibitory concentration (MIC) of colistin was determined by using the broth microdilution method in PCR-positive isolates. In addition, a macrorestriction analysis was performed using
Xba
I endonuclease. Of 17 meat samples, 12 samples from Poland (6/6), Germany (3/5) and the Czech Republic (3/4) proved positive for the presence of the
mcr-1
gene. Forty-two isolates carrying the
mcr-1
gene were obtained:
Escherichia coli
(
n
= 39) revealing 32 distinct
Xba
I profiles and
Klebsiella pneumoniae
(
n
= 3) with 2 distinct
Xba
I profiles. The minimal inhibitory concentration (MIC) of the
mcr-1
positive isolates was as follows: 4 mg/L (
n
= 28), 8 mg/L (
n
= 12), 32 mg/L (
n
= 1) and 64 mg/L (
n
= 1). The high prevalence (70.6%; 12/17 samples) of
mcr-1-
mediated colistin-resistant
Enterobacteriaceae
found in the turkey meat samples analysed in this study, builds on previously published evidence that poultry, and their products, represent a substantial risk for the dissemination of plasmid-mediated colistin resistance in Europe.
Clostridioides difficile infections (CDI) are traditionally attributed to an older adult patient group but children can also be affected. Although the causative pathogen is the same in both ...populations, the management of CDI may differ.
To discuss the current literature on CDI in the paediatric population and to provide CDI diagnostics and treatment guidance.
The literature was drawn from a search of PubMed from January 2017 to July 2021.
In the paediatric population, laboratory diagnostics for CDI should preferably be combined with laboratory diagnostics for other gastrointestinal pathogens. Coinfections of CDI are also possible. Though the detection of toxigenic C. difficile using a molecular assay may simply reflect colonisation rather than infection, detection of C. difficile free toxins A/B in faeces is much more indicative of true infection. CDI in children below 2 years of age and in the absence of risk factors is very difficult to diagnose and requires careful clinical judgement pending additional studies.
Fidaxomicin has been shown to be superior to vancomycin with a sustained clinical response up to 30 days after the end of CDI treatment in children. Metronidazole is less effective than vancomycin in adults and there are no supporting data for its use in children. In recurrent CDI, treatment should be adjusted according to the drug or drug regimen used for the treatment of a previous episode(s). In multiple recurrent CDI, faecal microbiota transplantation can be effective.
If CDI laboratory testing is indicated in children with diarrhoea, the likelihood of C. difficile colonisation and coinfection with other intestinal pathogens should be considered. The currently available data support a change in the treatment strategy of CDI in children.
Clostridioides (Clostridium) difficile is an important pathogen of healthcare- associated diarrhea, however, an increase in the occurrence of C. difficile infection (CDI) outside hospital settings ...has been reported. The accumulation of antimicrobial resistance in C. difficile can increase the risk of CDI development and/or its spread. The limited number of antimicrobials for the treatment of CDI is matter of some concern.
In order to summarize the data on antimicrobial resistance to C. difficile derived from humans, a systematic review and meta-analysis were performed.
We searched five bibliographic databases: (MEDLINE PubMed, Scopus, Embase, Cochrane Library and Web of Science) for studies that focused on antimicrobial susceptibility testing in C. difficile and were published between 1992 and 2019. The weighted pooled resistance (WPR) for each antimicrobial agent was calculated using a random- effects model.
A total of 111 studies were included. The WPR for metronidazole and vancomycin was 1.0% (95% CI 0-3%) and 1% (95% CI 0-2%) for the breakpoint > 2 mg/L and 0% (95% CI 0%) for breakpoint ≥32 μg/ml. Rifampin and tigecycline had a WPRs of 37.0% (95% CI 18-58%) and 1% (95% CI 0-3%), respectively. The WPRs for the other antimicrobials were as follows: ciprofloxacin 95% (95% CI 85-100%), moxifloxacin 32% (95% CI 25-40%), clindamycin 59% (95% CI 53-65%), amoxicillin/clavulanate 0% (0-0%), piperacillin/tazobactam 0% (0-0%) and ceftriaxone 47% (95% CI 29-65%). Tetracycline had a WPR 20% (95% CI 14-27%) and meropenem showed 0% (95% CI 0-1%); resistance to fidaxomicin was reported in one isolate (0.08%).
Resistance to metronidazole, vancomycin, fidaxomicin, meropenem and piperacillin/tazobactam is reported rarely. From the alternative CDI drug treatments, tigecycline had a lower resistance rate than rifampin. The high-risk antimicrobials for CDI development showed a high level of resistance, the highest was seen in the second generation of fluoroquinolones and clindamycin; amoxicillin/clavulanate showed almost no resistance. Tetracycline resistance was present in one fifth of human clinical C. difficile isolates.
Clostridioides difficile is one of the most important human pathogens. The identification of its possible sources is important for the understanding of C. difficile infection (CDI) epidemiology. A ...total of 16 water samples from wastewater and surface water in South Moravia in the Czech Republic and 82 samples of fish and gulls were collected between May and July 2019. C. difficile isolates were cultured by direct plating and after enrichment on chromogenic media. Susceptibility testing to eight antimicrobials was performed by Etest. C. difficile isolates were characterized by ribotyping, multilocus sequence typing, multilocus tandem repeats analysis, and toxin gene detection. Samples from fish and gulls were C. difficile negative; a total of 15 C. difficile isolates from 8 out of 16 water samples were cultured (6 out of 14 surface water samples yielded 6 isolates, and 2 out of 2 wastewater samples yielded 9 isolates). Direct plating was culture positive in 6 out of 16 samples (12 isolates), and enrichment culture was positive in an additional 2 out of 16 samples (3 isolates). Twelve different ribotyping profiles and 14 sequence types of clades 1, 4, and 5 were identified. Five isolates did not carry genes for toxins, and eight isolates carried genes for toxins A and B; the remaining two isolates (RT078) carried the genes for toxins A, B, and binary. All C. difficile isolates were susceptible to amoxicillin, moxifloxacin, tetracycline, and vancomycin and resistant to ciprofloxacin. A high level of erythromycin resistance (>256 mg/L) was detected in eight isolates. Clindamycin resistance was found in 14 isolates, 6 of which showed a high level of resistance (>256 mg/L) and carried ermB. Surprisingly, one isolate (RT010, ST15) showed resistance to metronidazole (12 mg/L) with the presence of the plasmid pCD-METRO. In conclusion, a diverse spectrum of C. difficile strains was found in wastewater and surface water. A recently discovered plasmid-bound resistance to metronidazole was detected in C. difficile from the surface water sample. IMPORTANCE The combination of direct plating and culture after enrichment was used in order to gain a spectrum of C. difficile ribotypes present in the water samples. Toxigenic C. difficile ribotypes detected in surface water and in wastewater treatment plants overlapped with those derived from patients with CDI and/or animals. Importantly, a recently discovered plasmid-mediated resistance to metronidazole, a drug used for the treatment of CDI, was detected in C. difficile from river water.
Antimicrobial resistance of H. pylori can lead to treatment failure. Importantly, several studies have reported on heteroresistance, i.e. the presence of resistant and susceptible H. pylori ...populations in the same sample and/or a difference in the susceptibility patterns between biopsy samples. This meta-analysis aims to provide comprehensive data on the prevalence of metronidazole and clarithromycin heteroresistance and the approaches to their detection.
A systematic review was performed after the search of MEDLINE, Scopus and Web of Science. The study outcomes were the weighted pooled prevalence of heteroresistance to clarithromycin and metronidazole in H. pylori positive samples and/or isolates with a subanalysis by continent.
A total of 22 studies that had investigated 3852 H. pylori positive patients were included in the meta-analysis. Heteroresistance to clarithromycin was reported in 20 studies, with a weighted pooled prevalence of 6.8% (95% CI 5.1-8.6; 3654 H. pylori positive patients; the substantial heterogeneity I
= 55.6%). Heteroresistance to metronidazole was reported in 12 studies, with a weighted pooled prevalence of 13.8% (95% CI 8.9-18.6; 1670 H. pylori positive patients; the substantial heterogeneity I
= 60.9%). The weighted pooled prevalence of clarithromycin heteroresistance was similar in Asia and Europe (p = 0.174584), however, metronidazole heteroresistance was detected more often in Europe (p < 0.00001). Clarithromycin heteroresistance was detected more often by phenotype rather than by using genotyping methods (12 vs 8 studies), whereas heteroresistance to metronidazole was detected only by phenotype.
The prevalence of heteroresistance to clarithromycin and/or metronidazole is not negligible and can be detected in approximately 7 and 14% of H. pylori positive samples, respectively. These findings highlight the need to raise the awareness of gastroenterologists and microbiologists to the heteroresistance to clarithromycin and metronidazole in patients with a H. pylori infection.
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