Role of cephalosporins in the era of Clostridium difficile infection

Current and Ongoing Developments in Targeting Clostridioides difficile Infection and Recurrence

Clostridioides difficile is a Gram-positive, spore-forming anaerobic bacterial pathogen that causes severe gastrointestinal infection in humans. This review provides background information on C. difficile infection and the pathogenesis and toxigenicity of C. difficile. The risk factors, causes, and the problem of recurrence of disease and current therapeutic treatments are also discussed. Recent therapeutic developments are reviewed including small molecules that inhibit toxin formation, disrupt the cell membrane, inhibit the sporulation process, and activate the host immune system in cells. Other treatments discussed include faecal microbiota treatment, antibody-based immunotherapies, probiotics, vaccines, and violet-blue light disinfection.

The Extent of Antibiotic Dispensing in Self-Medication Encounters in Sudan: A Simulated Patient Study Focusing on Cefixime Sale

Background

Antibiotics play an important role in decreasing morbidity and mortality worldwide. However, inappropriate use of them by patients or healthcare professionals contributes to their resistance rendering them less efficacious. Community pharmacists (CPs) have a significant part in reducing antibiotic resistance. Therefore, this study aimed to investigate the dispensing of antibiotics without prescription in community pharmacies with an emphasis on cefixime dispensing.

Methods

A cross-sectional, simulated patient (SP) study was conducted in the Khartoum locality. A total of 238 community pharmacies were randomly chosen using simple random sampling. One scenario of uncomplicated urinary tract infection was designed, and six female pharmacy students who were trained to act as SPs presented the scenario. Descriptive statistics were applied to report the study outcomes.

Results

In the 238 pharmacy visits, at least one antibiotic was dispensed without a prescription in 69.3% of the simulated visits. Among the dispensed antibiotics, ciprofloxacin was the most dispensed antibiotic followed by cefixime representing 51.5% and 41.8%, respectively, of total dispensed antibiotics. Cefixime was dispensed as a first choice by CPs in 29% of the visits, and in the rest of the visits, only 37.3% of CPs refused to dispense cefixime after SP demand.

Conclusion

The findings revealed a high rate of antibiotics dispensing without prescription by CPs in Khartoum state, and cefixime was obtained with ease before and after the patient's demand. Urgent corrective actions such as imposing strict regulations, monitoring pharmacists' practice, and endorsing educational programs for pharmacists are needed to prevent inappropriate antibiotic dispensing practices.

Probiotics in Orthopedics: From Preclinical Studies to Current Applications and Future Perspective

In recent years, probiotics have been emerging as an attractive therapeutic strategy for several diseases. In orthopedics, probiotics seem to be a promising supplementation for treatment of osteoporosis, osteoarthritis, muscle loss-related disease, wound and ulcer issues, and prevention of surgical antibiotic prophylaxis side effects. Although probiotics are still not included in guidelines for these conditions, several studies have reported theoretical benefits of their administration. Further high-level clinical trials are necessary to convert research into solid clinical practice. However, probiotics represent a cost-effective future perspective and may play a role in association with traditional orthopedic therapies.

#AMRrounds: a systematic educational approach for navigating bench to bedside antimicrobial resistance

Antimicrobial resistance (AMR) continues to serve as a major global health crisis. Clinicians practising in this modern era are faced with ongoing challenges in the therapeutic management of patients suffering from antimicrobial-resistant infections. A strong educational understanding and synergistic application of clinical microbiology, infectious disease and pharmacological concepts can assist the adventuring clinician in the navigation of such cases. Important items include mobilizing laboratory testing for pathogen identification and susceptibility data, harnessing an understanding of intrinsic pathogen resistance, acknowledging epidemiological resistance trends, recognizing acquired AMR mechanisms, and consolidating these considerations when constructing an ideal pharmacological plan. In this article, we outline a novel framework by which to systematically approach clinical AMR, encourage AMR-related education and optimize therapeutic decision-making in AMR-related illnesses.

Antimicrobial susceptibility of Clostridioides difficile to omadacycline and comparator antimicrobials

BACKGROUND

Omadacycline is a novel aminomethylcycline tetracycline antimicrobial that was approved for the treatment of community-associated bacterial pneumonia (CABP) and acute bacterial skin and skin structure infections (ABSSSI) in 2018. Omadacycline has demonstrated a high degree of in vitro activity towards Clostridioides difficile and previous data have hypothesized that use of omadacycline for CABP or ABSSSI may decrease the risk of C. difficile infections.

OBJECTIVES

To compare the in vitro antimicrobial activity of omadacycline versus commonly used antimicrobials for the approved indications of use.

METHODS

We compared the antimicrobial activity of eight antimicrobials approved for CABP and ABSSSI against omadacycline by agar dilution on 200 clinically relevant contemporary C. difficile isolates representing local and national prevalent strain types.

RESULTS

The in vitro omadacycline geometric mean MIC was 0.07 mg/L. Ceftriaxone resistance was noted in >50% of all isolates tested. The epidemic strain group, identified as restriction endonuclease analysis (REA) group BI, was commonly resistant to azithromycin (92%), moxifloxacin (86%) and clindamycin (78%). REA group DH strains had an elevated trimethoprim/sulfamethoxazole geometric mean MIC of 17.30 mg/L compared with the geometric mean MIC of 8.14 mg/L noted in all other isolates. In the REA group BK isolates that had a doxycycline MIC of ≥2 mg/L, the omadacycline MIC was <0.5 mg/L.

CONCLUSIONS

Among 200 contemporary C. difficile isolates, there were no notable elevations in the in vitro omadacycline MIC, indicating a high level of activity towards C. difficile in comparison with commonly used antimicrobials for CABP and ABSSSI.

Risk factors for recurrent healthcare-facility associated Clostridioides difficile infection in a Swedish setting

PURPOSE

The objectives were to determine the risk factors for recurrent healthcare facility-associated Clostridioides difficile infection (HCF-CDI) in a high CDI incidence, low antibiotic use setting and to determine if length of cefotaxime exposure is a risk factor for recurrent HCF-CDI.

METHODS

The risk factors for recurrent HCF-CDI were evaluated with a retrospective nested case control study based on chart reading. The risk factors were evaluated univariately and multivariately. Length of risk antibiotic exposure was evaluated further in a subanalysis.

RESULTS

Risk factors for recurrent HCF-CDI were renal insufficiency (25.4% of cases compared to 15.4% of controls p = 0.006) and metronidazole treatment of initial CDI episode (88.4% compared to 71.7% p = 0.01). Exposure to cefotaxime and risk for recurrent CDI showed a dose-dependent relationship (linear by linear p = 0.028).

CONCLUSIONS

Renal insufficiency and metronidazole treatment were independent risk factors for recurrent HCF-CDI in our setting. The relationship between cefotaxime exposure and risk for recurrent HCF-CDI, dose-dependent, could be evaluated further in a setting with high cefotaxime use.

Penicillin-Binding Proteins and Alternative Dual-Beta-Lactam Combinations for Serious Enterococcus faecalis Infections with Elevated Penicillin MICs

Ampicillin-ceftriaxone has become a first-line therapy for Enterococcus faecalis endocarditis. We characterized the penicillin-binding protein (PBP) profiles of various E. faecalis strains and tested for synergy to better inform beta-lactam options for the treatment of E. faecalis infections. We assessed the affinity of PBP2B from elevated-MIC strain E. faecalis LS4828 compared to type strain JH2-2 using the fluorescent beta-lactam Bocillin FL. We also characterized pbp4 and pbpA structures and PBP4 and PBP2B expression and used deletion and complementation studies to assess the impact of PBP2B on the levels of resistance. We tested penicillin-susceptible and -resistant E. faecalis isolates against ceftriaxone or ceftaroline combinations with other beta-lactams in 24-h time-kill studies. Two penicillin-susceptible strains (JH2-2 and L2052) had identical pbp sequences and similar PBP expression levels. One reduced-penicillin-susceptibility strain (L2068) had pbp sequences identical to those of the susceptible strains but expressed more PBP4. The second decreased-penicillin-susceptibility strain (LS4828) had amino acid substitutions in both PBP4 and PBP2B and expressed increased quantities of both proteins. PBP2B did not appear to contribute significantly to the elevated beta-lactam MICs. No synergy was demonstrable against the strains with both mutated PBPs and increased expression (L2068 and LS4828). Meropenem plus ceftriaxone or ertapenem plus ceftriaxone demonstrated the most consistent synergistic activity. PBP2B of strain LS4828 does not contribute significantly to reduced penicillin susceptibility. Neither the MIC nor the level of PBP expression correlated directly with the identified synergistic combinations when tested at static subinhibitory concentrations.

Appropriateness of Empirical Prescriptions of Ceftriaxone and Identification of Opportunities for Stewardship Interventions: A Single-Centre Cross-Sectional Study

Third-generation cephalosporins are widely used due to the convenient spectrum of activity, safety, and posology. However, they are associated with the emergence of multidrug-resistant organisms, which makes them important targets for antimicrobial stewardship interventions. We aimed to assess the appropriateness of empirical prescriptions of ceftriaxone in a tertiary hospital. This cross-sectional study analysed empirical ceftriaxone prescriptions in January and June 2021. Patients under other antimicrobials 48 h before admission were excluded. The quality of ceftriaxone prescription was assessed regarding the initial appropriateness, duration of inappropriate ceftriaxone therapy, and missed opportunities for de-escalation. Of 465 prescriptions, 46.5% were inappropriate. The ceftriaxone prescription was inappropriate in 95.7% of lower respiratory tract infections (LRTI) globally and in nearly 40% of urinary tract infections (UTI) in medical and intensive care departments. Intensive care, internal medicine, and palliative care departments showed the highest number of inappropriate ceftriaxone prescriptions and longer length of inappropriate ceftriaxone prescriptions compared to the hospital's average. Improvement of empirical ceftriaxone prescription in LRTI and urinary infections, adherence to local guidelines and de-escalation practices, and targeted interventions focusing on critical departments may significantly reduce the inappropriate empirical use of ceftriaxone.

Structural equation modelling the impact of antimicrobials on the human microbiome. Colonization resistance versus colonization susceptibility as case studies

The impact of antimicrobials on the human microbiome and its relationship to human health are of great interest. How antimicrobial exposure might drive change within specific constituents of the microbiome to effect clinically relevant endpoints is difficult to study. Clinical investigation of each step within a network of causation would be challenging if done 'step-by-step'. An analytic tool of great potential to clinical microbiome research is structural equation modelling (SEM), which has a long history of applications to research questions arising within subject areas as diverse as psychology and econometrics. SEM enables postulated models based on a network of causation to be tested en bloc by confrontation with data derived from the literature. Case studies for the potential application of SEM techniques are colonization resistance (CR) and its counterpart, colonization susceptibility (CS), wherein specific microbes within the microbiome are postulated to either impede (CR) or facilitate (CS) invasive infection with pathogenic bacteria. These postulated networks have three causation steps: exposure to specific antimicrobials are key drivers, clinically relevant infection endpoints are the measurable observables and the activity of key microbiome constituents mediating CR or CS, which may be unobservable, appear as latent variables in the model. SEM methods have potential application towards evaluating the activity of specific antimicrobial agents within postulated networks of causation using clinically derived data.

Association between Antibiotic Use and Hospital-Onset Clostridioides difficile Infection in University Tertiary Hospital in Serbia, 2011–2021: An Ecological Analysis

This ecological study is the largest to date examining the association between rates of antibiotic use (AU) and hospital-onset (HO) Clostridioides difficile infection (CDI) in a tertiary university hospital in Serbia. There was no clear trend in the incidence of HO-CDI over time. Total utilization of antibacterials for systemic use increased from 38.57 DDD/100 bed-days (BD) in 2011 to 56.39 DDD/100 BD in 2021. The most commonly used antibiotics were third-generation cephalosporins, especially ceftriaxone, with maximum consumption in 2021 (19.14 DDD/100 BD). The share of the Access group in the total utilization of antibiotics ranged from 29.95% to 42.96% during the observed period. The utilization of the Reserve group of antibiotics indicated a statistically significant increasing trend (p = 0.034). A statistically significant difference in the consumption of medium-risk antibiotics from 2011 to 2021 was shown for penicillins and a combination of sulfamethoxazole and trimethoprim. The consumption of cefotaxime showed a statistically significant negative association with the rate of HO-CDI (r = −0.647; p = 0.031). Ampicillin and the combination of amoxicilline with clavulanic acid have shown a negative statistically significant correlation with the ID of HO-CDI (r = −0.773 and r = −0.821, respectively). Moreover, there was a statistically significant negative correlation between consumption of “medium-risk antibiotics” and the rate of HO-CDI (r = −0.677). The next challenging step for the hospital multidisciplinary team for antimicrobials is to modify the antibiotic list according to the Access, Watch, and Reserve classification, in such a way that at least 60% of the AU should be from the Access group, according to the World Health Organization recommendation.

Decalogue for the selection of oral antibiotics for lower respiratory tract infections

Lower respiratory tract infections, including chronic obstructive pulmonary disease exacerbations (COPD-E) and community acquired pneumonia (CAP), are one of the most frequent reasons for consultation in primary care and hospital emergency departments, and are the cause of a high prescription of antimicrobial agents. The selection of the most appropriate oral antibiotic treatment is based on different aspects and includes to first consider a bacterial aetiology and not a viral infection, to know the bacterial pathogen that most frequently cause these infections and the frequency of their local antimicrobial resistance. Treatment should also be prescribed quickly and antibiotics should be selected among those with a quicker mode of action, achieving the greatest effect in the shortest time and with the fewest adverse effects (toxicity, interactions, resistance and/or ecological impact). Whenever possible, antimicrobials should be rotated and diversified and switched to the oral route as soon as possible. With these premises, the oral treatment guidelines for mild or moderate COPD-E and CAP in Spain include as first options beta-lactam antibiotics (amoxicillin and amoxicillin-clavulanate and cefditoren), in certain situations associated with a macrolide, and relegating fluoroquinolones as an alternative, except in cases where the presence of Pseudomonas aeruginosa is suspected.

Retrospective audit of antibiotic use in a university general pediatrics department using hospital pharmacy dispensing data

Antibiotics are among the most frequently prescribed drugs in children's hospitals, which is why regular monitoring of antibiotic use in hospitals is of great importance. This retrospective audit (60 months, January 2014 - December 2018) analyzes the antibiotic consumption at a university inpatient department of general pediatrics including neonatal and pediatric intensive care based on pharmacy dispensing data in units of grams per 100 patient days and in Defined Daily Doses per 100 patient days. The results provide potential targets for Antibiotic Stewardship interventions. Conversely, this audit elicits methodological limitations of the method of antibiotic surveillance in pediatrics recommended by the Robert Koch Institute, Berlin.

The use of first-generation cephalosporin antibiotics, cefalexin and cefradine, is not associated with induction of simulated Clostridioides difficile infection

Objectives

The use of broad-spectrum cephalosporins is associated with induction of Clostridioides difficile infection (CDI). Recent knowledge on the importance of the healthy microbiota in preventing pathogen colonization/outgrowth highlights the caution needed when prescribing broad-spectrum antibiotics. The use of historical narrow-spectrum antibiotics, such as first-generation cephalosporins, is gaining increased attention once more as they have a reduced impact on the microbiota whilst treating infections. Here, the effects of two first-generation cephalosporins, compared with a third-generation cephalosporin, on the human microbiota were investigated and their propensity to induce simulated CDI.

Methods

Three in vitro chemostat models, which simulate the physiochemical conditions of the human colon, were seeded with a human faecal slurry and instilled with either narrow-spectrum cephalosporins, cefalexin and cefradine, or a broad-spectrum cephalosporin, ceftriaxone, at concentrations reflective of colonic levels.

Results

Instillation of cefalexin was associated with reduced recoveries of Bifidobacterium and Enterobacteriaceae; however, Clostridium spp. recoveries remained unaffected. Cefradine exposure was associated with decreased recoveries of Bifidobacterium spp., Bacteroides spp. and Enterobacteriaceae. These changes were not associated with induction of CDI, as we observed a lack of C. difficile spore germination/proliferation, thus no toxin was detected. This is in contrast to a model exposed to ceftriaxone, where CDI was observed.

Conclusions

These model data suggest that the minimal impact of first-generation cephalosporins, namely cefalexin and cefradine, on the intestinal microbiota results in a low propensity to induce CDI.

[Safety in the selection of oral antibiotic treatment in community infections, beyond COVID-19]

Los antibióticos orales son uno de los fármacos más utilizados en la comunidad. Sus efectos adversos son generalmente poco frecuentes y leves, e incluyen toxicidad e interacciones medicamentosas. El mecanismo de producción es variado y no siempre bien conocido. El conocimiento de los efectos adversos con relevancia clínica puede permitir hacer un uso más juicioso de los antibióticos basados en el principio primero no hacer daño, primun non nocere. En esta revisión exploramos los principales efectos adversos de los antibióticos orales con énfasis en los β-lactámicos, macrólidos y fluoroquinolonas.

Impact of duration of antibiotic prophylaxis on rates of surgical site infection (SSI) in patients undergoing mastectomy without immediate reconstruction, comparing a single prophylactic dose versus continued antibiotic prophylaxis postoperatively: a multicentre, double-blinded randomised control trial protocol

INTRODUCTION

In breast surgeries, prophylactic antibiotics given before the surgical incision as per Joint Commission Surgical Care Improvement Project guidelines have been shown to decrease the rate of postoperative infections. There is, however, no clear consensus on postoperative antibiotic prophylaxis in patients undergoing mastectomy with indwelling drains. This trial protocol proposes to study the difference in rates of surgical site infection (SSI) with or without continuation of postoperative antibiotics in patients undergoing mastectomy without immediate reconstruction and with indwelling drains.

METHODS AND ANALYSIS

In this multicentre, double-blinded clinical trial, all patients undergoing mastectomy (without immediate reconstruction) will receive a single prophylactic dose of preoperative antibiotics at induction of anaesthesia and will then get randomised to either continue antibiotic prophylaxis or a placebo postoperatively, for the duration of indwelling drains. The primary and secondary outcomes will be development of an SSI and antibiotic-associated adverse effects, respectively. Data will be collected through a standard questionnaire by wound assessors. Intention-to-treat analysis will be carried out using STATA V.12. For categorical variables, frequencies and percentages will be assessed by χ2 test/Fisher's exact test as appropriate. The quantitative variables will be computed by their mean±SD or median (IQR) and will be assessed by independent t-test/Mann-Whitney test as appropriate. Unadjusted and adjusted relative risk with their 95% CI will be reported using Cox proportional regression. A p value of <0.05 will be considered statistically significant.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from each site's Ethical Review Board. The study background and procedure will be explained to the study participants and informed consent will be obtained. Participation in the study is voluntary. All data will be deidentified and kept confidential. The study findings will be published in scientific media and authorship guidelines of International Committee of Medical Journal Editors will be followed.

TRIAL REGISTRATION NUMBER

NCT04577846. (patient recruitment).

Clostridioides difficile Infection among Cirrhotic Patients with Variceal Bleeding

Clostridioides difficile infection (CDI) stands as the leading cause of nosocomial infection with high morbidity and mortality rates, causing a major burden on the healthcare system. Driven by antibiotics, it usually affects older patients with chronic disease or immunosuppressed or oncologic management. Variceal bleeding secondary to cirrhosis requires antibiotics to prevent bacterial translocation, and thus patients become susceptible to CDI. We aimed to investigate the risk factors for CDI in cirrhotic patients with variceal bleeding following ceftriaxone and the mortality risk in this patient’s population. We retrospectively screened 367 cirrhotic patients with variceal bleeding, from which 25 patients were confirmed with CDI, from 1 January 2017 to 31 December 2019. We found MELD to be the only multivariate predictor for mortality (odds ratio, OR = 1.281, 95% confidence interval, CI: 0.098–1.643, p = 0.042). A model of four predictors (age, days of admission, Charlson index, Child–Pugh score) was generated (area under the receiver operating characteristics curve, AUC = 0.840, 95% CI: 0.758–0.921, p < 0.0001) to assess the risk of CDI exposure. Determining the probability of getting CDI for cirrhotic patients with variceal bleeding could be a tool for doctors in taking decisions, which could be integrated in sustainable public health programs.

[Current microbiological aspects of community respiratory infection beyond COVID-19]

From a microbiological point of view, both empirical and targeted antimicrobial treatment in respiratory infection is based on the sensitivity profile of isolated microorganisms and the possible resistance mechanisms that they may present. The latter may vary in different geographic areas according to prescription profiles and vaccination programs. Beta-lactam antibiotics, fluoroquinolones, and macrolides are the most commonly used antimicrobials during the exacerbations of chronic obstructive pulmonary disease and community-acquired pneumonia. In their prescription, different aspects such as intrinsic activity, bactericidal effect or their ability to prevent the development of resistance must be taken into account. The latter is related to the PK/PD parameters, the mutant prevention concentration and the so-called selection window. More recently, the potential ecological impact has grown in importance, not only on the intestinal microbiota, but also on the respiratory one. Maintaining the state of eubiosis requires the use of antimicrobials with a low profile of action on anaerobic bacteria. With their use, the resilience of the bacterial populations belonging to the microbiota, the state of resistance of colonization and the collateral damage related to the emergence of resistance to the antimicrobials in pathogens causing the infections and in the bacterial populations integrating the microbiota.

Antibiotic susceptibility screening of primate-associated Clostridium ventriculi

Clostridium ventriculi (syn. Sarcina ventriculi) is a Gram-positive opportunistic pathogen with sarcina morphology. In the case of gastrointestinal disorders, the treatment is often empirical. Due to the common occurrence in primates and the potential risk of dysbiosis; the antibiotic susceptibility screening of C. ventriculi strains isolated from guenon monkeys and crested gibbons to 58 antibiotics was performed to reduce potentially ineffective antibiotic use in case of disease. Isolates were found to be susceptible to the majority of the tested antibiotics, mainly to (fluoro)quinolones, macrolides, penicillins, and tetracyclines. The susceptibility profiles were similar despite the hosts. Tested strains showed also natural resistance to a few antibiotics on the genus level. Detected in vitro antibiotic efficiency is consistent with documented human treatment cases.

Eravacycline, a novel tetracycline derivative, does not induce Clostridioides difficile infection in an in vitro human gut model

OBJECTIVES

The approval of new antibiotics is essential to combat infections caused by antimicrobial-resistant pathogens; however, such agents should be tested to determine their effect on the resident microbiota and propensity to select for opportunistic pathogens, such as Clostridioides difficile. Eravacycline is a new antibiotic for the treatment of complicated intra-abdominal infections. Here, we determined the effects of eravacycline compared with moxifloxacin on the microbiota and if these were conducive to induction of C. difficile infection (CDI).

METHODS

We seeded in vitro chemostat models, which simulate the physiological conditions of the human colon, with a human faecal slurry and instilled gut-reflective concentrations of either eravacycline or moxifloxacin.

RESULTS

Eravacycline instillation was associated with decreased Bifidobacterium, Lactobacillus and Clostridium species, which recovered 1 week after exposure. However, Bacteroides spp. levels decreased to below the limit of detection and did not recover prior to the end of the experiment. Post-eravacycline, a bloom of aerobic bacterial species occurred, including Enterobacteriaceae, compared with pre-antibiotic, which remained high for the duration of the experiment. These changes in microbiota were not associated with induction of CDI, as we observed a lack of C. difficile spore germination and thus no toxin was detected. Moxifloxacin exposure sufficiently disrupted the microbiota to induce simulated CDI, where C. difficile spore germination, outgrowth and toxin production were seen.

CONCLUSIONS

These model data suggest that, despite the initial impact of eravacycline on the intestinal microbiota, similar to clinical trial data, this novel tetracycline has a low propensity to induce CDI.

The use of interval-compressed chemotherapy with the addition of vincristine, irinotecan, and temozolomide for pediatric patients with newly diagnosed desmoplastic small round cell tumor

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a rare aggressive sarcoma that affects children and young adults, and portends poor outcomes despite intensive multimodal treatment approaches. We report toxicity, response, and outcomes of patients with DSRCT treated with the addition of vincristine, irinotecan, and temozolomide (VIT) to interval-compressed chemotherapy as per Children's Oncology Group ARST08P1.

METHODS

All newly diagnosed pediatric patients with DSRCT treated at Dana-Farber Cancer Institute and Boston Children's Hospital between 2014 and 2019 as per ARST08P1, Arm P2 with replacement of VAC cycles with VIT, were identified. Medical records were reviewed for clinical and disease characteristics, and treatment response and outcomes.

RESULTS

Six patients were treated as per the above regimen. Median age at diagnosis was 15.1 years (range 3.2-16.4) and five patients were male. Five patients had abdominal primary tumors, of which one had exclusively intraabdominal and four had extraabdominal metastases. Two initial cycles of VIT were well tolerated with nausea, vomiting, diarrhea, and constipation as the most common adverse events. Overall response rate defined as partial or complete response after two initial cycles of VIT was 50%. For local control, all patients had surgical resection followed by radiotherapy, and two patients received hyperthermic intraperitoneal chemotherapy at the time of surgery. Of the four patients who have completed therapy to date, three remain disease-free with median follow-up time of 46.7 months.

CONCLUSIONS

The addition of VIT to interval-compressed chemotherapy is tolerable and active in DSRCT, with activity warranting additional investigation.

Switching From Ceftriaxone to Cefotaxime Significantly Contributes to Reducing the Burden of Clostridioides difficile infections

We analyzed Clostridioides difficile infection (CDI) rates and various antimicrobials' application densities from 2013 to 2019 at Leipzig University Hospital, Germany, by using multivariate linear regression. Ceftriaxone application was the only independent predictor of CDI incidence. Thus, antibiotics' specific pharmacokinetic and pharmacodynamic properties such as biliary excretion of ceftriaxone in its active form should be considered when determining their potential to cause CDI.

Changes in blood biomarkers in Arabian horses with Clostridium difficile-induced enterocolitis

Clostridium difficile (CD) is considered a major health care problem both in developing and developed countries; frequently reported to be associated with enterocolitis and diarrhea in horses and other animals. In this study, we examined acute phase response (APR), cytokines response, neopterin (NP) procalcitonin (PCT) production and oxidative stress condition in horses and foals with C. difficile-induced enterocolitis (CDIE) and evaluated the effectiveness of these parameters as biomarkers for the disease. A total of 407 Arabian horses in 35 stables were examined between January 2017 to December 2018. Only 24 out of 407 horses showed two or more signs of CDIE. The blood level of serum amyloid A (SAA), haptoglobin (HP), proinflammatory cytokines (TNF-α, IL-6 and IL1-β), serum malondialdehyde (MDA), PCT and NPT in horses with CDIE were higher than in healthy horses. Nevertheless, the levels of nitric oxide (NO), superoxide dismutase (SOD) and total antioxidant concentration (TAC) were considerably lower in diseased horses compared to those that were healthy. The ROC curves for eleven selected blood parameters, both in healthy horses and horses with CDIE demonstrated that all examined blood markers had significant levels of differentiation between CDIE cases and healthy controls (AUC > 87.5). The data in this study suggest that the evaluation of acute-phase proteins, cytokines, PCT, NPT, and oxidative stress biomarkers may well be used as a tool for diagnosis and assessment of CDIE and in disease pathogenesis in Arabian horses.

A Critical Review of Cephalexin and Cefadroxil for the Treatment of Acute Uncomplicated Lower Urinary Tract Infection in the Era of "Bad Bugs, Few Drugs"

First-generation oral cephalosporins (cephalexin and cefadroxil) have traditionally been considered second-line treatment options for uncomplicated lower urinary tract infections (uLUTIs).  However, in the current age of "bad bugs, few drugs", where there are increasingly limited oral options against resistant Enterobacteriaceae, there is an urgent need to rethink how best to utilize the available antibiotic armamentarium.  This review examines the historical clinical trials and experimental studies of cephalexin and cefadroxil, particularly through the modern lens of pharmacokinetics/pharmacodynamics (PK/PD), to better appreciate the efficacy of these drugs in uLUTIs.  Furthermore, newer cefazolin-cephalexin surrogate testing, as recommended by the Clinical and Laboratory Standards Institute (CLSI) and the United States Committee on Antimicrobial Susceptibility Testing (USCAST), has recategorized cephalexin in many instances from resistant to susceptible.  We conclude that cephalexin and cefadroxil have very good early bacteriological and clinical cures in uLUTIs due to non-extended-spectrum beta-lactamase-producing (ESBL) Enterobacteriaceae comparable to many traditionally first-line agents.  Cephalexin can be conveniently administered as 500 mg twice or thrice daily, similar to cefadroxil (500 mg twice daily); therefore, either agent may be used as a fluoroquinolone-sparing alternative. Cephalexin may be the more practical choice for many clinicians because reliable antimicrobial susceptibility test interpretative criteria (STIC) are provided by CLSI, USCAST, and the European Committee on Antimicrobial Susceptibility Testing (EUCAST), whereas direct cefadroxil STIC is offered only by EUCAST.

Clostridioides difficile incidence related to in-hospital cephalosporin use: a tale of two highly comparable hospitals

Background

Antibiotic treatment is a well-known risk factor for healthcare facility-associated Clostridioides (Clostridium) difficile infection (HCF-CDI). Antibiotic stewardship programmes (ASPs) targeting high-risk antibiotics have been shown to decrease HCF-CDI incidence. HCF-CDI incidence is high in Nordic countries despite relatively low antibiotic use in hospital.

Objectives

To determine if HCF-CDI incidence was modified by a hospital ASP that restricted cephalosporin use.

Methods

The effects of an ASP on HCF-CDI incidence were evaluated in a two-centre setting using a retrospective design. We exploited a strategy of both individual case ascertainment based on chart reviews and aggregated data from the hospitals. Cases were attributed to the antibiotics given prior to disease onset, in proportion to the number of DDDs used. Three periods were studied: 2007 (before the ASP), 2012 and 2015.

Results

At the ASP hospital, cephalosporin use decreased by 87% and the number of HCF-CDI/1000 hospital admissions decreased significantly from 2.25 (2007) to 1.16 (2015) (P = 0.0014). The corresponding results at the non-ASP hospital showed a non-significant increase from 2.09 to 2.38. A high number of cases could be attributed to cephalosporins at both hospitals. The increased use of other broad-spectrum antibiotics, e.g. piperacillin/tazobactam, at the ASP hospital was not associated with offsetting increases in attributable HCF-CDI cases.

Conclusions

Decreased use of cephalosporins is an effective strategy to decrease HCF-CDI incidence over time in a setting with high incidence and low antibiotic use.

Regional differences in temporal incidence of Clostridium difficile infection: a systematic review and meta-analysis

BACKGROUND

Previous decades have witnessed a change in the epidemiology of Clostridium difficile infections. This study aimed to determine temporal trends in the incidence of C difficile infection across geographic regions.

METHODS

An initial search of the relevant literature was conducted from date inception to October 2018 without language restriction. We estimated the pooled incidences using logit transformation, weighted by inverse variance. The Joinpoint Regression Analysis Program was used to explore its temporal trend.

RESULTS

Globally, the estimated incidence of C difficile infection increased from 6.60 per 10,000 patient-days in 1997 to 13.8 per 10,000 patient-days in 2004. Thereafter, a significant downward trend was observed, at -8.75% annually until 2015. From 2005 to 2015, the incidences in most European countries decreased at a rate between 1.97% and 4.11% per annum, except in France, where an increasing incidence was observed (β = 0.16; P < .001). The incidences have stabilized in North America over the same period; however, in Asia, the incidence increased significantly from 2006 to 2014 (annualized percentage change = 14.4%; P < .001). The increase was greatest in Western Asian countries, including Turkey and Israel (β > 0.10; P < .004).

CONCLUSIONS

This study revealed rapid changes in the incidence of C difficile infection. This meta-analysis should inform the allocation of resources for controlling C difficile infection and future surveillance efforts in countries where epidemiologic information on C difficile infection remains sparse.

Clostridium difficile colitis in patients undergoing surgery for hip fractures: an analysis of 17,474 patients

BACKGROUND

We compiled evidence from a large national surgical database to identify the incidence, risk factors and postoperative impact of Clostridium difficile infection (CDI) in patients undergoing hip fracture repair.

METHODS

We identified 17,474 patients who underwent hip fracture repairs in 2015 using the ACS-NSQIP database. Interventions studied were open reduction/Internal fixation, total hip arthroplasty or hemiarthroplasty being performed for traumatic hip fractures. Outcomes studied were incidence, preoperative and postoperative risk factors for occurrence of CDI were studied using descriptive and statistical analysis.

RESULTS

A total of 92 patients (0.53%) developed CDI within 30 days of the operation. Following adjustment using multi-variate logistic regression, preoperative and hospital-associated factors associated with development of CDI were smoking (OR 1.75 [95% CI 1.03-2.99]), hypertension (OR 1.70 [95% CI 1.01-2.85]), hyponatraemia (OR 1.65 [95% CI 1.04-2.63]), prior systemic inflammatory response syndrome (SIRS) (OR 2.18 [95% CI 1.32-3.59]) and a length of stay >7 days (OR 1.98 [95% CI 1.11-3.53]. Postoperative factors associated with occurrence of CDI were occurrence of a deep surgical site infection (SSI) (OR 5.89 [95% CI 1.31-26.6]), a stay in the hospital >30 days (OR 6.56 [95% CI 2.56-16.9]) and unplanned reoperations (OR 2.78 [95% CI 1.29-5.99]).

CONCLUSION

As we move toward an era of bundled-payment models, identification of risk factors associated with the occurrence of postoperative complications, such as CDI, will help curb excess healthcare utilisation and costs associated with the management of this complication.

Survey of the pattern of antibiotic dispensing in private pharmacies in Nepal

OBJECTIVES

Private pharmacies are widely established in most low/middle-income countries (LMICs) including Nepal, and are often considered as a patient's first point of contact for seeking healthcare. The aim of this study was to investigate the pattern of antibiotic dispensing in private pharmacies through exit interviews with patients to review their medication information.

DESIGN AND SETTING

Cross-sectional study. Data collection was carried out in 60 days at 33 randomly selected private pharmacies in the Rupandehi district of Nepal.

PARTICIPANTS

Patients attending private pharmacies (n=1537).

MAIN OUTCOME MEASURE

The pattern of antibiotic prescribing and dispensing was investigated using WHO's core prescribing indicator, 'the percentage of patients prescribed an antibiotic'. Frequency distributions were presented based on patients' characteristics, sources of antibiotic, registration status of pharmacies and education of the pharmacist or drug retailer, and disease or condition. χ² tests and regression analysis were applied to explore factors associated with the pattern of antibiotic dispensing.

RESULTS

Of patients attending private pharmacies, the proportion receiving at least one antibiotic (38.4%) was above the WHO recommended value (20.0%-26.8%). The most commonly dispensed antibiotics were cefixime (16.9%) and the third-generation cephalosporins (38.0%) class. High dispensing rates of antibiotics for selected conditions (eg, respiratory infections, diarrhoeal cases) appeared contrary to international recommendations. The percentage of antibiotic dispensed was highest for patients who obtained their medicines from unlicensed pharmacies (59.1%). Young people were more likely to receive antibiotics than other age groups.

CONCLUSIONS

The antibiotic dispensing pattern from private pharmacies in Nepal was high compared with WHO guidelines, suggesting initiatives to reduce inappropriate use of antibiotics should be implemented. The findings of this study may be generalisable to other LMICs in order to assist in developing policies and guidelines to promote more appropriate dispensing and prescribing practices of antibiotics and limit the spread of antibiotic resistance.

Antimicrobial use in acute care hospitals: national point prevalence survey on healthcare-associated infections and antimicrobial use, Switzerland, 2017

BackgroundA point prevalence survey (PPS) on healthcare-associated infections (HAI) and antimicrobial use was conducted in Swiss acute care hospitals in 2017.AimOur objective was to assess antimicrobial use in Swiss acute care hospitals.MethodsAll patients hospitalised in any acute care hospital in Switzerland were eligible. We used the most recent version of the PPS protocol of the European Centre for Disease Prevention and Control.ResultsData from 12,931 patients of 96 hospitals were collected. Of these, 4,265 (33%; 95% confidence interval (CI): 32.2-33.8) were on 5,354 antimicrobials for 4,487 indications. Most of the 2,808 therapeutic indications addressed 1,886 community-acquired infections (67.2%; 95% CI: 65.4-68.9). Of the 1,176 surgical prophylaxes, 350 (29.8%; 95% CI: 27.1-32.4) exceeded the duration of 1 day. Of the 1,090 antimicrobial regimens that were changed, 309 (28.3%; 95% CI: 25.7-31.0) were escalated and 337 (30.9%; 95% CI: 28.2-33.7) were de-escalated. Amoxicillin/clavulanic acid was the most frequent antimicrobial (18.8%; 95% CI: 17.7-19.8), prescribed mainly for therapeutic indications (76.0%; 95% CI: 73.3-78.7). A total of 1,931 (37.4%; 95% CI: 36.1-38.8) of the 5,158 antimicrobials for systemic use were broad-spectrum antibiotics, most frequently third- and fourth-generation cephalosporins (35.9%; 95% CI: 33.8-38.1).ConclusionsAntimicrobial consumption was at European average, the use of broad-spectrum antibiotics in the lower third. Swiss acute care hospitals should invest in antimicrobial stewardship, particularly in reducing the use of broad-spectrum antibiotics.

National Surveillance for Clostridioides difficile Infection, Sweden, 2009-2016

We report results from a national surveillance program for Clostridioides difficile infection (CDI) in Sweden, where CDI incidence decreased by 22% and the proportion of multidrug-resistant isolates decreased by 80% during 2012-2016. Variation in incidence between counties also diminished during this period, which might be attributable to implementation of nucleic acid amplification testing as the primary diagnostic tool for most laboratories. In contrast to other studies, our study did not indicate increased CDI incidence attributable the introduction of nucleic acid amplification testing. Our results also suggest that successful implementation of hygiene measures is the major cause of the observed incidence decrease. Despite substantial reductions in CDI incidence and prevalence of multidrug-resistant isolates, Sweden still has one of the highest CDI incidence levels in Europe. This finding is unexpected and warrants further investigation, given that Sweden has among the lowest levels of antimicrobial drug use.

Treatment of infections caused by multidrug-resistant Gram-negative bacteria: report of the British Society for Antimicrobial Chemotherapy/Healthcare Infection Society/British Infection Association Joint Working Party

The Working Party makes more than 100 tabulated recommendations in antimicrobial prescribing for the treatment of infections caused by multidrug-resistant (MDR) Gram-negative bacteria (GNB) and suggest further research, and algorithms for hospital and community antimicrobial usage in urinary infection. The international definition of MDR is complex, unsatisfactory and hinders the setting and monitoring of improvement programmes. We give a new definition of multiresistance. The background information on the mechanisms, global spread and UK prevalence of antibiotic prescribing and resistance has been systematically reviewed. The treatment options available in hospitals using intravenous antibiotics and in primary care using oral agents have been reviewed, ending with a consideration of antibiotic stewardship and recommendations. The guidance has been derived from current peer-reviewed publications and expert opinion with open consultation. Methods for systematic review were NICE compliant and in accordance with the SIGN 50 Handbook; critical appraisal was applied using AGREE II. Published guidelines were used as part of the evidence base and to support expert consensus. The guidance includes recommendations for stakeholders (including prescribers) and antibiotic-specific recommendations. The clinical efficacy of different agents is critically reviewed. We found there are very few good-quality comparative randomized clinical trials to support treatment regimens, particularly for licensed older agents. Susceptibility testing of MDR GNB causing infection to guide treatment needs critical enhancements. Meropenem- or imipenem-resistant Enterobacteriaceae should have their carbapenem MICs tested urgently, and any carbapenemase class should be identified: mandatory reporting of these isolates from all anatomical sites and specimens would improve risk assessments. Broth microdilution methods should be adopted for colistin susceptibility testing. Antimicrobial stewardship programmes should be instituted in all care settings, based on resistance rates and audit of compliance with guidelines, but should be augmented by improved surveillance of outcome in Gram-negative bacteraemia, and feedback to prescribers. Local and national surveillance of antibiotic use, resistance and outcomes should be supported and antibiotic prescribing guidelines should be informed by these data. The diagnosis and treatment of both presumptive and confirmed cases of infection by GNB should be improved. This guidance, with infection control to arrest increases in MDR, should be used to improve the outcome of infections with such strains. Anticipated users include medical, scientific, nursing, antimicrobial pharmacy and paramedical staff where they can be adapted for local use.

Choice of Empirical Antibiotic Therapy and Adverse Outcomes in Older Adults With Suspected Urinary Tract Infection: Cohort Study

Background

Nitrofurantoin is widely recommended for empirical treatment of urinary tract infection (UTI), but primary care clinicians may prescribe alternative antibiotics to improve prognosis in older, sicker patients. We assessed whether prescribing alternative antibiotics was associated with reduced risk of adverse outcomes in older patients.

Methods

This retrospective cohort study included patients aged ≥65 years empirically treated for a UTI with nitrofurantoin, cefalexin, ciprofloxacin, or co-amoxiclav. We matched patients on their propensity to receive a nitrofurantoin prescription and used mixed-effects logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for reconsultation and represcription (proxy for treatment failure), hospitalization for UTI, sepsis, or acute kidney injury, and death.

Results

We identified 42 298 patients aged ≥65 years prescribed empirical nitrofurantoin, cefalexin, ciprofloxacin, or co-amoxiclav for a UTI. Compared with nitrofurantoin, patients prescribed cefalexin, ciprofloxacin, or co-amoxiclav had lower odds of reconsultation and represcription (OR for cefalexin = 0.85, 95% CI = 0.75–0.98; OR for ciprofloxacin = 0.48, 95% CI = 0.38–0.61, OR for co-amoxiclav = 0.77, 95% CI = 0.64–0.93). Patients prescribed cefalexin or ciprofloxacin had greater odds of hospitalization for sepsis (OR for cefalexin = 1.89, 95% CI = 1.03–3.47; OR for ciprofloxacin = 3.21, 95% CI = 1.59–6.50), and patients prescribed cefalexin had greater odds of death (OR = 1.44, 95% CI = 1.12–1.85).

Conclusions

Compared with nitrofurantoin, prescribing of alternative antibiotics for UTI in older people may be associated with lower rates of treatment failure but was not associated with reduced risk of UTI-related hospitalization or death.

Intrinsic Class D β-Lactamases of Clostridium difficile

Clostridium difficile is the causative agent of the deadly C. difficile infection. Resistance of the pathogen to β-lactam antibiotics plays a major role in the development of the disease, but the mechanism of resistance is currently unknown. We discovered that C. difficile encodes class D β-lactamases, i.e., CDDs, which are intrinsic to this species. We studied two CDD enzymes, CDD-1 and CDD-2, and showed that they display broad-spectrum, high catalytic efficiency against various β-lactam antibiotics, including penicillins and expanded-spectrum cephalosporins. We demonstrated that the cdd genes are poorly expressed under the control of their own promoters and contribute only partially to the observed resistance to β-lactams. However, when the cdd1 gene was expressed under the control of efficient promoters in the antibiotic-sensitive Clostridium cochlearium strain, it produced high-level resistance to β-lactams. Taken together, the results determined in this work demonstrate the existence in C. difficile of intrinsic class D β-lactamases which constitute a reservoir of highly potent enzymes capable of conferring broad-spectrum, clinically relevant levels of resistance to β-lactam antibiotics. This discovery is a significant contribution to elucidation of the mechanism(s) of resistance of the clinically important pathogen C. difficile to β-lactam antibiotics.IMPORTANCEC. difficile is a spore-forming anaerobic bacterium which causes infection of the large intestine with high mortality rates. The C. difficile infection is difficult to prevent and treat, as the pathogen is resistant to many antimicrobial agents. Prolonged use of β-lactam antibiotics for treatment of various infectious diseases triggers the infection, as these drugs suppress the abundance of protective gut bacteria, allowing the resistant C. difficile bacteria to multiply. While resistance of C. difficile to β-lactam antibiotics plays the major role in the development of the disease, the mechanism of resistance is unknown. The significance of our research is in the discovery in C. difficile of β-lactamases, enzymes that destroy β-lactam antibiotics. These findings ultimately can help to combat deadly C. difficile infections.

Management of adult Clostridium difficile digestive contaminations: a literature review

Clostridium difficile infections (CDI) dramatically increased during the last decade and cause a major public health problem. Current treatments are limited by the high disease recurrence rate, severity of clinical forms, disruption of the gut microbiota, and colonization by vancomycin-resistant enterococci (VRE). In this review, we resumed current treatment options from official recommendation to promising alternatives available in the management of adult CDI, with regard to severity and recurring or non-recurring character of the infection. Vancomycin remains the first-line antibiotic in the management of mild to severe CDI. The use of metronidazole is discussed following the latest US recommendations that replaced it by fidaxomicin as first-line treatment of an initial episode of non-severe CDI. Fidaxomicin, the most recent antibiotic approved for CDI in adults, has several advantages compared to vancomycin and metronidazole, but its efficacy seems limited in cases of multiple recurrences. Innovative therapies such as fecal microbiota transplantation (FMT) and antitoxin antibodies were developed to limit the occurrence of recurrence of CDI. Research is therefore very active, and new antibiotics are being studied as surotomycin, cadazolid, and rinidazole.

Combination probiotics may prevent Clostridium difficile infection among elderly patients undergoing an orthopedic surgery

The incidence of Clostridium difficile infection (CDI) is greater in elderly orthopedic patients. We conducted a retrospective case-control study by selecting elderly patients who underwent proximal femoral fracture surgery to investigate the effect of probiotics on CDI prevention. Cases were diagnosed with CDI by an enzyme-linked immunosorbent assay for C. difficile toxins using frozen stool specimens. The primary method of exposure was receipt of combination probiotics such as Streptococcus faecalis, Bacillus mesentericus, and Clostridium butyricum. The crude odds ratio between developing CDI and receiving combination probiotics was 0.074 (95% CI: 0.010–0.565; p=0.002). Adjunctive combination probiotics among elderly patients who undergo proximal femoral fracture surgery likely reduces the probability of CDI.

In Vitro Activity of Tedizolid, Dalbavancin, and Ceftobiprole Against Clostridium difficile

Background:Clostridium difficile (C. difficile) is a major nosocomial pathogen that colonizes in the human gut. Recently, the U.S. FDA approved three new antimicrobial agents against gram-positive bacteria: Tedizolid, Dalbavancin, and Ceftobiprole. The efficacy of these antibiotics for treatment of C. difficile infection has not been thoroughly examined. The current study aimed to examine the in vitro activity of these antibiotics against C. difficile. In addition, to compare between Dalbavancin and Ceftobiprole to antibiotics from the same class: Vancomycin and Ceftriaxone, respectively. Methods: Eighty-four C. difficile isolates were tested for susceptibility to Tedizolid, Dalbavancin, Ceftobiprole, Vancomycin, and Ceftriaxone by Etest technique in order to determine the minimum inhibitory concentration (MIC). Results: Upon comparison of the novel antibiotic agents, Dalbavancin demonstrated the lowest MIC values and ceftobiprole the highest at MIC₅₀ (0.016, 0.38, and 1.5 μg/mL, for Dalbavancin, Tedizolid, and Ceftobiprole, respectively) and MIC₉₀ (0.03, 0.78, and 3.17 μg/mL, respectively). Dalbavancin demonstrated significantly lower MIC₅₀ and MIC₉₀ values compared to Vancomycin (0.016 vs. 0.38 and 0.03 vs. 3.5, respectively) (p < 0.001) and ceftobiprole had significantly lower MIC values compare to ceftriaxone (1.5 vs. 32 and 3.17 vs. 28.8, respectively) (p < 0.001). Conclusion: Dalbavancin and Tedizolid may play a role as potential therapeutic agents for treatment of C. difficile infection. Examination of antibiotic effect on the intestinal microbiome and clinical trials are needed for more accurate results.

Antibiotic susceptibility and resistance profiles of Romanian Clostridioides difficile isolates

This study investigated the antibiotic susceptibility patterns and genetic resistance markers of 35 C. difficile strains isolated from patients with C. difficile infection. Vancomycin, metronidazole, tigecycline, teicoplanin, rifampicin, moxifloxacin, cefotaxime, tetracycline, erythromycin, clindamycin, chloramphenicol, linezolid and imipenem MICs were determined for toxigenic strains belonging to PCR ribotypes (PR) 012 (2), 014 (4), 017 (3), 018 (2), 027 (17), 046 (2), 087 (3) and 115 (2). Results showed vancomycin, metronidazole, tigecycline and teicoplanin to be active against all isolates. High resistance rates were noticed against cefotaxime (n = 35), clindamycin (n = 33), imipenem (n = 31), moxifloxacin (n = 25), erythromycin (n = 25) and rifampicin (n = 22). Linezolid-resistance was found in three isolates (PR 017/2, PR 012/1), showing complex resistance (7-9 antibiotics). PR 012, 017, 018, 027 and 046 isolates (n = 26) were resistant to 5-9 antibiotics. Twelve resistance profiles (2-9 antibiotics) were detected. Rifampicin-moxifloxacin-cefotaxime-erythromycin-clindamycin-imipenem-resistance was predominant, being expressed by 18 strains (PR 027/17, PR 018/1). PCR results suggested tetracycline-resistance to be induced by the gene tetM. Three tetM-positive isolates (PRs 012, 046), were also tndX-positive, suggesting the presence of a Tn5397-like element. Only two MLSB-resistant strains (PR 012) had the ermB gene and chloramphenicol-resistance determinant catD was not detected, leaving room for further investigating resistance mechanisms. Multidrug resistance could be attributed to most analysed strains, underlining, once more, the impact of wide-spectrum antimicrobial over prescription, still a tendency in our country, on transmission of antimicrobial resistance and emergence of epidemic C. difficile strains generating outbreaks.

Risk factors for Clostridium difficile infections - an overview of the evidence base and challenges in data synthesis

Background

Recognition of a broad spectrum of disease and development of Clostridium difficile infection (CDI) and recurrent CDI (rCDI) in populations previously considered to be at low risk has renewed attention on differences in the risk profile of patients. In the absence of primary prevention for CDI and limited treatment options, it is important to achieve a deep understanding of the multiple factors that influence the risk of developing CDI and rCDI.

Methods

We conducted a review of systematic reviews and meta–analyses on risk factors for CDI and rCDI published between 1990 and October 2016.

Results

22 systematic reviews assessing risk factors for CDI (n = 19) and rCDI (n = 6) were included. Meta–analyses were conducted in 17 of the systematic reviews. Over 40 risk factors have been associated with CDI and rCDI and can be classified into three categories: pharmacological risk factors, host–related risk factors, and clinical characteristics or interventions. Most systematic reviews and meta–analyses have focused on antibiotic use (n = 8 for CDI, 3 for rCDI), proton pump inhibitors (n = 8 for CDI, 4 for rCDI), and histamine 2 receptor antagonists (n = 4 for CDI) and chronic kidney disease (n = 4 for rCDI). However, other risk factors have been assessed. We discuss the state of the evidence, methods, and challenges for data synthesis.

Conclusion

Several studies, synthesized in different systematic review, provide valuable insights into the role of different risk factors for CDI. Meta–analytic evidence of association has been reported for factors such as antibiotics, gastric acid suppressants, non–selective NSAID, and some co–morbidities. However, despite statistical significance, issues of high heterogeneity, bias and confounding remain to be addressed effectively to improve overall risk estimates. Large, prospective primary studies on risk factors for CDI with standardised case definitions and stratified analyses are required to develop more accurate and robust estimates of risk effects that can inform targeted–CDI clinical management procedures, prevention, and research.

Contribution of bacteriophage and plasmid DNA to the mobilization of antibiotic resistance genes in a river receiving treated wastewater discharges

In this study, we quantified eleven antibiotic compounds and nine antibiotic resistance genes (ARGs) in water samples collected upstream and downstream of the discharge point from a municipal wastewater treatment plant (WWTP) into the Ter River. Antibiotics were analyzed by liquid chromatography coupled to mass spectrometry, whereas the concentration of ARGs in bacterial, phage and plasmid DNA fractions was determined by real-time PCR to explore their contribution to environmental antibiotic resistance. WWTP discharges resulted in higher concentrations of antibiotic residues as well as ARGs in water samples collected downstream the impact point. Specifically, genes conferring resistance to macrolides (ermB), fluoroquinolones (qnrS) and tetracyclines (tetW) showed significant differences (p<0.05) between upstream and downstream sites in the three DNA fractions (i.e. bacteria, plasmids and phages). Interestingly, genes conferring resistance to β-lactams (bla_TEM, bla_NDM and bla_KPC) and glycopeptides (vanA) only showed significant differences (p<0.05) between upstream and downstream sites in phage and plasmid DNA but not in the bacterial DNA fraction. Our results show for the first time the extent to which phages and plasmids contribute to the mobilization of ARGs in an aquatic environment exposed to chronic antibiotic pollution via WWTP discharges. Accordingly, these mobile genetic elements should be included in further studies to get a global view of the spread of antibiotic resistance.

Molecular, microbiological and clinical characterization of Clostridium difficile isolates from tertiary care hospitals in Colombia

In Colombia, the epidemiology and circulating genotypes of Clostridium difficile have not yet been described. Therefore, we molecularly characterized clinical isolates of C.difficile from patients with suspicion of C.difficile infection (CDI) in three tertiary care hospitals. C.difficile was isolated from stool samples by culture, the presence of A/B toxins were detected by enzyme immunoassay, cytotoxicity was tested by cell culture and the antimicrobial susceptibility determined. After DNA extraction, tcdA, tcdB and binary toxin (CDTa/CDTb) genes were detected by PCR, and PCR-ribotyping performed. From a total of 913 stool samples collected during 2013-2014, 775 were included in the study. The frequency of A/B toxins-positive samples was 9.7% (75/775). A total of 143 isolates of C.difficile were recovered from culture, 110 (76.9%) produced cytotoxic effect in cell culture, 100 (69.9%) were tcdA+/tcdB+, 11 (7.7%) tcdA-/tcdB+, 32 (22.4%) tcdA-/tcdB- and 25 (17.5%) CDTa+/CDTb+. From 37 ribotypes identified, ribotypes 591 (20%), 106 (9%) and 002 (7.9%) were the most prevalent; only one isolate corresponded to ribotype 027, four to ribotype 078 and four were new ribotypes (794,795, 804,805). All isolates were susceptible to vancomycin and metronidazole, while 85% and 7.7% were resistant to clindamycin and moxifloxacin, respectively. By multivariate analysis, significant risk factors associated to CDI were, staying in orthopedic service, exposure to third-generation cephalosporins and staying in an ICU before CDI symptoms; moreover, steroids showed to be a protector factor. These results revealed new C. difficile ribotypes and a high diversity profile circulating in Colombia different from those reported in America and European countries.

Clostridium difficile bacteremia: Report of two cases in French hospitals and comprehensive review of the literature

We report two cases of bacteremia due to Clostridium difficile from two French hospitals. The first patient with previously diagnosed rectal carcinoma underwent courses of chemotherapy, and antimicrobial treatment, and survived the C. difficile bacteremia. The second patient with colon perforation and newly diagnosed lung cancer underwent antimicrobial treatment in an ICU but died shortly after the episode of C. difficile bacteremia. A review of the literature allowed the identification of 137 cases of bacteremia between July 1962 and November 2016. Advanced age, gastro-intestinal disruption, severe underlying diseases and antimicrobial exposure were the major risk factors for C. difficile bacteremia. Antimicrobial therapy was primarily based on metronidazole and/or vancomycin. The crude mortality rate was 35% (21/60).