Objective: The use and impact of antibiotics and the impact of causative pathogens on clinical outcomes in a large real-world cohort covering the entire clinical spectrum of necrotizing... Show moreObjective: The use and impact of antibiotics and the impact of causative pathogens on clinical outcomes in a large real-world cohort covering the entire clinical spectrum of necrotizing pancreatitis remain unknown.Summary Background Data: International guidelines recommend broad-spectrum antibiotics in patients with suspected infected necrotizing pancreatitis. This recommendation is not based on high-level evidence and clinical effects are unknown.Materials and Methods: This study is a post-hoc analysis of a nationwide prospective cohort of 401 patients with necrotizing pancreatitis in 15 Dutch centers (2010-2019). Across the patient population from the time of admission to 6 months postadmission, multivariable regression analyses were used to analyze (1) microbiological cultures and (2) antibiotic use.Results: Antibiotics were started in 321/401 patients (80%) administered at a median of 5 days (P25-P75: 1-13) after admission. The median duration of antibiotics was 27 days (P25-P75: 15-48). In 221/321 patients (69%) infection was not proven by cultures at the time of initiation of antibiotics. Empirical antibiotics for infected necrosis provided insufficient coverage in 64/128 patients (50%) with a pancreatic culture. Prolonged antibiotic therapy was associated with Enterococcus infection (OR 1.08 [95% CI 1.03-1.16], P=0.01). Enterococcus infection was associated with new/persistent organ failure (OR 3.08 [95% CI 1.35-7.29], P<0.01) and mortality (OR 5.78 [95% CI 1.46-38.73], P=0.03). Yeast was found in 30/147 cultures (20%).Discussion: In this nationwide study of patients with necrotizing pancreatitis, the vast majority received antibiotics, typically administered early in the disease course and without a proven infection. Empirical antibiotics were inappropriate based on pancreatic cultures in half the patients. Future clinical research and practice must consider antibiotic selective pressure due to prolonged therapy and coverage of Enterococcus and yeast. Improved guidelines on antimicrobial diagnostics and therapy could reduce inappropriate antibiotic use and improve clinical outcomes. Show less
Daptomycin is a last-resort antibiotic used for the treatment of infections caused by Gram-positive antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA).... Show moreDaptomycin is a last-resort antibiotic used for the treatment of infections caused by Gram-positive antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA). Treatment failure is commonly linked to accumulation of point mutations; however, the contribution of single mutations to resistance and the mechanisms underlying resistance remain incompletely understood. Here, we show that a single nucleotide polymorphism (SNP) selected during daptomycin therapy inactivates the highly conserved ClpP protease and is causing reduced susceptibility of MRSA to daptomycin, vancomycin, and β-lactam antibiotics as well as decreased expression of virulence factors. Super-resolution microscopy demonstrated that inactivation of ClpP reduced binding of daptomycin to the septal site and diminished membrane damage. In both the parental strain and the clpP strain, daptomycin inhibited the inward progression of septum synthesis, eventually leading to lysis and death of the parental strain while surviving clpP cells were able to continue synthesis of the peripheral cell wall in the presence of 10× MIC daptomycin, resulting in a rod-shaped morphology. To our knowledge, this is the first demonstration that synthesis of the outer cell wall continues in the presence of daptomycin. Collectively, our data provide novel insight into the mechanisms behind bacterial killing and resistance to this important antibiotic. Also, the study emphasizes that treatment with last-line antibiotics is selective for mutations that, like the SNP in clpP, favor antibiotic resistance over virulence gene expression. Show less
Clostridioides difficile infection (CDI) remains a significant healthcare burden. Non-toxigenic C. difficile (NTCD) strains have shown a benefit in preventing porcine enteritis and in human... Show moreClostridioides difficile infection (CDI) remains a significant healthcare burden. Non-toxigenic C. difficile (NTCD) strains have shown a benefit in preventing porcine enteritis and in human recurrent CDI. In this study, we evaluated the efficacy of metronidazole-resistant NTCD-E4 in preventing CDI facilitated by a range of antimicrobials in an in vitro human gut model. NTCD-E4 spores (at a dose of 10(7)) were instilled 7 days before a clinical ribotype (RT) 027 (at the same dose) strain (210). In separate experiments, four different antimicrobials were used to perturb gut microbiotas; bacterial populations and cytotoxin production were determined using viable counting and Vero cell cytotoxicity, respectively. RT027 and NTCD-E4 proliferated in the in vitro model when inoculated singly, with RT027 demonstrating high-level cytotoxin (3-5-log(10)-relative units) production. In experiments where the gut model was pre-inoculated with NTCD-E4, RT027 was remained quiescent and failed to produce cytotoxins. NTCD-E4 showed mutations in hsmA and a gene homologous to CD196-1331, previously linked to medium-dependent metronidazole resistance, but lacked other metronidazole resistance determinants. This study showed that RT027 was unable to elicit simulated infection in the presence of NTCD-E4 following stimulation by four different antimicrobials. These data complement animal and clinical studies in suggesting NTCD offer prophylactic potential in the management of human CDI. Show less
Clostridioides difficile infection (CDI) remains a significant healthcare burden. Non-toxigenicC. difficile (NTCD) strains have shown a benefit in preventing porcine enteritis and in human... Show moreClostridioides difficile infection (CDI) remains a significant healthcare burden. Non-toxigenicC. difficile (NTCD) strains have shown a benefit in preventing porcine enteritis and in human recurrentCDI. In this study, we evaluated the efficacy of metronidazole-resistant NTCD-E4 in preventingCDI facilitated by a range of antimicrobials in an in vitro human gut model. NTCD-E4 spores (ata dose of 107) were instilled 7 days before a clinical ribotype (RT) 027 (at the same dose) strain(210). In separate experiments, four different antimicrobials were used to perturb gut microbiotas;bacterial populations and cytotoxin production were determined using viable counting and Vero cellcytotoxicity, respectively. RT027 and NTCD-E4 proliferated in the in vitro model when inoculatedsingly, with RT027 demonstrating high-level cytotoxin (3-5-log10-relative units) production. Inexperiments where the gut model was pre-inoculated with NTCD-E4, RT027 was remained quiescentand failed to produce cytotoxins. NTCD-E4 showed mutations in hsmA and a gene homologous toCD196-1331, previously linked to medium-dependent metronidazole resistance, but lacked othermetronidazole resistance determinants. This study showed that RT027 was unable to elicit simulatedinfection in the presence of NTCD-E4 following stimulation by four different antimicrobials. Thesedata complement animal and clinical studies in suggesting NTCD offer prophylactic potential in themanagement of human CDI. Show less
Clostridioides difficile infection (CDI) remains a significant healthcare burden. Non-toxigenic C. difficile (NTCD) strains have shown a benefit in preventing porcine enteritis and in human... Show moreClostridioides difficile infection (CDI) remains a significant healthcare burden. Non-toxigenic C. difficile (NTCD) strains have shown a benefit in preventing porcine enteritis and in human recurrent CDI. In this study, we evaluated the efficacy of metronidazole-resistant NTCD-E4 in preventing CDI facilitated by a range of antimicrobials in an in vitro human gut model. NTCD-E4 spores (at a dose of 107) were instilled 7 days before a clinical ribotype (RT) 027 (at the same dose) strain (210). In separate experiments, four different antimicrobials were used to perturb gut microbiotas; bacterial populations and cytotoxin production were determined using viable counting and Vero cell cytotoxicity, respectively. RT027 and NTCD-E4 proliferated in the in vitro model when inoculated singly, with RT027 demonstrating high-level cytotoxin (3-5-log10-relative units) production. In experiments where the gut model was pre-inoculated with NTCD-E4, RT027 was remained quiescent and failed to produce cytotoxins. NTCD-E4 showed mutations in hsmA and a gene homologous to CD196-1331, previously linked to medium-dependent metronidazole resistance, but lacked other metronidazole resistance determinants. This study showed that RT027 was unable to elicit simulated infection in the presence of NTCD-E4 following stimulation by four different antimicrobials. These data complement animal and clinical studies in suggesting NTCD offer prophylactic potential in the management of human CDI. Show less
Aims: Arthroplasty surgery of the knee and hip is performed in two to three million patients an-nually. Periprosthetic joint infections occur in 4% of these patients. Debridement, antibiot-ics, and... Show moreAims: Arthroplasty surgery of the knee and hip is performed in two to three million patients an-nually. Periprosthetic joint infections occur in 4% of these patients. Debridement, antibiot-ics, and implant retention (DAIR) surgery aimed at cleaning the infected prosthesis often fails, subsequently requiring invasive revision of the complete prosthetic reconstruction. Infection-specific imaging may help to guide DAIR. In this study, we evaluated a bacteria -specific hybrid tracer (99mTc-UBI29-41-Cy5) and its ability to visualize the bacterial load on fem-oral implants using clinical -grade image guidance methods. Methods: 99mTc-UBI29-41- Cy5 specificity for Stapylococcus aureus was assessed in vitro using fluorescence confocal imaging. Topical administration was used to highlight the location of S. aureus cul-tured on femoral prostheses using fluorescence imaging and freehand single photon emis-sion CT (fhSPECT) scans. Gamma counting and fhSPECT were used to quantify the bacterial load and monitor cleaning with chlorhexidine. Microbiological culturing helped to relate the imaging findings with the number of (remaining) bacteria. Results: Bacteria could be effectively stained in vitro and on prostheses, irrespective of the presence of biofilm. Infected prostheses revealed bacterial presence on the transition zone between the head and neck, and in the screw hole. Qualitative 2D fluorescence images could be com-plemented with quantitative 3D fhSPECT scans. Despite thorough chlorhexidine treatments, 28% to 44% of the signal remained present in the locations of the infection that were iden-tified using imaging, which included 500 to 2,000 viable bacteria.Conclusion: The hybrid tracer99mTc-UBI29-41-Cy5 allowed effective bacterial staining. Qualitative real -time fluorescence guidance could be effectively combined with nuclear imaging that enables quantitative monitoring of the effectiveness of cleaning strategies. Show less
Aims Arthroplasty surgery of the knee and hip is performed in two to three million patients an-nually. Periprosthetic joint infections occur in 4% of these patients. Debridement, antibiot-ics, and... Show moreAims Arthroplasty surgery of the knee and hip is performed in two to three million patients an-nually. Periprosthetic joint infections occur in 4% of these patients. Debridement, antibiot-ics, and implant retention (DAIR) surgery aimed at cleaning the infected prosthesis often fails, subsequently requiring invasive revision of the complete prosthetic reconstruction. Infection-specific imaging may help to guide DAIR. In this study, we evaluated a bacteria -specific hybrid tracer (99mTc-UBI29-41-Cy5) and its ability to visualize the bacterial load on fem-oral implants using clinical -grade image guidance methods.Methods 99mTc-UBI29-41- Cy5 specificity for Stapylococcus aureus was assessed in vitro using fluorescence confocal imaging. Topical administration was used to highlight the location of S. aureus cul-tured on femoral prostheses using fluorescence imaging and freehand single photon emis-sion CT (fhSPECT) scans. Gamma counting and fhSPECT were used to quantify the bacterial load and monitor cleaning with chlorhexidine. Microbiological culturing helped to relate the imaging findings with the number of (remaining) bacteria.Results Bacteria could be effectively stained in vitro and on prostheses, irrespective of the presence of biofilm. Infected prostheses revealed bacterial presence on the transition zone between the head and neck, and in the screw hole. Qualitative 2D fluorescence images could be com-plemented with quantitative 3D fhSPECT scans. Despite thorough chlorhexidine treatments, 28% to 44% of the signal remained present in the locations of the infection that were iden-tified using imaging, which included 500 to 2,000 viable bacteria.Conclusion The hybrid tracer99mTc-UBI29-41-Cy5 allowed effective bacterial staining. Qualitative real -time fluorescence guidance could be effectively combined with nuclear imaging that enables quantitative monitoring of the effectiveness of cleaning strategies. Show less
The optimal drug of choice, its time of administration and duration of antibiotic prophylaxis in patient undergoing a TURP procedure are still matters of debate. In this study, we evaluated the... Show moreThe optimal drug of choice, its time of administration and duration of antibiotic prophylaxis in patient undergoing a TURP procedure are still matters of debate. In this study, we evaluated the concentrations of cefazolin, ciprofloxacin and fosfomycin in the human prostate in a cohort of men undergoing TURP. We compared prostate tissue concentrations to the serum concentrations and MICs of common uropathogens, to determine the appropriateness of the current presurgical prophylactic antibiotics and to gain supportive data about the suitability of fosfomycin for antibiotic prophylaxis in men undergoing urological procedures of the prostate. After a single intravenous dose of cefazoline or an oral dose of ciprofloxacin prior to TURP, concentrations in serum and prostate tissue of well above the MIC (EUCAST breakpoint) of common uropathogens (Enterobacterales) were reached, and both antibiotics seem potentially effective in preventing postsurgical infections. A single dose of oral and intravenous administration of fosfomycin both led to serum concentrations above the MIC for uncomplicated urinary tract infections (8 µg/mL). The MIC for other infections (32 µg/mL) was only reached after a single dose of intravenous fosfomycin. We were unable to detect fosfomycin concentrations in prostate tissue. Show less
Aptekorz, M.; Sacha, K.; Gofron, Z.; Kabala, M.; Harmanus, C.; Kuijper, E.; Martirosian, G. 2022
Clostridioides difficile is an important health care-associated pathogen. The aim of this study was to analyze the antibiotic susceptibility of C. difficile isolates from feces of patients from 13... Show moreClostridioides difficile is an important health care-associated pathogen. The aim of this study was to analyze the antibiotic susceptibility of C. difficile isolates from feces of patients from 13 hospitals in Silesia, Poland. The incidence of CDI per 100.000 people in Silesia in 2018-2019 was higher than the average in Poland (39.3-38.7 vs. 30.2-29.5, respectively). The incidence doubled from 26.4 in 2020 to 55.1 in 2021. Two hundred and thirty stool samples tested positive for GDH (glutamate dehydrogenase) and toxins were cultured anaerobically for C. difficile. The isolates were characterized, typed, and tested for susceptibility to 11 antibiotics by E-test (EUCAST, 2021). The genes of toxins A/B and binary were detected by mPCR. Of 215 isolates, 166 (77.2%) were classified as RT 027 and 6 (2.8%) as related RT 176. Resistance to ciprofloxacin (96.7%), moxifloxacin (79.1%), imipenem (78.1%), penicillin (67%), and rifampicin (40.5%) was found. The ermB gene was detected in 79 (36.7%) strains. Multidrug resistance (MDR) was confirmed in 50 (23.3%) strains of RT 027 (94%). We concluded that a high prevalence of MDR among hypervirulent RT 027/176 C. difficile was found in the Silesian region of Poland, emphasizing the need to enhance regional infection control on CDI and antibiotic stewardships. Show less
Diepstraten, F.A.; Meijer, A.J.M.; Grotel, M. van; Plasschaert, S.L.A.; Hoetink, A.E.; Fiocco, M.; ... ; Heuvel-Eibrink, M.M. van den 2022
Background: Some children with central nervous system (CNS) and solid tumors are at risk to develop ototoxicity during treatment. Up to now, several risk factors have been identified that may... Show moreBackground: Some children with central nervous system (CNS) and solid tumors are at risk to develop ototoxicity during treatment. Up to now, several risk factors have been identified that may contribute to ototoxicity, such as platinum derivates, cranial irradiation, and brain surgery. Comedication, like antibiotics and diuretics, is known to enhance ototoxicity, but their independent influence has not been investigated in childhood cancer patients. Recommendations for hearing loss screening are missing or vary highly across treatment protocols. Additionally, adherence to existing screening guidelines is not always optimal. Currently, knowledge is lacking on the prevalence of ototoxicity.Objective: The aim of the Study on Prevalence and Determinants of Ototoxicity During Treatment of Childhood Cancer (SOUND) is to determine the feasibility of audiological testing and to determine the prevalence and determinants of ototoxicity during treatment for childhood cancer in a national cohort of patients with solid and CNS tumors.Methods: The SOUND study is a prospective cohort study in the national childhood cancer center in the Netherlands. The study aims to include all children aged 0 to 19 years with a newly diagnosed CNS or solid tumor. Part of these patients will get audiological examination as part of their standard of care (stratum 1). Patients in which audiological examination is not the standard of care will be invited for inclusion in stratum 2. Age-dependent audiological assessments will be pursued before the start of treatment and within 3 months after the end of treatment. Apart from hearing loss, we will investigate the feasibility to screen patients for tinnitus and vertigo prevalence after cancer treatment. This study will also determine the independent contribution of antibiotics and diuretics on ototoxicity.Results: This study was approved by the Medical Research Ethics Committee Utrecht (Identifier 20-417/M). Currently, we are in the process of recruitment for this study.Conclusions: The SOUND study will raise awareness about the presence of ototoxicity during the treatment of children with CNS or solid tumors. It will give insight into the prevalence and independent clinical and cotreatment-related determinants of ototoxicity. This is important for the identification of future high-risk patients. Thereby, the study will provide a basis for the selection of patients who will benefit from innovative otoprotective intervention trials during childhood cancer treatment that are currently being prepared. Show less
Lelie- van der Zande, R.; Bouvy, M.; Teichert, M. 2021
Aim:To study whether changes in drug preferences in the Dutch guideline for the treatment of Urinary Tract Infection (UTI) for General Practitioners (GPs) in 2013, resulted in corresponding changes... Show moreAim:To study whether changes in drug preferences in the Dutch guideline for the treatment of Urinary Tract Infection (UTI) for General Practitioners (GPs) in 2013, resulted in corresponding changes in antibiotic dispensing.Background:For the treatment of uncomplicated UTI, nitrofurantoin remained the first choice, while fosfomycin became the second choice and changed ranks with trimethoprim. For a subsequent febrile UTI, ciprofloxacin became the first choice and changed ranks with amoxicillin/clavulanic acid, co-trimoxazole remained the third choice.Methods:In this observational cross-sectional study, routinely collected dispensing data from the Dutch Foundation of Pharmaceutical Statistics from 2012 to 2017 were used. The number of women 18 years and older, treated with one of the guideline antibiotics for uncomplicated UTI and subsequent febrile UTI were analysed annually. Proportions were calculated. Data were stratified for age categories. Failure of uncomplicated UTI treatment was defined as the dispensing of an antibiotic for febrile UTI within 14 days after the dispensing of an antibiotic for uncomplicated UTI.Findings:Data were available from 81% of all pharmacies in 2012 to 89% in 2017. Percentages of women dispensed nitrofurantoin were relatively stable with 87.4% in 2012 and 84.4% in 2017. Percentages of women dispensed fosfomycin increased from 5.4% in 2012 to 21.8% in 2017, whereas percentages of women dispensed trimethoprim decreased from 17.8% to 8.0%. Within age categories, the percentage of women dispensed fosfomycin increased from 12.4% in women 18-30 years old to 36.7% in women above 80 years old. Percentages of women dispensed antibiotics for febrile UTI remained stable at 5% annually. Percentages of women receiving ciprofloxacin increased from 1.9% in 2012 to 3.3% in 2017, while those receiving amoxicillin/clavulanic acid decreased from 2.9% to 1.8%. New guideline recommendations resulted in corresponding changes in dispensed antibiotics for uncomplicated UTI and subsequent febrile UTI. Drug choices differed for age categories. Show less
Background: Non-contact induction heating (NCIH) is a noninvasive treatment modality that can be used to cause thermal damage to bacterial biofilms on a metal implant surface in the context of a... Show moreBackground: Non-contact induction heating (NCIH) is a noninvasive treatment modality that can be used to cause thermal damage to bacterial biofilms on a metal implant surface in the context of a prosthetic joint infection. The purpose of this study was (1) to determine the effectiveness of NCIH on killing Staphylococcus aureus from biofilm and (2) to determine the possible synergistic effect of NCIH and cocktails of antibiotics and N-acetylcysteine (NAC). Methods: Staphylococcus aureus biofilms were grown on titanium alloy (Ti6Al4V) coupons. These coupons were heated to 50 degrees C, 60 degrees C, 70 degrees C, 80 degrees C, and 90 degrees C for 3.5 min and subsequently exposed to cocktails of vancomycin, rifampicin and NAC at clinically relevant concentrations over 24 h. Results: In the control group without induction heating, 2.2*10(7) colony forming units (CFU)/cm(2) were observed. At 50 degrees C, 60 degrees C, 70 degrees C, 80 degrees C, and 90 degrees C, a reduction of 0.3-log, 3.9-log, 4.2-log, 4.3-log, and 6.6-log CFU/cm(2) were observed, respectively. There was synergy between antibiotics and induction heating that resulted in less than 100 CFU/cm(2) remaining after 3.5 min at 60 degrees C, and exposure to vancomycin and rifampicin. Total eradication was observed at 80 degrees C. Total eradication was also observed at 60 degrees C and a cocktail of antibiotics with NAC. Conclusion: Induction heating of titanium alloy coupons is effective for the reduction of bacterial load in vitro in S. aureus biofilms. Induction heating and cocktails of antibiotics and NAC have a synergistic effect that results in the total eradication of the biofilm at 60 degrees C and higher for clinically relevant concentrations of vancomycin, rifampicin and NAC. Show less
Ojha, R.P.; Asdahl, P.H.; Steyerberg, E.; Schroeder, H. 2018
Introduction: Clostridium difficile is the major etiological agent of nosocomial antibiotics associated diarrhoea. C. difficile infection is associated with considerable morbidity and mortality... Show moreIntroduction: Clostridium difficile is the major etiological agent of nosocomial antibiotics associated diarrhoea. C. difficile infection is associated with considerable morbidity and mortality among hospitalized patients worldwide. Despite its known importance, there is no study on this important pathogen in Algeria.Methodology: In this prospective study, undertaken between 2013 and 2015, faecal specimens were collected from 159 hospitalized patients with antibiotic-associated diarrhoea in two tertiary health care hospitals in Chlef, Algeria. Faecal samples were cultured on CLO plates Agar with cefoxitin, cycloserine antibiotics and sodium taurocholate. C. difficile suspected colonies were analysed by multiplex PCR for the detection of the toxin genes. C. difficile isolates were analysed by PCR ribotyping and multi-locus tandem repeat analysis. Antimicrobial susceptibility was determined by the E-test method, according to the Clinical and Laboratory Standards Institute protocol.Results: C. difficile was cultured from 11 of 159 stool specimen (6.9%). Seven strains were toxigenic, mainly represented by the 020 and 014 PCR ribotypes and four non toxigenic belong to PCR ribotype 084. All 11 isolates were susceptible to both vancomycin and metronidazole and resistant to ciprofloxacin.Conclusions: This study, which reported for the first time C. difficile ribotypes circulating in Algerian health care facilities, could paves the way for further more comprehensive studies on this important pathogen, and could be useful to the local health authorities to implement a surveillance program of C. difficile in Algeria. Show less
Kachrimanidou, M.; Tsachouridou, O.; Ziogas, I.A.; Christaki, E.; Protonotariou, E.; Metallidis, S.; ... ; Kuijper, E. 2017
