Induction heating for eradicating Staphylococcus epidermidis from biofilm

AimsInduction heating is a noninvasive, nonantibiotic treatment modality that can potentially be used to cause thermal damage to the bacterial biofilm on the metal implant surface. The purpose of this study was to determine the effectiveness of induction heating on killing Staphylococcus epidermidis from biofilm and to determine the possible synergistic effect of induction heating and antibiotics.MethodsS. epidermidis biofilms were grown on titanium alloy (Ti6Al4V) coupons for 24 hours (young biofilm) and seven days (mature biofilm). These coupons with biofilm were heated to temperatures of 50 degrees C, 55 degrees C, 60 degrees C, 65 degrees C, 70 degrees C, 80 degrees C, and 90 degrees C for 3.5 minutes and subsequently exposed to vancomycin and rifampicin at clinically relevant concentrations.ResultsFor the young biofilm, total eradication was observed at 65 degrees C or higher for 3.5 minutes followed by 24 hours of vancomycin 10 mg/l and rifampicin 1 mg/l. For the mature biofilm, total eradication was observed at 60 degrees C for 3.5 minutes followed by 24 hours of vancomycin 10 mg/l and rifampicin 1 mg/l. Total eradication was also observed at 60 degrees C for 3.5 minutes followed by 24 hours of vancomycin 1 mg/l and rifampicin 1 mg/l followed by anotherthermal shock of 60 degrees C for 3.5 minutes (two thermal shocks).ConclusionInduction heating of Ti6Al4V coupons is effective in reducing bacterial load in vitro for S. epidermidis biofilms. Induction heating and antibiotics have a synergistic effect resulting in total eradication of the biofilm at 60 degrees C or higher for clinically relevant concentrations of vancomycin and rifampicin.Molecular basis of bacterial pathogenesis, virulence factors and antibiotic resistanc

The bacterial gut microbiota of adult patients infected, colonized or noncolonized by clostridioides difficile

Gut microbiota composition in patients with Clostridioides difficile colonization is not well investigated. We aimed to identify bacterial signatures associated with resistance and susceptibility to C. difficile colonization (CDC) and infection (CDI). Therefore, gut microbiota composition from patients with CDC (n = 41), with CDI (n = 41), and without CDC (controls, n = 43) was determined through 16S rRNA gene amplicon sequencing. Bacterial diversity was decreased in CDC and CDI patients (p < 0.01). Overall microbiota composition was significantly different between control, CDC, and CDI patients (p = 0.001). Relative abundance of Clostridioides (most likely C. difficile) increased stepwise from controls to CDC and CDI patients. In addition, differential abundance analysis revealed that CDI patients' gut microbiota was characterized by significantly higher relative abundance of Bacteroides and Veillonella than CDC patients and controls. Control patients had significantly higher Eubacterium hallii and Fusicatenibacter abundance than colonized patients. Network analysis indicated that Fusicatenibacter was negatively associated with Clostridioides in CDI patients, while Veillonella was positively associated with Clostridioides in CDC patients. Bacterial microbiota diversity decreased in both CDC and CDI patients, but harbored a distinct microbiota. Eubacterium hallii and Fusicatenibacter may indicate resistance against C. difficile colonization and subsequent infection, while Veillonella may indicate susceptibility to colonization and infection by C. difficile.Molecular basis of bacterial pathogenesis, virulence factors and antibiotic resistanc

Clostridioides difficile infection with isolates of cryptic clade C-II: a genomic analysis of polymerase chain reaction ribotype 151

Objectives: We report a patient case of pseudomembranous colitis associated with a monotoxinproducing Clostridioides difficile belonging to the very rarely diagnosed polymerase chain reaction (PCR) ribotype (RT) 151. To understand why this isolate was not identified using a routine commercial test, we performed a genomic analysis of RT151. Methods: Illumina short-read sequencing was performed on n = 11 RT151s from various geographical regions to study their genomic characteristics and relatedness. Subsequently, we used PacBio circular consensus sequencing to determine the complete genome sequence of isolates belonging to cryptic clades CeI and C-II, which includes the patient isolate. Results: We found that 1) RT151s are polyphyletic with isolates falling into clades 1 and cryptic clades C eI and C-II; 2) RT151 contains both nontoxigenic and toxigenic isolates and 3) RT151 C-II isolates contained monotoxin pathogenicity loci. The isolate from our patient case report contains a novelpathogenicity loci insertion site, lacked tcdA and had a divergent tcdB sequence that might explain the failure of the diagnostic test. Discussion: This study shows that RT151 encompasses both typical and cryptic clades and provides conclusive evidence for C. difficile infection due to clade C-II isolates that was hitherto lacking. Vigilance towards C. difficile infection as a result of cryptic clade isolates is warranted. Quinten R. Ducarmon, Clin Microbiol Infect 2023;29:538.e1-538.e6 (c) 2022 The Author(s). Published by Elsevier Ltd on behalf of European Society of Clinical Microbiology and Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).Molecular basis of bacterial pathogenesis, virulence factors and antibiotic resistanc

Microbiota-associated risk factors for asymptomatic gut colonisation with multi-drug-resistant organisms in a Dutch nursing home

Background Nursing home residents have increased rates of intestinal colonisation with multidrug-resistant organisms (MDROs). We assessed the colonisation and spread of MDROs among this population, determined clinical risk factors for MDRO colonisation and investigated the role of the gut microbiota in providing colonisation resistance against MDROs. Methods We conducted a prospective cohort study in a Dutch nursing home. Demographical, epidemiological and clinical data were collected at four time points with 2-month intervals (October 2016-April 2017). To obtain longitudinal data, faecal samples from residents were collected for at least two time points. Ultimately, twenty-seven residents were included in the study and 93 faecal samples were analysed, of which 27 (29.0%) were MDRO-positive. Twelve residents (44.4%) were colonised with an MDRO at at least one time point throughout the 6-month study. Results Univariable generalised estimating equation logistic regression indicated that antibiotic use in the previous 2 months and hospital admittance in the previous year were associated with MDRO colonisation. Characterisation of MDRO isolates through whole-genome sequencing revealed Escherichia coli sequence type (ST)131 to be the most prevalent MDRO and ward-specific clusters of E. coli ST131 were identified. Microbiota analysis by 16S rRNA gene amplicon sequencing revealed no differences in alpha or beta diversity between MDRO-positive and negative samples, nor between residents who were ever or never colonised. Three bacterial taxa (Dorea, Atopobiaceae and Lachnospiraceae ND3007 group) were more abundant in residents never colonised with an MDRO throughout the 6-month study. An unexpectedly high abundance of Bifidobacterium was observed in several residents. Further investigation of a subset of samples with metagenomics showed that various Bifidobacterium species were highly abundant, of which B. longum strains remained identical within residents over time, but were different between residents. Conclusions Our study provides new evidence for the role of the gut microbiota in colonisation resistance against MDROs in the elderly living in a nursing home setting. Dorea, Atopobiaceae and Lachnospiraceae ND3007 group may be associated with protection against MDRO colonisation. Furthermore, we report a uniquely high abundance of several Bifidobacterium species in multiple residents and excluded the possibility that this was due to probiotic supplementation.Molecular basis of bacterial pathogenesis, virulence factors and antibiotic resistanc

Periodic screening of donor faeces with a quarantine period to prevent transmission of multidrug-resistant organisms during faecal microbiota transplantation: a retrospective cohort study

Background On June 13, 2019, the US Food and Drug Administration issued a warning after transfer of faeces containing an extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli by faecal microbiota transplantation led to bacteraemia in two immunocompromised patients. Consequently, we evaluated the effectiveness of the faeces donor-screening protocol of the Netherlands Donor Faeces Bank, which consists of screening of donors for multidrug-resistant organisms every 3 months, combined with additional screening on indication (eg, after travelling abroad) and application of a quarantine period for all faecal suspensions delivered within those 3 months.Methods We did a retrospective cohort study of data collected between Jan 1, 2015, and Oct 14, 2019, on the multidrug-resistant organism testing results of donor faeces. Additionally, we tested previously quarantined faecal suspensions approved for faecal microbiota transplantation between Dec 12, 2016, and May 1, 2019, for the presence of multidrug-resistant organisms using both aselective and selective broth enrichment media. Whole-genome sequencing with core-genome multilocus sequence typing (cgMLST) was done on all multidrug-resistant isolates.Findings Among initial screenings, six (9%) of 66 tested individuals were positive for multidrug-resistant organisms and 11 (17%) of 66 tested individuals were positive for multidrug-resistant organisms at any timepoint. Multidrug-resistant organisms were detected in four (25%) of 16 active donors, who had a median donation duration of 268 days (IQR 92 to 366). Among all screening results, 14 (74%) of 19 detected multidrug-resistant organisms were ESBL-producing E coli. 170 (49%) of 344 approved faecal suspensions had corresponding research faeces aliquots available and were tested (from 11 active donors with a median of eight [IQR five to 26] suspensions per donor). No multidrug-resistant organisms were detected in the 170 approved faecal suspensions (one-sided 95% CI 0 to 1.7). cgMLST revealed that all multidrug-resistant organisms were genetically different.Interpretation Healthy faeces donors can become colonised with multidrug-resistant organisms during donation activities. Our screening protocol did not result in approval of multidrug-resistant organism-positive faecal suspensions for microbiota transplantation. Copyright (C) 2020 Elsevier Ltd. All rights reserved.Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Human transmission of blastocystis by fecal microbiota transplantation without development of gastrointestinal symptoms in recipients

Background. Patients with multiple recurrent Clostridioides difficile infections (rCDI) are treated with fecal microbiota transplantation (FMT), using feces provided by healthy donors. Blastocystis colonization of donors is considered an exclusion criterion, whereas its pathogenicity is still under debate. Methods. The introduction of molecular screening for Blastocystis sp. at our stool bank identified 2 donors with prior negative microscopies but positive polymerase chain reactions (PCRs). Potential transmission of Blastocystis sp. to patients was assessed on 16 fecal patient samples, pre- and post-FMT, by PCR and subtype (ST) analyses. In addition, clinical outcomes for the treatment of rCDI (n = 31), as well as the development of gastrointestinal symptoms, were assessed. Results. There was 1 donor who carried Blastocystis ST1, and the other contained ST3. All patients tested negative for Blastocystis prior to FMT. With a median diagnosis at 20.5 days after FMT, 8 of 16 (50%) patients developed intestinal colonization with Blastocystis, with identical ST sequences as their respective donors. Blastocystis-containing fecal suspensions were used to treat 31 rCDI patients, with an FMT success rate of 84%. This success rate was not statistically different from patients transferred with Blastocystis sp.–negative donor feces (93%, 76/82). Patients transferred with Blastocystis sp.–positive donor feces did not report any significant differences in bowel complaints in the first week, after 3 weeks, or

Low risk of transmission of Clostridium difficile to humans at petting farms

Molecular basis of bacterial pathogenesis, virulence factors and antibiotic resistanc

Non-contact electromagnetic induction heating for eradicating bacteria and yeasts on biomaterials and possible relevance to orthopaedic implant infections

Molecular basis of bacterial pathogenesis, virulence factors and antibiotic resistanc

Effectiveness of mechanical cleaning, antibiotics, and induction heating on eradication of Staphylococcus aureus in mature biofilms

Aims: Here we used a mature seven -day biofilm model of Staphylococcus aureus, exposed to antibiotics up to an additional seven days, to establish the effectiveness of either mechanical cleaning or antibiotics or non-contact induction heating, and which combinations could eradicate S. aureus in mature biofilms. Methods: Mature biofilms of S. aureus (ATCC 29213) were grown on titanium alloy (Ti6Al4V) coupons for seven days and were subjected to the following treatments or their combinations: antibiotics, mechanical cleaning, or heat shock by induction heating of 60 & DEG;C for one minute. Experiments were repeated at least five times. Results: In the untreated biofilm, growth up to 1.8x1011 colony-forming units (CFU)/cm2 was observed. Treatment with ciprofloxacin, flucloxacillin, vancomycin, cefuroxime, and amoxicillin all with rifampicin gave 6.0 log, 6.1 log, 1.4 log, 4.8 log, and 3.6 log reduction in CFU/cm2, respectively. Mechanical cleaning alone resulted in 4.9 log reduction and induc-tion heating in 7.3 log reduction. There was an additional effect of ciprofloxacin, fluclox-acillin, and induction heating when used in combinations. There was no additional effect for mechanical cleaning. No bacterial growth could be detected after induction heating followed by seven days of ciprofloxacin with rifampicin. Conclusion: Mechanical cleaning, antibiotics, and non-contact induction heating reduced the bacterial load of mature S. aureus biofilms with approximately 5 log or more as a single treatment. The effect of mechanical cleaning on mature S. aureus biofilms was limited when used in combination with antibiotics and/or induction heating.</p

Non-contact electromagnetic induction heating for eradicating bacteria and yeasts on biomaterials and possible relevance to orthopaedic implant infections

Molecular basis of bacterial pathogenesis, virulence factors and antibiotic resistanc