Assessing the Risk of Hypoglycemia Secondary to Propranolol Therapy for the Treatment of Supraventricular Tachycardia in Infants.

Supraventricular tachycardia (SVT) is the most common arrhythmia among infants. Prevention of SVT is frequently managed through propranolol therapy. Hypoglycemia is a known adverse effect of propranolol therapy, but little research has been done on the incidence and risk of hypoglycemia in treatment of SVT in infants with propranolol. This study attempts to offer insight into the risk of hypoglycemia associated with propranolol therapy when treating infantile SVT to help inform future glucose screening guidelines. We conducted a retrospective chart review of infants treated with propranolol in our hospital system. Inclusion criteria were infants < 1 year of age who received propranolol for the treatment of SVT. A total of 63 patients were identified. Data was collected on sex, age, race, diagnosis, gestational age, nutrition source (Total Parenteral Nutrition (TPN) vs oral), weight (kg), weight for length (kg/cm), propranolol dose (mg/kg/day), comorbidities, and whether or not a hypoglycemic event was identified (< 60 mg/dL). Hypoglycemic events were identified in 9/63 (14.3%) patients. Of the patients with hypoglycemic events, 9/9 (88.9%) had comorbid conditions. Patients with hypoglycemic events had significantly lower weight and propranolol dose than those without hypoglycemic events. Weight for length also tended to increase risk for hypoglycemic events. The high incidence of comorbid conditions in the patients who had hypoglycemic events suggests that hypoglycemic monitoring may only be necessary in patients with conditions predisposing to hypoglycemia.

The microbiome of diabetic foot ulcers: a comparison of swab and tissue biopsy wound sampling techniques using 16S rRNA gene sequencing.

BACKGROUND: Health-care professionals need to collect wound samples to identify potential pathogens that contribute to wound infection. Obtaining appropriate samples from diabetic foot ulcers (DFUs) where there is a suspicion of infection is of high importance. Paired swabs and tissue biopsies were collected from DFUs and both sampling techniques were compared using 16S rRNA gene sequencing. RESULTS: Mean bacterial abundance determined using quantitative polymerase chain reaction (qPCR) was significantly lower in tissue biopsies (p = 0.03). The mean number of reads across all samples was significantly higher in wound swabs [Formula: see text] = 32,014) compared to tissue ([Formula: see text] = 15,256, p = 0.001). Tissue biopsies exhibited greater overall diversity of bacteria relative to swabs (Shannon's H diversity p = 0.009). However, based on a presence/absence analysis of all paired samples, the frequency of occurrence of bacteria from genera of known and potential pathogens was generally higher in wound swabs than tissue biopsies. Multivariate analysis identified significantly different bacterial communities in swabs compared to tissue (p = 0.001). There was minimal correlation between paired wound swabs and tissue biopsies in the number and types of microorganisms. RELATE analysis revealed low concordance between paired DFU swab and tissue biopsy samples (Rho = 0.043, p = 0.34). CONCLUSIONS: Using 16S rRNA gene sequencing this study identifies the potential for using less invasive swabs to recover high relative abundances of known and potential pathogen genera from DFUs when compared to the gold standard collection method of tissue biopsy.

Biofilm contamination of high-touched surfaces in intensive care units: epidemiology and potential impacts.

The aim of this study was to determine the epidemiology (location, microbial load, microbiome, presence/absence of biofilm and pathogens, including ESKAPE-Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter species, and antimicrobial susceptibility profiles) of the bacterial contamination on intensive care units (ICUs) surfaces. Fifty-seven high-touched surfaces were collected from adult, paediatric and neonatal ICUs from two large public Brazilian hospitals from central and north regions. Samples (c. 4 cm2 ) were subjected to culture (qualitative), qPCR targeting 16s rRNA gene (microbial load-bacteria per cm2 ), 16s rRNA amplicon sequencing (microbiome analysis) and scanning electron (SEM) or confocal laser scanning microscopy (CLSM) (biofilm presence). Multidrug resistant organisms (MROs) were detected using specific chromogenic agar. The average bacterial load was 1·32 × 104 bacteria per cm2 , container for newborn feeding bottles, stretcher mattress, humidicrib mattress filling and computer keyboards presented the higher bioburden. However, only 45·6% (26/57) were culture-positive, including 4/26 with MROs. ESKAPE organisms were detected in 51·8% of the samples subjected to next-generation sequencing. Viability staining and CLSM demonstrated live bacteria on 76·7% of culture-negative samples. Biofilm was present on all surfaces subjected to microscopy (n = 56), demonstrating that current cleaning practices are suboptimal and reinforcing that MROs are incorporated into hospital surfaces biofilm. SIGNIFICANCE AND IMPACT OF THE STUDY: Contamination of healthcare facilities surfaces has been shown to play a major role in transmission of pathogens. The findings of this study show that dry surface biofilms are widespread and can incorporate pathogens and multidrug-resistant organisms (MROs). Biofilms on highly touched surfaces pose a risk to patients, as dry surface biofilms persist for long period and micro-organisms within biofilm have been shown to be transmitted. This study also provides a better understanding of microbial populations in hospital environments, reinforcing that pathogens and MROs are found incorporated into biofilm, which impacts the difficulty in cleaning/disinfection.

Evaluation of short exposure times of antimicrobial wound solutions against microbial biofilms: from in vitro to in vivo.

Objectives: Test the performance of topical antimicrobial wound solutions against microbial biofilms using in vitro, ex vivo and in vivo model systems at clinically relevant exposure times. Methods: Topical antimicrobial wound solutions were tested under three different conditions: (in vitro) 4% w/v Melaleuca oil, polyhexamethylene biguanide, chlorhexidine, povidone iodine and hypochlorous acid were tested at short duration exposure times for 15 min against 3 day mature biofilms of Staphylococcus aureus and Pseudomonas aeruginosa; (ex vivo) hypochlorous acid was tested in a porcine skin explant model with 12 cycles of 10 min exposure, over 24 h, against 3 day mature P. aeruginosa biofilms; and (in vivo) 4% w/v Melaleuca oil was applied for 15 min exposure, daily, for 7 days, in 10 patients with chronic non-healing diabetic foot ulcers complicated by biofilm. Results: In vitro assessment demonstrated variable efficacy in reducing biofilms ranging from 0.5 log10 reductions to full eradication. Repeated instillation of hypochlorous acid in a porcine model achieved <1 log10 reduction (0.77 log10, P = 0.1). Application of 4% w/v Melaleuca oil in vivo resulted in no change to the total microbial load of diabetic foot ulcers complicated by biofilm (median log10 microbial load pre-treatment = 4.9 log10 versus 4.8 log10, P = 0.43). Conclusions: Short durations of exposure to topical antimicrobial wound solutions commonly utilized by clinicians are ineffective against microbial biofilms, particularly when used in vivo. Wound solutions should not be used as a sole therapy and clinicians should consider multifaceted strategies that include sharp debridement as the gold standard.

Effect of cadexomer iodine on the microbial load and diversity of chronic non-healing diabetic foot ulcers complicated by biofilm in vivo.

Objectives: The performance of cadexomer iodine was determined against microbial populations from chronic non-healing diabetic foot ulcers (DFUs) complicated by biofilm in vivo , using molecular, microscopy and zymography methods. Methods: Chronic non-healing DFUs due to suspected biofilm involvement were eligible for enrolment. DNA sequencing and real-time quantitative PCR was used to determine the microbial load and diversity of tissue punch biopsies obtained pre- and post-treatment. Scanning electron microscopy and/or fluorescence in situ hybridization confirmed the presence or absence of biofilm. Zymography was used to determine levels of wound proteases. Results: Seventeen participants were recruited over a 6 month period. Scanning electron microscopy and or fluorescence in situ hybridization confirmed the presence of biofilm in all samples. Eleven participants exhibited log 10 reductions in microbial load after treatment (range 1-2 log 10 ) in comparison with six patients who experienced <1 log 10 reduction ( P = 0.04). Samples were tested for levels of wound proteases pre- and post-treatment. Reductions in the microbial load correlated to reductions in wound proteases pre- and post-treatment ( P = 0.03). Conclusions: To the best of our knowledge, this study represents the first in vivo evidence, employing a range of molecular and microscopy techniques, of the ability of cadexomer iodine to reduce the microbial load of chronic non-healing DFUs complicated by biofilm. Further analyses correlating log reductions to optimal duration of therapy and improvements in clinical parameters of wound healing in a larger cohort are required.

Can molecular DNA-based techniques unravel the truth about diabetic foot infections?

Diabetes foot infections are a common condition and a major causal pathway to lower extremity amputation. Identification of causative pathogens is vital in directing antimicrobial therapy. Historically, clinicians have relied upon culture-dependent techniques that are now acknowledged as both being selective for microorganisms that thrive under the physiological and nutritional constraints of the microbiology laboratory and that grossly underestimate the microbial diversity of a sample. The amplification and sequence analysis of the 16S rRNA gene has revealed a diversity of microorganisms in diabetes foot infections, extending the view of the diabetic foot microbiome. The interpretation of these findings and their relevance to clinical care remains largely unexplored. The advent of molecular methods that are culture-independent and employ massively parallel DNA sequencing technology represents a potential 'game changer'. Metagenomics and its shotgun approach to surveying all DNA within a sample (whole genome sequencing) affords the possibility to characterize not only the microbial diversity within a diabetes foot infection (i.e. 'which microorganisms are present') but the biological functions of the community such as virulence and pathogenicity (i.e. 'what are the microorganisms capable of doing'), moving the focus from single species as pathogens to groups of species. This review will examine the new molecular techniques for exploration of the microbiome of infected and uninfected diabetic foot ulcers, exploring the potential of these new technologies and postulating how they could translate to improved clinical care. Copyright © 2016 John Wiley & Sons, Ltd.

Comparison of two endoscope channel cleaning approaches to remove cyclic build-up biofilm.

INTRODUCTION: Biofilm contributes significantly to bacterial persistence in endoscope channels. Enhanced cleaning methods capable of removing biofilm from all endoscope channels are required to decrease infection risk to patients. This head-to-head study compared cyclic build-up biofilm removal of an automated endoscope channel cleaner (AECC) with standard manual cleaning according to instructions for use (IFU) in polytetrafluorethylene channels. METHODS: Cyclic build-up biofilm was grown in 1.4-mm (representing air/water and auxiliary channels) and 3.7-mm (representing suction/ biopsy channels) inner diameter polytetrafluorethylene channels. All channels were tested for residual total organic carbon, protein, and viable bacteria. Internationally recognized ISO 15883-5:2021 alert levels were used as cleaning benchmarks for protein (3 µg/cm2) and total organic carbon (6 µg/cm2). RESULTS: The automated cleaner significantly outperformed manual cleaning for all markers assessed (protein, total organic carbon, viable bacteria) in 1.4-mm and 3.7-mm channels representing air/water/auxiliary and suction/biopsy channels, respectively. Manual cleaning failed to remove biofilm from the air/water and auxiliary channels. According to the IFU, these channels are not brushed, suggesting a potential root cause for a portion of the numerous endoscopy-associated infections reported in the literature. CONCLUSION: AECC shows potential to deliver enhanced cleaning over current practice to all endoscope channels and may thereby address infection risk.

Dry surface biofilms: what you need to know.

Environmental dry surface biofilms are a new type of biofilm found on dry surfaces, that are not visible to the human eye. Dry surface biofilms harbour multidrug-resistant organisms, are resistant to cleaning and disinfection and cannot be detected by wet or dry swabbing, so may play an important role in the persistence of pathogens in the healthcare environment.

Hinged surgical instruments: efficacy of double manual cleaning versus automated cleaning on biofilm removal.

The efficacy of double manual cleaning (DMC) with enzymatic detergent followed by alkaline detergent on biofilm removal on hinged surgical instruments was compared to automated cleaning. Biofilm-covered haemostatic forceps were divided into four groups: positive control (soaked in sterile water); DMC; DMC plus extra brushing of the inner hinge; and automated cleaning. All DMC, DMC plus brushing the hinge, and automated cleaning significantly (P < 0.001) reduced 94.8%, 99.8%, and 100% viable bacteria and 82.3%, 93.8%, and 95.1% residual protein, respectively, compared to positive control. DMC instruments had significantly more viable bacteria (P < 0.05) and residual protein (P < 0.01) than those in instruments subjected to DMC with hinge brushing and automated cleaning. However, there was no significant difference in residual protein between DMC with hinge brushing and automated cleaning. In sterilizing service units with no access to automated cleaning equipment, it is important to brush the inner hinge during manual cleaning, and DMC plus brushing the inner hinge could be considered a viable alternative for cleaning hinged surgical instruments.

Contribution of usage to endoscope working channel damage and bacterial contamination.

BACKGROUND: Biofilm formation has been shown to be associated with damaged areas of endoscope channels. It was hypothesized that the passage of instruments and brushes through endoscope channels during procedures and cleaning contributes to channel damage, bacterial attachment and biofilm formation. AIM: To compare surface roughness and bacterial attachment in used and new endoscope channels in vivo and in vitro. METHODS: Surface roughness of 10 clinically used (retired) and seven new colonoscope biopsy channels was analysed by a surface profiler. For the in-vitro study, a flexible endoscope biopsy forceps was passed repeatedly through a curved 3.0-mm-diameter Teflon tube 100, 200 and 500 times. Atomic force microscopy was used to determine the degree of inner surface damage. The number of Escherichia coli or Enterococcus faecium attached to the inner surface of the new Teflon tube and the tube with 500 forceps passes in 1 h at 37oC was determined by culture. RESULTS: The average surface roughness of the used biopsy channels was found to be 1.5 times greater than that of the new biopsy channels (P=0.03). Surface roughness of Teflon tubes with 100, 200 and 500 forceps passes was 1.05-, 1.12- and 3.2-fold (P=0.025) greater than the roughness of the new Teflon tubes, respectively. The number of E. coli and E. faecium attached to Teflon tubes with 500 forceps passes was 2.9-fold (P=0.021) and 4.3-fold (P=0.004) higher compared with the number of E. coli and E. faecium attached to the new Teflon tubes, respectively. CONCLUSION: An association was found between endoscope usage with damage to the biopsy channel and increased bacterial attachment.

The efficacy of topical agents used in wounds for managing chronic biofilm infections: A systematic review.

OBJECTIVES: Clinicians have increasingly adopted the widespread use of topical agents to manage chronic wound infections, despite limited data on their effectiveness in vivo. This study sought to evaluate the evidence for commonly employed topical agents used in wounds for the purpose of treating chronic infections caused by biofilm. METHOD: We included in vitro, animal and human in vivo studies where topical agents were tested for their efficacy against biofilms, for use in wound care. For human studies, we only included those which utilised appropriate identification techniques for visualising and confirming the presence of biofilms. RESULT: A total of 640 articles were identified, with 43 included after meeting eligibility. In vitro testing accounted for 90% (n = 39) of all included studies, five studies using animal models and three human in vivo studies. Sixteen different laboratory models were utilised, with the most frequent being the minimum biofilm eradication concentration (MBEC™) / well plate assay (38%, n = 15 of 39). A total of 44 commercially available topical agents were grouped into twelve categories with the most commonly tested agents being silver, iodine and polyhexamethylene biguanide (PHMB). In vitro results on efficacy demonstrated iodine as having the highest mean log10 reductions of all agents (4.81, ±3.14). CONCLUSION: There is large disparity in the translation of laboratory studies to researchers undertaking human trials relating to the effectiveness of commercially available topical agents. There is insufficient human in vivo evidence to definitively recommend any commercially available topical agent over another for the treatment of chronic wound biofilms. The heterogeneity identified between study designs (in vitro to in vivo) further limits the generalisability of results.

Effect of disinfectant formulation and organic soil on the efficacy of oxidizing disinfectants against biofilms.

BACKGROUND: Biofilms that develop on dry surfaces in the healthcare environment have increased tolerance to disinfectants. This study compared the activity of formulated oxidizing disinfectants with products containing active ingredients against Staphylococcus aureus dry-surface biofilm (DSB) alone. METHODS: DSB was grown in the CDC bioreactor with alternating cycles of hydration and dehydration. Disinfectant efficacy was tested before and after treatment with neutral detergent for 30 s, and in the presence or absence of standardized soil. Biofilms were treated for 5 min with peracetic acid (Surfex and Proxitane), hydrogen peroxide (Oxivir and 6% H2O2 solution) and chlorine (Chlorclean and sodium dichloroisocyanurate tablets). Residual biofilm viability and mass were determined by plate culture and protein assay, respectively. FINDINGS: Biofilm viability was reduced by 2.8 log10 for the chlorine-based products and by 2 log10 for Proxitane, but these products failed to kill any biofilm in the presence of soil. In contrast, Surfex completely inactivated biofilm (6.3 log10 reduction in titre) in the presence of soil. H2O2 products had little effect against DSB. Biofilm mass removed in the presence and absence of soil was <30% by chlorine and approximately 65% by Surfex. Detergent treatment prior to disinfection had no effect. CONCLUSION: The additives in fully formulated disinfectants can act synergistically with active ingredients, and thus increase biofilm killing whilst decreasing the adverse effect of soil. It is suggested that purchasing officers should seek efficacy testing results, and consider whether efficacy testing has been conducted in the presence of biological soil and/or biofilm.

Difficulty in removing biofilm from dry surfaces.

Cleaning is fundamental to infection control. This report demonstrates that a Staphylococcus aureus biofilm is significantly more difficult to remove than dried planktonic bacteria. A single wiping action removed >99.9% (>3 log10) of dried planktonic bacteria, whereas only 1.4 log10 of biofilm (96.66%) was removed by 50 wiping actions with a standardized wiping process.

Understanding the microbiome of diabetic foot osteomyelitis: insights from molecular and microscopic approaches.

OBJECTIVES: Rigorous visual evidence on whether or not biofilms are involved in diabetic foot osteomyelitis (DFO) is lacking. We employed a suite of molecular and microscopic approaches to investigate the microbiome, and phenotypic state of microorganisms involved in DFO. METHODS: In 20 consecutive subjects with suspected DFO, we collected intraoperative bone specimens. To explore the microbial diversity present in infected bone we performed next generation DNA sequencing. We used scanning electron microscopy (SEM) and peptide nucleic acid fluorescent in situ hybridization (PNA-FISH) with confocal microscopy to visualize and confirm the presence of biofilms. RESULTS: In 19 of 20 (95%) studied patients presenting with DFO, it was associated with an infected diabetic foot ulcer. By DNA sequencing of infected bone, Corynebacterium sp. was the most commonly identified microorganism, followed by Finegoldia sp., Staphylococcus sp., Streptococcus sp., Porphyromonas sp., and Anaerococcus sp. Six of 20 bone samples (30%) contained only one or two pathogens, while the remaining 14 (70%) had polymicrobial communities. Using a combination of SEM and PNA-FISH, we identified microbial aggregates in biofilms in 16 (80%) bone specimens and found that they were typically coccoid or rod-shaped aggregates. CONCLUSIONS: The presence of biofilms in DFO may explain why non-surgical treatment of DFO, relying on systemic antibiotic therapy, may not resolve some chronic infections caused by biofilm-producing strains.

Complex design of surgical instruments as barrier for cleaning effectiveness, favouring biofilm formation.

BACKGROUND: Inadequately reprocessed reusable surgical instruments (RSIs) may harbour infectious agents which may then be transferred to a suitable site for replication. AIM: To determine the cumulative effect of 20 cycles of contamination, cleaning (manual or manual followed by automated) and steam sterilization on high-complex-design RSIs used for orthopaedic surgery. METHODS: New flexible medullary reamers and depth gauges were contaminated by soaking in tryptone soya broth, containing 5% sheep blood and 109 cfu/mL of Staphylococcus aureus (ATCC 25923), for 5 min. To mimic a worse-case scenario, RSIs were dried 7 h and subjected to either (a) rinsing in distilled water, (b) manual cleaning or (c) manual plus automated cleaning (reference standard), and steam sterilization. The contamination, cleaning, and sterilization cycle was repeated 20 times. Adenosine triphosphate (ATP) was measured after cleaning procedures; microbial load and residual protein were measured following the 10th and 20th reprocessing, in triplicate. Scanning electron microscopy (SEM) was used to confirm soil and biofilm presence on the RSIs after the 20th reprocessing. FINDINGS: Manual and manual plus automated cleaning significantly reduced the amount of ATP and protein residues for all RSIs. Viable bacteria were not detected following sterilization. However, SEM detected soil after automated cleaning, and soil, including biofilms, after manual cleaning. CONCLUSION: Soil and/or biofilms were evident on complex-design RSIs following 20 cycles of contamination and reprocessing, even using the reference standard method of cleaning. Although the depth gauges could be disassembled, biological residues and biofilm accumulated in its lumen. The current design of these RSIs prevents removal of all biological soil and this may have an adverse effect on patient outcome.

Determination of bacterial species present in biofilm contaminating the channels of clinical endoscopes.

BACKGROUND: Outbreaks of endoscopy-related Carbapenem-resistant Enterobacteriaceae has highlighted failures in endoscope decontamination resulting in biofilm formation. Biofilms are tolerant to detergents and disinfectants. We evaluated decontaminated endoscope channels for residual bacterial contamination and biofilm presence. METHODS: 64 channels were collected from 12 gastroscopes and 11 colonoscopes. Aerobic bacteria were isolated from inside the endoscope tubing by scrapping, sonication, and aerobic plate culture. Total number of contaminating bacteria was determined by quantitative real-time PCR with 16s rRNA eubacterial universal primers. Microbial diversity was assessed using next generation DNA sequencing. Biofilm presence was visually confirmed by confocal laser scanning and scanning electron microscopy. RESULTS: 47% of channels were culture positive, with α-haemolytic Streptococci from gastroscopes and coliforms from colonoscopes the most frequently isolated species. Sphingomonas spp., Staphylococcus spp., Streptococcus spp., and Pseudomonas aeruginosa were also isolated. An average of 1.2 × 103 bacteria/cm contaminated air-water channels, 2.8 × 102 and 6.6 × 102 bacteria/cm contaminated gastroscope and colonoscope working channels, respectively. Biofilm was on all 39 channels examined and was principally composed of environmental bacteria, although all samples contained potential pathogens. CONCLUSION: Biofilm is present on many endoscope channels obtained from Australian hospitals. Any soil including biofilm can compromise disinfectant action.

The validity of adenosine triphosphate measurement in detecting endoscope contamination.

BACKGROUND: Endoscopic procedures are vital to gastrointestinal disease diagnosis and management, but risk infection transmission. In Australia, endoscopes undergo monthly-to-quarterly microbiological testing, to prevent patient infection. Endoscopes are used more frequently, meaning contamination may not be detected by this surveillance before infection transmission occurs. AIM: To evaluate the use of adenosine triphosphate (ATP) measurement, alongside standard microbiological cultures, in detecting endoscope contamination before high-level disinfection. Using these results, we also aimed to confirm the efficacy of manual cleaning in reducing levels of ATP and cfu/mL. METHODS: Seventeen in-clinical-use gastroscopes and 24 in-clinical-use colonoscopes from the Liverpool Hospital Endoscopy unit were sampled across three separate cleaning stages before high-level disinfection. Colony counts and ATP measurements were then performed on these samples. FINDINGS: The correlation between the cfu/mL and RLU of samples collected from colonoscopes was 0.497 (95% confidence interval: 0.28-0.66; P < 0.0001). The correlation between cfu/mL and RLU for samples collected from gastroscopes was 0.377 (0.08-0.61; P = 0.0138). RLU and cfu/mL values were shown to fall significantly (P < 0.005) following precleaning and manual cleaning. CONCLUSION: There was a significant correlation between ATP and cfu/mL measured from samples collected before high-level disinfection. Precleaning and manual cleaning were shown to reduce ATP and microbiological load significantly. ATP measurement can be performed within minutes with little training and produces results that are easy to interpret. These findings warrant further research on the utility of ATP measurement as a screening tool for detecting endoscope contamination after high-level disinfection.

Rabacfosadine for relapsed canine B-cell lymphoma: Efficacy and adverse event profiles of 2 different doses.

Rabacfosadine (RAB), a novel double prodrug of the acyclic nucleotide phosphonate PMEG, preferentially targets neoplastic lymphocytes with reduced off target toxicity. Historical studies have suggested that every 21-day dosing is effective with acceptable toxicity. The purpose of this study was to evaluate RAB's safety and efficacy at 2 different doses every 21 days in dogs with relapsed B-cell lymphoma. Dogs that had failed 1 doxorubicin-based chemotherapy protocol were eligible for inclusion in this prospective trial. Once enrolled, dogs were randomized to receive RAB at either 0.82 mg/kg or 1.0 mg/kg as a 30-minute IV infusion every 21 days for up to 5 treatments. Response assessment and adverse event (AE) evaluation were performed every 21 days via VCOG criteria. Fifty dogs were enrolled, with 16 treated at 0.82 mg/kg and 34 treated at 1.0 mg/kg. The overall response rate was 74%, with 45% of dogs experiencing a complete response (CR). The median progression free intervals (PFIs) were 108 days, 172 days and 203 days for all dogs, all responders, and all CRs, respectively. Response rates and PFIs were similar in both treatment groups. The incidence of AEs, dose delays, dose reductions and withdrawals were not statistically different between the 2 groups. The AEs observed were similar to those previously reported and included hematologic, gastrointestinal, dermatologic and pulmonary AEs. One dog had grade 5 pulmonary fibrosis; otherwise, AEs resolved with supportive treatment. Rabacfosadine is a generally well tolerated, effective chemotherapy option for dogs with relapsed B-cell lymphoma.

Staphylococcus aureus dry-surface biofilms are more resistant to heat treatment than traditional hydrated biofilms.

BACKGROUND: The importance of biofilms to clinical practice is being increasingly realized. Biofilm tolerance to antibiotics is well described but limited work has been conducted on the efficacy of heat disinfection and sterilization against biofilms. AIM: To test the susceptibility of planktonic, hydrated biofilm and dry-surface biofilm forms of Staphylococcus aureus, to dry-heat and wet-heat treatments. METHODS: S. aureus was grown as both hydrated biofilm and dry-surface biofilm in the CDC biofilm generator. Biofilm was subjected to a range of temperatures in a hot-air oven (dry heat), water bath or autoclave (wet heat). FINDINGS: Dry-surface biofilms remained culture positive even when treated with the harshest dry-heat condition of 100°C for 60min. Following autoclaving samples were culture negative but 62-74% of bacteria in dry-surface biofilms remained alive as demonstrated by live/dead staining and confocal microscopy. Dry-surface biofilms subjected to autoclaving at 121°C for up to 30min recovered and released planktonic cells. Recovery did not occur following autoclaving for longer or at 134°C, at least during the time-period tested. Hydrated biofilm recovered following dry-heat treatment up to 100°C for 10min but failed to recover following autoclaving despite the presence of 43-60% live cells as demonstrated by live/dead staining. CONCLUSION: S. aureus dry-surface biofilms are less susceptible to killing by dry heat and steam autoclaving than hydrated biofilms, which are less susceptible to heat treatment than planktonic suspensions.

Transfer of dry surface biofilm in the healthcare environment: the role of healthcare workers' hands as vehicles.

BACKGROUND: Dry surface biofilms (DSBs) persist for extended periods in hospital, and may play a significant role in transmission of healthcare-associated infections. AIM: To determine whether DSBs may be transferred from hospital surfaces to healthcare workers' hands. METHOD: Twelve-day Staphylococcus aureus DSB was grown on polycarbonate and glass coupons in a CDC Biofilm Reactor®. A total of 1.8 × 106 and 8.8 × 105 bacteria grew on the polycarbonate and glass coupons respectively. Transmission was tested by lifting the coupon with forefinger and thumb of ungloved hands to a height of 30 cm, then touching horse blood agar (HBA) plates 19 sequential times. Transferred bacterial number was determined by colony-forming units. The effect of DSB wetting on biofilm transfer was tested with 5% neutral detergent treatment for 5 s. FINDINGS: Between 5.5 and 6.6% of the DSB bacteria were transferred to hands with one touch and ∼20% were then transferred to HBA with one touch, giving an overall transfer rate of 1.26% and 1.04% for polycarbonate and glass coupons, respectively. Detergent treatment had little effect on bacterial removal from coupons, but, for biofilm grown on polycarbonate, significantly increased transferral to HBA (P < 0.001) to 5.2%. Large numbers of bacteria were transferred by bare hands to multiple fomites. One-third of polycarbonate coupons transferred >1000 colonies during the first five sequential touches. Sufficient bacteria to cause infection were transmitted up to 19 times following one touch of the DSB. CONCLUSION: DSB bacteria are transferred by hands from one fomite to multiple fomites, suggesting that DSB may serve as a persistent environmental source of pathogens.