Khalid Johani

Bacterial Biofilm Infection Detected in Breast Implant-Associated Anaplastic Large-Cell Lymphoma.

Background: A recent association between breast implants and the development of anaplastic large-cell lymphoma (ALCL) has been observed. The purpose of this study was to identify whether bacterial biofilm is present in breast implant–associated ALCL and, if so, to compare the bacterial microbiome to nontumor capsule samples from breast implants with contracture. Methods: Twenty-six breast implant–associated ALCL samples were analyzed for the presence of biofilm by real-time quantitative polymerase chain reaction, next-generation sequencing, fluorescent in situ hybridization, and scanning electron microscopy, and compared to 62 nontumor capsule specimens. Results: Both the breast implant–associated ALCL and nontumor capsule samples yielded high mean numbers of bacteria (breast implant–associated ALCL, 4.7 × 106 cells/mg of tissue; capsule, 4.9 × 106 cells/mg of tissue). Analysis of the microbiome in breast implant–associated ALCL specimens showed significant differences with species identified in nontumor capsule specimens. There was a significantly greater proportion of Ralstonia spp. present in ALCL specimens compared with nontumor capsule specimens (p < 0.05). In contrast, significantly more Staphylococcus spp. were found associated with nontumor capsule specimens compared with breast implant–associated ALCL specimens (p < 0.001). Bacterial biofilm was visualized both on scanning electron microscopy and fluorescent in situ hybridization. Conclusions: This novel finding of bacterial biofilm and a distinct microbiome in breast implant–associated ALCL samples points to a possible infectious contributing cause. Breast implants are widely used in both reconstructive and aesthetic surgery, and strategies to reduce their contamination should be more widely studied and practiced. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, V.

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

Abstract 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 log10 reductions in microbial load after treatment (range 1–2 log10) in comparison with six patients who experienced <1 log10 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.

Hypochlorous Acid Versus Povidone-Iodine Containing Irrigants: Which Antiseptic is More Effective for Breast Implant Pocket Irrigation?

Background Capsular contracture induced by chronic subclinical infection is a major cause of poor outcomes and reoperation in breast implant surgery. The use of pocket irrigation with antiseptic/antibiotic has been shown to reduce the incidence of contracture. A new formulation of hypochlorous acid solution PhaseOne has been proposed as potential agent for irrigation. Objectives This study aimed to test the efficacy of hypochlorous acid solution PhaseOne for use in breast pocket irrigation as an alternative to povidone iodine solution Betadine. Methods The efficacy of PhaseOne, a hypochlorous acid formulated wound and skin cleanser, was tested in vitro against planktonic and biofilm Staphylococcus aureus with or without biological soil and in an implant attachment assay. Its activity was compared with Betadine containing 10% povidone iodine. Results Our findings showed that PhaseOne was unable to eradicate planktonic and/or biofilm S. aureus in the presence of either tryptone soy broth or bovine calf serum (protein soil) in a variety of in vitro assays. Conclusions We advise that povidone iodine containing irrigants are superior to hypochlorous acid containing irrigants in the clinical setting and should remain the recommended solution for pocket irrigation to reduce bacterial contamination at breast implants surgery.

The Role of Bacterial Biofilm in Adverse Soft-Tissue Filler Reactions: A Combined Laboratory and Clinical Study

Background: The development of chronic nodules and granulomatous inflammation after filler injections has been attributed to bacterial biofilm infection. The authors aimed to investigate the relationship between filler and bacterial biofilm using a combined in vitro and in vivo study. Methods: In vitro assays to investigate the ability of filler materials to support the growth of Staphylococcus epidermidis biofilm and the effect of multiple needle passes through a biofilm-contaminated surface were designed. Analysis of clinical biopsy specimens from patients presenting with chronic granulomas following filler administration using a number of laboratory tests for biofilm was performed. Results: All fillers (i.e., hyaluronic acid, polyacrylamide gel, and poly-L-lactic acid) supported the growth of S. epidermidis biofilm in vitro. Multiple needle passes through a biofilm-contaminated surface resulted in significantly increased contamination of filler material by a factor of 10,000 (p < 0.001). Six clinical samples from five patients all demonstrated bacterial biofilm. The mean number of bacteria was found to be 2.2 × 107 bacteria/mg tissue (range, 5.6 × 105 to 3.7 × 107 bacteria/mg tissue). Microbiome analysis detected a predominance of Pseudomonas, Staphylococcus, and Propionibacterium as present in these samples. Conclusions: Filler material can support the growth of bacterial biofilm in vitro. Multiple needle passes can significantly increase the risk of filler contamination. Biofilm appears to be associated with high numbers in clinical samples of patients presenting with chronic granulomatous inflammation. Strategies to reduce the risk of bacterial contamination need to be further studied and translated into clinical practice. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Microscopy visualisation confirms multi-species biofilms are ubiquitous in diabetic foot ulcers

Increasing evidence within the literature has identified the presence of biofilms in chronic wounds and proposed that they contribute to delayed wound healing. This research aimed to investigate the presence of biofilm in diabetic foot ulcers (DFUs) using microscopy and molecular approaches and define if these are predominantly mono‐ or multi‐species. Secondary objectives were to correlate wound observations against microscopy results in ascertaining if clinical cues are useful in detecting wound biofilm. DFU tissue specimens were obtained from 65 subjects. Scanning electron microscopy (SEM) and peptide nucleic acid fluorescent in situ hybridisation (PNA‐FISH) techniques with confocal laser scanning microscopy (CLSM) were used to visualise biofilm structures. Next‐generation DNA sequencing was performed to explore the microbial diversity. Clinical cues that included the presence of slough, excessive exudate, a gel material on the wound bed that reforms quickly following debridement, poor granulation and pyocyanin were correlated to microscopy results. Of the 65 DFU specimens evaluated by microscopy, all were characterised as containing biofilm (100%, P < 0·001). The presence of both mono‐species and multi‐species biofilms within the same tissue sections were detected, even when DNA sequencing analysis of DFU specimens revealed diverse polymicrobial communities. No clinical correlations were identified to aid clinicians in identifying wound biofilm. Microscopy visualisation, when combined with molecular approaches, confirms biofilms are ubiquitous in DFUs and form either mono‐ or multi‐species biofilms. Clinical cues to aid clinicians in detecting wound biofilm are not accurate for use in DFUs. A paradigm shift of managing DFUs needs to consider anti‐biofilm strategies.

Next generation DNA sequencing of tissues from infected diabetic foot ulcers

We used next generation DNA sequencing to profile the microbiome of infected Diabetic Foot Ulcers (DFUs). The microbiota was correlated to clinical parameters and treatment outcomes to determine if directed antimicrobial therapy based on conventional microbiological cultures are relevant based on genomic analysis. Patients ≥ 18 years presenting with a new Diabetic Foot Infection (DFI) who had not received topical or oral antimicrobials in the two weeks prior to presentation, were eligible for enrolment. Tissue punch biopsies were obtained from infected DFUs for analysis. Demographics, clinical and laboratory data were collected and correlated against microbiota data. Thirty-nine patients with infected DFUs were recruited over twelve-months. Shorter duration DFUs (< six weeks) all had one dominant bacterial species (n = 5 of 5, 100%, p < 0.001), Staphylococcus aureus in three cases and Streptococcus agalactiae in two. Longer duration DFUs (≥ six weeks) were diversely polymicrobial (p < 0.01) with an average of 63 (range 19–125) bacterial species. Severe DFIs had complex microbiomes and were distinctly dissimilar to less severe infections (p = 0.02), characterised by the presence of low frequency microorganisms. Nineteen patients (49%) during the study period experienced antimicrobial treatment failure, but no overall differences existed in the microbiome of patients who failed therapy and those who experienced treatment success (p = 0.2). Our results confirm that short DFUs have a simpler microbiome consisting of pyogenic cocci but chronic DFUs have a highly polymicrobial microbiome. The duration of a DFU may be useful as a guide to directing antimicrobial therapy.

Characterization of microbial community composition, antimicrobial resistance and biofilm on intensive care surfaces

BACKGROUND Organisms causing healthcare associated infections can be sourced from the inanimate environment around patients. Residing in a biofilm increases the chances of these organisms persisting in the environment. We aimed to characterise bacterial environmental contamination, genetically and physiologically, and relate this to general intensive care unit (ICU) cleanliness. METHODS Cleanliness was determined by adenosine triphosphate (ATP) measurements of 95 high-touch objects. Bacteriological samples were obtained from the same sites (n=95) and from aseptically removed sections (destructive samples, n=20). Bacterial enrichment culture was conducted using tryptone soya broth prior to plating on horse blood agar, MacConkey agar, and screening chromogenic agar for identification of multidrug resistance organism (MDRO). Bacterial load and microbial diversity were determined using quantitative PCR (qPCR) and next generation DNA sequencing respectively. Confocal laser scanning microscopy and scanning electron microscopy were used to visually confirm the biofilm presence. RESULTS Many intensive care surfaces (61%) were highly contaminated by biological soil as determined by ATP bioluminescence testing. The degree of biological soiling was not associated with bacterial contamination as detected by qPCR. Bacterial load ranged from 78.21 to 3.71×108 (median=900) bacteria/100cm2. Surface swabs from 71/95 sites (75%) were culture-positive; of these 16 (22.5%) contained MDRO. The most abundant genera were Staphylococcus, Propionibacterium, Pseudomonas, Bacillus, Enterococcus, Streptococcus and Acinetobacter. Biofilm was visually confirmed by microscopy on 70% (14/20) of items. CONCLUSION Bacterial biofilms and MDROs were found on ICU surfaces despite regular cleaning in Saudi Arabia, suggesting that biofilm development is not controlled by current cleaning practices.

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

Abstract 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.

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.