Anita Jacombs

Presence of biofilm containing viable multiresistant organisms despite terminal cleaning on clinical surfaces in an intensive care unit

BACKGROUND Despite recent attention to surface cleaning and hand hygiene programmes, multiresistant organisms (MROs) continue to be isolated from the hospital environment. Biofilms, consisting of bacteria embedded in exopolymeric substances (EPS) are difficult to remove due to their increased resistance to detergents and disinfectants, and periodically release free-swimming planktonic bacteria back into the environment which may may act as an infection source. AIM To establish whether reservoirs of MROs exist in the environment as biofilms. METHODS Following terminal cleaning, equipment and furnishings were removed aseptically from an intensive care unit (ICU) and subjected to culture and scanning electron microscopy (SEM). Samples were placed in 5 mL of tryptone soya broth, sonicated for 5 min before plate culture on horse blood agar, Brillance MRSA and Brilliance VRE agar plates. Samples for SEM were fixed in 3% glutaraldehyde and hexamethyldisilizane (HMDS) prior to sputter-coating with gold and examination in an electron microscope. FINDINGS Biofilm was demonstrated visually on the sterile supply bucket, the opaque plastic door, the venetian blind cord, and the sink rubber, whereas EPS alone was seen on the curtain. Viable bacteria were grown from three samples, including MRSA from the venetian blind cord and the curtain. CONCLUSION Biofilm containing MROs persist on clinical surfaces from an ICU despite terminal cleaning, suggesting that current cleaning practices are inadequate to control biofilm development. The presence of MROs being protected within these biofilms may be the mechanism by which MROs persist within the hospital environment.

Chronic biofilm infection in breast implants is associated with an increased T-cell lymphocytic infiltrate: implications for breast implant-associated lymphoma.

Background: Biofilm infection of breast implants significantly potentiates capsular contracture. This study investigated whether chronic biofilm infection could promote T-cell hyperplasia. Methods: In the pig study, 12 textured and 12 smooth implants were inserted into three adult pigs. Implants were left in situ for a mean period of 8.75 months. In the human study, 57 capsules from patients with Baker grade IV contracture were collected prospectively over a 4-year period. Biofilm and surrounding lymphocytes were analyzed using culture, nucleic acid, and visualization techniques. Results: In the pig study, all samples were positive for bacterial biofilm. There was a significant correlation between the bacterial numbers and grade of capsular contracture (p = 0.04). Quantitative real-time polymerase chain reaction showed that all lymphocytes were significantly more numerous on textured compared with smooth implants (p < 0.001). T cells accounted for the majority of the lymphocytic infiltrate. Imaging confirmed the presence of activated lymphocytes. In the human study, all capsules were positive for biofilm. Analysis of lymphocyte numbers showed a T-cell predominance (p < 0.001). There was a significant linear correlation between the number of T and B cells and the number of detected bacteria (p < 0.001). Subset analysis showed a significantly higher number of bacteria for polyurethane implants (p < 0.005). Conclusions: Chronic biofilm infection around breast prostheses produces an increased T-cell response both in the pig and in humans. A possible link between bacterial biofilm and T-cell hyperplasia is significant in light of breast implant-associated anaplastic large-cell lymphoma. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, V.

In vitro and in vivo investigation of the influence of implant surface on the formation of bacterial biofilm in mammary implants.

Background: Capsular contracture remains the most common complication following breast augmentation surgery, and evidence suggests that bacterial biofilm on the implant surface is responsible. The authors investigated whether the interaction of bacterial biofilm with implants independently determines progression to capsule formation. They also studied the rate of bacterial growth and adhesion to implants. Methods: Sixteen adult female pigs had 121 breast implants inserted. Sixty-six implants—23 smooth and 43 textured—were inoculated with a human strain of Staphylococcus epidermidis and received no other treatment. After an average period of 19 weeks, Baker grading was performed and implants were retrieved. For the in vitro study, samples underwent both quantitative bacterial analysis and imaging using confocal laser scanning and scanning electron microscopy. Results: At explantation, there was no significant difference (p = 1.0) in the presence of capsular contracture (Baker grade III and IV) between smooth (83 percent) and textured implants (84 percent). Biofilm was confirmed on 60 of the 66 capsules. Capsules from smooth and textured implants had the same number of infecting bacteria (textured: 3.01 × 108 bacteria/g; smooth: 3.00 × 108 bacteria/g). In vitro, the surface of textured implants showed 11-, 43-, and 72-fold more bacteria at 2, 6, and 24 hours, respectively, compared with smooth implants (p < 0.001). These findings were confirmed by imaging analysis. Conclusions: These results show that textured implants develop a significantly higher load of bacterial biofilm in comparison with smooth implants. Furthermore, in vivo, once a threshold of biofilm forms on either smooth or textured implant surfaces, there seems to be an equal propensity to progress to capsular contracture.

Prevention of Biofilm-Induced Capsular Contracture With Antibiotic-Impregnated Mesh in a Porcine Model

BACKGROUND A growing body of evidence implicates subclinical (biofilm) infection around breast implants as an important cause of capsular contracture (CC). OBJECTIVES The authors use an in vivo porcine model to investigate the potential of antibiotic-impregnated mesh as a prophylactic measure against biofilm formation and CC. METHODS A total of 28 implants (14 untreated controls, 14 treated with antibiotic mesh) were inserted into 5 adult female pigs. All implants and pockets were inoculated with a human clinical strain of Staphylococcus epidermidis. The implants were left in situ for 16 weeks and then analyzed for contracture using both Baker grading and applanation tonometry. The presence of biofilm infection was assessed by subsequent microbiological analysis of implants and capsules. RESULTS One untreated implant had extruded and was excluded from analysis. The tissue surrounding the 13 untreated control implants had Baker Grade III/IV CC, whereas no CC was identified around the 14 antibiotic mesh-treated implants. This difference was highly significant (P < .001). Tonometry findings were consistent with the Baker assessments. Although bacterial biofilm was detected on all implants and capsules, the biofilms on the antibiotic-treated implants and surrounding capsules were generally single-layered or isolated in contrast to the multilayer biofilms found on untreated implants and capsules. CONCLUSIONS Based on the findings from this study of a porcine model, the use of antibiotic-impregnated mesh reduces bacterial access to breast implants at the time of surgical insertion and may subsequently protect against subclinical infection and CC.

Preoperative abdominal muscle elongation with botulinum toxin A for complex incisional ventral hernia repair

Surgical repair of recurrent abdominal incisional hernia(s) can be challenging due to complex operative conditions, intense post‐operative pain, potential respiratory compromise and lateral muscle traction predisposing to early recurrence. We report our preliminary results with botulinum toxin A (BTA) injection causing flaccid paralysis (relaxation) of the lateral abdominal wall muscles prior to surgery.

A review of bacterial biofilms and their role in device-associated infection

Abstract Background Most of the worlds bacteria live in biofilms, three-dimensional clusters attached to surfaces.Manyhospital-acquired infections are associated with biofilm infections of implantable medical devices such as orthopaedic prostheses and intravascular catheters. Within biofilms, bacteria are significantly less susceptible to antibiotics and host defences, making biofilm infections difficult to diagnose and treat, and often necessitating removal of the infected implant. Method In this review article we describe the process of biofilm formation, quorum sensing, and biofilm infection of the healthcare environment, surgical instruments and implantable medical devices. Conclusion The inability to treat biofilm-infected devices means that therapies targeting biofilm-specific processes and targeting prevention of biofilm formation are required.

A new dry-surface biofilm model: An essential tool for efficacy testing of hospital surface decontamination procedures.

UNLABELLED The environment has been shown to be a source of pathogens causing infections in hospitalised patients. Incorporation of pathogens into biofilms, contaminating dry hospital surfaces, prolongs their survival and renders them tolerant to normal hospital cleaning and disinfection procedures. Currently there is no standard method for testing efficacy of detergents and disinfectants against biofilm formed on dry surfaces. AIM The aim of this study was to develop a reproducible method of producing Staphylococcus aureus biofilm with properties similar to those of biofilm obtained from dry hospital clinical surfaces, for use in efficacy testing of decontamination products. The properties (composition, architecture) of model biofilm and biofilm obtained from clinical dry surfaces within an intensive care unit were compared. METHODS The CDC Biofilm Reactor was adapted to create a dry surface biofilm model. S. aureus ATCC 25923 was grown on polycarbonate coupons. Alternating cycles of dehydration and hydration in tryptone soy broth (TSB) were performed over 12 days. Number of biofilm bacteria attached to individual coupons was determined by plate culture and the coefficient of variation (CV%) calculated. The DNA, glycoconjugates and protein content of the biofilm were determined by analysing biofilm stained with SYTO 60, Alexa-488-labelled Aleuria aurantia lectin and SyproOrange respectively using Image J and Imaris software. Biofilm architecture was analysed using live/dead staining and confocal microscopy (CM) and scanning electron microscopy (SEM). Model biofilm was compared to naturally formed biofilm containing S. aureus on dry clinical surfaces. RESULTS The CDC Biofilm reactor reproducibly formed a multi-layered, biofilm containing about 10(7) CFU/coupon embedded in thick extracellular polymeric substances. Within run CV was 9.5% and the between run CV was 10.1%. Protein was the principal component of both the in vitro model biofilm and the biofilms found on clinical surfaces. Continued dehydration and ageing of the model biofilm for 30 days increased the % of protein, marginally decreased gylcoconjugate % but reduced extracellular DNA by 2/3. The surface of both model and clinical biofilms was rough reflecting the heterogeneous nature of biofilm formation. The average maximum thickness was 30.74±2.1 μm for the in vitro biofilm model and between 24 and 47 μm for the clinical biofilms examined. CONCLUSION The laboratory developed biofilm was similar to clinical biofilms in architecture and composition. We propose that this method is suitable for evaluating the efficacy of surface cleaners and disinfectants in removing biofilm formed on dry clinical surfaces as both within run and between run variation was low, and the required equipment is easy to use, cheap and readily available.

Single Nucleotide Primer Extension (SNuPE) analysis of the G6PD gene in somatic cells and oocytes of a kangaroo (Macropus robustus)

cDNA sequence analysis of the X-linked glucose-6-phosphate dehydrogenase (G6PD) gene has shown a base difference between two subspecies of the kangaroo, Macropus robustus robustus (wallaroo) and M. r. erubescens (euro). A thymine residue in the wallaroo at position 358 in exon 5 has been replaced by a cytosine residue in the euro, which accounts for the previously reported electrophoretic difference between the two subspecies. This base difference allowed use of the Single Nucleotide Primer Extension (SNuPE) technique to study allele-specific expression of G6PD at the transcriptional level. We began by examining G6PD expression in somatic cells and observed complete paternal X inactivation in all somatic tissues of adult female heterozygotes, whereas we found partial paternal allele activity in cultured fibroblasts, thus confirming previous allozyme electrophoresis studies. In late dictyate oocytes from an adult heterozygote, the assay also detected expression of both the maternal and paternal alleles at the G6PD locus, with the maternal allele showing preferential expression. Thus reactivation of the inactive paternally derived X chromosome occurs during oogenesis in M. robustus, although the exact timing of reactivation remains to be determined.

Single port component separation: endoscopic external oblique release for complex ventral hernia repair

BackgroundComponent separation (CS) is a technique which mobilizes flaps of innervated, vascularized tissue, enabling closure of large ventral hernia defects using autologous tissue. Disadvantages include extensive tissue dissection when creating these myofascial advancement flaps, with potential consequences of significant post-operative skin and wound complications. This study examines the benefit of a novel, ultra-minimally invasive single port anterior CS technique.MethodsThis was a prospective study of 16 external oblique (EO) releases performed in 9 patients and 4 releases performed in 3 fresh frozen cadavers. All patients presented with recurrent complex ventral hernias, and were administered preoperative Botulinum Toxin A to their lateral oblique muscles to facilitate defect closure. At the time of elective laparoscopic repair, patients underwent single port endoscopic EO release using a single 20-mm incision on each side of the abdomen. Measurements were taken using real-time ultrasound. Postoperatively, patients underwent serial examination and abdominal CT assessment.ResultsSingle port endoscopic EO release achieved a maximum of 50-mm myofascial advancement per side (measured at the umbilicus). No complications involving wound infection, hematoma, or laxity/bulge have been noted. All patients proceeded to laparoscopic or laparoscopic-open-laparoscopic intraperitoneal mesh repair of their hernia, with no hernia recurrences to date.ConclusionsSingle port endoscopic EO release holds potential as an adjunct in the repair of large ventral hernia defects. It is easy to perform, is safe and efficient, and entails minimal disruption of tissue planes and preserves abdominal wall perforating vessels. It requires only one port-sized incision on each side of the abdomen, thus minimizing potential for complications. Further detailed quantification of advancement gains and morbidity from this technique is warranted, both with and without prior administration of Botulinum Toxin A to facilitate closure.

Abdominal Wall Miscellaneous

Methods: From March 2008 to June 2013, a total of 11 hepatic cirrhotic patients with intractable ascites and umbilical hernia received mesh repair. All the patients were placed a Jackson-Pratt drain in lower abdominal cavity for ascites decompression. The drain tube was placed for one month and the amount of ascites drainage was around 1000 ml per day. Patients were followd up one to six months after operation ..Burst abdomen, incisional hernias and stomal hernias : a Swedish population-based register study