Sampling and recovery of infectious SARS-CoV-2 from high-touch surfaces by sponge stick and macrofoam swab.

Effective sampling for severe acute respiratory syndrome 2 (SARS-CoV-2) is a common approach for monitoring disinfection efficacy and effective environmental surveillance. This study evaluated sampling efficiency and limits of detection (LODs) of macrofoam swab and sponge stick sampling methods for recovering infectious SARS-CoV-2 and viral RNA (vRNA) from surfaces. Macrofoam swab and sponge stick methods were evaluated for collection of SARS-CoV-2 suspended in a soil load from 6-in2 coupons composed of four materials: stainless steel (SS), acrylonitrile butadiene styrene (ABS) plastic, bus seat fabric, and Formica. Recovery of infectious SARS-CoV-2 was more efficient than vRNA recovery on all materials except Formica (macrofoam swab sampling) and ABS (sponge stick sampling). Macrofoam swab sampling recovered significantly more vRNA from Formica than ABS and SS, and sponge stick sampling recovered significantly more vRNA from ABS than Formica and SS, suggesting that material and sampling method choice can affect surveillance results. Time since initial contamination significantly affected infectious virus recovery from all materials, with vRNA recovery showing limited to no difference, suggesting that SARS-CoV-2 vRNA can remain detectable after viral infectivity has dissipated. This study showed that a complex relationship exists between sampling method, material, time from contamination to sampling, and recovery of SARS-CoV-2. In conclusion, data show that careful consideration be used when selecting surface types for sampling and interpreting SARS-CoV-2 vRNA recovery with respect to presence of infectious virus.

Efficacy of chemical disinfectants against SARS-CoV-2 on high-touch surface materials.

AIMS: This study aimed to provide operationally relevant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) surface disinfection efficacy information. METHODS AND RESULTS: Three EPA-registered disinfectants (Vital Oxide, Peroxide, and Clorox Total 360) and one antimicrobial formulation (CDC bleach) were evaluated against SARS-CoV-2 on material coupons and were tested using Spray (no touch with contact time) and Spray & Wipe (wipe immediately post-application) methods immediately and 2 h post-contamination. Efficacy was evaluated for infectious virus, with a subset tested for viral RNA (vRNA) recovery. Efficacy varied by method, disinfectant, and material. CDC bleach solution showed low efficacy against SARS-CoV-2 (log reduction < 1.7), unless applied via Spray & Wipe. Additionally, mechanical wiping increased the efficacy of treatments against SARS-CoV-2. The recovery of vRNA post-disinfection suggested that vRNA may overestimate infectious virus remaining. CONCLUSIONS: Efficacy depends on surface material, chemical, and disinfection procedure, and suggests that mechanical wiping alone has some efficacy at removing SARS-CoV-2 from surfaces. We observed that disinfectant treatment biased the recovery of vRNA over infectious virus. SIGNIFICANCE AND IMPACT OF STUDY: These data are useful for developing effective, real-world disinfection procedures, and inform public health experts on the utility of PCR-based surveillance approaches.

Residual antimicrobial coating efficacy against SARS-CoV-2.

AIMS: This study evaluated the residual efficacy of commercially available antimicrobial coatings or films against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on non-porous surfaces. METHODS AND RESULTS: Products were applied to stainless steel or ABS plastic coupons and dried overnight. Coupons were inoculated with SARS-CoV-2 in the presence of 5% soil load. Recovered infectious SARS-CoV-2 was quantified by TCID50 assay. Tested product efficacies ranged from <1.0 to >3.0 log10 reduction at a 2-h contact time. The log10 reduction in recovered infectious SARS-CoV-2 ranged from 0.44 to 3 log10 reduction on stainless steel and 0.25 to >1.67 log10 on ABS plastic. The most effective products tested contained varying concentrations (0.5%-1.3%) of the same active ingredient: 3-(trihydroxysilyl) propyldimethyloctadecyl ammonium chloride. Products formulated with other quaternary ammonium compounds were less effective against SARS-CoV-2 in this test. CONCLUSIONS: The residual antimicrobial products tested showed varied effectiveness against SARS-CoV-2 as a function of product tested. Several products were identified as efficacious against SARS-CoV-2 on both stainless steel and ABS plastic surfaces under the conditions evaluated. Differences in observed efficacy may be due to variation in active ingredient formulation; efficacy is, therefore, difficult to predict based upon listed active ingredient and its concentration. SIGNIFICANCE AND IMPACT: This study highlights the formulation-specific efficacy of several products against SARS-CoV-2 and may inform future development of residual antiviral products for use on non-porous surfaces. The identification of antimicrobial coatings or films showing promise to inactivate SARS-CoV-2 suggests that these products may be worth future testing and consideration.

Evaluation of pilot experience with robotic-assisted proctectomy and coloanal anastomosis for rectal cancer.

BACKGROUND: Robotic-assisted proctectomy with coloanal anastomosis (RPCA) is an innovative technique of pelvic dissection for low rectal cancer. Our objective was to evaluate our pilot experience with this procedure compared with open proctectomy with coloanal anastomosis (OPCA). METHODS: We performed a retrospective 5-year review of all consecutive cases of RPCA and OPCA performed at our institute. We focused on tumour characteristics, quality of surgery, analgesic requirements, average length of hospital stay (LOS), complications and long-term outcomes. RESULTS: Three patients underwent RPCA and 25 had OPCA. The average duration of surgery was similar (288 min for RPCA v. 285 min for OPCA). Four patients in the OPCA group had positive or very close margins, and 2 had a mesorectal defect less than 5 mm. The average LOS was 6.66 and 9.29 days in the RPCA and OPCA groups, respectively, and the average duration of epidural or patient-controlled anesthesia was 2.67 and 5.16 days, respectively. We did not perform a statistical comparison because of the discordant size and sex distribution between the groups. There were no perioperative complications in the RPCA group, and all patients had negative margins and adequate lymph node retrievals with no long-term complications or recurrence recorded so far. CONCLUSION: Our very early experience with RPCA is quite encouraging, suggesting that it is a safe alternative to OPCA with a similar duration and the added benefits of a minimally invasive procedure, including decreased LOS and reduced postoperative analgesic requirements.

CONTEXTE: La proctectomie robot-assistée avec anastomose colo-anale est une technique novatrice de dissection pelvienne pour les cancers du bas rectum. Notre objectif était d'évaluer notre expérience pilote avec cette intervention, comparativement à la proctectomie ouverte avec anastomose colo-anale. MÉTHODES: Nous avons procédé à une revue rétrospective sur 5 ans de tous les cas consécutifs de proctectomie robot-assistée et de proctectomie ouverte avec anastomose coloanale effectuées dans notre établissement. Nous nous sommes concentrés sur les caractéristiques des tumeurs, la qualité de l'intervention chirurgicale, les besoins analgésiques, la durée moyenne du séjour hospitalier (DSH), les complications et l'issue à long terme. RÉSULTANTS: Trois patients ont subi une proctectomie robot-assistée et 25 une proctectomie ouverte. La durée moyenne des interventions a été similaire (288 minutes pour la proctectomie robot-assistée c. 285 minutes pour la proctectomie ouverte). Quatre patients du groupe soumis à la proctectomie ouverte présentaient des marges positives ou très étroites et 2 présentaient des anomalies mésorectales de moins de 5 mm. La DSH moyenne a été de 6,66 et de 9,29 jours dans les groupes soumis à la proctectomie robotassistée et à la proctectomie ouverte, respectivement, et la durée moyenne de l'anesthésie péridurale ou contrôlée par les patients a été de 2,67 et 5,16 jours, respectivement. Nous n'avons pas procédé à une comparaison statistique entre les groupes en raison de la disparité de leur taille et de la distribution inégale du sexe des participants. Nous n'avons enregistré aucune complication périopératoire dans les groupes soumis à la proctectomie robot-assistée et tous les patients présentaient des marges négatives; les prélèvements ganglionnaires ont été adéquats, sans complications à long terme ni récurrences à ce jour. CONCLUSION: Notre expérience très récente avec la proctectomie robot-assistée est plutôt encourageante et donne à penser qu'il s'agit d'une solution de rechange sécuritaire à la proctectomie ouverte étant d'une durée similaire et procurant les avantages supplémentaires d'une intervention minimalement effractive, assortie d'une DSH plus brève et d'une diminution des besoins en analgésie postopératoire.

Identification and characterization of an immunogenic hybrid epitope formed by both HIV gp120 and human CD4 proteins.

Certain antibodies from HIV-infected humans bind conserved transition state (CD4 induced [CD4i]) domains on the HIV envelope glycoprotein, gp120, and demonstrate extreme dependence on the formation of a gp120-human CD4 receptor complex. The epitopes recognized by these antibodies remain undefined although recent crystallographic studies of the anti-CD4i monoclonal antibody (MAb) 21c suggest that contacts with CD4 as well as gp120 might occur. Here, we explore the possibility of hybrid epitopes that demand the collaboration of both gp120 and CD4 residues to enable antibody reactivity. Analyses with a panel of human anti-CD4i MAbs and gp120-CD4 antigens with specific mutations in predicted binding domains revealed one putative hybrid epitope, defined by the human anti-CD4i MAb 19e. In virological and immunological tests, MAb 19e did not bind native or constrained gp120 except in the presence of CD4. This contrasted with other anti-CD4i MAbs, including MAb 21c, which bound unliganded, full-length gp120 held in a constrained conformation. Conversely, MAb 19e exhibited no specific reactivity with free human CD4. Computational modeling of MAb 19e interactions with gp120-CD4 complexes suggested a distinct binding profile involving antibody heavy chain interactions with CD4 and light chain interactions with gp120. In accordance, targeted mutations in CD4 based on this model specifically reduced MAb 19e interactions with stable gp120-CD4 complexes that retained reactivity with other anti-CD4i MAbs. These data represent a rare instance of an antibody response that is specific to a pathogen-host cell protein interaction and underscore the diversity of immunogenic CD4i epitope structures that exist during natural infection.

An alteration of human immunodeficiency virus gp41 leads to reduced CCR5 dependence and CD4 independence.

Human immunodeficiency virus (HIV) type 1 infection requires functional interactions of the viral surface (gp120) glycoprotein with cell surface CD4 and a chemokine coreceptor (usually CCR5 or CXCR4) and of the viral transmembrane (gp41) glycoprotein with the target cell membrane. Extensive genetic variability, generally in gp120 and the gp41 ectodomain, can result in altered coreceptor use, fusion kinetics, and neutralization sensitivity. Here we describe an R5 HIV variant that, in contrast to its parental virus, infects T-cell lines expressing low levels of cell surface CCR5. This correlated with an ability to infect cells in the absence of CD4, increased sensitivity to a neutralizing antibody recognizing the coreceptor binding site of gp120, and increased resistance to the fusion inhibitor T-20. Surprisingly, these properties were determined by alterations in gp41, including the cytoplasmic tail, a region not previously shown to influence coreceptor use. These data indicate that HIV infection of cells with limiting levels of cell surface CCR5 can be facilitated by gp41 sequences that are not exposed on the envelope ectodomain yet induce allosteric changes in gp120 that facilitate exposure of the CCR5 binding site.

Canadian Association of University Surgeons annual symposium: Continuity of care: Toronto, Ontario, Sep. 6, 2007.

This 2007 symposium of the Canadian Association of University Surgeons brought together surgeons from a number of jurisdictions to discuss the challenges and opportunities that reduced physician work hours will bring to the care of the surgical patient. Dr. Brian Taylor, president of the association, underscored the need to find a balance between the benefits of diminished workloads/work hours and the loss of continuity of care. He opined that Canada needs to learn from our European colleagues' experience. Dr. Per-Olof Nyström, professor of surgery, presented the modern Swedish model of surgical care, which had to be developed as a consequence of the European Union's legal restrictions on the amount of time an individual surgeon may work. Sweden employs a team-based shared-care model driven by the individual surgeon's expertise rather than the "village factory" model of the multiskilled, multitasking approach of surgical care more prevalent in Canada. Dr. Chris de Gara, secretary treasurer of the association, presented the evidence base for (and against) work-hour restrictions and how well-designed systems can ensure effective continuity of care. Dr. Stewart Hamilton illustrated how one such system for the delivery of the emergency general surgical services has evolved at the University of Alberta Hospital, which demonstrated its effectiveness in providing quality surgical continuity of care. Dr. Debrah Wirtzfeld underscored the importance of trainee lifestyle and how modern Web-based technologies can ensure reduced errors with the implementation of a "sign-out" system.

Use of Serotonergic Drugs in Canada for Gastrointestinal Motility Disorders: Results of a Retrospective Cohort Study.

Background. Surgery for GI dysmotility is limited to those with severe refractory disease. Though effective, use of serotonergic promotility drugs has been restricted in Canada due to adverse events. We aimed to investigate utilization of promotility serotonergic drugs in patients under consideration for surgical management. Methods. A retrospective cohort study was conducted using prospectively collected data. The study population included consecutive patients referred to a motility clinic for consideration of bowel resection at a Canadian tertiary hospital (1996-2011). Univariable tests and multivariable logistic regression analyses were used to assess predictors of serotonergic drug use. Results. Of 128 patients, the majority (n = 98, 76.6%) had constipation-dominant symptoms. Only 25% (n = 32) had tried serotonergic promotility drugs. There was no association between use of these drugs and severity of constipation nor was there an association between serotonergic drug use and presence of diffuse dysmotility (all p > 0.05). The majority of patients (n = 97, 75.8%) underwent some type of surgical resection, which was associated with considerable morbidity (n = 13, 13.4%). Conclusions. Surgical management of GI dysmotility results in serious morbidity. Serotonergic promotility drugs may allow patients to avoid surgery but disease severity does not predict use of these drugs.

Improved health-related quality of life after surgical management of severe refractory constipation-dominant irritable bowel syndrome.

Irritable bowel syndrome (IBS) is the most common of the functional gastrointestinal disorders (FGIDs). Despite its prevalence and health-care costs, there are few effective therapies for patients with severe symptoms. Our objective was to determine whether surgical management would improve health-related quality of life (HRQOL) in severe refractory constipation-dominant FGIDs. From 2003 to 2005, 6 patients underwent total colectomy with end ileostomy or primary anastomosis. They completed Short Form 36 (SF-36) and IBS-36 questionnaires preoperatively and postoperatively. HRQOL was compared with age- and sex-matched Canadian norms using Welch's unpaired t test. Preoperative SF-36 physical and mental health summary scores were significantly lower than Canadian norms (P < 0.0001), while postoperative scores were not significantly different than Canadian norms (P = 0.50 and P = 0.57, respectively). After surgical management, HRQOL in patients with severe constipation-dominant IBS improved from drastically below that of Canadian norms to a comparable level. This finding questions the convention of avoiding operations in IBS patients and demonstrates that surgical management may be suitable for the appropriately screened patient.

Histological findings in resected bowel of motility-disordered patients.

Gastrointestinal (GI) motility disorders are prevalent conditions associated with pain and bowel dysfunction. Some motility-disordered patients with intractable symptoms have undergone bowel resection aimed at palliating their symptoms. Our objective was to describe a population of motility-disordered patients with histopathological abnormalities identified in full-thickness surgical biopsies. A retrospective cohort study using prospectively collected clinical data and pathology reports was conducted. All adult patients referred to a tertiary motility clinic from 1996 to 2011 who had bowel resection for motility disorder were consecutively sampled. Fisher's exact test was used. Ninety-seven patients were referred for motility disorder during this time and pathology reports were available for 62 patients (63.9%). Hypertrophy or hyperplasia of the myenteric plexus was reported in 13 patients (21.0%). These patients were predominantly females with constipation-dominant symptoms. They were more likely to have objective evidence of colonic inertia (P = 0.01) than patients without myenteric plexus hypertrophy/hyperplasia. Consistent histopathologic abnormalities of myenteric plexus hypertrophy/hyperplasia were described in 21 per cent of patients with refractory GI motility disorders referred for surgical management. Our findings contrast with the hypoganglionosis reported in the slow transit constipation literature. Future studies are needed to systematically investigate these novel histologic findings through a follow-up immunohistochemical study of stored bowel specimens.

Appendicovesical fistula: case report and review.

Appendicovesical fistulae are rare and occur secondary to acute or missed acute appendicitis. A 15 year old boy presented with urinary symptoms and a pelvic abscess on imaging studies. At laparotomy an appendicovesical fistula was encountered and was successfully managed by a right colectomy and ileal transverse colon anastomosis. The presentation and management of appendicovesical fistula is discussed.

Abacavir, didanosine and tenofovir do not induce inflammatory, apoptotic or oxidative stress genes in coronary endothelial cells.

BACKGROUND: The use of abacavir and didanosine in HAART has been associated with an increased risk of myocardial infarction in HIV-infected patients. The aim of this study was to address the development of endothelial dysfunction in cultivated coronary artery endothelial cells (HCAECs) in response to abacavir, didanosine and tenofovir. We examined the impact of these drugs on the expression levels of the proinflammatory, oxidative stress and apoptosis regulating genes in HCAECs. METHODS: We tested gene and protein expression changes in HCAECs in response to abacavir, didanosine and tenofovir using quantitative real-time reverse transciptase PCR, FACS and ELISA. The assessed genes/proteins included the proinflammatory molecules VCAM-1, ICAM-1, MCP-1, RANTES and IL-6. In addition, we assessed the gene expression of the intracellular reactive oxygen producing NADPH oxidase subunit gp91(PHOX) and the apoptosis regulating molecules Bcl-2 and BAD. RESULTS: Exposure of HCAECs to abacavir, didanosine and tenofovir resulted in no statistically significant changes in any of the tested genes/proteins at any time point or at any concentration. CONCLUSIONS: We found no evidence that abacavir, didanosine or tenofovir had direct in vitro effects on coronary endothelial cell gene transcription and protein expression of the selected mediators. If abacavir or didanosine increase cardiovascular risk, it is likely not through the direct endothelial activation pathways tested in these experiments. However, further studies are needed to completely exclude the toxicity of abacavir or didanosine on endothelial cells.