Infections associated with mesh repairs of abdominal wall hernias: Are antimicrobial biomaterials the longed-for solution?

The incidence of mesh-related infection after abdominal wall hernia repair is low, generally between 1 and 4%; however, worldwide, this corresponds to tens of thousands of difficult cases to treat annually. Adopting best practices in prevention is one of the keys to reduce the incidence of mesh-related infection. Once the infection is established, however, only a limited number of options are available that provides an efficient and successful treatment outcome. Over the past few years, there has been a tremendous amount of research dedicated to the functionalization of prosthetic meshes with antimicrobial properties, with some receiving regulatory approval and are currently available for clinical use. In this context, it is important to review the clinical importance of mesh infection, its risk factors, prophylaxis and pathogenicity. In addition, we give an overview of the main functionalization approaches that have been applied on meshes to confer anti-bacterial protection, the respective benefits and limitations, and finally some relevant future directions.

Correction to: Fraction of high-grade cervical intraepithelial lesions attributable to genotypes targeted by a nonavalent HPV vaccine in Galicia, Spain.

After publication of the article [1], it was brought to our attention that the author E. López-Díez is missing their second affiliation. The author would also like to indicate an affiliation to "Universidade de Vigo, Pontevedra, Spain".

Fraction of high-grade cervical intraepithelial lesions attributable to genotypes targeted by a nonavalent HPV vaccine in Galicia, Spain.

BACKGROUND: Human papillomavirus (HPV) bivalent and quadrivalent vaccines have been widely implemented in worldwide organized immunization programs. A nonavalent HPV vaccine is now available in several countries. The objective was to describe the fraction of squamous non-invasive high-grade cervical intraepithelial lesions attributable to genotypes targeted by bi-quadrivalent vaccines and by nonavalent vaccine according to age and diagnosis in women living in the city of Vigo (Galicia, Spain). METHODS: Cervical scrapings (2009-2014) of women with histological diagnosis of cervical intraepithelial neoplasia grade 2 (CIN2, n = 145) and grade 3-carcinoma in situ (CIN3-CIS, n = 244) were tested with Linear Array HPV Genotyping test (Roche diagnostics, Mannheim, Germany). Hierarchical estimation of the fraction attributable to HPV 16/18 or HPV 31/33/45/52/58 detected alone or in combination was calculated. Absolute additional fraction attributable to genotypes targeted by nonavalent vaccine compared to genotypes targeted by bi-quadrivalent vaccines was calculated as the increment of attributable cases with respect to all studied cases. Age group 1, 2 and 3 included women 18 to 34, 35-44 and ≥45 years old, respectively. EPIDAT 3.1 was used. RESULTS: Fraction attributable to genotypes targeted by bi-quadrivalent vaccines was 59% CIN2 vs. 69% CIN3-CIS (p < 0.001). It was 63/51/50% of CIN2 and 78/66/45% of CIN3-CIS in age group 1, 2, 3, respectively. Fraction attributable to genotypes targeted by nonavalent vaccine was 86% CIN2 and 86% CIN3-CIS. It was 87/91/75% of CIN2 and 90/86/76% of CIN3-CIS in age group 1, 2, 3, respectively. Fraction attributable to genotypes targeted by these vaccines tended to decrease as age increased (p-trend <0.05). Globally, absolute additional attributable fraction was 16%, 26% and 29% in age group 1, 2 and 3, respectively (p < 0.005). CONCLUSIONS: Absolute additional fraction of CIN2 and CIN3-CIS attributable to genotypes targeted by nonavalent vaccine was observed in women of any age, especially in those over 35 years old.

Evaluation of bacterial adherence of clinical isolates of Staphylococcus sp. using a competitive model: An in vitro approach to the "race for the surface" theory.

OBJECTIVES: Implant-related infection is one of the most devastating complications in orthopaedic surgery. Many surface and/or material modifications have been developed in order to minimise this problem; however, most of the in vitro studies did not evaluate bacterial adhesion in the presence of eukaryotic cells, as stated by the 'race for the surface' theory. Moreover, the adherence of numerous clinical strains with different initial concentrations has not been studied. METHODS: We describe a method for the study of bacterial adherence in the presence of preosteoblastic cells. For this purpose we mixed different concentrations of bacterial cells from collection and clinical strains of staphylococci isolated from implant-related infections with preosteoblastic cells, and analysed the minimal concentration of bacteria able to colonise the surface of the material with image analysis. RESULTS: Our results show that clinical strains adhere to the material surface at lower concentrations than collection strains. A destructive effect of bacteria on preosteoblastic cells was also detected, especially with higher concentrations of bacteria. CONCLUSIONS: The method described herein can be used to evaluate the effect of surface modifications on bacterial adherence more accurately than conventional monoculture studies. Clinical strains behave differently than collection strains with respect to bacterial adherence.Cite this article: M. Martinez-Perez, C. Perez-Jorge, D. Lozano, S. Portal-Nuñez, R. Perez-Tanoira, A. Conde, M. A. Arenas, J. M. Hernandez-Lopez, J. J. de Damborenea, E. Gomez-Barrena, P. Esbrit, J. Esteban. Evaluation of bacterial adherence of clinical isolates of Staphylococcus sp. using a competitive model: An in vitro approach to the "race for the surface" theory. Bone Joint Res 2017;6:315-322. DOI: 10.1302/2046-3758.65.BJR-2016-0226.R2.

Mycological profile of tinea capitis in schoolchildren in rural southern Ethiopia.

Tinea capitis is a known common infection among schoolchildren in developing countries that is still underreported in Ethiopia. The aim of this study was to examine the epidemiologic and etiologic profile of tinea capitis among school-aged children in a rural area in southern Ethiopia. We collected demographic and clinicodermatological data from school children aged 3-12 years with tinea infections. Pathologic specimens were taken for potassium hydroxide (KOH) mount and mycological culture. Dermatophyte species were identified by macroscopic examination of the colony and microscopic examination of fungal cultures. A total of 634 schoolchildren were screened in the study; 128 cases were suspected for tinea capitis based on clinical examination of which 99 patients (mean age 6.7 years within a range of 4-12 years), who were subsequently positive, either based on KOH examination or showed growth of dermatophytes on culture, were included in our study. The ratio of males to females was 3:1. A total of 88 patients (89.9%) had a culture positive for dermatophytes. The zoophilic species Trichophyton verrucosum was the most prevalent isolate (n = 29 cases), followed by the anthropophilic species T. tonsurans (n = 27). The other Trichophyton species implicated were T. mentagrophytes (n = 14), as well as T. schoenleinii, T. soudanense, and T. violaceum. Only 11 of the isolates belonged to the genus Microsporum: M. audouinii (n = 8), M. ferrugineum (n = 2), and M. gallinae (n = 1). T. verrucosum, followed by T. tonsurans were the most frequent causative agents in this study.

Effect of S53P4 bone substitute on staphylococcal adhesion and biofilm formation on other implant materials in normal and hypoxic conditions.

To study the effect of bioactive glass bone substitute granules (S53P4) on bacterial adhesion and biofilm formation on other simultaneously used implant materials and the role of the hypoxic conditions to the adhesion. Bacterial and biofilm formation were studied on materials used both in middle ear prostheses and in fracture fixtures (titanium, polytetrafluoroethylene, polydimethylsiloxane and bioactive glass plates) in the presence or absence of S53P4 granules. The experiments were done either in normal atmosphere or in hypoxia simulating atmospheric conditions of middle ear, mastoid cavity and sinuses. We used two collection strains of Staphylococcus aureus and Staphylococcus epidermidis. In the presence of bioglass and hypoxic conditions the adhesion of the planktonic bacterial cells was decreased for most of the materials. The biofilm formation was decreased for S. epidermidis on titanium and polydimethylsiloxane in both atmospheric conditions and on bioglass plates in normoxia. For S. aureus the biofilm formation was decreased on bioglass plates and polytetrafluoroethylene in normoxia. Hypoxia produces a decrease in the biofilm formation only for S. aureus on polytetrafluoroethylene and for S. epidermidis on bioglass plates. However, in none of the cases bioactive glass increased the bacterial or biofilm adhesion. The presence of bioglass in normoxic and hypoxic conditions prevents the bacterial and biofilm adhesion on surfaces of several typical prosthesis materials in vitro. This may lead to diminishing postoperative infections, however, further in vivo studies are needed.

Effects of S53P4 bioactive glass on osteoblastic cell and biomaterial surface interaction.

To study the effect of bioactive glass bone substitute granules (S53P4) and hypoxic atmospheric conditions on human osteoblastic cell adhesion on different biomaterials. Cellular adhesion and cytoskeletal organization were studied on titanium, polytetrafluoroethylene, polydimethylsiloxane and S53P4 plates in the presence or absence of S53P4 granules. Cells used were human osteoblast-like SaOS-2 cells. The experiments were done either in normal atmospheric conditions or in hypoxia which simulates conditions prevailing in chronically infected bone or bone cavities. Vinculin-containing focal adhesions, organization of actin cytoskeleton and nuclear staining of cells on biomaterial surfaces were studied at 4.5 h, 2 and 4 days. In normoxic conditions S53P4 granules alkalinized the cell culture medium but cellular adhesion and cytoskeletal organization were usually not affected by their presence. Hypoxic conditions associated with lower pH and impaired cellular adhesion, vinculin-containing focal adhesion formation and rearrangement of the actin filaments to actin cytoskeleton. On most materials studied in hypoxic conditions, however, S53P4 granules prevented this impairment of cellular adhesion and cytoskeletal reorganization. The S53P4 granules promote the adhesion of SaOS-2 cells to various biomaterial surfaces especially in hypoxic conditions, in which S53P4 granules increase pH. The presence of S53P4 granules may protect biomaterial surface from bacterial colonization and promote osteointegration of implants used together with S53P4 granules for fixation and weight bearing.

Bacterial adhesion on biomedical surfaces covered by micrometric silver Islands.

A set of Cu-Mn-O and Ag-Cu-Mn-O films were sputter-deposited onto polished Ti-6Al-4V coupons and the microbiological adherence of Staphylococcus sp. was studied in these biomedical surfaces modified by using advanced ternary and quaternary oxides, these latter incorporated micrometric silver islands. Silver is known to have a natural biocidal character and its presence in the surface of Ti-6Al-4V forming large micrometric islands. In principle, predicted to enhance the antimicrobial properties of biomedical surfaces. Microbial adhesion tests were performed using collection strains and six clinical Staphylococcus aureus and Staphylococcus epidermidis strains. The adherence study was performed using a previously published protocol by Kinnari et al. Collection strains and clinical strains showed decreased adherence to modified materials; however, only on the clinical strains were there statistically significant differences between Cu-Mn-O and Ag-Cu-Mn-O containing silver islands. Nanocrystalline silver dissolves and releases both Ag(+) and Ag(0) whereas other silver sources release only Ag+. We can conclude that nanocrystalline silver coating, confirmed by XRD, appears to alter the biological properties of the solution, particularly antimicrobial activity.