Skin infection

Wound healing is a dynamic phenomenon that results in the restoration of anatomic continuity and function on which can be delayed by pathogenic bacteria. This research was designed to explore the antimicrobial efficacy of Tillandsia usneoides against skin infections in wound healing. Physical and chemical evaluations were done through phytochemical screening and thin layer chromatography. The effect of methanolic, ethanolic and aqueous extracts of Tillandsia usneoides against pathogenic bacteria were evaluated on antimicrobial activities using disc diffusion and broth dilution susceptibility assay. The excision bioassay analysis was used in examining the wound healing process in mice. The result of the qualitative phytochemical screening showed the presence of flavonoids and alkaloids. Thin layer chromatography revealed a high Rf value for flavonoids (0.75mm) and alkaloids (0.60mm). The antibacterial assay showed a high zone of inhibition (ZI) for both methanolic extract (>23mm, >22mm and >20mm) and ethanolic extract (>22mm, >22mm and >17mm) for P.aeruginosa, S.aureus and S.epidermis respectively. Resistance against aqueous extract was observed based on the lowest zone of inhibition (<4mm). Gentamicin was used as the positive control (>28mm) and DMSO as the negative control. The minimum inhibitory concentration and minimum bactericidal concentration results confirmed that methanolic and ethanolic extracts restrained the growth of tested bacteria in the range of 125 to 500mg/mL and showed bactericidal efficacy. Wound healing assay indicated that methanolic extract had a higher potency of wound closure (12 days; <1mm) compared to ethanolic and aqueous extracts (13days; >1.5mm and 13days: >1.8mm respectively). Povidone-Iodine was used as the gold standard (15days; <2mm) in the study. In conclusion, methanolic extract of T. usneoides has a great potential with regard to its antimicrobial and wound healing activity to be developed as a novel drug in the future.

Key messages: Recalcitrance of wounds can be partly ascribed to the presence of bacterial biofilms situated subcutaneously in the wound bed. 54 mice from two immunologically diverse inbred mouse strains were used for assessing the impact of the host/pathogen interplay on wound closure. Image J software was used for macroscopical assessment of healing. Results showed that host response towards infection correlates to wound healing. One sentence summary: Host response towards biofilm infection is perturbed and correlates to wound healing in a murine chronic wound model. ABSTRACT The impact of Pseudomonas aeruginosa biofilm infections in chronic wounds and clinical implication for healing is receiving increased attention. However, the pathophysiology of host/pathogen interplay is not fully understood. By further revealing the mechanisms, necessary new treatment strategies may be identified. Since the background for chronic wounds is diverse, representative animal models are important. We assessed host response and spontaneous wound closure in the relatively resistant C3H/HeN and the susceptible BALB/c mouse strain. Full-thickness burn wounds were inflicted in 108 mice. Pseudomonas aeruginosa biofilm (10 6 colony forming units) was injected subcutaneously in 72 mice, euthanised day 4, 7 or 10 days post-infection. Wounds were analysed for neutrophil host response markers: S100A8/A9, keratinocyte-derived chemokine and granulocyte-colony stimulating factor. Total peripheral blood leucocyte and polymorphonuclear count were assessed in parallel. Histopathology evaluated wound inflammatory burden. Photoplanimetry described macroscopical wound closure. Stable chronic wound infection was established in all challenged mice. Pseudomonas aeruginosa biofilm suppressed neutrophil host response in wounds. C3H/HeN mice achieved earlier systemic inflammatory control and healed faster than BALB/c mice. Pseudomonas aeruginosa biofilms perturb host defence thereby inducing a steady state of chronic infection which may impair wound healing. These results indicate therapeutic options for immune modulation of biofilm-infected wounds.

Introduction: Low counts & lack of effective protocols has limited microbial hazard identification on new single-use gloves (SUG) employed in food & healthcare (HC). In 2019 Eagle Protect PBC developed a methodology w/ rinse, count/enrichment, & genomic sequencing. Here we report the first large scale microbial survey of SUG brands, all claiming FDA food contact status & some for HC patient exam use.
Purpose: Metagenomic analysis has shown cross-contamination w/ identification of foodborne pathogens & indicators, but little study has taken place examining sufficient numbers/ unused SUGs employed in either venue.
Methods: Inside (I) & outside (O) plus I&O combined SUG rinse samples from 50-glove pools of 26 SUG brands (25 nitrile & 1 vinyl) were subjected to MPN determination w/ multiple enrichment/ broths. Positive broths pooled / brand samples, w/ DNA extracted subjected to 16S/ITS1 amplicon & Shotgun WGS metagenomic sequencing.
Results: 1,300 SUGs were tested w/ bacterial count range from 102 to ~2 x 105 CFU /100 gloves (a box) having geometric mean = 3.11 Log10. From >5.5 x 105 total CFU, >900 unique taxa, 229 genera and 245 species (+ >150 subsp., strains, serotypes/serovars) were identified. The taxa represented 21 phyla from, Archaea (2), Bacteria (14), Fungi (4) & Viruses (1). Differences in discrimination was seen between 16S & WGS methods w/ overlaps. Numerous food spoilage, frank & opportunistic pathogens and fecal indicator taxa were identified. Pathogenic genera/species included significant food-borne, dermal & respiratory pathogens. Based on knowledge of SUG production & early data, an extensive 16S inside/outside glove comparison examining 16 brands using multivariate cluster analysis determined that populations were significantly different inside from out.
Significance:
This, a first in depth study examining SUG associated microbiome that due to flaws in manufacturing allows survival of pathogens & fecal indicators having public health and economic importance in food & HC applications.

ETHNOPHARMACOLOGICAL RELEVANCE:
Before the advent of modern antibiotics, microbial infections were treated with herbal medicine or cauterization. Literature from the latter half of the nineteenth to the early mid-twentieth century, when antibiotics became widely available, arguably holds the most progressive information about herbal remedies to treat bacterial skin diseases. The corpus of literature produced in Italy during that period is not easily accessible and mostly out of print.
MATERIAL AND METHODS:
Plant-based remedies utilized in popular Italian medicine to treat anthrax, boils, erysipelas, impetigo, pustules, and whitlow were sourced from literature indexed in and available through the National Library Service website of the Italian Libraries Network. The remedies are assessed for their antimicrobial potential based on a detailed search of the herbal drug species in scientific databases.
RESULTS:
A considerable part of the reviewed recipes included specific excipients (41 out of 139) and others were produced with fresh plant material (48 out of 139). Out of the 52 identified herbal drug species used in popular Italian medicine against dermatologic infections, extracts of 43 were shown to have moderate in vitro activity against Gram-positive and Gram-negative bacteria.
CONCLUSION:
The antibacterial activity of the extracts and pure compounds as reported in the reviewed literature is mostly based on in vitro assays and generally does not encourage follow up studies. The effectiveness of the reported recipes, which include fresh plant material and excipients can only be assessed through in vivo studies. Those remedies including herbal drugs with reported antimicrobial activity might have the potential as complementary therapies. The reviewed plant based antimicrobial recipes might serve as inspirations in the search for alternative topical antibacterial strategies and the search for their synergistic and potentiating ingredients.