Antimicrobial and Wound Healing Activity of Gardenia aqualla Stem Bark Methanol Extract

Aim: This study was aimed at examining the antimicrobial and wound healing activities of Gardenia aqualla stem bark methanol extract (GASBME) in order to provide scientific basis for its antimicrobial and wound healing properties. Methodology: Preliminary phytochemical screening was done and antimicrobial activity determined using some pathogenic micro-organisms were evaluated following its wound healing effectiveness in Wistar rats using the model of superficial skin excision wound. Data were analysed using one-way analysis of variance (ANOVA) followed by Dunnet’s t-test. Results: The results of preliminary phytochemical screening revealed the presence of carbohydrate, cardiac glycosides, saponins, flavonoids, triterpenes, tannins, alkaloids with anthraquinones being absent. The extract showed antimicrobial activity on Staphylococcus aureus, Corynebacterium ulcerans, Escherichia coli, Klebsiella pneumonia and Salmonella typhi and significant (p< 0.05, p< 0.001) decrease in wound measurement by the 11th day. Conclusion: This study demonstrated that GASBME possesses antimicrobial activity with wound healing properties that justifies the ethno-medicinal use of the plant in wound/ulcer healings.

Corynebacterium hindlerae sp. nov., derived from a human granuloma, which forms black colonies and black halos on modified Tinsdale medium but is not closely related to Corynebacterium diphtheriae and related taxa

Corynebacterium diphtheriae , Corynebacterium belfantii , Corynebacterium rouxii , Corynebacterium ulcerans , Corynebacterium pseudotuberculosis and Corynebacterium silvaticum are the only taxa from among ~121 Corynebacterium species deemed potentially able to harbour diphtheria tox genes. Subsequently tox-gene bearing species may potentially produce diphtheria toxin, which is linked to fatal respiratory distress if a pharyngeal pseudomembrane is formed or toxaemia develops in those unimmunized or under-immunized. Detection of diphtheria toxin-producing species may also invoke a public health response and contact tracing. Recovery of such species from the respiratory tract or other contaminated sources such as non-healing ulcerative wounds are expedited by use of differential and selective media such as modified Tinsdale medium (MTM). This medium is supplemented with potassium tellurite, which supresses most normal flora present in contaminated specimens, as well as l-cystine and thiosulphate. Most diphtheria-tox-gene bearing species grow well on MTM, producing black colonies with a black halo around each colony. This is due to an ability to produce cystinase in the presence of tellurite, cystine and thiosulphate, resulting in black tellurium deposits being observed in the agar. Other Corynebacterium species may/may not be able to grow at all in the presence of tellurite but if able to grow, will have small beige or brownish colonies which do not exhibit black halos. We describe here an unusual non-tox-gene-bearing isolate, NML 93-0612T, recovered from a human wrist granuloma, which produced black colonies with black halos on MTM agar but was otherwise distinguishable from Corynebacterium species which can bear tox genes. Distinctive features included its unusual colony morphology on MTM and sheep blood agar, by proteomic, biochemical and chemotaxonomic properties and by molecular methods. Its genome contained 2 680 694 bytes, a G+C content of 60.65 mol% with features consistent with the genus Corynebacterium and so represents a new species for which we propose the name Corynebacterium hindlerae sp. nov.

Prepatellar Bursitis with Abscess due to Corynebacterium ulcerans

Corynebacteria are ubiquitous and reside as skin and mucosa commensals in animals. They are considered contaminants in clinical specimens, but significant clinical data points to their virulence and pathogenic potential over the last two decades. Corynebacteria can cause both community-acquired and nosocomial infections. Corynebacterium diphtheriae (C. diphtheriae) responsible for diphtheria has declined over the previous two decades with an increase in a similar clinical syndrome by Corynebacterium ulcerans (C. ulcerans) in Europe. As per recent studies, C. ulcerans shares similar virulence factors with C. diphtheriae. C. ulcerans has been implicated in airway infections, skin and soft tissue infections, lymphadenitis, wound infections, and rarely necrotizing fasciitis. Pet or farm animals have been the source of these infections to humans, as per recent reports. Strains can be either toxigenic or nontoxigenic. Due to recent advances, methods to characterize strains have become easier with mass spectrometry. Antimicrobial susceptibility testing is a must for definite treatment as C. ulcerans can be resistant to first-line antibiotic therapy. If resources are available, it is prudent to find if there is any toxin production. Here, we describe a rural farmer in central Missouri presenting with acute-onset right knee pain diagnosed with right prepatellar bursitis with abscess due to C. ulcerans infection. He recovered with surgical debridement and antimicrobial therapy. This is the first case of C. ulcerans causing prepatellar bursitis with an abscess as per medical literature review.

Case Report: Toxigenic Corynebacterium ulcerans Diphtheria-Like Infection in a Horse in the United Kingdom

Corynebacterium ulcerans (C. ulcerans) may cause diphtheria in humans and can be carried by a wide range of animal species including dairy cows and, more recently, dogs and cats that have been increasingly involved in zoonotic trasmission. We isolated and characterized, by WGS, a toxigenic C. ulcerans strain from a diseased horse in the United Kingdom showing clinical signs of respiratory diphtheria comparable to those seen in people. Our results indicate a role for horses as reservoirs for zoonotic C. ulcerans.

Antimicrobial and wound healing properties of the methanol extract of Ficus platyphylla Del. (Moraceae) stem bark

Ficus platyphylla (Fp) has been used in Nigerian traditional medicine for the management of pain, ulcer, wound, epilepsy and inflammation. The efficacy of its gum from the stem bark for the management of wound has been widely acclaimed among the Hausa communities of Northern Nigeria and therefore, this study was aimed at examining the antimicrobial and wound healing potential of methanol extract of F. platyphylla stem bark (MEFpSB) in order to provide scientific basis for its antimicrobial and wound healing properties. Preliminary phytochemical screening was done and antimicrobial activity using some pathogenic micro-organisms were evaluated following its wound healing effectiveness in Wistar rats using the model of superficial skin excision wound. Data were analysed using one-way analysis of variance (ANOVA) followed by Dunnet’s t-test. The results of preliminary phytochemical screeningrevealed the presence of carbohydrate, cardiac glycosides, saponins, flavonoids, triterpenes, tannins, alkaloids with anthraquinones absent. The extract showed antimicrobial activity on Staphylococcus aureus, Corynebacterium ulcerans, Escherichia coli, Klebsiella pneumonia and Salmonella typhi and significant (p< 0.05, p< 0.001) decrease in wound measurement for 11 days. This study demonstrated that MEFpSB possesses antimicrobial activity with wound healing properties that justifies the ethno-medicinal use of the plant in wound/ulcer healings. Keywords: Wound healing; Antimicrobial; Ficus platyphylla; Formulation; Topical

Newly Isolated Animal Pathogen Corynebacterium silvaticum Is Cytotoxic to Human Epithelial Cells

Corynebacterium silvaticum is a newly identified animal pathogen of forest animals such as roe deer and wild boars. The species is closely related to the emerging human pathogen Corynebacterium ulcerans and the widely distributed animal pathogen Corynebacterium pseudotuberculosis. In this study, Corynebacterium silvaticum strain W25 was characterized with respect to its interaction with human cell lines. Microscopy, measurement of transepithelial electric resistance and cytotoxicity assays revealed detrimental effects of C. silvaticum to different human epithelial cell lines and to an invertebrate animal model, Galleria mellonella larvae, comparable to diphtheria toxin-secreting C. ulcerans. Furthermore, the results obtained may indicate a considerable zoonotic potential of this newly identified species.