In vitro antimicrobial activity of a black currant oil based shampoo versus a chlorhexidine 4% shampoo on bacteria strains isolated from canine pyoderma: A comparative study

Over the last few years, antimicrobial shampoo therapy has been increasingly used to treat skin infections in order to reduce systemic use of antibiotics. This study was aimed to compare the In vitro bactericidal effect of a black currant oil based shampoo (S1) to a chlorhexidine 4% shampoo (S2) against methicillin-sensitive Staphylococcus pseudintermedius (MSSP), methicillin-resistant Staphylococcus pseudintermedius (MRSP), Staphylococcus aureus (SA), Escherichia coli (EC) and Pseudomonas aeruginosa (PA) isolates. A collection of 50 bacterial strains from skin swabs of dogs with superficial recurrent pyoderma was selected: 10 MSSP, 10 MRSP, 10 SA, 10 EC and 10 PA. The two shampoos were blindly tested in duplicate with a microdilution plate method, with scalar concentrations from 1:2 to 1: 256. The MBC was performed for each dilution. A linear regression was used to detect a statistically significance between the two shampoos. All isolates were completely killed at 1:2 up to 1:16 dilution of the two antiseptic products. At the 1:32 dilution the first bacterial growths were observed, in particular for 2 and 4 strains of MRSP by S1 and S2 respectively. The first lethal dilution for SA was at 1:64 for S1/S2 and only for S2 against SP. No significant difference was observed between the two shampoos according to the results of linear regression significant for: i) MRSP, PA and EC (p < 0.05); ii) MSSP and SA (p < 0.1). This study showed that both black currant oil based shampoo and chlorhexidine 4% shampoo have a similar In vitro bactericidal activity

Efficacies of 11% Lactoferricin and 0.05% Chlorhexidine Otological Solution compared, in the treatment of microbial otic overgrowth: A randomized single blinded study

Background:Topical therapy with antimicrobial agents is used in otitis treatment. Due to increase of antibiotic resistance, new strategies are needed. Antiseptics are used but they may induce contact dermatitis. Natural antimicrobial peptides may represent future effective drugs. Objectives:The objectives were to test the efficacy of an 11% lactoferricin otological solution (LCF) in bacterial and yeasts otic overgrowth and compare LCF with a commercial one containing chlorhexidine (CLX) 0.05%. Materials and methods:Forty-one dogs diagnosed with bacterial or yeasts otitis overgrowths were included according to general good practice. They were randomly assigned to lactoferricin or chlorhexidine group for treatment. Otological solution were applied twice a day for a week and then daily for another week. Clinical and cytological score was assessed at day 1 and day 14. At the end of the study, the owners had to express an opinion on the overall efficacy of the products. Statistical analyses were performed using Wilkoxon’s test and T test for paired samples. Results in lesional and cytological score were significative with a p<0.05. Results:Forty dogs completed the study. All cases, receiving lactoferricin or chlorhexidine, were successfully treated with clinical signs remission and regression of infection (p<0.05). The owners’ judgment was good in 87%, mild in 13% for LCF group. For CLX they scored good in 41%, mild in 24% and unuseful in 35% of cases. Conclusions:Lactoferricin, an antimicrobial natural peptide, showed the same efficacy of chlorhexidine in the treatment of otitis characterized by bacterial or/and yeast overgrowth

p63 immunoexpression in hair follicles of normal and alopecia X-affected skin of Pomeranian dogs

Background: Alopecia X in Pomeranians is caused by a hair cycle deregulation, associated with downregulation of key regulatory genes of the Wnt and Shh pathways, and stem-cell markers. However, the pathogenesis remains unclear. p63 is an important transcription factor correlated with the aforementioned hair cycle modulating genes. Hypothesis/objectives: The aim of this study was to highlight possible changes of p63 immunohistochemical expression within the hair follicles in canine alopecia X compared with normal skin. Animals: Skin biopsies from 19 alopecia X-affected and six control Pomeranians were analysed. Materials and methods: Serial histological sections of skin biopsies harbouring anagen, telogen and kenogen hair follicles were immunohistochemically evaluated for differences in p63 expression in the affected and control samples. Results: Dogs with alopecia X had a significantly decreased immunoexpression of p63 in telogen and kenogen hair follicles. Conclusions and clinical relevance: The decrease of p63 immunoexpression observed in canine alopecia X suggests an involvement of p63 in hair cycle

Maternal thyroid hormones are transcriptionally active during embryo–foetal development: results from a novel transgenic mouse model

Abstract Even though several studies highlighted the role of maternal thyroid hormones (THs) during embryo–foetal development, direct evidence of their interaction with embryonic thyroid receptors (TRs) is still lacking. We generated a transgenic mouse model ubiquitously expressing a reporter gene tracing TH action during development. We engineered a construct (TRE2×) containing two TH-responsive elements controlling the expression of the LacZ reporter gene, which encodes β-galactosidase (β-gal). The specificity of the TRE2× activation by TH was evaluated in NIH3T3 cells by cotransfecting TRE2× along with TRs, retinoic or oestrogen receptors in the presence of their specific ligands. TRE2× transgene was microinjected into the zygotes, implanted in pseudopregnant BDF1 (a first-generation (F1) hybrid from a cross of C57BL/6 female and a DBA/2 male) mice and transgenic mouse models were developed. β-gal expression was assayed in tissue sections of transgenic mouse embryos at different stages of development. In vitro, TRE2× transactivation was observed only following physiological T3 stimulation, mediated exclusively by TRs. In vivo, β-gal staining, absent until embryonic day 9.5–10.5 (E9.5–E10.5), was observed as early as E11.5–E12.5 in different primordia (i.e. central nervous system, sense organs, intestine, etc.) of the TRE2× transgenic embryos, while the foetal thyroid function (FTF) was still inactive. Immunohistochemistry for TRs essentially colocalized with β-gal staining. No β-gal staining was detected in embryos of hypothyroid transgenic mice. Importantly, treatment with T3 in hypothyroid TRE2× transgenic mice rescued β-gal expression. Our results provide in vivo direct evidence that during embryonic life and before the onset of FTF, maternal THs are transcriptionally active through the action of embryonic TRs. This model may have clinical relevance and may be employed to design end-point assays for new molecules affecting THs action

DNA microarray validation: Spearman correlation analysis of normalized DNA microarray data and corresponding qPCR results for the whole set of samples.

<p>***<i>p</i><0.001; statistical analysis was performed for each target gene-specific probe available on the array.</p

Target genes mRNA expression in differentiated and undifferentiated MCT samples.

<p>Data are expressed in arbitrary units. FC: -fold change.</p

Principal component analysis of differentiated and undifferentiated reference samples.

<p>Analysis was performed using gene expression data of 597 differentially expressed genes obtained through the comparison of reference samples (13 differentiated and 5 undifferentiated mast cell tumors) with SAM, fixing a fold change of 2 as well as a False Discovery Rate of 0.01 as parameters. Each colored sphere corresponds to a reference sample (differentiated mast cell tumors are indicated in yellow, while undifferentiated ones in red). The value of each principal component is reported on the graph. The sum of the three principal components accounted to the 79.883% of the total variance.</p

qPCR confirmatory analysis.

<p>Marker genes identified by class prediction analysis were amplified in an independent cohort of 22 mast cell tumors in order to comprehend their utility for mast cell tumor classification. Clustering analysis and PCA of gene expression data were performed using MultiD-Genex software for qPCR data, using the following settings: mean center scaling, Ward’s algorithm and Manhattan distance. (A) Clustering tree and (B) principal component analysis of independent mast cell tumor samples. Cases characterized by MCT-related death are indicated in red. The two groups identified are named group 1 and 2 (differentiated and undifferentiated MCTs, respectively). (C) Kaplan-Meyer survival plot stratified by molecular classification (group 1 and 2).</p