Novel mutations in the toll like receptor genes cause hyporesponsiveness to Mycobacterium avium subsp. paratuberculosis infection

Toll like receptors play a central role in the recognition of pathogen associated molecular patterns (PAMPs). Mutations in TLR1, TLR2 and TLR4 genes may change the PAMP reorganization ability which causes altered responsiveness to the bacterial pathogens. A case control study, performed to assess the association between TLR gene mutations and susceptibility to Mycobacterium avium subsp. paratuberculosis (MAP), revealed novel mutations (TLR1 - Ser150Gly and Val220Met; TLR2 - Phe670Leu) that hindered either PAMP recognition or further downstream TLR pathway activation. A cytokine expression experiments (IL-4, IL-8, IL-10, IL-12 and IFN-γ) in the challenged mutant and wild type moDCs (mocyte derived dendritic cells) confirmed the negative impact of these mutations and altered TLR downstream activation. Further In silico analysis of the TLR1 and TLR4 ectodomains (ECD) revealed the polymorphic nature of the central ECD and irregularities in the central LRR motifs. The most critical positions that may alter the pathogen recognition ability of TLR were: the 9th amino acid position in LRR motif (TLR1, LRR10) and 4th residue downstream to LRR domain (exta LRR region of TLR4). The study describes novel mutations in the TLRs and presents their association with the MAP infection

Antibiofilm Activity of Weissella spp. and Bacillus coagulans Isolated from Equine Skin against Staphylococcus aureus

The aim of this study was to evaluate the antimicrobial and antibiofilm activity of Weissella cibaria, Weissella hellenica and Bacillus coagulans, isolated from equine skin, against biofilm-forming Staphylococcus aureus CCM 4223 and clinical isolate methicillin-resistant S. aureus (MRSA). Non-neutralized cell-free supernatants (nnCFS) of tested skin isolates completely inhibited the growth and biofilm formation of S. aureus strains and caused dispersion of the 24 h preformed biofilm in the range of 21–90%. The majority of the pH-neutralized cell-free supernatants (nCFS) of skin isolates inhibited the biofilm formation of both S. aureus strains in the range of 20–100%. The dispersion activity of B. coagulans nCFS ranged from 17 to 77% and was significantly lower than that of nnCFS, except for B. coagulans 3T27 against S. aureus CCM 4223. Changes in the growth of S. aureus CCM 4223 in the presence of catalase- or trypsin-treated W. hellenica 4/2D23 and W. cibaria 4/8D37 nCFS indicated the role of peroxides and/or bacteriocin in their antimicrobial activities. For the first time, the presence of the fenD gene, associated with biosurfactants production, was detected in B. coagulans. The results of this study showed that selected isolates may have the potential for the prevention and treatment of biofilm-forming S. aureus infections

Novel mutations in TLR genes cause hyporesponsiveness to Mycobacterium avium subsp. paratuberculosis infection

<p>Abstract</p> <p>Background</p> <p>Toll like receptors (TLR) play the central role in the recognition of pathogen associated molecular patterns (PAMPs). Mutations in the TLR1, TLR2 and TLR4 genes may change the ability to recognize PAMPs and cause altered responsiveness to the bacterial pathogens.</p> <p>Results</p> <p>The study presents association between TLR gene mutations and increased susceptibility to <it>Mycobacterium avium </it>subsp. <it>paratuberculosis </it>(MAP) infection. Novel mutations in TLR genes (TLR1- Ser150Gly and Val220Met; TLR2 – Phe670Leu) were statistically correlated with the hindrance in recognition of MAP legends. This correlation was confirmed subsequently by measuring the expression levels of cytokines (IL-4, IL-8, IL-10, IL-12 and IFN-γ) in the mutant and wild type moDCs (mocyte derived dendritic cells) after challenge with MAP cell lysate or LPS. Further <it>in silico </it>analysis of the TLR1 and TLR4 ectodomains (ECD) revealed the polymorphic nature of the central ECD and irregularities in the central LRR (leucine rich repeat) motifs.</p> <p>Conclusion</p> <p>The most critical positions that may alter the pathogen recognition ability of TLR were: the 9^thamino acid position in LRR motif (TLR1–LRR10) and 4^thresidue downstream to LRR domain (exta-LRR region of TLR4). The study describes novel mutations in the TLRs and presents their association with the MAP infection.</p

Inhibitory Effect of Bacillus licheniformis Strains Isolated from Canine Oral Cavity

Bacillus licheniformis is used in a broad spectrum of areas, including some probiotic preparations for human and veterinary health. Moreover, B. licheniformis strains are known producers of various bioactive substances with antimicrobial and antibiofilm effects. In searching for new potentially beneficial bacteria for oral health, the inhibitory effect of B. licheniformis strains isolated from canine dental biofilm against pathogenic oral bacteria was evaluated. The antimicrobial effect of neutralized cell-free supernatants (nCFS) was assessed in vitro on polystyrene microtiter plates. Furthermore, molecular and morphological analyses were executed to evaluate the production of bioactive substances. To determine the nature of antimicrobial substance present in nCFS of B. licheniformis A-1-5B-AP, nCFS was exposed to the activity of various enzymes. The nCFS of B. licheniformis A-1-5B-AP significantly (p &lt; 0.0001) reduced the growth of Porphyromonas gulae 3/H, Prevotella intermedia 1/P and Streptococcus mutans ATCC 35668. On the other hand, B. licheniformis A-2-11B-AP only significantly (p &lt; 0.0001) inhibited the growth of P. intermedia 1/P and S. mutans ATCC 35668. However, enzyme-treated nCFS of B. licheniformis A-1-5B-AP did not lose its antimicrobial effect and significantly (p &lt; 0.0001) inhibited the growth of Micrococcus luteus DSM 1790. Further studies are needed for the identification of antimicrobial substances

Interleukin-4, hemopexin, and lipoprotein-associated phospholipase A2 are significantly increased in patients with unstable carotid plaque

This study aimed to compare the plasma levels of lipoprotein-associated phospholipase A2 (Lp-PLA2), hemopexin (Hpx), and interleukin-4 (IL-4) in patients with carotid artery atherosclerosis based on neurological symptoms and plaque histopathology and to find association between plaque stability and neurological symptoms. This single-center study included patients treated surgically for significant stenosis of the internal carotid artery. Serum levels of biomarkers were determined, and a histopathological analysis of the carotid plaques was performed. Within 70 patients, 40 asymptomatic and 30 symptomatic; 38 patients (54.3%) were diagnosed with unstable carotid plaque and 32 patients (45.7%) had a stable carotid plaque. Significantly higher incidence of unstable carotid plaque was detected in symptomatic patients (p <0.001). Compared to asymptomatic patients, higher expression of Lp-PLA2 (285.30 ± 2.05 μg/l), Hpx (0.38 ± 0.01 ng/l), and IL-4 (65.77 ± 3.78 ng/l) in plasma were detected in symptomatic patients. Subsequently, higher expression of Lp-PLA2 (297.34 ± 2.3 μg/l), Hpx (0.41 ± 0.02 ng/l), and IL-4 (64.74 ± 4.47 ng/l) in plasma was observed in patients with unstable plaques (n=38). Statistically significant (p <0.001) differences in expression of Lp-PLA2, Hpx, and IL-4 between patients with unstable and stable plaques were detected. Moreover, only the differences between symptomatic and asymptomatic patients in the expression of Lp-PLA2 and IL-4 in plasma were statistically significant (p <0.001). This study showed that Lp-PLA2, IL-4, and Hpx levels are significantly increased in patients with an unstable carotid plaque