[Association between phage-mediated shiga toxin and molecular distribution of CRISPR in Escherichia coli O26 ∶ H11 or NM]

Objective: To investigate the association between phage-mediated shiga toxin and molecular distribution of CRISPR in Escherichia (E.) coli O26∶H11 or NM. Methods: A total of 135 E. coli O26 ∶ H11 or NM strains were collected from NCBI database. Software CRT and CRISPR Finder were used to extract CRISPR and Excel was used to assign the spacer of unique number and type CRISPR. And the relationship between CRISPR and stx phage was analyzed. Results: All the 135 E. coli O26 ∶ H11 or NM strains had the CRISPR. For CRISPR1, CRISPR2.1, CRISPR2.2 and CRISPR3-4, 19, 22, 1 and 1 subtypes were found, respectively. According to the four CRISPR sites, the strains could be divided into 40 subtypes. Stx-phage was only observed in the group C of CRISPR. Compared with E. coli of stx-phage negative, E. coli with stx-phage harbored more spacers. Conclusions: CRISPR loci was extensively existed in E. coli O26∶H11 or NM, and many subtypes were found in these strains. The presence of stx-phage was related to the molecular distribution of CRISPR in E. coli O26∶H11 or NM. CRISPR might be a valuable biomarker to identify strains with high virulent potential.

Control of experimental spasticity by targeting the degradation of endocannabinoids using selective fatty acid amide hydrolase inhibitors

BACKGROUND

It has been previously shown that CB1 cannabinoid receptor agonism using cannabis extracts alleviates spasticity in both a mouse experimental autoimmune encephalomyelitis (EAE) model and multiple sclerosis (MS) in humans. However, this action can be associated with dose-limiting side effects.

OBJECTIVE

We hypothesised that blockade of anandamide (endocannabinoid) degradation would inhibit spasticity, whilst avoiding overt cannabimimetic effects.

METHODS

Spasticity eventually developed following the induction of EAE in either wild-type or congenic fatty acid amide hydrolase (FAAH)-deficient Biozzi ABH mice. These animals were treated with a variety of different FAAH inhibitors and the effect on the degree of limb stiffness was assessed using a strain gauge.

RESULTS

Control of spasticity was achieved using FAAH inhibitors CAY100400, CAY100402 and URB597, which was sustained following repeated administrations. Therapeutic activity occurred in the absence of overt cannabimimetic effects. Importantly, the therapeutic value of the target could be definitively validated as the treatment activity was lost in FAAH-deficient mice. Spasticity was also controlled by a selective monoacyl glycerol lipase inhibitor, JZL184.

CONCLUSIONS

This study demonstrates definitively that FAAH inhibitors provide a new class of anti-spastic agents that may have utility in treating spasticity in MS and avoid the dose-limiting side effects associated with cannabis use.

Blockade of endocannabinoid-degrading enzymes attenuates neuropathic pain

Direct-acting cannabinoid receptor agonists are well known to reduce hyperalgesic responses and allodynia after nerve injury, although their psychoactive side effects have damped enthusiasm for their therapeutic development. Alternatively, inhibiting fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), the principal enzymes responsible for the degradation of the respective endogenous cannabinoids, anandamide (AEA) and 2-arachydonylglycerol (2-AG), reduce nociception in a variety of nociceptive assays, with no or minimal behavioral effects. In the present study we tested whether inhibition of these enzymes attenuates mechanical allodynia, and acetone-induced cold allodynia in mice subjected to chronic constriction injury of the sciatic nerve. Acute administration of the irreversible FAAH inhibitor, cyclohexylcarbamic acid 3'-carbamoylbiphenyl-3-yl ester (URB597), or the reversible FAAH inhibitor, 1-oxo-1-[5-(2-pyridyl)-2-yl]-7-phenylheptane (OL-135), decreased allodynia in both tests. This attenuation was completely blocked by pretreatment with either CB(1) or CB(2) receptor antagonists, but not by the TRPV1 receptor antagonist, capsazepine, or the opioid receptor antagonist, naltrexone. The novel MAGL inhibitor, 4-nitrophenyl 4-(dibenzo[d][1,3]dioxol-5-yl(hydroxy)methyl)piperidine-1-carboxylate (JZL184) also attenuated mechanical and cold allodynia via a CB(1), but not a CB(2), receptor mechanism of action. Whereas URB597 did not elicit antiallodynic effects in FAAH(-/-) mice, the effects of JZL184 were FAAH-independent. Finally, URB597 increased brain and spinal cord AEA levels, whereas JZL184 increased 2-AG levels in these tissues, but no differences in either endo-cannabinoid were found between nerve-injured and control mice. These data indicate that inhibition of FAAH and MAGL reduces neuropathic pain through distinct receptor mechanisms of action and present viable targets for the development of analgesic therapeutics.