Anticandidial and anticryptococcal activity of <Emphasis Type="Italic">Euphorbia fusiformis</Emphasis>, a rare medicinal plant

The present work demonstrates the screening of extracts of the rare medicinal herb Euphorbia fusiformis for antifungal activity. The main aim was to investigate its antifungal properties against Candida albicans and Cryptococcus neoformans, the causative agents of human candidiasis and cryptococcosis, respectively. Aqueous and organic solvent extracts from the leaves and rootstock of the plant were tested against the fungi by the well-in-agar method. Almost all the organic solvent extracts exhibited an inhibitory effect against C. albicans and to some extent on C. neoformans, except for the aqueous extracts, which had no effect. The combined formulations of the extracts also had better activity against C. albicans than C. neoformans. This study thus concludes by demonstrating the antifungal properties of E. fusiformis and also the potential research in identifying the active principles, which may have future therapeutic value.     

Renoprotective effect of grape seeds extract in ethylene glycol induced nephrotoxic mice

Grape seed extract treatment in ethylene glycol (EG) induced nephrotoxic mice improved antioxidant status and significantly decreased urinary lactate dehydrogenase (LDH) and lipid peroxidation. The extract rendered antioxidant protection against oxidative stress induced by EG and may help in protecting renal tissue against EG toxicity.     

Feasibility of an alcohol intervention programme for TB patients with alcohol use disorder (AUD)--a qualitative study from Chennai, South India

Background

The negative influences of alcohol on TB management with regard to delays in seeking care as well as non compliance for treatment has been well documented. This study is part of a larger study on the prevalence of AUD (Alcohol Use Disorder) among TB patients which revealed that almost a quarter of TB patients who consumed alcohol could be classified as those who had AUD. However there is dearth of any effective alcohol intervention programme for TB patients with Alcohol Use Disorder (AUD).

Methodology

This qualitative study using the ecological system model was done to gain insights into the perceived effect of alcohol use on TB treatment and perceived necessity of an intervention programme for TB patients with AUD. We used purposive sampling to select 44 men from 73 TB patients with an AUDIT score >8. Focus group discussions (FGDs) and interviews were conducted with TB patients with AUD, their family members and health providers.

Results

TB patients with AUD report excessive alcohol intake as one of the reasons for their vulnerability for TB. Peer pressure has been reported by many as the main reason for alcohol consumption. The influences of alcohol use on TB treatment has been elaborated especially with regard to the fears around the adverse effects of alcohol on TB drugs and the fear of being reprimanded by health providers. The need for alcohol intervention programs was expressed by the TB patients, their families and health providers. Suggestions for the intervention programmes included individual and group sessions, involvement of family members, audiovisual aids and the importance of sensitization by health staff.

Conclusions

The findings call for urgent need based interventions which need to be pilot tested with a randomized control trial to bring out a model intervention programme for TB patients with AUD.     

Role of the Campylobacter jejuni Cj1461 DNA methyltransferase in regulating virulence characteristics

Mutation of the cj1461 predicted methyltransferase gene reduced the motility of Campylobacter jejuni 81-176. Electron microscopy revealed that the mutant strain had flagella but with aberrant structure. The Δcj1461 mutant was sevenfold more adherent to but 50-fold less invasive of INT-407 human epithelial cells than the wild type.     

Chemical validation of molecular mimicry: interaction of cholera toxin with Campylobacter lipooligosaccharides

It is generally believed that molecular mimicry between bacterial lipooligosaccharide (LOS) and nerve glycolipids may play an important pathogenic role in immune-mediated peripheral neuropathy. One of the putative infectious agents is Campylobacter jejuni (C. jejuni). To elucidate the structural basis for the molecular mimicry, we investigated the structure of the lipooligosaccharide (LOS) fraction of C. jejuni, strain HS19, and found that it includes at least two components, characterized as fast-and slow-moving bands (LF and LS) by thin-layer chromatography as revealed by cholera toxin B subunit (Ctxb) overlay. Structural analysis of the oligosaccharide portion of LS established that it had the following structure: Gal-GalNAc-(NeuAc)Gal-Hep-(Glc;PO₃H)Hep-Kdo. The GM1-like epitope was validated by a terminal tetrasaccharide unit within this structure. On the other hand, analysis of LF revealed an entirely different structure: 1, 4′-bisphosphoryl glucosamine disaccharide N, N’-acylated by 3-(2-hydroxytetracosanoyloxy)octadecanoic acid at 2- and 2′-positions, which is consistent with that of lipid A. No GM1-like epitope was observed in LF. Both LS and LF interacted with Ctxb as demonstrated by TLC-overlay and sucrose density gradient centrifugation. Surprisingly, LF does not have the basic GM1 structure for interacting with Ctxb. Instead, the affinity of LF to Ctxb required that one or both of the phosphate groups be present in the glucosamine disaccharide residue because after alkaline phosphatase treatment the dephosphorylated LF was unable to bind to Ctxb. We conclude that LS is likely the component contributing to GM1-mimicry in autoimmune peripheral neuropathy and that the role of LF is not clear but may be associated with the initial activation of autoreactive T cells. Ganglioside nomenclature is based on that of Svennerholm [50]     

A temperature-regulated Campylobacter jejuni gluconate dehydrogenase is involved in respiration-dependent energy conservation and chicken colonization

Campylobacter jejuni is a gastrointestinal pathogen of humans but can asymptomatically colonize the avian gut. C. jejuni therefore grows at both 37°C and 42°C, the internal temperatures of humans and birds respectively. Microarray and proteomic studies on temperature regulation in C. jejuni strain 81–176 revealed the upregulation at 42°C of two proteins, Cj0414 and Cj0415, orthologous to gluconate dehydrogenase (GADH) from Pectobacterium cypripedii . 81–176 demonstrated GADH activity, converting d -gluconate to 2-keto- d -gluconate, that was higher at 42°C than at 37°C. In contrast, cj0414 and cj0415 mutants lacked GADH activity. Wild-type but not cj0415 mutant bacteria exhibited gluconate-dependent respiration. Neither strain grew in defined media with d -gluconate or 2-keto- d -gluconate as a sole carbon source, revealing that gluconate was used as an electron donor rather than as a carbon source. When administered to chicks individually or in competition with wild-type, the cj0415 mutant was impaired in establishing colonization. In contrast, there were few significant differences in colonization of BALB/c-ByJ mice in single or mixed infections. These results suggest that the ability of C. jejuni to use gluconate as an electron donor via GADH activity is an important metabolic characteristic that is required for full colonization of avian but not mammalian hosts.     

The CprS sensor kinase of the zoonotic pathogen Campylobacter jejuni influences biofilm formation and is required for optimal chick colonization

Campylobacter jejuni , a prevalent cause of bacterial gastroenteritis, must adapt to different environments to be a successful pathogen. We previously identified a C. jejuni two-component regulatory system (Cj1226/7c) as upregulated during cell infections. Analyses described herein led us to designate the system CprRS ( C ampylobacter p lanktonic growth r egulation). While the response regulator was essential, a cprS sensor kinase mutant was viable. The Δ cprS mutant displayed an apparent growth defect and formed dramatically enhanced and accelerated biofilms independent of upregulation of previously characterized surface polysaccharides. Δ cprS also displayed a striking dose-dependent defect for colonization of chicks and was modestly enhanced for intracellular survival in INT407 cells. Proteomics analyses identified changes consistent with modulation of essential metabolic genes, upregulation of stress tolerance proteins, and increased expression of MOMP and FlaA. Consistent with expression profiling, we observed enhanced motility and secretion in Δ cprS , and decreased osmotolerance and oxidative stress tolerance. We also found that C. jejuni biofilms contain a DNase I-sensitive component and that biofilm formation is influenced by deoxycholate and the metabolic substrate fumarate. These results suggest that CprRS influences expression of factors important for biofilm formation, colonization and stress tolerance, and also add to our understanding of C. jejuni biofilm physiology.