Lipooligosaccharide (LOS) is an integral component of the Campylobacter cell membrane with a structure of core oligosaccharides forming inner and outer core regions and a lipid A moiety. The gene content of the LOS core biosynthesis cluster exhibits extensive sequence variation, which leads to the production of variable cell surface LOS structures in Campylobacter. Some LOS outer core molecules in Campylobacter jejuni are molecular mimics of host structures (such as neuronal gangliosides) and are thought to trigger neuronal disorders (particularly Guillain-Barré syndrome and Miller Fisher syndrome) in humans. The extensive genetic variation in the LOS biosynthesis gene cluster, a majority of which occurs in the LOS outer core biosynthesis gene content present between lgtF and waaV, has led to the development of a classification system with 23 classes (A-W) and four groups (1-4) for the C. jejuni LOS region. This review presents an updated and simplified classification system for LOS typing alongside an overview of the frequency of C. jejuni LOS biosynthesis genotypes and structures in various C. jejuni populations.

Campylobacter is a worldwide foodborne pathogen, associated with human gastroenteritis. The efficient translocation of Campylobacter and its ability to secrete toxins into host cells are the 2 key features of Campylobacter pathophysiology which trigger inflammation in intestinal cells and contribute to the development of gastrointestinal symptoms, particularly diarrhoea, in humans. The purpose of conducting this literature review is to summarise the current understanding of: i) the human immune responses involved in the elimination of Campylobacter infection and ii) the resistance potential in Campylobacter against these immune responses. This review has highlighted that the intestinal epithelial cells are the preliminary cells which sense Campylobacter cells by means of their cell-surface and cytosolic receptors, activate various receptorsdependent signalling pathways, and recruit the innate immune cells to the site of inflammation. The innate immune system, adaptive immune system, and networking between these systems play a crucial role in bacterial clearance. Different cellular constituents of Campylobacter, mainly cell membrane lipooligosaccharides, capsule, and toxins, provide protection to Campylobacter against the human immune system mediated killing. This review has also identified gaps in knowledge, which are related to the activation of following during Campylobacter infection: i) cathelicidins, bactericidal permeability-increasing proteins, chemokines, and inflammasomes in intestinal epithelial cells; ii) siglec-7 receptors in dendritic cell; iii) acute phase proteins in serum; and iv) T-cell subsets in lymphoid nodules. This review evaluates the existing literature to improve the understanding of human immunity against Campylobacter infection and identify some of the knowledge gaps for future research.

The present study was conducted to explore the potential fungal isolates for maximum production of phytase by optimizing solid substrate preference and growth parameters (pH, temperature, fermentation time) of solid state fermentation (SSF). It has been inferred from the results that all the tested fungi (Aspergillus niger, Aspergillus flavus, Aspergillus versicolor, Aspergillus nidulans, Cladosporium cladosporioides, Trichoderma reesei, and Trichoderma viride) showed inducible expression of phytase. Fungal isolates showed different preference of solid substrate out of wheat bran, lentil, oat, corn and bagasse for maximum production of phytase. Lentil and bagasse were not used preferably by any tested fungi. Among the tested fungi, maximum phytase production was observed in A. flavus (80 U/g of solid substrate) using wheat bran as solid substrate at pH 6 after 7 days of fermentation period at 30°C. It was established that solid substrates with high phytate and low inorganic phosphate (Pi) contents are substrate of choice for phytase production by SSF.

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