IgE-mediated fish allergy in Singaporean children.

BACKGROUND: Fish is one of the common causes of food allergy and there is limited literature about fish allergy in Singapore. OBJECTIVE: We aimed to describe the demographics, clinical features, and natural history of children with IgE-mediated fish allergy. METHODS: A retrospective review was conducted for children diagnosed with fish allergy in a tertiary pediatric hospital in Singapore between 2015 and 2020. RESULTS: The diagnosis of fish allergy was made in 108 patients based on a convincing history of IgE-mediated allergic reaction and a positive skin prick test. The median age at first reaction was 12 months (range 6-168) with most reacting on first ingestion (62.0%). The most common fish causing reactions were threadfin (48.1%), salmon (33.3%) and cod (31.5%). Majority presented with cutaneous symptoms (97.2%). Anaphylaxis occurred in 6.5%. Five were mono-sensitized (4.6%), 77 were oligo-sensitized (71.3%) and 26 were polysensitized (24.1%). Most can tolerate another species of fish (75.9%), most commonly salmon (37.0%), tuna (24.1%) and cod (22.2%). Median duration of follow up was 24 months (range 0-176). Twenty-eight out of 108 children (25.9%) acquired natural tolerance to index fish at a median age of 60 months (range 18-159). CONCLUSIONS: Most children with fish allergy can tolerate at least one other species of fish and resolution of fish allergy is possible. Thus, it is important to follow-up with an allergist to evaluate which fish species can be included in their diet to avoid unnecessary dietary restrictions.

Cytokine release syndrome - a unique entity of Augmentin hypersensitivity reaction.

Cytokine release syndrome (CRS) is a type of hypersensitivity reaction which has been previously described with chemotherapy and monoclonal antibodies, but not with antibiotics. We present 2 pediatric cases of Amoxicillin/Clavulanic acid (Augmentin) anaphylaxis resembling CRS. Both our patients presented during the index reaction with symptoms suggestive of an acute systemic inflammatory response mimicking sepsis. Their symptomology was reproducible at drug provocation test as anaphylaxis, but with suboptimal response to intramuscular adrenaline. Their infective workups were unremarkable and illnesses followed a self-limiting course. All these point towards a severe hypersensitivity reaction resembling CRS.

Proteomic analysis of pH and strains dependent protein secretion of Trichoderma reesei.

Bioenergy, particularly biofuel, from lignocellulosic biomass has been considered as one of the most promising renewable and sustainable energies. The industrial productivity and efficiency of microbial lignocellulolytic enzymes for cellulosic biofuel applications are significantly affected by pH of culture condition. This study established and compared hydrolytic protein expression profiles of Trichoderma reesei QM6a, QM9414, RUT C30 and QM9414MG5 strains at different pH in cellulosic culture media. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of secretome of T. reesei cultured from pH 3.0-9.0 revealed significantly higher hydrolytic protein expressions at acidic pH. The Bray-Curtis similarity indices, clustering, and Shannon diversity index elucidated differences in protein secretion at different pHs in individuals and among the strains. This study demonstrated a comparative lignocellulolytic enzyme secretion profile of T. reesei and its mutants at different pHs and provides pH sensitive and resistance enzyme targets for industrial lignocellulose hydrolysis.

A rapid fingerprinting approach to distinguish between closely related strains of Shewanella.

One of the big operational problems facing laboratories today is the ability to rapidly distinguish between strains of bacteria that, while physiologically distinct, are nearly impossible to separate based on 16S rRNA gene sequence differences. Here we demonstrate that ITS-DGGE provides a convenient approach to distinguishing between closely related strains of Shewanella, some of which were impossible to separate and identify by 16 rRNA gene sequence alone. Examined Shewanella genomes contain 8-11 copies of rrn (ribosomal RNA gene) operons, and variable size and sequence of 16S-23S ITS (intergenic transcribed spacer) regions which result in distinct ITS-DGGE profiles. Phylogenetic constructions based on ITS are congruent with the genomic trees generated from concatenated core genes as well as with those based on conserved indels, suggesting that ITS patterns appear to be linked with evolutionary lineages and physiology. In addition, three new Shewanella strains (MFC 2, MFC 6, and MFC 14) were isolated from microbial fuel cells enriched from wastewater sludge and identified by ITS-DGGE. Subsequent physiological and electrochemical studies of the three isolates confirmed that each strain is phenotypically/genotypically distinct. Thus, this study validates ITS-DGGE as a quick fingerprint approach to identifying and distinguishing between closely related but novel Shewanella ecotypes.