BackgroundStreptococcus pneumoniae is still one of the major causes of morbidity and mortality worldwide. The prevalent serotype distribution had shown variation along different studies conducted at different time intervals. In order to efficiently assess the epidemiology of the diseases for effective preventive and treatment strategies, serotype prevalence need to be periodically reassessed.ObjectivesConducting a reassessment of the prevalent S. pneumoniae serotypes in Egypt as an essential step in the search for a regional vaccine. In addition, monitoring the antibiotic susceptibility patterns of pneumococcal strains currently causing infections as an evaluation of therapeutic strategies applied.Materials and MethodsA total of 100 specimens of different sources were collected in Cairo, Egypt, from 2011 to 2013, representing almost all different types of diseases caused by S. pneumoniae such as meningitis, pneumonia, otitis media and sinusitis. Conventional and molecular identification methods were performed, the antimicrobial susceptibility patterns were assessed and serotyping was done using PCR assays to identify the most prevalent types. In addition, detection of certain virulence genes for the most prevalent serotypes was carried out.ResultsOur results revealed that in Egypt, currently, the most prevalent serotypes were serogroup 6 and serotype 19F as they represented 58% of all isolates. High rates of resistance were found to different antibiotic classes. The lytA and psaA genes were found to be more sensitive for S. pneumoniae identification than ply.ConclusionsOur study illustrates the importance of constantly monitoring the prevalent serotypes in any region in order to aid in the development of more effective vaccines.

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Streptococcus pneumoniae is a pathogen that causes serious invasive infections, such as septicemia, meningitis and pneumonia in addition to mild upper respiratory tract infections. Protection from pneumococcal diseases is thought to be mediated mainly by serotype-specific antibodies to capsular antigens. Pneumococcal conjugate vaccine consists of sugars (polysaccharides) from the capsule of the bacterium S. pneumoniae that are conjugated to a carrier protein. Three pneumococcal conjugated vaccines, each directed against a group of serotypes, are registered in Egypt; however, local vaccine production is required to cover the most prevalent serotypes. In this work, capsular polysaccharide from the most current and prevalent serotypes in Egypt were extracted, purified and conjugated to bovine serum albumin (BSA). The polysaccharide protein conjugate was purified through ultrafiltration technique and molecular size distribution was compared to an available vaccine. The immunogenicity of the prepared vaccine was examined via two methods: First, by measuring the levels of the elicited antibodies in the sera of the vaccinated mice; second, by challenging the vaccinated groups of mice with approximately 107 CFU of each specific serotype and determining the degree of protection the developled vaccine offers. Our results show that the developed conjugated capsular polysaccharide vaccine is highly immunogenic and protective in mice. This finding illustrates the importance of tracking the most recent and predominant peneumococcal serotypes to generate effective vaccines, instead of using expensive imported vaccines with large number of serotypes which might not be even present in the community.

Objective: This study aims to control type 2 of diabetes mellitus by a hypoglycemic substance that extensively produced by Streptomyces bacteria. The antidiabetic action of this substance depends on prevention of starch hydrolysis and then the liberation of glucose monomers via an inhibition of α-glucosidase as one of starch hydrolyzing enzymes.Methods: The strains of marine actinomycetes were isolated on starch nitrate agar, and then qualitatively and quantitatively screened to prevent starch hydrolysis. The most potent strain was identified by classical and genetical methods. The genetic improvement of the most potent strain was carried out by using UV radiations at different exposure periods per second. The optimization of environmental conditions was studied to obtain the maximum activity of the α-glucosidase inhibitory protein, which purified and electrically separated to determine its molecular weight.Results: Among 55 marine actinomycetes, only 7 strains were found have antidiabetic activity. This activity was assayed spectrophotometrically at 400 nm, where p-nitrophenyl-α-d-glucopyranoside and acarbose were used as a substrate and a positive control respectively. The most potent strain which marked as AD-7 was identified as Streptomyces coelicolor, which exposed to the genetic improvement using UV radiations to obtain a highly activity of an inhibitory protein at 10 s of the exposure period. The activity and stability continued for 5 d at 37 °C. The maximum activity and stability of an improved inhibitory protein were obtained with optimization of environmental conditions included inoculum size (106 cfu/ml/300 µl), incubation period (14 d), agitation speed (160 rpm), incubation temperature (30 °C), and pH (8.5). An inhibitor was purified and separated at 34 KDa.Conclusion: Alpha-glucosidase inhibitory protein as a powerful hypoglycemic agent was extracted from the filtrate of S. coelicolor. The mutant strain of the latter had been produced most active and stable inhibitory protein, which prevents the starch hydrolysis via an inhibition of α-glucosidase enzyme for 5 d at 37 °C.

Aims: Lower respiratory tract infections (LRTIs) have been identified by the World Health Organization as the most deadly infectious diseases and a pervasive public health problem, causing increased hospital admissions, mortality and antibiotic use.This study aims to determine the most common and resistant bacteria that cause LRTIs and prepare an appropriate vaccine to reduce and prevent potential future infections. Methods and Results:Our survey was conducted by collecting respiratory exudate specimens. The most predominant and resistant types were Klebsiella pneumonia and Pseudomonas aeruginosa. The lipopolysaccharides (LPS) were extracted using a modified hot phenol method to prepare the vaccine. The LPS were then activated and conjugated. The immunogenicity of the prepared singles and combined vaccines was determined through an in vivo assay using BALB/c mice. The prepared vaccine provided high protection against the lethal dose of both bacteria in mice. The combined vaccine shows a significant value in achieving high immunization. Conclusion:These findings demonstrate the potential of the bacterial LPS molecules to be used as effective vaccines.Significance and Impact of Study: Developing an effective single and combined vaccine against P. aeruginosa and K. pneumonia can protect and reduce LRTI incidence.