• Clinical and Experimental Vaccine Research
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• v.13 no.2
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• pp.91-104
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• 2024

This narrative review describes genomic characteristic, serotyping, immunogenicity, and vaccine development of Streptococcus pneumoniae capsular polysaccharide (CPS). CPS is a primary virulence factor of S. pneumoniae. The genomic characteristics of S. pneumoniae CPS, including the role of biosynthetic gene and genetic variation within cps (capsule polysaccharide) locus which may lead to serotype replacement are still being investigated. One hundred unique serotypes of S. pneumoniae have been identified through various methods of serotyping using phenotypic and genotypic approach. The advantages and limitations of each method are various, emphasizing the need for accurate and comprehensive serotyping for effective disease surveillance and vaccine targeting. In addition, we elaborate the critical role of CPS in vaccine development by providing an overview of immunogenicity, ongoing research of pneumococcal vaccines, and the impact on disease burden.

• Journal of Microbiology and Biotechnology
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• v.22 no.10
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• pp.1336-1342
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• 2012

In Burkholderia pseudomallei, the pathogen that causes melioidosis, the gene cluster encoding the capsular polysaccharide, is located on chromosome 1. Among the 19 capsular genes in this cluster, wzm has not been thoroughly studied. To study the function of wzm, we generated a deletion mutant and compared it with the wild-type strain. The mutant produced less biofilm in minimal media and was more sensitive to desiccation and oxidative stress compared with the wild-type strain, indicating that wzm is involved in biofilm formation and membrane integrity. Scanning electron microscopy showed that the bacterial cells of the mutant strain have more defined surfaces with indentations, whereas cells of the wild-type strain do not.

• Journal of fish pathology
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• v.26 no.2
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• pp.77-88
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• 2013

Starry flounder, Platichthys stellatus (body length $4.4{\pm}0.51cm$) that became sick during an outbreak of disease at mariculture facilities at Ulsan, Korea in August of 2012, were examined to identify the cause of the disease. Diseased fish didn't show a unique sign, but the oxidase-positive and gram negative rod was isolated from moribund fish. The bacterium was revealed as Photobacterium damselae subsp. piscicida by biochemical analysis and sequence analysis of the 16S rRNA and capsular polysaccharide (CPS) genes. The isolates (AD5) was carrying susceptible to ofloxacin and gentamycin and showed high growth value at $18^{\circ}C$ and $25^{\circ}C$ compared to four other P. damsela strains.

• Journal of Microbiology and Biotechnology
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• v.31 no.11
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• pp.1545-1551
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• 2021

Exopolysaccharides (EPSs) such as capsular polysaccharide (CPS) are important bioactive carbohydrate compounds and are often used as bioenrichment agents and bioabsorbers to remove environmental pollutants like di-n-butyl phthalate (DBP). Among the EPS-producing bacteria, lactic acid bacteria (LAB) have gained the most attention. As generally recognized as safe (GRAS) microorganisms, LAB can produce EPSs having many different structures and no health risks. However, EPS production by LAB does not meet the needs of large-scale application on an industrial scale. Here, the capA gene (encoding CPS biosynthesis protein) was overexpressed in Lactobacillus plantarum P1 to improve the production of EPSs and further enhance the DBP adsorption capability. Compared with P1, the CPS production in capA overexpressed strain was increased by 11.3 mg/l, and the EPS thickness was increased from 0.0786 ± 0.0224 ㎛ in P1 to 0.1160 ± 0.0480 ㎛ in P1-capA. These increases caused the DBP adsorption ratio of P1-capA to be doubled. Overall, the findings in this study provide a safe method for the adsorption and removal of DBP.

• KSBB Journal
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• v.11 no.1
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• pp.115-123
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• 1996

Two kinds of mutants were isolated to clone a cluster of genes essential for zooglan biosynthesis. Zoogloea ramigera 115 strains produce capsular polysaccharide. To achieve conjugation in strain 115 and to facilitate recovery of product, a capsule non-forming strain was isolated via successive centrifugation and screening. The other kind of mutants devoid of or producing altered exopolysaccharides were obtained using classical transposon(Tn5) technique and screened for altered colony morphology and celluflour binding properties. Complementation of these mutants was achieved with Z. ramigera 115 slime gene library constructed in a broad host range cosmid vector and helper plasmid by triparental conjugation.

• Molecules and Cells
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• v.21 no.1
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• pp.82-88
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• 2006

The global pattern of growth-dependent gene expression in Streptococcus pneumoniae strains was evaluated using a high-density DNA microarray. Total RNAs obtained from an avirulent S. pneumoniae strain R6 and a virulent strain AMC96-6 were used to compare the expression patterns at seven time points (2.5, 3.5, 4.5, 5.5, 6.0, 6.5, and 8.0 h). The expression profile of strain R6 changed between log and stationary growth (the Log-Stat switch). There were clear differences between the growth-dependent gene expression profiles of the virulent and avirulent pneumococcal strains in 367 of 1,112 genes. Transcripts of genes associated with bacterial competence and capsular polysaccharide formation, as well as clpP and cbpA, were higher in the virulent strain. Our data suggest that late log or early stationary phase may be the most virulent phase of S. pneumoniae.

• Korean Journal of Veterinary Research
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• v.43 no.2
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• pp.247-253
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• 2003

Actinobacillus pleuropneumoniae causes a highly contagious pleuropneumoniae in swine. The bacterium produces several virulence factors such as exotoxin, LPS, capsular polysaccharide, etc. Among them, the exotoxin, called Apx, has been focused as the major virulence factor, and the toxin consists of 4 gene cluster. apx CABD. apxA is the structural gene of toxin and has four different types, I, II, III, and IV. As the first step of development of a new subunit vaccine, the three different types of apxA gene were amplified from A. pleuropneumoniae isolated from Korea by PCR with primer designed based on the N- and C-terminal of the toxin. The sizes of apxIA, IIA and IIIA were 3,073, 2,971 and 3,159bps, respectively. The comparison of whole DNA sequences of apxIA, IIA and IIIA genes with those of the reference strain demonstrated 98%, 99% and 98% homology, respectively. In addition, the phylogenetic analysis was performed based on the amino acid sequences compared with 12 different RTX toxin family using the neighbor-joining method. ApxA proteins of Korean isolates were identical with reference strains in this study. All ApxA proteins were expressed in E. coli with pQE expression vector and identified using Western blot with polyclonal antibodies against culture supernatants of A. pleuropneumoniae serotype 2 or 5. The sizes of each expressed ApxA protein were about 120, 110, 125 kDa (M.W.), respectively. The results obtained in this study could be used for the future study to develop a new vaccine to porcine pleuropneumoniae.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.448-452
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• 2018

The full genome sequence of Bacillus safensis KCTC 12796BP which had been isolated from the marine sponge in the seawater of Jeju Island, was determined by Pac-Bio next-generation sequencing system. A circular chromosome in the length of 3,935,874 bp was obtained in addition to a circular form of plasmid having 36,690 bp. The G + C content of chromosome was 41.4%, and that of plasmid was 37.3%. The number of deduced CDSs in the chromosome was 3,980, whereas 36 CDS regions were determined in a plasmid. Among the deduced CDSs in chromosome, 81 tRNA genes and 24 rRNA genes in addition to one tmRNA were allocated. More than 30 CDSs for sporulation, 16 CDSs for spore coat, and 20 CDSs for germination were also assigned in the chromosome. Several genes for capsular polysaccharide biosynthesis and for flagella biosynthesis and chemotaxis in addition to genes for osmotic tolerance through glycine-choline betaine pathway were also identified. Above all, the biosynthetic gene cluster for anti-allergic compounds seongsanamides were found among two non-ribosomal peptide synthetase (NRPS) gene clusters for secondary metabolites.

• Korean Journal of Veterinary Research
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• v.36 no.3
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• pp.665-680
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• 1996

Bovine Pneumonic Pasteurellosis는 수송열(輸送熱)로 일반적으로 알려져 있는 질병으로서, 여러가지 요인의 복합적(複合的)인 작용에 의해 발병하는 것으로 알려져 있으나, Pasteurella haemolytica A1이 가장 주요(主要)한 인자(因子)로 밝혀져 있다. P haemolytica A1은 leukotoxin(LKT), lipopolysaccharide(LPS), capsular polysaccharide 등 여러가지의 병원성인자(病原性因子)을 생성한다. 이들 인자중 LKT가 가장 중요한 병원성인자로 밝혀져 있다. 이에 본 실험은 P haemolytical A1의 LKT 유전자를 Bacillus subtilis에서 발현(發現)시킴으로서 LPS에 오염(汚染)되지 않은 LKT을 대량으로 생산할 목적으로 실시되었다. 실험의 첫 단계(段階)로서 pLKT52 plasmid을 Sau3 A1의 제한효소을 이용하여 부분소화(部分消化)시킨 후 이 부분 소화(消化)된 유전자들로부터 3~5kb 크기의 유전자들을 순수분리하여 pUC18와 결합시킨 후 E coli NM522에 형질전환(形質轉換)시켰다. 이때 형질전환된 균주들은 LKT에 대한 단크론 항체인 MAb601을 이용하여 colony blot 법에 의해서 LKT 유전자 보유 및 발현여부(發現與否)을 조사하였다. 이들 양성 clone들은 제한효소분석(制限酵素分析), 염기서열분석(鹽基序列分析) 및 Western blot 등에 의해서 재확인(再確認)하였다. 총 9개의 양성 clone중 위의 방법에 의해서 한 clone을 선택(選擇)하여 lktCA insert를 재분리하여 shuttle vector에 subcloning 하였다. Subcloning된 LKT 유전자들은 shuttle vector의 종류(種類)(pHPS9, p602/20, pHPS9-Sac)와 각기(各其) 다른 종류(種類)의 B subtilis(spoO12A, BR121, WB3O, Raj1105) 숙주내(宿主內)에서 발현정도를 Western blot 법에 의해서 비교(比較)하였다. 이때 최적발현조건(最適發現條件)은 p602/20와 pBL1의 dual plasmid system을 이용하여 B subtilis spoO12A에서 2시간동안 IPTG로 발현을 유도(誘導)하는 것이었다. B subtilis에서 발현된 LKT을 visual 법과 neutral red uptake 법을 이용하여 소 폐포(肺胞) 대식구(大食求)에 대한 biological activity를 확인하였다. 발현된 LKT에 대한 LPS 오염은 LKT을 SDS-PAGE 후 silver stain에 의해서 확인하였다. 본 실험을 통해서 볼 때에 lktCA 유전자를 보유(保有)하고 있는 p602/20는 B subtilis에서 매우 불안정(不安定)하였고, 발현된 LKT는 세균자체(細菌自體)에서 생성되는 protease들에 의해서 파괴(破壞)됨으로서 농도(濃度)가 매우 낮았다. 이러한 문제점들은 다음 단계(段階)의 실험에서 해결되어야할 문제들이다.