Journal of Microbiology

Review

Adenoviral Vector System: A Comprehensive Overview of Constructions, Therapeutic Applications and Host Responses.: Anyeseu Park, Jeong Yoon Lee; J. Microbiol. 2024;62(7):491-509. Published online July 22, 2024; DOI: https://doi.org/10.1007/s12275-024-00159-4

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Abstract: Adenoviral vectors are crucial for gene therapy and vaccine development, offering a platform for gene delivery into host cells. Since the discovery of adenoviruses, first-generation vectors with limited capacity have evolved to third-generation vectors flacking viral coding sequences, balancing safety and gene-carrying capacity. The applications of adenoviral vectors for gene therapy and anti-viral treatments have expanded through the use of in vitro ligation and homologous recombination, along with gene editing advancements such as CRISPR-Cas9. Current research aims to maintain the efficacy and safety of adenoviral vectors by addressing challenges such as pre-existing immunity against adenoviral vectors and developing new adenoviral vectors from rare adenovirus types and non-human species. In summary, adenoviral vectors have great potential in gene therapy and vaccine development. Through continuous research and technological advancements, these vectors are expected to lead to the development of safer and more effective treatments.

Journal Article

Lactobacillus rhamnosus KBL2290 Ameliorates Gut Inflammation in a Mouse Model of Dextran Sulfate Sodium‑Induced Colitis: Woon-ki Kim , Sung-gyu Min , Heeun Kwon , SungJun Park , Min Jung Jo , GwangPyo Ko; J. Microbiol. 2023;61(7):673-682. Published online June 14, 2023; DOI: https://doi.org/10.1007/s12275-023-00061-5

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Abstract: Ulcerative colitis, a major form of inflammatory bowel disease (IBD) associated with chronic colonic inflammation, may be induced via overreactive innate and adaptive immune responses. Restoration of gut microbiota abundance and diversity is important to control the pathogenesis. Lactobacillus spp., well-known probiotics, ameliorate IBD symptoms via various mechanisms, including modulation of cytokine production, restoration of gut tight junction activity and normal mucosal thickness, and alterations in the gut microbiota. Here, we studied the effects of oral administration of Lactobacillus rhamnosus (L. rhamnosus) KBL2290 from the feces of a healthy Korean individual to mice with DSS-induced colitis. Compared to the dextran sulfate sodium (DSS) + phosphate-buffered saline control group, the DSS + L. rhamnosus KBL2290 group evidenced significant improvements in colitis symptoms, including restoration of body weight and colon length, and decreases in the disease activity and histological scores, particularly reduced levels of pro-inflammatory cytokines and an elevated level of anti-inflammatory interleukin-10. Lactobacillus rhamnosus KBL2290 modulated the levels of mRNAs encoding chemokines and markers of inflammation; increased regulatory T cell numbers; and restored tight junction activity in the mouse colon. The relative abundances of genera Akkermansia, Lactococcus, Bilophila, and Prevotella increased significantly, as did the levels of butyrate and propionate (the major short-chain fatty acids). Therefore, oral L. rhamnosus KBL2290 may be a useful novel probiotic.

Research Support, Non-U.S. Gov't

Pregnancy - associated human listeriosis: Virulence and genotypic analysis of Listeria monocytogenes from clinical samples: Dharmendra Kumar Soni , Durg Vijai Singh , Suresh Kumar Dubey; J. Microbiol. 2015;53(9):653-660. Published online August 1, 2015; DOI: https://doi.org/10.1007/s12275-015-5243-9

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30 Citations

Abstract: Listeria monocytogenes, a life-threatening pathogen, poses severe risk during pregnancy, may cause abortion, fetal death or neonatal morbidity in terms of septicemia and meningitis. The present study aimed at characterizing L. monocytogenes isolated from pregnant women based on serotyping, antibiotic susceptibility, virulence genes, in vivo pathogenicity test and ERIC- and REP-PCR fingerprint analyses. The results revealed that out of 3700 human clinical samples, a total of 30 (0.81%) isolates [12 (0.80%) from placental bit (1500), 18 (0.81%) from vaginal swab (2200)] were positive for L. monocytogenes. All the isolates belonged to serogroup 4b, and were + ve for virulence genes tested i.e. inlA, inlC, inlJ, plcA, prfA, actA, hlyA, and iap. Based on the mice inoculation tests, 20 isolates showed 100% and 4 isolates 60% relative virulence while 6 isolates were non-pathogenic. Moreover, 2 and 10 isolates were resistant to ciprofloxacin and cefoxitin, respectively, while the rest susceptible to other antibiotics used in this study. ERIC- and REP-PCR collectively depicted that the isolates from placental bit and vaginal swab had distinct PCR fingerprints except a few isolates with identical patterns. This study demonstrates prevalence of pathogenic strains mostly resistant to cefoxitin and/or ciprofloxacin. The results indicate the importance of isolating and characterizing the pathogen from human clinical samples as the pre-requisite for accurate epidemiological investigations.

Journal Articles

The Molecular Characterization of Serogroup C Neisseria meningitidis Strains Circulating in Beijing: Tie-gang Zhang , Jing-guo He , Xiong He , Li-Juan Chen , Zhu-jun Shao , Mei-ping Sun; J. Microbiol. 2006;44(6):685-688.; DOI: https://doi.org/2455 [pii]

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Abstract: The aim of this study was to characterize the molecular features of serogroup C Neisseria meningitidis strains circulating in Beijing, China. Twenty out of 23 strains belonged to ST 4821. The causative serosubtype for meningococcal meningitis was P1.12-1,16-8. All of the strains expressed class 3 PorB protein. Among the five pulsed-field gel electrophoresis patterns observed, pattern III predominated.

Isolation of Cryptococcus neoformans var. grubii (serotype A) from Pigeon Droppings in Seoul, Korea: Hee Youn Chee , Kyung Bok Lee; J. Microbiol. 2005;43(5):469-472.; DOI: https://doi.org/2273 [pii]

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Abstract: Seventy-two pigeon dropping samples were collected from 26 different localities in Seoul and investigated for the occurrence of Cryptococcus neoformans. Seventeen samples from 8 different localities were found to be positive for C. neoformans. All isolates were obtained from withered pigeon droppings. Identification and serotyping of the isolates were determined by means of serological testing and DNA fingerprinting. All isolates belonged to C. neoformans var. grubbi (serotype A).

Review

Shigellosis: Swapan Kumar Niyogi; J. Microbiol. 2005;43(2):133-143.; DOI: https://doi.org/2172 [pii]

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Abstract: Shigellosis is a global human health problem. Four species of Shigella i.e. S. dysenteriae, S. flexneri, S. boydii and S. sonnei are able to cause the disease. These species are subdivided into serotypes on the basis of O-specific polysaccharide of the LPS. Shigella dysenteriae type 1 produces severe disease and may be associated with life-threatening complications. The symptoms of shigellosis include diarrhoea and/or dysentery with frequent mucoid bloody stools, abdominal cramps and tenesmus. Shigella spp. cause dysentery by invading the colonic mucosa. Shigella bacteria multiply within colonic epithelial cells, cause cell death and spread laterally to infect and kill adjacent epithelial cells, causing mucosal ulceration, inflammation and bleeding. Transmission usually occurs via contaminated food and water or through person-to-person contact. Laboratory diagnosis is made by culturing the stool samples using selective/differential agar media. Shigella spp. are highly fragile organism and considerable care must be exercised in collecting faecal specimens, transporting them to the laboratories and in using appropriate media for isolation. Antimicrobial agents are the mainstay of therapy of all cases of shigellosis. Due to the global emergence of drug resistance, the choice of antimicrobial agents for treating shigellosis is limited. Although single dose of norfloxacin and ciprofloxacin has been shown to be effective, they are currently less effective against S. dysenteriae type 1 infection. Newer quinolones, cephalosporin derivatives, and azithromycin are the drug of choice. However, fluoroquinolone-resistant S. dysenteriae type 1 infection have been reported. Currently, no vaccines against Shigella infection exist. Both live and subunit parenteral vaccine candidates are under development. Because immunity to Shigella is serotype-specific, the priority is to develop vaccine against S. dysenteriae type 1 and S. flexneri type 2a. Shigella species are important pathogens responsible for diarrhoeal diseases and dysentery occurring all over the world. The morbidity and mortality due to shigellosis are especially high among children in developing countries. A recent review of literature (Kotloff et al.,1999) concluded that, of the estimated 165 million cases of Shigella diarrhoea that occur annually, 99% occur in developing countries, and in developing countries 69% of episodes occur in children under five years of age. Moreover, of the ca.1.1 million deaths attributed to Shigella infections in developing countries, 60% of deaths occur in the under-five age group. Travellers from developed to developing regions and soldiers serving under field conditions are also at an increased risk to develop shigellosis.

Serotyping of Cryptococcus neoformans Strains Isolated in Korea: Soo-Myung Hwang; J. Microbiol. 2002;40(2):166-169.

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Abstract: Twenty strains of Cryptococcus neoformans isolated from environmental and clinical sources in Korea were examined for their serotypes. Two environmental isolates from pigeon excreta belonged to C. neoformans var. neoformans serotype A. Of the 18 isolates from clinical specimens, 17 belonged to C. neoformans var. neoformans (serotype A : 16, serotype D : 1) and one belonged to C. neoformans var. gattii serotype B, which was culturally unusual, producing mucous colonies. This is the first report of the identification of C. neoformans var. gattii serotype B from a patient in Korea.

Genetic Relatedness within Streptococcus pneumoniae Serotype 19F and 23F Isolates in Korea by Pulsed-Field Gel Electrophoresis: Kwang Jun Lee , Song Mee Bae , Kyu Jam Hwang , Young Hee Lee , Ki Sang Kim; J. Microbiol. 2003;41(1):1-6.

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Abstract: The genetic relatedness of multidrug-resistant pneumococcal isolates of serotypes 19F and 23F was investigated. The DNA fragments digested with Sma I were resolved by pulsed-field gel electrophoresis (PFGE). PFGE analysis of 36 S. pneumoniae isolates showed 13 different patterns. Among 22 isolates of serotype 19F, 9 different PFGE patterns were present and 14 isolates of serotype 23F isolates represented 5 distinct PFGE patterns. Two isolates of serotype 19F and six isolates of serotype 23F shared the same PFGE pattern (Pattern I). Based on the genetic relatedness within the strains (one genetic cluster was defined as having more than 85% homology), we divided the pneumococcal strains into 6 genetic clusters (I, II, III, IV, V, and VI). The 22 strains of serotype 19F belonged to five distinct genetic clusters (I, II, III, IV, V and VI) and 14 strains of serotype 23F represented two genetic clusters (I and II ). These results showed that strains of serotype 19F are genetically more diverse than those of serotype 23F. Serotype 19F isolates with PFGE patterns H and I appeared to be less related to those of the remaining PFGE patterns (A to G) (less than 60% genetic relatedness), but those strains were genetically closely related with serotype 23F. These results suggest that the latter isolates originated from horizontal transfer of the capsular type 19F gene locus to 23F pneumococcal genotypes. In conclusion, the multidrug-resistant pneumococcal isolates of serotype 19F and 23F isolated in Korea are the result of the spread of a limited number of resistant clones.

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