Journal of Microbiology

Volume 55(1); January 2017

Review

MINIREVIEW] The therapeutic applications of antimicrobial peptides (AMPs): a patent review: Hee-Kyoung Kang , Cheolmin Kim , Chang Ho Seo , Yoonkyung Park; J. Microbiol. 2017;55(1):1-12. Published online December 30, 2016; DOI: https://doi.org/10.1007/s12275-017-6452-1

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284 Citations

Abstract: Antimicrobial peptides (AMPs) are small molecules with a broad spectrum of antibiotic activities against bacteria, yeasts, fungi, and viruses and cytotoxic activity on cancer cells, in addition to anti-inflammatory and immunomodulatory activities. Therefore, AMPs have garnered interest as novel therapeutic agents. Because of the rapid increase in drug-resistant pathogenic microorganisms, AMPs from synthetic and natural sources have been developed using alternative antimicrobial strategies. This article presents a broad analysis of patents referring to the therapeutic applications of AMPs since 2009. The review focuses on the universal trends in the effective design, mechanism, and biological evolution of AMPs.

Journal Articles

Epidemiological relationships of Campylobacter jejuni strains isolated from humans and chickens in South Korea: Jae-Young Oh , Yong-Kuk Kwon , Bai Wei , Hyung-Kwan Jang , Suk-Kyung Lim , Cheon-Hyeon Kim , Suk-Chan Jung , Min-Su Kang; J. Microbiol. 2017;55(1):13-20. Published online December 30, 2016; DOI: https://doi.org/10.1007/s12275-017-6308-8

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33 Citations

Abstract: Thirty-nine human isolates of Campylobacter jejuni obtained from a national university hospital during 2007–2010 and 38 chicken isolates of C. jejuni were collected from poultry farms during 2009–2010 in South Korea were used in this study. Campylobacter genomic species and virulence-associated genes were identified by PCR. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were performed to compare their genetic relationships. All isolates were highly resistant to ciprofloxacin, nalidixic acid, and tetracycline. Of all isolates tested, over 94% contained seven virulence associated genes (flaA, cadF, racR, dnaJ, cdtA, cdtB, and cdtC). All isolates were classified into 39 types by PFGE clustering with 90% similarity. Some chicken isolates were incorporated into some PFGE types of human isolates. MLST analysis for the 39 human isolates and 38 chicken isolates
result
ed in 14 and 23 sequence types (STs), respectively, of which 10 STs were new. STs overlapped in both chicken and human isolates included ST-21, ST-48, ST-50, ST-51, and ST-354, of which ST-21 was the predominant ST in both human and chicken isolates. Through combined analysis of PFGE types and STs, three chicken isolates were clonally related to the three human isolates associated with food poisoning (VII-ST-48, XXII-ST-354, and XXVIII-ST-51). They were derived from geographically same or distinct districts. Remarkably, clonal spread of food poisoning pathogens between animals and humans was confirmed by population genetic analysis. Consequently, contamination of campylobacters with quinolone resistance and potential virulence genes in poultry production and consumption may increase the risk of infections in humans.

Effects of diet type, developmental stage, and gut compartment in the gut bacterial communities of two Cerambycidae species (Coleoptera): Jeong Myeong Kim , Min-Young Choi , Jae-Woo Kim , Shin Ae Lee , Jae-Hyung Ahn , Jaekyeong Song , Seong-Hyun Kim , Hang-Yeon Weon; J. Microbiol. 2017;55(1):21-30. Published online December 30, 2016; DOI: https://doi.org/10.1007/s12275-017-6561-x

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62 Citations

Abstract: The gut bacterial community of wood-feeding beetles has been examined for its role on plant digestion and biocontrol
method
development. Monochamus alternatus and Psacothea hilaris, both belonging to the subfamily Lamiinae, are woodfeeding beetles found in eastern Asia and Europe and generally considered as destructive pests for pine and mulberry trees, respectively. However, limited reports exist on the gut bacterial communities in these species. Here, we characterized gut bacterial community compositions in larva and imago of each insect species reared with host tree logs and artificial diets as food sources. High-throughput 454 pyrosequencing of bacterial 16S rRNA gene revealed 225 operational taxonomic units (OTUs) based on a 97% sequences similarity cutoff from 138,279 sequence reads, the majority of which were derived from Proteobacteria (48.2%), Firmicutes (45.5%), and Actinobacteria (5.2%). The OTU network analysis revealed 7 modules with densely connected OTUs in specific gut samples, in which the distributions of Lactococcus-, Kluyvera-, Serratia-, and Enterococcus-related OTUs were distinct between diet types or developmental stages of the host insects. The gut bacterial communities were separated on a detrended correspondence analysis (DCA) plot and by c-means fuzzy clustering analysis, according to diet type. The results from this study suggest that diet was the main determinant for gut bacterial community composition in the two beetles.

Functional characterization of the cutI gene for the transcription of carbon monoxide dehydrogenase genes in Mycobacterium sp. strain JC1 DSM 3803: Jae Ho Lee , Sae Woong Park , Young Min Kim , Jeong-Il Oh; J. Microbiol. 2017;55(1):31-36. Published online December 30, 2016; DOI: https://doi.org/10.1007/s12275-017-6572-7

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Abstract: Carbon monoxide dehydrogenase (CO-DH) in Mycobacterium sp. strain JC1 is a key enzyme for the carboxydotrophic growth, when carbon monoxide (CO) is supplied as a sole source of carbon and energy. This enzyme is also known to act as nitric oxide dehydrogenase (NO-DH) for the detoxification of NO. Several accessory genes such as cutD, cutE, cutF, cutG, cutH, and cutI, are clustered together with two copies of the CO-DH structural genes (cutB1C1A1 and cutB2C2A2) in Mycobacterium sp. strain JC1 and are well conserved in carboxydotrophic mycobacteria. Transcription of the CO-DH structural and accessory genes was demonstrated to be increased significantly by acidified sodium nitrate as a source of NO. A cutI deletion (ΔcutI) mutant of Mycobacterium sp. strain JC1 was generated to identity the function of CutI. Lithoautotrophic growth of the ΔcutI mutant was severely affected in mineral medium supplemented with CO, while the mutant grew normally with glucose. Western blotting, CO-DH activity staining, and CO-DH-specific enzyme assay revealed a significant decrease in the cellular level of CO-DH in the ΔcutI mutant. Northern blot analysis and promoter assay showed that expression of the cutB1 and cutB2 genes was significantly reduced at the transcriptional level in the ΔcutI mutant, compared to that of the wildtype strain. The ΔcutI mutant was much more susceptible to NO than was the wild type.

RraAS1 inhibits the ribonucleolytic activity of RNase ES by interacting with its catalytic domain in Streptomyces coelicolor: Sojin Seo , Daeyoung Kim , Wooseok Song , Jihune Heo , Minju Joo , Yeri Lim , Ji-Hyun Yeom , Kangseok Lee; J. Microbiol. 2017;55(1):37-43. Published online December 30, 2016; DOI: https://doi.org/10.1007/s12275-017-6518-0

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Abstract: RraA is a protein inhibitor of RNase E, which degrades and processes numerous RNAs in Escherichia coli. Streptomyces coelicolor also contains homologs of RNase E and RraA, RNase ES and RraAS1/RraAS2, respectively. Here, we report that, unlike other RraA homologs, RraAS1 directly interacts with the catalytic domain of RNase ES to exert its inhibitory effect. We further show that rraAS1 gene deletion in S. coelicolor
results
in a higher growth rate and increased production of actinorhodin and undecylprodigiosin, compared with the wild-type strain, suggesting that RraAS1-mediated regulation of RNase ES activity contributes to modulating the cellular physiology of S. coelicolor.

Biosynthesis and uptake of glycine betaine as cold-stress response to low temperature in fish pathogen Vibrio anguillarum: Yue Ma , Qiyao Wang , Xiating Gao , Yuanxing Zhang; J. Microbiol. 2017;55(1):44-55. Published online December 30, 2016; DOI: https://doi.org/10.1007/s12275-017-6370-2

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23 Citations

Abstract: Fish pathogen Vibrio anguillarum, a mesophile bacterium, is usually found in estuarine and marine coastal ecosystems worldwide that pose a constant stress to local organism by its fluctuation in salinity as well as notable temperature change. Though V. anguillarum is able to proliferate while maintain its pathogenicity under low temperature (5–18°C), so far, coldadaption molecular mechanism of the bacteria is unknown. In this study, V. anguillarum was found possessing a putative glycine betaine synthesis system, which is encoded by betABI and synthesizes glycine betaine from its precursor choline. Furthermore, significant up-regulation of the bet gene at the transcriptional level was noted in log phase in response to cold-stress. Moreover, the accumulation of betaine glycine was only found appearing at low growth temperatures, suggesting that response regulation of both synthesis system and transporter system are cold-dependent. Furthermore, in-frame deletion mutation in the two putative ABC transporters and three putative BCCT family transporters associated with glycine betaine uptake could not block cellular accumulation of betaine glycine in V. anguillarum under coldstress, suggesting the redundant feature in V. anguillarum betaine transporter system. These findings confirmed that glycine betaine serves as an effective cold stress protectant and highlighted an underappreciated facet of the acclimatization of V. anguillarum to cold environments.

Proteomic characterization of the outer membrane vesicle of the halophilic marine bacterium Novosphingobium pentaromativorans US6-1: Sung Ho Yun , Sang-Yeop Lee , Chi-Won Choi , Hayoung Lee , Hyun-Joo Ro , Sangmi Jun , Yong Min Kwon , Kae Kyoung Kwon , Sang-Jin Kim , Gun-Hwa Kim , Seung Il Kim; J. Microbiol. 2017;55(1):56-62. Published online December 30, 2016; DOI: https://doi.org/10.1007/s12275-017-6581-6

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18 Citations

Abstract: Novosphingobium pentaromativorans US6-1 is a Gram-negative halophilic marine bacterium able to utilize several polycyclic aromatic hydrocarbons such as phenanthrene, pyrene, and benzo[a]pyrene. In this study, using transmission electron microscopy, we confirmed that N. pentaromativorans US6-1 produces outer membrane vesicles (OMVs). N. pentaromativorans OMVs (hereafter OMVNovo) are spherical in shape, and the average diameter of OMVNovo is 25–70 nm. Proteomic analysis revealed that outer membrane proteins and periplasmic proteins of N. pentaromativorans are the major protein components of OMVNovo. Comparative proteomic analysis with the membrane-associated protein fraction and correlation analysis demonstrated that the outer membrane proteins of OMVNovo originated from the membrane- associated protein fraction. To the best of our knowledge, this study is the first to characterize OMV purified from halophilic marine bacteria.

Performance of nested multiplex PCR assay targeting MTP40 and IS6110 gene sequences for the diagnosis of tubercular lymphadenitis: Pallavi Sinha , Pradyot Prakash , Shashikant C.U. Patne , Shampa Anupurba , Sweety Gupta , G. N. Srivastava; J. Microbiol. 2017;55(1):63-67. Published online December 30, 2016; DOI: https://doi.org/10.1007/s12275-017-6127-y

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5 Citations

Abstract: The conventional methods for diagnosis of tubercular lymphadenitis (TBLN) such as - fine needle aspiration cytology, Ziehl-Neelsen staining and culture have limitations of low sensitivity and/or specificity. So, it becomes essential to develop a rapid, sensitive, and specific method for an early diagnosis of TBLN. Therefore, the present study was conducted to evaluate nested multiplex polymerase chain reaction (nMPCR) targeting MTP40 and IS6110 gene sequences of Mycobacterium tuberculosis and Mycobacterium tuberculosis complex, respectively in 48 successive patients of TBLN and 20 random patients with non-tubercular lymph node lesions. Out of the 48 cases of TBLN, 14 (29.2%) were found to be positive by Ziehl-Neelsen staining, 15 (31.2%) were positive by culture and 43 (89.6%) cases were positive after first round of PCR while 48 (100%) cases were positive by nMPCR assay. The sensitivity and specificity of nMPCR was found to be 100% for the diagnosis of TBLN. The results thus obtained indicate that nMPCR assay is a highly sensitive and specific tool for the diagnosis of TBLN.

Identification of essential genes of Pseudomonas aeruginosa for its growth in airway mucus: Mohammed Abd Alrahman , Sang Sun Yoon; J. Microbiol. 2017;55(1):68-74. Published online December 30, 2016; DOI: https://doi.org/10.1007/s12275-017-6515-3

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9 Citations

Abstract: Pseudomonas aeruginosa has been identified as an important causative agent of airway infection, mainly in cystic fibrosis. This disease is characterized by defective mucociliary clearance induced in part by mucus hyper-production. Mucin is a major component of airway mucus and is heavily O-glycosylated, with a protein backbone. Airway infection is known to be established with bacterial adhesion to mucin. However, the genes involved in mucin degradation or utilization remain elusive. In this study, we sought to provide a genetic basis of P. aeruginosa airway growth by identifying those genes. First, using RNASeq analyses, we compared genome-wide expression profiles of PAO1, a prototype P. aeruginosa laboratory strain, grown in M9-mucin (M9M) and M9-glucose (M9G) media. Additionally, a PAO1 transposon (Tn) insertion mutants library was screened for mutants defective in growth in M9M medium. One mutant with a Tn insertion in the xcpU gene (PA3100) was determined to exhibit faulty growth in M9M medium. This gene contributes to the type II secretion system, suggesting that P. aeruginosa uses this secretion system to produce a number of proteins to break down and assimilate the mucin molecule. Furthermore, we screened the PAO1 genome for genes with protease activity. Of 13 mutants, one with mutation in PA3247 gene exhibited defective growth in M9M, suggesting that the PA3247-encoded protease plays a role in mucin utilization. Further mechanistic dissection of this particular process will reveal new drug targets, the inhibition of which could control recalcitrant P. aeruginosa infections.

Reovirus safety study for proliferation and differentiation of human adipose-derived mesenchymal stem cells: Jeong-Soo Park , Manbok Kim; J. Microbiol. 2017;55(1):75-79. Published online December 30, 2016; DOI: https://doi.org/10.1007/s12275-017-6542-0

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12 Citations

Abstract: Naturally occurring reoviruses are live replication-proficient viruses specifically infecting human cancer cells while sparing the normal counterparts. Stem cells can be highly susceptible to viral infection due to their innate high proliferation potential and other active signaling pathways of cells that might be involved in viral tropism. In the previous study, we showed that reoviruses could adversely affect murine embryonic stem cells’ integrity in vitro and in vivo. Oncolytic viruses, delivered systemically face many hurdles that also impede their localization and infection of, metastatic tumors, due to a variety of immune and physical barriers. To overcome such hurdles to systemic delivery, several studies supported the idea that certain types of cells, including mesenchymal stem cells, might play a role as cell carriers for oncolytic viruses. Thus, it would be interesting to examine whether human adult stem cells such as human adipose-derived mesenchymal stem cells could be saved by the reoviral challenge. In this study, we report that biological activities such as proliferation and multipotency of human adipose-derived stem cells are not affected by wild-type reovirus challenge as evidenced by survival, osteogenic and adipogenic differentiation potential assays following treatment with reoviruses. Therefore, unlike murine embryonic stem cells, our study strongly suggests that human adipose-derived adult stem cells could be spared in vivo during wild-type reoviral anti-cancer therapeutics in a clinical setting. Furthermore, the results support the possible clinical use of human adipose-derived stem cells as an effective cell carrier of oncolytic reovirus to maximize their tumor tropism and anti-tumor activity.

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