International Journal of Medical Microbiology最新文献

{"title":"Machine learning on the road to unlocking microbiota’s potential for boosting immune checkpoint therapy","authors":"Szymon Wojciechowski ,&nbsp;Monika Majchrzak-Górecka ,&nbsp;Paweł Biernat ,&nbsp;Krzysztof Odrzywołek ,&nbsp;Łukasz Pruss ,&nbsp;Konrad Zych ,&nbsp;Jan Majta ,&nbsp;Kaja Milanowska-Zabel","doi":"10.1016/j.ijmm.2022.151560","DOIUrl":"10.1016/j.ijmm.2022.151560","url":null,"abstract":"<div><p>The intestinal microbiota is a complex and diverse ecological community that fulfills multiple functions and substantially impacts human health. Despite its plasticity, unfavorable conditions can cause perturbations leading to so-called dysbiosis, which have been connected to multiple diseases. Unfortunately, understanding the mechanisms underlying the crosstalk between those microorganisms and their host is proving to be difficult. Traditionally used bioinformatic tools have difficulties to fully exploit big data generated for this purpose by modern high throughput screens. Machine Learning (ML) may be a potential means of solving such problems, but it requires diligent application to allow for drawing valid conclusions. This is especially crucial as gaining insight into the mechanistic basis of microbial impact on human health is highly anticipated in numerous fields of study. This includes oncology, where growing amounts of studies implicate the gut ecosystems in both cancerogenesis and antineoplastic treatment outcomes. Based on these reports and first signs of clinical benefits related to microbiota modulation in human trials, hopes are rising for the development of microbiome-derived diagnostics and therapeutics. In this mini-review, we’re inspecting analytical approaches used to uncover the role of gut microbiome in immune checkpoint therapy (ICT) with the use of shotgun metagenomic sequencing (SMS) data.</p></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"312 7","pages":"Article 151560"},"PeriodicalIF":4.1,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1438422122000133/pdfft?md5=0d74e8769f00bcfd5011f5239bd38ac5&pid=1-s2.0-S1438422122000133-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40361546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive investigation of antibiotic resistance gene content in cfiA-harboring Bacteroides fragilis isolates of human and animal origins by whole genome sequencing","authors":"Huiluo Cao ,&nbsp;Melissa Chun-Jiao Liu ,&nbsp;Man-Ki Tong ,&nbsp;Shuo Jiang ,&nbsp;Kin-Hung Chow ,&nbsp;Kelvin Kai-Wang To ,&nbsp;Cindy Wing-Sze Tse ,&nbsp;Pak-Leung Ho","doi":"10.1016/j.ijmm.2022.151559","DOIUrl":"10.1016/j.ijmm.2022.151559","url":null,"abstract":"<div><h3>Introduction</h3><p>The emergence of multidrug resistance in <em>Bacteroides fragilis</em>, especially the phylogenetic lineage carrying the carbapenemase gene <em>cfiA</em>, represents an increasing threat to human health. However, knowledge on the diversity of the multidrug-resistant strains and the genetic elements carrying the antibiotic resistance genes (ARGs) remains limited.</p></div><div><h3>Aim</h3><p>The objective of the study was to describe the resistome in <em>cfiA</em>-positive <em>B. fragilis</em>.</p></div><div><h3>Methods</h3><p>A collection of <em>cfiA</em>-positive <em>B.</em> fragilis from diverse human (8 bacteremias, 15 wound infections) and animal (2 chickens, 2 pigs, 6 dogs, 3 cats) sources in Hong Kong, 2015–2017 was analysed by whole genome sequencing.</p></div><div><h3>Results</h3><p>In the 36 isolates, 13 distinct ARGs (total number 83, median 2, range 0–7 per isolate) other than <em>cfiA</em> were detected. ARGs encoding resistance to aminoglycosides, β-lactams, macrolides, sulphonamides and tetracyclines were carried by CTn<em>341</em>-like, CTn<em>Hyb</em>-like, Tn<em>5220</em>-like, Tn<em>4555</em>-like and Tn<em>613</em>-like transposons and were detected in phylogenetically diverse isolates of different host sources. Only few ARGs encoding resistance to metronidazole and tetracyclines were localized on plasmids. In two chicken isolates, a novel transposon (designated as Tn<em>6994</em>) was found to be involved in the dissemination of multiple ARGs mediating resistance to multiple antibiotics, including metronidazole and linezolid that are critically important for treatment of anaerobic infections. In mating experiments, Tn<em>6994</em> and the associated phenotypic resistance could be transferred to <em>Bacteroides nordii</em> recipient.</p></div><div><h3>Conclusion</h3><p>This study illustrates the importance of transposons in the dissemination of ARGs in the <em>cfiA</em>-positive division of <em>B. fragilis</em>. One Health approach is necessary to track the dissemination of ARGs.</p></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"312 6","pages":"Article 151559"},"PeriodicalIF":4.1,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1438422122000121/pdfft?md5=ec6ba4bea6a4f65a403484d3af7ce49b&pid=1-s2.0-S1438422122000121-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40692597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Klebsiella pneumoniae activates the TGF-β signaling pathway to adhere to and invade intestinal epithelial cells via enhancing TLL1 expression","authors":"Jun Liu ,&nbsp;Shiliang Zhang ,&nbsp;Hao Pei ,&nbsp;Fan Tu ,&nbsp;Bin Liu ,&nbsp;Jie Yan ,&nbsp;Xuai Lin","doi":"10.1016/j.ijmm.2022.151561","DOIUrl":"10.1016/j.ijmm.2022.151561","url":null,"abstract":"<div><p><em>Klebsiella pneumoniae</em> is a gram-negative bacterium that can cause many diseases in hospitals and communities. Intestinal <em>K. pneumoniae</em> infections are relatively rare. Most <em>K. pneumoniae</em> infections begin with the colonization of the gastrointestinal system. In this study, clinically isolated <em>K. pneumoniae</em> strains were used to infect intestinal epithelial Caco-2 cells to study the possible intestinal translocation mechanism of <em>K. pneumoniae</em>. We found that of the three <em>K. pneumoniae</em> strains tested, KP1821 exhibited the strongest adhesive and invasive abilities and that the adhesion to Caco-2 intestinal epithelial cells was affected by the acidic environment of the stomach. Transcriptome sequencing revealed the involvement of molecules associated with the extracellular matrix and cell adhesion, inflammatory response, calcium ion and transforming growth factor β (TGF-β) signaling pathways, and other abnormalities in biological processes and cell signaling pathways. Additionally, tolloid-like protein 1 (TLL1) was significantly upregulated. Knocking down TLL1 with shRNA significantly reduced KP1821's ability to invade and adhere to intestinal epithelial cells. TLL1 is involved in the activation of the TGF-β signaling pathway. Inhibition of this pathway using the inhibitor SB431542 induced significantly reduced adhesion and invasion capabilities of KP1821. Our findings demonstrate that TLL1 participates in <em>K. pneumoniae</em> adhesion and invasion of intestinal epithelial cells by activating the TGF-β signaling pathway.</p></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"312 6","pages":"Article 151561"},"PeriodicalIF":4.1,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1438422122000145/pdfft?md5=ef071adda834e849d3b41b62a6025e8e&pid=1-s2.0-S1438422122000145-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33458066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Can Mycobacterium tuberculosis infection lead to cancer? Call for a paradigm shift in understanding TB and cancer","authors":"Asrar A. Malik ,&nbsp;Javaid A. Sheikh ,&nbsp;Nasreen Z. Ehtesham ,&nbsp;Subhash Hira ,&nbsp;Seyed E. Hasnain","doi":"10.1016/j.ijmm.2022.151558","DOIUrl":"10.1016/j.ijmm.2022.151558","url":null,"abstract":"<div><p>Infections are known to cause tumours though more attributed to viruses. Strong epidemiological links suggest association between bacterial infections and cancers as exemplified by <em>Helicobacter pylori</em> and <em>Salmonella spp</em>. Infection with <em>Mycobacterium tuberculosis</em> (<em>M. tb</em>)<em>,</em> the etiological agent of tuberculosis (TB), has been reported to predispose patients to lung cancers and possibly in other organs as well. While this etiopathogenesis warrant inclusion of <em>M. tb</em> in IARC’s (International Agency for Research on Cancer) classified carcinogenic agents, the lack of well-defined literature and direct experimental studies have barred the research community from accepting the role of <em>M. tb</em> as a carcinogen. The background research, case studies, and experimental data extensively reviewed in Roy et al., 2021; provoke the debate for elucidating carcinogenic properties of <em>M. tb</em>. Moreover, proper, timely and correct diagnosis of both diseases (which often mimic each other) will save millions of lives that are misdiagnosed. In addition, use of Anti Tubercular therapy (ATT) in misdiagnosed non-TB patients contributes to drug resistance in population thereby severely impacting TB disease control measures. Research in this arena can further aid in saving billions of dollars by preventing the superfluous use of cancer drugs. In order to achieve these goals, it is imperative to identify the underlying mechanism of <em>M. tb</em> infection acting as major risk factor for cancer.</p></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"312 5","pages":"Article 151558"},"PeriodicalIF":4.1,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S143842212200011X/pdfft?md5=b995fc8620dee04097add0d8dff22bac&pid=1-s2.0-S143842212200011X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40511006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of OXA-181-producing Pseudomonas aeruginosa in Germany","authors":"Jennifer Schauer ,&nbsp;Sören G. Gatermann,&nbsp;Jessica Eisfeld,&nbsp;Jörg Hans,&nbsp;Niels Pfennigwerth","doi":"10.1016/j.ijmm.2022.151557","DOIUrl":"10.1016/j.ijmm.2022.151557","url":null,"abstract":"<div><h3>Objectives</h3><p>To report the detection of the class D carbapenemase OXA-181 in an MDR clinical <em>Pseudomonas aeruginosa</em> isolate in Germany.</p></div><div><h3>Methods</h3><p>Carbapenemase detection was performed by using several phenotypic tests such as the modified Hodge test, a combined disc test with boronic acid, EDTA or cloxacillin, a lysate-based inhibition assays and by PCR for common and rare carbapenemase genes. Antibiotic susceptibilities were determined by broth microdilution. The genetic environment of <em>bla</em>_OXA-181 in the clinical <em>P. aeruginosa</em> isolate was characterised by Illumina and MinION sequencing.</p></div><div><h3>Results</h3><p>An multidrug-resistant <em>P. aeruginosa</em> was isolated from a tracheal swab in 2019 and was sent to the German National Reference Centre for multidrug-resistant Gram-negative bacteria for carbapenemase detection. Several phenotypic tests indicated the presence of a carbapenemase which was not inhibited by EDTA nor by boronic acid. PCRs for common and rare carbapenemase genes revealed the presence of a <em>bla</em>_OXA-181 gene. WGS data confirmed that the gene was located on the chromosome as part of a Tn<em>2013</em> transposon. The genetic organisation of <em>bla</em>_OXA-181 has already been described in a <em>P. aeruginosa</em> isolate from England, but both isolates differed significantly in their sequence types (ST111/ST235). Analysis of the genetic environment of the <em>bla</em>_OXA-181 gene also revealed high homology to a plasmid from a <em>Klebsiella pneumoniae</em> isolate.</p></div><div><h3>Conclusions</h3><p>To our knowledge, this is the first report of <em>bla</em>_OXA-181 in a clinical <em>P. aeruginosa</em> isolate in Germany which emphasises the ongoing spread of yet unusual carbapenemases among different Gram-negative species and therefore complicating their detection in routine laboratories.</p></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"312 5","pages":"Article 151557"},"PeriodicalIF":4.1,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1438422122000108/pdfft?md5=ece77fe4623d6788d66c9eafd6b60c25&pid=1-s2.0-S1438422122000108-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40511007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regulatory interplay of RpoS and RssB controls motility and colonization in Vibrio cholerae","authors":"Martina Wölflingseder ,&nbsp;Sarah Tutz ,&nbsp;Vera H. Fengler ,&nbsp;Stefan Schild ,&nbsp;Joachim Reidl","doi":"10.1016/j.ijmm.2022.151555","DOIUrl":"https://doi.org/10.1016/j.ijmm.2022.151555","url":null,"abstract":"<div><p>Cholera is a life-threatening diarrheal disease caused by the human pathogenic bacterium <em>Vibrio cholerae</em>. Regulatory elements are essential for bacterial transition between the natural aquatic environment and the human host. One of them is the alternative sigma factor RpoS and its anti-sigma factor RssB. Regulation principles seem to be conserved among RpoS/RssB interaction modes between <em>V. cholerae</em> and Enterobacteriaceae species, however the associated input and output pathways seem different. In <em>Escherichia coli</em>, RpoS/RssB is important for the activation of an emergency program to increase persistence and survival. Whereas, it activates motility and chemotaxis in <em>V. cholerae</em>, used strategically to escape from starvation conditions. We characterised a starvation-induced interaction model showing a negative feedback loop between RpoS and RssB expression. We showed by genotypic and phenotypic analysis that <em>rssB</em> influences motility, growth behaviour, colonization fitness, and post-infectious survival. Furthermore, we found that RssB itself is a substrate for proteolysis and a critical Asp mutation was identified and characterised to influence <em>rssB</em> phenotypes and their interaction with RpoS. In summary, we present novel information about the regulatory interaction between RpoS and RssB being active under <em>in vivo</em> colonization conditions and mark an extension to the feedback regulation circuit, showing that RssB is a substrate for proteolysis.</p></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"312 4","pages":"Article 151555"},"PeriodicalIF":4.1,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S143842212200008X/pdfft?md5=53677ef4a5fa12951d3c24513a1fcad2&pid=1-s2.0-S143842212200008X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136891334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Treponema pallidum Tp0751 alters the expression of tight junction proteins by promoting bEnd3 cell apoptosis and IL-6 secretion","authors":"Simin Lu ,&nbsp;Jianye Wang ,&nbsp;Zhangping He ,&nbsp;Siqin He ,&nbsp;Kang Zheng ,&nbsp;Man Xu ,&nbsp;Shuai Yuan ,&nbsp;Yimou Wu","doi":"10.1016/j.ijmm.2022.151553","DOIUrl":"10.1016/j.ijmm.2022.151553","url":null,"abstract":"<div><h3>Background</h3><p>Neurosyphilis is a serious complication caused by the invasion of the central nervous system by <em>Treponema pallidum subsp. pallidum</em> (<em>T. pallidum</em>). However, the molecular mechanism by which <em>T. pallidum</em> crosses the blood-brain barrier has not been fully elucidated.</p></div><div><h3>Objectives</h3><p>The primary purpose of this experimental design was to explore the effect of the <em>T. pallidum</em> adhesion protein Tp0751 on the blood-brain barrier and cerebrovascular endothelial cells.</p></div><div><h3>Methods</h3><p>BEnd3 cells were used to construct a monolayer blood-brain barrier model in vitro. The integrity of blood-brain barrier model was evaluated by a transendothelial cell resistance meter and transmission electron microscope after the stimulation of recombinant protein TP0751. Hoechst 33258 staining and flow cytometry were used to detect the apoptosis rate. Western blotting assay was used to measure the expression of tight junction proteins and apoptosis-related proteins. The enzyme activity detection kit was responsible for detecting the enzyme activities of Caspase 3, Caspase 8 and Caspase 9. The expression of pro-inflammatory cytokines TNF-α, IL-1β and IL-6 at the transcription and translation levels were detected by qRT-PCR and ELISA, respectively.</p></div><div><h3>Results</h3><p>The results showed that, the tight junction structures between cells showed no obvious fragmentation, but the levels of the tight junction proteins zonula occludens-1 and occludin were reduced by the effects of Tp0751 on bEnd3 cells. In addition, further research demonstrated that after incubation with bEnd3 cells, Tp0751 induced cell apoptosis in a concentration- and time-dependent manner via the caspase 8/caspase 3 pathway. These apoptotic processes may have contributed to the changes in tight junction proteins expression. Furthermore, the Tp0751 protein may be involved in the pathogenic process by which <em>T. pallidum</em> crosses the blood-brain barrier by promoting secretion of the proinflammatory factor interleukin-6.</p></div><div><h3>Conclusions</h3><p>On the whole, this study is the first to reveal and highlight that Tp0751 may affect the expression of tight junction proteins by inducing apoptosis and promoting the secretion of the inflammatory cytokine IL-6, thus playing a role in the progression of neurosyphilis caused by <em>T. pallidum</em>.</p></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"312 4","pages":"Article 151553"},"PeriodicalIF":4.1,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1438422122000066/pdfft?md5=23b7e00b78977ae4c73e783709fe8c3f&pid=1-s2.0-S1438422122000066-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128209089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of the cagA-gene in Helicobacter pylori in Mongolia and detection of two EPIYA-A enriched CagA types","authors":"Oyunbaatar Altanbayar ,&nbsp;Avarzed Amgalanbaatar ,&nbsp;Chimeddorj Battogtokh ,&nbsp;Narmandakh Bayarjargal ,&nbsp;Dana Belick ,&nbsp;Malte Kohns Vasconcelos ,&nbsp;Colin R. Mackenzie ,&nbsp;Klaus Pfeffer ,&nbsp;Birgit Henrich","doi":"10.1016/j.ijmm.2022.151552","DOIUrl":"10.1016/j.ijmm.2022.151552","url":null,"abstract":"<div><p><em>Helicobacter pylori</em> infection is strongly associated with gastritis, gastroduodenal ulcer disease and gastric carcinoma. The virulence of <em>H. pylori</em> strains increases with the presence of the pathogenicity island PAI, which encodes a Type 4 Secretion System and the oncoprotein CagA. Two major CagA types can be distinguished by differences in the repetitive EPIYA region in the C-terminal sequence; the more virulent East Asian CagA type with EPIYA-A, -B, and -D motifs and the Western CagA type with EPIYA-A, -B, and C motifs, the virulence of which is associated with the multitude of EPIYA-C motifs.</p><p>In this study, the <em>cag</em>A gene was characterized in <em>H. pylori</em> strains isolated from Mongolians suffering from gastritis (80%) or ulcer (20%). The EPIYA region of 53 isolates was determined by PCR-amplification of overlapping <em>cag</em>A regions and subsequent Sanger sequencing. Only one <em>H. pylori</em> isolate carried the East Asian type (ABD) and 52 isolates the Western type of CagA, thereof 30 the EPIYA type ABC, 19 the ABCC type and one each of type ABCCCC, AAABC and AAAAB. An amino acid exchange from EPIY<strong>A</strong>-B to EPIY<strong>T</strong>-B was predominantly found in CagA proteins in strains with &lt; 2 EPIYA-C copies (n = 25/32; p = 0.015) including the two EPIYA-A enriched CagA proteins, which have not been described to date. Due to the amino acid triplet preceding the EPIYA motif and strength of predicted phosphorylation, the multiple EPIYA-A motifs A2, A3 and A4 were shown to cluster with EPIYA-B and EPIYT-B with the unique feature of amino acid E in position − 4 to Y of EPIYA. It has been described that tyrosine-phosphorylated EPIYA-A and -B motifs counteract the EPIYA-C-driven signaling towards host cell transformation and malignancy. Thus, Mongolian <em>H. pylori</em> strains carrying CagA proteins not only with a few EPIYA-C segments but also with multiplied EPIYA-A segments are probably less virulent; a thesis that needs further investigation at the protein level.</p></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"312 3","pages":"Article 151552"},"PeriodicalIF":4.1,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1438422122000054/pdfft?md5=9a4c488ef670b2f2b9c34cf8ccaf5699&pid=1-s2.0-S1438422122000054-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121372323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global epidemiology of antimicrobial resistance in commensal Neisseria species: A systematic review","authors":"Thibaut Vanbaelen ,&nbsp;Christophe Van Dijck ,&nbsp;Jolein Laumen ,&nbsp;Natalia Gonzalez ,&nbsp;Irith De Baetselier ,&nbsp;Sheeba S. Manoharan-Basil ,&nbsp;Tessa De Block ,&nbsp;Chris Kenyon","doi":"10.1016/j.ijmm.2022.151551","DOIUrl":"10.1016/j.ijmm.2022.151551","url":null,"abstract":"<div><h3>Background</h3><p>Commensal <em>Neisseria</em> species (spp). represent an important reservoir of antimicrobial resistance genes for pathogenic <em>Neisseria</em> spp. In this systematic review, we aimed to assess the antimicrobial susceptibility of commensal <em>Neisseria</em> spp<em>.</em> and how this has evolved over time. We also aimed to assess if commensal <em>Neisseria</em> spp. showed intrinsic resistance to four antimicrobials - penicillin, azithromycin, ceftriaxone and ciprofloxacin.</p></div><div><h3>Methods</h3><p>Pubmed and Google Scholar were searched following the PRISMA guidelines. Articles reporting MICs of commensal <em>Neisseria</em> spp. were included according to inclusion/exclusion criteria, and the quality of the articles was assessed using a pre-designed tool. Individual and summary measures of penicillin, azithromycin, ceftriaxone and ciprofloxacin MICs were collected. Additional data was sought to perform a comparison between the MICs of pathogenic and commensal <em>Neisseria</em> spp.</p></div><div><h3>Results</h3><p>A total of 15 studies met our criteria.We found no evidence of intrinsic AMR in commensal <em>Neisseria</em> spp. We did find evidence of an increasing trend in MICs of commensal <em>Neisseria</em> spp. over time for all antimicrobials assessed. These findings were similar in various countries. Eight additional studies were included to compare pathogenic and commensal <em>Neisseria</em> spp.</p></div><div><h3>Conclusion</h3><p>The MICs of commensal <em>Neisseria</em> spp. appear to be increasing in multiple countries. Surveillance of MICs in commensals could be used as an early warning system for antimicrobial resistance emergence in pathogens. Our findings underline the need for antibiotic stewardship interventions, particularly in populations with high antimicrobial consumption.</p></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"312 3","pages":"Article 151551"},"PeriodicalIF":4.1,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1438422122000042/pdfft?md5=b8ea8456cca2b1b855d2e92764c21919&pid=1-s2.0-S1438422122000042-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133083847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Virulent Staphylococcus aureus colonizes pediatric nares by resisting killing of human antimicrobial peptides","authors":"Ziyu Yang ,&nbsp;Bijun Qiu ,&nbsp;Danhong Cheng ,&nbsp;Na Zhao ,&nbsp;Yao Liu ,&nbsp;Min Li ,&nbsp;Qian Liu","doi":"10.1016/j.ijmm.2022.151550","DOIUrl":"10.1016/j.ijmm.2022.151550","url":null,"abstract":"<div><h3>Background</h3><p>The nasal carriage of <em>Staphylococcus aureus</em> introduces risks for subsequent infections, the rate of which is particularly high in children. The colonization mechanisms of <em>S. aureus</em> are not fully understood.</p></div><div><h3>Methods</h3><p>The epidemiological characteristics of nasal colonizing strains from pediatric patients undergoing liver transplantation and healthy pre-school children were analyzed first. Phenotypes, including biofilm formation and hemolytic activity, were tested for all the isolates. Bacterial pathogenicity indicated by a mouse skin abscess model and resistance to antimicrobial peptides (AMPs) was compared between the predominant genotypes from each group.</p></div><div><h3>Results</h3><p>The ST188 clone dominated in healthy children, whereas ST59 was prevalent for the pediatric patients. Although ST22 was the second most abundant genotype in the patient group, it was rarely found in healthy children. Interestingly, the colonizing ST59 and ST22 genotypes were more virulent, as indicated by the increased ability for hemolysis in vitro and severe subcutaneous abscesses in the mouse model, compared with ST188. We observed that the virulent ST59 and ST22 displayed higher resistance to antibiotics compared with ST188. Most of the ST59 and ST22 were methicillin-resistant <em>S. aureus</em> (MRSA), and all of the ST188 strains were methicillin-susceptible (MSSA). Moreover, we observed that the virulent ST59 and ST22 can resist killing by human antimicrobial peptides (AMPs). Mechanically, upon stimulation by AMPs, the virulent <em>S. aureus</em> can induce high expression of a phenol-soluble modulin transporter (Pmt) system.</p></div><div><h3>Conclusion</h3><p>Pediatric patients can be colonized by virulent <em>S. aureus</em> clones, which are able to resist AMPs’ killing through the Pmt system. The residence of virulent strains necessitates the continuous monitoring of potential infections, as well as annealing, to take protective decolonization measures.</p></div>","PeriodicalId":50312,"journal":{"name":"International Journal of Medical Microbiology","volume":"312 2","pages":"Article 151550"},"PeriodicalIF":4.1,"publicationDate":"2022-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1438422122000030/pdfft?md5=61961791de3709d8724567d0b4e82700&pid=1-s2.0-S1438422122000030-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39958318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}