Journal of global antimicrobial resistance最新文献

{"title":"Epidemiological pattern and genomic insights into multidrug-resistant ST491 Acinetobacter baumannii BD20 isolated from an infected wound in Bangladesh: Concerning co-occurrence of three classes of beta lactamase genes","authors":"Israt Islam ,&nbsp;Badriya Mubashshira ,&nbsp;Spencer Mark Mondol ,&nbsp;Otun Saha ,&nbsp;M. Shaminur Rahman ,&nbsp;Afroza Khan ,&nbsp;Amiruzzaman ,&nbsp;Md. Mizanur Rahaman","doi":"10.1016/j.jgar.2024.07.009","DOIUrl":"10.1016/j.jgar.2024.07.009","url":null,"abstract":"<div><h3>Objective</h3><p>Multidrug-resistant (MDR) <em>Acinetobacter baumannii</em> is a major issue within healthcare facilities in Bangladesh due to its frequent association with hospital-acquired infections. In this study we report on a carbapenem-resistant draft genome sequence of an <em>A. baumannii</em> BD20 sample isolated from an infected wound in Bangladesh.</p></div><div><h3>Methods</h3><p><em>A. baumannii</em> BD20 was isolated from an infected burn wound. Whole-genome sequencing was carried out and annotated using PGAP and Prokka. Sequence type, antimicrobial resistance genes, virulence factor genes, and metal resistance genes were investigated. Core genome multilocus sequence typing–based phylogenomic analysis between <em>A. baumannii</em> BD20 and 213 <em>A. baumannii</em> strains retrieved from the NCBI GenBank database was performed using the BacWGSTdb 2.0 server.</p></div><div><h3>Results</h3><p><em>A. baumannii</em> BD20 (MLST 491) was resistant to all the antibiotics tested, except for colistin and polymyxin B. Along with many other antibiotic resistance genes, the isolate harbored three classes of beta lactamase–producing genes: <em>bla</em>_GES-11 (class A), <em>bla</em>_OXA-69 (class D), <em>bla</em>_ADC-10 (class C), and <em>bla</em>_ADC-11 (class C). Additionally, the strain carried several virulence genes and metal resistance determinants, which may contribute to its increased virulence. Core genome MLST–based phylogenomic analysis revealed that <em>A. baumannii</em> BD20 was closely related to another ST491 strain isolated from Singapore.</p></div><div><h3>Conclusions</h3><p>The findings of this study underscore the growing challenge of MDR <em>A. baumannii</em>, emphasizing the need for vigilant surveillance and infection-control measures in healthcare settings in order to address these emerging threats effectively.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 327-331"},"PeriodicalIF":3.7,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001395/pdfft?md5=c90865ae9f0839867ab7ef6c308f03b5&pid=1-s2.0-S2213716524001395-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141766239","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":"Antimicrobial susceptibilities, resistance mechanisms and molecular characteristics of toxigenic Clostridioides difficile isolates in a large teaching hospital in Chongqing, China","authors":"Zijun Dang,&nbsp;Bingxue Yang,&nbsp;Peiwen Xia,&nbsp;Jinzhu Huang,&nbsp;Jiajia Liao,&nbsp;Yuqiong Li,&nbsp;Shiyu Tang,&nbsp;Qi Han,&nbsp;Shengli Luo,&nbsp;Yun Xia","doi":"10.1016/j.jgar.2024.07.006","DOIUrl":"10.1016/j.jgar.2024.07.006","url":null,"abstract":"<div><h3>Objectives</h3><p><em>Clostridioides difficile</em> ranks among the primary sources of healthcare-related infections and diarrhoea in numerous nations. We evaluated the drug susceptibility and resistance mechanisms of <em>C. difficile</em> isolates from a hospital in Chongqing, China, and identified resistance rates and resistance mechanisms that differed from previous findings.</p></div><div><h3>Methods</h3><p>The toxin genes and drug resistance genes of clinical strains were detected using Polymerase Chain Reaction (PCR), and these strains were subjected to Multilocus Sequence Typing (MLST). The agar dilution technique was employed for assessing susceptibility of antibiotics. Clinical data collection was completed through a review of electronic medical records.</p></div><div><h3>Results</h3><p>A total of 67 strains of toxin-producing <em>C. difficile</em> were detected. All <em>C. difficile</em> isolates demonstrated susceptibility to both metronidazole and vancomycin. However, resistance was observed in 8.95%, 16.42%, 56.72%, 56.72%, 31.34% and 5.97% of the isolates for tigecycline, tetracycline, clindamycin, erythromycin, moxifloxacin and rifampin, respectively. Among the strains with toxin genotypes A + B + CDT - and belonging to the ST3, six strains exhibited reduced susceptibility to tigecycline (MIC=0.5mg/L) and tetracycline (MIC=8mg/L). The <em>tetA(P)</em> and <em>tetB(P)</em> genes were present in these six strains, but were absent in tetracycline-resistant strains. Resistance genes (<em>ermB, tetM, tetA(P)</em> and <em>tetB(P)</em>) and mutations (in <em>gyrA, gyrB</em>, and <em>rpoB</em>) were identified in resistant strains.</p></div><div><h3>Conclusions</h3><p>In contrast to prior studies, we found higher proportions of ST3 isolates with decreased tigecycline sensitivity, sharing similar resistance patterns and resistance genes. In the resistance process of tigecycline and tetracycline, the <em>tetA(P)</em> and <em>tetB(P)</em> genes may play a weak role.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 198-204"},"PeriodicalIF":3.7,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001383/pdfft?md5=64886bf1fb49bd1132f375290153d0a9&pid=1-s2.0-S2213716524001383-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141759169","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":"Clonal dissemination of Klebsiella pneumoniae carrying blaOXA-48 gene in a central Italy hospital","authors":"Gloria D'Achille ,&nbsp;Ilaria Nunzi ,&nbsp;Simona Fioriti ,&nbsp;Oscar Cirioni ,&nbsp;Lucia Brescini ,&nbsp;Andrea Giacometti ,&nbsp;Lucia Teodori ,&nbsp;Andrea Brenciani ,&nbsp;Eleonora Giovanetti ,&nbsp;Marina Mingoia ,&nbsp;Gianluca Morroni","doi":"10.1016/j.jgar.2024.07.004","DOIUrl":"10.1016/j.jgar.2024.07.004","url":null,"abstract":"","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 339-340"},"PeriodicalIF":3.7,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001358/pdfft?md5=ff5dc34d77329d1d29466e7c8cfe71de&pid=1-s2.0-S2213716524001358-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141734324","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":"Risk factors for mortality in Acinetobacter baumannii bloodstream infections and development of a predictive mortality model","authors":"Silvia Corcione ,&nbsp;Bianca Maria Longo ,&nbsp;Silvia Scabini ,&nbsp;Emanuele Pivetta ,&nbsp;Antonio Curtoni ,&nbsp;Nour Shbaklo ,&nbsp;Cristina Costa ,&nbsp;Francesco Giuseppe De Rosa","doi":"10.1016/j.jgar.2024.06.010","DOIUrl":"10.1016/j.jgar.2024.06.010","url":null,"abstract":"<div><h3>Objectives</h3><p><em>Acinetobacter baumannii</em> (<em>A. baumannii</em>) nosocomial infections represent a serious hazard to public health, given high mortality rates and rapid spread of multidrug-resistance. The primary outcome of this study was to evaluate predictors of 14- and 30-d mortality in bloodstream infections (BSIs) due to both carbapenem-resistant and carbapenem-sensitive <em>Acinetobacter.</em> Secondary end points were to identify risk factors for BSIs due to carbapenem-resistant <em>A. baumannii</em> (CRAB) and to develop a predictive model for mortality in CRAB-related BSIs.</p></div><div><h3>Methods</h3><p>Between 2019 and 2023, all consecutive hospitalized adult patients with bacteraemia due to <em>A. baumannii</em> were retrospectively enrolled at a single-centre<em>.</em></p></div><div><h3>Results</h3><p>One hundred twenty-six episodes of BSI caused by <em>A. baumannii</em> were recorded, 89.7% of which were due to CRAB. Recent burn injuries, older age, previous CRAB colonization, and antibiotics exposure were identified as risk factors for acquiring CRAB BSI. Overall, 14-d mortality was observed in 26.1% of the patients and 30-d mortality in 30.9% of the patients. On multivariate analysis, the Sequential Organ Failure Assessment (SOFA) score was associated with both 14- and 30-d mortality, whereas burn injuries correlated with 30-d survival. Concurrent coronavirus disease (COVID) was associated with mortality, although not reaching statistical figures. No major impact of receiving appropriate treatment was observed. Based on these findings, a multivariable model to predict mortality among patients with CRAB BSI was built and internally validated.</p></div><div><h3>Conclusions</h3><p><em>A. baumannii</em> BSIs are characterized by poor outcomes and limited therapeutic options. This study aimed to assist physicians in prompt identification of patients who are at greater risk of death, contributing to more informed clinical decision making.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 317-326"},"PeriodicalIF":3.7,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001255/pdfft?md5=85f8dfbe57eb332ca4389320273c36ca&pid=1-s2.0-S2213716524001255-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141727304","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":"Genetic and structural basis of colistin resistance in Klebsiella pneumoniae: Unravelling the molecular mechanisms","authors":"Sahar Alousi ,&nbsp;Jamal Saad ,&nbsp;Balig Panossian ,&nbsp;Rita Makhlouf ,&nbsp;Charbel Al Khoury ,&nbsp;Kelven Rahy ,&nbsp;Sergio Thoumi ,&nbsp;George F. Araj ,&nbsp;Rony Khnayzer ,&nbsp;Sima Tokajian","doi":"10.1016/j.jgar.2024.06.019","DOIUrl":"10.1016/j.jgar.2024.06.019","url":null,"abstract":"<div><h3>Objective</h3><p>Antimicrobial resistance (AMR), together with multidrug resistance (MDR), mainly among Gram-negative bacteria, has been on the rise. Colistin (polymyxin E) remains one of the primary available last resorts to treat infections caused by MDR bacteria during the rapid emergence of global resistance. As the exact mechanism of bacterial resistance to colistin remains undetermined, this study warranted elucidation of the underlying mechanisms of colistin resistance and heteroresistance among carbapenem-resistant <em>Klebsiella pneumoniae</em> isolates.</p></div><div><h3>Methods</h3><p>Molecular analysis was carried out on the resistant isolates using a genome-wide characterisation approach, as well as MALDI-TOF mass spectrometry, to identify lipid A.</p></div><div><h3>Results</h3><p>Among the 32 carbapenem-resistant <em>K. pneumoniae</em> isolates, several isolates showed resistance and intermediate resistance to colistin. The seven isolates with intermediate resistance exhibited the “skip-well” phenomenon, attributed to the presence of resistant subpopulations. The three isolates with full resistance to colistin showed ions using MALDI-TOF mass spectrometry at <em>m/z</em> of 1840 and 1824 representing bisphosphorylated and hexa-acylated lipid A, respectively, with or without hydroxylation at position C’-2 of the fatty acyl chain. Studying the genetic environment of <em>mgrB</em> locus revealed the presence of two insertion sequences that disrupted the <em>mgrB</em> locus in the three colistin-resistant isolates: IS1R and IS903B.</p></div><div><h3>Conclusions</h3><p>Our findings show that colistin resistance/heteroresistance was inducible with mutations in chromosomal regulatory networks controlling the lipid A moiety and insertion sequences disrupting the <em>mgrB</em> gene, leading to elevated minimum inhibitory concentration values and treatment failure. Different treatment strategies should be employed to avoid colistin heteroresistance-linked treatment failures, mainly through combination therapy using colistin with carbapenems, aminoglycosides, or tigecycline.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 256-264"},"PeriodicalIF":3.7,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001280/pdfft?md5=cd915c9fadd273bed6ecafe07b38089b&pid=1-s2.0-S2213716524001280-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141727303","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":"Pseudomonas aeruginosa epidemic high-risk clones and their association with multidrug-resistant","authors":"Jeannete Zurita ,&nbsp;Gabriela Sevillano ,&nbsp;María Belén Solís ,&nbsp;Ariane Paz y Miño ,&nbsp;Beatriz Rizkallah Alves ,&nbsp;Jessica Changuan ,&nbsp;Pablo González","doi":"10.1016/j.jgar.2024.07.003","DOIUrl":"10.1016/j.jgar.2024.07.003","url":null,"abstract":"<div><h3>Objective</h3><p>In Ecuador, data on molecular epidemiology, as well as circulating clones, are limited. Therefore, this study aims to know the population structure of <em>Pseudomonas aeruginosa</em> by identifying clones in clinical samples in Quito-Ecuador.</p></div><div><h3>Methods</h3><p>A significant set (45) clinical <em>P. aeruginosa</em> isolates were selected, including multidrug and non-multidrug resistant isolates, which were assigned to sequence types (STs) and compared with their antibiotic susceptibility profile. The genetic diversity was assessed by applying the multilocus sequence typing (MLST) scheme and the genetic relationships between different STs were corroborated by phylogenetic networks.</p></div><div><h3>Results</h3><p>The MLST analysis identified 24 different STs and the most prevalent STs were ST-3750 and ST-253. The majority of the multidrug-resistance (MDR) isolates were included in ST-3750 and ST-253, also 3 singleton STs were identified as MDR isolates. The 21 different STs were found in non-multidrug resistance (non-MDR) isolates, and only 3 STs were found in more the one isolate.</p></div><div><h3>Conclusions</h3><p>The population structure of clinical <em>P. aeruginosa</em> present in these isolates indicates a significant association between MDR isolates and the clonal types: all ST-3750 and ST-253 isolates were MDR. ST-3750 is a closely related strain to the clonal complex ST111 (CC111). ST-253 and ST111 are a group of successful high-risk clones widely distributed worldwide. The multiresistant isolates studied are grouped in the most prevalent STs found, and the susceptible isolates correspond mainly with singleton STs. Therefore, these high-risk clones and their association with MDR phenotypes are contributing to the spread of MDR in Quito, Ecuador.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 332-338"},"PeriodicalIF":3.7,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001309/pdfft?md5=3b58ad5e6062fb8d5645e15ef495d76b&pid=1-s2.0-S2213716524001309-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141633739","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":"Prevalence and characterization of an integrative and conjugative element carrying tet(X) gene in Elizabethkingia meningoseptica","authors":"Sérgio M. Morgado,&nbsp;Érica L. Fonseca,&nbsp;Ana Carolina P. Vicente","doi":"10.1016/j.jgar.2024.07.001","DOIUrl":"10.1016/j.jgar.2024.07.001","url":null,"abstract":"<div><h3>Objectives</h3><p>To investigate the <em>tet</em>(X) gene, a determinant of tigecycline resistance, in the emerging pathogen <em>Elizabethkingia meningoseptica</em> and its association with an integrative and conjugative element (ICE).</p></div><div><h3>Methods</h3><p><em>All E. meningoseptica</em> genomes from the National Center for Biotechnology Information (<em>n</em> = 87) were retrieved and annotated for resistome searches using the CARD database. A phylogenic analysis was performed based on the <em>E. meningoseptica</em> core genome<em>.</em> The ICE was identified through comparative genomics with other ICEs occurring in <em>Elizabethkingia</em> spp.</p></div><div><h3>Results</h3><p>Phylogenetic analysis revealed <em>E. meningoseptica</em> genomes from six countries distributed across different lineages, some of which persisted for years. The common resistome of these genomes included <em>bla</em>_BlaB, <em>bla</em>_CME, <em>bla</em>_GOB, <em>ran</em>A/B, <em>aad</em>S, and <em>cat</em>B (genes associated with resistance to β-lactams, aminoglycosides, and chloramphenicol). Some genomes also presented additional resistance genes (<em>dfr</em>A, <em>ere</em>D, <em>bla</em>_VEB, <em>aad</em>S, and <em>tet</em>(X)). Interestingly, <em>tet</em>(X) and <em>aad</em>S were located in an ICE of 49 769 bp (ICEEmSQ101), which was fully obtained from the <em>E. meningoseptica</em> SQ101 genome. We also showed evidence that the other 27 genomes harboured this ICE. The distribution of ICEEmSQ101, carrying <em>tet</em>(X), was restricted to a single Chinese lineage.</p></div><div><h3>Conclusions</h3><p>The <em>tet</em>(X) gene is not prevalent in the species <em>E. meningoseptica</em>, as previously stated for the genus <em>Elizabethkingia</em>, since it is present only in a single Chinese lineage. We identified that several <em>E. meningoseptica</em> genomes harboured an ICE that mobilized the <em>Elizabethkingia tet</em>(X) gene and exhibited characteristics similar to the ICEs of other <em>Flavobacteria</em>, which would favour their transmission in this bacterial family.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 227-230"},"PeriodicalIF":3.7,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001322/pdfft?md5=92abea5f89a5b94615fef94dba806c60&pid=1-s2.0-S2213716524001322-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141616623","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":"Genetic elements harbouring oxazolidinone resistance genes detected in swine enterococci circulate in clinical isolates, Italy","authors":"Sonia Nina Coccitto ,&nbsp;Marzia Cinthi ,&nbsp;Francesca Romana Massacci ,&nbsp;Elisa Albini ,&nbsp;Chiara Francesca Magistrali ,&nbsp;Andrea Brenciani ,&nbsp;Eleonora Giovanetti","doi":"10.1016/j.jgar.2024.06.016","DOIUrl":"10.1016/j.jgar.2024.06.016","url":null,"abstract":"","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 245-246"},"PeriodicalIF":3.7,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001292/pdfft?md5=1a543ced99be3ea382d3780d3d8a7b5e&pid=1-s2.0-S2213716524001292-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141616622","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":"Characteristics of multidrug-resistant hypervirulent Klebsiella pneumoniae strains ST29 and K212 harbouring tmexC2-tmexD2-toprJ2","authors":"Xingming Li ,&nbsp;Min Fu ,&nbsp;Yaxu Len ,&nbsp;Renjing Hu ,&nbsp;Changwen Xu ,&nbsp;Xia Xiong ,&nbsp;Yingshun Zhou","doi":"10.1016/j.jgar.2024.06.014","DOIUrl":"10.1016/j.jgar.2024.06.014","url":null,"abstract":"<div><h3>Objectives</h3><p>This study aimed to characterize a tigecycline-resistant hypervirulent <em>Klebsiella pneumoniae</em> (HvKP) strain, identified as KLZT, which carries the tigecycline resistance gene cluster <em>tmexC2-tmexD2-toprJ2</em> belonging to ST29 and serotype K212.</p></div><div><h3>Methods</h3><p>Antimicrobial susceptibility and virulence phenotypes were assessed, followed by whole-genome sequencing (WGS) using PacBio II and MiSeq sequencers. Genome annotation was carried out using the RAST server and bioinformatics analysis revealed the genetic characteristics of this strain.</p></div><div><h3>Results</h3><p>Antimicrobial and virulence phenotype testing indicated that <em>K. pneumoniae</em> strain KLZT could be considered as a multidrug-resistant HvKP. WGS analysis showed that KLZT has a single 5,536,506-bp chromosome containing three plasmids 290,963 bp (pKLZT-1), 199,302 bp (pKLZT-2), and 4820 bp (pKLZT-3) in size, and also includes the ST29 and K212 serotypes. Four (<em>bla</em>_SHV-187, <em>oqxA, oqxB</em>, and <em>fosA6</em>) and six resistance genes (<em>tmexC2-tmxeD2-toprJ2, bla</em>_OXA-1, <em>aac(6′)-Ib-cr, catB3, arr-3</em>, and <em>bla</em>_LEN27) were identified from chromosomal and plasmid pKLZT-1, respectively. Gene-based analysis of the resistance genes of plasmid pKLZT-1 showed that the tigecycline resistance gene cluster-carrying region was flanked by <em>umuC</em> and <em>umuD</em> (<em>umuD</em>-<em>hps</em>-<em>IS5</em>-<em>tmexC2-tmexD2-toprJ2</em>-<em>umuC</em>), as well as other resistance genes and virulence factors (<em>ureB, ureC</em>, and <em>ureG</em>), which were carried by <em>IS5075</em>-<em>Tn3-intI1 -aac(6′)-Ib-cr-bla</em>_OXA-1<em>-catB3-arr-3-bla</em>_LEN27<em>-Tn3-ISkpn26-ureBCG-IS5075</em>.</p></div><div><h3>Conclusions</h3><p>WGS has revealed that a multidrug-resistant strain, HvKP KLZT, belonging to ST29 with capsular serotype K212, contains a multidrug-resistance plasmid.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 349-353"},"PeriodicalIF":3.7,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S221371652400122X/pdfft?md5=4ff437c688ce99f06347d0313582ae8a&pid=1-s2.0-S221371652400122X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141603754","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":"Insertion with long target duplication in polymyxin B-induced resistant mutant of Salmonella","authors":"Tongtong Zhang ,&nbsp;Huifen Jiang ,&nbsp;Ying Zhao ,&nbsp;Tingting Yao ,&nbsp;Rui Li","doi":"10.1016/j.jgar.2024.07.002","DOIUrl":"10.1016/j.jgar.2024.07.002","url":null,"abstract":"<div><h3>Objectives</h3><p>A <em>Salmonella enterica</em> subsp. <em>diarizonae</em> (hereafter <em>S. diarizonae</em>) clinical strain S499 demonstrated unique genomic features. The strain S499 was treated with polymyxin B in vitro to investigate the mechanism of resistance.</p></div><div><h3>Methods</h3><p>S499 was treated with polymyxin B by increasing concentration gradually to obtain a resistant mutant S499V. Whole genomes of the two strains were sequenced using Illumina HiSeq X<strong>-</strong>10 and PacBio RS II platforms. Reverse transcription–quantitative polymerase chain reaction (RT-qPCR) was performed to compare the gene expression.</p></div><div><h3>Results</h3><p>The chromosome of strain S499 contained a 40-kb DNA region that was replicated after treatment with polymyxin B and generated a triple tandem DNA repeat region in the chromosome of mutant strain S499V. This repeat region in S499V was flanked by IS<em>1</em> and contained <em>pmrD, pmrG</em>, and <em>arnBCADTEF</em> operon<em>.</em> In comparison to the homologous 40-kb DNA region of strain S499, a few genes in the repeat DNA region of strain S499V contained truncating mutations that generate two open reading frames (ORFs). The expression of <em>pmrD, pmrG</em>, and <em>arnT</em> was significantly upregulated in S499V.</p></div><div><h3>Conclusion</h3><p>The duplication and overexpression of <em>pmrD, pmrG</em>, and <em>arnT</em> operon may be responsible for the polymyxin B resistance of mutant strain S499V.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 231-235"},"PeriodicalIF":3.7,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001334/pdfft?md5=b614bd4747185be867b00655dbb4f751&pid=1-s2.0-S2213716524001334-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141620160","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}