Journal of global antimicrobial resistance最新文献

{"title":"Coexistence of blaMIR-1 and blaNDM-1 resistance genes with a novel ST type in Enterobacter roggenkampii from a stool sample: A genome sequencing study","authors":"Qin Wang ,&nbsp;Sayyed Salman ,&nbsp;Ye Luo ,&nbsp;XiaoMei Tong","doi":"10.1016/j.jgar.2024.11.006","DOIUrl":"10.1016/j.jgar.2024.11.006","url":null,"abstract":"<div><h3>Objective</h3><div>The <em>Enterobacter cloacae</em> complex, known for causing infections in hospitalised patients, displays resistance to β-lactam antibiotics due to AmpC β-lactamase expression. This study emphasises the genome sequence of <em>Enterobacter roggenkampii</em>, which coexists with MIR-1 and NDM-1 genes, isolated from the stool of a hospitalised patient in China.</div></div><div><h3>Methods</h3><div>A faecal sample was diluted in Luria-Bertani broth and incubated overnight. Cultures were then spread on MacConkey agar containing meropenem and incubated for 18–24 h to select carbapenem-resistant Enterobacteriaceae. Individual colonies were isolated, and bacterial species were identified using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and 16S rRNA gene sequencing. Genomic DNA was extracted and sequenced via Illumina and Oxford Nanopore sequencing.</div></div><div><h3>Results</h3><div>Genomic analysis of <em>E. roggenkampii</em> L3897 revealed a 4 897 636 bp genome with 55.9% GC content and confirmed its classification as <em>E. roggenkampii</em> through average nucleotide identity-based analysis. A new sequence type distinct from ST2392, ST3014, with a unique <em>rplB</em> genotype was identified. Additionally, the genome harbours three antibiotic resistance genes and a newly discovered plasmid, pL3897_NDM, highlighting the need for surveillance of drug-resistant pathogens.</div></div><div><h3>Conclusions</h3><div>The discovery of a new sequence type and the presence of an antibiotic resistance gene in <em>E. roggenkampii</em> L3897 underscores the need for ongoing genomic surveillance to effectively manage multidrug-resistant pathogens.</div></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"40 ","pages":"Pages 37-41"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142780368","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":"Association between the rifampicin resistance mutations and rifabutin susceptibility in Mycobacterium tuberculosis: A meta-analysis","authors":"Wenli Wang,&nbsp;Hongjuan Zhou,&nbsp;Long Cai,&nbsp;Tingting Yang","doi":"10.1016/j.jgar.2024.11.014","DOIUrl":"10.1016/j.jgar.2024.11.014","url":null,"abstract":"<div><h3>Objective</h3><div>Certain rifampicin-resistant <em>Mycobacterium tuberculosis</em> (MTB) strains are susceptible to rifabutin (RFB) and may be amenable to RFB treatment. We performed a meta-analysis of available cross-sectional studies to determine the rifampicin (RIF) resistance mutations associated with RFB susceptibility.</div></div><div><h3>Methods</h3><div>We identified studies through PubMed, Web of Science, Embase, and the Cochrane Library up to September 30, 2024. Studies that investigated RpoB mutations and reported phenotypic drug susceptibility to RIF and RFB met our criteria. The relationship between RIF-resistance mutations to RFB-susceptibility was evaluated using odds ratios (OR).</div></div><div><h3>Results</h3><div>Twenty-seven studies comprised 9222 clinical RIF-resistant MTB strains from 25 countries met the inclusion criteria. Of these strains, 14.93% (1377/9222) were susceptible to RFB. We found that 14 RIF-resistance mutations were associated with susceptibility to RFB. Among these, nine had high confidence (OR&gt;10) in predicting RFB susceptibility: RpoB D435V, H445L, D435Y, D435F, S441L, L430P, H445G, S441Q, L430R. Among the strains carrying these mutations, 59.04% (702/1189) were susceptible to RFB. The ratio increased to 83.45% in studies following CLSI guidelines. The minimum inhibition concentrations (MICs) of these mutations revealed that they had low MIC to RFB and exhibited a lack of correlation between MICs for RIF and RFB. L452P, I491F, H445C, H445N, and D435G exhibited moderate confidence (5&lt;OR≤10) in predicting susceptibility to RFB. S450L and S450W were associated with RFB-resistance (OR&lt;1).</div></div><div><h3>Conclusions</h3><div>These results provide a theoretical basis for the molecular detection of RFB-susceptible tuberculosis and alternative treatment with RFB in patients with multidrug-resistant/rifampicin-resistant tuberculosis.</div></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"40 ","pages":"Pages 53-61"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142769675","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":"Genomic insights into a clinical Salmonella Typhimurium isolate carrying plasmid-mediated blaNDM-5","authors":"Fan Huang ,&nbsp;Genglin Guo ,&nbsp;Lu Feng ,&nbsp;Tongbo Cai ,&nbsp;Xu Huang","doi":"10.1016/j.jgar.2024.11.009","DOIUrl":"10.1016/j.jgar.2024.11.009","url":null,"abstract":"<div><h3>Objective</h3><div>Highly carbapenem-resistant <em>Salmonella</em> has emerged worldwide in recent years and is largely associated with the multiform transmission of resistance genes, which poses a huge challenge in clinical practice. Our study delves into the resistance mechanisms and epidemiology of <em>bla</em>_NDM-carrying plasmids.</div></div><div><h3>Methods</h3><div>Whole-genome sequencing was utilised to analyse the molecular characteristics and antimicrobial resistance mechanisms of <em>Salmonella</em> isolates recovered from the faeces of a paediatric patient at the Children's Hospital of Nanjing Medical University. Moreover, we conducted an epidemiologic analysis and focused on studying the mechanisms of plasmid-mediated <em>bla</em>_NDM transmission, incorporating genomes deposited in the NCBI Pathogen Detection database.</div></div><div><h3>Results</h3><div>The clinical isolate 23S9 belonged to serovar Typhimurium, antigenic profile 4:i:-, ST34, and carried pNDM_23S9 harbouring several antimicrobial resistance genes, including aac(6′)-Ib-cr6, OXA-1, catB3, arr-3, qacEdeltal and <em>bla</em>_NDM. Comparative analysis revealed that <em>bla</em>_NDM-5 can exist in different plasmids of different isolates, proving its transmission through plasmids. Furthermore, <em>bla</em>_NDM-carrying isolates are mostly resistant to beta-lactams, aminoglycosides, sulphonamide, macrolides, and trimethoprim.</div></div><div><h3>Conclusions</h3><div>These findings provided thorough and intuitive insights into the intercontinental spread of <em>bla</em>_NDM-carrying <em>Salmonella</em>. Ongoing surveillance is essential for effectively monitoring the worldwide dissemination of this high-risk carbapenem-resistant <em>Salmonella</em>.</div></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"40 ","pages":"Pages 90-95"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142780375","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":"First detection of the high‐risk Klebsiella pneumoniae ST147 clone producing NDM‐14 in a community setting in Morocco: A new public health concern","authors":"Aboubakr Khazaz ,&nbsp;Fatima El Otmani ,&nbsp;Ihssane Benzaarate ,&nbsp;Adil El Hamouchi ,&nbsp;Fatna Bourjilat ,&nbsp;Sylvain Brisse ,&nbsp;Kaotar Nayme","doi":"10.1016/j.jgar.2024.11.010","DOIUrl":"10.1016/j.jgar.2024.11.010","url":null,"abstract":"","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"40 ","pages":"Pages 96-97"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142755111","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":"Genomic characterization of Achromobacter genogroup 20 and identification of a potential species-specific marker","authors":"Mariana Papalia ,&nbsp;Rocio Stucchi ,&nbsp;Valeria Alexander ,&nbsp;Liliana Clara ,&nbsp;Mariángeles Visus ,&nbsp;Gabriel Gutkind ,&nbsp;Marcela Radice","doi":"10.1016/j.jgar.2024.11.012","DOIUrl":"10.1016/j.jgar.2024.11.012","url":null,"abstract":"<div><h3>Objective</h3><div>To describe the genome of <em>Achromobacter</em> genogroup 20 and explore the presence of resistance determinants.</div></div><div><h3>Methods</h3><div>Isolate 413638 was identified through <em>nrd</em>A and MLST analysis. Antimicrobial susceptibility testing was performed according CLSI 2024. NGS was conducted using Illumina MiSeq, on the NextSeq500 platform with 150 bp paired-end reads, and de novo assembly was assessed using Unicycler (Galaxy). Coding sequences were predicted and confirmed with RAST and BLAST, and resistance determinants were evaluated using Resfinder and manual curation. All <em>Achromobacter</em> spp. genomes were obtained from NCBI, and the presence of <em>bla</em>_OXA was investigated. Average nucleotide identity (ANI) and tetranucleotide analysis (TETRA) were calculated. Phylogenetic analysis of the new OXA variant was conducted against other species-specific markers in <em>Achromobacter</em>.</div></div><div><h3>Results</h3><div>Isolate 413638 was identified as <em>Achromobacter</em> genogroup 20 ST365, showing resistance to third- and fourth-generation cephalosporins, aminoglycosides, and fluoroquinolones. The genome included coding sequences for three putative β-lactamases (one new OXA type-class D β -lactamase and two new class C), 32 efflux pump proteins, two aminoglycoside-modifying enzymes and a dihydropteroate synthase; also, substitutions in <em>par</em>C and <em>par</em>E were detected. The OXA enzyme, designated OXA-1238 (PP446293), differs from OXA-114a by 85 amino acids, with 69% identity. In silico analysis found OXA-1238 variants in three additional <em>Achromobacter</em> spp. genomes, with 97% identity. Based on ANI and tetra analysis, the three genomes corresponded to <em>Achromobacter</em> genogroup 20.</div></div><div><h3>Conclusion</h3><div>Several resistance markers were found, probably contributing to the resistance profile observed in <em>Achromobacter</em> genogroup 20 ST365. The new OXA variant identified, OXA-1238, could constitute a useful molecular marker for species identification.</div></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"40 ","pages":"Pages 26-28"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142755116","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":"Pharmacokinetic/pharmacodynamic analysis of tedizolid phosphate against Staphylococcus aureus and Streptococcus pneumoniae in children, adolescents, and adults by Monte Carlo simulation","authors":"Xiao-Chen Wei ,&nbsp;Ming-Feng Zhao ,&nbsp;Hai-Rong Lv ,&nbsp;Xia Xiao","doi":"10.1016/j.jgar.2024.11.011","DOIUrl":"10.1016/j.jgar.2024.11.011","url":null,"abstract":"<div><h3>Objective</h3><div>The objective of this study was to investigate the cumulative fraction of response of various dosage regimens of tedizolid phosphate against <em>Staphylococcus aureus</em> and <em>Streptococcus pneumoniae</em> in children, adolescents, and adults.</div></div><div><h3>Methods</h3><div>Monte Carlo simulations were performed using previously published pharmacokinetic parameters and pharmacodynamic data to evaluate the efficacy of the simulated dosage strategies in terms of area under the concentration-time curve/minimum inhibitory concentration targets of tedizolid.</div></div><div><h3>Results</h3><div>According to the results of the Monte Carlo simulations, currently approved dosage regimens of tedizolid phosphate were effective in the treatment of acute bacterial skin and skin structure infections (ABSSSIs) caused by methicillin-susceptible <em>S. aureus</em> and methicillin-resistant <em>S. aureus</em> (MRSA) including vancomycin-intermediate, heterogeneous vancomycin-intermediate, and daptomycin-non-susceptible MRSA in adult and paediatric patients aged 12 y and older. High-dose regimens of tedizolid phosphate should be the preferred option to optimize efficacy against ABSSSIs caused by linezolid-resistant MRSA, particularly chloramphenicol-florfenicol resistance-mediated isolates. The dosage regimens of 3 and 4 mg/kg/d of tedizolid phosphate were appropriate to treat ABSSSIs caused by methicillin-susceptible <em>S. aureus</em> and MRSA in children aged 2–6 and 6–12 y, respectively. Approved dosage regimens of tedizolid phosphate for patients older than 12 y may be sufficient against <em>S. pneumoniae</em> pneumonia but insufficient for <em>S. aureus</em> pneumonia. For neutropenic patients, almost all the simulated regimens of tedizolid phosphate were ineffective against <em>S. aureus</em> and <em>S. pneumoniae</em>.</div></div><div><h3>Conclusions</h3><div>These pharmacokinetics/pharmacodynamics-based simulations rationalize and optimize the dosage regimens of tedizolid phosphate against <em>S. aureus</em> and <em>S. pneumoniae</em> in children, adolescents, and adults.</div></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"40 ","pages":"Pages 15-25"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142755132","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":"ISAC news and updates","authors":"","doi":"10.1016/j.jgar.2025.01.004","DOIUrl":"10.1016/j.jgar.2025.01.004","url":null,"abstract":"","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"40 ","pages":"Pages 100-101"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143006608","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 of oral Neisseria from men on HIV pre-exposure prophylaxis in Hanoi, Vietnam","authors":"Huan Vinh Dong ,&nbsp;Paul Adamson ,&nbsp;Dieu Hoa Pham ,&nbsp;Quynh Hoa Pham ,&nbsp;Hai Ha Long Le ,&nbsp;Loc Quang Pham ,&nbsp;Hao Thi Minh Bui ,&nbsp;Giang Minh Le ,&nbsp;Jeffrey D. Klausner","doi":"10.1016/j.jgar.2024.11.008","DOIUrl":"10.1016/j.jgar.2024.11.008","url":null,"abstract":"<div><h3>Background</h3><div>Antimicrobial resistance (AMR) in <em>Neisseria gonorrhoeae</em> (<em>N. gonorrhoeae</em>) is an urgent global health concern. Commensal <em>Neisseria</em> species in the oropharynx are an important reservoir of AMR genes that are transferred to <em>N. gonorrhoeae</em>, yet few data about AMR among commensal <em>Neisseria</em> in populations at risk for AMR exist.</div></div><div><h3>Methods</h3><div>From May 2022 to December 2023, men in an HIV pre-exposure prophylaxis program in Hanoi, Vietnam, were recruited for this study. Participants self-collected oral specimens using phosphate buffer solution, for culture on LB agar media containing sucrose, vancomycin, and trimethoprim (LBVT.SNR). Oxidase-positive Gram-negative diplococci were identified using the Remel RapID NH system. Minimum inhibitory concentrations (MICs) to azithromycin, ceftriaxone, cefixime, and doxycycline were determined using Etests.</div></div><div><h3>Results</h3><div>There were 42 male participants, the median age was 26 years and 29% (<em>n</em> = 12) reported using antibiotics in the past 6 months. In total, 48 <em>Neisseria</em> isolates were recovered; <em>N. sicca/subflava</em> was the most common species (50%; <em>n</em> = 24), followed by <em>N. mucosa</em> (38%; <em>n</em> = 18). For azithromycin, 85% (<em>n</em> = 41) of isolates were resistant with MICs ≥ 1 ug/mL, including 25% (<em>n</em> = 12) with high-level resistance (MICs ≥ 256 ug/mL of which 67% (8/12) were <em>N. mucosa</em>. Among non-gonococcal <em>Neisseria</em> isolates, the prevalence of resistance was 6% (<em>n</em> = 3) for ceftriaxone, 6% (<em>n</em> = 3) for cefixime, and 54% (<em>n</em> = 26) for doxycycline; the most non-susceptible isolates were <em>N. mucosa.</em></div></div><div><h3>Conclusions</h3><div>A High frequency of azithromycin resistance, moderate doxycycline resistance, and low cephalosporin resistance was found in oropharyngeal <em>Neisseria</em> isolates from men who have sex with men (MSM) in a pre-exposure prophylaxis (PrEP) program in Hanoi, Vietnam. <em>N. mucosa</em> was over-represented among resistant isolates.</div></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"40 ","pages":"Pages 11-14"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142755142","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 an NDM-2-producing Acinetobacter baumannii ST103 clone resulting in an outbreak in an intensive care unit of a Lebanese tertiary care hospital","authors":"Tania Nawfal Dagher ,&nbsp;Linda Hadjadj ,&nbsp;Fadi Bittar ,&nbsp;Fadi Fenianos ,&nbsp;Elias Abdo ,&nbsp;Jean-Marc Rolain ,&nbsp;Charbel Al-Bayssari","doi":"10.1016/j.jgar.2024.11.016","DOIUrl":"10.1016/j.jgar.2024.11.016","url":null,"abstract":"<div><h3>Objective</h3><div>Multidrug-resistant bacteria, including carbapenem-resistant <em>Acinetobacter baumannii</em> (CRAB), are considered a major public health threat, particularly those which are responsible for nosocomial infections. This study aimed to investigate the molecular mechanism of carbapenem resistance and the clonal relationship of CRAB isolates of a probable outbreak in the intensive care unit (ICU) of Saydet Zgharta University Medical Center, in north Lebanon.</div></div><div><h3>Methods</h3><div>Thirty-two non-duplicate CRAB isolates were collected from patients hospitalised in the ICU. Antibiotic susceptibility testing was carried out using the disk diffusion method and carbapenemase-encoding genes were searched for using standard polymerase chain reaction. Epidemiological relatedness was studied using multilocus sequence typing.</div></div><div><h3>Results</h3><div>Polymerase chain reaction and multilocus sequence typing results suggested the presence of two different periods: period 1 (November 2018 to February 2019), where 15 CRAB isolates were collected harbouring the <em>bla</em>_OXA-23 and <em>bla</em>_OXA-24 genes mainly and belonging to several clones; and period 2 (March to May 2019), considered an outbreak period where 17 carbapenem-resistant isolates were isolated, harbouring mostly the <em>bla</em>_NDM-2 gene, never previously described in Lebanon and belonging to ST103. Infection control measures implemented in Saydet Zgharta University Medical Center successfully eradicated the NDM-2-producing CRAB ST103 clone, thus putting an end to this outbreak in the ICU department.</div></div><div><h3>Conclusions</h3><div>This study showed that infection control measures and adequate identification of NDM-producing <em>A. baumannii</em> remain a powerful tool to limit the spread of such resistant micro-organisms.</div></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"40 ","pages":"Pages 66-71"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142780367","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":"Molecular characterization of ST15 carbapenem-resistant Klebsiella pneumoniae isolated in a single patient","authors":"Yongjin Hu ,&nbsp;Rong Tang ,&nbsp;Shanshan Jin ,&nbsp;Jiahao Guan ,&nbsp;Xiaoxiao Meng ,&nbsp;Zengpeijie Dan ,&nbsp;Ruilan Wang ,&nbsp;Hong-Yu Ou ,&nbsp;Jian Lu","doi":"10.1016/j.jgar.2024.11.003","DOIUrl":"10.1016/j.jgar.2024.11.003","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Background&lt;/h3&gt;&lt;div&gt;The carbapenem-resistant &lt;em&gt;Klebsiella pneumoniae&lt;/em&gt; (CRKP) poses a serious threat to antibiotic applicability and public health. During treatment, &lt;em&gt;K. pneumoniae&lt;/em&gt; (KP) frequently exhibits shifts in drug-resistant phenotypes, complicating clinical treatment as it transitions from sensitivity to resistance. In this study, we analysed the clinical and molecular characteristics of drug resistance changes in KP strains isolated from a single patient, and the potential mechanisms underlying these resistance changes.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Methods&lt;/h3&gt;&lt;div&gt;Antimicrobial susceptibility test and string test were conducted to evaluate the resistant and virulent characterization of the strains. Pulsed-field gel electrophoresis (PFGE) was used to investigate the homology relationship between the strains. The whole genome sequencing and phylogenetic analysis of 9 representative isolates was also performed. The transfer ability of the drug-resistant plasmid was studied by plasmid conjugation experiment. The transconjugants were verified by polymerase chain reaction amplification of specific genes, antimicrobial susceptibility test and PFGE.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;Our results revealed that 9 KP strains, isolated from the same patient, exhibited ‘resistance-sensitivity-resistance-sensitivity’ alternately to carbapenems. The differences in DNA fingerprint bands among the nine KP isolates were ≤3, which can be classified as the same PFGE type. Phylogenetic analysis showed that these 9 strains constituted a distinct branch within the phylogenetic tree. All nine KP strains belonged to the ST15-KL19 clone. Six of the strains were classified as CRKP, all of which carried 11 drug resistance genes: &lt;em&gt;oqxB, oqxA, fosA6, aac(3)-lld, bla&lt;/em&gt;&lt;sub&gt;SHV-28&lt;/sub&gt;, &lt;em&gt;bla&lt;/em&gt;&lt;sub&gt;KPC-2&lt;/sub&gt;, &lt;em&gt;bla&lt;/em&gt;&lt;sub&gt;OXA-1&lt;/sub&gt;, &lt;em&gt;mph(A), tet(A), catB3&lt;/em&gt; and &lt;em&gt;aac(6′)-lb-cr&lt;/em&gt;, mediating drug resistance to quinolones, fosfomycin, aminoglycosides, β-lactam, carbapenems, macrolides and chloramphenicol, belonging to multi-drug resistant bacteria. The carbapenem-resistant plasmid p2-KP3762–1 was found to transfer within species, from CRKP to hypervirulent KPRJF293HA, carbapenem-sensitive KP KP3657 and &lt;em&gt;Escherichia coli&lt;/em&gt; C600 at a frequency of (1.19 ± 1.58) ×10&lt;sup&gt;−6&lt;/sup&gt;, (1.09 ± 1.38) ×10&lt;sup&gt;−7&lt;/sup&gt; and (10.9 ± 9.53) ×10&lt;sup&gt;−6&lt;/sup&gt; respectively, resulting in the dissemination of carbapenem resistance genes.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Conclusions&lt;/h3&gt;&lt;div&gt;In this study, KP strains isolated from a single patient exhibited an alternating phenotype of resistant-sensitive-resistant-sensitive to carbapenems. The 9 KP isolates share a high degree of genetic similarity. The plasmid p2-KP3762–1, harbouring the carbapenem resistance gene &lt;em&gt;bla&lt;/em&gt;&lt;sub&gt;KPC-2&lt;/sub&gt;, may undergo inter-strain and inter-clone transfer via conjugation in the patient during treatment. Furthermore, our findings suggest that the pathogens in this pati","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"40 ","pages":"Pages 72-80"},"PeriodicalIF":3.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142780323","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}