{"title":"KSA-1,一种天然存在于肠道细菌 Kosakonia sacchari 中的 Ambler A 类广谱 β-内酰胺酶。","authors":"","doi":"10.1016/j.jgar.2024.07.008","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><p>Several bacterial species belonging to the <em>Gammaproteobacteria</em> possess intrinsic class A β-lactamase genes that may represent a source of further dissemination and acquisition to other Gram-negative species. Here we characterised KSA-1 class A β-lactamase, the gene of which was identified within the chromosome of an environmental Enterobacterales species, namely <em>Kosakonia sacchari</em>, which was also recently identified as the progenitor of an MCR-like colistin-resistance determinant.</p></div><div><h3>Methods</h3><p>In silico analysis using the GenBank database identified a class A β-lactamase gene within the chromosome of <em>K. sacchari</em> SP1 (GenBank accession no. WP_017456759). The corresponding protein KSA-1 shared 63% amino acid identity with the intrinsic CKO-1 from <em>Citrobacter koseri</em> and 53% with TEM-1. Using the <em>K. sacchari</em> DSM 100203 reference strain as a template, <em>bla</em><sub>KSA-1</sub> was amplified, cloned into the plasmid pUCp24 and expressed in <em>Escherchia coli</em> TOP10. Minimal inhibitory concentrations and kinetic parameters were obtained from the purified enzyme.</p></div><div><h3>Results</h3><p><em>K. sacchari</em> strain SP1 conferred resistance to amino-, carboxy- and ureido-penicillins only. Once produced within <em>E. coli</em>, KSA-1 showed a typical clavulanic acid-inhibited extended spectrum β-lactamase associated with a peculiar temocillin resistance profile. Kinetic assays were performed using a purified extract of KSA-1 and demonstrated a high hydrolysis rate for benzylpenicillin and piperacillin, as well as weakly extended spectrum cephalosporins. Determination of inhibitory constants showed 50% inhibitory concentration values of 2.2, 3 and 1.8 nM for clavulanic acid, tazobactam and avibactam, respectively. Analysis of sequences surrounding the <em>bla</em><sub>KSA-1</sub> gene did not reveal any mobile element that could have been involved in the acquisition of this β-lactamase gene in that species.</p></div><div><h3>Conclusion</h3><p>KSA-1 is a class A extended spectrum β-lactamase distantly related to known extended spectrum or broad-spectrum Ambler class A β-lactamases, which is highly resistant to temocillin. The <em>bla</em><sub>KSA-1</sub> gene could be considered as intrinsic within the species.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001413/pdfft?md5=392f7b968cc0284a79adaa986b33316d&pid=1-s2.0-S2213716524001413-main.pdf","citationCount":"0","resultStr":"{\"title\":\"KSA-1, a naturally occurring Ambler class A extended spectrum β-lactamase from the enterobacterial species Kosakonia sacchari\",\"authors\":\"\",\"doi\":\"10.1016/j.jgar.2024.07.008\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><h3>Background</h3><p>Several bacterial species belonging to the <em>Gammaproteobacteria</em> possess intrinsic class A β-lactamase genes that may represent a source of further dissemination and acquisition to other Gram-negative species. Here we characterised KSA-1 class A β-lactamase, the gene of which was identified within the chromosome of an environmental Enterobacterales species, namely <em>Kosakonia sacchari</em>, which was also recently identified as the progenitor of an MCR-like colistin-resistance determinant.</p></div><div><h3>Methods</h3><p>In silico analysis using the GenBank database identified a class A β-lactamase gene within the chromosome of <em>K. sacchari</em> SP1 (GenBank accession no. WP_017456759). The corresponding protein KSA-1 shared 63% amino acid identity with the intrinsic CKO-1 from <em>Citrobacter koseri</em> and 53% with TEM-1. Using the <em>K. sacchari</em> DSM 100203 reference strain as a template, <em>bla</em><sub>KSA-1</sub> was amplified, cloned into the plasmid pUCp24 and expressed in <em>Escherchia coli</em> TOP10. Minimal inhibitory concentrations and kinetic parameters were obtained from the purified enzyme.</p></div><div><h3>Results</h3><p><em>K. sacchari</em> strain SP1 conferred resistance to amino-, carboxy- and ureido-penicillins only. Once produced within <em>E. coli</em>, KSA-1 showed a typical clavulanic acid-inhibited extended spectrum β-lactamase associated with a peculiar temocillin resistance profile. Kinetic assays were performed using a purified extract of KSA-1 and demonstrated a high hydrolysis rate for benzylpenicillin and piperacillin, as well as weakly extended spectrum cephalosporins. Determination of inhibitory constants showed 50% inhibitory concentration values of 2.2, 3 and 1.8 nM for clavulanic acid, tazobactam and avibactam, respectively. Analysis of sequences surrounding the <em>bla</em><sub>KSA-1</sub> gene did not reveal any mobile element that could have been involved in the acquisition of this β-lactamase gene in that species.</p></div><div><h3>Conclusion</h3><p>KSA-1 is a class A extended spectrum β-lactamase distantly related to known extended spectrum or broad-spectrum Ambler class A β-lactamases, which is highly resistant to temocillin. The <em>bla</em><sub>KSA-1</sub> gene could be considered as intrinsic within the species.</p></div>\",\"PeriodicalId\":15936,\"journal\":{\"name\":\"Journal of global antimicrobial resistance\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.7000,\"publicationDate\":\"2024-08-13\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S2213716524001413/pdfft?md5=392f7b968cc0284a79adaa986b33316d&pid=1-s2.0-S2213716524001413-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of global antimicrobial resistance\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2213716524001413\",\"RegionNum\":3,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"INFECTIOUS DISEASES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of global antimicrobial resistance","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2213716524001413","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"INFECTIOUS DISEASES","Score":null,"Total":0}
KSA-1, a naturally occurring Ambler class A extended spectrum β-lactamase from the enterobacterial species Kosakonia sacchari
Background
Several bacterial species belonging to the Gammaproteobacteria possess intrinsic class A β-lactamase genes that may represent a source of further dissemination and acquisition to other Gram-negative species. Here we characterised KSA-1 class A β-lactamase, the gene of which was identified within the chromosome of an environmental Enterobacterales species, namely Kosakonia sacchari, which was also recently identified as the progenitor of an MCR-like colistin-resistance determinant.
Methods
In silico analysis using the GenBank database identified a class A β-lactamase gene within the chromosome of K. sacchari SP1 (GenBank accession no. WP_017456759). The corresponding protein KSA-1 shared 63% amino acid identity with the intrinsic CKO-1 from Citrobacter koseri and 53% with TEM-1. Using the K. sacchari DSM 100203 reference strain as a template, blaKSA-1 was amplified, cloned into the plasmid pUCp24 and expressed in Escherchia coli TOP10. Minimal inhibitory concentrations and kinetic parameters were obtained from the purified enzyme.
Results
K. sacchari strain SP1 conferred resistance to amino-, carboxy- and ureido-penicillins only. Once produced within E. coli, KSA-1 showed a typical clavulanic acid-inhibited extended spectrum β-lactamase associated with a peculiar temocillin resistance profile. Kinetic assays were performed using a purified extract of KSA-1 and demonstrated a high hydrolysis rate for benzylpenicillin and piperacillin, as well as weakly extended spectrum cephalosporins. Determination of inhibitory constants showed 50% inhibitory concentration values of 2.2, 3 and 1.8 nM for clavulanic acid, tazobactam and avibactam, respectively. Analysis of sequences surrounding the blaKSA-1 gene did not reveal any mobile element that could have been involved in the acquisition of this β-lactamase gene in that species.
Conclusion
KSA-1 is a class A extended spectrum β-lactamase distantly related to known extended spectrum or broad-spectrum Ambler class A β-lactamases, which is highly resistant to temocillin. The blaKSA-1 gene could be considered as intrinsic within the species.
期刊介绍:
The Journal of Global Antimicrobial Resistance (JGAR) is a quarterly online journal run by an international Editorial Board that focuses on the global spread of antibiotic-resistant microbes.
JGAR is a dedicated journal for all professionals working in research, health care, the environment and animal infection control, aiming to track the resistance threat worldwide and provides a single voice devoted to antimicrobial resistance (AMR).
Featuring peer-reviewed and up to date research articles, reviews, short notes and hot topics JGAR covers the key topics related to antibacterial, antiviral, antifungal and antiparasitic resistance.