CINXE.COM

<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="120"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "www.microbiologyresearch.org",cType: 'non-interactive',cRay: '917ca17eecbdfdbc',cH: 'cywQ9VEmYoE5YwpEkfQ6PqJ6t8pT5ahqXa6vO9Qhs3U-1740538260-1.2.1.1-.oMLQPlBcouhooSTraXBthkn4.6S.FloxuwAjvQYx6dPVXio0q7U4725lxsti93F',cUPMDTk: "\/content\/journal\/jgv\/10.1099\/0022-1317-76-8-1909?__cf_chl_tk=GqpIR9oYUQxxAfzc6i5mRRh53z9pgGeh8NuNSfeFQy0-1740538260-1.0.1.1-asqacLiCgIOILSdgIJNaTw8ymAla7H2.DgCNgeyQ9zs",cFPWv: 'b',cITimeS: '1740538260',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/content\/journal\/jgv\/10.1099\/0022-1317-76-8-1909?__cf_chl_f_tk=GqpIR9oYUQxxAfzc6i5mRRh53z9pgGeh8NuNSfeFQy0-1740538260-1.0.1.1-asqacLiCgIOILSdgIJNaTw8ymAla7H2.DgCNgeyQ9zs",md: "T.Kykqu7XuGJLK305rIHNDYoA0an01B_DG.I7DkuJSo-1740538260-1.2.1.1-GYE.RY018y4WjZ7C3V8x7aHpA9GkT35rlqTfnKUBeO07QheHlVKMuYJB56NjaQvTLfWcOzjN3AITC_at5o5.iP.J5NWQmvgrZ5TZGM3ZBjUo1Y1g9C71GhmdAP.SxPWskV9.LaF50E87L4JGVbqc7sc82a7Leeagm.U2TW2JseXYjT66qL__2pNjYnN4HBuYLwSqcTzLcqNafKI6O6SAESVBbFlq_68de1vVG6OZewEH.zbJ_ab9hZWssn4utwby_T3_f3cJejqkqzPvZRoSy1R4fQ3u.MkIjlBnB.KsG00l6Bi2PmeX7sHz_JEARqJwvM_1GEmyNPzVZMkE1uxMMNCUW2T1jkR8BFOfKLcx6Qz0l6ABb5gVcs2t5LFEhJUNdwLHYwqfz3JagIMu.clbi9omrMlyBk0KExI1rzqqxrJ6WM.45GCWC5fqVCqQx.VBGqV4t66S.sChD3OTBp1Rlsb5JTVbDsjP2IPRRRtlm5Gj6TfzSNcJ7kyySZZEIM.RwHQhz8llu3T9v9Ut_prBha8TgjOGZrduNerfrDs2.PvumE8knjiBeH5JZ_22bSeTjJZGvd4wZ8pgBs8dJUB9UqEWIwwe2AMIdM2qCbXj1g2p4QxjVyMZR3WSiZIZraYDKtm8bUZXGMLIAGlYgGmP4KsvOVNfBkCw5ekxsPquB2S7d5pCIVJmMWn5wZp2bXU1_ymbKuCjzrJB80Gi3IcibTIIBTvePiVGYzTG0zAvzbQwYTB2wBUZn7eaeV.rbTfpDtM_lusAkKiaYAO7uRqvt7W3mHvtDDY1y.cgNPtt7_9sENZvI8fysjfk0BYAyk8T9NaHE1YgQ5csEA6_6y5qMAM3t4ZCA05aySLc7qJJePIo_mxs6ppfOByKVy6CnBYSwpEcwVXnVN6qOSVrKYnHAZNtmVG_KMuK.fGlS.kH2CuslKDQUmKUZemAPIRkcv6pGedOBD4XwVC3OUfow7LP0OSf2gVfW1hBmkm75GGhEX_pdVnMHO1QFbTO0NSALcwmSEkqb0gffG6qqns9DX1KhBT34S3a1.Xsk5zMZAhqciCg1TftVtSLssDsbyxq02myuvtQeioVcylRVUivR3aYZHSxpXnbMpNwQPVnmO2uzrNFUiL2fL7QWfxgZspuhhgv6SB2CnyAfkmBEtEtxBPgE5rlJzeodvZSWzAE9U_SGV5x5na7QGw930QLA7FB1vCxT1bsIubhjGGeVoO1.xBnlFJQ7vUNbmQjvpLkJGMMHYRFG5C7.jr6SObLjrH1J0QI353wK2_ASrTQ.Afi3IY0Lxc31Ln9BrN6rreDUG_BSJGEUzzvxlMfwcsWOEf.et_BUK26JwyjfxnBw5G9NgNr5XL78CgeOrSLajblC7khKa.LTfjmtVglAix85SINx4f5YpZs_ZBYUi0ERFsoqWPJv1cXRGYD3xh4Wpnlc.sv.cZI6jjsqMa7rgaxlwnt96HJt8MdVilRcaqnEp1meXUMOMW5Cb41g570qADvb40PPzHT7WmzsIjsNO411kxjX9U5vBP68K3BYykwUGOYwjxssv8kp8dEJTxkTUnTcYvOSh.uDCw3D5dfPjdViXotWpp33BB3VFen.7VcwwZMWJu1TlLIjkUiFv_qxShJjyDLnA8ndmAwPoE.noRS9e8W0hLd94IGy2U89Gh09CXJFa0DIdscKtsk6os1Ehz3MtVlrjDh.WeWoqCHNzG.sJaFXkgxx1tcAKu.wqDiE.Ri7wbbeNlKK8hzWmm3d0TfoV2veUUlmfE7M9qcSRzYCalQ_yljonzqMvXXiV2ttu.DUUGxVC8AfMebZR17bF5Ot7YyO7o24K5vP6xF0Lc9KK6Rs9SzWu26_ZYJJJ4KfdDqDxyMyQ",mdrd: "xTVnx5WI7zjAMTwDdGB3n7RMNBKxHubgFqYkvjN.Rz4-1740538260-1.2.1.1-cPos1kIkoBO9IyIvNaMLWlxzONj1NEudqPlE7BGszIKSf0EREps4FEpQYoLc3TGkKfQuLJiFY3.G_vQAOtey_780bmnmmcIouNwDUiKb2r8sLD75Ao2n1CTZn_EHLGi8SgurXMvvOFZ7s2FTswcB_aCufpE.2IQyFG70vi6foxsvblvxKONObL5Gj4iP0BUvOgfC3G7a7D1jFmf0JH0I_PtIIJn8R_D1JEgFTMkDh8RdAVeKxPffTPhZ1BuekjZa2lvGk8Rnc4rUT0tGNvc1Q8RONc2ONTtnCCPzYaRMzaXzNKmKCNMnJ5EM9Ve2.tgMAY7vEfYxmYfdaIixwhFvCOS_sKrdxse7njWi66BrwwQcckUDce3iwNkiUYMF6w2zq5puFfyIG1OddyQMcaZY27J8USCV_muJO2.Mq9dO4zQo173OSIqME1HPdOsFXmeHhSq5MVk9vhw8saojBQGhAU8rNWKGdK9swyK0c.ZPSDp9eSxQ9bKGWvxoQuTpQ9a5szvhH6KT.xNj_XiqxNhkE5H1QtZue8btScTfsCJvLCaAV4ZCv22v5vSsTkC_dTWmnDLI1WPzGKur6WCT9lFxK_O4a8aoWRDvMWBnaVOWaYHdJTpSROB9HZLbFb5AH5qAyBwXWW6RHpWgmb4GjLv2pX0FNcAU.uwwbMkoQalct1wlUVDNELYfAmIMAacKHFhn5CvpHQWF82R0CdHFjKf8IeckCkPc_RfuepK8stc4UPziSk66QQEQnO7lRTpe3qz.yY5gHW_7h6t2eULugRMg6exthwwws5x5e4SLC8q0CeTHU1UgsQyRHfx95AcULC5zVhUokJt2u..6cHmwPEYOlpQQ5pR2BZ.x6rj.oHUZsuvXp3w3K70b8b9QewwxZSIcgimAI4XYFeV2xEUSXeewJu8hgXnwmlNCW6dKyew.uE23LcAFJlblYoKtjP4uryFQ2XnaXHYpg0C.1kXAmQ582DZevomATI0fplcVEnLd.zmRSxyKet_AxVSZunhMqoPcGZ1e9tQ6tUQmDd1mn1KBq._aArFRNfVSK9iZ5RkHg85kvsvQ_NjAFLvos5pg8hVOjdTJyJ8bmRXA81dN0aIANZrFrsSK8.YEfNYV7CKd3JICWzm4S9UgoKl0SpbjkzwfcJ1yf_hL1E284Aa8EhLfxKUkKCmeUF6t_BBTNwuZazorWrxNGzldX6Vz_wHSlYMYkpzcYUgEoJvP3MnHemeP9J7gmRYUcNMSC2vjEBnaCxI9UZ7LDMaokfChk.b6zGsMr.BphE4xzlC6dwuEVgtXMb.ivE6QSnDlHCcuPoj4V3uu0QZYAuh0jPFcpM.xh9wq6haITmnm2Aga38PtqZbOuK6qLmRNj.ZnSt999jqiEKIQFvWO1RzgHY_vOfxQMCpED4V3b.ZxhzDAb4.QAWmX5mtj77SlpMa2SV4AXZ51WkgWCAS5Ae0SqTb1dBSMAOfbJBrL3NZQvUTvf.gOeyLYJlSk1WcDySvq4gqpG0yeoyMkgmECVklGdd5FkQQyyQqsWV_8sA7eqcsNPfs.bpoQ4jH2d3szpX3sA_ZtJIZMwdPoHL8D0Nhgf9.Cxy4YH8fmcibJRGQt3IaGXb7oUyVG4encPvBmYcgD2g6gQ8NBWpHI2grgmdTT69mQDuVp2htA5iAcBL78c0lPFk2QHIYJbVxRq7a2r11YwFvjfmlsFiYzaqo4CUE7JxBYQW9KwoQUUX6hH4gjI6N8FoFsFIYj2fCKPsNGBlQW7xHrVgLTkArUbPiQ_6JU5m_50YHAkE7YkT0HikQMKMMtG6aKe_AYTNniJYwbD5v.WpUvdCC8rnuNxQq6ROXZRqwqBJM0UMn8.Vw4Z1g3nHhD3EGPzLbaMlLLY6UvT6qOPLkyLLFP7SLvV8dWt1orvO4ZGwFzg6L5j6ISW7CWxJPOgIO68PIv9PkMhUQeaBhKOnVeZoml..NhyIkFl9Y0TfqZ4qregtdnuOz8KcIGQxUi3iCo6f8I8Q"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=917ca17eecbdfdbc';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/content\/journal\/jgv\/10.1099\/0022-1317-76-8-1909?__cf_chl_rt_tk=GqpIR9oYUQxxAfzc6i5mRRh53z9pgGeh8NuNSfeFQy0-1740538260-1.0.1.1-asqacLiCgIOILSdgIJNaTw8ymAla7H2.DgCNgeyQ9zs" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>