en Microbiology Microbiology مقالات مروری Narrative review <div><strong>Introduction: </strong><em>Citrobacter freundii</em> (<em>C. freundii</em>) is an opportunistic infection agent in hospitalized patients, especially in the intensive care units (ICUs). The prevalence of antibiotic resistance in <em>C. freundii</em> is increasing in the worldwide, and this may cause significant clinical problems. This paper aims at evaluating the rate of antibiotic resistance of <em>C. freundii</em> using meta-analysis.<br> <strong>Materials and methods: </strong>A total of eight qualified antibiotics in 21 published articles were chosen randomly to estimate the antibiotic resistance percentage of <em>C. freundii</em> in different countries. The data were analyzed by meta-analysis (random effect model) and the heterogeneity was determined using Cochran&rsquo;s Q and I² index. Also, Forest plot with confidence interval 95% were attained by R software.<br> <strong>Results: </strong>Our data showed that the antibiotic resistance pattern of <em>C. freundii</em> in different parts of the world was not absolutely same but the maximum range of resistance was related to gentamicin and the minimum range of resistance was related to imipenem. Q and I²were attained 45.25 (P<0.05) and 56%, respectively.<br> <strong>Conclusion: </strong>The findings of this study showed that the variability in antibiotic resistance pattern of <em>C. freundii</em> in different studies across the world was due to heterogeneity in hygiene level that resulted from various geographic regions.</div> Citrobacter freundii, Antibiotic resistance, Nosocomial pathogen 58 63 http://jbrms.medilam.ac.ir/browse.php?a_code=A-10-355-2&slc_lang=en&sid=1 Arman Rostamzad arostamzad381@yahoo.com 10031947532846003320 10031947532846003320 No Department of Biology, Faculty of Basic Science, Ilam University, Ilam, Iran Aboozar Karami Cherag Abad akerami.95@gmail.com 10031947532846003321 10031947532846003321 No Department of Biology, Faculty of Basic Science, Ilam University, Ilam, Iran Mehdi Omidi omidi_280@yahoo.com 10031947532846003322 10031947532846003322 Yes Department of Mathematics‎, ‎Ilam University‎, ‎Ilam‎, ‎Iran Aliasghar Hatamnia hatamniya60@gmail.com 10031947532846003323 10031947532846003323 No Department of Biology, Faculty of Basic Science, Ilam University, Ilam, Iran