Soltan Dallal Mohammad Mehdi, Mazaheri Nezhad Fard Ramin, Kavan Talkhabi Morteza, Aghaiyan Leyla, Salehipour Zohre
PhD, Professor of Microbiology, Division of Food Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Food Microbiology Research Center, Tehran University of Medical Sciences, Tehran, Iran.
PhD, Division of Food Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Germs. 2016 Sep 1;6(3):91-6. doi: 10.11599/germs.2016.1094. eCollection 2016 Sep.
Aeromonas spp. cause various intestinal and extraintestinal diseases. These bacteria are usually isolated from fecal samples, especially in children under five years old. The aim of this study was to assess the prevalence of Aeromonas spp. and their antimicrobial resistance profile in children with diarrhea referred to the Children Medical Center in Tehran, between 2013 and 2014.
A total number of 391 stool samples were collected from children with ages between 1 day and 14 years old, with diarrhea (acute or chronic), referred to the Children Hospital, Tehran, Iran, between 2013 and 2014. Samples were enriched in alkaline peptone water broth for 24 hours at 37 °C and then cultured. Suspicious colonies were analyzed through biochemical tests. Furthermore, antimicrobial susceptibility tests were carried out for the isolates. Isolates were further studied for act, ast, alt, aerA and hlyA virulence genes using polymerase chain reaction.
In total, 12 isolates (3.1%) were identified as Aeromonas spp.; all were confirmed using the API-20E test. Of these isolates, five A. caviae (42%), four A. veronii (33%) and three A. hydrophila (25%) were identified in cases with gastroenteritis. Second to ampicillin (which was included in the growth medium used), the highest rate of antimicrobial resistance was seen against nalidixic acid and trimethoprim-sulfamethoxazole (5 isolates each, 41.6%) and the lowest rate of antimicrobial resistance was seen against gentamicin, amikacin and cefepime (none of the isolates). Results included 76.4% act, 64.7% ast, 71.5% alt, 83.3% aerA and 11.7% hlyA genes.
Aeromonas spp. are important due to their role in diarrhea in children; therefore, isolation and identification of these fecal pathogens should seriously be considered in medical laboratories. Since virulence genes play a significant role in gastroenteritis symptoms caused by these bacteria, Aeromonas species that include virulence genes are potentially suspected to cause severe infections. Moreover, bacterial antimicrobial resistance is increasing, especially against trimethoprim-sulfamethoxazole and nalidixic acid.
气单胞菌属可引起各种肠道和肠道外疾病。这些细菌通常从粪便样本中分离出来，尤其是在5岁以下的儿童中。本研究的目的是评估2013年至2014年期间转诊至德黑兰儿童医学中心的腹泻儿童中气单胞菌属的流行情况及其抗菌药物耐药谱。
2013年至2014年期间，从伊朗德黑兰儿童医院收集了391份年龄在1天至14岁之间、患有腹泻（急性或慢性）的儿童粪便样本。样本在37℃的碱性蛋白胨水中富集培养24小时，然后进行培养。通过生化试验分析可疑菌落。此外，对分离株进行了抗菌药物敏感性试验。使用聚合酶链反应对分离株进一步研究act、ast、alt、aerA和hlyA毒力基因。
总共鉴定出12株（3.1%）气单胞菌属；所有菌株均通过API-20E试验得到确认。在这些分离株中，5株豚鼠气单胞菌（42%）、4株维罗纳气单胞菌（33%）和3株嗜水气单胞菌（25%）在胃肠炎病例中被鉴定出来。仅次于氨苄西林（其包含在所使用的生长培养基中），对萘啶酸和甲氧苄啶-磺胺甲恶唑的抗菌药物耐药率最高（各5株，41.6%），对庆大霉素、阿米卡星和头孢吡肟的抗菌药物耐药率最低（无分离株）。结果包括76.4%的act、64.7%的ast、71.5%的alt、83.3%的aerA和11.7%的hlyA基因。
气单胞菌属因其在儿童腹泻中的作用而很重要；因此，医学实验室应认真考虑对这些粪便病原体进行分离和鉴定。由于毒力基因在这些细菌引起的胃肠炎症状中起重要作用，包含毒力基因的气单胞菌属可能会引起严重感染。此外，细菌的抗菌药物耐药性正在增加，尤其是对甲氧苄啶-磺胺甲恶唑和萘啶酸。
