Shahraki-Zahedani Shahram, Rigi Shahnaz, Bokaeian Mohammad, Ansari-Moghaddam Alireza, Moghadampour Mehdi
Infectious Diseases and Tropical Medicine Research Center, Zahedan University of Medical Sciences, Zahedan, Iran.
Department of Microbiology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran.
Rev Soc Bras Med Trop. 2016 Jul-Aug;49(4):441-5. doi: 10.1590/0037-8682-0114-2016.
Extended-spectrum beta-lactamases (ESBLs) are bacterial enzymes capable of hydrolyzing beta-lactams. The aim of this study was to describe the prevalence of TEM- and SHV-type ESBL-producing Klebsiella pneumoniae strains in Zahedan, Southeast Iran.
A total of 170 non-repetitive K. pneumoniae strains were collected from patients referred to three teaching hospitals of Zahedan. Antibiotic susceptibility testing was determined for 17 antibiotics using the Kirby-Bauer disc diffusion method. The frequency of ESBL-producing strains was calculated, and minimum inhibitory concentrations of ESBL-producing strains were determined for cefotaxime, ceftazidime, ceftriaxone, and cefpodoxime. The presence of bla TEM and bla SHV genes was tested in all ESBL-producing strains using polymerase chain reaction and DNA sequencing.
Among the 170 K. pneumoniae clinical isolates, 55 (32.4%) were ESBL producers; 92.7% (n=51) and 72.7% (n=40) of the isolates carried the bla SHV and bla TEM genes, respectively, and 67.3% (n=37) carried both genes. The sequencing results showed that all bla TEM types were bla TEM-1, except for two isolates that were bla TEM-104. The bla SHV types were bla SHV-1, bla SHV-11, bla SHV-12, bla SHV-99, bla SHV-108, and bla SHV-110.
The percentage of bla TEM and bla SHV among ESBL-producing K. pneumoniae isolates from Zahedan is relatively high, indicating the need for further surveillance and consideration in antibiotic use. To the best of our knowledge, this is the first report of TEM-104-, SHV-99-, SHV-108-, and SHV-110-type ESBLs among clinical isolates of K. pneumoniae from Iran, and TEM-1, SHV-1, SHV-11, and SHV-12 appear to be the dominant ESBLs in this region.
超广谱β-内酰胺酶（ESBLs）是一类能够水解β-内酰胺类抗生素的细菌酶。本研究旨在描述伊朗东南部扎黑丹地区产TEM型和SHV型ESBL的肺炎克雷伯菌菌株的流行情况。
从扎黑丹的三家教学医院收治的患者中总共收集了170株非重复的肺炎克雷伯菌菌株。采用 Kirby-Bauer 纸片扩散法对17种抗生素进行药敏试验。计算产ESBL菌株的频率，并测定产ESBL菌株对头孢噻肟、头孢他啶、头孢曲松和头孢泊肟的最低抑菌浓度。使用聚合酶链反应和DNA测序检测所有产ESBL菌株中bla TEM和bla SHV基因的存在情况。
在170株肺炎克雷伯菌临床分离株中，55株（32.4%）为产ESBL菌株；分别有92.7%（n = 51）和72.7%（n = 40）的分离株携带bla SHV和bla TEM基因，67.3%（n = 37）的分离株同时携带这两个基因。测序结果显示，除两株为bla TEM-104外，所有bla TEM类型均为bla TEM-1。bla SHV类型包括bla SHV-1、bla SHV-11、bla SHV-12、bla SHV-99、bla SHV-108和bla SHV-110。
扎黑丹地区产ESBL的肺炎克雷伯菌分离株中bla TEM和bla SHV的比例相对较高，这表明需要进一步监测并在抗生素使用方面加以考虑。据我们所知；这是伊朗肺炎克雷伯菌临床分离株中首次报道TEM-104型、SHV-99型、SHV-108型和SHV-110型ESBLs，并且TEM-1、SHV-1、SHV-11和SHV-12似乎是该地区的主要ESBLs。
