Mahmoudi Shima, Pourakbari Babak, Rahbarimanesh Aliakbar, Abdosalehi Mohammad Reza, Ghadiri Keyghobad, Mamishi Setareh
Pediatric Infectious Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran.
Department of Pediatric Infectious Diseases, Bahrami Children Hospital, Tehran University of Medical Sciences, Tehran, Iran.
Infect Disord Drug Targets. 2019;19(1):46-54. doi: 10.2174/1871526518666180507121831.
Klebsiella pneumoniae is a common cause of nosocomial infections; however, there is limited information in Iran regarding nosocomial outbreaks due to extended-spectrum β-lactamase (ESBL) producing K pneumoniae strains, particularly using molecular methods. The present study focused on the molecular mechanism of ESBL resistance and genetic relatedness in K. pneumoniae isolates causing nosocomial infections in an Iranian referral hospital.
This study evaluated the antimicrobial resistance and molecular epidemiology of K. pneumoniae causing nosocomial infections in children between October 2013 and March 2014. The ESBL detection was carried out for all the isolates by the CLSI method and PCR was carried out for the detection of the blaSHV, blaTEM, and blaCTX-M genes among ESBL-producing K. pneumonia. Molecular typing of the K. pneumoniae was performed using random amplification of polymorphic DNA-polymerase chain reaction (RAPD-PCR).
A total of 30 isolates of K. pneumoniae were used for epidemiological analysis. High rates of resistance to cefotaxime (n=29, 97%), cefazolin (n=29, 97%), cefepime (n=25, 83%) and gentamicin (n=23, 77%) were observed. A total of 29 strains (97%) produced ESBLs. The frequency of blaSHV, blaCTX-M and blaTEM genes among these isolates was 83% (n=25), 70% (n=21) and 57% (n=17), respectively. Surprisingly 11 isolated (37%) carried blaSHV, blaCTX-M and blaTEM genes simultaneously. Moreover, the concurrent presence of "blaSHV and blaCTX-M" and "blaSHV and blaTEM" was seen in 8 (27%) and 4 (13%) isolates, respectively. RAPDPCR analyses revealed that K. pneumoniae isolates belonged to 2 RAPD-PCR types among which one cluster counted for 28 isolates.
To our knowledge, this is the first published report of a nosocomial outbreak of ESBL-producing K. pneumoniae in children in Iran. Although the epidemiology of nosocomial infections with ESBL-producing organisms has not yet been explored in depth in Iran, our findings suggest that ESBL-producing organisms are already an established public health threat in our country.
肺炎克雷伯菌是医院感染的常见病因；然而，在伊朗，关于产超广谱β-内酰胺酶（ESBL）的肺炎克雷伯菌菌株引起医院感染暴发的信息有限，尤其是使用分子方法的相关信息。本研究聚焦于伊朗一家转诊医院中引起医院感染的肺炎克雷伯菌分离株中ESBL耐药的分子机制及基因相关性。
本研究评估了2013年10月至2014年3月期间引起儿童医院感染的肺炎克雷伯菌的抗菌药物耐药性及分子流行病学情况。所有分离株均采用美国临床和实验室标准协会（CLSI）方法进行ESBL检测，对产ESBL的肺炎克雷伯菌进行blaSHV、blaTEM和blaCTX-M基因检测采用聚合酶链反应（PCR）。肺炎克雷伯菌的分子分型采用随机扩增多态性DNA-聚合酶链反应（RAPD-PCR）。
共30株肺炎克雷伯菌分离株用于流行病学分析。观察到对头孢噻肟（n = 29，97%）、头孢唑林（n = 29，97%）、头孢吡肟（n = 25，83%）和庆大霉素（n = 23，77%）的高耐药率。共有29株（97%）产ESBLs。这些分离株中blaSHV、blaCTX-M和blaTEM基因的频率分别为83%（n = 25）、70%（n = 21）和57%（n = 17）。令人惊讶的是，11株（37%）同时携带blaSHV、blaCTX-M和blaTEM基因。此外，分别在8株（27%）和4株（13%）分离株中观察到“blaSHV和blaCTX-M”以及“blaSHV和blaTEM”的同时存在。RAPD-PCR分析显示，肺炎克雷伯菌分离株属于2种RAPD-PCR类型，其中一个簇包含28株分离株。
据我们所知，这是伊朗首次发表的关于儿童中产ESBL肺炎克雷伯菌医院感染暴发的报告。尽管伊朗尚未深入探究产ESBL生物引起医院感染的流行病学情况，但我们的研究结果表明，产ESBL生物在我国已构成既定的公共卫生威胁。
