Al-Agamy Mohamed Hamed
Pharmaceutics and Microbiology Department, King Saud University, Riyadh, Saudi Arabia.
Pak J Pharm Sci. 2013 Mar;26(2):291-8.
The incidence of resistance to extended-spectrum cephalosporins (ESC) among Egyptian isolates of Klebsiella pneumoniae has already been increasing and previously reported. This work devotes to investigate the genetic basis of resistance to ESC in K. pneumoniae isolates. Disc diffusion test, minimum inhibitory concentrations (MIC) determination and phenotypic screening for extended spectrum β-lactamases (ESBLs) and plasmid-mediated AmpC β-lactamases (PABLs) were carried out for 21 K. pneumoniae isolates, collected during 2011 at Sayed Galal Hospital, Cairo. Genes for ESBLs, PABLs and class 1 integrase were sought by PCR and DNA sequencing. Matting out assay was performed to determine the mobility of bla genes. Six (28.57%) of 21 clinical isolates K. pneumoniae were non-sensitive to ESC. ESBL and PABL phenotypes were identified in 5 and one K. pneumoniae isolates, respectively. PABL-producing isolate was found to carry blaCMY-2 and blaSHV-1. All five ESBL-producing isolates carried blaCTX-M-15. CTX-M-15 was associated with SHV-1 and SHV-12 in three isolates and two isolates respectively.TEM-1 was associated with CTX-M-15 and SHV in two isolates. Both CTX-M-15 and CMY-2 genes were located on conjugative plasmids and associated with class 1 integrase. Resistance to ESC was due to CTX-M-15, SHV-12 and CMY-2 in K. pneumoniae. This study represents the first report of CMY-2 and SHV-12 β-lactamase-producing K. pneumoniae isolates in Egypt.
埃及肺炎克雷伯菌分离株对超广谱头孢菌素（ESC）的耐药率一直在上升，此前已有报道。本研究致力于探究肺炎克雷伯菌分离株对ESC耐药的遗传基础。对2011年在开罗赛义德·加拉勒医院收集的21株肺炎克雷伯菌分离株进行了纸片扩散试验、最低抑菌浓度（MIC）测定以及超广谱β-内酰胺酶（ESBLs）和质粒介导的AmpCβ-内酰胺酶（PABLs）的表型筛选。通过聚合酶链反应（PCR）和DNA测序寻找ESBLs、PABLs和1类整合酶的基因。进行接合试验以确定bla基因的可移动性。21株临床分离的肺炎克雷伯菌中有6株（28.57%）对ESC不敏感。分别在5株和1株肺炎克雷伯菌分离株中鉴定出ESBL和PABL表型。发现产PABL的分离株携带blaCMY-2和blaSHV-1。所有5株产ESBL的分离株均携带blaCTX-M-15。CTX-M-15分别与3株和2株分离株中的SHV-1和SHV-12相关。TEM-1与2株分离株中的CTX-M-15和SHV相关。CTX-M-15和CMY-2基因均位于接合质粒上，并与1类整合酶相关。肺炎克雷伯菌对ESC的耐药性归因于CTX-M-15、SHV-12和CMY-2。本研究是埃及产CMY-2和SHV-12β-内酰胺酶的肺炎克雷伯菌分离株的首次报道。
