Dziri Raoudha, Klibi Naouel, Alonso Carla Andrea, Jouini Ahlem, Ben Said Leila, Chairat Sarra, Bellaaj Ridha, Boudabous Abdellatif, Ben Slama Karim, Torres Carmen
1 Laboratoire des Microorganismes et Biomolécules Actives, Faculté de Sciences de Tunis, Université de Tunis El Manar , Tunis, Tunisia .
2 Área de Bioquímica y Biología Molecular, Universidad de La Rioja , Logroño, Spain .
Microb Drug Resist. 2016 Jul;22(5):399-403. doi: 10.1089/mdr.2015.0354. Epub 2016 Mar 9.
To investigate the possible role of the hospital environment in the dissemination of extended-spectrum-beta-lactamase (ESBL)-producing Escherichia coli isolates, 300 samples were taken during 2013 from abiotic surfaces (n = 250), healthcare worker hands (n = 27), and hands of patients (n = 23) in a Tunisian Hospital. ESBL-producing E. coli isolates were recovered in 3.7% of analyzed samples (4% abiotic surfaces; 4.3% hands of patients; 0% in healthcare worker hands), and one isolate/sample was further studied. The characterization of beta-lactamase genes, as well as the genetic environment of blaCTX-M gene, was performed by PCR and sequencing. The ESBL genes found were as follows: blaCTX-M-15 (eight isolates), blaCTX-M-15+blaSHV-12 (two isolates), and blaSHV-12 (one isolate). The blaTEM-1b gene was detected in seven ESBL-positive isolates. The orf477 was found downstream of blaCTX-M-15 gene in 10 strains, whereas the ISEcp1 sequence was identified upstream of this gene in two isolates. The analysis of class 1 integrons by PCR and sequencing revealed five positive isolates with the following gene cassette arrangements: dfrA1-aadA1 (two isolates), aadA1 (two isolates), and aadA2 (one isolate). The virulence-encoding genes aer, eae, bfp, and hly were detected by PCR in six, four, four, and three isolates, respectively. The following sequence types and associated phylogroups were detected among ESBL-producing strains: ST167-phylogroup-A (six isolates) and ST131-phylogroup-B2 (two isolates). In conclusion, the hospital environment could be a reservoir of multiresistant bacteria, including ESBL-positive E. coli isolates, which could be acquired by the patient population, and strict control measures should be established to minimize this problem.
为调查医院环境在产超广谱β-内酰胺酶（ESBL）大肠埃希菌传播中可能发挥的作用，2013年期间从突尼斯一家医院的非生物表面（n = 250）、医护人员手部（n = 27）和患者手部（n = 23）采集了300份样本。在3.7%的分析样本中分离出产ESBL的大肠埃希菌（非生物表面为4%；患者手部为4.3%；医护人员手部为0%），并对每个样本中的一株分离菌进行了进一步研究。通过PCR和测序对β-内酰胺酶基因以及blaCTX-M基因的遗传环境进行了鉴定。发现的ESBL基因如下：blaCTX-M-15（8株分离菌）、blaCTX-M-15+blaSHV-12（2株分离菌）和blaSHV-12（1株分离菌）。在7株ESBL阳性分离菌中检测到blaTEM-1b基因。在10株菌株中，orf477位于blaCTX-M-15基因下游，而在2株分离菌中，ISEcp1序列位于该基因上游。通过PCR和测序对1类整合子进行分析，发现5株阳性分离菌，其基因盒排列如下：dfrA1-aadA1（2株分离菌）、aadA1（2株分离菌）和aadA2（1株分离菌）。通过PCR分别在6株、4株、4株和3株分离菌中检测到毒力编码基因aer、eae、bfp和hly。在产ESBL菌株中检测到以下序列类型和相关系统发育群：ST167-系统发育群A（6株分离菌）和ST131-系统发育群B2（2株分离菌）。总之，医院环境可能是包括ESBL阳性大肠埃希菌分离菌在内的多重耐药菌的储存库，患者群体可能会感染这些病菌，因此应制定严格的控制措施以尽量减少这一问题。
