Carvalheira Ana, Silva Joana, Teixeira Paula
Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401, Porto, Portugal.
Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401, Porto, Portugal.
Food Microbiol. 2017 Jun;64:119-125. doi: 10.1016/j.fm.2016.12.005. Epub 2016 Dec 20.
The role of ready-to-eat products as a reservoir of pathogenic species of Acinetobacter remains unclear. The objective of the present study was to evaluate the presence of Acinetobacter species in lettuces and fruits marketed in Portugal, and their susceptibility to antimicrobials. Acinetobacter spp. were isolated from 77.9% of the samples and these microorganisms were also found as endophytes (i.e. present within the plant tissue) in 12 of 20 samples of lettuces analysed. Among 253 isolates that were identified as belonging to this genus, 181 presented different PFGE profiles, representing different strains. Based on the analysis of the partial sequence of rpoB, 175 strains were identified as members of eighteen distinct species and the remaining six strains may represent five new candidate species since their rpoB sequence similarities with type strains were less than 95%. Acinetobacter calcoaceticus and Acinetobacter johnsonii were the most common species, both with the frequency of 26.5%; and 11% of the strains belong to the Acinetobacter baumannii group (i.e. A. baumannii, Acinetobacter pittii, Acinetobacter seifertii and Acinetobacter nosocomialis), which is most frequently associated with nosocomial infections. Overall, the strains were least susceptible to piperacillin (80.1%), piperacillin-tazobactam (64.1%), ceftazidime (43.1%), ciprofloxacin (16.6%), trimethoprim-sulfamethoxazole (14.9%), imipenem (14.4%) and colistin (13.3%). The most active antimicrobials were minocycline and tetracycline, with 0.6% and 3.9% of strains resistant, respectively. About 29.8% of the strains were classified as multidrug-resistant (MDR), 4.4% as extensively drug-resistant (XDR) and the prevalence of MDR strains within the A. baumannii group (25%) was similar to other species (30.4%). The presence of clinically important species as well as MDR strains in lettuces and fruits may be a threat to public health considering that they may transmit these pathogens to environments such as the community and hospital settings.
即食产品作为不动杆菌致病菌种储存库的作用尚不清楚。本研究的目的是评估葡萄牙市场上销售的生菜和水果中不动杆菌属菌种的存在情况及其对抗菌药物的敏感性。从77.9%的样本中分离出了不动杆菌属菌种，并且在所分析的20份生菜样本中的12份中，这些微生物还以内生菌（即存在于植物组织内）的形式被发现。在253株被鉴定属于该属的菌株中，181株呈现出不同的脉冲场凝胶电泳（PFGE）图谱，代表不同的菌株。基于rpoB部分序列的分析，175株菌株被鉴定为18个不同菌种的成员，其余6株菌株可能代表5个新的候选菌种，因为它们与模式菌株的rpoB序列相似性低于95%。醋酸钙不动杆菌和约翰逊不动杆菌是最常见的菌种，频率均为26.5%；11%的菌株属于鲍曼不动杆菌组（即鲍曼不动杆菌、皮氏不动杆菌、塞弗特不动杆菌和医院不动杆菌），该组最常与医院感染相关。总体而言，这些菌株对哌拉西林（80.1%）、哌拉西林-他唑巴坦（64.1%）、头孢他啶（43.1%）、环丙沙星（16.6%）、甲氧苄啶-磺胺甲恶唑（14.9%）、亚胺培南（14.4%）和黏菌素（13.3%）的敏感性最低。活性最高的抗菌药物是米诺环素和四环素，耐药菌株分别占0.6%和3.9%。约29.8%的菌株被归类为多重耐药（MDR），4.4%为广泛耐药（XDR），鲍曼不动杆菌组内MDR菌株的流行率（25%）与其他菌种（30.4%）相似。考虑到生菜和水果中存在具有临床重要性的菌种以及MDR菌株可能会将这些病原体传播到社区和医院环境等，这可能对公众健康构成威胁。
