Department of Clinical Analysis, Toxicology and Food Science, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, Brazil.
J Appl Microbiol. 2018 Aug;125(2):506-512. doi: 10.1111/jam.13885. Epub 2018 May 31.
We investigated the resistance profile, presence of β-lactamases encoding genes and the clonal relationships in Acinetobacter baumannii isolated from Brazilian soils.
Soil isolates of A. baumannii were subjected to antimicrobial susceptibility testing by disk diffusion and minimum inhibitory concentration methods. Different β-lactamases encoding genes were screened by PCR and the molecular typing of these isolates was performed through the multilocus sequence typing. Non-susceptibility to different antibiotics was found, since environmental isolates were classified as multidrug-resistant. The bla gene was the most prevalent, followed by bla All sequence types (STs) found (ST1584, ST1607, ST1608, ST1609, ST1610, ST1611 and ST1612) were described for the first time in this study.
The wide variety of new alleles and new STs detected in the present study indicates a divergent population compared to studies that are carried out in the clinical environment and points to an even larger genetic diversity within the species than was anticipated.
A number of the environmental isolates represented multidrug-resistant strains, a phenotype that has been more commonly reported for clinical isolates of A. baumannii; the detection of several β-lactamase encoding genes in the investigated isolates is of great concern suggesting that there is a large reservoir of these resistance genes in the environment.
我们研究了从巴西土壤中分离的鲍曼不动杆菌的耐药谱、β-内酰胺酶编码基因的存在情况和克隆关系。
对土壤分离的鲍曼不动杆菌进行了药敏试验，采用纸片扩散法和最低抑菌浓度法。通过 PCR 筛选不同的β-内酰胺酶编码基因，并通过多位点序列分型对这些分离株进行分子分型。由于环境分离株被归类为多药耐药菌，因此对不同抗生素的耐药性。bla 基因最为普遍，其次是 bla 所有发现的序列型（ST）（ST1584、ST1607、ST1608、ST1609、ST1610、ST1611 和 ST1612）均为首次在本研究中描述。
本研究中检测到的新等位基因和新 ST 的广泛多样性表明，与在临床环境中进行的研究相比，该种群存在差异，并表明该物种的遗传多样性比预期的更大。
许多环境分离株代表多药耐药菌株，这一表型在鲍曼不动杆菌的临床分离株中更为常见；在所研究的分离株中检测到几种β-内酰胺酶编码基因令人担忧，表明环境中存在大量这些耐药基因。
