**5.2. Data collection and methods**

**4.4. Discussion**

64 Contemporary Topics of Pneumonia

tion solutions [44].

**5.1. General considerations**

In this study, commercial undiluted EOs were tested. There are some differences on viscosity, dispersion, vaporization, and other physical properties that, no doubt, influence the antibacterial activity. Although no proof can be given, the presence of antibiotic-resistance genes does not influence the efficiency of EOs. Therefore, an intuitive feeling turned our attention to the utility of these products in prevention or, why not, treatment of antibiotic-resistant Gramnegative bacillary respiratory infections. Although there are precise methods for identifying the chemicals with antibacterial activity, these are not important for our purpose. Note that here we are speaking of a screening of some commercial EOs that anyone can buy without medical prescription. Some authors demonstrate discrepancy of antimicrobial activity of EOs from different herbal varieties [37–40]. Of course, as we observed in our study, accurate description of physicochemical properties are needed [41], but for clinical purpose, the overall activity of EOs is relevant. In our opinion, a plant product should be considered as a distinct entity, and we can be certain that each component is synergistic to each other in a manner that exceeds the individual action of separated molecules. As we are speaking of living things, plant properties greatly depends on geographic area of collection, weather influence, manufacturing protocols, preservation conditions, species variety, and so on. Because natural plant products are considered safe, diverse possible applications were investigated: in agriculture for preventing crop diseases, monitoring soil characteristics [42, 43], or as industrial preserva-

**5. Environmental source of carbapenem-resistant strains**

Extensive studies are devoted to the ecotoxicity of industrial compounds or of pharmaceutical wastes [45]. Even though existing tools permit measurement of the concentration of any chemical in a certain geographic area, it is almost impossible to accurately estimate the influence of external factors that, no doubt, interfere with the spread or chemical transformation of any substance—like antibiotics. When biology occurs, the problems become more complicated. Nowadays, a different approach in follow-up to the intricate relationships of abundant microorganisms from a specific environment is needed. Antibiotics, like any other chemicals, do not differ in the way of spreading, accumulation, and changing certain environmental characteristics. It is not an exaggeration to state that multidrugresistant microorganisms from hospital facilities are the nightmare of health practitioners. Analyzing bacterial species one by one provides certain information, but the big picture contains much more. Before starting to accumulate new data, there are huge unexplored resources, like public databases. Our concern was related to the magnitude of change on environmental microbiome by medical activities, especially the use of carbapenems. We extensively searched carbapenemases, or similar beta-lactamases, in protein databases available, and we compared their similitudes depending on their isolation source. The goal of searching similitudes between carbapenemase of clinical samples and their counterpart Herein, we have focused on comparison of the carbapenemases, from different sources, deposited in public databases—NCBI/National Center for Biotechnology Information (https:// www.ncbi.nlm.nih.gov/protein). The preliminary results were briefly presented in the First Conference of the Romanian Association of Laboratory Medicine [46]. Carbapenemase sampling was carried out to cover all beta-lactamase classes. In summary, 40 FASTA carbapenemase sequences were collected, and then a pairwise sequence alignment (EMBOSS Needle Program) and multiple sequence alignment (Clustal Omega tool) were performed [47–49]. The default settings were used. **Table 3** lists the characteristics of the sequences used for further comparisons. Sequences for Classes A, B, and D belonging to Archaea and bacteria were selected. Alignment sequence based on protein crystal structure was not possible due to lack of crystal structures available for beta-lactamases isolated from environmental samples.
