**6. Final remarks**

**Environmental samples** *Enterobacteria* **Nonfermenters** *P***-value**

*Serratia* sp. (ALL98459) 51.07 (±70.37) 40.30 (±42.34) 0.65 *A.junii* (YP\_009062718) 51.07 (±70.37) 40.30 (±42.34) 0.65

*H. archaeon* (KUO42968) 11.00 (±5.81) 13.18 (±2.57) 0.25 *A. fulgidus* (WP\_010877604) 15.27 (±2.67) 15.38 (±1.59) 0.89

*E. asburiae* (AIL29239) 54.87 (±17.00) 31.40 (±18.06) 0.02 Uncultured (ALJ52278) 73.03 (±26.33) 40.20 (±26.23) 0.03

*E. coli* (AJA05008) 69.85 (±29.32) 28.54 (±2.37) 0.02 *C. freundii* (AJA05009.1) 67.78 (±25.43) 27.94 (±2.63) 0.01 *Peucalypti* (AJA05006) 60.93 (±21.63) 25.58 (±2.28) 0.01 Uncultured (AJF40233) 80.35 (±34.61) 32.26 (±3.02) 0.02

**Table 4.** Pairwise comparison of beta-lactamase sequences of environmental sources with *Enterobacteria* and non-

highlights the notable differences between Archaea and bacteria. Residues involved in Zn2+ ions are very well conserved with the exception of Cys221, which is replaced by Asp in Archaea. However, nearby Cys residues were noticed. Since their crystal structures are not

The observation that Archaea contain different beta-lactamases demonstrates that human behavior has not profoundly altered natural environment. Or some microorganism communities have regulatory mechanisms so flexible that rapidly adapt at new environmental factors. For example, *Acinetobacter* is no longer considered just a free-living organism found in soil, water, and skin of human and warm-blooded animals, but an important multidrug-resistant pathogen.

solved, we can just assume their involvement in metal ion binding.

**Identity% Mean (CI 95)**

51.07 (±70.37) 40.30 (±42.34) 0.65

15.47 (±0.75) 15.56 (±3.04) 0.93

14.93 (±1.11) 14.48 (±2.88) 0.69

16.50 (±1.51) 16.60 (±2.21) 0.91

**Identity% Mean (CI 95)**

**Class B** Bacteria

68 Contemporary Topics of Pneumonia

*A. calcoaceticus* (YP\_009060354)

*S. acidocaldarius* (WP\_015385554)

*V. distributa* (WP\_013336995)

**Class A**

**Class D**

CI 95—Confidence Intervals 95%.

fermenters carbapenemases.

Archaea *S. acidocaldarius* (WP\_011278945)

> Carbapenems remain a valid option for the treatment of ESBL *Enterobacteriaceae* pneumonia. Prolonged treatments with beta-lactamine associated with other co-morbidities of the patients, rapidly changed the phenotypic pattern of resistance.

> Essential oils have, no doubt, beneficial effects, but some providers excessively claim many possible effects—from antibacterial activity to neurological benefits—not always consistent with reality. Moreover, nowadays, there exists all sort of mixtures, and we can only hope that the ingredients are chosen following logical connections between their activities. Herein, these problems were not debated, but it is not a trivial question about the validity of all plant extracts. Just notice that the only mixture tested (an inhalant) proved no antibacterial activity, at least against *A. baumannii* and *E. coli* strains. On the other hand, tyme-clove association proved to be beneficial in Gram-negative bacilli respiratory infections. The oregano EO has an excellent antibacterial activity, but its effect is antagonized by negril EO. Other plant extracts could be added for their anti-inflammatory effect or just for changing the scent [52].

> One important question arises from here—what else, apart from widely using of antibiotics, could influence the persistence of antibiotic genes in hospital facilities? Industrial wastes could remain for a long period of time in the environment, notably in groundwater [8]. Carbapenemases from hospital sources are, no doubt, the major factor in the evolution of these enzymes, hospital residues being, definitely, a source of wastewater pollution. Further, the carbapenemases produced by natural environmental bacteria and Archaea significantly contribute to selection of new mutations. Soil bacterial species greatly influences our life; therefore, a genome-scale metabolic network [53] has proved to be a valid approach to evaluate the complex dynamics of soil bacterial species, mostly in geographic areas near huge hospitals with many departments. Also, innate resistance to antibiotics has raised over time a growing interest for a rational design of new antibacterial compounds [54].
