Source Of Bacterial Resistance Research Articles

Antimicrobial Stewardship Program: Reducing Antibiotic's Spectrum of Activity Is not the Solution to Limit the Emergence of Multidrug-Resistant Bacteria.

Overconsumption of antibiotics in hospitals has led to policy implementation, including the control of antibiotic prescriptions. The impact of these policies on the evolution of antimicrobial resistance remains uncertain. In this work, we review the possible limits of such policies and focus on the need for a more efficient approach. Establishing a causal relationship between the introduction of new antibiotics and the emergence of new resistance mechanisms is difficult. Several studies have demonstrated that many resistance mechanisms existed before the discovery of antibiotics. Overconsumption of antibiotics has worsened the phenomenon of resistance. Antibiotics are responsible for intestinal dysbiosis, which is suspected of being the source of bacterial resistance. The complexity of the intestinal microbiota composition, the impact of the pharmacokinetic properties of antibiotics, and the multiplicity of other factors involved in the acquisition and emergence of multidrug-resistant organisms, lead us to think that de-escalation, in the absence of studies proving its effectiveness, is not the solution to limiting the spread of multidrug-resistant organisms. More studies are needed to clarify the ecological risk caused by different antibiotic classes. In the meantime, we need to concentrate our efforts on limiting antibiotic prescriptions to patients who really need it, and work on reducing the duration of these treatments.

High frequency of gram-negative bacilli harboring blaKPC-2 in the different stages of wastewater treatment plant: A successful mechanism of resistance to carbapenems outside the hospital settings

Wastewater treatment plants (WWTPs) are considered to be a reservoir and a source of bacterial resistance. Worryingly, the presence of carbapenem-resistant Gram-negative bacilli (CRGNB) in WWTPs has recently been reported, but there are still many research gaps regarding its emergence and impact. The distribution of CRGNB in the different stages of a WWTP in Colombia and the relationship between the physicochemical factors involved with their presence are described in this paper. Additionally, given the impact on public health, the CRGNB detected were compared with isolates previously found in hospital patients. Residual water samples were taken from five different stages of a WWTP between January and July 2017. A total of 390 GNB were isolated, and a significant frequency of CRGNB harboring blaKPC-2 (38.2%, n = 149/390) was detected, of which 57% were Enterobacteriaceae, 41.6% Aeromonadaceae, and 1.3% Pseudomonadaceae. The Enterobacteriaceae were more frequent in the raw effluent compared to the Aeromonadaceae, which in turn were more prevalent in the recycled activated sludge and final effluent. Environmental variables such as pH, oxygen, chemical oxygen demand, and temperature were significantly correlated with the quantification of carbapenem-resistant Enterobacteriaceae (CRE) at specific points in the WWTP. Interestingly, isolated K. pneumoniae harboring blaKPC-2 from the WWTPs were diverse and did not relate genetically to the hospital strains with which they were compared. In conclusion, these results confirm the worrying scenario of the dissemination and persistence of emerging contaminants such as CRGNB harboring blaKPC-2, and reinforce the need to establish strategies aimed at containing this problem using multifocal interventions.

High clonal diversity of multidrug-resistant and extended spectrum beta-lactamase-producing Escherichia coli in a wastewater treatment plant

Increasing beta-lactam resistance has led to the exploration of different places, such as wastewater treatment plants (WWTPs) which have been considered to be reservoirs and sources of bacterial resistance. This work aims to determine the presence of beta-lactamase-producing-Enterobacteriaceae in different points of a WWTP in Colombia. Six samplings were carried out in 2017 in the raw influent, aeration tanks, recycled sludge and final effluent of a WWTP. The beta-lactamase-producing-Enterobacteriaceae were detected and identified using phenotypic and molecular methods. Of the 353 isolates included, 28.3% corresponded to enterobacteria. The most frequent microorganisms were Escherichia coli (83%), Citrobacter freundii (11%) and Enterobacter cloacae complex (4%). The 97% of enterobacteriaceae had at least one beta-lactamase, and the most prevalent were the blaTEM (43.8%) and blaCTX-M-1group (35.8%) which were detected specially in recycled sludge and final effluent sample points. High percentage of multidrug resistance (to beta-lactams and non-beta-lactam antibiotics) was detected in E. coli (63.2%). Additionally, the typing by PFGE and MLST showed high genotypic diversity and the presence of the successful ST131 clone, globally spread. This work highlights the strong role of E. coli as a vector for the dissemination of resistance and the beta-lactamases in aquatic environments.