Concern levels of beta-lactamase-producing Gram-negative bacilli in hospital wastewater: hotspot of antimicrobial resistance in Latin-America.

Hospital wastewater (HWW) discharges are among the main sources of antibiotic-resistant bacteria. This study detected a high frequency of beta-lactamase-producing Gram-negative Bacilli in HWW of different geographical regions of Colombia, even in the presence of the wastewater treatment plant, highlighting the importance of regulating these environments in developing countries.

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.

Transposicion de cerumen en casos de otomicosis / Cerumen transposition in cases of otomycosis

La otomicosis es una enfermedad del Conducto Auditivo Externo (CAE) que con frecuencia se hace de difícil manejo como consecuencia de diferentes factores atribuibles al microorganismo y al paciente. El cerumen es un producto de las glándulas localizadas en la piel del CAE que tiene propiedades antimicóticas, bacteriostáticas y repelente de insectos. Bajo estas consideraciones se realiza la transposición de cerumen de personas sanas a otras con otomicosis de difícil manejo. Los resultados del cultivo antes de la transposición fueron Aspergillus (níger y flavus) 73.7 por ciento y Cándida (albicans y no albicans) 26.3 por ciento. Después de la colocación de cerumen de donador sano, se obtuvo mejoría total con 203 aplicaciones en un lapso de 1 a 3 meses.