Ecological aspects of the antimicrobial resistence in bacteria of importance to humn infections

Abstract

In view of the intimate relationship of humans with coastal lagoons (used for recreation, tourism, water supply, etc.), the discharge of domestic effluents may lead to the establishment of routes of dissemination of pathogenic microorganisms, including microorganisms carrying genes for resistance to antimicrobials, through the surrounding human communities. The objective of the present investigation was to relate the presence of antimicrobial-resistant bacteria to the environmental characteristics of three coastal lagoons, comparing the results with those from hospital sewage. Of the lagoons evaluated, two (Geribá and Imboassica) receive domestic sewage discharge, and the other (Cabiúnas) is still in a natural state. We isolated in a culture medium containing 32 ¼ µg/ml of Cephalothin, fecal coliforms (E. coli), non-fecal coliforms (Klebsiella, Enterobacter, Serratia, and Citrobacter), non-glucose-fermenting Gram-negative bacilli, and Aeromonas sp. In cultures from the hospital drain we found strains showing numerous markers for resistance to most of the 11 antimicrobials tested. On the other hand, in cultures from Cabiúnas and Imboassica lagoons, we found strains showing resistance only to antibiotics frequently observed in non-selective situations (considered as "common" markers). The capacity for dilution in the ecosystem, and salinity appeared related with the occurrence of multi-resistant bacterial strains. The intensity of recent fecal contamination was not shown to be associated with the numbers and types of markers found.

Detección y caracterización microbiológica de enterobacterias multidrogorresistentes transportadoras del gen modificador de aminoglicósidos durante tres décadas en un hospital universitario de Río de Janeiro

“…Several environmental and nosocomial bacteria can contain transferable plasmids that carry genes expressing several traits, one of which is multidrugresistance to antimicrobial drugs (23)(24)(25). In fact, we found plasmids with molecular weights varying between 147 kb or more and 7 kb or less in multidrug-resistant strains isolated from especimens of patients hospitalized in different units and in different decades.…”

Prevalence and Antibiogram of Generic Extended-Spectrum β-Lactam-Resistant Enterobacteria in Healthy Dogs

“…Morosini et al (2006) reported crossresistance of ESBL-resistant enterobacteria to aminoglycosides. The aminoglycoside resistance in this study calls for serious concern, because there is a high correlation between gentamicin resistance and multiresistance profiles in nosocomial strains including ESBL-resistant enterobacteria (Meirelles-Pereira et al, 2002;Carvalho et al, 2016).…”

Multiple antibiotic-resistance of Enterococcus isolated from coastal water near an outfall in Brazil

“…According to Boehm et al (2002), the transportation of fecal bacteria in the sewage to the surf zone depends on the following conditions: oceanographic (stratification of the water column), wave, tidal range and currents. Thus, this contamination in marine waters might contribute to the establishment of resistance routes for environmental bacteria (Meirelles-Pereira et al 2002).…”