Presence of β-Lactamase-producing Enterobacterales and Salmonella Isolates in Marine Mammals

Abstract

Marine mammals have been described as sentinels of the health of marine ecosystems. Therefore, the aim of this study was to investigate (i) the presence of extended-spectrum β-lactamase (ESBL)- and AmpC-producing Enterobacterales, which comprise several bacterial families important to the healthcare sector, as well as (ii) the presence of Salmonella in these coastal animals. The antimicrobial resistance pheno- and genotypes, as well as biocide susceptibility of Enterobacterales isolated from stranded marine mammals, were determined prior to their rehabilitation. All E. coli isolates (n = 27) were screened for virulence genes via DNA-based microarray, and twelve selected E. coli isolates were analyzed by whole-genome sequencing. Seventy-one percent of the Enterobacterales isolates exhibited a multidrug-resistant (MDR) pheno- and genotype. The gene blaCMY (n = 51) was the predominant β-lactamase gene. In addition, blaTEM-1 (n = 38), blaSHV-33 (n = 8), blaCTX-M-15 (n = 7), blaOXA-1 (n = 7), blaSHV-11 (n = 3), and blaDHA-1 (n = 2) were detected. The most prevalent non-β-lactamase genes were sul2 (n = 38), strA (n = 34), strB (n = 34), and tet(A) (n = 34). Escherichia coli isolates belonging to the pandemic sequence types (STs) ST38, ST167, and ST648 were identified. Among Salmonella isolates (n = 18), S. Havana was the most prevalent serotype. The present study revealed a high prevalence of MDR bacteria and the presence of pandemic high-risk clones, both of which are indicators of anthropogenic antimicrobial pollution, in marine mammals.

Antimicrobial and Biocide Resistance among Canine and Feline Enterococcus faecalis, Enterococcus faecium, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii Isolates from Diagnostic Submissions

“…The chlorhexidine MICs determined in the present study were in a similar range, although we could not detect E. coli isolates with the lowest and highest MICs of 0.00003% and 0.002%. In a third study, 27 E. coli isolates from marine mammals exhibited benzalkonium chloride MICs that ranged between 0.000125 and 0.002%, with most isolates (24/27) displaying a MIC of 0.002% [ 59 ]. The corresponding chlorhexidine MICs were distributed over six dilution steps from 0.0003% to 0.001% with the majority of isolates (24/27) ranging between 0.00006 and 0.0005% [ 59 ].…”

“…In a third study, 27 E. coli isolates from marine mammals exhibited benzalkonium chloride MICs that ranged between 0.000125 and 0.002%, with most isolates (24/27) displaying a MIC of 0.002% [ 59 ]. The corresponding chlorhexidine MICs were distributed over six dilution steps from 0.0003% to 0.001% with the majority of isolates (24/27) ranging between 0.00006 and 0.0005% [ 59 ]. Again, these MICs were in an excellent agreement with the benzalkonium chloride and chlorhexidine MICs determined in the present study.…”

Occurrence of Antimicrobial-Resistant Escherichia coli in Marine Mammals of the North and Baltic Seas: Sentinels for Human Health

“…The occurrence of resistant E. coli was higher in the samples from the Baltic Sea (44.4%) compared to those from the North Sea (33.3%), but without statistical significance. Although not many studies have investigated antimicrobial resistance in marine mammals thus far, resistant bacteria have been reported in various marine mammal species, including pinnipeds and cetaceans from different areas of the world [ 8 , 83 , 84 , 85 , 86 , 87 ]. The occurrence of resistant E. coli isolates varied in the different studies, with reported figures of 10% [ 86 ], 26.9% [ 87 ], 47% [ 8 ], and 50% [ 83 ].…”

“…Multidrug resistance, defined as resistance to at least one antimicrobial of three or more antimicrobial classes [ 89 ], occurred in the present study in 37.2% of the resistant E. coli isolates, which is in accordance with an Irish study on harbour and grey seals that found multidrug resistance in 43.5% of the E. coli isolates [ 90 ]. Another study investigating Enterobacterales observed a higher prevalence, with 71% of the isolates exhibiting multidrug resistance [ 85 ]. In the present study, harbour porpoises were found to carry significantly higher numbers of multidrug-resistant E. coli isolates compared to the investigated seal species, while there was no significant difference between species regarding the carriage of E. coli isolates with resistance to at least one antimicrobial drug.…”

The First Report of mcr-1-Carrying Escherichia coli Originating from Animals in Serbia

“…Biocides are used to control infectious diseases on poultry farms and in slaughterhouses and can contribute to the emergence and spread of bacteria resistant to antibiotics [ 54 , 55 ]. In addition, resistance to biocides has already been reported.…”