Antimicrobial Resistance Genes in Porcine Pasteurella multocida Are Not Associated with Its Antimicrobial Susceptibility Pattern

Abstract

Forty-eight Pasteurella multocida isolates were recovered from porcine pneumonic lungs collected from farms in “Castilla y León” (north-western Spain) in 2017–2019. These isolates were characterized for their minimal inhibition concentrations to twelve antimicrobial agents and for the appearance of eight resistance genes: tetA, tetB, blaROB1, blaTEM, ermA, ermC, mphE and msrE. Relevant resistance percentages were shown against tetracyclines (52.1% for doxycycline, 68.7% for oxytetracycline), sulphamethoxazole/trimethoprim (43.7%) and tiamulin (25.0%), thus suggesting that P. multocida isolates were mostly susceptible to amoxicillin, ceftiofur, enrofloxacin, florfenicol, marbofloxacin and macrolides. Overall, 29.2% of isolates were resistant to more than two antimicrobials. The tetracycline resistance genes (tetA and tetB) were detected in 22.9% of the isolates, but none were positive to both simultaneously; blaROB1 and blaTEM genes were found in one third of isolates but both genes were detected simultaneously in only one isolate. The ermC gene was observed in 41.7% of isolates, a percentage that decreased to 22.9% for msrE; finally, ermA was harbored by 16.7% and mphE was not found in any of them. Six clusters were established based on hierarchical clustering analysis on antimicrobial susceptibility for the twelve antimicrobials. Generally, it was unable to foresee the antimicrobial susceptibility pattern for each family and the association of each particular isolate inside the clusters established from the presence or absence of the resistance genes analyzed.

Extended-Spectrum β-Lactam Resistant Klebsiella pneumoniae and Escherichia coli in Wild European Hedgehogs (Erinaceus europeus) Living in Populated Areas

“…Regarding the bacterial isolates, a total of 90 bacterial isolates were identified from those 67 analysed animals, and AMR genes were detected in 52 isolates. Thus, in line with other studies [28,29], we observed that some of the AMRB did not have any of the AMR genes. This could be explained by the possible existence of other mechanisms of resistance such as chromosomal mechanisms that were not included as a target of this study.…”

Antimicrobial Stewardship for Respiratory Pathogens in Swine

“…In the case of APP and PM, 13 and 12 clusters have been defined, respectively, according to their antimicrobial susceptibility pattern using a hierarchical clustering analysis. This multivariate statistical tool allows defining groups with similar antimicrobial susceptibility patterns in a visual and comprehensive way as recently published for Pasteurella multocida in swine [16], Escherichia coli in humans and animals [17], and uropathogenic Escherichia coli in humans [18]. The number of clusters for both bacteria could look very high, taking into account that the antimicrobial susceptibility pattern is favorable for many antimicrobials, but combinations of two or three antimicrobials with low antimicrobial susceptibility generated the observed clusters as published for other microorganisms [16][17][18][19].…”

“…This multivariate statistical tool allows defining groups with similar antimicrobial susceptibility patterns in a visual and comprehensive way as recently published for Pasteurella multocida in swine [16], Escherichia coli in humans and animals [17], and uropathogenic Escherichia coli in humans [18]. The number of clusters for both bacteria could look very high, taking into account that the antimicrobial susceptibility pattern is favorable for many antimicrobials, but combinations of two or three antimicrobials with low antimicrobial susceptibility generated the observed clusters as published for other microorganisms [16][17][18][19]. The distribution of antimicrobial susceptibility observed for these respiratory pathogens clearly shows that a proper diagnostics and sensitivity testing should be performed for each clinical case.…”

Antimicrobial Resistance in Escherichia coli Strains Isolated from Humans and Pet Animals

“…Cases of infections in which ESBLs are produced usually have quite an unpredictable course. E. coli is an example of a multidrug-resistant and ESBL-producing bacterium that can be the source of extremely severe infections [ 72 , 73 , 74 ]. As has previously been stated, some strains of E. coli can also cause very serious medical conditions connected with urinary and gastrointestinal tract and central nervous system [ 75 ].…”