Low prevalence of zoonotic multidrug-resistant bacteria in veterinarians in a country with prudent use of antimicrobials in animals

The occurrence of multidrug-resistant zoonotic bacteria in animals has been increasing worldwide. Working in close contact with livestock increases the risk of carriage of these bacteria. We investigated the occurrence of extended-spectrum beta-lactamase (ESBL) and plasmidic AmpC beta-lactamase producing Enterobacteriaceae (ESBL/pAmpC-PE) and livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in Finnish veterinarians (n = 320). In addition to microbiological samples, background information was collected. Bacterial whole genome sequencing was performed to deduce sequence types (STs), spa types and resistance genes of the isolates. In total, 3.0% (9/297) of the veterinarians carried ESBL producing Escherichia coli, with one ESBL producing E. coli isolate producing also AmpC. Seven different STs, sequences of several different plasmid groups as well as several different bla(ESBL/pAmpC )genes existed in different combinations. No carbapenemase or colistin resistance genes were detected. MRSA was detected in 0.3% (1/320) of the samples. The strain belonged to LA-MRSA clonal complex (CC) 398 (ST398, spa type 011, lacking Panton-Valentine leukocidin genes). In conclusion, this study shows low carriage of multidrug-resistant zoonotic bacteria in Finnish veterinarians. However, finding LA-MRSA for the first time in a sample from a veterinarian in a country with prudent use of animal antimicrobials and regarding the recent rise of LA-MRSA on Finnish pig farms, a strong recommendation to protect people working in close contact with animals carrying LA-MRSA CC398 is given. Further studies are needed to explain why the prevalence of LA-MRSA in veterinarians is lower in Finland than in other European countries.Peer reviewe

Antimicrobial susceptibility and proposed microbiological cut-off values of lactobacilli by phenotypic determination

This article summarizes published and unpublished data of antibiotic resistances in strains (n = 675) of fourteen Lactobacillus species. Minimum inhibitory concentrations (MICs) were determined against antibiotics representing different classes, namely ampicillin (penicillins), tetracycline (tetracyclines), gentamicin and streptomycin (aminoglycosides), and erythromycin and clindamycin (macrolide-lincosamide-and streptogramin B group, MLSB).The Lactobacillus species under study included the L. delbrueckii group (n = 218), L. plantarum (n = 121), L. sakei (n = 83), L. rhamnosus (n = 75), L. paracasei (n = 66, including one L. casei), L. reuteri (n = 56) and L. fermentum (n = 56). The strains were of human, animal and food origin. The MICs were determined with microdilution and/or Etest methods using LSM (Lactic acid bacteria susceptibility test medium) agar and broth. In general, the results obtained with the microdilution method were one or two dilution steps higher than with the E-test. Accordingly, tentative microbiological cut-off values are given separately according to the method and species used. A vast majority of the strains were phenotypically susceptible to ampicillin and erythromycin, whereas many species showed a wide range of MICs for tetracycline. A broad range in distribution of MICs was also observed with aminoglycosides and clindamycin, especially in L. plantarum