Molecular epidemiology and extended-spectrum β-lactamases production of Klebsiella pneumoniae isolated from three dairy herds

The objectives of this study were to isolate Klebsiella pneumoniae from different sources in three dairy cattle herds, to use the pulsed-field gel electrophoresis (PFGE) to measure genotypic similarities between isolates within a dairy herd, to verify the production of extended-spectrum β-lactamases (ESBLs) by the double-disk synergy test (DDST), and to use the PCR to detect the main ESBLs subgroups genes. Three dairy farms were selected based on previous mastitis outbreaks caused by K. pneumoniae. Milk samples were collected from lactating cows and from the bulk tank. Swabs were performed in different locations, including milking parlors, waiting room, soil, animal's hind limbs and rectum. K. pneumoniae was isolated from 27 cases of intramammary infections (IMI) and from 41 swabs. For farm A isolates from IMI and bulk tank were considered of the same PGFE subtype. One isolate from a bulk tank, three from IMI cases and four from environmental samples were positive in the DDST test. All eight DDST positive isolates harbored the bla shv gene, one harbored the bla tem gene, and three harbored the bla ctx-m gene, including the bulk tank isolate. Our study confirms that ESBL producing bacteria is present in different locations in dairy farms, and may be responsible for IMI. The detection of ESBLs on dairy herds could be a major concern for both public and animal health

Presença de Pseudomonas spp em função de diferentes etapas da ordenha com distintos manejos higiênicos e no leite refrigerado Presence of Pseudomonas spp in milking phases with different hygienic handling procedures and in refrigerated milk

O experimento foi conduzido, visando detectar Pseudomonas spp, em leite proveniente de propriedades leiteiras, de acordo com o sistema de produção. A presença de Pseudomonas spp, em leite cru recém - obtido e leite cru refrigerado (5 a 8&deg;C), foi relacionada com as diversas etapas de ordenha em quatro propriedades leiteiras com diferentes sistemas de manejo higiênico. A contagem média de Pseudomonas spp, nas diversas fontes, nas propriedades, variou de 2,48 X 10²UFC mL-1 (superfície de tetos) a 1,97X10(4)UFC mL-1 (equipamentos), quando a higiene praticada foi adequada, mas de 8,71 X 10²UFC mL-1 (superfície de tetos) a 1,6X10(5)UFC mL-1 (leite refrigerado), quando o manejo foi inadequado.<br>The occurrence of Pseudomonas spp, in raw and refrigerated (e to 8&deg;C) bulk milk was related to milking steps at four dairy farms with distinct sanitary handling procedures. Average count for Pseudomonas spp at different sources, in the farms, varied from de 2.48X10²CFU mL-1 (teats surface) to 1.97X10(4)CFU mL-1 (equipments), when sanitary procedures were adequate, but from de 8.71X10²CFU mL-1 (teats surface) to 1.6X10(5)CFU mL-1 (refrigerated milk) when sanitary procedures were inadequate