Dissemination and persistence of Pseudomonas spp. in small-scale dairy farms

Abstract

This study was aimed at collecting data on presence, dissemination and persistence of <em>Pseudomonas</em> in small-scale dairy farms. Six farms (located in Piedmont) were visited three times over 2014: 116 waters (wells and different faucets/pipes) and 117 environmental samples (milking equipments and drains) were collected. Enumeration of <em>Pseudomonadaceae</em> was performed, 3-5 colonies/samples were selected for identification via 16SrDNA/oprI polymerase chain reaction (PCR), and typed by enterobacterial-repetitive- intergenic-consensus (ERIC)-PCR. Pseudomonadaceae were detected in 77% of samples. No statistical differences were found among proportions of positives across farms, sample typologies and seasons. Most isolates were <em>Pseudomonas fluorescens</em> (45%), and ERIC-PCR showed 32 persistent types diffused across farms. All in all, <em>Pseudomonas</em> spp. represents a challenge, considering its presence over time in water as well as in teat cups, indicating a continuous source of contamination. Moreover, persistency of strains may indicate biofilm-formation and/or sanitisers resistance, therefore emphasising the role of primary production for preventing milk contamination by <em>Pseudomonas</em> spp.