Detection of Listeria spp. in cattle and environment of pasture-based dairy farms

Abstract

The aim of the study was to detect Listeria spp., particularly Listeria monocytogenes, in cattle and environment of pasture based dairy farms in Paysandú, Uruguay. A two-stage sampling was conducted, 10 farms were selected by probability proportional to size. A single visit was made to each farm. Samples from bovine faeces, feedstuffs, bulk tank milk, drinking water and soil from the entry and exit pens of the milking parlour were collected for bacteriological studies. PCR assays were used to confirm species and determine the serotype profile of L. monocytogenes isolates. AscI-pulsed-field gel electrophoresis was done to genetically compare them. Listeria spp. were isolated from eight of ten dairy farms, whereas L. monocytogenes in three of them. Serotype distribution in L. monocytogenes was as follows: 1/2a, three isolates; 4b, one isolate. L. monocytogenes or L. innocua excreted from clinically healthy milking cows was detected via faeces. In feedstuffs, only one L. monocytogenes 1/2a isolate from a pasture was obtained. The strain was identical by PFGE to an isolate 1/2a obtained from a pool of milking cow feces that grazed on this farm. No isolation of Listeria spp. was retrieved from the bulk tank milk or drinking water from any of the farms. Listeria innocua was detected in 13 feedstuffs and seven samples of soil from the entry and exit pens of the milking parlour. This is a first local study that confirms the presence of Listeria spp. including L. monocytogenes in healthy cattle and environment of pasture-based dairy farms. These results suggest the potential role that healthy cattle and their sub-products would play as a source of these agents for humans and/or others animals. More detailed studies that include genetic comparison of human and animal isolates are required in order to clearly establish the epidemiological relationship.

Listeria innocua isolated from diseased ruminants harbour minor virulence genes of L. monocytogenes

“…innocua, shedding this microorganism in the faeces (Hofer & Reis, 2005;Matto et al, 2018). However, there are only two reports of L. innocua as the cause of meningoencephalitis in ruminants (Rocha et al, 2013;Walker et al, 1994), to be contrasted to the numerous reports of animal listeriosis due to L. monocytogenes strains (Walland et al, 2015).…”

“…L. innocua is genetically close to L. monocytogenes , but classically considered non‐pathogenic (Buchrieser et al., 2003 ). It has a wide distribution in the environment, including in ruminant farms as well as in the food industries (Matto et al., 2018 ; Moreno et al., 2012 ). Contradicting the classical idea, it has been shown that haemolytic strains of L. innocua are capable of infecting eukaryotic cells in experimental models like mouse and zebrafish (Moura et al., 2019 ).…”

Listeriosis in a peri-urban area: Cultural and molecular characterization of Listeria monocytogenes isolated from encephalitic goats

“…(33.3%) was reported from vegetables where L. monocytogenes was detected in 22.5% of the vegetables in retail level in Malaysia [ 18 ] and 15.3% in raw vegetable salads collected from Chile [ 19 ]. L. monocytogenes were detected in the feedstuffs (33%) in a dairy farm in Paysandu, Uruguay [ 6 ].…”

“…It is caused by the pathogenic species of Gram-positive, facultative anaerobic intracellular bacteria of the genus Listeria . Till now, 17 species of the genus have been identified [ 5 , 6 ]. Vestibular ataxia, circling, head tilt, and unilateral cranial nerve deficits are common meningoencephalitis form of the disease seen in small animals such as sheep and goat [ 7 ].…”

Prevalence, Antibiogram and Biofilm Production of Listeria Monocytogenes from Faeces and Foetuses of Slaughtered Pregnant Cows: Environmental and Public Health Implications

“…Foetuses from pregnant infected animals are 18 very rich in L. monocytogenes [18]. Similarly, faeces play a significant role in the spread of listeriosis to humans and animals [35]. It is associated with severe foodborne infec tions in humans; thus, this organism is considered one of the most important pathogens responsible for foodborne infections.…”