In Ecuador, the impact of listeriosis on public health is unknown because it is not a reportable disease. Soft cheese is consumed in most urban households in the country.

A total of 260 artisanal cheese samples were collected from March to September 2018 in street markets of 18 of 24 provinces of Ecuador. Cheeses didn’t have a sanitary registration certificate issued by the national authority.

Of the 260 food isolates, 37 were positive for Listeria monocytogenes.

“The presence of Listeria monocytogenes in our samples suggests the need to demand thermal treatments in cheese processing as well as better epidemiological surveillance of the pathogen and the disease in our country,” said researchers.

Scientists also compared serogroups isolated from cheeses with clinical isolates from June 2015 to July 2018 provided by the Laboratory for Antibiotic Resistance of the National Institute of Public Health Research of Ecuador.

Two provinces, Pichincha and Carchi, showed the most prevalence of Listeria monocytogenes in cheeses. Pichincha had the highest number of clinical cases of listeriosis but also showed better medical and surveillance services than other provinces.

Listeria innocua, Listeria welshimeri and Listeria grayi were also found, according to the brief report in the journal Revista Argentina de Microbiología.

“The presence of other Listeria spp. such as Listeria welshimeri and Listeria grayi, found in cheeses, may be associated with inadequate processing, storage, or transportation of these products,” said researchers.

All strains in the study were sensitive to the antibiotics analyzed suggesting that antibiotic treatment may adequately work in listeriosis cases in Ecuador.

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