Pathogenic potential of <i>Listeria monocytogenes</i> isolated from cattle faeces in Adoekiti

Abstract

Listeria monocytogenes is an opportunistic food-borne pathogen causing listeriosis especially among immune-compromised persons. Its high rate of morbidity and mortality has classed the organism among the top watch list in foods. It is known to produce several virulence factors which aid its survival in harsh conditions and its dissemination within host cells. The pathogenicity of L. monocytogenes, isolated from cattle faeces in Ado-Ekiti, was determined in Wister albino rats for two weeks and the relative virulence was calculated. Rats were challenged with isolates producing listeriolysin O and phospholipase orally, intraperitoneally and subcutaneously. Biochemical parameters and haematoxylin and eosin (H and E) stained sections of selected organs were examined for significant changes (p < .05) and histopathological effects post-experiment. Relative virulence was recorded at 0% with rats showing no signs of infection or death. However, significant changes in total protein, lipid profile and some selected antioxidant enzymes, as well as cytological changes in the examined H and E sections of organs showed that an infection had occurred. Bacteria may have however been eradicated by the immune-competent rats. This study therefore concludes that isolates may be pathogenic especially for persons tagged 'high risk' due to low immunity.

A review of the literature of Listeria monocytogenes in Africa highlights breast milk as an overlooked human source

“…Subsequently, the first reported listeriosis epidemic in buffalo occurred in Nigeria ( Chukwu et al, 2006 ) and cases have also been detected in laboratory animals and cattle ( Akpavie and Ikheloa, 1992 ; Chukwu et al, 2006 ). These epidemics led to large-scale monitoring of LMO contamination in several African countries, resulting in its detection in ruminants (sheep, cattle and goats) in Nigeria ( Lawan et al, 2013 ; Oyinloye et al, 2018 ), poultry in Nigeria ( Ogbonna et al, 2004 ; Okwori et al, 2011 ) and Kenya ( Njagi et al, 2004 ), fish in Nigeria ( Ikeh et al, 2010 ; Adeshina and Adewale, 2015 ) and Egypt ( Ahmed et al, 2013 ), shellfish in Egypt ( Ahmed et al, 2013 ), and dogs in South Africa ( Schroeder and van Rensburg, 1993 ; Table 3 , Figure 3 ).…”

“…Distribution of Listeria monocytogenes in Africa. detection in ruminants (sheep, cattle and goats) in Nigeria (Lawan et al, 2013;Oyinloye et al, 2018), poultry in Nigeria (Ogbonna et al, 2004;Okwori et al, 2011) and Kenya (Njagi et al, 2004), fish in Nigeria (Ikeh et al, 2010;Adeshina and Adewale, 2015) and Egypt (Ahmed et al, 2013), shellfish in Egypt (Ahmed et al, 2013), and dogs in South Africa (Schroeder and van Rensburg, 1993; Table 3, Figure 3).…”