Studies of Listeria Monocytogenes (Bacterium) in some Selected Local Government Areas of Plateau State, Nigeria
ABSTRACT
Studies were carried out on the distribution, characterization, pathogenicity and antibiotic susceptibility of Listeria monocytogenes in Six Local Government Areas of Plateau State, Nigeria.
A total of One hundred and fifty (150) experimental samples were taken from each test Local Government Area. The isolation was carried out with the aid of cold enrichment, selective broth and selective Listeria agar.
The experimental samples examined included: cow, goat, poultry, rabbit and sheep wastes (faecal samples). The other samples investigated included: cultivated soil particles, farm wastes, human wastes (faeces), decaying leaves and water.
A total of nine hundred samples were examined in all. Out of these, 189 (21%) were found to contain Listeria species which was found to be highly significant at 5% and 10% level of probability (P = 0.01; P = 0.05). The Listeria isolates included L. monocytogenes (41.3%), L. ivanovii (20.1%), L. grayi (14.3%), L. welshimeri (8.4%), L. innocua (6.9%), L. murrayi (5.8%) and L. seeligeri (3.2%).
The molecular characterization of the various L. monocytogenes isolates through polymerase chain reaction (PCR) technique into serotypes, revealed that they belonged to 13 serotypes (serovars).
Listeria species occurrences were found to be highest in rabbit wastes (33.3%), followed by sheep wastes (27.8%), farm debris (23.3%), soil samples (22.4%), cow waste (22.2%), poultry droppings (20.0%), leaves (17.8%) and then water (13.3%).
Samples of Human wastes were found to contain the least percentage of Listeria species (11.1%). It was observed that temperature, pH range and moisture content affected the colonization of the experimental samples by Listeria.
The polymorphic nature but peculiar morphological characteristics of Listeria monocytogenes were helpful in the identification of the organism.
INTRODUCTION
Background of Study
Despite the remarkable advances in medical research and treatments during the 20th century, infectious disease remains among the leading causes of death worldwide for three reasons:
The emergence of new infectious pathogens; re-emergence of old infectious pathogens and persistence of intractable infectious pathogens (WHO, 1984).
These have revealed a number of previously unknown human and animal pathogens such as Listeria monocytogenes (WHO, 1988; Gillespie et al., 2006).
Listeria monocytogenes has been reported as the most heat resistant non- spore-forming foodborne pathogen (Brown, 1991).
It is the agent of listeriosis, a serious zoonotic infection caused by eating foods contaminated with L. monocytogenes.
L. monocytogenes infects tens of millions of people every year in tropical and temperate countries, causing flulike symptoms and even death (Schuchat et al., 1991a).
The disease can manifest itself in several ways, but the three principal ones are abortion, septicemia and meningitis or meningoencephalitis in humans with a fatality rate, greater than 20 – 25% and animals with a case fatality rate of 30 – 60% respectively (WHO, 1987; WHO, 1988; Gellin and Broome, 1989; Schuchat et al., 1991a).
REFERENCES
Adak, K. G., Mealkins, M. S., Yip, H., Lopman, A. B. and O’Brien, J. S. (2005). Disease Risks from Foods, England and Wales, 1996 – 2000. Emerging Infectious Diseases; 11(3)365 – 375.
Ali, R. R. and Ibrahim, A. (1992). Prevalence of Listeria monocytogenes in retail beef and poultry. The proceedings of the National Intensification of Research in priority areas Seminar in Malaysia. In: (Agriculture sector): eds. Ho, W. Y., Vidyadarian, K. M., Abdullah, N., Jama, R.and Bahaman, R. A. Kuala Lumpur. Pp 336 – 337.
Anonymous (1995). Monoclonal antibodies for detection of live bateria. Organon Teknika Capel Update; Pp1 – 3.
Annukka, M., Tiina, A., Jane, L. and Hannu, K. (2005). Raw and Processed Fish Show Identical Listeria monocytogenes Genotypes With Pulsed – Field Gel Electorphoresis. Journal of Food Protection Volume 68, (6) 1228 – 1231.
Archer, L. D, (1990). L. monocytogenes: What is its ecological niche: In: Foodborne listeriosis (ed.): A.J. Miller, Smith, J.L. and Somkuti, A. G Amsterdam: Elsevier Pp 5-8.
Art, D. and Andre, P. (1991). Comparison of Three Selective Isolation Media for the detection of L. monocytogenes in foods. Zbl. Bakt. 275:78 – 84.
