Salmonella and Escherichia coli contamination of poultry meat from a processing plant and retail markets in Ibadan, Oyo State, Nigeria

Abstract

Salmonella spp and Escherichia coli are the two most important food-borne pathogens of public health interest incriminated in poultry meat worldwide. This study is to access their levels in frozen poultry meat obtained in Ibadan, Oyo State and compare those obtained from a commercial Nigerian-registered poultry company having a broiler-processing plant, Sayed Farms Ltd(R), with that obtained from retail stores. These retail stores source their products as illegal imports from neighboring Benin Republic or Togo because of a ban imposed by Government policy in Nigeria since July 2002 (USDA, GAIN report #NI2025:1-6, 2002).

Microbiological Standards and Guidelines by USDA (National Agricultural library) (USDA 2011) and NCCLS guidelines (from Global Salm-Surv, 2003) were used during the research work. The study was approved by the Ethical Research Review Board (ERRB, Research Management Office 2011), University of Ibadan, Nigeria. A total of one hundred and fifty-two (152) frozen poultry meat samples comprising ninety-nine retail poultry (53 chicken and 46 turkey) and 53 chicken from the processing plant were accessed. ISO Standards catalogue 07.100.30 (2011) was used in accessing the levels of Salmonella, Escherichia coli, Enterobacteriaceae counts and Aerobic plate count. ISO 6579: 2002 was used for Salmonella isolation and ISO-16654:2001 for Escherichia coli isolation.

There was a higher level of Aerobic plate counts and Enterobacteriaceae counts in frozen retail poultry meat than from the processing plant. Salmonella contamination from the ninety-nine poultry samples (53 chicken and 46 turkey) obtained from retail markets was at 33% [chicken 32.1% (17/53) and turkey 34.8% (16/46)] while Escherichia coli at 43.4% [chicken 47.2% (25/53) and turkey 39.1% (18/46)]. From the processing plant, twelve (12) Salmonella isolates were obtained and prevalence rate calculated as 22.6% while three (3) Escherichia coli isolates at 5.7% was obtained.

Antibiotic sensitivity for isolates using eight different Gram-negative antibiotics showed different resistance patterns. Nitrofurantion and augmentin showed a decrease in their sensitivity to isolates than they normally should. Salmonella enterica spp. showed 93% resistance to tetracycline and 100% resistance to augmentin and amoxicillin, while Escherichia coli showed 100% resistance to augmentin and amoxicillin.