Escherichia coli O157:H7 in Retail Lettuce (Lactuca sativa) in Addis Ababa City: Magnitude of Contamination and Antimicrobial Susceptibility Pattern

Aklilu Feleke Haile; Silvia Alonso; Nega Berhe; Tizeta Bekele Atoma; Prosper N Boyaka; Delia Grace

doi:10.3389/fmicb.2021.694506

Escherichia coli O157:H7 in Retail Lettuce (Lactuca sativa) in Addis Ababa City: Magnitude of Contamination and Antimicrobial Susceptibility Pattern

Front Microbiol. 2021 Jul 16:12:694506. doi: 10.3389/fmicb.2021.694506. eCollection 2021.

Authors

Aklilu Feleke Haile^{1

2}, Silvia Alonso³, Nega Berhe¹, Tizeta Bekele Atoma⁴, Prosper N Boyaka^{5

6

7}, Delia Grace^{8

9}

Affiliations

¹ Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.
² Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, United States.
³ International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia.
⁴ Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
⁵ Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States.
⁶ Department of Microbial Immunity and Infection, The Ohio State University, Columbus, OH, United States.
⁷ Infection Diseases Institute, The Ohio State University, Columbus, OH, United States.
⁸ International Livestock Research Institute (ILRI), Nairobi, Kenya.
⁹ Natural Resources Institute, Chatham, United Kingdom.

Abstract

Escherichia coli O157:H7 is an important foodborne pathogen but largely under investigated in Africa. The objectives of this study were to estimate the prevalence and pattern of antimicrobial resistance of E. coli O157:H7 in lettuce in Addis Ababa, Ethiopia. A total of 390 retail lettuce samples were collected across the 10 subcities of Addis Ababa. E. coli O157:H7 was isolated and identified following ISO-16654:2001 standard. The isolates were further tested for antimicrobial susceptibility to 13 antimicrobials using the Kirby-Bauer disk diffusion method. Out of the 390 lettuce samples examined, two (0.51%) carried E. coli O157:H7. The antimicrobial susceptibility pattern of strains showed resistance to ampicillin (100%) and tetracycline (50.0%). One of the two isolates was multidrug resistant to two antimicrobials tested. The results of this study demonstrate the presence of drug-resistant E. coli O157:H7 in lettuce in markets in Addis Ababa. Despite the low prevalence, its presence in a product that is eaten raw highlights potential public health risk in the area associated with this pathogen.

Keywords: Addis Ababa; Escherichia coli O157:H7; antimicrobial; lettuce; prevalence.