Prevalence, Distribution and Antimicrobial Resistance Profile of Salmonella Isolated From Food Items and Personnel In Addis Ababa, Ethiopia
No Thumbnail Available
Date
2004-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababauniversity
Abstract
A cross-sectional study to determine the prevalence, distribution and antimicrobial profile of
Salmonella serotypes isolated from food items and apparently healthy supermarket butchery
workers was undertaken from September 2003 to February 2004. A total of 1200 food items
consisting of chicken carcass (208), pork (194), mutton (212), minced beef (142), cottage cheese
(190), Tilapia fish meat (128) and ice cream (126) were purchased in Addis Ababa. Additionally
sixty-eight stool samples were analyzed. Chicken carcass, pork, mutton and minced beef samples
were collected from 32 randomly selected supermarkets while cottage cheese, fish and ice cream
samples were collected from open markets (3), fish shops (6) and pastry shops (17) in Addis
Ababa, respectively.
Out of the food items, 7.8% were positive for Salmonella and of sixty-eight stool samples five
gave positive result (7.4%). About 14% of chicken carcass, 11.3% of pork, 10.8% of mutton,
8.5% of minced beef, 2.1% of cottage cheese, 2.3% of fish and none of the ice cream yielded
Salmonella. Salmonella was recovered from samples taken from 21 of the 32 supermarkets
considered in the study. On the other hand one open market out of three, two fish shops out of six
and none of the 17 pastry shops gave Salmonella positive results.
A total of 14 different serotypes out of 98 Salmonella isolates were identified. Salmonella
Newport (41.8%) was the most prevalent serotype, followed by S. Braenderup (12.2%), S. Hadar
(8.2%), S. Typhimurium (7.1%), S. Dublin (6.1%) and S. Haifa (6.1%). Less commonly isolated
Salmonella serotypes included: S. Infantis, S. Kentucky, S. Bovismorbificans, S. Anatum, S.
Zanzibar, S. Kottbus, S. Saintpaul and S. 1: 9, 12:-. Salmonella Newport and S. Kentucky were
reported for the first time in Ethiopia. Salmonella Newport was isolated from all sample types
except ice cream, while S. Braenderup, S. Kottbus, S. Saintpaul were detected only from chicken
carcass, pork and minced beef samples, respectively.
There was a statistically significant difference in the rate of Salmonella isolation between meats
(chicken carcass, pork, mutton and minced beef) and the rest of the samples (cottage cheese, fish
and ice cream) (Pearson’s X2 = 37.569, df = 1, p-value = 0.000). The level of antimicrobial
x i
resistance was significantly higher for chicken carcass and pork isolates as compared to other
samples (p = 0.003).
Assay of antimicrobial resistance revealed that 32.7% of Salmonella isolates were resistant to one
or more of the 24 antimicrobials tested. Generally resistance for 13 different antimicrobial drugs
was recognized. The most common resistance was to streptomycin (24/32, 75%), ampicillin
(19/32, 59.4%), tetracycline (15/32, 46.9%), spectinomycin (13/32, 40.6%) and sulfisoxazole
(13/32, 40.6%). All the three Salmonella Kentucky isolates showed resistance to at least 8
antimicrobials, which includes: ampicillin, amoxicillin/clavulanic acid, ciprofloxacin, nalidic
acid, spectinomycin, streptomycin, sulfisoxazole and tetracycline. Out of the 12 Salmonella
Braenderup isolates, 10 (83.3%) showed multidrug resistance to ampicillin, spectinomycin,
streptomycin, sulfisoxazole, sulfamethoxazole/trimethoprim, amoxicillin/clavulanic acid and
trimethoprim. Among the 8 S. Hadar isolates 7 (86.5%) showed antimicrobial resistance of which
three isolates showed resistance to streptomycin and tetracycline, two isolate showed resistance
to tetracycline and the other two for streptomycin. All the 6 S. Dublin isolates were resistant to
carbadox (100 %) while one was additionally resistant to tetracycline. All the 6 S. Haifa strain
isolated were resistant for at least ampicillin, streptomycin and tetracycline. Up to ten different
antimicrobial resistances pattern was observed. Antimicrobial resistance was most common
among Salmonella isolated from chicken carcass (18/29, 62.1%) followed by pork (5/22, 22.7%).
Multiple antimicrobial drug resistance was observed in 23 Salmonella isolates (23.5 %). The
detection of 7.4% Salmonella carriers’ supermarket workers shedding S. Newport, the most
prevalent serotype, suggests possible linkage and potential source of infection.
The findings of the present study ascertain that Salmonella serotypes were widely distributed
particularly in supermarket meat samples and significant proportion have developed resistance
for routinely prescribed antimicrobial drugs both in veterinary and public health sectors. This
poses considerable health hazards to the consumers unless prudent antimicrobial usage, adequate
heat treatment, improvement of standards of hygiene and development and enforcement of
suitable legislation, which safeguard consumers, are urgently instituted.
Key words: Prevalence, Salmonella, serotype, antimicrobial resistance, food items, supermarket,
personnel, Addis Ababa
Description
Keywords
Prevalence, Salmonella, serotype, antimicrobial resistance, food items, supermarke, personnel, Addis Ababa