Prevalence and antimicrobial susceptibility profiles of campylobacter coli isolated from broilers and layers in Mwanza and Arusha, Tanzania
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Date
2022
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Sokoine university of agriculture
Abstract
Campylobacteriosis is an emerging zoonotic disease which poses threat to both human
health and animal productivity. Recent emergence of Campylobacter resistance to
antimicrobial agents that are commonly used and recommended by the World Health
Organization (WHO) for treating human gastroenteritis has been reported from different
countries worldwide. Globally, chickens are one of the major sources of animal proteins
and are the primary reservoirs of Campylobacter spp. Antimicrobials are being added to
chicken feeds in low doses in order to accelerate their growth that can lead to
development of antimicrobial resistant Campylobacter strains within chicken gut. When
chicken products are consumed, antimicrobial resistant (AMR) Campylobacter strains can
be transferred to humans. In this study surveillance was conducted on antimicrobial
resistant Campylobacter isolated from broiler and layer chickens from Mwanza and
Arusha regions in Tanzania. Antimicrobial resistance data were generated in a cross-
sectional study which was carried out using a total of 402 cloaca swabs collected from
apparently health broilers (202) and layers (200) in Arusha and Mwanza regions.
Collected samples were enriched into Bolton broth supplemented with 5% laked horse
blood. Enriched samples were cultured onto blood agar by filtration method using a
0.45μm nitrocellulose membrane. Screening of colonies was based on colony
characteristics and Gram staining. Presumptive Campylobacter colonies were then sub-
cultured onto Muller Hinton (MH) agar supplemented with 5% laked horse blood for
purification of isolates. DNA was extracted from isolated colonies by boiling method
while Multiplex PCR was used for genus and species confirmation with specific primers.
All isolates were subjected to susceptibility test by disc diffusion method against six
antimicrobials including ciprofloxacin, tetracycline, nalidixic acid, gentamycin, ampicillin
and erythromycin. Antimicrobial susceptibility results were interpreted as Susceptible (S), Intermediate (I) or resistant (R) using the Clinical Laboratory Standard Institute (CLSI)
cut-off values, and isolates that were resistant to three or more of antimicrobial classes
were considered to be multidrug resistant (MDR).
Out of 402 samples and from Mwanza and Arusha 31(7.71%) were positive for
Campylobacter isolates in layers (13/200) and broilers18/202). All 31 bacterial isolates
were confirmed to be C. coli spp. In Mwanza, the overall prevalence of C. coli was 6.5%
(13/200), and by chicken type the values were 6% (6/100) and 7% (7/100) for broilers and
layers, respectively. In Arusha, the overall prevalence of C. coli was 8.9% (18/202), and
prevalence values by chicken breed were 10.8% (11/102) and 7% (7/100) for broilers and
layers respectively. Antimicrobial results indicated that 6.5% (2/31) of all isolates were
susceptible to all antimicrobials used in the study. The highest proportion of antimicrobial
resistance was observed for ampicillin (80.6%), followed by nalidixic acid (16.1%), and
tetracycline (9.7%). The lowest resistance was observed for gentamycin (3.2%). Four out
of thirty-one (12.9%) isolates were MDR to four different antimicrobials tested each with
different patterns. Campylobacter coli was the only specie isolated from cloaca swabs of
chicken with the overall prevalence of 7.71%. The isolates were resistance to at least one
antimicrobial
agent
with
ciprofloxacin
showing
a
significant
difference
(p-value=0.049%) in AMR prevalence among chicken types which was higher in broilers
than in layers and four of the isolates were MDR with different resistance patterns.
Results from this study show that emerging foodborne MDR is a threat to human and
surveillance is required to establish supportive data that will be used in formulation of
country regulations and policy regarding the use of antimicrobials in both human and
veterinary medicine.
Description
Dissertation
Keywords
Antimicrobial, Susceptibility, Campylobacter coli, Broilers, Mwanza, Arusha, Tanzania