MEDICINSKI GLASNIK

etween them (p>0.05). The resistance rates to
erythromycin and ciprofloxacin of clinical isolates
were higher in C. jejuni, 29.7% and 35.1%,
respectively, than in C. coli, 20.0% and 26.7%,
respectively (p>0.05). It is true for retail poultry
and poultry isolates too. All ciprofloxacin positive
isolates had a high-level resistance (≥ 32 μg/mL),
and 94.4 % of erythromycin positive isolates had
high-level resistance (≥128 μg/mL) (Table 2).
Significantly higher prevalence of resistance
for both erythromycin and ciprofloxacin was observed
in the isolates from the age group of 20-64
(53.8% for both antibiotics) as compared to the
age group of 0-6 (23.3% for ciprofloxacin and
22.3% for erythromycin) (data not shown).
DISCUSSION
Resistance rates to one or more antibiotics
as found in this study for Campylobacter strains
have surpassed the highest previously reported
resistance rates for human and poultry meat isolates
(4,23,24). Reportedly, multidrug resistant
(MDR) isolates are usually present in humans to
a much lesser extent (0.8% to 21%) compared to
the results from this study (23-25).
A significant increase in ciprofloxacin resistance
of human isolates in this region between
1998 (14%) and 2002 (32.1%) was observed
(1). Several studies have shown that food animals
can be a substantial source of human infections
and that the same serotypes and genotypes
can be isolated from humans and food animals
(10,14). The consumption of imported chickens
was identified as a possible risk factor for the
acquisition of fluoroquinolone-resistant strains
(10,13). Widespread use of antimicrobials in veterinary
medicine has resulted in the emergence
Table 2. Number of strains according to level of resistance to erythromycin and ciprofloxacin*
Origin of isolates
(No)
Species (No)
of strains of Campylobacter displaying a MDR
phenotype (26). These strains are transmitted to
humans usually through the consumption of undercooked
contaminated food, particularly poultry.
Of concern to public health is the increase in
strains resistant to fluoroquinolone and macrolide
drugs, important antibiotics used in the front-line
treatment of campylobacteriosis (27).
The results of our study do not show a significant
difference in ciprofloxacin-resistance
between domestic and imported poultry meat
samples. We have got a confirmation of the examined
farm owner that no antibiotics were applied
to animal food, but still there is a possibility
for an increase in their use for therapeutic purposes
instead (28). The fact that the decrease of
fluoroquinolone-resistant campylobacters had
been observed before and during the use of antimicrobial
growth promoters suggests that other
factors might be involved (29).
The reports about the connection between
individual fluoroquinolone used in humans and
development of fluoroquinolone-resistance in
Campylobacter isolates are still controversial
(4,10,12). It is worth mentioning that 56.6% of
isolates from this study and 67% isolates from
the previous study (11), all from the Zenica-
Doboj region, originated from children up to 6
years old. High ciprofloxacin-resistance in this
age group (23.3%) was found and due to the fact
that the use of quinolones is restricted for children,
the high ciprofloxacin-resistance is probably
not influenced by overuse of this drug. It is
unlikely that the human use of fluoroquinolones
alone could be responsible for high-resistance
rates of human Campylobacters to fluoroquinolones
observed in many countries (4,10,12). Our
results indicate the resistance of an animal origin
No of strains inhibited at MIC(µg/mL) of erythromycin:
No of strains inhibited at
MIC(µg/mL) of ciprofloxacin:
512 32
Human (52) C. jejuni (37) 23 3 2 3 3 3 24 12 1
C. coli (15) 12 2 1 11 4
Retail poultry (51) C. jejuni (22) 12 1 1 3 4 15 1 6
C. coli (29) 19 1 1 3 3 2 24 1 4
Poultry (15) C. jejuni (7) 4 3 4 3
C. coli (8) 7 1 6 1
*cutoff values: erythromycin MIC ≥ 32 mg/L; ciprofloxacin MIC ≥ 4mg/L;
Uzunović-Kamberović et al Antimicrobial resistance C. jejuni and C. coli
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