International Journal of Aquaculture, 2016, Vol.6, No.3, 1
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were resistant to more than two antibiotics. MAR index of these isolates were relatively low when compared to
our previous observations in the gut associated bacteria of freshwater aquarium fishes and farm raised shrimps
(Nifty and Hatha, 2012)
Table 1 Variation in prevalence of antibiotic resistance among different bacterial genera from the gut of fresh water fish
Aplocheilus
lineatus
Antibiotics
% of resistance among different genera of bacteria
Lactobacillus
(n=14*)
Aeromonas
(n=3)
Bacillus
(n=4)
Micrococcus
(n=4)
Pseudomonas
(n=1)
Carbenicillin
7.14
0
0
25
0
Cephalothin
50
33.33
25
25
0
Cephalothin
50
33.33
25
25
0
Cefpodoxime
92.85
100
75
50
100
Gentamicin
0
0
0
0
0
Chloramphenicol
21.42
0
25
0
100
Ciprofloxacin
7.14
0
0
0
0
Nalidixic acid
21.42
0
50
0
100
Streptomycin
0
0
0
0
0
Sulfafurazole
0
0
0
25
0
Tetracycline
7.14
0
25
0
0
Trimethoprim
21.42
0
25
0
0
Note: *Number of bacterial isolates.
Table 2 Variation in prevalence of antibiotic resistance among different bacterial genera from the gut of fresh water fish
Etroplus
maculatus
% of resistance among different bacterial genera
Antibiotics
Lac* (5)
Aer* (1)
Bac* (6)
Mic* (11)
Vib* (1)
Ent* (5)
Cor* (1)
Carbenicillin
40
100
50
54.54
0
40
100
Cefpodoxime
80
100
100
90.9
100
100
100
Cephalothin
40
100
16.66
36.36
100
80
0
Chloramphenicol
0
0
16.66
0
0
0
0
Ciprofloxacin
0
0
0
0
0
0
0
Gentamicin
20
0
0
0
0
0
0
Nalidixic acid
20
100
33.33
0
0
20
0
Streptomicin
0
0
0
0
100
20
0
Sulfafurazole
40
0
0
18.18
0
80
0
Tetracycline
20
0
0
0
0
20
0
Trimethoprim
0
0
16.66
9.09
0
20
0
Note: (Lac* -
Lactobacillus
; Aer* -
Aeromonas
; Bac*-
Bacillus
; Mic*-
Micrococcus
; Vib*--
Vibrios
spp.; Ent*-
Enterobacterium
;
Cor*-
Corynebacterium
.)
MAR index and resistance patterns of gut associated bacteria from
E. maculatus
are given in Table 4. Prevalence
of multidrug resistance among the bacteria from this fish gut was considerably higher when compared to those
from
A. lineatus
. MAR index ranged from 0.09 to 0.63. Gut associated bacteria from the gut of
E. maculatus
collectively exhibited 18 different resistance patterns. While CbCpd was the most frequently encountered
resistance pattern (20%), nearly 70% of them were multidrug resistant with 13 diverse patterns. The most
common multi resistance patterns were CbCepCpd, CbCpdSf and CepCpdSf, with each one of them contributing
6.66% to overall resistance patterns. Unlike
A. lineatus
,
E. maculatus
is a bottom feeder and pick up decaying
vegetation and detritus from the bottom along with the associated microbiota. Our studies have revealed relatively
higher load bacteria in the sediment samples of the study area (Deborah et al., 2012). Antibiotic resistance among
