Comparision of biofilm production and multiple drug resistance in ...

M. Dheepa et al., Int J Pharm Biomed Sci 2011, 2(4), 103-107
Table 5
Antibiotic susceptibility pattern of the 50 A.baumannii isolates tested are
given in this table
Antibiotic
Number (% sensitive)
n=50
Amikacin 30 µg 22
Ceftazidime 30 µg 28
Ciprofloxacin 5 µg 38
Cefepime 30 µg 28
Imipenem 10 µg 46
Pipercillin 100 µg 28
Ampicilllin + sulbactum 10 µg +10µg 44
Gentamicin 10 µg 28
Co-trimoxazole 1.25µg +23.75 µg 32
Doxycyline 30 µg 52
Piperacillin + tazobactum 100 µg + 10 µg 50
Meropenem 10 µg 32
Tobramycin 10 µg 50
Levofloxacin 10 µg 62
Aztreonam 30 µg 18
Netilmycin 30 µg 72
Ofloxacin 5 µg 24
Table 6
Antibiotic susceptibility results (percentage) of A. baumannii isolates
Antibiotics
Resistance of
Biofilm positive
isolates N=20
Biofilm negative
isolates N=30
Amikacin 80 73.3 78
Ceftazidime 95 86.6 72
Ciproflox 85 80 62
Cefepime 95 86.6 72
Imipenem 65 70 54
Pipercillin 95 93.3 72
Ampicilllin + sulbactum 55 66 56
Gentamicin 70 70 72
Co-trimoxazole 75 76 68
Doxycyline 35 56 48
Piperacillin + tazobactum 40 50 50
Meropenem 70 66 68
Tobramycin 75 33 50
Levoflox 50 30 38
Aztreonam 85 76.6 82
Netilmycin 20 20 28
Ofloxocin 60 76 76
Table 7
Multiple drug resistant patterns of A. baumannii
Multiple drug combinations
Number of isolates
showing resistance
Resistance
of all
isolates
N =50
Percent
Ak, Ao, Cf, I, Of 31 62
Ak, Ao, I 31 62
Cf, I 33 66
Ak, I, Of 30 60
Ao, Cf, I 33 66
Ak- amikacin, Ao- aztreonam, Cf- ciprofloxacin, I- imepenem, Of –
ofloxacin
chloramphenicol 94.7%, amoxicillin/clavulinic acid 94.7%,
netilmycin 93.9%, ceftazidime 90.9%, gentamicin 87.9%,
pipercillin/tazobactam 84.8%, nalidixic acid 84.2%,
tobramycin 75%, imipenem 7.2%, colistin 7.1% [10].
106
Another study done in Estonia showed 60 % of A.
baumanii isolates sensitive to ampicillin + sulbactum, 95%
to imepenem and meropenum and 70 % to amikacin [11]. In a
study conducted in UK showed resistance to piperacillin +
tazobactum 39%, imipenam 7%, ciprofloxacin 46%,
meropenem 0.5%, ceftazidime 46%, pipercillin 72%,
gentamicin 43%, amikacin 21% respectively [12]. Similar
study conducted in Ankara in 2002 shows the resistance
rates were 31.2% for netilmicin, 44.6% for sulbactamcefoperazone,
53.6% for imipenem, 59.8% for amikacin,
59.9% for tobramycin, 74% for ciprofloxacin, 78% for
gentamicin, 79.5% for sulbactam-ampicillin, 82.3% for
cotrimoxazole, 84.8% for ticarcillin, 87.3% for piperacillintazobactam,
88.1% for ceftazidime and 92.1% for piperacillin
[13].
Another study was conducted in USA regarding the multi
drug resistance. The results showed, about 79.5% (66/83)
were multi-drug resistant (MDR) A. baumanii. Among these,
62 were resistant to ceftazidime and 66 were resistant to
imipenem. The imipenem resistant isolates (66/83) were also
resistant to kanamycin, amikacin, gentamicin, streptomycin,
tetracycline, ciprofloxacin and nalidixic acid [14].
In a study conducted in India, Hyderabad Acinetobacter
baumannii showed 77% resistance to piperacillin-tazobactam
[15]. In another study conducted in India, Pune 75% of the
isolates were multidrug resistant (MDR) and resistance to
aztreonam 60% and for imipenem 29% was noted [16].
In our study biofilm producers showed increased
resistance to Ceftazidime 95%, Cefepime 95% and Pipercillin
95%. A recent study showed significantly higher resistance to
cefotaxime, amikacin, ciprofloxacin and aztreonam among
biofilm producers. Non-biofilm producers showed increased
resistance only for netillin and ofloxacin [7].
5. CONCLUSIONS
In conclusion, continuous surveillance of the in-vitro
antimicrobial susceptibility of Acinetobacter baumannii
isolates in various geographical areas are necessary in order
to generate data useful for optimising empirical antimicrobial
treatment of patients with infections that are likely to be
caused by this pathogen. Our investigation reveals a
simultaneous emergence of resistance to many antimicrobial
agents when the organisms produce biofilm and represents a
severe threat in the treatment of hospitalized patients. It is a
challenge to treat and also to eradicate this multidrug
resistant organism because the overall healthcare costs which
are attributed to the treatment of biofilm associated infections
will be much higher. The high rate of invitro antibiotic
resistance of the Acinetobacter baumanii strains indicate the
importance of controlled antibiotic usage and appliance of
hospital infection control measures.
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