1. ISOALTION, HEMOLYTIC ACTIVITY AND
ANTIBIOTIC SUSCEPTIBILITY OF
AEROMONAS SPECIES FROM
DRINKING WATER OBTAINED FROM
WATER RESERVOIRS (FASGHIA) IN
TRIPOLI-LIBYA
Zakia M. El-Agili, Halima Nashnoush,
Khalifa Sifaw Ghenghesh*, and Amal Rahouma*
Dept. of Botany1, Faculty of Science, and
*Dept. of Medical Microbiology2, Faculty of Medicine,
Tripoli University, Tripoli-Libya

2. INTRODUCTION
Aeromonas
Gram -ve, oxidase +ve bacilli.
Habitat
Natural waters
Disease
bacteremia,
wound infections and
gastroenteritis.
Virulence factors
hemolysins,
Cytotoxins
Adherence
– Mannose-resistant hemagglutination

3. Treatment
Resistant to β-lactams
Chromosomally mediated
Cephalosporins, fluoroquinolones
Aims
Fasghia is an underground reservoir to
collect rain water used for drinking.
To isolate Aeromonas species from drinking
water obtained from fasghias in Tripoli.
To determine the virulence factors of the
isolated Aeromonas.
To determine the susceptibility of the
isolated Aeromonas to antibiotics.

4. MATERIAL AND METHODS
Samples
From October 2003-July 2004, 56 samples obtained
from fasghias in Tripoli were examined
Microbiology
Samples were enriched in alkaline peptone water
(APW, pH 8.6) at 37oC.
After overnight incubation, a loopful from APW was
plated on ampicillin blood agar (ABA, 15mg/L).
Plates were incubated at 37oC.
After overnight incubation, suspected colonies were
tested for oxidase and identified using standard
microbiological procedures and API20E
Isolated Aeromonas were tested for hemolysin
production on BA, agglutination of RBCs in absence
and presence of mannose, and susceptibility to
antibiotics by the disc diffusion method.

5. RESULTS
Of 56 water samples examined, 41 (73%)
were positive for Aeromonas species.
Speciation of Aeromonas
10 (24.4%) A. hydrophila,
10 (24.4%), A. caviae,
9 (22%) A. sobria, and
12 (29.2%) atypical aeromonads.
Hemolysin production was detected in
all (100%) Aeromonas isolates.

6. Of the 41 Aeromonas isolates
20 (48.8%) showed mannose-sensitive
hemagglutination.
14 (34.1%) showed mannose-resistant
hemagglutination.

7. Resistance of Aeromonas from drinking water
obtained from fasghias in Tripoli-Libya
Antibiotic
No (%) resistant
(n=41)
---------------------------------------------------------------------Ampicillin
31 (75.6)
Amoxicillin +
14 (34.1)
clavulanic acid
Amikacin
3 (7.3)
Chloramphenicol
15 (36.6)
Ciprofloxacin
1 (2.4)
Nalidixic acid
3 (7.3%)
Tetracycline
1 (2.4%)
Trimethoprim2 (4.8%)
sulphamethoxazole

8. CONCLUSION
Antibiotic-resistant pathogenic
Aeromonas species are common in
drinking water from water
reservoirs (Fasghia) in Tripoli.