ABSTRACT
The aim of the study was to evaluate the prevalence of bacterial antibiotic resistance in
seawater and the anthropogenic influence from five beaches in Algiers.
The rates of resistance of the total flora were significant for amoxicillin and ticarcillin,
whereas they are relatively low for ceftazidime, céfotaxime and imipenem. The level of
resistance is higher in beaches receiving the anthropogenic inputs (amoxicillin, 52.2% and
43.1%; ticarcillin, 47.7% and 19.6%; céfotaxime, 2.8% and 8.3%) than in the unpolluted
beaches (amoxicillin, 9.4% and 1.15% ; ticarcillin, 7.6% and 0.8% ; céfotaxime, 0.1% and
0.6%).
In total coliforms, high rates of resistance were found against amoxicillin (20.7%, 8.3%,
16.2% and 43.2%) and ticarcillin (10.3%, 10.4%, 13.5% and 40.9%). Resistance to
cefotaxime and imipenem was observed with rates of 8.3% and 0.4% in Réghaia.
59 strains resistant to at least one of the major antibiotics, imipenem, cefotaxime, cefoxitin
and ceftazidime were identified as Pseudomonas aeruginosa (n=23), Pseudomonas
fluorescens (n=10), Stenotrophomonas maltophilia (n=6), Burkholderia cepacia (n=3),
Bordetella spp (n=3), Pontoea spp (n=2), Acinetobacter baumanii, Chrysiomonas luteola,
E.coli, Ochrobactrum anthropi, Citrobacter freundii, Enterobacter cloacae, Aeromonas
hydrophila and Shigella spp.
The study of their antibiotic sensitivity showed a high rates of resistance to beta-lactam
antibiotics including penicillins (amoxicillin, 86.4% ; ticarcillin, 84.7%), cefoxitin (93.2%)
and third generation cephalosporins (cefotaxime, 84.7% ; ceftriaxone , 84.7% and cefsulodin,
81.3%). Resistance to ceftazidime, aztreonam and cefepime was average (54.2%, 66% and
39%, respectively). Whereas the imipenem resistance was lower (25.4%). Concerning the
other families of antibiotics, a high resistance was observed to the acid nalidixic (84.7%) and
triméthoprime (79.6%) followed by chloramphenicol (54.2%), tétracycline (44%),
triméthoprime+sulfamides (28.8%), and sulphamides (22%). A very low resistance was
observed against aminoglycosides (K, GM), ciprofloxacin and rifampicin (4%, 10% and
15.2%, respectively).
The production of inducible chromosomal AmpC was observed at 32.2% of strains. The
synthesis of extended-spectrum beta-lactamase (ESBL) was found at only one strain: E.coli
selected on cefotaxime. The genetic characterization of this enzyme showed the presence of
CTX-M gene of group 1 carried by a selfconjugative plasmid of approximately 54Kb.
Key words: BLSE – résistance - beta-lactamines – beaches - total flora – total coliforms.
The aim of the study was to evaluate the prevalence of bacterial antibiotic resistance in
seawater and the anthropogenic influence from five beaches in Algiers.
The rates of resistance of the total flora were significant for amoxicillin and ticarcillin,
whereas they are relatively low for ceftazidime, céfotaxime and imipenem. The level of
resistance is higher in beaches receiving the anthropogenic inputs (amoxicillin, 52.2% and
43.1%; ticarcillin, 47.7% and 19.6%; céfotaxime, 2.8% and 8.3%) than in the unpolluted
beaches (amoxicillin, 9.4% and 1.15% ; ticarcillin, 7.6% and 0.8% ; céfotaxime, 0.1% and
0.6%).
In total coliforms, high rates of resistance were found against amoxicillin (20.7%, 8.3%,
16.2% and 43.2%) and ticarcillin (10.3%, 10.4%, 13.5% and 40.9%). Resistance to
cefotaxime and imipenem was observed with rates of 8.3% and 0.4% in Réghaia.
59 strains resistant to at least one of the major antibiotics, imipenem, cefotaxime, cefoxitin
and ceftazidime were identified as Pseudomonas aeruginosa (n=23), Pseudomonas
fluorescens (n=10), Stenotrophomonas maltophilia (n=6), Burkholderia cepacia (n=3),
Bordetella spp (n=3), Pontoea spp (n=2), Acinetobacter baumanii, Chrysiomonas luteola,
E.coli, Ochrobactrum anthropi, Citrobacter freundii, Enterobacter cloacae, Aeromonas
hydrophila and Shigella spp.
The study of their antibiotic sensitivity showed a high rates of resistance to beta-lactam
antibiotics including penicillins (amoxicillin, 86.4% ; ticarcillin, 84.7%), cefoxitin (93.2%)
and third generation cephalosporins (cefotaxime, 84.7% ; ceftriaxone , 84.7% and cefsulodin,
81.3%). Resistance to ceftazidime, aztreonam and cefepime was average (54.2%, 66% and
39%, respectively). Whereas the imipenem resistance was lower (25.4%). Concerning the
other families of antibiotics, a high resistance was observed to the acid nalidixic (84.7%) and
triméthoprime (79.6%) followed by chloramphenicol (54.2%), tétracycline (44%),
triméthoprime+sulfamides (28.8%), and sulphamides (22%). A very low resistance was
observed against aminoglycosides (K, GM), ciprofloxacin and rifampicin (4%, 10% and
15.2%, respectively).
The production of inducible chromosomal AmpC was observed at 32.2% of strains. The
synthesis of extended-spectrum beta-lactamase (ESBL) was found at only one strain: E.coli
selected on cefotaxime. The genetic characterization of this enzyme showed the presence of
CTX-M gene of group 1 carried by a selfconjugative plasmid of approximately 54Kb.
Key words: BLSE – résistance - beta-lactamines – beaches - total flora – total coliforms.