Fig. 1.
Geographical location of Sekkak dam.
Fig. 2.
Seasonal variations of the physicochemical parameters of the Sekkak dam.
T – temperature (°C), pH – potential hydrogen, DO2 – dissolved oxygen (%), OM – organic matter (mg/l), BOD5 – biological oxygen demand 5 (mg/l), COD – chemical oxygen demand (mg/l), NO3– – nitrates (mg/l), NO2– – nitrites (mg/l), NH4+ – ammonium (mg/l), Ds – dry residue (mg/l), PO43– – phosphorus (mg/l), SD – standard deviation
Fig. 3.
Seasonal variations of different bacterial groups.
Table I
Characterization and identification of isolates.
| Strains | Catalase | Oxydase | Gram | Identification | |
|---|---|---|---|---|---|
| S33, S41• | + | − | − | Acinetobacter johnsonii* | Gram- (n = 45 stains) |
| S60, S58 | + | + | − | Aeromonas hydrophila* | |
| S43• | + | + | − | Alcaligenes aquatilis | |
| S32• | + | + | − | Comamonas testosteroni | |
| S40, S39• | + | − | − | Citrobacter freundii* | |
| S28, S62 | + | − | − | Edwardsiella tarda* | |
| S1, S10, S5, S2, S9• | + | − | − | Enterobacter cloacae | |
| S42 | + | − | − | Klebsiella sp. | |
| S44 | + | + | − | Photobacterium damselae | |
| S23, S34, S35 | + | − | − | Proteus mirabilis* | |
| S26 | + | − | − | Proteus vulgaris* | |
| S30, S29, S27 | + | − | − | Providencia rettgeri* | |
| S21• | + | − | − | Providencia vermicola* | |
| S11, S18, S16 | + | + | − | Pseudomonas aeruginosa* | |
| S24, S31 | + | + | − | Pseudomonas fluorescens* | |
| S17, S12 | + | + | − | Pseudomonas lactis | |
| S15, S19 | + | + | − | Pseudomonas luteola* | |
| S6, S36, S61• | + | − | − | Serratia fonticola | |
| S4, S56, S38 | + | + | − | Vibrio alginolyticus* | |
| S57, S37 | + | + | − | Vibrio fluvialis* | |
| S14, S13, S59• | + | + | − | Psychrobacter pulmonis* | |
| S55 | − | − | + | Aerococcus urinaeequi) | Gram+ (n = 17 stains |
| S8• | + | + | + | Bacillus flexus | |
| S54 | − | − | + | Enterococcus faecalis* | |
| S51, S3•, S50• | + | − | + | Leucobacter aridicollis | |
| S46• | + | + | + | Salinicoccus roseus | |
| S7• | + | + | + | Sporosarcina aquimarina | |
| S20 | + | + | + | Sporosarcina globispora | |
| S22• | + | + | + | Sporosarcina newyorkensis | |
| S25• | − | − | + | Vagococcus fluvialis | |
| S53, S52• | + | − | + | Microbacterium maritypicum | |
| S48, S49• | + | − | + | Staphylococcus equorum subsp. linens | |
| S45•, S47 | + | − | + | Staphylococcus aureus* | |
| Total | 62 strains |
Fig. 4.
Neighbor-joining phylogenetic tree of Gram-negative bacteria strains isolated from Sekkak dam using 16S rRNA sequences.
Fig. 5.
Neighbor-joining phylogenetic tree of Gram-positive bacteria strains isolated from Sekkak dam using 16S rRNA sequences.
Fig. 6.
Antibiotic resistance frequencies and percentage of resistant strains for each antibiotic. 
penicillins (beta-lactams family) 
cephalosporins (beta-lactams family) 
polymyxins family. 
aminoglycosides family. 
macrolides family. 
tetracyclins family. 
streptogramins family. 
novobiocin
Table II
Pattern of antibiotic resistance of isolates.
| Strains | Number of antibiotic | Patterns |
| Klebsiella sp. | 3 | OX AMP / E |
| Edwardsiella tarda | 4 | CX OX AMP / K |
| Proteus vulgaris | 4 | OX AMP CJ / E |
| Proteus mirabilis | 4 | CX OX AMP CJ |
| Edwardsiella tarda | 5 | CX OX AMP / K / NV |
| Proteus mirabilis | 5 | CX OX AMP CJ / NV |
| Proteus mirabilis | 5 | CX OX AMP AX CJ |
| Enterobacter cloacae | 5 | CX OX TI CJ CEP |
| Serratia fonticola | 5 | CX TI CEP / E / NV |
| Pseudomonas lactis | 6 | CX OX AMP CJ CFP / E |
| Pseudomonas lactis | 6 | CX OX AMP CJ / E / VI |
| Vibrio fluvialis | 6 | CX OX AMP AX TI NV |
| Pseudomonas aeruginosa | 6 | CX OX TI CJ CEP CTR |
| Pseudomonas luteola | 6 | CX OX AMP CJ CFP CAZ |
| Acinetobacter johnsonii | 6 | CX OX AMP AX TI CJ |
| Enterobacter cloacae | 6 | CX OX TI CJ CEP / VI |
| Vibrio fluvialis | 6 | CX OX AMP AX CFP / NV |
| Psychrobacter pulmonis | 7 | CX OX AMP AX TI CFP CAZ |
| Enterococcus faecalis | 7 | CX OX AMP AX CFP / CS / O |
| Salinicoccus roseus | 7 | CX AMP AX CFP CAZ / CS / O |
| Pseudomonas luteola | 7 | CX OX AMP CJ CFP CAZ / E |
| Vibrio alginolyticus | 7 | CX OX AMP AX CEP / K / NV |
| Vibrio alginolyticus | 7 | CX OX AMP AX CFP CEP / K |
| Pseudomonas aeruginosa | 7 | CX OX TI CJ CEP CFP CTR |
| Enterobacter cloacae | 7 | CX OX TI CJ CEP / E / O |
| Providencia rettgeri | 7 | CX OX AMP AX TI CJ / CS |
| Serratia fonticola | 7 | CX TI CEP CFP / GM / E / VI |
| Pseudomonas fluorescens | 7 | CX OX TI CJ CEP CTR / E |
| Enterobacter cloacae | 7 | CX OX TI CJ CEP / O / VI |
| Bacillus flexus | 8 | CX TI CEP CFP CAZ / CS / GM / VI |
| Staphylococcus equorum subsp. linens | 8 | CX AMP AX TI CEP CTX / CS / NV |
| Microbacterium maritypicum | 8 | CX OX AMP AX TI CJ CEP / CS |
| Acinetobacter johnsonii Providencia rettgeri | 8 | CX OX AMP AX TI CJ / CS / NV |
| Sporosarcina aquimarina Sporosarcina globispora | 8 | CX CFP CAZ CTR / CS / GM / E / VI |
| Citrobacter freundii | 8 | CX OX AMP AX TI CJ CEP / O |
| Pseudomonas aeruginosa | 8 | CX OX TI CJ CEP CFP CAZ CTR |
| Vibrio alginolyticus | 8 | CX OX AMP AX CFP CEP / K / NV |
| Aerococcus urinaeequi | 9 | CX OX TI CEP CFP CAZ / CS / GM / VI |
| Aeromonas hydrophila | 9 | CX OX AMP CJ CAZ / CS / E / O / VI |
| Aeromonas hydrophila | 9 | CX OX AMP AX CJ / CS / E / O / VI |
| Staphylococcus aureus | 9 | CX OX AMP AX CEP CTX / CS / O / NV |
| Staphylococcus aureus | 9 | CX OX AMP AX TI CEP CTX / CS / O |
| Citrobacter freundii | 9 | CX OX AMP AX CJ CEP CTX / CS / O |
| Comamonas testosteroni | 9 | CX OX AMP AX TI CEP CAZ / TOB / O |
| Serratia fonticola | 9 | CX TI CEP CFP CAZ / GM / E / VI / NV |
| Vagococcus fluvialis | 10 | CX OX TI CJ CEP CTX CFP / CS / GM / VI |
| Pseudomonas fluorescens | 10 | CX OX TI CJ CEP CFP CTR / CS / TOB / E |
| Leucobacter aridicollis | 10 | CX OX TI CJ CEP CFP CAZ CTR / CS / O |
| Staphylococcus equorum subsp. linens | 10 | CX AMP AX TI CEP CTX CFP CAZ / CS / NV |
| Psychrobacter pulmonis | 10 | CX OX AMP AX TI CJ CEP CFP CAZ / O |
| Providencia vermicola | 10 | CX OX AMP AX CJ CFP CAZ / E / O / NV |
| Enterobacter cloacae | 10 | CX OX CJ CEP CFP CAZ / GM / E / VI / NV |
| Psychrobacter pulmonis | 11 | CX TI CJ CEP CFP CAZ CTR / GM / E / VI / NV |
| Photobacterium damselae | 11 | CX TI CJ CEP CFP CAZ / GM / K / E / O / NV |
| Microbacterium maritypicum | 11 | CX OX AMP AX TI CJ CEP CFP CAZ / CS / O |
| Leucobacter aridicollis | 11 | CX OX TI CJ CEP CFP CAZ CTR / CS / GM / O |
| Leucobacter aridicollis | 11 | CX OX AMP AX TI CEP CFP CTR CAZ / CS / O |
| Alcaligenes aquatilis | 12 | CX OX AMP AX TI CEP CFP CAZ / E / O / VI / NV |
| Sporosarcina newyorkensis | 13 | CX OX TI CJ CEP CFP CAZ CTR / CS / E / O / VI / NV |
| Providencia rettgeri | 14 | CX OX AMP AX TI CJ CFP CAZ / CS / TOB / E / O / VI / NV |