Distribution, Diversity and Antibiotic Resistance of Pseudomonas spp. Isolated from the Water Dams in the North of Tunisia.

Natural environment is one of the important reservoirs to disseminate antibiotic resistance, most of the antibiotics resistance researches were focused on clinical isolates. Thus, this work aimed to analyze surface water samples collected from dams and rivers in the north of Tunisia. Pseudomonas species were confirmed using biochemical and molecular identifications. Resistance was studied by testing their susceptibility against 19 antibiotics using the disc diffusion method moreover the virulence factors were studied by PCR targeting 13 genes. 104 isolates were confirmed as Pseudomonas genera distributed into 21 species. The most abundant species is P. aeruginosa (22.11%), followed by P. protegens (12.5%). No resistance phenotypes were observed towards imipenem, meropenem, ceftazidime, colistin, ciprofloxacin and amikacin. A high resistance level was observed against cefoxitin (94.23%), amoxicillin-clavulanic acid (67.31%), nalidixic acid (62.5%), streptomycin (57.69%), ticarcillin (43.27%), fosfomycin (64.42%) and tetracycline (23.08%). A low rate of resistance was observed against cefotaxime (16.35%) and gentamicin (7.69%). The majority (70.19%) of isolates were Multidrug-resistant (MDR). 12 of virulence genes were found in all P. aeruginosa isolates. Our results showed that Pseudomonas isolates could be an important reservoir of antibiotic resistance from environment sites.