Virulence and antibiotic susceptibility of Aeromonas spp. isolated from drinking water.
Aeromonas isolates from tap water, mineral water, and artesian well water were investigated for their ability to produce different potential virulence factors or markers such as hemolysins, cytotoxins, phospholipase, DNase, hydrophobicity and their ability to adhere to epithelial cells and to abiotic surfaces. The susceptibility to antibiotics of Aeromonas isolates was also examined. Majority of the isolates displayed hemolytic activity against sheep erythrocytes, while only 7 of the 23 Aeromonas strains displayed DNase activity and 4 of the 23 Aeromonas strains tested were regarded as positive for phospholipase production. Most of the isolates showed cytotoxic activities in culture filtrate dilutions at titer of 1/8 or lower. No general relation between the strain isolated and the ability to interact with epithelial cells could be established. Using the bacterial adherence to hydrocarbons method, most of the strains were classified as highly hydrophilic. All five Aeromonas jandaei strains isolates, 9 of the 12 Aeromonas sp strains and four of the five Aeromonas hydrophila were multidrug resistant. The most active antimicrobial was ciprofloxacin (susceptible in 100% of the isolates), and the least active antibiotic was ampicillin (resistance in 92% of the isolates). The majority of the isolates tested were not killed by chlorine at 1.2 mg/l. Whether the high tolerance to chlorine of Aeromonas isolates can be linked to greater virulence is not know.
Scoaris
Denise de Oliveira
Dde O
Programa de Pós-graduação em Microbiologia, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid, Pr 445 Km 380, Cx. Postal 6001, 86051-990, Londrina, PR, Brazil.
Colacite
Jean
J
Nakamura
Celso V
CV
Ueda-Nakamura
Tânia
T
de Abreu Filho
Benício A
BA
Dias Filho
Benedito P
BP
D000333:Aeromonas / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004912:Erythrocytes / Q000382:microbiology; D006461:Hemolysis; D006801:Humans; D050296:Microbial Viability / Q000187:drug effects; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012756:Sheep; D013045:Species Specificity; D014774:Virulence; D014871:Water Microbiology; D014881:Water Supply
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial