Production Of Some Virulence Factors Under Different Growth Conditions And Antibiotic Susceptibility Pattern Of <i>Aeromonas hydrophila </i>

Abstract

The production of some virulence factors under different growth conditions and antibiotic suscept bility pattern of Aeromonas hydrophila were investigated in this s udy. The virulence actors tested on the isolates included haemolytic activity, exopolysaccharide (capsule) and toxin production. Other cell property evaluated was antibiotic resistance. Of the several chemotherapeutants tested, streptomycin had Minimal Inhibitory Concentration (MIC) and Minimal Cidal Concentration (MCC) at 25 µg/ml; flumequine, MIC 15 µg/ml and MCC 20 µg/ml; nitrofurantoin, MIC 20 µg/ml and MCC at 20 µg/ml; chloramphenicol, MIC 15 µg/ml and MCC 30 µg/ml and nalidixic acid, MIC 25 µg/ml, MCC 30 µg/ml, respectively. Virulence characteristics were apparent from the study; the properties exhibited such as ß-haemolytic activity (F= 1.32551; p < 0.001) and toxin product on (F = 0.141; p > 0.05) were evidence of the pathogenic potential of A. hydrophila.

Determination of beta-haemolytic activity and minimum inhibitory concentrations of antimicrobial drugs against Aeromonas hydrophila strains isolated from fish products

“…Our results were in agreement with these data, with MIC values for cefoxitin of ≤0.5-16 µg/mL and for ceftriaxone of ≤0.25-32 µg/mL. Dibua & Okpokwasili (2006) indicated that MIC of chloramphenicol vs. A. hydrophila was 15 µg/mL, and that of tetracycline -80 µg/mL. Jones et al (1988) reported that the MIC of azithromycin against A. hydrophila was 4 µg/mL.…”

“…Unlike us, Thayumanavan et al (2003) showed a resistance to gentamicin (3.6%). The MIC of gentamicin according to Dibua & Okpokwasili (2006) is 50 µg/mL, of kanamycin -45 µg/mL and of streptomycin -25 µg/mL vs. A. hydrophila. The MIC values obtained in this study for gentamicin (≤1-4 µg/mL) and kanamycin (≤8-16 µg/mL) were lower, and the results for streptomycin -comparable (≤ 32 µg/mL).…”

In vitro antimicrobial and antihelminthic activity of the ethanolic extracts of Allium sativum, Allium cepa, Lantana camara, Averrhoa carambola and Syzygium aromaticum

“…Ten (10) of the earthworms (P. posthuma) of similar sizes were gently dropped into 20 mg/ml of each ethanolic extract; 20 mg/ml of piperazine; and 20 mg/ml of the control (5% DMF), respectively, in 50 ml conical flask. These were then observed for 24 h for significant behavioral responses (morbidity behaviors) ranging from erratic movement, contraction and relaxation of circular and longitudinal muscles, slower or irregular movement and pale appearance as well as time of killing as described by Dibua and Okpokwasili, (2006).…”