Aeromonas hydrophilain livestock: incidence, biochemical characteristics and antibiotic susceptibility

Abstract

Faecal samples from 110 horses, 115 pigs, 111 sheep and 123 cows were examined for the presence of Aeromonas hydrophila, which was also sought in the available drinking water. The overall faecal rate was 11.8%, but significantly more bovine than other samples were found to be positive. There was significant association between the isolation of A. hydrophila from all animal faeces and its presence in drinking water, but this was not found when individual animal groups were analysed separately. An enrichment technique increased the total number of isolates by 77.1%. Strains of differing origins could not be differentiated by biotyping, although fermentation of sorbitol was associated with bovine isolates. There was a strong positive correlation between positive reactions for V--P, gluconate oxidase and haemolysis of rabbit erythrocytes, tests which had previously been shown to correlate with production of enterotoxin and cytotoxin. Biotypes giving positive reactions for these tests were most frequently isolated from cows, sheep and untreated water, and less frequently from pigs and horses. Most strains of A. hydrophila were resistant to amoxycillin, carbenicillin and cephradine, and sensitive to gentamicin, chloramphenicol and neomycin.

Biochemical Characteristics, Enterotoxigenicity and Susceptibility to Antimicrobial Agents of Clinical Isolates of Aeromonas Species Encountered in the Western Region of Saudi Arabia

“…are generally self-limiting, but antimicrobial treat-ment may be necessary in serious infections, particularly systemic infection in immunocompromised patients. The antimicrobial susceptibility patterns observed in strains isolated in Saudi Arabia were similar to those reported from Great Britain, Canada and the United States of America (Smith, 1980;Fainstein et al, 1982;Gray, 1984). Most strains were resistant to broad-spectrum penicillins and many were also resistant to cefuroxime and cefoxitin.…”

The incidence of virulence factors in mesophilicAeromonasspecies isolated from farm animals and their environment

“…It has been suggested that environmental [24] and animal isolates [19] may be important reservoirs of aeromonads that are capable of causing human infection. Aeromonads have been isolated from a variety of food products [25][26][27], and as aeromonads multiply during chill-storage of foods [26,27], this has generated speculation that there may be an increasing hazard of human food poisoning from this source.…”

“…As lysine decarboxylase production in API 20E may be unreliable [19], all lysine reactions were checked by heavy inoculation of M6llers lysine broth (Taylor modification, Oxoid), overlayered with sterile liquid paraffin (> 1 cm depth). Tests were incubated for 5 days at 30°C and read daily.…”

“…Tests were incubated for 5 days at 30°C and read daily. Gluconate broth was used to detect gluconate oxidase as described by Gray [19]. Aesculin hydrolysis was detected by the agar plate method of Lee and Donovan [20].…”

Microbiological, physical and chemical studies on fresh red meats packaged under different modified gas atmospheres

“…The organism has also been isolated from chlorinated water, livestock feces and bone man'ow (Burke et al, 1984;Stern et al, 1987). Gray (1984) detected A. hydrophila in about 12% of healthy farm animals including cows, sheep, pigs and horses.…”