Cwikova Olga, Alena Hovorkova, O. Mrtz, Iva Steinhauserova and Z. Matyas: Aeromonads in SlaUghtered Chickens: Their Species and Pathogenic Factors. Acta vet. Brno, 62, 1993: 95-102. Washings from 155 eviscerated chicken carcasses coming from 16 agricultural co-operatives were examined at 14-day intervals during one yeat. The isolation attempts yielded 91 aeromonad strains which were further specified, tested for cytotoxicity and examined for pathogenicity for the white mouse. Aeromonads were found in 13 (81 %) agricultural co-operatives, being detected in 58 (41.4%) out of 140 chickens. Examination of the washings detected 36 (39.6%) A. sobria strains, 21 (23.1)% A. trota strains, 17 (18.7%) A. hydrophila strains, 9 (9.9%) A. caviae strains and 8 (8.8) A. jandaei strains. On the respective farms 2 to 3 species were generally found in cOmbination. Of the 91 strains 89 (97.8%) grew in S-phase, 85 (93.4%) haemolysed blood agar and 67 (73.6%) produced cytotoxic effect on tissue culture of MDBK cells. Agreement between all these characteristics was found in 63 (69.2%) strains. In bioassays the pathogenicity agreed with the results of S-phase -growth in -17 (77.3%) out of 22 strains, with the results of beta-haemolysis in 16 (72.7%) out of 22 strains and with those of cytotoxicity in9 (69.2%) out of 13 strains. Agreement between alI these thr~e characteristics was found in 9 (52.9%) out of 17 virulent strains. As pathogenic were classified 3 out of 4 A. caviae strains, 5 out of 8 A. hydrophila strains, 6 out of 8 A. sobria strains (the remaining two strains grew in R-phase) and all A. trota strains examined. Aeromonads, slaUghter~d chickens, food hygiene Only motile aeromonads and then particularly A. hydrophila, A. sobria-and A. caviae, associated'. with gastroenteritis, were described as important from the viewpoint of food hygiene (Janda et al. 1984). Recently, however, ithas become applfrei:J.fthat some other species, naml'ly A.jandaei (Carnahan et al. 1991b), A. veronii (Hickman Brenner et al. 1987) and possibly alsoA. trota.(Carna,han et al. 1991c) may also be entl;l'Opathogenic. Data on thc;se species are fewerin number and none at all have been recorded in this country. The only published data on food hygiene-related aeromonads in this country so far have been the findings of.i4. hydrophila in faeces (Pauc:kova and Fukalova 1986) and the information contained in two reports (Kamenik 1990, Aldova and Schindler 1991). The present study on aeromona<ls in slaughtered chickens was therefore. carried out to draw attention to this question. in our countrY. Relevant published data along this line provide information only on the species A. hydrophila; these microorganisms were isolated from pOUltry purchased from retail dealers (palumbo et a1. 1989) and from refrigerated raw (Nagel et a1. 1960) or cooked pOUltry (Toule and Murphy1978). Th¢ pnly study approaching our objective ,is#Ult of Barnhart et al. (1989) who reported the recovery of. A. hydrophila from broiler carcasses. Our study is concerned in addition withthe other aeronionad species and their pathogenic factors.