Sinyangwe, P.G(PhD)Nyeleti, Charles2022-05-112023-11-082022-05-112023-11-081999-12http://etd.aau.edu.et/handle/123456789/31602A cross-sectional study was carried out for the period of 6 months in selected sites of Addis Ababa in order to determine the prevalence and distribution of Salmonel/a in the cattle chain fj'om abattoir to the consumer. The sources analyzed were pooled cattle faeces, pooled mesenteric Iymphnodes, single muscles from the diaphragm as well as \i'om the abdominal region. Additional minced beef from supermarkets destined for human consumption and additinally stool samples from the abattoir personnel were included in the survey. The iso lated Salmonella- strains were serotyped and resistance against antibiotics determined. for the culture method, the technique recommended by the International Organization for Standardization (ISO 6579, 1998) was chosen. Antimicrobial results were analyzed based on the descrption by A VlD (1987). All the data collected on the pl'evalence and Salmollella distribution Irom the samples were presented in form of tables and figures. The Chi- Square test analyzed stati stically whether there was association between Salmollella prevalence with animal condition or mode of transport conditions, supermarkets or storage conditions in supermarkets. Analyzing prevalence and distribution of Salmonel/a from 235 abattoir cattle randomly selected samples leads to the following results: in 47 pooled samples of faeces (containing five samples) 5 Salmollel/a strains (10.6 %) were isolated, in 47 pooled samples of mesenteric Iymphnodes there were 9 strains (19.6 %). In 235 single samples of the abdominal (oblique and transverse muscle) 23 (9.8 %) and in 235 diaphragmatic muscles 28 Salmonella were found (11.9 %). From 300 stool samples of the abattoir personnel in 18 cases (6.0 %) Salmollella were isolated. Minced beef from the 22 supermarkets with an overall of 330 samples contai ned in 26 of the units (7.9 %) Salmollella cases. In the entire study, 98 surviving Salmollel/a strains were serotyped and identified as 27 S. Anatum, 53 S. Dublin, 5 S. Meleagridis, 1 S. Muenchen, 9 S. Saintpaul alld 3 S. rough form. From the pooled samples of faeces 4 S. Dublin and I S. Muenchen, of the pooled samples of mesenteric Iympllllodes 3 S. Analum and 2 S. Dubl in have been found. In single samples of abdominal muscl es 18 S. Dublin and 3 S Anatum and in diaphragmatic muscle samples 2 1 S. Dublin and 2 S. Anatum occurred. The cattle specific S. Dublin was the most dominant serovar in all the cattle samples. The 18 Salmollel/a iso lates from the abaltoir personnel consisted of 7 S. Aantum, 4 S. Dublin, 5 S. Meleagridis and 2 Salmonella roughforms. In this case S. Allalllll/ was the most predomi nant serovar fo llowed by S. Meleagridis which was never iso lated from the cattle chain. From minced beef 26 Salmol/ella strains were cultivated comprising 12 S. Anatum, 4 S. Dublin, 9 S. Saintpaul and 1 S. rough form. 3 Salmonella serotypes, (2 S. Anatum, I S. Dublin and 6 S. Saintpaul) originated fi'om Kaliti abatloir. In this of Kara abattoir all 3 strains belonged to S. Saintpaul. In llIinced meat originating from Addis Ababa lOS. Anatum, 3 S. Dublin and I S. rough form but no S. Saintpaul were found. In all the samples of Addis Ababa abattoir (faeces, mesenteric I ymphnodes, beef cuts and minced meat) no S. Saintpaul was detected neither. The 98 Salmonella isolates were tested for resistance against the seventeen antibioti cs. This result is an indication of rarely using antimicrobial agents in Ethiopian cattle, hence no drug resistance was observed during the antimicrobial tests. Low prevalence of Salmonella in the li ving cattle, indicated by low isolation rates from faeces and Iymphnodes, at one hand and high Salmonella prevalence in samples of beef cuts (abdominal and diaphragmatic muscles) on the other hand lead to the conclusion that there must have been severe contamination during the skinning process as a resu lt of bad hygiene during subsequent dressing operations. To reduce the Salmonella burden to the public it is therefore essential to improve the hygienic conditions at slaughterhouse and to slaughter only health animals. In future there should be planned a study containing all the meat products with a considered Salmonella contamination risk to quantify the total hazard of Salmonella infection for the consumer.enThesis