Occurrence of bacterial agents in lungs of pigs and evaluation of their resistance to antibiotics

The goal of this work was to investigate the type and etiology of bacterial porcine pneumonia by analyses of autopsy findings made in the Tierarztlichen Ambulant Schwarzenbek, Aussenstelle der Freien Universitat Berlin, and in the Institut fur Tiergesundheit, Milchhygiene und Lebensmittelqualitat der Landwirtschaftskamner Westfalen-Lippe in Munster in the years from 1991 to 1993. The evaluation of the results of total 6560 autopsies (N = 6560) of pigs shows: 1. Pneumonia as the main diagnosis was found in 24.4% (n = 1599), as the second diagnosis in 14.3% (n = 941) of the sections. 2. Fattening pigs show signs of pneumonia (43.2% (n = 1096) vs. 27.8% (n = 706); N = 2540) more frequently than younger pigs, 3. The most frequently isolated etiologic agents from lung specimens (N = 2337) were Pasteurella multocida (49.3%; n = 1152), Actinobacillus pleuropneumoniae (5.4%; n = 125) and Bordetella bronchiseptica (5.3%; n = 124). 4. With increasing age the isolation rate of Pasteurella multocida (piglets [N = 210]: 21.4%, n = 45; fattening pigs [N = 652]: 61.8%, n = 403) and Actinobacillus pleuropneumoniae !piglets: 1.4%, n = 3; fattening pigs: 7.1%, n = 46) increased while Bordetella bronchiseptica (piglets: 10.0%, n = 21; fattening pigs: 1.1%,, n = 7) and Haemophilus parasuis (piglets: 3.8%, n = 8; fattening pigs: 0%, n = 0) were isolated at decreasing rates. 5. Most cultures of the lung samples (N = 2337) showed multiple infections (1087 = 54.2%). 6. The highest rate of single bacterial isolates was found for Pasturella multocida (40.9%, n = 471, N = 1152) in relation to Haemophilus parasuis (30.9%, n = 11, N = 36), Actinobacillus pleuropneumoniae (24.0%, n = 30, N = 125), and Bordetella bronchiseptica (20.2%, n = 25, N = 124). 7. Less than 10% of the examined Pasteurella multocida, Actinobacillus pleuropneumoniae, Bordetella bronchiseptica and Haemophilus parasuis strains were resistant to tetracycline, oxytetracycline, enrofloxacin and kanamycin, but more than 55% were resistant to sulfonamides.