Thumbnail Image

Thesis

Browse

Show more
20151
Reset filters
Subject: Veterinary Pathology × Author: CHINJU BOSE × End date: 2019 × Start date: 2011 ×
Reset filters

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    ThesisItemOpen Access
    BACTERIAL ETIOPATHOLOGY OF PULMONARY INFECTIONS IN PIGLETS
    (COLLEGE OF VETERINARY AND ANIMAL SCIENCES-MANNUTHY,THRISSUR, 2015) CHINJU BOSE; Mammen J Abraham
    The present study was undertaken to determine the bacterial etiopathology of pulmonary infection in piglets. Twenty five piglet carcasses with gross respiratory lesions were selected for detailed pathological and microbiological examination. Brain heart infusion agar (BHIA) supplemented with sterile defibrinated bovine blood at 7 to 10 per cent and chocolate agar were used for cultural isolation of organisms. Identification of isolated agents was carried out, following the methods described by Quinn et al. (1994). Five different microorganisms, with Salmonella being dominant followed by E. coli, Proteus, Staphylococcus and Actinobacillus were obtained from lung, heart blood or tracheal exudates. Salmonella and E. coli were further confirmed by polymerase chain reaction as per the methods elaborated by Krithiga et al. (2014) for ExPEC and Chiu et al. (2005) for S. enterica serovar Choleraesuis. All Salmonella isolates generated expected PCR product, with a molecular mass of 963 bp. PCR amplification of two virulent genes fimH and iucD of E. coli revealed presence of fimH in all isolates and iucD in 40 per cent of E. coli isolates. The gross and histopathological features of obtained etiological agents have been described separately. Prominent pathological lesions encountered in porcine salmonellosis were suppurative bronchopneumonia, pulmonary edema, circulatory disturbances and lymphoid depletion in lymph nodes. Pathogenicity studies with mice revealed that Salmonella infection could be achieved via intranasal inoculation, indicating aerosol transmission as a possible route in salmonellosis. Most of the pathological lesions observed in mice were comparable with those of porcine salmonellosis, with some variations in lung lesions. Porcine E. coli infection was characterised by interstitial pneumonia, pulmonary congestion, pleurisy and bronchial lymph node congestion. Experimental studies in mice with porcine E. coli isolates proved them to be highly pathogenic. Suppurative pneumonia was evident in Staphylococcosis. In Actinobacillosis, hyperaemia of airways and consolidation of cardiac lobes of lungs were seen. Results of this study proved the role played by Salmonella and E .coli in inducing respiratory infections, in addition to gastrointestinal problems. This study also highlights the necessity of screening porcine pneumonic lung for Salmonella sp. and E. coli considering their high zoonotic potential.