Phenotypic characterization and PCR-ribotyping of pseudomonas fluorescens isolates, in tracking contamination routes in the production line of pasteurized milk

Contamination sites of Pseudomonas fluorescens were traced in the production line for milk pasteurization in a large dairy plant in Shiraz, Iran. Samples of raw and pasteurized milk were collected at six sites along the line. All milk samples were incubated at 7[degree sign] C until the aerobic plate count had reached 10[6] - 10[7] cfu mL[-1]. Colonies were picked randomly and identified. No growth of gram negative psychrotrophic bacteria [GNP] was detected in the immediately pasteurized milk samples [just after the pasteurization], during long incubation at 7 [degree sign] C. Recontamination most often occurred in the filling step. In this study 34.1 and 4.9% of the milk packages showed contamination with GNP and P. fluorescens, respectively. Twenty three P. fluorescens isolates were examined for phenotypic characteristics and 16S-23S PCR ribotyping. Phylogenetic analysis was conducted on the phenotypic and genotypic characteristics. The P. fluorescens isolates were shown to belong to 6 biotypes [B1-B6]. The predominance of a particular ribotype was often observed for a given biotype, although there were two ribotypes in each of the B2 and B6 biotypes. The 16S-23S PCR-ribotyping technique allowed differentiation between the isolates. Based on this method, the isolates belonged to 5 subtypes. Phylogenetic analysis based on 16S-23S PCR-ribotyping and phenotypic characterization could be helpful in tracking contamination routes in the production line form milk pasteurization

[ study on internal teat sealant for mastitis prevention in a dairy cows]

Mammary glands are particularly susceptible to new infections during the dry and early lactation periods. Dry cow antibiotic therapy in all quarters of all cows has been a traditional method to reduce the effect of these new infections. The objective of this study which was done for the first time in Iran was to determine the effect of infusion with Masti-Seal at dry off. Eighty Holstein Frisian dairy cows parity of 2 to 5 in 7 month of pregnancy were selected from a commercial dairy farm. All cows didn't show clinical mastitis in last month. The cows of group A [n=10] were randomly assigned to be treated in two quarters [LF/RR or RF/LR] with the sealant while two quarters in each cow remained as untreated controls. The cows of group B [n=10] were randomly treated with the dry cow therapy [DCT] and sealant. The cows of group C were randomly assigned to be treated in two quarters [LF/RR or RF/LR] with the DCT and sealant while two quarters were treated just with antibiotic DCT. In group D the effect of Masti-seal and Orbiseal in rear quarters were compared. Milk samples were collected for bacterial culture and somatic cell count [SCC] at dry off, 10-15 DIM. At calving, the Mastiseal was manually stripped from each quarter prior to collecting of colostrum. The clinical evaluations of teats were done in all groups at days 7, 14 and 28 after treatment. No changes in teats of cows were seen. Corynebacterium bovis and one yeast were isolated from 2 and 1 samples, respectively. The SCC of cows in group B increased significantly after parturition compared with cows treated by DCT. In other groups there were no significant differences between dry period and after parturition. Results revealed that using of Masti-seal in combination with DCT is useful. However, use of Masti-seal is a necessity even without antibiotics

Histopathologic and bacteriologic survey of nocardial pyothorax in a cat

A two year old male Iranian cat was presented to the pathology department of veterinary school of Shiraz University with lethargy anorexia progressive weight loss and severe acute respiratory signs and death. In autopsy thoracic cavity was full of a brown yellow blood tinged creamy like exudates. Sulphur granules were not observed. Thickening of pleura and pericardium associated with fibrino purulent exudates was observed. In histopathologic examination chronic pleuritis and pericarditis, chronic interstitial pneumonia and atelectasis were observed. Gram positive and acid fast organisms with branching filamentous bacilli were found by bacteriological studies of the thoracic exudates but no bacteria were recovered aerobically or anaerobically. A diagnosis of nocardial pyothorax was made on the basis of pathologic findings and bacteriologic examination of the thoracic exudates