ISOLATION AND CHARACTERIZATION OF PASTEURELLA MULTOCIDA FROM CATTLE IN PLATEAU STATE, NIGERIA
ISOLATION AND CHARACTERIZATION OF PASTEURELLA MULTOCIDA FROM CATTLE IN PLATEAU STATE, NIGERIA
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Date
2012-06
Authors
SUGUN, Manasa Yohana
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Abstract
Pasteurella multocida is associated with haemorrhagic septicaemia in cattle and buffaloes, pneumonic pasteurellosis in sheep and goats, fowl cholera in poultry, atrophic rhinitis in pigs and snuffles in rabbits. Haemorrhagic septicaemia is caused by P. multocida type B: 2, B: 2, 5 and B: 5 in Asian countries and type E: 2 in African countries. The present research work was undertaken with a view to isolate and characterize P. multocida from cattle in Plateau state, Nigeria. This contemporary study was necessary as available information indicates that such similar studies were conducted about 3 decades ago. A total of 396 samples of tissues and nasal swabs from cattle were examined for the presence of P. multocida. The isolates were studied for their species using PM-PCR, different serotypes, the presence of plasmids and in vitro antibiotic sensitivity. Of the 396 samples tested 4.5 % were non-haemolytic, round, greyish, smooth and mucoid colonies on casein sucrose yeast agar (CSY) and blood agar, failed to grow on MacConkey agar, and produced no gas in glucose and were lactose negative. They were found to be coccobacillus, Gram negative and non-motile. All the isolates produced oxidase, catalase, were indole positive and reduced nitrate, but did not utilize simmons citrate. They fermented glucose, sucrose, mannitol and mannose but not maltose, arabinose, lactose, dulcitol, salicin, inositol and trehalose. The eighteen isolates were confirmed by Microbact GNB 24E and the supplied software version Microbact TM 200 identification package V2.03 (Windows TM). By the software interpretation package, the percentage probabilities of 12 isolates were above 75% and 6 others were below 75%. Two of the isolates were detected to have somatic antigen 3,4 and one isolate 2,5 while in the remaining fifteen, somatic antigens were not detected. There were no significance differences between sexes and age by fisher‟s exact test P >
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0.05. In the distribution of P. multocida according to organs, lung, liver and spleen distribution were found to be significant by chi square P<0.05. Among the 18 isolates studied, (55.6%) were sensitive to sulphamethoxazole/trimethoprim, (44.4%) sensitive to gentamicin, amoxycillin/clavulanic and penicillin respectively. The % susceptibilities to other agents were: ciprofloxacin (38.9%), chloramphenicol (11.1%), oxacillin and vancomycin (5.6%) each and ampicillin (1.1%). All the isolates (100%) were resistant to tetracycline and erythromycin. Molecular characterisation of the isolates was carried out.The genotypic studies carried out included species-specific PCR assay, capsular grouping using multiplex capsular PCR typing system, determination of capsular groups A and B by PCR and determination of the carriage of plasmids by the isolates. All isolates produced P. multocida species-specific amplicons. Seventeen (94.4 %) of the isolates were identified as capsular group E and one (5.5 %) as capsular group F by multiplex PCR. The profiles of plasmids of each isolate were estimated by agarose gel electrophoresis. All the isolates harboured plasmids of 5kb. Three of the group E isolates had additional plasmid of 3kb, and one isolate (ka3) had a plasmid of 6kb; but none of the isolates carried all 3 plasmids. None of the eighteen isolates studied had capsular group A or B. The study confirmed the presence of the African capsular strain (E), but of greater interest is capsular group F that was identified for the first time in calves in Nigeria. P. multocida E: 3, 4 and P. multocida E: 2, 5 were identified amongst the isolates. These could redefine the vaccine strategy as the current vaccine used in Nigeria contain P multocida B: 3,4 and E: 2. However more work needs to be carried out in other parts of the country to gather more relevant information with regards to capsular and somatic types.
Description
A DISSERTATION SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES AHMADU BELLO UNIVERSITY IN PARTIAL FULFILLMENT FOR THE AWARD OF DOCTOR OF PHILOSOPHY IN VETERINARY MICROBIOLOGY DEPARTMENT OF VETERINARY PATHOLOGY AND MICROBIOLOGY FACULTY OF VETERINARY MEDICINE, AHMADU BELLO UNIVERSITY, ZARIA, NIGERIA
Keywords
ISOLATION AND CHARACTERIZATION,, PASTEURELLA MULTOCIDA,, CATTLE,, PLATEAU STATE,, NIGERIA.