A Okwori, S Agina, A Olabode, A Ochapa, A Turay, L Lombin
A Okwori, S Agina, A Olabode, A Ochapa, A Turay, L Lombin. Profiles Of Yersinia Enterocolitica Isolated From Apparently Healthy Pigs In Jos, Nigeria. The Internet Journal of Microbiology. 2008 Volume 6 Number 1.
A total of three hundred and twenty pig samples were collected from Jos and its environs. The samples comprised of tonsils (160) and faeces (160) from five different study areas. Identification of isolates was based on cultural method by the use of cold enrichment and direct plating on differential and selective culture media. Fifty six (56) strains of
There is a strong indirect evidence that swine constitute an important reservoir for human infection with
The pig is the only food animal which regularly harbours pathogenic
In Nigeria, 11 and 12 reported the oocurrence of
This study was aimed at establishing the frequency and profiles of pathogenic
Materials And Methods
Three pig herds (Kaduna Vom, Kuru, and Vwang) located in Jos South Local Government Area and one large weekly pig market in Kafanchan, Kaduna State (neighbouring Local Government Area to Jos) were selected for this study (Fig.1). A total of 320 tonsil and faecal samples were screened for the presence of
1g of faeces and tonsil swab samples were aseptically transferred into 10 ml of phoshate buffered saline (pH 7.2) (Life Technologies Ltd, Paisely, Scotland), vortexed and homogenized for about 30 s and incubated at 4°C for three weeks and subsequently subcultured into Deoxycholate Citrate Agar (DCA), MacConkey Agar (MCA) and Cefsulodin Irgasan Novobiocin Agar (CIN). The culture plates were incubated at 30°C for between 18 - 24 h 15 .
Bacterial isolation and identification
Culture plates (DCA (Oxoid, UK), MCA (Fluka, Sigma Aldrich
Chemie, GmBH, Germany), CIN (Oxoid, UK) were examined. Suspected colonies were further subjected to motility test by hanging drop technique both at 25 and 37°C. Isolates that were motile at 25 ° C but non motile at 37°C were selected. Biochemical test (API 20E, Biomereux, France) including urease activity were used for the bacterial identification 16 .
Serological typing was done by slide agglutination test using specific typing sera O:1, O:2, O:3, O:5, O:8, O:9 for
Isolates were biotyped according to the revised scheme of 17 using pyrazinamidase activity, esculin hydrolysis, salicin acidification, tween-esterase activity, indole production, xylose acidification and nitrate reduction. All strains were recognised as pathogenic by virtue of their biochemical classification of 17 .
The sensitivity spectrum of each of the isolates to eight different antibiotics was determined by standardized diffusion method 18,19 . The antimicrobial agents used were ciprofloxacin (10µg/ml), tarivid (10µg/ml), gentamycin (10µg/ml), streptomycin (20µg/ml), amoxicillin (10µg/ml), ampicillin (10µg/ml), and erythromycin (10µg/ml) (Abtek biological Ltd, Liverpool, UK). The diameters of the zones of inhibition around each antibiotic disc were measured in millimetres.
Data management and analysis
Chi-square test with Yates continuity correction was used to test if there was any difference in the prevalence of
Samples from the three pig farms visited in Jos and the weekly pig market in Kafanchan, Kaduna State were all positive for
All isolates belonged to predominant human and animal serotypes in Nigeria 14,20 , 18 and 14
(Table 4). All strains of
Our findings are further proof that the pig population in the study areas are reservoir of human infections as serotypes and biovars isolated in these herds have been found to be responsible for most epizootics diseases as documented in a similar study by 21 . This is perhaps the only biogroups present among swines in this part of the world. The prevalence rate (17.5%) found in this study are consistent with the rates found by 22 in Denmark and Norway 23 . These findings are also similar to reports in other parts of the world particularly in India 24 and Finland 25 where
Although this study can not give complete information about the true prevalence of
Prevalence rates of 15% and 20% recorded for faecal and tonsil samples in our studies confirms previous studies that have identified this bacteria (
Exceptionally high susceptibility to spectrum of antibiotics such as ciprofloxacin, tarivid and gentamycin as documented in our finding has been similarly reported in Nigeria by 14,20 .
Our results support the assumption that the use of conventional cultivation methods may lead to considerable underestimation of pathogenic
Overall, our findings implicated tonsils as the most volunerable tissue to