an epidemiological study of listeriosis in dairy cattle

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serotyping) and found that PFGE was the most powerful technique in discriminating subtypes while MEE and serotyping were less discriminating. Destro and others (1996) used PFGE and RAPD to trace the contamination of a shrimp processing plant with L. monocytogenes . They suggested that to reach the best conclusion the two methods should be used together. This brief summary of information about typing methods employed in the field of listeriosis may lead one to conclude that no single method meets the criteria stated above because each technique lacks one or more important factor. However the superiority of RAPD over some techniques has been acknowledged (Mazurier and others 1992, Boerlin and others 1995, Wiedmann and others 1996). Others have suggested that a combination of two or more techniques will allow the best results (Norrung and Gerner-Smidt 1993, Destro and others 1996 and Louie and others 1996). The use of typing methods in epidemiological investigations of listeriosis has enabled the discrimination of individual strains of L. monocytogenes. An epidemiological link between contaminated foodstuffs and listeriosis in people has been established (McLauclin and others 1986, Nocera and others 1990, Norrung and Skovgaard 1993). Similarly a link between silage (Vazquez -Boland and others 1992, Baxter and others 1993, Wiedmann and others 1994), bedding (Green and Morgan 1994) and clinical listeriosis in animals has been established using these techniques. However there is little detail regarding the distribution and temporal occurrence of these strains in the veterinary field (Low and Donachie 1997). 1. 6. Pathogenesis, infectious dose, virulence and resistance: a) Pathogenesis: The ways in which L. monocytogenes reaches and causes systemic illness and disturbances in the brain have long been the subject of interest. The existence of different forms of clinical listeriosis and their irregular distribution in 15
animals suggests that L. monocytogenes gains entry in several ways. Numerous naturally occurring epidemic and sporadic cases of listeriosis and experimental studies have shown the importance of the oral route as the initial exposure site. The clinical occurrence of encephalitis and experiments carried out by Asahi and others (1957) and Barlow and McGorum (1985) suggest that encephalitis follows infection of the brain stem, resulting from L. monocytogenes ascending via cranial nerves following minute wounds in buccal mucosa, inhalation and conjunctival contamination. Intranasal infection of sheep with L. monocytogenes (Gill 1933) and conjunctival inoculation of rabbits (Gray and others 1948) resulted in encephalitis. Asahi and others (1957) produced encephalitis by instilling L. monocytogenes into the conjunctiva, lips, gum, parotid region, oral cavity and tongue of mice, rabbits and goats after breaking the integrity of mucosal membranes, and also by feeding L. monocytogenes contaminated feed to the animals. Their histopathologic and clinical examination revealed that encephalitis occurred after instillation of L. monocytogenes through bruised and wounded membranes and feeding contaminated feed to goat, mice, rabbits. Mucosal damage played an important role in infecting the trigeminal nerve which then carried the organism to the brain. Barlow and McGorum (1985) produced encephalitis in sheep by inoculating L. monocytogenes into the dental cavity and they also acknowledged the role of the trigeminal nerve in the occurrence of encephalitis. These studies have contributed to the hypothesis that forages such as grass, silage, grain awns, straw and hay can break up the integrity of mucosal membranes and allow L. monocytogenes to penetrate them. Having penetrated the mucosal membrane L. monocytogenes can then travel along cranial nerves (especially trigeminal nerve) to reach the brain (Dennis 1993). Subcutaneous injection of mice with L. monocytogenes also resulted in encephalitis and this points to the role of infected wounds and the 16
Page 1 and 2: AN EPIDEMIOLOGICAL STUDY OF LISTERI
Page 3 and 4: In the second part of the study a l
Page 5 and 6: I would like to thank to Metin Oztu
Page 7 and 8: DECLARATION I declare that apart fr
Page 9 and 10: 2. 2. Materials and Methods 47 2. 2
Page 11 and 12: 4. 4. Discussion 125 CHAPTER 5 A pi
Page 13 and 14: CHAPTER 1 LIST OF TABLES AND FIGURE
Page 15 and 16: Table 3. 11. The relationship betwe
Page 17 and 18: CHAPTER 5 Table 5. 1. Date of visit
Page 19 and 20: Figure 6. 4. The monthly faecal exc
Page 21 and 22: Listeralla hepatolytica. In the sam
Page 23 and 24: Listeriolysin O (Fernandaz-Garayzab
Page 25 and 26: L. monocytogenes was the only recog
Page 27 and 28: Table 1. 2. Serovar distribution of
Page 29 and 30: Serotyping is based on the identifi
Page 31 and 32: electrophoresis. Different strains
Page 33: and others (1995) came to the concl
Page 37 and 38: Immunity reducing Septicaemia facto
Page 39 and 40: monocytogenes and a prerequisite to
Page 41 and 42: a variable number of cases of encep
Page 43 and 44: The relationship between age and Li
Page 45 and 46: a reservoir from which it spreads t
Page 47 and 48: 1. 8. Clinical signs and pathology
Page 49 and 50: is seldom clinical illness in the d
Page 51 and 52: Bacterial culture is widely used fo
Page 53 and 54: Differential diagnosis: Listerial m
Page 55 and 56: Since elimination of L. monocytogen
Page 57 and 58: first description, it was only 1980
Page 59 and 60: and meat products have resulted in
Page 61 and 62: infectious dose for the infection i
Page 63 and 64: a longitudinal study involving five
Page 65 and 66: in Britain. In this part of the stu
Page 67 and 68: groups were excluded from analysis.
Page 69 and 70: The proportions of farms with cases
Page 71 and 72: Table 2. 3. The proportion of anima
Page 73 and 74: percentage 50 45 40 35 30 25 20 15
Page 75 and 76: Milking cows (%) Rep. heifers (%) D
Page 77 and 78: Abortion 274 (57.8%) 28 (21.9%) Ner
Page 79 and 80: with others (Kanuk and Berenson 197
Page 81 and 82: occurred in replacement heifers and
Page 83 and 84: CHAPTER 3 The relationship between
Page 85 and 86:
(ii) Cases in milking cows: Farms r
Page 87 and 88:
To assess the relationship between
Page 89 and 90:
) Duration of housing: If animals w
Page 91 and 92:
d) Presence of moles: Farmers were
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listeriosis. Maize silage feeding a
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found between the duration of feedi
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a) Type of housing : Housing animal
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Herd sizes n Y N OR P value x Y N O
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of disease. Similarly storing feed
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a) Type of forages: Feeding maize s
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) Use of bedding: Using straw beddi
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) Source of forages: Home made gras
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1.29-18.22) whereas straw bedding i
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100 2 34 2.33 0.01 X 2 22 3.35 0.01
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a) Dung disposal: Storage of manure
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vaccination against Leptospirosis +
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suppression of the growth of Lister
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1989, Sargison 1993). It is also po
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L. monocytogenes has been isolated
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association (Kirkwood 1988, Thrusfi
Page 125 and 126:
The predictor variables that met ou
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Forage feeding Maize silage Hay Str
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indoor feeding fed ad libitum on th
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cases of Listeriosis in sheep 2.9 1
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and controlling moles in fields wer
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Cases of Listeriosis in beef cattle
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This model was similar to the Model
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Table 4. 9. The multivariate relati
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5) Nervous signs: Cases of Listerio
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feeders, maize silage feeding in ri
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A contradictory finding was made ab
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selective enrichment broth, at refr
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growth of some strains of Listeria
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5. 2. 2. Bacteriology : a) Culture
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culturing negative LSEB (1/10w/v) s
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6) Sugar tests: Listeria are capabl
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uffered saline (PBS), pH 7.2, centr
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Investigation of non-specific bindi
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and 0.94 for L. monocytogenes (17/1
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Detection limit of the method: A si
Page 165 and 166:
Relationship between housing, silag
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5 13 3 3 1 3 1 1 1 6 14 1 4 5 3 1 0
Page 169 and 170:
Table 5. 11. The relationship betwe
Page 171 and 172:
frequency of isolation of L. monocy
Page 173 and 174:
CHAPTER 6 A study of the dynamic of
Page 175 and 176:
There were no sample size calculati
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4 of the farms had their silage ana
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a) Faecal samples: Faecal samples w
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• • • 1 5 9 6. 2. 5. Sample p
Page 183 and 184:
A total of 944 isolates of L. monoc
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UK), 0.5μM DNA primer, 1 unit Supe
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entered and left the herd over the
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Table 6. 7. Monthly frequency of ex
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Table 6. 8. The relationship betwee
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(MA) mean age, (n) number, (R) rang
Page 195 and 196:
frequency of excretion (P
Page 197 and 198:
There was no evidence from this far
Page 199 and 200:
) Environmental samples: Both L. in
Page 201 and 202:
monocytogenes. By April the proport
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A total of 211 milking cows were ex
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100 % 90 80 70 60 50 40 30 20 10 0
Page 207 and 208:
The number of new cases each month
Page 209 and 210:
monocytogenes was also isolated fro
Page 211 and 212:
Table 6. 18 The isolates, their ori
Page 213 and 214:
Table 6. 19. The distribution of th
Page 215 and 216:
On farm C pattern 1 was detected in
Page 217 and 218:
Figure 6. 8. The repeatability of R
Page 219 and 220:
Figure 6. 10. The distribution of s
Page 221 and 222:
Figure 6. 12a. The RAPD pattern obt
Page 223 and 224:
1988, Husu 1990) and from zero to a
Page 225 and 226:
experimentally been shown that ther
Page 227 and 228:
periods. However, on farms B and E
Page 229 and 230:
A large number of L. monocytogenes
Page 231 and 232:
Figure 6. 13. Animal-environment cy
Page 233 and 234:
Some important farming practices we
Page 235 and 236:
chance finding of L. monocytogenes
Page 237 and 238:
Asahi, O., Hosoda, T. and Akuyama,
Page 239 and 240:
Bourry, A. and Poutrel, B. (1996) B
Page 241 and 242:
Chakraborty, T., Ebel, F., Wehland,
Page 243 and 244:
delGarso, L. and Wallop, W. (1975)
Page 245 and 246:
Eveland, W.C. (1963) Demonstration
Page 247 and 248:
Fraser, J.A. and Sperber, W.H. (198
Page 249 and 250:
Golden, D.A, Beuchat, L.R. and Brac
Page 251 and 252:
humans. In Miller, A.J.,. Smith, J.
Page 253 and 254:
Jones, F.S. and Little, R.B. (1934)
Page 255 and 256:
Listeria innocua by oral inoculatio
Page 257 and 258:
Low, J.C. and Donachie, W.A. (1997)
Page 259 and 260:
McBride, M.E. and Girard, K.F. (196
Page 261 and 262:
Nieman, R.E. and Lorber, B. (1980)
Page 263 and 264:
Peters, M., Pohlenz, J., Jaton, K.,
Page 265 and 266:
Bakteriologie, Mikrobiologie und Hy
Page 267 and 268:
Seeliger, H.P.R. (1981) Apathogenic
Page 269 and 270:
Tilney, L.G. and Portnoy, D.A. (198
Page 271 and 272:
Walker, J.K., Morgan, J.H., McLauch
Page 273 and 274:
APPENDIX 3 PREPARATION OF BACTERIOL
Page 275 and 276:
Cool to 50 0 C Mix Solution A with
Page 277 and 278:
Phosphate buffered saline (PBS; 10x
Page 279 and 280:
APPENDIX 2 THE OVERALL RESULTS OF U
Page 281 and 282:
Grass silage Y N OR (95% CL) p Valu
Page 283 and 284:
storage Y N OR (95% CL) p Value cla
Page 285 and 286:
source home made 38 182 0.6 (0.1-16
Page 287 and 288:
source home made 34 345 0.8 (0.3-2.
Page 289 and 290:
source barley 27 251 0.93(0.6-1.6)
Page 291 and 292:
source potatoes 2 11 1.4 (0.-7.7) 0
Page 293 and 294:
in a covered barn 73 595 0.8 (0.4-1
Page 295 and 296:
sawdust 0 16 0.0 (0.0-2.73) 0.3 str
Page 297 and 298:
APPENDIX 5 THE QUESTIONNAIRE AND TH
Page 299 and 300:
Abbreviations: 1 first blood sampli
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B 113 1 114 1 115 1 116 1 117 1 118
Page 303 and 304:
B 104 1 104 2 104 3 105 1 105 2 105
Page 305 and 306:
B 20 1 20 2 20 3 21 1 21 2 21 3 19
Page 307 and 308:
0.169 1.157 1.134 1.467 1.356 0.145
Page 309 and 310:
Plate 4 Layout and ODs B 73 1 73 2
Page 312 and 313:
UNIVERSITY OF BRISTOL LISTERIOSIS I
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PART C : HERD SIZE :--BETWEEN JULY
Page 316 and 317:
(please circle one for each) 3. Wha
Page 318 and 319:
etween which months were your milki
Page 320 and 321:
not stored beneath the slats compos
Page 322 and 323:
STUDY OF LISTERIOSIS IN DAIRY CATTL
Page 324 and 325:
STUDY OF LISTERIOSIS IN DAIRY CATTL
Page 326 and 327:
Now I would like to get some detail
Page 328 and 329:
Root crops : ______________________
Page 330 and 331:
In this section I will be asking qu
Page 332 and 333:
33. Which days of the week bulk tan
Page 334 and 335:
-what was used to treat? -what was
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an epidemiological study of listeriosis in dairy cattle

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