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1.
Intensive longitudinal investigations of breeding and growing pig populations in two multiple-site swine production systems were conducted in NC, USA. Five cohorts of sows and individually identified growing pigs from their litters were serially sampled in order to determine the prevalence and serotypes of Salmonella enterica in each stage of production based on fecal culture. In addition to fecal samples, feed and environmental samples were obtained. Fifteen different serotypes were isolated from the two systems, the most frequently isolated serotypes were S. typhimurium var Mbandaka and S. typhimurium var Copenhagen. Pig prevalence estimates ranged from 0 to 48.1%. Environmental contamination was frequently encountered despite cleaning and disinfection. Feed was rarely (2/800, 0.25%) identified as S. enterica positive. We observed highly variable patterns of S. enterica prevalence and serotype profiles within cohorts over time and among cohorts within systems. These observations indicate that point estimates of S. enterica prevalence and serotypes cannot be considered as reliable indicators of the S. enterica status of farms, and that uncontrolled studies of interventions to control S. enterica may yield misleading results. These findings are critical to the design of epidemiological studies of S. enterica on swine farms and may suggest that cohort level, as opposed to farm or company level events or management practices, may be important as potential risk factors for S. enterica fecal shedding in market age pigs.  相似文献   

2.
From 10 egg production poultry farms 1516 samples were collected and examined for the presence of salmonella. The samples were: 201 chicken, 36 sparrows, 35 rats, 35 pools of 20 flies each, 450 eggs, 60 mattresses, 188 feces, 425 feedstuffs and 86 water samples. Salmonellae were isolated only from 163 (10.8%) samples. From the 146 (89.6%) of these S. gallinarum was isolated. From the rest 17 (10.4%) the following mobile salmonella strains were isolated: two strains of S. virchow and Salmonella of subgroup II, four strains of S. typhimurium var. Copenhagen, seven strains of S. Livingstone, one S. enteritidis and one S. infantis The S. gallinarum was isolated from dead or sick chicken (46%), eggs (10.4%), rats Rattus norvegicus (14.3%) and mattresses 1.6%. The mobile salmonellae were isolated from feedstuffs (2%), flies (14.3%), rats (2.8%), feces (1%). From the present study, it seems that rats, chicken and eggs are important for the salmonella dissemination.  相似文献   

3.
Salmonella livingstone is one of the more common salmonella serotypes isolated in the United Kingdom. The characterization of 70 different isolates of S. livingstone using biochemical tests and plasmid profile analysis is described. The isolates could be divided into four groups by their ability to grow in d-tartrate, l-tartrate and Stern's glycerol. Further subdivision was achieved by the use of plasmid profile analysis; 24 of the isolates possessed light plasmids (less than 9.5 MD) and four possessed heavy plasmids (greater than 30 MD). The combination of biotyping and plasmid profile analysis can be used as the basis of a scheme to 'fingerprint' S. livingstone for epidemiological studies.  相似文献   

4.
Sources of Salmonellae in broiler chickens in Ontario.   总被引：3，自引：2，他引：1       下载免费PDF全文
Sources of Salmonellae infecting broiler chicken flocks in Ontario were investigated from July, 1975 to April, 1976. Three broiler flocks were investigated on each of four farms which received chicks from a common hatchery. Samples of feed and new litter were preenriched in nonselective broth subcultured to Salmonella-selective enrichment broth and plated on Salmonella-selective differential agar.Samples of used litter, water, culled chicks, insects, mice, wild birds and environmental swabs were not cultured initially in the nonselective broth. Fecal samples from principal and occasional flock attendants were examined for Samonellae. Salmonella infection, as judged by contaminated flock litter was detected in six flocks on two of the farms while the flocks on the other farms remained negative. Salmonellae were isolated from 23 of 412 feed samples (nine serotypes), six of 35 new wood shaving samples (four serotypes), one of 29 pools of culled chick viscera (one serotype) and 44 of 267 used litter samples (14 serotypes). These results indicate that broiler chicken flocks were infected with diverse Salmonellae introduced in day old chicks, pelleted feeds, wood shavings and residual contamination from the preceding flock.  相似文献   

5.
In the last years the number of isolations of Salmonella enterica subspecies enterica serovar paratyphi B (S. paratyphi B) sent to the national salmonella reference laboratory of Germany has increased steadily. Most of the isolates originated from fowl or poultry products. The bacteriological, serological and biochemical properties of the isolates were investigated. Special emphasis was given to the utilization of d-tartrate which subgroups the serovar. All of them belonged to the d-tartrate positive variant, which is generally considered less virulent for humans and was formerly called S. java. The performance of various tests is compared and in addition the possibility of the spread within the production line is discussed.  相似文献   

6.
Feces from 1,451 horses entering a veterinary hospital over a 13-month period were cultured for salmonella. A total of 46 horses (3.2%) yielded 1 or more salmonella-positive fecal cultures. Twenty horses were found to be excreting salmonella in the feces on admission, and 5 of these later had severe diarrhea associated with enteric salmonellosis. Abdominal surgery and other severe stresses were associated with all cases of severe enteric salmonellosis. Serotypes of salmonella isolated included Salmonella agona (15), S anatum (14), S typhimurium (7), S typhimurium var copenhagen (4), S infantis (2), S montevideo (1), S meleagridis (1), S drypool (1), and an unnamed Salmonella serotype (1). Seven deaths were attributed to 4 serotypes (S typhimurium, 3; S anatum, 2; S typhimurium var copenhagen, 1; and S montevideo, 1). A marked seasonal incidence is isolations was found with isolations highest in later summer to early fall and lowest in the spring. It was also found that horses can shed salmonella intermittently, and a minimal of 5 consecutive negative fecal cultures is recommended before considering a horse not to be infected with salmonella.  相似文献   

7.
1. A comprehensive ecological survey was conducted from April 1997 to June 1999 on 4 turkey flocks (F1 to F4) to identify key pre-harvest sources/vectors of Salmonella colonisation. 2. Turkey caecal and crop content, litter, drinker, air, feed, feeder and environmental swab samples were collected. Conventional microbiological and serological procedures were used to isolate, identify, and confirm the presence or absence of Salmonella. 3. Salmonella was isolated from 13% of litter, 11% of turkey caeca, 10% of drinker, 5% of environmental swab, 3% of feed and 1% of feeder samples. Salmonella heidelberg (65%), S. senftenberg (19%), S. muenster (10%), S. anatum (3%), and S. worthington (3%) were identified. 4. Identifying environmental sources associated with Salmonella colonisation and characterising serotypes would assist in designing pre-harvest controls for this poultry-borne pathogen. Integrators and poultry producers may be able to design hazard analysis and critical control point (HACCP) protocols to reduce the incidence of Salmonella arriving at the processing plant.  相似文献   

8.
Fattening pigs are frequently contaminated with salmonella bacteria. In 1983 and 1984 some 40 pig fattening farms in the Dutch province of Gelderland were examined to test the hypothesis that acidic byproducts from the dairy industry could influence the degree of contamination in groups of fattening pigs. Clear differences were observed: first salmonella was found in a lower percentage of farms using whey as part of the feed mix (40%) than on farms using only water (80%). Of the farms on which salmonella bacteria were demonstrated, the percentage of positive samples was lower for the 'whey' farms than for the 'water' farms (19.4% compared with 64.1%).  相似文献   

9.
Summary

Fattening pigs are frequently contaminated with salmonella bacteria. In 1983 and 1984 some 40 pig fattening farms in the Dutch province of Gelderland were examined to test the hypothesis that acidic byproducts from the dairy industry could influence the degree of contamination in groups of fattening pigs. Clear differences were observed: first salmonella was found in a lower percentage of farms using whey as part of the feed mix (40%) than on farms using only water (80%). Of the farms on which salmonella bateria were demonstrated, the percentage of positive samples was lower for the ‘whey’ farms than for the ‘water’ farms (19.4% compared with 64.1%).  相似文献   

10.
The prevalence of verocytotoxin-producing Escherichia coli and Salmonella in Ontario broiler chickens was determined by culturing cloacal samples from 500 individual birds selected from 50 poultry farms. Resistance to antimicrobials was determined for each of the isolates. In addition, abattoir and farm-level management data were obtained to evaluate variables that may be considered risk factors for infection. The variables selected included: Percentage of birds condemned at slaughter, percentage of birds dead-on-arrival, bird weight, truck number, farm size, hatchery source, litter source and type, feed source, mortality levels, type of water drinker, water sanitization, down time, barn clean out and history of antibiotic treatment. None of the cloacal samples revealed the presence of verocytotoxin-producing E. coli, though 19/500 (3.8%) contained Salmonella organisms. Nine different Salmonella serotypes were isolated; the most common being S. hadar, S. heidelberg and S. mbandaka. Resistance to tetracycline and streptomycin was common among Salmonella (63%) and E. coli (25.2%) isolates. Resistance to two or more antimicrobials occurred in 420/500 (84%) of the E. coli isolates. No statistically significant associations between abattoir or farm-level management variables and the Salmonella-status of farms were demonstrated.  相似文献   

11.
The feasibility of producing salmonella-free turkeys was investigated over a 5-year period. In Phase 1, a hatchery-breeder flock operation was monitored extensively for 4 years. Hatching eggs from a primary breeder over this period (1978-81) resulted in salmonella-free day-old poults from which 7500 hens and 600 tons were selected for breeders each of the 4 years. Approximately 2.5 million poults were produced over the 4 years. Salmonella arizonae was isolated from the hatchery debris over a 2-week period in 1980. The pelleted feed contained no animal protein products except fish solubles. A sample of feed from each delivery was cultured with no salmonella isolations. Environmental samples of dust and litter remained negative for salmonella. Phase 2 involved monitoring seven grow-out flocks initiated with salmonella-free poults with extra precautions directed at the feed and environment. The intestinal tracts of five of seven flocks at the time of marketing were negative for salmonella. Phase 3 involved a primary breeder-hatchery that had a 10-year history of S. sandiego infection in its breeder flocks and poults. A vaccination program using an autogenous oil-adjuvant bacterin supplementing other sanitation and management efforts resulted in elimination of S. sandiego. Because the breeder went out of business, it was not possible to determine if the freedom from salmonella could be sustained over a period of years.  相似文献   

12.
One hundred and eighty-seven salmonella strains were isolated from 4006 samples collected from camels in the United Arab Emirates between 1987 and 1991. One hundred and sixty-five (4.3%) strains were isolated from 3801 faecal and 22 from 205 organ samples of 62 autopsied camels. In total, 28 different serotypes were identified with S. saintpaul being the most frequent (69), followed by S. frintrop (31) and S. hindmarsh (15). Salmonella typhimurium was isolated from only two faecal specimens. All salmonellas isolated from faecal samples originated from carrier camels, and those isolated from organs were secondary findings. The camels from which salmonella organisms were found died from diseases other than salmonellosis. Most of the S. saintpaul isolates originated from one herd suffering from Clostridium perfringens type A enterotoxaemia which suggests that salmonella infections may predispose camels to clostridial enterotoxaemias.  相似文献   

13.
The prevalence of salmonellas in captive Crocodylus porosus and C. johnstoni was investigated at 2 Northern Territory crocodile farms. Similar proportions of each species at one farm (20.0 and 27.8% for C. porosus and C. johnstoni, respectively) carried salmonellas, but at the other farm there was a significant difference between the 2 species (81.0 and 5.0%, respectively). Procedures for the slaughter of crocodiles and processing of crocodile flesh for human consumption are outlined and discussed from the viewpoint of minimising salmonella contamination. The prevalence of salmonellas on flesh for human consumption (16.0% of carcases) was higher than that reported for beef and mutton, but lower than that for poultry products (Murrell 1986). Serotypes most often isolated from cloacai and faecal swabs were S. cerro, S. singapore, S. enteritidis and S. arizonae. Of the 10 serotypes isolated from processed carcases, S. singapore was most frequently isolated (33.3% of serotypes identified).  相似文献   

14.
Over a 3-year period, 1178 faecal samples were cultured from 462 horses admitted to the equine clinic of the University of Queensland; 185 samples were positive for salmonella yielding 213 isolations consisting of 21 serotypes. S. anatum was the predominant serotype isolated (54%) followed by S. ohio (11.27%) and S. typhimurium (9.4%). One hundred and ten horses (23.81%) were positive on one or more occasion, and 42 (9.09%) on more than one occasion.
S. anatum was the most common serotype isolated (71.43%) from the main drains in the stable block (33.57% positive samples).
The prevalence of salmonella excretors among a large non-clinic population of horses in south east Queensland was 1.65%.
Acute salmonellosis did not occur in the hospitalised animals. However, salmonellas were incriminated in 6 cases of chronic diarrhoea, which all yielded S. anatum , although the most severe involved both S. anatum and S. typhimurium , and these serotypes were isolated from multiple locations at the subsequent autopsy of 3 cases.  相似文献   

15.
Horses in a riding stable sporadically excreted Salmonella agona, S anatum, and S newington in the feces. The three serotypes were isolated from apparently normal horses. The horses were sampled (the number sampled varied between 10 and 21) six times throughout a 13-month period. The greatest percentage of the horses (12 of 19, or 63%) were found to be excreting salmonella in September. Among the 12 horses excreting salmonella during this month, 8 (67%) were found to be excreting S agona.  相似文献   

16.
The present study provides the first data about the prevalence of Salmonella contamination of broilers and slaughterhouses in the region of Constantine, Algeria. The serotypes and anti-microbial resistance phenotypes of the isolates were determined, and risk factors contributing to the contamination were evaluated. A total of 2490 samples, 1800 originating from 30 broiler farms and 690 from 15 slaughterhouses, were taken during two periods: March 2005-June 2006 and September 2006-March 2007. Salmonella contamination concerned 37% of the broiler farms and 53% of the slaughterhouses. Among the 55 isolates recovered, 10 different serotypes were identified. The most frequently recovered serotypes in both slaughterhouses and breeder farms were S. Hadar (36%, n = 20), S. Virchow (16%, n = 9), S. Infantis (10.9%, n = 6), S. Albany (11%, n = 6) and S. Carnac (7%, n = 4). Isolates belonging to S. Heidelberg (2%, n = 1) and S. Rissen (2%, n = 1) were found only in farms, while those belonging to S. Typhimurium (9%, n = 5), S. Enteritidis (4%, n = 2) and S. Montevideo (2%, n = 1) were recovered only from slaughterhouses. Thirty-nine isolates (80%) were resistant to at least one anti-microbial and 51% were multi-resistant, i.e. resistant to two or more anti-microbial molecules. About 58% (n = 32) were resistant to streptomycin, 36% (n = 20) to tetracyclines, 27% (n = 15) to nalidixic acid, 13% (n = 7) to ofloxacin and one isolate to enrofloxacin. Finally, seven distinct anti-microbial resistance profiles were identified. In parallel, four risk factors were found to be significantly associated with Salmonella contamination. Together with the huge spread of Salmonella in the broiler production chain in Constantine, Algeria, these risk factors highlight the hazards of the broiler channels, particularly linked to poor technical and hygiene practices.  相似文献   

17.
Antibiotics are used in food animal production to treat diseases and also to improve performance. Antibiotics are not used on all farms, and antibiotic resistance is occasionally found on farms that do not use antibiotics. Rendered animal protein products are often included in poultry feeds and could potentially serve as a source of antibiotic-resistant bacteria. One hundred sixty-five rendered animal protein products from cattle, poultry, and fish were aseptically collected from poultry feed mills. Fifty-five percent of the poultry meal samples had detectable levels of gram-negative bacteria ranging from 40 to 10,440 colony-forming units/g of sample. Poultry meal and meat and bone meal had the greatest number of samples with bacteria resistant to five or more antibiotics. A high percentage of feed samples (85%) contained bacteria resistant to amoxicillin, ampicillin, clavulanic acid, or cephalothin, whereas few samples contained bacteria resistant to ciprofloxacin, kanamycin, or trimethoprim/sulfamethoxazole. Acinetobacter calcoaceticus, Citrobacter freundii, and Enterobacter cloacae were the most commonly isolated antibiotic-resistant bacteria. Isolation for Salmonella was also performed, with 14% of the meat and bone meal samples containing Salmonella sp. Only one of the meat and bone meal isolates, Salmonella livingstone, was resistant to five or more antibiotics. Many of the antibiotic-resistant bacteria contained integrons, genetic elements that mediate multiple drug resistance.  相似文献   

18.
Cloacal swabs were sampled from 100 duck farms in Taiwan between March 2000 and January 2001 for isolation and standard cultivation of Salmonella spp. and thermophilic Campylobacter spp. Salmonella spp. were isolated from 4.6% (91/2000) of ducks from 20% (20/100) of duck farms. Ten serotypes of Salmonella enterica were identified: S. Potsdam (31.9% of isolates), S. Dusseldorf (18.7%), S. Indiana (14.3%), S. Typhimurium (7.7%), S. Hadar (5.5%), S. Newport (4.4%), S. Derby (4.4%), S. Montevideo (2.2%), S. Schwarzengrund (2.2%), and S. Asinnine (1.1%). Isolation of S. Asinnine or S. Indiana from poultry had not hitherto been described in Taiwan. The salmonella isolation rate in ducklings under two weeks of age was significantly higher than the other age groups (P<0.05). Campylobacter spp. were isolated from 43.5% (1045/2400) of ducks from 92% (92/100) of duck farms. Among them, 991 isolates (94.8%) were identified as C. jejuni and 54 isolates (5.2%) as C. coli. The campylobacter isolation rate in ducklings under two weeks of age was significantly lower than other age groups (P<0.05). Antimicrobial susceptibility testing was conducted by the disk diffusion and E- test methods. The results indicated that Salmonella isolates were 100% susceptible to amikacin, amoxicillin/clavulanic acid, ceftraxone, cephalothin, ciprofloxacin, norfloxacin, ofloxacin, and polymyxin B. A markedly higher antimicrobial resistance to amoxicillin, florfenicol, flumequine, josamicin/trimethoprim, nalidixic acid, nitrofurantoin, norfloxacin, ofloxacin, polymyxin B, sulfamethoxazole/trimethoprim and tetracycline was found in campylobacter isolates.  相似文献   

19.
In Sweden, only a few cattle farms are infected with salmonella each year and this can be attributed to the Swedish salmonella control programme. All findings of salmonella in animals, feed and food of animal origin are notifiable and restrictions are always put on infected herds until they have been cleaned up from the infection. However, there has been concern about increasing costs for clean-up of salmonella-infected farms as well as increasing length of the restriction periods. Our aim was to investigate potential risk factors associated with the length of restriction periods on Swedish cattle farms between 1993 and late 2002. All 112 cattle farms that were notified to the Swedish Board of Agriculture as infected with salmonella during the study period, were included in this longitudinal and retrospective study. The putative risk factors were analysed using the proportional-hazards model. There was a lower hazard for release from salmonella control restrictions after the European Union (EU) accession in 1995, and/or change of testing from one to two negative herd tests for release of restrictions (hazard ratio (HR)=0.56, 95% confidence interval (CI)=0.38, 0.84), for every additional number of 100 cows (HR=0.83; CI=0.7, 0.97), if rodents and/or wild birds were abundant (HR=0.5, CI=0.27, 0.98) and if there was more than one farm site in the company (HR=0.47, CI=0.28, 0.81).  相似文献   

20.
Fifteen floor litter samples were collected from each of 60 broiler chicken houses in Nova Scotia. Salmonella was recovered from 270 litter samples (30%) in 33 of 60 (55%) houses. All isolates were serotyped. Salmonella heidelberg and S. infantis were the most common of the 13 serotypes found. Isolates of selected serotypes were phage typed. Most isolates were susceptible to all common antimicrobial agents.  相似文献   

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