Cattle Fecal Samples Research Articles

Prevalence of Shiga Toxin–Producing Escherichia coli in Ground Beef and Cattle Feces from King County, Washington

Shiga toxin–producing Escherichia coli (STEC) is increasingly recognized as a common cause of diarrhea. STEC infection is a major public health threat because of its ability to cause serious and potentially life-threatening illnesses. The main reservoirs of STEC are believed to be the intestinal tracts of animals. Several studies have investigated the prevalence of STEC in various food items. The objective of this study was to determine the prevalence of STEC in the Seattle ground beef supply. In addition, the relative amount of STEC contamination between stores was compared, and possible differences between types of ground beef based on fat content (9, 16, and 23%) were investigated. A survey of Stx-I and/or Stx-II genes in fecal samples from cattle at a local slaughter house was also conducted. Of 296 ground beef samples tested from area retail grocery stores, 16.8% were positive for the presence of the toxin genes. Our data showed that there was no statistically significant difference (P > 0.05) in the prevalence of STEC between the ground beef samples of different fat contents and between grocery store chains. Of the 103 cattle fecal samples tested, 19 (18.4%) were found positive for the presence of Stx-I and/or Stx-II genes. The presence of a rather high percentage of STEC in the food supply in the absence of large number of cases suggests that not all STEC lineages are pathogenic for humans.

Isolation and characterization of Escherichia coli O157:H7 and shiga toxin-converting bacteriophages from strains of human, bovine and porcine origin

Toxin-converting bacteriophages encoding the Stx2 gene were induced from strains of Escherichia coli O157:H7 isolated from sewage, bovine and porcine faeces. Toxin synthesis can be stimulated by the induction of integrated toxin-converting phages from the host E. coli O157:H7 organism by ultra-violet (UV) exposure. The UV-mediated DNA damage of E. coli O157:H7 triggers a bacterial SOS response resulting in phage release. Free ranging phages outside their E. coli O157:H7 hosts were detected but could not be isolated directly from environmental samples such as sewage and river water. E. coli O157:H7 colonies carrying the genes coding for Stx2 were isolated from 1 sewage sample (0.76% of positive samples), 8 cattle faecal samples (16.67% of positive samples) and 2 pig faecal samples (14.28% of positive samples). Characterization of E. coli O157:H7 was done by repetitive sequence analysis using ERIC-PCR to determine the relationships between the individual E. coli O157:H7 strains. The ERIC-PCR analysis revealed distinct patterns for all E. coli O157:H7 strains with some small differences between the strains. DNA sequencing of some of the E. coli O157:H7 positive isolates carrying the Stx2 genes were performed confirming the amplified DNA nucleotide sequences of Stx2. Electron microscopic analysis revealed, for the first time in South Africa, that Stx2-converting phages induced from E. coli O157:H7 have different morphologies to that of phage lambda which was previously described. The role of the induced integrated Stx2 phages in natural environments such as river and dam water remains unclear. With the induction of Stx2-converting phages from environmental E. coli O157:H7 isolates, it is now possible to determine the potential of these phages to convert non-pathogenic E. coli strains and other enterobacteriaciae into pathogenic strains.

Isolation and characterization of Shiga toxin-producing Escherichia coli O157:H7 from beef, pork and cattle fecal samples in Changchun, China.

Meat samples and fecal specimens from adult cattle were collected in Changchun, China and were examined for presence of Shiga toxin-producing Escherichia coli (STEC) serogroup O157. STEC O157 strains were isolated from 2 (5%) of 40 beef, 1 (3.3%) of 30 pork, and 3 (1.7%) of 176 adult cattle fecal samples. The strains belonged to phage types (PT) 4, 8, or 47. Two beef strains and a strain previously isolated from a patient in Shandong, China, were PT-4 and showed a similar PFGE pattern, suggesting the possibility of food-borne transmission. It is suggested that cattle are a reservoir of STEC O157:H7 and meat products are contaminated by this pathogen in Changchun, China as well as in other countries.

The prevalence and characterization of verotoxin-producing Escherichia coli isolated from cattle and pigs in an abattoir in Hong Kong.

The aim of the study was to define the prevalence of verotoxin-producing Escherichia coli (VTEC) in cattle and pigs in a Hong Kong abattoir. Faecal and carcass samples collected from 986 cattle and 487 pigs from an abattoir were tested for verotoxin (VT) by PCR and cytotoxicity assays. VTEC was isolated from 415 and 1-8% of cattle faecal and carcass samples and from 2.1 and 0.2% of porcine faecal and carcass samples, respectively. Amongst 409 VTEC isolates from cattle, 9 were serotype O157:H7 and eaeA+. The most prevalent vt genotype among bovine VTEC was vtl+vt2 (73.8%) and in porcine VTEC was vt2e+ (30%). None of the porcine VTEC isolates and 9.3% of the bovine VTEC isolates was eaeA+. The non-O157 serogroup VTEC isolates carrying eaeA and EHEC-hlyA belonged to serogroups O172, O15, O84, O91, O110 and O121. The local dietary preference for pork or chicken (rather than beef), the low VTEC carriage in pigs, the rarity of additional virulence factors (caeA) in VTEC isolated from cattle may explain the apparently low incidence of human diarrhoeal disease associated with VTEC in Hong Kong hitherto. However, the presence of non-O157 VTEC strains carrying the eacA virulence marker in cattle highlights the fact that sole reliance on sorbitol-MacConkey agar for screening human VTEC isolates may underestimate the human disease burden. The changing dietary habits of the population in Hong Kong reinforce the need for continued vigilance.

Effects of Single Administration of Half-dose Injectable Doramectin, Full-dose Injectable Doramectin, or Fenthion on Fecal Egg Counts, Growth Performance and Carcass Characteristics in Cattle

This clinical trial was designed to compare the effects of a single administration of half-dose doramectina, full-dose doramectin, or fenthionb only on growth performance, hot carcass weight, carcass quality grade and fecal egg count in a group of cattle of western US origin and finished in eastern Nebraska. Two hundred ninetyfive crossbred steers (mean weight 667 lb; 303 kg) were purchased from auction barns in California, processed and allocated to the study in Idaho, and finished in a commercial feedlot in eastern Nebraska. At arrival to the backgrounding yard in Idaho, the calves were randomly assigned to one of three treatment groups: 1) fenthion only (0.5 oz/cwt); 2) half-dose (0.55 ml/cwt) of injectable doramectin; or 3) full-dose (1.1 ml/cwt) of injectable doramectin. Cattle in the fenthion treated group were poured with fenthion for ectoparasite control. At arrival, individual weights were recorded and fecal samples collected and assayed to determine nematode egg counts. Individual cattle weights and fecal samples were collected and recorded again when cattle were reimplanted (day 76). Carcass data were collected at harvest and individual live weights were calculated from individual carcass weight and group dressing percentage. In this study, there was significant improvement (p = 0.022) in hot carcass weight (HCW) in cattle administered full-dose doramectin as compared to cattle administered half-dose doramectin or fenthion pour-on only. Average daily gain (ADG) was greater in the group treated with full-dose doramectin than in the fenthion only group (p = 0.016). Significant differences in fecal egg counts were not found between experimental treatment groups (p = 0.078).

Fecal shedding of Campylobacter and Arcobacter spp. in dairy cattle.

Campylobacter jejuni, Campylobacter coli, and Arcobacter spp. were detected in feces of healthy dairy cows by highly specific multiplex-PCR assays. For C. jejuni, at this one-time sampling, cows from 80.6% of farm operations (n = 31) and 37.7% of individual dairy cattle fecal samples (n = 2,085) were positive. Farm management factors were correlated with prevalence in herds in which >25% of cows were positive for C. jejuni. Statistical significance was set at a P of 0.20. Using these criteria, application of manure with broadcast spreaders (P = 0.17), feeding of whole cottonseed or hulls (P = 0.17) or alfalfa (P = 0.15), and accessibility of feed to birds (P = 0.17) were identified as possible risk factors for C. jejuni infection. C. coli was detected in at least one animal in 19.4% of operations and 1.8% of individual cows (n = 2,085). At the herd level, use of broadcaster spreaders was not a risk factor for C. coli infection. For Arcobacter, cows from 71% of dairy operations (n = 31) and 14.3% of individual dairy cattle fecal samples (n = 1,682) were positive. At the herd level, for Arcobacter spp., feeding of alfalfa (P = 0.11) and use of individual waterers (P = 0.19) were protective. This is the first description of Arcobacter spp. in clinically healthy dairy cattle and the first attempt to correlate their presence with C. jejuni.

A longitudinal study of Shiga-toxigenic Escherichia coli (STEC) prevalence in three Australian dairy herds

Over a 12 month period, 588 cattle faecal samples and 147 farm environmental samples from three dairy farms in southeast Queensland were examined for the presence of Shiga-toxigenic Escherichia coli (STEC). Samples were screened for Shiga toxin gene ( stx) using PCR. Samples positive for stx were filtered onto hydrophobic grid membrane filters and STEC identified and isolated using colony hybridisation with a stx-specific DNA probe. Serotyping was performed to identify serogroups commonly associated with human infection or enterohaemorrhagic Escherichia coli (EHEC). Shiga-toxigenic Escherichia coli were isolated from 16.7% of cattle faecal samples and 4.1% of environmental samples. Of cattle STEC isolates, 10.2% serotyped as E. coli O26:H11 and 11.2% serotyped as E. coli O157:H7, and the E. coli O26:H11 and E. coli O157:H7 prevalences in the cattle samples were 1.7 and 1.9%, respectively. Prevalences for STEC and EHEC in dairy cattle faeces were similar to those derived in surveys within the northern and southern hemispheres. Calves at weaning were identified as the cattle group most likely to be shedding STEC, E. coli O26 or E. coli O157. In concurrence with previous studies, it appears that cattle, and in particular 1–14-week-old weanling calves, are the primary reservoir for STEC and EHEC on the dairy farm.

Management and nutritional factors associated with the detection of Salmonella sp. from cattle fecal specimens from feedlot operations in the United States

In a convenience sample of 100 feedlot operations (included in the United States Department of Agriculture: Animal and Plant Health Inspection Service 1994 Cattle on Feed Evaluation), up to 25 cattle fecal samples were collected and tested for the presence of Salmonella from each of two pens (the pen which contained the most-recent arrivals, and the pen with cattle that had been on feed the longest). One or more Salmonella spp. were recovered from 38 (38.0%) of the 100 feedlots, 52 (26.0%) of the 200 pens and 273 (5.5%) of the 4977 fecal samples collected. Multivariable logistic regression indicated that feeding tallow and feeding whole cottonseed or cottonseed hulls within seven days prior to fecal sample collection was associated with an increased risk of finding Salmonella in a pen. Variables not found to be significantly associated with the detection of Salmonella in a pen included region, operation size, use of sprinklers, time on feed, type of cattle in the pen, number and concentration of cattle in a pen, feeding probiotics, and various other feeds.

A milk-borne campylobacter outbreak following an educational farm visit.

After a nursery school trip to a dairy farm, 20 (53%) of 38 children and 3 (23%) of 13 adult helpers developed gastrointestinal infection. Campylobacter jejuni was isolated from 15 primary cases and from 3 of 9 secondary household cases. A cohort study of the school party found illness to be associated with drinking raw milk (relative risk 5.4, 95% confidence interval 1.4-20.4, P = 0.001). There was a significant dose response relationship between amount of raw milk consumed and risk of illness (chi 2-test for linear trend 12.1, P = 0.0005) but not with incubation period, severity of symptoms or duration of illness. All 18 human campylobacter isolates were C. jejuni resistotype 02 and either biotype I (number 16) or biotype II (number 2). Campylobacter was also isolated from samples of dairy cattle and bird faeces obtained at the farm but these were of different resisto/biotypes. Educational farm visits have become increasingly popular in recent years and this outbreak illustrates the hazard of exposure to raw milk in this setting.

Dispersal of seeds of giant Sporobolus spp. after ingestion by grazing cattle

Samples of fresh cattle faeces were taken from 2 grazing paddocks on the North Coast of New South Wales. One paddock was heavily infested with giant Parramatta grass (GPG, Sporobolus indicus var. major) and the other paddock had a medium-light infestation. Fifty-two and 14 viable GPG seeds/kg were recovered from the dung samples collected in May from these paddocks, respectively. Seeds of GPG and giant rat's tail grass (GRTG, S. pyramidalis) were fed to caged Friesian heifers in 2 experiments, and the time taken for all of the seeds to be excreted was measured: 4 days in experiment 1 and 7 days in experiment 2. Consequently, a 7-day withholding period is suggested for cattle grazing pastures infested with giant sporobolus. The number of viable seeds excreted was estimated as a proportion of seeds fed to each heifer using average viability of seeds recovered, concentration of viable seeds collected daily, and daily manure weights. Based on this, the number of seeds ingested by gazing stock was estimated to be 8300 and 2200 seeds/head.day for the paddocks with heavy and medium-light infestation, respectively. Manure collected 2 and 3 days after feeding had the highest concentrations of viable seeds. This manure was placed outdoors in styrofoam boxes and left for 7 months. No GPG seedlings or plants were present in the manure after this time, and further subsampling of the manure indicated that no viable seeds remained. Processes that disperse fresh manure, such as heavy rain or the hosing down of transport vehicles, may allow successful germination and emergence of giant sporobolus seeds. However, where dung pats are left intact for some months, establishment of giant sporobolus plants is unlikely. Adhesion to machinery and the hair of stock are likely to be more important causes of dispersal of giant sporobolus than ingestion by stock.

Manure P fractionation

The proportion of organic (P o) and inorganic (P i) P in animal wastes affects their value as crop fertilizers. This study was conducted to develop a manure P fractionation method. Samples of beef and dairy cattle manure were lyophilized and ground to pass through a 2-mm screen. The fecal P in these samples was then partitioned into phospholipid (P l), inorganic (P i), acid-soluble organic (P aso) and residual (P r) forms using the McAuliffe and Peech (MP) method. Methods (MP and an Association of Official Analytical Chemists (AOAC) procedure developed for flour), sequential extractions, and grinding size (2 vs 0·25 mm) were compared for fecal P l extraction. The AOAC method removed more P l with less variability and fewer chemicals, required less time than the MP procedure, and had no effect on other P forms. All lipid dry matter was removed in the first ether or ethanol extraction, but not P. More lipid dry matter and P were removed in the first extraction of coarser (2 mm) dairy cattle fecal material than from feces ground finer (0·25 mm). Two beef and one dairy cattle fecal samples contained 6·4, 7·2 and 8·8 mg g −1 of total P (P t) with 50·0, 51·6 and 70·0, as P i, 27·0, 25·3 and 15·9% as P r, 23·0, 22·3 and 12·4% as P aso, and 0·0, 0·8 and 1·7% as P l, respectively. The AOAC flour method can be used to extract fecal P l and the MP procedure to extract P i, P aso and P r forms.

Amplification of 16S rRNA sequences to detect Mycobacterium paratuberculosis.

A probe based on 16S ribosomal RNA (rRNA) sequences was developed to detect Mycobacterium paratuberculosis, the causative agent of Johne's disease in cattle. Three universal primers were used to sequence the amplified fragments of the 16S rRNA gene of various species of mycobacteria. When the nucleotide sequences were analysed, a deletion was detected in the sequence of the fast-growing species. An oligonucleotide probe (P) directed to this region was synthesised and hybridised directly with total RNA of various mycobacterial strains in a dot-spot assay. The probe detected M. paratuberculosis, some other slow-growing mycobacteria of the M. avium-intracellulare (MAI) complex, and one atypical strain, M. gordonae. To increase the sensitivity of the probe, a 413-bp fragment of the 16S rRNA gene of M. paratuberculosis between P and a second oligonucleotide primer was amplified and hybridised with a M. paratuberculosis/M. avium-specific probe. When faecal samples of cattle were tested, all culture-positive samples were positive in the PCR assay.

Procedures for processing cattle fecal samples for NIRS analysis

Factors related to and methods for processing cattle fecal samples for rapid analysis with near-IR reflectance spectroscopy (NIRS) for forage diet quality predictions were investigated. No differences ( P < 0.05) were found between mean prediction values for crude protein (CP) and 48-h in vitro digestible organic matter (IVDOM) for 1 and 4 h periods post-grinding. Sample hydration status, however, had a marked effect on predictions for both CP and IVDOM, indicating the necessity for control of sample moisture to obtain rapid and accurate analyses. Predictions for both CP and IV-DOM for microwave dried (MW) and forced-air oven dried (OD) samples were only slightly different in magnitude but differences were statistically significant using calibration equations developed from OD samples. These differences suggested the need for MW calibrations. Procedures for microwave drying and combined microwave and forced-air oven drying of cattle fecal samples were developed which resulted in NIRS calibrations which were statistically equivalent to calibrations with samples which had been dried in a forced-air oven.

Comparative Studies on Enrichment And Selective Media for Isolation of Salmonellae from Faecal Specimens

Enrichment media (tetrathionate, selenite and Rapp ap ort broths) and selective media (desoxycholate citrate agar and brilliant green agar) were tested in different combinations to ascertain their capacity for isolation of salmonella bacteria. The material consisted of 299 samples of cattle faeces from two herds infected with salmonella (Table 1), and of 111 artificially contaminated samples of pig faeces (Table 3). The tetrathionate and selenite broths were equally useful for the material as a whole, whereas the results varied between different species of salmonella which is of great practical interest. The number of salmonella isolations was much lower when enrichment with Rappaport broth was used. The rate of salmonella isolations can often be increased by parallel enrichments with two different media. Of the selective agar media tested, brilliant green agar was superior to desoxycholate citrate agar.

Salmonella in cattle abattoirs in Costa Rica.

Salmonella organisms were sought in five Costa Rican cattle abattoirs whose products are approved for export to the United States. No Salmonella were found in samples of cattle feces. From one sample of meat, Salmonella saint paul was isolated. Five samples of meat from each of two slaughterhouses yielded multiple isolations of other enteric bacteria. Swabs taken from equipment, floors and walls, and workers' clothing in the five abattoirs were all negative for Salmonella spp. From floor-drain swabs collected from four of the five plants, Salmonella group E1 was isolated. Fecal samples from workers in two of the five plants were tested for Salmonella spp.; there were seven isolations from one plant and none from the others.

An evaluation of the standard biochemical and elevated temperature tests for differentiating faecal and non-faecal coliforms

In this study the relative efficacies of the biochemical IMViC and the elevated temperature (FC) tests have been compared for differentiating the faecal and non-faecal coliforms. Altogether 1628 coliform strains comprised of 427 from 143 samples of human faeces, 301 from 101 samples of cattle faeces, 631 from 113 samples of sewage and 269 from 120 samples of soil were classified as to their IMViC types and response to elevated temperature reactions. Parr's Escherichia group (+ + − −, + − − − and − + − −) was represented by 83 and 85 per cent of the coliform strains isolated from human and cattle faeces respectively. Of the coliform strains isolated from human and cattle faeces 82.0 and 76.4 per cent respectively were found positive for the FC test. Hence, neither the IMViC nor the FC tests by themselves can be considered adequate for differentiating coliforms of faecal and non-faecal origin. Based on the results obtained in this study the authors have interpreted the sanitary significance of the coliforms present in various sources.