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Biomedical subjects

W R Hudson

Publications and source records attributed to W R Hudson.

At least 19 recordsLinked to original sources

Sources of Salmonella on broiler carcasses during transportation and processing: modes of contamination and methods of control.

AIMS: The prevalence and types of salmonella in broiler chickens during transportation and during slaughter and dressing were studied. This was part of a comprehensive investigation of salmonellas in two UK poultry companies, which aimed to find the origins and mechanisms of salmonella contamination. METHODS AND RESULTS: Salmonellas were isolated using cultural methods. Serovars of Salmonella detected during rearing were usually also found in a small proportion of birds on the day of slaughter and on the carcasses at various points during processing. There was little evidence of salmonellas spreading to large numbers of carcasses during processing. Many serovars found in the feedmills or hatcheries were also detected in the birds during rearing and/or slaughter. Transport crates were contaminated with salmonellas after washing and disinfection. CONCLUSIONS: Prevalence of salmonellas fell in the two companies during this survey. A small number of serovars predominated in the processing plants of each company. These serovars originated from the feed mills. Reasons for transport crate contamination were: (1) inadequate cleaning, resulting in residual faecal soiling; (2) disinfectant concentration and temperature of disinfectant too low; (3) contaminated recycled flume water used to soak the crates. SIGNIFICANCE AND IMPACT OF THE STUDY: Efforts to control salmonella infection in broilers need to concentrate on crate cleaning and disinfection and hygiene in the feed mills.

Abattoirs↗

Assessing abattoir hygiene with a marker organism.

A study was made to evaluate the use of a marker organism for assessing whether hygienic slaughter practices were being followed at red meat abattoirs. The organism, a nonpathogenic strain of Escherichia coli K12 that was resistant to nalidixic acid, was detected and counted on a highly specific isolation medium. With beef carcases, the practice of bagging the excised anus reduced, but did not prevent the spread of the organism from an inoculum applied in the anal region before the hide was removed. The carcases of sheep that were processed at a low-throughput abattoir, were contaminated with the marker after the fleece had been inoculated at a single site. The contamination was significantly reduced (P<0.001) when the operative responsible for flaying had cleaned his hands, arms and apron before and during the handling of each carcase, and used a knife which was freshly pasteurised on several occasions. However, the subsequent washing of carcases had little or no effect on the levels of the marker organism. It was concluded that the marker may be of value in assessing hygiene control, improving present practices, and training abattoir staff.

Abattoirs↗

Relevance of abattoir hygiene assessment to microbial contamination of British beef carcases.

Eleven beef abattoirs were visited, each on five separate occasions. On each occasion, an audit was carried out according to the official Hygiene Assessment System (HAS) and 10 carcases were sampled at four different sites to assess total viable counts and counts of presumptive coliform bacteria. The HAS scores ranged from 11 to 84 (maximum 100), and the logarithmic mean total viable counts for all sampling sites on each batch of carcases varied between 1.98 and 4.14 colony forming units/cm2. The mean prevalence of coliform contamination ranged from 0 to 85 per cent. There was a significant negative correlation (P < 0.001) between the mean HAS scores and the mean total viable count for each abattoir, but not between the HAS scores and the numbers of coliforms. Within the HAS, the mean scores for all five categories, before weighting, showed a significant correlation with the mean total viable count (P < 0.001); however, the categories concerned with slaughter and dressing, and personnel and practices were of most value in determining trends in carcase contamination. A new advisory classification is proposed for levels of microbial contamination on beef carcases.

Abattoirs↗

Effect of changes in processing to improve hygiene control on contamination of poultry carcasses with campylobacter.

Examination of neck skin and caecal samples taken at a commercial processing plant from 15 randomly chosen poultry flocks showed that all flocks were contaminated initially with thermophilic Campylobacter spp., even in the apparent absence of caecal carriage. During processing, numbers of campylobacter on skin samples were reduced by between 10 and 1000-fold. To improve hygiene control generally, chlorinated-water sprays were used to limit microbial contamination on equipment and working surfaces. In addition, chlorine concentrations in process water were increased and any unnecessary carcass contact surfaces in the processing plant were removed. When comparing flocks before and after the changes, it was found that numbers of campylobacter on packaged carcasses were significantly lower after the changes had been made (P 0.001). In practice, however, the reduction would be likely to have little impact on consumer exposure to campylobacter infection.

Animals↗

Use of a marker organism in poultry processing to identify sites of cross-contamination and evaluate possible control measures.

1. Nine different sites at a poultry processing plant were selected in the course of a hazard analysis to investigate the degree of microbial cross-contamination that could occur during processing and the effectiveness of possible control measures. 2. At each site, carcases, equipment or working surfaces were inoculated with a non-pathogenic strain of nalidixic acid-resistant Escherichia coli K12; transmission of the organism among carcases being processed was followed qualitatively and, where appropriate, quantitatively. 3. The degree of cross-contamination and the extent to which it could be controlled by the proposed measures varied from one site to another.

Animals↗

Microbiological survey of five poultry processing plants in the UK.

1. Neck skin samples were taken from chickens and turkeys at all the main stages of processing to monitor changes in total viable count (TVC) and counts of coliforms and pseudomonads. 2. Processing reduced TVC by up to 100-fold. Geometric mean counts after packaging were log10 4.4 to 5.3 CFU/g whilst corresponding counts of coliforms were 2.7 to 3.8 CFU/g. 3. Increases in mean TVC or coliforms as a result of either defeathering or evisceration did not exceed 0.6 log. 4. Pseudomonads represented only a minor fraction of the initial microflora of the bird and were often reduced by scalding to a figure which could not be detected by direct plating of samples; however, subsequent contamination resulted in means between log10 2.9 and 4.0 CFU/g for packaged carcases. 5. Although Staphylococcus aureus was readily isolated from defeathering equipment, mean counts from defeathered carcases were always below log10 3.0 CFU/g.

Animals↗

Penile metastasis secondary to supraglottic squamous cell carcinoma: review of the literature.

We report an unusual supraglottic carcinoma metastasis to the penis. Review of the literature revealed more than 300 cases of metastatic lesions to the penis, excluding primary neoplasms from skin, urethra and blood. Of these metastatic neoplasms 16 originated above the diaphragm, only 4 of which were from the head and neck region. The most common neoplastic metastases to the penis in order of frequency were from the bladder, prostate, rectum and rectosigmoid areas, and kidney in 32, 30, 13 and 8% of the cases, respectively. The incidence of other primary tumor sites that metastasize to the penis is extremely rare.

Carcinoma, Squamous Cell↗

Origin of anuran calling: description of toad releasing.

Electromyographic electrodes were implanted in forelimb muscles of male American toads (Bufo americanus). Toads then were allowed to clasp an artificial clasp object incorporating a pair of solenoids that, when activated, produced a stimulus simulating the side vibrations normally associated with release signalling by conspecific males. Electromyographic activity, in response to the release stimulus, was recorded. The adductor muscle contracted immediately after stimulus onset (causing intensified clasping), responding to the stimulus as a displacement threat. Then the abductor muscle contracted (causing rapid unclasping, or releasing), responding to the stimulus as a release signal. These techniques have provided a better understanding of releasing than has been possible with natural objects (i.e., living males).

Animal Communication↗

Factors affecting the survival of Campylobacter jejuni in relation to immersion scalding of poultry.

Potential measures for reducing the survival of campylobacters during commercial scalding of poultry have been evaluated in a series of laboratory trials. At 50 degrees C, the lower temperature limit of commercial scalding, raising the pH of a buffered heating medium from 6.0 to 9.0 markedly increased the heat sensitivity of Campylobacter jejuni but the effect was largely nullified in the presence of 1 per cent 'organic material' (50:50 horse blood and milk). Either in the presence or absence of organic material a more rapid rate of kill was observed at 60 degrees C and it was again enhanced by raising the pH to 9.0. Use of a mild detergent at a concentration of 1000 ppm had little effect on the survival of C jejuni at 50 degrees C, but the addition of a cationic quaternary ammonium product at 50 to 100 ppm was highly effective in enhancing the rate of kill, even in the presence of organic material. It is suggested that such products should be evaluated in commercial scalding systems as a possible means of preventing the spread of campylobacters and other organisms of significance to public health.

Animals↗

Sex steroid receptor distribution in the human larynx and laryngeal carcinoma.

Previous reports of estrogen receptor (ER) and progesterone receptor (PgR) in the human larynx and laryngeal carcinoma have relied on ligand-binding techniques using cytosol from tissue homogenates. These methods obscure the contribution of different tissue components to total receptor content. Recently developed, highly specific monoclonal antibodies to human ER and PgR were able to discern the presence of ER and PgR at the cellular level in 12 specimens of normal laryngeal tissue and eight laryngeal squamous cell carcinomas. Localization of ER and PgR was observed in the nuclei of vocalis muscle. No evidence of ER or PgR was found in epithelial components of the normal larynges or in laryngeal carcinomas. These results extend previous findings in lower primates and rodents to the human larynx and clarify previously reported receptor analyses of laryngeal carcinomas.

Adult↗

Major ambulatory surgery of the otolaryngologic patient.

Many otolaryngologic procedures can be performed safely on an ambulatory basis. Complications can be minimized by careful patient and procedure selection. This article describes common procedures adaptable to outpatient surgery and addresses the surgeon's added responsibility in this setting.

Ambulatory Surgical Procedures↗

Bacteriological status of beef carcasses at a commercial abattoir before and after slaughterline improvements.

The bacteriological status of beef carcasses was monitored at a commercial abattoir before and after two stages of modernization to the beef slaughterline which included changing from cradle dressing to dressing on an overhead rail, and the introduction of hot water spray cleaning of carcasses. Although small significant (P less than 0.05) differences in bacterial count occurred among carcass sites within modernization stages, significant visit within stage variation and stage X site interactions prevented any significant change in overall count being observed among stages and carcass sites. Principal components analysis revealed small changes in the distribution of bacterial numbers on the sites sampled.

Abattoirs↗

Oligodendroglioma arising in heterotopic brain tissue of the soft palate and nasopharynx.

A child with heterotopic brain tissue in her soft palate and nasopharynx is presented. Within the mass there was a small oligodendroglioma. Eighteen previous cases of heterotopic brain tissue in the nasopharynx and soft palate are also reviewed. These differ from nasal gliomas in that the latter do not contain ependyma, choroid plexus, retinal components, or neoplastic tissue. Both nasal gliomas and heterotopic brain tissue in the soft palate and nasopharynx are believed to result from embryonic brain trapped in inappropriate areas during development.

Brain↗

Gorlin's basal cell nevus syndrome.

A case report is used to illustrate the characteristics of Gorlin's syndrome and to emphasize the need for early recognition by the physician and for thorough lifetime follow-up by the patient to prevent severe sequelae.

Adult↗