Associations between bovine, human, and raw milk, and beef isolates of non-O157 Shiga toxigenic Escherichia coli within a restricted geographic area of the United States.

A survey for Shiga toxigenic Escherichia coli in raw milk and beef was conducted within a defined geographic region of the United States. Prevalence rates based on detection of Shiga toxin gene (stx) were 36% for retail beef, 23% for beef carcasses, and 21% for raw milk samples, which were significantly higher than were Shiga toxigenic E. coli isolation rates of 7.5, 5.8, and 3.2%, respectively. Seasonal prevalence differences were significant for stx positivity among ground beef and milk samples. Distribution of stx subtypes among isolates varied according to sample type, with stx1 predominating in milk, stx2 on carcasses, and the combination of both stx1 and stx2 in beef. Ancillary virulence markers eae and ehx were evident in 23 and 15% of isolates, respectively. Pulsed-field gel electrophoresis demonstrated associations between food isolates and sympatric bovine fecal, and human clinical isolates. These data demonstrate that non-O157 Shiga toxigenic E. coli is present in the food chain in the Pacific Northwest, and its risk to health warrants critical assessment.

Longitudinal study of fecal shedding of Escherichia coli O157:H7 in feedlot cattle: predominance and persistence of specific clonal types despite massive cattle population turnover.

Identification of the sources and methods of transmission of Escherichia coli O157:H7 in feedlot cattle may facilitate the development of on-farm control measures for this important food-borne pathogen. The prevalence of E. coli O157:H7 in fecal samples of commercial feedlot cattle in 20 feedlot pens between April and September 2000 was determined throughout the finishing feeding period prior to slaughter. Using immunomagnetic separation, E. coli O157:H7 was isolated from 636 of 4,790 (13%) fecal samples in this study, with highest prevalence earliest in the feeding period. No differences were observed in the fecal or water trough sediment prevalence values of E. coli O157:H7 in 10 pens supplied with chlorinated drinking water supplies compared with nonchlorinated water pens. Pulsed-field gel electrophoresis of XbaI-digested bacterial DNA of the 230 isolates obtained from eight of the pens revealed 56 unique restriction endonuclease digestion patterns (REDPs), although nearly 60% of the isolates belonged to a group of four closely related genetic subtypes that were present in each of the pens and throughout the sampling period. The other REDPs were typically transiently detected, often in single pens and on single sample dates, and in many cases were also closely related to the four predominant REDPs. The persistence and predominance of a few REDPs observed over the entire feeding period on this livestock operation highlight the importance of the farm environment, and not necessarily the incoming cattle, as a potential source or reservoir of E. coli O157:H7 on farms.

Correlation between geographic distance and genetic similarity in an international collection of bovine faecal Escherichia coli O157:H7 isolates.

Evidence from epidemiological and molecular studies of bovine Escherichia coli O157:H7 suggests that strains are frequently transmitted across wide geographic distances. To test this hypothesis, we compared the geographic and genetic distance of a set of international bovine Escherichia coli O157:H7 isolates using the Mantel correlation. For a measure of genetic relatedness, pulsed-field gel electrophoresis of six different restriction enzyme digests was used to generate an average Dice similarity coefficient for each isolate pair. Geographic distance was calculated using latitude and longitude data for isolate source locations. The Mantel correlation between genetic similarity and the logarithm of geographic distance in kilometers was -0.21 (P<0.001). The low magnitude of the Mantel correlation indicates that transmission over long distances is common. The occurrence of isolates from different continents on the same cluster of the dendrogram also supports the idea that Escherichia coli O157:H7 strains can be transferred with considerable frequency over global distances.

Endonasal approaches for sinonasal and nasopharyngeal tumors.

This article reviews the published literature on endonasal approaches for sinonasal and nasopharyngeal tumors and synthesizes this information with the author's personal experience into a rational approach to patients with the following disorders: inverted papilloma, adenocarcinoma, hemangioendothelioma, olfactory neuroblastoma, carcinosarcoma, squamous cell carcinoma, melanoma, juvenile angiofibroma, chordoma, and chondrosarcoma.

Livestock drinking water microbiology and the factors influencing the quality of drinking water offered to cattle.

The microbial quality of livestock drinking water was evaluated in 473 cattle water troughs located at 99 different cattle operations. The mean log10-transformed coliform and Escherichia coli concentrations per milliliter of trough water were 1.76 +/- 1.25 (SD) and 0.98 +/- 1.06 (SD), respectively. The degree of E. coli contamination was positively associated with the proximity of the water trough to the feedbunk, protection of the trough from direct sunlight, lower concentrations of protozoa in the water, and warmer weather. Salmonella sp. were isolated from 2/235 (0.8%) troughs and shigatoxigenic-E. coli O157 was recovered from 6/473 (1.3%) troughs. Four experimental microcosms simulating cattle water troughs were used to further evaluate the effects of protozoal populations on the survival of E. coli O157 in cattle water troughs. Escherichia coli O157 of bovine fecal origin proliferated in all microcosms. Reduction of protozoal populations by treatment with cycloheximide was associated with increased persistence of E. coli O157 concentrations in the microcosms. Water troughs are a major source of exposure of cattle to enteric bacteria, including a number of foodborne pathogens, and this degree of bacterial contamination appeared to be associated with potentially controllable factors.

Methods for the isolation of water-borne Escherichia coli O157.

AIMS: To develop improved methods for the detection of Escherichia coli O157 from water and sediments. METHODS AND RESULTS: The effects of different broth enrichment media (unsupplemented tryptic soya broth, tryptic soya broth with antibiotics, and gram-negative broth), incubation durations (5 and 24 hrs), incubation temperatures (37 and 44.5 degrees C) and the use of immunomagnetic separation (IMS) on the sensitivity of E. coli O157 detection were evaluated on artificially and naturally-contaminated water and sediment samples. The sensitivity of recovery of E. coli O157 from samples was dependent upon the media composition, temperature duration of incubation and the use of IMS. CONCLUSION: Use of high temperature (44.5 degrees C) incubation for 24 hrs in unsupplemented tryptic soya broth and the use of IMS improved the sensitivity of E. coli O157 culture from water and sediment samples. SIGNIFICANCE AND IMPACT OF THE STUDY: The methods described can be used to increase the sensitivity of E. coli O157 detection from water and sediments.

Escherichia coli O157:H7 infection of calves: infectious dose and direct contact transmission.

Cattle are considered to be a reservoir host of Escherichia coli O157:H7 and contaminated foods of bovine origin are important vehicles of human infection. In this study, the susceptibility of calves to experimental E. coli O157:H7 infection following low oral exposures was determined. Two of 17 calves exposed to very low (< 300 c.f.u.) doses, and 3 of 4 calves exposed to low (< 10,000 c.f.u.) doses, subsequently excreted the challenge strains in their faeces. All calves (n = 12) sharing isolation rooms with calves that excreted the challenge strain in their faeces similarly began faecal excretion of the same strains within 21 days or less. The identity between the challenge strains and the strains excreted in calf faeces was confirmed by restriction digestion electrophoretic patterns using pulsed field gel electrophoresis. Calves shed E. coli O157:H7 in their faeces after very low dose exposures at concentrations ranging from < 30 to > 10(7) c.f.u./g, and for durations similar to the values previously reported for calves challenged by larger doses. The susceptibility of calves to infection following very low exposures or direct contact with infected calves has important implications for programmes for pre-harvest control of this agent.

A comparison of Escherichia coli O157 isolates from cattle in Japan and the USA by molecular biological methods.

Escherichia coli O157 isolates from cattle in Japan (n = 91) and in the USA (n = 415) were compared by pulsed-field gel electrophoresis of endonuclease-cleaved genomic DNA, location of the stx genes and bacteriophage typing. Three isolates from cattle in Japan with high similarity to isolates from cattle in the USA were found. Isolates from cattle farms in Japan and the USA may share a common source.

Multiresistant Salmonella Typhimurium DT104 infections of humans and domestic animals in the Pacific Northwest of the United States.

Salmonella Typhimurium definitive type 104 with chromosomally encoded resistance to five or more antimicrobial drugs (R-type ACSSuT+) has been reported increasingly frequently as the cause of human and animal salmonellosis since 1990. Among animal isolates from the northwestern United States (NWUS), R-type ACSSuT+ Typhimurium isolates increased through the early 1990s to comprise 73% of Typhimurium isolates by 1995, but subsequently decreased to comprise only 30% of isolates during 1998. NWUS S. Typhimurium R-type ACSSuT+ were consistently (99%) phage typed as DT104 or the closely related DTu302. S. Typhimurium isolates from cattle with primary salmonellosis, randomly selected from a national repository, from NWUS were more likely to exhibit R-type ACSSuT+ (19/24, 79%) compared to isolates from other quadrants (17/71, 24%; P < 0.01). Human patients infected with R-type ACSSuT+ resided in postal zip code polygons of above average cattle farm density (P < 0.05), while patients infected with other R-types showed no similar tendency. Furthermore, humans infected with R-type ACSSuT+ Typhimurium were more likely to report direct contact with livestock (P < 0.01) than humans infected with other R-types.

Rebuilding the inferior turbinate with hydroxyapatite cement.

This article describes a method of reconstructing a totally resected inferior turbinate with hydroxyapatite cement in patients who experience symptoms often associated with an overzealous resection of the turbinate (the "empty nose" syndrome).

Changes in antimicrobial resistance among Salmonella enterica Serovar typhimurium isolates from humans and cattle in the Northwestern United States, 1982-1997.

We compared antimicrobial resistance patterns of Salmonella enterica serovar Typhimurium (ST) of isolates from humans (n = 715) and cattle (n = 378) in the Pacific Northwest from 1982 through 1997. The major changes in antimicrobial resistance can be attributed to the widespread clonal dissemination of multidrug-resistant definitive phage type 104 ST.

Endoscopic surgical management of sphenoid sinus disease.

OBJECTIVES: To assess the outcome of functional endoscopic sphenoid sinus surgery, and to determine the predictors of outcome. STUDY DESIGN: Retrospective chart review of 651 consecutive endoscopic sinus procedures performed between 1992 and 1997. SETTING: USC University Hospital, University of Southern California, Los Angeles. MATERIALS AND METHODS: Seventy-four patients (11.4% of all endoscopic procedures) with sphenoid sinus disease were selected. All 74 patients were mailed a sinusitis-specific questionnaire, and 46 of them (62.2%) responded. Outcome measures derived from clinician ratings were applied to all 74 patients, and those derived from self-report were applied to 46. Outcome measures were determined from patient questionnaires at a minimum of 6-month postoperative follow-up, operative complications, and clinician perceptual ratings. Patient questionnaires addressed general patient satisfaction, symptom score, and medication usage. A statistical analysis was performed using chi2 test, linear regression, and one-way nonparametric ANOVA. RESULTS: Favorable surgical outcomes based on general patient satisfaction (84.8%, n = 39) and clinician perceptual rating (78.4%, n = 58) were noted. Minor postoperative complications were noted in 10 patients (13.5%) and 8 patients (10.8%) needed revision endoscopic procedures during follow-up. Of the complications, eight (80%) occurred in revision endoscopic procedures. The use of an expanded, sinus-specific symptom score revealed far fewer favorable outcomes (56.5%, n = 26). Seven outcome predictors were established, although none of the predictors held for more than one of the six outcome measures used. CONCLUSION: Endoscopic sphenoid sinus surgery is safe and effective. An expanded symptom score is recommended to assess the outcome of this procedure.

High levels of GM(1)-ganglioside and GM(1)-ganglioside beta-galactosidase in the parotid gland: a new model for secretory mechanisms of the parotid gland.

A new model for the subcellular basis of parotid secretion is presented in this article. GM(1)-ganglioside, typically found in neural tissues, is shown to be abundant in the parotid gland. This ganglioside may play a central role in membrane turnover mechanisms underlying exocytosis/endocytosis in its role as a promoter of membrane fusion or a fusogen. The lysosome and lysosomal hydrolases also play a central role in this model in catabolism of GM(1)-ganglioside. Consequently, high levels of the lysosomal hydrolase acidic beta-galactosidase are demonstrated in the salivary gland. GM(1)-gangliosidosis of the parotid glands, as described in mice, appears to be the first single-gene heritable disease found so far in the salivary glands.

Chronic inflammatory disorders of the salivary glands.

When dealing with salivary gland disease, the otolaryngologist must be familiar with the various chronic inflammatory disorders that patients may be inflicted with. Physicians may have to treat such disorders as chronic sialadenitis, tuberculosis, sarcoidosis, animal scratch disease, actinomycosis, and Sjögren's syndrome. Symptoms, causes, and treatments of these chronic inflammatory disorders are discussed in this article.

Noninflammatory, non-neoplastic disorders of the salivary glands.

Noninflammatory, non-neoplastic diseases comprise a diverse group of disorders that can present in a variety of ways. In general, a careful history will sharply focus the diagnostic possibilities. Although the diagnosis usually will be certain following the physical examination, additional testing may be needed to facilitate treatment planning. Sialolithiasis, cystic lesions, radiation injury, treatment to the parotid glands, sialodenosis, and other disorders are discussed in this article.

Malignant salivary gland neoplasms.

The treatment of salivary gland malignant neoplasms is challenging because of their infrequency, their unpredictable and varied biologic behavior, and their prolonged risk of recurrence. This article covers the pathophysiology of malignant neoplasms of the salivary glands. Emphasis is placed on the more common neoplasms. Histologic classification and management of neoplasms are also reviewed in this article.

Genetic subtyping of Escherichia coli O157 isolates from 41 Pacific Northwest USA cattle farms.

Escherichia coli O157 (n = 376) from 41 cattle farms were subtyped using pulsed field gel electrophoresis of endonuclease cleaved chromosomal DNA. Cleavage with XbaI resulted in 81 subtypes. Fifty-one isolates from subtypes found in more than one herd, or in herds on multiple sample collection dates were compared using the endonuclease NotI, resulting in 23 additional subtypes. Up to 11 XbaI subtypes were found per farm with up to 7 subtypes/farm identified from a single date. Indistinguishable subtypes (both XbaI and NotI) were found to persist on 4 farms for 6-24 months. Five subtypes were found on more than one farm separated by up to 640 km. Dairy farms where cattle had moved onto the farm had a similar number of subtypes as farms with no movement of cattle, and feedlots had more subtypes than dairy farms. These data indicate that there is a mechanism for multiple herd exposure to specific subtypes, there are multiple sources of exposure for cattle on farms, and on-farm reservoirs other than cattle may exist.