Influence of season and geography on Campylobacter jejuni and C. coli subtypes in housed broiler flocks reared in Great Britain.

Geographical and seasonal variation in the incidence and prevalence of Campylobacter jejuni and C. coli in housed broiler flocks reared in Great Britain in 2004 to 2006 was investigated in this study. Ceca (30) from 797 flocks, not subject to prior partial depopulation and reared on 211 farms, were examined individually for the presence of Campylobacter spp. The best-fitting climatic factors explained approximately 46% of the prevalence of Campylobacter-colonized flocks at slaughter and consisted of a combination of temperature at slaughter, number of sunshine hours in placement month, and millimeters of rainfall in placement month. Positive flocks were more likely to be slaughtered between June and November than during the rest of the year and to be reared in northern Great Britain than in central or southern Great Britain. C. jejuni was identified in approximately 90% of flocks, and C. coli was present in 10% of flocks. The most common clonal complexes identified in 226 isolates typed by multilocus sequence typing (MLST) were ST-45, ST-21, ST-574, ST-443, and ST-828. Flocks slaughtered at the same time were more likely to have similar complexes, and ST-45 had a seasonal pattern, with the highest prevalence in June, and was also more likely to be present in flocks reared in northern Great Britain.

Campylobacter spp. contamination of chicken carcasses during processing in relation to flock colonisation.

The presence and numbers of campylobacters on chicken carcasses from 26 slaughter groups, originating from 22 single-house flocks and processed in four UK plants, were studied in relation to the level of flock colonisation determined by examining the caecal contents of at least ten birds per group. The prevalence of campylobacters on carcasses from five campylobacter-negative flocks processed just after other negative flocks was low (8.0 log(10) cfu) than carcasses originating from low prevalence flocks (average of 2.3 log(10) cfu; range: <1.1 to 4.1 log(10) cfu). There was a reduction in the numbers of campylobacters on carcasses between plucking and chilling in eight of ten fully colonised flocks. In another eight flocks, a significant (P<0.001) decrease (0.8 log(10) cfu) in the number of campylobacters on carcasses from just before to after chilling was detected. Campylobacter spp. could be isolated from aerosols, particles and droplets in considerable numbers in the hanging-on, defeathering and evisceration areas but not in the chillers. This was the case even when campylobacters were not isolated from the target flock. Campylobacters on carcasses from two partly colonised flocks were either the same subtype, as determined by speciation, Multi-Locus Sequence Typing (MLST) and flaA Restricted Fragment Length Polymorphism (RFLP) typing, as those in the fully colonised flocks processed previously, although not necessarily the most prevalent ones; or were the same subtypes as those found in the caeca of the flock itself. The prevalences of the different campylobacter subtypes found on carcasses from two fully colonised flocks did not closely reflect those found in the caeca. MLST combined with flaA RFLP provided a good method for ascertaining the relatedness of strains isolated from carcasses and caecal contents. This study showed that carcass contamination is related to the within-flock prevalence of campylobacter colonisation, but that contamination from previously processed flocks was also significant, especially on carcasses from low prevalence flocks. Forced dry air cooling of carcasses reduced contamination levels.

Barbiturates, smoking, and bladder cancer risk.

Phenobarbital treatment has been observed to be negatively associated with bladder cancer risk in a few studies. It has been suggested that phenobarbital may induce drug-metabolizing enzymes that detoxify the bladder carcinogens found in cigarette smoke. We examined the relationship of barbiturate use to bladder cancer risk and the potential modifying effect of cigarette smoking in a large cohort of Kaiser Permanente Medical Care Program members with computerized pharmacy prescriptions and smoking information. Newly diagnosed bladder cancers were identified among individuals in the study cohort by linkage with data from cancer registries. The overall standardized incidence ratio associated with barbiturate use was 0.71 [95% confidence interval (CI), 0.51-0.99]. Among current smokers, former smokers, and never smokers, the standardized incidence ratios were 0.56 (95% CI, 0.23-1.16), 0.68 (95% CI, 0.27-1.40), and 1.04 (95% CI, 0.48-1.98), respectively. Although our estimates were imprecise, the finding of an inverse association between barbiturate treatment and bladder cancer risk only among current and former cigarette smokers is consistent with the hypothesis that treatment with these medications induces drug-metabolizing enzymes that deactivate bladder carcinogens found in cigarette smoke.

Factors associated with clinical assessment of overactive bladder and selection of treatment.

BACKGROUND: Overactive bladder (OAB) affects >17 million individuals in the United States, but the symptoms of OAB are frequently underreported by patients and therefore untreated by physicians. OBJECTIVE: The purpose of this observational study was to investigate the demographic and clinical factors associated with the decision to treat OAB pharmacologically and identify factors associated with physicians' assessment of symptom severity. METHODS: We studied 31 physicians treating 217 patients with OAB and collected data on patient demographic characteristics, OAB symptoms, previous management strategies, physicians' assessments of OAB severity, and treatment prescribed. Stepwise logistic regression was used to identify factors associated with selecting pharmacologic treatment and with physician assessment of severity of OAB symptoms. RESULTS: The mean age of the patients was 61.3 years; approximately 82% were female, and approximately 73% were white. Participants with urinary incontinence were significantly (P < 0.001) more likely to be treated with medication than were those with only symptoms of nocturia or urinary frequency. Other significant factors associated with pharmacologic treatment were being white (odds ratio [OR], 9.5; 95% CI, 2.9-30.8); being black (OR, 5.9; 95% CI, 1.2-29.7); physician's clinical assessment of OAB as moderate (OR, 3.5; 95% CI, 1.5-8.2) or severe (OR, 3.8; 95% CI, 1.1-13.7); previous use of medication (OR, 2.9; 95% CI, 1.1-8.1); and number of incontinence episodes in the last 24 hours (OR, 1.2; 95% CI, 1.0-1.5). Factors associated with physician assessment of OAB severity included distress due to OAB symptoms (OR, 2.1; 95% CI, 1.3-3.2), number of incontinence episodes in the last 24 hours (OR, 1.2; 95% CI, 1.1-1.4), and use of previous treatment(s) (OR, 0.4; 95% CI, 0.2-0.8). CONCLUSIONS: Both demographic and clinical symptoms of OAB were associated with the decision to treat OAB with medication, whereas physicians' assessment of OAB severity was associated only with clinical symptoms. Urinary incontinence was the key symptom associated with the decision to treat patients with medication and with the assessment of OAB symptom severity.

The challenge of integrating monoclonal antibodies into the current healthcare system.

Although there are few monoclonal antibody (MoAb) products on the market, the biotechnology industry has made considerable progress over the last decade. The industry has developed new technology to address the primary hurdles facing the development of MoAbs--including the immune response to murine-derived antibodies as well as lack of tumor specificity. As the techniques for development become more refined, more products will be approved by the Food and Drug Administration. Integrating these products into the existing healthcare system will be a challenge, given their high acquisition costs. Recent pharmacoeconomic examples outlined in this paper confirm that MoAb products will need to be supported with proven clinical and economic profiles. As long as a global clinical and economic perspective is taken and patient care benefits can be demonstrated, the place of MoAbs in the future of healthcare will be assured.

Detection of Cryptosporidium oocysts in wild mammals of mainland Britain.

This paper combines the results from a preliminary survey of occurrence of Cryptosporidium species in faecal samples from a range of wild mammal species inhabiting mainland Britain with a tabulated literature review of world-wide reports of the parasite in those British mammals. In the literature, C. parvum was reported from 11 wild mammals found in Britain and elsewhere, mainly in rodents but also in insectivores, lagomorphs and ungulates. C. muris has been reported only in wild rodents. The sample survey detected C. parvum in seven additional British species, including carnivores. Overall, 12% of 184 faecal samples tested with a genus-specific monoclonal antibody contained oocysts of C. parvum. The results further emphasise the widespread distribution of Cryptosporidium amongst wild mammals in Britain, highlight the potential for transmission between host species and warn of the possibility of direct exposure for anybody using the countryside for professional or recreational purposes (e.g. farmers and ramblers) to previously unregarded sources of infection. It seems increasingly likely that most, if not all, mammalian species can be infected with C. parvum.

The Norway rat as a reservoir host of Cryptosporidium parvum.

The potential of Norway rats (Rattus norvegicus) to spread the parasite Cryptosporidium parvum was investigated by examining parasite prevalence in relation to the structure and movements of three permanent rat populations living on farmland in Warwickshire (UK) from October 1994 to March 1997. One population lived among a group of farm buildings housing cattle, while the other two had no contact with livestock, one living around a pond and its outflowing stream and the other on a rubbish tip. Overall, parasite occurrence was 24% (n = 438), but it varied according to body weight (age) with 40% of juveniles (< or =100 g) infected decreasing to 12% for adults >400 g, suggesting that actively breeding populations are potentially more likely to spread the parasite than non-breeding populations. There was no difference in prevalence between the three populations. The parasite was detected in more males (29%) than females (19%). Seasonally, on the livestock farm, prevalence was significantly lower in autumn (10%), but varied little (31-36%) from winter to summer. In contrast, on the arable farm, prevalence peaked in summer (50%) with a trough in winter (6%). Infection in rats appeared to last <67 days. Rats living on the livestock farm had home ranges largely confined to the cattle sheds, thereby maintaining a potential source of infection for livestock if rodent control was not part of a decontamination program. Equally, rats living around the pond on the arable farm provided a source of oocysts to contaminate the pond water, as well as being able to carry the parasite to nearby farm buildings or even to neighboring farms.

Antibiotic-associated inhibition of steroidogenesis during short-term culture of ovarian tissues of the domestic fowl.

The effects of antibiotics on bovine luteinizing hormone (bLH)-stimulated output of androstenedione were examined in intact small white follicles (SWF, n = six hens), aliquots of 100,000 F1 and F2 theca cells (n = six hens), and aliquots of 10,000 F1 and F2 granulosa cells (n = eight hens). Cells and SWF were isolated from ovaries of Leghorn hens killed 20 h prior to ovulation and were incubated for 3 h in 1 mL of Medium 199 (Sigma Chemical Co., St. Louis, MO) at 37 C. Cells and follicles were incubated with 10 ng bLH and Penicillin-streptomycin (Pen-Strep; 20, 100, and 200 micrograms), gentamicin sulfate (gentamicin; 10, 50, and 100 micrograms), and fungizone (.5, 2.5, and 5.0 micrograms). Two control treatments consisted of tissues incubated alone (no bLH, no antibiotic) and tissues incubated with 10 ng bLH (no antibiotic). Androstenedione output by SWF and F1 and F2 theca cells and progesterone output by F1 and F2 granulosa cells were determined by radioimmunoassay of incubation media. The steroid contents of the incubation media were significantly increased in SWF and theca and granulosa cells with the addition of bLH. Neither Pen-Strep nor gentamicin significantly affected steroid output. Progesterone output by F1 and F2 granulosa cells was significantly reduced by the inclusion of fungizone. The inhibition of steroid output with the use of fungizone should be considered when using this antibiotic in studies of steroidogenesis in preparations of ovarian cells.

Sources of Campylobacter spp. colonizing housed broiler flocks during rearing.

The study aimed to identify sources of campylobacter in 10 housed broiler flocks from three United Kingdom poultry companies. Samples from (i) the breeder flocks, which supplied the broilers, (ii) cleaned and disinfected houses prior to chick placement, (iii) the chickens, and (iv) the environments inside and outside the broiler houses during rearing were examined. Samples were collected at frequent intervals and examined for Campylobacter spp. Characterization of the isolates using multilocus sequence typing (MLST), serotyping, phage typing, and flaA restriction fragment length polymorphism typing was performed. Seven flocks became colonized during the growing period. Campylobacter spp. were detected in the environment surrounding the broiler house, prior to as well as during flock colonization, for six of these flocks. On two occasions, isolates detected in a puddle just prior to the birds being placed were indistinguishable from those colonizing the birds. Once flocks were colonized, indistinguishable strains of campylobacter were found in the feed and water and in the air of the broiler house. Campylobacter spp. were also detected in the air up to 30 m downstream of the broiler house, which raises the issue of the role of airborne transmission in the spread of campylobacter. At any time during rearing, broiler flocks were colonized by only one or two types determined by MLST but these changed, with some strains superseding others. In conclusion, the study provided strong evidence for the environment as a source of campylobacters colonizing housed broiler flocks. It also demonstrated colonization by successive campylobacter types determined by MLST during the life of a flock.

The prevalence of Cryptosporidium parvum and C. muris in Mus domesticus, Apodemus sylvaticus and Clethrionomys glareolus in an agricultural system.

Wild mice and voles were tested for Cryptosporidium during a 2-year survey at an agricultural site in Warwickshire, United Kingdom. C. parvum and C. muris, the two cryptosporidial species known to infect mammals, were detected. Prevalence figures of 22%, 21% and 13% noted for C. parvum for Mus domesticus, Apodemus sylvaticus and Clethrionomys glareolus, respectively, were higher than those recorded for C. muris at 10%, 6% and 2%. C. parvum causes the sometimes severe diarrhoeal disease cryptosporidiosis in many hosts, but the wild rodents were asymptomatic. The discovery of C. muris in A. sylvaticus and C. glareolus confirms a wider distribution in wild rodents than has previously been reported. Rodents may represent a significant reservoir of Cryptosporidium with a high potential for infection of man and livestock due to cohabitation.