Species-specific identification of campylobacters is problematic, primarily due to the absence of suitable biochemical assays and the existence of atypical strains. 16S rRNA gene (16S rDNA)-based identification of bacteria offers a possible alternative when phenotypic tests fail. Therefore, we evaluated the reliability of 16S rDNA sequencing for the species-specific identification of campylobacters. Sequence analyses were performed by using almost 94% of the complete 16S rRNA genes of 135 phenotypically characterized Campylobacter strains, including all known taxa of this genus. It was shown that 16S rDNA analysis enables specific identification of most Campylobacter species. The exception was a lack of discrimination among the taxa Campylobacter jejuni and C. coli and atypical C. lari strains, which shared identical or nearly identical 16S rDNA sequences. Subsequently, it was investigated whether partial 16S rDNA sequences are sufficient to determine species identity. Sequence alignments led to the identification of four 16S rDNA regions with high degrees of interspecies variation but with highly conserved sequence patterns within the respective species. A simple protocol based on the analysis of these sequence patterns was developed, which enabled the unambiguous identification of the majority of Campylobacter species. We recommend 16S rDNA sequence analysis as an effective, rapid procedure for the specific identification of campylobacters.Campylobacter species are important pathogens that cause a variety of diseases in humans and animals (26, 43). The most prominent members of these proteobacteria are the species Campylobacter coli and C. jejuni, the latter of which is considered the most common cause of acute bacterial enteritis worldwide (3). To date, the genus Campylobacter comprises 16 species, and among them several species other than C. jejuni and C. coli are becoming increasingly recognized as significant human pathogens (26). However, recovery and identification of these species require specialized preparatory procedures for specimens, such as filtration steps and selective incubation methods (e.g., the use of a hydrogen-enriched atmosphere) (26). Since most routine laboratories do not use these techniques, infections caused by these taxa are likely to be underdiagnosed (13,27). In addition, phenotypic tests have only a limited discriminatory potential for the distinctive identification of Campylobacter species. These pathogens are slowly growing, fastidious organisms and are considered biochemically unreactive. As a result, extensive identification schemes comprising up to 67 phenotypic features are used to correctly identify the entire spectrum of campylobacteria (40). Moreover, the phenotypic tests used in most routine laboratories lack standardization, although it is known that even minor parameters such as the inoculum size affect the results (39). The existence of biochemically atypical strains, which exhibit unusual phenotypic profiles, represents an additional challenge (36). In these cases no...
A total of 585 persons from several occupational groups (farmers, slaughterhouse staff, hunters, veterinarians) exposed to Toxocara infestations and 50 persons of a control group were tested for the presence of specific antibodies to the Toxocara canis antigen using an enzyme-linked immunosorbent assay and a western blot. Farmers showed the highest seroprevalence (44%), followed by veterinarians (27%), slaughterhouse staff (25%) and hunters (17%), whereas only 2% of the individuals of the control group were seropositive. Thus, the risk to Toxocara infestation is 39, 18, 16 and 9 times higher for farmers, veterinarians, slaughterhouse staff (some workers were part-time farmers) and for hunters, respectively, when compared to the control group. The main source of infection in rural areas seems to be (roaming) farm cats and dogs that have not been dewormed. The results are discussed with a view to potential risk factors and preventive measures, in terms of veterinary and human medicine.
Electronic drug application records from farmers from 75 conventional pig farms were revised and checked for their plausibility. The registered drug amounts were verified by comparing the farmers' records with veterinarians' dispensary records. The antimicrobial consumption was evaluated from 2008 to 2011 and expressed in weight of active substance(s), number of used daily doses (nUDD), number of animal daily doses (nADD) and number of product-related daily doses (nPrDD). All results were referred to one year and animal bodyweight (kg biomass). The data plausibility proof revealed about 14 per cent of unrealistic drug amount entries in the farmers' records. The annual antimicrobial consumption was 33.9 mg/kg/year, 4.9 UDDkg/kg/year, 1.9 ADDkg/kg/year and 2.5 PrDDkg/kg/year (average). Most of the antimicrobials were applied orally (86 per cent) and at group-level. Main therapy indications were metaphylactic/prophylactic measures (farrow-to-finish and fattening farms) or digestive tract diseases (breeding farms). The proportion of the ‘highest priority critically important antimicrobials’ was low (12 per cent). After determination of a threshold value, farms with a high antimicrobial use could be detected. Statistical tests showed that the veterinarian had an influence on the dosage, the therapy indication and the active substance. Orally administered antimicrobials were mostly underdosed, parenterally administered antimicrobials rather correctly or overdosed.
Amplification of free fetal DNA in maternal plasma is a valid and rapid technique for predicting fetal sex in first- and second-trimester pregnancies and could allow the restriction of invasive sampling procedures to male fetuses at risk of X-linked disorders.
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