Folks Seemed To Laugh At Tryptophan synthase - Today I Laugh At All Of Them
This is an interesting observation that is currently being investigated further because A+B? negative strains have not been reported previously. Avbersek et?al. [20] recovered PCR ribotype 033 isolates with a remnant of the toxin A gene and a binary toxin gene, but Tryptophan synthase these strains failed to produce either toxins A or B phenotypically and were therefore referred to as ToxA?B?. Different sample sources were used for the collection of isolates, and this may have resulted in a bias reflecting different sampling strategies. As a consequence, the isolation frequencies observed among different host animals may not reflect the true prevalence in the animal populations. Several factors may have contributed to the variation in isolation rates in samples from various sources, such as sample storage conditions, age of the sampled animals and prior antibiotic use. This study was not set up as a prevalence survey, and interpretation of the data must be carried out with care. However, the isolation rates in samples from food animals in the Netherlands (3.4% in cattle, 5.8% in poultry and 6.6% in pigs) are in agreement with other recent European reports, with isolation frequencies up to 3% in meat samples and Alectinib concentration 5% in samples taken from animals prior to slaughter [21,22]. Studies performed in the USA and Canada reported the presence of C.?difficile in food animals and meat with rates up to 42% [19,23,24]. This may reflect differences in geographical and/or temporal variation in C.?difficile prevalence, although other aspects, such as age of the sample animals, could also play a role. Despite the limitations in sample strategy, we feel that the comparison of animal and human isolates from a restricted geographical region may help to understand the ecology of C.?difficile. We found that the occurrence of C.?difficile PCR ribotypes in animals is predominantly animal host specific, although shared PCR ribotypes are found among various animal species. Interestingly, almost all toxinogenic animal-related types found in this survey were also recovered from hospitalized diarrhoeal patients in the Netherlands during 2009/2010. PCR ribotypes 035 and 051 were not recovered from human samples in this particular period, although they have been found sporadically in signaling pathway previous years since 2005. On the other hand, ribotypes 001, 002 and 027, which are frequently detected in human patients in the Netherlands, were not detected among animals in this survey. The corresponding presence of toxinotypes and PCR ribotypes from animal and human sources in various reports has led to the suggestion of a possible epidemiological relation between human CDI and animals [4,5,25,26], although transmission from food animals or foods to humans has never been documented [27,28]. In this study, an evident overlap was seen with regard to PCR ribotypes 078, 012 and 014.
