Do microbes evade domestication? - Evaluating potential ferality among diastatic Saccharomyces cerevisiae

Certain lineages of the wine, beer and bread yeast Saccharomyces cerevisiae have diastatic activity. They contain the chimeric gene STA1 that codes for an extracellular glucoamylase which enables the strains to degrade starch and dextrins. Beer contaminations by diastatic yeasts can be dangerous because they can cause super-attenuation due to the consumption of otherwise non-fermentable oligosaccharides, gushing and off-flavours. Given that diastatic yeasts can be used for beer fermentation it is important to understand the relationship between production and contaminant strains, their natural reservoirs and entry routes into the brewery. Here, we analyze real cases of contamination in a Portuguese craft brewery over a period of 18 months. By analyzing with whole genome sequencing several contaminants, we show that recurrent contaminations by diastatic yeasts are caused by environmental strains. Moreover, some beer contaminants were closely related to diastatic environmental strains isolated in Botswana. We observed the widespread presence of domestication signatures in diastatic strains. Moreover, the combined phylogeny of STA1 and its ancestor, SGA1, suggested a single STA1 origin, as ancient as the entire lineage of diastatic yeasts. Together, our results suggest that diastatic yeasts isolated in natural settings could be escaping from domestication settings and becoming feral.

Epididymectomy as a novel surgical procedure; application in the domestic cat

Feline overpopulation raises issues concerning health, ecology, economy, and ethics. Procedures to limit overpopulation should carefully address animal welfare, efficiency, costs, and feasibility. Vasectomy in unowned cats is suggested as preferable to standard neutering as it maintains male sexual behaviour which may induce ovulation and pseudopregnancy in intact females and may prevent immigration of other males. Vasectomy is not performed routinely because it is fastidious, time consuming and requires more material than standard neutering. We describe epididymectomy as an alternative. In a first experiment, we analysed semen, testosterone, behaviour and pain in six experimental cats before and after epididymectomy, and after castration two months later. Excised tissues were analysed histologically. Testosterone concentrations did not differ significantly between intact and epididymectomised animals but were significantly different after castration. Sexual behaviour and testicular spermatogenesis persisted after epididymectomy, but with a marked drop in the semen count after 7 days. The Glasgow pain scores did not differ significantly after epididymectomy and castration. In a subsequent experiment, 20 privately owned cats were epididymectomised and castrated immediately afterwards, to analyse the learning curve and perioperative complications. The time required for an epididymectomy was significantly shorter than for castration. The study confirms that epididymectomy is quicker and less invasive than castration, it is associated with minimal risks and post-operative pain while easy to learn and inexpensive. Further field studies are required to test its efficiency for feline feral population control or in other species such as in bears, lions or deer, where infertility is required and castration not wanted.

Site selection by geese in a suburban landscape

Background

In European and North American cities geese are among the most common and most visible large herbivores. As such, their presence and behaviour often conflict with the desires of the human residents. Fouling, noise, aggression and health concerns are all cited as reasons that there are “too many”. Lethal control is often used for population management; however, this raises questions about whether this is a sustainable strategy to resolve the conflict between humans and geese when, paradoxically, it is humans that are responsible for creating the habitat and often providing the food and protection of geese at other times. We hypothesise that the landscaping of suburban parks can be improved to decrease its attractiveness to geese and to reduce the opportunity for conflict between geese and humans.

Methods

Using observations collected over five years from a botanic garden situated in suburban Belgium and data from the whole of Flanders in Belgium, we examined landscape features that attract geese. These included the presence of islands in lakes, the distance from water, barriers to level flight and the size of exploited areas. The birds studied were the tadornine goose Alopochen aegyptiaca (L. 1766) (Egyptian goose) and the anserine geese, Branta canadensis (L. 1758) (Canada goose), Anser anser (L. 1758) (greylag goose) and Branta leucopsis (Bechstein, 1803) (barnacle goose). Landscape modification is a known method for altering goose behaviour, but there is little information on the power of such methods with which to inform managers and planners.

Results

Our results demonstrate that lakes with islands attract more than twice as many anserine geese than lakes without islands, but make little difference to Egyptian geese. Furthermore, flight barriers between grazing areas and lakes are an effective deterrent to geese using an area for feeding. Keeping grazing areas small and surrounded by trees reduces their attractiveness to geese.

Conclusion

The results suggest that landscape design can be used successfully to reduce the number of geese and their conflict with humans. However, this approach has its limitations and would require humans to compromise on what they expect from their landscaped parks, such as open vistas, lakes, islands and closely cropped lawns.

Toxocara canis and Toxocara cati in domestic dogs and cats in the United States, Mexico, Central America and the Caribbean: A review

Toxocara prevalence ranges from 0 to >87% and 0 to >60% in dogs and cats, respectively, within the United States, Mexico, Central America and the Caribbean. Higher prevalence occurs in animals less than 1 year of age. Overall, prevalence is higher in cats compared to dogs. The lowest prevalence occurs in the US owned dog population. Specific populations in this industrialized nation, in animal shelters or resource-limited locations, have prevalences similar to those seen in populations from other regions reviewed here. Conversely, subpopulations in Central America and the Caribbean have very low prevalence. Apparent contributors to prevalence, excluding animal age and climate, are socio-economic factors, attitudes towards pet management and animal population density. The lack of data from some regions pose a challenge in assessing trends; however, with the exception of the US owned dog population, there is no strong indication of any decrease in prevalence from historical levels.

Donkey and Mule Welfare

Donkeys and mules have been critical to the development of human civilization, since being domesticated some 6000 years ago. However, they suffer from being undervalued or ignored by development agencies and animal protection nongovernmental organizations. Where they are recognized as affecting agriculture and the economy it is often because they are seen as being either invasive pests or an anachronism in the developing countries of the twenty-first century. Even in the wealthier societies of the world, donkeys suffer from ignorance about their proper management or a booming industry in health care products based on donkey skin gelatin and milk byproducts.

Correlation between fecal egg count, presence of Strongylus vulgaris, and body score of feral horses on Fort Polk, Louisiana

Approximately 700 feral horses, dubbed "trespass horses" by the United States Army, occupy Fort Polk, Louisiana and the surrounding Kisatchie National Forest. These horses are considered a nuisance and hazard, and the military is seeking to remove the horses via adoption. The aim of this research was to evaluate the fecal egg count (FEC), body condition score (BCS), and the presence of Strongylus vulgaris within this previously unstudied horse population prior to removal. The feral horse data was compared to domestic horses living on a single farm in the same area. A modified McMaster FEC, Henneke body scoring via photography, and PCR were used to evaluate 10 domestic horses and 28 feral horses. A significantly higher FEC was identified for feral horses when compared to domestic horses (p = 0.004), and 69.2% of feral horses were positive for S. vulgaris while all domestic horses tested negative. Additionally, no correlation was found between FEC and BCS for domestic (p = 0.213) or feral (p = 0.099) horses, and no association was found between FEC and S. vulgaris presence (p = 0.21) or BCS and S. vulgaris presence (p = 0.52). This study provides insight into S. vulgaris and strongyle prevalence in a previously unstudied group of horses and indicates a need for anthelmintic treatment and monitoring of the feral horses once they are adopted.

Evidence of antimicrobial and disinfectant resistance in a remote, isolated wild pig population

The spread of antimicrobial resistant E. coli within the environment is a global concern. Wildlife such as feral pigs have been identified as a possible reservoir of antimicrobial resistant bacteria. A cross-sectional survey of free-ranging, feral pigs within the Kimberley region of northwestern Australia was conducted to estimate the prevalence of antimicrobial and disinfectant resistant E. coli in this population. Of the 493 faecal samples collected, 115 E. coli isolates were randomly selected and their identity confirmed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS). Isolates were screened for susceptibility to 14 veterinary antimicrobials (including antimicrobials not permitted for use in Australia) using MIC broth microdilution using Sensititre™ (BOPO6F) and breakpoints according to CLSI and EUCAST guidelines. Isolates also underwent disinfectant susceptibility testing to six disinfectants at their recommended concentration for use as well as at a twofold dilution, based on methods adapted from the CLSI agar plate dilution method. A moderate prevalence of resistance was observed to sulfadimethoxine (50.4%; 58/115) and florfenicol (27.0%; 31/115). A low prevalence of resistance was estimated to chlortetracycline (5.2%; 6/115) and multi-drug resistance was only identified in 1.7% (2/115) of E.coli isolates tested. Isolates were susceptible to five of the six disinfectants screened. Feral pigs could potentially act as a reservoir of antimicrobial resistance in the environment with possible implications for domestic livestock. The role that feral pigs might play in transmission of antimicrobial resistance requires further investigation, and the occurrence of resistance in such isolated populations needs to be considered when attempting to infer source attribution of antimicrobial resistance in livestock and human populations.