Antibiotic Resistance in Salmonella Isolated from Tegus (Tupinambis spp.)

In recent years, an increase in human clinical cases of reptile-associated salmonellosis has been identified, and it has been attributed to the increased popularity of these animals as pets. Limited information is available regarding the distribution of Salmonella spp. serotypes in different reptile species and the antimicrobial resistance patterns of Salmonella spp. isolated from pet reptiles. This article describes the prevalence of Salmonella spp., distribution of serotypes, and antibiotic susceptibility patterns from isolates cultured from cloacal swabs obtained from 14 tegu lizards (Tupinambis spp.). Eighteen strains of Salmonella belonging to different serotypes were obtained from the 14 tegu lizards. Of the 18 Salmonella spp. isolates, 8 (44.4%) were from Salmonella subspecies I, with a majority of isolates belonging to the Eastbourne serotype (3 strains), Nottingham serotype (2 strains), and Brancaster serotype (2 strains), and only 1 belonging to the Apapa serotype. Less common serotypes were detected in 5 isolates, including 2 each belonging to Salmonella subspecies II and IIIb, respectively, and 1 to Salmonella subspecies IIIa. The serotype of 5 other Salmonella isolates could not be determined. All 18 isolates were resistant to at least 6 of the antimicrobial drugs tested. These results confirm the potential zoonotic risk from handling reptiles, suggesting that measures to educate the reptile-owning public are necessary.     

Simple and rapid liquid chromatography-tandem mass spectrometry confirmatory assay for determining amoxicillin and ampicillin in bovine tissues and milk

A simple specific and rapid confirmatory method for determining the two amphoteric penicillins, that is, amoxicillin and ampicillin, in bovine muscle, liver, kidney, and milk is presented. This method is based on the matrix solid-phase dispersion technique with hot water as extractant followed by liquid chromatography (LC)-tandem mass spectrometry. With this instrumentation, the selected reaction monitoring acquisition mode with two fragmentation reactions for each analyte was adopted. After acidification and filtration of the aqueous extracts, 25 microL of the tissue final extracts and 50 microL of the milk final extract were injected into the LC apparatus. Absolute recovery of the two analytes in any biological matrix at the 50 ppb level in tissues and the 4 ppb level in milk was 74-95% with relative standard deviations (RSDs) of no larger than 9%. When penicillin V was used as surrogate internal standard, relative recovery of the targeted compounds present in bovine tissues and milk at, respectively, 25 and 2 ppb levels ranged between 100 and 106% with RSDs of no larger than 11%. When fractionation of analytes by using a short chromatographic run was attempted, remarkable signal weakening for the two analytes was experienced. This effect was traced to polar endogenous coextractives eluted in the first part of the chromatographic run that interfered with the gas-phase ion formation of the two penicillins. Slowing the chromatographic run eliminated this unwelcome effect. Limits of quantification of the two analytes in bovine milk were estimated to be <1 ppb, whereas amoxicillin and ampicillin could be quantified in bovine tissues down to 3.1 and 0.8 ppb levels, respectively.     

Polychlorodibenzodioxin and -furan (PCDD and PCDF) and dioxin-like polychlorobiphenyl (DL-PCB) congener levels in milk of grazing sheep as indicators of the environmental quality of rural areas

An observational study was set up to evaluate how the quality of the environment may influence the levels of of PCDDs, PCDFs, and DL-PCBs in sheep's milk. Seven farms under natural and anthropogenic pressures were considered, along with an inventory of the surrounding regular and natural sources of emissions. Analysis by HRGC-HRMS revealed the highest cumulative levels (2.1 pg of WHO(1998)-TE/g fat) in one organic and one conventional farm, each close to a relevant bushfire. Their pattern was characterized by a noticeable contribution (24%) from mono-ortho-PCB congeners to the cumulative WHO-TE. For the other farms, close to potential anthropogenic sources, the levels recorded in milk ranged from 0.7 to 1.3 pg of WHO-TE/g fat. The health and reproductive indicators were in all herds within the physiological range. Results suggest the environmental quality in extensive farming system should be eligible as a food safety factor, also for organic productions.     

Contribution of molecular studies to botanical epidemiology and disease modelling: grapevine downy mildew as a case-study

After being accidentally introduced from the USA at the end of the 19^th century, downy mildew caused by Plasmopara viticola (Berk. et Curt.) Berlese et De Toni became one of the most damaging diseases affecting Vitis vinifera in Europe. Downy mildew causes both direct and indirect losses and can lead to severe reduction of yield. Our understanding of the life cycle and epidemiology of P. viticola has been recently altered by molecular studies that revealed that the overwintering inoculum (i.e., the oospores) does more than initiate disease, as was previously thought. A mechanistic model was developed for predicting the entire chain of processes leading to primary infections, and this primary infection model was linked to other models of secondary infection cycles. The model for primary infections defines the length of the primary inoculum season and a seasonal oospore dose consisting of several cohorts of oospores that progressively mature. The model was evaluated by means of Bayesian analysis in both Italy and eastern Canada, and showed high sensitivity, specificity, and accuracy both for potted plants and vineyards. Fungicide applications are necessary to control downy mildew because preventive agronomic practices are not very effective, including host resistance. The use of warning systems based on weather-driven models leads to a reduction in the use and cost of chemicals and a reduction in their environmental impact.     

Kin selection in cooperative alliances of carrion crows

In most cooperative vertebrates, delayed natal dispersal is the mechanism that leads to the formation of kin societies. Under this condition, the possibility that kin-based cooperative breeding is an unselected consequence of dispersal patterns can never be ruled out because helpers can only help their relatives. Here we show that a population of carrion crows (Corvus corone corone) fully fits the central prediction of kin selection theory that cooperative breeding should arise among relatives. On their territory, resident breeders are aided not only by nonbreeding retained offspring but also by immigrants (mainly males), with whom they share matings. Philopatry cannot account, however, for the high degree of genetic relatedness found between breeders and immigrants of the same sex that cooperate at a nest, indicating that crows actively choose to breed cooperatively with their relatives.     

Production of <Emphasis Type="Italic">Guignardia bidwellii</Emphasis> conidia on grape leaf lesions is influenced by repeated washing events and by alternation of dry and wet periods

The ascomycete Guignardia bidwellii is an economically important pathogen in many grapevine-growing areas. Primary infections are caused by ascospores and conidia produced in mummified berries and in cane lesions. Secondary infections are caused by the conidia produced by pycnidia formed in leaf lesions and, in later season, in rotted berries. Environment-controlled experiments were conducted to study the production dynamics of G. bidwellii conidia on grape leaf lesions as influenced by: i) repeated washing events, and ii) alternate dry and wet periods. Under optimal environmental conditions (25 °C, 100 % relative humidity), production of conidia declined over washings and was almost completely depleted after four washings. When pycnidia were kept in a low humidity environment (average of 54 % relative humidity) between two successive washings, the production of conidia progressively diminished as the time between washings increased, with few conidia being still produced after 87 days. This decline in conidial production was faster at 29 °C than at 20 °C. This information is relevant in that it determines the potential of black-rot lesions to produce conidia along the grape-growing season and, therefore, their contribution to epidemic development.     

Plot size and shape for the early assessment of post-fire regeneration in Aleppo Pine Stands

Aleppo pine stands account for a third of the burned forests in the Mediterranean basin. The early assessment of post-fire regeneration is essential for the management of such stands. The assessment should be based on reliable and objective methods. In the Mediterranean basin, plot size and shape applied in regeneration survey designs and sampling schemes differ considerably. A study involving twelve stands (7 unharvested and 5 harvested) in the Province of Taranto (southern Italy) was carried out 38 months after a fire, by comparing plots of different shape and size within a plot-count sampling frame. The relative efficiency method was used to compare the efficiency of each size and shape. Early regeneration of Aleppo pine proved to be best assessed by 8m × 2m plots, i.e. by a plot size four times wider than the most commonly used one (2m × 2m). The need for such wide plots depends upon the typical spatial arrangement of the seedlings whose clustering is associated with the presence of seed bearing trees.