DNA-based analysis of protein variants reveals different genetic variability of the paralogous equine ß-lactoglobulin genes LGB1 and LGB2

The genetic variability of milk protein genes may influence the nutritive value or processing and functional properties of the milk. While numerous protein variants are known in ruminants, knowledge about milk protein variability in horses is still limited. Mare's milk is, however, produced for human consumption in many countries. Beta-lactoglobulin belonging to the protein family of lipocalins, which are known as common food- and airborne allergens, is a major whey protein. It is absent from human milk and thus a key agent in provoking cow's milk protein allergy. Mare's milk is, however, usually better tolerated by most affected people. Several functions of β-lactoglobulin have been discussed, but its ultimate physiological role remains unclear. In the current study, the open reading frames of the two equine β-lactoglobulin paralogues LGB1 and LGB2 were re-sequenced in 249 horses belonging to 14 different breeds in order to predict the existence of protein variants at the DNA-level. Thereby, only a single signal peptide variant of LGB1, but 10 different putative protein variants of LGB2 were identified. In horses, both genes are expressed and in such this is a striking previously unknown difference in genetic variability between the two genes. It can be assumed that LGB1 is the ancestral paralogue, which has an essential function causing a high selection pressure. As horses have very low milk fat content this unknown function might well be related to vitamin-uptake. Further studies are, however, needed, to elucidate the properties of the different gene products.

Cholesterol transporters in lactating and nonlactating human mammary tissue

In mammals milk is the principal nutrient for neonates at birth. The basic milk composition is similar between different mammals, but the content of individual constituents such as lipids may differ significantly from one species to another. The milk fat fraction is mainly composed of triglycerides which account for more than 95% of the lipids found in human and bovine milk. Though sterols and in particular cholesterol, the predominant milk sterol, represent less than 0.5% of the total milk lipid fraction, they are of ultimate importance for biological processes such as the formation of biological membranes or as precursors for steroid hormone synthesis. Cholesterol found in milk originates either from blood uptake or from local synthesis. This chapter provides an overview of cholesterol exchanges between the blood, the mammary tissue and the milk. The current knowledge on the expression, localization and function of candidate cholesterol transporters in mammary tissues of human, murine and bovine origin is summarized. Different mechanisms of how cholesterol can be transferred via the mammary tissue into milk, and which active cholesterol transporters are likely to play a role in this process will be discussed.

Antimicrobial susceptibility of gram-positive udder pathogens from bovine mastitis milk in Switzerland

We evaluated the susceptibility of the gram-positive mastitis pathogens S. aureus, Str. uberis, Str. dysgalactiae, E. faecalis and L. garviae to antibiotics that are of epidemiological interest or are critically important for mastitis therapy and human medicine. Penicillin resistance was found to be most frequent in S. aureus, and nearly 5 % of the Str. uberis strains displayed a decreased susceptibility to this antibiotic. Resistance to aminoglycosides and macrolides was also detected in the strains tested. The detection of methicillin-resistant S. aureus (MRSA) and of a ciprofloxacin-resistant Str. dysgalactiae isolate corroborated the emergence of mastitis pathogens resistant to critically important antibiotics and underscores the importance of susceptibility testing prior to antibiotic therapy. The monitoring of antibiotic susceptibility patterns and antibiogram analyses are strongly recommended for targeted antimicrobial treatment and to avoid the unnecessary use of the latest generation of antibiotics.

Role of milk and meat products as vehicles for antibiotic-resistant bacteria

This subject is reviewed under the following headings: Microbial contamination of raw meat and raw milk; Antibiotic resistance of food-borne pathogens; Antibiotic resistance of commensal and potentially pathogenic bacteria as a new threat in food microbiology; Antibiotic-resistant staphylococci in fermented meat and [in] milk products; Antibiotic-resistant Enterococcus sp. in fermented meat and [in] milk products; Enterococci in farm animals and meat; Enterococci in fermented food; Molecular characterization of resistance of food-borne enterococci; and Further ecological and epidemiological considerations of resistant live bacteria in food. It is concluded that further research is needed, particularly into the possible transfer of the resistance of bacteria consumed in meat or milk products to the indigenous bacteria of the human consumer.

HIV and human herpesvirus 8 co-infection across the globe: Systematic review and meta-analysis.

HIV-infection is an important risk factor for developing Kaposi sarcoma (KS), but it is unclear whether HIV-positive persons are also at increased risk of co-infection with human herpesvirus 8 (HHV-8), the infectious cause of KS. We systematically searched literature up to December 2012 and included studies reporting HHV-8 seroprevalence for HIV-positive and HIV-negative persons. We used random-effects meta-analysis to combine odds ratios (ORs) of the association between HIV and HHV-8 seropositivity and conducted random-effects meta-regression to identify sources of heterogeneity. We included 93 studies with 58,357 participants from 32 countries in sub-Saharan Africa, North and South America, Europe, Asia, and Australia. Overall, HIV-positive persons were more likely to be HHV-8 seropositive than HIV-negative persons (OR 1.99, 95% confidence interval [CI] 1.70-2.34) with considerable heterogeneity among studies (I(2) 84%). The association was strongest in men who have sex with men (MSM, OR 3.95, 95% CI 2.92-5.35), patients with hemophilia (OR 3.11, 95% CI 1.19-8.11), and children (OR 2.45, 95% CI 1.58-3.81), but weaker in heterosexuals who engage in low-risk (OR 1.42, 95% CI 1.16-1.74) or high-risk sexual behavior (OR 1.66, 95% CI 1.27-2.17), persons who inject drugs (OR 1.66, 95% CI 1.28-2.14), and pregnant women (OR 1.68, 95% CI 1.15-2.47), p value for interaction <0.001. In conclusion, HIV-infection was associated with an increased HHV-8 seroprevalence in all population groups examined. A better understanding of HHV-8 transmission in different age and behavioral groups is needed to develop strategies to prevent HHV-8 transmission.

Towards science-based sediment quality standards-Effects of field-collected sediments in rainbow trout (Oncorhynchus mykiss).

Sediments can act as long-term sinks for environmental pollutants. Within the past decades, dioxin-like compounds (DLCs) such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) have attracted significant attention in the scientific community. To investigate the time- and concentration-dependent uptake of DLCs and PAHs in rainbow trout (Oncorhynchus mykiss) and their associated toxicological effects, we conducted exposure experiments using suspensions of three field-collected sediments from the rivers Rhine and Elbe, which were chosen to represent different contamination levels. Five serial dilutions of contaminated sediments were tested; these originated from the Prossen and Zollelbe sampling sites (both in the river Elbe, Germany) and from Ehrenbreitstein (Rhine, Germany), with lower levels of contamination. Fish were exposed to suspensions of these dilutions under semi-static conditions for 90 days. Analysis of muscle tissue by high resolution gas chromatography and mass spectrometry and of bile liquid by high-performance liquid chromatography showed that particle-bound PCDD/Fs, PCBs and PAHs were readily bioavailable from re-suspended sediments. Uptake of these contaminants and the associated toxicological effects in fish were largely proportional to their sediment concentrations. The changes in the investigated biomarkers closely reflected the different sediment contamination levels: cytochrome P450 1A mRNA expression and 7-ethoxyresorufin-O-deethylase activity in fish livers responded immediately and with high sensitivity, while increased frequencies of micronuclei and other nuclear aberrations, as well as histopathological and gross pathological lesions, were strong indicators of the potential long-term effects of re-suspension events. Our study clearly demonstrates that sediment re-suspension can lead to accumulation of PCDD/Fs and PCBs in fish, resulting in potentially adverse toxicological effects. For a sound risk assessment within the implementation of the European Water Framework Directive and related legislation, we propose a strong emphasis on sediment-bound contaminants in the context of integrated river basin management plans.

Canine rabies in Australia: a review of preparedness and research needs

Australia is unique as a populated continent in that canine rabies is exotic, with only one likely incursion in 1867. This is despite the presence of a widespread free-ranging dog population, which includes the naturalized dingo, feral domestic dogs and dingo-dog cross-breeds. To Australia's immediate north, rabies has recently spread within the Indonesian archipelago, with outbreaks occurring in historically free islands to the east including Bali, Flores, Ambon and the Tanimbar Islands. Australia depends on strict quarantine protocols to prevent importation of a rabid animal, but the risk of illegal animal movements by fishing and recreational vessels circumventing quarantine remains. Predicting where rabies will enter Australia is important, but understanding dog population dynamics and interactions, including contact rates in and around human populations, is essential for rabies preparedness. The interactions among and between Australia's large populations of wild, free-roaming and restrained domestic dogs require quantification for rabies incursions to be detected and controlled. The imminent risk of rabies breaching Australian borders makes the development of disease spread models that will assist in the deployment of cost-effective surveillance, improve preventive strategies and guide disease management protocols vitally important. Here, we critically review Australia's preparedness for rabies, discuss prevailing assumptions and models, identify knowledge deficits in free-roaming dog ecology relating to rabies maintenance and speculate on the likely consequences of endemic rabies for Australia.