The Identification and Quantification of 21 Antibacterial Substances by LC-MS/MS in Natural and Organic Liquid Fertilizer Samples

Antibiotics in animal production are widely used around the world for therapeutic and preventive purposes, and in some countries, they still serve as antibiotic growth stimulants. Regardless of the purpose of using antibiotics in livestock, they may be present in animal tissues and organs as well as in body fluids and excretions (feces and urine). Farm animal excrement in unprocessed form (natural fertilizers) or processed form (organic fertilizers) is applied to agricultural fields because it improves soil fertility. Antibiotics present in fertilizers may therefore contaminate the soil, surface, groundwater, and plants, which may pose a threat to the environment, animals, and humans. Therefore, it is important to develop analytical methods that will allow for the control of the presence of antibacterial substances in natural and organic fertilizers. Therefore, in this study, an LC-MS/MS method was developed and validated for the determination of 21 antibacterial substances in natural and organic liquid fertilizers. The developed method was used to analyze 62 samples of natural and organic liquid fertilizers, showing that over 24% of the tested samples were contaminated with antibiotics, mainly from the group of tetracyclines and fluoroquinolones. Studies of post-fermentation sludge from biogas plants have shown that the processes of anaerobic methane fermentation, pH, and temperature changes taking place in bioreactors do not lead to the complete degradation of antibiotics present in the material used for biogas production. For this reason, monitoring studies of natural and organic fertilizers should be undertaken to limit the introduction of antibiotics into the natural environment.

HPLC-FLD-Based Method for the Detection of Sulfonamides in Organic Fertilizers Collected from Poland

Antibacterial substances such as sulfonamides are widely used in veterinary medicine to treat many bacterial diseases. After their administration to animals, up to 90% of the initial dose of the antibiotic is excreted in the feces and/or urine, which can be applied to farmland as natural or organic fertilizers. In this work, an analytical method was developed with the use of HPLC-FLD for the detection and quantification of five sulfonamides (sulfaguanidine, sulfadiazine, sulfamerazine, sulamethazine and sulfamethoxazol) in poultry and pig feces, slurry and digestates. The method was validated according to EU requirements (Commission Decision 2002/657/EC and VICH GL49). Linearity, decision limit, detection capability, detection and quantification limits, recovery, precision, and selectivity were determined, and adequate results were obtained. Using the HPLC-FLD method for all analyzed matrices, recoveries were satisfactory (77.00–121.16%), with repeatability and reproducibility in the range of 4.36–17.34% to 7.94–18.55%, respectively. Decision limit (CCα) and detection capability (CCβ) were 33.87–67.63 and 53.36–92.00 µg/kg, respectively, and limit of detection (LOD) and limit of quantification (LOQ) were 13.53–23.30 and 26.02–40.38 µg/kg, respectively, depending on the analyte. The forty-four samples of natural and organic fertilizers were analyzed, and four samples showed sulfamethoxazole in the amount from range 158 to 11,070 µg/kg. The application of antibiotics including sulfonamides for farming animals is widespread and may lead to the development of antibiotic resistance and other environmental effects.

Information literacy of Polish state administration officials in the context of the concept of "good governance"

The article presents the results of research on information literacy (IL) of employees of selected state administration offices, those in which the concept of improving the quality of work, named "good governance", has been implemented. The first aim of the study was to determine the components of IL necessary for state administration employees and the deficiencies occurring in this respect. Another goal was to develop research methods and techniques which would be useful to achieve the first aim and to identify challenges of this study. The research was conducted in two stages. The first of them, carried out at the Lublin Provincial Office in Poland, was aimed at determining the information needs of individual official positions, identifying the IL essential for officials and the shortcomings in this regard. At this stage, the following research methods have been used: analysis of cards describing individual job positions in the office, the method of mapping knowledge in the office and the method of focused group interview. The second stage of the research was carried out in five provincial offices. This time, the main goal was to check whether the questionnaires developed by Polish researchers to study the information culture (the system of human attitudes towards information) of various social groups could be effectively used to study the IL of officials. It was assumed that the information culture of staff determined their ability to undertake information activities, including untypical ones, expected from them in line with the concept of "good governance". The conclusion reached was that IL of employees was underestimated in the current practice of state administration. A set of components of the information skills useful for working in various office job positions have been developed. It was reported that the information culture of the studied group was characterised by an optimistic perception of their own skills and their professional usefulness. Studies have shown that obtaining conclusive results indicating the level of specific information skills in the office environment is often not possible for reasons beyond the control of a researcher. Traditional IL testing methods are assumed to fail there. This is due to the Dunning-Kruger effect (Kruger & Dunning, 1999), as well as constraints imposed by the way offices function and decisions of the management of the office. It seems that achieving more precise results requires establishing close cooperation with the management of an examined group. Undertaking such research is necessary in the context of implementing the concept of "good governance" and a model of one of the methodologies has been presented in the article.

Bayesian Estimation of the True Seroprevalence and Risk Factor Analysis of Bovine Leukemia Virus Infection in Pakistan

Simple Summary

The enzootic bovine leucosis is the most common and economically important viral disease of cattle, caused by bovine leukemia virus (BLV). In cattle, infection with BLV leads to decreased milk production and premature culling and also impairs the immune system predisposing animals to other infections and increasing severity of disease. The aim of this study was to estimate the true seropositivity to BLV at the farm and within-farm levels in Pakistan, using a latent class analysis. In addition, some factors influencing BLV seropositivity were analyzed. We tested 1380 dairy cattle from 451 herds and 92 water buffalo. Analysis at the within-herd and herd levels showed 3.8% of cattle and 1.4% of herds were truly seropositive. All 92 serum samples from water buffalo were negative. The study demonstrated strong association between BLV seroprevalence and herd size but not with common housing of cattle representing indigenous breeds with exotic breed or their crossbred and also common housing of cattle and water buffalo.

Abstract

The objective of this study was to determine the true seroprevalence of bovine leukemia virus (BLV) infection in dairy cattle from Pakistan at the animal and herd-level. We tested 1380 dairy cattle from 451 herds and 92 water buffalo. The sera were tested by ELISA and the results were analyzed using Bayesian inference. The median posterior estimate of the herd level true BLV prevalence was 1.4%, with a 95% credible interval (CI) 0.7–3.1, whereas the median posterior estimate of the within-farm true seroprevalence was 3.8% with a 95% CI 2.8–4.8. All 92 sera collected from water buffalo were negative. Several risk factors potentially associated with seropositivity to BLV infections in Pakistan were analyzed using logistic regression model based on calculation of an odds ratio (OR). The study showed an association between seropositivity and medium herd (≥50) size (OR = 23.57, 95% CI: 3.01–103.48). Common housing of indigenous cattle with exotic-breed cattle (OR = 0.67, 95% CI: 06–2.35) or housing indigenous or their crossbred cattle with exotic-breed cattle (OR = 0.95, 95% CI: 0.14–3.01) had no effect on the BLV seroprevalence. Similarly, common housing of cattle and water buffalo was not risk factor for increased BLV seropositivity (OR = 27.10, 95% CI: 0.63–119.34).

Seroprevalence of small ruminant lentivirus (SRLV) infection in wild cervids in Poland

Small ruminant lentiviruses (SRLV) are widespread amongst domesticated sheep and goats worldwide. Infection of wild ruminants in close contact with affected domesticated small ruminants has been proposed as an actor in SRLV epidemiology, but studies are limited. The aim of this study was to estimate the apparent (AP) and estimated prevalence (EP) of exposure to SRLV infection in wild ruminants from Poland. Samples originating from 198 free-living cervids comprising 142 European red deer and 56 roe deer were serologically tested using a multi-epitope recombinant antigen ELISA representing subtypes A1, A13, B1, and B2 of SRLV and a commercial ELISA test. The estimated prevalence of SRLV infection was estimated using the Bayesian approach with models that adjusted for the misclassification of animals because of a small population and lack of sampling method, the imperfect performance of the ELISAs and because sera of different species were tested. The calculated estimated prevalence ranged from 5.3 % (95 % CI 0.3, 12.5) to 24.6 % (95 % CI 3.3, 38.5) for the ELISA with multi-epitope antigens while estimated prevalence using the commercial ELISA was 2.5 % (95 % CI 0.2, 6.6). These results may suggest the existence of a new SRLV reservoir in Poland and highlight the importance of surveilling and controlling SRLV infection in domestic and wild ruminants sharing pasture areas.

Prevalence of pectus excavatum (PE), pectus carinatum (PC), tracheal hypoplasia, thoracic spine deformities and lateral heart displacement in thoracic radiographs of screw-tailed brachycephalic dogs

Pectus excavatum, thoracic spine deformities, tracheal hypoplasia and lateral heart displacement are frequently described in brachycephalic dog breeds. Pectus carinatum is described sporadically, although the authors' observations demonstrate that it may occur in certain brachycephalic dog breeds. It was hypothesised that dogs of screw-tailed brachycephalic breeds carry a greater risk of these anomalies than normal-tailed brachycephalic breeds, and that there could a relation between the presence of pectus excavatum or pectus carinatum and thoracic spine deformities, tracheal hypoplasia and lateral heart displacement. During retrospective studies, these anomalies were identified in lateral and dorso-ventral radiographs of the thorax in brachycephalic dog breeds. A statistical analysis revealed that the frequency of pectus excavatum occurrence in screw-tailed and normal-tailed brachycephalic dog breeds is similar. The greatest risk of pectus excavatum occurrence is carried by two breeds: Maltese (60%) and English Bulldog (58%), while for pectus carinatum: Pug (41%) and French Bulldog (18%). Dogs of screw-tailed brachycephalic breeds carry a greater risk of kyphosis (p < 0.0001), tracheal hypoplasia occurrence (p < 0.0001), compared to "normal-tailed" breeds. The hypothesis concerning a relation between the presence of pectus excavatum or pectus carinatum and the other anomalies studied was not confirmed (p > 0.05). It was demonstrated that in dogs of brachycephalic breeds there was a greater risk of co-incidence between kyphosis of the thoracic spine and lateral heart displacement (p = 0.038), as well as kyphosis of the thoracic spine and tracheal hypoplasia (p = 0.003).

Detection of viral DNA of myxoma virus using a validated PCR method with an internal amplification control

Recognition of myxomatosis is usually based on clinical symptoms, but amyxomatous cases of the disease require the use of laboratory methods. Nowadays PCR assays are routinely employed for detection of MYXV DNA, but none of them have had their diagnostic usefulness conclusively confirmed through validation. The aim of the study was the development and validation of a PCR with an internal amplification control (IAC) for intravital and postmortem detection of viral DNA of myxoma virus. To avoid false negative results a chimeric internal amplification control (IAC) was prepared and incorporated into the PCR and amplified by the same primer set as the target DNA (M071L). The optimal concentration of particular ingredients in the PCR mixture (including IAC concentration and volume of DNA sample) was determined. To minimize the risk of amplicon carry-over contamination, uracil N-glycosylase was added to the reaction. Before proper validation the robustness of the IAC-PCR was verified. Validation of the method encompassed the following parameters: the analytical and diagnostic specificity (ASp, DSp) and sensitivity (ASe, DSe) of the assay, repeatability, and intra-laboratory reproducibility. The assay LOD was established at 2 TCIU of the virus particles/0.2 ml tissue homogenate with a 100% capacity to detect different MYXV strains (ASp). The method was characterized by good DSp of 0.955 (0.839-0.999 CI) and DSe of 0.976 (0.914-1.00 CI). In addition, it was repeatable and reproducible and confirmed its suitability for the detection of MYXV in clinical material. The IAC-PCR developed meets OIE validation requirements for virological methods and can be used in diagnostic or epidemiological studies of rabbit myxomatosis.

Comparison of Cryptosporidium oocyst recovery methods for their applicability for monitoring of consumer-ready fresh shellfish

Growing demand for fresh, unprocessed food favours the emergence of Cryptosporidium infections in humans. Mainly it is food of plant origin or unpasteurized milk which have been involved in food-borne outbreaks of cryptosporidiosis. So far consumption of shellfish contaminated with Cryptosporidium were not associated with human infections although such as possibility exists. In this study an attempt was undertaken to evaluate the analytical performance of three commonly used methods for recovery of Cryptosporidium oocysts from shellfish: i) pepsin digestion of shellfish in conjunction with immunomagnetic separation (IMS) of oocysts (method A), ii) pepsin-HCl treatment of shellfish homogenate without IMS (method B), and iii) a strainer method with direct oocyst extraction and separation from shellfish tissue using IMS (method C). Each method's performance was assessed according to the ISO standard requirements by testing shellfish homogenates seeded with different numbers of C. parvum oocysts. Two groups of parameters were compared, encompassing precision (coefficient of variation (CV)) and accuracy of measurements. These were described by linear regression models allowing calculation of the methods' limits of detection (LOD) and quantification (LOQ). In addition, oocyst recovery efficiencies from shellfish were calculated for each method. All three compared methods allowed for at least 66% recovery of Cryptosporidium oocysts from the tested samples. The best recovery (83.3-100%) in the whole range of tested suspensions was obtained for method C. The accuracy of method B was better (linearity of r² = 0.9996 in the full measurement range) than that of method A (r² = 0.968). Method C showed the best accuracy (r² = 1) and precision (CV 0.2-14.1). Compared to other methods it was also characterised by the best LOD and LOQ, attaining ≅4 and ≅12 oocysts per 3 g of tested shellfish sample respectively. Despite a lack of the ability of method A to give the proportional results in oocysts recovery (non-linearity of the method) compared to the reference values, it achieved the highest LOD and LOQ values among the tested methods. As demonstrated here, the most efficient method for extraction of Cryptosporidium oocysts from shellfish tissues was method C employing sample homogenisation and separation of oocysts from tissue debris using IMS. Used alone this method does not in fact allow for identification of Cryptosporidium species but delivers quantitative results concerning the level of food contamination by parasites.

Development of a Recombinant Protein-based ELISA for Detection of Antibodies Against Bovine Foamy Virus

Introduction

Infections with bovine foamy virus (BFV) were found in many countries but there is a lack of large-scale surveys on the prevalence of BFV among dairy cattle. The aim of this study was to develop and validate the recombinant Gag protein-based ELISA and to estimate the prevalence of antibodies against BFV.

Material and Methods

Gag coding region from BFV was cloned into expression vector pT7Arg-STOP, which expressed a high level of recombinant Gag protein from E.coli. The ELISA was standardised, and the cut-off value and sensitivity and specificity of the test were calculated using a receiver operating characteristic and Bayesian estimation.

Results

A total of 3,051 serum samples were tested by ELISA and 939 (30.8%) sera were recognised as positive. When Bayesian approach was used, the overall true BFV prevalence was 29.7% (95% CI: 25.9–33.4%).

Conclusion

Expressed Gag protein of BFV has been used successfully as an antigen for ELISA. Eventually, this study provides basic information about the epidemiological status of infection with BFV in dairy cattle in Poland, which can be used for further studies on dissemination and transmission of BFV infection.

Determination of reference values and frequency of occurrence of patella alta in German shepherd dogs: a retrospective study

Background

Patella alta and patella baja are important conditions underlying a predisposition to many joint diseases, including patellar luxation and patellar chondromalacia of the articular cartilage. The frequencies of patella alta and patella baja have not yet been determined. The objectives of this study were to determine the frequency of patella alta and to determine reference values to the position of the vertical patella according to two modified techniques of the Insall–Salvati method in a group of 65 German shepherd dogs (115 stifle joints).

Results

The upper limits of reference values for the normal vertical position of the patella were 1.79 and 2.13, depending on the method of measurement. A high prevalence of patella alta was observed in the group of German shepherd dogs. A correlation was demonstrated between the classification of dogs’ joints in the patella alta group and the multiplied risk of canine hip dysplasia (CHD) through the estimation of odds ratios.

Conclusions

Dogs with patella alta were healthy dogs that did not exhibit orthopaedic problems in the stifle joints. The results revealed that the risk of CHD is twice as high in dogs with higher patellar ligament length to patella length ratio.

Viability assessment of Ascaris suum eggs stained with fluorescent dyes using digital colorimetric analysis

The aim of the study was to develop a method for the colorimetric evaluation of nematode eggs using appropriate instruments. The materials for the study were live and dead (inactivated) eggs of the Ascaris suum. Viability of the eggs was assessed using four different kits for fluorescent staining (for each technique, a series of photos were taken). Images of stained eggs were analysed using graphic software with RGB (red-green-blue) function. The viability of the eggs was assessed according to the relative positions of the distributions of colour intensities of live or dead eggs - distributions area's overlap index (DAOI), and distributions area's separation index (DASI) were calculated. Computer analysis of the intensity of green colour was not satisfactory. However, analysis of images in the spectrum of red colour proved useful for the effective differentiation between live or dead eggs. The best parameters were observed using the Annexin V FITC Apoptosis Detection Kit (DASI = 41 and 67). The investigation confirmed the usefulness of fluorescent dyes used in conjunction with digital analysis for the assessment of the viability of A. suum eggs. The use of computer software allowed a better objectivity of the assessment, especially in the case of doubtful staining.

Risk factors associated with small ruminant lentivirus infection in eastern Poland sheep flocks

An analysis of the risk factors for ovine lentivirus infection was performed in sheep flocks located throughout the central-eastern region of Poland. Here, we report the infection details for 98 flocks with a total of 6470 ewes, 15 sheep breeds. The identification of infected animals and a review of the epidemiological status of each flock were based on an evaluation of serological tests performed on collected blood serum samples. Blood for examination was obtained from 2925 ewes of the 98 flocks under observation. Specific antibodies for Maedi Visna Virus (MVV) were detected via ELISA. Data illustrating the conditions at each sheep farm were obtained through questionnaires completed by farmers, as well as observations, measurements, and breeding records that were available. These observations were used to assess risk factors contributing to small ruminant lentivirus (SRLV) infection in sheep flocks. It was found that both sheep flock size and the type of management system had a significant effect on the increased risk of lentiviral infection. In addition, we demonstrate that there is a significant (p<0.0001) relationship between the occurrence of mastitis (OR 2.01, CI: 1.55-2.61) and diarrhea (OR 4.22, CI: 3.30-5.39) with SRLV infection in the observed sheep. Additionally, the infection rate of the animals translated directly to an impaired physical condition. Notably, the risk of infection could potentially be reduced if sheep producers are further acquainted with SRLV detection and invoke a control program based on diagnostic tests. Moreover, marketing approval should be granted for solely SRLV-seronegative animals.

Analysis of the accuracy and precision of the McMaster method in detection of the eggs of Toxocara and Trichuris species (Nematoda) in dog faeces

The aim of this study was to determine the accuracy and precision of McMaster method with Raynaud's modification in the detection of the eggs of the nematodes Toxocara canis (Werner, 1782) and Trichuris ovis (Abildgaard, 1795) in faeces of dogs. Four variants of McMaster method were used for counting: in one grid, two grids, the whole McMaster chamber and flotation in the tube. One hundred sixty samples were prepared from dog faeces (20 repetitions for each egg quantity) containing 15, 25, 50, 100, 150, 200, 250 and 300 eggs of T. canis and T. ovis in 1 g of faeces. To compare the influence of kind of faeces on the results, samples of dog faeces were enriched at the same levels with the eggs of another nematode, Ascaris suum Goeze, 1782. In addition, 160 samples of pig faeces were prepared and enriched only with A. suum eggs in the same way. The highest limit of detection (the lowest level of eggs that were detected in at least 50% of repetitions) in all McMaster chamber variants were obtained for T. canis eggs (25-250 eggs/g faeces). In the variant with flotation in the tube, the highest limit of detection was obtained for T. ovis eggs (100 eggs/g). The best results of the limit of detection, sensitivity and the lowest coefficients of variation were obtained with the use of the whole McMaster chamber variant. There was no significant impact of properties of faeces on the obtained results. Multiplication factors for the whole chamber were calculated on the basis of the transformed equation of the regression line, illustrating the relationship between the number of detected eggs and that of the eggs added to the'sample. Multiplication factors calculated for T. canis and T. ovis eggs were higher than those expected using McMaster method with Raynaud modification.