Monitoring of iron deficiency in calves by determination of serum ferritin in comparison with serum iron: A preliminary study

Background: Iron deficiency can cause anemia in calves and is therefore of economic importance for the cattle industry. Low iron levels are commonly caused by feeding whole milk without the addition of dietary supplements and led to the most frequent cause of anemia in calves. Other reasons for the development of anemia include congenital iron deficiency, malnutrition, bleeding ulcers or bloodsucking parasites. Aim: This study compared laboratory parameters that are commonly used to diagnose iron deficiency anemia in calves. Additionally, serum ferritin values were compared amongst calves fed different milk meals. Methods: For this purpose, blood samples from 40 calves were analyzed for different hematologic parameters as well as the content of copper, glutathione peroxidase, serum iron and serum ferritin. Results: Eight calves showed decreased hemoglobin and hematocrit values and a significantly lower number of erythrocytes compared with non-anemic calves. Interestingly, 19 of 40 calves had a low serum iron. Considering their serum ferritin levels, only fourteen calves, including six calves with both low iron and low ferritin levels, were classified as iron deficient. No direct correlation between serum ferritin and serum iron was detected. Comparing milk diets, more calves fed milk replacer showed reduced levels of ferritin compared with calves fed whole milk. Conclusion: Our data indicate that the determination of hemoglobin and serum iron is of limited suitability for the diagnosis of iron deficiency in calves. We suggest that the determination of serum ferritin should be the preferred parameter, since serum iron levels are subject to physiological fluctuation and a deficiency can be caused by inflammation or neoplastic diseases

Phylogenetic diversity, antimicrobial susceptibility and virulence gene profiles of Brachyspira hyodysenteriae isolates from pigs in Germany

Swine dysentery (SD) is an economically important diarrheal disease in pigs caused by different strongly hemolytic Brachyspira (B.) species, such as B. hyodysenteriae, B. suanatina and B. hampsonii. Possible associations of epidemiologic data, such as multilocus sequence types (STs) to virulence gene profiles and antimicrobial susceptibility are rather scarce, particularly for B. hyodysenteriae isolates from Germany. In this study, B. hyodysenteriae (n = 116) isolated from diarrheic pigs between 1990 and 2016 in Germany were investigated for their STs, susceptibility to the major drugs used for treatment of SD (tiamulin and valnemulin) and genes that were previously linked with virulence and encode for hemolysins (tlyA, tlyB, tlyC, hlyA, BHWA1_RS02885, BHWA1_RS09085, BHWA1_RS04705, and BHWA1_RS02195), outer membrane proteins (OMPs) (bhlp16, bhlp17.6, bhlp29.7, bhmp39f, and bhmp39h) as well as iron acquisition factors (ftnA and bitC). Multilocus sequence typing (MLST) revealed that 79.4% of the isolates belonged to only three STs, namely ST52 (41.4%), ST8 (12.1%), and ST112 (25.9%) which have been observed in other European countries before. Another 24 isolates belonged to twelve new STs (ST113-118, ST120-123, ST131, and ST193). The temporal distribution of STs revealed the presence of new STs as well as the regular presence of ST52 over three decades (1990s–2000s). The proportion of strains that showed resistance to both tiamulin und valnemulin (39.1%) varied considerably among the most frequent STs ranging from 0% (0/14 isolates resistant) in ST8 isolates to 46.7% (14/30), 52.1% (25/48), and 85.7% (6/7) in isolates belonging to ST112, ST52, and ST114, respectively. All hemolysin genes as well as the iron-related gene ftnA and the OMP gene bhlp29.7 were regularly present in the isolates, while the OMP genes bhlp17.6 and bhmp39h could not be detected. Sequence analysis of hemolysin genes of selected isolates revealed co-evolution of tlyB, BHWA1_RS02885, BHWA1_RS09085, and BHWA1_RS02195 with the core genome and suggested independent evolution of tlyA, tlyC, and hlyA. Our data indicate that in Germany, swine dysentery might be caused by a limited number of B. hyodysenteriae clonal groups. Major STs (ST8, ST52, and ST112) are shared with other countries in Europe suggesting a possible role of the European intra-Community trade of pigs in the dissemination of certain clones. The identification of several novel STs, some of which are single or double locus variants of ST52, may on the other hand hint towards an ongoing diversification of the pathogen in the studied area. The linkage of pleuromutilin susceptibility and sequence type of an isolate might reflect a clonal expansion of the underlying resistance mechanism, namely mutations in the ribosomal RNA genes. A linkage between single virulence-associated genes (VAGs) or even VAG patterns and the phylogenetic background of the isolates could not be established, since almost all VAGs were regularly present in the isolates

Suppression of reproductive function in juvenile rams by a slow-release gonadotropin-releasing hormone implant

Background: Regarding animal welfare and reversible suppression of reproduction the need for alternatives to surgical castration, like slow-release gonadotropin-releasing hormone (GnRH) implants, is increasing.Aim: In this study, we evaluated whether the onset of puberty can be suppressed by implantation of a slow-release GnRH implant (4.7 mg deslorelin) in juvenile rams.Methods: Seven juvenile rams (3–5.5 months) were treated with the GnRH analog deslorelin to analyze the effects on testicular development, sonographic findings of testicular tissue, testosterone concentration in the blood, spermatogenesis, and sperm parameters from the epididymis after castration. Seven rams of the same age without an implant served as controls.Results: Follow-up examinations were conducted over 5 months, after which four rams per group were castrated. No significant group differences were found in the andrological parameters on the group level, but testicular development was suppressed in three rams in the treated group. Histological examination revealed spermatogenesis in the testicular tissue in three of four animals treated with a GnRH analog.Conclusion: The onset of puberty in juvenile rams cannot be reliably suppressed by using the slow-release GnRH implant Suprelorin®

Single nucleotide polymorphism in the <i>B</i>. <i>hyodysenteriae</i> ribosomal protein L3 gene/protein in relation to sequence type and pleuromutilin susceptibility.

<p>Single nucleotide polymorphism in the <i>B</i>. <i>hyodysenteriae</i> ribosomal protein L3 gene/protein in relation to sequence type and pleuromutilin susceptibility.</p

Fig 1A and 1B. MSTs of 746 <i>B</i>. <i>hyodysenteriae</i> isolates (n = 741 from pigs; n = 5 from birds and mice) from the MLST database and from this study.

<p>MST A mirrors the spatial distribution of isolates. Each circle represents a different sequence type (n = 186), the color indicates the country of origin and the size reflects the number of isolates deposited. MST B depicts the temporal distribution of isolates. Each circle represents a different year of isolation and the size reflects the number of isolates from the year in question. Clonal complexes (CC) of STs sharing at least six common loci are indicated by grey shading. The predicted founder of a CC is marked with an asterisk (*); # = CCs with unclear founders.</p

Patterns of virulence-associated genes (VAGs) in 116 <i>B</i>. <i>hyodysenteriae</i> field isolates from pigs in Germany.

<p>Patterns of virulence-associated genes (VAGs) in 116 <i>B</i>. <i>hyodysenteriae</i> field isolates from pigs in Germany.</p

MIC₅₀^* values of pleuromutilins for <i>B</i>. <i>hyodysenteriae</i> isolates of major multilocus sequence types according to the year of isolation.

<p>MIC₅₀^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0190928#t004fn001" target="_blank">*</a>} values of pleuromutilins for <i>B</i>. <i>hyodysenteriae</i> isolates of major multilocus sequence types according to the year of isolation.</p

Minimum inhibitory concentration of pleuromutilins used in this study and classification of isolates as being resistant, intermediate or susceptible.

<p>Minimum inhibitory concentration of pleuromutilins used in this study and classification of isolates as being resistant, intermediate or susceptible.</p