A Web-Based Global Educational Model for Training in Semen Analysis during the COVID-19 Pandemic

Infertility affects between 2.5% and 12% of couples worldwide, with male factor infertility solely accounting for 20% to 30% and contributing to 50% of the overall infertility cases [1]. In the United States alone, infertility affects 9.5% of men [2]. The clinical evaluation of male infertility is based on the semen analysis where the results can significantly influence the diagnostic interpretation and management. While many clinicians rely on semen parameters as a surrogate marker of a man’s ability to father a child, the results of semen analysis should, however, be interpreted with caution considering its inherent limitations [3,4]. A properly performed semen analysis and an adequate clinical examination of the male along with questions regarding current medical conditions and lifestyle circumstances that could affect sample quality, can provide valuable information related to a man’s fertility potential. This information facilitates a better understanding of the physiology of the reproductive organs and the underlying causes of dysfunction [5- 7]. However, manual semen analysis has its inherent challenges associated with high subjectivity, lack of standardization, inadequate quality control and quality assurance, as well as inadequate assessment of competency, and training of laboratory personnel performing the test [7,8]. Unlike sperm concentration and motility, sperm morphology has even more subjectivity in reporting the results, with increased intra- and intervariability [8-10]. Therefore, quality control is imminent in preventing such variations and retaining uniformity in all assessments by all operators. This includes preanalytical (test requisition, correct sample collection, delivery of sample), analytical (mixing and loading of sample, correct preparation of smears or calculation of results), and post-analytical (correct reporting of results to the clinician) indicators. To minimize errors, daily, weekly, or monthly quality control of reagents and equipment is imperative

A peptide derived from human bactericidal/ permeability-increasing protein (BPI) exerts bactericidal activity against Gram-negative bacterial isolates obtained from clinical cases of bovine mastitis

Gram-negative bacteria are responsible for approximately one-third of the clinical cases of bovine mastitis and can elicit a life-threatening, systemic inflammatory response. Lipopolysaccharide (LPS) is a membrane component of Gram-negative bacteria and is largely responsible for evoking the inflammatory response. Antibiotic and anti-inflammatory therapy for treating Gram-negative infections remains suboptimal. Bactericidal/permeability-increasing protein (BPI) is a neutrophil-derived protein with antimicrobial and LPS-neutralizing properties. Select peptide derivatives of BPI are reported to retain these properties. The objective of this study was to evaluate the antimicrobial activity of a human BPI-derived synthetic peptide against clinical bovine mastitis isolates of Gram-negative bacteria. A hybrid peptide was synthesized corresponding to two regions of human BPI (amino acids 90–99 and 148–161), the former of which has bactericidal activity and the latter of which has LPS-neutralizing activity. The minimum inhibitory (MIC) and bactericidal (MBC) concentrations of this peptide against various genera of bacteria were determined using a broth microdilution assay. The MIC’s were determined to be: 16–64 mg/ml against Escherichia coli; 32–128 mg/ml against Klebsiella pneumoniae and Enterobacter spp.; and 64–256 mg/ml against Pseudomonas aeruginosa. The MBC’s were equivalent to or 1-fold greater than corresponding MIC’s. The peptide had no growth inhibitory effect on Serratia marcescens. The antimicrobial activity of the peptide was retained in the presence of serum, but severely impaired in milk. Further functional evaluation of the peptide demonstrated its ability to completely neutralize LPS. Together, these data support additional investigations into the therapeutic application of BPI to the treatment of Gram-negative infections in cattle

Staphylococcus aureus intramammary infection elicits increased production of transforming growth factor-alpha, beta 1, and beta 2

In contrast to other mastitis pathogens, the host response evoked during Staphylococcus aureus intramarnmary infection is marked by the absence of the induction of critical cytokines, including IL-8 and TNF-alpha, which have established roles in mediating host innate immunity. The elucidation of changes in the expression of other mediators with the potential to regulate mammary inflammatory responses to S. aureus remains lacking. Transforming growth factor (TGF)-alpha, TGF-beta 1, and TGF-beta 2 are cytokines that regulate mammary gland development. Because these cytokines also have a demonstrated role in mediating inflammation, the objective of the current study was to determine whether S. aureus intramammary infection influences their expression. Ten cows were challenged with S. aureus and milk samples collected. Increases in milk levels of TGF-alpha were evident within 32 h of infection and persisted for 16 h. Increases in TGF-beta 1 and TGF-beta 2 levels were detected within 40 It of S. auretts infection and persisted through the end of the study. Thus, in contrast to IL-8 and TNF-a, S. aureus elicits host production of TGF-alpha, TGF-beta 1, and TGF-beta 2. This finding may suggest a role for these cytokines in mediating mammary gland host innate immune responses to S. aureus. Published by Elsevier B.V

Increased milk levels of transforming growth factor-alpha, beta 1, and beta 2 during Escherichia coli-induced mastitis

Among the gram-negative bacteria that cause mastitis, Escherichia coli are the most prevalent. The innate immune system provides initial protection against E. coli infection by detecting the presence of the foreign pathogens and by mounting an inflammatory response, the latter of which is mediated by cytokines such as IL-1 beta, IL-8, and tumor necrosis factor (TNF)-alpha. Although changes in these cytokines during mastitis have been well-described, it is believed that other mediators moderate mammary gland inflammatory responses as well. The growth factors/cytokines transforming growth factor (TGF)-alpha, TGF-beta 1, and TGF-beta 2 are all expressed in the mammary gland and have been implicated in regulating mammary gland development. In other tissues, these growth factors/cytokines have been shown to moderate inflammation. The objective of the current study was to determine whether TGF-alpha, TGF-beta 1, and TGF-beta 2 milk concentrations were altered during the course of E. coli-induced mastitis. The contralateral quarters of 11 midlactating Holstein cows were challenged with either saline or 72 cfu of E. coli, and milk samples were collected. Basal milk levels of TGF-alpha, TGF-beta 1, and TGF-beta 2 were 98.81 +/- 22.69 pg/mL, 3.35 +/- 0.49 ng/mL, and 22.36 +/- 3.78 ng/mL, respectively. Analysis of whey samples derived from E. coli-infected quarters revealed an increase in milk levels of TGF-alpha within 16 h of challenge, and these increases persisted for an additional 56 h. Elevated TGF-beta 1 and TGF-beta 2 milk concentrations were detected in E. coli-infected quarters 32 h after challenge, and these elevations were sustained throughout the study. Because TGF-alpha, TGF-beta 1, and TGF-beta 2 have been implicated in mediating inflammatory processes, their induction during mastitis is consistent with a role for these molecules in mediating mammary gland host innate immune responses to infection

The bovine innate immune response during experimentally-induced Pseudomonas aeruginosa mastitis

Almost half of all clinical cases of mastitis are caused by Gram-negative bacteria. Among these bacteria, intramarnmary infection by Pseudomonas aeruginosa remains one of the most refractory to antibiotic therapy. The ability to recognize potentially harmful pathogens whether previously encountered or not, as well as the induction of an initial pro-inflammatory response to these pathogens, are critical components of host innate immunity. Although the innate immune response to another Gram-negative mastitis-causing pathogen, Escherichia coli, has been well-characterized, little is known about the response to other Gram-negative bacteria, including P. aeruginosa. The objective of the current study was to characterize the systemic and localized. bovine innate immune response to intramammary infection with R aeruginosa. The contralateral quarters of ten mid-lactating Holstein cows were challenged with either saline or P aeruginosa. Following the establishment of infection, milk samples were collected and assayed for changes in cytokine and growth factor concentrations, complement activation, and changes in the levels of soluble CD14 (sCD14) and lipopolysaccharide (LPS)-binding protein (LBP), two accessory molecules involved in host recognition of Gram-negative bacteria. Initial increases in milk somatic cell counts were evident within 12 h of experimental challenge and remained elevated for >= 3 weeks. Increased permeability of the mammary gland vasculature, as evidenced by elevated milk levels of BSA, was initially observed 20 h post-infection and persisted for 2 weeks. Within 32 h of challenge, increased levels of IL-8, TNF-alpha, IL-10, and IL-12 were detected, however, the elevated levels of these cytokines were not sustained for longer than a 24 h period. In contrast, elevations in IL-1 beta, IFN-gamma, TGF-alpha, TGF-beta 1, TGF-beta 2, sCD14, LBP, and activated complement factor 5 (C5a) were sustained for periods of > 48 h. Systemic changes were characterized by elevated body temperature, induction of the acute phase protein synthesis of serum amyloid A and LBP, and a transient decrease in circulating neutrophils and lymphocytes. Together, these data demonstrate the capability of the mammary gland to mount robust innate immune response to P. aeruginosa that is characterized by the induction of pro-inflammatory cytokines, complement activation, and increased levels of accessory molecules involved in Gram-negative bacterial recognition. Published by Elsevier B.V

An expert commentary on essential equipment, supplies and culture media in the assisted reproductive technology laboratory

International audienceThe assisted reproductive technology (ART) laboratory is a complex system designed to sustain the fertilization, survival, and culture of the preimplantation embryo to the blastocyst stage. ART outcomes depend on numerous factors, among which are the equipment, supplies and culture media used. The number and type of incubators also may affect ART results. While large incubators may be more suitable for media equilibration, bench-top incubators may provide better embryo culture conditions in separate or smaller chambers and may be coupled with time-lapse systems that allow continuous embryo monitoring. Microscopes are essential for observation, assessment, and micromanipulation. Workstations provide a controlled environment for gamete and embryo handling and their quantity should be adjusted according to the number of ART cycles treated in order to provide a steady and efficient workflow. Continuous maintenance, quality control and monitoring of equipment are essential and quality control devices such as the thermometer, and pH-meter are necessary to maintain optimal culture conditions. Tracking, appropriate delivery and storage conditions, and quality control of all consumables are recommended so that adequate quantity and quality are available for use. Embryo culture media have evolved: preimplantation embryos are cultured either by sequential media or single-step media that can be used for interrupted or uninterrupted culture. There is currently no sufficient evidence that any individual commercially-available culture system is better than others in terms of embryo viability. In this review, we aim to analyze the various parameters that should be taken into account when choosing the essential equipment, consumables and culture media systems that will create optimal culture conditions and provide the most effective patient treatment

Optimizing embryological aspects of oocyte retrieval, oocyte denudation, and embryo loading for transfer

International audienceOocyte retrieval, oocyte denudation, and embryo transfer are crucial processes during assisted reproduction technology (ART). Air quality in the ART laboratory, temperature, pH of the media used and the time interval between oocyte retrieval and insemination are all critical factors. Anesthesia is required for oocyte retrieval, however, evidence regarding the potential impact of different methods (general anesthesia, conscious sedation, and local anesthesia) on the clinical outcomes is unclear. The optimal timing of oocyte denudation following retrieval has not been established. Regarding the mechanical denudation process, there is a lack of evidence to demonstrate the safest minimum inner diameter of denuding pipettes used to complete the removal of granulosa cells surrounding the oocytes. During embryo transfer, many clinics worldwide flush the catheter before embryo loading, in an attempt to potentially rinse off any toxic agents; however, there is insufficient evidence to show that flushing the embryo transfer catheter before loading increases the success of ART outcome. Considering the serious gaps in knowledge in ART practice, the aim of this review is to provide an updated overview of the current knowledge regarding the various steps and techniques involved in oocyte retrieval, oocyte denudation, and embryo loading for transfer