Streptococcus agalactiae is a primary pathogen associated with subclinical mastitis in dairy herds, requiring accurate identification and characterization for effective management due to its highly contagious nature. This study evaluated the use of Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) for grouping S. agalactiae isolates from subclinical mastitis in cattle and buffaloes associating the antimicrobial susceptibility profiles of the isolates with the grouping results. A total of 198 milk samples were collected from three farms (Farm A: 67 cow isolates, Farm B: 101 cow isolates, Farm C: 30 buffalo isolates). Antimicrobial susceptibility testing using the Minimum Inhibitory Concentration (MIC) method was performed for 10 antimicrobials. High sensitivity (>90%) was observed for ceftiofur, penicillin, oxacillin, amoxicillin, cefquinome, gentamicin, and cefoxitin, while low sensitivity (<15%) was detected for enrofloxacin and cephalexin. Clustering was conducted using Random Amplified Polymorphic DNA (RAPD) and grouped by MALDI-TOF MS. RAPD identified 33 clusters at an 80% similarity breakpoint, while MALDI-TOF MS identified 8 distinct groups. MALDI-TOF MS successfully grouped all isolates, whereas RAPD clustered only 100. Both methods grouped isolates from the same herd with similar susceptibility profiles. These findings highlight the use of MALDI-TOF MS for rapid grouping pathogens but emphasize differences when compared to RAPD.
Immunogenetic factors such as human leucocyte antigen (HLA) alleles, have yielded contrasting associations with protection or increased chances of hospitalization due to COVID-19 worldwide. This case-control study included834 patients with confirmed COVID-19 diagnosis from five Brazilian states: Ceará (n=110), Mato Grosso (n=192), Pará (n=209), Rio de Janeiro (n=211) and Rio Grande do Sul (n=112). Genotyping was performed using the Axiom™ Human Genotyping SARS-CoV-2 array, targeting single nucleotide polymorphisms in HLA class I and II genes, and HLA alleles were imputed for eight loci. Among the 15 preselected candidate alleles, only DQA1*05:01 (p=0.015) in the state of Ceará remained significantly associated with hospitalization. The meta-analysis of the most frequent alleles in all states revealed that HLA-DPA1*01:03 (p=0.0229, OR=0.76, 95% CI=0.60-0.96) and -DPB1*04:01 (p=0.0474, OR=0.78, 95% CI=0.611.00) were associated with protection against hospitalization, whereas HLA-DPA1*02:01 (p=0.0259, OR=1.37, 95% CI=1.04-1.80), -DQA1*05:01 (p=0.0133, OR=1.40, 95% CI=1.07-1.82), and -DRB1*03:01 (p=0.0276, OR: 1.59, 95% CI: 1.05-2.40) were associated with increased risk. HLA evolutionary divergence (HED) scores were significantly higher among the non-hospitalized group for the HLA-A locus, which has been shown to be a protective factor for the most severe forms and consequently hospitalization due to COVID-19.
Mycoplasma gallisepticum (MG) can infect a wide range of birds, seriously jeopardizing the development of the poultry industry. A nested-PCR method was constructed based on mgc2 gene for evaluating the prevalence of MG in duck flocks. A total of 1002 samples were detected from Shandong and Inner Mongolia by this method. The total positive rate of MG was 22.75% (228/1002), with the highest prevalence in commercial laying ducks (34.83%), the lowest in dead duck embryos (6.67%), and a proportionate prevalence of 17.33% in commercial meat ducks. Genetic evolutionary analysis by mgc2 gene showed that the homology among the wild strains of duck derived MG was 73.3%-99.8%, which revealed genetic diversity, and the homology with the international chicken-derived MG reference strain was ranged 68.4%-98.4%, indicating that some duck-derived MG strains had an independent origin. Duck embryo pathogenicity tests showed only the mortality rate of duck embryos infected by strain 1-9 reached 60%. To clarify the genetic background of strain 1-9, the data of whole genome sequencing showed that the full length of 1-9 was 962,503 bp, and the GC content was 31%. Among the predicted 1576 genes, a total of 599 genes were functionally classified, and the virulence genes were distributed in 21 virulence factors. Phylogenetic tree based on 16S rRNA and single copy gene set were confirmed that there was a far genetic evolutionary distance between the isolate 1-9 and the chicken-derived reference strains. Our findings provided a scientific basis for the research on the pathogenicity and exploring functional genes of duck-derived MG.
The novel coronavirus, COVID-19, which was first identified in December 2019 rapidly spread worldwide and was declared a global pandemic. Beyond respiratory symptoms, COVID-19 often results in coagulation and vascular endothelium disorders, causing increased clotting and bleeding, which are closely linked to the acute phase of the infection. Factor VIII is a crucial protein in the blood coagulation cascade, and elevated FVIII levels have been linked to thrombotic events in COVID-19, highlighting the need to understand its behavior during treatment. Remdesivir is an antiviral drug that has shown promise in reducing recovery time and mortality rates in COVID-19 patients. This study aims to examine the changes in blood factors and the expression of the factor VIII gene in patients treated with Remdesivir. Blood samples were collected from 30 COVID-19 patients before and after Remdesivir treatment and from 20 healthy individuals. Patients with underlying diseases were excluded from the study. RNA was extracted from these samples, followed by cDNA synthesis. The expression of the factor VIII gene was analyzed using Real-Time PCR. The results indicated that blood factors such as Urea, ALK, AST, WBC, and CRP were elevated in the patient group compared to the control group. At the same time, FBS, Urea, ALK, AST, WBC, RDW, INR, and K levels increased in the Remdesivir treatment group (P<0.001). Conversely, MCHC, RBC, and Ca levels decreased in both patient and treatment groups compared to the control group (P<0.001). The expression of the FVIII gene was upregulated approaching 2 times in COVID-19 patients and 1.5-fold in the treatment group compared to the control group (P<0.001). However, no significant changes were observed in FVIII expression before and after Remdesivir treatment. However, a positive correlation between RBC, FBS, and Urea in the patient group and a negative correlation between RDW and FVIII expression levels was observed. In the treatment group, FVIII expression level correlated negatively with Urea, P, and RDW. These findings suggest that elevated FVIII levels are associated with disease severity and excessive coagulation in COVID-19 patients. Additionally, Remdesivir does not appear to exacerbate the coagulation process.