Polymerase Chain Reaction Products Research Articles

Evidence of “Silent” Hepatitis B Virus Infection in Psoriasis, Vitiligo, and Pityriasis Rosea Cases: A Pilot Study

Abstract Background: Psoriasis (PS), vitiligo (VT), and Pityriasis rosea (PR) are chronic skin diseases often occurring as a consequence of exaggerated immune responses. These skin manifestations can be triggered as a result of the molecular mimicry between viral protein (s) and host protein (s), which could generate auto-antibodies. In addition, it can be hypothesised that skin diseases are manifestations of the reduced immunity that is observed in chronic hepatitis B virus (HBV)-infected individuals. Aims and Objective: To investigate the presence of HBV in PS, VT, and PR cases and Human Herpes Virus (HHV) 6 and 7 in PR cases. Materials and Methods: DNA extracted from healthy controls (n = 20), PS (n = 10), VT (n = 11), and PR (n = 12) were subjected to HBV-S gene-specific polymerase chain reactions (PCRs) and HHV 6-UL57 and HHV7-UL10 gene-specific PCRs. PCR products of positive samples (HBV and HHV 6 and 7 DNA) of expected length were bi-directionally sequenced using overlapping primers. Sequence identification was performed by NCBI BLAST and analysed by multiple sequence alignment. HBV DNA copy number was determined through quantitative real-time PCR. The blood samples were also tested for HBV serological markers and Interferon gamma (IFN-γ) by enzyme immunoassays. Results: The PCR data and Immunoassay study revealed that seven out of 12 PR, six out of 10 PS, and six out of 11 VT cases had signs of HBV infection. HHV 6 DNA was detected in four, whereas HHV 7 DNA was found in two of the 12 PR blood samples. PR6 presented the evidence of both HHV 6 and 7 co-infections. Conclusion: Observing the correlation of HBV with skin diseases, albeit at the pilot level, a larger study is warranted to identify HBV infection in skin disease patients. The evidence of HHV 6 and HHV 7 DNA in PR cases supports the HHV infection linkage with PR.

Pharmacogenetic Approach to Tramadol Use in the Arab Population.

Tramdol is one of most popular opioids used for postoperative analgesia worldwide. Among Arabic countries, there are reports that its dosage is not appropriate due to cultural background. To provide theoretical background of the proper usage of tramadol, this study analyzed the association between several genetic polymorphisms (CYP2D6/OPRM1) and the effect of tramadol. A total of 39 patients who took tramadol for postoperative analgesia were recruited, samples were obtained, and their DNA was extracted for polymerase chain reaction products analysis followed by allelic variations of CYP2D6 and OPRM A118G determination. Numerical pain scales were measured before and 1 h after taking tramadol. The effect of tramadol was defined by the difference between these scales. We concluded that CYP2D6 and OPRM1 A118G single nucleotide polymorphisms may serve as crucial determinants in predicting tramadol efficacy and susceptibility to post-surgical pain. Further validation of personalized prescription practices based on these genetic polymorphisms could provide valuable insights for the development of clinical guidelines tailored to post-surgical tramadol use in the Arabic population.

CagA 3' region polymorphism of Helicobacter pylori and its association with chronic gastritis in the Chinese population.

Introduction. Cytotoxin-associated gene A (CagA) from Helicobacter pylori is highly related to chronic gastritis. Tyrosine phosphorylation of Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs from CagA determines the pathogenicity of H. pylori.Gap statement. The precise amino acid variations surrounding the EPIYA motifs and their correlation with clinical outcomes have been poorly explored.Aim. The purpose of this study was to examine the CagA 3' region polymorphism of H. pylori and its association with chronic gastritis in the Chinese population.Method. A total of 86 cagA-positive H. pylori strains were isolated from patients with chronic gastritis in two different hospitals in Beijing, PR China. Genomic DNA was extracted commercial kits, and the cagA 3' variable region of H. pylori was amplified by polymerase chain reaction (PCR). The PCR products were sequenced and analysed using the CLC Sequence Viewer, BioEdit, and WebLogo 3.Results. Two hundred and fifty-nine EPIYA motifs were identified from cagA-positive H. pylori strains. Notably, EPIYA-B exhibited a higher frequency of variation in comparison to EPIYA-A, EPIYA-C, and EPIYA-D. The prevalent sequences for East-Asian-type CagA were QVNK and TIDF, while KVNK and TIDD were most commonly observed for Western-type CagA. The CRPIA motifs of East-Asian-type CagA and Western-type CagA varied at positions 4, 6, 7, 8, and 10. CagA-ABD (73.2%) was the most prevalent type, followed by CagA-ABC (18.6%) and CagA-AB (3.4%). The ratio of CagA-ABD was observed to be higher in cases of chronic non-atrophic gastritis with erosive (NAGE) or chronic atrophic gastritis (AG) compared to chronic non-atrophic gastritis (NAG), and the difference was found to be statistically significant (χ2=59.000/64.000, P<0.001).Conclusions. The EPIYA segments of Western-type CagA and East-Asian-type CagA differ significantly and the presence of CagA-ABD may be associated with severe chronic gastritis from this study.

Long-range and real-time PCR identification of a large SERPINC1 deletion in a patient with antithrombin deficiency.

Congenital antithrombin (AT) or serpin C1 deficiency, caused by a SERPINC1 abnormality, is a high-risk factor for venous thrombosis. SERPINC1 is prone to genetic rearrangement, because it contains numerous Alu elements. In this study, a Japanese patient who developed deep vein thrombosis during pregnancy and exhibited low AT activity underwent SERPINC1 gene analysis using routine methods: long-range polymerase chain reaction (PCR) and real-time PCR. Sequencing using long-range PCR products revealed no pathological variants in SERPINC1 exons or exon-intron junctions, and all the identified variants were homozygous, suggesting a deletion in one SERPINC1 allele. Copy number quantification for each SERPINC1 exon using real-time PCR revealed half the number of exon 1 and 2 copies compared with controls. Moreover, a deletion region was deduced by quantifying the 5'-upstream region copy number of SERPINC1 for each constant region. Direct long-range PCR sequencing with primers for the 5'-end of each presumed deletion region revealed a large Alu-mediated deletion (∼13kb) involving SERPINC1 exons 1 and 2. Thus, a large deletion was identified in SERPINC1 using conventional PCR methods.

Novel Gammaherpesvirus Infections in Narrow-Ridged Finless Porpoise (Neophocaena asiaeorientalis) and False Killer Whales (Pseudorca crassidens) in the Republic of Korea.

A female narrow-ridged finless porpoise (Neophocaena asiaeorientalis) stranded on a beach on Jeju Island showed epithelial proliferative skin lesions on its body. Two false killer whales (Pseudorca crassidens), caught using nets near Gangneung and Samcheok, respectively, had multiple plaques on their penile epidermis. Histological examination of the epidermis revealed that all the lesions had common features, including accentuated rete pegs, ballooning changes, and eosinophilic intranuclear inclusion (INI) bodies. Based on the histopathological results, herpesvirus infection was suspected, and thus further analysis was conducted using herpesvirus-specific primers. Based on nested polymerase chain reaction (PCR) tests using the herpesvirus-detectable primers, the PCR products demonstrated two fragments: a 222-base-pair (bp) sequence of the DNA polymerase gene, SNUABM_CeHV01, showing 96.4% identity with a bottlenose dolphin herpesvirus from the Jeju narrow-ridged finless porpoise; and a 222 bp sequence of the DNA polymerase gene, SNUABM_CeHV02, showing 95.95% identity with the same bottlenose dolphin herpesvirus from the Gangneung and Samcheok false killer whales. The significance of this study lies in its ability to demonstrate the existence of novel cetacean herpesviruses in South Korean seawater, representing an important step forward in studying potentially harmful pathogens that affect endangered whale and dolphin populations.

Mutation Analysis of Exon 1 in the Hemoglobin Subunit Beta (HBB) Gene in Beta-Thalassemia.

Introduction Thalassemia is a widely prevalent monogenic hematological disorder found worldwide. It exists in two forms: alpha- and beta-thalassemia. Alterations in the hemoglobin subunit beta (HBB) gene cause beta-thalassemia, with missense and point mutations affecting beta-globin synthesis. Consequently, genetic screening for beta-thalassemia is essential for genetic counseling, carrier screening, and prenatal diagnosis. Aim and objective This study aims to examine and identify mutations in the exon 1 region of the HBB gene in beta-thalassemia patients from the Vijayapura region. Methods This study involved 47 clinically diagnosed children with beta-thalassemia from a hospital in Vijayapura, India. Detailed clinical histories of all patients were recorded. Genomic DNA was extracted from the blood samples of these patients and subjected to polymerase chain reaction (PCR) using exon-specific primers for the HBB gene. The PCR products were then sequenced using the capillary-based Sanger sequencing method to identify mutations in the HBB gene. Results A total of 47 clinically diagnosed beta-thalassemia patients were included in the study, comprising 30 males and 17 females, aged between one and 20 years. Sequencing analysis of exon 1 in the beta-globin gene identified 17 beta-thalassemia variants. The most common mutation observed was T>G, G>C, C>A, and C>T in the exon 1 region of the HBB gene. Conclusion This study identifies the pattern of beta-thalassemia mutations, aiding in the prevention of the disorder through prenatal diagnosis and genetic counseling. Mutations can alter codon sequences, affecting protein production. Research highlights the importance of a primary prevention program to analyze mutations and sequence variations at the molecular level, thereby helping to address numerous genetic disorders.

L-DNA-Based Melt Analysis Enables Within-Sample Validation of PCR Products.

The melt analysis feature in most real-time polymerase chain reaction (PCR) instruments is a simple method for determining if expected or unexpected products are present. High-resolution melt (HRM) analysis seeks to improve the precision of melt temperature measurements for better PCR product sequence characterization. In the area of tuberculosis (TB) drug susceptibility screening, sequencing has shown that a single base change can be sufficient to make a first-line TB drug ineffective. In this study, a reagent-based calibration strategy based on synthetic left-handed (L)-DNA, designated LHRM, was developed to confirm validation of a PCR product with single base resolution. To test this approach, a constant amount of a double-stranded L-DNA melt comparator was added to each sample and used as a within-sample melt standard. The performance of LHRM and standard HRM was used to classify PCR products as drug-susceptible or not drug-susceptible with a test bed of nine synthetic katG variants, each containing single or multiple base mutations that are known to confer resistance to the first-line TB drug isoniazid (INH). LHRM achieved comparable classification to standard HRM relying only on within-sample melt differences between L-DNA and the unknown PCR product. Using a state-of-the-art calibrated instrument and multiple sample classification analysis, standard HRM was performed at 66.7% sensitivity and 98.8% specificity. Single sample analysis incorporating L-DNA for reagent-based calibration into every sample maintained high performance at 77.8% sensitivity and 98.7% specificity. LHRM shows promise as a high-resolution single sample method for validating PCR products in applications where the expected sequence is known.

Study of the DNA Extraction from the Nail by Spin Column-based Nucleic Acid Purification

Abstract Background: Nails are one of the objects that are more durable than other witness objects. This study was interested in whether the Spin column-based nucleic acid purification technique could extract DNA from nails to give satisfactory results. Aims and Objectives: This study aimed to evaluate the yield and quality of DNA extracted from the nail. Materials and Methods: Nail samples from 15 males and 15 females over 18 were extracted using GeneAll® Exgene™ Cell SV Mini Kit. The DNA concentration and purity were measured using a NanoDrop Spectrophotometer, and the quality of DNA was assessed by polymerase chain reaction (PCR) using primers specific for human growth hormone (HGH). Results: The average yield of DNA was 0.816 μg (0.141–2.706 μg) obtained from the average nail weight of 30.2 mg (22.2–40.0 mg). The average DNA concentration was 27.2 ng/μL (4.7–90.2 ng/μL), corresponding to 30 μL in volume. Almost all DNA samples (96.7%) had high purity (A260/A280 ≥1.80) and gave a band of PCR product of the HGH gene on agarose gel electrophoresis. Conclusion: Spin column-based nucleic acid purification is recommended for nail DNA extraction due to its simplicity and high quality.

UNVEILING THE GENETIC BASIS OF BACTERIOCIN PRODUCTION FROM Enterococcus faecium ATCC 19434

The prevalence of resistance to traditional antimicrobials is increasing rapidly, leading to a significant rise in annual deaths from antibiotic-resistant illnesses. In 2020, the global death toll from such diseases was approximately 500,000. If current trends continue, this figure could exceed 10 million by 2050, with associated economic damages surpassing 100 trillion USD. These alarming statistics highlight the urgent need for alternative antimicrobials. Bacteriocins are considered among the most promising options. Enterococcus faecium ATCC 19434 is known to produce a potent bacteriocin effective against Listeria monocytogenes and Staphylococcus aureus, though its specific bacteriocin and genetic properties have not been fully explored. This study aimed to identify the gene responsible for bacteriocin production in Enterococcus faecium ATCC 19434. DNA was extracted from the bacterium, and polymerase chain reaction (PCR) was conducted. The PCR products were analyzed through agarose gel electrophoresis, sequenced, and subjected to homology searches using the BLASTN and BLASTX tools from the National Center for Biotechnology Information (NCBI). Results revealed that Enterococcus faecium ATCC 19434 contains a gene encoding enterocin B. Additionally, it was found to harbor the gene for enterocin A immunity protein production. This discovery paves the way for future genetic modification of Enterococcus faecium ATCC 19434 to enhance enterocin B synthesis, facilitating its commercial application.

Effect of DNA Template Concentration on Standard Polymerase Chain Reaction

The polymerase chain reaction (PCR) was an essential fundamental procedure widely used in molecular biology to amplify specific deoxyribonucleic acid (DNA) sequences. To investigate the efficiency and specificity of PCR using DNA extracted from human blood cells as sample, several concentrations of DNA templates were used to obtain accurate and reproducible results during this optimisation process. The principal objective was to identify which concentration was the best for amplifying the DNA target sequence and study the effects of the scale of concentrations to standard PCR. For this study, a series of PCR were conducted using various concentrations of DNA template ranging from 1 ng/μL to 100 ng/μL per reaction under optimized conditions of primer concentrations, annealing temperature and extension time. The results demonstrated that DNA template concentration significantly influenced the efficiency and specificity of PCR as the intensity of the target gene amplification band was increased on the agarose gel electrophoresis under ultraviolet light indicating the PCR product yield. Formation of primer-dimers became more prominent as the DNA template concentration reduced resulting in non-specific amplification. The concentrations ranging from 10 ng/μL to 70 ng/μL were the most optimal reactions profiting a remarkable feat of target gene amplification while concentrations less than 1 ng/μL produced none and non-specific outcomes retaining little amount of target gene amplification. In conclusion, our study highlights the pivotal role of DNA template concentration optimises PCR to increase reliability and reproducibility, extending our understanding of genetic analysis, diagnostic, and forensic sciences.

Identification of an endonuclease and N6-adenine methyltransferase from Ureaplasma parvum SV3F4 strain

Here, we report a novel endonuclease and N6-adenine DNA methyltransferase (m6A methyltransferase) in the Ureaplasma parvum SV3F4 strain. Our previous study found that the SV3F4 strain carries 17 unique genes, which are not encoded in the two previously reported U. parvum serovar 3 strain, OMC-P162 and ATCC 700970. Of these 17 unique genes, UP3_c0261 and UP3_c0262, were originally annotated as encoding hypothetical proteins. Comparative genomics analyses more recently indicated they encode a Type II restriction endonuclease and an m6A methyltransferase, respectively. The UP3_c0261 and UP3_c0262 genes were individually expressed and purified in Escherichia coli. The UP3_c0261 recombinant protein showed endonuclease activity on the pT7Blue vector, recognizing and cleaving a GTNAC motif, resulting in a 5 base 5’ extension. The UP3_c0261 protein digested a polymerase chain reaction (PCR) product harboring the GTNAC motif. The endonuclease UP3_c0261 was designated as UpaF4I. Treatment of the PCR product with the recombinant protein UP3_c0262 completely blocked the restriction enzyme activity of UpaF4I. Analysis of the treated PCR product harboring a modified nucleotide by UP3_c0262 with HPLC-MS/MS and MS/MS showed that UP3_c0262 was an m6A methyltransferase containing a methylated A residue in both DNA strands of the GTNAC motif. Whole genome methylation analysis of SV3F4 showed that 99.9 % of the GTNAC motif was m6A modified. These results suggest the UP3_c0261 and UP3_c0262 genes may act as a novel Type II restriction-modification system in the Ureaplasma SV3F4 strain.

Identification of novel bacterial species in the blood of patients with neonatal sepsis

BackgroundThe clinical diagnosis of neonatal sepsis remains difficult because of various challenges, such as culturing the bacteria and avoiding contamination. Therefore, this study aimed to identify bacterial pathogens in patients with clinically diagnosed neonatal sepsis by next-generation sequencing (NGS).MethodsHigh-throughput NGS and traditional culture identification were performed by comparing samples from newborns with neonatal sepsis with healthy control infants. All blood samples were separately inoculated into anaerobic and aerobic bottles and incubated for 7 days at 37 °C, the positive specimens were then identified. Novel bacteria identified through high-throughput NGS were analysed using polymerase chain reaction (PCR), PCR products were verified by Sanger sequencing. Wilcoxon rank-sum and chi-square tests were performed to assess the significance of differences in species abundance between groups. Subjects were clinically diagnosed and hospitalized at the Pediatrics Department of Shenzhen Seventh People’s Hospital and Pediatrics Department of the Longhua Branch of Shenzhen People’s Hospital. Experiments were performed at the Shenzhen Seventh People’s Hospital. The experimental group comprised 45 newborns clinically diagnosed with neonatal sepsis (age: 0–28 days; 28 males, 17 females). Fifteen normal newborns aged 0–28 days (7 males, 8 females) were included as the control group.ResultsHigh-throughput NGS showed a positivity rate of 44% (20/45) for bacteria in patients clinically diagnosed with neonatal sepsis, whereas traditional bacterial culture identification showed a positivity rate of 0% (0/45). The four main bacterial species identified were Anoxybacillus kestanbolensis, Geobacillus vulcani, Klebsiella oxytoca, and Acinetobacter guillouiae.ConclusionsA. kestanbolensis, G. vulcani, K. oxytoca, and A. guillouiae, newly discovered bacteria in patients with neonatal sepsis, were identified with high-throughput NGS. Which may result from maternal intrauterine infection or birth-canal infection and have a high clinical-cure rate. Owing to a lack of methods to culture these bacteria, their role in neonatal sepsis remains unclear. A definite diagnosis cannot rely solely on bacterial culture identification for patients with a suspected diagnosis and clinical diagnosis of neonatal sepsis and should involve other effective diagnostic techniques.

Genotype-phenotype analyses of Iranian patients with hemophilia B (Leyden -) and hemophilia B (Leyden +): A single-center study

BackgroundThere is a high prevalence of inherited bleeding disorders in Iran, such as hemophilia A (HA) and hemophilia B (HB). This study aimed to analyze the molecular and clinical profiles of patients with HB. MethodsA single-center study was conducted among patients with severe HB between March 20, 2000, and June 31, 2023. The polymerase chain reaction (PCR) amplification was used for all of the major regions, such as the promoter, the exons, the adjacent intronic regions, and the untranslated regions of the F9 gene. Finally, Sanger sequencing was performed on the PCR products. ResultsA total of 111 HB patients (17 with HB [Leyden +] and 94 with HB [Leyden -]) were enrolled in this study. Among 94 patients with HB (Leyden -), 59 (62.8 %) had missense, 21 (22.3 %) had nonsense, and 8 (8.5 %) had frameshift mutations. Moreover, the most frequent pathogenic variant in HB (Leyden +) was c.–17 A>G in this study. ConclusionThe results of this study confirm that HB is caused by a wide range of molecular defects in Iran. Thus, by knowing the genotypes and phenotypes, we would be able to stratify the patients which is important in terms of their management and outcome.

Anaplasmosis concurrent with copper deficiency in a Salem Black kid

Four months old Salem black kid was brought with the history of alopecia around the face and ear. Clinical examination revealed severe alopecia on ears, face, trunk and easy epilation of hairs along with depigmentation, mild scaling in ear margins, steely appearance, pale mucosa and loss of body condition. Detailed dermatological analysis like skin scrapings and trichogram revealed negative for ectoparasites and hair growth abnormalities. Blood smear examination revealed Anaplasma ovis organisms, with blood picture of normochromic microcytic anemia. Amplified Polymerase chain reaction product found to be positive for Anaplasma ovis. Serum biochemistry revealed low level of copper (0.0598 mg/L), elevated total bilirubin (3.6 mg/dl), direct bilirubin (2.83 mg/dl), creatinine kinase (73 mg/dl) and LDH (348 U/L). Based on above findings and treatment response, the case was diagnosed as anaplasmosis in a kid with concurrent copper deficiency.

Non-typhoidal Salmonella contributes to gastrointestinal infections in Morogoro: Evidence from patients attending Morogoro regional referral hospital in Tanzania.

Salmonella is one of the most common causes of food-borne outbreaks and infection worldwide. Non-typhoidal Salmonella (NTS) infections are common and remain a significant public health problem among important bacterial foodborne diseases. The current study aimed to establish the Non typhoidal Salmonella infection and antimicrobial resistance status among selected patients at Morogoro Regional Referral Hospital (MRRH), Morogoro Region, Tanzania, to inform clinical care management and public health interventions. A cross-sectional study was conducted using medical records and samples were collected from hospitalised and outpatients between October and December 2021. A total of 153 participants were enrolled in the study and 132 consented to being sampled. The collected samples were analysed using standard microbiological techniques. The isolates were subjected to molecular genotyping, where Polymerase Chain Reaction (PCR) was performed targeting the 16S rDNA gene. PCR products were then submitted for sequencing to establish phylogenetic relatedness. Antimicrobial susceptibility testing and resistance genes screening were also conducted. The phylogenetic analysis identified two Salmonella serovars; Salmonella Enteritidis and Salmonella Typhimurium. The isolates were from four adults and seven children patients. The isolates were tested against six antimicrobial agents: tetracycline, trimethoprim, gentamycin, ciprofloxacin, ampicillin and cefotaxime. Further antimicrobial assays were performed by screening 10 antimicrobial resistance genes using PCR. Overall, the highest resistance was observed in ampicillin (100%), whereas the lowest resistance was recorded for ciprofloxacin and gentamicin (9.1%). In addition, four (36.4%) of the isolates were resistant to cefotaxime and three (27.3%) to tetracycline and trimethoprim. The isolates also exhibit the presence of resistance genes for sulfamethoxazole 1&2, tetracycline (tet) A&B, Beta-lactamase CTXM, Beta-lactamase TEM, Beta-lactamase SHV, Gentamycine, Acra and acc3-1 in different occurrences. The overall prevalence of Salmonella species in Morogoro region was 8.3% (11/132) with Salmonella Enteritidis and Salmonella Typhimurium being the only serovars detected from adults and children stool samples. Our investigation showed that both children and adults had been exposed to Salmonella spp. However, the occurrence of NTS was higher in children (5.3% (7/132) compared to adults (3.0% (4/132). To stop zoonotic infections and the development of antimicrobial resistance in the community, this calls for Infection Prevention and Control (IPC) and stewardship programmes on rational use of antimicrobials in both health facilities and at the community level.

First identification of Cytauxzoon manul in Eurasian lynx (Lynx lynx) in northwestern China

BackgroundMultiple species of the genera Cytauxzoon and Hepatozoon can infect wild felines, but the diversity of these and other apicomplexan parasites in Eurasian lynx is scarcely known. The aim of this study was to detect Cytauxzoon and Hepatozoon species with molecular methods in Eurasian lynxes and their ticks in northwestern China.MethodsDNA was extracted from the heart, liver, spleen, lung, and kidney samples of three Eurasian lynxes as well as from their five ixodid ticks. These DNA samples were screened with polymerase chain reactions (PCRs) for Cytauxzoon with the partial cytochrome b gene (CytB), cytochrome c oxidase subunit I gene (COI), and small subunit ribosomal RNA gene (18S rRNA), and Hepatozoon with three different fragments of small subunit ribosomal RNA gene (18S rRNA). PCR products were sequenced, aligned, and phylogenetically analyzed.ResultsOne adult female of Eurasian lynx (#1, adult female) was co-infected with Cytauxzoon manul and Hepatozoon felis genotype I, while an adult male lynx (#2) was infected with C. manul. Interestingly, H. felis genotype I was both detected in a male cub (#3) and two out of five infesting Hyalomma asiaticum ticks.ConclusionsFor the first time, Cytauxzoon manul is reported here from Eurasian lynx. In addition, H. felis has not been known to occur in this host species in China and Central Asia. Thus, the findings of this study extend our knowledge on the geographical distribution and host range of these haemoprotozoan parasites. Moreover, this is also the first evidence of C. manul and H. felis co-infection in Eurasian lynx.Graphical

First Report of Botrytis cinerea Causing Stem Rot on Hydrangea macrophylla in China.

Hydrangea (Hydrangea macrophylla), commonly referred to as big leaf hydrangea, is a species within the Hydrangeaceae family notable for its ornamental value. Characterized by its vividly colored sepals and lush, striking inflorescences, this species is globally esteemed as both a potted and landscape plant. Notably, in 2022, an alarming incidence of stem rot was observed in approximately 40% of H. macrophylla plants aged between six and twelve months within 16 greenhouses situated in Nanjing City (N 31°14', E 118°22'), Jiangsu Province, China. Initial symptoms of the disease manifested as wet gray-black spots at the base of the seedlings and stems, progressing to a necrotic gray-white discoloration in the stems and accompanied by the growth of gray mold on the affected parts. This infection ultimately led to the wilting of the leaves and the death of the seedlings. For pathogen identification, stem tissues at the interface of diseased and healthy sections were excised, surface-sterilized with 75 % ethanol for 30 s, followed by a 2 - 3 min treatment with 3% sodium hypochlorite, and subsequently rinsed three times with sterile water before air drying. Sections measuring 2 - 3 mm were then cultured on potato dextrose agar (PDA) medium, supplemented with 50 mg/mL rifampicin (RFP), and incubated at 25 ℃ for 3 - 5 d (Zhou et al. 2022). Upon 2 - 3 days of incubation, notable growth of fungal colonies was observed. Mycelial clusters from the periphery of these colonies were subsequently transferred to fresh PDA plates and incubated at 25 ℃ for an additional 5 - 7 d. A particular colony, designated JSNJ2022-2 and now preserved at the Jiangsu Academy of Agricultural Sciences, was selected for detailed examination. This colony exhibited a flocculent texture, with a coloration ranging from grey-white to light brown. It was characterized by the presence of irregularly formed, hard sclerotia within the hyphae. The conidiophores were observed to be slender and erect, featuring dendritic branches at their extremities. The conidia were clustered on the conidiophore like grapes. These conidia were generally colorless or grey, oval in shape, smooth and transparent, and measured between 6.4 - 12.2 × 7.3 - 18.2 μm (n = 50). For genetic analysis, genomic DNA (gDNA) was extracted using the DNA secure Plant Kit (Tiangen Biotech, Beijing, China). Polymerase chain reaction (PCR) amplification was performed using a set of universal primers of ITS1/ITS4 (White et al. 1990), primers corresponding to the specific sequences of glyceraldehyde-3-phosphate dehydrogenase (G3PDH), heat-shock protein 60 (HSP60), and DNA-dependent RNA polymerase subunit II (RPB2) (Yang et al. 2020). The resultant PCR products were sequenced, and the resulting sequences were submitted to the GenBank database, under the accession numbers OP131597, OP142320, OP142321, and OP142322, respectively. BLAST analysis of the sequences obtained from the isolate JSNJ2022-2 revealed a high degree of genetic similarity, ranging from 99 to 100%, with known sequences of Botrytis cinerea (accessions MK051124.1, MH796662.1, MH479931.1, and KU760986.1). To elucidate the phylogenetic position of the isolate, a phylogenetic tree was constructed using the maximum likelihood method, supported by 1,000 bootstrap replications, in the Mega7 software (Kumar et al. 2016). The results of this analysis confirmed that the strains under study clustered within the same branch as B. cinerea. To establish the pathogenicity of the isolate, Koch's postulates (Falkow 1988) were employed. Healthy potted H. macrophylla seedlings, approximately three months old, were wound inoculated at the base of the seedlings with a 6 mm diameter mycelium plug of JSNJ2002-2 cultivated on PDA for 3 days, which was subsequently covered with moistened degreasing cotton. Control plants were treated with moistened degreasing cloths minus the pathogen. Post-inoculation, these plants were placed in a growth chamber maintained at 25 ℃ with a relative humidity range of 60 - 80%. After a 3-d incubation period, the inoculated plants displayed symptoms identical to those initially observed in the greenhouse. The pathogen was successfully re-isolated from these inoculated plants and was morphologically re-confirmed as B. cinerea, thus satisfying the criteria of Koch's postulates. To our knowledge, this report represents the first documented incidence of B. cinerea causing stem rot in H. macrophylla in China.

Molecular identification of Entamoeba spp. in humans and cattle in Baghdad, Iraq.

A total of 10% of the global population succumbs to amoebiasis yearly, equating to 50,000-100,000 recorded fatalities. It is closely associated with contaminated food and water supplies due to human feces. The disease's pathophysiology remains a subject of ongoing debate among experts. Some experts attribute the role of the host's conditions, parasite species and strain, and infection intensity in eliciting clinical symptoms. The aim of this study was to perform molecular identification of Entamoeba species isolated from humans and cattle. Stool samples from three hundred patients and one hundred cattle were collected from different regions, age groups, and sexes in Baghdad for microscopic examination. One hundred randomly chosen patient and cattle stool samples underwent microscopic examination and conventional polymerase chain reaction (PCR) targeting the 18S rRNA gene. Phylogenetic tree analyses were performed for Entamoeba species identification. The infection rate in humans differed significantly (p < 0.05) between age groups and genders, totaling 38%. The infection rate in cattle, determined by conventional PCR, differed significantly (p < 0.05) between age groups and genders, amounting to 58%. Ten PCR products with positive results were sequenced and deposited in GenBank database. Sequence analysis detected that Eight sequences belong to E. histolytica (OM268853.1, OM268854.1, OM268855.1, OM268857.1, OM268858.1, OM268860.1, OM268861.1, and OM268862.1) and two sequences belong to E. dispar (OM268856.1 and OM268859.1) in humans, while 10 sequences (ON724165.1 to ON724174.1) belongs to E. histolytica in cattle. The increased susceptibility of cattle to E. histolytica suggests a considerable role in human infection and substantial public health risks. Further research should be conducted on the many virulence factors such as HM1:IMSS strain, cysteinprotease (Cp1), Gal/lectin, etc. of E. histolytica and E. dispar.

Molecular Characterization of Methicillin-resistant Staphylococcus aureus (MRSA) Isolates from Ruminants

Background: Methicillin-resistant Staphylococcus aureus (MRSA) infection is one of the leading causes of infections in animals as well as human beings and is associated with significant morbidity, mortality, length of stay and cost burden. Methods: In this study, 725 samples of nasal swabs and milk were collected randomly from cattle, buffalo, sheep and goats and these samples were inoculated on Mannitol salt agar mixed with Oxacillin Resistance Selective Supplement for the molecular characterization of MRSA isolates through sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and polymerase chain reaction (PCR) test. Result: Out of 725 samples, 171 were found positive for Oxacillin resistant S. aureus. The SDS-PAGE showed different bands of molecular weight 13, 17, 20, 24, 26, 28, 33, 36, 39, 43, 47, 59, 64, 72, 86, 97 and 121 kDa. An amplified mec A DNA fragment (137) of 533 base pairs (bp) and PCR product of fem A (133 isolates) of 510 bp were detected in isolates.

Thermally resistant nuclease in Serratia marcescens hinders PCR reactions and degrades PCR products.

Polymerase chain reaction (PCR) is an important tool for exogenous gene acquisition and recombinants identification. There exist two problems when using Serratia marcescens as a template for PCR amplification: amplified PCR products are rapidly degraded, and the results of PCR amplification are unstable. The aim of the present work was to elucidate the reasons for this. By mixing PCR products amplified from Escherichia coli DH5α with S. marcescens supernatant or pellet, we found that the DNA-degrading substance in S. marcescens is thermally resistant and present both intracellularly and extracellularly. We then determined that it is protein, and most likely S. marcescens nuclease, that degrades PCR products since the addition of SDS and EDTA can effectively inhibit or block the degradation of PCR products. By knocking out the S. marcescens nuclease encoding gene, nucA, we confirmed that the nuclease is responsible for the degradation of PCR products and the instability of PCR amplification. This work is the first to show that the S. marcescens nuclease is temporarily and partially inhibited by high temperatures during PCR and recovers rapidly at room temperature after PCR.