Isolation of two Kocuria species capable of growing on various polycyclic aromatic hydrocarbons

Different samples collected from crude oil contaminated beach were enriched for isolation of bacterial strains capable of growing on naphthalene, phenanthrene and fluoranthene. Respiratory reduction ofWST-1{4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate} to a colored formazan showed that one isolated strain CMG2028, identified as Kocuria flava by 16s rRNA, grew onnaphthalene and phenanthrene while CMG2042, identified as Kocuria rosea grew on all three polycyclic aromatic hydrocarbons (PAHs). In naphthalene degradation test, 64 and 47% residual naphthalene was extracted after ten days of incubation from culture medium of K. rosea CMG2042 and K. flava CMG2028, respectively, when provided with 0.5 mg ml-1 concentration as sole carbon source. Due to addition of 0.5 mg ml-1 yeast extract as additional carbon source, residual naphthalene extracted was 41 and 55% from K. rosea CMG2042 and K. flava CMG2028, respectively. Both strains exhibited growth on 0.01 mg ml-1 phenanthrene and fluoranthene in yeast extract added or omitted medium but only K. rosea CMG2042degraded 9% phenanthrene as a sole carbon source. Both strains had growth on minimal agar plates coated with Iranian light crude oil as sole carbon source and on agar medium added with yeast extract

Dear Editor

I refer to your editorial in the SADJ April 2022 77(3), and wish to highlight the need of the dental profession to take heed of rising antimicrobial resistance rates, and to focus on modifying their prescribing practices in an effort to mitigate this global crisis. To understand and contribute to antibiotic stewardship, it is important that dental practitioners, including dental students, have the necessary knowledge of correct antibiotic prescribing guidelines and antimicrobial resistance. The overuse and misuse of antibiotics have contributed to the rise of antimicrobial resistance worldwide, with dentistry playing a part in the rise of antimicrobial resistance globally

Comparative study of peroxidase purification from apple and orange seeds

This paper reports the isolation and purification of peroxidase from low cost material; moreover, no significant work has been done on the isolation and purification of peroxidase from such cost effective sources (apple and orange seeds). Peroxidases had attracted considerable interest in recent years because of their activities towards a wide variety of chromogenic substances. Peroxidase activity in crude extract of apple and orange seeds was measured by recording a spectrophotometric value. Partial purification of crude enzyme extract was done by ammonium sulfate precipitation and ion exchange chromatography. It was observed that after partial purification, the enzyme activity was increased as compared to crude enzyme extract. Peroxidase from orange seed was purified up to 17.17 fold with specific activity of 10.17 U/mg and that from apple seed was 6.82 fold with specific activity of 7.53 U/mg after diethyl amino ethyl (DEAE) cellulose chromatography. It was shown that orange seed peroxidase had more activity than apple seed peroxidase in crude extract and each step of purification. Further purification was obtained through gel filtration chromatography by using sephadex-G-75 column. Peroxidase from orange and apple seeds got purified up to 30.64 and 8.34 fold with their specific activity of 18.16 and 9.20 U/mg, respectively. It is more evident that peroxidase is the most heat stable enzyme; therefore, it is concluded that it may be potentially useful for industrial purposes.Key words: Apple and orange seeds, extraction, peroxidase, purification

Transcriptomic profiling disclosed the role of DNA methylation and histone modifications in tumor-infiltrating myeloid-derived suppressor cell subsets in colorectal cancer

Increased numbers of myeloid-derived suppressor cells (MDSCs) are positively correlated with poor prognosis and reduced survivals of cancer patients. They play central roles in tumor immune evasion and tumor metastasis. However, limited data are available on phenotypic/transcriptomic characteristics of the different MDSCs subsets in cancer. These cells include immature (I-MDSCs), monocytic (M-MDSCs), and polymorphonuclear/granulocytic (PMN-MDSCs). Phenotypic characterization of myeloid subsets from 27 colorectal cancer (CRC) patients was assessed by flow cytometric analyses. RNA-sequencing of sorted I-MDSCs, PMN-MDSCs, and antigen-presenting cells (APCs) was also performed. We found that the levels of I-MDSCs and PMN-MDSCs were increased in tumor tissues (TT), compared with normal tissues (NT) in colorectal cancer. Our functional annotation analyses showed that genes associated with histone deacetylase (HDAC) activation- and DNA methylation-mediated transcriptional silencing were upregulated, and histone acetyl transferase (HAT)-related genes were downregulated in tumor-infiltrating I-MDSCs. Moreover, pathways implicated in cell trafficking and immune suppression, including Wnt, interleukin-6 (IL-6), and mitogen-activated protein kinase (MAPK) signaling, were upregulated in I-MDSCs. Notably, PMN-MDSCs showed downregulation in genes related to DNA methylation and HDAC binding. Using an ex vivo model, we found that inhibition of HDAC activation or neutralization of IL-6 in CRC tumor tissues downregulates the expression of genes associated with immunosuppression and myeloid cell chemotaxis, confirming the importance of HDAC activation and IL-6 signaling pathway in MDSC function and chemotaxis. This study provides novel insights into the epigenetic regulations and other molecular pathways in different myeloid cell subsets within the CRC tumor microenvironment (TME), giving opportunities to potential targets for therapeutic benefits

Transcriptomic profiling of tumor-infiltrating CD4 + TIM-3 + T Cells reveals their suppressive, exhausted, and metastatic characteristics in colorectal cancer patients

T cell immunoglobulin mucin-3 (TIM-3) is an immune checkpoint identified as one of the key players in regulating T-cell responses. Studies have shown that TIM-3 is upregulated in the tumor microenvironment (TME). However, the precise role of TIM-3 in colorectal cancer (CRC) TME is yet to be elucidated. We performed phenotypic and molecular characterization of TIM-3+ T cells in the TME and circulation of CRC patients by analyzing tumor tissues (TT, TILs), normal tissues (NT, NILs), and peripheral blood mononuclear cells (PBMC). TIM-3 was upregulated on both CD4+ and CD3+CD4− (CD8+) TILs. CD4+TIM-3+ TILs expressed higher levels of T regulatory cell (Tregs)-signature genes, including FoxP3 and Helios, compared with their TIM-3− counterparts. Transcriptomic and ingenuity pathway analyses showed that TIM-3 potentially activates inflammatory and tumor metastatic pathways. Moreover, NF-κB-mediated transcription factors were upregulated in CD4+TIM-3+ TILs, which could favor proliferation/invasion and induce inflammatory and T-cell exhaustion pathways. In addition, we found that CD4+TIM-3+ TILs potentially support tumor invasion and metastasis, compared with conventional CD4+CD25+ Tregs in the CRC TME. However, functional studies are warranted to support these findings. In conclusion, this study discloses some of the functional pathways of TIM-3+ TILs, which could improve their targeting in more specific therapeutic approaches in CRC patients

Cerebral Infarcts and Vasculopathy in Tanzanian Children With Sickle Cell Anemia

BACKGROUND: Cerebral infarcts and vasculopathy in neurologically asymptomatic children with sickle cell anemia (SCA) have received little attention in African settings. This study aimed to establish the prevalence of silent cerebral infarcts (SCI) and vasculopathy and determine associations with exposure to chronic hemolysis, anemia, and hypoxia. METHODS: We prospectively studied 224 children with SCA with transcranial Doppler (TCD), and magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA). Regressions were undertaken with contemporaneous hemoglobin, reticulocyte count, mean prior hemoglobin, oxygen content, reticulocyte count, and indirect bilirubin. RESULTS: Prevalence of SCI was 27% (61 of 224); cerebral blood flow velocity was abnormal (>200 cm/s) in three and conditional (>170<200 cm/s) in one. Vasculopathy grades 2 (stenosis) and 3 (occlusion) occurred in 16 (7%) and two (1%), respectively; none had grade 4 (moyamoya). SCI was associated with vasculopathy on MRA (odds ratio 2.68; 95% confidence intervals [95% CI] 1.32 to 5.46; P = 0.007) and mean prior indirect bilirubin (odds ratio 1.02, 95% CI 1.00 to 1.03, P = 0.024; n = 83) but not age, sex, non-normal TCD, or contemporaneous hemoglobin. Vasculopathy was associated with mean prior values for hemoglobin (odds ratio 0.33, 95% CI 0.16 to 0.69, P = 0.003; n = 87), oxygen content (odds ratio 0.43, 95% CI 0.25 to 0.74, P = 0.003), reticulocytes (odds ratio 1.20, 95% CI 1.01-1.42, P = 0.041; n = 77), and indirect bilirubin (odds ratio 1.02, 95% CI 1.01 to 1.04, P = 0.009). CONCLUSIONS: SCI and vasculopathy on MRA are common in neurologically asymptomatic children with SCA living in Africa, even when TCD is normal. Children with vasculopathy on MRA are at increased risk of SCI. Longitudinal exposure to anemia, hypoxia, and hemolysis appear to be risk factors for vasculopathy

Transcriptome of tumor-Infiltrating T cells in colorectal cancer patients uncovered a unique gene signature in CD4 + T cells associated with poor disease-specific survival

Colorectal cancer (CRC) is influenced by infiltration of immune cell populations in the tumor microenvironment. While elevated levels of cytotoxic T cells are associated with improved prognosis, limited studies have reported associations between CD4+ T cells and disease outcomes. We recently performed transcriptomic profiling and comparative analyses of sorted CD4+ and CD8+ tumor-infiltrating lymphocytes (TILs) from bulk tumors of CRC patients with varying disease stages. In this study, we compared the transcriptomes of CD4+ with CD8+ TILs. Functional annotation pathway analyses revealed the downregulation of inflammatory response-related genes, while T cell activation and angiogenesis-related genes were upregulated in CD4+ TILs. The top 200 deregulated genes in CD4+ TILs were aligned with the cancer genome atlas (TCGA) CRC dataset to identify a unique gene signature associated with poor prognosis. Moreover, 69 upregulated and 20 downregulated genes showed similar trends of up/downregulation in the TCGA dataset and were used to calculate “poor prognosis score” (ppScore), which was significantly associated with disease-specific survival. High ppScore patients showed lower expression of Treg-, Th1-, and Th17-related genes, and higher expression of Th2-related genes. Our data highlight the significance of T cells within the TME and identify a unique candidate prognostic gene signature for CD4+ TILs in CRC patients