Epidemiological, Microbiological, and Clinical Characteristics of Multi-Resistant Pseudomonas aeruginosa Isolates in King Fahad Medical City, Riyadh, Saudi Arabia.

Increasing rates of serious multi-drug resistant (MDR) Pseudomonas aeruginosa infections have been reported globally, including in Saudi Arabia. This retrospective study investigates the epidemiological, microbiological, and clinical characteristics of multi-resistant P. aeruginosa (n3579 clinical isolates) in King Fahad Medical City, Riyadh, Saudi Arabia (2019-2021). Information on antimicrobial susceptibility and medical history was collected from the hospital database. P. aeruginosa infections occurred in 55.6% of males and 44.4% of females, and P. aeruginosa was more prevalent in children than in adults. Our analysis showed that P. aeruginosa had the highest sensitivity to amikacin (92.6%) and greatest resistance to aztreonam (29.8%), imipenem (29.5%), ceftazidime (26.1%), meropenem (25.6%), and cefepime (24.3%). MDR and extensively drug resistant (XDR) strains were more prevalent in male than female patients. Female patients showed higher rates of infection with pan-drug resistant (PDR) strains. Respiratory samples contained the majority of resistant isolates. Septic shock and liver disease were strongly correlated with mortality in the ICU patient group after analysing the relative risk associated with mortality. Our study emphasises the threat of multi-resistant P. aeruginosa in Saudi Arabia (and potentially the Middle East) and highlights important sources and contexts of infection that inhibit its effective control and clinical management.

Study of gene expression of CD30 variant (CD30v) and CD30 ligand (CD30L) in acute leukemia.

Proliferation of malignant lymphohematopoietic cells is thought to be regulated by a number of surface molecules on tumour cells whose expression may contribute to neoplastic transformation. In this work, reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect the gene expression (mRNA) of CD30 variant (CD30v) and CD30 Ligand (CD30L) on the peripheral blood mononuclear cells (PBMCs) of 15 healthy individuals as a control group, 15 patients with newly diagnosed acute myeloid leukemia (AML) and 15 patients with newly diagnosed acute lymphocytic leukemia (ALL). The results revealed that simultaneous positive expression of both CD30v and CD30L was found in 46.7%, 40% and 53.3% of whole leukemic patients and those with AML and ALL respectively, with significant difference from controls in whom no expression was found (P=0.007, 0.021 and 0.005, respectively). Patients with positive expression of CD30v and CD30L were found to have significantly increased blast cell % (p<0.001), increased total leucocytic count (P<0.001) and decreased platelets count (P<0.001) than those with negative expression. No significant difference in expression could be noticed in relation to age (p>0.05), sex (P=0.998.) or hemoglobin (Hb) level (P=0.20). As regard to immunophenotypes of ALL, positive expression was found to be significantly higher in B-cell than T-cell subtype (77.8% versus 16.7%, P=0.02). It could be concluded that frequent expression of CD30V and CD30L was detected only in newly diagnosed cases of AML and ALL, but not in healthy individuals. Positive expression was also significantly associated with more aggressive disease and with B-cell than T-cell subtypes. These results suggested a possible role of these molecules in pathogenesis of such hematopoietic malignancy. Further studies are needed for better understanding of the involved mechanisms.

GB virus C/hepatitis G virus in serum and liver of patients with chronic C and non B non C hepatitis: molecular and immunological aspects.

GB virus C/hepatitis G Virus (HGV) is a single-stranded RNA virus that is transmitted parenteraly. This study investigates GB virus C in 62 patients with chronic hepatitis C (CHC) and non B non C hepatitis (CNBNC). The viral E2 protein was examined in the sera of the patients (using western blott assay) while viral replication in the liver was examined by detecting the negative strand of HGV-RNA and its E2 protein in liver tissue using in situ hybridization and immunohistochemical staining respectively. E2 protein was detected in 28% of patients with chronic hepatitis C and in 13.3% of patients with non B non C chronic hepatitis, while not detected in healthy blood donors (0%). HGV- E2 protein and the negative strand of HGV -RNA were detected in hepatocytes of only 3 out of the 13 examined liver biopsies from HGV infected patients (23%). The mean level of ALT in chronic HCV hepatitis patients who were +ve for HGV was significantly lower than those who were -ve for HGV. There was a significant difference between the mean value of HCV -RNA level by real time PCR in sera of hepatitis C positive patients with + ve HGV-E2 when compared with HCV patients with - ve HGV-E2 (p < 0.001). It is concluded that HGV co-infection may occur in some cases with CHC and CNBNC. Sites of replication, other than liver, are suggested as the virus was detected in liver tissue of only 23 % of cases inspite of its presence in their sera.

Study of HLA-DR expression on skin lesions of leprosy before and during multiple drug therapy.

Leprosy is a dynamic disease in which cell mediated immunity (CMI) plays an important role in host defense and control of the clinical spectrum. This study was carried out to detect immune activation in the granuloma of leprosy during multiple drug therapy (MDT) by studying the expression of human leukocytic antigen-DR (HLA-DR) in the granuloma before and during therapy. Skin punch biopsies were taken before and at least once 2-4 weeks after starting MDT in 20 newly diagnosed patients. Two biopsies, 2-4 weeks apart, were also taken from 10 new patients who did not yet receive any treatment, for comparison. Furthermore, biopsies were taken before and during corticosteroid therapy in five patients who developed reversal reaction during MDT. The biopsy specimens were studied for the expression of HLA-DR using the immunofluorescent staining which was found to be visibly increased in 17 out of 20 new cases (85%) within 2-4 weeks after starting MDT, while no change in the expression was noticed in those who did not receive any treatment (p < 0.001). This might reflect the increased production of interferon gamma (IFN gamma) specially from granuloma lymphocytes after being stimulated with the excessive release of mycobacterial antigen from killed bacilli during therapy. The five patients who developed reversal reaction during MDT had strong HLA-DR expression in the first biopsies which declined subsequently 2-6 weeks after starting prednisolone therapy. Our results suggest that CMI was activated in skin lesions of leprosy during MDT. Such activation was not only restricted to those who developed reversal reaction across the therapeutic course, which indicates that the difference between patients who developed such reaction and those who did not, was likely to be quantitative rather than qualitative, with a more exaggerated CMI response in the former. Furthermore, it seems that the beneficial effect of MDT is accompanied by important changes in the immune cell profile which have a great role in overcoming such infection.

Study of HLA-DR expression on skin lesions of leprosy before and during multiple drug therapy

Leprosy is a dynamic disease in which cell mediated immunity (CMI) plays an important role in host defense and control of the clinical spectrum. This study was carried out to detect immune activation in the granuloma of leprosy during multiple drug therapy (MDT) by studying the expression of human leukocytic antigen-DR (HLA-DR) in the granuloma before and during therapy. Skin punch biopsies were taken before and at least once 2-4 weeks after starting MDT in 20 newly diagnosed patients. Two biopsies, 2-4 weeks apart, were also taken from 10 new patients who did not yet receive any treatment, for comparison. Furthermore, biopsies were taken before and during corticosteroid therapy in five patients who developed reversal reaction during MDT. The biopsy specimens were studied for the expression of HLA-DR using the immunofluorescent staining which was found to be visibly increased in 17 out of 20 new cases (85%) within 2-4 weeks after starting MDT, while no change in the expression was noticed in those who did not receive any treatment (p < 0.001). This might reflect the increased production of interferon gamma (IFN gamma) specially from granuloma lymphocytes after being stimulated with the excessive release of mycobacterial antigen from killed bacilli during therapy. The five patients who developed reversal reaction during MDT had strong HLA-DR expression in the first biopsies which declined subsequently 2-6 weeks after starting prednisolone therapy. Our results suggest that CMI was activated in skin lesions of leprosy during MDT. Such activation was not only restricted to those who developed reversal reaction across the therapeutic course, which indicates that the difference between patients who developed such reaction and those who did not, was likely to be quantitative rather than qualitative, with a more exaggerated CMI response in the former. Furthermore, it seems that the beneficial effect of MDT is accompanied by important changes in the immune cell profile which have a great role in overcoming such infection.