Occurrence of some common carbapenemase genes in carbapenem-resistant Klebsiella pneumoniae isolates collected from clinical samples in Tabriz, northwestern Iran.

OBJECTIVES: This study aimed to evaluate the antibiotic resistance patterns and prevalence of carbapenemase genes in Klebsiella pneumoniae isolates in different clinical samples from Tabriz city, northwestern Iran. RESULTS: This cross-sectional study was conducted in the Department of Microbiology, Islamic Azad University, Ahar Branch, Iran, in 2020. K. pneumoniae isolates were collected from different clinical samples, including blood, wounds, sputum, and urine. The isolates were identified using a series of standard bacteriological tests. Antibiotic resistance was determined by the disc diffusion method. The presence of blaVIM, blaNDM, blaKPC, blaOXA, and blaIMP genes were screened by polymerase chain reaction (PCR). A total of 100 non-duplicated K. pneumoniae isolates were collected from 57 urine samples, 27 blood samples, 13 wound samples, and 3 sputum samples. Overall, 70.0% of the samples were from inpatients, while 30.0% were from outpatients. The most resistance rate was related to ampicillin (94.0%), while the lowest resistance rate was related to imipenem (18.0%) and meropenem (20.0%). Overall, 25.0% of the isolates were carbapenem-resistant, of which 13.0% were resistant to both imipenem and meropenem. The PCR showed the total prevalence of 23.0% for carbapenemase genes, including 18.0% for blaKPC, 3.0% for blaVIM, 1.0% for blaIMP, and 1.0% for blaOXA gene. The blaNDM gene was not detected in any isolate. The prevalence of carbapenemase-producing K. pneumoniae isolates was relatively lower in northwestern Iran than in other regions of the country. However, special attention should be paid to the proper use of antibiotics, particularly carbapenems, to prevent further spread of antibiotic resistance and its related genes.

Role of cytomegalovirus on the maturation and function of monocyte derived dendritic cells of liver transplant patients.

AIM: To study the impact of association between cytomegalovirus (CMV) pathogenesis with dendritic cell (DC) maturation and function was evaluated in CMV reactivated liver transplanted patients in comparing with non-reactivated ones, and healthy controls. METHODS: Monocyte derived dendritic cells (MoDCs) was generated from collected ethylenediaminetetraacetic acid-treated blood samples from patient groups and controls. In these groups, expression rates and mean fluorescent intensity of DC markers were evaluated using flowcytometry technique. Secretion of cytokines including: interleukin (IL)-6, IL-12 and IL-23 were determined using enzyme-linked immunosorbent assay methods. The gene expression of toll-like receptor 2 (TLR2), TLR4 and IL-23 were analyzed using in-house real-time polymerase chain reaction protocols. RESULTS: Results have been shown significant decreases in: Expression rates of MoDC markers including CD83, CD1a and human leukocyte antigen DR (HLA-DR), the mean fluorescence intensitys for CD1a and HLA-DR, and secretion of IL-12 in CMV reactivated compared with non-reactivated liver transplanted patients. On the other hand, significant increases have been shown in the secretions of IL-6 and IL-23 and gene expression levels of TLR2, TLR4 and IL-23 from MoDCs in CMV reactivated compared with non-reactivated liver transplanted recipients. CONCLUSION: DC functional defects in CMV reactivated recipients, such as decrease in expression of DC maturation markers, increase in secretion of proinflammatory cytokines, and TLRs can emphasize on the importance of CMV infectivity in development of liver rejection in transplanted patients.

Maturation state and function of monocyte derived dendritic cells in liver transplant recipients.

BACKGROUND: Dendritic cells (DCs) are potent antigen presenting cells for triggering of the immune reaction post transplantation. These cells are centrally involved in the initiation of T cell-dependent immune responses. OBJECTIVE: To compare the level of DC maturation and function in liver transplant recipients with healthy controls. METHODS: In this study, twelve peripheral blood samples were selected from six liver transplant patients and six healthy controls. After the generation of DCs from monocytes, expression levels and mean fluorescent intensity (MFI) of several DC maturation markers were evaluated using flow cytometry. Secretion of IL-6, IL-12 and IL-23 proinflammatory cytokines was determined using ELISA. Gene expressions of TLR-2, TLR-4 and IL-23 were analyzed using real-time PCR. RESULTS: DC expression markers including CD83 (p=0.007) and CD86 (p=0.02), as well as secretion of IL-6 (p=0.02) and IL-12 (p=0.007) by DCs were significantly increased in liver transplant patients compared with healthy controls. The MFI of CD86 (p=0.009) and HLA-DR (p= 0.005) expression on DCs was also higher in patients. The expression of TLR-2 transcripts in DCs of patients was higher than that of the controls (p=0.03). CONCLUSION: Based on these findings, increased frequency of DCs expressing CD83 and CD86, higher expression of CD86, HLA-DR, and TLR-2 as well as elevated secretion of proinflammatory cytokines in DCs of liver transplant recipient's point to the more mature phenotype and active function of DCs in patients compared with controls.