Molecular epidemiology of Escherichia coli sequence type 131 and its H30/H30-Rx subclones recovered from extra-intestinal infections: first report of OXA-48 producing ST131 clone from Iran.

Multidrug-resistant (MDR) O25b-ST131 clone of Escherichia coli is well established as a significant cause of extra-intestinal infections worldwide. However, there have been no studies about the prevalence of ST131 and its H30/H30Rx subclones from Iran. The prevalence of ST131 was 29.8% among phylogroups B2, D, and F of E.coli isolates recovered from extra-intestinal infections. Fifty-seven (90.4%) and six (9.6%) of isolates belonged to serogroups O25b and O16 respectively, and exhibited high rates of MDR (98.4% and 83.3%) and extended spectrum ß-lactamase (ESBL) production (96.8% and 83.3%). The majority (56/57, 98.2%) of O25b isolates belonged to H30 lineage; of those, 24 isolates (42.8%) belonged to H30-Rx subclone. O16-ST131 isolates were H30-negative. The resistance rate values of O16-ST131subgroup were lower for fluoroquinolones/aminoglycosides and higher for carbapenems, cephalosporins, ß-lactam/ß-lactamase inhibitors and trimethoprim/sulfamethoxazole, as compared to O25b-ST131 isolates. Among H30 sub lineage and in comparison with non-Rx isolates, H30-Rx subclone showed higher resistance score and virulence genes (papA and papC), and was also associated with CTX-M group 1. bla OXA-48 carbapenemase was detected in seven O25b and one O16 isolates; of those, one O25b-ST131 isolate was carbapenem-susceptible. The ST131 isolates comprised 15 'enterobacterial repetitive intergenic consensus' (ERIC) clusters, and O16 isolates remained distributed in five groups in cluster with O25b-ST131 isolates. In conclusion, this is the first report of the presence of MDR, bla OXA-48/CTX-M-positive O25b/O16-ST131 isolates in Iran. Contrary to lower prevalence of O16-ST131 subgroup, higher resistance rates to ß-lactam antibiotics may indicate the importance of this subgroup in the spread of MDR E.coli isolates.

Detection of Epstein-Barr virus DNA in plasma and lymph node biopsy samples of pediatric and adult patients with Hodgkin lymphoma.

Hodgkin lymphoma (HL) is commonly associated with latent Epstein-Barr virus (EBV) infection. The aim of this study is a molecular analysis of the EBV status in both involved lymph node biopsies and plasma samples of patients with HL. Plasma and lymph node biopsy samples obtained from 15 pediatric and 10 adult HL patients were examined for EBV DNA using conventional polymerase chain reaction (PCR). The control group consisted of 30 healthy pediatrics and adults. In addition, immunoglobulin G (IgG) anti-EBV nuclear antigen (EBNA)-1 antibody was determined in sera of patients and controls using enzyme-linked immunosorbent assay (ELISA). IgG Anti EBNA-1 antibody was detected in 21 (84%) and 8 (26%) of patients and controls, respectively (P < .05). EBV DNA was detected in 12 (48%) and 1 (3%) plasma samples of patient and control cases, respectively. Significant difference was observed in plasma DNA detection between patients and controls (P < .05). Comparison of EBV DNA detection in plasma and biopsy samples between children and adult patients was only significant for plasma samples (P = .025). Significant correlation was observed in positive detection of EBV DNA between plasma and biopsy samples of the same individual (P < .001, r = .923). Frequency of EBV DNA in plasma and biopsy samples obtained from mixed-cellularity subgroup was higher than the nodular sclerosis; however, no significant difference was observed between these 2 subgroups. EBV detection in plasma of childhood Hodgkin lymphoma in a population with EBV seroconversion might be of value as a biomarker for EBV-associated Hodgkin lymphoma.

Comparison of antigenemia assay and semiquantitative polymerase chain reaction test for monitoring active cytomegalovirus infection in allogeneic hematopoietic cell transplant recipients.

OBJECTIVES: We sought to compare the antigenemia assay and in-house semiquantitative polymerase chain reaction to monitor human cytomegalovirus infection after transplant in hematopoietic cell transplant recipients. MATERIALS AND METHODS: A pp65 antigen test for polymorphonuclear leukocytes and a semiquantitative polymerase chain reaction for whole blood were performed for 201 samples obtained from 26 hematopoietic cell transplant recipients over a 3-month surveillance period. RESULTS: Fourteen episodes of antigenemia positivity were detected in 7 patients in whom human cytomegalovirus DNA loads and pp65-positive cells ranged between < 102 to 2.96 x 104 copies/mL and 0-35/ 5 x 104 polymorphonuclear leukocytes, respectively. A significant correlation was detected between human cytomegalovirus DNA load and the antigenemia test. A receiver operating characteristic analysis determined 5000 copies/mL of human cytomegalovirus as the threshold value for initiation of ganciclovir therapy. CONCLUSIONS: Based on a comparison of the pp65 antigenemia assay, quantification of human cytomegalovirus DNA in whole blood can be used to guide clinical management of hematopoietic cell transplant recipients. This approach may have important advantages including superior sensitivity and efficient monitoring of preemptive therapy, allowing inclusion of kinetic criteria in clinical guidelines. Furthermore, a high human cytomegalovirus load among patients with grade II-IV acute graft-versus-host disease may indicate a high risk of human cytomegalovirus disease among hematopoietic cell transplant patients. Human cytomegalovirus reactivation must be monitored using more-sensitive assays such as real-time polymerase chain reaction.