Post-neurosurgical meningitis; gram negative bacilli vs. gram positive cocci.

Background: Post-neurosurgical meningitis is a significant cause of mortality and morbidity. In this study we aimed to compare the differences of clinical, laboratory features and outcomes between the post-neurosurgical meningitis caused by gram-negative bacilli (GNB) and gram-positive cocci (GPC). Methods: Cases of post-neurosurgical meningitis (with positive CSF culture) were included. After classifying patients as GNB and GPC groups, clinical and paraclinical data were compared. Results: Out of 2667 neurosurgical patients, CSF culture was positive in 45 patients. 25 (54.3%) were GNB, 19 (41.3%) GPC. The most common microorganisms were Klebsiella pneumoniae (n=14, 31.1%), Coagulase negative staphylococcus (n=8, 17.8%), Staphylococcus aureus (n=6, 13.3%), Acinetobacter baumannii (n=4, 8.9%), Pseudomonas aeruginosa (n=2, 4.4%), and Escherichia coli (n=2, 4.4%). There were no correlation between CSF Leakage, Surgical site appearance, presence of drain, Age and GCS between two groups (P=0.11, P=0.28, P=0.06, P=0.86, P=0.11 respectively). The only different laboratory indexes were ESR (86.8 mm/h vs. 59.5 mm/h, P=0.01) and PCT (13.1 ng/ml vs. 0.8 ng/ml, P=0.02) which were higher in GNB cases. 20% (n=5) of patients with GNB meningitis received preoperative corticosteroid, while none of GPC cases received (P=0.03). The median length of hospitalization for GNB and GPC cases was 56 and 44.4 days respectively (P=0.3). Conclusion: The GNB antibiotic coverage should be designed more carefully in post-neurosurgical meningitis especially in patients with recent corticosteroid therapy and elevated ESR and procalcitonin.

Detection of bacterial agents causing prostate infection by culture and molecular methods from biopsy specimens.

Background and Objectives: Prostatitis affects about 16% of men in their lifetime and sometimes leading to prostate cancer. Bacterial infections are the most common causes of prostatitis. Diagnosis of the causative agents of bacterial prostate infections plays an essential role in timely treating and preventing secondary complications. This study isolated bacterial infectious agents in patients' surgical prostate and evaluated them by routine and molecular microbiological methods. Materials and Methods: In this cross-sectional study, 72 prostate biopsy specimens were collected from the Orology Departmen of hospitals of Qazvin University of Medical Sciences. All samples were cultured in aerobic and anaerobic conditions. Antibiotic susceptibility test by Kirby-Bauer standard method was performed for all isolated bacteria. In addition, all isolated bacteria were identified using 16S rDNA PCR and sanger sequencing methods. Also, TaqMan real-time PCR was applied to detect Ureaplasm aurealyticum, Mycoplasma hominins, and Mycoplasma genitalium. Results: In conventional culture method, out of 18 positive samples, 15 samples (83.3%) were Gram-negative bacteria and 3 samples (16.6%) were Gram-positive bacteria, containing Escherichia coli (55.5%), Klebsiella pneumoniae (11.1%), Enterobacter cloacae (5.5%), Pseudomonas aeruginosa (11.1%), Staphylococcus aureus (11.1%), and Enterococcus faecalis (5.5%). The results of molecular identification methods were the same as conventional culture results. Also, four patients were Ureaplasm aurealyticum, and three patients were positive for Mycoplasma hominis. Conclusion: Most bacteria isolated from prostate specimens belonged to the Enterobacteriaceae family, especially Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae. Staphylococcus aureus and Enterococcus faecalis were cocci isolated in the specimens too. Also, Ureaplasma urealyticum, and Mycoplasma hominis were identified in prostatitis.

Distribution of smf-1, rmlA, spgM and rpfF genes among Stenotrophomonas maltophilia isolates in relation to biofilm-forming capacity.

OBJECTIVES: The molecular mechanisms involved in biofilm formation inStenotrophomonas maltophilia are poorly understood. Here, we examined whether the presence of smf-1, rmlA, spgM and rpfF genes is associated with biofilm formation and antibiotic resistance in S. maltophilia. METHODS: A total of 150 S. maltophilia isolates were collected from three tertiary-care hospitals in Iran and were identified through PCR amplification of the 23S rRNA gene. Biofilm formation was determined by microtitre plate assay. Presence of smf-1, rmlA, spgM and rpfF genes was examined by PCR. RESULTS: Among the isolates examined, 148 (98.7%) were able to produce biofilm, of which 69 (46.0%) were strong biofilm-producers, whereas 32 (21.3%) and 47 (31.3%) were moderate and weak biofilm-producers, respectively. The frequency ofsmf-1, rmlA, spgM and rpfF was 99.3%, 98.0%, 97.3% and 70.0%, respectively. Statistical analysis indicated a direct correlation between presence of the rpfF gene and biofilm formation (P < 0.001). The high prevalence of smf-1 (99.3%) among the isolates is noted and there was a significant association between smf-1 and biofilm-forming ability (P < 0.01), but lower than rpfF. Additionally, a direct association was found between resistance to ticarcillin/clavulanate, ceftazidime, ciprofloxacin and doxycycline and strong biofilm formation in the S. maltophilia isolates (P < 0.01). CONCLUSION: This study demonstrated thatS. maltophilia clinical isolates significantly differ in biofilm-forming ability. Moreover, presence of rpfF and smf-1, but not spgM, could be associated with biofilm formation. This study highlights the importance of rpfF in formation of biofilm compared with the other genes involved.

DNA binding and cytotoxicity studies of magnetic nanofluid containing antiviral drug oseltamivir.

In this work, the possibility of preparing a nanoparticle with improved treatment properties was investigated. In this regard, synthesis, characterization, in vitro cytotoxicity and DNA binding of Fe3O4@oleate/oseltamivir magnetic nanoparticles (MNPs) were investigated. Fe3O4 nanoparticles were synthesized via chemical co-precipitation and coated by oleate bilayers. Then, Fe3O4@OA MNPs were functionalized with an antiviral drug (oseltamivir), for better biological applications. The MNPs were subsequently characterized by zeta sizer and Zeta potential measurements, Fourier transform infrared (FT-IR) spectroscopy, vibrating sample magnetometer (VSM) and transmission electron microscopy (TEM) analyses. The TEM image demonstrated that average sizes of Fe3O4@OA/oseltamivir MNPs were about 8 nm. The in vitro cytotoxicity of Fe3O4@OA/oseltamivir MNPs was studied against cancer cell lines (MCF-7 and MDA-MB-231) and compared with oseltamivir drug. The results illustrated that Fe3O4@OA/oseltamivir magnetic nanoparticles have better antiproliferative effects on the mentioned cell lines as compared with oseltamivir. Also, in vitro DNA binding studies were done by UV-Vis, circular dichroism, and Fluorescence spectroscopy. The results indicated that Fe3O4@OA/oseltamivir MNPs bound to DNA via groove binding. Moreover, this magnetic nanofluid has potential for magnetic hyperthermia therapy due to magnetic core of its nanoparticles. Communicated by Ramaswamy H. Sarma.