Identification of virulence genes carried by bacteriophages obtained from clinically isolated methicillin-resistant Staphylococcus aureus.

Bacteriophages play an important role in the pathogenicity of Staphylococcus aureus (S. aureus) either by carrying accessory virulence factors or several superantigens. Despite their importance, there are not many studies showing the actual distribution of the virulence genes carried by the prophages obtained from the clinically isolated Staphylococcus. In this study, we investigated prophages obtained from methicillin-resistant S. aureus (MRSA) strains isolated from hospital- and community-associated (HA-CA) infections for the virulence factors. In the study, 43 phages isolated from 48 MRSA were investigated for carrying toxin genes including the sak, eta, lukF-PV, sea, selp, sek, seg, seq chp, and scn virulence genes using polymerase chain reaction (PCR) and Southern blot. Restriction fragment length polymorphism was used to analyze phage genomes to investigate the relationship between the phage profiles and the toxin genes' presence. MRSA strains isolated from HA infections tended to have higher prophage presence than the MRSA strains obtained from the CA infections (97% and 67%, respectively). The study showed that all the phages with the exception of one phage contained one or more virulence genes in their genomes with different combinations. The most common toxin genes found were sea (83%) followed by sek (77%) and seq (64%). The study indicates that prophages encode a significant proportion of MRSA virulence factors.

Comparison of hybrid capture and reverse transcriptase polymerase chain reaction methods in terms of diagnosing human cytomegalovirus infection in patients following hematopoietic stem cell transplantation.

OBJECTIVE: Human cytomegalovirus (CMV) is a life threatening cause of infection among hematopoietic stem cell recipients. Developing reliable methods in detecting the CMV infection is important to identify the patients at risk of CMV infection and disease. The aim of this study was to compare the 2 tests- hybrid capture test, which is routinely used in the diagnosis of CMV infection among hematopoietic stem cell recipients, and reverse transcriptase polymerase chain reaction (RT-PCR) detecting UL21.5 mRNA transcripts of the active virus. METHODS: In this prospective study, a total of 178 blood samples obtained from 35 patients following allogeneic hematopoietic stem cell transplantation at the Bone Marrow Transplantation Unit of the Hematology Department, Ibn-i Sina Hospital of Ankara University School of Medicine, Turkey between January 2003 and September 2003 were analyzed. Hybrid capture and RT-PCR using UL21.5 gene transcript method to investigate HCMV in blood samples were performed at the Department of Microbiology and Clinic Microbiology Ankara University School of Medicine, Turkey. RESULTS: When hybrid capture test was accepted as the golden standard, the sensitivity of RT-PCR was 33%, specificity 100%, false negativity 67%, false positivity 0%, positive predictive value 100%, negative predictive value 74%, and accuracy was 77%. CONCLUSION: Improving this test by quantification, and application of additional gene transcripts, primarily the late gene transcripts can help increase the sensitivity and feasibility.

Detecting of Mycoplasma genitalium in male patients with urethritis symptoms in Turkey by polymerase chain reaction.

OBJECTIVE: The aim of this study was to investigate the incidence of Mycoplasma genitalium in the urine samples of 63 male patients who had urethritis symptoms. Along with Neisseria gonorrhoeae (N. gonorrhoeae) and Chlamydia trachomatis (C. trachomatis). We also investigated Mycoplasma hominis (M. hominis) and Ureaplasma urealyticum (U. urealyticum), both of which are known to cause urethritis. METHODS: Microorganisms were investigated in urine samples of the patients with polymerase chain reaction. The study was conducted between September 2003 - February 2004 at the Department of Microbiology and Clinical Microbiology Ankara University School of Medicine, Ankara, Turkey. RESULTS: A total of 63 urine samples were analyzed and 6 (9.52%) patients had N. gonorrhoeae, 4 (6.34%) had C. trachomatis, while 4 (6.34%) urines were positive in terms of M. genitalium. Nevertheless, 3 (4.76%) patients had U. urealyticum and 2 (3.17%) patients had M. hominis. One urine sample was positive in terms of both N. gonorrhoeae and U. urealyticum, and another urine sample was positive in terms of both M. hominis and U. urealyticum. The results were compared with the control group and found no statistically significant difference. CONCLUSION: Mycoplasma species are found in normal flora of urogenital system and also as an agent of urogenital infection. In our study, we found low microorganism rates when compared with Europe and America. This difference may be due to the conservative sexual behavior in Turkey.

[Herpes simplex virus type 1 in the samples of patients with clinically prediagnosed as herpetic keratitis or keratoconjunctivitis]. / Klinik olarak herpetik keratit veya keratokonjunktivit ön tanisi alan hasta örneklerinde Herpes simpleks tip 1 virusunun arastirilmasi.

The aim of this study was to investigate the presence of Herpes simplex virus type 1, in the specimens from patients clinically prediagnosed as herpetic keratitis or keratoconjunctivitis, by virus isolation and direct immunoperoxidase methods. The samples obtained from a total of 33 patients included ulcerated corneal epithelium scrapings and, swabs from ulcer, corneal epithelium, and lower conjunctivas. For virus isolation, both scraping and swab samples for each patient, were inoculated into monolayered Vero cell lines which have previously cultivated on 24-well plates, and examined for the presence of cytopathic effects typical for HSV-1. At the end of 5-days incubation period, the culture media were discarded, the cells were fixed and stained with peroxidase labeled specific HSV-1 antibodies (direct immunoperoxidase--DIP--method). Simultaneously, the smears were prepared from the samples which were sufficient in amount, and stained with DIP method. As a result, cytopathic effects on cell cultures were observed in 4 (12.1%) of the samples, of which 2 were also positive with DIP method. Following DIP staining of smears prepared from 15 samples, HSV-1 antigen positivity was detected in only 1 of the samples. This sample was negative in cell culture. In contrast, one of the 2 cell culture positive samples yielded negative result in smear examination, while the other could not be examined since the sample was not enough. In conclusion, HSV-1 has been shown as the etiologic agent in 3 (9.1%) of our patients clinically prediagnosed as herpetic keratitis or keratoconjunctivitis, and lesion scrapings were determined as the most appropriate samples for virus isolation.

Preventive effect of pentoxifylline on renal scarring in rat model of pyelonephritis.

OBJECTIVES: To evaluate the efficiency of pentoxifylline (PTX), a methyl xanthine derivative, in preventing renal scar formation after the induction of pyelonephritis in an experimental rat model with delayed antimicrobial therapy. METHODS: An inoculum of 1 x 10(9) colony-forming units/0.1 mL of the K-12 strain of Escherichia coli, which has both type 1 and P pili, was injected directly into both renal parenchyma of Wistar rats (n = 40). Group 1 (control) received isotonic saline instead of bacterial solution (n = 10). Four equal groups were then formed: group 2 was not treated and group 3 was treated only with ciprofloxacin for 5 days, starting 3 days after bacterial inoculation; in group 4, 50 mg/kg of PTX, and in group 5, PTX (50 mg/kg) and ciprofloxacin (15 mg/kg) together were administered intraperitoneally for 5 days, starting 3 days after bacterial inoculation. Six weeks after bacterial inoculation, all the rats were killed, and both kidneys were examined histopathologically for renal scarring. RESULTS: Delayed treatment with antibiotics had no effect on scarring compared with the untreated controls. However, the addition of PTX to the delayed antibiotic therapy significantly inhibited renal scarring compared with the untreated or antibiotic-only groups (P <0.05). CONCLUSIONS: These results suggest that PTX is effective in preventing renal scar formation in pyelonephritis when the initiation of antimicrobial treatment is delayed in this rat model of pyelonephritis.