Nural Cevahir

Anticandidal activity of Pseudomonas aeruginosa strains isolated from clinical specimens.

Pseudomonads represent the major group of non‐differentiating microorganisms that produce antibiotics. The antibiotic substances produced by this group of organisms are pyocyanin, pyrolnitrin and pseudomonic acid. This study was designed to investigate the in vivo and in vitro anticandidal activity of Pseudomonas aeruginosa strains against Candida species. Forty‐four P. aeruginosa strains isolated from various specimens of intensive care patients were included in the study. All P. aeruginosa strains have pyocyanin pigment. Candida albicans ATCC 10231, Candida parapsilosis ATCC 22019, Candida krusei ATCC 6258 and a clinical isolate of Candida tropicalis were used to measure the anticandidal activity of Pseudomonas strains by Kerrs method. The total inhibition rates obtained by using blood agar of C. albicans, C. parapsilosis, C. krusei and C. tropicalis were 41%, 34%, 34% and 25% respectively. When Sabouraud dextrose agar (SDA) was used, the rates were detected as 45%, 39%, 48% and 25% respectively. In the mouse model of concomitant subcutaneous infection with Candida species and P. aeruginosa no yeast were recovered from skin cultures despite 100% detection of P. aeruginosa. Pseudomonas aeruginosa strains isolated from intensive care patients showed anticandidal activity against the Candida species in the present study and this point may be important in the following and treatment of patients.

Community-acquired Streptococcus mitis meningitis: a case report

BACKGROUND Streptococcus mitis is prevalent in the normal flora of the oropharynx, the female genital tract, gastrointestinal tract, and skin. Although it is usually considered to have low virulence and pathogenicity, Streptococcus mitis may cause life-threatening infections, particularly endocarditis. Meningitis with S. mitis is rare, but has been described in individuals with previous spinal anesthesia, neurosurgical procedure, malignancy, or neurological complications of endocarditis. CASE REPORT A 58-year-old, alcoholic male patient with a high fever, headache, and changes in mental status was admitted to hospital with the diagnosis of meningitis. S. mitis, isolated from cerebrospinal fluid, was sensitive to penicillin. He was given a 14-day course of ampicillin and made a full clinical recovery. CONCLUSIONS The purpose of this report is to emphasize the importance of the occurrence of S. mitis meningitis in patients with concomitant factors such as older age (>50 years), alcoholism, poor oral hygiene, and maxillary sinusitis.

Prevalence and risk factors for methicillin-resistant Staphylococcus aureus colonization in a diabetic outpatient population: A prospective cohort study

BACKGROUND Diabetes mellitus is a risk factor for methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection. We attempted to determine the prevalence and risk factors for MRSA colonization in a population of outpatients with diabetes. METHODS This prospective cohort study enrolled patients with diabetes. Anterior nares cultures were obtained from patients with diabetes admitted to outpatient endocrinology and metabolism clinics, and risk factors for MRSA colonization were analyzed. RESULTS Out of the 304 patients evaluated, 127 (41.9%) were colonized with S aureus and 30 (9.9%) were colonized with MRSA. Overall, 23.6% of all S aureus isolates were MRSA. In multivariate analysis, factors independently associated with an increased risk of MRSA colonization included the presence of connective tissue disease (odds ratio, 7.075; 95% confidence interval, 2.157-23.209; P = .001) and insulin therapy (odds ratio, 3.910; 95% confidence interval, 1.652-9.251; P = .002). CONCLUSIONS The prevalence of MRSA colonization in our sample of diabetic outpatients was 9.9%. Independent risk factors for MRSA colonization were the presence of connective tissue disease and insulin use. A better understanding of the epidemiology and risk factors for nasal MRSA colonization in the persons with diabetes may have significant implications for the treatment and prevention of MRSA infections.

Systemic and local antibiotic prophylaxis in the prevention of Staphylococcus epidermidis graft infection

BackgroundThe aim of the study was to investigate the in vivo efficacy of local and systemic antibiotic prophylaxis in the prevention of Staphylococcus (S.) epidermidis graft infection in a rat model and to evaluate the bacterial adherence to frequently used prosthetic graft materials.MethodsGraft infections were established in the subcutaneous tissue of 120 male Wistar rats by implantation of Dacron/ePTFE grafts followed by topical inoculation with 2 × 107 CFUs of clinical isolate of methicillin-resistant S. epidermidis. Each of the graft series included a control group, one contaminated group that did not receive any antibiotic prophylaxis, two contaminated groups that received systemic prophylaxis with teicoplanin or levofloxacin and two contaminated groups that received teicoplanin-soaked or levofloxacin-soaked grafts. The grafts were removed 7 days after implantation and evaluated by quantitative culture.ResultsThere was significant bacterial growth inhibition in the groups given systemic or local prophylaxis (P < 0.05). Methicillin-resistant S. epidermidis had greater affinity to Dacron graft when compared with ePTFE graft in the untreated contaminated groups (P < 0.05).ConclusionThe study demonstrated that the usage of systemic or local prophylaxis and preference of ePTFE graft can be useful in reducing the risk of vascular graft infections caused by staphylococcal strains with high levels of resistance.

Tempol reduces bacterial translocation after ischemia/reperfusion injury in a rat model of superior mesenteric artery occlusion

PurposeWe investigated whether Tempol, a water-soluble antioxidant, prevents the harmful effects of superior mesenteric ischemia/reperfusion on intestinal tissues in rats.MethodsThe rats were divided into three groups of 10. In group 1, the superior mesenteric artery (SMA) was isolated but not occluded, and in groups 2 and 3 the superior mesenteric artery was occluded for 60 min. After that, the clamp was removed and reperfusion began. In group 3, 5 min before the start of reperfusion, a bolus dose of 30 mg/kg Tempol was administered intravenously and continued at a dose of 30 mg/kg for 60 min. All animals were euthanized after 24 h and tissue samples were collected for analysis.ResultsThere was a significant increase in myeloperoxidase activity, malondialdehyde levels, and the incidence of bacterial translocation in group 2, with a decrease in glutathione levels. These parameters were found to be normalized in group 3. The intestinal mucosal injury score in group 2 was significantly higher than those in groups 1 and 3.ConclusionTempol prevents bacterial translocation while precluding the harmful effects of ischemia/reperfusion injury on intestinal tissues in a rat model of superior mesenteric artery occlusion.

The investigation of the possible relationship between Coxsackie viruses and pemphigus

Pemphigus is a group of autoimmune bullous diseases on which the etiopathogenesis of several viruses has been blamed. Coxsackie viruses (CVs) are the causative agents of hand, foot, and mouth disease, and herpangina, which have been strongly associated with several autoimmune diseases. The onset of pemphigus after CV infection and cephalosporin use has been reported.

Comparison of the therapeutic efficacy of linezolid and vancomycin and correlation of serum and tissue malondialdehyde and myeloperoxidase in an experimental mediastinitis model.

BACKGROUND We aimed to investigate the therapeutic efficacy of linezolid in an experimental mediastinitis model and to compare it with vancomycin, which is commonly used. The objective of this study was also to evaluate the role of the immune system in mediastinitis. MATERIALS AND METHODS Fifty adult Wistar rats were randomly divided into five groups: an uncontaminated and contaminated untreated control groups; a group that received sefazolin prophylaxis; and two groups treated with vancomycin or linezolid. Median sternotomy without access to pleural spaces was performed on all rats. All groups, except the uncontaminated one, were inoculated with 0.5 mL 10(8) colony-forming units/mL methicillin-resistant Staphylococcus aureus in the mediastinal and sternal layers. Postoperatively, vancomycin and linezolid groups were given antibiotic treatment for 7 d, starting 24 h after the end of the procedure. After 7-d treatment tissue samples from the upper ends of the sternotomy line and mediastinum were obtained and evaluated microbiologically. Additionally, serum, heart, lung, liver, kidney, and mediastinal tissues samples were obtained to determine malondialdehyde (MDA) and myeloperoxidase (MPO). RESULTS The study showed that either vancomycin or linezolid successfully reduced bacterial counts in mediastinum and sternotomy line. MDA and MPO levels were found to be decreased in the treated groups. There was a positive correlation between serum and tissues MDA and MPO in all of the groups. CONCLUSIONS Our study showed that linezolid appears to be a promising option for treating mediastinitis due to methicillin-resistant S. aureus. Additionally, it was demonstrated that a wide inflammatory process occurred after mediastinitis.

Linezolid compared with vancomycin for the prevention of methicillin-resistant Staphylococcus aureus or Staphylococcus epidermidis vascular graft infection in rats: A randomized, controlled, experimental study

BACKGROUND Graft infections are severe complications of vascular surgery that may result in amputation or mortality. Staphylococci are the most frequent cause of vascular graft infections. OBJECTIVE In this study we assessed the prophylactic efficacy of linezolid in comparison with vancomycin in preventing prosthetic vascular graft infection due to methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-resistant Staphylococcus epidermidis (MRSE). METHODS This randomized, controlled, experimental study using healthy adult (aged >5 months) male Wistar rats was conducted in the research laboratory of the Pamukkale University, Denizli, Turkey. The study consisted of an uncontaminated control group and 3 groups for both staphylococcal strains: a contaminated group that did not receive any antibiotic prophylaxis; a contaminated group that received preoperative intraperitoneal (IP) prophylaxis with vancomycin; and a contaminated group that received preoperative IP prophylaxis with linezolid. All rats received a vascular Dacron graft placed inside a subcutaneous pocket created on the right side of the median line. Sterile saline solution (1 mL), to which MRSA or MRSE at a concentration of 2 × 10(7) colony-forming units per milliliter had been added, was inoculated onto the graft surface using a tuberculin syringe to fill the pocket. The grafts were explanted 7 days after implantation and assessed by quantitative culture. RESULTS Seventy rats (mean [SD]weight, 323.7 [17.9]g; mean [SD]age, 5.98 [0.64] months) were evenly divided between the 7 groups. Statistical analysis of the quantitative graft culture suggested that both vancomycin and linezolid were effective in significantly inhibiting bacterial growth when compared with the untreated contaminated groups (all, P < 0.001). However, a statistically significant difference was not observed between the bacteria count in the vancomycin and linezolid prophylaxis groups. When a comparison was made between the bacterial growth in the contaminated control groups, MRSA had significantly greater affinity to the Dacron prostheses than MRSE (all, P < 0.001). CONCLUSION Our study found that linezolid was as effective as vancomycin in suppressing colony counts in MRSA- or MRSE-infected vascular Dacron grafts in rats.

Epidemiology and associated factors for nosocomial methicillin-resistant Staphylococcus aureus infection in a tertiary-care hospital.

We analysed nosocomial MRSA cases between January 2004 and December 2006 in a retrospective case-control study in a 250-bed tertiary-care teaching hospital. During the study period, 265 nosocomial Staphylococcus aureus infections were identified in 231 patients. There was a significant increase in methicillin resistance in isolates (MRSA) from these infections with frequencies for 2004 of 39/88 (44.3%), 2005 (62/80, 77.5%), and 2006 (75/97, 77.3%) (P<0.001). Multivariate analysis showed that associated factors for nosocomial MRSA infection were prolonged hospitalization (OR 3.982, 95% CI 2.235-7.094, P<0.001), mechanical ventilation (OR 3.052, 95% CI 1.666-5.590, P<0.001), surgical operation (OR 2.032, 95% CI 1.102-3.748, P=0.023), and male sex (OR 2.000, 95% CI 1.081-3.699, P=0.027). The determination of associated factors for methicillin resistance in nosocomial S. aureus infections in hospitals will play an important role in efforts to reduce MRSA infection rates.

The first report of Brucella suis biovar 1 isolation in human in Turkey

BACKGROUND Brucella melitensis and B. abortus are the species generally isolated from human samples in Turkey. Several studies have also demonstrated the presence of antibodies against B. canis. CASE REPORT AND STUDY Brucella spp. was isolated from blood culture from a 35-year-old male with clinical signs and symptoms of acute meningitis, including fever lasting for 1 week. Multiplex PCR demonstrated B. suis, and biochemical features indicated biovar 1. CONCLUSIONS This report is the first emphasizing that B. suis should be considered among the causes of brucellosis in Turkey.